Self-adjusting device for disc brakes

Claim 2

A self-adjusting device for a disc brake comprising: an actuating piston having a longitudinal axis and bore coaxial of said axis, said bore being closed at one end of said piston; an adjusting spindle in a fixed position coaxial of said axis having threads on the outer surface thereof and extending out of the other end of said piston; an adjusting nut having threads for threading onto said spindle; an arrangement associated with said nut to rotate said nut on said spindle to permit the desired self-adjustment; an abutment secured to said nut adjacent said one end of said piston; an abutment element coaxial of said axis and said nut fixed to the inner surface of said bore to prevent axial motion thereof; and a return spring disposed between said abutment and said abutment element; said abutment including a disc disposed in a transverse relation to said bore, said disc having teeth disposed at given intervals on the periphery of said disc, said teeth being in contact with said inner surface of said bore.

Claim 3

A device according to claim 1, wherein brake clearance is defined by a predetermined play between said threads of said spindle and said nut.

Claim 4

A self-adjusting device for a disc brake comprising: an actuating piston having a longitudinal axis and bore coaxial of said axis, said bore being closed at one end of said piston; an adjusting spindle in a fixed position coaxial of said axis having threads on the outer surface thereof and extending out of the other end of said piston; an adjusting nut having threads for threading onto said spindle; an arrangement associated with said nut to rotate said nut on said spindle to permit the desired self-adjustment; an abutment secured to said nut adjacent said one end of said piston; an abutment element coaxial of said axis and said nut fixed to the inner surface of said bore to prevent axial motion thereof; and a return spring disposed between said abutment and said abutment element; said abutmeNt element including an abutment housing disposed coaxially of said nut, said abutment housing having a portion thereof extending radially for contact with the inner surface of said bore; and further including a first annular groove in said portion, a second annular groove in the inner surface of said bore in a cooperating relationship with said first groove, and a spring ring disposed in both said first and second grooves to prevent axial motion of said abutment housing.

Claim 5

A self-adjusting device for a disc brake comprising: an actuating piston having a longitudinal axis and bore coaxial of said axis, said bore being closed at one end of said piston; an adjusting spindle in a fixed position coaxial of said axis having threads on the outer surface thereof and extending out of the other end of said piston; an adjusting nut having threads for threading onto said spindle; an arrangement associated with said nut to rotate said nut on said spindle to permit the desired self-adjustment; an abutment secured to said nut adjacent said one end of said piston; an abutment element coaxial of said axis and said nut fixed to the inner surface of said bore to prevent axial motion thereof; and a return spring disposed between said abutment and said abutment element; said abutmeNt element including an abutment housing disposed coaxially of said nut, said abutment housing having a portion thereof extending radially for contact with the inner surface of said bore; and further including a first annular groove in said portion, a second annular groove in the inner surface of said bore in a cooperating relationship with said first groove, and a spring ring disposed in both said first and second grooves to prevent axial motion of said abutment housing.

Claim 6

A device according to claim 3, wherein said abutment element includes a transverse surface of said abutment housing spaced a small distance from said abutment, and said return spring includes a disc spring encircling said nut and disposed between said transverse surface and said abutment.

Claim 7

A device according to claim 4, wherein said disc spring includes two disc springs disposed one on top of the other.

Claim 8

A device according to claim 3, wherein said arrangement includes an engaging sleeve disposed coaxially of said nut and between said nut and said abutment housing in a freely rotatable relationship therewith.

Claim 9

A device according to claim 6, wherein said abutment housing includes an annular bearing surface adjacent said one end of said piston; and said engaging sleeve includes a cone secured thereto, the base of said cone being disposed adjacent said one end of said piston, said cone cooperating with said bearing surface during said adjustment operation to provide a strong frictional connection between said cone and said abutment housing.

Claim 10

A device according to claim 7, wherein said arrangement further includes a helical torsion spring disposed coaxial of said nut adjacent said other end of said piston and interconnecting said engaging sleeve and said nut.

Claim 11

A device according to claim 8, wherein said helical torsion spring twists said engaging sleeve in the direction to cause said cone to move toward said bearing surface.

Claim 12

A device according to claim 9, wherein said helical torsion spring further exerts an axial force on said engaging sleeve to bring said cone into slight contact with said bearing surface, said contact not disturbing the rotation of said engaging sleeve.

Claim 13

A device according to claim 8, wherein said helical torsion spring exerts an axial force on said engaging sleeve to bring said cone into slight contact with said bearing surface, said contact not disturbing the rotation of said engaging sleeve.

Claim 14

A self-adjusting device for a disc brake comprising: an actuating piston having a longitudinal axis and bore coaxial of said axis, said bore being closed at one end of said piston; an adjusting spindle in a fixed position coaxial of said axis having threads on the outer surface thereof and extending out of the other end of said piston; an adjusting nut having threads for threading onto said spindle; an arrangement associated with said nut to rotate said nut on said spindle to permit the desired self-adjustment; an abutment secured to said nut adjacent said one end of said piston; an abutment element coaxial of said axis and said nut fixed to the inner surface of said bore to prevent axial motion thereof; and a return spring disposed between said abutment and said abutment element; said abutment element including an abutment housing disposed coaxially of and encircling said nut, said abutment housing including an internal cylindrical wall having an outwardly directed step adjacent said one end of said piston, the end of said cylindrical wall at said step providing an annular bearing surface and the end of said cylinder wall after said step providing a transverse surface; said arrangement including an engaging sleeve disposed coaxially of said nut and between said nut and said abutment housing in a freely rotatable relationship therewith, said engaging sleeve including a cone secured Thereto, the base of said cone being disposed adjacent said one end of said piston, said cone cooperating with said bearing surface during said adjusting operation to provide a strong frictional connection between said cone and said abutment housing; and said return spring including a disc spring encircling said nut and disposed between said transverse surface and said abutment.

Claim 15

A self-adjusting device for a disc brake comprising: an actuating piston having a longitudinal axis and bore coaxial of said axis, said bore being closed at one end of said piston; an adjusting spindle in a fixed position coaxial of said axis having threads on the outer surface thereof and extending out of the other end of said piston; an adjusting nut having threads for threading onto said spindle; an arrangement associated with said nut to rotate said nut on said spindle to permit the desired self-adjustment; an abutment secured to said nut adjacent said one end of said piston; an abutment element coaxial of said axis and said nut fixed to the inner surface of said bore to prevent axial motion thereof; and a return spring disposed between said abutment and said abutment element; said abutment element including an abutment housing disposed coaxially of and encircling said nut, said abutment housing including an internal cylindrical wall having an outwardly directed step adjacent said one end of said piston, the end of said cylindrical wall at said step providing an annular bearing surface and the end of said cylinder wall after said step providing a transverse surface; said arrangement including an engaging sleeve disposed coaxially of said nut and between said nut and said abutment housing in a freely rotatable relationship therewith, said engaging sleeve including a cone secured Thereto, the base of said cone being disposed adjacent said one end of said piston, said cone cooperating with said bearing surface during said adjusting operation to provide a strong frictional connection between said cone and said abutment housing; and said return spring including a disc spring encircling said nut and disposed between said transverse surface and said abutment.

Claim 16

A device according to claim 12, further including a retaining ring secured to the outer surface of said nut between said other end of said piston and said abutment housing and said engaging sleeve.

Claim 17

A self-adjusting device for a disc brake comprising: an actuating piston having a longitudinal axis and bore coaxial of said axis, said bore being closed at one end of said piston; an adjusting spindle in a fixed position coaxial of said axis having threads on the outer surface thereof and extending out of the other end of said piston; an adjusting nut having threads for threading onto said spindle; an arrangement associated with said nut to rotate said nut on said spindle to permit the desired self-adjustment; an abutment secured to said nut adjacent said one end of said piston; an abutment element coaxial of said axis and said nut fixed to the inner surface of said bore to prevent axial motion thereof; a return spring disposed between said abutment and said abutment element; and a retaining ring secured to the outer surface of said nut between said other end of said piston and said abutment element.

Claim 18

A self-adjusting device for a disc brake comprising: an actuating piston having a longitudinal axis and bore coaxial of said axis, said bore being closed at one end of said piston; an adjusting spindle in a fixed position coaxial of said axis having threads on the outer surface thereof and extending out of the other end of said piston; an adjusting nut having threads for threading onto said spindle; an arrangement associated with said nut to rotate said nut on said spindle to permit the desired self-adjustment; an abutment secured to said nut adjacent said one end of said piston; an abutment element coaxial of said axis and said nut fixed to the inner surface of said bore to prevent axial motion thereof; a return spring disposed between said abutment and said abutment element; and a retaining ring secured to the outer surface of said nut between said other end of said piston and said abutment element.

Claim 19

A self-adjusting device for a disc brake comprising: an actuating piston having a longitudinal axis and bore coaxial of said axis, said bore being closed at one end of said piston; an adjusting spindle in a fixed position coaxial of said axis having threads on the outer surface thereof and extending out of the other end of said piston; an adjusting nut having threads for threading onto said spindle; an arrangement associated with said nut to rotate said nut on said spindle to permit the desired self-adjustment; an abutment secured to said nut adjacent said one end of said piston; an abutment element coaxial of said axis and said nut fixed to the inner surface of said bore to prevent axial motion thereof; a return spring disposed between said abutment and said abutment element; a groove disposed in said piston adjacent said one end of said piston and coaxial of said axis; and said abutment is guided in said groove.

Claim 20

A self-adjusting device for a disc brake comprising: an actuating piston having a longitudinal axis and bore coaxial of said axis, said bore being closed at one end of said piston; an adjusting spindle in a fixed position coaxial of said axis having threads on the outer surface thereof and extending out of the other end of said piston; an adjusting nut having threads for threading onto said spindle; an arrangement associated with said nut to rotate said nut on said spindle to permit the desired self-adjustment; an abutment secured to said nut adjacent said one end of said piston; an abutment element coaxial of said axis and said nut fixed to the inner surface of said bore to prevent axial motion thereof; a return spring disposed between said abutment and said abutment element; a groove disposed in said piston adjacent said one end of said piston and coaxial of said axis; and said abutment is guided in said groove.

Claim 21

A device according to claim 15, wherein the length of said groove equals the thickness of said abutment.

Claim 22

A device according to claim 15, wherein said return spring is prestressed.

Claim 23

A self-adjusting device for a disc brake comprising: an actuating piston having a longitudinal axis and bore coaxial of said axis, said bore being closed at one end of said piston; an adjusting spindle in a fixed position coaxial of said axis having threads on the outer surface thereof and extending out of the other end of said piston; an adjusting nut having threads for threading onto said spindle; an arrangement associated with said nut to rotate said nut on said spindle to permit the desired self-adjustment; an abutment secured to said nut adjacent said one end of said piston; an abutment element coaxial of said axis and said nut fixed to the inner surface of said bore to prevent axial motion thereof; and a return spring disposed between said abutment and said abutment element; said arrangement including an engaging sleeve disposed coaxially of said axis encircling said nut in a freely rotatable relationship therewith, said engaging sleeve having a cone secured thereto adjacent said other end of said piston, said cone tapering towards said other end of said piston; and said abutment element including an abutment ring fixed to the inner wall of said bore adjacent said other end of said piston, the inner diameter of said abutmeNt ring cooperates with said cone to provide a strong frictional connection between said cone and said abutment ring during said adjustment operation.

Claim 24

A self-adjusting device for a disc brake comprising: an actuating piston having a longitudinal axis and bore coaxial of said axis, said bore being closed at one end of said piston; an adjusting spindle in a fixed position coaxial of said axis having threads on the outer surface thereof and extending out of the other end of said piston; an adjusting nut having threads for threading onto said spindle; an arrangement associated with said nut to rotate said nut on said spindle to permit the desired self-adjustment; an abutment secured to said nut adjacent said one end of said piston; an abutment element coaxial of said axis and said nut fixed to the inner surface of said bore to prevent axial motion thereof; and a return spring disposed between said abutment and said abutment element; said arrangement including an engaging sleeve disposed coaxially of said axis encircling said nut in a freely rotatable relationship therewith, said engaging sleeve having a cone secured thereto adjacent said other end of said piston, said cone tapering towards said other end of said piston; and said abutment element including an abutment ring fixed to the inner wall of said bore adjacent said other end of said piston, the inner diameter of said abutmeNt ring cooperates with said cone to provide a strong frictional connection between said cone and said abutment ring during said adjustment operation.

Claim 25

A device according to claim 18, wherein said return spring includes a helical pressure spring disposed coaxial of said axis and encircling said engaging sleeve and also disposed between said abutment and said abutment ring.

Claim 26

A device according to claim 19, further including an anti-twisting ring connected between said abutment and said helical pressure spring.

Claim 27

A device according to claim 20, further including longitudinal slots disposed in the inner surface of said bore, and said anti-twisting ring is supported in said slots so as to be torsionally strong yet axially displaceable.

Claim 28

A device according to claim 20, wherein the inner wall of said bore adjacent said one end of said piston is shaped to conform to the shape of said anti-twisting ring.

Claim 29

A device according to claim 18, wherein said arrangement further includes a helical torsion spring disposed coaxially of said axis and encircling said nut and disposed between said abutment and said engaging sleeve to exert a torque on said engaging sleeve for movement of said cone towards said abutment ring.

Claim 30

A device according to claim 18, wherein the inside and outside periphery of said abutment ring include vent slots.

Claim 31

A self-adjusting device for a disc brake comprising: an actuating piston having a longitudinal axis and bore coaxial of said axis, said bore being closed at one end of said piston; an adjusting spindle in a fixed position coaxial of said axis having threads on the outer surface thereof and extending out of the other end of said piston; an adjusting nut having threads for threading onto said spindle; an arrangement associated with said nut to rotate said nut on said spindle to permit the desired self-adjustment; an abutment secured to said nut adjacent said one end of said piston; an abutment element coaxial of said axis and said nut fixed to the inner surface of said bore to prevent axial motion thereof; and a return spring disposed between said abutment and said abutment element; said arrangement including a catch element secured to the outer surface of said nut; and said abutment element including a sheet metal housing disposed coaxial of said axis and encircling said nut, said sheet metal housing having cone elements secured to the end of said sheet metal housing adjacent said other end of said housing, said cone elements being tapered toward said other end of said housing and in a cooperative relationship with said catch element to provide a strong frictional connection between said cone elements and said catch element during said adjustment operation.

Claim 32

A self-adjusting device for a disc brake comprising: an actuating piston having a longitudinal axis and bore coaxial of said axis, said bore being closed at one end of said piston; an adjusting spindle in a fixed position coaxial of said axis having threads on the outer surface thereof and extending out of the other end of said piston; an adjusting nut having threads for threading onto said spindle; an arrangement associated with said nut to rotate said nut on said spindle to permit the desired self-adjustment; an abutment secured to said nut adjacent said one end of said piston; an abutment element coaxial of said axis and said nut fixed to the inner surface of said bore to prevent axial motion thereof; and a return spring disposed between said abutment and said abutment element; said arrangement including a catch element secured to the outer surface of said nut; and said abutment element including a sheet metal housing disposed coaxial of said axis and encircling said nut, said sheet metal housing having cone elements secured to the end of said sheet metal housing adjacent said other end of said housing, said cone elements being tapered toward said other end of said housing and in a cooperative relationship with said catch element to provide a strong frictional connection between said cone elements and said catch element during said adjustment operation.

Claim 33

A device according to claim 25, wherein said nut includes on the outer surface thereof a steep thread; and said catch element includes on the inner periphery thereof teeth to cooperate with said steep thread.

Claim 34

A self-adjusting device for a disc brake comprising: an actuating piston having a longitudinal axis and bore coaxial of said axis, said bore being closed at one end of said piston; an adjusting spindle in a fixed position coaxial of said axis having threads on the outer surface thereof and extending out of the other end of said piston; an adjusting nut having threads for threading onto said spindle; an arrangement associated with said nut to rotate said nut on said spindle to permit the desired self-adjustment; an abutment secured to said nut adjacent said one end of said piston; an abutment element coaxial of said axis and said nut fixed to the inner surface of said bore to prevent axial motion thereof; and a return spring disposed between said abutment and said abutment element; said bore including a first step on the inner surface thereof spaced from said one end of said piston to reduce the diameter of said bore by a first given amount, and a second step on the inner surface thereof between said first step and said one end of said piston to reduce the diameter of said bore by a second given amount greater than said first given amount; and further including an expanding ring disposed in cooperative relationship with said abutment element to cause said abutment element to be retained in place against said first step.

Claim 35

A self-adjusting device for a disc brake comprising: an actuating piston having a longitudinal axis and bore coaxial of said axis, said bore being closed at one end of said piston; an adjusting spindle in a fixed position coaxial of said axis having threads on the outer surface thereof and extending out of the other end of said piston; an adjusting nut having threads for threading onto said spindle; an arrangement associated with said nut to rotate said nut on said spindle to permit the desired self-adjustment; an abutment secured to said nut adjacent said one end of said piston; an abutment element coaxial of said axis and said nut fixed to the inner surface of said bore to prevent axial motion thereof; and a return spring disposed between said abutment and said abutment element; said bore including a first step on the inner surface thereof spaced from said one end of said piston to reduce the diameter of said bore by a first given amount, and a second step on the inner surface thereof between said first step and said one end of said piston to reduce the diameter of said bore by a second given amount greater than said first given amount; and further including an expanding ring disposed in cooperative relationship with said abutment element to cause said abutment element to be retained in place against said first step.

Claim 36

A device according to claim 27, wherein said abutment is disposed at the closed end of said bore; further including a spacer sleeve disposed coaxial of said axis, and encircling said nut and disposed in contact with said abutment and extending towards said other end of said piston beyond said second step; and wherein said return spring includes a disc spring disposed in transverse relation to said bore and encircling said nut, said disc spring being disposed between said first and second step in contact with said spacer sleeve and said abutment element.

Claim 37

A device according to claim 28, wherein said arrangement includes a helical torsion spring disposed to encircle said nut and to be between said nut and said spacer sleeve and said disc spring.