Abstract: A speed change control system for an automatic transmission for motor vehicles having a planetary gear mechanism and a brake band for altering the transmission ratio. The system is to tighten gradually the brake band. The system comprises a servo-piston, a piston rod secured to the servo-piston and to the brake band, and an accumulator piston axially slidably disposed in the bore of the servo-piston. The servo-piston is biased by a first spring for returning the servo-piston for releasing the brake band, and the accumulator piston is biased by a second spring. Apply side and release side oil chambers are formed on opposite sides of the servo-piston, and an accumulator oil chamber is formed by the accumulator piston in the bore. Pressure oil is applied to the apply side oil chamber, so that the servo-piston moves in a brake band engagement direction against the first spring. After that, the accumulator piston moves a predetermined stroke against the second spring.

Abstract: In a double-acting hydraulic press: an outer press ram having a cylinder formed therewithin for the piston of an inner press ram, the inner and outer ram cylinders in communication with one another and the rams being subject to a common hydraulic actuating means, each ram carrying a separate and distinct tool at its forward face, and means controllably feeding pressurized hydraulic fluid to an intermediate section of said inner ram cylinder, whereby to control the effective hydraulic force applied to said inner ram and the tool thereof.

Abstract: An apparatus for measuring and detecting the pressure in a fluid being injected into a closed system, for instance, fluid being injected into a dilitation catheter, such as a balloon catheter used for the purpose of percutaneous transluminal angioplasty. The apparatus provides a pressure measuring system that includes a housing for releasably and slidably holding the barrel of a syringe used to deliver fluid into the balloon catheter; and a device for measuring and indicating fluid pressure in the syringe barrel, which is also the balloon pressure. The pressure measuring system indirectly measures pressure changes of fluid within the syringe barrel by sensing movement of the barrel as a result of fluid pressure changes. Since a pressure change is sensed by sensing movement of the syringe barrel, the only parts of the system directly contacted by the fluid inflating the balloon are the syringe barrel and syringe plunger.

Abstract: A friction-welding machine of the type in which a cylinder arrangement applies pressure to urge two workpieces together upon the rotation of one of the workpieces against the other to prepare the interface for bonding. The cylinder arrangement which applies the welding pressure comprises a main cylinder whose piston acts upon the workpiece through a head formed with an auxiliary cylinder and piston arrangement greatly increasing the working range of the cylinder arrangement.

Abstract: A variable speed multi-cylinder assembly is provided with expandable bushing seals to block leakage of fluid from higher speed stages to lower speed stages.

Abstract: A force multiplier for a punch press which is sufficiently compact as to be placed in the normal throat opening of such press and yet enables the press to increase its working force by one and one-half to three times. The multiplier has a platen having a large diameter piston on its upper surface which piston has a sleeve on its upper surface, the outer surface of which is in engagement with a cylindrical wall in an upper base plate and the inner surface of which forms a cylinder wall for a second piston of smaller diameter which is engaged by the platen of the punch press.

Abstract: A fluid cylinder assembly comprising a cylindrical shell and movable plunger member having an annular retainer internally threaded into one end of the shell so as to limit the extensibility of the plunger from the shell, such annular retainer being specially designed so as to enable the outside diameter of the shell to be minimized without adversely affecting the performance of the cylinder assembly. The resilient fluid seal between the retainer and the shell, normally located at a position interior of the retainer threads, is instead located exterior of the threads at the end of the shell. The retainer includes a radially-projecting flange portion, exterior of the end of the shell, having a chamfered annular recess therein which encloses the end of the shell and resists any tendency of the end of the shell to expand radially when the force of the plunger is imposed upon the retainer by prestressing the flange against such expansion.

Abstract: A coupling for use in a vehicle having an extensible and retractable ram reacting between the vehicle frame and a rockable dump body for raising and lowering the latter comprises a pair of parallel links straddling the ram and being pivoted at corresponding ends to the body and at their opposite ends to the ram. The pivotal connection of the links to the body preferably is of the ball joint type to enable substantially universal movement of the links relative to the ram. The coupling enables limited relative movement between the body and the vehicle frame without necessitating extension and retraction of the ram.

Abstract: A hydraulically actuable piston and cylinder unit comprising a hollow piston rod, slidably housing, at least partially, an elongate extension piece having a circular outer periphery, means to connect mechanically, the extension piece to the piston rod at the outer end of the latter remote from the piston head, at least one fluid passageway communicating between the annulus side of the piston head and the hollow interior of the piston rod, and a fluid seal carried by the extension piece and sealing against the internal periphery of the hollow piston rod, the arrangement being such that the seal always lies between the passageway and the outer end of the hollow piston rod.

Abstract: A hydraulic cylinder assembly including an outer barrel having one or more internal sleeves and a center rod telescopically mounted therein. The outer barrel and internal sleeves each have a bottom end tube welded to one end thereof and a packing gland tube welded to the other end thereof. The center rod has a bottom end tube welded to one end thereof. The bottom end tubes on said barrel and sleeves have end caps removably mounted therein. Stop shoulders are formed integrally with the end tubes of the internal sleeves and center rod. Mating stop shoulders are formed integrally with the packing gland tubes of the outer barrel and internal sleeves. Said stop shoulders are adapted to move into engagement with each other when the hydraulic cylinder assembly is energized.

Abstract: In a cylinder with a two-stage movement, a first piston moves in a housing, and in the first piston a second piston moves, which has a piston rod sliding in an end of the housing. On its side facing away from the piston rod, the second piston is provided with a guide member which is guided in the first piston. The first piston can be held in a position in which the piston rod is extended far out of the housing. With the aid of the second piston, the piston rod can perform a certain axial movement relative to the first piston, at the same time as guiding is effected with the aid of the guide member and the first piston.

Abstract: An internal fluid communication system in combination with a fluid operated power cylinder, such as that used on industrial lift trucks, in which a pair of tubular sections in telescopic relationship is disposed lengthwise within the power cylinder, forming a fluid passageway through the cylinder for transmitting fluid from one end of the cylinder to the other. The cylinder may be of either the ram or the cylinder and piston type. Two or more tubular sections may surround the first tubular section and form a plurality of parallel fluid passages passing through the power cylinder from one end to the other without communicating with the operating fluid in the cylinder. In the embodiment of the invention applicable to a cylinder and piston type hydraulic motor, one tubular section is disposed in the piston rod and the other tubular section passes through the piston and is in telescopic relationship with the tubular section in the piston rod.

Abstract: A hydraulic actuator cylinder primarily for the actuation of aircraft landing gear in which the rod end is made integral with the piston rod with the attaching threads positioned inside the cylinder. The piston head is designed to float on the piston rod plus or minus the amount of adverse tolerance conditions that are possible in the landing gear installation.

Abstract: A paper roll-handling clamp for lift trucks of the pivoted arm type. The pivoting movement of the clamp arms with respect to one another to perform the clamping function is accomplished by use of a generally forwardly extending, selectively extensible and retractible multi-stage telescoping hydraulic piston and cylinder assembly, which gives the clamp arms an exceptionally wide range of motion.

Abstract: A hydraulic jack suitable for powering a large load such as an elevator or a drawbridge. In a first embodiment the hydraulic jack telescopes at a uniform rate over its entire distance of extension and includes a plunger member telescopingly enclosed within a sleeve member which, in turn, is telescopingly enclosed within a cylinder member, with the cylinder member encircled by an oil jacket within which the cylinder member is capable of limited angular movement. Means are provided for angularly aligning the various members within one another. Means are also provided to restrict the flow of hydraulic fluid as the hydraulic jack reaches a limit of its travel. Hydraulic jacks in accordance with the present invention can be coupled together in systems to lift large loads.

Abstract: A fluid pressure actuated piston of an aircraft multiple disc brake assembly is adapted to have an extended stroke by telescoping with a pressure actuated cylinder. The piston is slidably carried in a fluid pressure actuated cylinder which, in turn, is slidably carried in a fixed carrier. Initially, only the piston moves axially to extend its stroke with respect to the carrier. The cylinder's structure and axial position with respect to the carrier creates a fluid pressure responsive surface area initially sealed from the effects of the fluid pressure. Axial movement of the cylinder is initially resisted by either mechanical or differential pressure member until the stroke of the piston reaches a predetermined axial position to engage the cylinder. Continued extension of the piston's stroke urges the cylinder axially to break the fluid seal and expose the heretofore unaffected surface area of the cylinder to fluid pressure thereby extending the stroke of the cylinder a predetermined axial distance.

Abstract: A hydraulic pressure control device for use, for example, in an automatic transmission, in which a line pressure to be supplied from a hydraulic pressure source to a hydraulic pressure servo-device is controlled in three stages by means of a main spool which is displaced in a bleed-off valve of the line pressure by a subsidiary spool under a varying hydraulic control pressure. The subsidiary spool has at least one land forming a piston slidingly fitted in a movable sleeve having a closed end, the movable sleeve also forming a piston by being in turn slidingly fitted for limited movement in a stationary sleeve having a closed end. A first space between the outer wall of the closed end of the movable sleeve and the inner wall of the closed end of the stationary sleeve, and a second space within the piston chamber of the movable sleeve have ports for the introduction of hydraulic control pressure.

Abstract: A double-acting hydraulic cylinder includes a hollow cylinder body with a closed end and an end with a first rod opening. A first hollow piston and rod assembly, having a second rod opening at the piston end, projects through the first rod opening and slides in the cylinder body. A second hollow piston and rod assembly, secured at the rod end to the hollow cylinder body, projects through the second rod opening and slides in the first hollow piston and rod assembly. The first and second hollow piston and rod assemblies cooperate to form a first variable volume chamber. A rod secured to the rod end of the first hollow piston and rod assembly slidably projects into the second hollow piston and rod assembly and cooperates therewith to form a second variable volume chamber. The first variable volume chamber is connected to a first port in the cylinder body and is expandable and contractable in response respectively to retraction and extension of the first hollow piston and rod assembly.

Abstract: An extendible and contractible shaft comprises a number of shaft members on a common longitudinal axis, each except the outermost member being telescoped within the one next adjacent. Each telescoped member has a piston slidably sealed to the inner wall of the next adjacent outer member to form a series of tandem arranged sealed pistons. Fluid passageways are provided between adjacent shaft members so that fluid supplied under pressure to an inlet port of the device flows through the passageways to all the piston heads, thereby extending the telescoped shaft members and at the same time driving fluid out from under each piston through fluid passageways to an exit port of the device. When the pressurized fluid flow is reversed to send pressurized fluid to the undersides of the pistons, thereby driving fluid above the piston heads out through the first mentioned port, there would normally be incurred substantial shock as each piston head strikes its stop in the retraction operation.

Abstract: In an hydraulic actuating assembly for a vehicle shoe-drum brake comprising first and second relatively slidable members, the first member is provided with a longitudinally extending bore which is closed at one end and in which works a portion of the second member, and a sealed hydraulic chamber is defined within the bore between the closed end of the first member and the second member. One of the members incorporates an inlet port for the chamber and a vent port is located in a portion of the wall of that member to provide an indication, by external leakage of hydraulic fluid, of failure of the sealing of the chamber.

Abstract: This invention relates to a telescopic jack constituted by a main cylinder, a first piston sliding in said main cylinder, a first piston rod fast with the first piston which passes in tight manner through a first bottom of the cylinder, a second piston which may be disposed in a bore of the first rod and is mounted to slide with respect to the first piston, and by a second piston rod which is fast with the second piston.The second piston rod passes through the second bottom of the cylinder whilst the piston is separable from the rod.One application of the invention is the production of an inexpensive telescopic jack.

Abstract: A disc brake assembly comprises a housing affixed to a non-rotatable member and having a through-hole therein. A cylinder is slidably fitted in the through-hole in the housing and has a pressure oil inlet, and a piston therein in sliding relation therewith. A disc is rotatable together with a rotating member, and a yoke is affixed to the cylinder and is movable with the cylinder. A member movably couples the yoke to the housing. A first friction pad is supported by the yoke and is adapted to be urged against or detached from one side of the disc, and a second friction pad is mounted on one end of the piston and is adapted to be urged against or detached from the other side of the disc.

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.