Patent GB-544471-A (GB)
Title: Improvements in or relating to hydraulic copying devices for machine tools
IPC: B23Q35/18
Filed: 1939-12-27
Abstract: 544,471 Copying mechanism ; milling-machines ; shaping curved surfaces. RIGID, Ltd., RORSCHACH. Dec. 27, 1939, Nos. 32880, 32881 and 32882 Convention dates, Dec. 24, 1938, Nov. 6, 1939 and Nov. 6, 1939. [Class 83 (iii)] A hydraulic copying machine controlled by a tracer or similar form-determining element has a tracer positively connected to a valve control rod acting through helical guide means on a valve controlling the admission of fluid pressure to a hydraulic cylinder. In one form, Fig. 1, the tracer 1 is arranged above the pattern 3 adjacent the tool 2 operating on the work. The tracer is carried in a sleeve 7 which is adjustable by a screw and moves in a guide sleeve 9 secured to the tracer head 10 which may be angularly adjusted on a cross slide 15 movable in guideways 16 on a slide plate on the carrier arm 34. The sleeve 6 carries a roller 12 guided in a groove of a valve control rod 13 and the plate 17 carries roller levers 18, 19 engaging a groove in valve control rod 22. For vertical copying the rod 13 has a helical collar 27 co-acting with grooved guide rings 31, 32 and a head 28 urged against a coacting seating 29 by a spring 281 these control parts being carried in a head 33 secured to the carrier arm 34. A line 35 leads from the valve chamber 30 to a cylinder 36 actuating the vertical work and pattern slide 38. For transverse copying control rod 22 has a helical rib 42 coacting with grooves in members 43,44 and controls two oppositely arranged spring closed valve members 51, 52 working in valve chambers 49, 50, communicating with the opposite ends of a cylinder 56 and also with pressure lines 55, 57. Exhausti s effected through a line 41. The piston of cylinder 56 is connected to a slide carrying the angularly adjustable tool fixture 60, and also through a piece 63 to the tracer slide plate 17. In operation pressure in the line 35 raises the piston 37 until the tracer engages the pattern whereupon axial pressure on the tracer rocks the valve rod 13 and thus through the helical collar 27 shifts the rod axially and opens valve 28 thus allowing pressure fluid to escape and stopping the rise of the work table. Increase or decrease of the pressure on the tracer shifts the valve to cause corresponding fall or rise respectively of the work and pattern table. The copying in a transverse direction is similar. Transverse pressure on the tracer shifts the slide 15 and through the inclined levers 18, 19 rocks the valve rod 22 in one direction or other and causes corresponding axial movement. This opens one of the valves 51, 52 and causes a pressure fall in one end of the cylinder 56 so that movement of the piston is effected by the larger pressure in the other end. In a modification both vertical and transverse movements are imparted to the work and pattern. In a further modification the tool and tracer spindles are horizontally arranged and both the copying movements are imparted to the tool and tracer assembly. In a further modification Fig. 7, instead of using a pattern the cross slide 15 of the tracer head may be actuated by a feed screw 76 driven by a motor 74<SP>1</SP> thus actuating valve rod 22 to produce the corresponding tool movements. The movement may be limited by stops 79, 80, which may stop or reverse the feed motor. Similarly a vertical feed may be obtained without a pattern by the hand or power operation of gears 75 which through a vertical rack 83 actuate the valve rod 13 controlling the vertical movement. For biasing the transverse movement towards one side without a pattern a spring controlled arm 88 is associated with the valve rod 22 the arm being held on either side of a neutral position by a spring 89. In another modification, Fig. 8, applied to a lathe, the vertical movement is in accordance with a fixed pattern 3 and the traversing movement is obtained from a cylinder 56. The pattern is located so that the tracer exerts a pull on the control rod 13 as the vertical slide rises. In another modification Fig. 9, the vertical movement is imparted to a spindle head 108 and the machine is adapted for vertical copying only under the control of an edge templet 3. The head carries a cutting or grinding spindle 101. In some cases a rotating pattern mounted coaxially with rotary work may be employed. A further adaptation to a planing machine Fig. 11 has the work mounted on a reciprocating table A and the tool 120 and tracer 110 arranged on a vertical slide 119 on a slide D movable along a cross railB adjustable vertically on columns C. Transverse tracer movements are transmitted through a bell crank lever 112 to rotate a valve control rod 114 thus controlling the cylinder 116 which moves the slide D horizontally. Vertical tracer movements actuate a rod 128 connected to a slide 130 movable in a support 131 and actuating the valve rod 1141 through levers 133, 134 as described above. This controls fluid supply to the cylinder 139 imparting vertical movements to the slide. The valve rod 114 has an extension which drives valve sleeves 115a, 115b which are separated by a spring and have helical grooves engaged by rollers 146, 147 to open one or other valve when the valve rod is rotated. The tracer may be biased by means 121. Transverse quick adjustment may be obtained from a hand wheel 124 or by a gear drive 125. Vertical biasing of the tracer may similarly be obtained from a lever 121a and hand setting means 124a or power means 125a may also be provided. In a further modification, Fig. 13. a table 241 may be fed by a hydraulic cylinder 239 the supply to which is driven from lines controlled by escape valves 258, 259. The piston rod 240 is connected through toothed gearing to a rack rod 246 integral with a support 247 for a slide 248. Levers 250 are mounted on the support 247 and cooperate with the grooved valve rod 255. Movements of the slide 247 rotate the valve rod 255 and cause operation of the piston 238. Such feed may be controlled by manual movements of the slide 247 by a hand lever 249 or hand wheel 267 and screw 268. Alternatively, by opening the nut 2681 the slide 247 may be reciprocated continuously by a chain 271 and driving stud 272. In a vertical modification of this form, speed reducing gear is arranged between the piston rod and the control slide and only the vertical ascending movement is hydraulically operated, the descent being effected by gravity. In a further modification Fig. 15 of the vertical gravity-return form the gearing between the piston rod and the control rod 293 includes an adjustably inclined member 294, which is reciprocated by the piston to impart adjustable vertical movement to a roller 299 on the control rod. This device may be used to vary the scale of reproduction of the model 302.