Patent GB-358348-A (GB)
Title: Lathes for shaping fibre conduits
IPC: B23B5/16
Filed: 1930-11-24
Abstract: 358,348. Lathes for making fibre conduits. FREEMAN, R. F., c/o Fibre Conduits Canada, Ltd., Cornwall, Ontario, Canada. Nov. 24, 1930, No. 35399. [Class 83 (iii).] In a lathe particularly intended for turning tapers on the ends of sections of fibre conduit preparatory to joining such sections, the work section is centred by supports introduced into opposite ends thereof and the ends are taper-turned by tools mounted in a pair of hollow rotary cutter heads, the work supports each comprising a resilient element which is expanded into engagement with the inner walls of the work. The bed II is provided with a pair of carriages 13 which are adjusted simultaneously by means of a right-and-left-hand threaded spindle 16 actuated through bevel gearing from a hand-wheel 32. Each carriage is provided with semi-circular notches 33 coacting with similar notches on the bed so that a locking pin 35 may be inserted between a pair of notches to hold the carriage in its adjusted position. Each carriage has a cutter slide 37 longitudinally adjustable thereon, the cutter head 54 being screwed on to a hollow spindle 45 which is mounted in spaced bearings 38, 39 and is driven by a pulley 46. The taper-forming cutters 56 are secured in the cutter head by screws 57. Suitable end facing cutters may also be mounted in the cutter head. By means of plates 58, 59 the two cutter slides are secured to upper and lower racks 60 which engage opposite sides of a pinion which is operated to move the cutter slides simultaneously in opposite directions by means of a hand-wheel 64. Each of the carriages 13 also carries a movable workcentring support 66 which includes a cylinder 67 whose end wall 671 is recessed to receive the end of a tube 69 passing through the cutter spindle and bearing in bushes 70. The tube 69 is bushed internally at 71 and carries a rod 72 fixed to the piston 73 which is urged outwardly by an adjustable spring 74. The rod 72 carries a clamping disc 79 which coacts with a second disc 78 bearing against the end of the tube 69 so that the spring pressure causes the compression of a number of rubber discs 77 which are thus expanded radially into engagement with the walls of the work-piece. The outer end of the cylinder 67 is connected to a pipe 85 connected through a three-way valve 88 to a fluid-supply pipe 87. The valve is normally positioned to supply fluid to both cylinders 67 so that the pressure on the rubber discs is relieved and the work supports are in their contracted position. In the exhaust position of the valve, fluid escapes from the cylinders 67 and the discs 77 are expanded by the spring pressure to grip the work. In the retracted position shown in Fig. 1 the work support 66 and the cutter slide are connected together by a link 92 engaging over a pin 95. During the approach movement of the cutter slides produced by the wheel 64, a cam 97 on the link 92 engages a pin 98 and thereby disengages the work support from the cutter slide which then moves forward to its operative position, at which point it is arrested by the engagement of a pin 101 on the slide with a notch in a lever 99 pivoted to the bed. The workpiece 103a is placed on a number of fixed supports 103 and is further held during the operation of the cutters by means of spring clamps 107, 113, the upper clamp being moved downwardly by a lever 115. The clamping plates may be provided with projections to assist in gripping the work.