Sheet feeding or delivering – Feeding – By means to convey sheet
Reexamination Certificate
2002-05-07
2004-05-04
Crawford, Gene O (Department: 3651)
Sheet feeding or delivering
Feeding
By means to convey sheet
C271S274000, C198S604000, C198S621100
Reexamination Certificate
active
06729617
ABSTRACT:
The invention relates to a device for conveying flat objects in which said flat objects are moved along in series and edge-on in a conveying direction, while at the same time being separated each from the next by a spacing which is normally constant. The invention applies more particularly to a device for conveying flat objects for a postal sorting machine operating in synchronous mode.
In this type of machine, it is necessary that the conveying of flat objects in an upstream part of the machine, for example corresponding to the exit of a destacker of flat objects, be synchronized with the conveying thereof in a downstream part of this machine which, for example, might correspond to the entry to a bucket conveyor. The flat objects are generally conveyed in series and edge-on at constant speed by conveyor belts between the destacker and the bucket conveyor, and the spacing separating two consecutive objects needs to be large enough that a flat object can be transferred into a bucket in the period of time that separates the arrival of two flat objects entering the bucket conveyor.
Users of this type of sorting machine want to be able to process an ever broadening range of flat objects, that is to say flat objects the height, width and thickness dimensions of which vary greatly. The variations in thickness of the flat objects are, in particular, the source of offsets between consecutive objects as they are conveyed between the upstream part and the downstream part of the machine. If the sorting machine is operated in synchronous mode, these offsets are not tolerable and the objects which are offset from the reference time frame have to be rejected from the belt conveyor before they reach the bucket conveyor. The rejection of flat objects affects the sorting rate of the machine and one object of the invention is to overcome this drawback*.
<U.S. Pat. No. 4,077,620 discloses a synchronization system capable of compensation variations in spacing between objects. But this system operates only in a destacker and not at any position on a belt conveyor.>
To this end, the subject of the invention is a device for conveying flat objects in series and edge-on, in which the said flat objects are moved in a conveying direction, while at the same time being separated each from the next by a spacing which is normally constant, which device further comprises a synchronization system capable of compensating for any variations in spacing between two consecutive objects charaterized in that this system comprises two parallel rows of driven wheels made of elastically deformable elastomer and between which each object is gripped and moved in said conveying direction, each wheel having a rotation spindle, the position of which is fixed, and the wheels being rotated by a motorization system which is controlled to accelerate and/or retard the movement of each object between the two rows of wheels on the basis of a detection as to whether the front edge of the object has been early or late in passing a determined position upstream of the two rows of wheels, compared with a time reference which indicates the spacing between objects.
This synchronization system may in particular be arranged in the continuation of the exit of a destacker of a postal sorting machine to accelerate movement of the flat objects toward the bucket conveyor while at the same time keeping the spacing separating two consecutive objects constant. In this case, if the destacker of flat objects comprises a destacking plate on which the first object of the stack of objects that are to be sent out in sequence rest before being ejected at the exit of the destacker, this plate is preferably arranged in a vertical plane parallel to the two rows of wheels and offset from said direction of conveying between the two rows of wheels by a distance which essentially corresponds to half the maximum thickness of an object. With this construction, the thickest and therefore the most rigid, flat objects are not diverted as they enter between the two rows of wheels, thus simplifying the control of their position in the conveying direction.
The setup whereby the synchronization system comprises elastomer wheels is a mechanically very simple construction and furthermore allows the conveying of relatively thick flat objects, for example flat objects about 32 mm thick, using wheels of a diameter of 150 mm. In one particular embodiment of the conveying device according to the invention, each wheel comprises a hub and an annular tread strip connected to the hub by elastically deformable circular arc-shaped fins, the two ends of each fin which are for connecting to the hub and to the annular tread strip of the wheel being located on a radius of the wheel. The particular circular arc-shaped profile of the fins with points of attachment located on the radius of the wheel, allows the elastomer to work over the entire length of the fins when the wheel is compressed, without creating any stress concentration zones, thus extending the life of the wheels and therefore increasing the availability of the synchronization system.
REFERENCES:
patent: 4077620 (1978-03-01), Frank et al.
patent: 4451027 (1984-05-01), Alper
patent: 6170816 (2001-01-01), Gillmann et al.
patent: 6270070 (2001-08-01), Salomon et al.
patent: 6354583 (2002-03-01), Skadow et al.
patent: 6378859 (2002-04-01), Lubben et al.
patent: 6499733 (2002-12-01), Oberhoffner et al.
Buffat Laurent
Chaume Francois
Diebold Claude
Crawford Gene O
Pitney Hardin Kipp & Szuch LLP
Solystic
LandOfFree
Device for conveying flat objects with a synchronization system does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Device for conveying flat objects with a synchronization system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Device for conveying flat objects with a synchronization system will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3185475