J 16» 1929» o. J. BADERTscHER? 2,721,290 - VACUUM SERYO BRAKE FOR MOTOR DRIVEN VEHICLES Filed, Dec. 2. 1926 a ‘Sheets-Sheet 1 July 15, 1929» o. J. BADERTSCHER ' > 3,721,290 VACUUM SERVO BRAKE FOR MOTOR DRIVEN VEHICLES

Filed Dec. 2, 1926 s Sheets-Sheet 2 '

__V.7’ - QW/15%;“; - July 16, 1929» > o.‘ J‘. BADERTSCHER ‘ 1,721,290 VACUUM SERVO BRAKE FOR MOTOR DRIVEN VEHiCLES Filed Ded . 2. 1926 3 §heets~$heet 3

19 18a

110 - > 7]]

1/4 _

115a

22'

' "I’Alfll/l I .

Patented July .16,‘ 191-29.. _ v ' > .w . v i 5,721,290 NITED STA Ties,‘ IATENT OFFICE. » OTTO 3'. BADEBTSCHER, OE ZURICH, SWITZLEBILAND. vacuum sERvo-BIiAxE roiz mo'ron-nmvnnvnnrcnns; Applicatio 11 ?led December 2, 1926, Serial No. 152,090, and in Switzerland Ibecember 14‘, ‘1925. Vacuum servo-brakes on motor driven ve-' and requires as littld'power as the accelera hicles are known with which the action of tion.Constructional ' examples of the. subject' the s'ervo-brake-is controlled either by means matter of the present invention are illus 60 . of the brake pedal or by actuating levers or trated on the] accompanying drawings, in 5 pedals specially provided to that end‘. These known arrangements 'pre sent various dis-. which: ‘ _ ' advantages. In case a special controlling de Fig. '1 shows in a diagrammatic manner " one constructional example of the braking vice, such as a‘ hand lever or a pedal, is 65 provided , it involves an undesirable increase‘ arrangement according to the present in '10 of the levers an d handles already present, vention; _ ' L p ‘ in large numbers in a modern car and the ' Fig. 2 shows the regulating valve in a ver tical longitudinal section;_ “ driver is often compelled to release import Fig. 3is a?cross#section along line III— ant devices, such as the gas controlling de 70 vice or {devices for actuating a. signal, in III in Fig. 2; ' ' ' '15 order to operate'the device for controlling the Fig. 4 is a’secti on ‘along line 1v_1v in servo-brake. This may lead to'a fatal'delay - Fig. 2; _ ' of the braking action. If the actuation is . Figs. 5, 6 and 7 show'in diagrammatic e?e'c-ted by means of the brake pedal, in. longitu dinal sections the vregulating valvein different working positions; -_ 75 order to render the servo-brake operative, a Fig. 8 shows in a diagrammatic manner (2() ' change between the gas pedal or accelerator .. the positions of the throttle valve control ~ peda l and the brake pedal has to be e?ected nge in case of emergency may lead lever or gas lever; . which cha ' A Fig. 9 shows in a plan view the frame of to dangerous arti ons as for instance ‘the foot 80 of the operator in ay slip oil thebrake pedal. a motor car ‘provided with a,modi?ed -ar- and may depress the gas pedal so‘v that the rangement of the servo-brake, 1 car instead of being braked suddenly ‘dashes Fig. 10 shows in elevation with parts shown'in section the installation of the servo- , forward._ There is a ‘further objection‘that brake mechanism in a motor car of the Buick the actuation of the servo-brake by means of , - 85 type and , ' ' the brake pedal does not permit ?nely gradu th parts shown ' 30 ated brake actions owing to the lack of sup Fig. 11 is a plan view wi port of the foot on the ?oor and the >fact "in section of Fig. 11. ‘‘ that the foot has to follow the swinging Referring now ?rst to the constructional ‘movements of the car whereby a jerky brak ally illustrated in Fig; ing action results. example1,’1 denotes diagrammaéi‘c the‘ g s pedal or accelerator ‘ 5 are ‘now ‘overcome by the pedal with the retur ;spr ing 2. The acceler These drawback ator pedal is operatlvely connected to the present invention w lnch is characterlsed in regulating valve and is connected by'means ‘ that the gas .0 ontrolling devices, i,. e. ‘the’ ac- 9' celerator peda l and the throttle control hand of a lost motion device‘to the throttle valve. . ontrolling the' The lost motion device is shownmas com lcver,,are used as devices for 'c prising a sleeve 3 ?xed to the end of the, 4 0, servo-brakev meeh anism; whereby . the same devices which serve to accelerate the, car accelerator‘ rod 4 andva rod 5 displaceable in the sleeve 3, the freerend ‘of therod .5 'I ' serve- also to brake it. This'overc'omes ‘the carrying a pin 6 guided in a slotted part 7 > .above mentioned drawbacksand secures the of the lever, 8 by'means of which the oper 100 advantages of a simpli?ed and handier oper ating shaft 9 of the throttle valve is actu ' 4 ation of the car and of an automatic braking ated. A spring 10 acts upon the lever 8 > . action in emergen' vcies inasmuch as the brak and tends to press the latter against a stop ing action is rendered operative when the .11. At the end of the sleeve 3‘an- arm 12 is accelerator pedal is released'so that the car provided to which a rod 13, pro?de'dwith a 105 is automatically braked when, for'instance, collar 125 is linked, the latter cooperating ' 50 . the operator loses control/owing to a;su,dd_en indisposition. The starting on an incline with the lever 117 of the ‘regulating valve indicated at 101 which will be described here- v ~ , is facilitated as bydepressingzth e gas‘pedal - the brake .is ?rst released'and gas ‘is glven ,inafter. The regulating valve is connected to a pipe 18 for atmospheric pressure and .110 . ' immediately afterwards so that the di?icult manipulation with the hand brake is avoided. is connected by pipe 19 to a source of suc-' The braking of thecar is rendered "as-easy tion by‘ a pipe 21 to the cylinder 22 of the 2 1,721,290‘ servo-motor, the piston .23 of which is con- ‘The explanation ofthe manner of opera— nected by means of a rod 24 to the-brake tion of- the regulating valve ma .be given pedal 25. 26 indicates the ordinary con- with reference to Figs. 5-7 and . In Fig. nection between the brake pedal and the 8 G denotes the throttle control hand lever 5. brake gear so that _.the forceacting on the ‘or hand gas lever, and Z the ignition lever. _ servo-motor piston is transmitted to the The extent ofangtilar movement of the hand brake gear by the brake pedal. Inpraotice gas'lever G is subdivided into a range 9 in this connection to the brake pedal itself may which the regulations of- the gas from a . not al ays be feasible, but for purposes of maximum gas supply to the cut-off occurs, 10 explanaion of the invention this connection into a range a, in which the’ elements of the 75 is sufficient. ' ' 'regulating valve are in the position for re Figs. 2-8 show the regulating valve. 101 leasing the braking action andinto a range‘ . denotes the valve casing made of cast-iron B, which is again subdivided into a larger and provided with a longitudinal bore 102.‘ part b for normal braking and a smaller 15 At right angles to the longitudinal axis the part STN for special braking action. As 80' pipe 18 leading to atmosphere and the suc'cv is seen in Fig. 1 the actuating lever 117 of tion pipe 19 communicate with the bore 102 the ' regulating valve is connected to the to form ports admitting atmospheric pres hand gas lever as well as to the accelerator. sure and suction; the pipes are ‘connected to During travel the hand gas lever is' ad 20 the casing 101 by. means of stu?ing boxes justed in the range 9 so that the parts ~of 105. Between the pipes 18 and 19 and on the the regulating valve-occupy the position in opposite side of the bore 102 is. arranged the dicated in Fig. 2, in which the servo-brake pipe21 which leads to the cylinder 22 (Fig. is inoperative. If it is intended ‘to brake 1) of the servo-brake and-is also connected the vehicle the supply of gas is ?rst of all to the casing 101 by means of a stu?ing box cut oil‘ byturning the hand gas lever into 105. A di?'erential piston 107/108 is slid_ the range n. When the lever is further able in the bore 102, the two pistons 107 and turned over the range a the arm 116 presses 108 being connected to each other by means on the cup 111 and displaces thereby the 7 of a rod 109; the piston 108 controlling the di?'erential piston into the position indi 30 suction inlet having a larger- diameter than cated in Fig. 5 in which the admission of at 95 the piston 107 controlling the inlet of at mospheric air is cut off although no braking mospheric. pressure and bearing against a action yet takes lace. If now the gas lever shoulder 102a when the piston is in its posi ‘is’ turned into the part b of the range B, the 735' tion of rest. Each 'piston formsa- cup for arm 116 further displaces the differential a helical spring 110 and 112 respectively ' piston 117/118, therebyv compressing the 100 which at their other ends rest in cups 111 spring 112 into the position shown in Fig. and 113- respectively the spring 110 being 6 and opens thereby the suction inlet where considerably stronger .than the spring 112. by vacuum is admitted to one side of the The latter serves only for returning the dif_ brake cylinder 22 and the brake operated. 4 ' o ferential iston into its position of rest as ' In the brake cylinder 22 a certain suction 105 well as or overcoming the frictional re- is vthen present which also acts upon the sistances which otherwise might in?uence inner faces of theddilferential piston and re the accuracy of regulating the braking ac- Xturnsthe latter through overcommg the op tion. The spring 1.10 has an initial tension posing force ofthe spring 110 and compress, 4 01 - which approximately corresponds to the re *ing the latter towards the right, whereby 7110 sistance which the spring 112 generates at the] suction inlet is again closed. As soon the beginning of the compression. Rings as the unavoidable leakage losses reduce the 114 are inserted in the bore 102 for limit vacuum in the brake cylinderv and thereby ing the movement of the cups 111 and 113. the braking action, the power of the spring . 5 0 At one end of the casing 101 and transverse 110 urges the differential piston towards the 1151 to'the bore, 102 and below the latter a shaft left so that the suction inlet is again‘ uncov- " ‘ . 115 is mounted on which is ?xed an arm 116 ered whereupon the above described action _, ‘provided with an extension use which, by a is repeated. In this manner the pressure in turning motion of the‘ shaft 115 enters the the brake cylinder is kept constant during‘ ~ 5 ,bore v102 and displaces the spring cup 111 every adjustment of the gas lever. 12c - and thereby the differential piston. At the According to the condition of the road, _' - end of the axle 115 \projectlng beyond the" ’i. e. if the‘ vehicle has to be braked in snowy, casing is ?xed an arm 117 with which the rod or rainy weather, the gas lever is turned ‘up ' 13 cooperates‘. 60 to S or N whereby a larger uncovering of the Fig. 2 showsthevparts of the valve in suction inlet is obtained and a correspond‘ 125 their position of ' rest. Fig. 5 shows the ingly increased braking effect results; for valve parts positioned for suspending of the obtaining a quick or emergency braking ac I braking action, Fig. 6 the position for nor ”‘tion the gas lever is turned directly to the mal braking/action and Fig. 7 the position 6 position N whereby the parts of the valve _ for a quick or emergency braking e'?'ect. occupy the positions shown in Fig. 7 and a 130 1,721,290 _ 1 1‘ _- ~ 1:5 maximum" braking effect is obtained. When in dotted~ lines; in this position the maxi ' the gas lever‘ is returned into 'the' neutral mumbraki'ng effectvis obtained. ’ position' for suspending the‘ braking action Thellwhole braking action is thus released the spring 112 causes the differential piston. as a logical consequence of the cutting o? to return into the positionv indicated in of the gas supply and so to speak by a pas 70 sive action of the operator whereby the Fig. 2. - \ V . . ~ ‘ In practice immediately after starting the spring 2- yields the motive power. This ac vehicle the gas'lever is adjusted into the tion is of great importance with autobusses carrying a large number of passengers as desired braking range and the control of in this case, when the driver suddenly loses 75 1O the ,gas supply and of the braking is effected by means of the accelerator whereby the the control of his vehicle owing to some adjustment of-the gas lever ‘limits the ob; physiological trouble, as. soon as the foot tainable maximum braking e?ect. By of the driver releases the accelerator pedal suitably depressing the accelerator a locking the arrangement acts as a safety brake in a similar manner as the “dead man cra ” 80 ofv the wheels may be prevented. ‘ , ,..in vehicles running on rails. ' ' The operation of the ,above 1 described In order to suspend the" braking action servo-brake arrangement is as follows:; the accelerator pedal is depressed and when‘ I The‘ position of the parts illustrated in the position N is reached the piston of the ' full lines in Fig. 1 corresponds to the posi ‘regulating valve permits air to enter the S5 tion of the accelerator pedal 1 designated conduit 21 and the brake‘ cylinder, the pis by N, ife. the neutral position. Thereby ton 23 is returned into its initial position the throttle valve is closed so that no gas and the brake ‘is releasedby the ordinary is supplied to the motor, vand the parts of means provided in the brake mechanism of the regulating valve occupy the position il '00 lustrated in Fig. 2 in which no braking ac the car. In the position N the rod 5 abuts against the end of the bore of the tubular " ' ‘ tion ,occurs. During thev running of the car member 3 and when the accelerator pedal is the acceleratorypedal is depressed from the further depressed beyond the position N the . neutral position N to the position'G indi throttle valve is opened and gas is supplied cated in dash and dot lines. In the position 95 3O G the maximum quantity of gas is supplied\ to the motor. . ' to the motor, the throttle valve lever 8 oc The arrangement illustrated in Fig. 1 cupies the position indicated in dash and shows the accelerator pedal and the throttle dot lines in'which the throttle valve is com control hand 716K761" operatively connected with-‘each other, so that both serve to actuate ' 7 pletely opened as the'sleeve 3 is pushed into 100 its position shown in dash and dot' lines, and regulate to servo brake mechanism. The whilst the rod 13 is in its extreme leftposi range over which the hand gas lever 55 may’ be turned above the segment 56 at the steer tion (also shown in dash and dot lines in ing wheel 57 is subdivided‘ into two parts, Fig. 1) andthe regulating valve is in the the ends of which correspond to the posi~~ same position as explained above in. which 105 40 no braking action occurs. When the accele-_ tions B, N and G, i. e. in the range N——G" the rator is depressed between the positions N gas‘ supply is controlled by the hand lever andG the supply-of gas to thenmotor is andin the range N—B the braking action is" positioned according to the desired speed so controlled. ‘This subdivision slightly dif fers from that described above'with reference or to the gradient and the manner of utiliz 110" 45 ing the accelerator in the range N—Gr does to Fig. 8. At the lower, end of vthe shaft 58 .. not differ in any way from that in an or of the hand lever 55, which shaft is mounted . in a known manner inside the steering col- ' dinary car. _ . ' . 1 When the. foot of the operator permits umn 59_, a lever arm 60 -,1s ?xed and a rod . the accelerator to move by the in?uence of 61 sliding in a tubular melnber 62 is linked 115 ‘ 50 vthe spring 2, beyond the position N into the ‘to the onearm 63 ofla bell ‘crank lever, vthe . range between N and B the rod 4, sleeve other arm 64 of which is provided wlth a ' 3, rod 13 and its collar 125 is pulled towards slotted portion 65, whichcooperates with a. the right, and the parts of the regulating pin 66 ?xed’in the rod'4 of the accelerator \ pedal 1. - The throttle control hand lever valve*occupy ‘the positions indicated in Figs. 120 6 or 7.. The lever 8 of the throttle valve 55 'is shown in its neutral position in Fig.‘ - remains in the position in which it abuts 1; when it is turned into the extreme posi- V ' againstthe pin 11 and in which the throttle tion G'the‘rod 61 resting on the bottom of . - valve is closed and< the rod 5 moves in the the. tubular member 62 depresses ‘the ‘latter into the position shown in dash and dot lines sleeve-‘3. Suction is admitted to the brake 125‘ 60 cylinder 22 and the braking action starts. and the accelerator rod 4 will be dlsplaced ~Whenithe accelerator has reached the posi ‘towards the left by the cooperation of the tion B (braking position) the piston of the bell crank lever '63, 64,65 and the pin 66 ‘regulating valve admitting suction is com and the throttle valve will be opened to sup ply gas to the inotor. When the hand lever pletely open and the sleeve 3, rod'13, collar 130 65 125 and lever'116 occupy the positions shown 55 is’turned into the position B the rod 61,: 4 1,721,295 is lifted and the.pressure of the spring 2 is indicated. ‘The connection between the is now permitted to shift the accelerator rod lever 129’ and‘ the piston 23 by means of a 1 11 towards the right, as the rod 61 actslno chain 130 permits the depression of the brake longer as’a stop to the movement‘ of-the, pedal irrespective of the position of the pis tubular member 62, and thereby the braking ton'23. ‘4 i .. - 70 action occurs. It is thus possible to utilizev The interconnection between the hand gas the hand lever for regulating the gas sup lever 55 and the means for actuating the. - ply and the braking action.‘ When the regulating valve by the accelerator 1 con— driver wishes to utilize the accelerator pedal sists of a toothed segment 13.3 cooperating V 10 for regulating the gas supply and the brak with the bevel‘ wheel 134: at the end of the v‘ing action he has to adjust the hand lever‘ shaft 58 operated by the lever 55. The segj to the position B whereupon the use of the ment133 isn?xed to a vertical~ shaft 135 to ‘ accelerator pedal over the whole range the upper end of which is attached a lever G-——N—B is unrestricted. When the hand 136 which is linked to arod 61“. The. lat lever 55 is adjusted into the neutral position ter is linked with its other'end to a lever arm N a braking action will not occur when the 137 on ‘a pivot 138 ?xed in a bracket 139' accelerator is released as the members 61, which is mounted below-the foot board 73. I 62 act as a stop. ' - . ' The lever 137 is' so positioned'that it coop Fig. 9 shows a constructional example ‘of erates with the collar 126 on the‘r'od 4. It v20 ‘a vehicle for the‘ four wheel brakes a sepa will thus be seen that the adjustmentof the 85 rate servo-brake cylinder in which, instead hand gas lever 55 effects the adjustment of . of a single servo-brake cylinder 22a is pro the lever 137 and the latter acts as a stop vided for eachbrake. Each cylinder 2221 is to the displacement movement of the rod 4; ' . connected by means of a suction conduit 21a towards the right in Fig. 11 when the ac 25 to the regulating val’ve 101b and a conduit celerator 1 is released for braking so that 90, I 19 connects the valve 101b with the suction the desired braking effect can be‘controlled ‘manifold 71 of the motor 70. The construc by the hand gas lever as has been described ' tion and operation of the means for actuat above. ‘ ‘ ing the valve 101b may be similarto any .The servo-brake arrangements described 30 of, the arrangements described above. ' above are suit-able for being attached to ex 95 Figs. 10 and 11 show the installation of isting motor cars or other vehicles of any the servo-brake mechanism on‘amotor car _ make. of the Buick type. - . 1 “1 I claim: The ‘accelerator 1 is mounted on a lever 1. In a motor driven vehicle; in 'combina- ~ 35 120 turnable about'a‘ pivot pin 121. To the tion, a servo-brake mechanism operable by 100 free end of the lever 120 is linked the rod 4“ suction, a valve to control the admission of which is slidingly held in a guide-block 122 suction to said 'servo-brake mechanism, a attached to the end of a lever 8“ ?xed to the throttle valve forcontrolling the supply of shaft of the throttle valve 123 of the car gdsto said motor, a hand lever for control ,40 burettor 124. On the opposite end 'of the lingthe throttle valve, an accelerator pedal, 105 ' shaft .of the throttle valve a further lever 8’ means .to operatively connect said accelerator ; is ?xed on which a’ helical spring 10 acts. pedal to said controlling, valve and to con- '. Two collars 125 and 126 are ?xed on the rod nect. said accelerator pedal. to said throttle 4“ of.’ which the collar 125 is adapted to 'valve, xboth connecting. means including a 45 cooperate with the lever 1170f the regulat lost niotion device, and means to interconi 110 ing valve 101. The latter is ?xed to vthe car nect said ‘means connected to‘ said v'a'ccelera-‘ - ' ‘burettor 124 and connected by the pipe 18 ' tor pedal to said throttle control hand lever,‘ to the air inlet ‘127 of the carburettor, and the latter means including a stop, whereby _.by the pipe 19 (to the suction manifold 128 .with the throttle control hand ‘lever adjusted of the motor and by the pipe 21 to‘ the cyl in the braking position a release of the ac 115' -'inder 22- of the servo-b_rake.- A' spring 2 is celerator pedal causes an actuation of'said connected to the rod 4" and tends to return control valve and thereby an operation of the accelerator 1 into- its highest“ braking~ the servo-brake mechanism whilst a- depres- . position. ~ ., Y - .\ sion of the accelerator‘ pedal causes said 55 The brake cylinder 22is provided with ‘an throttle valve to be opened -for supplying 120 ' ‘upper hollow. extension .128 in which. a gas to the motor, and with the throttle con shaft’ 129 is rotatably mounted and a lever trol hand lever adjusted in'its'neutral posi . 129' is ?xed to said shaft 129. The free end tion the accelerator pedal is locked in its ' of the ‘lever 129’ is connected by means ofa neu ral position vas regards the braking ac- ' 60 chain 130' to ‘the piston 23 on which a com tion which is then prevented when the ac 125 . pression spring‘ 131 act's. ‘ A short lever'132' celerator pedal is released. - . ' - . ' ' is ?xed to the shaft 129 outside of the exten 2‘. In a‘motor driven vehicle, in\combina~ _ sion 128 and the lever 132' is connected by the" tion, a servo-brake-mechanism operable'by rod 26 to the‘ brake pedal 25" and to the ‘the suction of‘the explosion motor, a valve ve5 brakegeariofwhichlthe equalizing beam 132' to control the admission ofsuction to'said 139 5 ‘ 1,721,290

servo-brake mechanism and comprising a displacement of said piston valve in order casing having an inlet for suction and an to- admit suction when the latter has been inlet for atmospheric air, both inlets being reduced by leakage losses, a throttle valve controlled by a tubular ,valve body having for controlling the supply of gas to said mo differential pistons of' di?'erent diameters, a tor, an accelerator pedal, and means to op spring acting on vone end of said differential eratively connect said accelerator pedal to 20 piston, a more powerful spring acting on the the lever of said controlling valve and to other end of said differential piston and connect said accelerator pedal to said throt tending to press the differential piston into tle valve, both connecting means being adapted for unindirectional motion. 10 the inoperative position, and a lever to co 25 operate with said differential piston for dis- “ In testimony whereof, I have signed my placing the latter, said'springs in coopera name to this speci?cation. tion with ‘the- suction on the pistons of dif ferent diameters automatically causing a OTTO J. BADERTSOHER. '