| 摘要 |
1,246,523. Drilling machines. ATLAS COPCO A.B. 19 Aug., 1969 [10 Sept., 1968], No. 41337/69. Heading B3C. A drilling machine comprises a drill chuck 15 Fig. 1, rotated by a sliding vane air motor 16, and moved at a fast approach rate, and a low drilling rate, by a combined pneumatic and hydraulic feed system 14. A cylinder 26, Fig. 3, is filled with hydraulic fluid and is connected to an annular hydraulic fluid reservoir 28 via conduits 45-48 and valves 49-53. Cylinder, 26 and reservoir 28 are separated by an elastic membrane 29 forming an air chamber 27, which, along with an air cylinder 32, is connected to an air supply 35 by a valve 33. The rear end of motor 16 constitutes a feed piston which has a rod 18 carrying an hydraulic piston 19, an adjustable cam 68, and a plate 67. Air is supplied to motor 16 from a fitting 23, through rod 18, and the valve supplying the air is controlled by cam rod 22 when in its retracted position. In operation, air is supplied to cylinder 32 and exhausted from chamber 27, so that piston 19 forces the hydraulic fluid to flow from cylinder 26 through conduit 45 and one or both conduits 46 and 47, 48, into reservoir 28. The feeding rate of piston 19, and therefore drill 10, is controlled by the valves in the hydraulic feed system. The drill is retracted when plate 67 actuates a valve 42 so as to move valve 33, and air is supplied to chamber 27 and exhausted from cylinder 32. Hydraulic fluid is forced from reservoir 28, through conduits 48, 46, 47, 45 to cylinder 26, so that piston 19 is moved upwardly. Valve 53 is closed when the fast approach brings drill 10 into contact with the workpiece 9, and the slow drilling feed is determined by the flow through conduit 46 and valve 49, which is adjustable. To provide for change to drilling feed before the drill engages the work, cam 68 engages a spring biased ball 69, which retards the movement of parts 15, 16, 18, 19, 22 instantaneously, so that valve 53 closes. Several such machines may be fixed to a frame. |
