CA1198758A - Combined air reservoir/brake cylinder device - Google Patents
Combined air reservoir/brake cylinder deviceInfo
- Publication number
- CA1198758A CA1198758A CA000414085A CA414085A CA1198758A CA 1198758 A CA1198758 A CA 1198758A CA 000414085 A CA000414085 A CA 000414085A CA 414085 A CA414085 A CA 414085A CA 1198758 A CA1198758 A CA 1198758A
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- piston
- chamber
- fluid pressure
- end wall
- opening
- Prior art date
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Abstract
ABSTRACT OF THE DISCLOSURE
A pneumatic brake cylinder device employs a pair of dif-ferent sized fluid motors, the pressure chambers of which serve as air storage reservoirs. The cylinder of the larger fluid motor is formed by the main casting and contains a larger piston, while the cylinder of the smaller fluid motor is mounted to the main casting in coaxial relationship with the larger cylinder and contains a smaller piston having an elon-gated hollow body that is connected at its open end to one side of the larger piston to form a pressure chamber there-between. The smaller piston fits within the smaller cylinder in spaced-apart relationship therewith to form a pressure chamber delimited by a seal fixed on the main casting for engagement with the piston periphery at any point along its longitudinal axis. The larger piston cooperates with the larger cylinder to form pressure chambers on opposite sides thereof.
The arrangement provides for a design employing fewer seals and a simplified main casting in which all the passages to the respective pressure chambers are contained.
A pneumatic brake cylinder device employs a pair of dif-ferent sized fluid motors, the pressure chambers of which serve as air storage reservoirs. The cylinder of the larger fluid motor is formed by the main casting and contains a larger piston, while the cylinder of the smaller fluid motor is mounted to the main casting in coaxial relationship with the larger cylinder and contains a smaller piston having an elon-gated hollow body that is connected at its open end to one side of the larger piston to form a pressure chamber there-between. The smaller piston fits within the smaller cylinder in spaced-apart relationship therewith to form a pressure chamber delimited by a seal fixed on the main casting for engagement with the piston periphery at any point along its longitudinal axis. The larger piston cooperates with the larger cylinder to form pressure chambers on opposite sides thereof.
The arrangement provides for a design employing fewer seals and a simplified main casting in which all the passages to the respective pressure chambers are contained.
Description
~18'7~i~
IMPROVE~5ENTS I~ COMB IN13D AIR
RESERVOIR/BRAKE; CYLI.NDlE:R DEVICE
BACKGROU~D OF THE lN v~;N~ oN
United States Patent No. Re. 30,408, reissu~d September 30, 1981, to the assignee of the present applicationO dis-c~oses railway br~ke apparatus including a brake cylinder device and a control valve de~ice. The usual air reservoirs associated with conventional pneumatic brake e~uipment are eliminated in the disclosed apparatus in favor of storing the compresæed air within the brake cylinder de~ice it~elf~
The brake cylinder device embodi s a pair of tandem,connected pistons of unequal diameter, the larger piston cooperating with the brake cylinder body to form on the respective oppo~
site side~ of this piston two chambers that are charged with compressed air via the train brake pipe, and in w~ich chaD, bers the air required for use by the brake apparatus, includ-ing the brake c~linder device, is stored. The aforementioned control ~alv~ device operates in response to variations in the train brake pipe pressure to control the trans~er of air stored in the brake cylinder d~vice, so as to develop dif~er-ential forces across the respective pistons thereof, and thereby effect a brak~ application and brake release~
In addition to the typical packing cup type pressure seals as~ociated with the respective pistons of this brake c~linder deviceO there are several additional axeas in which dynamic sealing is required, all of which are critical in the sense that leakage thereat a~fects the desired operation of the brake cylinder device~
5~
Fuxther, passageway are required in the body of the brake cylinder devi~e to conduct pres,sure bekween the con-trol valve device and brake cylinder operating components.
It is well known that the expense in the manufacture of a casting increases with the complexity in the configuration of these passages, as well as in the shape of the casting itself.
SUMMARY OF THE l~v~ ON
It is an object of the present invention to provide an improved brake cylinder device of khe combined brake ~ylinder and air reservoir t~pei in which the construction o the brake ~ylinder device is such as to reduce the number of dynamiz seals heretofore required, in order to reduce the cost o the brake cylinder device and further to attain im~
proved operating reliability and service life with less main-tenance.
Another objact of the invention i.s to design the brake cylinder device to employ a sLmplified main body cast~ng to which the brake cylinder control valve device may be direct-ly mounted and in which all of ~he passages conducting ~luidpressure between the control valve device and the brake cyl-inder pres~ure ~h~m~rs are contained.
In accordance with a preferred e~bodiment of the present invention, the brake cylinder devic~ comprises a main body, which may be a casting in which is formed a first cylinder having opposike end walls, each with an opening kherein.
Connected to the main body casting about the opening in the
IMPROVE~5ENTS I~ COMB IN13D AIR
RESERVOIR/BRAKE; CYLI.NDlE:R DEVICE
BACKGROU~D OF THE lN v~;N~ oN
United States Patent No. Re. 30,408, reissu~d September 30, 1981, to the assignee of the present applicationO dis-c~oses railway br~ke apparatus including a brake cylinder device and a control valve de~ice. The usual air reservoirs associated with conventional pneumatic brake e~uipment are eliminated in the disclosed apparatus in favor of storing the compresæed air within the brake cylinder de~ice it~elf~
The brake cylinder device embodi s a pair of tandem,connected pistons of unequal diameter, the larger piston cooperating with the brake cylinder body to form on the respective oppo~
site side~ of this piston two chambers that are charged with compressed air via the train brake pipe, and in w~ich chaD, bers the air required for use by the brake apparatus, includ-ing the brake c~linder device, is stored. The aforementioned control ~alv~ device operates in response to variations in the train brake pipe pressure to control the trans~er of air stored in the brake cylinder d~vice, so as to develop dif~er-ential forces across the respective pistons thereof, and thereby effect a brak~ application and brake release~
In addition to the typical packing cup type pressure seals as~ociated with the respective pistons of this brake c~linder deviceO there are several additional axeas in which dynamic sealing is required, all of which are critical in the sense that leakage thereat a~fects the desired operation of the brake cylinder device~
5~
Fuxther, passageway are required in the body of the brake cylinder devi~e to conduct pres,sure bekween the con-trol valve device and brake cylinder operating components.
It is well known that the expense in the manufacture of a casting increases with the complexity in the configuration of these passages, as well as in the shape of the casting itself.
SUMMARY OF THE l~v~ ON
It is an object of the present invention to provide an improved brake cylinder device of khe combined brake ~ylinder and air reservoir t~pei in which the construction o the brake ~ylinder device is such as to reduce the number of dynamiz seals heretofore required, in order to reduce the cost o the brake cylinder device and further to attain im~
proved operating reliability and service life with less main-tenance.
Another objact of the invention i.s to design the brake cylinder device to employ a sLmplified main body cast~ng to which the brake cylinder control valve device may be direct-ly mounted and in which all of ~he passages conducting ~luidpressure between the control valve device and the brake cyl-inder pres~ure ~h~m~rs are contained.
In accordance with a preferred e~bodiment of the present invention, the brake cylinder devic~ comprises a main body, which may be a casting in which is formed a first cylinder having opposike end walls, each with an opening kherein.
Connected to the main body casting about the opening in the
- 2 -t~
one end wall of the first cylinder i~ a second smaller cyl~ ¦
indar that i8 closed at one end and is coaxial with the fir~t cylinder. A larger and a smaller piston abutment is operatively dispo~ed in the respectiv~e first and second cyl-inders. The larger piston ab~LI,~el-t includes a hollow piston rod that extends through the opening in the other end wall of the ~irst cylinder, thus admitting atmospheric pressure to the area of the larger pi~ton wi*hin the area of the hollow piston rod. The first cylinder i~ ~eparated ~y the larger piston a~u~ nt into first and second chambers in which fluid under pressure i~ normally stored. The small~r piston ab~.,c.lt is provided with an elongated body that 2X
tends through the opening in the one end wall o~ the first cylinder for connection with the larger piston abutment, 80 as to ~r.~m a dual-connected piston assembly. Being ~o con-nected to the larger piston abutment~ which is guidably sup-ported in the ~irst cylinderO the smaller piston abutment is arranged in the ~econd cylinder, ~o that an annular space is formed between the elongated body of the smaller piston abut-ment and the ~cond cylinder. The annular space is delimitedat one end by the pressure h ad of the second cylinder and at the other end by a seal fixed to the main casting at the open-ing in the one end of the first cylinder. m is seal engages the elongated body of the smallex piston abu~ent where it ~5 passes through the opening for connection with the larger piæton~ thus providing a pressure s~al between the ~irst chamber and the annular space forming a third chamber to
one end wall of the first cylinder i~ a second smaller cyl~ ¦
indar that i8 closed at one end and is coaxial with the fir~t cylinder. A larger and a smaller piston abutment is operatively dispo~ed in the respectiv~e first and second cyl-inders. The larger piston ab~LI,~el-t includes a hollow piston rod that extends through the opening in the other end wall of the ~irst cylinder, thus admitting atmospheric pressure to the area of the larger pi~ton wi*hin the area of the hollow piston rod. The first cylinder i~ ~eparated ~y the larger piston a~u~ nt into first and second chambers in which fluid under pressure i~ normally stored. The small~r piston ab~.,c.lt is provided with an elongated body that 2X
tends through the opening in the one end wall o~ the first cylinder for connection with the larger piston abutment, 80 as to ~r.~m a dual-connected piston assembly. Being ~o con-nected to the larger piston abutment~ which is guidably sup-ported in the ~irst cylinderO the smaller piston abutment is arranged in the ~econd cylinder, ~o that an annular space is formed between the elongated body of the smaller piston abut-ment and the ~cond cylinder. The annular space is delimitedat one end by the pressure h ad of the second cylinder and at the other end by a seal fixed to the main casting at the open-ing in the one end of the first cylinder. m is seal engages the elongated body of the smallex piston abu~ent where it ~5 passes through the opening for connection with the larger piæton~ thus providing a pressure s~al between the ~irst chamber and the annular space forming a third chamber to
- 3 -'75~
which air is connected from the first chamber vi.a a contro~
~alve device to effect movement of the dual piston assembly to brake application position~
The ~ontrol val~e device is mounted to the brake cyl-inder at a mounting boss formed on t'he main ca~ting. The fixed location of ~he seal in the main casting, and the mounting of the control valve to the brakP cylinder at the main casting makes possible the use of a passa~e ext~n~;ng directly from the ~rake cylinder/control valve inter~ace to the third chamber to control pressuri~ation thexeof. In addition, the other passage~ transmitting pressure to and from the irst and second ~h- '-crs via the control valv~
device are also contained solely in the main casting~ Con-sequently, no passage~ are re~uired in the other parts of the brake cylindar device, which is therefore more econom~
ical to build.
In addition, a second pressure seal is provided between the hollow piston rod and the op~n~ ng in the other end of the first cylinder. The first and second pressure seals have equal sea~ing diameters, such that the atmospheric area o~ the larger piston within the hollow piston gulde is egual to the effective pres~ure area of the smaller piston within the third chamber. This arrangem~nt opti-mizes the sealing requirement and brak.ing force capability.
Furthermore, the elongated body of the smaller piston abutment may be tubular, with one end dosed~ pen end i3 connected to the laxger piston abu~nent to provide a '7~
~ourth pres~ure chamber within the elongated tubular body and is in fluid pressure commllnlcation with the irst pres-sure ch~mber. This pr~sur~ effectlve in the fourth rhamber acts on opposite and equal pressure areas of the ~maller and larger piston abubme~ts and thus exerts no net directional force on the dual piston asse~bly. Conseguently, an addi~
tional volume i~ gained for the storage of air supplied to the first chamber without any pressure force beiny developed on the dual piston a~embly in opposition to the pre~sure in th~ third chamber urging piston ~.lo~e...ent in the brake appli-cation direction.
It is also noteworthy that this internal pressure tPnds to force the two piston abutments apart and this tension tends to ~lo...oLe favorable aligr--~ts of the dual piston axis with the c~linder axis.
33RIEF DESCRIPTIO~ OF ~E DRl~WING
~ hese and other o~ects and attendant advantages will appear in the following more detailed ,p~rl~n~tion of the ~ single figure drawing showing a cross-section assembly view 0 of the brake cylinder de~ice of the present invention.
n~ TpTIo~ AND OPERATION
~ he pre~erred embodiment comprising an i.~ o~ed brake cylinder device la of the present i~vention includes a main body memher 1, which may be a ca~ting :Eorming a power cylin-der 2 with a pressure head 3 ha~iny a central opening 4formed therein, and a positioning cylilldex 5 ha~ing an in~
tegral pressure head 6 conne~ted, as by cap scr~ws, to pressure head 3 of the power cylinder~ so as to enclose the opening 4. Power cylinder 2 and posilioning cylinder 5 are coaxially axranged to receive a dual piston assembly compris ing a power piston 7 operatively disposed in power cylinder 2, and a positioning piston 8 operatively disposed in posi-tioning cylinder 5. An end cover 9 is co~nected, as by cap scxews 10 to the left~hand end of main casting 1, ~o aæ to surround posi~ in~ cylinder 5 and fo~m a pressure chamb~r 11 therebetween. Sealingly connected to the righ~hand end of main ca~tlng 1 by cap ~crews 12a is an end cover 12 having a central opening 13 through which a hollow rod 14 of power piston 7 projects. The connectior. of hollow rod 14 with p~wer piston 7 may ba ~y screw threads, as shown. Disposed within hollow rod 14 i~ a piston push rod 15 haviny one end lS pivotably engaged with an arcuately-shaped end piece 15a of power piston 7, and the opposite end projecting beyond the extremity of hollow rod 14 for connection with conventional brake apparatus.
Po~itioning piston 8 is in the form of an elongated, tu-bular body, one end being closed by a head 16 and the opposite end open. Head 16 forms on the right-hand side thereof a posi-tioning pressure area. The open end of tubular positioning piston 8 fits over a flange 17 that projects coA~;~lly from the left-hand face of power piston 7. Flange 17 and the open end of the positioning piston are fo~oed with aligned holes 18 in which roll pins 19 are pressed to connect th~ power piston and positioning piston together or movement as an integral unit. The tubular shape of positionir,g pis~on 8, being closed at one end~ forms a holl~w interior which, when connected with power piston 7, forms a pressure chamber 20 therabetween. In addition, positioning piston 8 is disposed within positioning cylinder 5 in spaced-apart relationship therew.ith, the space between the piston and cylinder form.ing a pressure chamber 21. A pressure type seal 22 i5 fixed to pxessure head 3 of main casting 1 by means of an annular clamp ring 23 and screws 24, so as to surround openin~ 4 and sealingly engage the periphery of the tubular bod~ comprising po~itioning piston 8. In the extreme leftward or brake re-lease position, as shown, seal ~2 engages the periphery o~
piskon 8 near its open end and maintains constant ~ealing engagement therewith during rightward l-.o~ .Pnt of the piston ass~mbly t~ward br~ke application position. The continuou~
sealing efect of seal 22, therefore, establishes and main-tains a fluid pressure seal between pre~sure ~h~e~ 20 and another pressure chamber 25 formed between pressure head 3 and the left-hand side of p~wer piston 7 to thereby delimit an application pressure area of power piston 7. Pressure chamber 25, on the other hand, is in constant fluid pressure c~mm~lnication with pressure chamber 20, by way of the through openings of the respective roll pins 13.
Formed between the right hand side of power piston 7 and end co~er 12 is still another pressure chamber 26, which delimits a release pressure area of powsr piston 7O A retu.rn ~pring 27 is disposed in chamber 26 with one end supported by -- 7 ~
~Lt~ 75~
end cover 12 and the other end acting on power piston 7 to urge ~he power piston toward its extreme leftward or brake release position. A pressure type packing cup seal 27a is arranged on piston 7 to engage power c~linder 2 and effect a fluid pressure seal between pressure chambers 25 and 26.
An annular element 27b, preferably made of a rubber or plastic material, lockingly engages piston 7 and seal 27a to secure the seal in place and to further serve as a cushion stop to esta~lish t,he ~xtreme leftward or release position of the piston asse~bly by engagement with pr~ssure head 3. In order to establish fluid pre~sure across the entire applica-tion pressure area of piston 7, the stop abutting portion of element 27b is fluted, as shown. An annular gu.ide ring 28~
preferably of a long wearing plastic material is arranged in the periphery of power piston 7 to also engage power cylinder 2 and therehy support the pswer pi~ton concentrically within the cylinder bore.
End cover 12 is furthQr formed with an inwardly extend-ing annular guide flange 29 in surrounding relationship with central opening 13 in end cover 12. Power piston 7 i~ pro-vided with an inwardly extending annular projection 30 that lies concentrically within the annulus of guide flange 29.
The end o projection 30 cooperates with an annular end plate 31 to support a pressure type packing cup seal 32 r as well as an annular guide ring 33, each of which engages the inner peri.phery of guide flange 29. Pac~ing cup 32 establishes a fluid pressure ~eal between pressure cha~ber 26 and an ~ 77 ~7~
atmospheric chi~mber.3~ fo~med within the annuli of the annu-lar guide flanga 29 and projection 3n. Chambar 34 delimits a return pressure area on power piston 7. Guide ring 33 aids guide ring 28 in supporting the piston assembly and maintain-ing concentricity of pistons 7 and 8 within their respectivecylinders 2 and 5 during i~xial movement of the piston asse~bly.
Within the annulus of opening 13 in pressure head 12 i~
a scraper ring 35 that engages the periphery of hollow rod 14.
An annular filter element 36 is carried in the i~nnular spac~
of chamber 34 between projection 30 and hv110~7 rod 14, with one end abutting a plurality of reinforcing ribs 37 of pro-jection 30. The ~ilter element 36 is held in place against ribs 37 by the end plate 31, which is provided with passages 39 tharein. A lock ring 40 abuts end plate 31 and is welded or otllexwi~e cli~mped to holl~w rod 14 to secure the filter and end plate for movement with power piston 7 and hollow rod 14. On the left_hand side of filter element 36 i6 provid~d a plurality of holes 41 in hollow rod 14. Surrounding the ex~
~ernal end of holl~w rod 14 in spaced-apaxt relat;o~.~hip with end cover 12 i~ a collar 42 that is he:Ld in place by scr~w pins 43 that are scr~w-threaded in col:Lax 42~ Screw pins 43 are formed with a pin-like end adapted to enter conforming holes in the end of the hollow rod 14 to lock the collar in place.
Main casting 1 further includes mounting bo~s 44, one face 44a of which is adapted to receive the corresponding face of a control valv~ 45 or the like~ ~ich may be of the 5~
type similar to the control valve device 6 shown and dis-closed in U.S. Patent Re. 30,40~ or similar to the control valve device disclosed in U.S. Paten-t NoO 4,339,155, both of which are assigned to the assignee of the present invention.
S In so arranging the brake cylin~er and control vaLve devices as a unit assembly, external pipin~ heretofore required be-tween the brake cylinder and control valve devices is elimi-nated. A plurality of passages 46, 47, 48, and 49 extend from face 44a of mounting boss 44 directly into -the respect ive pressure chambers 11, 21, 25, and 2~. Another face 44b oE boss ~4 is arranged to receive a branch pipe 51 of the train brake pipe, which may be mollnted to face 44b in a con-ventiGnaL manner. A passage 50 in boss 44 extends between the brake pipe mounting face 44b and the control valve mounting face 44aO Finally a cavity 52 is formed in boss 44 at the control valve mounting Eace ~a. When connected in place, control valve device 45 closes cavity 52 to for~ a pressure chamber to which air may be supplied via a passage 53 in control valve 45.
A train equipped with brake apparatus includins a brake cylinder device in accordance with the present invention re-quires no externaL reservoirs for the storage of compressed air, thereby further eliminating a need Eor external piping~
except a branch pipe between the train bxake pipe and the car control valve device. When the train is charged, air is con-nected from the brake pipe and the branch pipe 51 at each car to passage 50, from where it is connected to the control vaLve ~ 10-45 mounted on the brake cylinder at mounting boss 44. Con-txol ~alve 45 is conditioned by the increase of brake pipe pressure to charge via passages 46, 48) and 49 the various chambers 11, 25, and 26 of the brake cylind~r device, which cha~bers are utilized for the storage of air, as well as or providiny pneumatic braking power.
The effective area of power piston 7 subject to the pneumatic pressure in chamber 26 is e~lal to the effective area o~ piston 7 subject to the pneumatic pressur~ in chamber 25. With both cha~bers 25 and 26 being charged to the same pressure~ that is, the pxe sure of the brake pipe, there is conse~uently no net pneumatic pressure force exerted on the brake cylinder piston a~sembly in either direction due to the charging of chambers 25 and 26. Ch~mber 20 provides an addi-tional volume into which the air stored in cha~ber 25 can flow via the co~--nication provided by the conventional throu~h passages in the several roll pins 19~ This pneumatic pres~
sure in chamber 23 likewise exerts no nPt force on the piston aæsembly, due to the opposing effec~ive pressure areas of the respective positioning piston 8 and power piston 7 subject to the pnaumatic pressure in chamber 20 being equal, so that the forces counteract. Accordingly, return spring 27 is ef~ective to force the piston assembly to its laftward-most position in which cll~h;on stop 27a engages pressure head 3, ther~by as-tablishing brake release position of the respective positioning and power plstons comprising the dual piston assembly.
5~
At this point, it should ~e noted that the arrangement of the present invention eliminates the need for a dynamic seal to isolate the pneumatic pressure in chamber 25 from the righ-t-hand side of the positioning piston, as required in the arrangement disclosed in the aforementioned Reissue Pa-tent No. ~e. 30,408 and U. S. Patent No. 4,339,155. This is accomplished by connecting the power piston so that the leftward-acting force of pressure in chamber 20 acting on the positioning piston is balanced by a counteracting force of pressure in chamber 20 acting on the power piston.
When a brake application is desired, brake pipe pressure is reduced in a well-known manner, in response to which the car control valve device 45 operates to transfer air stored in chan~er 26 to chamber 21 via passages 49 and 47. It will be appreciated that the tubular-shaped positioning piston 8, in addition to providing an annular space between it and the positioning cylinder to form chamber 21, aLso permits pres-sure seal 22 to be mounted on the main casting 1 for contin-uous engagement with the tubular positioning piston through-out the length of its stroke. This, in turn, permits passage 47 in main casting 1 to enter the annular space comprising chamber 21 at a location just adjacent seal 22, in order to effect pressurization of chamber 21. Accordingly, passage 47 may be formed antirely within main casting 1, so as to enter chamber 21 directly from the face 44a of boss ~4~ This represen-ts a significant improvement over the aforementioned ` r3` ';
~ - 12 -arrangem~nt disclo~ed in U. S. Patent No. Re. 30~408, wh~rein the design of the positioning piston and locakion of the piston ~eal require~ a complex design and additional sealirlg to provide a pa~sage to the positioning cylinder in order to pressurize the face of positioning piston 8.
Pressuriæa~ion of chamber 21 with the pne~unatic pressure stored in chamber 26 develops sufficient force on positicning plston 8 to overcome the opposing ~orcs of return spring 27 and force the dual piston asse~bly to move in a rightward direction to brake application position, In order to ac om~
modate this ~ v~r..ent of the piston assembly, the control valve operates to allow the air in ~e reduc:lng volume of chamd~er 26 to equali~a into the ~ n~ing volume of cha~er~ 25 and 21 via passageæ 49 and 48.
In brake àpplication po~ition of the dual piston assembly, the volume of chamber 26 is m;n~m; ~e~ and the control valve operat~ to ter~in~te the transfer of air from ~ m~r 26 to chamber 21, whila concurrently venting the aix from chamber 26 in proportion to the reduction of brake pipe pr~sure.
Accordingly, a pres~ure dif~erential is establi~hed across power pi~ton 7 to exert an increased force on the dual piston assembly, in addition to the force already exerted by the pre~sure on posit;on; n~ piston 8, to obkain the desired braking force. The m~;mllm pressure reduction in chamber 2~ 26 is limited to a predetermined value by the control valve during a service brake application, thereby establishing a m~ximllm brake orce during a ~ull service brake application.
_ 13 ;
s~
During an emergency brake ap~lication, the brake pipe reduct7on occur~ at a rate that is greater than the rate of reduction during a æervice application. ~hi3 emerg2ncy rate of brake pipe reduction is sensed by the control valve, which operates ~o completely vent the air in ch~mber 26 of the brake cyl;n~er device and to concurrently connect the air in ch~mber 11 to chamber 21 ~ia passages 46 and 47, whereby the pressure in chambers 11 and 21 essentially equalize.
Accordingly, th~ pres~ure in chamber l:L acting on position-ing piston 8 increases during an emergency application con-currently with an increasad pressure d:ifferential created acros~ power piston 7 to thereby cause the dual piston as~em~
bly ouL~u~ force during an emergency brake applicàtion to ~ee~ the m~imllm ~u~ orce capable o~ being ganerated during a ~ull service brake application.
In a~plying the brakes during either a service or emer~
gancy brake application, it will be appreciated that the volume of the posit;oni ng cylinder is increased to a nominal value of only 140 cu. inO, due to the relatively small area of positioning piston 8, so that only a small am~unt of air is required to take up the brake rigging slack during move~
ment of the dual piston as~embly ~o braXe ap~lication posi-tion.
It will be further appreciated, that in effectins move-ment of the pi~ton assembly to brake application position,the volume of air in chamber 26 is decrea ed to a no~i n~ 1 value of 350 cu. in.~ ~o that in s~sequently providing ~ 1~ ...
output brake orce ~y venting chamber 26, the 108~ 0~ air i~
ml";m~
Thus, the m~x;m~m~l air loss duriny.a service brake appli-cation i~ limited to the co~bined volwme of air in cllambers 11 and 26 in applicat.ion pos~tion of the dual brake assembly, and i~ only slightly more during emerglancy. The pnaumatlc afficiency of thls type braXe cylindex d~vice requires such a small amount of air, therefore, that the brake cylinder device itself can ~e used to ~tore the necessary compre~d air without increasing the overall 9ize of the bxake c~llnder relative to conventional single piston brake cylinders or adding ~eparate reservoir volumes. In accordance with the present invention, the design of this highly efficlent hrake cylinder device is urther improved by min;m;7ing ~he re~uired nu~ber of dynamic pres~ure seal~ and s.implifying the con~truc-tion, particularly as to the main cast:ing which contains all the pa~age~ 46, 47, 48O 49, and 50.
During a relaase of elther a service or emergency appli-catlon, braXe pipe pressure i~ increased, such increase being ~ensed ~y the control valve, w~ich operates to exhaust the pres~ure in ch~mber 21 via passag~ 47 while rechar~ing cham~
bers 11~ 25, and 26, as previously exp:Lained, to rees~ablish a forc~ balance acros~ the piston assel~bly and thereby allow return sp.ring ~7 to move the pi~ton asse~bly lef~ward to brake release positiun.
During the a~orementioned applical:ion and release brak-ing cycle, ~;o~e~.ent o~` the power piston projection 30 and pressure seal 32 within guide flange 29, and l.-o~e-..ent of the power piston hollow rod 14 within opening 13 of end cover 12 produces a pumping ~tion, ~y which means the air in atmos pheric chamber 34 is expelled and drawn in alternately via holes 41 and the open end of hollow rod 14 leading to atmos phere. Air within atmospheric cha~ber 34 is conseguently forced ~hrough filter element 36 to y~event the accu~ulation of dirt on thê area o guide fl~nge 29 with which s~al 32 is engageable, ther3by im~roving the reliability and extending the service lifa of seal 32. Scrap~r ring 35 further acts in a well-kn~wn m~nner to clean the surface of hollow rod 14 of any dirt accumulated thereon when the hollow xod is extended during brake applications, thereby furt:her preventing the entry of dirt and foreign material into cha~ber 34.
~hen maint~n~n~e or rapair service is required, the dual piston assembly may ba removed from main casting ~ with end cover 12, as an integral unit by removi.ng cap screws 12a. As the cap screws ~re unscrewed, end cover 12 is forced b~ æpring 27 apart from its sealed connection with main casting 1 ~mtil the end cover at opening 13 engages the hollow rod collar 42, thareb~ caging spring 27. ~he dual piston assPmbly is then ~ble to be ~ d with end cover 12 to facilitate servicingO
Although the foregoing preferred embodiment has been described as employing ~wo intercormected pistonæ of differ-ent sized cylinders, it is readily apparent that the twopistons may take the shape of a single piston having differ~
ent pressure areas constituting the two pistons 7 and 8.
For example ~ an alterna~e e~:~odiment of the invention contemplates an actuator assembl~ in which three dynam.ic pressure seals are arranged between the body of a ~ingle cylinder and a sinyle piston of the brake cyllnder device.
~he first seal separat~s the cylinder into an application .
portion and a release portion on opposite sides of the piston.
~he second seal acts between the ~ylinder and a sleeve-like projection on one side of the piston to separate the appli cation portion into an application cha~ber and a positioning chamber. Th~ application chamber delimits a first pressure area on the one side of the piston and the posi tioning chamber delimits a second pressure area al60 0~ the one side of the piston. The sleeve-like projection may be closed at its and, in w~ich case the area of the closed end constitutes the second pressure area and the chamber within the sleeve_like projection is ~omml-n;~ted with the application chamber. The third seal acts between the cylinder and a push rod of the piston to form a r~lease cha~ber that delimits a third pres~
sure area on the other side of the piston that is preferably e~ual to the first pressure area on the one side of the piston, in order to maintain the piston pressure balanced by 1uid normally stored in the application and release chambers in release portion of the piston. The push rod may be hollow to orm a retuxn chamber on the same side of th~ piston as the release chamber. This return chamber clelimits a fourth pres-sure area on this same side of the piston that is preferabl~
equal to the second pxessure area on the one side of th~
piston O
which air is connected from the first chamber vi.a a contro~
~alve device to effect movement of the dual piston assembly to brake application position~
The ~ontrol val~e device is mounted to the brake cyl-inder at a mounting boss formed on t'he main ca~ting. The fixed location of ~he seal in the main casting, and the mounting of the control valve to the brakP cylinder at the main casting makes possible the use of a passa~e ext~n~;ng directly from the ~rake cylinder/control valve inter~ace to the third chamber to control pressuri~ation thexeof. In addition, the other passage~ transmitting pressure to and from the irst and second ~h- '-crs via the control valv~
device are also contained solely in the main casting~ Con-sequently, no passage~ are re~uired in the other parts of the brake cylindar device, which is therefore more econom~
ical to build.
In addition, a second pressure seal is provided between the hollow piston rod and the op~n~ ng in the other end of the first cylinder. The first and second pressure seals have equal sea~ing diameters, such that the atmospheric area o~ the larger piston within the hollow piston gulde is egual to the effective pres~ure area of the smaller piston within the third chamber. This arrangem~nt opti-mizes the sealing requirement and brak.ing force capability.
Furthermore, the elongated body of the smaller piston abutment may be tubular, with one end dosed~ pen end i3 connected to the laxger piston abu~nent to provide a '7~
~ourth pres~ure chamber within the elongated tubular body and is in fluid pressure commllnlcation with the irst pres-sure ch~mber. This pr~sur~ effectlve in the fourth rhamber acts on opposite and equal pressure areas of the ~maller and larger piston abubme~ts and thus exerts no net directional force on the dual piston asse~bly. Conseguently, an addi~
tional volume i~ gained for the storage of air supplied to the first chamber without any pressure force beiny developed on the dual piston a~embly in opposition to the pre~sure in th~ third chamber urging piston ~.lo~e...ent in the brake appli-cation direction.
It is also noteworthy that this internal pressure tPnds to force the two piston abutments apart and this tension tends to ~lo...oLe favorable aligr--~ts of the dual piston axis with the c~linder axis.
33RIEF DESCRIPTIO~ OF ~E DRl~WING
~ hese and other o~ects and attendant advantages will appear in the following more detailed ,p~rl~n~tion of the ~ single figure drawing showing a cross-section assembly view 0 of the brake cylinder de~ice of the present invention.
n~ TpTIo~ AND OPERATION
~ he pre~erred embodiment comprising an i.~ o~ed brake cylinder device la of the present i~vention includes a main body memher 1, which may be a ca~ting :Eorming a power cylin-der 2 with a pressure head 3 ha~iny a central opening 4formed therein, and a positioning cylilldex 5 ha~ing an in~
tegral pressure head 6 conne~ted, as by cap scr~ws, to pressure head 3 of the power cylinder~ so as to enclose the opening 4. Power cylinder 2 and posilioning cylinder 5 are coaxially axranged to receive a dual piston assembly compris ing a power piston 7 operatively disposed in power cylinder 2, and a positioning piston 8 operatively disposed in posi-tioning cylinder 5. An end cover 9 is co~nected, as by cap scxews 10 to the left~hand end of main casting 1, ~o aæ to surround posi~ in~ cylinder 5 and fo~m a pressure chamb~r 11 therebetween. Sealingly connected to the righ~hand end of main ca~tlng 1 by cap ~crews 12a is an end cover 12 having a central opening 13 through which a hollow rod 14 of power piston 7 projects. The connectior. of hollow rod 14 with p~wer piston 7 may ba ~y screw threads, as shown. Disposed within hollow rod 14 i~ a piston push rod 15 haviny one end lS pivotably engaged with an arcuately-shaped end piece 15a of power piston 7, and the opposite end projecting beyond the extremity of hollow rod 14 for connection with conventional brake apparatus.
Po~itioning piston 8 is in the form of an elongated, tu-bular body, one end being closed by a head 16 and the opposite end open. Head 16 forms on the right-hand side thereof a posi-tioning pressure area. The open end of tubular positioning piston 8 fits over a flange 17 that projects coA~;~lly from the left-hand face of power piston 7. Flange 17 and the open end of the positioning piston are fo~oed with aligned holes 18 in which roll pins 19 are pressed to connect th~ power piston and positioning piston together or movement as an integral unit. The tubular shape of positionir,g pis~on 8, being closed at one end~ forms a holl~w interior which, when connected with power piston 7, forms a pressure chamber 20 therabetween. In addition, positioning piston 8 is disposed within positioning cylinder 5 in spaced-apart relationship therew.ith, the space between the piston and cylinder form.ing a pressure chamber 21. A pressure type seal 22 i5 fixed to pxessure head 3 of main casting 1 by means of an annular clamp ring 23 and screws 24, so as to surround openin~ 4 and sealingly engage the periphery of the tubular bod~ comprising po~itioning piston 8. In the extreme leftward or brake re-lease position, as shown, seal ~2 engages the periphery o~
piskon 8 near its open end and maintains constant ~ealing engagement therewith during rightward l-.o~ .Pnt of the piston ass~mbly t~ward br~ke application position. The continuou~
sealing efect of seal 22, therefore, establishes and main-tains a fluid pressure seal between pre~sure ~h~e~ 20 and another pressure chamber 25 formed between pressure head 3 and the left-hand side of p~wer piston 7 to thereby delimit an application pressure area of power piston 7. Pressure chamber 25, on the other hand, is in constant fluid pressure c~mm~lnication with pressure chamber 20, by way of the through openings of the respective roll pins 13.
Formed between the right hand side of power piston 7 and end co~er 12 is still another pressure chamber 26, which delimits a release pressure area of powsr piston 7O A retu.rn ~pring 27 is disposed in chamber 26 with one end supported by -- 7 ~
~Lt~ 75~
end cover 12 and the other end acting on power piston 7 to urge ~he power piston toward its extreme leftward or brake release position. A pressure type packing cup seal 27a is arranged on piston 7 to engage power c~linder 2 and effect a fluid pressure seal between pressure chambers 25 and 26.
An annular element 27b, preferably made of a rubber or plastic material, lockingly engages piston 7 and seal 27a to secure the seal in place and to further serve as a cushion stop to esta~lish t,he ~xtreme leftward or release position of the piston asse~bly by engagement with pr~ssure head 3. In order to establish fluid pre~sure across the entire applica-tion pressure area of piston 7, the stop abutting portion of element 27b is fluted, as shown. An annular gu.ide ring 28~
preferably of a long wearing plastic material is arranged in the periphery of power piston 7 to also engage power cylinder 2 and therehy support the pswer pi~ton concentrically within the cylinder bore.
End cover 12 is furthQr formed with an inwardly extend-ing annular guide flange 29 in surrounding relationship with central opening 13 in end cover 12. Power piston 7 i~ pro-vided with an inwardly extending annular projection 30 that lies concentrically within the annulus of guide flange 29.
The end o projection 30 cooperates with an annular end plate 31 to support a pressure type packing cup seal 32 r as well as an annular guide ring 33, each of which engages the inner peri.phery of guide flange 29. Pac~ing cup 32 establishes a fluid pressure ~eal between pressure cha~ber 26 and an ~ 77 ~7~
atmospheric chi~mber.3~ fo~med within the annuli of the annu-lar guide flanga 29 and projection 3n. Chambar 34 delimits a return pressure area on power piston 7. Guide ring 33 aids guide ring 28 in supporting the piston assembly and maintain-ing concentricity of pistons 7 and 8 within their respectivecylinders 2 and 5 during i~xial movement of the piston asse~bly.
Within the annulus of opening 13 in pressure head 12 i~
a scraper ring 35 that engages the periphery of hollow rod 14.
An annular filter element 36 is carried in the i~nnular spac~
of chamber 34 between projection 30 and hv110~7 rod 14, with one end abutting a plurality of reinforcing ribs 37 of pro-jection 30. The ~ilter element 36 is held in place against ribs 37 by the end plate 31, which is provided with passages 39 tharein. A lock ring 40 abuts end plate 31 and is welded or otllexwi~e cli~mped to holl~w rod 14 to secure the filter and end plate for movement with power piston 7 and hollow rod 14. On the left_hand side of filter element 36 i6 provid~d a plurality of holes 41 in hollow rod 14. Surrounding the ex~
~ernal end of holl~w rod 14 in spaced-apaxt relat;o~.~hip with end cover 12 i~ a collar 42 that is he:Ld in place by scr~w pins 43 that are scr~w-threaded in col:Lax 42~ Screw pins 43 are formed with a pin-like end adapted to enter conforming holes in the end of the hollow rod 14 to lock the collar in place.
Main casting 1 further includes mounting bo~s 44, one face 44a of which is adapted to receive the corresponding face of a control valv~ 45 or the like~ ~ich may be of the 5~
type similar to the control valve device 6 shown and dis-closed in U.S. Patent Re. 30,40~ or similar to the control valve device disclosed in U.S. Paten-t NoO 4,339,155, both of which are assigned to the assignee of the present invention.
S In so arranging the brake cylin~er and control vaLve devices as a unit assembly, external pipin~ heretofore required be-tween the brake cylinder and control valve devices is elimi-nated. A plurality of passages 46, 47, 48, and 49 extend from face 44a of mounting boss 44 directly into -the respect ive pressure chambers 11, 21, 25, and 2~. Another face 44b oE boss ~4 is arranged to receive a branch pipe 51 of the train brake pipe, which may be mollnted to face 44b in a con-ventiGnaL manner. A passage 50 in boss 44 extends between the brake pipe mounting face 44b and the control valve mounting face 44aO Finally a cavity 52 is formed in boss 44 at the control valve mounting Eace ~a. When connected in place, control valve device 45 closes cavity 52 to for~ a pressure chamber to which air may be supplied via a passage 53 in control valve 45.
A train equipped with brake apparatus includins a brake cylinder device in accordance with the present invention re-quires no externaL reservoirs for the storage of compressed air, thereby further eliminating a need Eor external piping~
except a branch pipe between the train bxake pipe and the car control valve device. When the train is charged, air is con-nected from the brake pipe and the branch pipe 51 at each car to passage 50, from where it is connected to the control vaLve ~ 10-45 mounted on the brake cylinder at mounting boss 44. Con-txol ~alve 45 is conditioned by the increase of brake pipe pressure to charge via passages 46, 48) and 49 the various chambers 11, 25, and 26 of the brake cylind~r device, which cha~bers are utilized for the storage of air, as well as or providiny pneumatic braking power.
The effective area of power piston 7 subject to the pneumatic pressure in chamber 26 is e~lal to the effective area o~ piston 7 subject to the pneumatic pressur~ in chamber 25. With both cha~bers 25 and 26 being charged to the same pressure~ that is, the pxe sure of the brake pipe, there is conse~uently no net pneumatic pressure force exerted on the brake cylinder piston a~sembly in either direction due to the charging of chambers 25 and 26. Ch~mber 20 provides an addi-tional volume into which the air stored in cha~ber 25 can flow via the co~--nication provided by the conventional throu~h passages in the several roll pins 19~ This pneumatic pres~
sure in chamber 23 likewise exerts no nPt force on the piston aæsembly, due to the opposing effec~ive pressure areas of the respective positioning piston 8 and power piston 7 subject to the pnaumatic pressure in chamber 20 being equal, so that the forces counteract. Accordingly, return spring 27 is ef~ective to force the piston assembly to its laftward-most position in which cll~h;on stop 27a engages pressure head 3, ther~by as-tablishing brake release position of the respective positioning and power plstons comprising the dual piston assembly.
5~
At this point, it should ~e noted that the arrangement of the present invention eliminates the need for a dynamic seal to isolate the pneumatic pressure in chamber 25 from the righ-t-hand side of the positioning piston, as required in the arrangement disclosed in the aforementioned Reissue Pa-tent No. ~e. 30,408 and U. S. Patent No. 4,339,155. This is accomplished by connecting the power piston so that the leftward-acting force of pressure in chamber 20 acting on the positioning piston is balanced by a counteracting force of pressure in chamber 20 acting on the power piston.
When a brake application is desired, brake pipe pressure is reduced in a well-known manner, in response to which the car control valve device 45 operates to transfer air stored in chan~er 26 to chamber 21 via passages 49 and 47. It will be appreciated that the tubular-shaped positioning piston 8, in addition to providing an annular space between it and the positioning cylinder to form chamber 21, aLso permits pres-sure seal 22 to be mounted on the main casting 1 for contin-uous engagement with the tubular positioning piston through-out the length of its stroke. This, in turn, permits passage 47 in main casting 1 to enter the annular space comprising chamber 21 at a location just adjacent seal 22, in order to effect pressurization of chamber 21. Accordingly, passage 47 may be formed antirely within main casting 1, so as to enter chamber 21 directly from the face 44a of boss ~4~ This represen-ts a significant improvement over the aforementioned ` r3` ';
~ - 12 -arrangem~nt disclo~ed in U. S. Patent No. Re. 30~408, wh~rein the design of the positioning piston and locakion of the piston ~eal require~ a complex design and additional sealirlg to provide a pa~sage to the positioning cylinder in order to pressurize the face of positioning piston 8.
Pressuriæa~ion of chamber 21 with the pne~unatic pressure stored in chamber 26 develops sufficient force on positicning plston 8 to overcome the opposing ~orcs of return spring 27 and force the dual piston asse~bly to move in a rightward direction to brake application position, In order to ac om~
modate this ~ v~r..ent of the piston assembly, the control valve operates to allow the air in ~e reduc:lng volume of chamd~er 26 to equali~a into the ~ n~ing volume of cha~er~ 25 and 21 via passageæ 49 and 48.
In brake àpplication po~ition of the dual piston assembly, the volume of chamber 26 is m;n~m; ~e~ and the control valve operat~ to ter~in~te the transfer of air from ~ m~r 26 to chamber 21, whila concurrently venting the aix from chamber 26 in proportion to the reduction of brake pipe pr~sure.
Accordingly, a pres~ure dif~erential is establi~hed across power pi~ton 7 to exert an increased force on the dual piston assembly, in addition to the force already exerted by the pre~sure on posit;on; n~ piston 8, to obkain the desired braking force. The m~;mllm pressure reduction in chamber 2~ 26 is limited to a predetermined value by the control valve during a service brake application, thereby establishing a m~ximllm brake orce during a ~ull service brake application.
_ 13 ;
s~
During an emergency brake ap~lication, the brake pipe reduct7on occur~ at a rate that is greater than the rate of reduction during a æervice application. ~hi3 emerg2ncy rate of brake pipe reduction is sensed by the control valve, which operates ~o completely vent the air in ch~mber 26 of the brake cyl;n~er device and to concurrently connect the air in ch~mber 11 to chamber 21 ~ia passages 46 and 47, whereby the pressure in chambers 11 and 21 essentially equalize.
Accordingly, th~ pres~ure in chamber l:L acting on position-ing piston 8 increases during an emergency application con-currently with an increasad pressure d:ifferential created acros~ power piston 7 to thereby cause the dual piston as~em~
bly ouL~u~ force during an emergency brake applicàtion to ~ee~ the m~imllm ~u~ orce capable o~ being ganerated during a ~ull service brake application.
In a~plying the brakes during either a service or emer~
gancy brake application, it will be appreciated that the volume of the posit;oni ng cylinder is increased to a nominal value of only 140 cu. inO, due to the relatively small area of positioning piston 8, so that only a small am~unt of air is required to take up the brake rigging slack during move~
ment of the dual piston as~embly ~o braXe ap~lication posi-tion.
It will be further appreciated, that in effectins move-ment of the pi~ton assembly to brake application position,the volume of air in chamber 26 is decrea ed to a no~i n~ 1 value of 350 cu. in.~ ~o that in s~sequently providing ~ 1~ ...
output brake orce ~y venting chamber 26, the 108~ 0~ air i~
ml";m~
Thus, the m~x;m~m~l air loss duriny.a service brake appli-cation i~ limited to the co~bined volwme of air in cllambers 11 and 26 in applicat.ion pos~tion of the dual brake assembly, and i~ only slightly more during emerglancy. The pnaumatlc afficiency of thls type braXe cylindex d~vice requires such a small amount of air, therefore, that the brake cylinder device itself can ~e used to ~tore the necessary compre~d air without increasing the overall 9ize of the bxake c~llnder relative to conventional single piston brake cylinders or adding ~eparate reservoir volumes. In accordance with the present invention, the design of this highly efficlent hrake cylinder device is urther improved by min;m;7ing ~he re~uired nu~ber of dynamic pres~ure seal~ and s.implifying the con~truc-tion, particularly as to the main cast:ing which contains all the pa~age~ 46, 47, 48O 49, and 50.
During a relaase of elther a service or emergency appli-catlon, braXe pipe pressure i~ increased, such increase being ~ensed ~y the control valve, w~ich operates to exhaust the pres~ure in ch~mber 21 via passag~ 47 while rechar~ing cham~
bers 11~ 25, and 26, as previously exp:Lained, to rees~ablish a forc~ balance acros~ the piston assel~bly and thereby allow return sp.ring ~7 to move the pi~ton asse~bly lef~ward to brake release positiun.
During the a~orementioned applical:ion and release brak-ing cycle, ~;o~e~.ent o~` the power piston projection 30 and pressure seal 32 within guide flange 29, and l.-o~e-..ent of the power piston hollow rod 14 within opening 13 of end cover 12 produces a pumping ~tion, ~y which means the air in atmos pheric chamber 34 is expelled and drawn in alternately via holes 41 and the open end of hollow rod 14 leading to atmos phere. Air within atmospheric cha~ber 34 is conseguently forced ~hrough filter element 36 to y~event the accu~ulation of dirt on thê area o guide fl~nge 29 with which s~al 32 is engageable, ther3by im~roving the reliability and extending the service lifa of seal 32. Scrap~r ring 35 further acts in a well-kn~wn m~nner to clean the surface of hollow rod 14 of any dirt accumulated thereon when the hollow xod is extended during brake applications, thereby furt:her preventing the entry of dirt and foreign material into cha~ber 34.
~hen maint~n~n~e or rapair service is required, the dual piston assembly may ba removed from main casting ~ with end cover 12, as an integral unit by removi.ng cap screws 12a. As the cap screws ~re unscrewed, end cover 12 is forced b~ æpring 27 apart from its sealed connection with main casting 1 ~mtil the end cover at opening 13 engages the hollow rod collar 42, thareb~ caging spring 27. ~he dual piston assPmbly is then ~ble to be ~ d with end cover 12 to facilitate servicingO
Although the foregoing preferred embodiment has been described as employing ~wo intercormected pistonæ of differ-ent sized cylinders, it is readily apparent that the twopistons may take the shape of a single piston having differ~
ent pressure areas constituting the two pistons 7 and 8.
For example ~ an alterna~e e~:~odiment of the invention contemplates an actuator assembl~ in which three dynam.ic pressure seals are arranged between the body of a ~ingle cylinder and a sinyle piston of the brake cyllnder device.
~he first seal separat~s the cylinder into an application .
portion and a release portion on opposite sides of the piston.
~he second seal acts between the ~ylinder and a sleeve-like projection on one side of the piston to separate the appli cation portion into an application cha~ber and a positioning chamber. Th~ application chamber delimits a first pressure area on the one side of the piston and the posi tioning chamber delimits a second pressure area al60 0~ the one side of the piston. The sleeve-like projection may be closed at its and, in w~ich case the area of the closed end constitutes the second pressure area and the chamber within the sleeve_like projection is ~omml-n;~ted with the application chamber. The third seal acts between the cylinder and a push rod of the piston to form a r~lease cha~ber that delimits a third pres~
sure area on the other side of the piston that is preferably e~ual to the first pressure area on the one side of the piston, in order to maintain the piston pressure balanced by 1uid normally stored in the application and release chambers in release portion of the piston. The push rod may be hollow to orm a retuxn chamber on the same side of th~ piston as the release chamber. This return chamber clelimits a fourth pres-sure area on this same side of the piston that is preferabl~
equal to the second pxessure area on the one side of th~
piston O
Claims (43)
1. A fluid pressure actuator device comprising:
(a) a cylinder including application and release por-tions;
(b) a piston slidably operable in said cylinder between application and release positions, said piston in-cluding a push rod having one end engageable with said piston and the other end arranged to operate working apparatus;
(c) first seal means engaging said piston and said cyl-inder for separating said cylinder into said respec-tive application and release portions on opposite sides of said piston;
(d) second seal means for separating said application portion into an application chamber that delimits an application pressure area on one side of said piston and a positioning chamber that delimits a positioning pressure area of said piston on the same side thereof as said application pressure area;
(e) third seal means for forming a release chamber in said release portion of said cylinder that delimits a release pressure area of said piston on the side opposite said one side and for establishing a return pressure area on said opposite side of said piston external to said release chamber;
(f) means for introducing fluid under pressure to said release chamber to urge said piston toward said release position;
(g) means for introducing fluid under pressure to said application chamber to urge said piston toward said application position; and (h) means for introducing fluid under pressure to said positioning chamber to urge said piston toward said application position.
(a) a cylinder including application and release por-tions;
(b) a piston slidably operable in said cylinder between application and release positions, said piston in-cluding a push rod having one end engageable with said piston and the other end arranged to operate working apparatus;
(c) first seal means engaging said piston and said cyl-inder for separating said cylinder into said respec-tive application and release portions on opposite sides of said piston;
(d) second seal means for separating said application portion into an application chamber that delimits an application pressure area on one side of said piston and a positioning chamber that delimits a positioning pressure area of said piston on the same side thereof as said application pressure area;
(e) third seal means for forming a release chamber in said release portion of said cylinder that delimits a release pressure area of said piston on the side opposite said one side and for establishing a return pressure area on said opposite side of said piston external to said release chamber;
(f) means for introducing fluid under pressure to said release chamber to urge said piston toward said release position;
(g) means for introducing fluid under pressure to said application chamber to urge said piston toward said application position; and (h) means for introducing fluid under pressure to said positioning chamber to urge said piston toward said application position.
2. A fluid pressure actuator as recited in claim 1, further comprising means for urging said piston toward said release position.
3. A fluid pressure actuator as recited in claim 1, wherein the effective areas of said application and release pressure areas are generally equal.
4. A fluid pressure actuator as recited in claim 3, further comprising spring means for urging said piston toward said release position.
5. A fluid pressure actuator as recited in claim 1, wherein the effective areas of said return pressure area and said positioning pressure area are generally equal.
6. A fluid pressure actuator as recited in claim 1, wherein said second and third seal mean are annular dynamic pressure seals having generally equal sealing diameters.
7. A fluid pressure actuator as recited in claim 1, wherein a cylindrical portion is formed on said one side of said piston and projects axially therefrom, said second seal means being an annular dynamic seal fixed on said application portion of said cylinder so as to engage said cylindrical portion of said piston along the periphery thereof during movement of said piston between said application and release.
positions.
positions.
8. A fluid pressure actuator as recited in claim 7, wherein said cylindrical portion of said piston is tubular in shape.
9. A fluid pressure actuator as recited in claim 8, wherein said cylindrical portion is closed on the protecting end and said projecting end provides said positioning pres-sure area of said piston.
10. A fluid pressure actuator as recited in claim 9, wherein said tubular-shaped cylindrical portion forms a hollow chamber, said hollow chamber being in fluid communi-cation with said application chamber.
11. A fluid pressure actuator as recited in claim 10, wherein the effective pressure area of said closed end of said cylindrical portion within said hollow chamber is equal to the effective pressure area of said one side of said piston within said hollow chamber.
12. A fluid pressure actuator as recited in claim 1, wherein said first, second, and third seal means comprise dynamic pressure seals.
13. A fluid pressure actuator as recited in claim 1 wherein said push rod comprises a tubular member that extends from said opposite side of said piston toward said release portion of said cylinder, and said third seal means is an annular dynamic seal engageable with said release portion of said cylinder and said tubular member of said push rod.
14. A fluid pressure actuator as recited in claim 13 wherein said tubular member of said push rod provides an atmospheric chamber within the annulus thereof that delimits said return pressure area on said piston, said push rod further comprising:
(a) a hollow rod disposed within said atmospheric cham-ber, said hollow rod being connected at one end thereof to said opposite side of said piston and having the other end projecting through an opening in said release portion of said cylinder, and (b) a solid push rod disposed within the annulus of said hollow rod, said solid push rod at one end thereof having abutting engagement with said oppo-site side of said piston.
(a) a hollow rod disposed within said atmospheric cham-ber, said hollow rod being connected at one end thereof to said opposite side of said piston and having the other end projecting through an opening in said release portion of said cylinder, and (b) a solid push rod disposed within the annulus of said hollow rod, said solid push rod at one end thereof having abutting engagement with said oppo-site side of said piston.
15. A fluid pressure actuator as recited in claim 7, wherein said cylinder further comprises:
(a) a mounting boss having a face portion, and (b) said application portion of said cylinder having said fixed seal cooperating with said cylindrical portion of said piston to form an annular chamber between said positioning chamber and said applica-tion chamber, and said means for introducing fluid under pressure to said positioning chamber includes at least one straight passage opening at one end at said face portion and opening at the other end there-of into said annular chamber on the side of said fixed seal adjacent said positioning chamber.
(a) a mounting boss having a face portion, and (b) said application portion of said cylinder having said fixed seal cooperating with said cylindrical portion of said piston to form an annular chamber between said positioning chamber and said applica-tion chamber, and said means for introducing fluid under pressure to said positioning chamber includes at least one straight passage opening at one end at said face portion and opening at the other end there-of into said annular chamber on the side of said fixed seal adjacent said positioning chamber.
16. A fluid pressure actuator device comprising:
(a) a first hollow cylindrical member having first and second end walls, each said end wall having an open-ing therethrough;
(b) a second hollow cylindrical member having one end closed and the other end open, said second cylindri-cal member being mounted at said open end thereof to said first end wall in surrounding relationship with said opening therethrough;
(c) a first piston abutment operably disposed within said first cylindrical member and cooperating with said first end wall to form a first pressure chamber on one side of said first piston abutment in which fluid under pressure is normally stored, said first piston abutment including means projecting through said opening in said second end wall for forming, in cooperation with said second end wall, a second pressure chamber on the other side of said first piston abutment, in which said second chamber fluid under pressure is normally stored, said other side of said first piston abutment without said second pressure chamber being subject to atmospheric pres-sure;
(d) a second piston abutment operably disposed within said second hollow cylindrical member so as to form in cooperation therewith a third pressure chamber between said closed end of said second cylindrical member and one side of said second piston abutment, said second piston abutment being connected with said first piston abutment at said one side thereof;
(e) first seal means for providing a fluid pressure seal between said first and third pressure chambers; and (f) second seal means in said opening in said second end wall for providing a fluid pressure seal between said second pressure chamber and atmosphere, said first and second seal means having sealing faces of equal diameter, whereby the effective pressure area of said one side of said second piston abutment is generally equal to the effective area of said other side of said first piston abutment subject to said atmospheric pressure.
(a) a first hollow cylindrical member having first and second end walls, each said end wall having an open-ing therethrough;
(b) a second hollow cylindrical member having one end closed and the other end open, said second cylindri-cal member being mounted at said open end thereof to said first end wall in surrounding relationship with said opening therethrough;
(c) a first piston abutment operably disposed within said first cylindrical member and cooperating with said first end wall to form a first pressure chamber on one side of said first piston abutment in which fluid under pressure is normally stored, said first piston abutment including means projecting through said opening in said second end wall for forming, in cooperation with said second end wall, a second pressure chamber on the other side of said first piston abutment, in which said second chamber fluid under pressure is normally stored, said other side of said first piston abutment without said second pressure chamber being subject to atmospheric pres-sure;
(d) a second piston abutment operably disposed within said second hollow cylindrical member so as to form in cooperation therewith a third pressure chamber between said closed end of said second cylindrical member and one side of said second piston abutment, said second piston abutment being connected with said first piston abutment at said one side thereof;
(e) first seal means for providing a fluid pressure seal between said first and third pressure chambers; and (f) second seal means in said opening in said second end wall for providing a fluid pressure seal between said second pressure chamber and atmosphere, said first and second seal means having sealing faces of equal diameter, whereby the effective pressure area of said one side of said second piston abutment is generally equal to the effective area of said other side of said first piston abutment subject to said atmospheric pressure.
17. A fluid pressure actuator device, as recited in claim 16, wherein there is formed a fourth pressure chamber between the other side of said second piston abutment and said one side of said first piston abutment, said fourth pressure chamber having fluid pressure communication with said first pressure chamber.
18. A fluid pressure actuator device, as recited in claim claim 17, wherein said one side of said first piston abut-ment within said fourth chamber and said other side of said second piston abutment have generally equal effective pres-sure areas.
19. A fluid pressure actuator device, as recited in claims 16, 17, or 18, wherein said second piston abutment is cylindrical.
20. A fluid pressure actuator device, as recited in claim 17, wherein said second piston abutment comprises an elongated tubular body with one end projecting through said opening in said first end wall for connection with said first piston abutment and the other end closed to form said fourth chamber within said tubular body.
21. A fluid pressure actuator device, as recited in claim 20, wherein said tubular body cooperates with said second cylindrical member and said opening in said first end wall to form an annular space comprising at least a portion of said third chamber, said annular space being delimited by said first seal means.
22. A fluid pressure actuator device, as recited in claim 21, wherein said first seal means is fixed on said first end wall about said opening therethrough for effecting sealing engagement with said tubular body to provide said fluid pressure seal between said first and third chambers.
23. A fluid pressure actuator device, as recited in claim 22, further comprising a main body in which is formed said first cylindrical member integral with said first end wall, said main body further forming a mounting boss having a first face portion and a passage, one end of said passage opening at said first face portion and the other end of said passage opening into said annular space at said opening in said first end wall.
24. A fluid pressure actuator device, as recited in claim 23, wherein said passage opens into said annular space at a point adjacent said first seal means on the same side thereof as said third chamber.
25. A fluid pressure actuator device, as recited in claim 20, further comprising:
(a) said first piston abutment having a flange extend-ing from said one side of said first piston abut-ment into said tubular body of said second piston abutment; and (b) pin means for securing said tubular body of said second piston abutment to said flange to provide said connection between said first and second piston abutments.
(a) said first piston abutment having a flange extend-ing from said one side of said first piston abut-ment into said tubular body of said second piston abutment; and (b) pin means for securing said tubular body of said second piston abutment to said flange to provide said connection between said first and second piston abutments.
26. A fluid pressure actuator device, as recited in claim 17, wherein said second end wall includes an annular guide flange formed about said opening in said second end wall and extending into said second chamber, and said pro-jecting means comprises:
(a) said first piston abutment having an annular pro-jection extending from said other side thereof through said opening in said second end wall, in telescopic relationship with said annular guide flange, said annular guide flange and said annular projection forming a fifth chamber within the annu-lus thereof, said fifth chamber being open to atmos-phere via said opening in said second end wall; and (b) said second seal means being provided between said annular guide flange and said annular projection for effecting said fluid pressure seal between said second chamber and atmosphere.
(a) said first piston abutment having an annular pro-jection extending from said other side thereof through said opening in said second end wall, in telescopic relationship with said annular guide flange, said annular guide flange and said annular projection forming a fifth chamber within the annu-lus thereof, said fifth chamber being open to atmos-phere via said opening in said second end wall; and (b) said second seal means being provided between said annular guide flange and said annular projection for effecting said fluid pressure seal between said second chamber and atmosphere.
27. A fluid pressure actuator device, as recited in claim 26, wherein said projecting means further comprises rod means projecting through said opening in said second end wall for connection with a brake apparatus, said rod means including:
(a) a hollow rod member having one end connected to said other side of said first piston abutment within said fifth chamber, the other end projecting through said opening in said second end wall, and at least one breather port in the wall of said hollow rod member via which said fifth chamber is vented to atmosphere;
and (b) a piston push rod disposed within said hollow rod member with one end thereof abutting said other end of said first piston abutment and its other end pro-jecting from within said hollow rod member to pro-vide for said connection of said rod means with said brake apparatus.
(a) a hollow rod member having one end connected to said other side of said first piston abutment within said fifth chamber, the other end projecting through said opening in said second end wall, and at least one breather port in the wall of said hollow rod member via which said fifth chamber is vented to atmosphere;
and (b) a piston push rod disposed within said hollow rod member with one end thereof abutting said other end of said first piston abutment and its other end pro-jecting from within said hollow rod member to pro-vide for said connection of said rod means with said brake apparatus.
28. A fluid pressure actuator device, as recited in claim 27, further comprising a filter mounted in the annular space between said hollow rod member and said annular pro-jecting member of said first piston abutment.
29. A fluid pressure actuator device, as recited in claim 27, further comprising:
(a) a return spring in said second chamber between said first piston abutment and said second end wall, said second end wall being removably secured to said first cylinder; and (b) stop means on the outer periphery of said hollow rod member external of said second end wall for caging said return spring during removal of said second end wall from said first cylinder member to permit removal of said piston abutments and said second end wall as a unit.
(a) a return spring in said second chamber between said first piston abutment and said second end wall, said second end wall being removably secured to said first cylinder; and (b) stop means on the outer periphery of said hollow rod member external of said second end wall for caging said return spring during removal of said second end wall from said first cylinder member to permit removal of said piston abutments and said second end wall as a unit.
30. A fluid pressure actuator device, as recited in claim 23, further comprising a cover member fixed to said main body so as to enclose said second cylinder in spaced relationship therewith to provide a fifth chamber in which fluid under pressure is normally stored.
31. A fluid pressure actuator device comprising:
(a) a main body including (i) a first cylinder with first and second end walls, each said end wall having an opening therethrough;
(ii) a seal fixed in said opening of said first end wall; and (iii) a mounting boss having a first face por-tion and a first passage with one end of said first passage opening at said first face portion;
(b) a second cylinder having one end closed and the other end open, said second cylinder being mounted at said open end to said first end wall in sur-rounding relationship with said opening thereof;
(c) first and second piston abutments operably dis-posed in the respective first and second cylinders, said first piston abutment including rod means pro-jecting through said opening in said second end wall for connection with a brake device;
(d) said first piston abutment cooperating with said first end wall to form a first pressure chamber between said first end wall and one side of said first piston abutment, and with said second end wall to form a second pressure chamber between said second end wall and the other side of said first piston abutment, said first and second chambers being normally stored with fluid under pressure;
(e) said second piston abutment having an elongated body projecting through said opening in said first end wall for connection with said one side of said first piston abutment, said elongated body coopera-ting with said second cylinder and with said opening in said first end wall to form an annular space com-prising a third pressure chamber, whereby said seal is engageable with the periphery of said elongated body to effect a fluid pressure seal between said first and third chambers; said first passage having its other end opening into said annular space at said opening in said first end wall adjacent said annular seal on the same side thereof as said third chamber.
(a) a main body including (i) a first cylinder with first and second end walls, each said end wall having an opening therethrough;
(ii) a seal fixed in said opening of said first end wall; and (iii) a mounting boss having a first face por-tion and a first passage with one end of said first passage opening at said first face portion;
(b) a second cylinder having one end closed and the other end open, said second cylinder being mounted at said open end to said first end wall in sur-rounding relationship with said opening thereof;
(c) first and second piston abutments operably dis-posed in the respective first and second cylinders, said first piston abutment including rod means pro-jecting through said opening in said second end wall for connection with a brake device;
(d) said first piston abutment cooperating with said first end wall to form a first pressure chamber between said first end wall and one side of said first piston abutment, and with said second end wall to form a second pressure chamber between said second end wall and the other side of said first piston abutment, said first and second chambers being normally stored with fluid under pressure;
(e) said second piston abutment having an elongated body projecting through said opening in said first end wall for connection with said one side of said first piston abutment, said elongated body coopera-ting with said second cylinder and with said opening in said first end wall to form an annular space com-prising a third pressure chamber, whereby said seal is engageable with the periphery of said elongated body to effect a fluid pressure seal between said first and third chambers; said first passage having its other end opening into said annular space at said opening in said first end wall adjacent said annular seal on the same side thereof as said third chamber.
32. A fluid pressure actuator device, as recited in claim 31, wherein said elongated body is cylindrical in shape.
33. A fluid pressure actuator device, as recited in Claim 31, further comprising a cover member fixed to said main body in surrounding, spaced-apart relationship with said second cylinder to provide a fourth chamber in which fluid under pressure is normally stored.
34. A fluid pressure actuator device, as recited in claim 33, wherein said mounting boss further includes second, third, and fourth passages having one end opening at said first face portion and the other end opening into said first, second, and fourth chambers, respectively.
35. Brake apparatus comprising:
(a) a brake cylinder device including (i) a main body having (1) a first cylinder with first and second end walls, each said end wall having an opening there-through;
(2) a seal fixed in said opening of said first end wall; and (3) a mounting boss having first and second face portions; and a first, second, third, and fourth passage, each said passage having one end opening at said first face portion;
(ii) a second cylinder having one end closed and and the other end open, said second cyl-inder being mounted at said open end to said first end wall in surrounding rela-tionship with said opening thereof;
(iii) first and second piston abutments operably disposed in the respective first and second cylinders, said first piston abutment in-cluding rod means projecting through said opening in said second end wall for connec-tion with a brake device;
(iv) said first piston abutment cooperating with said first end wall to form a first pres-sure chamber between said first and wall and one side of said first piston abutment, and with said second end wall to form a second pressure chamber between said second end wall and the other side of said first piston abutment, said first and second cham-bers being normally stored with fluid under pressure, (v) said second piston abutment having an elon-gated body projecting through said opening in said first end wall for connection with said one side of said first piston abutment, said elongated body cooperating with said second cylinder and with said opening in said first end wall to form an annular space comprising a third pressure chamber whereby said seal is engageable with the periphery of said elongated body to effect a fluid pressure seal between said first and third chambers; and (vi) said first, second and third passages having their other end opening into said first, second and third chambers, respec-tively, and said fourth passage having its other end opening at said second face por-tion;
(b) a fluid pressure conduit connected to said mounting boss at said second face portion to conduct fluid pressure to and from said fourth passage; and (c) valve means mounted to said brake cylinder device at said first face portion for controlling the flow of fluid pressure via said first, second, and third passages in response to variation of fluid pressure in said conduit.
(a) a brake cylinder device including (i) a main body having (1) a first cylinder with first and second end walls, each said end wall having an opening there-through;
(2) a seal fixed in said opening of said first end wall; and (3) a mounting boss having first and second face portions; and a first, second, third, and fourth passage, each said passage having one end opening at said first face portion;
(ii) a second cylinder having one end closed and and the other end open, said second cyl-inder being mounted at said open end to said first end wall in surrounding rela-tionship with said opening thereof;
(iii) first and second piston abutments operably disposed in the respective first and second cylinders, said first piston abutment in-cluding rod means projecting through said opening in said second end wall for connec-tion with a brake device;
(iv) said first piston abutment cooperating with said first end wall to form a first pres-sure chamber between said first and wall and one side of said first piston abutment, and with said second end wall to form a second pressure chamber between said second end wall and the other side of said first piston abutment, said first and second cham-bers being normally stored with fluid under pressure, (v) said second piston abutment having an elon-gated body projecting through said opening in said first end wall for connection with said one side of said first piston abutment, said elongated body cooperating with said second cylinder and with said opening in said first end wall to form an annular space comprising a third pressure chamber whereby said seal is engageable with the periphery of said elongated body to effect a fluid pressure seal between said first and third chambers; and (vi) said first, second and third passages having their other end opening into said first, second and third chambers, respec-tively, and said fourth passage having its other end opening at said second face por-tion;
(b) a fluid pressure conduit connected to said mounting boss at said second face portion to conduct fluid pressure to and from said fourth passage; and (c) valve means mounted to said brake cylinder device at said first face portion for controlling the flow of fluid pressure via said first, second, and third passages in response to variation of fluid pressure in said conduit.
36. Brake apparatus recited in claim 35, further comprising:
(a) a return spring acting on said other side of said first piston abutment to urge movement thereof toward a brake release position;
(b) said one and said other sides of said first piston abutment having equal effective pressure areas sub-ject to the fluid under pressure stored in said first and second chambers; and (c) said valve means being operative in response to charging of said fluid pressure conduit for venting said third passage and for establishing fluid pres-sure communication of said fourth passage with said first and second passages to provide said supply of fluid under pressure stored in said first and second chambers, and operative in response to a reduction of fluid pressure in said fluid pressure conduit during a service brake application for terminating said venting of said third passage and for estab-lishing fluid pressure communication of said second passage with said third and first passages to thereby exert a fluid pressure force on said second piston abutment to effect movement of said tandem-connected piston abutments from said brake release position to a brake application position in opposition to said release spring, and for subsequently interrupting said communication of said second passage with said third and first passages and venting said second passage to establish a braking force corresponding to the resultant fluid pressure differential between said first and second chambers.
(a) a return spring acting on said other side of said first piston abutment to urge movement thereof toward a brake release position;
(b) said one and said other sides of said first piston abutment having equal effective pressure areas sub-ject to the fluid under pressure stored in said first and second chambers; and (c) said valve means being operative in response to charging of said fluid pressure conduit for venting said third passage and for establishing fluid pres-sure communication of said fourth passage with said first and second passages to provide said supply of fluid under pressure stored in said first and second chambers, and operative in response to a reduction of fluid pressure in said fluid pressure conduit during a service brake application for terminating said venting of said third passage and for estab-lishing fluid pressure communication of said second passage with said third and first passages to thereby exert a fluid pressure force on said second piston abutment to effect movement of said tandem-connected piston abutments from said brake release position to a brake application position in opposition to said release spring, and for subsequently interrupting said communication of said second passage with said third and first passages and venting said second passage to establish a braking force corresponding to the resultant fluid pressure differential between said first and second chambers.
37. A brake cylinder device, as recited in claim 36, further comprising:
(a) a cover member fixed to said main body so as to enclose said second cylinder in spaced relation-ship therewith to provide a fifth chamber in which fluid under pressure is stored; and (b) said mounting boss further comprising a fifth passage having one end opening at said first face portion and the other end opening into said fifth chamber, said valve means being further operative in response to an increase of pressure in said fluid pressure conduit for establishing fluid pressure com-munication between said fourth and fifth passages to provide said stored fluid under pressure in said fifth chamber, and operative in response to a re-duction of fluid pressure in said fluid pressure conduit during an emergency brake application for interrupting said communication of fluid pressure between said fourth and fifth passages and for establishing fluid pressure communication between said fifth and said third passages, whereby said braking force during said emergency brake appli-cation is greater than during said service brake application.
(a) a cover member fixed to said main body so as to enclose said second cylinder in spaced relation-ship therewith to provide a fifth chamber in which fluid under pressure is stored; and (b) said mounting boss further comprising a fifth passage having one end opening at said first face portion and the other end opening into said fifth chamber, said valve means being further operative in response to an increase of pressure in said fluid pressure conduit for establishing fluid pressure com-munication between said fourth and fifth passages to provide said stored fluid under pressure in said fifth chamber, and operative in response to a re-duction of fluid pressure in said fluid pressure conduit during an emergency brake application for interrupting said communication of fluid pressure between said fourth and fifth passages and for establishing fluid pressure communication between said fifth and said third passages, whereby said braking force during said emergency brake appli-cation is greater than during said service brake application.
38. A brake cylinder device, as recited in claims 21, 31, or 35, wherein said openings through said first and said second end walls are coaxial.
39. A brake cylinder device, as recited in claims 16, 31, or 35, further comprising third seal means for effecting a fluid pressure seal between said first and second chambers.
40. A fluid pressure actuator device, as recited in claim 24, wherein said second end wall includes an annular guide flange formed about said opening in said second end wall and extending into said second chamber, and said pro-jecting means comprises:
(a) said first piston abutment having an annular pro-jection extending from said other side thereof through said opening in said second end wall, in telescopic relationship with said annular guide flange, said annular guide flange and said annular projection forming a fifth chamber within the annu-lus thereof, said fifth chamber being open to atmos-phere via said opening in said second end wall; and (b) said second seal means being provided between said annular guide flange and said annular projection for effecting said fluid pressure seal between said second chamber and atmosphere.
(a) said first piston abutment having an annular pro-jection extending from said other side thereof through said opening in said second end wall, in telescopic relationship with said annular guide flange, said annular guide flange and said annular projection forming a fifth chamber within the annu-lus thereof, said fifth chamber being open to atmos-phere via said opening in said second end wall; and (b) said second seal means being provided between said annular guide flange and said annular projection for effecting said fluid pressure seal between said second chamber and atmosphere.
41. A brake cylinder device, as recited in claim 31, wherein said one and said other sides of said first piston abutment have equal effective pressure areas subject to the fluid under pressure stored in said first and second chambers.
42. A brake cylinder device, as recited in claim 16, 31, or 35, wherein said first piston abutment further in-cludes means for guidably supporting said first piston abutment in said first cylinder.
43. A fluid pressure actuator device, as recited in claim 40, wherein said projecting means further comprises rod means projecting through said opening in said second end wall for connection with a brake apparatus, said rod means including:
(a) a hollow rod member having one end connected to said other side of said first piston abutment within said fifth chamber, the other end pro-jecting through said opening in said second end wall, and at least one breather port in the wall of said hollow rod member via which said fifth chamber is vented to atmosphere; and (b) a piston push rod disposed within said hollow rod member with one end thereof abutting said other end of said first piston abutment and its other end projecting from within said hollow rod member to provide for said connection of said rod means with said brake apparatus.
(a) a hollow rod member having one end connected to said other side of said first piston abutment within said fifth chamber, the other end pro-jecting through said opening in said second end wall, and at least one breather port in the wall of said hollow rod member via which said fifth chamber is vented to atmosphere; and (b) a piston push rod disposed within said hollow rod member with one end thereof abutting said other end of said first piston abutment and its other end projecting from within said hollow rod member to provide for said connection of said rod means with said brake apparatus.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000414085A CA1198758A (en) | 1982-10-25 | 1982-10-25 | Combined air reservoir/brake cylinder device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000414085A CA1198758A (en) | 1982-10-25 | 1982-10-25 | Combined air reservoir/brake cylinder device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1198758A true CA1198758A (en) | 1985-12-31 |
Family
ID=4123817
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000414085A Expired CA1198758A (en) | 1982-10-25 | 1982-10-25 | Combined air reservoir/brake cylinder device |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1198758A (en) |
-
1982
- 1982-10-25 CA CA000414085A patent/CA1198758A/en not_active Expired
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| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |