Patent GB-797883-A (GB)
Title: Improvements in or relating to vertical boring mills and like machine tools
IPC: G05B19/06
Filed: 1954-10-15
Abstract: 797,883. Boring- and turning-mills. BULLARD CO. Oct. 15, 1954 [Oct. 15, 1953], No. 29741/54. Class 83 (3). A vertical boring-mill or like machine tool comprises a frame, a rotatable work-supporting table, a tool-supporting head for movement on the frame in intersecting paths, a headstock transmission within a housing in the frame, a feed transmission separate from the headstock transmission located in a housing mounted on the headstock transmission housing within the frame, and driven thereby, and driving connections between the transmissions and the worksupporting table and tool support. A rotatable work-supporting table W, Fig. 1, is carried by a base B connected to a vertical standard S which supports a cross-rail C for vertical movement along ways on the front face of the standard. A main tool turret-head Hm and a ram-head Hr are mounted on the cross-rail for horizontal reciprocation. A side-head Hs with a horizontal power-fed tool-holder 108 is also mounted for vertical movement along additional ways formed on the standard S. Power is supplied to the machine through a V-belt pulley 24, Fig. 4, from which the drive passes through a main clutch and brake to toothed gearing and further clutch mechanism giving twenty speed changes to the bevel pinion 55 driving the work-table. This gearing is contained in a housing Th, Fig. 7, provided with lugs 12, 13, which slides into the base, the lugs resting on ways formed on the side walls of the standard. The shafts of the change-speed gearing are arranged in a horizontal plane so that the casing may be kept flat. Feed-drives. The heads Hr, Hm, Hs are power moved in either direction at a rapid traverse rate, or at one of sixteen feed rates by splined shafts 93, 94 and 111, Fig. 1, and screws 91, 92, 109, driven by bevel gearing from a number of interchangeable feed units Fr, Fm, Fs, Fig. 7, respectively, which are supported on the flat upper surface of the headstock housing Th. A toothed drive 145-148, Figs. 4 and 7, is taken off the headstock drive to drive a wheel 149 forming the input drive to feed unit Fm. Similar wheels 154, 155 on the other feed units, mesh with wheel 149 and form the input drives to these units. Additionally, a toothed drive 136, 138 is taken from the main drive to rotate a spindle 144 and toothed wheels 153 in the feed unit Fm, the drive being through bevel gears 140-143 and an inclined shaft 139. The toothed wheel 153 drives similar wheels 151, 152 on the adjacent feed units. These drives constitute the input for the rapid traverse motion. Output shafts 133, 135; 124, 126; and 128, 129 extend from the feed units to the gearing for moving the various heads. The gearing within the feed units comprises clutch and sliding gear arrangements. The cross-slide C is raised and lowered on the ways 69, 70, Fig. 1, by independent mechanism comprising vertical screwed spindles engaging nuts in the cross-slide and driven by a self-contained reversible double-ended electric motor through worm gearing. Controls. All of the sliding gears and clutch shifting elements for the main and feed drives are arranged to be parallel and directed towards the rear of the standard S, where they are adapted to be reciprocated hydraulically by piston-and-cylinder devices controlled by solenoid-operated valves mounted in a unitary support member 186, Fig. 4, which is removably attached to the rear of the standard within a housing Br. Quickly-detachable coupling elements 193, Fig. 9, are provided between the ends of the piston-rods, e.g. 191, and the operating rods for the gearing, e.g. 190. The piston- and-cylinder devices for moving the sliding gears are arranged to return to a " mid " neutral position and are constructed as shown in Fig. 13. The piston-and-cylinder devices for clutch operation are provided with throttling valves to give smooth engagement, and when friction clutches are employed, adjustable end stops for the piston movement are provided to take up wear. A plate 226 closes the rear end of the bracket 186 and is provided with a vertical main supply passage 225, Fig. 13, which supplies pressure to all the actuating pistons. All of the solenoids for controlling the hydraulic valves are wired to a central control pendant P, Fig. 1, suspended from a pivoting member 304 which may be adjusted vertically by a small electric motor from a switch at the base of the pendant. The construction of the pendant- and switch arrangements therein forms the subject-matter of Specification 797,884. Interlocks are provided in the switch mechanism to prevent " clashing " of any of the gears and to prevent shifting of the gears in the work-table drive while it is rotating.