Патент USA US2114991код для вставки
April 26, 1938. 2,114,991 H. C. BOWEN PRESSURE PRODUCING DEVICE FOR FLUID PRESSURE SYSTEMS Filed Nov. 30, 1935 96 ' 9o 24 a2 80 ,6 Z2 /8 v 94 64 . 50 30 96 | 62 74 v ‘ - 32 z '1) :a 92 7".| 66 56 72 76 88 as I 20 68 70 54 53 26 I4 INVENTOR. ' ATTORNEYS. ‘2,114,991 Patented Apr. 26, 1938 UNITED STATES PATENT OFFICE 2,114,991 , PRESSURE PRODUCING DEVICE FOR FLUID PRESSURE SYSTEMS ‘Herbert 0. Bowen, Detroit, Mich., assignor to Hydraulic Brake Company, Detroit, Mich., a I corporation of California Application November 30, 1935, Serial No.‘ 52,391 4 Claims. (Cl. 60-545) This invention relates to brakes, and more particularly to ?uid pressure brakes for motor vehicles. ~ - _ ' Broadly the invention comprehends a ?uid 6 brake system for motor vehicles including a manually operated ?uid pressure producing means connected by ?uid pressure delivery pipes or conduits to ?uid pressure actuated motors for the actuation of brakes associated with the wheels 10 of a vehicle, and means interposed between the ?uid pressure producing means and the ?uid pres-_ sure actuated motors operative to maintain a pre determined .pressure on the motors. An object of the invention is to provide a ?uid 15 pressure brake system having means for main taining a predetermined pressure on a part of the system. ~ Another object of the'invention is to provide a ?uid pressure brake system including a ?uid pres 20 sure producing device connected by ?uid pres sure delivery pipes to ?uid pressure actuated motors, and means associated. with the device for maintaining a predetermined pressure on the ?uid, pressure delivery pipes and motors. Other objects and structural details of the in ends are corresponding friction elements or shoes 44 and 46 for cooperation with the drum. A ?uid pressure actuated motor corresponding to the motors 38 is mounted on the backing plate between the separable ends of the shoes and is operative to spread the shoes‘ into engagement with the drum against the resistance of a retrac tile spring 48 connected between the shoes. The discharge port 28 is controlled by a two way valve. As shown, the inner face of the cylin 10 der head is counter-bored as indicated at 50. This bore forms in conjunction with the sleeve “at the base thereof an annular shoulder 52. A thimble 54, open at one end and closed at the other end, has at its open end a circumferential 15 ?ange 56 and a plurality of openings 58 in its wall. The ?ange 56 is ?tted snugly in the counter bore 50, and the shoulder is suitably deformed to secure the thimble against displacement. The closed end of the thimble provides a'seat for an 20 inverted collapsible sealing cup Bll having a co axial opening 62, and bearing against the cup is a disk 64 having an axial opening 66 registering with the opening 62 in the cup and a ?ange 68 including two cylindrical sections of di?erent 25 25 vention will appear from the subjoined description diameters, that section having the smaller diame-. ter ?ts the cylinder with a substantial clearance taken in connection with the drawing forming a and is provided with a plurality of openings 10 so part of this speci?cation, and in which,-— ' as to afford free passage of ?uid, and that section Fig. 1 is a schematic view of a hydraulic brake i‘ having the larger diameter is fitted snugly in the 30 system embodying the invention, and cylinder so as to guide the disk during its move 30 Fig. 2 is a vertical sectional view of the ?uid pressure producing device. v ’_ A piston reciprocable in the cylinder I2 is re Referring to the drawing 'for more speci?c tained against displacement by a washer ‘l4 details of the invention, l0 represents a reservoir seated on an annular shoulder 16 in the open end having a ?lling opening which may be closed by of the cylinder. and is secured in place by a split 35 a plug I! provided with suitable means, not shown, ring 18 seated in a circumferential groove in the for venting the reservoir to the atmosphere; and wall of the cylinder. The pistonghas a reduced ment. a cylinder l4 formed at the bottom of the reser- . voir has spaced ports I6 and I8 providing com munications between the cylinder and the 40 reservoir. 4 The cylinder has a detachable head 20. As shown, the head has a rim 22, preferably pro vided with polygonal faces for the reception of a wrench, and a concentric sleeve 24 which may be - V portion providing in conjunction with the wall of the cylinder an annular chamber 80 communi 40 eating with the reservoir III as by way of the ports IS. The skirt of the piston carries a leak-proof cup 82 providing against seepage of ?uid from the cylinder past the piston, and the head of the pis ton has a plurality of ports 84 providing com 45 munications between the annular chamber 80 and threaded into the cylinder with a suitable gasket‘ that portion of, the cylinder forward of the pis 26 interposed between the cylinder and the rim. ton. A collapsible sealing cup 86 on the head The head is also provided with a discharge port of the piston controls the port 84, and when the 28 connected as by a suitable ?tting 30 to a ?uid piston is in fully retracted position the rim of pressure delivery pipe 32 having branches 34 the cup uncovers the port, I 8 to establish com and 35 each connected to one pair of ?uid pres munication between that portion of the cylinder sure actuated motors 38. One pair of the motors forward of the piston and the reservoir. The cup 38 is arranged for the actuation of the brakes is‘ held against displacement by a spring 88 in associated with the front wheels of a vehicle and terposed between the cup and the disk 68 abutting the other pair is arranged for the actuation of the inverted sealing cup 68. This spring also . the brakes associated with the rear wheels of the serves to return the piston to its retracted posi vehicle. tion and to impose a load on the two-way'valve Each brake includes a ?xed support or backing plate 40 associated with a rotatable drum 42, and 60 pivoted on the backing plate by their articulate controlling the port 28. _ , The piston 12 has in its back a recess 88' for 2 2,114,991 the reception of one end of a thrust pin' 92, the - other end of which is suitably secured to a fitting 94 connected as by a ?exibleboot-JG to the open end of the cylinder for the exclusion of ‘dust and other foreign substances from the cylinder, and the principles involved are susceptible of numere ous other applications that will readilyv occur to persons skilled in the art. The invention is, therefore, to be limited only as indicated by the scope of the appended claims. I the ?tting 94 is connected by a rod 88 to a foot ' Having thus described the various features of pedal'lever I08 pivoted on a suitable support I82 the invention, what I claim as new and desire to and connected by a retractile spring I 04 to a secure by Letters Patent is:-—» ‘ 10 ?xed support. In operation, assuming that the system is ?lled with suitable ?uid and that the piston "I2 is in fully retracted position, the-two-way valve con 1; A ?uid pressure producing device including a cylinder, a piston reciprocable therein, a head for the cylinder having an opening providing '10 a discharge port for the cylinder, a sleeve on trolling the discharge port 28 maintains a prede termined pressureon the ?uid delivery pipes 32, ‘ the head threaded into the cylinder, and a two- , 15 34 and 36 and the ?uid pressure actuated motors way valve comprising a stationary valve element secured to the head within the sleeve, a perfo 15" 38, the magnitude of which is dependent upon the rated. collapsible sealing cup on the stationary tensile strength of the spring 88 acting on the two-way valve. ' Y " When it is desired to' apply the brakes, the op valve-element, a member seated on the cup, and a spring. interposed between the member and the head of the piston. 20 erator depresses the foot pedal lever I08 and this ' 2. A?uid pressure producing device including force is transmitted therefrom to the piston ‘I2 to a' cylinder, a piston “reciprocable therein, a head move the piston on its compression stroke. Dur ing the initial movement of the piston on ‘ts com- ' _ for the cylinder having an opening providing a discharge port for the cylinder, a sleeve on the head extending into the cylinder, a thimble se cured to the head within the sleeve having open pression stroke ?uid is displaced from the cylin ings in its wall, a collapsible sealing cup on the der I4 past the two-way valve whose rim is de thimble having an axial opening, said cup having ?ected by the passing ?uid, through the ?uid pressure delivery pipes ‘32, 34 and 36, into the' a rim extending away from said piston, a member seated on the cup, and a spring between the mem 30 ?uid pressure actuated motors 38, causing actu ber and the head of the piston. , 30 ation of the motors with the resultant spreading 3. A ?uid pressure producing device including of the shoes 44 and 46 into engagement with the drum 42 against the resistance of the retractile a cylinder, 9} piston reciprocable therein, a head for'the cylinder having an’ opening providing a spring 48. discharge port for the cylinder,-a sleeve on the 7 Upon release of the foot pedal lever I00, the re tractile spring I04 becomes eifective to return head extending into the cylinder, a thimble se 35 this lever to its normal or retracted position, and cured to the head within the sleeve having open during this movement of the foot pedal lever the ings in its side wall, a collapsible sealing cup on piston 12 is moved to its retracted position under» the thimble having an axial opening, said cup the influence of'the spring 88 augmented by the having a rim extending away from said piston, a- disk normally seated on the cup having an' pressure on the ?uid returning from‘ the ?uid 40, pressure actuated motors 38 under the in?uence opening registering with the opening in the cup, a double diametral ?ange on the disk, the smaller of the retractile spring 84 connected between the shoes 44 and 48 of the respective brake structures. section of the ?ange ?tting the cylinder with substantialclearance and having openings there 45 In returning to the master cylinder, the ?uid passes through openings 58 in thimble 54, then in, the larger section of the ?ange ?tting snugly 45 pression stroke, the cup 86 closes the port I8, and upon further movement of the piston on its com in the cylinder, and a spring interposed between moves cup 68 and disk 68 to the‘left so that a 'Y ' the disk and the head of the piston. space is formed between the base of the cupand the closed end of- the thimble, and ?ows through 50 the space thus produced, and thence through openings 62 and 66 into the'cylinder. Because of the friction on the ?uid pressure delivery pipes 32,_ 34 and 36 and the tensile‘ ' strength of the spring 88, the piston 12 is re turned to its retracted position slightly in ad vance of the return of ?uid from the pressure ac tuated motors 38 to the cylinder I4. This causes a partial vacuum in the cylinder '44 resulting in suction of ?uid from the reservoir I8, through the port I6, the annular chamber 80 and the ports 4. A ?uid pressure producing device including a reservoir, a cylinder supplied therefrom,'a pis ton‘ reciprocable in the cylinder, a collapsible sealing cup on the head of ‘the piston, a head on 60 the cylinder having an opening providing a dis charge port for the cylinder, a sleeve on the head threaded into the cylinder, the head having a counter-bore, a thimble open at one end and 55 closed at the other end and provided with a plu rality of openings in its wall, the open end of the thimble secured in the counter-bore so as tosup- ‘ port the thimble concentrically of the sleeve, a cup on the closed end'of the thimble hav-_ 84 in the head of the piston, past the collapsible sealing an axial opening, said cup having a rim ex cup 88 into that portion of the cylinder forward ing tending away from said piston, a disk on the cup ,of the piston to completely ?ll the cylinder I4. having an opening registering with thevopening Upon complete return of the piston to its re in the cup, a double diametral ?ange on the disk, 65 tracted position any excess ?uid in the cylinder ' the smaller ?ange ?tting the I.4, due to the ?uid returned to the cylinder from stantial clearance and having cylinder with sub 65 openings therein, , the ?uid pressure actuated motors 38, is dis-‘ charged from the cylinder throughthe port I8 the larger ?ange slidably engaging the wall of the cylinder, and a spring interposed between the cup into the reservoir. ' _ on the head of the piston and the disk. , Although ‘this invention has been described in .connection with certain speci?c embodiments, HERBERT _C. BOWEN.