Patent GB-1493887-A (GB)
Title: Machine tools
IPC: B23B31/26
Filed: 1975-09-16
Abstract: 1493887 Turning and boring machines, tool changing, frames and gauging, vertical boring machines BULLARD CO 16 Sept 1975 [16 Sept 1974] 38035/75 Headings B3T B3B and B3C A machine tool such as a vertical turning and boring machine comprises a rotatable worktable 12 a cross slideway 17 which is located above the work-table and extends transversely to the axis thereof and is supported on a frame 10. The slideway 17 carries ram housings 14, 15, which are displaceable thereon and which in turn support vertically displaceable rams 16 to the ends of which tool holders 20 are secured. Adjacent each end of the slideway there is located Carousel type rotary tool magazines 22, 23 and tool transfer 26 and tool changing devices 29 are provided between the ram housings and the magazine whereby, depending on the machinery operation required tools may be selectively changed between the magazine and the ram head. The tool transfer device in the form of a carriage 26 movable along a guide rod 202 parallel to the slideway 17 by a feed screw 207 between the magazine and a predetermined position adjacent the ram housing defined by an abutment. Clutch means 242 being provided within the carriage 26 to permit the carriage to be maintained in the predetermined location with respect to the ram housing whilst maintaining rotation of the feed screw and irrespective of the position of the ram housing along the slideway. The tool changing device 29 (30) is provided with two parallel extending pins 31, 32 so spaced as to simultaneously engage bores 33 in respective tool holders 20a, 20b when located respectively on the ram head and adjacent the ram housing, the device 29 being displaced laterally towards the slideway to effect engagement between the respective pins and bores. The tool changing sequence is then effected by automatically releasing the tool holder clamped in the ram head, displacing the changer device 29 parallel to the slideway to simultaneously remove the tool holder 20a from the ram head and the tool holder 20b from the transfer carriage 29 and locate it on the ram head where it is subsequently clamped. The device 29 (30) is then moved away from the slideway to disengage the pin 31 from the tool holder 20b whilst carrying the used tool holder 20a clear of the ram head. The device 29 is then moved in three successive directions to locate the used tool on to the transfer carriage 26 where it is subsequently replaced in the magazine. The sequence of operations is similar for changing L.H. or R.H. tools or whether changing tools for a turning and then boring operation. The displacements of the changing device 29 parallel to the slideway are effected by screw means 272 within housing 27, 28 at the ram housing and the transverse displacements of the changing devices 29 (30) are effected by a fluid actuated pivotal lever assembly 286 within the housing 27. The clamping of the tool holders to the ram heads is effected by way of a tool block clamping assembly 41 secured to the ram head 40, the clamping being provided by a drawer bar type mechanism 50, 52, which draws the tool holder 20 with its cutting tool 21 on to a wedge seating 46, 44, to ensure rigid clamping and accurate location of the tool holder. The machine is programmed to perform all the sequence of operations for the required machining of a workpiece.