Patent GB-678582-A (GB)
Abstract: 678,582. Reshaping mounts for electric discharge devices. BRITISH THOMSONHOUSTON CO., Ltd. March 27, 1950 [April 1, 1949], No. 7616/50. Class 39(ii) In apparatus for reshaping a mount comprising a pair of approximately parallel leading-in wires with a coiled cathode extending across and secured to their inner ends, the mount is carried through a series of consecutive work stations at which bending- devices, and subsequently, curling- devices, operate to bend the ends of the leading-in wires 5, 6 from the form shown in Fig. 2 to that shown in Fig. 4, so that the cathode 7 is re-arranged from a position transversely to the longitudinal axis of the mount to one in alignment with the axis. The apparatus may be embodied in the mount-making apparatus described in Specification 564,702, [Group XL], wherein the mount is held with the cathode lowermost and the leading-in wires 5, 6 arranged in the plane of the course of travel. As shown, the mount 1 is supported by a pair of jaws 8, 9 which grip the exhausting tube 10. The ends of the leading-in wires are first bent inwardly at right angles by means comprising an anvil 12, Fig. 5, mounted on the forward end of a slide 15 which is movable upon guideways on a horizontal bracket 16, the slide being also provided with a vertical pin 25 forming a pivot for a pair of jaws 23, 24 with bending fingers 13, 14 at their forward ends to co-operate with the anvil. Movement of the slide 15 is effected by a sub-slide 26 pivoted to one arm of a bellcrank 28 controlled by a vertical camactuated rod 36, a helical spring 29 being located between the inner ends of the slides 15, 26, so that when the slide 15 is arrested by an abutment which determines the extent of its operative movement, the sub-slide 26 continues to move inwardly. During the latter movement a slotted cam plate 55 secured to a block 31 on the subslide operates to close the jaws 23, 24 the rear ends of which carry studs 56 engaging within obliquely arranged cam slots 57 in the plate 55. Each cycle of operation is brought about by a single rotation of a cam shaft carrying a coaxial disc with a cam groove in one of its faces to receive a roller at one end of a rocking lever pivotally connected to the rod 36. While the bending fingers 23, 24 and anvil 12 are moving radially towards their operative position an arm 43 extending downwardly from the front end of the slide 15 bears against the lower end 41<SP>1</SP> of an adjusting finger 41 pivoted on a stationary standard 46 at the opposite side of the work station and in alignment with the leading-in wire 5, so that the finger 41 is swung around against the tension of a spring 44 and bears against the end of the wire 5, which is thus bent slightly out of alignment with the longitudinal axis of the mount. This bending is such that the ensuing operations of the jaws 23, 24 can bend the ends of both leading-in wires inwardly towards one another without mutual interference and without kinking the cathode connected between them. Towards the end of the movement of the slide 15, and after the anvil 12 has passed between the leading-in wires 5. 6, a lug on the underside of a pivoted block 21 supporting the anvil 12 strikes against an adjustable stop-screw, causing the block 21 to tilt and position the under surface 47 of the anvil at the parts of the leading-in wires at which bending is to take place. The centre of the cathode 7 is thus bent upwardly into a cavity 59, Fig. 7, in the bottom of the anvil 12. Following the disengagement of the bending devices from the mount, the latter is indexed to the curling mechanism 4, Fig. 8, which comprises a spindle 60 journalled in the offset upper end of a slide 62 which is located within a vertical guideway and provided with an axial housing for a helical spring 66 and a sub-slide 63, the latter being connected to a vertical rod 69 controlled by a cam 64, Fig. 9 (not shown). The slide 62 is thus lifted until arrested by a lateral stop when aligned correctly with the mount, whereupon the sub-slide 63 continues to move against the pressure of the spring 66, and lifts a cam plate 81 which has a slot 84 engaging a roller 82 on the lower end of a lever 76. The upper end of lever 76 is bifurcated to receive a roller 77 near one end of a long mandrel pin 61 extending axially through the curling spindle 60, so that the free end of the pin is projected outwardly from the spindle and positioned transversely across the leading-in wire 6 midway of its length. A fixed pin 75, located eccentrically relative to the mandrel 61 and parallel with it in the end of the spindle 60, operates to engage the leading-in wire 6 when the spindle is rotated, thereby bending the leading-in wire around the mandrel and into the form shown in Fig. 4, a peripheral groove being provided in the pin 75 to receive the leading-in wire and prevent it moving along the pin. Rotation of the spindle 60 is effected by a pinion 79 on its inner end engaging a vertical rack bar 80 which is reciprocated by the sub-slide 63 during the compression of the spring 66 subsequent to the halting of the slide 62.