Abstract: A cryogenic refrigerator and more particularly, the cryogenic refrigerator compressor assembly procedure and to a mechanism for supporting piston for use in such a cryogenic refrigerator is described. Embodiments of the present invention solve the above-mentioned drawbacks by avoiding the radial movements of the piston. The assembly procedure of a cooler compressor comprises coating at least one piston by a material, placing each piston in the cylinder, raising the temperature up until a predetermined temperature so as the piston and/or its coat expands to occupy all the cylinder, fixing each piston in the cylinder in this position until the temperature returns to ambient temperature. Another object of this invention is the cooler compressor piston spring having two flexure bearings separated by a gap connected together by a first and an outer ring.

Abstract: The present invention generally relates to cryogenic refrigerator and more particularly, the cryogenic refrigerator compressor assembly procedure and to means for supporting piston for use in such a cryogenic refrigerator. This invention solves the above-mentioned drawbacks by avoiding the radial movements of the piston. The assembly procedure of a cooler compressor comprises coating at least one piston by a material, placing each piston in the cylinder, raising the temperature up until a predetermined temperature so as the piston and/or its coat expand to occupy all the cylinder, fixing each piston in the cylinder in this position until the temperature returns to ambient temperature. Another object of this invention is the cooler compressor piston spring comprising two flexure bearings separated by a gap connected together by a first and an outer ring.

Abstract: A shaving apparatus is provided which has at least one cutting unit (3) comprising an external cutting member (4) and an internal cutting member (5) which is drivable relative thereto, which internal cutting member comprises at least one cutter rim (11), which external cutting member has at least one slot-shaped hair-entry aperture (15), a part of the cutter rim (11) constantly extending over an associated hair-entry aperture (15), and each point (A) of the cutter rim (11) performing a movement in accordance with a closed curve, the hair-entry aperture (15) being passed at least once when the closed curve is traversed one time. Preferably, both the cutter rim (11) and the slot-shaped hair-entry aperture (15) are circular and the movement of the cutter rim is an eccentric circular movement.

Abstract: The invention relates to a Stirling cooler, comprising a compressor for generating a time-varying pressure in a gaseous medium, a cooling element provided with at least a displacer and at least a regenerator and additionally comprising a connecting line between the compressor and the cooling element. The incorporation of heat flow-reduction means for reducing the heat flow from the compressor to the cooling element causes a sharp drop in temperature on the warm side of the cooling element as a result of which heat sinking will no longer be required.

Abstract: A motor compressor unit comprises a hermetically sealed housing, a vibration motor with a rotationally vibrating drive shaft, and a symmetrical twin free-piston compressor comprising two oppositely disposed identical free pistons which can be reciprocated in respective cylinders by the drive shaft. In order to minimize piston drift from the center position, each cylinder is formed with a duct connecting the respective compression space to the space between the housing and the motor-compressor where the suction pressure prevails, which ducts are situated at equal distances from the respective cylinder end walls and can be closed by the respective pistons. As a result of this, the pressure in both cylinders is built up with the same swept volume and piston drift is minimized.

Abstract: A motor-compressor unit is provided which comprises a vibration motor (1) having an armature (3) which can perform a rotationally vibrating movement about a drive shaft (4), and a compressor (10) having at least one piston (12) which can be reciprocated in a cylinder (11) by an arm (9) of the armature (3). The couping between the piston (12) and the arm (9) comprises a sleeve (15), which is slidable in a bore (16) in the piston and which is connected to the arm (9) by a ball joint (21). The oscillating movement of the arm (9) produces a helical reciprocating movement of the piston (12). This leads to an improved lubrication.