All gathering machines designed for uninterrupted operation have continuous feed and remove individual sections from the bottom of the respective piles, thereby making the top of the pile always accessible for the addition of sections.
Three different systems are used in gathering machines: the swinging gathering arm system, the rotary drum system, and the planetary system.
The swinging gathering arm system operates by pulling the section by suction along the fold edge from the pile, gripping it in jaws and dropping it onto the conveyer system. In the rotary drum system, the sections are removed by grippers built into the surface of the rotating drum. In the planetary system, the bottom of the pocket is a drum equipped with rotary vacuum suckers which roll the sections away from the bottom of the pile and transfers them to the grippers on a transfer cylinder, which, in turn deposits them on the conveyer system.
If a section is omitted, or if two sections from the pocket are deposited on one pile, mechanical devices, called calipers, stop the machine and indicate the pocket where the mistake occurred. The calipers are also capable of detecting an incomplete section.
The first gathering machine was introduced by Endicott D. Averell of the United States in 1875. This machine had feed problems which were eventually overcome by a machine developed by F. Wood in 1886. The period of greatest development of gathering machines was 1890 to 1903. (89 , 182 , 320 )
Timestamp: Saturday, 19-Nov-2011 13:18:41 PST
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