GB1280271A - Electrically controlled hand tool for friction-fusing non-metallic strap - Google Patents

Abstract

1280271 Seaming non-metallic sheet material SIGNODE CORP 19 Feb 1970 [20 Feb 1969] 8138/70 Heading B5K [Also in Division F2] A tool for friction welding the overlapping ends 28, 29, Fig. 4, of a strap L looped around an object, comprises a wheel 30 and an anvil 31 between which the ends 28, 29 can be gripped and means for rotating the wheel 30 selectively either intermittently in one direction to tension the strap about the object or with an oscillatory motion to friction weld the ends 28, 29. The anvil 31 is mounted at the lower end of a vertical plate 95, Fig. 4, having a pin 102, Figs. 4 and 6, rotatably journalled therein and which extends eccentrically through a shaft 98 urged anticlockwise of Fig. 6 by a torsion spring 99. An arm 103, Figs. 6 and 10, on the plate 95 engages a lever 126 to prevent oscillation of the wheel 30 until the anvil 31 has moved into engagement therewith. When a lever 114 is pivoted to the position of Fig. 4 to disengage a hook 113 from a detent 112 on a lever 110 fixed to the shaft 98 to bring the anvil 31 into strap compressing relation with the wheel. An electric motor M, Fig. 8, has a rotary output shaft 33 with a sleeve 37 mounted thereon. A block 42, Fig. 12, is slidably mounted on a pin 41 on the sleeve 37 and is also slidable on a pin 43. A rocker arm 50, Fig. 10, is connected to the pin 43 by parallel arms 51, 52 so that the arm 50 is oscillated about a shaft 55 of the wheel 30 as the sleeve 37 rotates. The wheel 30 is intermittently rotated in a strap tensioning direction by a one-way clutch means 75, Figs. 10 and 12, defined by-teeth 76 on the arm 50 and rollers 77 trapped between the teeth 76. A tension sensing finger 85, Fig. 4, of a lever 80, Fig. 8, is located above the strap end 29 and below the end 28. When a pre-selected tension is drawn in the loop L, the lever 80 is pivoted upwardly to pivot a release lever 120, Fig. 6, about a pin 121 against the action of a spring 122 to free a hook 124 on the lever 120 from a catch 125 on the lever 126. When the lever 126 pivots, a spring 144, Fig. 12, biased a toothed portion 142 of a pawl 140 into engagement with teeth 66 on a ratchet 64. When the pawl 140 is engaged with the ratchet 64, rotation of the wheel 30 in the tension drawing direction is prevented, and the ratchet and pawl mechanism co-operates with the clutch 75 to hold the shaft 55 against rotation so that, as the arm 50 oscillates, a high frequency, low amplitude oscillation is imparted to the wheel 30. This latter movement causes the end 28 to move relative to the end 29 whilst both ends are retained compressed and the facing portions of these ends become friction welded together. After welding, after the lever 110 has been pivoted to engage the lever 114 to establish a clearance between the wheel 30 and the anvil 31, the tool is slid rearwardly so that the upper end 28 is severed from the strap supply by a knife edge (161), Fig. 11 (not shown). In an alternative embodiment, Fig. 15, the strap end is severed from the supply in response to movement of a lever 314, corresponding to the lever 114, which has a surface 370 engageable with an abutment 317 on a pivoted cutter 372 to move a cutting edge 382 into engagement with a flat land area 383 on the anvil 231.