Abstract: An automatic clearance adjusting device 10 that automatically adjusts the position of brake shoes 3 and 4 based on the wear includes an adjuster gear 23 that is rotatably depending on the amount of how much the brake shoes are parted from each other, a cam plate 25 rotated integrally with the adjuster gear 23 to drive the strut 27 that restricts the position of the brake shoes 3 and 4, and an adjuster restricting lever 33 that restricts the rotation of the adjuster gear 23 based on the pressing force from the wheel cylinder 6 that parts between the pair of brake shoes 3 and 4.

Abstract: A brake apparatus having an automatic clearance adjusting mechanism with an overadjustment preventer constituted such that a piston is constituted by a structure of being divided in a plug piston 16 and a ring piston 14. The plug piston 16 is integrated with an adjusting nut 20, a bearing 21, a bearing support plate 22 and a spring holder 23. An outer side claw portion 23a of the holder is locked by an outer side groove 16 of the plug piston. The plug piston 16 integrated with the respective parts is inserted to fit to the ring piston 14 to thereby prevent the outer side claw portion 23a of the holder from being detached.

Abstract: In a drum brake device having a shoe drive cam, the braking force of which is mechanically controlled according to a reaction force acting on an anchor pin by a brake shoe, the cam plate 76 pivotally supported by the anchor pin 10 and the lever plate 30, to which a shoe operating force is given by the operating force generating means 6, are connected to each other being capable of rotating relatively via a pair of cam pins 21, 23 coming into contact with the brake shoes 3, 4, and the transmitting mechanism of the input system composed of the lever plate 30 and the pair of cam pins 21, 23 and the transmitting mechanism of the control system composed of the pair of cam pins 21, 23 and the cam plate 76 are put into a separate state in which a direct power transmission is not conducted between them.

Abstract: A cam mechanism 7 provided as a shoe drive mechanism includes a cam supporting plate 21 being loosely and rotatably fitted on an anchor pin 10 for receiving a shoe operating force, a first cam plate 23 rotatably connected to the cam supporting plate 21 at an outer cam supporting position which is a position shifted away from the anchor pin 10 radially outwardly of the drum, a second cam plate 25 rotatably connected to the cam supporting plate 21 at an inner cam supporting position which is away from the anchor pin 10 toward the operating force generating means 6, so that a pair of brake shoes 3, 4 are opened outwardly by the separate cam plates 23, 25, respectively.

Abstract: A shoe driving mechanism includes cam plates which respond to a shoe operating force to rotate about a main anchor pin on a back plate by a shoe operating force, and three pins consisting of an input pin, a secondary anchor pin and a primary anchor pin, which are uprightly disposed in a space between the cam plates. A secondary anchor pin and a primary anchor pin, respectively, expand a secondary shoe and a primary shoe by the rotating motions of the cam plates, caused by a shoe operating force. At forward braking and backward braking, those anchor pins cause rotation moments to act on the cam plates in such a direction as to lessen the shoe operating force in accordance with a braking force generated by each brake shoe.

Abstract: In a drum brake, a damper spring is provided for transmitting a shoe operating force outputted from a power lever to an input lever and for absorbing an impact force transmitted from brake shoes to the power lever via a link mechanism. The damper spring is mounted between the power lever driven by an electric motor of an operating force producing mechanism and the input lever of the link mechanism for receiving the shoe operating force outputted from the power lever for driving the shoes.

Abstract: In a drum brake, a damper spring is provided for transmitting a shoe operating force outputted from a power lever to an input lever and for absorbing an impact force transmitted from brake shoes to the power lever via a link mechanism. The damper spring is mounted between the power lever driven by an electric motor of an operating force producing mechanism and the input lever of the link mechanism for receiving the shoe operating force outputted from the power lever for driving the shoes.

Abstract: A drum brake device produces a stable braking force at a predetermined boosting ratio in response to a brake operation force input thereto, even if the friction characteristics of the interface of the brake drum and the brake shoe varies, without increasing the size of the wheel cylinder.

Abstract: A shoe driving mechanism for a drum brake for pressing brake shoes against a drum is formed as an assembly in which the following are assembled to base plates which are rotatably fitted to an anchor pin for a primary shoe: an anchor pin for the secondary shoe; first and second lever supporting pins; a balance lever which is swingably supported by the first and second lever supporting pins whose distal-end side outer periphery is brought into contact with one end of the primary shoe; and an input lever for transmitting to the balance lever and the secondary shoe a shoe operating force inputted from an operating-force generating mechanism.

Abstract: A drum brake device including, a pair of brake shoes, a wheel cylinder, anchor pins, and a control lever. The control lever is disposed between a wheel cylinder and a secondary shoe and has a structure that the flanges and are raised from both ends of a plate-like lever body. The first flange is formed at one end of the plate-like lever body and includes a piston contact portion. The second flange is formed at the other end thereof. The surface of the second flange, which faces an anchor pin, is used as an anchor contact portion, and the surface of the second flange, which faces the secondary shoe, is used as a shoe contact portion.

Abstract: A parking brake mechanism in the duo-servo type drum brake includes a link type shoe drive mechanism for expanding a pair of brake shoes and an operating force generator for inputting a shoe operating force into an input lever of the shoe drive mechanism according to the brake operation. The parking brake mechanism also includes a parking brake lever pivotally supported by one brake shoe, wherein a shoe operating force is inputted into the input lever by swing of the parking brake lever, and the brake shoes are expanded via the shoe drive mechanism.

Abstract: A parking brake mechanism in the duo-servo type drum brake includes a link type shoe drive mechanism for expanding a pair of brake shoes and an operating force generator for inputting a shoe operating force into an input lever of the shoe drive mechanism according to the brake operation. The parking brake mechanism also includes a parking brake lever pivotally supported by one brake shoe, wherein a shoe operating force is inputted into the input lever by swing of the parking brake lever, and the brake shoes are expanded via the shoe drive mechanism.

Abstract: An opposed piston type disc brake comprising an outer body, an inner body, cylinders, pistons, and pads. A rotor rotates together with a wheel being interposed between the outer and inner bodies. The cylinders are opposed to each other and arranged in both outer and inner bodies. The pistons are fluid-tightly arranged in the cylinders and capable of being freely displaced in the axial direction of the rotor. The pads are supported by the inner and outer bodies and capable of being freely displaced in the axial direction of the rotor. The outer and inner bodies are made separately from each other. The outer body includes a main body, a connecting portion, and an attaching portion. The main body is provided with the cylinders. The connecting portion extends from both end portions of the main body in the axial direction of the rotor and straddles the rotor.

Abstract: A valve opening and closing mechanism comprising a cylinder, a control piston, a valve guide, and a valve assembly. The cylinder includes an inlet for supplying fluid. The control piston is slidably fitted to the cylinder and includes a first fluid passageway for flowing the fluid supplied into the cylinder. The valve guide is supported in a fluid chamber defined by the cylinder and the control piston. The valve guide includes a shaft portion and a valve support portion. The shaft portion is inserted into the first fluid passageway with defining a first clearance, and the valve support portion is formed into a collar at a base end of the shaft portion and faced an end surface of the control piston. The shaft portion of the valve guide have a conical surface portion for reducing a first sectional area of flowing the fluid when the control piston is displaced toward the fluid chamber.

Abstract: A drum brake includes a first brake shoe, a second brake shoe and disposed opposite the first brake shoe within a brake drum, a backing plate supporting the first and second brake shoes, a wheel cylinder disposed between the first brake shoe and the second brake shoe, the wheel cylinder including a drive piston for pressing the first and the second brake shoes against an inner surface of the brake drum, a control piston for supplying hydraulic pressure in response to a braking reaction force from the second brake shoe, an anchor portion for receiving an anchor reaction force from the second brake shoe, a control lever for distributing the anchor reaction force to the anchor portion and to the control piston when the anchor reaction force reaches a predetermined braking force magnification, the drive piston has a base end in the pressure chamber and a leading end facing the first end of the second brake shoe and is movable to and from the second brake shoe by the hydraulic pressure supplied to the pressure cha

Abstract: Counter braking force acting on a secondary shoe is input to one end portion of a control lever supported with an anchor pin vertically provided on a backing plate in such a manner that the control lever is capable of swinging. An inner end portion in the radial direction of the control lever engages with a strut for pressing a primary shoe against a brake drum. Pressing force A with which the strut is pressing the primary shoe against the brake drum is drastically reduced when braking force, that is, the counter braking force increases and slightly reduced when the braking force, that is, the counter braking force decreases, whereby an increase or a decrease in the braking force is made automatically controllable.

Abstract: Disclosed is a drum brake device in which during a service brake application, a pair of brake shoes operates in a leading/trailing mode, and during a parking brake application, a parking brake mechanism operates to cause the brake shoes to operate in the duo servo mode. A first lever, an equalizer and a second lever, which make up the parking brake mechanism, are all assembled onto one of the brake shoes. The second lever includes an input portion, a lever contact portion and an equalizer contact portion. The input portion receives a force from a parking lever. The lever contact portion applies a turning force to the first lever. The equalizer contact portion applies a turning force to the equalizer. The second lever, when it is turned, turns the first lever and then the equalizer.

Abstract: A device for controlling pressure of brake fluid having an anti-lock control device arranged in a pipe communicating a master cylinder with a wheel cylinder, comprising: a passage shut-off device arranged in a passage communicating a holding valve, which is a component of the anti-lock control device, with a master cylinder, to shut off the passage when fluid pressure generated in the master cylinder exceeds a predetermined value; and a switch valve arranged in a bypass passage communicating an upper stream side passage of the passage shut-off device with a suction port of a hydraulic pump, to open the passage when the passage shut-off valve shuts off the passage, wherein when the passage shut-off device closes the passage, the hydraulic pump in the anti-lock control device is operated, so that brake fluid in the master cylinder can be sucked via the switch valve and fed into the wheel cylinder.

Abstract: Within a wheel cylinder, a drive piston and a control piston, the base ends of which receives a hydraulic pressure from a master cylinder, are oppositely disposed while being axially aligned with each other. A primary shoe is pressed by the drive piston, and an anchor reaction force output from a secondary shoe is distributed to and loaded on an anchor portion and the control piston through a control lever. When the anchor reaction force reaches a predetermined value of force or larger, an anchor-reaction-force control link mechanism operates to move the primary shoe apart from a brake drum, thereby checking the increase of the anchor reaction force.

Abstract: A wheel cylinder for expanding the opposed edges at one longitudinal end of a pair of brake shoes includes a pair of drive pistons for pressing the ends of the respective brake shoes under a hydraulic pressure supplied to the first pressure chamber, and a pair of control pistons which receive at the base ends the hydraulic pressure from the master cylinder and receive at the front ends anchor reaction force by way of levers, the control pistons being displaced to close a normally-open input control valve for supplying hydraulic pressure to the first pressure chamber when the anchor reaction force becomes larger than the hydraulic pressure received from the master cylinder by a predetermined magnifying power. Accordingly, it is possible to increase the stability of the braking effect of a duo-servo type drum brake.