Abstract: Provided is a clutch type driving wheel of an electric scooter. The clutch type driving wheel of the electric scooter includes a wheel body and a power shaft penetrating through the center of the wheel body, wherein a motor power input structure is arranged at one end of the power shaft, a central supporting shaft penetrates through the power shaft, a controlled clutch structure enabling the wheel body to be circumferentially positioned relative to the power shaft or enabling the wheel body to circumferentially rotate relative to the power shaft when the controlled clutch structure acts is arranged between the power shaft and the wheel body, and a clutch state locking structure is arranged on the controlled clutch structure. According to the clutch type driving wheel of the electric scooter, the clutch state locking structure is arranged between the power shaft and the wheel body.

Abstract: An automatic braking device for a manually propelled vehicle such as a standard wheelchair. The device is configured to substantially lock the wheel thus preventing the vehicle from rolling backwards when the occupant—while attempting to exit the vehicle—for example forgets to lock a standard brake of the vehicle, thereby preventing the sometimes-serious fall of the occupant. The impeding of the backward rotation of the wheel and/or substantially preventing of the wheel from so rotating is carried out with the use of a flexible leg of the brake pad, repositionable with respect to the stationary plate of the brake pad during the wheel rotation. The device is cooperated with the wheel of the vehicle to not interfere with the intentional movement of the wheelchair in any direction, nor does it interfere with the typical locking mechanism of the standard wheelchair.

Abstract: Breakaway detection and alerting is described for a towed vehicle. In one example, a system includes a wired breakaway detector having a detector to generate an electric breakaway detection signal when a breakaway cable is not in a breakaway cable socket and an electrical cable to indicate the electric breakaway detection signal, and a wireless interface configured to be attached to the towed vehicle outside of the interior driver's area, to receive the electric breakaway detection signal from the breakaway detector and having a wireless transceiver to transmit a wireless breakaway alert signal in response to receiving the electric breakaway detection signal. A portable brake activation system receives the wireless breakaway alert signal from the wireless interface in the interior driver's area of the towed vehicle and activates the towed vehicle braking system through the attached brake pedal in response to the wireless breakaway alert signal.

Abstract: Disclosed are systems and methods for reducing friction on a brake arm of a caster wheel brake. A washer can be positioned between the brake arm and the support arm to reduce friction in this area. Lubricant can also be provided between the brake arm and the support arm, and also between the brake arm and the brake cam, to reduce the friction in these areas. The presently disclosed embodiments therefore allow less force to actuate the brake arm as compared to prior art caster wheels.

Abstract: According to an aspect of some embodiments of the present invention there is provided a driving unit for an in-line skate system having roller wheels, the driving unit has a motor configured to generate a driving power, a transmission gear coupled to the motor, and a transmission belt interconnecting the transmission gear and the two or more roller wheels to transfer the driving power to the roller wheel. According to an aspect of some embodiments of the present invention there is provided an in-line skate system, comprising one or more in-line skates and a driving unit.

Abstract: Locking roller assemblies for locking and unlocking a roller of a roller conveyor. The disclosed locking roller assemblies include rollers that, by default, are locked from rotation in the absence of a transferred object such as a container, crate, or pallet. When an object is present over the roller, the roller is passively actuated by the object to unlock and release the roller, enabling the roller to rotate. When the package or article has passed by the roller, the locking roller assembly resumes the default configuration of locking the roller to prevent rotation. In some embodiments, actuation of the locking mechanism is parallel to the roller axis and accomplished by a lever and cam arrangement. In other embodiments, actuation of the locking mechanism is in a direction that is orthogonal to the roller axis and accomplished by a plunger arrangement.

Abstract: An apparatus for applying pressure to at least a portion of an edge surface, which bridges opposing faces of a workpiece, comprises a frame, a first roller, a second roller, a rotation-control member, a first biasing member, and a second biasing member. The first roller and the second roller are coupled to the frame, are rotatable relative to the frame, and are translationally fixed relative to the frame. The rotation-control member is movable relative to the frame, controlling rotation of the first roller and the second roller relative to the frame. The first biasing member is configured to operate in compression along a second axis. The second biasing member is positioned, in compression, between the frame and the rotation-control member.

Abstract: An apparatus for applying pressure to at least a portion of an edge surface, which bridges opposing faces of a workpiece, comprises a frame, a first roller, a second roller, a rotation-control member, a first biasing member, and a second biasing member. The first roller and the second roller are coupled to the frame and are rotatable relative to the frame. At least one of the first roller or the second roller is translatable relative to the frame along a first axis. The rotation-control member is movable relative to the frame, controlling rotation of the first roller and the second roller relative to the frame. The first biasing member is configured to operate in compression along a second axis. The second biasing member is positioned, in compression, between the frame and the rotation-control member.

Abstract: An apparatus for applying pressure to at least a portion of an edge surface, which bridges opposing faces of a workpiece, comprises a frame, a first roller, a second roller, a rotation-control member, a first biasing member, and a second biasing member. The first roller and the second roller are coupled to the frame, rotatable relative to the frame about a first pivot axis, and translationally fixed relative to the frame. The rotation-control member is movable relative to the frame, controlling rotation of the first roller and the second roller relative to the frame. The first biasing member is coupled to the frame and is configured to operate in tension. The second biasing member is positioned, in compression, between the frame and the rotation-control member.

Abstract: A brake device for braking a wheel includes a brake drum, a brake pad carrier which is arranged or can be arranged in the brake drum and has at least one brake pad, and an actuator apparatus for the reversible transfer of the brake pad carrier between a braking state, in which the brake pad is operatively connected to the brake drum, and a freewheeling state, in which the operative connection between the brake pad and the brake drum is canceled, the brake pad carrier being elastically deformable for the transfer from the freewheeling state into the braking state.

Abstract: A scooter includes a connecting seat and a connecting bar extending rearward of the connecting seat, at least one rotatable front wheel and at least one rear wheel; a handle bar to control turning of front wheel; and a foot pedal connected to the connecting bar, the foot pedal having a left foot pedal portion and a right foot pedal portion; each of the left and right foot pedal portions being configured to support a rider's left foot and right foot, respectively, to lie substantially parallel to the connecting bar. The front wheel has a diameter, and the front and rear wheels are spaced apart a lateral distance, and wherein a ratio of the diameter to the lateral distance is selected to allow a rider to propel the scooter along flat ground without pushing the feet along the ground. The front wheel may have a rounded shape as seen from front view to establish substantially tangential line contact with a rolling surface.

Abstract: A drive mechanism for a wheelchair may include a hand grip having a continuous track that moves over a drive rotator. The hand grip may have a flat, top surface that extends ventrally from the wheelchair. The drive mechanism may include a drivetrain connected to the drive rotator, such that movement of the hand grip in a dorsal or a ventral direction causes the drive rotator to rotate, and such rotation actuates the drivetrain. The drive mechanism may further comprise a switch. When the switch is in a first position, actuation of the drivetrain drives the wheels of the wheelchair. When the switch is in a second position, actuation of the drivetrain drives a mechanism that lifts the wheelchair into a standing position.

Abstract: A drive unit for actuating a brake device by a driver's operation, when a vehicle is parked or stopped, is disposed independently in a trailing arm for each of right and left rear wheels. Thus, the drive unit for actuating the brake device via a wire when the vehicle is stopped or parked can be loaded, even if the space of the vehicle is tight. That is, the drive unit for actuating the brake device via the wire when the vehicle is stopped or parked can be loaded, regardless of the space of the vehicle.

Abstract: In a preferred embodiment a friction bushing is configured to rotate a shaft with resistance having a housing with a bore to receive the shaft; a flange plate positioned on the housing around the bore; and a number of flanges that protrude axially from the flange plate to receive the shaft, where the flanges generate a radially-directed force by being flexible from a relaxed radius to a shaft radius of the shaft, and the flanges have internal circumferentially spaced surfaces in contact with an external surface of the shaft having a topology to control the resistance as the shaft rotates in the friction bushing.

Abstract: Wheelchair designs and enhancements are provided for use with conventional wheelchair design. The designs and enhancements include bariatric extension panels and security features making it suitable for use in high security areas such as prisons and psychiatric wards.

Abstract: A temperature insensitive locking apparatus for use with large optical mounts having at least one locking nut having an internal threaded portion adjacent to an internal tapered portion, at least one flexurized spring collet attached to a rigid base structure having an external threaded portion and a plurality of tapered flexures, a pivot shaft engaged with an optical yoke on a rotational axis of symmetry wherein when the internal threads of the locking nut engage with the external threads of the flexurized spring collet an increased level of a radial clamping force is provided around the pivot shaft.

Abstract: The invention relates to an electromechanically actuatable brake (2), comprising an electrically actuatable actuator (30) for applying the brake (2) in an application direction (42), which actuator (30) converts a rotary motion of a spindle (20) into a translational motion of an application element (26), in particular a piston, wherein the spindle (20) is driven by an electric motor (8), wherein a mechanical store for storing energy by twisting is provided, the first end of which store is coupled to the spindle (20) and the second end to a bracing element (80), wherein the store takes up energy during rotation of the spindle (20) in the application direction (42), by which energy the spindle (20) is rotated back against the application direction (42) in the currentless state of the electric motor (8), whereby the brake (2) is released.

Abstract: There is a braking assembly for limiting rotation of a drive shaft in a reverse direction. A hub is fixed for rotation with the drive shaft. The hub has an external cylindrical section and at least one hub pocket on the external cylindrical section. An actuatable brake portion is sized and shaped to be mounted for rotation around the hub. The actuatable brake portion has an internal cylindrical section, at least one brake pocket on the internal cylindrical section corresponding with the at least one hub pocket, and at least one brake shoe. The braking assembly also includes at least one ball.

Abstract: A thrust reverser drive arrangement is described for use in driving a thrust reverser cowl for movement relative to first and second guide tracks, the drive arrangement comprising a first actuator located, in use, close to the first guide track, and a second actuator located, in use, close to the second guide track, the actuators being arranged to be driven in synchronism and at the same speed by a drive motor to drive the cowl for movement, wherein at least one of the first and second actuators is provided with a load limiter to limit the transmission of loads through that actuator in the event that that actuator is subject to a compressive loading greater than a predetermined level.

Abstract: A locking differential for a vehicle includes a rotatable housing and a differential mechanism supported in the housing. The differential mechanism includes a pair of clutch members wherein each of the clutch members presents an inwardly directed face. Each face includes a groove disposed in spacing relationship with respect to the other. A cross pin is received in the groove and is operatively connected for rotation with the housing. The clutch members are axially moveable within the housing so that they may engage respective clutch members coupled to a pair of axle half shafts. A plurality of springs apply a pre-load to only the clutch members, wherein contact is maintained between the clutch members and the cross pin.

Abstract: The present invention discloses a method for producing brake drum, wherein three different metallic materials are used for the three-layer construction; and two layers made of different molten metallic materials are cast based upon the prefabricated steel shell (with steel or gray iron for the structural layer and the Mo-containing, abrasion-resistant alloy cast iron for the braking friction layer) so that atoms from these two adjacent but different metallic layers inter-diffuse across the interface to form a solid fusant or an inter-metallic compound, thereby generating a very strong metallurgical bond. The present invention also provides a brake drum, comprising a brake drum shell, a structural layer inside the brake drum shell, and a friction layer inside the brake drum structural layer and for braking.

Abstract: A machine tool braking device, particularly a hand-held machine tool braking device, includes at least one braking unit and at least one control unit. The control unit includes a moveably-mounted control element that is configured to activate and/or deactivate the braking unit. The control element has a movement axis and is mounted such that the control element can pivot about the movement axis.

Abstract: The invention relates to a braking apparatus, in particular for implements of motor-driven tool units comprising an arm having at least one bearing disposed therein for rotatable mounting of an axle and comprising a flange fastened on the rotatably mounted axle, wherein the axle and/or the flange are drivable by means of a drive motor, wherein a first friction element is firmly connected on the arm and a second friction element is connected to the axle and/or to the flange, wherein the first and the second friction element come into frictional contact with one another or not depending on the action of centrifugal force on at least one flyweight.

Abstract: A personal mobility vehicle, such as a scooter, includes at least one battery and motor for powering at least one driven wheel. The vehicle also includes a braking assembly configured to isolate the motor from the at least one driven wheel such that power is terminated from the motor to the at least one wheel in response to a user engaging a braking assembly of the vehicle. The vehicle can include a switch or position sensor that interacts with the braking assembly to initiate the isolation of the motor from the at least one driven wheel and the switch or position sensor preferably is inaccessible to the foot of the user.

Abstract: A braking operation lever for a rotor braking device of a spinning reel for applying a braking force to the rotation of a rotor rotatably supported by a reel body, the braking operation lever includes a lever main body, an operating section, a brake shoe, an elastic member, and a fall out prevention mechanism. The lever body is rotatably supported by the reel body. The operating section is configured to perform a braking operation, and is disposed on a first end part of the lever main body. The brake shoe is disposed on a second end part of the lever main body, and is configured to be pressed against the rotor by operation of the operating section. The elastic member is disposed between the brake shoe and the lever main body. The fall out prevention mechanism prevents the elastic member from falling out of the brake shoe.

Abstract: Safety systems for power equipment, components, cartridges and mounting systems for cartridges are disclosed. The safety systems, components, cartridges and mounting systems are specifically applicable for woodworking equipment such as saws. A cartridge system for use in safety systems for power tools might include a cartridge adapted to perform a predetermined action when triggered, where the predetermined action causes the deceleration and/or retraction of a working portion of the power tool, where the cartridge includes a first connector, and where a second connector is mounted in the power tool and adapted to connect to the first connector.

Abstract: An apparatus for transferring an optical element, the apparatus including: a support portion for supporting the optical element; a guide portion for guiding the support portion to move in a rectilinear direction; a brake disposed between a first position that contacts the support portion and restricts a movement of the support portion, and a second position that is spaced apart from the support portion and allows the movement of the support portion to change a position thereof; and a driving portion for driving the brake.

Abstract: A brake system of a drum brake includes a carrier unit and a brake cylinder, wherein a connecting element is provided, which has a first connection section for fixing the brake cylinder and is fixed in a second connection section to the carrier unit wherein, the first connection section is arranged offset to the second connection section while being parallel relative to the wheel axis, and wherein the first connection section can be fixed directly to the brake cylinder in order to keep the distance between the center of gravity of the brake cylinder and the first connection section low.

Abstract: A brake comprising a frame, a braking member mounted on the frame movably between braking position and released position, and a rotatable lever mounted on the frame, the lever being functionally connected to the braking member such that movement of the lever axially away from frame moves the braking member towards released position. At least one cylindrical roller is mounted on one of the brake frame and lever, to be positioned between the brake frame and the lever, and the other of the brake frame and lever comprises a recess for receiving said cylindrical roller, and in that rotation of the lever is configured to cause said cylindrical roller to roll outwards from the recess along an edge portion of the recess forcing the lever to move axially away from the frame, thereby causing the braking member to move towards released position.

Abstract: Disclosed is unit brake, which is equipped with a cylinder apparatus in which a clutch mechanism that switches between transmitting or cutting off a biasing force of a spring brake part is disposed, is capable of preventing a braking force due to the spring brake part from unintentionally decreasing due to a meshing section of the clutch mechanism disengaging, and is of a size that can replace an existing unit brake, and maintains the performance of bearings in the clutch mechanism even with long-term use.

Abstract: Arrangement and method for monitoring a structure at a fixed location, e.g., a house, parked boat or parked airplane, includes a monitoring or sensor system arranged to obtain information about the structure, an exterior of the structure and/or an interior of the structure different than the location of the structure, and a communication system coupled to the sensor system and being provided with a location of the structure. The communication system transmits the information about the structure obtained by the sensor system and the location of the structure to a remote facility. The remote facility can therefore monitor the structure, and take steps to ensure the integrity of the reservoir and the fluid therein. To enable wireless and powerless monitoring, a power source independent of a power grid extending outside of the trailer may be provided to supply power to the sensor system and the communications unit.

Abstract: The invention relates to an elevator brake, said elevator comprising a hoisting machine (1) provided with at least a frame part (2) and a traction sheave (3), and a brake drum (4) arranged to be rotatable with the traction sheave (3) and provided with a braking surface (5), and a brake (6) having an effect on the rotary motion of the traction sheave (3), said brake (6) comprising at least one brake block (8) provided with a braking surface, which brake block (8) has been arranged to act on the braking surface (5) of the brake drum (4) with a force directed substantially towards the braking surface (5). To allow adjustment of the size of the air gap (8a) between the braking surface of the brake block (8) and the braking surface (5) of the brake drum (4), the brake (6) is provided with at least one eccentric adjusting element (11).

Abstract: A volumetric braking device includes: a brake disk having an outer surface where a plurality of disk vanes are formed with a predetermined spacing therebetween; a cylinder case where the brake disk is arranged, and the internal space of a cylinder is sectioned into a plurality of spaces by the disk vanes; a piston-drive unit, which has a piston roller sliding on the brake disk, and where the compressed pressure resistance generated between the piston roller and any one disk vane and vacuum pressure resistance generated between the piston roller and another disk vane operate as a braking load for the brake disk to perform decelerating and braking operations; a drive motor, which receives an electrical signal from an ECU by a program to operate in a forward or reverse direction; and a drive unit operating module for operating the piston-drive unit by operating the drive motor.

Abstract: A central control braking system includes: a pedestal; at least one caster mounted at a bottom portion of the pedestal; a brake transmission shaft for controlling the caster; a plate girder movably connected to the pedestal; a pedal fixed to the plate girder; and a reversing rotary assembly connecting the plate girder and the brake transmission shaft, wherein the reversing rotary assembly enables the brake transmission shaft to rotate in reverse under the control of the pedal.

Abstract: A ladder system includes an overhead track system, a ladder, a latch and a carriage. The overhead track system includes a first guide track and a second guide track. The carriage is operatively configured to move longitudinally along the first and second guide tracks and to move laterally between the first and second guide tracks. The ladder is pivotally mounted to the overhead track system. A lateral carriage brake is provided which prevents lateral movement of the ladder, and a longitudinal carriage brake is provided to prevent longitudinal movement of the ladder. The latch is operatively configured to affix the ladder to the carriage.

Abstract: A rotary table includes a brake mechanism capable of providing a large and sufficient brake force. The brake mechanism includes an inner peripheral surface and outer peripheral surface of a sleeve formed coaxially with an axis of a rotatable table, an outer stationary portion provided to a stationary member rotatably supporting the rotatable table and defining an outer hydraulic chamber, and an inner stationary portion provided to the stationary member, arranged radially inward from the outer stationary portion and defining an inner hydraulic chamber. The outer stationary portion is elastically deformed in a radial direction by expansion of the outer hydraulic chamber to push the outer peripheral surface of the sleeve formed on the rotatable table, while the inner stationary portion is elastically deformed in a radial direction by expansion of the inner hydraulic chamber to push the inner peripheral surface of the sleeve formed on the rotatable table.

Abstract: A mechanical fixing interface for fixing a machinery brake in a hoisting machine, a machinery brake, and a method for installing the machinery brake are disclosed. The fixing interface is formed in the frame part of the hoisting machine. The fixing interface includes two fixing surfaces for receiving the fixing lugs of the machinery brake, and between the fixing surfaces is a space for the machinery brake.

Abstract: The invention relates to a braking apparatus, in particular for implements of motor-driven tool units comprising an arm having at least one bearing disposed therein for rotatable mounting of an axle and comprising a flange fastened on the rotatably mounted axle, wherein the axle and/or the flange are drivable by means of a drive motor, wherein a first friction element is firmly connected on the arm and a second friction element is connected to the axle and/or to the flange, wherein the first and the second friction element come into frictional contact with one another or not depending on the action of centrifugal force on at least one flyweight.

Abstract: A personal mobility vehicle, such as a scooter, includes at least one battery and motor for powering at least one driven wheel. The vehicle also includes a braking assembly configured to isolate the motor from the at least one driven wheel such that power is terminated from the motor to the at least one wheel in response to a user engaging a braking assembly of the vehicle. The vehicle can include a switch or position sensor that interacts with the braking assembly to initiate the isolation of the motor from the at least one driven wheel and the switch or position sensor preferably is inaccessible to the foot of the user.

Abstract: The apparatus for the brake of the walking support machine is characterized in that a connective tube 41 is formed at an upper part of a bracket 40 for rotatably supporting the wheels 30, a lower part of the body 10 is vertically and movably inserted into the connective tube 41, a brake pin 50 which is in contact with the wheels 30 in a descending state is installed at the lower part of the body 10 to receive elastic power of a spring 60, a pin hole 42 through which the brake pin 50 passes is formed at a center portion of a lower part of the connective tube 41, and a snap ring 70 is inserted into and is fixed to the brake pin 50 projected through the pin hole 42 to the lower part.

Abstract: Skateboard speed control is achieved by improved application of a mechanism to provide even force to the wheels by a simplified speed control system. The speed control system is durable, compact, simple, uses minimal components, is ergonomic, and has speed control pads that move in sync while simultaneously tolerating variations in wheel orientation and position while a rider is maneuvering the skateboard.

Abstract: A stopping device (10) for a segmented roll in a fiber-web machine for assisting the stopping of the rotation of one or more roll segment(s) (52) of the segmented roll (50) has at least one braking device (12), by means of which the roll segment (52) can be stopped, and at least one surface contact member (14, 14?), which surface contact member is connected to said braking device, and the stopping device further comprises actuators (16) for optionally bringing/releasing the surface contact member into/from surface contact with the shell of one or more roll segment(s) (52). The invention also relates to a segmented roll assembly (60) in a fiber-web machine, in which the segmented roll (50) comprises at least two, independently from one another rotatable roll segments (52) that are located end-to-end substantially in the transverse direction of the fiber-web machine.

Abstract: A balance bike brake is disclosed which may be affixed to a balance bike and provides a brake which may be operated by the rider's foot.

Abstract: A drum brake apparatus is provided with a backing plate, a brake shoe, a shoe guide portion formed integrally with a backing plate by cutting and press molding, a guide surface on a rear surface of the shoe guide portion, an engagement projection that is formed on the brake shoe and slidably engages with the guide surface, and end portions that is formed on the shoe guide portion at both ends of the shoe guide portion in a circumferential direction of the drum brake apparatus and is continuous to the backing plate. Uplift of the brake shoe from the backing plate is prevented by engagement between the guide surface and the engagement projection.

Abstract: A main drive shaft brake for a passenger conveyor includes a braking element, an actuator, and a counter-actuator. The actuator is de-energized to release the braking element and halt operation of the passenger conveyor during an abnormal or emergency condition. An energized counter-actuator permits release of the braking element but, when de-energized, inhibits release of the braking element by the actuator to prevent unintentional release of the braking element caused by, for example, an accidental loss of power to the actuator.

Abstract: A vehicle brake, in particular a disc brake or drum brake having pads or linings arranged on brake pad or lining carrier plates, and including an application device, is characterized in that at least one brake pad or lining of the vehicle brake is equipped with an electronic unit, which has an electronic memory for at least storing brake pad or lining specific data.

Abstract: A safety brake system for a trailer comprises a brake end, an actuation end and a biasing unit. The brake end comprises a brake unit adapted to be secured to a trailer and positioned to block at least one wheel of the trailer when actuated. The actuation end comprises a mount adapted to be secured to a front end of the trailer and a probe operatively supported by the mount for displacement with respect to the trailer. The probe is operatively connected to the brake unit for actuating same. The probe is displaceable between a hitching state in which the probe is adapted to contact the hitch of a vehicle, and a braking state in which the probe actuates the brake unit. The biasing unit biases the probe against the hitch of the trailer in the hitching state and toward the braking state, such that the brake unit is actuated when the hitch is separated from the trailer.

Abstract: A brake assembly for use with a portable generator includes a frame, a shaft, a brake surface, and an actuator. The frame is designed to be attached to the portable generator. The shaft is supported by the frame, and the brake surface is connected to an end of the shaft. The actuator includes a foot pedal, a cam, and a pivot, where the pivot is coupled to both the foot pedal and the cam and provides for rotation of the foot pedal and the cam about a portion of the frame. The cam of the actuator translates the shaft between a released position and a braked position during operation of the brake assembly.

Abstract: A conduit bender having a unitary frame is mounted to a wheeled base which provides for transportation of the bender. A braking assembly provides for simplified locking of the wheels to secure the bender in a location. The bender is mounted to the base through a pivoting assembly which allows for bending of conduit in either a horizontal or vertical plane. A circuit is provided for controlling the bending operation. An auto-sensing portion of the circuit receives information regarding the characteristics of the conduit to be bent upon placement of the conduit in the bender. A feed back portion of the circuit is used to provide a precise bending operation.

Abstract: A wheelchair safety device comprises a brake lever, four link levers, an upper brake plate, a brake wheel, a lower brake plate, a parking wheel, and an angularly adjustable mounting plate. One end of the first, the second and the third link levers is respectively articulated at the brake lever, another end of the first and the second link levers are articulated with one end of the fourth link lever. Another end of the fourth link lever is articulated at the upper brake plate and another end of the third link lever is articulated at the lower brake plate. One end of the upper and the lower brake plates is respectively articulated at the angularly adjustable mounting plate, and another end thereof is mounted with the brake wheel and the parking wheel, respectively. The brake wheel and the parking wheel respectively act on the wheelchair.