Patent GB-921792-A (GB)
Title: Web registration device for wrapping machines
IPC: B65B41/18
Filed: 1959-04-16
Abstract: 921,792. Feeding-webs. AMERICAN MACHINE & FOUNDRY CO. April 16, 1959 [April 22, 1958], No. 13036/59. Class 100 (1). [Also in Group XVII] A machine for wrapping articles with material from a continuous web having spaced indicia along its length has means for advancing the web and adapted to overfeed same and a web registering mechanism for automatically adjusting the position of the leading end of the web to a predetermined position in the machine, the mechanism including driving means for reversing the movement of the web and means adapted to coact with the indicia and operative to interrupt the reverse movement of the web when an indicium reaches a reference position in the machine, such coacting means including an electronic device for detecting printed indicia on the web. Wrapping material W is supplied to the machine from a roll R by a continuously driven feed roller 100, a loop being formed in the web by a roller 105. The web passes over guide plates 108, 112 and around guide roller 122 for engagement with an article L to be wrapped on a runway 38. The article L is pushed in the direction of the arrow L by a reciprocating pusher plate 48 actuated by a cam 72, lever 62, rod 64 and lever 58. As the article L is pushed on to a lifter table 10, a web is pressed against a displaceable plate 12 while a plate 14 wraps the web over the top of the article. The table 10, pivotally mounted on a shaft 16, is then raised by a cam 30, lever 24, and rod 20 towards a folder table F. Simultaneously, a roller 78 is moved downwardly by a cam 94 and lever 88, thus drawing more web forwards from the roll R and overfeeding the web by an amount d. When the article L reaches a position level with the table F, a knife 214, actuated through rod 216 and arm 218 by a cam 219, severs the web W. Segmental portions 147, 149, Fig. 2 (not shown), of a pair of feed rollers such as 147, Fig. 1, are brought into web feeding engagement with a roller 136. The feed rollers, such as 147, are driven in the reverse direction to normal web feed by a shaft 150 driven by a chain 258 so as to make one revolution per wrapping cycle, the shaft 150 being so timed that the segmental roller portions are only in feeding engagement with the roller 136 at the appropriate time. The feed rollers are slidably keyed to the shaft 150 to permit their adjustment, by a screwed shaft 162, to suit different widths of web. During reverse web travels the web is formed into a loop P by a deflector 167, Fig. 7, since brake shoes 128 prevent retrograde movement of the web. Reverse movement of the web by the segmental rollers is arrested by their engaging apertures 220, Fig. 8 (not shown), in the web W. Thus, the web is brought into registered position with respect to the next article to be wrapped. Alternatively, if the web is provided with printed indicia 222, Fig. 9 (not shown), a photo-electric detector 224, Fig. 7, detects the reduction in intensity of reflected light from the web due to the presence of the indicia to register the web. The photo-electric detector 224 is connected to an amplifier, not shown, by a camcontrolled switch 248, the amplifier being connected to a solenoid 234 which actuates a clamp arm 258, Fig. 1, carrying a clamp 260 which, upon energization of the solenoid, engages the web to prevent further reverse movement. The clamp 260 is raised upon de-energization of the solenoid. The clamp 260 is also operated prior to severing the web by a rod 264 connected to the rod 216 by a link 262 to hold stationary the web during severing. Specification 728,174 and U.S.A. Specification 2,385,706 are referred to.