GB2173483A - Sorting & stapling sheet sets - Google Patents

Abstract

A sorter for copy sheets comprises at least one adjustable end stop 36, 38 engaging one of the edges of the sheets 34 to be collated in each of a series of indexible bins 32; means 44, 46 for tamping the other edge of the sets of copy sheets towards the respective end stop, and means, eg on tamper 44, energisable when the sets of copy sheets are complete, for clamping together each set of copy sheets in sequence; withdrawing it from its respective bin, stapling the set together by stapler 48, and pushing the stapled set back into the bin for subsequent unloading. <IMAGE>

Description

SPECIFICATION Sheet sorter This invention relates to a sheet sorter, by which is meant a device for putting a series of M identical copy sheets into M individual bins, and for repeating the process as many times (N) as necessary to produce M sets of N sheets.

One method of 'finishing' the resultant sets is to secure the sheets in each set together with a staple.

Th present invention aims at providing a sheet sorter with an optionally-energised stapler designed to operate automatically on the sheets after they have been collated into sets.

Accordingly the present invention provides a sheet sorter which is as claimed in the appended claims.

The present invention will now be described by way of example with reference to the accompanying drawings, in which: Figure 1 is a diagrammatic side elevation showing the essential parts of a copier combined with the copy sheet sorter of the present invention; Figure 2 is a diagrammatic isometric view of the sheet sorter shown in Fig. 1, but on a larger scale; Figure 3 is a plan view of the sorter shown in Fig. 2, and Figure 4 is a diagrammatic side elevation of the sorter shown in Figs. 2 and 3.

Although the sheet sorter of this invention may be used to sort (and optionally staple together) sheets issuing from any reproduction machine, it has been designed primarily to deal with the copy sheet output of a xerographic copier, of which the main components are shown diagrammatically in Fig. 1.

In that copier, a copy sheet reservoir 2 has means for extracting copy sheets from either the top of a stack 4 or from individual trays 6 and 8 holding copy sheets of different sizes.

The base of the stack 4, and the trays 6 and 8, are individually driven as necessary to bring the top sheet of the respective store into contact with a driven sheet-extraction roll or belt 10. After the respective copy sheet has been started on its respective path, it moves down the substantially-vertical portion of its run 12, being kept there by having its previously-upper face engaged by the respective run of a continuous belt 14.After leaving belt 14, each copy sheet is bent through an angle of over 1800 and enters a xerographic module 16 at which an image of unfused toner powder is transferred from a photoconductive belt 18 to the respective copy sheet, after which the sheet passes through a fusing station 20 where the toner image is fused to become fixed to the respective surface of the copy sheet in a configuration replicating the arrangement of indicia on the respective sheet of the original documents being copied (not shown).

After leaving the fuser, the copy sheets are fed to a path junction 22. If the copy sheets are simplex, then they pass directly to a three-roll inverter 23, into which it is reinserted by feed rolls 28 to be fed to outlet rolls 24 which feed each complex sheet facedown into the sorter 26 of the present invention. However, if the copy sheets are to be duplex, then the sheets pass through the inverter 23 and feed rolls 28 to come to lie, copy face down, on a buffer tray 30. When duplex copying has been selected, a sheetextraction motor connected with the buffer tray 30 is energised to remove the face-down simplex sheets from the tray and feed them along the path described above, so that they have images placed on their previously-blank faces.

When the resultant duplex sheets reach junction 22, they were treated as if they were simplex sheets, and are fed by outlet rolls 24 into the sorter 26.

It is believed that the xerographic process is sufficiently well known as not to require any further explanation in this specification.

The sorter of this invention comprises a plurality of flat, i.e. unflanged, shelves 32 which are intended to be kept horizontal in use, and to be driven vertically in the appropriate sense with a differential motion. The effect of this latter drive is to move a shelf 32 faster as it leaves the location in which it is aligned with the feed rolls 24, so as to produce a space of greater height between adjacent shelves, to form a 'sheet entry bin'. When leaving this location, and prior to entering it, the spacing between adjacent shelves is reduced significantly so that they are able to accommodate the predetermined maximum number of sheets in each set, whereas the height of the sheet entry bin has to be sufficient to accommodate the sheets and to leave sufficient room for fresh copy sheets 34 to be introduced into the bin.

The means for effecting vertical translation and differential relative movement of the shelves 32 are already known, and so will not be described herein in any greater detail.

Because of their momentum, and because the shelves 32 are planar, each copy sheet 34 would tend to skid across the top of the respective shelf in the sheet entry bin when it is being fed in. To ensure that each sheet so fed comes to rest in vertical alignment both with other sheets in the same bin and with the sheets in adjacent bins, a pair of adjustable end stops 36 and 38 is provided, end stop 36 being intended to be about half way down the lead edge of each copy sheet 34, and end stop 38 being about half way down one of the side edges.As can be seen in Fig. 2, the end stops are oriented to remain vertical by extending between the movable ends of a pair of pivoted levers 40 which are movable (by means which are not shown) into selected positions corresponding to the size of copy sheet 34, the positions of the or each end stop being adjustable between runs made with copy sheets of different sizes. The levers 40 may be adjusted either manually or mechanically.

After each sheet has been fed into the re spectivesheet entry bin, it is pushed (tamped) into its final position in which it is in contact with both end stops 36 and 38 and with a desired orientation relative to the direction 42 along which the copy sheets enter the sorter.

To effect this, that side edge of each copy sheet which is not intended to come into contact with end stop 38 is engaged by a side tamper bar 44 which is mounted for horizontal reciprocal movement while remaining vertical.

Similarly, the trail edge of each sheet is engaged by a pair of spaced-apart tamper bars 46 which are likewise reciprocated and kept vertical. As indicated in Fig. 2, the bars 46 are interrupted intermediate their ends so as to leave a gap through which sheet 34 can pass into the sheet entry bin. When the respective sheet has settled in the bin, or after the respective shelf has been translated vertically so that the space above the shelf no longer functions as the sheet entry bin, the sheet is able to have its edge engaged by the tamper bars 46 to push it into contact with end stop 36 while preserving the above-mentioned orientation.

The sorter is designed so that there is one operation of the tamper bars 44 and 46 for each copy sheet fed into the sorter. Thus each sheet on each of the shelves, whether by itself or when forming part of a stack of sheets, has its respective edges registered by the tamper bars into positions determined by the locations of the end stops.

As shown in Fig. 2, associated with a corner of the shelves 32 is a stapler 48. For reasons which will be discussed in more detail below, this is spaced sufficiently far horizontally from the shelves 32 for the shelves to be able to be translated vertically without coming inadvertently into contact with any part of the stapler.

In accordance with the present invention, when the sets on the shelves 32 are complete, and the 'staple' mode has been selected, the sorter goes through a staple cycle, which is as follows: As shown more clearly in Fig. 3, associated with the side tamper bar 44 is a clamp which has its jaws normally spaced apart by about the height of the sheet entry bin, and aligned roughly with the upper and lower shelves defining that bin, so that as the side tamper bar is reciprocated, the jaws of the clamp remain out of contact with any sheets in the respective sheet entry bin. However, when the sorting operation is over, and the sets of sheets are to be stapled together, the tamper bar goes through two reciprocations, for each vertical translation of the shelves 32.In the first reciprocation, after the tamper bar has reached its usual inner limit position, the jaws of the clamp are driven so as to grip between them the set of sheets in the sheet entry bin.

This grip is maintained as the tamper bar goes through its first withdrawing motion, and, in so doing, partially withdraws the set of sheets while maintaining its relative registration. The extent of reciprocation is such that a corner of the clamped set is able to pass into the mouth of the stapler 48. After the side tamper bar has come to rest, the stapler is operated so as to drive a staple through the respective set of sheets, and to clinch the resultant protruding legs of the staple, so as to ensure that the sheets do not become separated from each other accidentally. After the staple has been applied, the tamper bar starts its second successive reciprocation. At some time during this movement this clamp is deenergised so as to release the set of sheets, but they stay together as they are pushed back into contact with the opposing end stop 38.The side tamper now withdraws from the sorter to permit the next vertical indexing to take place. This sequential gripping, extracting, stapling and reinserting sequence continues for as many times as there are sets of copy sheets, until the sorter has its respective slots containing only stapled sets. Either when this position has been reached or before, the stapled sets can be removed by the operator.

In all the drawings, those components which are shown in more than one drawing retain their original references.

As is already known, the sorter itself is designed for bi-directional operation. In other words, in order to sort M successive copy sheets, the shelves 32 are indexed in one vertical direction for as many times as are necessary to fill M bins, whereafter the direction of indexing is reversed, so that the next series of copy sheets is fed into the same bins but in reverse sequence, which is immaterial as far as the bins are concerned. It will also be appreciated from the drawings that the orientation of the copy sheets is face-down on the shelves 32, so that each set of sheets is in the order 1-to-N from the bottom up.

When the 'sort' mode has not been selected by the operator, the sorter can function simply as a catch tray. In this mode, the upper shelf 32 remains fixed and defines an exceptionally-tall sheet entry bin, so that far more unsorted sheets can be fed into the sorter when it is functioning as a catch tray than when it is functioning as a sorter.

When the sorter is in its 'sort' mode, the operator selects the number of copies to be made of each sheet of the original. The operator then either adjusts the positions of the end stops in accordance with the size of the copy sheets selected, or keys in that size for the sorter itself to adjust the position of the end stops. Alternatively, the copier could itself determine the paper size and adjust the sorter end stops accordingly.

Normally the sorter starts in its lower position (shown in broken lines in Fig. 2), and is driven or indexed vertically upwardly during the first sorting step, until the shelves 32 reach the upper position shown in solid lines in Fig. 2. If there is an odd number of pages to be copied, then the sorter finishes up in its upper position at the end of the sorting sequence.

If there is an even number of sheets, resulting in the sorter finishing up in its lower position, then before the sorter is unloaded, it is automatically driven to its upper position. In either case, end stop 36 is retracted (automatically or manually) to allow unloading of the sorted sheets to take place.

When the 'staple' mode has been selected, and there is an even number of pages to be copied, the bins remain in their lower position after the sorting sequence. The end stop 36 is retracted and the staple cycle is initiated, leading to the double reciprocation of the side tamper bar 44 and the elective clamping, stapling and unclamping. The sorter then successively indexes upwardly as the stapling process continues, with the prior retraction of end stop 36 permitting the operator to unload the collated and stapled sets one at a time.

If there is an odd number of pages, resulting in the sorter finishing in its upper position, then the bins are indexed rapidly downwards into the lower position, and the stapling cycle initiated which has just been described.

After the stapler has been unloaded, irrespective of whether there is an odd or an even number of sheets in the immediately-preceding sort and staple sequence, the bins index downwardly to the predetermined start position. This is triggered by an 'empty bin' sensor (not shown) which, when operated, initiates a short time delay before energising the indexing motor to drive all bins down to the lower, start, position.

Thus it will be seen that the present invention provides an optionally-selectable sorter, with an optional stapler, which is of compact construction, which ensures that partially-completed sets of copy sheets are automatically tamped during sorting without altering the desired spacing-apart of the bins, and in which the stapler is located adjacent to the bins so that only relatively-limited movement of each set of copy sheets is necessary to bring each set from its registered position to its stapling position.

Claims (1)

1. A sorter for copy sheets, comprising an indexible stack of sheet-receiving bins; a sheet inlet past which the stack is indexed so that the bins become successively aligned with the inlet in order that each bin receives one sheet while travelling in the same direction; means for tamping the sheet or sheets in each bin so that it is or they are forced into contact with at least one registration stop, and at least one optionally-energised clamp associated with at least one tamping means and which, when energised, clamps together all the sheets in a bin; withdraws the clamped set from the bin sufficiently to enter the mouth of a stapler; waits for the stapler to staple the set in at least one location, and pushes the stapled set back into the bin for subsequent removal.