Abstract: An overall pump assembly for smoothly pumping a compressable liquid from a supply is disclosed herein along with two intensifiers which form part of the assembly and a control arrangement for driving the intensifiers in specific phase relationship to one another. Each of the intensifiers includes its own reciprocating piston and a control device interconnected in feedback relationship with the piston in order to follow the latter through its movement. In each of the specific intensifiers disclosed, its piston and control device are interconnected by cable means configured to cause the control device to rotate about its own axis in a manner corresponding to the movement of the piston.

Abstract: A fluid pressure control device is described effective to actuate an external device when the differential-pressure between a high-pressure fluid source and a lower pressure fluid source rises to a predetermined magnitude. The control device comprises a housing having a partition wall therein dividing its interior into two compartments communicating with each other through an opening in the partition wall. A differential-pressure sensing member is disposed in one of the compartments and is movable therein in response to the sensed differential-pressure. A stem is fixed to the differential-pressure sensing member so as to be moved therewith and carries a valve member at one end for moving it with respect to the valve opening to control the flow of the fluid therethrough and thereby to actuate the external device.

Abstract: A fluid-operated cylinder to be used as a load lifting cylinder includes a cylinder casing defining a cylinder bore between two opposed ends, one of which ends is provided with a fluid supply/discharge port, a piston unit having a piston element and a piston rod, the piston unit being axially movably arranged in the cylinder bore of the cylinder casing, and a flow rate control valve unit axially movably mounted in the piston element so as to cause a gradual change in a flow rate of working fluid throughout a predetermined amount of piston stroke when the piston unit starts to move out of the cylinder casing and comes to a stop at a bottom position in the cylinder casing, thereby cushioning shock occurring in the fluid-operated cylinder.

Abstract: A cushioning mechanism in a pneumatic cylinder utilizing a supplied air pressure, and a method of cushioning a piston in the pneumatic cylinder. Cushioning chambers are provided at opposite ends of a cylinder body of the pneumatic cylinder. Respective differential pressure valves and relief valves are provided between each of the cushioning chambers and an air supply. A cushioning member is disposed between each cushioning chamber and a cylinder bore. Air supplied under pressure from the air supply is stored in one of the cushioning chambers. When the piston is displaced to push the cushioning member, the air in the cushioning chamber is compressed to cushion the piston. As the cushioning member is moved a prescribed interval, the cushioning chamber is vented to atmosphere.

Abstract: A hydraulic door closer has a housing including a bore and a piston supported for reciprocal sliding movement within the bore in door opening and closing directions corresponding, respectively, to opening and closing movements of an associated door. The piston has a head at one end and an open opposite end which receives a portion of a spring which biases the piston in its door closing direction. First and check second check valves within the head comprise part of a fluid control system for checking movement of the piston during at least a portion of its travel in either its door opening or door closing direction.

Abstract: The distributor defines two parallel fluid circuits (15, 16) each including serially arranged first (1;1') and second (2;2') valve means actuated by the primary control member (OP) of the distributor, two distribution lines (17, 18) for selectively supplying the chambers of an assistance motor-actuator (12) derivating from said circuits (15, 16) downstream the primary valve means (1;1'), and two additional return valve means (3;3'), upstream said second valve means (2;2') coupled to the piston (13) of the actuator (12) to form a restriction in the return circuit from the actuator chamber in relieved condition and thus create an over-pressure enabling effective return of the actuator to neutral position after return of distributor to rest condition.

Abstract: Valves are located at opposite ends of a cylinder and are automatically moved toward closed positions at a controlled rate as a piston approaches the ends of the cylinder. Upon being moved toward its closed position, each valve restricts the flow of exhaust air from the respective end of the cylinder and causes the piston to decelerate so as to cushion the piston as it comes to a stop.

Abstract: A system for resiliently supporting a load at a reference height includes a hydraulic cylinder for resiliently supporting a load about a reference height and an accumulator which cooperates with the cylinder for flowing hydraulic fluid therebetween in response to varying loads imposed on the cylinder. A valve is provided for dampening the rate of fluid flowing between the cylinder and the accumulator and a metering valve coacts with the cylinder for adjusting the reference height about which the load is supported.

Abstract: After the piston, in a piston/cylinder type fluid pressure motor, has moved past the fluid discharge port during termination of the stroke, fluid is forced to flow through a circuitous conduit formed into the outer surface of the piston. The rate of deceleration of the piston is proportional to the length, cross-sectional area, and surface finish of the channel forming the conduit.

Abstract: In a device for achieving speed control of a cylinder piston in relation to the cylinder, or vice versa, flow control means (12, 32) are utilized, and also cam profiles (15, 16 and 26, 27). The flow control means are composed of two constant flow valves (30a, 30b and 31a, 31b) which determine the flow for one each of the directions of the piston or the cylinder. The cam profile means have a first cam profile (15 and 26, respectively) which is connected when the piston (6) or the cylinder (5) moves in its first direction, and a second cam profile (16 and 27, respectively) which is connected when the piston or cylinder moves in its second direction. The flow control valves are controlled mechanically by the respective cam profiles via its respective control input (12c', 12c") and determine a flow for the piston or cylinder which is dependent on the controlling but independent of the load on the piston or the cylinder.

Abstract: The stroke of an air driven power cylinder is controlled through a load means attached to the piston rod, a control valve means connected to the cylinder to control air exhaust from the cylinder on the extension stroke of the piston, and an external cushion valve means operably connects to the control valve means and the load means for air exhaust flow therethrough in a controlled manner but for shut-off of the air exhaust as the piston approaches the end of its stroke to trap some air in the cylinder before the piston stroke ends, the cushion valve means having a member therein of adjustable position for control of the length of stroke of the piston.

Abstract: A hydraulic mine prop includes an inner piston-like prop guided within an outer cylinder-like prop, and a roof fall valve. The interior space of said inner prop communicates freely with the working chamber of the prop, and the roof fall valve is arranged outwardly on the prop and rigidly secured thereon, the valve being connected to the working chamber by an orifice provided in the prop and leading to the working chamber. The cross-sectional area of the roof fall valve in its open position.

Abstract: The invention comprises generally apparatus for use with an underground mine-shaft roof-bolting machine having a torque motor, a pinning rod held for rotation by the torque motor, a controllable arrangement for exerting upward thrust on the torque motor to force the pinning rod upwardly into the roof of a mine shaft, and a manual control for the upward thrust arrangement. In a first embodiment, a contoured cam rotates in dependence on the elevation of the torque motor, while a valve controlled by the cam limits the maximum upward thrust applied to the torque motor such that the maximum upward thrust on the torque motor is reduced when the torque motor is at a comparatively low elevation and is increased when the torque motor is at a comparatively higher elevation. Variations of the cam arrangement permit adjustment for use in mine shafts having different roof heights, and permit use with different types of roof-bolting machines.

Abstract: A bracing jack comprising a cylinder and a jack bar slidable in the cylinder from a bar extended position to a bar retracted position, the jack having an internal locking mechanism including a hydraulic and a mechanical actuator for unlocking under load.

Abstract: An apparatus for controlling the movement of a fluid-actuated hydraulic cylinder. A pumping mechanism is provided to pump fluid into the hydraulic cylinder; and a tank receives the fluid expelled from the hydraulic cylinder. A reversing valve between said pumping means and said hydraulic cylinder means controls the flow direction of the fluid into and out of the hydraulic cylinder and a valve mechanism between the pump means and the hydraulic cylinder, and operatively connected to the hydraulic cylinder, controls the fluid flow rate into and out of the cylinder corresponding to the motion of the hydraulic cylinder. One embodiment of the invention is specifically designed to power the main drive gear of an apparatus for stacking battery plates and separators.

Abstract: Apparatus is disclosed for an improved hydraulic piston and cylinder design wherein grooves in the piston surface create a dashpot effect at the respective ends of piston stroke and assist hydraulic oil porting into the cylinder for improved response during stroke reversal, where the piston at least partially covers the cylinder oil flow port.

Abstract: A scavenging air valve for cleaning at least one tubular filter body is disclosed. The air valve has a laminar valve body, one side of which forms, by means of its inner portion, the shutoff for the inlet of a scavenging air line. Its edge zones of said one side face toward a scavenging air chamber. The valve body is movable perpendicular to the side mentioned, inside of a maintaining chamber, under the effect of the scavenging air. The maintaining chamber is, on the one hand, in constant communication with the scavenging air chamber over at least one throttling point and, on the other hand, is connected to a blockable exhaust air line through means of a control valve.

Abstract: An air motor comprising a cylinder, a piston, and a valve mechanism for controlling the supply and exhaust of air to and from opposite ends of the cylinder, the valve mechanism comprising a D-valve and an actuator for the D-valve operable by the pressure air for driving the piston, movement of the actuator being controlled by valves at opposite ends of the cylinder for exhausting air from opposite ends of the actuator, these exhaust valves being operated by the piston, and the motor having means operable by the piston at each end of its stroke for restricting the exit of air from the cylinder to cushion the piston and prevent it from striking the ends of the cylinder.

Abstract: A compact, double-acting piston-type fluid activated device having an axially reciprocable piston for controlled, predetermined deceleration of the piston as it approaches the limit at each end of its travel within a cylindrical bore. The cylindrical bore is sealed at each end by end walls removably retained in the bore. Each end wall is provided with a central counterbore in its inner surface which in cooperation with the piston provides a cushioning chamber. The area of the counterbore central surface is critically related to the circular cross-sectional area of the cylindrical bore in which the end wall is to be secured, being in the range from about 60% to about 85% thereof. A vent passage places the cushioning chamber in preselectedly restricted flow communication with porting means in the wall of the device, each port being located intermediate the end walls. A method is provided for removably circumferentially locking each end wall in the operating cylinder with a wire snap ring having a hooked end.

Abstract: A fluid power system including a fluid power cylinder having a piston and fluid ports at its opposite ends, a directional valve for selecting the direction of piston actuation, and a metering control valve coupled between the directional valve and the cylinder. The control valve includes a cylinder section having a control piston therein and a valve body connected to the cylinder section and having a valve spool-receiving cavity therein. The valve body has first and second fluid ports therein communicating with the cavity, one of the valve body ports being coupled to one of the power cylinder ports and the other being coupled to the directional valve. A valve spool is disposed in the valve body cavity operatively connected to the control piston and movable therewith, the spool having a passage therein.

Abstract: An apparatus for closing the guide vanes of a water turbine, for example, by means of a servo-motor controlled by a distributing valve responsive to the variation in the speed of the water turbine. The closing speed of the servo-motor is controlled to vary stepwisely by controlling the flow of the operating oil discharged from the servo-motor by a throttle control valve. The throttle transfer valve is controlled by first and second fluid actuators which are controlled by a first transfer valve operated by the closing operation of the servo-motor, a second transfer valve, and a time delay means.

Abstract: This invention is a piston-cylinder hydraulic snubbing device to arrest or resist motion. The invention may be utilized as a snubbing device alone, or it may be incorporated into a hydraulically actuated piston-cylinder assembly. The principal feature is that an orifice, through which hydraulic fluid is forced, is in the form of a gap between the ends of a piston ring, which gap is varied by engagement of the ring with a tapered bore in the cylinder.

Abstract: A pneumatically buffered drive system is provided which quickly moves a movable member, such as a press safety curtain or press bolster, a predetermined length in three sequential speed stages to prevent maximum acceleration from occurring at the end of the predetermined length. The movable member is coupled to a differential pressure piston which is initially pressurized on only one side of the piston to initiate movement. After traversing approximately half the predetermined length both sides of the piston are pressurized to decelerate the piston during the member movement for approximately the next third of the predetermined length. The remaining length is traversed with the decelerating pressure being vented to positively finish the motion along the predetermined path. In vertical moving members having significant mass such as press safety curtains, a higher pressure is used to decelerate the piston than the pressure used to drive the piston.

Abstract: The invention is concerned with an improved fluid operated hydraulic ram wherein the travel of the piston thereof is cushioned to reduce impact by progressively restricting fluid flow. The ram of the invention comprises a housing defining a generally cylindrical ram bore having a first wall at a first end thereof with a first hole generally centrally therethrough and a second wall at a second end thereof with a second hole generally centrally therethrough leading to a chamber. A piston fits reciprocally within the ram bore and includes a piston rod extending therefrom through the first hole and a snubber extending from the opposite side thereof towards the second hole. The snubber is sized to pass into the second hole in spaced flow restrictive relation thereto towards the chamber to create a relatively higher pressure in the ram bore adjacent the second end thereof than in the chamber.

Abstract: A stitching apparatus for stitching tire components laid on a building drum, comprising a frame structure arranged opposingly to and spaced apart from the building drum, a central roller disposed opposingly to the mid-circumferential plane of the building drum and having a rotational axis parallel with the rotational axis of the building drum for stitching the mid-circumferential portions of the tire components on the building drum, at least a pair of side rollers circumferentially spaced apart from the central roller and arranged symmetrically to the mid-circumferential plane of the building drum for stitching both side portions of the tire components, each side roller having a rotational axis inclined to the rotational axis of the building drum and at least a surface portion made of an elastic material.

Abstract: A miniature piston assembly composed of an elongated cylinder containing a piston head which may be displaced in response to digital hydraulic signals or otherwise and which is arranged to provide self-snubbing without requiring check valves. In the side wall of the cylinder are one or more ports spaced from one or more of the distal ends of the cylinder by a predetermined distance. When the piston is in juxtaposition with a port and approaching the proximate end of the cylinder, the cylinder and the piston define an annular clearance space of ever increasing length and fluid impedance for snubbing the motion of the piston with respect to the cylinder.

Abstract: A piston-in-cylinder type pneumatic actuator is provided with an automatic cushioning facility to prevent the piston from returning to its fully retracted position at velocities exceeding a predetermined maximum velocity. Integrally-housed in the actuator is a velocity transducer arranged to sense the pressure in a cylinder working volume, which pressure is related to the piston velocity and is used to control the operation of an exhaust valve operable to vary the rate of flow of gas from the cylinder thereby to vary the rate of return of the piston.