US3654956A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sealed reservoir for hydraulic brake systems
Assignee: Aisin Corp
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Filing: 1970-12-22
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Granted: 1972-04-11
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Expires: 1990-12-22
Abstract
Abstract Disclosed herein is a reservoir of a master cylinder for hydraulic brake systems in which a cap is screw threaded over a casing, and the screw threads of the cap and the casing form a spiral air-passageway to communicate atmospheric pressure onto a brake fluid seal. The seal includes a float member and a resilient member having a radially extended annular portion, a thick-walled portion to form a chamber against the casing wall and a vertically expansible portion to hold the floating member at the top end thereof. The chamber between the casing wall and the resilient member stores excess brake fluid as well as contaminants therein and the resilient member lets the float member float up and down in accordance with increases and decreases of the brake fluid quantity so as to maintain constantly good sealing effect.
Inventors
- 👤 Kaoru Tsubouchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 06:09
CPC Classifications
G; G01; G01F; G01F23/00; G01F23/30; G01F23/64; G01F23/68; G01F23/70; B; B60; B60T; B60T11/00; B60T11/10; B60T11/26; B60T17/00; B60T17/18; B60T17/22; B60T17/225; G01F23/72; G01F23/74
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
254 words
A reservoir of a master cylinder for hydraulic brake systems, comprising a casing connected to the cylindrical bore of said master cylinder and provided with a stepped portion at the upper inner circumferential wall thereof, a cap detachably secured over the outer circumferential wall of a neck extending upward from said stepped portion, a resilient member including a radial extending annular portion interposed between the upper annular edge of said neck and the inner circumferential wall of said cap, a thick-walled portion extending downward from said radial extending annular portion, said thick-walled portion having the lower end thereof engaging the stepped portion of said casing and with the outer diameter thereof smaller than the diameter of the inner circumferential wall of said neck, and a vertically expansible annular portion extending from the lower end of said thick-walled portion, a float member in air-tight connection with the top end of said vertically expansible annular portion, and means for communicating the surrounding air with the chamber formed between said float member and the inner circumferential wall of said cap, said thick-walled portion of said resilient member and said inner circumferential wall of said neck cooperating to form a chamber to store an excess quantity of the brake fluid, said vertically expansible annular portion of said resilient member being adapted to move vertically in accordance with increases and decreases of the quantity of the brake fluid in the brake system by means of expanding and shrinking action of said vertically expansible annular portion of said resilient member.
Claim 2
Dependent Claim
254 words
A reservoir of a master cylinder for hydraulic brake systems, comprising a casing connected to the cylindrical bore of said master cylinder and provided with a stepped portion at the upper inner circumferential wall thereof, a cap detachably secured over the outer circumferential wall of a neck extending upward from said stepped portion, a resilient member including a radial extending annular portion interposed between the upper annular edge of said neck and the inner circumferential wall of said cap, a thick-walled portion extending downward from said radial extending annular portion, said thick-walled portion having the lower end thereof engaging the stepped portion of said casing and with the outer diameter thereof smaller than the diameter of the inner circumferential wall of said neck, and a vertically expansible annular portion extending from the lower end of said thick-walled portion, a float member in air-tight connection with the top end of said vertically expansible annular portion, and means for communicating the surrounding air with the chamber formed between said float member and the inner circumferential wall of said cap, said thick-walled portion of said resilient member and said inner circumferential wall of said neck cooperating to form a chamber to store an excess quantity of the brake fluid, said vertically expansible annular portion of said resilient member being adapted to move vertically in accordance with increases and decreases of the quantity of the brake fluid in the brake system by means of expanding and shrinking action of said vertically expansible annular portion of said resilient member.
Claim 3
Dependent Claim
34 words
A reservoir of a master cylinder as claimed in claim 1, wherein said vertically expansible annular portion of said resilient member has an annular bead connected to the upper portion of said float member.
Claim 4
Dependent Claim
36 words
A reservoir of a master cylinder as claimed in claim 2, wherein said float member and said resilient member are made of elastic material selected from the group including natural rubber, synthetic rubber or rubber-like materials.
Claim 5
Dependent Claim
64 words
A reservoir of a master cylinder as claimed in claim 1, wherein said float member is air-tightly but detachably connected to said vertically expansible annular portion of said resilient member, whereby said float member is freed from said expansible portion when the surface of the brake fluid within said casing is lowered beyond the level with said expansible portion in the full expansion thereof.
Claim 6
Dependent Claim
57 words
A reservoir of a master cylinder as claimed in claim 4, wherein said float member is made of rigid material selected from the group including light metal, hard natural rubber, hard synthetic resin and the like and said resilient member is made of elastic material selected from the group including natural rubber, synthetic rubber or rubber-like materials.
Claim 7
Dependent Claim
82 words
A reservoir of a master cylinder as claimed in claim 5, wherein the upper end of said vertically expansible portion of said resilient member is an annular bead having a circular cross-section and said float member is of a cylindrical shape with a U-shaped cross-section and has an annular groove at the upper outer circumference thereof with said bead of said expansible portion pressed therein, so that said float member is connected air-tightly but detachably to said bead of said expansible portion.
Claim 8
Dependent Claim
36 words
A reservoir of a master cylinder as claimed in claim 5, wherein said float member is provided with a sensing device for issuing an alarm when the brake fluid falls below the lowest normal level thereof.
Claim 9
Dependent Claim
103 words
A reservoir of a master cylinder As claimed in claim 1, wherein said means for communicating the surrounding air with said chamber between said float member and said inner circumferential wall of said cap comprises a radial passageway formed between said inner wall of said cap and a gasket placed on said radially extended annular portion of said resilient member and a spiral air-passage running through along the unengaging slopes of the said screw threads said screw threads each having a trapezoid cross-section in which the axial length at the recessed portion is substantially twice as long as that at the top end.
Claim 10
Dependent Claim
108 words
A reservoir of a master cylinder for hydraulic brake systems comprising a casing connected to the cylindrical bore of said master cylinder, a cap detachably screw-threaded over the upper opening portion of said casing, sealing means for sealing brake fluid within said casing against the surrounding air and communicating means for leading the surrounding air onto said sealing means, wherein said communicating means comprising a spiral air-passage formed between screw threads provided respectively on the outer circumference of said casing and on the inner perpendicular wall of said cap, both screw threads so designed as to have a longer width at the recessed portion than the projected portion.
Claim 11
Dependent Claim
108 words
A reservoir of a master cylinder for hydraulic brake systems comprising a casing connected to the cylindrical bore of said master cylinder, a cap detachably screw-threaded over the upper opening portion of said casing, sealing means for sealing brake fluid within said casing against the surrounding air and communicating means for leading the surrounding air onto said sealing means, wherein said communicating means comprising a spiral air-passage formed between screw threads provided respectively on the outer circumference of said casing and on the inner perpendicular wall of said cap, both screw threads so designed as to have a longer width at the recessed portion than the projected portion.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-04-11 | 1975-10-11 | 1976-04-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-04-11 | 1979-10-11 | 1980-04-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-04-11 | 1983-10-11 | 1984-04-11 | $7700.00 | Window Closed / Lapsed |