In recent years, many varied customer needs require rapid handling of printed products consisting of signatures which are gathered for binding, trimmed, bundled for minimal shipping costs, and shipped. In a binding line, a typical operation utilizes a multiple of inserter pockets, each of which receives signatures serially from a signature supply means, opens each signature, and drops the signatures to successively straddle a gathering chain which runs in front of the inserter pockets and carries the complete collection of gathered signatures to a location for further handling to complete the binding process. Moreover, because of the need for highly efficient plant operations, there has been a constant effort to increase the speed at which machines operate which has required the development of new techniques for handling the signatures at all stages of the binding process.
In addition to high speed operation, it will be appreciated that any apparatus necessarily has to be compatible with the limit on the space that is available in a binding line facility. In development of the present invention, it was established as a goal for the signature feeding apparatus to address the concerns in terms of ergonomic problems, such as carpal tunnel syndrome and the like.
Currently, a bindery operator retrieves a small stack of signatures, such as three to four inch pile, and carries the pile to the table surface at the pocket feeder. The signature pile is compressed and gripped between the fingers and thumb, and then it is turned 90.degree. for placement on the signature backbone. The operator aligns the signatures in the small pile, fans them, and jogs them, creating a uniform series of signatures. The signatures are again compressed between the fingers and thumb and are then placed with their backbones down into the bindery feed pocket. Some strains to the operator that may occur in such loading activities include possible wrist strain when rotating the signatures, possible arm strain when lifting the pile of signatures to the table height, possible finger and thumb strain when gripping and compressing the signatures, possible wrist and arm strain when fanning the signatures, and walking fatigue in moving between a pallet having the signatures and the bindery pocket machine.
The assignee of this invention has been addressing the problems caused by repetitive motion in current bindery and printing tasks performed manually by operators, as can be seen from a review of its U.S. Pat. No. 5,114,129 of Chang, et al. and also U.S. Pat. No. 5,451,040 of Crabtree, and U.S. Pat. No. 5,791,643 of Bumgardner, et al. It was established in the previous patents as a goal for the signature feeding apparatus to primarily address concerns in terms of ergonomic problems, such as carpal tunnel syndrome and the like; but it was also found in solving this problem, that it was possible to increase the capacity receiving stacked signatures for feeding to the binding line within the same or a similar amount of floor space, while operating at high speed and accepting signatures in a variety of ways. The present invention is aimed mainly at the ergonomic aspects, increasing production efficiency. Also, it is preferable that the device be portable to be moved between different bindery hoppers. Alignment, jogging and aerating by bindery personnel all need to be eliminated in order to prevent the strains caused by the repetitive motions that these tasks require. The present invention addresses the needs of being able to feed signatures at high speeds to graphic arts equipment including folders, trimmers, binding lines, etc., while maintaining an ergonomically safe process and providing portability.
The present invention is described herein in connection with feeding financial stock or signatures which have frictional surfaces that renders them difficult to shingle into a consistent stream in a contrast to the usual catalogue or magazine stock that shingles easily into a consistent stream. Hence, the financial stock signatures described herein are printed as closed head signatures that are fed as an entire "log" of signatures. The present invention will be described hereinafter with respect to the formation of logs of financial signatures and feeding them into a pocket of a bindery line pocket feeder; but the present invention is not limited to this described and illustrated embodiment of the invention.