Patent GB-633408-A (GB)
Title: Improvements in turret drill heads
IPC: B23B39/20
Filed: 1946-04-12
Abstract: 633,408. Turret heads for drilling-machines. NAAMLOOZE VENNOOTSCHAP NEDERLANDSCHE INSTRUMENTENFABRIEK WALDORP. April 12, 1946, No. 11372. Convention date, Oct. 19, 1942. [Class 83 (iii)] An inclined turret drill-head comprises a base 3 movable to and from a stationary part of the drilling machine, a rotatable body 7 carrying tool-holders 15 provided with coupling members 17, a movable coupling member 5 on a driving spindle 2 for engagement alternatively with one or other of the members 17 upon rotation of the body 7, a spring-loaded rod 30 for actuating both the member 5 and a device 21 for locking the body to the base 3, and a second rod 40, Fig. 2, serving intermittently to drive a device for rotating the body 7. The member 5 is slidable against a spring 6 on an extension 4 in driving engagement with the spindle 2 which is housed in a sleeve 1 secured to the base 3. The rod 30 carries an abutment 34 constraining a spring 35 and is notched at 29 to engage one end of a forked lever 26, the other end of which bears against the member 5. The lower end 23 of the rod passes through a slot in the device 21 which is loaded by a spring 22 and adapted to engage one of a number of recesses 20 in the body. A cross-shaft 44, Fig. 2, journalled in a bridge-piece 45 has pinned to it a bevelwheel segment 47 co-operating with a bevelwheel 48 and a toothed segment co-operating with rack teeth on a spring-loaded rod 40. The bevel-wheel 48 has a spindle 49 journalled in a bush 50 which has a spur-wheel 54 rotatably mounted thereon to mesh with teeth 56 on the body. The spur-wheel 54 is rotated by the spindle 49 through a " free-wheel " coupling comprising a spring-loaded catch 53 carried in a member 51 and two diametrically-disposed teeth on one side-face of the spur-wheel. Two recesses similarly disposed on the other side face co-operate with a spring-pressed ball 60 to lock the wheel. Similarly, a spring-pressed ball 61 ensures accurate indexing of the turret. In operation, the rod 30 is depressed against an adjustable stop on the machine frame when the drill is withdrawn from the work-piece, disengaging the coupling 5, 17 and withdrawing the device 21 to unlock the turret body. This rod is retained in the depressed position by a nose 32, Fig. 5, on the device 21 engaging a recess 33 in the rod so that the coupling 5 cannot be engaged with a tool holder until the turret body is re-locked. The rod 40 now engages a stop, by which it is depressed to rotate the cross-shaft 44 and spindle 49, thereby rotating the spur gear 54 through 180 degrees by means of the " free-wheel " coupling to index the turret body. As the turret reapproaches the work-piece, the two control rods are restored to their previous positions by their springs, the rod 30 engaging the coupling 5, 17 and locking the turret body. In an alternative embodiment the lower end of the control rod 30, Fig. 6, bears against one end of the lever 26. This arrangement dispenses with the spring 35 since the coupling spring 6 serves to force the rod 30 outwardly. A lever 66 pivoted at 65 engages the notch 29 in the rod at one end and at its other end engages in the catch 21. The load imposed by the spring 22 may be adjusted by a threaded plug 67. The notches 20 are formed in insets 68 and runner rings 62a, 62b are provided in addition to a separate gear ring 63. Indexing is effected as in the first embodiment.