Automatic adjusters

Claim 2

An automatically adjustable force transmitting mechanism comprising two relatively rotatable members, a non-reversible screw-thread connection between said members, a plurality of rolling elements, means circumferentially locating said rolling elements with respect to one of said members, screw-thread means in the other of said members, said rolling elements being disposed in rolling relation with the last-mentioned screw-thread means, and means for applying an axially directed force to said rolling elements responsively to a requirement for adjustment to thereby cause said rolling elements to roll along said screwthread means in said other member and thereby cause said one member to rotate relative to said other member.

Claim 3

A mechanism according to claim 1, in which said means for applying an axially directed force includes a thrust element disposed to engage said rolling elements and a spring acting on said thrust element.

Claim 4

A mechanism according to claim 2, in which said spring acts between said one member and said thrust element.

Claim 5

A mechanism according to claim 3, further comprising a rolling bearing between said spring and one of said member and thrust element.

Claim 6

A mechanism according to claim 1, in which said one member relative to which said rolling elements are circumferentially located comprises a nut and said other member comprises a spindle and in which said screw-thread connection and said screwthread means comprise an internal thread on said nut and an external thread on said spindle, said rolling members rolling in said external thread.

Claim 7

A mechanism according to claim 5, which further comprises a casing surrounding said nut and providing abutment means for said spring, said nut being urged by said spring against one end of said casing.

Claim 8

A mechanism according to claim 6 in which said nut and said casing have cooperating serrations, said spring biasing said serrations into interengagement.

Claim 9

A mechanism according to claim 6, in which said rolling bearing includes an intermediate race member, said spring surrounding said race member and acting between said race member and said casing and in which said rolling bearing is provided between said race member and said thrust element.

Claim 10

A mechanism according to claim 1, in which said one member relative to which said rolling elements are circumferentially located comprises a screw-member and said screw-thread connection comprises an external thread on said screw-member and an internal thread in said other member, said rolling elements rolling in said internal thread.

Claim 11

A mechanism according to claim 1 in which said rolling elements comprise balls.

Claim 12

A mechanism according to claim 1, in which said rolling elements comprise conical rollers journalled in said one member.

Claim 13

An automatically adjustable force transmitting mechanism comprising two relatively rotatable members, a non-reversible multi-start screw-thread connection between said members, a plurality of rolling elements equal in number to the number of starts of said multi-start screw-thread connection, said rolling elements being circumferentially located with respect to one of said members and rolling in respective starts of multi-start screw-thread means in the other of said members, and means for applying an axially directed force to said rolling elements responsively to a requirement for adjustment to thereby cause said rolling elements to roll along said screw-thread on said other member and thereby cause said one member to rotate on said other member.

Claim 14

An automatically adjustable force transmitting mechanism comprising two relatively rotatable members, a non-reversible multi-start screw-thread connection between said members, a plurality of rolling elements equal in number to the number of starts of said multi-start screw-thread connection, said rolling elements being circumferentially located with respect to one of said members and rolling in respective starts of multi-start screw-thread means in the other of said members, and means for applying an axially directed force to said rolling elements responsively to a requirement for adjustment to thereby cause said rolling elements to roll along said screw-thread on said other member and thereby cause said one member to rotate on said other member.

Claim 15

An automatically adjustable force transmitting mechanism comprising a nut and a spindle rotatable relatively to one another, a non-reversible screw-thread connection between said nut and spindle, said non-reversible screw-thread connection comprising a single start internal thread in said nut and a single start external thread on said spindle, balls, said nut having respective recesses receiving said balls to circumferentially locate said balls relative to said nut and rolling in said external thread in said spindle, and a thrust element disposed to engage said balls, and a spring acting on said thrust element for applying an axially directed force to said balls responsively to a requirement for adustment to thereby cause said balls to roll along said external screw-thread on said spindle and thereby cause said nut to rotate on said spindle, said thrust element being tilted relative to said nut.

Claim 16

An automatically adjustable force transmitting mechanism comprising a nut and a spindle rotatable relatively to one another, a non-reversible screw-thread connection between said nut and spindle, said non-reversible screw-thread connection comprising a single start internal thread in said nut and a single start external thread on said spindle, balls, said nut having respective recesses receiving said balls to circumferentially locate said balls relative to said nut and rolling in said external thread in said spindle, and a thrust element disposed to engage said balls, and a spring acting on said thrust element for applying an axially directed force to said balls responsively to a requirement for adustment to thereby cause said balls to roll along said external screw-thread on said spindle and thereby cause said nut to rotate on said spindle, said thrust element being tilted relative to said nut.

Claim 17

An automatically adjustable force transmitting mechanism comprising a nut and a spindle rotatable relatively to one another, a non-reversible screw-thread connection between said nut and spindle, said non reversible screw-thread connection comprising a multi-start internal thread in said nut and a multi-start external thread on said spindle, balls, at least one but not more than three such balls rolling in each of the spindle threads corresponding to each Thread start, said nut having respective recesses receiving said balls to circumferentially locate said balls relative to said nut, and a thrust element disposed to engage said balls and a spring acting on said thrust element, for applying an axially directed force to said balls responsively to a requirement for adjustment to thereby cause said balls to roll along said spindle thread and thereby cause said nut to rotate on said spindle, said thrust element being tilted relative to said nut.

Claim 18

An automatically adjustable force transmitting mechanism comprising a nut and a spindle rotatable relatively to one another, a non-reversible screw-thread connection between said nut and spindle, said non reversible screw-thread connection comprising a multi-start internal thread in said nut and a multi-start external thread on said spindle, balls, at least one but not more than three such balls rolling in each of the spindle threads corresponding to each Thread start, said nut having respective recesses receiving said balls to circumferentially locate said balls relative to said nut, and a thrust element disposed to engage said balls and a spring acting on said thrust element, for applying an axially directed force to said balls responsively to a requirement for adjustment to thereby cause said balls to roll along said spindle thread and thereby cause said nut to rotate on said spindle, said thrust element being tilted relative to said nut.

Claim 19

A mechanism according to claim 13, in which said nut has an inclined face and said thrust element comprises a thrust washer resting against said inclined face.

Claim 20

A mechanism according to claim 13, in which said nut comprises two parts, of which one part has said internal screw-thread therein and the other part has said recess therein receiving said balls, which two parts can be fitted together in any desired relative angular position.

Claim 21

A mechanism according to claim 13 which further comprises a casing which can be axially abutted by said nut, a race member and a rolling bearing between said race member and said casing said spring acting between said thrust element and said race member.

Claim 22

A mechanism according to claim 1 which is fitted to a hydraulic brake actuator comprising opposed pistons, an auxiliary mechanical actuator being fitted in one of said pistons, said mechanism being operative between said mechanical actuator and the other of said pistons.