Source: http://www.patentgenius.com/patent/4030575.html
Timestamp: 2017-12-14 21:06:31
Document Index: 103420745

Matched Legal Cases: ['art 25', 'art 26', 'art 25', 'art 26', 'art 26', 'art 26']

Piston assembly with safety vent means for brakes and the like - Patent # 4030575 - PatentGenius
4030575 Piston assembly with safety vent means for brakes and the like
Inventor: Moring, et al.
Application: 05/624,792
Inventors: Frauenhoff; Richard E. (Montgomery, IL)
Moring; Rodger L. (Bristol, IL)
U.S. Class: 188/151A; 188/170; 188/352; 188/71.1; 192/91A
Field Of Search: 188/71.1; 188/72.3; 188/72.4; 188/151A; 188/170; 188/352; 192/91A; 92/128; 305/10; 303/6M
U.S Patent Documents: 2698676; 3507373; 3526302; 3536230; 3581908; 3792910; 3831718; 3915433
Abstract: A brake assembly comprises a housing having a piston assembly reciprocally mounted thereon to selectively release the normally "on" brake assembly upon pressurization of an actuating chamber defined therein. The piston assembly comprises an annular piston having an opening formed therethrough to communicate with the actuating chamber. An annular pressure plate is releasably attached to the piston by a plurality of circumferentially disposed bolts. A cover plate is detachably mounted on an outboard side of the piston to normally cover and seal the opening formed therethrough and to further cover at least one of the bolts whereby the cover must be detached from the piston prior to releasing the bolt covered thereby.
cover means comprising a substantially flat plate detachably mounted directly on an outboard side of said piston and disposed thereon to cover said opening in sealing relationship therewith and having an end portion extending inwardly towardssaid piston to fully cover at least one of said fastening means whereby said cover means must be detached from said piston prior to release of the fastening means covered thereby.
8. The vehicle of claim 7 wherein said brake assembly further comprises an input shaft rotatably mounted in said housing, a member secured to an end of said shaft for simultaneous rotation therewith, a first set of annular friction discs havinginner ends thereof splined on the periphery of said member for limited axial movement thereon and a second set of friction discs having outer ends thereof splined internally on said housing for limited axial movement thereon and interleaved with saidfirst set of friction discs and wherein said pressure plate is disposed in axial opposition to said first and second friction discs for selectively compressing them together to prevent rotation of said shaft relative to said housing.
9. The vehicle of claim 8 wherein said brake assembly further comprising spring means disposed between said housing and said pressure plate for normally biasing said pressure plate against said first and second sets of friction discs to compressthem together to normally prevent rotation of said shaft relative to said housing.
10. The vehicle of claim 9 wherein said brake assembly further comprising means defining an annular actuating chamber between said housing and said piston adapted to be pressurized to move said piston axially away from said housing to releasesaid pressure plate from said friction discs.
11. The vehicle of claim 10 wherein said piston has an annular boss formed integrally on an inboard side thereof to partially define said actuating chamber, said boss slidably mounted in an annular bore formed on an outboard side of saidhousing.
16. The vehicle of claim 15 wherein another one of said spur gears is secured to an input shaft to said transfer gear mechanism for simultaneous rotation therewith and wherein said last mentioned input shaft is operatively connected to atransmission of said vehicle.
17. The vehicle of claim 16 wherein still another one of said spur gears is secured to an output shaft from said transfer gear mechanism for simultaneous rotation therewith and wherein said output shaft is operatively connected to roadwheels ofsaid vehicle.
18. The vehicle of claim 7 wherein said brake assembly further comprising a plurality of jack screw means mounted in a storage position on an outboard side of said piston and a plurality of threaded holes formed through piston to expose abearing surface formed on said housing whereby threading-down of said jack screw means in said holes will retract said piston relative to said housing.
This invention relates to a piston assembly adapted for use in brakes or clutches. A conventional brake of the axially engaging type comprises a member rotatably mounted in a housing and a plurality of interleaved friction discs alternatelymounted for limited axial movement on the member and on the housing and adapted to be compressed together to brake the member relative to the housing. The brake is normally held in its "on" condition of operation by a plurality of coil springs whichurge an annular pressure plate against the friction discs to compress them together. An actuating chamber is defined in the brake whereby pressurization thereof will reciprocate a piston to disengage the pressure plate from the friction discs to permitthe member to rotate relative to the housing.
In many such brakes, care must be taken to depressurize the actuating chamber prior to disassembly of the brake. Conventional brakes normally comprise a cap screw which normally closes a bleed orifice for relieving the air pressure in theactuating chamber upon removal of the cap screw. A typical bleeding arrangement is disclosed in U.S. Pat. No. 3,526,302, assigned to the assignee of this application.
This invention relates to a non-complex and improved piston assembly for use in a brake or clutch and further adapted to be assembled and disassembled expeditiously and safely. The piston assembly comprises an annular piston having an annularpressure plate attached thereto by a plurality of releasable fastening means, such as bolts. A cover is detachably mounted on an outboard side of the piston to normally cover and seal an opening formed therethrough and to also at least partially coverat least one of the bolts. Thus, the cover must be detached from the piston prior to release of the bolt to automatically vent an actuating chamber normally defined between the piston and a housing on which the piston is reciprocally mounted.
FIG. 1 illustrates a drive train for a construction vehicle, such as a wheel loader, wherein an internal combustion engine 10 is adapted to drive an input shaft 11 of a transfer gear mechanism 12 via a standard transmission 13. The input shaftwill thus rotate a first spur gear 14 to drive second and third spur gears 15 and 16, the latter gear in turn rotating an output shaft 17. The output shaft is suitably connected by standard drive lines to pairs of front and rear road wheels 18 and 19,respectively.
A brake assembly 20 has an input shaft 21 thereof secured to intermediate gear 15. The normally "on" brake assembly is adapted to be released by suitable actuation of a valve or air valve means 22 by the vehicle's operator which communicatespressurized air to the brake assembly via a conduit 23. It should be understood that although the hereinafter described invention specifically relates to a brake assembly, that such invention is equally applicable to a clutch assembly wherein valve 22would be employed to couple a pair of rotating members to each other rather than connecting a rotating member to a stationary member.
Referring to FIGS. 2-4, the brake assembly further comprises a multi-part housing 24 including an annular first part 25 and a cup-shaped second part 26 releasably attached together by a plurality of circumferentially disposed bolts 27. Shaft 21is rotatably mounted on part 25 of the housing by annular bearing means 28, preferably comprising a standard roller bearing assembly. An annular member 29 is releasably connected to an end of shaft 21 by a spline connection 30 and retained thereon by aplate 31 and a bolt 32.
A first set of annular friction discs 33 have their inner ends mounted on the periphery of member 29 at a spline connection 34. A second set of annular friction discs 35 are interleaved with the first set of friction discs and have their outerends suitably splined at 36 on part 26 of housing 24. The friction discs are thus adapted for limited axial movement to be compressed together to normally brake shaft 21 relative to the housing.
The brake assembly further comprises a piston assembly 37 including an annular piston 38 having an annular boss 39 integrally formed on an inboard side thereof. The boss is slidably mounted in a like-shaped bore 40 defined on an outboard side ofpart 26 of housing 24. An annular static sealing means 41 is mounted on the housing to seal an actuating chamber 42 partially defined by an annular cavity 43 formed internally on an inboard side of piston 38 and an annular wall 44 of the housing.
The piston assembly further comprises an annular pressure plate 45 disposed in axial alignment and opposition with respect to the piston and threadably attached thereto by a plurality of fastening means or bolts 46 extending through the piston. A spacer 47 is mounted on each of the bolts and is disposed axially between the piston and pressure plate in abutting relationship therebetween. Spring means for normally biasing pressure plate 45 against friction discs 33 and 35 to engage the brake inits normally "on" condition of operation preferably comprises a coil spring 48 disposed on each bolt 46 and spacer 47 to abut an annular flange 49, formed integrally with part 26 of the housing, and pressure plate 45.
A cover means preferably in the form of a substantially flat plate 50 is detachably mounted on an outboard side of piston 38 by a pair of cap screws 51. As shown in FIG. 4, the cover means is disposed on the piston to cover an opening or bleedorifice 52 formed therethrough and sealed by an O-ring seal 53 compressed between the cover means and the piston. In addition, the cover means at least partially covers at least one of fastening means 46, releasably attaching the piston to the pressureplate, and has an end portion bent inwardly towards the piston to fully cover the fastening means. In the embodiment illustrated, two such fastening means are covered whereby the cover means must be detached from the piston prior to release of suchfastening means.
Three jack screws 54 are threadably mounted in a storage position on an outboard side of piston 38. The jack screws are each adapted to be threadably mounted in a respective threaded hole 55 formed through a radial flange of the piston, todisable the brake should pressurized air become unavailable for actuating chamber 43. In particular, threading-down of the jack screws in circumferentially disposed holes 55 will engage the ends thereof with an annular bearing surface 56 of housing 24exposed by such holes (FIG. 3) to retract the piston to thus release the brake.
In operation, actuating chamber 42 is normally exhausted of air via valve 22 to permit springs 48 to urge pressure plate 45 against friction discs 33 and 35 to compress them to prevent rotation of shaft 21 relative to housing 24. When theoperator chooses to move the vehicle, valve 22 is actuated to communicate pressurized air to actuating chamber 42 whereby piston 38 moves rightwardly in FIG. 3 to release shaft 21 relative to the housing. Thus, transfer gear mechanism 12 will functionto connect transmission 13 with roadwheels 18 and 19 to permit the operator to move the vehicle in a conventional manner.
When it is desired to service the brake assembly for repair or replacement purposes, a workman is fully protected against any potential injury in that actuating chamber 42 will be depressurized automatically even though the exposed bolts 46 shownin FIG. 2 are removed. In particular, in order to remove the remaining two bolts covered by cover means 50, cap screws 51 must be released to thus automatically vent the actuating chamber via opening 52. The latter two bolts can thus be removed toremove the piston assembly from the housing.
Nozzle modulators
Processing method for the manufacturing of electronic components using a soft soldering flux based on carboxylic acid
Canopy forming grove tree trimmer
Truth table candidate reduction for cellular automata based random number generators