Abstract: A straightening machine (1) having upper straightening rollers (5.1, 5.2, . . . ) and lower straightening rollers (6.1, 6.2, . . . ) is provided, with the straightening rollers being drivable via coupling elements (5.1?, 5.2?, . . . ; 6.1?, 6.2? . . . ). The upper straightening rollers and the lower straightening rollers are arranged in upper and lower interchangeable cartridges, respectively, together with the pertaining coupling elements, with the cartridges being removable from the straightening machine. The straightening machine provides that at least one of the upper and lower interchangeable cartridges is configured to be separable in such a manner that the relevant straightening rollers (6.1, 6.2, . . . ) can be exchanged optionally together with at least the pertaining coupling elements (5.1?, 5.2?, . . . ; 6.1?, 6.2? . . . ) by removing the entire upper and/or lower interchangeable cartridge or without the pertaining coupling elements by removing only part of the relevant interchangeable cartridge.

Abstract: An improved roll for a roller press capable of withstanding very high nip forces in a press nip for interparticle crushing including embedding a plurality of spaced wear-resistant surface members in the pressing surface of the roll which are of a material harder than the material of the roll surface surrounding the inserts and by varying the size and number and material properties of the embedded pieces, the wear of the press roll is matched to the materials to be comminuted to minimize wear and to match the wear profile along the roll with extended pressing use.

Abstract: A high pressure roller press formed between opposed cylindrical rollers mounted to perform interparticle crushing or product bed comminution in the nip and having pockets in the surface of a size to retain compressed fine grained material which is pressed in the nip with the compressed material in the pockets being retained for full revolutions of the rollers and coacting with hard portions between the pockets to form the product bed comminution against material passing through the nip and drawing material into the nip.

Abstract: Wear-resistant armoring on the outer surface of a roller for a high pressure roller press capable of interparticle crushing of granular material wherein the armoring is composed of axially extending welding beads horizontally welded along the roller either without spacing from one another or with slight spacing.

Abstract: A method for measuring deformations of test samples in testing machines is carried out in a device including a light source, a detector, and signal processing circuitry. The deformations are sensed in that a light beam (2) from the light source (1) is reflected by at least one mirror (6, 6', 6a, 6b, 11a, 11b) arranged at an appropriate location, for example, directly on the test sample (4) so that test sample movements are imparted directly or indirectly to the reflecting mirror or mirrors, whereby the reflected light beam impinges upon a position detector (7) and the position of the impingement or rather its movement is determined and evaluated in an electronic evaluating circuit (8). This movement is a direct measure of the deformation. The device includes components for carrying out these method steps, whereby it is possible to measure static and/or dynamic deformations caused by tensile and compressive forces, as well as deformations resulting from twisting torques and bending moments.

Abstract: In a method and apparatus for measuring deformations of test samples in testing machines, a test sample (4) is clamped into force transmitting units (10, 11). A light source (1) emits a light beam (2) which is reflected from at least one mirror (6, 6') arranged on the force transmitting units (10, 11) to impinge upon a position detector (7) which generates an output signal. The output signal is input to an electronic evaluating circuit (8) to determine the location or rather the location movement of the point of impingement of the light beam on the position detector. Preferably, but not necessarily, each force transmitting unit (10, 11) includes its own mirror (6, 6'), whereby the light beam (2) emitted by the light source (1) is reflected in sequence by the first mirror (6) of the first force transmitting unit (10) onto a second mirror (6') of the second force transmitting unit (11) and then onto the position detector (7).

Abstract: In a test sample clamping apparatus for testing machines, having a clamping head or chuck and a force sensor (2) arranged on the chuck, testing forces are measured with a force sensor and displacements or test sample deformations are measured simultaneously with a light deflection. Thus, rapid test procedures such as fast tensile rupture tests are made possible. The clamping head or chuck includes a base plate (3), one side of which receives or holds clamping elements (15) and the other side of which clamps down the force sensor (2) against a support. A mirror surface (8, 8') is arranged on the base plate (3) or on other appropriate surfaces of the clamping head so as to reflect a ligth beam (10) emitted by a light source (9) onto a position detector (11). In order to measure a deformation caused displacement of the clamping head and correspondingly of the test sample (4), an electronic evaluating circuit (12) evaluates the position dependent output signal of the detector (11).

Abstract: The present differential pressure limiting valve is constructed with an axially movable valve body having hydrostatic bearings including bearing shafts, whereby the bearing shafts are connected to opposite sides of said valve body in axial alignment. Normally the valve body is biased against the valve seat by an adjustable closing spring acting on the bearing shaft or valve body opposite the valve seat to close the valve. In addition, the face end of the bearing shaft opposite the valve seat may be loaded by a pressure medium. The respective diameters of the bearings may differ. However, the effective cross-sections of the valve body are preferally equal on both sides of the valve seat.

Abstract: The present mechanical chucking device especially for a testing apparatus, has a friction reducing layer interposed between the clamping members and a base plate and another friction reducing layer interposed between the base plate and securing elements for the clamping members, whereby said clamping members may slide within a given range along the base plate without having to release the securing elements holding said clamping members to the base plate. The clamping members are driven by a spindle movably held in a guide block on the base plate which allows an exact concentric clamping of the sample.

Abstract: The leakage flow of a pressurized medium in gap type seals is controlled by a suction device at the sealing location of the gap seal. The suction device comprises a jet pump. The jet pump is driven by the pressurized medium in the gap seal or by an externally supplied fluid medium.

Abstract: This hydraulic chucking head, especially for testing machines wherein the test sample must be held without play in the direction of load application, includes at least two test sample holding pistons movable along a common axis toward each other and toward a central axis through the chucking head. These pistons are hollow inside and movable in respective cylinders in the housing with a certain initial play. The piston walls or jackets are elastically yielding when the pressure inside the piston is increased, whereby the test sample is held and simultaneously said play is removed since the piston walls are pressed against the respective cylinder bores. Preferably a non-metallic coating is provided between the piston walls and the cylinder bores which coating acts as a sealing and reduces friction.