Abstract: In a pressure butt welding process, in particular for welding chain link bent from round wire, the influence of disturbing factors on the quality of the welding result is compensated by measuring the welding forces F.sub.K exerted on the workpiece by the upsetting dies and setting and welding voltage applied to the workpiece according to the level of the measured forces F.sub.K. A control means adjusts the welding voltage via a thyristor control circuit and thereby the effective welding power in such a way that the welding forces F.sub.K remain constant.

Abstract: A machine for electrical resistance welding of chain links has upsetting bars (10) which are engaged against the arcuate ends of a chain link (1). On either side of the welding zone the legs of a link are gripped by pairs of electrodes (12) attached to the ends of a two-armed clamp (14). The arms (13) of the clamp are mounted for pivoting in a plane at right angles to the chain link, and also about an axis in this plane extending at right angles to the upsetting direction and passing through journalling head (20) attached to the end of a piston rod (21) of a counteraction cylinder (20). The ends remote from the electrode jaws (12) of the clamp arms (13) are acted on by an operation cylinder (30) which, via a link system (16, 16), gives the clamp a gripping movement about the link leg. The cylinder (20) with cylinder (30) and the clamp (14) commonly form a welding head which is pivotable about an axis (z-- z) at right angles to the upsetting direction.

Abstract: Welding of similar and dissimilar metals such as fine wires of gold, silver, brass and others to provide required strength without marring the surfaces of the link is accomplished by mounting an electrode (75,264) a selected distance from the surfaces to be welded. A first high voltage ionizing arc of a selected atmosphere between the electrode and the surfaces to be welded is followed by a low voltage, high amperage welding arc. An electrode (75) is mounted in a discontinuous link forming machine (10) so that it can be oriented in optimum position relative to the work piece (9). An electrode (264) is mounted in an automatic chain making machine (200 ) so that it can be optimally adjusted in x and y directions employing target adjustment block 320, as well as in the z direction employing vertical adjustment block 290.

Abstract: An electrode (75) disposed within an insulating sleeve (86) is placed adjacent a work piece (9) to provide a selected gap between the electrode and the work piece. The atmosphere between the electrode and the work piece is first ionized and then a welding arc discharges between the electrode and the work piece. The orientation of the electrode can be adjusted by rotation of the electrode assembly (36), the amount of the gap by rotation of member (78), vertical placement of the electrode head 36 by eccentric means 40 and spacing between the terminus of the forward movement of arm (32) and the work piece station by adjusting the position of stop (54). Spacing of the electrode from the work piece enables the welding of similar and dissimilar metals such as fine wires of gold, silver, brass and others used in such applications as jewelry, medical, and electronic to provide the required strength, but without marring the surface of the work piece.

Abstract: Apparatus for the successive welding of C-shaped, pre-bent interlinked chain links forming a chain. The apparatus comprises a saddle for supporting a chain link to be welded, the saddle having a trough and cup-shaped recesses at each end of the trough for accommodating the link. Guides are provided on either side of the saddle for guiding the chain links entering and leaving the saddle and clinchers are also provided for gripping the chain link during welding and following completion of the welding operation. The guide for the chain links entering the saddle is provided with a chain sprocket having crossed slots, and is pivotable about its axis to permit rotation of the link in the saddle after welding has been completed. The clinchers have claw-like recesses in their end for gripping the rounded portions of the chain link to be welded and the clincher adjacent the guide for the chain link entering the saddle has a trough-shaped recess for guiding the following link.

Abstract: A chain welding machine has a first cam-operated linkage for rapidly moving psetting dies into and away from the ends of a link to be welded and a second hydromechanical linkage for applying upsetting force to the ends of the link. The upsetting force is controlled by hydraulic pressure which is regulated as a function of time by a cam-controlled pressure-limiting valve.

Abstract: For the successive welding to immediately consecutive links of a chain at a welding station, the chain is advanced to bring each link in turn to the welding station, the links flanking the link to be welded are positioned in a common plane perpendicular to the orientation of the link to be welded by orienting edges of two guides disposed to respectively opposite sides of the welding station, and each guide is constituted by a pair of webs spaced from its respective orienting edge, and arranged to support the straight sides of alternating chain links, and a region between the webs and the orienting edge in which the chain is free to rotate or twist about its longitudinal axis.

Abstract: This disclosure relates to a chain welding machine for the electric resisce pressure butt welding of a length of chain having interlinked chain links pre-bent into a C-shape. The machine comprises a pair of oppositely movable upsetting tools for engaging the opposite rounded ends of a chain link to be welded. A drive train is provided for each upsetting tool and one of the drive trains includes as an element thereof a single acting hydraulic cylinder. A hydraulic system for activating the cylinder includes a hydraulic pump connected via a feed line with the cylinder through a control valve, pressure regulating valve and check valve. The check valve is arranged to block flow of hydraulic fluid from the cylinder during a portion of the upsetting stroke of the machine and is unblocked by the control valve after termination of a welding cycle.

Abstract: For the successive welding of the joints of consecutive links forming a link chain, the chain is advanced in a chain welding machine to bring a link to be welded directly below a welding position; the two links flanking the link to be welded are aligned in a common plane of alignment while a tensioning force is applied to the chain parallel to the direction of chain advance. Thereafter, the link to be welded is raised into a welding position in a plane disposed at 90.degree. to the plane of alignment. Subsequently, the link is immobilized in the welding position and its joint is welded. Upon completion of the welding step, the just-welded link is lowered from the welding position.

Abstract: In the electric butt welding of a workpiece having rod-like ends, a force measuring device senses the pressing force exerted on the workpiece by the upsetting tools. The welding current is started upon command from the force measuring device when the pressing force reaches a desired, preset value.

Abstract: A chain welding machine for the electrical resistance butt-welding of subntially C-shaped chain links is disclosed wherein two pair of electrodes are arranged symmetrically in relation to a median plane of the machine frame. Each pair of electrodes is supported on a pair of double-armed levers arranged for opposite rotation about a horizontal axis. Each electrode pair is adapted to grip, in plier-like fashion, one of the two ends of the chain link to be welded. Each lever pair is rotatably mounted to a trunnion which is, in turn, resiliently mounted in a bushing in the machine frame for absorbing any radial and/or axial loads imposed on the electrodes by misaligned or oversized chain links to be welded.

Abstract: For the successive welding of the joints of consecutive links forming a link chain, the chain is advanced in a chain welding machine to bring a link to be welded directly below a welding position; the two links flanking the link to be welded are aligned in a common plane of alignment while a tensioning force is applied to the chain parallel to the direction of chain advance. Thereafter, the link to be welded is raised into a welding position in a plane disposed at 90.degree. to the plane of alignment. Subsequently, the link is immobilized in the welding position and its joint is welded. Upon completion of the welding step, the just-welded link is lowered from the welding position.

Abstract: An automated system for producing chain wherein individual pins are fed one-at-a-time to a heating station. The pins are heated in stages at said station to a temperature suitable for bending of the pins. The pins are automatically moved from said station by transfer and conveyor means to a bender where the pins are clamped in place and then bent in stages into an open-ended link shape. A robot picks up the link-shaped pins and places the pins one-at-a-time on the supporting surface of a closer. The robot then interlinks a welded link with a pin on the closer, and the pin on th closer is then closed. The robot then moves the closed pin to the welder for welding of the ends.