Abstract: A three-position pneumatic tool having a toggle trigger for actuating a control rod which in turn controls a pair of pneumatic check-valves. Three interconnected, tandemly arranged piston assemblies are operatively associated with an air pressure source at one end while also being operatively associated with a work assembly at the other end. The trigger is spring-biased to a location wherein the tool is in a neutral workpiece engaging position. Actuation of the trigger in one direction will open one of the pneumatic valves whereupon air pressure acts upon the upper surface of one of the pistons so as to lower or retract the tool to a workpiece insertion position. Release of the trigger permits the tool to attain the workpiece engaged or neutral position. Rotation of the trigger in the opposite direction permits the other pneumatic valve to open whereupon air pressure acts upon the lower surfaces of all the pistons so as to raise and actuate the tool to the operating position.

Abstract: Disclosed is a leak retriever for the packing gland on oil well pumps. The leak retriever has a reservoir disposed about the packing gland to collect oil which leaks through the gland and an auxiliary pump which is mounted in the reservoir and connected to pump all oil collected back into the discharge line for the well. The auxiliary pump is mounted in the reservoir so that any leaks from the auxiliary pump are also collected by the reservoir, and is driven by a plate on the polish rod of the well pump driving apparatus. In the first form the reservoir is clamped onto the packing gland housing below the cap nut, and in the second form it is made integral with the cap nut.

Abstract: A clamping mechanism, effective to press a movable platen against a fixed platen in a terminal phase of a mold-closing stroke of an injection-molding machine, comprises a series of coaxial annular pistons received with progressively larger clearances in respective inner peripheral grooves of a stationary housing linked by tie rods with the fixed platen. The pistons, which can be interconnected by elastic bolts, bear upon a mounting frame, slidable along the tie rods, supporting a pair of laterally withdrawable shutters which in their retracted position give passage to a tubular thrust member coaxially surrounding a plunger secured to that thrust member and to the movable platen. The opposite end of the plunger carries a piston head received, within the housing, in a central driving cylinder to which hydraulic fluid can be admitted from either end for advancing or retracting the movable platen in a mold-closing or a mold-opening stroke.

Abstract: A unique double acting piston and cylinder assembly is disclosed wherein the assembly can be moved to any one of three positively determined positions by application of fluid pressure to any one of three ports.

Abstract: A fluid reservoir device for use in conjunction with fluid-filled systems, such as helicopter blade dampers, comprises a cylindrical chamber wall closed across its bottom by a mounting shank having a fluid inlet opening formed therethrough. A first piston is slideably mounted within the cylindrical chamber wall and spring biased downwardly therein, and a second piston is slideably mounted in the first piston, and is spring biased downwardly therein, the combined work surfaces of the first and second pistons closing the cylindrical chamber wall wherein a chamber is defined having a volume which varies according to the positions of the first and second pistons. The chamber is filled by moving the first piston (and the second piston mounted therein) upwardly, and the first piston is spring biased downward to force fluid from the chamber to the fluid-filled system as required.

Abstract: The ends of travel of pneumatic jacks are controlled so as to obtain signals which are directly utilizable in fluidics by means of a device comprising a main jack-piston with a hollow operating stem fitted with a plunger and a positionally-adjustable regulating stem, a main cylinder and auxiliary cylinder having control ports for driving fluid and communicating with stationary fluidic control ports, and adjustable fluidic control means actuated in dependence on the position of the regulating stem with respect to a cylindrical slide-valve.

Abstract: An actuating device comprises a cylinder of hollow cylindrical form a plurality of pistons respectively of different operational strokes slidably fitted within the cylinder and undergoing sliding displacements in a mutually unitary manner in regions where their strokes overlap and in a separate manner in regions where their strokes differ under driving force due to a working fluid supplied into and discharged from the cylinder interior through ports provided in the cylinder, a working fluid system for supplying the working fluid and having at least one changeover valve for controlling the working fluid supply into and discharge from the cylinder, the piston of longest stroke among the pistons being a driving piston, and a driven shaft coupled to the driving piston thereby to be driven by the sliding displacement thereof. The driving piston undergoes sliding displacement in a noncontinuous manner in multiple stages, whereby the driven shaft is driven in multiple stages.

Abstract: The brake, including a brake housing, is characterized by a housing having an inwardly extending flange forming a pressure chamber with an annular piston slidably positioned in the brake housing, and the annular piston and a secondary piston are operatively associated with opposed sides of the inwardly extending flange to form pressure chambers therewith for individual actions in the brake. Spring means operatively engage the secondary piston for moving the same into operative pressure braking position for fail safe braking operation. Air pressure is supplied to the two pressure chambers or cylinders for controlling brake release and braking action.

Abstract: A power cylinder of the multiple stage telescoping type that is characterized by a plurality of telescoping piston and cylinder assemblies, each of which comprises a composite cylinder and piston sleeve construction and an end closure construction that provides an extension stop for the piston sleeve of the next adjacent stage. The apparatus is further characterized by a quickly detachable base plate construction which permits ready access to the interior components of the cylinder via the base end thereof.