Sheet feeding or delivering – Delivering to stack and feeding therefrom – Sheets on edges
Patent
1997-10-22
1999-03-02
Skaggs, H. Grant
Sheet feeding or delivering
Delivering to stack and feeding therefrom
Sheets on edges
271 301, 414923, B65H 522
Patent
active
058760288
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
The invention relates to an apparatus for stacking flat letters.
In letter-processing systems, it is often necessary to store letters temporarily between two processing cycles. For example, for coupling asynchronously-working systems or parts, storage apparatus are used. One letter-storing technique involves temporarily stacking the letters.
Normally, a stacker comprises a stationary separating mechanism and a stacking mechanism that can move in the stacking direction, the letters being stacked therebetween. The base of the letter stack is formed by a stacking surface. Two endless belts that circulate around rollers form a transport path that conveys the individually-arriving letters to the end of the stack.
Between the stacking mechanism and the letter-loading loading station, the two belts form a straight section of the transport path on which the belts run freely, i.e., they are not guided by rollers in that section. The length of this partial section of the transport path is dependent on the momentary position of the stacker mechanism during the stacking process. As the letter stack grows, this partial section is shortened proportionally. It reaches its maximum length if there is no letter stack and the stacking mechanism is located directly at the separating mechanism.
Given a comparable engineering outlay, the storage capacity achievable with this design is, in fact, greater than that attainable with imbricated storage, where the letters are squeezed one on top of the other, in imbricated form, between belts. However, when working with the above-described type of apparatus, problems arise when the straight partial section of the transport path reaches its maximum length. In such a case, the situation may arise that a plurality of letters are located on the partial section at the same time. If this occurs in a manner such that a thin letter is situated between two thick letters on the straight section, the thin letter is not securely held by the belts. If a plurality of letters are situated between two thick letters, it can happen that the thin ones shift over on top of each other, causing a jam in the transport path and an interruption in the operation of the system. An additional problem is that the free-running belts hang increasingly lower as the length of the partial section in the transport path increases. Both problems may lead to a maximum stacker length of one meter for the type of stacker apparatus described above.
SUMMARY OF THE INVENTION
The object of the present invention is to provide a stacker apparatus with which larger storage capacities can be attained.
An embodiment of the invention entails securely holding the letters between the belts of the transport path by means of a curved transport path, and by providing multiple deflection of the belts around the rollers in the region of the transport path, ensuring free movement of the stacking mechanism because the belts are disposed between the stacking surface and the deflecting rollers in the region of the transport path. An apparatus according to this embodiment of the invention therefore has a stacking surface possessing a horizontal, concave curvature with respect to the side on which the transport path is located. The belts in the region of the transport path are deflected by a number of deflecting rollers that are arranged on a curve that has a curvature essentially the same as the stacking surface curvature so that the transport path has a curvature essentially the same as the curvature of the stacking surface, the belts being disposed between the stacking surface and the deflecting rollers in the region of the transport path.
In one preferred specific embodiment of the invention, the stacking surface is essentially annular. The stacking surface may comprise a number of segments or may be embodied as a rigid disk. In one particularly preferable embodiment of the invention, belt bridges are provided at the stacking mechanism and at the loading station, by means of which bridges the outer belt is guid
REFERENCES:
patent: 3682473 (1972-08-01), Kuyt
patent: 3690474 (1972-09-01), Kloppenecker
patent: 4299379 (1981-11-01), Preston et al.
patent: 4735407 (1988-04-01), Ozawa
Bretschneider Peter
Francke Jurgen
Siemens Aktiengesellschaft
Skaggs H. Grant
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