Patent GB-414226-A (GB)
Title: Boring machine
IPC: B23Q9/00
Filed: 1933-08-18
Abstract: 414,226. Boring-bar machines. STORM MANUFACTURING CO., Inc., 406, 6th Avenue South, Minneapolis, Minnesota, U.S.A. Aug. 18, 1933, No. 23079. Convention date, Nov. 7, 1932. [Class 83 (iii).] In a portable machine for re-boring engine cylinders, a hollow boring spindle 26, Fig. 3, is rotatably mounted in a bearing sleeve 25 which is rotated, at a speed different from that of the spindle, in bearings 22 in a frame 15, the spindle and sleeve being fed togetheraxially. The purpose of rotating the sleeve is to cause the spindle to rotate on a true axis, and the sleeve and spindle may rotate in the same or opposite directions. The bearings 22 are tapered and split and are movable in the frame to adjust for wear by means of nuts 23. Screws 24 prevent rotation of the bearings 22. The sleeve 25 is splined within a worm wheel 44 rotated by a worm driven by belt pulleys 39, 40, Fig. 1, from an electric motor 32 carried by a platform 33 which is adjustable along inclined ways 35 on the frame 15 to vary the belt tension. A gear 30, Fig. 3, secured to the sleeve 25 rotates the spindle 26 at an increased speed through a gear train 50, 54 and a pinion 56 on the spindle, the gears being enclosed in a casing 49 held to move axially with the sleeve 25 but prevented from rotating therewith by a rack bar 60, Fig. 1, secured to the frame 15. Axial feed is imparted to the casing and sleeve by a pinion 59, Fig. 7, rotatably mounted in the casing and engaging the rack bar 60. A worm 65 rotated from the gear 30 on the sleeve drives a compound gear 70 which rotates one part of a friction clutch 72, the other part being attached to a sleeve 76 which is connected by gears 78 to the pinion 59. The friction clutch is engaged or disengaged by a hand operated nut 81 rotatably attached to a rod 75 passing through the sleeve 76 and screwing on the sleeve, the rod and sleeve being attached to the two clutch parts. A hand feed may be used, when the clutch is disengaged, by means of a wheel 80 whose boss is attached to the sleeve 76. The spindle 26 and boring head 18 are secured against axial motion within the sleeve 25 by means of conical roller bearings 28, 29, Fig. 3. Brakes, applications of.-In order to prevent the sleeve 25 and spindle 26 from moving downwards under their own weight, and thereby producing an unsteady feed, a split conical friction ring 82, Fig. 3, is mounted in a recess in the boss of the worm-wheel 44 through which the sleeve slides, the action being such that the ring will grip the sleeve on downward movement but will have its pressure relieved on upward movement. Framing and supports.-The framing 15 has a transverse aperture 16, Fig. 3, for enabling the progress of the work to be observed, and including a central enlargement 17 to receive the boring head 18. Boring-heads; jigs.-The boring-head 18, Fig. 3, has a lower transverse aperture 86 in which a cutter holder 85 is radially adjustable by means of a screw 87. Three centring dogs 91 in the head are radially adjustable by a scroll plate 89 which has a ring of internal teeth engaged by an idle pinion 94 rotated by a central gear 93 in the head. An operating rod 92 passing through the spindle 26 is secured to the gear 93 and carries a handle 96. The centring dogs position the machine on a cylinder block 12 prior to its being secured thereto, but are withdrawn whilst a cylinder is being bored. Stands.-The machine frame 15 is secured to a cylinder block 12 to be bored by means of a yoke-shaped clamp 13, Fig. 1, which is clamped to the work by a bolt 100 engaging a T-slot 100<1> therein and screws into a nut 103 pivoted at the lower end to a bar 104 passing under the block. A spring 105 is inserted between the clamp and a plate 101 resting on the top of the block. Pressure is applied to the rear end of the clamp to force its other end into contact with the frame 15 by a hand operated screw 106 engaging a nut 107 in the slot 100<1> and carrying a universally jointed foot 108 acting on the top of the block. Stop-motions.-The driving motor 32, Fig. 1, is stopped when the sleeve 25 has reached its desired lower limit of feed by means of an adjustable collar 110 on the sleeve engaging a switch 109 in the motor circuit.