Патент USA US2130799код для вставки
sept. zo, ~193s. R. vl-lox-‘YsTl-:TTER HYDRAULIC BRAKE SYSTEM Filed March 16, 1934 È /////// A1. p, *q In. l lll E . 2,130,799 Patented Sept.' 20, 193s l ‘ 7 Y I. UNITED- 'STATES PATENT GFFICE" ' i 2,130,799 ' v > HYDRAULIC BRAKE SYSTEM nchen nofstetter, Jackson, Mich. Application March v16, 1934, Serial No. 715,846 2 claims. I (ci. sos-.sh ` 'I’hel present invention relates to improvements' in the hydraulic brake system for automotive ve- Fig. 1 a suitable casting Ill constitutes a master reservoir Il for> the operating ñuid. A master `hicles, and the like. _ . In hydraulic brake systems in use at the present cylinder I2 is provided centrally of the casting I@ and at' one end of which a piston I3 is received 5 >time frequently >line failures occur between the for longitudinal reciprocation. Located withîn‘ 5 cylinder directly associated with the brake shoe » the piston I3 for limited relative movement rela vand the master cylinder. When this happens the entire system is rendered useless. ' Thus one of the objects ofthe present inventionv m is to provide a system which overcomes the above ' stated condition and which greatly' increases the ltive thereto is provided a hollow valve I4. As shown,_ a springk seat I5 is associated with the valve It with which the spring I6» abuts to- con tinuously urge the valve It and the piston I3 to Al0 the right, as viewed in Fig. l. The valve It is ‘ factor of safety of the vehicle by assuring the closed at the right and with the left end opening proper operation of, at least, two brakes in the >into the cylinder I2 forward of the piston I3. 'A lconveriientyfour wheel‘brake system, upon line port Il is located in the valve Id which com 15 failure. ~ n p municates with the reservoir H through a pas- l5 Another object is'to provide simple, inexpensive and eifective means for assuring a proper supply of operating fluid` tol the braking system at all sage I8 opening into a space I9, located at the rear of the piston I3. Ports 2li are provided which communicate with >times as Well as providing for expansion and con- the auxiliary cylinders 2| which are two in num 20 traction of the ñuid under temperature changes. ber in the _embodiment illustrated. Pistons 22 20 A further object is to provide a simple and _ .are received within the cylinders 24 for longitudi ‘ effective mechanical booster for brake application' nal reciprocation. These pistons, as shown, have which is under the direct control of the manually operated v,braise pedal and which does not affect 25 the manual operation of the braking system, if ` desired, or should lt become necessary upon failure of-the mechanical booster. ’ longitudinally spaced cylinder engaging portions which approximate the diameter of the cylinders 2l for guiding purposes with the major extent of 5 the pistons, preferably of substantially less diam eter than the, cylinders 2|. ' Other objects and advantages of the invention residing in the combination and construction and 30 arrangement of parts will become apparent from the following description when considered in connection with the accompanying drawing. The With such a con» struction the pistons 22 will reciprocate without binding and aS the area 0f the DÍSÈODS 22 in actual sliding contactwith the walls of the cylinders 2l 30 is not greet e suñioient amount of oil is permitted to seep pest the pistons 22 to compensate for any ~ invention is clearly defined in the claims. slight leakage, in the system. I‘n order to take - In the drawing wherein there are illustrated, care of expansion due to temperature changes „by -way of' example, several of the innumerable Check Valves „23 are Preferably 100M/ed in the PÍS- 35 forms which the present invention may take, Fig. l is a longitudinal cross sectional view tOnS to enable the Operating fluid to flow back into the reservoir il. >Springs 24 continuously _ through the master cylinder, reservoir and me- urge the piston tothe left as viewed in Fig. 3. chanical booster showing the association with the Upon the directing 0f fluid pressure against the 40 brake pedal, , Fig. 2 is a >fragmentary end view taken from ,the left of Fig, 1, Fig. 3 is a cross sectional view taken upon line 3--3 of Fig. 2 `through the master'and auxiliary 45 cylinders, . l y Fig. 5 is an enlarged fragmentary cross _sec50 tional view of a modified auxiliary cylinder show« ing valve mechanism for sealing a line upon fail\ Fig. 6 is a fragmentary view taken on line 6-6 of Fig. 5 showing the washer construction. 55 through the outlets 25 which are coupled to the lines (not ShOWn) extending t0 the Operating Cy1-. ìnder located upon the wheel brake of the front and rear wheels, for example. Fig, 4 is a fragmentary longitudinal cross Sectional viewof a modmed form of mechanicalbooster, f - ure or rupture thereof, and left end of the pistons 22,»the fluid located for- 4o ward of the right ends cf‘the pistons is forced out ` Having specific reference to the drawing in Upon failure of 4f either line connected to the auxiliary cylinders 2I. the release of pressure forward of the piston will result in the piston 22 being urged to the right and the'ClOSing of the inner end- 26 of the outlet 25 by the forward end of the piston 22 to 50 avoid further loss of the operating fluid from the reservo i" , I " E It should become .apparent from the foregoing descripticnthat by coupling the front wheel brake cylinders with the `fline communicating with one do 2 arcaico of the auxiliary cylinders and the rear Wheel shown. The link dil, which may be connected brake cylinder with the other, upon line failure Atothe brake pedal in any suitable way, is shown only the front or the rear brakes, as the case may be, arerendered useless. @bviously an auxiliary cylinder may be provided for each wheel .brake with individual lines. It is further to be under ' stood that the present arrangement possesses the same equalizing characteristics of the systems now in use. Ml _ For creating the necessary operating pressure ' within` the system a longitudinally `slidable rod as attached at te to an arm ¿it which is rocked about the shaft äil as a unit with the brake pedal. At the upper end oi the arm ci) a horizontal link E) 5i is provided which has a lost motion connection with the rod 2li as at 52. In operation, with the brake pedal in the posi- l tion shown with the brakes released, fluid under pressure will :dow through the inlet hence into 10 the passage 35 filling the space_back of the piston É'l is provided which may be actuated by the usual , 29. Because of the light compression of the spring brake pedal, a mechanical booster or both as 35, the pressure of the fluid will force the valve will be hereinafter described. This rod is closely 3l .from its seat and ñowout through the outlet ñtted within the hole 2i’ which constitutes a guide therefor. Initial movement of the rod 2li to the left from the position shown in Fig. 1 will result in the valve lil _being moved to the left relative to the piston i3. Such movement by the rod 2l and valve ld Will result in the closing of the port Il by the guiding wall of the piston i3. Further movement of the rod 2l will bring the same into abutment with the piston i3 which will then be urged to the left to create the neces 25 sary additional operating pressure in the system. As illustrated in Fig. 1 a cylinder 28 is located at the Vright end of the casting it in axial align ment with the cylinder l2. A piston Z9 is re ceived with this cylinder for reciprocation through 30 which the rod 2l extends. The piston 29 may be either I'lxedly secured to the rod 2l or slidable thereupon. Preferably an annular shoulder 30 is provided upon the rod 2l against which the piston abuts when urged to the left, to mechan 35 ically operate the brakes. The shoulder 3u also acts to return the piston to the position shown in Fig. 1. With the piston 29 slidably received upon the rod 2l, manual actuation of the rod is vfacilitated as it is not necessary to traverse the 40 piston throughout'the length of the cylinder 28. The end of the cylinder 28 is closed by a casting Si having a bore 32 through which the rod 2l @t without building up sufl‘icient pressure to move 15 the piston 29 to the left. When the brake pedal is depressed thecarriage ¿il will be moved to the left gradually increasing the compression of the spring 38 to urge the valve 3l toward a seat to gradually decrease the flow of fluid through the 20 outlet 3G. The result is the gradually building up of pressure back of the piston 29 to move the same to the left to eiîect a smooth, uniform ap-, plication of the brakes. Additional movement of the link dil after the valve 3l has been fully 25 seated will result in the compression of the spring Alt which, it is to be understood is considerably stiller than the spring 38. In >the event of failure of the mechanical booster or desire to manually operate the brakes, the rod 21 is moved to the 30 leftthrough the lost motion linkage 52; the link 5l being capable of o‘nly a limited movement with out actuating the rod 2li; Conventional means ’ (not shown) return the brake pedal and the asso clated mechanism to the position shown in Fig. 1 after manipulation. Conduit. 53 communicating with the outlet 36 drains into the crankcase any of the operating fluid which may pass the piston 29. A conduit 5G, likewise communicating with ' the outlet 35, drains any accumulation of operat 40 ing ñuid which may pass the rod 2l and carriage di. ` extends. Within the casting 3i is disposed and In Fig. 4 is shown a modified embodiment of housed the necessary ports and valve mechanism my mechanical booster in which an inlet 55 com- , ` 45 for directing' the iiuid pressure against the pis ' municates with the cylinder 28 through a bore ton 29 to mechanically apply the brakes. In my 55. A hollow piston valve 5l having a tapered 45 preferred form, oil, or other suitable ñuid, under port 58 is slidably received within the bore 56 and _pressure is admitted through the inlet 33 and is . when mov‘ed to the left fromtheposition shown directed into the cylinder 28 against the piston permits a gradually increasing ñow of operating 29 through the passages Sil-35. An outlet 36, fluid to be directed against the piston 29. As the which would be connected with the crank case valve t1 is moved to the left to open the inlet 55 50 when the pressure oiling system of the vehicle is the forward end of the valve 5l gradually closes employed as a source of operating power, is in the outlet 5t’. As will be readily understood this communication with the passage 35. Such com varrangement will result in a smooth, gradual munication is interrupted or constricted by a actuation of the brake mechanism. 55 valve 31 Which is lightly urged to a seat by the l Referring to Fig. 5, a modii‘led auxiliary cylin spring 38 with the brake pedal 39 inthe manner der structure is shown in which the travel of the shown. The stern 40 of the valve 31 is» axially piston to the extreme right upon decrease in slidable relative in its carriage“ received for pressure upon the forward end of the piston, as 60 reciprocation in a bore 42 of the casting 3l. It would take place upon line failure, closes a check 60 vis to be understood that the slot of the lost mo valve to avoid loss of operating-huid. As illus; tion linkage 52 is-so designed and its relation so trated the piston 59 carries a plunger t0 which corelated'with reference to the strength of the extends beyond the forward end of thefpiston. A spring 38 that the ?luid pressure built up behind ball valve 6i is located within the chamber t2 65 the piston 29 always opens the Valve 3l before which communicates with the outlet t3 leading the piston 29 has moved sumciently to take up to the Wheel brake cylinder. A spring stressed 65 the lost motion and thus avoid urging the link plunger 56 urges the ball valve 6i to a seat 5i to the left under full pressure. This carriage against the washer t5 which has a serrated edge is reciprocated through the linkage connected to the brake pedal consisting of a rod 43 having one lend connected to the carriage di and the other end slidably received within the tubular link till. The link lill is enlarged at 45 to house the spring d6 which acts against an annular shoulder ¿l1 75 upon'the rodllä to urge the rod ¿i3 to the position t6 to permit the operating fluid to ñow past the ball valve through the channels 6l into the cham 70 ber t2 and hence to the outlet 63. Upon line fail ure the piston te will be urged to the extreme right of the auxiliary cylinder by the pressure in the master cylinder with the result that the ` ` plunger 60 forces the ball valve >to the dotted 75 ‘ .anonce ._ l . 3 - ' line >position closingthe outlet. The valve ¢iv NHaving described my invention what I claim as " in this position will` be held to a. seat bythe . new and desire to-protect by Letters Patent is: plunger M. After repair has been made it be , comes necessary to manually force the ball valve 'to the position shown in Fig. 5. 'K From theu i'oregoing- description it should be come apparent to those versed in th'e art that the present invention consists of three major fea.-` tures all of which may be advantageouslyvem 1. In ahydraulic brake system. a mastercylin der, a _plurality of auxiliary cylinders having communication with said master cylinder, out-> llets associated Vwith each of said auxiliary cylin ders, pistons located in said master and auxil iary cylinders. means acting upon said master piston to direct uuid under pressure against one v10 pioyed in combinations and arrangements other end of said auxiliary pistons to move Ãthe same 10 ln one direction to build up ñuid'pressure, valves ' than those shown. At the same time I have com hined all?- these features i'nto a compact unitary , located in said outlets and means' associated with "commercial structure, which may be inexpem," said pistons for actuating said valves to close said sively constructed, which provides a factor of voutlet‘upon reduction of fluid pressure in the 15 safety not heretofore obtained, and which re-_ outlet end of said auxiliary cylinders. suits in smooth. uniform actuation, at all times, - 2. In a hydraulic brake system. an auxiliary cylinder, an outlet from said cylinder, a piston of the brake mechanisml either manually or located in said cylinder, means directing fluid mechanically. It istol be understood that .I do ‘ under against said piston to _move the not intendv to limitl the invention to the exact same inpressure a direction to build up pressure in said 20 details and combinations and arrangement of cylinder, a valve in said outlet, and means con parts shown'but do intend to -include such obvi "nected to said piston for actuating` said valve to i ous changes and modiñcations as will readily sug close said outletv upon a reduction'of pressure ' gest themselves and fall within the scope of the .in said auxiliary cylinder. appended claims. y ' ROBERT HOFSTEITER.