GB2315832A - A disc brake system - Google Patents

A disc brake system Download PDF

Info

Publication number
GB2315832A
GB2315832A GB9616057A GB9616057A GB2315832A GB 2315832 A GB2315832 A GB 2315832A GB 9616057 A GB9616057 A GB 9616057A GB 9616057 A GB9616057 A GB 9616057A GB 2315832 A GB2315832 A GB 2315832A
Authority
GB
United Kingdom
Prior art keywords
brake
piston
brake pads
disc
force
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Withdrawn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
GB9616057A
Other versions
GB9616057D0 (en
Inventor
Edward Lee White
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.)
OSMAN DEREK JOHN
Original Assignee
OSMAN DEREK JOHN
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 OSMAN DEREK JOHN filed Critical OSMAN DEREK JOHN
Priority to GB9616057A priority Critical patent/GB2315832A/en
Publication of GB9616057D0 publication Critical patent/GB9616057D0/en
Publication of GB2315832A publication Critical patent/GB2315832A/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Withdrawn legal-status Critical Current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
    • F16D65/14—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
    • F16D65/00—Parts or details
    • F16D65/02—Braking members; Mounting thereof
    • F16D65/04—Bands, shoes or pads; Pivots or supporting members therefor
    • F16D65/092—Bands, shoes or pads; Pivots or supporting members therefor for axially-engaging brakes, e.g. disc brakes
    • F16D65/095—Pivots or supporting members therefor
    • F16D65/097—Resilient means interposed between pads and supporting members or other brake parts
    • 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
    • F16D65/42—Slack adjusters mechanical non-automatic
    • F16D65/46—Slack adjusters mechanical non-automatic with screw-thread and nut
    • 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
    • F16D2121/14—Mechanical
    • 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

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Braking Arrangements (AREA)

Abstract

A disc brake system comprises a brake disc 13, a pair of brake pads 11, 12 located either side of the brake disc and linked by a floating caliper, a piston 3 actuable to force the brake pads towards one another with a first force and grip the brake disc therebetween during a braking action, and at least one return spring 10 operable to force the piston away from the brake pads with a second force after a braking action, the first force being greater than the second force. In addition to, or instead of, the return spring(s), a resilient means (21-24 figure 3) is provided which is operable, after a braking action, to force the brake pads apart into a neutral position in which there is a clearance between the brake disc and the brake pads.

Description

"A disc brake eyetemn BACKOROUND OF THE INVTIOJ Field of the invention THIS INVENTION relates to a disc brake system and more particularly to a disc brake system having a positive release for retracting the disc pads from a brake disc or rotor.
Description of the prior art Conventionally, disc brake systems incorporate a brake disc that rotates with a wheel or other rotary mechanism. The brake disc or rotor is gripped between a pair of brake pads disposed on opposite sides of the brake disc in a pincer-like fashion. The pair of brake pads are held in a caliper housing which is operable to apply equal pressure on both brake pads to the brake disc. The brake pads are fitted with friction linings which engage the brake disc.
A hydraulic system is used to actuate the disc brake system. A hydraulic driving piston of the hydraulic system is fixedly mounted in the caliper housing. The piston is operable to force the brake pads towards one another thus sandwiching the brake disc between the brake discs. This causes a braking action on the brake disc and hence the wheel or other rotary mechanism to which the brake disc is attached. See Figures 4 and 5 of the accompanying drawings.
The driving piston is sealed with respect to the caliper housing by an O-ring or similar seal, the hydraulic braking fluid being located in a cylinder in the caliper housing. When hydraulic pressure is applied to the piston to cause braking, the seal deforms slightly as the piston is forced out of the cylinder in the caliper housing. When the hydraulic pressure is released, the elastic properties of the seal cause the seal to attempt to return to its unreformed state thereby returning the piston to a substantially non-braking position. The stroke of the piston is very small so there is little appreciable deformation of the seal.
This arrangement is not satisfactory since the only return action on the piston is provided by the seal and there is no positive action on the brake pads to remove them from the brake disc.
Thus, in conventional disc brake systems, the brake pads continue to ride on the brake disc even when braking is not required. This causes three main disadvantages.
The first is continual wear of the friction linings on the brake pads which are in constant contact with the brake disc resulting in reduced life of the brake pads.
The second is the presence of a certain amount of drag between the friction linings on the brake pads and the brake disc which not only reduces fuel economy but also unnecessarily heats up the friction linings thereby reducing the braking efficiency of the disc braking system. The third is that the disc brake system is constantly producing brake dust which is not only unsightly but can also contribute to possible seizing of the brakes due to a build-up of brake dust.
BRIEF SUMMARY OF THE INVENTION The present invention seeks to overcome the abovementioned disadvantages and provide a disc brake system in which the brake pads do not continually ride upon the brake disc and which incorporates means to retract the piston from the brake pads.
Accordingly, one aspect of the present invention provides a disc brake system comprising: a brake disc; a pair of brake pads located either side of the brake disc and linked by a floating caliper; a piston actuable to force the brake pads towards one another with a first force and grip the brake disc therebetween during a braking action; and at least one return spring operable to force the piston away from the brake pads with a second force after a braking action, the first force being substantially greater than the second force.
A further aspect of the present invention provides a disc brake system comprising: a brake disc; a pair of brake pads located either side of the brake disc and linked by a floating caliper; a piston actuable to force the brake pads towards one another and grip the brake disc therebetween during a braking action; and resilient means operable, after a braking action, to force the brake pads apart into a neutral position in which there is a clearance between the brake disc and the brake pads.
BRIEF DESCRITION OF ThE DRAWINGS In order that the present invention can be more readily understood, an embodiment thereof will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a cross-sectional side view of disc brake system embodying the present invention shown with the brakes applied; Figure 2 is a cross-sectional side view of the disc brake system of Figure 1 shown with the brakes released; Figure 3 is a cross-sectional side view of a further disc brake system embodying the present invention shown with the brakes released; Figure 4 is a cross-sectional side view of an existing disc brake system shown with the brakes applied; and Figure 5 is a cross-sectional side view of the disc brake system of Figure 4 shown with the brakes released.
DETAILED DESCRIPTION OF TBE INVENTION Referring to Figures 1 and 2, a disc brake system embodying the present invention comprises a caliper housing 1 incorporating therein a cylinder 2. A cylindrical piston 3 is slidingly engaged within the cylinder 2 and the piston 3 and cylinder 2 together define a chamber 4 which is filled with hydraulic brake fluid. A port 5 in the caliper housing 1 is in fluid communication with a conventional reservoir of brake fluid and a conventional master cylinder (not shown).
A retaining plate 6 having a piston receiving aperture 7 is fitted over an open end of the cylinder 2 such that a head 8 of the piston 3 projects through the aperture 7 in the retaining plate 6. The head 8 of the piston 3 has a smaller diameter than the piston 3 and is coaxially aligned therewith so as to define a step 9.
The piston 3 is biased into the cylinder 2 by a return spring 10 which is located around the head 8 of the piston and which is seated at one end on the retaining plate 6 and at the other end against the step 9 of the piston 3. The return spring 10 is a forty pound compression spring. The hydraulic system generates 1500 pounds pressure in the chamber 4 during braking to overcome the return spring 10 and force the head 8 of the piston 3 through the retaining plate 6.
When the head 8 of the piston 3 projects through the aperture 7, the head 8 abuts and is forced against an inner brake pad 11 with approximately 1500 pounds pressure. The same pressure is transmitted through a conventional floating caliper (not shown) in the caliper housing 1 to an outer brake pad 12 located on an opposite side of a brake disc 13 or rotor disposed between the brake pads 11,12. Each surface 14,15 of the brake pads 11,12 adjacent the brake disc 13 is provided with a friction lining 16,17 which is preferably adhered to a respective brake pad 11,12 rather than being fastened thereto by rivets or the like in the conventional manner.
The use of such adhesive friction linings 16,17 increases the useful thickness and hence the life of the friction linings 16,17.
During braking, the brake pads 11,12 grip the brake disc 13 with a pressure of approximately 1500 pounds.
However, in contrast to conventional disc brake systems, as soon as the braking action is stopped and the pressure in the braking system returns to substantially zero, the return spring 10 pushes the piston 3 back into the cylinder thereby positively removing all pressure between the brake pads 11,12 and the brake disc 13.
It should be noted that as the friction linings 16,17 wear down over time it is necessary to adjust the distance by which the head 8 of the piston 3 projects from the retaining plate 6. This is accomplished by means of a piston limiter 18 comprising a threaded stud 19 located in a threaded bore 20 in the cylinder housing 1 behind the piston 3. The threaded stud 19 projects into the brake fluid chamber 4 to limit the return of the piston 3 within the cylinder 2. The return of the piston 3 within the cylinder 2 can be increased by retracting the stud 19 from the chamber 4 or decreased by turning the stud 19 further into the chamber 4.
In addition to the return spring 10, the disc brake system embodying the present invention also incorporates further means to space the brake pads 11,12 from the brake disc 13 when not braking so as to prevent the friction linings continually riding on the brake disc 13.
In this regard, referring to Figure 3 in which the same reference numerals are used for common elements, two pairs of compression springs 21,22,23,24 are provided.
As can be seen from Figure 3, the brake pads 11,12 are slidingly received in the caliper housing 1 on a pair of posts 25,26 which guide movement of the brake pads 11,12 towards and away from the brake disc 13. One spring 21 is mounted at one end of the brake pads 11,12 on a first post 25 and is sandwiched between the inner brake pad 11 and the outer brake pad 12. Another spring 22 is mounted on the same post 25 and is sandwiched between the inner brake pad 11 and a portion 27 of the caliper housing 1.
A similar pair of springs 23,24 are mounted on the other post 26 at the other end of the brake pads 11,12 and are sandwiched respectively between the inner and outer brake pads 11,12 and another portion 28 of the caliper housing 1 and the inner brake pad 11. When no braking forces are applied to the brake pads 11,12, the springs 21,22,23,24 hold the brake pads in a neutral position in which there is a clearance between the brake disc 13 and the brake pads 11,12. During braking, the 1500 pounds pressure exerted by the piston 3 on the brake pads overcomes the resilience of the springs 21,22,23,24 and forces the brake pads 11,12 into contact with the brake disc 13.
When the braking action is stopped and the piston 3 is returned by the return spring 10, the first set of springs 21,23 expand slightly and the second set of springs 22,24 compress slightly to accommodate the expansion of the first set of springs 21,23 thereby returning the brake pads 11,12 to the neutral position shown in Figure 3.
It is envisaged that the return spring 10 can be replaced by two or more return springs located between the retaining plate 6 and the step 9 of the piston.
The elements of the prior art disc brake system shown in Figures 4 and 5 are labeled with the same reference numerals as corresponding elements of the disc brake systems shown in Figures 1 to 3. In addition to the common elements, the O-ring seal is labeled by reference numeral 29 and a dust boot 30 is provided at the open end of the cylinder 2 to prevent dust entering the area around the seal 29. The retaining plate 6 shown in Figures 1 to 3 performs the function of the dust boot 30.

Claims (9)

WHAT IS CLAIMED IS:
1. A disc brake system comprising: a brake disc; a pair of brake pads located either side of the brake disc and linked by a floating caliper; a piston actuable to force the brake pads towards one another with a first force and grip the brake disc therebetween during a braking action; and at least one return spring operable to force the piston away from the brake pads with a second force after a braking action, the first force being substantially greater than the second force.
2. A system according to Claim 1, wherein the piston is disposed in a cylinder having a retaining plate through which a portion of the piston projects, the return spring being located between the retaining plate and the piston such that one end of the return spring is seated on the retaining plate and the other end is seated against a part of the piston.
3. A system according to Claim 2, wherein the portion of the piston projecting through the retaining plate comprises a piston head which has a smaller diameter than the piston thereby defining a step, which step comprises the part of the piston against which the other end of the return spring is seated.
4. A system according to Claim 1, wherein resilient means force the brake pads apart into a neutral position in which there is a clearance between the brake disc and the brake pads.
5. A system according to Claim 4, wherein the brake pads are slidingly received on at least a pair of posts mounted on a housing, which posts guide movement of the brake pads towards and away from the brake disc, the resilient means comprising a series of springs, a first spring being mounted at one end of the brake pads on a first post and sandwiched between the brake pads, a second spring being mounted on the same post and sandwiched between one of the brake pads and a portion of the housing, and a third and a fourth spring being mounted on the other post at the other end of the brake pads and being sandwiched respectively between the brake pads and another portion of the housing and one of the brake pads such that when no braking forces are applied to the brake pads, the springs hold the brake pads in a neutral position in which there is a clearance between the brake disc and the brake pads.
6. A system according to Claim 1, wherein a return limiter is provided in a cylinder housing the piston, which limiter comprises a threaded stud located in a threaded bore in a housing of the cylinder behind the piston, the threaded stud projecting into a brake fluid chamber defined between the piston and the cylinder housing to limit the return of the piston back into the cylinder.
7. A system according to Claim 6, wherein the return of the piston back into the cylinder can be increased by retracting the stud from the chamber or decreased by turning the stud further into the chamber.
8. A system according to Claim 1, wherein the brake pads are provided with a friction lining adhered thereto.
9. A disc brake system comprising: a brake disc; a pair of brake pads located either side of the brake disc and linked by a floating caliper; a piston actuable to force the brake pads towards one another and grip the brake disc therebetween during a braking action; and resilient means operable, after a braking action, to force the brake pads apart into a neutral position in which there is a clearance between the brake disc and the brake pads.
GB9616057A 1996-07-31 1996-07-31 A disc brake system Withdrawn GB2315832A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB9616057A GB2315832A (en) 1996-07-31 1996-07-31 A disc brake system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB9616057A GB2315832A (en) 1996-07-31 1996-07-31 A disc brake system

Publications (2)

Publication Number Publication Date
GB9616057D0 GB9616057D0 (en) 1996-09-11
GB2315832A true GB2315832A (en) 1998-02-11

Family

ID=10797786

Family Applications (1)

Application Number Title Priority Date Filing Date
GB9616057A Withdrawn GB2315832A (en) 1996-07-31 1996-07-31 A disc brake system

Country Status (1)

Country Link
GB (1) GB2315832A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2179915A1 (en) * 1998-12-09 2010-04-28 GUSTAV MAGENWIRTH GmbH & Co. KG Brake cylinder for a hydraulic rim or disk brake
EP3269993A1 (en) * 2016-07-15 2018-01-17 KNORR-BREMSE Systeme für Nutzfahrzeuge GmbH Disc brake for a commercial vehicle

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110345177B (en) * 2019-07-17 2024-02-06 潍柴雷沃智慧农业科技股份有限公司 Disc brake and control method

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB583596A (en) * 1944-07-20 1946-12-20 Wingfoot Corp Improvements in or relating to brakes
GB738247A (en) * 1953-03-27 1955-10-12 Wingfoot Corp Automatic wear adjustment means for brakes
GB1154578A (en) * 1965-07-08 1969-06-11 Dayton Steel Foundry Co Improvements in or relating to Disk Brakes.
GB1243698A (en) * 1969-10-02 1971-08-25 Kelsey Hayes Co Disc brakes
US4382491A (en) * 1980-08-11 1983-05-10 Hurst Performance, Inc. Drag free disc brake assembly having automatically adjusting caliper
US4386682A (en) * 1981-04-09 1983-06-07 The Bendix Corporation Piston retraction and wear compensation for low-drag disc brakes
GB2146716A (en) * 1983-09-14 1985-04-24 Ford Motor Co Disc brake retraction device
US5462137A (en) * 1991-11-07 1995-10-31 Aerospatiale Societe Nationale Industrielle Gyroplane rotor braking unit
US5507369A (en) * 1993-03-26 1996-04-16 Freios Varga Ltda. S/A Reaction deam disc brake with sliding pins for vehicles

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB583596A (en) * 1944-07-20 1946-12-20 Wingfoot Corp Improvements in or relating to brakes
GB738247A (en) * 1953-03-27 1955-10-12 Wingfoot Corp Automatic wear adjustment means for brakes
GB1154578A (en) * 1965-07-08 1969-06-11 Dayton Steel Foundry Co Improvements in or relating to Disk Brakes.
GB1243698A (en) * 1969-10-02 1971-08-25 Kelsey Hayes Co Disc brakes
US4382491A (en) * 1980-08-11 1983-05-10 Hurst Performance, Inc. Drag free disc brake assembly having automatically adjusting caliper
US4386682A (en) * 1981-04-09 1983-06-07 The Bendix Corporation Piston retraction and wear compensation for low-drag disc brakes
GB2146716A (en) * 1983-09-14 1985-04-24 Ford Motor Co Disc brake retraction device
US5462137A (en) * 1991-11-07 1995-10-31 Aerospatiale Societe Nationale Industrielle Gyroplane rotor braking unit
US5507369A (en) * 1993-03-26 1996-04-16 Freios Varga Ltda. S/A Reaction deam disc brake with sliding pins for vehicles

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2179915A1 (en) * 1998-12-09 2010-04-28 GUSTAV MAGENWIRTH GmbH & Co. KG Brake cylinder for a hydraulic rim or disk brake
EP3269993A1 (en) * 2016-07-15 2018-01-17 KNORR-BREMSE Systeme für Nutzfahrzeuge GmbH Disc brake for a commercial vehicle
WO2018010989A1 (en) * 2016-07-15 2018-01-18 Knorr-Bremse Systeme für Nutzfahrzeuge GmbH Disc brake for a commercial vehicle

Also Published As

Publication number Publication date
GB9616057D0 (en) 1996-09-11

Similar Documents

Publication Publication Date Title
JPS56109934A (en) Disc brake
US4248329A (en) Disc brakes having an improved dust-proofing structure
US4375250A (en) Spot-type disc brake
KR100451408B1 (en) Disc Brake Device
US3498421A (en) Hydraulic disk brake with mechanical actuating means
WO1998002671A3 (en) Trailer brake system with dual piston calipers
US3476220A (en) Hydraulic disc brake apparatus and multiple operators therefor
EP0929758B1 (en) Play adjustment
US4519482A (en) Wedge actuated drum brake assembly
GB2099524A (en) Disc brake
GB2315832A (en) A disc brake system
JPS624745Y2 (en)
CN216969898U (en) Variable oil pressure brake structure
US4303148A (en) Single piston-cylinder duo-servo drum brake
KR100771041B1 (en) The Disk Brake
EP0169178B1 (en) Security caliper for disk brake of motor vehicles
KR20040071876A (en) The Shim for Disk Brake
KR200276252Y1 (en) Disc brake
KR20010002292U (en) Disc Brake System_
KR20020014209A (en) Guide rod combination structure of disk brake
KR20080024336A (en) Disc brake system for vehicle
KR100694014B1 (en) The Pad return springs of Disk Brake for Vehicles
KR100218164B1 (en) Disk brake having inner and outer piston
KR200153508Y1 (en) Wheel cylinder push rod
KR100269958B1 (en) 1 using wheel cylinder 2 leading type drum brake

Legal Events

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