Method and apparatus for opening signatures

Claim 3

A method as defined in claim 1, wherein said one edge of said sheets is the trailing edge of said sheets during travel along said path and wherein the sheets advance in a substantially horizontal plane during travel toward said position spaced from said path where said sheets are deposited.

Claim 4

A method as defined in claim 2, wherein said raising and pivoting step comprises engaging and holding the sheets by suction.

Claim 5

Apparatus for opening a plurality of sheets connected at one edge thereof to each other, said sheets being superimposed on each other and comprise at least one signature having a pair of center sheets and a pair of outer sheets respectively connected to each other at an edge thereof extending in a direction substantially transversely to the direction of said one edge, said apparatus comprising conveyor means for conveying said sheets along a path extending in a direction transverse to said one edge; a plurality of raising stations spaced from each other along said path and including a last station, each of said raIsing stations comprising raising means operative to raise the uppermost sheet of the sheets as they pass the respective station and pivoting said sheet about said one edge; at least one control means located adjacent to said path and intermediate two raising stations for detecting whether the sheet raised between said two raising stations is an outer signature sheet, said detecting means cooperating with said raising means for releasing the raised sheet if it is an outer signature sheet or maintaining the raised sheet in raised position while said sheets advance along said path if said sheet is not an outer signature sheet; and support means spaced from said path following said last raising station adapted to receive said sheets in open condition.

Claim 6

Apparatus for opening a plurality of sheets connected at one edge thereof to each other, said sheets being superimposed on each other and comprise at least one signature having a pair of center sheets and a pair of outer sheets respectively connected to each other at an edge thereof extending in a direction substantially transversely to the direction of said one edge, said apparatus comprising conveyor means for conveying said sheets along a path extending in a direction transverse to said one edge; a plurality of raising stations spaced from each other along said path and including a last station, each of said raIsing stations comprising raising means operative to raise the uppermost sheet of the sheets as they pass the respective station and pivoting said sheet about said one edge; at least one control means located adjacent to said path and intermediate two raising stations for detecting whether the sheet raised between said two raising stations is an outer signature sheet, said detecting means cooperating with said raising means for releasing the raised sheet if it is an outer signature sheet or maintaining the raised sheet in raised position while said sheets advance along said path if said sheet is not an outer signature sheet; and support means spaced from said path following said last raising station adapted to receive said sheets in open condition.

Claim 7

Apparatus as defined in claim 4, wherein said conveyor means includes an endless conveyor and said path includes a substantially horizontal first portion along which the signatures are transported past said raising means and an arcuate second portion located between said horizontal portion and said support means, said support means being located at a level below said first portion.

Claim 8

Apparatus as defined in claim 5, wherein said conveyor comprises entraining means for said sheets and gripper means for separably coupling the common edges of said sheets to the respective entraining means during travel along said first and second portions of said path.

Claim 9

Apparatus as defined in claim 6, wherein said conveyor further comprises second gripper means for separably coupling the other center sheets of said signatures to the respective entraining means upon opening of said signatures and prior to transfer of such signatures to said support means.

Claim 10

Apparatus as defined in claim 4, wherein said raising means comprises at least one device for raising the sheets of successive sheets by suction.

Claim 11

Apparatus as defined in claim 8, wherein said device is oscillatable about a substantially horizontal axis extending transversely of the direction of travel of said sheets past said raising means.

Claim 12

Apparatus as defined in claim 4, wherein each of said raising means comprises at least one suction head and said control means comprises photosensitive detector means.

Claim 13

Apparatus as defined in claim 10, wherein said photosensitive detector means is arranged to deactivate all but a single one of said control means in response to detection of successive signatures, said control means forming a series along said conveyor means and said single control means being the last of said series as considered in the direction of travel of said sheets.

Claim 14

Apparatus as defined in claim 4, wherein said path includes a first portion adjacent to said raising means and an arcuate second portion between said first portion and said support means, and further comprising retaining means for holding said sheets in open positions during travel along said second portion of said path.

Claim 15

Apparatus as defined in claim 12, wherein said retaining means comprises an arcuate shroud and wherein said support means is closely adjacent to and located below said second portion of said path.

Claim 16

Apparatus as defined in claim 4, wherein said conveyor means comprises at least one endless flexible element and includes an end turn disposed at a level between said raising means and said support means.