5356 5360.output

* GB785764 (A)

Description: GB785764 (A) ? 1957-11-06

Improvements in and relating to bearings

Description of GB785764 (A)

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BE535764 (A) ES219839 (A1) FR1167630 (A) US2798774 (A) BE535764 (A) ES219839 (A1) FR1167630 (A) US2798774 (A) less Translate this text into Tooltip

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PATENT SPECIFICATION Date of Application and filing Complete Specification: Feb 7, 1955. 785,764 No 3589/55. g e 1/C Application made in United States of America on May 3, 1954. Complete Specification Published: Nov 6, 1957. Index at acceptance:-Classes 12 ( 1), A( 6 A 1:6 E 2:7 B 2:7 X:20); and 12 ( 3), C 5 A 2. International Classification:-FO 6 c, n. COMPLETE SPECIFICATION Improvements in and relating to Bearings I, ADOLFO Vox Eusv, a Citizen of the Confederation of Switzerland, of 112, Arequipa, Mexico, D F, Mexico, do hereby declare the invention, for which I pray that a patent may be granted to me, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to bearling assemblies which can be, or are,

mounted in such a manner as to permit adequate relative and frequent displacement of the axle in relation to the load which it carries. This is particularly the case in railway stock journal bearings, but can also be found in other mechanical equipment. According to the invention there is provided a bearing assembly, particularly for a railway vehicle, comprising in combination an axle supported for rotation in a bearing, means between the bearing and the load permitting relative movement between the bearing and the load, thereby causing the assembly to align itself in accordance with variations in torque and tractive force applied to the load, and pumping means associated with the bearing and adapted to be actuated by relative movement between the bearing and the load about an axis substantially parallel to the axis of the axle, and adapted when so actuated to supply a lubricant under positive pressure to the interface between the axle and the bearing. The axis about which the relative movement takes place may be real or imaginary and is not necessarily fixed. The invention consists basically of the utilization of certain movements of the journal, bearing, oil sump, point of load application, supports, etc in relation to each other for the operation of lubrication pumps either directly or through levers -for the purpose of improving, enlarging or directing such movements as well as for the lPrice i; 4 Z absorption of shock and vibration. Specific embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, in which: 50 Fig 1 is a cross section of a rail vehicle bearing assembly, wherein the swinging effect occurs through a rolling contact between the bearing and a static element or load application; the mechan 55 ism is shown in the position of rest or at the precise moment at which a swinging motion passes through the centre positions; Fig 2 is a cross section of the same bearing assembly at one extreme position 60 of a movement which is provoked in this case by the horizontal tractive effect of the locomotive or by the application of brakes or anv other accelerating or decelerating force; 65 Figs 3 and 4 are cross sections in the extreme and central positions respectively of a bearing assembly with its pump in a fixed position in relation to the oil sump and, in this case, fixed in relation to the 7 opoint of application of the load; Figs 5 and 6 show another application of the invention to rail vehicle journals, wherein the swinging effect is favoured through the insertion of a resilient element 75 between the bearing and the static element (point of load application), which also assures a maximum degree of self-alignment and a certain shock and vibration absorbing capacity Fig 5) is a cross 80 section of the assembly in a central position and Fig 6 is a similar view at one extreme position

in its movement. In Figs 1 and 2 the movement is caused by any external application of 85 effort, and is favoured and controlled by a contact between bearing and static element, which is theoretically linear due to the difference in curvature of the corresponding contact surfaces The formation 90 785,764 of the two curves of contact previously mentioned can be such as to produce a movement requiring more or less effort and to limit the extension of the movement and to produce a desirable equilibrium of the static load on the bearing Furthermore, the formation of the contact surfaces will be adapted to their practical requirements which derive from the material, the load and other considerations. In Figs 1 and 2 an axle 12 rolls in a bearing 1 on which is movably supported a static element 9 having a relatively rigid curved surface 2 -As shown in the drawings, the radius of curvature of surface 2 is greater than that of the bearing 1 The pump 3 shown is of the double acting plunger type, pivoted at its centre by pin 11 in a forked member 4 This type of pump is one of many types which are applicable The difference in the position which is occupied by the bearing in Fins 1 and 2 shows the variations of volume which are obtained in the cylinders of the pump, which in turn causes the pumping effect in combination -with cheek valves 5 and 6 The lubricant is drawn from the sump in the bottom of the journal box 10 through pipes 7 and is delivered to the friction surfaces through appropriate conduits 8 The point of application is shown as an example only, as their exact location depends on the construction and working conditions of each bearing The cylinders of the pumps are shown as being an integral part of the bearing, but they could be connected by bolting welding or any other means. In the embodiment shown in Figs 3 and 4 the oscillating movement of the bearing is based on an elastic element 13 which is provided between the bearing 1 and the point of load application 10 (top of journal box) with the tripple object of favouring the movements which operate the pump and of securing a maximum degree of self-alignment and of absorbing shocks and vibrations. The resilient element can be of any material such as rubber, synthetic rubber, plastic, metal which is resilient by its nature or by its shape (springs, etc) or any organic, inorganic or synthetic material or mixture or composition which may have the desired characteristics of elasticity Its formation, as vwell as the formation of the elements vwhichl are separated by the resilient insert, may vary in each case with the object of producing a -miovermielnt with more or less effort and wh lich may limit the extension of the movement and which may produce the desirable equilibrium of the static load on the axle 12

Furthermore, the choice of material and the formation of the elements which are separated by said material will depend on practical considerations derived from load, temperature, nature of the equipment in which the bearing is installed, etc In this case the pump is fixed in 70 relation to the oil sump (and in relation to the point of load application) rather than in relation to the bearing A pump plunger 3 moves by a pivot pin 11 within a cylinder 14 fixed at the bottom of the 75 journal box 10 Check valves 5 are situated between the cylinder and the sump, and valves 6 connect the cylinder to flexible conduits 'S which lead the lubricant to select points of contact between 80 the bearing and the axle. In the embodiment shown in Figs 5 and 6 the movement of bearing is favoured by the insertion of a resilient element 13 similar to that shown in Fins:3 anal 4 85 The axle 12 rolls in bearinog I whieh as stated above, is cushioned from the point of application of load 9 lb the resilient element 13, which permits a lateral swinging movement of the bearing w Aith 90 variation in the traction ete In thxis embodiment, the lubricant pump or pumps may be built into the bearing as sho-wn. The two cylinders 14 are bored in thie lower portion of the bearing or journal 93 Each has a u Linger or piston 28 biased by a spring 3 a The pistons preferably have rounded heads 15, permitting tiltini' of the journals and pumps while maintaining,: contact of the head with the interior 100 of the journal box 10 The sump is in the lower portion of the journal box with cheek valves 5 and 6. Lubricant is drawn into the pump ceylinelr through the duets 7 and pumped to the 105 bearinga surface tlhrougl the conduits 8. It is understood that in the embodiment of Figs 5 and 6 the choice of the resilient element or the formation of the elements which are separated by said material, 110 wvill depend on practical considerations derived from the load, temperature naturle of the equipment in which the bearing is installed etc The pump shown in this example is of two plungers equipped with 115 springs It is however understood that any pump which can take advantage of the reciprocal or oscillatini movement of the bearing can be employed Another of many variations of localization of the oil 120 lead conduits 8 is shown Althotigh the cylinders of the pumps are shown as bieing integral with the hearing they may optionally be inistalled Lv bolts weldhig or other suitable means 125 Included among the advaiitioes of the invention are the following 1 Injection off lcri-ant bet-een t Le load surfaces of 2 onal and h earingo aetually before the Journal begins 130 785,764 turning. 2 Lubrication at a desirable pressure and at the exact point where it

is necessary. 3 Reliable and abundant lubrication and cooling in service. 4 An ample flow of lubricant without external mechanisms. Extremely simple automatic lubrication. 6 Highly reliable operation. 7 Ability to absorb shocks and vibrations in any or all directions. 8 Automatic alignment of the bearing in relation to its support. It will be seen that the invention, in its various embodiments, provides a means for utilizing the tractional displacements involved in the transmission of tractive or other power for the supply of a positive feed of a lubricant to bearings This is accomplished by maintaining the journal in such a manner that it is movable, within fixed limits, relative to the load or weight to be supported, and incorporating with it a pump or pumps in such manner that the motion of the journal actuates the pump meehanism and forces lubricant to the bearing surface For actuating the pump mechanism advantage is taken of those movements of the journal swinging or oscillating around an axis approximately parallel to the axis of the element that rotates within the bearing This is $ 5 done either by providing flexible or resilient members between the journal and the load or by providing relatively rigid surfaces of different degrees of curvatures as contact points between the load and the bearing, or by analogous structural means. The utilization of swinging or oscillating movements around an axis approximately parallel to the axis of the rotating element is particularly advantageous in the case of rail vehicle bearings. In all the embodiments described the bearing assembly functions by a swinging or oscillating movement of the journal which in turn actuates a pump incors O porated in, attached to, or working in co-operation with the journal, which is adapted to draw a lubricant from a sump preferably situated in the journal box and deliver it to a selected point of friction between the rotating part or axle and the bearing. As mentioned in the specification the invention also provides a means for selfalignment which is also particularly desirable in the case of rail vehicle bearings The term "self-aligning" is used in this specification in the same sense in which it is used in the art Actually, the term means that the stresses are taken out of such momentary misalignment as is inevitable conditions. under the prevailing load

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* GB785765 (A)

Description: GB785765 (A) ? 1957-11-06

Method of refining hydrocarbons or hydrocarbon fractions by catalytichydrogenation


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PATENT SPECIFICATION 7859765 4, / Date of Application and filing Complete Specification March 9, 1955. No 6983/55. Application made in Germany on Nov 25, 1954. Complete Specification Published Nov 6, 1957. Index at acceptance: -Class 91, 02 C. International Classification: -C'l Og. COMPLETE SPECIFICATION Method of R Iefining Hydrocarbons or Hydrocarbon Fractions by Catalytic Hydrogenation We, METALLGESELLSCHAFT AKTIENGESELLSCHAFT, of 45, Bockenheimer Anlage, Frankfurt-on-the-Main, Germany, a Body Corporate organised under the Laws of Germany, do hereby declare the

invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: - This invention relates to a method of refining hydrocarbons or hydrocarbon fractions by hydrogenating catalytic treatment. It is known to hydrogenate hydrocarbons or hydrocarbon fractions produced by the coking, low-temperature carbonisation, or gasification of mineral coals, brown coals, oil shale, or like fuels, and also produced in the working up of petroleum, in the presence of gases containing hydrogen and utilising a sulphur-resistant catalyst The undesirable compounds such as sulphur compounds, nitrogen compounds, and oxygen-containing organic compounds, contained in the hydrocarbons or hydrocarbon fractions, are thereby -catalytically reacted with the hydrogen to form hydrogen sulphide, ammonia, water and hydrocarbons For this process, use has been made of gases such as hydrogen, coke oven gas, coal gas, pressure gasification gas, water gas, or the like At reaction temperatures which lie in the region of about 4000 C and higher, carbon deposits are formed on the catalyst, which apparently originate from the decomposition of hydrocarbons and from the splitting of carbon monoxide when gases containing carbon monoxide are used In addition, the octane number of the refined hydrocarbons was reduced due to the simultaneous hydrogenation of the olefinic and aromatic products. It has now been found that these disadvantages can be to some extent overcome by introducing water vapour into the catalytic hydrogenation zone together with the mixture of hydrocarbons or hydrocarbon fractions and gas containing hydrogen The hydrogenation lPrig,,rr:6 d 'I itself is surprisingly not adversely affected by the presence of water vapour and in many cases it is even improved Damage to the catalyst-as a rule a sulphur-containing catalyst is used for the process-also is reduced. Based on the foregoing discovery, the present invention provides a method of refining hydrocarbons or hydrocarbon fractions by catalytic hydrogenation in the presence of a gas containing carbon monoxide and hydrogen, e g coke oven gas, coal gas, lowtemperature carbonisation gas, pressure gasification gas or water gas, and in the presence of a sulphur-resistant catalyst having a basis of cobalt and/or molybdenum compounds and alumina, in which water vapour is introduced into the catalytic hydrogenation zone in amounts ok about 5 to 50 % by volume, preferably 15 to 35 % by volume, referred to the fresh gas entering the process, and in which the catalytic hydrogenation is carried out under pressure of about 5 to 100 atmospheres and at a temperature of over 3000 C, preferably about 380 to 4200 C or higher. It is possible to operate the process according to the invention with

recycled gas, in which case, rather larger amounts of water vapour, referred to the fresh gas, are required. The process of the present invention will now be explained by way of example, with reference to the accompanying diagrammatic drawing. The gas containing carbon monoxide and hydrogen subch as town gas, coke oven gas, oil rzinery gas or the like, to be used for the refining is introduced into the compressor 2 through the pipe 1 The hydrogenation is preferably carried out at a pressure of 20 to atmospheres The compressed gas passes, preferably without undergoing cooling, through the pipe 3 into the heat exchanger 4, which it leaves through the pipe 5 Water vapour in an amount of 5 to 50 % by volume, for example 30 % by volume, is added to the gas containing hydrogen through the pipe 6. 785,765 The gas can however also be charged with water vapour by sprinkling with water in known ma-nner at an elevated temperature, for example about 100 to 3000 C, for example 170 C The mixture of water vapour and gas containing hydrogen then passes into the evaporator 7, which is filled in its upper part 8 with Raschig rings and equipped at 9 with a heating system In this evaporator the product to be refined, for example gasoline or benzene, which is stored in tank 10, is fed to the evaporator 7 through the pipe 11, pump 12, and pipe 13, if desired after preheating. A small proportion of the material to be refined, for example crude gasoline, is drawn off at 15 through the siphon 14 Through the pipe 16 the mixture of gas containing carbon monoxide, hydrogen, water vapour and gasoline vapour is fed to the second heating stage from the evaporator 7, for example through the heat exchangers 17 and 18 and the heater 19 The gases thus pass out of the heat exchanger 17 through the pipe 39 into the heat exchanger 18, and from the latter through the pipe 20 into the heater 19, in which they are brought almost to the reaction temperature, and pass further through the pipe 21 into the reactor 22, which is filled with the sulphur-resistant catalyst 23 consisting of 5 % by weight of cobalt oxide 15 % of molybdic acid and 80 % of alumina The catalyst can be disposed in known manner on a sieve Instead of the reactor 22 similar to a shaft furnace which is shown in the drawing, any other known type of reactor can also be used The hydrogenation takes place in the reactor 22 as the mixture of gas and vapour flows through the catalyst, for example in the direction from top to bottom The gas containing carbon monoxide, hydrogen, water vapour and gasoline vapours, leaves the reactor through the pipe 25 and, in counter-current to the mixture flowing to the reactor, gives up heat to the latter in the heat exchangers 17 and 18 The gas first passes into the heat exchanger 18, leaves the latter through the pipe 26, passes into the heat exchanger 17, and thence through the pipe 27

into the heat exchanger 4 Through the pipe 28 the mixture of gas containing hydrogen, water vapour, and gasoline vapours, which is already cooled to a temperature of for example 1200 C, is passed out of the heat exchanger into the cooler 29, in which water vapour and gasoline vapours are condensed by cooling to room temperature This cooler can be sprinkled if desired with fresh water in order to avoid precipitation of ammonium carbonate which is formed during the refining from organic nitrogen ( compounds contained in the original gas The cooling water enters the cooler at 30 and leaves it at 3 L Gas containing hydrogen, water, and the refined gasoline passes through the pipe 32 into the separator 33, from which the refined product is drawn off at 34 and water at 35. The refined product contains small amounts of dissolved hydrogen sulphide and ammonia and is thereupon washed with dilute lye and water to remove them The gas containing 70 carbon monoxide and hydrogen is withdrawn from the system at 36 and is preferably passed into the gas production plant, which supplies the fresh gas containing hydrogen entering the process It can for example be supplied to 75 this plant before the gasoline recovery stage in order to enable the gasoline contained therein to be recovered However, the refined product contained in this residual gas can also be recovered in known manner, for example 80 by adsorption with activated charcoal, cooling, or washing out with a washing oil. A part of the residual gas leaving the plant at 36 can be recycled, for example to a point before the compressor 2 or before the heat 85 exchanger 4. When employing the process of the invention for the hydrogenating refining of liquid hydrocarbons or liquid hydrocarbon fractions, these are introduced into the reactor 22, pre 90 ferably after suitable preheating The preheating, for example to close to reaction temperature, may be effected in the presence of gas containing carbon monoxide hydrogen and/or water vapour This may be achieved by pass 95 ing the hydrocarbons or hydrocarbon fractions through heat exchangers 17 and 18 and heater 19 The gas containing cabon monoxide and hydrogen can be supplied from the heat exchanger 4, after the admixture of the water 100 vapour, directly to the heat exchanger 17, in which if desired it is brought together with the liquid material to be refined. EXAMPLE In the gasification of an illuminating gas coal 105 with oxygen and water vapour at a pressure of atmospheres to produce long distance trunk gas, by-products include tar, tar oil and gas naphtha These products are produced in known manner from the gas which is under 110 pressure and which was produced by gasification For example gasoline is obtained by treating the gas with the aid of washing oil from which

the gasoline is subsequently distilled off. Tar and tar oil are together subjected to distil 115 lation, in which inter alia a fraction extending from the beginning of boiling to a temperature of about 210 C is taken off This light oil fraction, which contains about 25 % by volume of phenols, can be dephenolised in known 120 manner, for example by extraction with hot dephenolised water or with a caustic alkali solution However this dephenolisation is not absolutely necessary, because the phenols, even when they are contained in large amounts in 125 the starting material, are converted into hydrocarbons by the hydrogenating refining. Gasoline and the light oil fraction, which may be dephenolised, are combined and for the purN. 785,765 pose of producing a satisfactory motor fuel are subjected to catalytic refining according to this invention The feed mixture has for example the following composition: Density at 200 C Sulphur percentages by weight Acid oils, % by weight Beginning of boiling % by vol 15 %,, %,, %,, 45-/t %,, 65 %,, %,, %,, %,, End of boiling Boiling loss 0.813 0.65 2 640 C. 710 C. 930 C. 1000 C. 1070 C. 1160 C. 1280 C. 1430 C. 1600 C. 1800 C. 2030 C. 2100 C. 2.4 % The refining loss amounts to 39 Kg per 1,000 Kg of crude gasoline The refined product has the following composition: Density at 200 C Sulphur % by weight Acid oils % by volume Beginning of boiling % by vol %,, 25 %,, %,, %,, %,, %,, 75 %,, %,, %,, End of boiling Boiling loss 0.795 0.034 0 610 C. 740 C. 840 C. 920 C. 970 C. 1050 C. 113 C. 1250 C. 1430 C. 1580 C. 1930 C.

2030 C. 3 2 % Since it still contains hydrogen sulphide and ammonia, it is washed with caustic soda solution and water and then dried Further treatment of the refined product can in most cases be dispensed with In the case of certain hydrocarbons, particularly gasoline, it may sometimes occur that the refined product is not completely stable to light By a light aftertreatment, for example by washing with dilute sulphuric acid and/or treating with bleaching earth, alumina, silica gel or activated charcoal in the liquid phase, at normal or elevated temperature, or in the gas phase, if desired under pressure, the desired complete stability to light can however be obtained without difficulty. This treatment, which follows the hydrogenation with the sulphur resistant catalyst, can advantageously be carried out in the presence of a gas containing hydrogen and/or of water vapour. Instead of this after-treatment, however, the refined hydrocarbons or hydrocarbon fractions nay be fractionated It has in fact been found -hat when this fractionation is carried out a distillate stable to light passes overhead, while the substances causing the discoloration remain 65 hn the distillation residue The latter can be kept relatively small, for example only about 1 to 15 % of the fractionation feed The distillation residue is advantageously recycled to the hydrogenation feed In particularly difficult 70 cases, this fractionation and the after treatment with dilute sulphuric acid, or bleaching earth, can be applied one after the other, in any desired sequence. The refining of the crude gasoline is carried 75 out at a pressure which advantageously lies slightly above the pressure of the long distance trunk gas Thus, for example, with a long distance gas pressure of 20 atmospheres, the pressure in the refining plant is kept at 25 80 atmospheres 1,000 normal cubic metres of fresh gas are added per hour to the compressor 2 through the pipe 1, this fresh gas having been brought to a temperature of 170 to 180 in the heat exchanger 4, which if desired may 85 be supplemented by an additional heating device 250 Kg of water vapour, which is available at a pressure of 36 atmospheres, are added per hour to this gas in the pipe 5 The gas containing hydrogen passes together with 90 the water vapour into the evaporator 7, which is kept at a temperature of 1900 to 2200 C by the heating system 9 1,000 Kg of crude gasoline is supplied per hour to the evaporator through the pipe 13 15 Kg of evaporation 95 residue per hour are withdrawn from the pipe 15, and can be returned to the tar which is produced during the production of the gas, for example before the distillation of said tar. 1,000 normal cubic metres of gas, 250 Kg of 100 water vapour, and 985

Kg of gasoline vapour per hour leave the evaporator through the pipe 16, and by means of the heat exchangers 17 and 18 and the heater 19 are together brought to a temperature close to the reaction-tempera 105 ture The reactor 22 is filled with a sulphurresistant catalyst having a basis of cobalt and molybdenum compounds, and alumina The reactor is operated at a temperature of about 380 to 5000, for example at 400 to 4200 C 110 The crude gasoline is passed through the catalyst in amounts of about 0 1 to 1 ton per cubic metre of catalyst per hour, preferably 0 3 to 0 5 tons per cubic metre of catalyst per hour The catalyst used is for example 115 molybdic acid on alumina containing cobalt in the form of oxide or sulphide in which molybdic acid concentrations of about 10 % are used Another highly active catalyst for the treatment according to the present invention 120 can for example be obtained by intimately mixing 70 parts by weight of commercially available aluminium oxide hydrate having a bayerite structure, which acts essentially as carrier, with 10 parts by weight of molybdic 125 acid, 8 parts by weight of cobalt hydroxide and 785,765 4 parts by weight of graphite The mixture is converted into the form of small cylinders by pressing After cooling the gas-vapour mixture leaving the furnace, by heat exchange and in the cooler 29, 946 Kg of a refined gasoline are produced in the separator 33 1,000 normal cubic metres of gas are withdrawn through pipe 36 and are returned to the plant from which the hydrogen-containing gas is derived, for example before the gasoline washing, after pressure reduction of for example about 23 to 20 atmospheres The octane number of the crude gasoline was determined by the research method as 75 without the addition of tetraethyl lead The research octane number of the hydrogenated product according to the present invention was found to be 78, while the research octane number of a crude product refined under the same conditions 2 C without the addition of water vapour was only 68 The gasoline refined in the presence of water vapour and gases containing hydrogen is also substantially more sensitive to lead. The fresh gas from the pressure gasification which was used for the catalytic refining contained between 20 and 30 volumes percent of carbon monoxide. Thus in consequence of the addition of the water vapour, substantial amounts of carbon monoxide and water vapour reacted to form hydrogen and carbon dioxide It is therefore possible to introduce substantial amounts of gas containing carbon monoxide and hydrogen without diminishing the refining effect If no water vapour were added during the catalytic hydrogenation it would be necessary, in order to obtain a good refining action when using the same fresh gas, to effect a preliminary conversion of the carbon monoxide into carbon dioxide.

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* GB785766 (A)

Description: GB785766 (A) ? 1957-11-06

Improvements in hydraulic variable pitch propellers


PATENT SPECIFICATION Inventor: LEONARD GASKELL FAIR'HURST Date of filing Complete Specification: May 1, 1956. Application Date: May 5, 1955. No 13075/55. Complete Specification Published: Nov 6, 1957. Index at acceptance:-Class 114, I 2 C 4, International Classification;-B 63 h. COM-PLETE SPECIFICATION Improvements in Hydraulic Variable 'Pitch Propellers We, ROTOL LIMITED, a British Company, of 'Cheltenham Road, Gloucester, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: - This invention relates to hydraulically operated variable pitch propellers of the kind, hereinafter referred to as the kind described, including a double acting hydraulic pitch change motor actuable by hydraulic fluid under pressure to adjust the pitch of the propeller, an hydraulic fluid conduit (the coarse pitch conduit) for leading hydraulic fluid, under pressure to said pitch change motor to actuate the motor in the sense to adjust the pitch of the propeller towards coarse pitch, and an hydraulic fluid conduit (the fine pitch conduit), for leading hydraulic fluid under pressure to said pitch change motor

to actuate the motor in the sense to adjust the pitch of the propeller towards fine or reverse pitch. For the purpose of preventing fining off of the pitch of the propeller in the event of a serious leakage of hydraulic fluid from the hydraulic system of the propeller, for example by fracture of the fine pitch or the coarse pitch conduit, it has been proposed to provide a lock valve in the coarse pitch conduit which is maintained open against a closing force by a predetermined excess of pressure in the fine pitch conduit over drain pressure. The pitch control of variable pitch ppopellers of the kind described is effected by means of an hydraulic valve which is displaceable from an equilibrium' position to supply hydraulic fluid under pressure to said pitch change motor through either said fine pitch conduit or said coarse pitch conduit to adjust the pitch of the propeller towards fine pitch or coarse pitch respectively and this hydraulic valve is usually controlled by a speed' governor the speed governor and the valve being combined in a constant speed' governor unit The operation of such an hydraulic valve normally involves the generation of transient pressure fluclPrice 3 s 6 d l tuations simultaneously in the coarse pitch and fine pitch conduits, such transient pressure fluctuations being of opposite sign in these two conduits The existence of such transients in the fine pitch conduit makes it difficult to select a pressure difference between drain' pressure and the pressure in the fine pitch conduit at which the lock valve shall close to provide an adequate degree of safety without unnecessarily disturbing the normal operation of the propeller. To obviate this difficulty, according to the present invention, there is provided in a propeller of the kind described a lock valve in the coarse pitch conduit which lock valve is urged in the opening direction, against a closing force tending to close the valve, by opening means comprising a first member subject to the difference between the pressure in the fine pitch conduit and' drain pressure, a second member subject to the difference between the pressure in the coarse pitch conduit and drain pressure and' means for combining the loads produced upon the said first and second members 'by the said pressures and for acting upon the said lock valve with the said combined load, the arrangement being such that the combinedi load remains substantially constant when transient pressure fluctuations of opposite sign occur simultaneously in the coarse pitch conduit and the fine pitch conduit. The propeller preferably also includes' a non-return valve in, a conduit by-passing the lock valve, the non-return valve being arranged to close when the pressure on the pitch change motor sid'e of the non-return valve exceeds that on the other side of the non-return

valve. One embodiment of the present invention will now be described, merely by way of example, with reference to the drawing accompanying the provisional specification which diagrammatically illustrates, an arrangement according to the present invention. Referring to the drawing, the pitch-lchanen piston of a double acting hydraulic pitch change motor of a hydraulic variable pitch propeller is represented at 1 The piston oper, 785766 s ates in a cylinder 2 the ends of which are connected by conduits 3 and 4 to the contro ports of a constant speed governor unit, no. shown Hydraulic fluid supplied under pressure through the conduit 3 acts on the left hand side of piston 1, tending to move it in a direction giving a finer pitch setting in ahead pitch of the propeller, or a coarser pitch in, the reverse range in 'the case of a reversing propeller The conduit 3 is accordingly the fine pitch conduit Conversely, hydraulic fluid supplied under pressure through the conduit 4 tends to move the piston 1 in a direction giving a coarser pitch setting in ahead pitch of the propeller and the conduit 4 is accordingly the coarse pitch conduit. A lock valve 5, in the form of a piston, is provided in the coarse pitch conduit 4 and the lock valve 5 is urged in the direction to close the conduit 4 by a closing force produced by a spring 6 When the valve 5 is closed hydraulic fluid is trapped in the right hand end of the cylinder 2, and prevents movement of the piston 1 to the right in the drawing, that is to say in' the pitch-fining direction, in which direction the piston 1 normally tends to move under the action of the centrifugal twisting moment on the propeller blades when the propeller is rotating A conduit 7 is provided which by-passes the valve 5 The conduit 7 contains a non-return valve S arranged to close when the pressure on the pitch change motor side of the valve 8 exceeds that on the other side of the valve '8 'The hydraulic fluid trapped in the right hand end of the cylinder 2 when the valve 5 closes consequently cannot escape through the valve 8 but hydraulic fluid under pressure supplied through the conduit 4 can enter the right hand end of the cylinder 2 to coarsen the pitch of the propeller as soon as its pressure exceeds, by a predetermined amount, the pressure of the hydraulic fluid trapped in the cylinder. The valve 5 is slidable in a cylinder 1 '8 which is communicated ion the side 9 of the valve 5, by means of a duct 10 with the fine pitch conduit 3 ' and on the side 11 of 'the valve 5 by means of a duct 19 with a drain conduit 12 The valve 5 -is accordingly urged, in the 501 opening direction against the closing force produced by the spring 6 by a load which is proportional to the difference between the pressure in, the fine pitch conduit 3 and the pressure in the drain conduit -12

In addition to this opening load a further opening load is provided by a further piston and cylinder assembly 13, 15 The piston 13 has a piston red 14 which bears against the end 9 of the valve 5 The left hand end of the cylinder 15 is communicated by a duct 16 with the coarse pitch conduit -4 and the -right hand end -of the cylinder is communicated 'hv a duct 20 -with the drain conduit 12 During norimal working of the propeller, at least when the latter is in an on speed " or an " over-speed " condition, by which should be understood rotating either at the tspeed called for by the constant speed unit or a speed in excess of the speed called for 1 by the constant speed unit, pressure in excess 70 of drain pressure is present in the coarse pitch conduit 4 and a load is consequently produced upon the piston 13 proportional to the difference between these pressures, this load being added to the load acting directly upon 75 ithe valve 5 to hold the valve open against the closing force produced by the spring 6 Opening and closing of the control valve of the constant speed unit during operation of the propeller causes fluctuating pressures in the 80 fine pitch and coarse pitch conduits 3 ' and 4 but these fluctuations are of opposite sign in the two conduits so that the combined opening load upon the valve 5 remains substantially constant Thus when the propeller is in an 85 " underspeed condition " by which should be understood rotating at a speed less than is called for by the constant speed unit, although the pressure in the coarse pitch conduit may fall to a pressure approaching the drain pres 90 sure due to operation of the constant speed unit calling for a finer pitch, the pressure in the fine pitch conduit will rise sufficiently to maintain the valve 5 open against the closing force produced by the spring 6 To balance 95 any inequality in the fluctuations of pressure in the fine and coarse pitch conduits due to operation of the control valve of the constant speed unit the piston 13 and the valve 5 may be made with correspondingly different face 100 areas. In the event of a serious loss of hydraulic fluid from the hydraulic system of the propeller, due, for example to fracture of one of the conduits 3 and 4, the pressure in at least 105 one of the conduits 3 and 4 will drop immediately, thus reducing the load in the opening direction upon the valve 5, and it is arranged that such a reduction of load is sufficient to allow the spring 6 to close the valve 5 ' and 110 thus prevent a loss of propeller pitch. In the example described the lock valve 5 is a piston type valve The lock valve may however take the form of a lift valve to ensure maximum' fluid tightness when closed 115

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* GB785767 (A)

Description: GB785767 (A) ? 1957-11-06

Improvements in and relating to central heating and plant, and methods ofoperating such plant


PATENT SPECIFICATION Inventor: THEOPHIL EI Chivi ANN 785,767 Date of Application and filing Complete Specification May 21, 1955. No 14714/55. Complete Specification Published Nov 6, 1957. Index at Acceptance:-Classes 29, G 2 (E: L: R: No); 64 ( 2), F 2 C, Gl Ai 5, H, U 3; and 64 ( 3), S( 14: 23 A). International Classification: -F 24 d F 25 b, h. COMPLETE SPECIFI Ci ATI 1 ON Improvements in and relating to Central Heating and Plant, and methods of Operating such Plant We, CARBA AKTIENGESELLSCHAFT, a Swiss Company, of Bern-Liebefeld, Switzerland, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed to be particularly described in and by the following statement: - The present invention relates to a central heating and cooling plant which comprises a hermetically closed pipe system including a central heat exchange stage and decentralised heating bodies for direct heat transfer in the rooms by radiation and convection, similar to a hot water central heating system. The hot water heating in the hitherto generally used mode of hot water circulation has various disadavantages of which the most important may be mentioned: The sensitivity to freezing representing a danger to the plant at rest, a considerable inertness in operation and extremely

high heat losses along the ascending and distributing pipe lines both on account of the low speed of water circulation (about 4 inches to 1 foot per second, if the circulation is only due to gravity); the necessary provision of sufficiently large pipe cross-sections, of an expansion vessel and of venting means; and the formation of rust and scale on the inner wall of the pipe system. It has been proposed to use a refrigerant fluid as a circulating medium in a heating system in order to avoid the above mentioned disadvantages in that the medium flows as a vapour from the central stage to the decentralizing heating bodies However in all such cases the operation of the heating plant is limited to moderate heating temperatures up to about 450 C or the system employed is not a central heating plant but an air conditioner or a heat pump whereby air is separately heated somewhat above room temperature and is then supplied to the rooms to be heated i e socalled air heating. Thereagainst it is a feature of central heating that its opearting temperature range should extend up to 100 C or even higher in order to be able also on occasion of comparatively Low outdoor temperatures, as for instance -25 C, to meet the requirements involved by the direct heating of the room In this connection it must be born in mind that in central heating plants the circulating heat transfert medium must often be guided through an extensive and widely ramified pipe system of lor instance 200 yards or more to a plurality of radiators. As the ascending and distributing vapour pipe lines are usually not insulated, the heat losses along such extensive lines become considerable with an increasing difference between the pipe temperature and the ambient normal room temperature of about 18 C or less In the case that a conventional refrigerant fluid is used as heat transfer medium instead of hot water, considerable heat losses partially liquefy the saturated vapour flowing through such extensive pipe lines and the liquefied fluid pre vents or at least obstructs the circulation of the vapour At the same time the vapour undergoes a reduction in pressure due to fluid friction in the pipe and to the geodetic difference in height over which the vapour must mount lrom the evporator to the radiators This loss of pressure is a mere throttle process and occurs therefore without any change of the enthalpy of the vapour. It has now been found that the attempts made so far in using a conventional refrigerant as heat transfer medium in a central heating plant were not successful for heating temperatures above about 450 or 500 C due to the fact that above such a temperature heat losses cause a partial liquefaction and that in all hitherto known attempts the above mentioned loss of pressure shows at higher temperatures the tendency to increase the partial liquefac2 785,767 tion of the vapour

already caused by heat losses. It is the object of the invention to remove this disadvantage and with this end in view 5the invention consists in a central heating plant of the type which comprises central heat exchange means for changing the temperature of a fluid heat transfer medium, a plurality of outlying heat transfer units for directly heating rooms by radiation and natural air convection, and a distribution network Of pipes connecting said heat exchange means to said outlying units to form a vapour-tight hermetically closed system effectively free from air and moisture, characterized in that said closed system contains a volatile fluid heat-transfer medium being non-toxic and non-combustible and having a freezing point below the lowest climatic temperature prevailing on the surface of the globe and a boiling point at atmospheric pressure below + 30 ' C but above O' C, the vapour of said medium having its critical temperature point above + 1200 C and having thermodynamic characteristics on the whole temperature range from + 300 to + 100 ' C. such that its temperature-enthalpy and temperature-entropy diagrams exhibit lines of constant enthalpy and constant entropy, respectively, which extend for decreasing vapour pressure from the saturation line into the region of superheated vapour. A preferred fluid which complies with the aforesaid requirements is dicblorotetraiiuoroethane having, besides the above properties, still further qualities which are important in connection with its use in a central heating plant, in that for instance the vapour pressure at the maximum operating temperature at 1000 C remains with about 13 atmospheres over-pressure still at a degree which can be tightened without complications, while under inoperative condition the vapour pressure is even yet somewhat above 1 atmosphere at the ordinary room temperature Another fluid suitable for being used as a heat transfer medium in a central heating plant is bromochlorodifluoromethane. The invention includes further the possibility of employing the central heating plant containing such a heat transfer 'fluid under certain provisions in summer for a moderate cooling of about '/, of the heating output, if at high outdoor temperature dwelling rooms are to be cooled down to the ordinary room temperature of about 200 to 250 C. The method of operating a central heating plant for heating or cooling purposes according to the invention willl now be explained in connection with an embodiment of such plant shown by way of example in the accompanying drawings, wherein: Figure 1 shows a diagrammatic illustration of a combined central vapour heating and cooling plant for heating and cooling of rooms; Figures 2 and 3 show a room heating and cooling radiator body of the plant in longitudinal and cross

section, respectively, and Figures 4 and 5 show the disposition of a room heating and cooling connection body in side elevation and in cross-section, respectively 70 The vapour heating and cooling plant illustrated in Figure 1 comprises a central heat exchanging apparatus 1 and room heating and cooling radiators 2 joined to each other by means of pipes 3 and 4 and evacuated to form 75 a closed, substantially air free circulation system containing a non-combustible, nontoxic, scentless and volatile heat transfer medium, such as di-chiloiotetrafluoroethiane (C 2 C 1 F 4) known under the registered Trade 8 () Mark " Freon " by the designation Freon 114, or bromochlorodfifluoromethane (Cir CIF,) known under the designation Freon 12 Bkl which medium does not solidify at the lowest climatic temperature prevailing oil the surface 85 of the globe namnely about -6 J C, and has a boiling point at atmospheric pressure below ordinary room temperature During the heating operation the Liquid thermal medium contained in the heat exchanger 1 which is heated 90 by means of a relatively small quantity of hot water from a boiler 7 circulating t Izough a feed pipe 5 and a return pipe 6, is evaporated therein and leaves the evaporator at its upper end in the form of saturated or slightly super 95 heated vapour Through the pipe 3 thle vapour is supplied to the room heating radiators 2 connected in parallel and acting as condensers. The heat transfer mecdium being in the radiators 2 under e-vaporating pressure, is liquefied 100 by giving off its evaporation heat to the rooms to be heated The condensate flows due to its gravity into pipe 4 or if need be, first into a condenser and accumulating vessel (not shown), being afterwards fed by a gas-tight 105 circulation pump (not shown), and through a thermostatically controlled injection atomizer valve 8 to the heat exchanger 1 The regulation of the valve 8 is effected in such a manner that on increasing sunerheating of the 110 heat transfer vapour at the outlet of the heat exchanger 1 a known thermostat mounted in the pipe 3 causes an increased opening of the injection valve and, on lack of sup erheating of the vapour, causes a partial closing of said 115 injection valve The heat exchanger 1 is designed in such a manner that a slight superheating of the vapour occurs when the whole evaporator surface is in action For regulating the evaporation temperature in the heat 120 exchanger 1 a known thermostat is used which adjusts the oil or gas burner 9 of the boiler 7 and pressure is controlled by a known pressure sensitive means which, when the pressure reaches a limited value, as for instance on 125 failure of the thermostat, shuts off the burner 9 until the pressure in the evaporator has again dropped to its normal value The radiators 2 can be provided with a solenoid valve automatically controlled by a room thermostat or 130 785,767 the radiators 2 may be

provided with a dia t phragm valve only to be operated by hand r The pressure and the temperature of the heat transfer vapour can be adjusted by one/or x more thermostats and one pressure sensitive 1 device in accordance with the requirements or 1 the room to be heated in such a manner that the temperature in the radiators 2 can be fully automatically kept at a temperature value preset according to the prevailing requirements, e.g usually between 30 Y C and 60 ' C Preferably such a plant operates, for instance during the transition period between the seasons, at a temperature of about 40 C and a pressure of about 3 5 atmospheres absolute. In case all the radiators 2 and the condenser collector are loca Led above the heat exchanger 1 the resistance to circulation of the medium can be overcome by means of the force of gravity of the medium alone Since in large vapour heating plants the return quantity of condensate from the pipe network does not correspond in every moment with the feed liquid requirements of the heat exchanger 1 a condenser collecting vessel may be required fulfilling the duty of an accumulator. From the above explanation it will be seen that with the central vapour heating plant described, fully automatic control and regulation of the heating temperature is possible by the combined action of electrical, thermostatic and pressure sensitive means Heating temperature of less than 350 C can well be-maintained without disturbances in the circulation. In comparison with hot water systems the cross sections of the pipe lines can be relatively small, for instance '/, inch inner diameter, and as the thermal medium is noncorrosive the thickness of the pipe wall can also be comparatively thin Furthermore no expansion vessel, venting elements or pipe insulation are required for which reason the costs of the plant and its installation are considerably lower than those of a hot water central heating plant No refilling of heat transfer medium is necessary There is no danger of freezing The heat losses at the pipes are lower than those in a hot water central heating plant, and the heating of the rooms to be heated can be effected very quickly due to the comparatively small volume of thermal medium, the high flowing speed of the vapour and the immediate setting-in of the condensing action in the room radiators The plant has an extremely low inertia and thus operates far more efficiently than any hot water central heating plant The room heating bodies can as described below, consist of pipes of small cross-section provided with fins; their space requirement and their weight are therefore correspondingly small An average vapour temperature of about 60 C will usually be sufficient so that no dust smouldering occurs, the rooms are not overheated, and the climatic condition of the room air is not

affected For heating the evaporator also waste heat can be ised. In order to operate the plant for a moderate cooling of rooms it comprises a compressor 10, he suction side of which is connected through 70 a pipe 11 to the pipe 3 and the pressure side of which is connected through a condenser 14 and a pipe 15 to the pipe 4 The condenser 14 has a feed pipe 12 and return pipe 13 for cooling water In the pipe 15 are provided 75 an inlet valve 16 and in front thereof a stop valve 17 During heating operation of the plant the compressor and condenser are set out of action and the stop valve 17 and a stop valve 18 provided in the pipe 11 are closed, 80 while a stop valve 19 arranged in front of the injection valve 8 and a stop valve 20 arranged behind the heat exchanger 1 are open. During cooling operation the stop valves 17 and 18 are open, while the stop valves 19 and 85 are closed The heat transfer medium condensed in the cooled condenser 14 flows through the valve 16 (which may be thermostatically controlled in known manner), into the pipe 4 and from there into the room cool 90 ing bodies or radiators 2 operating now as evaporators By heat extraction from the room to be cooled the medium injected in the radiators 2 is evaporated The vapour of the medium is drawn through the pipes 3 and 11 95 by means of the compressor 10 and is fed by the same under pressure into the condenser 14 In the cooling operation the temperature of the heat transfer medium is suitably held e.g at about 15 ' C in the evaporator or radia 100 tor and at about 300 C in the condenser at a pressure of 2,2 to 1,5 atmospheres absolute. The room heating-and cooling bodies designated generally with the numeral 2 in Fig 2 are adapted according to their twofold purpose 105 of room heating and room cooling In the constructive embodiment shown in Figs 2 and 3 the body 2 comprises pipe windings X, through which the heat transfer medium passes, arranged in the hollow spaces 26 110 between the joists 27 of the ceiling of a room to be heated Below the pipe windings 2 metal plates 29, e g of aluminium, are arranged in the plaster ceiling 28 fixed to the joists which metal plates 29 are in metallic 115 connection with the pipe windings 2 by means of the carriers 30 and serve as radiation elements, said radiation plates 29 being arranged approximately uniformly over the whole surface of the ceiling (Figure 1) 120 The room heating and cooling body shown in Figs 4 and 5 is provided with lamella 31 arranged in the radial planes of, and evenly spaced side by side on, the pipe 2 and is disposed at a slight inclination towards the 125 pipe 4 below the window board 32 in a recess provided between the outer wall 33 and a wainscoting wall 34 or a grid, fence or the like, said recess 35 communicating with the room to be heated or cooled at least by means -130 j 785,767 of an upper and a lower opening 36 and 37, respectively In the recess 35

above the room heating and cooling body are located two electrically driven fans 38 for drawing the cooled air upwardly and driving it through the opening 37 into the room when the plant is operated for cooling With advantage a collecting vessel 39 for condensed water with a drain is provided below the radiator body.


* GB785768 (A)

Description: GB785768 (A) ? 1957-11-06

Improvement in or relating to methods of duplicating

Description of GB785768 (A) Translate this text into Tooltip



PATENT SPECIFICATION Date of application and filing Complete Specifci No 21266 /55. Application made in Germany on July 24, 1954. Complete Specification Published: Nov 6, 1957. 7855,768 ation: July 22, 1955. Index at acceptance:-Classes 96, B( 3 A: 14 D: 14 X: 28); 100 ( 2), CA( 3: 13), P 16 C 2; and 146 ( 3), C 10. International Classification:-B 41 f, n CO 9 d D 21 h. COMPLETE SPECIFICATION

Improvement in or relating to methods of Duplicating We, WILHELM RITZERFELD, of 14, Schor c lemer Allee, Berlin-Dahlem, Germany, and GERHARD Ri TZERFELD, of 21, Franzens E bader strasse, Berlin-Grunewald, Germany, f S both Citizens of the Federal Republic of a Germany, do hereby declare the invention, i for which we pray that a patent may be) granted to us, and the method by which it E is to be performed, to be particularly de c scribed in and by the following statement: X The invention relates to methods of duplicating, and more specifically to methods of duplicating in which directly effective inking materials are not made use of. Known hectographic duplicating methods 1 have the disadvantage that, when in preparing a hectographic master sheet a transfer sheet is used which is provided with a directly effective hectographic ink layer for transferring ink from the transfer sheet to the master sheet, it is difficult to avoid smudging of the hands of an operator, of a typewriter, of the operator's clothing and the like by the hectographic ink transfer sheet itself or by ink from the prepared hectographic master sheet. It is an object of the invention to provide a method of duplicating in which directly effective inking materials are not made use of. In Patent Specification No 737,605, there has already been proposed a method of producing a copy by a planographic system making use of a master, characterized by forming a planographic image of the master with a composition substantially free of dye colour and containing at least one of the components for reaction to form a dyestuff, wetting the surface of a copy sheet with a fluid containing a solvent for the dye forming component, and contacting the wetted surface of the copy sheet with the imaged surface of the master to dissolve off some of the dyeforming components to the wetted surface of the copy sheet for reaction to form the dyestuff in the imaged areas of the t Price 3 s 6 d l copy sheet. In specification No 712,216, there has been disclosed and claimed a transfer sheet :or use with a receiving sheet sensitized with 50 a colour reactant substance, having a coatng including a low-polarity hydrophobic vax in which there is incorporated a hydrophobic oil containing a substance capable of giving rise to a distinctive colouration 55 when brought into contact with a receiving surface having thereon said colour reactant mbstance. The invention consists in a method of duplicating comprising the steps of selecting 60 two chemical substances of which one is a crystalline violet lactone and each of which in the absence of the other is non-staining, but which co-react with each other and form a transferable dye when brought into con 65 tact with each other,

incorporating one of the said substances into a fatty layer of a transfer sheet, transferring portions of the layer on to a master to form a fatty script thereon, adding the other substance to a 70 liquid for moistening copy sheets to be printed by duplicating, the liquid being a solvent for the fatty substance in the said script, and bringing the fatty script on the master sheet in direct contact with the liquid on the copy 75 sheet to produce a print of the script on the copy sheet The other substance may be attapulgite. Thus, two chemical substances are made use of, each of which in the absence of the 50 other is colourless or is coloured but of such nature that the colour is non-staining and non-smudging, but which, when brought into contact with each other, co-react and form a transferable dye locally at the regions of 85 contact. A transfer sheet (replacing the hitherto usual hectographic ink transfer sheet) is provided with a layer of wax or fat, in which one of the co-reacting substances is incorpora 90 ted When preparing a duplicating master sheet, this transfer sheet comprising the one ' ad ( A |:' > ^ ' of the said co-reacting substances is placed with its layer against the back of a master sheet blank, and by pressure exerted during writing, printing, typing or the like on the front of the master sheet a fatty mirror script is created on its back at the corresponding places, the fatty mirror script comprising the one of the said co-reacting substances The other of the said co-reacting substances is dissolved or dispersed in a volatile solvent for the fatty substance with which a copy sheet or the like to be printed is moistened immediately prior to the duplicating Preferably, the moistening is effected during the duplicating process itself by means of a moistening device arranged immediately in front of the line of printing of a rotary duplicating machine, the device automatically moistening the copy sheets to be printed while the copy sheets are being fed to the line of printing Owing to the contact between the two co-reacting substances (one contained in the fatty mirror-script of the master sheet and the other in the moistened copy sheet) at the places where script is positioned, a reaction occurs, which forms a dye by ion exchange and/or adsorption, with the result that a visible script corresponding to the script of the master sheet is formed on the copy sheet being printed. Since the solvent, for example ethyl alcohol, benzine, amyl acetate, or the like, in which the other of the said co-reacting substances is contained also dissolves the wax or fat of the script on the master sheet containing the one of the said co-reacting substances, it is possible to repeat the dye forming reaction until the supply of the fat or wax or the like containing one of the said co-reacting substances at the places on the master sheet where script is

positioned is exhausted Thus, for obtaining a comparatively great number of copies, for example a hundred copies, from a mirror script master sheet, use is made of two dye creating coreacting substances in combination with the simultaneous use of a solvent for slowly removing the supply of fat or wax or the like containing one of the two co-reacting substances The result is a clean method of duplicating which results in copies of particularly high light fastness Moreover, for performing the method no special copy sheets need be used for printing. For performing the method a number of various chemical compounds may be used as one of the two co-reacting substances. In order to make the invention clearly unf derstood, reference will now be made to two examples which are given by way of illustration: EXAMPLE No 1. A comparatively high amount of attapulgite is incorporated into a combination of stearin, carnauba wax, castor oil and olein 65 and provided as a layer on a transfer sheet. The preparation of the mass and the forming of the layer of the transfer sheet is effected under heat For damping the copy sheet to be printed, denatured ethyl alcohol is used to 70 which crystalline violet lactone dissolved in chlorinated diphenyl has been added On contact of the moistened copy sheet with the mirror-script of the master sheet a blue dye reaction occurs 75 Instead of attapulgite, similar substances having adsorbing qualities, such as kaolin, aluminium oxide, aluminium phosphate, barium sulphate, betonite, calcium carbonate and calcium chloride, calcium citrate, cal 80 cium fluoride, calcium oxide, calcium phosphate, calcium sulphate, halloysit, magnesium carbonate, magnesium trisilicate, pyrophyllit or silicon dioxide may alternatively be used 85 EXAMPLE No 2. Crystalline violet lactone is incorporated into a wax or fat layer of a transfer sheet, and ethyl alcohol containing a small quantity of sulphuric acid is used for moistening 90 the copy sheets to, be printed On contact of the copy sheet with the mirror-script of the master sheet a blue-dye forming reaction takes place.


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