* GB785949 (A)

Description: GB785949 (A) ? 1957-11-06

High temperature control system and apparatus

Description of GB785949 (A)

PATENT SPECIFICATION 785 M 94Date of Application and Filing Complete Specification: June 24, 1955. No 1 893298/5. Application made in United States of America an June 28, 1954. Complete Specification Published: Nov 6, 1957. Index at Acceptance: Classes 64 ( 2), T( 3 C 4: i 3); 130 ( 3), G IOE(JB 5: 2 A); and 135, P(il E: 9 A 2: 2411 ( 5: 251 w), VT 4 A, International Classification: FO 2 c F 06 k G 01 k. COMPLETE SPECIFICAT 1 ON High Temperature Control System and Apparatus. We, NIANNING, MAXWELL & MOORE, i NCORPORATED, a corporation organised under ti e laws of the State of New Jersey, United states of America, of Stratford, Connecticut, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the mnethod by which it is to be performed, to be particularly described in and by the folo-ing statement: - The present invention relates to high temperature control systems and apparatus, and, more particularly, to high temperature control systems and apparatus employing a mercury vapor tension temperature sensn_ unit which is extremely rugged in construction, is quick acting in its response to Temperature changes and is simple and economical to manufacture. W hile the invention is of general utility, i is particularly adapted for use in and will he described in detail in connection with the control of an aircraft power plant of the gas turbine type in accordance with temperature variations in the turbine inlet or exhaust gas stream In the temperature control arrangements heretofore proposed in connection with gas turbine control, a thermocouple array is usually employed to detect temperature changes in the gas stream The

electrical thermocouple out;ut signal is amplified to a suitable power level in an electronic amplifier, which requires a separate power supply for the vacuum tubes thereof, and the amplified sigral is employed to control the driving motor or other device used to actuate the fuel valve or exercise a temperautre trim function While these prior art arrangements Orovide sufficiently accurate control, they are quite bulky and heavy for aircraft operation and are also complicated and hard to service and maintain in operation In other gas turbine control arrangements a temperature sensing unit of the rod expan(Price 316-) sion type has been employed However, these arrangements are subject to a considerable time lag between actual temperature change and the response of the thermal unit so that precise control is not obtained 5, in the general temperature indicating field it is customary to use a liquid, vapor or gas filled bulb connected through a capiliary tubing to a pressure responsive element in the form of a Bourdon tube to indi 55 cate at a remote point the temperature variations in the measuring zone adjacent the bulb However, for control applications such arrangements suffer from the disadvantage that a considerable pressure-trans 60 mission lag is experienced, i e, a lag in transmitting the pressure change in <he bulb through the capillary connecting tubing to the pressure-spring In some vapor pressure systems, wherein the bulb is partially 65 filled with a volatile liquid, the pressuretransmission lag may be as high as a minute or more, a condition which is entirely unsuitable for producing a sensitive control function Also, in the case of gas-Eflled 70 systems, the internal volume of the bulb should be made large in comparison to the internal volume of the capillary tubing and pressure-spring to reduce the effect of ambient temperature changes and a thermomet 75 ric lag in the heat transfer from the fluid being measured to the gas in the bulb is prcduced In addition, the Bourdon tube pressure-spring arrangements are not suitable for use in applications such as aircraft con 80 trol systems because they will not withstand the severe shock and vibration tests to which equipment of this type must be subjected Furthdrmore, in aircraft control systems the capillary tube arrangement 85 suffers from the disadvantage that when the system is subjected to extreme cold, i e, when the engine is idle, the mercury in the capillary tube freezes When the engine is started and the temperature rises, a con 90 785,949 siderabie length of time is required to thaw cut the complete system since heat is priniarily conducted through the small thread ofr mercury within the tube As a result the engine may overheat before the control system starts functioning and the system relay be permanently damaged due to the unequal expansion along the tube.

It is, therefore the primary object of the present invention to provide a new and improved high temperature control system and apparatus wherein one or more of the above described disadvantages of the prior art arrangements is eliminated or substantially reduced. The invention consists in a temperature sensitive control device for producing a control function when the temperature of a measured medium exceeds a predetermined temperature control point, said device including a flexible diaphragm, a rigid tube communicating with one side of said diaphragm and a thermosensitive material in said tube, said device being adapted to be mounted with said tube substantially entirely in a high temperature measuring zone so that a rapidly changing control function zay be effected in accordance with movenerent of said diaphragm when said tempertature control point is exceeded, character-zed by the provision of a metal bar in en-agement with a transverse fulcrum member, means connecting said bar to said diaragni on one side of said fulcrum member, and an adjustable rigid stressing member in engagement with said bar on the other side of said fulcrum member and adapted to bend said bar about said fulcrum member and exert a preloading force on said diaphragm, and means co-operating with said metal bar for producing said control function when the force exerted on said diaphragm by said thermosensitive material exceeds said preloading force. The invention, both as to its organization and method of operation, together with further objects and advantages thereof, will best be understood by reference to the folo ing specification taken in connection with the accompanying drawings, in which: Fig 1 is a diagrammatic view of a high temperature control system embodying the features of the present invention; Fig 2 is a plan view of the high temperature control unit employed in the system shown in Fig 1 with the cover of the unit removed; Fig: 3 is a sectional side elevational view taken along the lines 3-3 of Fig 2; and Fig 4 is a fragmentary sectional view, Waken on a larger scale, of the diaphragm nortion of the control unit shown in Fig 3. Referring now to the drawings, and more paricularly to the high temperature control system which illustrates one example of the use of a device in accordance with the invention and which is shown in Fig 1 thereof, the system is therein illustrated as comprising a high temperature control unit, indicated generally at 10, which employs mer 70 cury vapor as the thermosensitive fluid, and a fuel control valve of the servo type, indicated generally at 11, the movable control valve element 12 of the valve 11 being controlled by means of a pneumatically oper-75 ated pressure ratio control device 14 which is connected to the control unit 10 by means of the pneumatic control line 13 In the embodiment shown in Fig 1, the high teniperature

control system of the present in-80 vention is arranged to provide a temperature override control for an engine suitable for jet propulsion, propeller propulsion or combined propeller-and-jet propulsion of aircraft Such engines generally include an 85 air inlet, an air compressor, one or more combustion chambers, a gas turbine and a tail pipe for discharging combustion gases to the atmosphere Associated with the engine is a fuel pump (not shown) for deliv 90 ering fuel under the control of appropriate scheduling means through the conduit 19 to the fuel manifold of the engine, and the fuel valve 11 is arranged to bleed off fuel through the conduit 17 to the fuel return 95 or sump when engine speed and temnerature exceeds a predetermined maximum value or control point. The high temperature control unit I'D is secured to the side wall 15 of the annular 110 fluid flow passageway of the engine and includes a probe unit, indicated generally at 16, which extends into the turbine inlet gas stream, or other desired measuring zone in the engine In order to provide a tempera-105 ture sensing device which is sufficiently rugged to withstand the force of the jet stream and the normal shock and vibration of aircraft operation, while providing a sufficiently sensitive unit that precise con 110 trol can be maintained at the high temperatures involved without introducing substantial time lag in the system, the probe unit 16 comprises a mercury filled tube 20 which is surrounded by a tubular protective 115 member 21 provided with openings 22 and 23 through which the outer end portion of the tube 20 is directly exposed to the hot combustion gases As the temperature approaches the control point, a small bubble 120 a of mercury vapor is formed in the tube 20, in a manner to be explained in more detail hereinafter, the mercury vapor pressure exerting force on a flexible diaphragm 26 positioned with the housing 25 of the 125 control unit 10 and in direct communication with the mercury in the tube 20 The diaphragm 26 is arranged to exert force on a deflectable beam 27 which is mounted in the housing 25 in such manner that when a 130 niocouple input system is provided while requiring a much less complicated and lighter weight control system which is particularly desirable for aircraft applications In this connection it will be understood that a plur-70 ality of control units 10 may be provided, each connected to the control line 13, so that averaging of the temperature variations at various positions may be obtained. Considering now in more detail the fea-75 tures of the high temperature control unit shown in Figs 2 to 4, inclusive, of the drawings, whereby operation in the high temperature control system described above is provided in accordance with the present 80 invention, the control unit 10 includes a metallic body member 80 which is projection welded to the central portion of a mounting plate

81, the plate 81 preferably being of low heat conductivity metal and 85 provided with offset end portions 82 and 83 which are adapted to be bolted or otherwise secured to the side wall 15 of the annular fluid flow passageway of the engine A gasket 85 of suitable insulating material, 90 such as asbestos, is positioned between the centre portion of the mounting plate 81 and the side wall 15 so as to reduce direct heat conduction from the side wall 15 and to provide a gas tight seal A partial pressure 9 sealing element 88 is positioned between the members 80 and 81 to prevent loss of pressure through the member 21 in situations where the temperature measurement is made in a relatively high pressure zone 100 The tubular protective member 21 is positioned within a bushing 86 carried by the mounting plate 81 which extends through the clearance hole 87 in the side wall 15, the tubular member 21 being spun over the end 105 of the bushing 86 so as to form an integral part of the mounting plate 81 A spacer 89 is provided to maintain the tube 20 and protective member 21 in concentric relation, the spacer 89 contacting the tube 20110 at only one edge thereof to minimize heat conduction from the tube 20 to the lower temperature member 21 Also, the end portion of the member 21 is tapered so as to provide for minimum area of contact with 115 the tube 20 A plurality of apertures (not shown in the drawing) are provided in the tubular member 21 to provide more uniform temperature conditions along the length of the tube 20 The flexible dia 120 phragm 26 is positioned between an upper diaphragm supporting member 90 and a lower diphragm supporting member 91, the members 90 and 91 being provided with peripheral flanges 92 and 93 which are heli 125 arc welded around the circumference thereof so as to support the edges of the diaphragm 26 therebetween The lower diaphragm supporting member 91 is threaded into a central opening in the body member 80 and the member 91 is provided with an annular 13 G uiciently large force is exerted thereon wnc beam 27 is bent or deflected away from A control orifice 28 connected to the control tine 13. The pressure ratio control device 14 is upplied with unregulated compressor discharge air through the conduit 18 and inciudes a piston element 30 which is slidably mounted in the housing 31 and is connected to the valve element 12 so as to control the position thereof Compressor discharge air is supplied to a first chamber 35 of relativeEv small area, and is also supplied through the pressure reducing orifice 36 to a second chamber 37 on the other side of the piston 30, the control orifice 28 being connected through the control conduit 13 to the chamber 37 so as to control the pressure therein In order to prevent changes in the :20 position of the valve element 12 due to variations in the supply air pressure, the pressure drop across the orifice 36 and the active piston areas are so chosen that the

piston does not change position as long as the pressure ratio across it remains constant. However, variation of the control orifice 28 varies the pressure ratio across the piston so as to control the position of the valve element 12. Considering now the operation of the high temperature control system shown in Fig I and assuming that the temperature of the turbine inlet gas stream rises above the high temperature control point, as the pressure on the diaphragm 26 increases the beam 27 is deflected so as to increase the opening of the control orifice 28 thereby reducing the pressure in the chamber 37 As a result, the piston 30 is moved to the left and the slide valve element 12 is opened so that a greater amount of fuel is bled off to the sump through the conduit 17 and the supply of fuel to the combustion apparatus of the engine is reduced As the temperature of the turbine inlet gas stream is accordingly reduced, the pressure on the diaphram 26 is reduced so that the opening of the control orifice 28 is reduced with the consequent closure of the valve element 12. S It will be noted that since the mercury filled tube 20 is in direct communication with the diaphragm 26 a relatively small total volume if mercury is required so that the pressure transmission lag normally encountered in capillary tube arrangements is substantially eliminated and a very fast response ratio is achieved It will also be noted that the entire control system of Fig 1 is mechanically and pneumatically controlled so 60that electronic amplifiers and drive motors are not required to achieve the desired control function Furthermore, due to the rapid response rate of the mercury vapor tension control unit 10, a sensitivity of control substantially equal to the conventional ther785,949 4 78,4 depression 94 so that the upper end of the tube 20 can be secured to the member 91 bv a suitable welding operation or the like. Preferably, the tube 20 is of a high nickelchromium iron alloy having good corrosion resistance and good high temperature properties. In order to deflect the beam 27 in accordance with movement of the diaphragm 26 while providing an arrangement for protecting the diaphragm 26 against rupture in the event the control unit 10 is subjected to temperatures considerably in excess of the control point, there is provided a force 1 Stransrnitting member 95 which rests on the upper side of the diaphragm 26 and extends through a clearance hole 96 in the upper diaphragm supporting member to the underside of the beam 27 The member 2090 is provided with a conical seat portion 07 and the force transmitting member 95 is p 2 rovided with a conical head portion 98 -h ch es adapted to fit into the conical seat Portiou 97 when the diaphragmn 26 is moved tlnxwardlv against the bottomn

surface 100 of t re urper diaphragm supoorting member A -cordingly, when the force on the dia-'ram '6 becomes sufficientit i reat the br 95 seats in the conical nortion 97 and a flat supporting surface is provided tor the entire area of the diaphragm so that d'.manie to the diaphrag m is prevented. turt 1-hemnire, as the conical nead portion 98 is moved upwvardly, a self centering action is produced wvherey'v the position >i the r'-,eiber 95 on the diaphramii 26 is asdiuste i that the members 95 and 90 ft together and form a smooth surface which acts as a -,psitive stop for the diaphragm 26 In the cther extreme position the diaphragm 26 rests on the slightly inclined annular top surface 99 of the lower diaphragm supporting member 91 and the distance between the 2 members 90 and 91 at the outer edge of the conical head portion 93 is very small, po-referably 7 in the order ot S':: thou an 2 dths of an inch, so that the to'-1 travel of the diaphragm 26 is very small and the elastic l Enit of the diaphragm is not exceeded In 50,tids connection, it will be understood that she clearance hole 96 in the member 90 is sufficiently large to permit the above desceib'ed self centering action of the member e 35 as the head portion 98 is seated in the conical seat 97. The deflectable beam 27 is in the form of a flat, metal bar which is of sufficient thickess that the beam 27 is deflected only a few thousandths of an inch when subjected to forces developed in the mercury filled svstem of the order of several hundred rounds per square inch The beam 27 rests on the upper end of the force transmitting m-ember 95 and on the hexac-nal 'ead portion 109 of an adustable supporting post I)8 which is threaded into the bod: member 80 The beam 27 is also positioned against a transversely extending bearing pin 107 which is supported at either end thereof on a pair of upstanding bear 70 in posts 105 and 106 formed integrally with the body member 80 During periods wh lien the beam 27 is not forcibly held against the pin 107, the beam 27 is retained in approximately the correct position by 75 means of the retaining spring 110 which is spot welded to the beam 27 and clips over the pin 107 In this connection, it will be noted that the pressure responsive diaphragm and deflectable beam arrangement 80 of the present invention has a much higher force to mass ratio than the conventional Bourdon spring arrangement Thus, in a typical Bourdon type structure, the force acting at the tip of the tube may be only a 85 ic.; pounds for an applied force of several thousand pounds, whereas with the direct transmisson of force from the flexible dianhraen 26 to the beam 27 a much greater i.ai of force Lo mass is produced under the 9 1 O 'onditions As a result, the pressure r.uieve unit of the present invention is less susceptible to vibration and car -i hs l hive

aczelerations and deceleratior As l ithout affecting the operation of the 95 ('evice Furthermore lxith the deflectable Lu-a narrangement of the present invention a considerably greater control force is deve'7 on 2 so that a control function requirinr considerable power may be effected 100 In order to produce a pneumatic control f unction in accordance wlaith deflection of the beam 27 the bodv member 80 is proidled with a passageway 115 which is connece 11 to the control conduit 13 in the s 105 tam of Fig 1, for examp e, and the contro' orifice 28 is threaded into the body membeso as to communicate with the passagew-a-y 115 The orifice 28 is provided wi Lt an outwardly fared mzouth portion 116 for 111 increased sensitivity of control and a baffle member 117 is adapted to vary the effective opening of the mouth portion 116 of the control orifice 28 In order to permit positih, closure of the orifice 28 even though 115 the deflectable beam 27 may be positioned at a slight angle to the mouth portion 116, the baffle 117 is connected to the offset end portion 118 of the beam 27 by means of a universal joint arrangement so that positive 120 closure of the orifice 28 by the baffle member 117 is assured More particularly, an adjustment stud 119 is threaded into the end portion 118 of the beam 27 and is provided with a spherical end portion 120 on which 1125 the baffle 117 is seated The baffle 117 is provided with a flange portion 121 which is adapted to receive the bifurcated lower arm 122 of a U-shaned retaining spring 123, the vn ar eifui'cated nt -nf t' cpring 123 en 130 ' 785,949 785,949 gaging the upper side of the spherical end portion 120 so that the baffle member 117 is i held against the spherical end portion 120 E of the adjustment stud 119 and may be i tilted by the required amount to provide complete closure of the orifice 28 In this connection it will be understood that under certain conditions the control orifice 28 must be tightly closed to provide good seni siti;itv and speed up the response of the control system If the above described universal joint arrangement is not provided, the baffle member 117 may be tilted slightly and strike one edge of the mouth portion 116 of the control orifice 28 so that complete closure of the orifice is prevented It will also be noted that with the arrangement of the present invention a relatively small movement of the diaphragm 26 produces a proportionately larger movement of the baffle member 117 so that increased sensitivity of control is achieved. Considering now the manner in which the high temperature control unit 10 is assembled and functions in developing the desired control function, it will be understood that the diaphragm unit is first inserted into the protective member 21 with the force transmitting member 95 loosely positioned on top of the diaphragm 26 The deflectable beam 27 is then secured on the pin 107 and the height of

the post 109 is adjusted so as to develop the desired pre-loading force which must be overcome to provide movement of the baffle member 117 The tube and annular space 94, which together have a much smaller volume than the bulb of a conventional capillary tube instrument and may, for example, have a total volume of only 0025 cubic inches, are filled solidly with liquid mercury at a temperature from ' to 200 '1 F below the desired control point As the temperature increases the mercury expands linearly until the pressure of the system reaches the mercury vapor pressure at a temperature slightly below the control point, for example, 20 'F below the control point When this occurs, the small mercury vapor bubble 20 a is formed in the tube 20 and the pressure of the system increases rapidly as the control point is reached The bubble 20 a is formed at the highest temperature portion of the tube 20 and since the tube 20 is directly exposed to the gas stream through the opening 23, the bubble forms in the exposed portion of the tube and on the side of the tube exposed to the hot gas flow, as best illustrated in Fig. 1 In this connection it will be understood that the upper portion of the tube 20 and the extremity thereof are partially shielded by the tubular protective member 21 so that these portions of the tube 20 are cooler than the portion exposed through the opening 6523. As the temperature increases further the nercury vapor pressure rises exponentially and the mercury vapor bubble 20 a increases in size so that it extends across the entire Width of the tube 20 The movement of the 70 diaphragm 26 is so chosen that when the diaphragm 26 has been forced upwardly against the positive stop defined by the bottorn surface of the supporting member 90 and the co-extensive surface of the force 75 transmitting member 95, the mercury bubble 20 a is still sufficently small so that it is exposed to the gas stream flowing through the opening 23 If, for example, it is assumed that the volume of the system is in 80 creased by one-fifth when the diaphragm is in its uppermost position, the maximum length of the mercury bubble 20 a wll be approximately one-fifth the length of the tube and the length of the openings 22 and 83 23 is chosen accordingly In this connection it will be understood that the annular space 94 is not shown to scale in Fig 4 and is preferably a relatively small proportion of the total system volume With this ar 90 rangement, the meniscus formed at the mercury-mercury vapor junction is, at all times, positioned within the desired temperature measuring zone, i e, the hot gas stream flowing through the opening 23 Ing S this connection it will be understood that if the tube 20 is filled solidly with mercury at room temperature instead of the above described 100 ' to 200 'F below the desired control point, the volume of the system 100. must be made considerably larger to accommodate the additional volume

of liquid mercury expansion between the room temperature and the indicated filling temperature Thus, if the control point is 1050 'F 103 and the tube 20 is filled solidly with mercury at 800 'F instead of at room temperature, the expansion volume may be made approximately 35 %' smaller than if the tube 20 is filled with mercury at room temperature 110 In order to provide compensation for weakening of the defectable beam 27 at the extremely high temperatures at which the control unit 10 operates, the adjustable supporting post 108 is preferably constructed 1 of a metal having a higher temperature coefficient of expansion than the body member 80, the supporting members 90 and 91, an-d the force transmitting member 95 With this arrangement, as the beam 27 weakens 120 at high temperatures, a compensating increasing force on the beam 27 is produced due to the expansion of the post 108 relative to the pin 107 and the force transmitting member 95 It will also be noted that 125 the beam 27 is positioned substantially parallel to the temperature measuring zone and the unit 10 is of flat construction so that expansion of the parts due to the proximity to the high temperature measuring zone is 130 785,949 uniform and does not result in variations of the position of the baffle member 117 Also the body member 80 is provided with a recess 131 in the bottom portion thereof so S that conduction from the tube 20 to the mounting plate 81 is reduced Furthermore, since the entire mercury filled system is of extremely small volume and is located substantially entirely in the high temperature 1 measuring zone, the system is particularly adapted foy aircraft control Thus, if the temperature falls below the freezing point of mercury when the engine is idle and then the engine is started so that the temperature rises very rapidly, the mercury filled system will become fluid again very quickly and can function properly to prevent overheating However, when the conventional capillary tube system becomes frozen a considerable time lag is required to thaw out the system since most of the tube is not in the high temperature measuring zone and heat is transmitted relatively slowly through the mercury within the tube so that the system may not develop the desired control action in time to prevent overheating. While the control unit 10 has been illustrated in conjunction with a pneumatic control system it will be understood that movement of the deflectable beam 27 may be employed to effect any other desired control function For example, movement of the end portion 118 of the beam 27 may be employed to actuate an electrical contact arrangement so as to open and close an electrical contact arrangement so as to open and close an electrical circuit in any suitable electrical control system Obviously, other control functions may be derived from movement of the beam 27, as will be readily apparent to those skilled

in the art.

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* GB785950 (A)

Description: GB785950 (A) ? 1957-11-06

Improvements in or relating to telephone instruments

Description of GB785950 (A)

PATENT SPECIFICAON 78 ' Inventors:-ROBERT ANTHONY DERBYSHIRE and REGINALD BAILEY. Date of filing Complete Specification: May 29, 1956. Application Date: July 19, 1955 No 20801/55. Complete Specification Published: Nov 6,1957. Index at Acceptance-Class 40 ( 4), J 3 F.

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* GB785951 (A)

Description: GB785951 (A) ? 1957-11-06

Improvements in and relating to the stabilisation of phenol compounds

Description of GB785951 (A) Translate this text into Tooltip

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The EPO does not accept any responsibility for the accuracy of data and information originating from other authorities than the EPO; in particular, the EPO does not guarantee that they are complete, up-to-date or fit for specific purposes.

COMPLETE SPECIFICATION Improvements in and relating to the Stabilisation of Phenol Compound We, IMPERIAL CHEMICAL INDUSTRIES LIMITE, a British Company, of Imperial Chemical House, Millbank, London, S. W. 1, 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 und by the following statement :- This invention relates to the stabilisation of phenol compounds containing relatively small quantities of alpha-naphthol. In the production of phenolic substances, it is frequently observed that whereas immedi ately after preparation, the substances are light in colour, and posses a mild odour, they undergo more or less rapid deterioration on standing, developing a dark colour-and un- pleasant odour. This is a major disadvantage in many processes employing such phenolic substances, which in aonsequence frequently sufier considerable loss un value. The removal of the coloured and odoriferous substances is often'laborious an lexpensive, and accordingly attempts have been made to prevent loir limit their formation, rather than attempt to remove them once formed. It has been recognised that atmospheric oxidation often plays an

important part, generally by the formation of coloured product from impurities present in the phenolic compound. We have found that the rate of formation of coloured product in this way in phenyl phenols containing a relatively small quantity of alpha naphthol is greatly reduced by the presence of a small quantity of citric acid, tartaric acid or phosphoric acid. According to the present invention, there fore, we provide a process for stabilising a phenyl phenol containing less than 3% by weight of alpha naphthol which comprises treating it with not more than 5% by weight of citric acid, tartaric acid or phosphoric acid, or of any combination of these. Also according to the present invention we provide an intermediate composition of matter produced in the said stabilisation process and comprising a phenyl,'phenol contain- ing less than 3% by weight of alpha, naphthol and one or more of the acids, citric acid, tartaric acid and phosphoric adid to a total extent of not more than 5% by weight of the mixture of phenyl phenol and alpha naphthol. A suitable phenyl phenol is ortho phenyl phenol. The invention also provides a stabilised phenyl phenol containing less than 3% by weight of alpha naphthol, when prepared by the said process. A very suitable method of treatment is by the use of an aqueous solution of the stabilising acid, but the process, of the present invention may also be carried out by direct contact of the stabilising acid with the phenyl phenol or the phenyl phenol may be precipitated from a solution in an organic solvent containing the phenyl phenol and the stabilis- ing a. d ! d. It is not necessary that the acid or acids with which the phenyl phenol is treated should be soluble therein ; the stabilising effect remains if, after treatment with the stabilizing acid or acids the phenyl phenol is then subjected to processes such as washing or recrystaBisation, which might be expected to remove the stabilising acids which are present. It is a preferred feature of the process of the present invention thar : the concentration limits of stabilising acid amz 0. 1 ti} 1%'by weight of the phenyl phenol and alpha naphthiol to be treated. The process of the present invention is particularly valuable lin stabilising phenyl phenol prepared by synthesis involving the hydrolysis of chlorobenzene. Appreciable quantities of alpha naphthol

are formed and although much of this can b, tremoved by other means, the smal quantity which remains frequently gives rise to the formation of a coloured product on standing. The rate of formation of colour is greatly reduced by the addition of acids according to the process of the present invention, enhancing the value of the material by preserving lits light colour. The following example illustrates the effect of adding citric acid to ortho phenyl hydroxy benzene containing alpha naphthol. EXAMPLE. Each test in this Example was carried out on a mdlten sample in a one inch Lovibond cell, using a Lovibond Tintometer with red and yellow slides (The word "Lovibond" is a registered Trade Mark). The colours are expressed as C=Y+3R where C = colour, and Y and R are respec- tively the yellow and red colour units required to match the sample. See"Standard Methods for Testing Tar and its Products," 3rd Edition, 1950, page 214, published by the Standardization of Tar Products Tests Committee, London. When freshly distilled under vacuum, a sample of orthophenyl hydroxy benzene was found to contain approximately 1. 5% by weight of alpha naphthol, and was almost colourless. Storage tests at room temperature and 100 C., and a colour test were carried out on the freshly distilled material. Other freshly distilled samples were treated according to the following tables : TABLE 1 <img class="EMIRef" id="026415669-00020001" /> Colour Values according to C = Y + 3R Days at 100 C. Control 1st Test 2nd Test 0 1. 6 1. 6 1. 6 3 50.0 17. 17. 16. 16. 4 80.0 47.0 29.7 5 120.0 73.0 32.0 6 160. 0 102. 0 66. 0 7--87. 0 Control-untreated ortha Zhenyl hydroxy benzene. 1st Test-molten ortho phenyl hydroxy benzene at 80 C. was contacted with 1. 4% by weight of citric acid for 30 minutes with occasional string ; ortho phenyl hydroxy benzene was then decanted. 2nd Test-crushed ortho phenyl hydroxy benzene was stirred for 15 minutes with 1. 4% of its weight of citric acid dissolved in suffioient water to give a 1% solution by weight. The solid product was then collected and sucked dry. TABLE 2

<img class="EMIRef" id="026415669-00020002" /> Colour Values according to C = Y + 3R Days at 100 C. Control 1st Test 2nd Test 0 0. 8 0. 8 0. 8 1 3. 7 3. 6 3. 8 2 11. 3 7. 3 6. 1 3 21. 9 13. 2 9. 3 4 40. 4 26. 1 13. 4 7 105. 0 90. 0 51. 3 Control-untreated ortho phenyl hydroxy benzene. 1st Testmolten ortho phenyl hydroxy benzene at 80 C. was stiicred for 30 minutes with 1. 4% of its weight of citric acid dissolved in sufficient water to give a 1%'solution. The ortho phenyl hydroxy benzene was then removed from the aqueous solution. 2nd Test-40 grams ortho phenyl hydroxy benzene was dissolved in 20 mls, methanol, and 0. 56 grains (i. e. 1. 4%) citric acid dissolved in 25 mls. water were added. 35 mls. of methanol were added to restore homogeneity. 400 mls. water were then added, producing the product as an immiscible oil which crystaMis'edtonstirring,and which was collected and dtied in vacuo at 40 C. fotr 1 hour. TABLE 3 <img class="EMIRef" id="026415669-00030001" /> Colour according to C = Y + 3R See Table 1 for See Table 2 for Days at Test Conditions Test Conditions Room Temp. Control 1st Test 2nd Test Control 1st Test 2nd Test 0 1. 6 1. 6 1. 6 0. 8 0. 8 0. 8 4 18. 1 12. 9 15. 5 7 72 27. 5 48. 8 33. 2 18. 6 25. 9 What we claim is :- 1. A process for stabilising a phenyl phenol containing less than 3% by weight of alpha naphthol which comprises treating it with not more than 5% by weight of one or more of the following acids : citric acid, tartaric acid, phosphoftic acid.

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* 5.8.23.4; 93p

* GB785952 (A)

Description: GB785952 (A) ? 1957-11-06

Pressure transmitter

Description of GB785952 (A)

PATENT SPECIFICATION Date of Application and Filing Complete Specification: Aug 2, 19,55. Application made in United States of America on Aug. Complete Specification Published: Nov 6, 1957. Index at Acceptance:-Class 135, P(l C: ID: 3: 16 D: 96 E 3: 23: 249). International Classification:-GO 5 b. COMPLETE SPECIFICATION Pressure Transmitter. We, THE FOXBORO COMPANY, a corporation organized and existing under the laws of the Commonwealth of Massachusetts, of Neponset Avenue, Foxboro, Massuchusetts, United States of America, do hereby declare the invention, for which we Dray that a patent may be granted to us, and the method bv which it is to be performed, to be particularly described in and by the following statement:- This invention relates to pneumatic pressure transmitting devices in which pressure is transmitted from one point to another and more particularly to pneumatic transmission devices of the supply and bleed type. Such systems have been used, for example, to transmit pressure values of a fluid body in a tank This is accomplished by providing an aperture in the tank wall and using a diaphragm as a closure for this aperture. Further, a pneumatic system is used which is onerable in response to movement of such a diaphragm, as produced by pressure changes in the tank. These prior art systems provide the conventional air supply and bleed diaphragm pneumatic transmitters In these transmitters there is a constant pressure supply feedng through a fixed inlet restriction to the chamber behind the diaphragm Motion of the diaphragm operates a

relief valve to bleed air from this diaphragm chamber when the pressure behind the diaphragm exceeds the pressure on the tank side of 35the diaphragm This conventional system provides an air pressure output from the diaphragm chamber roughly equal to the tank pressure applied to the diaphragm. However, as the measured pressure in the tank varies, the diaphragm is deflected so that the pressure difference varies across both the inlet restrictor and the relief valve, the relief valve being moved to a different position so as to affect the manner in which the air is throttled in passing the relief valve or the area of the relief valve exposed tc the air The consequent variation of differential pressure across the relief valve are La introduces an additional force which varies with the measured pressure Consequently, 50 the air pressure behind the diaphragm differs from the measured pressure in the tank by an amount which varies with the measured pressure Where accurate duplication of tank pressure is desired, the above errors 53 become important if the pressure being measured varies appreciably, and one object of the present invention is to provide means whereby the diaphragm takes up the same position for each pressure within the range 60 of the apparatus. According to the present invention, a pneumatic pressure transmitting device in which pressure is transmitted from one point to another through the medium of a volume 65 of gas to which gas is supplied and from which it is simultaneously exhausted, is arranged for the supply to take place through a pressure regulator and for the exhaust to take place through a second pres 70 sure regulator, both pressure regulators being responsive to the output pressure of the device. The invention therefore provides means for overcoming the above errors, and the 75 main diaphragm may be held to the same position of balance throughout the operating range of the device The diaphragm is so held because predetermined pressure drops in the supply and exhaust systems are estab 80 lished and maintained throughout the operating range of the device. In the conventional transmitter the supply pressure is held constant, and the exhaust is to atmosphere, which is effectively at a 85 constant pressure Therefore when the measured pressure changes and the opposing pressure behind the diaphragm consequently changes this new diaphragm chamber pressure is related to the constant supplv and 90 785,952 No 22272/-55. 12, 1954. (Price 3/6) 785,952 exhaust pressures The result is the previously mentioned differences in supply and exhaust pressure drops with the consequent errors in measurement of the tank pressure. S In the transmitter of this invention, however, the diaphragm chamber

pressure throughout the range of the device is related to changing supply pressures and changing pressures into which the exhaust delivers in such a manner that the supply and exhaust pressure drops are maintained in a fixed predetermined relation with each other. Therefore, this invention provides a device wherein the output pressure is always exactly equal to the measured pressure throughout the operating range of the device. As a specific application, this invention is useful in measuring the pressures of corrosive liquids A suitable diaphragm or diaphragm assembly is used, wherein a resilient body is composed of or has one side faced with corrosion resistant material This may be a unitary homogenous structure, a lamination comprising two or more lavers stuck together or simply a juxtaposition of two layers not stuck together A tantalum diaphragm and a gasket made from the material known under the Registered Trade Mark "Teflon" are arranged in this case as 30the only portions of the transmitter unit -which are exposed to the liquid of which the pressure is to be measured In this particular arrangement, the inherently poor resilience characteristics of the tantalum diaphragm require that suitable supporting structure be used with this diaphragm, for example, a more resilient supporting diaphragm Other corrosion resistant diaphragm assemblies may be used, for example a bimetal sealed assembly of two different diaphragms, one of which is corrosion resistant and the other of which is resilient. In order that the invention may be clearly understood and readily carried into effect. constructions in accordance therewith will now be described, by way of example, with reference to the accompanying drawings in which: Fig 1 is a vertical central section through a pressure transmitter attached to a tank wall an doverlvine a tank wall opening for measurement of the pressure within the tank at the wall opening; Fig 2 is a showing of a pair of pressure 53 transmitters in association with a fluid containing tank and with a differential pressure device arranged to measure the pressure difference between the output pressures of the two pressure transmitters. Referring to Fig 1, the example of this invention shown therein comprises a supply and bleed diaphragm transmitter 10 secured to the wall 11 of a tank for fluid, and a supply and exhaust regulator unit 12, mounted on and operatively connected to the transmitter 10. The tank wall 11 is provided with a circular aperture 13 as a means of applying the pressure of fluid (not shown,) in the tank to the transmitter 10 The supply and bleed 70 transmitter 10 has a circular main body 15 with an annular boss 16 around the tank wall aperture 13 A resilient sealing ring 17 is matched to the annular boss 16 and is mounted as a fluid-tight seal, between the 75 tank wall 11 and the

boss 16, with the inner diameter of the sealing ring 17 and the inner diameter of the annular boss 16 flush with the circular aperture 13 of the tank wall 11 The transmitter main body 15 ex 80 tends radially outward along the tank wall and is spaced therefrom well beyond the aperture 13 Suitable bolts 18 extend through these spaced portions of the body and are threaded into the tank wall 11 85 A circular diaphragm 19 is held along its peripheral edge between the sealing ring 17 and the boss 16, as a closure for the aperture 13. The transmitter main body 15 is pro, ided 90 with a main chamber 20, behind the diaphragm 19 The chamber 20 has an air pressure supply inlet 21, an exhaust valve including an exhaust port 22, and an output port 23 The exhaust port 22 has an en 95 larged portion opening into the main chamiber 20, for receiving an exhaust valve stem 24 and an exhaust valve helical loading spring 25 The valve stem 24 has one end secured to the centre of the diaphragm l q 100 and its other end tapered for seatin-^a in thle smaller portion of the exhaust port 22 The helical loading spring 25 surrounds the valve stem 24, and acts between the end of the enlarged portion of the exhaust port 22 and 105 the diaphragm 19 Although the spring 25 resists the closina of the exhaust valve port 22, it exerts no effective pressure on the diaphragm 19 when the diaphragm is in its normal, balanced position i e with theello applied pressure in the tank and the pressure in the main chamber 20 exactly equal. The supply and exhaust regulator unit 12 is designed, as will be described below to hold constant a pressure drop in the supply 115 system to the transmitter, and another pressure drop in the exhaust system of the transmitter In effect, this regulator unit is a double differential pressure regulating valve. Taken in combination with the simple trans 120 mitter unit 10, the regulator unit 12 provides an overall system which may be termed a pressure divider, comparable in function to a voltage divider in an electrical circuit 125 The regulator unit 12 is a generally cylindrical body having three chambers therein: a supply chamber 22, a central chamber 27. and an exhaust chamber 28 The di',iding wall between the supply and central cham 130 785,952 Hers is a flexible supply diaphragm 29, and Jie dividing wall between the central and exhaust chambers is a flexible exhaust dia t phragm 30. The supply chamber 26 is provided with t air pressure from an air supply inlet pipe 31, through a supply regulator valve 32 A supply valve connection member 33 is secured to the central portion of the supply diaphragm 29 and the stem of the supply regulator valve 32 is secured to the connection member 33 A supply valve bias spring 34 tends to hold the supply regulator valve open, and whatever pressure

is in the supply chamber 26 tends to close the supply regulator valve 32 by pushing down on the supply diaphragm 29. From the supply chamber 26 air flow is provided to the central chamber 27 through the supply diaphragm 29 by way of a fixed restrictor passage 35 in the connection member 33 The air supply system is then completed from the central chamber 27 to the transmitter supply inlet 21, through a supply pipe 36. The exhaust chamber 28 is sealed off from the central chamber 27 by the exhaust diaphragm 30, and an exhaust connection pipe 37 connects the transmitter exhaust port 22 with the exhaust chamber 28 The size of the exhaust connection pipe 37 is not critical, but simply a matter of convenience. The exhaust chamber 28 has an outlet port 38 to atmosphere Also an exhaust regulator valve 39 is provided for opening and closing the exhaust chamber outlet port 38. The exhaust regulator valve consists of a stem 40, secured to the central portion of the exhaust diaphragm 30, and a bias spring 4041, which opposes the closing of the outlet port 38 by movement of the exhaust diaphragm 30. The transmitter output port 23 carries the output pressure of the whole transmitter, ordinarily to a dead-end pneumatic system (not shown) as a working force for indicating, recording, or controlling apparatus, or combinations thereof. OPERATION. Throughout the operating range of this device, i e throughout the operating range of fluid pressures in the tank to be transmitted by this device, the main diaphragm 19 is operated to balance at the same position This means that the exhaust port 22 is always open the same amount Also, in the supply system, the fixed restrictor passage 35 is, of course, always open the same o amount A constant pressure drop is supplied across the supply restrictor 35 and a constant pressure drop is also supplied across the exhaust port 22. The constant pressure drop across the 6 supply restrictor 35 is provided as follows: An input pressure is provided through the pipe 31 which is substantially more, perhaps ten pounds more, than the maximum presure expected from the test tank through the ank wall 11 The supply regulator valve 70 32 is arranged so that in order to close the valve 32, the pressure in the supply chamber 26 must be a fixed amount, for example, Pour pounds, more than the pressure in the central chamber 27 Since the main dia-75 phragm 19 balancing pressure is always equal to the pressure in the central chamber 27, there is always a flow through the fixed restrictor 35, and the pressure drop across the fixed restrictor 35 is always the same, 80 i.e the pressure difference

required to enable the spring 34 to hold the supply regulator valve 32 open. Similarly, the constant pressure drop across the transmitter exhaust valve arrange 85 ment is provided as follows: The exhaust regulator valve spring 41 provides a force which aids the pressure on the exhaust chamber 28 as a means of opening the exhaust output port 38 Thus, in order to 9 g keep open the exhaust port 38, the pressure in the exhaust chamber 28 need only be a fixed amount, for example, four pounds, less than the pressure in the central chamber 27, that is, four pounds less than the gs pressure on the right hand side of the diaphragm 19 Accordingly, there is always a flow through the exhaust port 22, and there is always a fixed pressure drop across the exhaust valve arrangement which in 100 eludes the port 22. The supply and bleed condition of the whole system is such that for any balance condition of the system, all the valves, that is the supply regulator valve 32, exhaust o 1 s valve stem 24, and regulator valve stem 40, are open somewhat, and air is constantly flowing from supply to exhaust: Since the supply and exhaust conditions are always the same, that is, there are constant pressure 110 drops in each, the balancing pressure in the main diaphragm chamber 20, in balance condition, is exactly the same as the measured tank pressure, throughout the operating range of the device 1 l S Thus the supply regulator valve 32 reduces the supply pressure to a value three or four p s i greater than the actual main diaphragm balancing pressure This differential pressure is then applied to the fixed 120 restrictor 35, thereby providing a constant air in-flow regardless of the actual main diaphragm balancing pressure Similarly, the exhaust regulator valve restricts the out-flow to atmosphere, holding the pressure down 125 stream of the exhaust port 22 at a value consistently three or four pounds less than the actual main diaphragm balancing pressure This eliminates the error from varying differential pressure across the relief 130 725,952 valve Note that the supply and exhaust pressure drops need not be equal but their sum or differential remains constant With such relations holding throughout the operatin range of the device, variations in the measured pressure do not affect the exactly equal relation between the measured pressure and the output pressure of the device. In the showing of Fig 1 all the valves are shown as slightly open, indicating a condition of pneumatic balance in the overall s-Vstem. Fi 2 illustrates an application of this inrention in the form of a differeiitial pressure responsive system for liquid level measurermees, using a pair of pneumatic pressure tra nsm- stters 42 and 43 to comnare the diffeorence between the pressure abole the licuild and the pressure at a fixed point below the liquid surface

Each of these transritters may be in duplication of the strttcture anid arrangemen of Fin l in Fi- 2 a tatnkl 44 is shown, with a liquid body 45 i'.1 'in The ti N -all hias a"n upper rr -ru 13 d and low P-er a'r'-r'Lrx 3 h the transinitters 1 ' ad A 3 rn-n oiverlin R relation tiierewtth The transm It ter output pipes 46 and 47 lead in oposog siees of a suitable digerential prce e ncsuritg unit 48 vibiach is provided, asq Slroti. f. i'1 an air suprly pipe 49 and an output, pressure pipe 50 in the usual "tnr for sucii devices. The air supply to both the transnitter units 42 and 43 is supplied from a single source, through a supply pipe 51. This invention, therefore, prov=idtes a new. a id mproved pressure transmitter of t he s-pply and bleed type, whcrein the output pressure is exactly equal to the measured pressure throughout the operatin rarije of the device by reason of constant, pressure drops in the suppnlyl and exhaust systems.

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* GB785953 (A)

Description: GB785953 (A) ? 1957-11-06

An improved rest head for vehicles

Description of GB785953 (A)

PATENT SPECIFICATION Date of Application and Filing Complete Specification: Aug 3, 1955. 785,953 No 22242155. j '' Complete Specification Published: Nov 6, 1957. Index at Acceptance:-Classes 52 ( 2), J 2 CX; and 52 ( 5), B( 2 A: 23: 3 B: 5 AX).

International Classification:-A 47 c. COMPLETE SPECIFICATION An Improved Rest Head for Vehicles. I, FRANK ARNAU, of Apartment 34, R. Buarque de Macedo, 5 Praia do Flamengo, Rio de Janeiro, Brazil, of Swiss Nationality, 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 an adjustable head-rest fitting for vehicles, and particularly for the driver of motor vehicles, having a head-piece in the form of an upholstered supporting shell Every traveller, particularly a motor driver, is aware that on long journeys the head or the neck muscles and the adjoining shoulder muscles become unavoidably strained, this strain being generally less felt by the driver, whose attention is diverted by his duties, than by the passengers. The head rests heretofore used for overcoming this trouble are generally fixed to the upper edge of the seat back Adjustment is to some extent possible in the vertical direction in the plane of the seat back. In a known construction the head piece of a head rest fitting consists of two separate parts, each of which is adjustable in itself on the fitting in an arcuate curve The fitting is comparatively complicated and does not permit of universal adjustment of the head rest Also in this case, the arrangement is dependent on the presence of a suitable seat back As such seat backs are generally comparatively softly upholstered, they are hardly suitable for the attachment of a head rest In some conditions they can even be a hindrance to the motor vehicle driver by the vibration of the head rest. The invention avoids the drawbacks of the head rests heretofore known and consists in an adjustable head rest fitting for a vehicle seat comprising a bracket for fastening to a support, a first intermediate member pivotally attached to said bracket on a first hinge joint, a second intermediate menmber pivotally attached to said first intermediate member on a hinge joint, the axis of which is at right angles to the axis of said first hinge joint, and a head piece adjustably 5 O attached to said second intermediate member by means enabling pivotal movement of the head rest relative to said second intermediate member about two axes at right angles to each other The fitting can be 55 fixed to a wall of the carriage body independent of the seat back and is adjustable in length and direction as desired The head piece mounted on the fitting is rotatable about the longitudinal axis of the fitting 60 and at right angles thereto.

The head piece can thus be universally adjusted in any desired position independently of the seat or seat back, which is of great importance, particularly for the 65 driver for protection against over-exhaustion Moreover, the support from the wall of the carriage body provides a stable fixture in which all undesirable vibration of the head rest can be avoided 70 The arrangement of the head rest fittings on the carriage body further allows the rest to be swung away against the wall of the carriage body when not required, where it does not interfere with the driver or other 75 occupants of the vehicle and takes up no space otherwise required By telescopic shortening, the space required by the rest when not in use can be still further reduced. Also, the rest is of simple and cheap con 80 struction. It is also of particular advantage if the supporting bracket of the head rest fitting is provided with an auxiliary part for detachable attachment to a part of the car 85 riage body. In a preferred constructional form of the invention the head rest fitting has two ratchet type hinged joints with their pivotal axes set at right angles to each other and 90 (Price 3/6) 785,953 the jointed parts of the fitting can be connected together by a flexible element. Further features of the invention will be apparent from the following description of one example of a construction shown in the accompanying drawing in which: Fig I is a longitudinal sectional view; Fig 2 a view from inside the vehicle; and Fig 3 a side view. A bush or socket 1 is sunk into a pillar of the vehicle body A spring catch 2, which is firmly anchored at 4 a in a base piece or bracket consisting of a base plate 3 and tube 4, engages in one or other of two slots 5 set at 90 degrees to each other in the socket 1 By pressure on a stud 6, the catch can be disengaged after loosening a wing nut 7 On the tube 4 is a slotted tube 8 The wing nut 7 holds the tube 8 firmly on the tube 4 along which the tube 8 is slidable within the limits of a slot 6 a. Hinged to the tube 8 by means of a ratchet joint 9 is a tubular part 10, which is movable relatively to the tube 8 about an axis at right angles to the plane of the drawing. By the term "ratchet joint" is meant that adjacent disc surfaces of the joint are roughened or crown-toothed, as in the known type of cycle saddle fixture The tube part 10 is connected by a blade spring 11 to a tubular part 12 with a second ratchet joint 13, the axis -of which is set at 90 degrees to the ratchet joint 9 The joints can be firmlv clamped by clamping screws 14 and 15 In a joint piece 16 is inserted a hinge pin 18 rotatable about its axis and adapted to be adjustably secured by a clamping screw 17, and in a sleeve 19 fitted

in a bore at right angles to-the axis of rotation of the hinge pin 18 is a pin 20 projecting from a shell-shaped head piece 21 and rotatable in the sleeve 19. The head piece 21 is adjustable in all directions relatively to the support consisting of the parts 3-16 The stud 6 permits of lengthwise adjustment within the length of the slot 6 a, while the joints 9 and 13 allow of any desired adjustment of the head rest. By means of the clamping screw 17 the head rest can be fixed against rotation about the longitudinal axis of the part 16 while turning movement of the pin 20 in the sleeve 19 allows a slight amount of movement of the head The thick upholstery on the shellshaped head piece 21 together with the spring 11 provides af restful shock-free position for the head. When not in use, the head rest can be quickly loosened from the socket 1 and on suitably adjusting the jointed parts can be collapsed into a compact folded condition and the pin 18 can be removed from the part 16 after loosening the clamping screw It will be seen that the parts 2-8 provide a bracket means for fastening the head rest fitting to a support, the parts 10, 11, 12 and 13 constitute a first intermediate member, and the part 16 constitutes a second intermediate member between the head piece and 70 the bracket means, the head piece being adjustably attached to the member 16 by means 18, 19, 20 enabling pivotal movement of the head piece relative to the member 16 about two axes at right angles to each other 73

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