Abstract: The invention relates to a piston compressor (15) which is used to compress gaseous media and which contains a differential piston (1) provided with a first piston part (16) and a second piston part (17) which are arranged on an axis. Two cylinders (7, 8) having internal holes with different diameters form two working chambers (21, 22). The cylinders are closed by plates (2, 9) comprising valve arrangements. The piston part (17) with the smaller diameter is guided through an opening (20) in the plate (2). The valves are more particularly lamella valves, reed valves or values with a spring return position.

Abstract: The crank mechanism of the piston compressor comprises individual crank disks (5), which each support on their outer circumference a rolling bearing (6) for the bearing of a connecting rod (4). The crank disks (5) are pressed together to form a package by means of tensioning bolts (7). The crank case (1) is preferably closed off by a case cover (10), the inside of which is formed as a bearing mount for the crank mechanism. Assembly and disassembly of a crank mechanism of this type is particularly simple and efficient and can be undertaken by personnel who are not specially trained. In addition, special relubrication devices provide simple and error free servicing, and thus greater longevity.

Abstract: The device has a pedestal (3) that is fastened tightly to base (2). The pedestal has two receiving openings for screws as well as an arc-shaped slot (6) in a plate (4). An adjustable element (7) can be fastened to pedestal (3). This adjustable element (7) has two parallel slots (9,9') as well as a receiving opening for a screw. Depending on the placement of screws (11,11'), adjustable element (7) can be moved plane parallel to base (2) in slots (9,9') or swiveled within arc-shaped slot (6) at an angle to base (2).

Abstract: The drive motor (1) drives a machining tool (2) which can be fed forwardly by means of a feed motor (3). Both motors (1, 3) are supplied with pressure fluid by the same hydraulic pump (4). A quantitative divider valve (5) divides the oil flow coming from the hydraulic pump, a control valve (24) controlling the flow of pressure fluid in the forward feed motor in such a way that the power output at the forward feed motor falls with increasing resistance at the machining tool, thereby providing for output-regulated operation of the machining tool. In the same way as the forward feed movement, the feed movement in respect of depth of the machining tool can also be produced by way of a depth feed motor (7).

Abstract: The piston of a piston-type machine has on its surface a heat-barrier layer of plastic material which is cast into a recess formed in the piston crown. A pouring means formlockingly enclosing the upper edge is put on the piston, held in a vertical position, to permit the recess to be overfilled with the material. The pouring means is removed after the material has hardened. Due to the shrinkage of material when the material hardens, the material and the upper edge form a flat surface on the piston.