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.