US2038055A - Fluid braking apparatus and compressor therefor - Google Patents

Fluid braking apparatus and compressor therefor Download PDF

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Publication number
US2038055A
US2038055A US580573A US58057331A US2038055A US 2038055 A US2038055 A US 2038055A US 580573 A US580573 A US 580573A US 58057331 A US58057331 A US 58057331A US 2038055 A US2038055 A US 2038055A
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US
United States
Prior art keywords
compressor
liquid
piston
cylinder
bore
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US580573A
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English (en)
Inventor
Wallace F Oliver
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hydraulic Brake Co
Original Assignee
Hydraulic Brake Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to BE392971D priority Critical patent/BE392971A/xx
Application filed by Hydraulic Brake Co filed Critical Hydraulic Brake Co
Priority to US580573A priority patent/US2038055A/en
Priority to GB35066/32A priority patent/GB411537A/en
Priority to FR747821D priority patent/FR747821A/fr
Priority to DEH138715D priority patent/DE614631C/de
Application granted granted Critical
Publication of US2038055A publication Critical patent/US2038055A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D49/00—Brakes with a braking member co-operating with the periphery of a drum, wheel-rim, or the like
    • F16D49/08—Brakes with a braking member co-operating with the periphery of a drum, wheel-rim, or the like shaped as an encircling band extending over approximately 360 degrees
    • F16D49/12—Brakes with a braking member co-operating with the periphery of a drum, wheel-rim, or the like shaped as an encircling band extending over approximately 360 degrees fluid actuated
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
    • B60T11/00—Transmitting braking action from initiating means to ultimate brake actuator without power assistance or drive or where such assistance or drive is irrelevant
    • B60T11/10—Transmitting braking action from initiating means to ultimate brake actuator without power assistance or drive or where such assistance or drive is irrelevant transmitting by fluid means, e.g. hydraulic
    • B60T11/16—Master control, e.g. master cylinders
    • B60T11/22—Master control, e.g. master cylinders characterised by being integral with reservoir
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
    • B60T11/00—Transmitting braking action from initiating means to ultimate brake actuator without power assistance or drive or where such assistance or drive is irrelevant
    • B60T11/10—Transmitting braking action from initiating means to ultimate brake actuator without power assistance or drive or where such assistance or drive is irrelevant transmitting by fluid means, e.g. hydraulic
    • B60T11/16—Master control, e.g. master cylinders
    • B60T11/228—Pressure-maintaining arrangements, e.g. for replenishing the master cylinder chamber with fluid from a reservoir

Definitions

  • My invention is concerned with improvements in hydraulic braking apparatus of the type in which a liquid is caused to flow to and from braking positions in the setting and releasing of 5 brakes.
  • One object of my invention isan improved means of maintaining a constant amount of liquid in the system, compensating for volumetric losses by contraction or leakage, and relieving any volumetric excess caused by the replenishing means or by heat expansion. Maintaining a constant liquid volume for the system is desirable, for otherwise the brakes may either drag or develo dangerous slack. 4
  • Another object is the simplification of the operation of initially filling the system with liquid, which I secure by a check valve readily insertable between the compressor and the rest of the system thereby transforming the compressor into a p p-
  • I contemplate an improved design of compressor unit which, without material 30 changes, is adapted more or less universally for all commercial makes of automobiles so that the compressor unit can be standardized and incorv porated in the standard makes of automobiles without necessitating structural redesigning oi of the body, thereby simplifying the manufac- K 40 turers assembly problems.
  • a still further object is to make available to the driver some kind of alarm indicating that the reserve supply of liquid is about exhausted, before the brakes are actually unusable, and especially before the reserve liquid has been so far depleted that it will be necessary, in replenishing the reserve, to bleed the line to exhaust any air which may have been introduced.
  • Figure 1 is a plan view of a skeleton chassis, of an automobile equipped with the improved bydraulic braking system of my invention
  • Figure 2 is a verticaLelevation from the side which may be considered as taken on the line 22 of Figure 1, and shows the compressor unit Figure 3 is an elevation of the inner side of the right front wheel brake assembly taken on the line 3-3 of Figure 1, the wheel cylinder being broken into longitudinal section;
  • Figure 4 is a transverse vertical section of th same brake mechanism as Figure 3, and is taken. on the lines 4-4 of Figures 1 and.3;
  • I Figure 5 is a longitudinal vertical section through the compressor unit, which may be considered as taken on the line 5 5 of Figure 1;
  • Figure 6 is a transverse vertical section of the compressor unit taken on the somewhat irregular line 6-6 of Figure 5;
  • Figure 7 is a fragme ary transverse section similar to Figure 6, but taken along the .line
  • Figure 8 is another fragmentary viewof the compressor showing the compressor at the time the brakes are fully applied
  • Figure .9 is a fragment of Figure 5 showing the check valve moved to a position between the compressor and the rest of the system to transform the compressor into a pump for filling the system.
  • Figure 10 is a view similar to Figure 5 (but looking toward the lefthand side of the automobile, rather than toward the right hand side as in Figure 5) showing a modified form of the compressor unit.
  • Figure 11 is a detailed section taken on the line llll of Figure 10 showing the check valves of Figures 5, 8,'and 9 as applied to a modification I the piston.
  • a brake pedal pivot shaft 18 is supported'with the-aid ofa bracket. 19 from the transmission'housing 2
  • the shaft l8 "pivotally supports the brake pedal 20' which though a link rod 2
  • the brake pedal is returned to normal under the influence of a light spring 2
  • hoses connect with cylinder blocks 25 which are secured by bolts 26 to the steering spindles 21, in the case of the front wheels, and to the rear axle housing in the case of the rear axles.
  • the hose 24 communicates through passages 28 with the interior of the cylinder 25 midway between its ends.
  • is centrally suspended be tween the proposed packings by radial pins 32 and serves as an abutment to limit the inward movement of the pistons 29.
  • a molded rubber apron 33 may be slipped over each end of the cylinder 25 and also fitted over the central boss of the corresponding piston to exclude water and dirt.
  • a pivot bracket 34' stamped from sheet steel is secured by bolts 35 to the upper side of the cylinder block 25.
  • the pivot shanks 36 of the actuating levers 31 are journaled.
  • the lower ends of these levers are goose-necked around the shell-like ends of the cylinder block 25 and abut the central bosses of the pistons 29.
  • These bosses preferably carry hardened steel inserts 38 for engagement by the levers 31.
  • the upper ends of the levers 31 are goose-necked over the brake drum 39 of the wheel l6 and are provided with holes 40 for the passage of shanks 4
  • the shanks are screw-threaded to receive adjusting nuts 43 against which the upper ends of the levers bear in contracting the brake band.
  • the ends of the bands are normally urged apart and the levers 31 rotated to push the pistons 29 in by means of compression springs 44- surrounding the shanks 4
  • the band is anchored against rotation and adjustable radially by the usual bracket '46 supported from the mud plate 41 and preferably lo-.
  • the compressor need not be supported in this particular manner and I provide another pair of bosses 5
  • the closure plate 53 which forms the bottom of the housing 50 is clamped with a fluid tight seal against the bottom edge of the housing by a munber of cap screws 54.
  • the housing together with the bottom closure plate 53 forms a liquid reservoir and the compressor cylinder 55 is preferably cast integrally with the plate 53 on its upper side so that the cylinder is mounted wholly within the housing 50.
  • This compressor actuating crank comprises a horizontally disposed shaft 56, a downwardly ex-' 6) so that the only possibleleakage of fluid would be along the bushing 62, and such fluid leakage is further prevented by a packing 63.
  • abuts the inner end of the bore 6
  • Both arms of the crank are of course non-rotatably secured to the shaft 56 and one of the arms, the inner arm 51 in the drawings, is adjustable with relation to the shaft by a serration of the shaft 56 and by the clamping screw 64.
  • carries a screw threaded clevis on each end, the forward clevis being pivoted to the brake pedal 29v by a pin 65 and the rear wheel brakes.
  • the provision of the three holes 59 in the, crank arm 58 gives a-reasonable leverage adjustment so that the foot pressure for applying the brakes can be suited to the preferences of the individual driver.
  • the compressor cylinder is open at its rearward end and in its bore a piston 61 is slidably mounted.
  • the piston 61 carries an annular packing 68 which is V or U-shaped in section and preferably formed of vulcanized rubber. It is fixed to the piston by slipping it over the enlarged head of the centrally protruding hollow boss 69 at the forward end of the piston 61.' Pressure forwardly of the piston tends to seal the packing 68 against both the boss 69 and the bore of the cylinder 55 and effectively prevents leakage past the piston even though a very high pressure is built up on the liquid.
  • the cylinder 55 communicates with the conduit tubes 22 leading to the brake cylinders by means of a vertical-passage 1
  • the compressor acts as a compressor in the strict sense of the term, that is, the piston of the cylinder serves merely to displace the liquid and when released the return springs of the brakes push the liquid back into the compressor, there being no check valves.
  • I' I prefer that such a'trapping or replenishing device be combined, for the sake of economy and simplicity, with the compressor itself and to this end I'provide the piston 61 of the compressor with a central bore 10.
  • the rear of the bore 18 is connected with the reservoir of the housing through a backwa'rdlyseating check valve while in the other end of the bore there is a stationary piston which also incorporates a backwardly seating check valve,thereby forming a pump.
  • the check valve at the rear of the bore 19 is in the form of a vulcanized rubber packing 14 mounted on a steam 14A fixed to aldisc 15 of hardened steel which is secured in the rear face of'the piston 61 by a 4" ring 15A.
  • the purpose of the hardened disc 15 is to provide a wear resisting abutment for engagement by the end of the in-' end of the arm 51, so that when, as will belater explained, the compressor is used as a pump for filling the system, the piston .can be actuated positively in its rearward as wellas its forward movement.
  • the forward check valve and fixed piston for the pumpbore 10 is formed by a vulcanized packing 11 which may be identical with the packing 14 and which is mounted at the rearward end of a small piston rod 18.
  • the rod 18 also carries a perforated disc 19 to re-enforce the packing 11 when the latter acts as a piston.
  • the forward end of the piston rod 18 is rather loosely held by a cross pin 19 in a plug 80 threaded into the forward end of the cylinder 55 to give the rod 9. limited universal movement and permit the packing 11 and disc 19 to center themselves in the bore 19' of the piston.
  • the aperture in the end of the cylinder 55 'into which the plug 80 is inserted is of sufficient diameter to permit the withdrawal of the packing 11 so that the packing rod and plug can all be assembled and inserted as a unit into the end of the cylinder.
  • the relief port 83 does not cause any appreciable loss of fluid from the system in actuating the compressor for three reasons: First, it is located so close to the packing 68 that as soon as there has been any apprecialtle forward movement of the piston 61, the'port will be closed on; second, the port is so small that pump to introduce an excess amount of liquid into the. system which would readily compensate for any loss through the port.
  • the port 83 acts to relieve the system not only of the excess liquid pumped into it by the piston packing 11 but also to relieve it from an excess volume which might develop by a general heating of the liquid in the system as for example by driving along a hot pavement in summer weather or by driving the automobile down a longhill where the 'heat generated by the friction of the brakes would serve to heat-the liquid and expand it.
  • the pump feature on the other hand havevbeen iost from the system. by a slight leakage, evaporation, seepage past the piston packing 68, or otherwise. a
  • the fluid system ' (not including the reserve of course,) contains about twenty-one cubic inches of liquid and in the normal maximum application of the brakes, the compressor displaces about 1.25-cubic inches of liquid. It will be; seen from Figure 8 that the piston is then still capable of a movement a half more than the normal movement, thereby giving a fifty per cent margin of safety in the event that the brake linings become worn down, the linkage develops slack, or the reserve of liquid becomes depleted-and no other adjustment is made to compensate for it. The amount of excess liquid introduced by the displacement of liquid from the bore 18 of the piston would be about .196 cubic inches or a little less than one-sixth of the normal displacement.
  • are positioned at the extreme rearward or closed end of the bore 12 and beyond the intersection of the bore 12 by the cross bores 13, so that the check valve 90-!!! does not affect free communication between the cylinder 55 and the conduit lines.
  • the filling plug 85 is removed from the top wall of the housing 58 and liquid is poured in to fill the housing.
  • the relief valves 88 at the wheel brakes are opened.
  • One of these valves 88 as shown in pistons.
  • the valve is in the form of a plug which seats against a counter-bore in the cylinder block 25' and which has a small bore 81 leading from its outer end to a cross bore adjacent its inner end.
  • the wheel cylinder is thus relieved to at-. mosphere by simply turning ,back the valve 88 a short distance from its seat.
  • the relief valves are located at the tops of the wheel cylinder blocks 25 because they are the highest points at the extremities of the system.
  • a suitable vent is provided for the housing 5v either through the filling plug 85, or preferably, as shown in Figure 5, by a small hole 92 in the vertical wall of the housing extension that provides room for the top of the arm 51, as that is well above the highest liquid level and where there is little danger of dirt being introduced.
  • the pump should be of suflicient capacity to compensate for minor fluid losses from the system, but still it should not be of such capacity that it. will cause all of the slack to be taken up by pump ing an excess of fluid into the system should the' driver successively apply full and then relaxed pressures by the compressor without letting the compressor pistoncome back to normal where the cylinder will be drained of excess fluid by the port 83.
  • the pump could be actuated two or three times or more without an intervening relief, without pumping so much liquid into the system as to take up the slack on the brakes and cause them to lock.
  • the cylinder 550 forms a part of 'a more or less circularend plate 53a rather than a part ofthe bottom plate, so that I the cylinder is inserted from the end of. the main housing 50.
  • the wire is bent into a C-shape of somewhat more than 180 degrees so that it will securely grasp the cylindrical periphery of the end 01 the cylinder. It has hair pin-rehent ends 91, with the terminals oflset'inwardly as at 98 on a diam eter. The offset ends extend through holes ill in the wall of the cylinder 55!; and project a short distance inwardly therebeyond as a stop for the piston 61a. jI'he purpose of therelatively great developed length is to minimize the danger oi the spring wire being bent beyond its elastic limit in removing it.
  • a discharge passage I00 leads'irom the inner end of the bore of the cylinder 55a down past the normally inoperative check valve 890. and to the line 22a leading to the wheel brakes.
  • I claim 1 In a hydraulic brake system of the-class de- -scribed having brake mechanisms operated in one direction by fluid pressure and springs for opercompressor, and valve means for draining the system of excess liquid when the compressor is in its position of rest.
  • a compressor in fluid communication with said motor, said compressor having a reciprocating piston, said piston having one area effective on the discharge stroke and a second area effective on the return stroke, said first-mentioned area being greater than said last-mentioned area whereby said piston on its forward stroke discharges from said compressor a larger quantity of fluid than can be accommodated in said compressor by the return stroke of said piston, and means for conducting said difference in quantity of said fluid to a. fluid reservoir.
  • a compressor comprising a cylinder element and a piston element
  • a pump coaxiaily arranged with the compressor and comprising a cylinder element and a piston element, one of said pump elements being carried byone of said compressor elements, and a common actuating member for the compressor and the pump compressor cylinder and for pumping the surcharge of liquid from the pump cylinder into the compressor cylinder, a fluid reservoir, andmeans for conducting to said reservoir the .excess of the surcharge returned through the operation of said springs.
  • a compressor in liquid communication with i said wheel brakes, said compressor comprising a cylinder, a compressor piston reciprocable therein, said piston having a bore, a pump piston actingin said bore and including a check valve permitting the liquid to pass from. the bore forwardly into the cylinder, a liquid reservoir for supplying i iiluiclv tosaid compressor and bore, a check valve ⁇ carried by the compressor piston permitting the for simultaneously compressing the liquid in the 5.
  • a compressor in liquid communication with said hydraulically operated means, said compressor comprising a liquid reservoir, a master cylinder submerged therein, a compressor piston reciprocable in said cylinder, said piston having a bore constituting the cylinder bore of a pump, a pump piston .working in the pump bore and including a cup packing having a check valve action permitting the flow of liquid from the pump bore to the cylinder, a check valve between the pump bore and the reservoir located outwardly from said pump piston, means for actuating .the compressor piston to operate the compressor and the pump, means for returning the compressor piston independently of any back.
  • a master cylinder unit for a hydraulic brake system having brake mechanism operated in one direction by hydraulic pressure and in the opposite direction by spring means comprising a compressor cylinder, a piston therein, a reservoir communicating with the outer end of the piston, means for reciprocating the piston for compressing the liquid in the cylinder, and a reciprocating pump formed within the piston and actuated by the reciprocation of the piston for pumping a surcharge of liquid from the reservoir into the cylinder, and means for returning tothe reservoir excess liquid returned under the influence of said spring means.
  • a hydraulic brake system comprising means and said pumpmeans, said reciprocable 8.
  • a hydraulic braking system having liquid operated wheel brakes, the combination of an actuating compressor in liquid communication with said brakes, and normally inoperative means manually manipulable to operable condition as a discharge check valve for the compressor to prevent recession of liquid from the brakes to the compressor whereby the compressor may be actuated as a pump to fill the liquid system therebeyond.
  • a hydraulic braking system including liquid operated wheel brakes
  • an actuating compressor having liquid inlet means from a source of liquid supply, there being operating liquid connections between said compressor and said wheel brakes and normally in operative means manually rendered operable as a discharge check valve for the compressor to prevent recession of liquid from the brakes to the compressor whereby the compressor may be actuated as a pump to fill the liquid system.
  • a hydraulic braking system having liquid operated wheel brakes
  • a hydraulic pressure system of the class described,including hydraulically actuated mechanism the combination of a compressor, liquid lines leading from the compressor to said means, a liquid passage between the compressor and the lines comprising intersecting bores, a check valve in one 01 said bores comprising a stem, a perforate head making a substantially fluidtight fit with the check valve bore, a check valve element cooperating with the perforate head, and manual means for reciprocating the check valve in its bore across the intersection of said bores whereby in one position the check valve is operably inserted in the passage and in the other position it is rendered inoperative.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Transportation (AREA)
  • Valves And Accessory Devices For Braking Systems (AREA)
  • Transmission Of Braking Force In Braking Systems (AREA)
  • Braking Arrangements (AREA)
US580573A 1931-12-12 1931-12-12 Fluid braking apparatus and compressor therefor Expired - Lifetime US2038055A (en)

Priority Applications (5)

Application Number Priority Date Filing Date Title
BE392971D BE392971A (enrdf_load_stackoverflow) 1931-12-12
US580573A US2038055A (en) 1931-12-12 1931-12-12 Fluid braking apparatus and compressor therefor
GB35066/32A GB411537A (en) 1931-12-12 1932-12-10 Improvements in hydraulic power transmission mechanism
FR747821D FR747821A (fr) 1931-12-12 1932-12-10 Perfectionnements aux systèmes de freins actionnés par un fluide
DEH138715D DE614631C (de) 1931-12-12 1932-12-11 Nachfuellvorrichtung einer hydraulischen Bremsvorrichtung, insbesondere fuer Kraftfahrzeuge

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US580573A US2038055A (en) 1931-12-12 1931-12-12 Fluid braking apparatus and compressor therefor

Publications (1)

Publication Number Publication Date
US2038055A true US2038055A (en) 1936-04-21

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Family Applications (1)

Application Number Title Priority Date Filing Date
US580573A Expired - Lifetime US2038055A (en) 1931-12-12 1931-12-12 Fluid braking apparatus and compressor therefor

Country Status (5)

Country Link
US (1) US2038055A (enrdf_load_stackoverflow)
BE (1) BE392971A (enrdf_load_stackoverflow)
DE (1) DE614631C (enrdf_load_stackoverflow)
FR (1) FR747821A (enrdf_load_stackoverflow)
GB (1) GB411537A (enrdf_load_stackoverflow)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2912999A (en) * 1955-07-18 1959-11-17 Ronald C Kersh Fluid check valve
US3006363A (en) * 1958-11-20 1961-10-31 Gen Motors Corp Check valve

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2844940A (en) * 1953-06-22 1958-07-29 Clarence W Huber Master cylinder
FR2777329B1 (fr) * 1998-04-10 2000-06-23 Valeo Emetteur hydraulique a reservoir integre et commande hydraulique comprenant un tel emetteur
JP2002505732A (ja) 1998-04-10 2002-02-19 ヴァレオ リザーバを一体化した油圧吐液器、および当該吐液器を備える油圧制御システム

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2912999A (en) * 1955-07-18 1959-11-17 Ronald C Kersh Fluid check valve
US3006363A (en) * 1958-11-20 1961-10-31 Gen Motors Corp Check valve

Also Published As

Publication number Publication date
FR747821A (fr) 1933-06-24
GB411537A (en) 1934-06-11
BE392971A (enrdf_load_stackoverflow)
DE614631C (de) 1935-06-17

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