Patent EA-000551-B1 (EA)
Title: Device for the automatic conveyance of workpieces on a multiple metal-forming machine tool
Inventor: STEINHAUSER ULRICH
IPC: B21K27/00
Filed: 1997-09-29
Abstract: 1. A device for the automatic conveyance of workpieces on a multistage metal-forming machine tool for forming workpieces without fins, wherein in each case one workpiece (W1, W2, W3) is grasped on a forming station (U1, U2, U3) by one pair of tongs with twin interacting grippers (130, 140) for conveyance to a neighboring forming station (U2, U3, U4), comprising a cross conveyor tube (2), which operates simultaneously with said forming device and moves into the forming zone to provide the cross conveyor tube moving back and forth and on which a tong case (1) is located, which provides conveyance of the tongs via connected via a means of transmission which is operatively associated to the tong and to a control shaft (3), which is placed rotatably in the cross conveyor tube (2) for lateral conveyance, characterized in that the tong case comprises a base body (10) on which arranged one or plurality of interchangeable tong cartridges (12a, 12b, 12c), each having a pair of tongs enabling workpiece (W1, W2, W3) to be grasped laterally from above, wherein each pair of tongs is connected via a coupling point (19) to means of transmission associated thereto said means is located in the base body (10) and provided with a catch (16) to control opening and closing movement of tongs, wherein tong travel can be adapted to workpieces (W1, W2, W3) by using tong cartridges (12a, 12b, 12c) with tongs having appropriate lever ratios and/or by regulation and change of the tong catches (16). 2. A device according to Claim 1, characterized in that each pair of tongs comprises two rotatable tong arms (13, 14) which are designed as a double arm lever with tong grippers (130, 140), one arm (14) of which is rotatable towards the coupling point via the associated means of transmission and simultaneously rotates another arm (13) via operatively connected to it guide surfaces (135, 145) located on both arms (13, 14), wherein, due to the different design of lever arms and different arrangement of hinge axes (132, 142) of tong arms (13, 14) for interchangeable tong cartridges (12a, 12b, 12c) lever ratios can be different, adequate coupling points (19). 3. A device according to Claim 1 and 2, characterized in that a driving mechanism, intended for one pair of tongs, comprises a tong driving shaft (15) arranged at the right angle to the control shaft (3) and operatively connected to said control shaft via a mechanism (150) of conic gears and on which a tong catch (16) is arranged, using which opening and closing of tongs movement is controlled via at least one additional lever, one end of which is operatively connected tongs or to one tong arm via the coupling point (19). 4. A device according to any of the preceding Claim, characterized in that the cross conveyor tube (2) is rotatable and due to this a mechanism (5), arranged outside the forming zone, enables the tong case (1) to rise or to lower. 5. A device according to Claim 4, characterized in that the tong cartridges (12a, 12b, 12c) are positioned in a holder (11), connected to the base body (10) via a link axis (113) so that when the tong case (1) is raised, the holder (11) with the tong cartridges (12a, 12b, 12c) can rotate in the opposite direction. 6. A device according to Claim 5, characterized in that at least one rotatable cam (111) is mounted on the control shaft (3) for regulating rotation of the holder (11), wherein a push rod (112) or a lever is arranged between the rotatable cam (111) and the holder (11). 7. A device according to Claims 5 to 6, characterized in that the coupling points (19) are arranged in the area of the link axis (113) of the cartridge holder. 8. A device according to any of the preceding Claim, characterized in that the coupling points comprise a connection means (180), each of which comprises two elements (181, 182) of cubical shape and which are positioned rotatably on transverse connecting pins (146, 185) thus providing a connection via sliding surfaces (183, 183'), superimposed each other. 9. A device according to any of Claims 4 to 8, characterized in that a forming station comprises an anvil (8) in the die zone, characterized in that the tong case (1), being in its lowest position, rests on the anvil (8) via a guiding means, based on using rocking or sliding, which guaranties exact positioning of tongs vertically in the forming stations (U1, U2, U3, U4). 10. A device according to Claim 9, characterized in that the guiding means, based on using rocking, comprises a ruler (80) and, at least, one roller (101), wherein a ruler (80) is on the anvil and a roller (101) or rollers are arranged on the tong case (1), or vise verse a roller (101) or rollers, or a ruler (80) are arranged on the base body (10) or on a positioning element (103), which can be rotatable towards said base body and, even when the tong case (1)is raised, provides contact of said roller (101) or rollers with said ruler. 11. A device according to any one of the preceding Claim, characterized in that one end of the cross conveyor tube (2) is mounted in a crossbar (40), located outside of the forming zone and supported by two guiding rods, parallel to the cross conveyor tube (2), enabling to move back and forth so that said one end of said tube is connected to said crossbar enabling to rotate in an axial direction. 12. A device according to Claim 11, characterized in that the driving means (4) for moving back and forth the cross conveyor tube (2) comprises a driving shaft (41) with one or two cranks (42, 43) and correspondingly one or two connecting rods (44, 45) enabling the crossbar (40) to move back and forth. 13. A device according to any one of the preceding Claim, characterized in that the forming machine is a machine of hot forming.