GB2146716A - Disc brake retraction device - Google Patents

Disc brake retraction device Download PDF

Info

Publication number
GB2146716A
GB2146716A GB08324556A GB8324556A GB2146716A GB 2146716 A GB2146716 A GB 2146716A GB 08324556 A GB08324556 A GB 08324556A GB 8324556 A GB8324556 A GB 8324556A GB 2146716 A GB2146716 A GB 2146716A
Authority
GB
United Kingdom
Prior art keywords
disc
piston
brake
disc brake
reaction member
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
GB08324556A
Other versions
GB8324556D0 (en
Inventor
Richard John Leslie Stace
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Ford Motor Co
Original Assignee
Ford Motor Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Ford Motor Co filed Critical Ford Motor Co
Priority to GB08324556A priority Critical patent/GB2146716A/en
Publication of GB8324556D0 publication Critical patent/GB8324556D0/en
Priority to DE8484306155T priority patent/DE3470785D1/en
Priority to EP84306155A priority patent/EP0140549B1/en
Publication of GB2146716A publication Critical patent/GB2146716A/en
Withdrawn legal-status Critical Current

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D65/00—Parts or details
    • F16D65/38—Slack adjusters
    • F16D65/40—Slack adjusters mechanical
    • F16D65/52—Slack adjusters mechanical self-acting in one direction for adjusting excessive play
    • F16D65/54—Slack adjusters mechanical self-acting in one direction for adjusting excessive play by means of direct linear adjustment
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D65/00—Parts or details
    • F16D65/14—Actuating mechanisms for brakes; Means for initiating operation at a predetermined position
    • F16D65/16—Actuating mechanisms for brakes; Means for initiating operation at a predetermined position arranged in or on the brake
    • F16D65/18—Actuating mechanisms for brakes; Means for initiating operation at a predetermined position arranged in or on the brake adapted for drawing members together, e.g. for disc brakes
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D2121/00—Type of actuator operation force
    • F16D2121/02—Fluid pressure
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D2127/00—Auxiliary mechanisms
    • F16D2127/02—Release mechanisms

Description

1
GB2146716A 1
SPECIFICATION
Disc brake retraction device
5 This invention relates to disc brakes and is particularly suitable for application to motor vehicle disc brakes.
Disc braking systems currently in use in motor vehicles include a calliper with a piston 10 working in a cylinder and arranged to urge a brake pad into pressure contact with a brake disc when hydraulic fluid is supplied to the cylinder. There is no return device for displacing the brake pad from the brake disc after a 15 brake application and the brake pad remains held in contact with the disc by friction in the hydraulic actuating system unless urged back by run out of the disc or by vibration of the calliper relative to the disc.
20 We have found that the frictional drag between brake pad and disc when the brakes are not actuated gives rise to an increase of average fuel consumption of the order of 1 %. In city driving on smooth roads and at rela-25 tively low speeds the percentage increase is higher.
The invention in its broadest aspect provides a disc brake calliper with a device which positively retracts the brake pad from the disc 30 to reduce brake drag when the brake is not actuated.
According to an embodiment of the invention, there is provided a disc brake calliper including a housing formed with a cylinder, a 35 piston for moving a brake pad into pressure contact with a brake disc, a reaction member slidably contacting the inner wall of the cylinder and a retraction spring acting between the reaction member and the piston to retract the 40 piston a predetermined distance following a brake application.
Preferably the reaction member includes friction means contacting the main wall of the cylinder and providing sufficient friction to 45 prevent movement of the reactive member by the retraction spring.
The invention will now be described further, by way of example, with reference to the accompanying drawing which is a fragmen-50 tary cross-section along the axis of the cylinder in a brake calliper embodying the invention.
A disc brake calliper 10 comprises a housing 1 2 formed with a cylinder 14. A piston 55 16 is arranged to urge brake pads 18 and 20 into pressure contact with opposite faces of a brake disc 22 when hydraulic fluid 24 is forced through inlet 26 into the cylinder 14 by a conventional brake pedal and master 60 cylinder arrangement (not shown).
The piston 16 comprises and inner element 28 and an outer element 30 joined by a spigot element 32.
A annular ring shaped reaction member 34 65 is positioned in the annular space between the inner and outer piston elements 28 and 30 and has an axial length which is less than the spacing between the inner and outer elements by a distance X equal to the required predetermined retraction distance of the piston.
An "0" ring friction element 36 is received in a groove in the outer surface of the reaction member and slidably engages the inner surface of the cylinder 14.
A coil shaped retraction spring 38 is located in a recess 40 in the reaction member 34 open towards the inner piston element 28 so that the retraction spring urges the reaction member 34 and the inner piston element 28 apart.
The force exerted by the spring 38 on the reaction member 34 is insufficient to overcome the friction between the "0" ring 36 and the cylinder 14 but is sufficient to overcome the frictional forces affecting the piston 16 and the hydraulic actuating system.
In operation, after the brakes are released the retraction spring moves the piston back from the disc until the outer piston element 30 contacts the reaction member 34. The distance by which the piston 16 is moved is equal to X, the free movement of the reaction member relative to the piston 16.
As the brake pads wear the reaction member 34 is moved along the cylinder 14 by contact with the inner piston element 28 upon successive applications of the brakes.
Alternatively, the reaction member and retraction spring may be formed by a plate spring device in friction contact with the cylinder 14.

Claims (7)

1. A disc brake calliper with a device which positively retracts the brake pad from the disc to reduce brake drag when the brake is not actuated.
2. A disc brake calliper including a housing formed with a cylinder, a piston for moving a brake pad into pressure contact with a brake disc, a reaction member slidably contacting the inner wall of the cylinder and a retraction spring acting between the reaction member and the piston to retract the piston a predetermined distance following a brake application.
3. A disc brake calliper as claimed in Claim 2, in which the reaction member comprises and annular element having limited axial movement relative to the piston, the limited axila movement being equal to the required predetermined retraction distance of th piston.
4. A disc brake calliper as claimed in Claim 3, in which the annular element has a recess for receiving the retraction spring.
5. A disc brake calliper as claimed in any one of Claims 2 to 4, in which the reaction member includes friction means contacting the inner wall to the cylinder and providing
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sufficient friction to prevent movement of the reaction member by the retraction spring.
6. A disc brake calliper as claimed in Claim 5, in which the friction means is an "0" ring mounted in the outer surface of the annular member.
7. A disc brake calliper substantially as hereinbefore described with reference to and as shown in the accompanying drawing.
Printed in the United Kingdom for
Her Majesty's Stationery Office, Dd 8818935. 1985. 4235. Published at The Patent Office. 25 Southampton Buildings,
London, WC2A 1AY, from which copies may be obtained.
GB08324556A 1983-09-14 1983-09-14 Disc brake retraction device Withdrawn GB2146716A (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
GB08324556A GB2146716A (en) 1983-09-14 1983-09-14 Disc brake retraction device
DE8484306155T DE3470785D1 (en) 1983-09-14 1984-09-10 Disc brake retraction device
EP84306155A EP0140549B1 (en) 1983-09-14 1984-09-10 Disc brake retraction device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB08324556A GB2146716A (en) 1983-09-14 1983-09-14 Disc brake retraction device

Publications (2)

Publication Number Publication Date
GB8324556D0 GB8324556D0 (en) 1983-10-19
GB2146716A true GB2146716A (en) 1985-04-24

Family

ID=10548746

Family Applications (1)

Application Number Title Priority Date Filing Date
GB08324556A Withdrawn GB2146716A (en) 1983-09-14 1983-09-14 Disc brake retraction device

Country Status (3)

Country Link
EP (1) EP0140549B1 (en)
DE (1) DE3470785D1 (en)
GB (1) GB2146716A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2315832A (en) * 1996-07-31 1998-02-11 Edward Lee White A disc brake system
GB2373828A (en) * 2001-03-05 2002-10-02 Prodrive 2000 Ltd Self-adjusting mechanism

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3767073B2 (en) * 1997-03-12 2006-04-19 住友電気工業株式会社 Disc brake
DE10012358A1 (en) * 2000-03-14 2001-09-20 Magenwirth Gmbh Co Gustav Model racing auto hydraulic brake has self-adjusting piston
CN101351655B (en) * 2005-11-16 2013-08-28 弗雷尼·布雷姆博有限公司 Apparatus for controlling backspacing of piston
IT1397889B1 (en) 2009-12-24 2013-02-04 Freni Brembo Spa BRAKE CALIPER WITH DISC BRAKE PISTON DEVICE.

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1235367A (en) * 1967-11-22 1971-06-16 Sumitomo Electric Industries Disc brake devices
GB1255561A (en) * 1968-02-09 1971-12-01 Sumitomo Electric Industries Device for restoring a movable member of disc brakes to its original position
GB1327326A (en) * 1970-11-28 1973-08-22 Snc Omds Officine Meccaniche D Self adjusting disc brakes
GB2036898A (en) * 1978-11-06 1980-07-02 Lucas Industries Ltd Disc Brakes
GB1600998A (en) * 1978-05-09 1981-10-21 Dormer R J Disc brake piston retraction means
GB2097876A (en) * 1981-03-25 1982-11-10 Sumitomo Electric Industries A disc brake with caliper retract mechanism

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2731999C2 (en) * 1977-07-15 1983-12-29 Wabco Westinghouse Fahrzeugbremsen GmbH, 3000 Hannover Application device of a pressure medium-operated full-lined disc brake

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1235367A (en) * 1967-11-22 1971-06-16 Sumitomo Electric Industries Disc brake devices
GB1255561A (en) * 1968-02-09 1971-12-01 Sumitomo Electric Industries Device for restoring a movable member of disc brakes to its original position
GB1327326A (en) * 1970-11-28 1973-08-22 Snc Omds Officine Meccaniche D Self adjusting disc brakes
GB1600998A (en) * 1978-05-09 1981-10-21 Dormer R J Disc brake piston retraction means
GB2036898A (en) * 1978-11-06 1980-07-02 Lucas Industries Ltd Disc Brakes
GB2097876A (en) * 1981-03-25 1982-11-10 Sumitomo Electric Industries A disc brake with caliper retract mechanism

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2315832A (en) * 1996-07-31 1998-02-11 Edward Lee White A disc brake system
GB2373828A (en) * 2001-03-05 2002-10-02 Prodrive 2000 Ltd Self-adjusting mechanism

Also Published As

Publication number Publication date
GB8324556D0 (en) 1983-10-19
EP0140549B1 (en) 1988-04-27
EP0140549A1 (en) 1985-05-08
DE3470785D1 (en) 1988-06-01

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Legal Events

Date Code Title Description
WAP Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1)