Patent GB-365391-A (GB)
Title: Improvements in and relating to planing, milling and like machine tools
IPC: B23D1/02
Filed: 1931-03-07
Abstract: 365,391. Planing, milling, &c. WATERBURY TOOL CO., East Aurora Street, Waterbury, Connecticut, U.S.A. March 7, 1931, No. 7173. Convention date, April 4, 1930. [Class 83 (iii).] In a planing, milling, or like machine of the type in which a reciprocating table is driven by variable speed reversible hydraulic gearing comprising co-operating pump and motor units, the work table at each end of its strike actuates a valve which controls fluid-operated means which actuates the control device of the pump unit to effect the reversal. The table 12 is reciprocated on ways 11 by means of rack-andpinion gearing 13, 14, the pinion being mounted on a shaft 15 driven from a shaft 18 through change-speed reduction gearing 17, 16, this gearing incorporating both a direct drive for the high-speed table movement required for planing operations and a slow-speed indirect drive for milling operations. The shaft 18 is driven by the motor unit of a variable speed reversible pump-and-motor system comprising a pump unit A and motor unit B. These units are of similar construction. The unit A, Fig. 6, which is driven by a uniform speed electric motor 25 by a belt 27 includes a rotary cylinder block 28 having pistons whose stroke is regulated by a tilting swash plate 32 which is operated to control the direction and volume of the pump discharge by means of a rod 35 engaging a rotatable nut 36 which may be operated selectively according to the position of a clutch 63, either by a hand-wheel 66 or by a pinion 37. The pump discharge passes to the motor unit along pipes 22, 23. The pinion 37 is operated by a rack rod 38 of a cylinder 42 which is supplied by a small pump 47 under the control of a piston valve 43, which is operated from dogs 59, 60 on the table through a toggle device 55, link 54 and a link pivoted at 53 to the rack rod. The valve 43 is thus operated to cause the rack rod to move alternately in opposite directions and so reverse the flow of the pump unit at the ends of the stroke, the valve being moved to a neutral position through the connection 53 when the rack rod has completed its stroke. When the machine is to be used for milling, this automatic reversing gear is disengaged and the clutch 63 is engaged with the hand-wheel 66 to control the pump output. A crosshead 70 is vertically adjustable on uprights 71, 72 and carries a planer head 73 and a milling head 74. The planing tool is mounted in a vertical slide 76 operated from a cross shaft 77 which is operated intermittently through the usual planer feed gearing from a crank disc 78g through a rack rod 78d, a wheel incorporating ratchet mechanism, pinion 77a and other gearing controlled by a clutch device 77b. This gearing also drives a pinion 78a on a feed screw 78 for the cross feed of the planer head. The milling head 74 comprises an outer housing 80 which is angularly adjustable on a vertical slide 87, the cutter 83 being driven from a shaft 94 through worm gearing 92, shaft 90 and bevel gearing 89, 85. The shaft 94 is driven from a variable speed pump-and-motor unit 99, 96 driven by an electric motor 102. Vertical feed of the milling cutter is effected from a splined shaft 77<1> through helical gears 119a and feed screw 119. Transverse feed of the milling head is obtained by means of a screwed shaft 78<1>. The shafts 771, 78<1> are driven from another variable speed hydraulic system consisting of a pump unit 105 and motor unit 104, the pump being driven by an electric motor 107. The shaft 108 driven from the motor unit 104 is connected through reduction gearing 109 to a shaft 110 which carries a sliding pinion 111 engageable selectively either with a pinion 113, on the transverse feed screw 78<1> or with a pinion 112 on the shaft 77<1> operating the vertical milling feed. Both transverse feed screws co-operate with split nuts on the respective tool heads. The speed of rotation of the hydraulic motor operating the feed screw 781 is controlled from a hand-wheel 115 through a shaft 116.