US4544045A — Mechanical actuator for a disc brake

Claim 1

Independent Claim 302 words

A dual toggle mechanical actuator for a disc brake within a caliper assembly cooperates with at least one friction pad to engage the latter with a rotor, the caliper assembly including a housing with a bore receiving a piston assembly which is movable in the bore to engage the friction pad with a rotor, and a mechanical actuator disposed in the bore for moving the piston assembly, characterized in that the mechanical actuator comprises an easily reversible, dual toggle mechanical actuator having a cam shaft extending into the bore, a reaction toggle cooperating with the cam shaft and the housing and an output toggle disposed between the piston assembly and the cam shaft for imparting movement to the piston assembly in response to rotation of the cam shaft, each of the toggles having a pair of pivot points about which the toggles move, the reaction toggle and output toggle cooperating with grooves of said cam shaft to define asymmetric interfaces therebetween so that angular travel of said toggles is different when said cam shaft is rotated and said cam shaft moves in the direction of said piston assembly, and an end wall enclosing said bore, the reaction toggle pivoting relative to said cam shaft and relative to said end wall during a first stage of braking when said cam shaft is rotated, and said reaction toggle moving with said cam shaft to pivot relative to said end wall during a second stage of braking, the output toggle approaching a lock position and the reaction toggle attaining a lock position relative to the respective grooves when said cam shaft has completed rotation wherein longitudinal center lines of the toggles remain a distance apart along a radius of said cam shaft so that the cam shaft may be counter-rotated easily to a rest position.

Claim 2

Dependent Claim 302 words

A dual toggle mechanical actuator for a disc brake within a caliper assembly cooperates with at least one friction pad to engage the latter with a rotor, the caliper assembly including a housing with a bore receiving a piston assembly which is movable in the bore to engage the friction pad with a rotor, and a mechanical actuator disposed in the bore for moving the piston assembly, characterized in that the mechanical actuator comprises an easily reversible, dual toggle mechanical actuator having a cam shaft extending into the bore, a reaction toggle cooperating with the cam shaft and the housing and an output toggle disposed between the piston assembly and the cam shaft for imparting movement to the piston assembly in response to rotation of the cam shaft, each of the toggles having a pair of pivot points about which the toggles move, the reaction toggle and output toggle cooperating with grooves of said cam shaft to define asymmetric interfaces therebetween so that angular travel of said toggles is different when said cam shaft is rotated and said cam shaft moves in the direction of said piston assembly, and an end wall enclosing said bore, the reaction toggle pivoting relative to said cam shaft and relative to said end wall during a first stage of braking when said cam shaft is rotated, and said reaction toggle moving with said cam shaft to pivot relative to said end wall during a second stage of braking, the output toggle approaching a lock position and the reaction toggle attaining a lock position relative to the respective grooves when said cam shaft has completed rotation wherein longitudinal center lines of the toggles remain a distance apart along a radius of said cam shaft so that the cam shaft may be counter-rotated easily to a rest position.

Claim 3

Dependent Claim 32 words

The mechanical actuator of claim 1 in which said cam shaft moves in the direction of said piston assembly in an amount equal to 12-15% of the movement for said piston assembly.

Claim 4

Dependent Claim 43 words

The mechanical actuator of claim 1 in which said reaction toggle is disposed at a 13 degrees angle relative to a horizontal axis in a rest position and said output toggle is disposed at a 16 degrees angle relative to the horizontal axis.

Claim 5

Dependent Claim 41 words

The mechanical actuator of claim 3 in which said output toggle is disposed at a 7 degrees angle relative to the horizontal axis in an applied position and said reaction toggle has moved past the horizontal axis in the applied position.

Claim 6

Dependent Claim 96 words

The mechanical actuator of claim 1 in which said housing bore defines a horizontally extending center line, said output toggle engaging said piston assembly in a rest position at said bore center line, said cam shaft defining a center disposed above said bore center line, said reaction toggle engaging the end wall closing said bore in the rest position at a horizontal position between said cam shaft center and said bore center line, and said reaction toggle engaging said cam shaft in the rest position at a horizontal position above the center of said cam shaft.

Claim 7

Dependent Claim 36 words

The mechanical actuator of claim 5 in which the engagement between said reaction toggle and said cam shaft moves horizontally below said cam shaft center when said cam shaft is rotated to a brake applied position.

Claim 8

Dependent Claim 44 words

The mechanical actuator of claim 1, further comprising a sleeve disposed in the bore and about said cam shaft, the movement of the cam shaft causing the cam shaft to disengage one side of the sleeve and engage an opposite side of said sleeve.

Claim 9

Dependent Claim 30 words

The mechanical actuator of claim 7, wherein the sleeve extends about less than the entire circumference of said cam shaft in order to permit said movement of the cam shaft.

Claim 10

Dependent Claim 205 words

An easily reversible, dual toggle mechanical actuator for a disc brake assembly wherein a caliper assembly cooperates with a pair of friction elements to engage the latter with a rotor, said mechanical actuator comprising a cam shaft and a pair of toggles with each toggle having a pair of pivot points about which the toggle moves, said cam shaft defining grooves having interfaces with said pair of toggles wherein one of said pair of toggles rotates more than the other of said pair of toggles during operation of said mechanical actuator to limit movement of said cam shaft, said cam shaft being rotatable relative to said pair of toggles during one stage of operation for said mechanical actuator and said cam shaft rotatable with said other toggle as a unit during a second stage of operation for said mechanical actuator, the one toggle approaching a lock position and the other toggle attaining a lock position relative to the respective grooves when said second stage of operation is completed wherein longitudinal center lines of the toggle do not cross over one another and remain a distance apart along a radius of said cam shaft so that the mechanical actuator is returned easily to a rest position.

Claim 11

Dependent Claim 205 words

An easily reversible, dual toggle mechanical actuator for a disc brake assembly wherein a caliper assembly cooperates with a pair of friction elements to engage the latter with a rotor, said mechanical actuator comprising a cam shaft and a pair of toggles with each toggle having a pair of pivot points about which the toggle moves, said cam shaft defining grooves having interfaces with said pair of toggles wherein one of said pair of toggles rotates more than the other of said pair of toggles during operation of said mechanical actuator to limit movement of said cam shaft, said cam shaft being rotatable relative to said pair of toggles during one stage of operation for said mechanical actuator and said cam shaft rotatable with said other toggle as a unit during a second stage of operation for said mechanical actuator, the one toggle approaching a lock position and the other toggle attaining a lock position relative to the respective grooves when said second stage of operation is completed wherein longitudinal center lines of the toggle do not cross over one another and remain a distance apart along a radius of said cam shaft so that the mechanical actuator is returned easily to a rest position.

Claim 12

Dependent Claim 45 words

The mechanical actuator of claim 9 in which said other toggle defines an angle relative to a horizontal axis and said other toggle angle approaches said horizontal axis and crosses the same as said mechanical actuator moves from said one stage to said second stage.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1988-09-30	1989-04-01	1989-10-01	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1992-09-30	1993-04-01	1993-10-01	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1996-09-30	1997-04-01	1997-10-01	$7700.00	Window Closed / Lapsed

Mechanical actuator for a disc brake

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