Bridgestone Corporation

Bridgestion Corporation

Yuji Sakaguchi

Takeo Takagi

Yoshinori Imamura

Tatuo Terahama

A pneumatic actuator includes a tubular body made of a rubber-like elastic material and a braided structure made of organic or inorganic high-tensile-strength fibers reinforcing an outside of the tubular body. Closure members sealingly close ends of the tubular body; at least one of the closure members has a fluid connecting passage. The tubular body deforms to expand its diameter when pressurized fluid is introduced through the connecting passage to cause contractive force in the longitudinal direction. Contraction-detecting strain gauges at one closure member provide signals corresponding to the contractive force of the actuator.

Flexible tubular wall pneumatic actuator with position transducer

Flexible tubular wall actuator with end-mounted strain gauge

A magnet for control valve includes a housing having an inlet and an outlet for a pressurized fluid, a valve seat member having a conical inner surface valve seat, a spherical valve body adapted to be in line contact with the valve seat, a throttle adjusting plate made of a magnetic material shiftable toward and away from the valve seat, and an electromagnet for attracting and releasing the throttle adjusting plate to shift the valve body toward and away from the valve seat. According to the invention a sheet, preferably made of urethane foam is arranged on a side of the throttle adjusting plate opposite to the valve body, thereby eliminating noise caused by self-oscillation of the valve body and throttle adjusting plate, while maintaining high responsibility as a magnetic control valve.

Magnetic flow control valve

A magnet for control valve includes a housing having an inlet and an outlet for a pressurized fluid, a valve seat member having a conical inner surface valve seat, a spherical valve body adapted to be in line contact with the valve seat, a throttle adjusting plate made of a magnetic material shiftable toward and away from the valve seat, and an electromagnet for attracting and releasing the throttle adjusting plate to shift the valve body toward and away from the valve seat. According to the invention, a sheet, preferably made of urethane foam is arranged on a side of the throttle adjusting plate opposite to the valve body, thereby eliminating noise caused by self-oscillation of the valve body and throttle adjusting plate, while maintaining high responsibility as a magnet control valve.

A driving device having tactility includes at least one set of two elastic extensible and contractible bodies having one ends connected to a stationary portion of the device and the other ends connected to a driven member driven by contractive force in axial directions of said elastic bodies caused by expanded diameters by introducing pressurized fluid into the elastic bodies. The driving device comprises detecting means for detecting movements of said driven member, valve means for supplying and exhausting the pressurized fluid into and out of the respective elastic bodies, positioning means for actuating the valve means in response to output signals from the detecting means to position the driven member in predetermined positions, and control means for comparing output signals from the detecting means produced by external actions on the driven member positioned in at least one predetermined position with a reference level to control the positioning means. The driving device can perceive external actions acting on the overall device without requiring any separate tactile sensor.

Driving device having tactility

A brake device for use in an arm of a robot or manipulator cmprises a brake drum, a lever pivotally supported at its intermediate portion, a brake shoe provided on the lever between its pivotally supported point and its one end, a pneumatic actuator axially contractible upon applying internal pressure thereinto and having a movable end connected to the one end or the other end of the lever, and a spring connected to one end of the lever not connected to the actuator so as to operate to elongate the actuator. This brake device is remarkably small-sized and of light-weight and consumes only small amount of fluid pressure to contribute economy of energy in comparison with prior art brake devices. The brake device according to the invention is applicable to a robot arm comprising a rotating member connected to the brake drum so as to rotate together, and two elastic actuators whose one ends are connected to a stationary member and the other are connected to each other through the rotating member in a manner to rotate the rotating member by contraction of the one actuator and simultaneous extension of the other actuator. At least one of the actuators is a pneumatic actuator axially contractible upon applying internal pressure thereinto.

Brake device for robot arm

A pneumatic actuator includes an elastic tubular body, closure members sealingly closing its ends and a braided structure made of braided cords reinforcing the tubular body. The braided structure is expanded in its radial direction and simultaneously contracted in its axial direction together with the tubular body when pressurized fluid is supplied into the tubular body. According to the invention the braided cords of the braided structure comprises monofilaments each having a smoothly rounded outer surface of a large radius of curvature. A protective layer may be provided between the tubular body and the braided structure or a filler such as an incompressible fluid substance having no constant shape is provided in the tubular body, or diameters of both ends of the braided structure and braided angles at both the ends are made larger than those at a substantially mid portion of the braided structure. The actuator according to the invention decreases damage of the tubular body to elongate its service life and exhibits an improved contacting performance and high fatigue strength and can greatly save air consumption to eliminate the disadvantage of much air consumption of the air-bag type actuator without adversely affecting its advantages.

Growing community of inventors

Kodaira, Japan

Yuji Sakaguchi