Back to results
US 5,158,160 AGranted
Automatic adjusting apparatus for a duo-servo drum brake
AssigneeAlfred Teves GmbH
InventorAndreas Doell
Life of this patent
Estimating the term…
Abstract
An automatic one-shot adjusting apparatus which is applicable both for mechanically and for hydraulically actuatable duo-servo drum, brakes and which includes two ratchets (6, 14) interacting through springs (11, 15) and is capable of adjusting only upon the release of the brake.
Claims19
An automatic adjusting apparatus for a duo-servo drum brake comprising:
- first and second brake shoe assemblies each mounted for outward movement away from one another and inward movement toward one another and each having a brake shoe and a brake lining adapted to abut against a brake drum upon outward movement of said first and said second brake shoe assemblies, said first brake shoe assembly having first adjusting means for adjusting said brake shoes;
- a supporting lug for limiting inward movement of said first and said second brake shoe assemblies and against which said first and said second brake shoe assemblies abut in their rest positions;
- an expanding device extending from said first brake shoe assembly to said second brake shoe assembly for moving said first and said second brake shoe assemblies outward;
- a first spring extending between said first and said second brake shoe assemblies for urging said first and said second brake shoe assemblies to move inward;
- and second adjusting means extending from said first brake shoe assembly to brake shoe assembly for adjusting said brake shoes.
2 more elements
An automatic adjusting apparatus for a duo-servo drum brake comprising:
- first and second brake shoe assemblies each mounted for outward movement away from one another and inward movement toward one another and each having a brake shoe and a brake lining adapted to abut against a brake drum upon outward movement of said first and said second brake shoe assemblies,
- (a) said first brake shoe assembly including:
- (1) a lever having a first set of ratchet teeth, and
- (2) first adjusting means for adjusting said brake shoes and including:
- (i) a ratchet lever mounted for pivotal movement on said brake shoe of said first brake shoe assembly and having a second set of ratchet teeth engaging said first set of ratchet teeth, and
- (ii) a first spring for urging said first set of ratchet teeth and said second set of ratchet teeth into engagement as said first brake shoe assembly is moved outward, and
- (b) said brake shoe of said second brake shoe assembly having an oblong hole;
- an expanding device extending between said lever of said first brake shoe assembly and said brake shoe of said second brake shoe assembly for moving said first and said second brake shoe assemblies outward;
- a second spring extending between said lever of said first brake shoe assembly and said brake shoe of said second brake shoe assembly for urging said first and said second brake shoe assemblies to move inward;
- a supporting lug positioned, with respect to said brake drum, radially outward of said second spring for limiting inward movement of first and said second brake shoe assemblies and against which said lever of said first brake shoe assembly and said brake shoe of said second brake shoe assembly abut in their rest positions;
- and second adjusting means positioned, with respect to said brake drum, radially outward of said supporting lug and including a stepped adjusting unit in the form of a ratchet extending between said lever of said first brake shoe assembly and said brake shoe of said second brake shoe assembly for adjusting said brake shoes, said stepped adjusting unit having an end received by said oblong hole of said brake shoe of said second brake shoe assembly and engaging said oblong hole only upon a prescribed amount of relative movement between said oblong hole and said stepped adjusting unit.
8 more elements
An automatic adjusting apparatus for a duo-servo drum brake comprising:
- first and second brake shoe assemblies each mounted for outward movement away from one another and inward movement toward one another and having symmetrical brake shoes and a brake lining adapted to abut against a brake drum upon outward movement of said first and said second brake shoe assemblies,
- (a) said first brake shoe assembly including:
- (1) a lever having an oblong hole and a first set of ratchet teeth, and
- (2) first adjusting means for adjusting said brake shoes and including:
- (i) a ratchet lever mounted on said brake shoe of said first brake shoe assembly for pivotal movement about a pivot axis and having a notch and a second set of ratchet teeth engaging said first set of ratchet teeth, and
- (ii) a spiral spring for urging said first set of ratchet teeth and said second set of ratchet teeth into engagement as said first brake shoe assembly is moved outward and having:
- a pivot axis coincident with said pivot axis of said ratchet lever,
- a first arm bearing against said brake shoe of said first brake shoe assembly, and
- a second arm received in said notch in said ratchet lever,
- (b) said brake shoe of said second brake shoe assembly having an oblong hole;
- an expanding device extending between said lever of said first brake shoe assembly and said brake shoe of said second brake shoe assembly for moving said first and said second brake shoe assemblies outward;
- a second spring extending between said lever of said first brake shoe assembly and said brake shoe of said second brake shoe assembly for urging said first and said second brake shoe assemblies to move inward, said second spring having an end received by said oblong hole of said lever of said first brake shoe assembly and engaging said oblong hole only upon a prescribed amount of relative movement between said oblong hole and said second spring;
- a supporting lug positioned, with respect to said brake drum, radially outward of said second spring for limiting inward movement of said first and said second brake shoe assemblies and against which said lever of said first brake shoe assembly and said brake shoe of said second brake shoe assembly abut in their rest positions;
- second adjusting means positioned, with respect to said brake drum, radially outward of said supporting lug and including a stepped adjusting unit in the form of a ratchet extending between said lever of said first brake shoe assembly and said brake shoe of said second brake shoe assembly for adjusting said brake shoes;
- and an equilibrant of forces unit positioned diametrically opposite from said expanding device and extending between said first and said second brake shoe assemblies and including:
- (a) a housing,
- (b) a cylindrical compression spring within said housing,
- (c) a plate having a first face against which one end of said cylindrical compression spring bears,
- (d) a threaded pin fixed to said housing and extending through said cylindrical compression spring and said plate, and
- (e) a nut screwed onto said threaded pin and bearing against a second face of said plate opposite from said first face to prestress said cylindrical compression spring.
17 more elements
Dependencies are inferred from the claim text.