Hartmann & Lammle Gmbh Co., Kg

Linde Aktiengesellschaft

Hartmann & Laemmle Gmbh & Co. Kg

Hartmann & Lammle Gmbh & Co.

Trumpf Gmbh & Company

Gräbener Pressensysteme Gmbh & Co. Kg

Firma Hartman & Lammle Gmbh & Co. Kg

Kristhäl Gmbh

Eckehart Schulze

Horst Deininger

Peter Bytow

Werner Kuttruf

Jakob Hermann

Heinz Groos

Hans-Werner Kutscher

Dieter Budenbender

Winfried Beisel

Günter Hommel

The invention relates to an electrohydraulic monitoring device for a dual effect hydraulic cylinder in which certain operating pressures must be maintained. A pressure reduction valve is provided for setting said pressures, this pressure reduction valve being used to set a defined pressure ( ) by adjusting the pretension of the valve spring ( ). The valve spring is situated in a spring chamber ( ) which is bordered by a regulating sleeve ( ) on one side, in an axially moveable manner. Said regulating sleeve is displaceable between two end positions within a limited axial stroke area. The alternative switching positions of a micro-switch ( ) are linked to these end positions. Two sensor chambers, each of which is connected to one of the pressure chambers of the cylinder in such a way that they communicate, are provided and are delimited by sensor pistons ( ) in order to determine the operating pressure that is being coupled into the hydraulic cylinder at a particular time. The alternative subjection to pressure and relief from said pressure of these sensor chambers forces the regulating sleeve into the same end position, respectively.

Electrohydraulic monitoring device for a dual effect hydraulic cylinder

A device for integrally joining a metal block ( &prime;) that can consist of a number of plates, by hard-soldering or brazing. The hard-solder provides a connection covering a large surface and with a minimal thickness in solder gaps ( ; j&equals;1, 2, . . . , n&minus;1) located between adjacent segment plates ( ; i&equals;1, 2, . . . , n). At least one capillary solder inflow path ( ) is provided. Said solder inflow path starts at a solder depot containing a supply of hard solder or braze material ( ), which melts as the stack ( ) of plates is heated. The melted solder material flows directly to the individual, also capillary solder gaps ( ; j&equals;1, 2, . . . , n&minus;1) via said solder inflow path, the solder gaps being provided between surfaces of the segment plates ( ) that face towards each other.

Device for integrally joining a metal block that can be made up of plates

A valve system is provided for the hydraulic work system of a work vehicle, in particular of an industrial truck, with a elevating drive system for raising and lowering a load and a tilting drive system, each of which can be actuated by a control valve, in particular by an electrically actuated control valve, the opening width of which determines the speed of movement of the user. The elevating drive system is realized in the form of a single-action hydraulic cylinder and a check valve in the form of a seat valve that can be opened toward the hydraulic cylinder is located in a hydraulic line leading from the control valve to the hydraulic cylinder. The tilting drive system is realized in the form of a double-action hydraulic cylinder. The valve system has an improved function with low energy losses.

Control valve system for the hydraulic work system of a work vehicle

A hydrostatic axial piston machine employs a swash plate construction in which the diagonal position of the swash plate can be controlled by at least one positioning piston pressurized with a control pressure. A control valve is in a line which leads to at least one positioning piston. A simple electrical-hydraulic control of the swash plate can be accomplished by the electrical actuation of the control valve. The control valve may be in the form of a rotary disk valve which can be actuated by a stepper motor.

Hydrostatic axial piston machine with electro-hydraulic swash plate control

Hydrostatic axial piston machine

Hydraulic drive unit

Press for cold working of metal workpieces

A workpiece being processed on a machine tool is moved by control devices to the tool head or work station of the machine mechanically or automatically. A stop defines an area around the work station from which the holding devices must be kept to prevent damage. As soon as a holding device reaches the limit of the danger zone around the tool head, it is switched into a setting releasing the workpiece and moves into a position away from the work station. The machine has a switching element connected to each holding device to be so movable, and the switching element has a switching slide which is acted on by an applied force and is supported in a first position until it abuts the stop when one slide position connects the energy source to the drive of the holding device to move it away from the stop. In another slide position, the connection to the energy source is broken and the holding device returns to the workpiece holding position.

Workpiece processing machine with retractable clamping device

Hydraulic drive mechanism for a machine element with rapid feed movement and under-load feed movement, comprising a double-acting hydrocylinder power drive and a pressure switching valve responding to the pressure at least in a larger operating chamber of the hydrocylinder when the pressure in the operating chamber exceeds a threshold value higher than 1/4 of the operating pressure of the pressure supply source, but lower than half the operating pressure thereof, switches to under-load feed operation and, when the pressure in the drive pressure or operating chamber falls below the threshold value, switches back to rapid feed operation. The pilot valve for the main control valve is equipped with two windings effective in opposite directions. A switching device is included which, in a position- or time-controlled fashion, excites the second control winding, and a return signaling stop is provided which brings about, in the point of reversal of the piston movement of the hydrocylinder on the workpiece side, a mechanical switchover of the pilot valve into the position required for the retraction movement.

Hydraulic drive mechanism

A hydraulic drive system for a machine element performing in one work cycle a sequence of motions comprising a rapid feed motion, a working stroke under load and an oppositely directed rapid-return motion. The drive element includes a hydraulic cylinder having three working surfaces A.sub.1, A.sub.2, A.sub.3. Motion control is effected by an electro-hydraulic follow-up control valve with a pre-setting device controlled by a stepping motor and a mechanical actual-value feed-back device. During rapid feed motion, the relatively small working surface A.sub.1 is subjected to the output pressure of the follow-up control valve only, while during the working stroke the pressure acts additionally on the working surface A.sub.3. The rapid-return movements of the piston of the cylinder are controlled by applying pressure to the working surface A.sub.2, or by relieving pressure from the two other working surfaces A.sub.1 and A.sub.3. A pressure-controlled reversing valve is moved by the output pressure of a pilot valve control arrangement into its operating position corresponding to the working stroke when the output pressure P.sub.A of the follow-up control valve exceeds a pre-determined threshold value P.sub.sl, and returned to its operating position corresponding to the rapid motion conditions when the output pressure P.sub.A of the follow-up control valve has dropped to a value P.sub.s2 below or at least equal to the value P.sub.s1.A.sub.1 /A.sub.L, wherein in the particular case described L.sub.L =(A.sub.1 +A.sub.3).

Hydraulic driving arrangement

A hydraulic driving arrangement for circular indexing tables for the precise positioning of workpieces, with the exact position of the workpieces being determined by an index. A hydraulic motor is provided with an electro-hydraulic follow-up governor using a stepping motor for setting the desired values and a mechanical actual value indication arrangement. A monitoring arrangement positively coupled with the circular indexing table and/or a driving gear of the hydraulic motor indicates whether or not the circular indexing table is in a position suitable for bringing the indexing gear into engagement and, if so, emits a signal triggering the indexing process or, if the circular indexing table is not in the desired position, deactivates the indexing mechanism. The monitoring arrangement comprises a cam disk coupled with the circular indexing table via a gearing so that it performs exactly one rotation by 360.degree. between two desired positions.

Hydraulic driving arrangement for positioning workpieces in correct

A hydraulic pivot drive comprising a rotary-piston hydraulic cylinder and control device for maintaining the pressure difference between pressure chambers defined by the rotary vane and at least one radial wall of the cylinder housing required for maintaining a defined relative rotary position between the vane and the housing of the rotary piston hydraulic cylinder. The control a follow-up control valve, wherein the actual condition relative to the pivot angle is fed back via a measuring spindle coupled with the rotating part of the rotary piston hydraulic cylinder and the desired value is pre-set by rotation of a spindle nut engaging the spindle, an actuating member arranged for axial displacement together with the spindle nut and for actuating pairs of seat valves for enabling alternative connection of the at least two pressure chambers of the rotary-piston hydraulic cylinder with a system to obtain the desired rotation.

Hydraulic pivot drive

An energy-saving hydraulic driving arrangement includes a motor having two chambers separated by a reciprocable or angularly movable output element which can accelerate or decelerate a mass. One of the chambers receives pressurized fluid from one of a battery of accumulators containing fluid at different pressures (namely, from the accumulator wherein the pressure is slightly higher than the desired pressure in the one chamber) during acceleration of the output element while the other chamber discharges fluid directly into a sump. During deceleration of the output element, the one chamber draws fluid directly from the sump whereas the other chamber discharges pressurized fluid into that accumulator wherein the pressure is slightly less than the pressure of fluid in the other chamber.

Hydraulic driving arrangement for reciprocable masses or the like

Feeding device for the cycled feeding of rod or tape-like material into a press, cutter or the like, which includes a metering wheel which rolls off directly or indirectly on the material being fed, serving as a true value indicator. The metering wheel is coupled with a true value input metering spindle which acts upon a hydraulic control valve device. The exactly maintained feeding path is made possible by the mechanical coupling of the true value feeding with the true value input on the control hydraulic valve device.

Feeding device, in particular for the cycled feeding of rod or tape like

A servomechanism in which the mutual angular position of a threaded spindle relative to a tap is adjustable by a stepper motor wherein the unit of the threaded spindle and tap is connected directly or indirectly with a hydraulic working unit, the servomechanism includes a ball bearing arranged between the spindle and the tap. Consequently, by actuating the stepper motor to which the tap is connected via a coupling, the tap being rotated and moved in axial direction relative to the spindle, thereby actuating a switching mechanism connected to the working unit by which the spindle is caused to rotate. Accordingly, the relative axial movement between the spindle and the tap is compensated and the working unit is in a different position.

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Weissach, Germany

Eckehart Schulze