Patent GB-1352556-A (GB)
Title: Machine tool having power driven transfer means
IPC: B23Q3/155
Filed: 1971-04-19
Abstract: 1352556 Tool and workpiece changing; lathes KEARNEY & TRECKER CORP 19 April 1971 [17 Feb 1970] 21872/71 Headings B3B and B3T [Also in Division F2]  A machine tool comprises a frame 30, 67; operating means, e.g. a tool spindle head 35, and a rotatable support, e.g. a workpiece carrying spindle 41, carried by said frame for relative movement, said support carrying a first workpiece W; a storage support 80 carrying a second workpiece WM, said storage support being pivotable about a shaft 89 to a position parallel to the spindle 41; power driven transfer means 112 to bodily interchange said first and second workpieces; velocity control means connected to be driven by movement of the transfer means to predeterminately vary the acceleration and deceleration of the transfer means 112 during transfer of the workpieces; and selectively operable power drive means to effect movement of the transfer means 112 at a velocity controlled by the velocity control means. The transfer means is in the form of an arm 112 having a gripper at each end and pivotable 90 degrees from a parked position to grip the workpieces; pivotable 180 degrees in the same direction to interchange the workpieces; and pivotable 90 degrees in the opposite direction to a new parked position. Either tools or workpieces may be interchanged. Automatic means are also provided to exchange rotary or non-rotary tools from a magazine 66 to the spindle head 35. Hydraulic drive and control means are provided to accelerate and decelerate the velocity of the transfer arm 112 in each of its three stages of pivoting. This comprises a cam (198) (Fig. 6, not shown) rotated with the drive shaft of the transfer arm 112 to actuate a valve spool relative to a pair oforifice portions (243), (244) to control the speed of rotation of an hydraulic motor( 260) which pivots the transfer arm 112. An alternative arrangement (Fig. 8, not shown) has a cam (198A) actuating two separate restrictor valves (406), (407). Workpiece transferring.-The workpiece W, WM are mounted on interchangeable chucks 108, 109 and the spindle 41 and storage support 80 include means for releasably clamping the chucks by means of draw bars (178), (179) (Fig. 6) and jaws (184), and means for angularly orienting the spindle 41. This latter comprises a servo-drive (49) driving the spindle 41 through clutch teeth (388), (389) until stops (391), (392) engage. The chucks 108, 109 are angularly fixed on the spindle 41 and support 80 by interengaging annular arrays of teeth (224), (226) (225), (227). The transfer arm 112 includes spring biased links 128, 134 in respectively each of the grippers 114, 115 that engage the chucks 108, 109 at flat peripheral portions to orient the chucks in the transfer arm 112. The links are positively latched by releasable means (153), (168), (142), (143), (Fig. 6). Machine tool details.-The spindle headstock 31 is movable on ways 32 by a lead screw drive 34, 36, 37. The tools 55 are supported in the spindle head for movement along inclined ways 60 of the frame part 67, which is movable on ways 63 on the bed 30.