Patent GB-696789-A (GB)
Title: Improvements in multi-tool lathes, particularly for machinery crankshafts and the like
IPC: B23B5/18
Filed: 1951-07-18
Abstract: 696,789. Crank-shaft lathes. BOEHRINGER GES., GEB. July 18, 1951 [Aug. 1, 1950], No. 17090/51. Class 83 (iii). A multi-tool lathe for machining crank-shafts comprising tools on a pivotal support operating on the lower front quadrant of the work, further tools for transverse operation carried by a support behind the work and still further tools on an auxiliary bed above the work, is characterized in that additional guideways are provided on the auxiliary bed for a pair of independently-operated longitudinal slides which carry cross slides for tools engaging the top of the work. The machine comprises vertical housing parts 52, 53, Fig. 2, spaced apart to accommodate the work W between centres 91 and joined by two hollow bed members 54, 51, the latter extending to a higher level than the centre axis to provide an inclined face 50 with T-slots 55, Fig. 5. The housing parts 52, 53 also extend upwardly to provide horizontal guideways 23 for longitudinally movable slides 24, 25 carrying tool cross-slides 66, 67. Three tool carriers 26 ... 28 are shown secured to these cross-slides but the latter two carriers may be combined. All the longitudinal turning is done by tools on these carriers and includes (1) a tool 29, Fig. 2, for machining the end pin 18; (2) a tool 30 for machining the line bearing 13; (3) a tool 31 for the periphery 21 of crankarm 32; (4) a pair of tools 33, 34 to machine peripheries 21 of the two crank-arms adjacent to the line bearing 12; (5) a tool 35 for machining the periphery 21 of the crank-arm adjacent to line bearing 14, and (6) a tool 36 to machine the periphery of the flange 15. The slides 24, 25 are fed by a screw 60 driven by gearing in the housing 53 and the cross-slides may be moved towards and away from the work by a splined shaft 64 extending above the top of the machine. The slides 24, 25, extend in cantilever fashion beyond the inner ends of the guideways 23 and the latter is cut-away at its lower edge to provide clearance for a tool-carrier 73, Fig. 5, provided with a tool 49 for engaging one of the main bearings of the crankshaft. This toolcarrier and, similarly, a second carrier for the other main bearing surface, are mounted on slides which are bolted by the T-slots 55 to the sloping bed surface 50. Transverse feed of these parts is by a shaft 76 driving through worm gearing 75 and screw-feed mechanism. Carriers 84 ... 86, with sets of tools mounted therein for cutting the side faces of the crank webs, the shoulders, and for other facing operaations are secured to the surface 81 of a leverrest 79 pivoted in the frame about a bearing 78. The surface 81 is approximately in line with sloping bed face 50 and the tools carried by the lever-rest engage the work diametrically opposite to the transversely fed tools previously described for turning the main bearing surfaces. The rear end of lever 79 is connected by a link 87 to a vertical screwed spindle 88 engaging a threaded bore of a worm wheel (not shown). The worm wheel is driven by a worm with a shaft extending into the housing 53. Driving machine - spindle.-The work is driven by a known-type chuck mounted within a toothed rim 93, Fig. 2, in a casing 94. The foot 95 of the casing is bolted to a part 54 of the machine bed. The toothed rim 93 is driven by a pinion engaging therewith and attached to a shaft 96 that extends into the housing 52. The transmission in housing 53 is operated by a shaft 97 which extends between the housing parts, and an electric motor within the housing 52 effects the drive through gearing not described in detail. Catching and removing cuttings.-The parts of the bed are arranged to provide a free passage for cuttings between bed members 51, 54, leading to a pit beneath the machine, and sheet-metal plates are provided for the front of the machine to assist in directing the cuttings into the passage.