Patent GB-524127-A (GB)
Title: Improved process and apparatus for making base assemblies for sealed glass envelopes
IPC: H01J9/32
Filed: 1939-01-23
Abstract: 524,127. Sealing leading-in wires. CORNING GLASS WORKS. Jan. 23, 1939, No. 2298. Convention date, Feb. 28, 1938. [Class 36] A process of making base assemblies for sealed glass envelopes of electron discharge tubes, electric lamps and the like, comprises passing a plurality of leading-in wires through apertures in a preformed glass press-member, heating the press-member to a plastic condition, sealing an exhaust tube to glass surrounding an aperture in the press-member, and pressing the plastic glass surrounding the leading-in wires into intimate contact therewith. The leading-in wires are carried in grooves 49<1> between an outer sleeve 19 and flexible fingers 49 formed by slotting an inner sleeve 19<1>, both sleeves being mounted in a hollow shaft 18. Co-operating cam surfaces 35, 36 on the sleeves force the fingers 49 inwards to free the wires when the sleeve 191 is moved downwardly with respect to the sleeve 19 : such movement is limited by stops 37 and axial movement between the shaft 18 and sleeve 19 is also limited by a flange 20 ; a pin 43 prevents radial displacement. The lower ends of the sleeves 19, 19<1> are threaded into collars 56 56<1> connected to pedals 69, 69<1>. The shaft 18 is connected by gears 26, 28 to a driving shaft 17 on which is mounted an arm 31, engagement of which with a guide 65 ensures a coaxial relation of the support 30 on the shaft 18 and a spacing element 34 carried by the arm. Within the sleeve 19<1> is a knock-out shaft 41 carried in a collar 44 on a lever 45, having an operating handle 46. Within the shaft 41 is a shaft 47 carrying a pin 47<1> and connected to an operating lever 50. A burner 51 is mounted on a support 52 pivoted to a post 21 and is moved by means of a handle 96. A gear case 53, mounted on a sleeve 55 for lengthwise movement on and rotation about the shaft 17, is linked to a pedal 60 ; a tooth 62 on the case 53 co-acts with a guide 63 to ensure coaxial relation of the support 30 and housing 64 ; the sleeve 67 carries a pressing unit holder 70 having an insert 75 and tube collar 76 ; the insert 75 and bell 72 are heated' by a burner 78; the gear 80 coacts with a gear 81 on the sleeve 55. A motor 83 is connected to the shaft 17 through a clutch 86 and worm gear 84, 85, the clutch being operated by a pedal 88. In a modification, the sleeves 19, 19<1> are replaced by a single sleeve bored to receive the leading-in wires. Several units may be mounted on a turret with automatic feed and cam track operating rollers on the various levers in place of the pedals and handles. In operation of the machine, leading-in wires are inserted in apertures 29 in the support 30 and are held in the grooves 49<1> : the arm 31 is swung over and depressed to even up the tops of the wires. A preformed press-member 90, preferably preheated, is placed on the wires and the pedal 88 depressed to rotate the assembly. The press-member is rendered plastic by heat and the pedal 69 depressed causing the sleeves 19, 19<1> to be depressed in unison, drawing the plastic glass around the wires down to the inner surface of the press-member. Heating is continued and the lever 50 lifted, forcing the pin 47<1> through the central aperture of the pressmember : the gear case is rotated until the tooth 62 engages the bar 63 and the pedal 60 or handle 66 is then depressed to bring the exhaust tube 77 over the pin 47<1> ; heating is discontinued and the final pressing effected by further depression of the pedal 60. The latter is then released and the pedal 69<1> depressed, forcing the fingers 49 inwards to release the wires : the knock-out lever is then operated to raise the assembly clear of the box 30, the gear case rotated and the assembly removed. When the modification, referred to above, is employed, the press-member is held off the support 30 by slight elevation of the knock-out sleeve.