Patent GB-121636-A (GB)
Title: Improvements in or relating to Apparatus for "Marking-off" Angular Positions on Wheel-rims or the like.
Inventor: LAWS FREDERICK TUDOR
IPC: B23Q1/52
Filed: 1917-12-27
Abstract: 121,636. Laws, F. T., and Crouch, A. P. Dec. 27, 1917. Hoops and rings.-In apparatus for marking-off angular positions on wheel rims, brake drums, or other ring-like members of the kind comprising a jig provided with gripping-jaws by which the rim &c. is sprung into circular form while the positions are marked, the gripping-jaws are in the form of a floating segmental ring surrounding the rim and are contracted on to the rim by a wedge moving in a direction normal to the plane of the rim. A segmental ring d, mounted in a box-like member a is adapted to be contracted to grip the wheel rim c by means of a conical sleeve e which is forced between the box a and the ring d by means of a collar b screwed in the box a. The ring segments are held together by spiral springs d<2> and are formed with ribs d<1> which engage shoulders on the rim c so as to hold the rim in the plane of the ring d. The collar b and sleeve e are operatively connected together by a flange b<2> and channel e', the flange and lower wall of the channel being cut away at different points so that the sleeve can be readily attached to and detached from the collar. This attachment and detacbtment and the turning of the collar b is effected by a member f which by means of a tubular part h is supported in a rotatable and vertically movable manner from a depending tubular support (not shown). The member f is provided with depending lugs f<1> provided with slots f<2> to receive tongues e<3> on the sleeve e and with tongues f<3> to engage notches b<3> in the collar b. Hasps g passing round hooks e' on the tongues e<3> and round eccentrics g<1> pivoted to the lugs f<1> connect the member f with the sleeve e. To assemble the parts of the apparatus, the rim c and ring d are placed in the box a and the member f lowered to insert the sleeve e between the box a and ring d. The member f is then turned by a lever to interlock the sleeve e and collar b and thereby bring the tongues f<3> above the notches b<3>. The eccentrics g<1> are then turned so as to pull the member f down so that the tongues f<3> engage the notches b<3>. By further turning the member f, the collar b is turned, forcing the sleeve e downwards and pressing the rim c to circular form. The hasps g are then disconnected from the hooks e<4> and the member f moved out of the way. The box a is rotatably mounted in a frame j, Fig. 2, which is pivoted at one side so that, after assembling the parts, it can be turned into a vertical position to facilitate the marking operation. The marking is effected by one or more centre-punches m carried by brackets k on the frame j, the punches being arranged preferably at the same angle to the rim c as is to be assumed by the spokes of the wheel. The box a is provided with a flange a<3>, Fig. 1, having ratchet teeth engaged by one or more pawls on a reciprocating pawl plate which is moved in one direction by a cord o<4>, Fig. 4, attached to an operating treadle p and is returned by a second cord attached to a spring. A flange a<4> on the box is provided with a number of recesses or holes a<5> arranged in circles and spaced apart in the circles to correspond with the number and position of the spokes in different wheels and a separate centrepunch is provided to correspond with each circle. The holes a<5> are adapted to be engaged by a spring locking detent q which is adjusted laterally according to the circle of holes a<5> in use, by a rack bar q<1> carrying the detent and adjusted by a handlever q<2> and toothed sector. The detent q is connected by a Bowden wire q<5> to a lever r, Fig. 4, pivoted on the pivot shaft r<4> of the treadle p and carrying a pivoted trip-pawl r<1> co-acting with a projection r<2> on a spring-controlled lever r' pivoted to the treadle p. When the treadle is depressed, the projection r<2> depresses the lever r thereby withdrawing the detent q. Further movement of the treadle rotates the box a but, as the lever r has only a limited movement, the lever r<3> yields so that the trip pawl r<1> is released before the end of the movement of the box a and the detent q is therefore free to engage the next hole a<5> in the circle. The pawl r<1> has a bevelled end and is pivoted to turn vertically and laterally so that, on the upstroke of the treadle, it yields to allow passage of the projection r<2>. The punches m are normally held clear of the rim c by springs m<1> and are brought into contact with the rim by Bowden wire mechanism before being struck by the operator. These Bowden wires m<3> are connected to vertically slidable thimbles s mounted in guides s', Figs. 2 and 10, which are arranged concentrically about a spindle t<1> which is rotatable and also vertically slidable.. The thimbles s have side notches to receive an operating arm t<2> secured to the spindle t<1> and connected by a spring t<3> to a rotatable sleeve u having an arm u<3> to which is pivoted a hand-lever t. connected to the spindle t<1>. By turning the lever t horizontally, the arm t<2> is engaged with any of the thimbles s, a spring- controlled detent u<2> engaging recesses in the sleeve u indicating to the operator when the arm is in correct position. The lever b is then depressed, pushing down the thimble s and bringing the corresponding punch into contact with the rim c. The punches may be struck by mechanical means, and instead of Bowden wires, pneumatic means may be employed to bring the punches into contact with the work and also to strike the punches. Drills may be mounted similarly to the punches so that, after being marked, the rims may be drilled for the spokes.