Patent GB-657332-A (GB)
Title: Improvements in or relating to spindle head stock
IPC: B23B39/02
Filed: 1948-11-16
Abstract: 657,332. Boring, milling and planing machines. STEVENS, A. H. (Giddings & Lewis Machine Tool Co.). Nov. 16, 1948, No. 29769. [Class 83 (iii)] A headstock for horizontal boring, drilling and milling machines comprises a spindle 22, Fig. 1, mounted in a housing 20, a rotatable driving member engaging and rotating the spindle, a feed member slidable in the housing for translating the spindle axially, on elongated support or arm 35 which is mounted in the housing for longitudinal translation in laterally-spaced relation to the spindle, rotatable driving member and feed member and is adapted to support a tool element adjacent and in driving relation to the projecting end of the spindle, and drive connections from a feed shaft 81 in the housing for effecting translation of the spindle and support in synchronism. The housing 20, which is mounted for vertical movement on a column 21, is arranged with the spindle 22 splined at its forward end in a rotary drive quill and extending at its rear end through a tubular feed ram 24, Fig. 10, both the rotational and feed drives being obtained from a motor M, Fig. 1. The arm 35, Fig. 4, is of rectangular box form and supported slidably on the underside of the housing by vertical and horizontal rollers 45, 46 engaging side ribs 40 on the arm, additional support being provided at the forward end of the housing by bearing plates 52, 53. To provide for taking up wear of the bearing surfaces, two tapered gibs 55, 56 are arranged between the guideway 51 at one side of the arm and the adjacent rib 40 ; relative adjustment between the two gibs is effected by a screw threaded into one gib and engaging a lateral extension on the other gib, and after adjustment the gib 55 is secured by clamp screws. The arm 35 is clamped in adjusted position by the head 65, Fig. 4, of a shaft 63 which passes through a resilient tongue 62 struck out of the plate 53 and is in screw-threaded engagement with a nut 64 anchored in the housing 20. The shaft 63 has an operating handle 68 adapted to be swung between clamping and release positions in which it is held by a spring detent 69, and a cam on the upper end of the shaft actuates a switch so as to cut out the feed drive when the arm is clamped. Slidably mounted in a groove in the top plate 38 of the arm is a rack 75, Fig. 7, which is adapted to be releasably latched to the arm by means of two plungers 87 movable vertically in the latter into engagement with two spaced sockets 91 in the rack according to the desired position of the forward end of the arm in relation to the nose of the spindle 22. The rearmost plunger 87 is operable also to engage a socket 92 rigidly mounted in the housing when the spindle is to be used in the ordinary manner without movement of the arm. The two plungers are operable by a hand lever 105 on a shaft 103 which is connected through gearing with pinions coacting with rack teeth on the plungers so that, when one plunger is engaged with a socket, the other plunger is disengaged ; in .an intermediate position of the lever 105, neither plunger is engaged and the arm 35 is free for adjustment. Both the ram 24 and rack 75 are moved axially by the motor M through speed-change mechanism 27, Fig. 1, and the feed shaft 81, the latter being arranged to drive a pinion 83 engaging rack teeth on the ram and, through further gearing 85, a pinion 78 meshing with the rack 75. The rack 75 is mounted outside the housing 20 which constitutes a sealed lubricant reservoir. The means for coupling the spindle 22 to the ram 24 comprises a tubular member 106, Fig. 10, slidably mounted in the ram and anchored by bearings 108 on a shouldered portion of the spindle. A tubular bracket 110 is mounted at the rear of, and axially aligned with, the ram so as to receive the member 106 in its retracted position. Grooves 114, 115 are provided in the ram and bracket for coaction with teeth 113 on a key 112 slidable in a diametral slot III in the member 106. In the position shown in Fig. 10, the key 112 is projected from one end of the slot so that its teeth 113 interlock with the grooves 114 in the ram and enter an axial slot 117 interrupting the grooves 115 in the bracket ; the spindle and ram are then coupled together for axial movement. When the key is projected from the opposite end of the slots a similar interengagement locks the spindle to the bracket but permits axial movement of the ram. The key 112 is actuated by a pinion which engages rack teeth on the side of the key and is operated by a lever 130, Fig. 10, having a handle 131 projecting through an arcuate slot 130<SP>1</SP> in a guard plate 131<SP>1</SP>. As the spindle and coupling member are advanced from retracted position, the handle is drawn through the slot and rendered inaccessible. Withdrawal of the key from latched position when the spindle is coupled to the bracket 110 and the ram is advanced, is prevented by a pin 137 which is urged by a spring 139 on a plunger 135 into a hole 138 in the lever 130 ; movement of the ram to its retracted position operates the plunger to withdraw the pin. When used for milling, the arm 35 may be connected in driving relation with the rack, 75 with its forward end projecting beyond the nose of the spindle 22 as shown in Fig. 12 and arranged. to support a housing 146 carrying an angularly-adjustable head 147 providing a rotatable support for a tool spindle 148 ; a shaft 152 projecting from the housing 146 is clutched at 153 with the end of the spindle 22 and drives the spindle through gearing 149, 151. Alternatively, a large milling cutter 167, Fig. 14, may be mounted on an auxiliary spindle 166 which is coupled to the spindle 22 by a tapered shank 30, and a housing 165 for the spindle 166 is bolted to the arm 35. In another arrangement, a shaping attachment 155, Fig. 13, is mounted on the underside of the arm 35 which is then fed forwardly while the spindle 22 is disengaged from the drive and locked to the housing. The direction and extent of movement of the ram may be controlled during shaping and like operations by switches 160, 161, Fig. 1, mounted on the housing 20 for alternate operation by dogs 162, 163 adjustably mounted on the arm 35.