NOV. 5, 1946. 'E_ ROCKWELL 2,410,750 HIGH~TO-LOW PRES SURE CONVERTER ‘ Original Filed Jan. 4, 1940 2 Sheets-Sheet l‘ 2 a 1 a" Y ‘r’ a A 275 6%.] 5 2% 274a 223 6 219 2:7? 25a 43% 25¢ l 54. 26? 26'|5\ 26o - 37 2% " 2 2w’ 267 ATTOR EY Nov. 5, 1946'. 2,410,750 E. A. ROCKWELL > HIGH-TO-L‘OW PRESSURE CONVERTER Original Filed Jan. 4, i940 # NAN 2 Sheets-Sheet 2 N. QSQN TOR ' 2,4350% 2,410,150 . mom in LGWFPRESSURE convening Edward A. Rockwell, Cleveland, Ohio, assignor to The New Britain Machine ?ompany, New Britain, Comm, a, corporation of Connecticut Original eppllcutionl’anuery 4, 1940, Serial No. 312,356, new Putent No. 2,331,800, dated October 12, 1943. Divided and this application Febru any 17, 1943, Serial No. 476,248., lln Canada December 30, 1M5 13 Claims. l ' (Cl. .60—54.6) 2 My invention relates particularly to an appamodulated high pressure to said brakes for ob l‘BLtHS designed for controlling the application of taining the braking force. In this form of my power for the operation of diiierent parts or ac~ invention I have provided a reserve tank i hav cessories of automotive vehicles, as, for example, ing an outlet port 5 leading to a supply pipe 6. automobiles,'aeroplanes, railroad cars, mine loco- 5 This supply pipe 6 communicates with a spill motlves, eilcback tank 2% which has a vent pipe 2% leading This application is a division of my co-pending up through the tank I beneath the cap 2 thereon. - application Ser. No. 312,356, died January 4, 1940, The vent pipe 2st opens from the top of the spill upon System for controlling the application of back tank 258. The pipe 6. however, continues power, Patent No. 2,331,800, granted October 12, i0 inwardly into the latter to communicate with 1943, t The objector my invention is to provide asys- the inlet side of a rotary pump 2% which may be a gear pump and which is driven by an electric tem whereby the different parts of automotive vehicles may be operated in an advantageous motor 259. This pump 25!) is connected so as to deliver, by a port, the high pressure liquid to‘ an manner so as to maintain adequate control over 15 accumulator 253 constructed with the same parts the slime at 8-11 times- An?ther Object 15 ‘310 DI‘Oas described in connectionlwith the accumulator vide an apparatus of this character, in accordH, in said Patent No. 2,331,800, and has the same ance with which the part to be operated maybe circuit connections to the electric motor as there moved into position initially by means of a ?uid described, except that a pressure otabout 1500" applied at one pressure, and thereafter operated 20‘ lbs. pensquare inch is capable of being supplied to Cause the Performance Of WOrk by said part by ?uid at another Pressure, this being accom- thereby. The high pressure liquid thus accumu \ lated in the accumulator 253 is delivered by a pllshed, if desired, by various di?erentlals bepipe 2st from a passageway zeta therein having tWeBn the pressures ?lppliedfor moving said part 1 a. check valve 25%, to a regulator valve 255 for and the manual or actuating pressures utilized '25 maintaining a, definite pressure, which has 8. f0? 001130111118 the Pressures 50 applied- My inventlon is adapted to be applied, not only for the - operation of heavy-duty parts, as, for instance, on heavy trucks, requiring a, considerable volume of pressure ?uid for the operation of the same but also for the Operation of relatively light parts on aeroplanes and other automotive vehicles, such, for instance, as light trucks, etc. Still another Object is 130 provide an unloader valveAnother object is to provide a- converter valve. Further objects of my invention will appear from the detailed description of the some hereinafter. While my invention is Capable of embodiment in many di?erent f?l'ms. I have ShQWn only Oertain embodiments thereof m the accompanying drawings in Which-f ‘ valve structuresubstaintially the same as in the valve lt'l in said Patent No. 2,331,800. This reg ulator valve 255 is connected by a port 265 to the pipe 256 from which the valve receives thepres 30 sure liquid delivered by the accumulator 253. The low pressure, or exhaust liquid, leave the valve 255 by a. pipe 268110 returnto the spill-back _ tank 2%. In this valve structure the valve I52, I53 is normally closed by the spring 260a and the 35 valve ass, 568 normally open and the compres-' sion of the spring ztta. normally maintains the pressure of the liquid at a. given desired pressure. When this pressure is exceeded’ the said two valves open and close, respectively, and the ex 40 must liquid passes out by the valve 852, I53. ~ This construction produces a. regulated pressure _ Fig. 1 is an’elevation of a form of the system of approximately 1000 lbs. per square inch, which involving the manual application of high pres- is delivered by the said valvev 255 through a port sure to apply thereby a modulated low and then a high Pressure; . 26'? to a pipe 266 which then conveys it to .a, high 45 pressure port 269 of a modulator valve 210, and Fig- 218 a Plan View Of a detail therevf. with which is constructed substantially the same as parts in section on line 2—2 of Fig. 1; the modulator valve 831 in said Patent No. _ Fig. 3 is .a. transverse section of a converter 2,331,800 except in this instance inside the spring from high to low pressure used in Fig. 1; and In there is a light spring 21 la, to normally keep ' F18‘. 4 is a diagrammatic representation 01’ the 50 the valve I52 open. On the side of said modu clrcuitinFls. 1'’ lator valve 210 ‘the pipe 268, has a connection The form of my invention shown in Figs. 1 and whichconveys the high pressure‘ liquid by a. pipe 2 isdesi‘gned for heavy-duty Operation and may _ 212-110 the high'pressure port 213 of a hand-op be used, for example, in connection with the operated modulator valve 2'" provided with a. dis cretion of mine locomotives 'or railway cars. 55 charge pipe 2142 leading to the reserve tank I, This form of my invention is designed, further- ~ and having a handle #15 to operate the same, all more, to modulate a. regulated high pressure to of which is constructed exactly like the said mod produce a modulated low pressure for bringing ulator valve I 31. This handle 215 thus enables the brakes into position preparatory to applying modulated high pressure to be delivered from the braking. force and thereafter to apply av 60 a. port 216 thereof by a pipe ill to a delayed-ac r 2,410,750 ' hand lever 215, but only after the brake shoes have‘ been moved up into position. Thus‘, aiter the brakes have been moved up into braking po- sition by a supply 01 modulated low pressure liq uid thereto, as hereinafter described, the modu lated high pressure liquid is discharged by the modulator valve 218 from a port 218 and thence by a pipe 288 to a brake operating mechanism connected to a pipe Joint 28I to thus apply high 4 ,sure ?uidreceived from the pipe 288 through the pipe 281 to the high pressure end of the high to-low pressure converter 288 so as to thereby force out of the low pressure side ‘01' the same, ~ through the pipe 289, a low pressure liquid which passes directly through the modulator valve 218 10 becauserthe valve 152 is kept open at this stage pressure liquid for the braking ‘effect. While the modulated high pressureliquid is thus de livered by the pipe 211 to‘ the hydraulic element . 218, a portion of this same liquid from thepipe .> 211, for preliminarily moving the brakes into p0~ 'sition, passes by a pipe 282 \to a hydraulic .device 288 constructed the same asthe device 218 except , that'in this instance a light spring "I is used, and which in turn operates a modulator valve 284 constructed the same as the modulator “Valves T previously described, as, for instance, said modu~ ,- 288 so as to modulatingly release the high pres whichoperates the said modulator valve 218 hy- ‘ draulically vaccording to the operation of ‘the . by said valve from the pipe 212 is applied through the pipe 282 to the light spring hydraulic control tion hydraulic modulator controlling device 218 constructed with a vstrong spring 28I‘ therein by the strong spring control 218,‘ 28I, this low pressure liquid being thus delivered by the pipe ' 288 to the brakes to move the brake shoes initially into position. As the pressure applied increases in the pipe 211 this brings about no increased action on the part of the control 288 but acts to overcome the strong spring-2M in the control 218, thus closing the valve I52 and opening. the valve I81 in the modulator valve 218, and thus supplying a modulated high pressure liquid through the pipe 288 to apply the braking force on the brake shoes. In this way any desired increments of increasing pressure,‘ initially low and thereafter high pressure, can be‘ applied for the operation of the brakes. In the oil modula tion of the valve 218 the liquid flows in the re verse direction in the pipe 288, and from the mod lator valve I81. In this instance the high pres sure liquid to be modulated by the hydraulic ele-, ,ment 288 is received’by 'a pipe ‘288 from the‘ otherv side of the accumulator 258 and is thus received ' ulator valve 214 back to the reserve tank 'I through the pipe 214a and from the modulator in a high pressure port 288 of the modulator valve 284 from which the modulated. pressure liquid 80 valve 284 through the pipe 2881' back to the spill back tank 248. ' is delivered by a pipe 281 to the high pressure side . While I have described my invention above in 2 of a high-tc-low pressure converter 288. This is detail I wish it to be ‘understood that, many ' comprised of a small cylinder 288a, having‘ a nor changes may be made therein without departing '“ mally closed air bleeder 2881), in which there is I ; a piston 288c with a checkon unloader valve, 35 from the spirit of the same. 288d. v The check valve 288d isin a passageway 1. A pressure transformer comprising a hy 288a leading to a low pressure large cylinder 2188!, draulic inlet,~a hydraulic-outlet line, a manually‘ having a piston 288a, and provided with an air 'bleeder 2887». An air ?lter 288i is on the cylinder ‘ controlled member comprising a small piston and 288f. The ‘said modulator valve 284 is provided 40 a large piston connected together for forcing liquid through‘ said outlet line, a supply reservoir with a discharge or exhaust port 2881 leading for said member‘ and an unloader valve, seating back to. the spill-back tank 248. The low pres in the same direction with the inlet and mounted ‘ sure side of the said low pressure converter 288 is connected by a pipe 288 to a low pressure port‘ ‘ in‘ a passageway extending through said pistons _ 288‘ ‘in the modulator valve 218.‘ This low‘ pres 48 to prevent by seating the flow of ?uid from the inlet through ‘said passageway and adapted to dis— ‘ sure supplied through the port 298, due to the charge the liquid from said line to said reservoir, strong spring. 28I keeping the valve I82‘ open in Iclaim: the initial operation of the brakes,.permits the . , _ ‘ ‘ operatively connected to the manually controlled -member. , ‘ low pressure ?uid to pass between the valve I82 and its seat and thence to the pipe 288 for the 50 2. A construction, comprising a’ hydraulic line, _a movable member, having a small piston and movement of the brake shoes up to tne braking position. When the pressure in the pipe 288 has , va large piston connected'together, with the large piston nearer to said line, said member being been applied to such an'extent as to move the controllable manually for iorcingliquid there brake shoes into position, the increase in pres through, cylinders for said pistons, resilient means sure within the pipe 211 will seat the valve I52 which moves said member away from said line in the modulator valve 218 to’ permit the entry when not being controlled manually, a source of of'high' pressure liquid by the valve I81, thus supplying the high pressure liquid through the pipe 288 to apply the braking effect as previously described. The exhaust ?ow of liquid from the ‘ modulator valve 218 is received in the pipe 288. In this way a relatively high pressure may be used for applying a comparatively low pressure for the initial seating 01' the brakes, as, for instance, on mine locomotives or railway cars, .while high supply of hydraulic liquid for said member, and a valve to normally‘ cut o?! the liquid from the source of supply to said‘line and adapted to dis-' charge the liquid from said line to said source of supply, operatively connected to the movable member. A construction, comprising a hydraulic line, a movable member controllable manually by sup plying hydraulic pressure to the member, for forcing liquid therethrough, a cylinder for the pressure liquid is applied thereafter to the brakes to obtain the desired braking force. movable member, a source of supply of hydraulic In the form of my invention shown in Figs. 1, liquid for said member, and a valve, seating in 2, 3 and 4, there is utilized a-relatively highpres sure which initially brings a relatively low pres 70 the same direction with the manually controlled hydraulic pressure to normally-cut of! the liquid sure into action for setting the brakes into posi from the source of supply to said line and adapted tion,-after which a modulated high pressure is ‘to discharge the liquid from said line to said applied for applying the braking force. In this source of supply, mounted on the movable instance, when the hand control modulator valve ‘ 214 is operated the high pressure liquid received 78 member. 2,410,750 5 6 4. A construction, comprising a hydraulic line, through, cylinders for said pistons, resilient means a movable member, having a small piston and which moves said member away from said line a large ‘piston connected together, with the large when not being controlled manually, a source of piston nearer to said ‘line, said member being supply of hydraulic liquid for said member, and controllable manually for forcing liquid there $1 a valve to normally cut off the liquid from the through, cylinders for said pistons, resilient source of supply to said line and adapted to dis means which moves said member away from said > line when not being controlled manually, a source of supply of hydraulicliquid for said member, and a valve to normally cut oil the liquid from the source of supply to said line and adapted to dis charge‘the liquid from said line'to said/source of supply, mounted on the movable member. 5. A low pressure converter comprising a small charge the liquid from said line to said ‘source _ of supply, operatively connected to the movable member, said pistons having a passageway con taining said valve passing through both said _ pistons. . ', 10; A construction, comprising a hydraulic line, a movable member controllable manually for forcing liquid therethrough, a cylinder for. the cylinder, 9, large cylinder, pistons connected to 15 movable member, a source of supply of hydraulic gether to form a double piston to operate in said liquid for said member, and a valve to normally . cylinders, resilient means which moves the pistons cut off the liquid from the source of supply to towards the small cylinder, a liquid supply inlet 'said line and adapted to discharge the liquid and outlet on the smal1 cylinder at one end of from ‘said line to said source of supply, mounted the double piston, a valve movable with said' 20 on the movable member,. said movable member _ pistons adapted to close in the same direction comprising small and large pistons with the. large with said inlet of liquid, and an inlet for liquid piston nearer to the hydraulic line, resilient in the large cylinder at the other end of the means which moves the pistons away from said double piston, which has a passageway contain ing said valve passing through both said pistons. ~ line, and an intermediate breather chamber, said 6. A low pressure converter comprising a small cylinder, a large cylinder, pistons connected to-. gether to form a double piston adapted to oper movable member being provided with a com municating passageway between the same con . taining said valve, 11. A construction, comprising a hydraulic line, ate in said cylinders, resilient means which moves > movable member, having a small piston and the pistons towards the small ~cylinder, a liquid 30 aa large piston connected together, with the large supply inlet and outlet on the small cylinder at piston nearer to said line, said member being one end of the double piston, a valve movable controllable manually for ‘forcing liquid there with said pistons, adapted to close in the same through, cylinders for said pistons, resilient direction with said inlet-of liquid, an inlet for means which moves said member away from said liquid in the large cylinder at the other end of 35 line when not being controlled manually, a source the double piston, and a breather opening in of supply of hydraulic liquid for said member, the large cylinder, having an air ?lter communi and a valve to normally cut off the liquid from cating therewith, located between the two pistons the source of supply to said line and adapted to which have a passageway containing said valve discharge the liquid from said line to said source passing through both said pistons. ' 40 of supply, mounted on the movable member, said 7. A pressure transformer comprising a hy- pistons having a passageway containing said draulic line, a manually controlled member com valve passing through both said pistons. prising a small and a large piston connected to 12. A low pressure converter comprising a gether for forcing liquid therethrough with the small cylinder, a large cylinder, said converter large piston nearer to the hydraulic, line, resilient r45 being provided with a breather chamber, pistons means which moves the pistons away from said connected together to form a double piston to line, a breather chamber between the pistons, a operate in said cylinders, resilient ‘means which supply reservoir for said member and an un- _ moves the pistons towards the small cylinder, a loader valve mounted in a passageway extending ~ liquid supply inlet and outlet on the small cyl-_ through said pistons and adapted to discharge the 50 inder at one end of the double piston, a valve, liquid from said line to said reservoir, operatively movable with said pistons, adapted to close in connected to the manually controlled member. the same direction with said inlet of liquid and > 8. A construction, comprising a hydraulic line, an inlet for liquid on the large cylinder at the -a' movable member controllable manually for other of the double piston, said double piston forcing liquid therethrough, a cylinder for the 65 havingend a passageway containing said valve and movable member, a source of supply of hydraulic passing through both said pistons. liquid for said member, and a valve to normally cut o? the liquid from the sources of supply to 13.‘ A low pressure'converter comprising a small ‘ cylinder, a large cylinder, said converter being said line and adapted to discharge the liquid provided with a breather chamber, pistons con from said line to said source of supply, oper» , 60 nected together to form a double piston to oper atively connected to the movable member, said ate in said cylinders, resilient means which moves movable member comprising , small ‘and large the pistons towards the small cylinder, a liquid pistons with the large piston nearer to the hy supply inlet and outlet on the small cylinder draulic line, resilient means which ‘moves the at one end of the double piston, a valve, movable pistons away from said line, and an intermediate 65 with said pistons, adapted to close in the same breather chamber, said movable member being direction with said inlet of liquid, an inlet for provided with a communicating passageway‘be liquid on the large cylinder at the other end tween the same containing said valve. ' 9. A construction, comprising a hydraulic line, ' ' of the double piston, and a breather opening for the breather chamber in the large cylinder a movable member, having a small piston and‘ 70 located between the two pistons, said double a large piston connected together, with the large piston having a passageway containing said valve ' i piston nearer to said line, said member being and passing through both said pistons. controllable manually for forcing liquid there EDWARD A. ROCKWELL.