Patent GB-190202887-A (GB)
Title: Improvements in Machines for Turning and Screwing Bolts
Inventor: BIRKBECK HENRY
Filed: 1902-02-04
Granted: 1902-11-27
Abstract: 2887. Birkbeck, H., [Atterbury, W. W.]. Feb. 4. Lathes; screwing.- Relates to a machine for turning and screwing bolts, particularly stay-bolts, such as are shown in Figs. 55 and 56, for locomotive and other boilers, the bolts being turned and cut off from a long rod. The rod is gripped in a split chuck D, Fig. 1, in the front end of a hollow feed-shaft C, while being machined, and is released after a finished bolt has been cut off, so that it may be fed through the shaft against a stop J<5>, and again gripped. The feed - shaft and rod are then moved backwards, so that a turning-tool on the slide - rest R turns down the centre portion of the bolt, commencing at the end nearest the chuck, the feed-shaft being feathered in a sleeve B mounted in a headstock A', and driven by a belt pulley B<10>. On reaching the outer end of the reduced portion, the turning-tool is withdrawn, and the movement of the feed-shaft continued at a higher speed till screwing-dies, also carried by the sliderest, are clear of the rod, as shown diagrammatically in Fig. 52, in which S is the turning-tool and T the ties. The dies, normally open, are then closed, and the feed-shaft and rod moved forwards at the proper speed to screw the front end of the rod, the speed of traverse being increased while the dies pass over the central portion of the bolt blank, and reduced while screwing the other end. The dies are then opened, and the traverse of the rod and feed-shaft continued at an increased speed till the cutting-off tool R<27>, Fig. 52, is in the proper position, when the traverse ceases and the tool is advanced to cut off the finished bolt, as shown in Fig. 54. The tool is then withdrawn, and the stop J advanced to regulate the next feed of the rod. The mechanism for rotating the sleeve B, and, with it, the feed-shaft and rod, comprises a pulley B<10> loose on the sleeve, and clutched to it by a ring B<8>, either directly or through back gear, so that the rod may be rotated at a fast or slow speed. The traverse of the feed-shaft is effected by a screw C<6> in a head C<3> mounted on the rear end of the feed-shaft, and travelling on guides C<4>, the screw engaging a nut fixed in a hollow shaft E. This shaft may be driven at a fast speed by a wheel B<16> on the sleeve B, or at a slow speed in the opposite direction by a wheel B<3> also on the sleeve, or it may be driven from a shaft F<4> in one direction, and through change gearing in the opposite direction, the shaft F' being driven from a wheel B<12> on the face of the pulley. The various clutches for controlling the speed of the work and the rate of feed are operated by levers and camdiscs K<1>, K<2>, K<3>, K' on a cam shaft I<1>. The cam shaft is driven from the shaft F' through a shaft H<6>, on which are two sleeves driven in the same direction at different speeds from the shaft F<4>, a clutch sleeve on the shaft, controlled by levers Q<5>, Q, link Q<3>, and cam-disc K<5>, bringing either speed into use. The shaft H<6> drives a worm shaft F<21> gearing with a worm-wheel I on the cam shaft, and also drives friction feed-rollers in a box G" through chain and sprocket gearing F<24>. The rollers are mounted on spindles carrying wormwheels engaging a right and left handed worm carrying the sprocket-wheel G. The roller spindles are carried by slides normally pressed together by springs, so that the rollers engage the rod to feed it. The slides are separated by forcing a wedge between screws projecting from the slides, the movement of the wedge being controlled by a lever G<15> and cam-disc K, so that the feed takes place while the chuck is open. The chuck is opened and closed by a lever D<17> operated by a cam-disc K<6>, the lever only engaging the disc when the feed-shaft is in its forward position. The feed-shaft is supported in a slide C<15>, which has a pin V for engaging levers V<1>, v<1> at opposite ends of the stroke, to stop the feed definitely by throwing out the clutches till they are engaged by the cam-discs. The cam shaft drives a shaft P, carrying a cam I<8> for pressing forward the stop J<5> against the action of a spring, and also a cam I<11> for controlling the movement of the cutting-off tool R<27>, carried by a slide R<16> operated by the cam-lever R<28>, and moving in the slide-rest R, which is adjustably clamped on the machine bed. The turning-tool S is clamped in a slide S', Fig. 11, moving on the left face (as seen in Fig. 1) of the vertical portion of the slide-rest. A similar slides', carrying adjustable steady plates s<a>, is arranged diametrically opposite the slide S' to support the work while being turned. The two slides are normally retracted by springs S<5>, but are moved in simultaneously, when the work is to be turned, by cam-plates U', Figs. 52 and 54, adjustably secured to bars U pivoted to the slide C<15>, and passing between lugs S<3>, s<3> on the slides S<1>, s<1> and abutments S<8> on slides S<6>. The slides S<6> are normally held apart by a spring s<9> inserted between lugs S<9> at their inner ends, in which position the camplates have no effect on the slides S<1>, s<1>, but the slides can be moved inwards by rotating pinions S<18> with cam faces engaging projections S<10> on the lugs S<9>, the inward movement varying with the amount of rotation imparted to the pinions. The pinions are journalled on pins S<13>, and gear with a pair of wheels on a rock-shaft S<24>, Fig. 1, connected by an arm S<25> and link S<27> to a lever S<28> operated by a cam-disc K<8> with interchangeable cams l<10>, the movement of the rock-shaft being indicated by a pointer S<26> and scale. The position of the tool can be further adjusted by means of the screwed sleeves S<12>, with knurled heads S<15> in which the pins S<13> are held, the pins being connected by a sliding joint. The screwing-die is in two parts corresponding and mounted similarly to the slides S<1>, s<1> on the opposite face of the slide-rest. The slides carrying the die are operated by wheels s<22> on a rock-shaft s2', connected by an arm s<25> and link s<27> to a lever s<28> operated by a cam-disc K<7>, the wheels engaging pinions s<18> with cam surfaces engaging lugs on the die slides to close the dies or release them.