In a parallel inverter having a transformer with centre-tapped primary winding, an auxiliary thyristor is connected via the commutating inductor between the centre-tap and the junction of two series connected diodes bridged across the primary winding. A second winding on the commutating inductor inductively coupled to the first is inserted in series with a D.C. source.

A parallel printer including an improved reset mechanism for resetting a ratchet and pawl mechanism after printing, is provided. An axially rotatable shaft having notched portions associated with each pawl effects a pivoting of each pawl out of engagement with the corresponding ratchet wheel and returns each pawl to a rest position to complete a printing cycle.

A parallel vise with a tunnel-shaped base portion in which a correspondingly shaped guiding rail carrying the movable jaw is displaceable, and in which said guiding rail has longitudinally extending inclined guiding surface means slidably engaged by correspondingly inclined surface means of a spring-loaded bushing which is adjustable from the outside of the vise, clutch means being provided between said bushing and adjusting means operable from the outside of said vise.

A carving apparatus including a spaced axially aligned tool and tracer and parallel mechanism including two spaced surfaces for carrying a workpiece and a pattern and for simultaneously presenting the pattern and workpiece to the tracer and tool, respectively. The parallel mechanism includes a base portion moveable on a reference surface and includes a mechanism for rendering the workpiece and pattern-carrying surfaces movable toward and away from the reference surface while continuously maintai...

A parallel computer of a MIMD array type suitable for high speed computations in engineering and science, comprising a master unit, N submaster units and a two dimensional array of N.sup.2 arithmetic units having own processors and private memories respectively, and further N common memories each of which is used for transferring some data between a submaster and a corresponding set of N arithmetic units, and finally a three dimensional array of buffer memories with a capacity being composed of ...

A ruler, especially a parallel ruler having a parallel guidance system comprising a cord (6) extending between four points (A,B,C&D) and crossing itself diagonally in a corner to corner-fashion in the central portion of the ruler, which ruler consists of two flexible parts, a ruler body (1) and a finger rail (2) being in slidable engagement by dovetailing (9) and having clamping devices in both ends in the form of a tapped sleeve (3) and a screw (4) in holes (7), whereby, upon imparting upon the...

A parallel straightedge which may be attached to any drawing table wherein the straightedge is arranged for adjustment and is provided with a braking arrangement to allow the straightedge to be fixedly held in any given position and/or orientation. The bottom of the straightedge is arranged on a pair of rollers outboard the working area in order not to smudge the drawing contained thereon. A removable plastic insert along the edge of the metal straightedge bar provides a consistent transparent r...

A forwardly opening parallel vice has a housing (1) which can be fixed to a workbench (3) and which carries the stationary clamping jaw (2) and which is provided with a quadrangular guide structure. Displaceable in the guide structure is a hollow slider which is supported with a plurality of guide surfaces (13) on the guide tracks (11) of the guide structure and which carries the movable clamping jaw (14). Of a screw spindle-nut assembly (15-17) which is provided in the slider (12), one part (15...

In this parallel gripper suitable for gripping a work for a robot or the like, in which a pair of fingers are opened and closed by keeping the parallel condition between them by the transmission of the driving force of a fluid pressure actuator to the fingers by means of a power transmission mechanism, use is made of a pair of pistons, that are relatively slidable in a single cylinder bore under the action of fluid pressure, as the fluid pressure actuator, thereby obtaining substantially twice a...

A parallel rule including a rule body, a gripping attachment and two rolling devices which are installed at each end of the rule body. The rolling device has a cylindrical roller and a pair of anchorage portions extending from its end so that the roller is retractable. An opening is provided at each end of the rule body for the roller of the rolling device to project from. By use of the rolling device, the parallel rule is movable.