The Bendix Corporation

Alliedsignal Inc.

Clark Equipment Compnay

Orla L Holcomb, Jr

Donald D Johannesen

Clyde E Carr

Andrew F Kazmierzak

Louis S Rodino

Bruce D Anderson

The shoe hold down spring (40) comprises a single wave form or serpentine shaped leaf spring (40) which is engaged at opposite ends (42, 44) by hold down pins (53, 55) of a drum brake. The hold down pins (53, 55) are connected with the backing plate (12) and extend through respective openings (21, 23) within a brake shoe web (20). The hold down spring (40) includes opposite ends (42, 44) and a middle portion (41) all of which extend away and are spaced-apart from the shoe web (20), and two intermediate curved portions (47, 49) which engage the web (20). The opposite ends (42, 44) of the hold down spring (40) have slots (43, 45) extending inwardly from spring edges (42A, 44A), and small curved recesses (42B, 44B) which effect securement of ends (53A, 55A) of the pins (53, 55) to the spring (40). The pins (53, 55) have laterally extending wings (53B, 55B) at the pin ends (53A, 55A) which are received within the small curved recesses (42A, 44A) at the respective ends (42, 44) of the spring (40).

Brake shoe hold down spring

The mechanically actuated brake (10) comprises a laterally movable sleeve housing (22) which is attached by way of slots (24) and connections (26) with the support plate (28). A mechanical actuator and adjuster mechanism (40) has parts (42, 48) received within a longitudinal through opening (27) of the housing (22), a first part (42) of the mechanism (40) abutting one brake shoe end (20) while a second part (48) of the mechanism (40) abuts the other brake shoe end (18). A lever (50) for service brake operation is attached pivotably by a connection pin (30) with the housing (22) and extends through a transverse through opening (29) of the housing (22). The lever (50) is received within a slot (49) of the second part (48) of the mechanism (40), and includes an actuating arm (57) which extends through the housing (22) and is engagable with an actuating arm (66) of a pawl (60) that actuates the adjuster portion of the mechanism (40). The pin connection (30) also mounts rotatably the pawl (60) to the housing (22). The pawl (60) includes a spring support flap (67) which receives one end of a spring (70) attached to the one brake shoe end (20).

Mechanically actuated brake with automatic adjustment

The present invention relates to an improvement in a band brake wherein a plurality of rotors and stators provide for braking a rotatable member when a friction lining on the band brake is engageable with the rotatable member. The rotatable member carries an axially extendible assembly which is engageable with the friction lining to provide for extension of the axially extendible assembly. When the assembly is extended, the rotors which rotate with the rotatable member and the stators which are carried by a support housing are moved axially into frictional engagement with each other. The extendible assembly comprises a first element carried by a key on the rotatable member to impart rotation with the rotatable member and permit axial movement relative to the rotatable member, and a second element resiliently connected to the first element. The first element and second element include a cam therebetween such that when the second element engages the friction lining of the band brake, the second element rotates through a limited angle relative to the first element to increase the axial spacing between the elements by the action of the cam. The first element is also engageable with the friction lining to eliminate noise and instability in the action between the elements and the cam. In order to engage the friction lining with the rotatable member, the support housing forms a hydraulic actuator with at least one piston and a pair of links which are pivotably connected to each other cooperate with the friction lining when the hydraulic actuator is operated to contract the friction lining into engagement with the rotatable member.

Band brake assembly

A band brake assembly includes a band which carries a friction lining for engagement with a rotatable member. A casing surrounds the band and a hydraulic actuator cooperates with a pair of links which are engaged with respective ends of the band. When the hydraulic actuator is operated, the hydraulic actuator is moved toward the rotatable member such that the pair of links are pivoted oppositely about the moving hydraulic actuator. The pivoting links are coupled to the band such that movement of the hydraulic actuator causes the band to contract the friction lining into engagement with the rotatable member. The pair of links are optionally provided with rollers which roll on the casing and the hydraulic actuator when the latter is operated. It is also possible to eliminate the casing so that the rollers roll on the band when the hydraulic actuator is operated.

Band brake and actuator therefor

A drum brake is provided with a pair of brake shoes having axially inner and outer webs for supporting friction linings. A backing plate mounts the pair of brake shoes by providing radially outwardly extending lugs which are disposed between the inner and outer webs to prevent axial movement of the pair of brake shoes. Moreover, springs are disposed between respective lugs and portions extending between the webs to bias the portions into engagement with recesses on the backing plate. A double hydraulic actuator is positioned between the pair of braking shoes with one actuator cooperating with the inner webs and the other actuator cooperating with the outer webs during a braking application to urge the friction linings into engagement with a drum. The inner and outer webs also include slots substantially opposite the double hydraulic actuator for receiving plates which mount an adjustment mechanism between the pair of brake shoes.

Drum brake and mounting means therefor

A rigid and deformable hydraulic seal for a force-applying mechanism, the seal being interposed between a piston and a housing cavity. This seal is generally cup-shaped and has an annular outer end portion that is rigidly retained in a peripheral groove of the housing cavity. Adjacent to this end portion is a half torus or single convolution hoop portion open toward the cavity, with the seal further including a generally cylindrical side surface and a circular bottom portion, with this seal, together with the cavity, defining a fluid-tight variable volume chamber. Fluid pressure supplied to this chamber causes plastic deformation of the seal and permits relative motion to occur between the piston and housing. When used in a hydraulic brake apparatus, the plastic deformation of the seal provides automatic brake adjustment as a factor of lining material wear, whereas the elastic deformation which occurs as the fluid pressure in the chamber is reduced provides a slight retraction capability of the friction lining from the rotating brake member.

Deformable rigid seal for a hydraulic brake apparatus

An automatically operative brake adjuster includes a cup-shaped member attached to a brake carrier member, with this member cooperating with a stepped bore in the carrier member to form an annular chamber having spaced opposed end surfaces. An annular follower member, slidably received and spring-biased within the annular chamber, has flange portions on opposite ends, with these flange portions cooperating with the opposed end surfaces to limit the movement of the follower member in both the brake-release and the brake-application directions. A piston, extending freely through the annular chamber, includes a tapered portion that carries a deformable hollow member in the annular chamber and is interference-fitted therewith. The hollow member, which preferably takes the shape of a circular or elliptical cylinder, is in abutment with one of the flange portions and, in response to pressurized fluid, the piston moves together with the hollow member and follower in the brake-application direction until the other flange portion engages one of the opposed end surfaces whereupon the piston is forceably urged through at least an axial portion of the hollow member and causes deformation thereof and axially repositions the piston to take up the undesired brake clearance. Brake release, in response to depressurization of the piston and the urging of the spring on the follower member, moves the piston together with the hollow and follower members until the latter engages one of the opposed end surfaces and thereby establishes a constant brake running clearance.

Growing community of inventors

South Bend, IN, United States of America

Orla L Holcomb, Jr