Patent ID: 7296726
Filing Date: 2007-11-20
Classification: B23K,B23P,B62D

Abstract:
1. A system for welding structures consisting of elements of pressed sheet metal, designed to operate in an automatic way on a plurality of different types of structures to be welded, comprising: a welding station; a conveying line, for carrying the structures to be welded through the welding station, or at least part thereof; a plurality of pairs of side gates provided with means for clamping the structures to be welded and capable of being guided along the conveying line, the clamping means provided on the side gates of each pair being adapted to a configuration of a corresponding type of structure to be welded; a first and a second store of side gates, located downstream and upstream of the welding station, respectively, each store comprising one or more parking stations on two sides of the conveying line, each parking station having a guide section, designed to support in a slidable way a side gate in a respective parking position, wherein: the side gates are mobile on guide means provided along each longitudinal side of the conveying line, to enable replacement, according to the type of structure to be welded, of the pair of side gates that is located in the vicinity of the welding station, each side gate being displaceable between a position, close to the welding station, and at least one position, remote from the welding station, each pair of side gates, when located in said position close to the welding station, is moreover displaceable between an open condition and a closed condition, in which the respective side gates are operative for clamping parts of the structure to be welded in a configuration of welding on the welding station, the system moreover comprises means for moving the side gates, for their displacement between the respective position close to the welding station and parking position said means for moving comprising, for each longitudinal side of the conveying line, a first and a second tractor, independent with respect to said side gates, each tractor being selectively coupleable in an automatic way to side gates of different pairs, for the purposes of displacement said guide means comprise fixed guiding sections and first mobile guiding sections, each of said first mobile guiding sections being arranged in correspondence of the welding station and extending between a first and a second fixed guiding section, the first mobile guiding sections being mounted for sliding in a direction perpendicular to the longitudinal direction of the conveying line, for the purpose of displacing the side gates of one pair between the respective open and closed conditions, in the open position a first mobile guiding section being longitudinally aligned to the respective first and second fixed guide sections, and wherein: each tractor comprises a carriage supporting a respective motor assembly, the carriage of the first tractor being mounted for movement onto said first fixed guiding section and the carriage of the second tractor being mounted for movement onto said section fixed guiding section, each side gets selectively coupleable, when in said position close to the welding station, either with said first tractor or with said second tractor, such that a side gate displaced by a tractor from one of said stores to the welding station can be subsequently displaced by the other tractor from the welding station to the other store, the guide means further comprises second mobile guiding sections, wherein each second mobile guiding section extends at an end of a respective fixed guiding section being remote from the welding station and is capable of being translated between a respective first position and one or more second positions, in its first position the second mobile guiding section being longitudinally aligned to the respective fixed guiding section and in its second position, or in each second position, the second mobile guiding section being longitudinally aligned to a respective guide section of a parking station, and the carriage of said first tractor is mounted for moving also onto the second mobile guiding section extending at the end of the first fixed guiding section remote from the welding station and the carriage of said second tractor is mounted for moving also onto the second mobile guiding section extending at the end of the second fixed guiding section remote from the welding station, for the purpose of displacing a side gate between said first mobile guiding section and a guide section of a respective store.