Patent GB-292743-A (GB)
Title: Improvements in or relating to the production of coiled filamentary bodies
IPC: B21F3/06
Filed: 1927-05-13
Abstract: 292,743. Cachemaille, A. S., (Westing- house Lamp Co.). May 13, 1927. Coiling; dies; shearing-adjuncts.-Coiled filamentary bodies of outside diameter 60 mils or less formed of fine wires of the order of ¢ to 5 mils in diameter for making filaments for electric lamps &c., are made by coiling without the use of a mandrel. The wire is drawn over a measuring wheel and forced into a die by a pair of grooved rolls rotated at the same peripheral speed and the coil is automatically cut into lengths by cutters operated by the measuring wheel. Filaments are thus obtained without stretching the wire and having predetermined lengths of wire, and coils of uniform diameter and pitch, free from stresses so that they do not sag after flashing. the wire 41 is conducted to th6 feed rolls 39, 33, Fig. 12, by way of a measuring wheel 49, Fig. 22, being supplied from a flanged spool 47 mounted so as to prevent abrasion of the wire by the flanges. The feed roll 33 is of larger diameter than the roll 39 so that a set is given to the wire prior to entering the die 53. The rolls are driven at the same peripheral speed by gearing from a motor. The roll 33 is mounted on a, shaft coupled to its driving shaft and is prevented from moving endwise by a stop plate 34, Fig. 1. The roll 39 is mounted on a shaft carried by a plate 37 which, to facilitate inspection of the die 53, is pivoted at 42 to a plate 43, which is itself pivoted at its lower end to a bracket and adjustable thereon by a set-screw 46. The plate 37 mav also be adjusted laterally by screws 43<1> to allow for play of the set-screw 46 in its threaded aperture so as to bring the rolls into alignment. The plate 37 is slotted at 82 and is held down during operation by a shoulder 84, Fig. 7, on the portion 83 of a rotatable spindle 85, which has a cam face 86 and is pressed down by a spring and forked lever 95 into contact with a cam face 87 on a screwed member 90. This member may be angularly adjusted to vary the operative position of the roll 39 by a pair of set screws 88<1> engaging flattened portions 92 thereon. The roll shaft 35 is connected by a clutch 98 to its driving shaft 25. For this purpose a pin 102 on the end 101 of the shaft 25 engages slots in one end of tha member 98, which is normally pressed by a spring J04 so as to engage its other slotted end with a pin 105 on the shaft 35. When the spindle 85 is turned to bring it into such a position that the plate 37 may be raised therefrom, a plunger 109, which is normally pressed by a spring 114 against a flattened portion 113 thereon is pressed forward to engage a lever 107 to disengage the ctutch. The spindle 85 has a shoulder 88 which :in its raised position may act as a stop for the plate 37 to avoid damage to the rolls if the plate is dropped. The die, which may consist of a diamond secured to its rod 56, or may consist of hardened steel integral therewith, is formed near one edge with a semi-circular cavity 54 into which the wire is forced, one edge of the cavity being formed as a lip 55 to determine the pitch of the helix. The rod 56 is secured by a screw 61 to a slidable cross bar 59 and is axially adjustable in a holder 57 by a set-screw 58 and then secured in position by a set-screw 63. The holder 57 is mounted on a pivot 65 in a saddle 64 so that the die may be angularly adjusted to make coils of diameter greater or smaller than the normal as shown respectively in Figs. 15 and 18. The saddle is angularly adjustable about a pivot 66 so as to obtain coils of pitch smaller or greater than the normal as shown in Figs. 17 and 20. Such adjustments are required to suit wires of different hardness &c. In order to effect such small adjustments the holder 57 has an extension 68 inserted through a guide 71 adjustable laterally by screws 77, 78 on a head 74 which is slidably mounted on an arcuate plate 76. Vertical adjustment is limited by screws 72, 79. Scales and pointers may be used to indicate the adjustment. After the coil 40, Fig. 23, is formed it passes through a guide 116 and is severed by a disc cutter 124<1> mounted in a slide 126 which is pressed down by a spring and is connected by a pin 136, Fig. 22, to a lever 133 provided at its other end with a trigger 139. A cam member 142 on the measuring wheel engages a spring-pressed lever 143 so that it is moved in one direction over the trigger and in the other direction engages the trigger to move the lever 133 and operate the cutter. The cutter may be operated by an electromagnet. The severed coils may be discharged .through a shoot and counting mechanism. The guide for the cutter slide consists of a member 119 which is mounted on pivots consisting of setscrews 121, 121<1> and may be swung thereon into the position shown in Fig. 1 to facilitate inspection of the die. It is locked in its closed position by a ward 122 and lug 124. The guide may be adjusted by the set screws to vary the pitch of the coil. A lever 149 pivoted at 152 on the casing 31 has an aperture through which a rotatable threading tool 152<1> may be inserted. The casing has a stud 155, Fig. 25, with a groove 156 to receive the wire 41 and a flattened portion to receive the tool, which has a knurled end 153 and a tapered end 154. The wire is inserted in a notch 158 in the tool and the tool rotated to thread a few turns thereon. Thereupon the arm 149 is swung round to place the turn 159 into the rolls and the tool is then removed. The feed rolls may be separated from the die by a two-part guide and may be equal in diameter.