DISC BRAKE ANTI SQUEAL MEANS

• US 3,722,634 A
• Filed: 09/18/1970
• Issued: 03/27/1973
• Est. Priority Date: 09/29/1969
• Status: Expired due to Term

• Current Assignee: Masakazu Ishikawa, Takeo Ogasawara
• Original Assignee: Masakazu Ishikawa, Takeo Ogasawara
• Inventors: Ogasawara, Takeo, Ishikawa, Masakazu
• Primary Examiner(s): Halvosa, George A.
• Application Number:
  US05/073,358
• Time in Patent Office: 921 Days
• Field of Search: 188/264G,73.5,73.1,72.4,72.5,1B,217 192/3V,113A,19A 92/84,129
• US Class Current: 188/73.37
• CPC Class Codes: F16D 2125/06 Pistons
• CPC Class Codes: F16D 65/0006 Noise or vibration control
• CPC Class Codes: F16D 65/0975 Springs made from wire

Abstract

A disc brake of simple construction wherein an intermediate member is interposed between the brake pad and the brake actuating piston. Anti-friction means extends between the transverse adjacent surfaces of the piston and the intermediate member so that vibrations from the brake pad are thus not transmitted to the piston and brake squeal is effectively eliminated.

Claims

1. A disc brake comprising a rotatable disc, a caliper straddling a portion of the periphery of said disc, a pad of friction material associated with the caliper and opposed to the disc, an axially movable piston in the caliper hydraulically movable to force the pad into frictional engagement with the disc for braking action, an axial cylindrical hollow portion opening into the side of the piston adjacent said pad, an intermediate cylindrical member inserted into said hollow portion, said hollow portion having a flat inner bottom surface extending substantially parallel to the rotating plane of said disc, said intermediate member having a flat inner surface opposed to the bottom surface of the hollow portion and an outer surface in frictional engagement with the pad, sliding surfaces on the inner surface of said intermediate member and the inner bottom surface of the hollow portion of said piston so as to allow the pad to slide a predetermined limited distance with respeCt to the piston, antifriction means interposed between the adjacent flat inner surfaces of said intermediate member and the hollow portion of the piston, whereby to isolate the coupled vibration between the disc, pad, piston and caliper to eliminate brake squeal, and means interposed between said cylindrical member and cylindrical hollow portion to retain said anti-friction means between said flat inner surfaces.

2. A disc brake according to claim 1, wherein said anti friction means comprises a lubricating material interposed between the adjacent flat inner surfaces of said intermediate member and the hollow portion of said piston.

3. A disc brake according to claim 2, wherein said lubricating material is a liquid lubricant.

4. A disc brake according to claim 2, wherein said lubricating material is a solid lubricant powder and is interposed between the adjacent flat inner surfaces of said intermediate member and the hollow portion of said piston.

5. A disc brake according to claim 1, wherein at least one relatively large bore is provided on the inner surface of said intermediate member opposed to and contacted with the inner bottom surface of the hollow portion of said piston and said antifriction means comprises a filler consisting of porous material impregnated with a liquid lubricant disposed in said bore.

6. A disc brake according to claim 5, wherein an annular groove is provided circumferentially along the outerwall of said intermediate member and said retaining means comprises a sealing ring member disposed in said groove to seal a space existing between said intermediate member and said piston whereby the leakage of the liquid lubricant is prevented.

7. A disc brake according to claim 1, wherein said anti-friction means comprises at least three anti-friction balls provided between the inner surfaces of said intermediate member and the bottom surface of said hollow portion of the piston and supported rotatably.

8. A disc brake according to claim 1 wherein said retaining means comprises a supporting plate having holes symmetrically arranged about its center and said balls are supported rotatably in the respective holes.

9. A disc brake according to claim 8, wherein said supporting plate is composed of two plates having projections disposed about each of said holes, said plates being bonded together between said holes.

10. A disc brake according to claim 1, wherein a plate member made of hard, low friction material is interposed between the inner surface of said intermediate member and the inner bottom surface of said hollow portion of said piston.

11. A disc brake according to claim 10 wherein said plate member is held against the inner surface of said intermediate member.

12. A disc brake according to claim 10 wherein said plate member is formed of material selected from the group consisting of low frictional metal, sintered material and synthetic resin.

13. A disc brake according to claim 12 wherein said plate member is made of metal and coated with a layer made of solid lubricant which is selected from the group consisting of molybdenum disulphide, graphite, a mixture of said metals, polyamide resin, polytetrafluoroethylene, a mixture of said resin, talc and a mixture of talc and said resin.

14. A disc brake according to claim 10, wherein said plate member is formed from a sintered material impregnated with a liquid lubricant.

15. A disc brake according to claim 14, wherein a bore extends axially into the outer surface of said intermediate member, a passage is provided in said intermediate member to interconnect the inner surfaces of said intermediate member and the bore in its outer surface, and said anti-friction an expandable member associated with said passage to hold liquid lubricant therein.

16. A disc brake according to claim 15, in which said intermediate member has an annular groove extending circumferentially in the outer wall of the extending circumferentially in the outer wall of the intermediate member, and sAid retaining means comprises a sealing ring member disposed in said groove to seal the space existing between the intermediate member and piston whereby the leakage of the liquid lubricant is prevented.