US3731487A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Master cylinder
Assignee: Old Carco LLC
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Filing: 1971-08-23
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Granted: 1973-05-08
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Expires: 1991-08-23
Abstract
Abstract Master cylinder for automotive hydraulic brake system. Two pistons are slideable in a bore in a cylinder body and provide two chambers which communicate with front and rear brake circuits. Two stops are provided for limiting the outward movement of the pistons.
Inventors
- 👤 N Beyer
- 👤 J Zuk
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 15:27
CPC Classifications
B; B60; B60T; B60T11/00; B60T11/10; B60T11/16; B60T11/20
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
585 words
A master cylinder comprising a body having a first reservoir and a second reservoir, a bore extending through said body adjacent said reservoirs, a first piston movable in said bore, a second piston movable in said bore, the space between said first piston and second piston defining a first chamber, the space between the second piston and the end of the bore defining a second chamber, said body having outlets from said chambers adapted to be connected to hydraulic lines attached to front and rear sets of brakes, ports normally connecting said chambers to said reservoirs, an actuating rod means extending from one end of said first piston outwardly from said bore, connecting rod means extending from the other end of said first piston toward said second piston, said connecting rod means having an enlarged head portion, an annular ring-shaped member having an internal dimension smaller than the diameter of said enlarged head portion, the ring-shaped member being between said enlarged head and said second piston, a ring-shaped seal surrounding said enlarged head portion and engaging said ring-shaped member and said bore, a cup-shaped retainer slideably connected to said connecting rod, said cup-shaped retainer having a bottom and a side wall portion, a spring surrounding said rod and extending between said annular ring-shaped member and said retainer, said spring biasing said retainer and enlarged head apart, said retainer thus being biased toward the outer end of said connecting rod means, stop means between the bottom of said cupshaped retainer and the end of the connecting rod means closer to said second piston for preventing the separation of said connecting rod means and said retainer by said spring, the distance between the second piston and the end of said connecting rod means adjacent said second piston determining the maximum amount of movement of said first piston toward said second piston, said second piston at the end thereof adjacent said connecting rod means being adapted to have a portion thereof removed to increase the maximum amount of movement of said first piston toward said second piston, a second spring between said second piston and the inner end of said bore biasing said second piston toward and into engagement with said retainer, a first stop located adjacent the outer end of said bore and providing a positive stop for said piston, a second stop extending from one of said reservoirs into said bore, said second stop being adapted to prevent movement of said second piston out of said bore beyond a predetermined point, said second stop comprising a threaded member having a threaded portion and a shank portion of smaller diameter than said threaded portion extending from one end of said threaded portion, a head on the other end of said threaded portion, a shoulder between said shank portion and said threaded portion, a second bore in said body extending from said second reservoir to said first bore, said second stop passing through said second bore, said second bore having a threaded portion in which said threaded portion of said second stop is threadingly engaged, a shoulder portion against which said shoulder of said second stop is seated and a portion having a Diameter sufficiently greater than the diameter of said shank portion to provide a space therebetween, the length of said second stop from said shoulder thereon to said head thereon being greater than the distance between said shoulder portion in said second bore and the end of said second bore which opens into said second reservoir.
Claim 2
Dependent Claim
585 words
A master cylinder comprising a body having a first reservoir and a second reservoir, a bore extending through said body adjacent said reservoirs, a first piston movable in said bore, a second piston movable in said bore, the space between said first piston and second piston defining a first chamber, the space between the second piston and the end of the bore defining a second chamber, said body having outlets from said chambers adapted to be connected to hydraulic lines attached to front and rear sets of brakes, ports normally connecting said chambers to said reservoirs, an actuating rod means extending from one end of said first piston outwardly from said bore, connecting rod means extending from the other end of said first piston toward said second piston, said connecting rod means having an enlarged head portion, an annular ring-shaped member having an internal dimension smaller than the diameter of said enlarged head portion, the ring-shaped member being between said enlarged head and said second piston, a ring-shaped seal surrounding said enlarged head portion and engaging said ring-shaped member and said bore, a cup-shaped retainer slideably connected to said connecting rod, said cup-shaped retainer having a bottom and a side wall portion, a spring surrounding said rod and extending between said annular ring-shaped member and said retainer, said spring biasing said retainer and enlarged head apart, said retainer thus being biased toward the outer end of said connecting rod means, stop means between the bottom of said cupshaped retainer and the end of the connecting rod means closer to said second piston for preventing the separation of said connecting rod means and said retainer by said spring, the distance between the second piston and the end of said connecting rod means adjacent said second piston determining the maximum amount of movement of said first piston toward said second piston, said second piston at the end thereof adjacent said connecting rod means being adapted to have a portion thereof removed to increase the maximum amount of movement of said first piston toward said second piston, a second spring between said second piston and the inner end of said bore biasing said second piston toward and into engagement with said retainer, a first stop located adjacent the outer end of said bore and providing a positive stop for said piston, a second stop extending from one of said reservoirs into said bore, said second stop being adapted to prevent movement of said second piston out of said bore beyond a predetermined point, said second stop comprising a threaded member having a threaded portion and a shank portion of smaller diameter than said threaded portion extending from one end of said threaded portion, a head on the other end of said threaded portion, a shoulder between said shank portion and said threaded portion, a second bore in said body extending from said second reservoir to said first bore, said second stop passing through said second bore, said second bore having a threaded portion in which said threaded portion of said second stop is threadingly engaged, a shoulder portion against which said shoulder of said second stop is seated and a portion having a Diameter sufficiently greater than the diameter of said shank portion to provide a space therebetween, the length of said second stop from said shoulder thereon to said head thereon being greater than the distance between said shoulder portion in said second bore and the end of said second bore which opens into said second reservoir.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-05-07 | 1976-11-06 | 1977-05-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-05-07 | 1980-11-06 | 1981-05-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-05-07 | 1984-11-06 | 1985-05-08 | $7700.00 | Window Closed / Lapsed |