US 3108801 A
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Description (OCR text may contain errors)
Oct. 29, 1963 c. J. VAN DALEN 3,108,801
DEVICE FOR CONDUCTING POSTAL ARTICLES, FORMS OR THE LIKE Filed June 27, 1961 2 Sheefs-Sheet 1 Hi, I
IN VEN TOR.
E. J- YANDALEN. BY
AT T'YI Oct. 29, 1963' l c. J. VAN DALEN 3,108,301
' DEVICE FOR CONDUCTING POSTAL ARTICLES, FORMS OR THE LIKE Filed June 27, 1961 2 Sheets-Sheet 2 FIG.2
IN V EN TOR.
[1i VAN DALEN. BY
United States Patent Ian! 3,193,891 DiEVl CE FOR tJSNDUtITlNG PHSTAL ARTEQLES, FORMS 9R THE Eli Christiaan Johannes van Balen, Lei-:lscheinam, Netherlands, assignor to De taat tier Nederlanden, ten Dene Vertegenwoordigd Door de Birecteur-Generaal der il oserijen, Telegrafie en Teiefonie, The Hague, Nether- Filed June 27, 1961, Ser. No. 12$,tlli4 Claims priority, application Netherlmds June 23, 1960 16 Claims. (Cl. 271-57) The invention relates to a device for guiding on postal articles, forms or the like, into which said articles or documents are fed from piles thereof, and which device takes them from the pile one by one and guides them successively on their way with a predetermined spacing between them.
A part of this device is disclosed in the prior co-pending US. patent application SN. 84,268, filed June 23, 1961, wherein letters or similar sheet articles are taken from a pile and moved along one by one by a continuously driven conveyor belt in an erect position onto another conveyor belt which conveys them while still erect past a number of processing stations and at certain points moves them into gutters or chutes to follow various further routes. In this prior device introduction of double documents is prevented by a flexibly driven counter-rotation roller at the inlet to the conveyor belt. Said device has the drawback that the spaces between successive letters can only be increased to a usable value by giving the second conveyor belt for their further transport a greater speed than the feeding conveyor belt, but by then the space between one letter and a next longer-sized document will be greater than the space between one letter and a next shorter-sized document.
It is an object of this invention to provide a device which will produce uniform spaces between articles in such conveying systems, independent of the size or length of such articles within the limits of between 14 and 22 centimeters set by law for the sizes of letters on postal articles.
Generally speaking, this device according to this invention comprises a continually running conveyor belt with a retractable elastic pressing device which presses the conveyor belt against the end of a pile of articles to frictionally move from said pile the end article or document and move it past a switching device which causes the pressing device to retract when the leading edge of the document passes said switching device, thereby releasing the conveyor belt from acting on the next document in the pile until the trailing edge of the former document passes said switching device, and then said pressing device again presses the conveyor belt against said next document to start it moving from the pile a uniformly spaced distance from the trailing edge of said former document.
Further according to the invention a small roller located between the belts is permanently pressed by spring action against the counter-rotation roller which causes documents loosely sliding forward from the pile in the period when the pressing device has released the belt from acting on the pile, to be returned to the pile.
In the embodiment to be described hereinafter the switching device may comprise one or more photocells located along the belt connected to corresponding relays which together control an electromagnet that actuates the pressing device. The photocells receive light from sources of light placed opposite the photocells. When and as long as one of the light beams is intercepted by a passing document, the pressing device is in its retracted position and, consequently, the supply or feeding of documents from the pile is interrupted.
By means of the device of this invention regular spaces can be obtained between the documents. The length of these spaces can be determined by adjusting the distance between the counter-rotation roller and the photocell located farthest therefrom. The number of photocells to be used depends on the spaces desired between the documents. If spaces are desired shorter than the minimum length of a document, one photocell will do. If longer spaces are desired, two or more photocells are required, since even the shortest document must control the switching device from the moment it has entirely passed the counter rotation roller till the moment it has entirely passed the last photocell. To this end it is necessary that the distance between counter-rotation roller and first photocell, and between each adjacent pair of photocells is slightly less than the length of the shortest document to be conducted by the device of this invention. 7
The invention will now be described in detail with reference to the drawings, wherein:
FIG. 1 is a schematic plan diagram of one plan of the device according to this invention for conducting postal articles;
FIG. 2 is a perspective view of a specific device according to the plan diagram of FIG. 1;
FIG. 3 is a schematic wiring diagram of a control circuit for the pressing mechanism shown in FIGS. 1, 2 and 4; and
HG. 4 is an enlarged plan view of the pressing rollers of the device shown in F168. 1 and 2, and in dotted lines the retracted position thereof.
In the diagram of FIG. 1 are shown a receptacle 10 for the pile, a continually driven belt conveyor 20, a second belt conveyor 30 co-operating with the belt conveyor 20, a counter-rotation roller 49, a lever 50 bearing a small roller 51, the pressing-rollers 71 and '72- of the retractable elastic pressing device 79 and two light systems 3% and 90, each comprising a source of light 8 1 and 9 1 and a photocell 82 and 92.
FIG. 2 shows a more detailed view of these elements in which the belt conveyors 26 and 3e are twin belts 21, 22 and 31, 32 separated by a space to let pass the light beams from sources 81 and 91. In the receptacle 10- the documents D (FIG. 1) are permanently pushed by a force 11, such as a spring (not shown) towards the counter-pressure plate 12. This plate is provided with two slots 13 and 14, through which, according to the state of the electro-magnetically controlled rollers 71 and 72, the belts 21 and 2 2, can or cannot act on the end of the pile of documents D (see FIG. 1). Further there are the counter-rotation roller 40, the lever 50 hearing the roller 51, which also lies between the two belts 21 and 22a, and the light beams of the systems St and 99 of the sources of light 81 and 91 and photocells 82. and 92, from which the control of the pressure rollers '71 and 72 is derived.
The operation of the device is as follows:
The pile of letters or documents D placed in the receptacle 10 is permanently pushed towards the conveyor belts 21 and 22. The first letter D (see FIG. 2) is moved along by these belts 21 and 2a to the space 23 and there fed between the belts 21 and 2.2 and a counter-rotation roller 40. This roller 40 is driven in a direction contrary to the rotation it assumes when in contact with the conveyor belts 21 and 22 by a slipping coupling adjusted so loose that in the case of a reduced friction between the belts 21 and 2-2 and roller 49, it assumes this contrary rotation (as shown in the above mentioned co-pending application SN. 84,268) so that if two documents would slip between belts 2.1 arid 2,2 and roller 40, the roller'4tl would push the second letter erroneously removed from the pile back onto the pile, and only the first document would be moved forward. Before this document D 29 has entirely left the counter rotation roller 40, the leading edge of the document D reaches the first photocell 32 and intercepts the beam of light 83 for this photocell 32. The current through the photocell ceases to flow and relay A in FIG. 3 releases and closes its break contact a. The electromagnet E is energized and attracts the rollers 71 and 72 mounted on a steel rod 73, as a result or which the conveyor belts 2'1 and 22 recede between the slots 13 and 14 of plate 12. During this interruption in the beam 83 to the photocell 82 by the document D, this document is moved forward and is seized between the belts ZL-ZZ; and 3l-32. When the document D has almost entirely passed the photocell 82, the leading edge of the document D reaches the photocell 92, intercepting the light beam 93 for this cell, so that the current flow through relay B in FIG. 3 is interrupted. Relay B releases and closes its break contact b. This contact takes over the function of contact a, so that also after the trailing edge of the document D has passed photocell 62 and relay A has attracted its armature again, the electromagnet E retracting rollers 71 and 72 remains energized.
When now the trailing edge of the document D reaches photocell 92, this cell receives light again, relay B reenergizes and the circuit of the electromagnet E is broken. The rollers 71 and 72 then push the belts 2i and 22. again through the slots 13 and 14 of plate 12 against the pile, and a fresh or the next document D is removed therefrom. This document will follow the preceding one D at a distance corresponding to the distance between the counter rotation roller 4e and the photocell 92. Thus the distance between the successive documents can be fixed by the choice of the distances between the roller 4% and the photocells 82 and 2, independently of the size of the document.
In the withdrawn condition of the pressure rollers '71 and 72 it is possible that documents may erroneously slide forward from the pile. To avoid this the small roller 51 (see FIG. 4), co-operating with the counter-rotation roller 40 has been provided. This roller 51 is mounted on a lever 56', which has its fulcrum in 52. By means of a spring 53 the roller 51 is pressed, between two belts 21 and 22, against the counter-rotation roller 40. In the case of withdrawn belts 2A1 and 22 the latter roller 44} will assume the counter-rotation imparted to it by the slipping coupling (shown in said previously mentioned. prior co-pending application). Thus letters loosely moving forward from the pile will soon impinge on the rollers 40 and 51, which shoot them back onto the pile.
While I have illustrated and described what I regard to be the preferred embodiment of my invention, nevertheless it will be understood that such is merely exemplary and that numerous modifications and rearrangements may be made therein without departing from the essence of the switching means operated by said removed sheet for controlling the retraction and engagement of said reciprocal means to prevent the engagement of the next sheet in said pile until said removed sheet is moved past said switching means by said conveyor belt. 2. A device according :to claim 1 wherein said reciprocal means comprises a roller, and electromagnetic means controlled by said switching means for moving said roller against the inside of said belt towards and away from the end of said pile.
3. A device according to claim 1 wherein said switching means comprises alight source producing a beam and a photoelectric cell responsive to said beam and located so that said removed sheet interrupts said beam between said source and said cell for controlling said reciprocal means.
4. A device according to claim 1 including counterrotating roller means near the end of said pile for returning sheets to said pile which may be erroneously removed while said reciprocal means is retracted, and including means for overriding said returning means when said reciprocal means is opera-ted to frictionally engage said belt with a sheet to be removed from said pile.
5. A device according to claim 4 wherein said means for overriding said roller means comprises a slipping couplin for driving said roller means.
6. A device according to claim 4 wherein said overriding means comprises a second roller means resiliently pressed against said counter-rotating roller means.
7. A device for conducting postal articles successively alon a path at a predetermined distance apart from a pile of said articles comprising:
(a) a conveyor belt continuously moving transversely of the end of said pile,
(b) reciprocal means for intermittently retracting and frictionally engaging said belt with the article at the end of said pile for its removal from said pile and movement along said path,
(0) switching means operated by said removed article for controlling the retraction of said reciprocal means to prevent the engagement of the next article in said pile until the removed article is moved past said switching means by said conveyor belt,
(d) counter-rotating roller means located near the end of said pile and facing said conveyor belt for returning articles to said pile which may be removed erroneously from said pile by said belt while said reciprocal means is retracted, and
(0) means for overriding said counter-rotating roller means when said reciprocal means is operated to frictionall-y engage said conveyor belt with an article from said pile for movement along said path.
8. A device according to claim 7 wherein said means for overriding said roller means comprises a slipping coupling for driving said counter-rotating roller means.
9. A device according to claim 7 wherein said conveyor belt comprises a pair of parallel spaced belts.
10. A device according to claim 9 wherein said means for overriding said roller means includes a second roller means frictionally engaging said counter-rotating roller means between said pair of spaced belts.
11. A device according to claim 9 wherein said switching means includes means projecting between said belts for interruption by said article.
12. A device according to claim 11 wherein said switching means comprises an electric light source producing said projecting means and a photoelectric cell responsive to said projecting means.
13. A device according to claim 7 wherein said reciprocal means comprises a pair of rollers inside said belt, one opposite said pile and the other opposite said counterrotating roller means, and electro-magnetic means controlled by said switching means for retracting both of said rollers.
14. A device according to claim 7 including a plurality of said switching means spaced along said path at distances slightly less than the shortest article to be moved along said path for maintaining said reciprocal means retracted as long as said article is in contact with one of said switching means.
15. A device for removing one sheet at a time from a pile of said sheets, composing:
(a) reciprocal means for intermittently retracting and frictionally engaging one side of the end sheet of said pile for its removal from said pile,
(b) counter rotating roller means located adjacent the end of said pile and facing said engaging means for returning additional sheets to said pile which may be removed erroneously from said pile when said engaging means is engaging a sheet, and
(c) a second roller means pressed against said counter rotating roller means for preventing the erroneous removal of a sheet from said pile when said engaging means is not engaging a sheet.
16. A device for conducting sheets successively along a path at a predetermined distance apart from a pile of said sheets, comprising:
'(a) a conveyor belt continuously moving away from the end of said pile,
(b) reciprocal means for intermittently retracting and frictionally engaging one side of the end sheet of said pile for its removal firom said pile and for movement by said conveyor along said path,
(a) switching means operated by said removed sheet for controlling the reciprocal engaging means to prevent the removal of the next sheet from said pile until the removed sheet is a predetermined distance firom said pile,
(d) counter rotating roller means located near the end of said pile and facing said reciprocal engaging means for returning additional sheets to said pile which may be removed erroneously from said pile when said reciprocal engaging means is engaging a sheet, and
(e) a second roller means pressed against said counter rotating roller means for preventing the erroneous removal of a sheet from said pile when said reciprocal engaging means is not engaging a sheet.
References Cited in the file of this patent UNITED STATES PATENTS Breuers July 17, 1962