Patent GB-833372-A (GB)
Title: Improvements in or relating to an automatic machine for drilling series of holes in a work-piece
IPC: B23B39/08
Filed: 1957-02-05
Abstract: 833,372. Drilling-machine details. USINES CHAUSSON S.A., DES. Feb. 5, 1957 [April 14, 1956], No. 3970/57. Class 83 (3). In an automatic drilling-machine for drilling parallel rows of holes, a frame 1, Fig. 2, carries a drill-head column 11 movable at right-angles to the movement of a work-table 5, and a drillspindle 14 is reciprocated continuously in synchronism with stepped feed of the work-table, which spaces the holes in a row. The column 11 is displaced a step after each table-stroke to space the rows of holes, by oil-pressure acting on a piston 97 in a cylinder 98 on the frame 1. The stepped table-feed is derived from an electric motor 49 driving, through an electromagnetic clutch 45, a shaft 40, carrying an integral cam 42, Fig. 1, engaging a roller 52 to rock a lever 50, pivoted at 51 and carrying a pawl 54 engaging a ratchet 56. A pinion 58 on the ratchet-shaft 51 drives, through gearing 60, 59, a shaft 61 carrying a pinion 63, Fig. 3, engaging a rack 64 on the table 5. The table is returned rapidly by a motor 71, Fig. 1, driving an electromagnetic clutch 67, Fig. 3, on the shaft 61, the pawl 54 being raised from pinion 56 by an hydraulic piston. The shaft 40 also reciprocates the drillspindle 14, Fig. 2, through a chain 41 and a shaft 33 carrying a crank 32, Fig. 5, whose pin 31 engages a slotted-arm 29 on a shaft 26 carrying a pinion 22 meshing with a quill 21 on the spindle 14. A friction-coupling 27 is incorporated in the drive, and shaft 24 is rotatable by hand at 25. In operation, with work on the table 5, motors 49, 71, rotating and the electromagnetic clutch 45 energized, the shaft 40, Fig. 1, drives the table 5 intermittently through cam 42, lever 50, pawl, 54, ratchet 56, pinions 58, 60, 59, 63 and rack 64. The drillspindle 14 reciprocates in synchronism with the stepped feed of table 5, being driven by shaft 40, chain 41, crank 32, Fig. 5, arm 29, pinion 22 and quill 21, to drill a row of holes. Before the table 5 is rapidly returned by motor 71, Fig. 1, energized electromagnetic clutch 67, belt 70 and shaft 61, the pawl 54 is raised hydraulically from pinion 56, the drill-spindle 14 is held in retracted position, and the electromagnetic clutch 45 deenergized. The column 11 is displaced to space the rows of holes by the piston 97, Fig. 2, which is controlled by a slide-valve 85 engageable with a push-rod 84 carrying a roller 83. A cam 81 and a pinion 73 are keyed to a shaft 72 on column 11, and an arm 75, freely-mounted on the shaft 72 and having a pawl 74 engaging the teeth of pinion 73, is movable angularly by a rod 76 of a compressed-air-operated piston in a cylinder 77 on the column 11. The cam 81, engaging the roller 83 by stepped teeth representing the spacing of the rows of holes, is rotated by piston 76, arm 75, pawl 74 and pinion 73, causing the roller 83 to engage the succeeding tooth. The slide-valve 85, urged by spring 88, displaces the column 11 by connecting the piston 97 to fluidpressure medium. On completion of the work, the slide-valve 86, moved by handle 87a, Fig. 2, allows pressure medium to move the piston 97, returning the column 11. Templets 125, 126, Fig. 1, having a plate 127, Fig. 8, with teeth 129, engage switches to control the machine: Drums such as 65, and friction-bands 68, 79, arrest momentum of table and column respectively, preventing over-run.