Fael S.a.

L. Schuler Gmbh

Fred E Schalch

Franz Schneider

Walter Panknin

Zelimir Belamaric

Anton Szoky

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.

Method of and apparatus for producing can bodies welded along the

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. The guide rail is constructed at both ends of a linear section thereof so as to have two sections extending in an arc-shaped or curved configuration at the region of the sprocket wheels in such a manner that upon arrival of a pawl in a workpiece feed plane the pawl arm having the contact surface is pivoted in a controlled manner into its workpiece-engagement position and upon departure of the pawl out of the feed plane the contact surface of such pawl arm retains its essentially vertical position with regard to the direction of transport of the workpiece body.

Transport device for an electrical resistance welding machine

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. A clamping element is arranged in each slot and each such clamping element is urged with its contact surfaces against the shaft of the electrode roll as well as against the slot walls in the welding arm by means of an adjustable pressure element which is arranged at the end of each leg member of the welding arm.

Electrode roll arrangement for a resistance roll-welding machine

A method of, and apparatus for, respectively controlling the start of welding and the termination of welding during continuous resistance welding with the aid of an alternating-current at a roll-welding machine, wherein at least at one measuring station or location arranged ahead or upstream of the welding station or location and the workpiece to be welded passing through the measuring station there is determined the position as a function of time of the leading end as well as the trailing end of the workpiece to be welded with respect to the frequency and the phase of the welding current. By means of a computer processing the determined value there is accommodated to one another the speed of the workpiece to be welded and the frequency and phase of the welding current in such a manner that the first welding spot and the last welding spot are applied at an adjustable spacing from the leading end and the trailing end, respectively, of the workpiece to be welded.

Method and apparatus for controlling welding operations during

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. At least one of the welding rolls is operatively coupled with a drive device which imparts to the electrode wire which is guided by means of said one welding roll a speed of travel coinciding with the desired feed speed of the workpieces during the formation of the welding seam. The difference between the tension force exerted by the tension device upon the wire and the brake force exerted by the brake device upon the wire is smaller than the entrainment force exerted by the periphery of said one welding roll upon the electrode wire.

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Le Landeron, Switzerland

Fred E Schalch