US 5,350,042 A · Automatic adjusting apparatus for a disc brake

Abstract

An automatic adjusting apparatus for a disc brake with a brake caliper housing. The disc brake is furnished with a brake piston which is slidingly positioned within a cylinder for the actuation of a brake shoe and which is actuatable by means of a hydraulic actuating device and a mechanical actuating device. The apparatus also includes an extendable adjusting unit which is disposed between the brake piston and the mechanical actuating device and includes an adjusting nut threadedly mounted on an adjusting spindle. The apparatus is arranged with a friction clutch to hold back one of the adjusting elements in the event of a mechanical actuation. The brake piston has a cylindrical portion which is directed into the interior of the brake piston and projects from the brake piston. The cylindrical portion of the brake piston is surrounded by the adjusting nut and a ring-shaped circumferential sealing element bears against an external surface of the cylindrical portion of the brake piston.

Claims54

Dependent claims

An automatic adjusting apparatus for a disc brake with a brake caliper housing,

the disc brake being furnished with a brake piston, having a bottom, which is slidingly positioned within a cylindrical bore of the brake caliper housing for the actuation of a brake shoe and which is actuatable by means of a hydraulic actuating device and a mechanical actuating device;
with an extendable adjusting member which is disposed between said brake piston and said mechanical actuating device and is furnished with two adjusting elements being connected to each other through a thread free of nonreversibility, said adjusting elements being configured in the shape of an adjusting nut and of an adjusting spindle;
and
with a friction clutch to hold back one of said adjusting elements in the event of a mechanical actuation,
characterized in that said brake piston includes a cylinder directed into the interior of said cylindrical bore and which projects out of the bottom of said brake piston, wherein said cylinder is encased by said adjusting nut, and in that an external cylindrical surface of said cylinder interacts with a ring-shaped circumferential sealing element.

2 more elements

An automatic adjusting apparatus for a disc brake with a brake caliper which is furnished with a brake cylinder and a hollow brake piston, having a bottom, being slidingly positioned within said brake cylinder;

with a hydraulic and a mechanical actuating device;
with an extendable adjusting member which is positioned between said brake piston and said mechanical actuating device and which is comprised of an adjusting spindle and of an adjusting nut being coupled to said adjusting nut through a thread which is free of nonreversibility;
with a cylindrical projection which juts out of the bottom of said brake piston into its interior space, said adjusting nut extending beyond the peripheral area of said projection;
and with at least one ring-shaped circumferential, elastic sleeve which is positioned on said peripheral area of said cylindrical projection, wherein said at least one sleeve includes at least one of:
(a) one sleeve which is formed with at least two circumferential sealing lips and
(b) two sleeves interacting with each other and each formed with at least one circumferential sealing lip at an axial distance from each other and in abutment against said peripheral area of said cylindrical projection,
wherein a radially internal surface of said at least one sleeve is not in abutment against said peripheral area as long as the hydraulic pressure does not exceed a determined value, and in that said at least one sleeve is unrotatably coupled to said adjusting nut.

4 more elements

Apparatus for automatically adjusting a disc brake, said apparatus comprising:

a brake shoe;
a housing having a cylindrical bore;
a brake piston positioned within said cylindrical bore for sliding movement along said cylindrical bore to actuate said brake shoe in response to a hydraulic actuating device and a mechanical actuating device, said brake piston having a cylindrical portion extending into the interior of said brake piston from an end of the said brake piston which actuates said brake shoe;
an extendable adjusting unit disposed between said brake piston and said mechanical actuating device and including:
(a) a threaded spindle coupled to said mechanical actuating device, and
(b) a nut threadedly engaging said threaded spindle and having a portion which:
(i) extends over and surrounds said cylindrical portion of said brake piston, and
(ii) is adapted to bear against said brake piston to prevent relative rotation between said nut and said brake piston;
and a ring-shaped circumferential sealing element disposed between said cylindrical portion of said brake piston and said portion of said nut which extends over and surrounds said cylindrical portion of said brake piston.

6 more elements

Apparatus for automatically adjusting a disc brake, said apparatus comprising:

a brake shoe;
a brake cylinder;
a hollow brake piston positioned for sliding movement within said brake cylinder to actuate said brake shoe and having a cylindrical portion extending into the interior of said brake Distort from an end of said brake piston which actuates said brake shoe;
a hydraulic unit for moving said brake piston to actuate said brake shoe;
a mechanical unit for moving said brake piston to actuate said brake shoe;
an extendable adjusting unit disposed between said brake piston and said mechanical actuating device and including:
(a) a threaded spindle coupled to said mechanical unit, and
(b) a nut threadedly engaging said threaded spindle and having a portion which:
(i) extends over and surrounds said cylindrical portion of said brake piston, and
(ii) is adapted to bear against said brake piston to prevent relative rotation between said nut and said brake piston;
and a ring-shaped, circumferential elastic sleeve fixed to said adjusting nut and formed with:
(a) at least two circumferential, axially spaced apart sealing lips which bear against said cylindrical portion of said brake piston, and
(b) a circumferential surface between said sealing lips and spaced from said cylindrical portion of said brake piston as long as hydraulic pressure applied by said hydraulic unit does not exceed a predetermined level.

10 more elements

Apparatus for automatically adjusting a disc brake, said apparatus comprising:

a brake shoe;
a brake cylinder;
a hollow brake piston positioned for sliding movement within said brake cylinder to actuate said brake shoe and having a cylindrical portion extending into the interior of said brake piston from an end of said brake piston which actuates said brake shoe;
a hydraulic unit for moving said brake piston to actuate said brake shoe;
a mechanical unit for moving said brake piston to actuate said brake shoe;
an extendable adjusting unit disposed between said brake piston and said mechanical actuating device and including:
(a) a threaded spindle coupled to said mechanical unit, and
(b) a nut threadedly engaging said threaded spindle and having a portion which:
(i) extends over and surrounds said cylindrical portion of said brake piston, and
(ii) is adapted to bear against said brake piston to prevent relative rotation between said nut and said brake piston;
and first and second ring-shaped, circumferential elastic sleeves each fixed to said adjusting nut and formed with a sealing lip which bears against said cylindrical portion of said brake piston, said sealing lips being apart axially and having a circumferential surface between them which is spaced from said cylindrical portion of said brake piston as long as hydraulic pressure applied by said hydraulic unit does not exceed a predetermined level.

8 more elements

Dependencies are inferred from the claim text.

Automatic adjusting apparatus for a disc brake

Life of this patent

Automatic adjusting apparatus for a disc brake

Life of this patent

Abstract

Claims54