摘要:
The pneumatic actuator of the invention is constructed from a plate (1) that is for example level and is secured in a reference system (9). On the one side of the plate (1), a first web (2) of a highly resistant and poorly extensible woven textile is secured such as by gluing alongside several strips (3). A second web (4), which is preferably made from the same material, is applied to the first web (2) and connected to the first web (2) along the strips (3). Between the strips (3), bladders (7) made of an elastic plastic material are inserted in the loose portions of the first and the second web (2, 4), said bladders being closed on both sides and comprising one valve (8) each. The bladders (7) can be pressurized with compressed gas through said valves (8). This causes the second web (4) to arch, the thus generated forces effecting onto the plate (1) a bending moment that causes the latter to laterally bend away.
摘要:
A process is disclosed for the preparation of monoalkyl ethers of polyoxyalkyleneglycols having a boiling point greater than 290.degree. C and suitable for use as a hydraulic brake fluid, wherein a mixture of ethylene oxide and propylene oxide is reacted in an anhydrous alkaline medium, and at elevated temperatures and with a monoalkylether of diethylene glycol, in a preferred weight ratio oxides/glycol-ether comprised between 1.2 and 1.8. Preferably, the monoalkylether of diethylene glycol is the monomethylether which may contain a small amount of monoethylene glycol. The reaction product may be adjusted as regards viscosity by dilution with a minor amount of an alkoxy triglycol, e.g., butoxy triethyleneglycol.
摘要:
The invention relates to a method and a device for reducing the piston speed in a piston and cylinder assembly (1), as the piston approaches the end position. The piston end position is sensed, and a signal is generated for starting the end position dampening. Dampening is effected in two steps. In the first step (14), a time delay is provided and in the next step (15), the actual braking (retardation) of the piston is effected.The invention also comprises an electronic braking device comprising a dampening activation unit (13) which is connected to transducers (6), a braking delay unit (14) connected to the unit (13) and also to the control lever (5) at issue and a reference signal source, as well as a braking unit (15) connected to the delay unit (14) and adapted, upon activation, to provide a signal (U) to a setting system (3) for controlling the supply of pressure fluid to the piston and cylinder assembly (1).
摘要:
A fluid arrangement for the alternating operation of an apparatus includes a working cylinder with a working piston endowed with an alternating movement and a control cylinder with an alternatingly moving control piston. Each of the cylinders has for the respective piston a driving chamber which is alternately connected to a supply source of fluid under pressure and to a discharge opening for the fluid through a distributor, and a return chamber permanently connected to the supply source of fluid under pressure. The distributor connected to the driving chamber in the working cylinder is the control cylinder, and the distributor connected to the driving chamber in the control cylinder is the working chamber.
摘要:
An integrated transmission-engine control for a transmission, such as a hydrostatic transmission having a variable displacement unit connectable to an engine and a second displacement unit connected to an output shaft, including fluid pressure-operated ratio governor means for the transmission, fluid pressure-operated means for controlling the supply of fuel to an engine, a power demand valve for converting a particular power demand to a particular fluid pressure primary control signal. The primary control signal is applied to the ratio governor means in opposition to a signal representing engine speed to set the transmission ratio for a desired engine speed and also applied to the fuel supply controlling means to establish a fuel setting to match engine horsepower to engine speed for minimum fuel consumption.
摘要:
This hydraulic system for controlling and driving a movable member in a machine tool, for example the movable apron performing sheet-metal bending or shearing operations, comprises a single distributor incorporating a slide valve responsive either to a push member manually actuated by the operator of the machine or to another push member responsive in turn to a mechanical device actuated by one or a plurality of separate control members associated with said movable member or the like for automatically changing the speed of said movable member and stopping same at the end of its stroke.
摘要:
A double-acting regeneratively controlled piston-cylinder device or tilt cylinder for tilting a spring-supported truck cab relative to the truck chassis to permit access to the truck engine positioned below the cab embodies means therein which enable slight relative reciprocating movement of the piston and cylinder from an ''''at rest'''' position in response to slight relative bouncing movement of the cab with respect to the chassis as the truck operates over-the-road. The piston-cylinder device is of the double-acting type and embodies means to provide an oil passage around the piston over part of the piston stroke. The oil passage may take the form of a concentric chamber, an eccentric chamber, a helical groove, or a longitudinal groove, each formed in the cylinder wall or may be a separate tube on the cylinder for by-passing the piston. Relative piston-cylinder motion results because, if the piston is pushed inwardly of the cylinder by cab bounce, oil can escape from the base end of the cylinder via the passage to the rod end of the cylinder. Or, if the piston is pulled outwardly of the cylinder by cab bounce, oil can flow from the rod end of the cylinder via the passage to the base end of the cylinder.
摘要:
The invention concerns a cylinder-piston combination actuated by a pressure medium, comprising an outstretched cylinder space (1) and a two-part piston assembly (3, 8) movable in opposite directions in the longitudinal direction of the cylinder space (1). The piston rod (6) of the first part (3) of the piston assembly is of a tubular construction. The first part (3) is provided with a sealing between the piston (4) and the inner surface (2) of the cylinder space (1). The cylinder space (1) is provided with a connection (27) through which the pressure medium can be passed into the space (31) limited by the cylinder space (1) and the outer surface of the first part (3). The second part (8) is constructed to dimensions allowing it to fit inside the first part (3) and arranged to be movable relative to the latter. The combination includes an auxiliary piston (14) fitted around the piston rod (13) of the second part and sealed relative to the inner surface (2) of the cylinder space (1). The cylinder space is provided with a connection (25) permitting the passage of the pressure medium into the space (29) limited by the cylinder space (1) and the auxiliary piston end face (20) facing away from the first part (3). The cylinder space (1) is provided with another connection (26) permitting the passage of the pressure medium to the auxiliary piston end face (21) facing towards the first part (3) when the piston (9) of the second part (8) is in engagement with the auxiliary piston (14).
摘要:
Fluid-flow control apparatus and method are disclosed by which magnetically-positionable elements within a rigid body can be externally manipulated using a controlling source of magnetic flux. The relative attractive forces which bias internal magnetic elements into normally-closed sealing engagement are substantially altered by repositioning the magnetic elements in response to the controlling magnet flux. Complete sealing or isolation against back flow through the valve under conditions of net positive outlet pressure is inhibited by the internal double-acting sealing elements which respond in unified manner to the controlling magnetic flux.
摘要:
A hydraulic jack is disclosed for simultaneously tensioning a plurality of reinforcing cables anchored to a structure by means of an anchor plate and anchor wedges seated in corresponding seats in the anchor plate. An aligning template is provided for aligning the cables with a tensioning head assembly in the jack, thereby facilitating placement of the jack on the cables. The tensioning head assembly includes a gripping plate having a bore for each cable with each bore having a wedge-shaped seat to receive gripping jaws biased towards the seat. The assembly further includes an unclamping plate, mounted in one embodiment for movement with the gripping plate, provided for dislodging the gripping jaws from their seats to release the cables after tensioning. The tensioning head assembly is mounted at one end of an hydraulically actuated plunger and is urged away from the structure to seat the gripping jaws about the cables and thereafter tension the cables. An hydraulically actuated striker assembly operates to seat the anchor wedges in the anchor plate after tensioning is completed. In one embodiment, the aligning template is received within the front end of the jack and serves as a striker plate in transmitting the seating force from the striker assembly to the anchor wedges.