Material or article handling – Apparatus for moving intersupporting articles into – within,... – Stack forming apparatus
Reexamination Certificate
2001-12-20
2002-11-19
Ellis, Christopher P. (Department: 3652)
Material or article handling
Apparatus for moving intersupporting articles into, within,...
Stack forming apparatus
C414S789500, C414S789900, C271S211000
Reexamination Certificate
active
06481952
ABSTRACT:
BACKGROUND OF THE INVENTION
“This application is a continuation division of international application number PCT/EP00/04689, filed May 23, 2000 (status, abandoned, pending, etc.).”
The present invention relates to improvements in methods of and in apparatus for manipulating sheets of paper, cardboard, metallic foil, plastic material or the like. More particularly, the invention relates to improvements in methods of and in apparatus for accumulating successive stacks of superimposed sheets on discrete supports in the form of platforms such as pallets or the like. Still more particularly, the invention relates to improvements in methods of and in apparatus for introducing empty supports (hereinafter called platforms or pallets) into and for withdrawing or otherwise removing filled pallets from a stacking station wherein a continuously advancing layer or stream of sheets is converted into a succession of stacks or piles reach containing a preselected number of superimposed sheets and each supported by a discrete pallet.
It is already known to introduce into a stacking station successive empty pallets at intervals which are required to gather on each empty pallet a stack or pile of superimposed sheets or to place onto each introduced empty pallet a fully grown stack of superimposed sheets. Empty pallets must be introduced at a rate and in a manner to ensure that they cannot interfere with movements of preceding pallets at, and with evacuation of preceding (loaded) pallets from, the stacking station.
Successive sheets of a stream or flow of sheets are normally obtained by repeatedly severing a running strip or web of paper, foil or the like and by feeding successive sheets from the severing station to a stacking station. The apparatus at the stacking station is arranged to convert the stream into a succession of discrete stacks each of which contains a predetermined number of superimposed sheets and each of which is supported by a discrete pallet. Filled or loaded pallets must be withdrawn from the stacking station in a manner and at a rate to permit for the introduction of empty pallets in good time to ensure that each introduced empty pallet can receive a growing stack or a fully grown stack following the finished stack on the loaded pallet. Problems which arise in conventional aparatus are attributable, either primarily or exclusively or to a certain extent, to the fact that the stacking apparatus receives or should receive or can receive a continuous (uninterrupted) flow or stream of discrete sheets which are or which can be partly superimposed upon each other. The formations of sheets in a series or flow of partially overlapping sheets are known as imbricated patterns.
German patent application Serial No. 36 16 470 A1 (filed by Martini et al. on May 15, 1986 and published Jun. 26, 1987) discloses a method of and an apparatus for accumulating successive piles of superimposed sheets at a stacking station. The apparatus is intended to ensure a reasonably problem-free evacuation of filled pallets from and a reasonably problem-free introduction of empty pallets to the stacking station. Successive sheets of the imbricated stream of partly overlapping sheets are fed into the stacking station by an endless belt conveyor and are gathered on a descending first pallet in such a way that each preceding sheet is fully overlapped by the next-following sheet. A separating finger is thereupon introduced into the stacking station to overlie the topmost sheet of the completed stack and to be overlapped by the first (lowermost) sheet of the next-following (growing) stack. The inserted finger descends at a speed less than that of the pallet and of the fully grown stack on the pallet to thus cause the formation of a clearance between the topmost sheet of the finished stack and the lowermost sheet of the growing stack. The clearance receives a first clamping jaw and the finger is thereupon withdrawn and lifted to a level above the topmost sheet of the next fully grown stack. The just described sequence of steps is thereupon repeated, i.e., the finger is introduced into the pile of superimposed sheets at a level such that it is located above the number of sheets piled up above the first clamping jaw and required to form a second fully grown stack above the stack below the inserted first clamping jaw (i.e., above the stack on the pallet). The thus inserted separating finger is again caused to descend at a speed less than that of the descending fully grown stack on the pallet. The thus obtained fresh (second) clearance receives a second clamping finger. The second fully grown stack (namely the stack between the two clamping jaws) is thereupon clamped by such jaws in that one of the jaws is moved toward the other jaw.
In a next-following step, the lower clearance is enlarged in that the pallet and the fully assembled stack thereon are lowered so that the lower clearance can receive a table which intercepts the clamping jaw and the (second) stack between the two clamping jaws. This renders it possible to evacuate the pallet and the fully grown stack thereon from the stacking station and to introduce an empty pallet which receives and supports the second fully grown stack, This involves the withdrawal of the table and a lowering of the clamped stack so that the first clamp is immediately adjacent the introduced empty pallet. The second clamp is lifted slighty above and further away from the first clamp to thus release the fully grown second stack. A lowering of the first clamp is not possible because this clamp is immediately adjacent the freshly introduced second pallet. The first clamp is thereupon withdrawn so that the second stack can descend onto the second pallet, the second clamp is withdrawn in a next-following step and the aforedescribed sequence of steps is thereupon repeated in connection with the second pallet, the second stack and a third stack which is being or which has been gathered above the second stack.
A drawback of the just described conventional method and apparatus is that the number of steps to be carried out in connection with the gathering and removal of successive stacks is rather high as well as that the apparatus is bulky and its manipulation must be effected by resorting to a complex control system. Furthermore, the frequency at which filled pallets can be withdrawn from, and empty pallets can be introduced into, the stacking station has a relatively low upper limit.
OBJECTS OF THE INVENTION
An object of the invention is to provide a novel and improved method of gathering successive stacks or piles of superimposed sheets at a stacking station and of manipulating the supports (such as platforms or pallets) for the stacks in a manner which is simpler than but at least as reliable as heretofore known undertakings.
Another object of the present invention is to provide a method which can dispense with the step of clamping successively gathered fully grown stacks of sheets between pairs of clamping jaws or the like.
A further object of the invention is to provide a method which can dispense with the step or steps of lifting any parts which are inserted into the accumulation of superimposed sheets at the stacking station.
An additional object of the present invention is to provide a novel and improved apparatus for the practice of the above outlined method.
Still another object of the invention is to provide an apparatus which need not employ clamping jaws for fully grown stacks of sheets at the stacking or gathering station.
A further object of the invention is to provide an apparatus which is simpler, more compact and less expensive than heretofore known apparatus for palletizing stacks of paper sheets or the like.
Another object of the invention is to provide novel and improved means for establishing and varying the dimensions of clearances in the accumulation of superimposed sheets at the stacking station.
An additional object of the invention is to provide novel and improved distancing means for use between the piles of sheets at the stacking station of the above outlined app
Deutschle Robert
Rilitz Norbert
E.C.H. Will GmbH
Ellis Christopher P.
Kinberg Robert
Kwon Michael J.
Venable
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