Abstract: A drum brake device for a vehicle includes a first brake shoe and a second brake shoe movably coupled to a back plate, and spaced apart from each other; a wheel cylinder positioned between one end of the first brake shoe and one end of the second brake shoe, and configured to expand the distance between the one end of the first brake shoe and the one end of the second brake shoe; and an actuator positioned between another end of the first brake shoe and another end of the second brake shoe, and configured to provide a driving force to expand the distance between the one end of the first brake shoe and the one end of the second brake shoes and to expand the distance between the another end of the first brake shoe and the another end of the second brake shoe.

Abstract: Provided is an electric parking brake device in which an actuator case of an electric actuator is mounted to a backplate of a drum brake which includes a parking brake lever, with which electric actuator it is possible to obtain a parking brake state by pulling a brake cable linked with the parking brake lever. The backplate is formed with a through-hole for passing the brake cable and has a connecting tube portion integrally protruding therefrom and enclosing the through-hole. A mounting tube includes, on one end in an axial direction, a joint portion which is formed separately from the backplate and joined to the connecting tube portion. The actuator case is mounted to the mounting tube at certain axial and circumferential positions with respect to the mounting tube. This allows increased freedom of the mounting attitude of the electric actuator with respect to the backplate without increased cost.

Abstract: In an electric parking brake device in which a parking brake state is released by loosening a brake cable: a nut is screwed onto a screw shaft in such a way as to be capable of moving in an axial direction; a movement restricting portion which is caused to abut the screw shaft or a linked member that moves in the axial direction together with the screw shaft, thereby restricting an axial direction movement end of the screw shaft to the side loosening the brake cable, is disposed in a fixed position inside an actuator case; and a resilient member which is compressed in response to axial direction movement of the nut after movement restriction has been effected by the movement restricting portion when the screw shaft moves in the axial direction toward the side loosening the brake cable is interposed between the nut and an insertion member.

Abstract: An expansion device for drum brakes, which is floatingly and approximately centrally arranged between two substantially symmetrical brake shoes, the expansion device including at least two gear levers articulated to each other and each supported on a brake shoe, at least one of the gear levers of the expansion lock being coupled to an actuating element of an actuator system such that the brake shoes carry out an even, translationally directed expanding movement, which is converted by a gearing, in the direction of the brake drum. At least one of the gear levers of the spreader lock has a spring element integrated into it that can be elastically reversibly deformed by a brake application force about a defined elasticity ?S of at least 1 mm in a defined manner.

Abstract: A drum brake apparatus includes first and second brake shoes, a wheel cylinder, an anchor portion, an adjuster, an expansion mechanism for expanding the first and second brake shoes, a switch lever mechanism rotatable by an action force of a given or higher value from the expansion mechanism, and a switch strut, following the rotation of the switch lever mechanism, for expanding the anchor-portion side adjoining ends of the first and second brake shoes.

Abstract: A cam assisted centrifugal brake or clutch system provides increased mechanical advantage to improve the output torque relative to prior art devices such as leading brake shoes. The brake or clutch engagement is cammed radially outwardly to engage a brake housing in one direction and guided to a disengaged position in the other direction. Centrifugal forces retain the brake in the disengaged position. Embodiments of the present invention are applied as a backspin braking system that is incorporated into a drive head for a progressing cavity pump drive system.

Abstract: A brake assembly having a brake shoe and an anchor pin. The brake shoe may have an anchor pin slot that may include first and second connecting surfaces that extend from an arcuate bearing surface. The anchor pin may have a flat and may be inserted into the anchor pin slot when the flat is aligned with the second connecting surface.

Abstract: A brake shoe for a drum brake is provided. The brake shoe includes an arcuate brake table defining a radially outer side configured to receive a brake lining and a radially inner side opposite the radially outer side. The brake table further defines a plurality of sleeves proximate a first end of the brake table. The sleeves are aligned along an axis and axially spaced from one another. Each of the sleeves is configured to receive an anchor pin therein through which the brake shoe may be pivotally coupled to a brake spider. The sleeves are disposed about more than half of a perimeter of the anchor pin.

Abstract: Disclosed is a wheel cylinder and a drum brake having the same, in which the number of position as well as other elements accompanied with the piston may be reduced, resulting in reduced manufacturing cost.

Abstract: A brake has a pair of brake pads (12), each pad being moveable generally radially outwardly into contact with a brake drum by a respective operating lever (14) acted on at one end by a brake applying means (15) and pivoted (16) at the other end from a backplate (11). Each pad is contacted by a portion (14c) of the respective operating lever intermediate the lever ends and moving radially outwardly between a pair of circumferentially spaced abutments (45) which extend generally perpendicular to the backplate and which react braking torque when the brake is applied. One end of each abutment (45) is supported from the backplate and the other free ends of the abutments is linked circumferentially (46) to each other to brace the pair of abutments against relative circumferential deflection when the brake is applied. The pivots (16) of the levers may also be connected by a bracing link (75) to help to control the deflection of the pivots when the brake is applied.

Abstract: A drum brake has a pair of brake shoes (40) moveable radially outwardly into contact with an associated brake drum to provide a handbrake function by a cross strut (100) which acts between the brake shoes or between pivoting brake operating levers (14) which actuate the brake shoes. A handbrake lever (18) is pivoted on one brake shoe or brake operating lever (14) and contacts one end of the strut to displace the other brake shoe or brake operating lever towards the drum to apply the associated shoe against the drum and by reaction through the strut to also force the other brake shoe or brake operating lever toward the drum to apply the other shoe against the drum. The strut (100) is in two parts (101,102), one part being connected for movement with each respective brake shoe or operating lever, the strut parts having inter-engageable formations in the form of teeth (103,104) which when engaged allow the strut (100) to transmit axial force between the shoes or operating levers.

Abstract: An actuator for a drum brake comprises a housing (1), a screw mechanism having at least one screw (3, 6) and a nut (4, 7), which screw mechanism (2) is supported with respect to the housing (1), and drive means (3) which are drivingly connected to the screw mechanism for providing a linear movement of at least one of the screw and nut with respect to the housing upon driving the screw mechanism. The screw mechanism comprises two axially aligned screws which have opposite lead angles and two corresponding nuts, said screws each engaging a respective nut, the drive means being connected to both screws or to both nuts.

Abstract: A drum brake assembly (10) having first (12) and second (14) brake shoes retained on a backing plate (16). Each of the first (12) and second (14) brake shoes have an end (22,24) aligned on a hydraulic actuator assembly (26) and an end (28,30) aligned on an anchor block (40). An adjustable strut mechanism (32) has a extendable shaft (33) that includes a first end member (34) that engages the first end (22) of said first brake shoe (12), a second end member (36) that engages the first end (24) of the second brake shoe (14) and a rotatable stem (35). A first resilient member (150) urges the first (12) and second (14) brake shoes toward the hydraulic actuator assembly (26) and second resilient member (48) urges the first (12) and second (14) brake shoes toward the anchor block (40). The length of the extendable shaft (33) is adjusted by ratcheting a pawl (65) rotating the stem (35) to establish a predetermined running clearance between the first (42) and second (44) friction members and drum (46).

Abstract: A wear insert is provided for receiving trunnions on the ends of pieces used in affixing brake shoes to a brake shoe assembly. A vehicle brake shoe assembly has brake shoes which may be urged outwardly against a brake drum when a S-cam is rotated. The brake shoe has an arcuate brake table on which friction liners are installed. A brake web, comprising a pair of brake web elements, extends inwardly from the brake table toward the center of radius of the arcuate brake table. Each of these spaced apart web elements has a first and a second end, and each of the ends is provided with a trunnion receiving slot. The trunnion receiving slots at one end receive the trunnions of an anchor pin, and the trunnion receiving slots at the other end receive the trunnions of a cam follower. The wear insert is removably seated in at least one of the trunnion slots to be interposed between the slot and the trunnion.

Abstract: A drum-in-hat park brake assembly having a first brake shoe retained on a backing plate by a first pin and a second brake shoe retained by a second pin. The first and second pins permit the first and second brake shoes to be moved in a radial plane and to rotate about an axis of an opening in the backing plate. The first and second brake shoes each have a first engagement end which is aligned on the backing plate by an anchor post and a second engagement end which is selectively spaced apart by an adjuster mechanism. A spring arrangement urges the first and second brake shoes toward the anchor post and into engagement with the adjuster mechanism. An actuator assembly is connected to the first engagement end of the first and second brake shoes and upon receiving an input force moves first and second friction pads associated with the first and second brake shoes into radial engagement with a drum.

Abstract: A drum brake assembly (10) having first (12) and second (14) brake shoes retained on a backing plate (16). The first (12) and second (14) brake shoes have a first end (22,24) aligned on a hydraulic actuator assembly (26) and a second end (28,30) aligned on an anchor block (40). An adjustable strut mechanism (32) has an extendable shaft (33) with first end member (34) which engages the first brake shoe (12) and a second end member (36) which engages the second brake shoe (14). The first end member (34) is separated from the second end member (36) by a stem member (35). Stem member (35) has a threaded first end (39) which is mated with the second end member (36) and a smooth second end (31) which is retained in a bore of the first end member (34). The first (12) and second (14) brake shoes are urged toward the hydraulic actuator assembly (26) by a first resilient member (150) and toward the anchor block (40) by a second resilient member (48).

Abstract: A wire return spring for providing bias for brake shoes in a drum brake system urging the brake shoes to deactuated positions, with the wire spring having a circular like contour as assembled with the brake shoes.

Abstract: A drum brake for use in a brake system (10) having first (14) and second (16) shoes retained on a backing plate (20). The first brake shoe (14) has a first end (22) connected to an actuator (12) and a second end (26) connected to an anchor arrangement (24) and the second brake shoe (16) has a first end (36) connected to the actuator (12) and a second end (38) connected to the anchor arrangement (24) The actuator (12) responds to an input signal during a brake application by moving the first (14) and second (16) brake shoes into engagement with a drum (18). The anchor arrangement (24) includes a load sensor (64) for measuring a torque generated between the first (14) and second (16) brake shoes and the drum (18). The anchor arrangement (24) has a bracket (44) with a base (46) having first (48) and second (50) side walls which are secured to the backing plate (20). The first side wall (48) has a first central opening (56) therein while the second side wall (50) has a second central opening (58) therein.

Abstract: The present invention provides a vehicle wheel cylinder for a drum type brake. The sealing boot which seals the wheel cylinder frame and piston is provided in a preferred embodiment with annular rings which help protect the integrity of the sealed relationship of the annular boot with the bore of the wheel cylinder against damage which can be caused by contact of the sealing boot with a web of a brake shoe.

Abstract: An improved drum brake includes a brake drum rotating along with a wheel, a backing plate provided to a stationary portion of a vehicle, a pair of brake shoes that are movably supported on the backing plate and a wheel cylinder attached to the backing plate. The wheel cylinder is adapted to expand the brake shoes to an operating position whereby friction linings attached to the brake shoes are frictionally engaged with an inner peripheral surface of the brake drum. An adjustable strut is disposed between the brake shoes to maintain the spacing therebetween and a return spring is provided adjacent the strut for retracting the brake shoes away from the inner peripheral surface of the brake drum. An end portion of the strut is provided with a bend portion parallel to a web of one of the brake shoes, the bend portion being sandwiched between the web of the brake shoe and an end of the return spring.

Abstract: A drum brake comprises two brake shoes (4,5) which are operable hydraulically and/or mechanically. A first brake shoe (4) is supported trailingly in forward travelling direction and leadingly in backward travelling direction. In the forward travelling direction both brake shoes (4,5) are supported trailingly so as to obtain soft response behavior. And a lever (7) is supported at the second brake shoe (5), having one arm pressurized by the piston (2) of the wheel brake cylinder (1), while the other arm (7b) acts directly or indirectly on the first brake shoe (4).

Abstract: For automobile drum brakes of the simplex and duo-duplex forms of construction, each having two brake shoes (10) floatingly mounted on a brake bracket (1), a special support is proposed for the one end of the brake shoe web (10) of each brake shoe (8), this support being constituted basically of a support pin (26) rotatable about its central axis, which possesses a recessed bearing surface, on which a corresponding counter-surface (35) of the brake shoe web (10) is slidably journalled. The new support makes possible the maintaining of a constant brake coefficient throughout the full range of wear of the brake lining (12).

Abstract: A brake shoe assembly incorporates unitary retainers for anchor pins about which a pair of brake shoes may pivot. In a preferred form, the anchor pin retainers are spring steel structures formed of drawn heat treated wire, each retainer defining a pair of spaced legs joined at one end by an arcuate or bowed portion adapted to engage one of a pair of spaced grooves in one of the associated anchor pins. Each brake shoe contains a web portion which includes a cradle for pivotal support against an anchor pin. Each web has a pair of apertures disposed for engagement by a hook formed at the end of each retainer leg.

Abstract: An internal shoe-drum brake is disclosed in which a pair of arcuate shoes can be applied to a rotatable drum by an hydraulic actuation system for normal service braking when the brake acts as a brake of the "two-leading" shoe type and a mechanical actuation system for parking or emergency braking when the brake acts as a brake of the "duo-servo" type. The hydraulic system comprises two hydraulic pistons, each of which acts on the leading end of a respective shoe, and first and second abutments are provided against which the trailing ends of the shoes are adapted to rest. One abutment is fixed but the other abutment includes an auxiliary hydraulic piston which is adapted to be urged against a fixed stop by hydraulic pressure applied to the pistons. The reaction from the trailing end of a respective shoe tends to urge the piston away from the stop, but the area of the piston is sufficient to prevent this happening when the hydraulic pressure is acting on the piston.

Abstract: A vehicle drum brake has a shoe mounted on a back plate, one end of the shoe engaging an actuator and the other end engaging an abutment. To avoid the use of a fluid pressure control valve to vary the braking effort of the brake in dependence upon vehicle loading, the abutment is in the form of a roller which engages an arcuate member on the shoe, the roller being movable laterally of the shoe to vary the braking effort for a given actuating force. The roller may be connected to a pivoted lever which is rotatably mounted in the back plate and which is connected to a sprung part of the vehicle by a linkage. Movement of the sprung part due to changes in vehicle loading rotates the lever and moves the roller.

Abstract: A drum brake includes a backing plate with an anchor for pivotally engaging one end of a pair of brake shoes. A hydraulic actuator is engageable with the other end of the pair of brake shoes and is operable to move the pair of brake shoes from a rest position to a braking position. An extendible strut extends between the pair of brake shoes to limit the retraction of the pair of brake shoes upon termination of a braking application. A lever is pivitally coupled to one of the brake shoes and a pawl is pivotally coupled to the other brake shoe. The pawl and lever are releasably interlocked with their respective brake shoes via hooks which are received in slanted slots or openings. A resilient member cooperates with the pawl to retain the latter in engagement with the extendible member and also cooperates with the pair of brake shoes to urge the same into engagement with the hydraulic actuator.

Abstract: An improved adjuster for a shoe drum brake comprising a strut of adjustable length extending between one of the brake shoes and an arm of an operating lever that is actuated by a hand brake. The strut has a threaded part or spindle and a ratchet threadedly engaging with the threaded part. The adjuster also comprises a pawl arm carried by the arm of the operating lever and having a pawl cooperating with the ratchet. The arm of the operating lever is formed with a nose positioned for engagement with the other one of the brake shoes. The threaded part of the strut is formed with a stopper which is adapted to engage with the ratchet to define the minimum length of the strut.