Abstract: Double-spot welding machine for producing wire grids (G), having welding lines (S.sub.1, S.sub.2) of top and bottom electrodes (2, 3), which welding lines (S.sub.1, S.sub.2) are arranged at a mutual distance apart in a longitudinal wire advance direction and run transversely to the longitudinal-wire advance direction. A cross-wire feed apparatus (9) feeds two cross wires (Q.sub.1, Q.sub.2) along two insertion lines (E.sub.1, E.sub.2) arranged in front of the welding lines (S.sub.1, S.sub.2) at their predetermined distance from one another. A cross-wire transfer apparatus (10) transfers the cross wires (Q.sub.1, Q.sub.2) from the insertion lines (E.sub.1, E.sub.2) into the welding lines (S.sub.1, S.sub.2). The longitudinal wires (L) are advanced to the welding lines (S.sub.1, S.sub.2) and the welded wire grid (G) is pushed out of the welding lines (S.sub.1, S.sub.2). A holding arrangement (15, 18) holds the cross wires (Q.sub.1, Q.sub.

Abstract: In a grid welding machine with a horizontal longitudinal wire guide path (4) and transverse wire feeders (27, 28) arranged above and below the latter and transverse rows of active welding electrodes (7, 8), the two rows of electrodes (7, 8) are moved up or down away from the longitudinal wire path (B--B) in synchronization with the welding cycle before transverse wires (Q1, Q2) are placed simultaneously on each side of the longitudinal wire assemblage (L). The transverse wires (Q1, Q2) are then brought into the welding position between the two rows of electrodes (7, 8) and the electrodes are applied to these transverse wires (Q1, Q2). Finally, a row of electrodes (7) are stopped as an abutment against which the welding pressure is applied through the other row of electrodes (8) so that a welding current flows between each electrode pair (7, 8) in series over the point of intersection of each longitudinal wire (L) with two contacting transverse wires (Q1, Q2).

Abstract: A method and installation for feeding longitudinal elements of round or flat material to a welding machine (41) for grates or gratings, in which method the longitudinal elements (L), cut off from at least one line of longitudinal-element material after straightening of the same, are arranged in a group with selectable spacing, without longitudinal displacement, in the direction transverse to a push-in line (S) to the welding machine (41), are secured in place by a, for example magnetic, holding force and are moved essentially continuously into the push-in line, and in which arrangement the front ends of the longitudinal elements are mutually aligned before delivery of the longitudinal elements to the welding machine.

Abstract: A convertible single or double spot welding machine operating by the electrical resistance method for producing grids or bar grates by single spot welding or double spot welding, has a transverse row of electrodes and at least one welding transformer on one side of the welding plane. Electrically conductive connections, which pass through the welding plane, connect the welding transformer to the electrodes located on the other side of the welding plane and close the welding current circuit for single spot welding. In order to convert from single spot welding to double spot welding, the connections which pass through the welding plane are removed, selected electrodes on the side of the welding plane remote from the welding transformer are connected in pairs by current bridges, and the supply lines from the welding transformer are respectively connected to the two electrodes opposite the electrodes connected by the current bridges.

Abstract: Apparatus for the feeding of transverse wires from a feed position to the welding line of a grid welding machine has at least one nozzle (9) which is directed towards the welding line, and which can be supplied with compressed air in time with the welding cycle. Parallel guides (5, 6) lead out from the nozzle, bounding either side of the transverse wire feed path, but ending ahead of the region of the welding electrodes. There are provided, in the region of the welding electrodes (1, 2), devices (11) preferably designed as magnets, for the catching and holding of the respectively fed transverse wire at the welding line. Conveyance with compressed air means that mechanical parts engaging in the welding area and susceptible to faults are avoided and at the same time changing of the longitudinal pitch of the transverse wires is facilitated.

Abstract: An apparatus for supplying cut-to-length longitudinal elements to the intake of a grid welding machine includes a revolving endless transverse conveyor 3 which receives the longitudinal elements 16 into open receptacles 9 and conveys them over the upper side, a turning location and a part of the lower side of the transverse conveyor 3 into the intake area of the welding machine, in which the receptacles 9 for the longitudinal elements 16 are arranged on the periphery of the transverse conveyor 3 in groups forming magazines 8a, 8b and 8c. The mutual distance A between these magazines being at least equal to the width B of the same.

Abstract: A multi-spot resistance-welding machine for manufacturing welded grids consisting of a group of longitudinal wires and crosswires crossing the longitudinal wires at right-angles, to enable grids to be manufactured in which the length of at least some of the crosswires is smaller than the width of the grid and in which the relative position of these shorter crosswires can be selected with respect to the group of longitudinal wires, is equipped with two crosswire feed devices (16, 40) of which at least one, but preferably both, can be displaced and fixed in an allocated guide (15, 17; 51, 52) transversely to the feed path of the group (70) of longitudinal wires and relative to a delivery device (60) transferring the crosswires from the feed devices into the welding area.

Abstract: A multispot grid-welding machine has an electrode-carrier beam movable up and down and a plurality of guide rods mounting a plurality of electrode units for movement on the beam. Pressure springs bias the electrode units in a direction towards the grid being welded, each electrode unit being movable into a working position and a rest position in which it is retracted. A plurality of return springs act on the electrode units, the return springs being considerably weaker than the pressure springs and acting to shift the respective electrode units on the working position into the retracted position. Devices are provided for advancing selected electrode units into the working position by overcoming the force of the return springs.

Abstract: This multispotwelding machine serving for the production of grids or gratings has a welding electrode system (50, 51, 52) suitable for double spotwelding in the direction of the longitudinal members (L) and having two lines of weld (S1, S2), two crosswire feed lines (E1, E2) arranged in a fixed position at a distance apart (A), two crosswire transfer tools (4, 5) which are arranged on a common bearer (1), which can be shifted in the direction of the grid feed by a length of stroke (H) corresponding with the distance of the plane of symmetry (ME) of the feed lines from the plane of symmetry (MS) of the lines of weld (S1, S2) of the welding electrode system, as well as a grid feed mechanism (67).

Abstract: The invention relates to apparatus for and a method of moving a grid (G) longitudinally in stepwise fashion through a multi-spot welding machine by means of an element (5) arranged to engage a transverse rod (D) of the grid at a starting position, move the grid (G) forward through a number of steps at a first mean speed, and thereafter disengage from the rod (D) and return to the starting position at a mean speed greater than the first mean speed. The movement of the element (5) is controlled by a computer (31) so as to return to its starting position if the time required for its return from the position which it would occupy after the next step is greater than a preset maximum standstill time between steps.

Abstract: The invention relates to electrical multi-spot resistance welding machine for the production of welded bar gratings produced by welding cross-bars into the narrow side of parallel, upright flat bars. Such a machine has a pressure-beam which is guided vertically on a frame for lowering onto and raising away from the bars to be welded. Two rows of electrodes are disposed on the pressure beam, the rows being transverse to the feed path of the flat bars and the electrodes in the two rows being aligned in the feed direction of the flat bars and the electrodes of each aligned pair thus formed are connected to the secondary terminals of opposite polarity of a respective welding transformer.

Abstract: Device for feeding lengths of wire to a processing machine, particularly a lattice welding machine, by separating a bundle of wire into smaller portions, aligning the smaller portions, and removing individual wire lengths from the smaller portions for conveyance to the processing machine.