Patent GB-1279632-A (GB)
Title: Apparatus for adjusting the position of a cutting tool in a machine tool
Inventor: DARBY WALTER
IPC: B23Q15/28
Filed: 1968-06-25
Abstract: 1279632 Boring machines; machine-tool details STUART DAVIS MACHINES Ltd 25 June 1969 [25 June 1968] 30155/68 Headings B3B and B3C [Also in Division F2] A machine tool, e.g. boring machine, includes a rotary tool head in which a tool-carrying means is adjustable by apparatus comprising an axially movable member 13 (Fig. 1) for effecting radial adjustment of the tool, the member being movable between two stop-limited positions defined by stops 40, 43, and control means including an actuator operable to effect movement of one of the stops, such as stop 43, in preset increments in one of two opposite directions and a further actuator operable to effect movement of said stop in preset increments in the other direction.  As shown, member 13 is connected to piston 34 of a piston-and-cylinder arrangement 21, 26. Stop 40 has a micrometer adjustment. Stop 43 is formed by an end of a sleeve 44 which is axially slidable and rotatable. Gear 53 on sleeve 44 engages a worm gear 52 (Figs. 3 and 5) on a shaft 49 which is rotatable and makes geared  engagement with an intermediate shaft which itself makes geared engagement with a shaft 79. Shaft 49 has affixed thereto a ratchet 78 (Fig. 2) co-operable with a pawl 77 on the end of a C-shaped member 72, pivoted at 73, actuated by fluid-pressure ram 61 having a stop 67 with a micrometer adjustment. Shaft 79 has a similar pawl and ratchet mechanism operable by a similar ram 62. Additionally, shaft 49 has a knob 54, calibrated, for manual operation. Operation.-For making a rough-cut bore, end stop 43 is set to the desired position of adjustment, and pressure fluid is supplied to port 38 of cylinder 21 to urge the piston 26 against that stop. For finish-boring, end stop 40 is set to the desired position and pressure fluid is supplied to port 37 of cylinder 21 to urge the piston 26 against that stop. For automatic setting or adjustment of the stop 43, a control circuit (Fig. 6, not shown), is provided. A measuring device (96) determines whether the bore is outside an allowable tolerance, and if it is, causes a solenoid-valve (93) to supply fluid to either one of cylinders 61, 62. Actuation of cylinder 62 causes the tool to be extended as follows:- Movement of the piston-rod of cylinder 62 causes the C-shaped member to pivot about its pivot 73 until this member abuts a fixed stop. At this position, the pawl is pressed into engagement with the ratchet. Further movement of the piston-rod causes the C-shaped member to rotate about the axis of shaft 79, and hence, via the pawl and ratchet, causes rotation of the shaft 79. This causes rotation of sleeve 44, and hence, while fluid pressure urges piston 26 against stop 43, causes advancement of the piston 26 and extension of the tool. The amount of tool extension is determined by the stroke of the piston-rod of cylinder 62, as set by its micrometer. When pressure fluid is no longer supplied to cylinder 62, its piston-rod retracts under spring action. The pawl is pivoted away from the ratchet, to return to its initial position. Similar operation of cylinder 61 causes retraction of the tool by rotation of shaft 49. The cylinders may also be supplied by fluid at other times if one of two control buttons (91, 92) is depressed to operate solenoid valve (93). Extension or retraction of the tool beyond an allowable limit is prevented by a cam 85 on the forward end of sleeve 44 engageable with a stop and microswitches. Backlash between the worm gear 52 and the gear 53 is prevented by using a worm gear having two halves (Fig. 5) urged axially apart so as to engage oppositely-facing flanks of adjacent teeth of the gear 53. The machine may include a boring head as disclosed in Specification 1,275,061.