Patent GB-604019-A (GB)
Title: Improvements relating to windows
IPC: B60H1/26
Filed: 1945-11-21
Abstract: 604,019. Seaming sheet materials. SINGER MANUFACTURING CO. Nov. 20, 1945, No. 31273. Convention date, Feb. 7. [Class 42(i)] [Also in Group XI] An electrostatic bonding machine comprises a frame including a work-support, a shaft journalled in the frame, non-rotary electrodes carried by the frame and providing a bonding-zone, a high frequency electronic oscillator connected to the electrodes. means operated by the shaft for imparting relative movements to the electrodes to cause them intermittently to clamp the material, and for giving them feed and return movements to advance the material while the electrodes are in contact therewith, and a presser member for holding the material against the work-support on the return movement of the electrodes. The feeding movements may be greater or less than the length of the work-engaging faces of the electrodes. The machine has a work-supporting bed 10 and an overhanging arm 11 terminating in a hollow head 12. A main shaft 15, having a combined balance-wheel and driving pulley 16, is journalled in the arm 11, and carries an adjustable eccentric 23, controlled by an external nut. A pitman 24 connects the eccentric 23 to a pivot 25. Fig 3, on an arm 26 on a segment 27 carried by a rock-shaft 28 journalled beneath the bed 10. A slideblock 31 in a slideway formed in the segment 27 has pivoted to it a link 33. the other end of which is pivoted at 34 to an arm 35 clamped to a further rockshaft 37. The remote end of the latter is formed with two upstanding arms 40, Figs. 4 and 7, between which an electrode-carrying bar 42 is pivotally mounted on the pin 41, and thus receives workfeeding movement. The extent of such movement may be reduced during operation by a treadle connected by a chain 116 to a plate 117 pivoted at 32 to the link 33, which causes the slide-block 31 to approach the rock-shaft 28, against the action of a spring 118, until arrested by an adjustable stop 120. Up-and-down movement of the bar 42 is secured by forming it with arms 44 which embrace an eccentric 45, Fig. 4, on a shaft 19 which is driven from the main shaft 15 by a clipbelt 17<1> running over sprockets 17, 18. The lower electrode 46 is secured to a block of polystyrene 48 mounted on the arm 42 and protrudes through a slot in a plate 53 attached to the bed 10. An arm 58 is clamped to the rock-shaft 37 and carries an elongated pivot pin 59, to the free end of which is pivoted a link 60, which connects it with an arm 62 clamped on an upper rock-shaft 63. A cranked arm 65 on the remote end of the shaft 63 is in operative connection with a frame 67 and causes it to oscillate about its pivot 68. A vertical tubular bar 71, carrying a shank terminating in the upper electrode 73 is journalled for axial movement in the frame 67 at 70. A presser-bar 76 having a clamping foot 77 with a bifurcated toe which straddles the electrode 73, is journalled in bearings 74, 75 and is urged downwardly by a flat spring 78 pressing on a collar 79. A bell-crank 81, 82 is fulcrumed on a block 81 carried by the presser-bar 76, and is connected by a pivoted link 80 to the bar 71, and by a link 83 to an arm 84 depending from a rock-shaft 85. A further arm 87 on the latter is connected by a pitman 88 with an adjustable eccentric 90 secured to the main shaft 15. The presser foot 77 and upper electrode 73 are thus reciprocally urged towards the material, and the lift of the electrode above' the material remains constant, irrespective of the thickness of the latter. A knee control is provided, operating through links and levers to raise the presser foot. The machine is driven by an electric motor and power transmitter located beneath the bed 10 and controlled by a treadle. A high frequency electric oscillator, operating at 30 mc/s., and having its output controlled by a variable D.C. supply obtained by means of an adjustable transformer from an A.C. supply is also situated beneath the bed 10, and is connected to the apparatus by a co-axial cable 103, the outer conductor being connected to the frame. A fixed inductance 107 is connected across the ends of the cable to tune out the capacitance of the latter, and the inner conductor is connected through the inductance 109 and variable capacitor 110 to the lower electrode 46. A neon lamp 112, one terminal of which is connected to a point between the inductance 109 and the cable terminal 104, and the other terminal left free, is provided as a tuning indicator.