Abstract: A servo valve for precisely controlling a position of a pneumatic cylinder does not require a servo amplifier and a small sized and/or high durability servo valve unit. The servo valve comprises a unit body having first and second portions, first and second valve portions, first and second seal members that open and close the first and second valve portions, respectively, first and second drive mechanisms that drive first and second seal members by first and second electric pulses, respectively, a supply flow path between the first end and first valve, an exhaust flow path between the second end and second valve, a common flow path connected to the supply and exhaust flow paths via first and second valve portions, and a drive flow path connected to the pneumatic actuator. First and second drive mechanisms are arranged in a drive mechanism arrangement portion located between first and second end portions.

Abstract: Provided is a rotation drive device that has a wide rotary driving range, e.g. a rotary driving range of 0°-180°. Disclosed is a rotation drive device comprising a crank member rotatable about a crank axis, a first cylinder having a first piston and rotatable about a first cylinder rotation axis, and a second cylinder having a second piston and rotatable about a second cylinder rotation axis. The crank member and the first piston are coupled for rotation about a first piston rotation axis spaced from the crank axis. The crank member and the first piston are coupled for rotation about a second piston rotation axis spaced from the crank axis.

Abstract: Provided is a rotation drive device that has a wide rotary driving range, e.g. a rotary driving range of 0°-180°. Disclosed is a rotation drive device comprising a crank member rotatable about a crank axis, a first cylinder having a first piston and rotatable about a first cylinder rotation axis, and a second cylinder having a second piston and rotatable about a second cylinder rotation axis. The crank member and the first piston are coupled for rotation about a first piston rotation axis spaced from the crank axis. The crank member and the first piston are coupled for rotation about a second piston rotation axis spaced from the crank axis.

Abstract: A servo valve unit capable of precisely controlling the position of a pneumatic cylinder that does not require a servo amplifier and a small sized and/or high durability servo valve unit are disclosed. The servo valve unit comprises a unit body having a first end portion and a second end portion, a first valve portion, a second valve portion, a first seal member that opens and closes the first valve portion, a second seal member that opens and closes the second valve portion, a first drive mechanism that drives the first seal member by a first electric pulse, a second seal member that drives the second seal member by a second electric pulse, a supply flow path that extends between the first end and the first valve, an exhaust flow path that extends between the second end and the second valve, a common flow path connected to the supply flow path and the exhaust flow path via the first valve portion and the second valve portion, and a drive flow path connected to the pneumatic actuator.

Abstract: A cleaner has a power source, a vacuum generator, a waste liquid tank and a wiper-nozzle unit. Liquids and/or contaminants may be removed by slidably moving a wiper on a flat surface to collect a mass of liquid and inserting a small-sized nozzle into the collected liquid to suck it through the nozzle when the interior of the cleaner is drawn into vacuum. Since the small-sized nozzle is located adjacent the wiper, less air will be sucked in by the cleaner when the collected liquid is sucked in by the nozzle. Therefore, the cleaner can be driven by a reduced power and also reduced in size and weight.

Abstract: A lifter includes a grasping device for grasping and holding a handle in the lane maintenance machine, vertically driving device for driving the grasping device in the vertical direction, horizontally driving device for driving the grasping device in the horizontal direction, and lifter moving device for moving the lifter. When the handle of the bowling lane maintenance machine is grasped by the grasping device and if the horizontally driving device, vertically driving device and lifter moving device are used step-by-step in a combination, the bowling lane maintenance machine can be safely and easily shifted from one position to the other position or vice versa.

Abstract: The present invention provides a bowling-lane maintenance machine having a driving mechanism which includes four turnable drive units and four lift cylinders. Each of the drive units includes a lane running wheel, a ride-on-approach and transverse running wheel having a diameter larger than that of the lane running wheel, and a drive motor operatively connected with the wheels. When the bowling-lane maintenance machine is moved on the approach by the rotation of the ride-on-approach and transverse running wheels, the lane running wheels will not be brought into contact with the surface of the approach. When the bowling-lane maintenance machine is lifted under the actuation of the lift cylinders, the drive units may be turned to change the direction of movement in which the machine is to be moved.

Abstract: The present invention provides an apparatus for controlling the flow of a liquid supplied to a system applying a liquid to a substantially flat surface, the apparatus including a source of pressurized air, an enclosed tank containing a predetermined amount of liquid and connecting with the source of pressurized air through an air line, a pressure reducing valve arranged in the air line and adapted to control the pressure of air to be fed into the enclosed tank, a nozzle connecting with the liquid outlet of the enclosed tank through a liquid supply line and also coupling with the liquid applying system, a two-way valve disposed in the liquid supply line between the enclosed tank and the nozzle and adapted to intermittently blocking the flow of the liquid in the liquid supply line, and a restrictor disposed in the liquid supply line downstream of the two-way valve.

Abstract: The present invention provides a two-position and three-way valve system having a fluid supply port, a fluid inlet port and a fluid outlet port, the valve system being characterized by a first section connecting the fluid supply port with the fluid inlet port, a second section connecting the fluid outlet port with the fluid inlet port, a valve device including a valve member mounted in each of the first and second sections to open or close a flow passage associated therewith, and an actuator mounted to actuate each of the valve members in an independent manner, the actuator means being rapidly operable in response to a control signal.

Abstract: The present invention provides a two-position and three-way valve system having a fluid supply port, a fluid inlet port and a fluid outlet port, the valve system being characterized by a first section connecting the fluid supply port with the fluid inlet port, a second section connecting the fluid outlet port with the fluid inlet port, a valve device including a valve member mounted in each of the first and second sections to open or close a flow passage associated therewith, and an actuator mounted to actuate each of the valve members in an independent manner, the actuator means being rapidly operable in response to a control signal.

Abstract: A cleaning roller rotatably driven to wipe off a liquid cleaner applied to a floor by an applying roller includes a core rotatably supportable at the opposite ends thereof and a resilient body mounted about the core and having one end inwardly spaced away from each of the opposite ends of the core, the external diameter of the resilient body progressively increasing from each of the opposite ends of the resilient body toward the central portion thereof.

Abstract: The present invention a method of applying a liquid to a plane surface in very thin and uniform layer, the method including the steps of supplying a liquid at a predetermined rate to a liquid impregnating member through a variable displacement pump the displacement of which can optionally be controlled, maintaining the liquid impregnating member at its saturated state and contacting the liquid impregnating member in the saturated state with a roller with a predetermined pressure under the action of a spring.

Abstract: The present invention provides a bowling lane maintenance apparatus moving on a bowling lane along the length thereof to effect a maintenance and thereafter traversing to the adjacent bowling lane across a division capping therebetween to effect a similar maintenance, the maintenance apparatus including a body, a first link pivotally connected at one end with the body and spring-biased in one direction, the first link having a relatively long length, a second link pivotally connected with the other end of the first link and spring-biased in the same direction, the second link having a length smaller than that of the first link, a roller rotatably mounted on the end of the second link opposite to the first link and a detection mechanism on the first and second links for detecting a relative position between the first and second links.

Abstract: The present invention provides a bowling lane maintenance apparatus of applying a conditioning oil to the surface of a bowling lane and then buff finishing the oil applied bowling lane surface, said maintenance apparatus including a body, a box member pivotally mounted on said body and including a pair of parallel spaced side plates, oil applicator and buffing rollers rotatably supported within said box member perpendicular to said side plates and disposed on the opposite sides about the pivot, and a positioning air cylinder mechanism operably interposed between said body and one edge of said box member at its longitudinal center, said positioning air cylinder mechanism being adapted to pivot said box member such that one of said oil applicator and buffing rollers will be brought into contact with the surface of the bowling lane or both the rollers will be separated from the bowling lane surface.

Abstract: The present invention provides a variable displacement pump including a cylinder member, a piston member slidably received in said cylinder member, a rack rigidly mounted on one of said members and extending parallel to the longitudinal axis of said one member, a pulse motor having an output shaft, said output shaft including a pinion rigidly connected therewith and engaged by said rack, one of said cylinder and piston members being formed with an opening used in both the suction and discharge of a liquid, and check valves disposed respectively between said opening and an upstream source of liquid and between said opening and a downstream discharging system, whereby the displacement of said pump can be controlled by controlling electric input pulses to said pulse motor.