Abstract: A fluid-driven linear actuator comprises a piston configured for reciprocating motion in a piston chamber and a spool valve in a valve chamber. The valve chamber is fluidly connected to a fluid input and to a fluid output. The spool valve is configured to be hydraulically moved within the valve chamber between a plurality of spool valve configurations, comprising a first spool valve configuration wherein the valve chamber is fluidly connected to the piston chamber to thereby create a first fluid pressure differential which tends to force the piston in a first axial direction and a second spool valve configuration wherein the valve chamber is fluidly connected to the piston chamber to thereby create a second fluid pressure differential which tends to force the piston in a second axial direction.
Type:
Grant
Filed:
October 2, 2012
Date of Patent:
March 22, 2016
Inventors:
James Victor Hogan, Robert James Pletscher
Abstract: The invention relates to a control valve, a percussion device and a method of controlling a working cycle of a percussion device. A percussion device (1) for breaking rock includes an impact element (8) controlled by a control valve (2). The control valve includes a control element (5) arranged to control channels (7b) leading to a working pressure surface (9) of the impact element (8). The control element, during a working cycle of the control valve, is arranged to open and close pressure channels at several connecting moments so that during one working cycle of the valve, several impact pulses are arranged to be produced.
Type:
Grant
Filed:
February 23, 2004
Date of Patent:
February 20, 2007
Assignee:
Sandvik Tamrock Oy
Inventors:
Antti Koskimäki, Markku Keskiniva, Jorma Mäki, Mauri Esko, Erkki Ahola, Aimo Helin
Abstract: A fluid motor for converting reciprocation of a piston within a cylinder to rotation by a crankshaft includes a valve for supplying a fluid to the cylinder and discharging the fluid therefrom. The valve comprises a rotary valve member rotatable with the crankshaft and a fixed valve body slidably in contact with the rotary valve member. When the motor stops, at least one-half portion of a fluid intake groove formed in the rotary valve member is positioned at one side, toward a direction opposite to the direction of rotation of the rotary valve member, of a position opposed to a cylinder connection port formed in the fixed valve body so that a sufficient amount of pressure fluid can be supplied to the cylinder at the start when the motor is initiated into operation again.
Abstract: A reciprocating piston fluid powered motor having fluid inlet and outlet, wherein reciprocation is controlled by a reciprocable valve spool carrying a manifold communicating with said fluid inlet and outlet and cooperating with a valve slide shiftable on said valve spool to control reciprocation of said valve spool.
Abstract: A multi-function valve device for controlling the operation of a pneumatically-driven motor. A spring-biased linkage couples a cam-operated push pin to a valve spool assembly. The valve spool assembly coaxially combines the movable elements of a pressure regulator valve, a run valve, and a park valve into a single unit slidable axially within the valve housing and positioned by the spring-biased linkage. The pressure regulator valve permits an increasing pressure to be applied to a slowed or stopped pneumatic motor, approaching the pressure of the pneumatic source to aid in restarting the motor or to provide the additional force necessary to drive a heavily loaded motor. Automatic park and shutoff functions are also provided.