Patent GB-419581-A (GB)
Title: Machine for welding nails to metal strips or the like
IPC: B23K11/00
Filed: 1934-03-22
Abstract: 419,581. Welding nails. DEHN, F. B., 103, Kingsway, London.-(Randall Co. ; 5000, Spring Grove Avenue, Cincinnati, Ohio, U.S.A.) March 22, 1934, No. 9043. [Classes 83 (ii) and 83 (iv).] In a machine for welding nails to metal sheets, moulding or other strips, the strip &c. is fed into a position to receive the heads of the nails from a nail feed, individual nails are separated from the nail feed and received in a member which brings the head thereof into contact with the strip and welds it thereto. The nails are fed from a tumbler 71 which is driven by a belt 75 from a shaft 15 rotated by a belt 17 from an electric motor 11. The nails move down an inclined shoot comprising a pair of spaced strips 79 under a cover strip 80 until they are received between the jaws of a pair of spring closed pivoted fingers 82, with the foremost nail engaging an abutment 96 on a superposed strip 93. The shoot is engaged by a flexible strip 85 which is vibrated by a ratchet wheel 86 driven by a belt 89 from the shaft 15 so as to prevent the nails from jamming. The foremost nail is then separated from the rest by a hooked lever 97 and brought under the abutment 96 and the shank pressed thereby into one of a number of hollow holders or electrodes 69 on an intermittently rotated disc 68 carried by a vertically reciprocating slide 23. The abutment 96 projects through a slot in the strip 80. The lever 97 is drawn inwards by a spring and is pressed out by a cam 100 on the face of the slide. The disc is intermittently rotated by a shaft 18 which is driven by chain or belt gear from the shaft 15 and carries a partially toothed gear 67 connected by a gear 65, bevel gear 40, 39, 35, 34, universally jointed flexible shaft 28 and spur gear 63 to the disc shaft 26. The slide is reciprocated by lever 41, link 53, and lever 51 on a shaft 52, which is oscillated by a cam 63 on the shaft 18 engaging an arm 61. The stroke is varied by a screw adjustment 56. The lever 41 is connected to the slide through a spring 48 on a pivoted rod 45 so as to obtain a yielding pressure. During the down stroke of the slide the disc is rotated to bring the heads of the nails in turn into contact with the strip 7 to which they are to be welded. The nails are prevented from dropping out by a spring controlled curved strip 103. Welding is effected by connecting the slide to one terminal of a transformer secondary, the other terminal being connected to a member 114 secured by a resilient member 111 to a copper block 161. The member 114 has a pair of contact arms 117, 118 which overhang the upper surface of the strip and is connected by spring-pressed rods 108 to the forward end of the lever 51 which is pressed down during the down stroke of the slide. Secured to the block 161 is a member 116 on which is adjustably mounted a block 164 having studs 165 engaging the under side of the strip opposite the arms 117, 118. The block also carries a recessed centre pad 166. The strip is first fed in by hand until it passes over the pad, whereupon the first nail is welded thereto, the recess preventing marking or burning of the outer surface of the strip. Then the strip feed comes into operation ; this consists of a hookended slide 130 which engages the previously welded nail. This slide is reciprocated in a guide 131 by a bell-crank 126, ball jointed at 125 to a link 124, which is connected to a camoperated lever 119. In order to obtain a uniform feed, a bifurcated member 140 comes into operation after five nails have been welded. This member is transversely reciprocated in guides by a link 139, bell-crank 136 and link 135 on the arm 61. The motor is controlled by a switch 143. The pulley 16 is connected to its shaft by a clutch 147 controlled by a solenoid 145 energized by a circuit containing a spring- opened switch 144 which is closed during operation by a pedal 148. The welding circuit contains a switch 149 which is opened and closed by a cam 153 on the shaft 52 through a spring-pressed arm 150.