GB678776A - A method of manufacturing reinforcing bars having depressed portions and a machine for manufacturing such bars - Google Patents

Abstract

678,776. Making reinforcing bars. GILLBERG, J. Oct. 30, 1950 [Nov. 4, 1949], No. 26419/50. Classes 83 (ii) and 83 (iv). Rolling; shearing.-In a method of making reinforcing bars for concrete, an iron rod is coldworked to form depressions arranged in staggered fashion on opposite sides of the bar, a length of iron rod being unwound from a reel, passed between a pair of rolls having projections for forming the depressions and a cutting device for cutting the rolled rod to the required length. A bar 1 is formed with depressions which may be disposed as in Fig. 1 and may have the effect of corrugating the bar as shown in Fig. 4. Iron rod is unwound from a coil, formed with the depressions by means of toothed rolls 34, 35 mounted on intergeared shafts 59, 60 and then straightened by being passed over an adjustable support 37 and through a tapering tunnel 38 on its way to a cutting device. Several pairs of forming rolls are mounted in a block 33 which can be moved along guides 50, 51 by means of a hand wheel so as to bring different pairs into operative position according to the form of the depressions required in the bars. A motor 45 drives the rolls through a clutch 47, gear-box 46 and gears 62, 63 and also drives the cutting device through a clutch 49, gear-box 48 and shaft 73 on which is mounted an eccentric coupled to a reciprocating slide 40 carrying a moving blade 41 which co-operates with a fixed blade 42. Projecting from the machine frame beyond the cutters is a bar-supporting channel 192 with a hinged bottom 193 within which is a longitudinally-movable runner 85 with a transverse abutment 86 for the end of the bar. A chain 90 secured to the runner passes through a guide 91 and around a sprocket 92, Figs. 12 and 19, which is adjustable by a hand-wheel 95 to determine the position of the abutment and consequent lengths of the severed bars, which length is indicated on a device 108. When the end of the rod being fed through the machine by the rolls 34, 35 contacts the abutment, the resulting rotational movement of the sprocket 92 is utilized to disengage the clutch 47 and engage the clutch 49 to operate the cutting device. When the bar has been cut, a crankarm 84 on the shaft 73 operates through a telescopic arm 82 to rotate the pivot 80 of the bottom 193 of the channel and so release the cut-off bar. The shaft 96 of the sprocket 92 carries a gear 98 which is normally engaged with a tooth 100 projecting from the lower end of a pivoted lever 99 which carries at its upper end a cross-bar 142. From the clutches 47 and 49 respectively extend arms 112 and 114 connected to horizontal rails 110 and 111 carrying plates 125 and 126 formed with notches adapted to be engaged by pins 129 and 130 on arms 131 and 132. Arm 131 is mounted for rotation with a shaft 133 on which the arm 132 is rotatably mounted. The lower ends of the arms may be brought together to grip the cross-bar 142 and may be interlocked in this position by a pin 134 so that a movement of the lever 99 serves to actuate the clutches. By pressing a knob 138 to disengage the pin 134, the clutches may be manually operated by a hand wheel 148 on the shaft 149. Braking clutches 160 and 161 are provided to stop the rolls and cutting mechanism immediately on the disengagement of the clutches 47 and 49. When a length of rod has been severed, the clutch 49 is disengaged by means of a projection 120 on a gear 74 acting through a rod 121, while a projection 162 co-operating with a rod 163 prevents the engagement of the clutch 47 if the movable cutter is in the path of the bar.