Patent GB-1487263-A (GB)
Title: Packaging apparatus
IPC: B65B51/30
Filed: 1975-01-23
Abstract: 1487263 Packaging apparatus MASTER PACKAGING EQUIPMENT Inc 23 Jan 1975 [23 Jan 1974] 3026/75 Heading B8C The invention relates to packaging apparatus comprising means for feeding forward units U to be wrapped and flexible packaging material F for wrapping the units, with the units spaced apart in the direction of feed, means 5 for effecting intermittent operation of the feeding means intermittently to feed forward the units and the packaging material, with a dwell interval between successive feed cycles, and means 7 for forming a seal across the width of the material between two successive units during each dwell interval. According to the invention the means 5 for operating the feeding means comprises a chain and sprocket drive including a crank 11, rotatable about a predetermined axis A1, means, 159, 13, Fig. 7, for rotating the crank in one direction about said axis A1, a first sprocket 15 secured to the crank 11 with the axis of the first sprocket offset from the crank axis A1 without rotation of said first sprocket about its own axis, a second sprocket 17, a chain 9 trained around the first and second sprockets, the first sprocket 15 acting to pull a reach 19a of the chain in a forward direction to effect rotation of the second sprocket 17 in a forward direction for driving the feed means during a portion of a revolution of said first sprocket 15 about the crank axis A1, and to discontinue forward drive of the chain 9 during another portion of said revolution for a feed and dwell of the feed means during each revolution of the crank 11, and means 21 for maintaining the chain 9 relatively taut around said sprockets 15, 17. As shown, the packaging apparatus comprises a main conveyer 1 which is driven intermittently by the means 5 for feeding forward, correctly spaced, the units U to be wrapped with flexible packaging material F, e.g. heat shrinkable plastics film, supplied by two webs F 1 , F 2  interconnected at 131. A motor 159, Fig. 7, continuously drives, via a sprocket drive 13 and a safety clutch 165, the sprocket 11 in the means 5 which, by means of the sprocket 17, imparts a corresponding intermittent operation to a take-out belt-conveyer 85, and to the main belt conveyer 1 via a chain drive 95. The crank 11 is connected, by a chain 169, to a second intermittent drive means 157 which is similar to the means 5 and which comprises a sprocket 175 connected to a second crank 171, a driven sprocket 179 and a spring-loaded tension sprocket 183. The shaft 181 of the sprocket 179 intermittently drives a pair of crank-shafts 145, Fig. 3, 180 degrees out of phase with each other, for one revolution during each dwell period of the conveyers 1, 85, to move upper and lower sealing bar assemblies 107, 109 towards and away from each other to form the seals S 1 , S 2  and sever the webs F 1 , F 2  as shown in Figs. 2A, 2B. Overtravel-linkages 156, 158 in the operating linkage for the upper sealing bar assembly 107 ensure a dwell time sufficient to form the seals S 1 , S 2 , and an upward movement of shield plates 125 relative to a bar 111 in the upper assembly 107 operates the safety clutch 165 and de-energizes the motor 159. The crank 171 continuously drives a sprocket cluster 207 on the shaft 181 by means of a chain connection 209, which is chain connected, at 81, to a sprocket 83 which continuously rotates a cam-shaft 77, a chain 57 connected between the sprocket 83 and a sprocket 27 continuously operating an infeed, belt conveyer 43. The cam-shaft 77 controls inwardly and outwardly-inclined positions of rocker abutments (59L, 59R and 61L, 61R), Figs. 4-6, not shown, so that the units U are fed, at the correct intervals, to the packaging material F 1 , F 2 , which is supplied from rolls R 1 , R 2 . The conveyer 85 passes the wrapped units U to rollers 97 which deliver the packaged units, e.g. to a shrink tunnel, not shown.