Abstract: In conventional methods for welding can bodies along their longitudinal seams, high frequency substantially rectangular a.c. currents are used for the welding current to avoid the problem of arcing found in d.c. welders. However, the high frequency a.c. current causes an undesirable degree of heating which produces eddy currents and necessitates cooling equipment. To overcome this problem, a method of producing can bodies welded along their longitudinal seam is provided in which the length of a half wave of the substantially rectangular welding current is matched in length and concurrent with the amount of time required for a can body to pass between the welding electrodes.

Abstract: A transport device for use with an electrical resistance welding machine producing longitudinal seams at workpiece bodies or the like which, prior to reaching the welding rolls of the machine, are transported at a desired welding speed by means of the transport device. The transport device comprises at least one endless chain revolving above the workpiece bodies to be transported and having workpiece body-engaging members in the form of pawls hingedly connected in spaced relationship with the endless chain. Each pawl has oppositely extending pawl arms, of which one arm possesses a contact or impact surface intended to bear against the end of a workpiece body engaged thereby and the other arm possesses a control surface which bears against a guide rail stationarily arranged above the lower chain run of the endless chain which revolves over at least two sprocket wheels.

Abstract: An electrode roll-welding arrangement for a resistance roll-welding machine comprising a welding arm adapted to be supported at a machine frame and an electrode roll mounted at an end of the welding arm, the electrode roll being supplied with the welding current by means of the welding arm acting as an electrical conductor and a shaft of the electrode roll mounted in such welding arm. The end of the welding arm receiving the electrode roll is bifurcated or fork-shaped and embodies two fork-like or bifurcated leg members situated essentially in parallelism and opposite one another, each bifurcated leg member having a slot which opens towards the front side or face of the end of the welding arm. Each such slot has at its inward or proximal slot end a bearing cradle for the reception of the shaft of the electrode roll.

Abstract: An electrical resistance-roll seam welding machine having a pair of welding rolls or rollers and at least one electrode wire which is guided from a supply station for the infeed of fresh welding wire by means of at least one of the welding rolls to a collecting station or location for used or consumed wire. The electrode wire can be brought into contact by means of the welding rolls with the workpiece which is to be welded. A brake device is arranged between the supply station and the welding rolls and a tension device for the electrode wire is disposed between the welding rolls and the collecting station or location. The sum of the tension force exerted by the tension device upon the wire and the brake force exerted by the brake device upon the wire is great enough in order to continuously maintain in tensioned state the electrode wire through its path of travel between the brake device and the tension device.