Abstract: A current mirror includes first through eighteenth transistors. The load paths of the first and second transistors are in series for carrying an input current to a first supply potential. The control terminals of the first through eighth transistors receive the input current. The load paths of the fourth, third, ninth and tenth transistors are in series between the first and a second supply potential. The third and ninth transistors form a tap being connected to the control terminals of the ninth, tenth, eleventh, twelfth and thirteenth transistors. The load paths of the fifth, sixth, eleventh and fourteenth transistors are in series between the first and second supply potentials. The sixth and eleventh transistors form a tap being connected to the control terminals of the fourteenth through sixteenth transistors. The load paths of the seventeenth, seventh, twelfth and fifteenth transistors are in series between the first and second supply potentials.

Abstract: A switched capacitor network includes a first capacitor being charged and discharged in alternation by a first switch device and being connected to a first voltage source for charging. A second capacitor is charged and discharged by the second switch device in synchronism with the first capacitor and is switched between the first voltage source and the second voltage source for charging. A product of the capacitance of the first capacitor and the voltage of the first voltage source is equal to a product of the capacitance of the second capacitor and a voltage difference between the two voltage sources. A product of the capacitance of the first capacitor and a contact resistance of the first switch device in a supply line path thereof, is equal to a product of the capacitance of the second capacitor and a sum of an internal resistance of the second voltage source and a contact resistance of the second switch device in a supply line path of the second capacitor.

Abstract: A switched capacitor network includes a switch device alternatingly charging two first capacitors having the same capacitance from a signal voltage source with polarities being opposite relative to a ground potential and then discharging each of the two first capacitors through the input circuit of a respective differential amplifier. The switch device alternatingly charges two second capacitors having the same capacitance in phase opposition with one another from a reference voltage source with the same polarities relative to the ground potential and then discharges each of the two second capacitors through the input circuit of a respective one of the differential amplifiers, in synchronism with the charging and discharging of the two first capacitors.

Abstract: The artificial joint part consists of a distal spherical bearing member (1), which can be attached by attachment means (16) to the capitate bone (14) or/and hamate bone (15), and also of a platform (18), which is attached to the radius (6) and at right angles to the longitudinal axis (7) of the radius (6) towards the ulna (8) comprises a guide surface (5). An intermediate member (2) is supported at the proximal end with a sliding surface (4) on the guide surface (5) and is displaceable in the direction of the ulna (8), whereas at the distal end it forms a spherical bearing (3) for the bearing member (1).

Abstract: The invention relates to a process for the continuous treatment of silicon in which a slag in a pivotable low-shaft furnace (1) with a discharge pipe (4) reaching the bottom of the furnace tank is taken to a temperature of 1450.degree. to 1800.degree. C. and this slag is used to melt solid silicon and/or liquid silicon is continuously refined and the liquid refined silicon is then sprayed with compressed air or nitrogen (7) and continuously conveyed into a transport crucible (11) by being poured into a stream of water (9) in the channel (8) via a dewatering filter (10) and thus obtained in granular form. The invention also relates to devices for implementing the process.

Abstract: A hipjoint socket has an outer cup and an inner cup disposed within and secured to the outer cup. The inner cup has a hemispherical bearing surface which is concentric with an axis and terminates at the end face, which is perpendicular to the axis. An open groove formed in the end face is concentric with the axis. A closed ring has axially relatively longer and shorter portions and a cylindrical guiding surface having a diameter about equal to a diameter of the hemispherical guiding surface. The ring includes tongues engaging the groove and thereby securing the ring to the inner cup when the ring abuts the end face. The tongues are able to slide along the groove and position the cylindrical guiding surface concentric with the axis and substantially contiguous with an end of the hemispherical bearing surface at the end face.

Abstract: The invention shows a double-cup hipjoint socket of oval cross-section with a spherical bearing cup (4). the metallic outer cup (1) exhibits a constant thickness of wall and is provided with openings (3) for anchoring in the pelvic bone. The inner cup (2) of plastics may be latched to the outer cup (1) and by springy tongues (11) on the opposite side. The oval shape is generated by inserting straight intermediate pieces (5,6) in the inner and outer cups. Through the elongated shape of the outer cup (1) which may be inserted in different directions, an optimum fastening may be striven for. The definitive position of the spherical bearing cup (4) is established for the first time by the insertion of a fitting inner cup (2). In doing so the spherical bearing cups (4) may be shifted in the equatorial plane of the outer cup (1) and/or in the direction of the polar axis of the outer cup.

Abstract: An error amplifier includes a differential amplifier stage having two inputs and one output. An MOS transistor has a gate terminal connected to the output of the differential amplifier stage, a source terminal connected to a first supply potential and a drain terminal forming an output of the error amplifier. A diode is connected in the conducting direction between the drain terminal of the MOS transistor and a second supply potential.

Abstract: A sigma-delta modulator includes a first integrator receiving a difference between an input signal being weighted by a first coefficient, and a first reference signal being weighted by a second coefficient. A second integrator receives a difference between the output signal of the first integrator being weighted by a third coefficient, and the first reference signal being weighted by a fourth coefficient. A first quantizer receives the output signal of the second integrator being weighted by a fifth coefficient. A first digital/analog converter converts the output signal of the first quantizer into the first reference signal. A third integrator receives a difference between the output signal of the second integrator being weighted by a sixth coefficient, and a second reference signal being weighted by a seventh coefficient. A second quantizer receive the output signal of the third integrator being weighted by an eighth coefficient.

Abstract: A finger joint prosthesis, made of metal, has a bearing shell (1) attached to a shaft (2) in the metacarpal and a bearing journal (3) attached to a shaft (5) in the phalange. The bearing journal (3) is designed as a barrel (4), which at right angles to its axis (8) in its center comprises a piece (7) connecting it to its shaft (5). The bearing shell (1) is C-shaped and encloses the barrel (4) with clearance to restrict lateral excursion of the phalange shaft (5), whereas an open area formed by the C-shaped shell restricts the flexion at the connecting piece (7). The C-shaped bearing shell (1) can be forced open when the barrel (4) is inserted because its shaft (2) is divided in the longitudinal direction (13) into two halves (14, 15) by a slit-shaped notch (11) so that the shell and the bearing shell can be engaged by moving them radially towards each other.

Abstract: A bone implant is provided with undercut anchoring areas for bone tissue which extend from the surface of the implant into the interior. Geometrically shaped cavities are generated through the openings in an interconnected manner to provide for the ingrowth of bone tissue. A high pressure liquid jet is used to form the cone-shaped cavities in the implant on spacings to provide for intercommunication between the respective cavities.

Abstract: An output buffer amplifier includes one end stage for small output capacities and one end stage for large output capacities. The end stages have outputs being connected to one another. A control stage is connected upstream of the end stage for small output capacities. The control stage has one input being triggered by a signal proportional to an input signal of the end stage for large output capacities and another input being triggered by a signal proportional to an output signal of the end stage for small output capacities.

Abstract: The knee joint prosthesis is formed of a tibia metal plate which can be attached to a tibia and a femur part which can be secured in a femur. An intermediate plastic part is provided on the tibia metal plate to receive the femur part in bearing relation. In order to reduce abrasion of the intermediate plastic part, support members of hard material are distributed in the bearing surface of the intermediate plastic part to receive the femur part thereon. The bearing surfaces of the support members are integrated in the bearing surface of the intermediate part and are provided with dual surfaces to receive different bearing surfaces of the femur part, each of which has a different radius of curvature.

Abstract: The invention shows knock-out instruments for the shanks of hipjoint prostheses, the said instrument consisting of a shank (1) with a coupling-part for a sliding hammer (not shown) as well as of an extension-piece (3) which may be applied in the knock-out direction. The extension-piece (3) is connected rigidly to the shank and stands away from it like a foot at an angle .alpha. of between 20.degree. and 60.degree.. The extension-piece exhibits a recess (8) which may be slid from one side over the neck of a hipjoint prosthesis and encircles it over an angle of up to 180.degree., the width inside the recess measured across the 180.degree. being greater by a clearance than the smallest diameter of the neck of the prosthesis, measured in the same direction.

Abstract: The implant may be used as prosthetic replacement for a ligament and/or tendon. The implant has a plurality of discrete longitudinal strands disposed in side-by-side relation with transverse filaments about the strands. Individual sub-zones of the ligament are folded over in a transverse manner about a longitudinal axis of the sub-zone with intermediate zones being in an unfolded state. The intermediate zones may be formed solely of longitudinal strands to enhance flexibility.

Abstract: The implant is made of two members which are relatively movable relative to each other. One member is made of hard material while the second member is made of a soft material. In addition, a plurality of support members of hard material are embedded in the soft member and each has a sliding surface to receive the hard member thereon in bearing relation.

Abstract: The invention shows a patella prosthesis, which consists of an artificial slide member (2) made from polyethylene with sliding surface (3), with the slide member (2) being mounted on the rear of the patella (1) by means of an attachment. The sliding surface (3) consists of the sector of a polyethylene sphere, which comprises a metal grid (4) of an attachment member (9). The attachment member consists of a metal sandwich construction having a central support sheet and metal grids (4, 6) spot welded on both sides, with bevelled sheet metal flanges (7) for the primary attachment of the support sheet (5) protruding through recesses (8) in the metal grid (6) on the side of the patella.

Abstract: Valve top, in particular for water fittings, with a spindle rotatable in a head-piece and a sealed grease chamber in the head-piece. The lower end of the spindle is mounted and supported in the head-piece by means of a bearing element of plastic, the bearing and supporting faces being arranged inside the sealed grease chamber. Preferably the bearing element is made in one piece with a damping element of plastic.

Abstract: The ligament prosthesis is formed of concentric tubes of filaments threads. In addition, a layer of elastomer is disposed over at least the outermost tube to act as an impermeable layer to the passage of abraded material from within the tubes into the lining. The thickness of the elastomer layer is at most 0.1 millimeter. The elastomer may also be provided on and about the threads of the inner tubes to reduce a migration of abraded particles therein.

Abstract: A prosthetic ligament implant is sheathed at one end in the sock in order to facilitate pulling of the implant through a hole drilled in a bone. The sock is provided with a separable proximal portion which does not envelope the implant and which can be cut off after pulling of the implant through the hole in the bone. With removal of the proximal portion, the remaining textile structure of the sock becomes asunder so that the sock can be readily pulled off from the end of the implant.