Patent US4030576A successfully refreshed from Google Patents.
US4030576A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Disc brake assembly including a self-contained actuator with wear take-up and anti-drag device
Assignee: United States Steel Corp
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Filing: 1976-04-16
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Granted: 1977-06-21
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Expires: 1996-04-16
Abstract
Abstract A disc brake assembly including a self-contained actuator for urging a brake shoe into frictional engagement with a friction disc; the actuator including an actuated piston movably supported within a cylinder for moving the brake shoe into engagement with the friction disc, an actuating piston movably supported within the cylinder which is separated from the actuated piston by a fluid-filled chamber which defines a fluid link therebetween and a rotatable, threaded shaft member connected to the actuating piston for transmitting rotational motion to axial motion whereby rotation movement of the shaft member causes axial movement of the actuating piston which in turn causes axial movement of the actuated piston through the fluid link. In order to compensate for separation between the actuated and actuating pistons as a result of brake wear, the cylinder includes a fluid reservoir for supplying additional fluid to the fluid-filled chamber upon separation of these two members. The assembly also includes a wear take-up and antidrag device.
Inventors
- 👤 William L. Pringle
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 09:33
CPC Classifications
F; F16; F16D; F16D55/00; F16D55/02; B; B60; B60T; B60T1/00; B60T1/02; B60T1/06; F16D65/00; F16D65/38; F16D65/40; F16D65/52; F16D65/54; F16D65/72; F16D65/74; F16D65/02; F16D2065/024; F16D2125/00; F16D2125/18; F16D2125/20; F16D2125/34; F16D2125/40
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
244 words
A brake assembly comprising: a friction disc, a brake shoe, a support plate mounted adjacent said friction disc, guide pins extending between said support plate and said brake shoe for movably supporting said brake shoe, return spring means for urging said brake shoe toward said support plate, a self-contained actuator carried by said support plate for urging said brake shoe toward said friction disc; said actuator including a cylinder, an actuated piston within said cylinder operatively engaging said brake shoe, an actuating piston, a rotatable threaded shaft member for translating rotational motion to axial motion operatively connected to said actuating piston, means for rotating said shaft member, a fluid-filled chamber between said actuated and actuating pistons defining a fluid link therebetween whereby axial movement of said actuating piston causes axial movement of said actuated piston, wear take-up and anti-drag means for permitting substantially free forward movement of said actuated piston in unison with said actuating piston to move said brake shoe toward said friction disc and for limiting retraction of said actuated piston and said brake shoe against the force of said spring means to a predetermined maximum distance, and fluid supply means contained within said cylinder for supplying additional fluid to said chamber in response to retraction of said actuating piston a distance greater than the predetermined maximum for said actuated piston and brake shoe to thereby accommodate the increase in volume of said chamber occasioned by the resultant separation of said pistons.
Claim 2
Dependent Claim
244 words
A brake assembly comprising: a friction disc, a brake shoe, a support plate mounted adjacent said friction disc, guide pins extending between said support plate and said brake shoe for movably supporting said brake shoe, return spring means for urging said brake shoe toward said support plate, a self-contained actuator carried by said support plate for urging said brake shoe toward said friction disc; said actuator including a cylinder, an actuated piston within said cylinder operatively engaging said brake shoe, an actuating piston, a rotatable threaded shaft member for translating rotational motion to axial motion operatively connected to said actuating piston, means for rotating said shaft member, a fluid-filled chamber between said actuated and actuating pistons defining a fluid link therebetween whereby axial movement of said actuating piston causes axial movement of said actuated piston, wear take-up and anti-drag means for permitting substantially free forward movement of said actuated piston in unison with said actuating piston to move said brake shoe toward said friction disc and for limiting retraction of said actuated piston and said brake shoe against the force of said spring means to a predetermined maximum distance, and fluid supply means contained within said cylinder for supplying additional fluid to said chamber in response to retraction of said actuating piston a distance greater than the predetermined maximum for said actuated piston and brake shoe to thereby accommodate the increase in volume of said chamber occasioned by the resultant separation of said pistons.
Claim 3
Dependent Claim
54 words
An assembly as set forth in claim 1 wherein said fluid supply means includes a fluid reservoir within said cylinder, pressurization means for constantly maintaining the fluid contained in said reservoir under pressure, and a check valve between said reservoir and said chamber for permitting passage of fluid from said reservoir into said chamber.
Claim 4
Dependent Claim
32 words
An assembly as set forth in claim 2 wherein said pressurization means includes a displacement piston and means for urging said piston into engagement with the body of fluid in said reservoir.
Claim 5
Dependent Claim
31 words
An assembly as set forth in claim 3 wherein said displacement piston includes a rear face and said cylinder includes breather ports communicating with the rear face of said displacement piston.
Claim 6
Dependent Claim
29 words
An assembly as set forth in claim 4 wherein said means for urging said piston into engagement with the body of fluid in said reservoir includes a spring member.
Claim 7
Dependent Claim
44 words
An assembly as set forth in claim 1 wherein said wear take-up and anti-drag means includes one-way clutch means for resisting retraction of said actuated piston and lost motion means for permitting limited movement of said actuated piston independently of said one-way clutch means.
Claim 8
Dependent Claim
42 words
An assembly as set forth in claim 6 wherein said cylinder includes a sleeve member supported therein for supporting said threaded shaft member and said one-way clutch means includes an annular gripping member having inwardly extending, inclined fingers engaging said sleeve member.
Claim 9
Dependent Claim
59 words
An assembly as set forth in claim 7 wherein said lost motion means includes an internal groove in said actuated piston for receiving said annular gripping member, said groove defining a pair of shoulders spaced apart a distance greater than the thickness of said gripping member to permit limited relative movement between said actuated piston and said gripping member.
Claim 10
Dependent Claim
23 words
An assembly as set forth in claim 8 wherein said actuated piston includes a snap-ring member defining one shoulder of said internal groove.
Claim 11
Dependent Claim
26 words
An assembly as set forth in claim 11 wherein said means for rotating said shaft member includes a lever and power means for operating said lever.
Claim 12
Dependent Claim
16 words
An assembly as set forth in claim 10 wherein said power means includes an air-operated cylinder.
Claim 13
Dependent Claim
15 words
An assembly as set forth in claim 11 wherein said brake assembly includes two actuators.
Claim 14
Dependent Claim
26 words
An assembly as set forth in claim 1 wherein said friction disc comprises an annular conical member having a pair of continuous, relatively diverging friction surfaces.
Claim 15
Dependent Claim
30 words
An assembly as set forth in claim 13 wherein said assembly includes connection means between said brake shoe and said guide pins for permitting two-component motion of said brake shoe.
Claim 16
Dependent Claim
52 words
An assembly as set forth in claim 14 wherein said brake shoe comprises an arcuate, wedge-shaped member having a rear wall, said connection means including enlarged openings in said rear wall through which said guide pins extend, said openings having at least one dimension greater than the diameter of said guide pins.
Claim 17
Dependent Claim
27 words
An assembly as set forth in claim 15 wherein said return spring means includes a coil spring member carried by at least one of said guide pins.
Claim 18
Dependent Claim
21 words
An assembly as set forth in claim 1 wherein said assembly includes means for preventing transverse motion of said brake shoe.
Claim 19
Dependent Claim
35 words
An assembly as set forth in claim 17 wherein said means for preventing transverse motion of said brake shoe includes a pair of stop members carried by said support plate and engaging said brake shoes.
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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) | 1980-06-20 | 1980-12-20 | 1981-06-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-06-20 | 1984-12-20 | 1985-06-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-06-20 | 1988-12-20 | 1989-06-21 | $7700.00 | Window Closed / Lapsed |