GB417686A - Milling machines and like machine tools - Google Patents

Abstract

417,686. Milling-machines. HERBERT SIR A., LLOYD, A. H., and JINMAN, C. H., c/o Herbert, Ltd., A., Canal Road, Edgwick, Coventry. July 5, 1933, No. 19060. Addition to 393,380. [Class 83 (iii).] A milling or like machine tool according to the parent Specification is modified by the provision of means associated with the table and spindle drive whereby the spindle is automatically disconnected at a predetermined table position, preferably at or near the end of its forward travel so as to prevent the work being damaged by the tool during the return movement. As applied to the machine shown in Figs. 7-10 of the parent Specification, the spindle drive includes a clutch 12 operated through a lever 15 connected with lost motion at 16 to a rod 17 hinged to a crank 18 on the hand control lever 14. To engage the clutch the hand lever is raised, whereupon the end 19 of the lever 15 is held against the force of a disengaging spring 21 by a latch lever 20 which is biassed into latching position by a spring 24. When the hand lever is released the lost motion connection allows it to return towards the clutch disengaging position wherein a cam portion 22 engages the top of the latch part 23. A slight pressure on the hand lever moves the rod 23 downwards and disengages the latch, whereupon the spindle clutch is disengaged and a brake (not shown) applied to the spindle. For automatic release of the latch mechanism a Bowden cable 25 is actuated from a striker 28 on the table through a bell crank 27, this action being preferably timed to occur just before the switching means disconnects the feed drive to allow the motor to return the table so that the work cannot be damaged. In a modification, Fig. 4, the rod 17 is moved to the left by the hand control lever to engage the clutch, which is held in against the pressure of a disengaging spring 21 by a pivoted latch 20, the latch being disengaged against a spring 24 either by the hand lever acting through the boss 29 on the rod 23 or by Bowden cable 25 operated automatically from the striker 28 on the table.