Master cylinder

Abstract

A master cylinder has a housing with a bore therein having a tapered section located between first and second compensator ports connecting the bore to a reservoir. A sleeve locates first and second lip seals adjacent the first and second compensator ports, respectively. A first piston engages the first lip seal and a second piston engages the second lip seal to define first and second chambers within the bore. A bearing member which surrounds the first piston engages the sleeve and holds the first and second lip seals in a stationary position within the bore. Thereafter, an input member moves the first and second pistons past the first and second lip seals to pressurize the fluid in the first and second chambers and provides fluid pressure responsive devices with an operational input through first and second outlet ports in the housing.

I claim: .[.1. A master cylinder comprising: 
     
        through said first and second outlet ports..]. 2. The master cylinder, as recited in claim .[.1.]. .Iadd.32.Iaddend., wherein said second cylindrical body further includes: a plurality of openings located in said first diameter section to allow fluid to freely flow between the tapered bore and the first chamber with   
     
     
        relative movement between the first and second cylindrical members. 3. The master cylinder, as recited in claim .[.1.]. .Iadd.32.Iaddend., further including: a wall for separating the reservoir into first and second compartments;   a diaphragm having a first bead on its peripheral surface and a second bead, said first and second beads having grooves thereon; and   cover means having first and second ribs thereon located in said grooves for biasing said first and second beads against said housing and wall to   
     
     
        seal said first and second chambers from the surrounding environment. 4. The master cylinder, as recited in claim .[.1.]. .Iadd.32.Iaddend., wherein said second cylindrical body further includes: a second bore that extends through said first diameter section and into said second diameter section, said first spring being located in said bore and said first cylindrical member telescoping into said second bore to   
     
     
        provide a compact unitary structure. 5. The master cylinder, as recited in claim 4, wherein said second cylindrical body further includes: a plurality of openings located in said first diameter section to allow fluid to freely flow between the second bore and the first chamber with   
     
     
        relative movement between the first and second cylinder members. 6. The master cylinder, as recited in claim 5, further including: a wall for separating the reservoir into first and second compartments;   a diaphragm having a first bead on its peripheral surface and a second bead, said first and second beads having grooves thereon; and   cover means having first and second ribs thereon located in said grooves for biasing said first and second beads against said housing and wall to   
     
     
        seal said first and second chambers from the surrounding environment. 7. A master cylinder comprising: a housing having a tapered bore therein, said housing having first and second compensator ports for connecting said tapered bore to a fluid reservoir and first and second outlet ports connected to fluid pressure responsive devices;   a sleeve located in said tapered bore;   first and second seals located in said tapered bore, said first and second seals each having a plurality of radial grooves for establishing definite flow paths between the first and second compensator ports and the tapered bore.Iadd., said sleeve holding said second seal in a stationary position.Iaddend.;   bearing means located in said tapered bore for holding said first .[.and second seals.]. .Iadd.seal .Iaddend.in a stationary position;   piston means having first and second cylindrical members located in said tapered bore by said bearing means and .[.engaging.]. said first and second seals, respectively, to define first and second chambers in said tapered bore adjacent said first and second outlet ports, each of said first and second cylindrical members having a .[.fluted.]. section located on the end thereof for defining an extension between said definite flow path and the first and second chambers, .[.said second cylindrical member having a first diameter section and a second diameter section, said first diameter section having a lip on the peripheral surface thereof for engaging.]. said sleeve .[.to hold.]. .Iadd.holding .Iaddend.said second .[.diameter section.]. .Iadd.cylindrical member .Iaddend.in the axial center of the tapered bore in the second chamber; and   input means responsive to an input force for moving the first and second cylindrical members past said first and second seals to interrupt communication between the reservoir and the tapered bore through said definite flow paths and extension thereof to allow further movement of the first and second cylindrical members to pressurize the fluid in the first and second chambers and thereby supply the fluid pressure responsive devices with operational fluid through said first and second outlet ports.   
     
     
        . The master cylinder, as recited in claim 7 further including: a first spring located between said first and second cylindrical members to establish the size of said first chambers; and   a second spring located between .[.said.]. .Iadd.a .Iaddend.lip on the first cylindrical member and said sleeve member for urging said first and second cylindrical members out of said first and second chambers toward a   
     
     
        rest position. 9. The master cylinder, as recited in claim 8 wherein said second cylindrical body further includes: a second bore that extends through .[.said.]. .Iadd.a .Iaddend.first diameter section and into .[.said.]. .Iadd.a .Iaddend.second diameter section, said first spring being located in said second bore and said first cylindrical member telescoping into said second bore to provide a   
     
     
        compact unitary structure. 10. The master cylinder, as recited in claim 9 wherein said second cylindrical body further includes: a plurality of openings located in said first diameter section to allow fluid to freely flow between the second bore and the first chamber with   
     
     
        relative movement between the first and second cylindrical members. 11. The master cylinder, as recited in claim 7 wherein said sleeve .[.member.]. includes: a plurality of openings through which fluid is communicated to said first   
     
     
        outlet port. 12. The master cylinder, as recited in claim 7 wherein said first cylindrical member telescopes into said second cylindrical member to provide a compact unitary structure. .[.13. A master cylinder comprising: a housing having a tapered bore therein, said housing having first and second compensator ports for connecting said tapered bore to a reservoir and first and second outlet ports;   a sleeve located in said tapered bore;   first and second seals positioned in said tapered bore adjacent said first and second compensator ports, each of the first and second seals having a radial groove therein for defining a definite flow path between the compensator ports and the tapered bore;   bearing means engaging said sleeve to hold said first and second seals in a stationary position within said bore;   piston means having first and second cylindrical members located in said sleeve and engaging said first and second seals to define first and second chambers in the tapered bore, said second cylindrical member having a first diameter section and a second diameter section, said first diameter section engaging said sleeve to hold said second diameter section in the axial center of the tapered bore in the second chamber; and   input means responsive to an input force for moving the first and second cylindrical members past said first and second seals to interrupt communication between the reservoir and the tapered bore through said definite flow paths to allow further movement of the first and second cylindrical members to pressurize the fluid in the first and second chambers and thereby supply the fluid pressure responsive devices with   
     
     
        operational fluid through said first and second outlet ports..]. 14. The master cylinder, as recited in claim .[.13.]. .Iadd.33 .Iaddend.further including: a first spring located between said first and second cylindrical members to establish the size of said first chamber; and   a second spring located between said sleeve member and .[.the first diameter section of.]. said second cylindrical member for urging said first and second .Iadd.cylindrical .Iaddend.members out of the first and   
     
     
        second chambers toward a rest position. 15. The master cylinder, as recited in claim 14 wherein said first and second cylindrical members each include: a fluted section located on the end of said first and second cylindrical members for defining an extension between said definite flow path and the   
     
     
        first and second chambers. 16. The master cylinder as recited in claim 15 wherein said second cylindrical member further includes: a .[.second.]. .Iadd.blind .Iaddend.bore that extends through .[.said.]. .Iadd.a .Iaddend.first diameter section and into .[.said.]. .Iadd.a .Iaddend.second diameter section, said first spring being located in said .[.second.]. .Iadd.blind .Iaddend.bore and said first cylindrical member telescoping into said .[.second.]. .Iadd.blind .Iaddend.bore to provide a   
     
     
        compact unitary structure. 17. The master cylinder, as recited in claim 16 wherein said second cylindrical body further includes: a plurality of openings located in said first diameter section to allow fluid to freely flow between the .[.second.]. .Iadd.blind .Iaddend.bore and the first chamber with relative movement between the first and second   
     
     
        cylindrical members. 18. A master cylinder comprising: a housing having a stepped bore therein, said housing having first and second inlet ports for connecting said stepped bore to a reservoir and first and second outlet ports;   .[.a.]. sleeve .Iadd.means .Iaddend.located in said stepped bore;   first and second seals positioned in said stepped bore adjacent said first and second inlet ports;   bearing means .[.engaging.]. .Iadd.cooperating with .Iaddend.said sleeve .Iadd.means .Iaddend.to hold said first and second seals in a stationary position within said stepped bore;   passage means between said first .[.and second seals.]. .Iadd.seal .Iaddend.and bearing means .Iadd.and said second seal and sleeve means .Iaddend.for defining definite flow paths between the first and second inlet ports and the stepped bore;   piston means having first and second cylindrical members located in said sleeve .Iadd.means .Iaddend.and engaging said first and second seals to define first and second chambers in the stepped bore, .[.said second cylindrical member having a first diameter section and a second diameter section, said first diameter section engaging.]. said sleeve .[.to hold.]. .Iadd.means holding .Iaddend.said second .[.diameter section.]. .Iadd.cylindrical member .Iaddend.in substantially the axial center of the stepped bore in the second chamber; and   input means responsive to an input force for moving the first and second cylindrical members past said first and second seals to interrupt communication between the reservoir and the stepped bore through said definite flow paths to allow further movement of the first and second cylindrical members to pressurize the fluid in the first and second chambers and thereby supply the fluid pressure responsive devices with   
     
     
        operational fluid through said first and second outlet ports. 19. The master cylinder, as recited in claim 18 further including: a first spring located between said first and second cylindrical member to establish the size of said first chamber; and   a second spring located between said sleeve member and .[.the first diameter section of.]. said second cylindrical member for urging said first and second members out of the first and second chambers toward a   
     
     
        rest position. 20. The master cylinder, as recited in claim 19 wherein said first and second cylindrical members each include: a fluted section located on the end of said first and second cylindrical members for defining an extension between said definite flow path and the   
     
     
        first and second chambers. 21. The master cylinder as recited in claim 20 wherein said second cylindrical member further includes: a .[.second.]. .Iadd.blind .Iaddend.bore that extends .[.through said.]. .Iadd.from a .Iaddend.first diameter section and into .[.said.]. .Iadd.a .Iaddend.second diameter section, said first spring being located in said .[.second.]. .Iadd.blind .Iaddend.bore and said first cylindrical member telescoping into said .[.second.]. .Iadd.blind .Iaddend.bore to provide a   
     
     
        compact unitary structure. 22. The master cylinder, as recited in claim 21 wherein said second cylindrical body further includes: a plurality of openings located in said first diameter section to allow fluid to freely flow between the second bore and the first chamber with relative movement between the first and second cylindrical members. .Iadd. 23. A master cylinder comprising:   a housing having a bore therein, said housing having first and second inlet ports for connecting said bore to a reservoir and first and second outlet ports;   first and second pistons located in said bore to define first and second chambers;   first and second seals located in said bore for engaging said first and second pistons, respectively;   a sleeve located in said bore between said first and second seals for guiding said first piston in said bore;   a bearing member for guiding said second piston in said bore, said bearing member fixedly positioning said sleeve in said bore and the first seal between a shoulder in the bore and a first end of the sleeve and the second seal between a shoulder on the sleeve and a first end of the bearing member,   said first seal having grooves located adjacent said first end of said sleeve and said second seal having grooves located adjacent said first end of said bearing member, to establish a definite flow path between the reservoir and said first and second chambers through said first and second ports, respectively; and   an input member responsive to an input force for moving said first and second piston with respect to said first and second seals to pressurize fluid in said first and second chamber for distribution to said first and second outlet ports. .Iaddend..Iadd. 24. The master cylinder, as recited in claim 23 wherein, said sleeve means includes:   a plurality of openings through which fluid in said second chamber is   
     
     
        communicated to said second outlet port. .Iaddend..Iadd. 25.  The master cylinder, as recited in claim 23, wherein said first and second pistons each include a fluted section on the end thereof, said fluted section providing an extension for said definite flow path to assure free communication between the reservoir and first and second chambers in the absence of an input force on said input member. .Iaddend..Iadd. 26. A master cylinder comprising: a housing having a bore therein, said housing having first and second inlet ports for communicating said bore with a reservoir and first and second outlet ports;   a first seal located in said bore;   a first piston having a first cylindrical body located in said bore and engaging said first seal, said first cylindrical body having a first end and a second end, said first cylindrical body having an outwardly projecting lip adjacent said first end, a blind bore extending from said first end toward said second end and a plurality of substantially radial openings extending from the blind bore through said first cylindrical body;   sleeve means having a cylindrical member with a first end and a second end, said sleeve means being restrained in said bore, said first end engaging said first seal to substantially fix the position of said first seal within said bore, said first seal, first piston and housing defining a first chamber within said bore, said first chamber communicating with said first inlet port via a first passage between said first seal, said sleeve means and said second end of said cylindrical body to allow fluid in said reservoir to flow into said first chamber, said first chamber communicating with said first outlet port, said cylindrical member having a bearing surface that contacts said first piston to hold the first piston to hold the first piston in substantially the axial center of said first chamber and a shoulder adjacent a second end;   a second seal that engages said shoulder adjacent said second end of the cylindrical member of said sleeve means to substantially fix its position within said bore;   a second piston having a second cylindrical body located in said bore and engaging said second seal, said second cylindrical body having a first end and a second end, said first end extending into said blind bore of said first piston, said first piston, first seal, housing, second seal, and second piston defining a second chamber within said bore, said second chamber communicating with said second inlet via a second passage between said second end of said cylindrical body and said second seal to allow fluid in said reservoir to flow into said second chamber, said blind bore communicating with said second chamber through said plurality of openings in said first piston, said second chamber communicating with said second outlet port; and   an input member responsive to an input signal for moving said first and second pistons with respect to said first and second seals to interrupt fluid communication between said reservoir and said first and second chambers and thereafter pressurizing the fluid in the first and second chambers for providing said first and second outlet ports with pressurized   
     
     
        fluid. .Iaddend..Iadd. 27.  The master cylinder, as recited in claim 26 wherein said master cylinder further includes: a first spring located between said first end of said sleeve and said lip on said first cylindrical body for returning said first piston to a first rest position in the absence of an input signal on said input member. .Iaddend..Iadd. 28. The master cylinder, as recited in claim 27 wherein said master cylinder further includes:   a second spring located in said blind bore of said first cylindrical body for urging said second piston to a second rest position in the absence of an input signal on said input member. .Iaddend..Iadd. 29. A master cylinder comprising:   a housing having a bore therein, said housing having first and second inlet ports for connecting said bore to a reservoir and first and second outlet ports;   first and second seals located in said bore adjacent said first and second inlet ports respectively;   a sleeve located in said bore for substantially defining fixed positions for said first and second seals;   a first piston located in said bore and engaging said first seal to substantially define a first chamber, said first piston having a first end and a second end, said first chamber being connected to said first outlet port;   a second piston located in said bore and engaging said second seal to substantially define a second chamber, said second piston having a first end and a second end, said second chamber being connected to said second outlet port;   a first passage located between said first end of said first piston and said first seal;   a second passage located between said first end of said second piston and said second seal;   retainer means for holding said second piston in said bore;   spring means for urging said first and second pistons toward said retainer means to allow substantially unrestricted fluid communication between said reservoir and said first and second chambers through said first and second passages, respectively; and   input means responsive to an input force for moving said first and second pistons to terminate fluid communication through said first and second passages and thereafter generate fluid pressure in said first and second chamber for distribution to said first and second outlet ports.   
     
     
        .Iaddend..Iadd. 30.  The master cylinder, as recited in claim 29 wherein said first piston includes: a blind bore that extends from said second end toward said first end, said blind bore receiving at least a portion of said second piston; and   a radial outward flange adjacent said second end. .Iaddend. .Iadd. 31. The master cylinder, as recited in claim 30 wherein said spring means includes:   a first spring located between said sleeve and said radial flange for urging said first end of said first piston toward said first seal whereby fluid communication is established through said first passage; and   a second spring located in said blind bore for urging said first end of said second piston toward said second seal whereby fluid communication is established through said second passage. .Iaddend. .Iadd. 32. A master cylinder comprising:   a housing having a tapered bore therein, said housing having first and second compensator ports for connecting said tapered bore to a fluid reservoir and first and second outlet ports connected to fluid pressure responsive devices;   a sleeve member located in said tapered bore having a plurality of openings through which fluid is communicated to said first outlet port;   first and second seals associated with said sleeve member;   bearing means engaging said sleeve member, said bearing means and sleeve member holding said first and second seals in a substantially stationary position within said bore while defining flow paths from the reservoir into said tapered bore;   piston means having a first cylindrical member located in said tapered bore by said bearing means and a second cylindrical member being located in said tapered bore by a lip on said sleeve member, said first and second cylindrical members engaging said first and second seals, respectively, and cooperating with said housing to define first and second chambers adjacent said first and second outlet ports, respectively, each of said first and second cylindrical members having a fluted section located on the end thereof for defining an extension for said flow paths to allow fluid communication to the first and second chambers, said second cylindrical member having a first diameter section and a second diameter section, said first diameter section having a lip on the peripheral surface thereof for engaging said sleeve member to hold the second diameter section in substantially the center of said bore in said second chamber;   a first spring located between said first and second cylindrical members to establish the size of said first chamber;   a second spring located between said first cylindrical member and said sleeve member for urging said first and second cylindrical members out of said first and second chambers toward a rest position; and   input means responsive to an input force for moving said piston means past said seals to interrupt communication between the reservoir and the bore and pressurizing the fluid in said first and second chambers to supply the fluid pressure responsive devices with an operational fluid pressure through said first and second outlet ports. .Iaddend..Iadd. 33. A master cylinder comprising:   a housing having a tapered bore therein, said housing having first and second compensator ports for connecting said tapered bore to a reservoir and first and second outlet ports;   a sleeve located in said tapered bore;   first and second seals positioned in said tapered bore adjacent said first and second compensator ports;   bearing means cooperating with said sleeve to hold said first and second seals in a substantially stationary position within said bore and to define flow paths adjacent each of said first and second seals to connect the compensator ports with the tapered bore;   piston means having first and second cylindrical members located in said sleeve and engaging said first and second seals to define first and second chambers in the tapered bore, said sleeve holding said second cylindrical member in the axial center of the tapered bore in the second chamber; and   input means responsive to an input force for moving the first and second cylindrical members past said first and second seals to interrupt communication between the reservoir and the tapered bore through said definite flow paths to allow further movement of the first and second cylindrical members to pressurize the fluid in the first and second chambers and thereby supply the fluid pressure responsive devices with operational fluid through said first and second outlet ports. .Iaddend.