Patent GB-990967-A (GB)
Title: Boring and like cutting machines
IPC: B23B29/034
Filed: 1961-07-26
Abstract: 990,967. Boring machines. H. R. WARSEWA, and K. H. WOLFRAM. July 26, 1961 [July 27, 1960; Jan. 19, 1961], No. 27013/61. In a boring machine, the boring bar 1 has a radial aperture for the tool bit 11, a toggle 10, 10<SP>1</SP> hinged at 24, and located in the aperture, and means to adjust the toggle to advance the bit. Toggle lever 10<SP>1</SP> is seated in a screw 16, which permits coarse radial adjustment of the bit, and the bit is clamped by a grub screw 22. A rod 2 is supported for axial adjustment by a sleeve sleeve 3, having different threads of the same or opposite pitch on its outer and inner peripheries, one thread co-operating with rod 2 and the other with a screwed bore in bar 1, and rod 2 can be secured to produce the required mechanical advantage of the toggle, by a screw 9, which engages any one of four flats 2a-2c, on rod 2. A spindle 4 is connected to sleeve 3 by a pin 25, carried by an elongated slot in the sleeve, and is rotated relative to the machine spindle 26 to produce axial movement of rod 2, and therefore axial feed of bit 11. Spindle 26, Fig. 5, is driven from a motor 27 through gears 28, 29 and has a housing 30 secured thereto. A spindle 32 is secured to spindle 4 by a pin 36, and elongated slot 37<SP>1</SP>, and is normally rotated at the same speed as spindle 26 by housing 30, through a spring-urged friction disc 34. To move rod 2 axially to adjust bit 11, spindle 26 is stopped, and a motor 40 having a piston 41 is moved axially to engage a clutch 44, 45, thus disconnecting disc 34 from housing 30, and spindle 4 is rotated relative to spindle 26, and bar 1 connected thereto. Motor 40 may be omitted, and rod 43 directly coupled to member 45 and locked against rotation. Bit 11 is adjusted in this case by engaging clutch 44, 45, with spindle 26 rotating, and spindle 4 stationary. In a modification, Fig. 6, adjustment can be made continuously whilst a workpiece is being machined. Spindle 25 is rotated by means (not shown) and has secured thereto a gear-box 51 which, along with a second gear-box 49, having gears driven from a bevel 46 on spindle 26 rotate a bevel 53 secured to spindle 4, at the same speed, and in the same direction, as bevel 46, thus producing no axial feed of rod 2. A variable speed reversible motor 50 is also connected to gear-box 49, so that relative rotation between spindle 26 and spindle 4 to produce feed of bit 11 is supplied when motor 50 is switched on. A roughing boring bit 21 may be supplied, and a number of adjustable boring bits may be provided and the boring bar, or the work may be rotated. A method of adjusting the bit 11, Fig. 7, comprises boring a hole in the work K by bits 21, 11, gauging the bore by calipers 61 on a measuring head 60, which is connected electrically or pneumatically to a gauge 62, which due to errors in the reading, transmits electrical impulses to a control unit 63, which transmits electrically, hydraulically, pneumatically &c. a signal to an adjusting head 64 on spindle 26, which corrects the position of the bit 11. Calipers 61 may follow bit 11 in the work to produce constant adjustment of the bit, and unit 63 may produce an acoustic or optical warning, and may supply the signal to the controls of a production line instead of to head 64.