Abstract: A fail safe mechanism is provided for locking an actuating piston rod of a fluid operated actuator in a selected axial position in the event of a failure, or significant decrease in, the fluid pressure applied to the actuator. Preferably, a secondary cylinder is provided within the actuator cylinder and is in fluid communication therewith. A piston in the secondary cylinder is biased toward a locking position by a spring and is shiftable toward a released position by the existence of a predetermined amount of fluid pressure in the main cylinder. An annularly extending locking mechanism is provided in surrounding relationship to the actuating piston rod and is radially movable into engagement with a locking shoulder on such piston rod when the rod is shifted to one of its selected axial positions by the application of fluid pressure to the cylinder.

Abstract: The invention relates to a ram comprising a piston rod in two parts mounted for relative rotation.A first part extends out of the cylinder, beyond each of the heads, while the second part extends out of the cylinder only beyond one head, namely the upper one, and comprises two axial shoulders directed in opposite directions, located at the two ends of this second part and each cooperating with a shoulder, fast with the first part, corresponding to the maintenance of a fixed relative axial position between the two parts, and two radial bearing surfaces located at the two ends of the second part and cooperating with two radial bearing surfaces fast with the first part, corresponding to the centering of the two parts. The present invention is particularly applied to a rotatable clam-shell bucket.

Abstract: An actuator comprising a housing, a piston movable in the housing, a rod coupled to the piston and movable therewith, and a tubular member mounted in the housing and having a rod extending therethrough. A frangible section retains the tubular member against axial inward movement from a first position in the housing. When an axial inward force of at least a predetermined magnitude is applied to the tubular member, the frangible section ruptures to allow at least a portion of the tubular member to move axially inwardly. Armor is provided for protecting at least a portion of the housing.

Abstract: A rack and pinion power steering system includes a housing within which a rotatable pinion engages a rack to impart movement thereto. The rack is substantially U-shaped having a pair of arms with coaxial openings to slidably receive a rod. The rod extends from the housing to operatively engage a pair of dirigible wheels and the rod is movable relative to the housing when the rack is moved to change the direction of the pair of dirigible wheels. A sleeve on the rod is disposed between the pair of arms and is provided with a valve member to communicate pressurized fluid from a pressure source to a pressure chamber to assist the movement of the rod.

Abstract: A system for porting of hydraulic fluid in a hydraulically driven seismic energy vibrator of the reciprocating mass type. A mass is reciprocated relative to an earth contacting frame which includes at least two hydraulic piston rods coacting with internal cylinders within the mass. The piston rods, of the type having double rod ends, each include a single axial bore therethrough in communication with respective opposite sides of the piston ring assemblies, and cross porting is effected between opposite ends of the mass cylinders.

Abstract: An imprint marking device utilizing transfer tape moved from a tape supply reel to a take-up reel across an imprint station with a moving marker head having raised indicia movable against the tape to press the tape against an article to be marked. A tape drive system includes a drive roller and an opposed idler roller. Both the tape drive system and the marker head are actuated by a single power cylinder which has power rods extending from opposite ends connected to a single common internal piston, one of the rods operating the marker head and the other of the rods operating the tape drive system.

Abstract: A rack and pinion power steering device includes a housing within which the pinion engages the rack to impart movement to the rack upon rotation of the pinion. The rack includes a bore for slidably receiving a pair of plugs which support the rack and a rod which extend through the plugs and housing to engage a pair of dirigible wheels. The plugs cooperate with the rod to form pressure chambers and a valve member carried by the rack cooperates with projections on the rod to communicate pressurized fluid from a pressure source to either of the pressure chambers whereupon the pressurized fluid therein urges the rod to move relative to the housing. The rod also provides for communication of pressurized fluid from the pressure source to the valve member via a passage therein.

Abstract: A fluid operated stepping motor comprising a cylinder housing having one or more fluid cylinders to alternately displace at least two cam engaging members when pressure from a pressure source is applied to one of the cylinders. The cam engaging members are diametrically opposed. A cam is secured relative to the cylinder housing and having a plurality of teeth asymmetrically disposed thereon, is also provided. Each tooth has a power profile surface and an idle profile surface. The power profile surface is slidingly engageable by one of the cam engaging members when pressure is applied to displace the said one cam engaging member axially whereby the power profile surface will cause relative rotational displacement between the cylinder housing and the cam.

Abstract: An improved fluid cylinder including a housing defining a cylinder bore and having aligned piston rod openings at opposite ends thereof, which openings are nominally coaxial with the bore. A piston rod is within the bore and extends through both of the openings and a piston is located within the bore and includes a central opening receiving the rod and having a shape complementary to that of the rod while being slightly larger than the rod so that the piston may move radially on the rod. Securing elements are provided for fixing the axial position of the piston on the rod and include an annular shoulder abutted by the piston. A seal is interposed between the piston and the shoulder to preclude leakage of the working fluid therebetween. The relative radial movement of the piston on the rod compensates for lack of precise concentricity of the bore with respect to the rod receiving openings.

Abstract: A rack and pinion steering gear mechanism for use with the dirigible wheels of a road vehicle comprising a steering gear pinion adapted to be connected to a vehicle steering linkage, a power rack engageable with the pinion and adapted for reciprocating linear motion, said rack including a power piston mounted within a power cylinder which define a pair of opposed pressure chambers, a steering shaft connected yieldably to the pinion by a torsion shaft, fluid pressure control valve means including relatively displaceable parts forming in part fluid connections between a pressure source and each of said pressure chambers, one valve part being connected to the pinion and the other part being connected to the steering shaft whereby distribution of working pressure to the pressure chambers is dependent upon the direction of torque applied to the steering shaft, the magnitude of the pressure buildup in the pressure chambers being proportional to the degree of displacement of the steering shaft relative to the pinion

Abstract: A hopper having a bottom opening into an open topped chamber portion of a housing which defines a discharge passageway leading from the chamber to a discharge end portion. A piston is mounted for reciprocatory movements in the chamber portion and passageway. The piston having a pumping surface normal to the direction of its movement and facing the discharge end portion of the passageway. The piston has an opposite surface which slopes angularly upwardly toward the pumping surface. A check valve is disposed in the passageway at the discharge end portion of the passageway.

Abstract: A hydraulic impact device has a hammer member carrying a piston which is reciprocally disposed in a cylinder chamber to form an expansible chamber. When the expansible chamber is pressurized, the hammer is retracted against an air spring or other energy storage device by the high pressure. A sleeve valve is reciprocally disposed in the cylinder chamber between the piston and the energy storage device and is held against the piston by an imbalanced fluid pressure as the hammer is retracted against the spring. When the piston and sleeve valve have been retracted to a predetermined position, high pressure fluid is ported between the sleeve valve and piston to hydraulically separate the two members.

Abstract: An impact motor has a reciprocating piston that has its piston rod guided in bushings in the housing. The bushings are lubricated by oil-loaded compressed air but the piston is forced to reciprocate by oil-free compressed air.