Patent ES-346004-A1 (ES)
Title: Bundle tying equipment
IPC: B65B27/08
Filed: 1967-10-11
Abstract: A bundle tying machine comprises a feeding section 21 along which a stack or bundle of folded box blanks is fed and a tying section 22 at which the stack is compressed and tied with loops of string. The feeding section 21 consists of a rectangular frame having legs 23 movable transversely on tracks 25 and longitudinal U-shaped channel members 36, 37 mounting transverse conveyer rollers 41 driven by an endless drive belt 43. The belt 43 is driven from motor 64 through a variable pitch diameter pulley so that the speed of rollers 41 can be varied. A pusher plate assembly 71 is mounted on a beam 35 above the conveyer rollers, can be set in any desired position dependent on the width of the stack of boxes, and consists of a carriage 75 slidable on rods 74 and having a depending pivotally mounted pusher plate 81. The latter has a curved cam arm engaging a pin 85 carried by a piston-rod 86 of an air cylinder 87 such that operation of the latter will raise the plate 81 to and lower it from the broken line position. The carriage 75 may be located at any desired position along rod 74 by means of a reversible motor driving chain 94 attached to the carriage. Suitable deflectors 111 are provided above the rollers adjacent the outlet end of the feeding section to guide the stack of boxes to the tying section. As illustrated, the tying section has two tying machines 150, 1501 to provide two spaced tied cords around the stack B and each consists of a base 151, a table 152 (with an extension 1521) on which the bundles are positioned during tying, and a housing 153 for drive mechanism operating the tying means. The base 151 has rollers 154 running in tracks 155 to permit alignment of table 152 with the outlet end of the feeding section 22 and rising from the base is a column 156 (Fig. 4), having slidably mounted thereon a sleeve 157 which in turn carries arm 159 on which is mounted a vertically directed actuator 161 for operating a clamp plate 163 to press against the stack of boxes to be tied. The bundles are tied with string 201 from source 202, the string passing through an eye 2051 of a needle 205 to be fed around stack B through an opening in table 152 by conventional mechanism to known clutching and tying mechanism. In operation stacks B of folded boxes are moved at spaced intervals into the inlet end 44 of feeding section 21 on to rollers 41. At this time pusher plate 81 is in its raised position so that the advancing bundle passes beneath it. The leading edge of the blanks engage a microswitch 117 and thereby operates the pusher plate mechanism to pivot plate 81 to its vertical position. At substantially the same time carriage 75 is moved to the left, thereby feeding the bundle B into the tying section 22. Consequently the leading edge L of the bundle will be forced against the span S (Fig. 3) of string 201 and as the bundle is moved forward the string will extend around the bundle over the top thereof. When the bundle is in position for tying a control arm on carriage 75 operates limit switch 114 which actuates means to raise pusher plate 81 and move carriage 75 to the right. Switch 114 also energizes means to move plate 163 downwards so as to compress the bundle of boxes ready for tying. Movement of carriage 75 to the right actuates control switch 211 for energizing motors 182 to start the tying cycle. Needle 205 is moved through an arcuate path so that the free end moves the string 201 to a knot-tying head beneath table 152. The tying head 215 (Fig. 10) incudes an upper stationary jaw 216 and a co-operating lower movable jaw 217 to form a bill which can rotate through 360 degrees while tilting backward and forward to form a knot in known manner. After the knot is formed a pair of stripper fingers 221 (Fig. 15) act on the knot to force it from the bill of the tying head leaving a loop (d) of string (Fig. 16, not shown) clamped between the jaws 216, 217 and held by an inclined shoulder (222) on the underside of the upper jaw. The knot is tightened by further movement of the stripping fingers and rearward movement of the tying head and as the head continues to move rearward, the loop of string forces the jaws open against spring means and is thus released. The ends of string are then severed by being brought into contact with a stationary knife (236, Fig. 17, not shown) which may be heated. After release of the loop from the tying head an air jet (251, Figs. 18-20, not shown) is operated to deflect the loop out of the path of movement of the tying head back to its starting position. After formation of the knot, needles 205 are restored to their starting position, providing a span S for the next operation and the pressure plates 163 are moved away from the tied bundle. The next bundle to be tied is then pushed into position displacing the previously tied bundle.