Patent GB-1468537-A (GB)
Title: Apparatus for machining cardan crosses and the like workpieces
IPC: B24B5/35
Filed: 1974-04-02
Abstract: 1468537 Grinding WERKZEUGMASCHINENKOMBINAT 7 OCKTOBER BERLIN VEB 2 April 1974 [6 April 1973] 14547/74 Heading B3D. An apparatus for machining Cardan crosses comprises a movable frame 3 having a top stepping magazine 5 above a bottom stepping magazine 4, first and second vertically movable members I, II arranged on opposite sides of the apparatus, each member having horizontally movable workpiece supports 30, a machining station located between the members, a vertically movable turning device mounted beside the first member and having two vertical spindles 36 each carrying a cross prism 38 for receiving a workpiece, a transfer device associated with the turning device and constituted by a double arm lever 42 carrying transfer prisms 51, at its top and bottom ends and a positional aligning station 17 between the first member I and the transfer prism 51 at the bottom end of the lever. The frame 3 is secured to a bracket 2 movable along a guide frame 1. The workpieces are fed onto the bottom stepping magazine 4 and discharged from the top magazine. Each magazine has four rigid guides 6 and two movable stepping guides 7 with transporting cylinders 8, 9. The guides 7 have wheels 10 which rest on stepping skids 11 and guide bars 12. Each stepping skid has a roller 13 engaging a control groove 14 of reversing plates 15 controlled by reversing cylinders 16. Operation of the cylinder 8 causes the stepping guides 7 to move the workpieces a step towards a grinding gap 54 by way of the wheels 10 rolling on the guides 11, the front two workpieces being deposited between gripper pairs 30 of the first member I. When the cylinder 16 is operated, the skids 11 are displaced by the rollers 13 engaging the grooves 14 of the reversal plates and the wheels 10 from the interior to the exterior of the skid profile for the return movement of the guides. The grippers pairs 30 of member I, which is substantially identical to member II, are carried by an arm 29a horizontally displaceable by a cylinder 28a in a member 27a, and the gripper pairs engage the workpiece by way of springs 32. The member 27a is carried by a plate 25a vertically movable along a guide 22a by a cylinder 24a. Simultaneously with the member I gripping the workpieces at the front of magazine 4, the member II grips the workpieces on the support 63 at the gap 54 between grinding and regulating wheels. The members I and II lift the work-pieces and carry them horizontally so that those in member I can be lowered into the grinding gap while those in member II are moved to a position to be received by the discharge magazine 5. After grinding of the workpieces in member I about their first axis the member 1 carries the workpiece to a position in front of the bottom magazine and deposits them on the transfer prisms 51 which are connected by links 46 to the lower ends of the double arm levers 42 and are guided by rollers 49. When the levers are rocked by a cylinder 45 the workpieces engage the position aligning device 17 which has rubber plates (18 Fig. 8 not shown) and leaf springs (19) and rocks the workpieces so that both axes of each workpiece are horizontal and places the workpieces above the cross prisms 38 of the turning device. The cross prisms 38 are carried on vertical spindles which are connected by a cross member 39 to a vertical cylinder 41 which displaces the spindles vertically and positions the workpieces above the transfer prisms 52 at the upper ends of the double arm levers 42. A drive 65 rotates the spindles through 90‹ to align the unground axes of the workpieces with the grinding gap. The levers 42 are rocked back by the cylinder 45 so that the workpieces are deposited in the upper transfer prisms and can then be moved to be engaged by the gripper arms 30 of member II for conveying to the grinding gap for grinding the workpieces about their second axis.