MANUFACTURING APPARATUS

1,248,069. Manufacturing plant. CINCINNATI MILLING MACHINE CO. 11 Dec., 1968 [15 Dec., 1967], No. 58842/68. Headings B3B, B3C and B3K. [Also in Division G3] A complete manufacturing plant comprises a primary conveyer loop 11 and secondary conveyer branches 12-16 that lead to machining stations 25, 26, 27, 32, 33. A control system, including a computer, a bulk memory bank and a central data source, controls the movements of workpiece carrying pallets around the conveyer and also the operation of the machines. The pallets include non-magnetic slug identifying means that are read by reading heads 39, 44 at the entrance of the branch conveyers from the primary loop 11 and also at the machining stations. The control system allows a queue of pallets to form in each conveyer branch, but after a specified number, any extra pallet that is directed under a primary programme to a "full" branch conveyer is re-directed by an alternative contingency programme to either another machining station to have a later operation performed early, to cruise in the conveyer loop 11 until its primary station can accept it, or to a holding stage in the conveyer. The plant includes cuttings removal equipment (Figs. 11 and 12, not shown), and a cleaning device for wiping the identifying slugs on the pallets before they reach a reading head. At the machining stations a section (201) (Fig. 13, not shown) of the conveyer is separable from the branch conveyer (197) (199) to feed a pallet and workpiece into a machine station and attach it to a machining abutment, to return to pick up a fresh pallet and workpiece, and then to feed the fresh one to the machine station and push the machined one out on to the conveyer (199). The work pallets (206) (Figs. 16-18, not shown) include an annular member (214) having radial teeth (216) that engage with a similar annular member (213) on each machining abutment (70) (Fig. 7, not shown) at the work stations. When a pallet and workpiece are fed into a machine station, mating slots and guides (225), (219) on the pallet and abutment are engaged. The pallet is then raised an initial distance by a pressure device (223) and rotated by an electric motor (200) to a desired orientation. The pallet is fully raised to clamp the annular members (213) (214) together. A locking key (220) is also used. The workpieces are attached to the pallets by means of plates and fixtures (Figs. 4-6, not shown) and are inverted at turnover stations 36 before entering the conveyer loop 11. Types of machine tools; beds and frames.- Station 25 comprises a heavy duty milling machine (Fig. 7, not shown) having a column (63) movable on a bed (59), a saddle (66) movable vertically along the column, and a spindle head (68) movable axially of the spindle to present a milling cutter to a workpiece (74). Station 26 comprises a machine (Fig. 7A, not shown) used primarily for hole generating by single tool operations and comprises a movable column (76) having a vertically movable saddle 78, an axially movable spindle 82, and a tool changing mechanism (85), (86). Station 27 comprises a boring machine (Figs. 8 and 9, not shown) having a single spindle that drives multi-spindle toolheads exchangeable from a tool-head store. The machine comprises a movable column carrying a vertically movable saddle and an axially movable spindle. A further machine tool (Fig. 10, not shown) may be used with milling, boring, facing or other rotary cutting tools and comprises a bore (133) along which moves a saddle (135) carrying a column (137) that is movable along guides (136) on the saddle. A spindle head 141 is movable vertically along the column. In a modification (Fig. 10A, not shown) the machine may have two separate independently movable spindle heads on the vertical column. Tool changing mechanisms.-Station 26 comprises a machine tool (Fig. 7A, not shown) having a tool changing mechanism that includes a movable chain with tool sockets (85) carrying the tools (84). A tool -interchanger (87) comprises a pair of arms that move in and out and rotate to exchange a new tool for an old one. The station 27 comprises a store (100) (Fig. 8, not shown) 'for the multi-spindle tool heads (102). The store comprises a vertical stack of independently rotatable magazines having radial holding means for the individual tool heads. Each tool head can be picked off by a transfer device (103) which can be moved vertically to the required level. The tool head is then brought level with a top conveyer and fed into the machine tool by a pressure actuator (109). A used tool head is taken from the spindle head of the machine at its lowest level and transferred via a lower conveyer (110) (Fig. 9, not shown) to a pivotable transfer device 111 which returns it to the store. Control means are provided to determine in advance the tools required at the spindle and to transfer tools from a bulk store to a ready-access store. 'The tool stores are manually loaded with tools carrying identification tags with punched apertures that are read by computer controlled reading heads.