GB2068837A - Duplicator trays - Google Patents

Abstract

A moulded plastics duplicator tray is provided for holding a gelatinous bed from which copies can be taken in accordance with print patterns laid on the bed as dyes or inks. A central dishing is surrounded by edges (14) of which first upper portions (22) extend outwardly and second portions (18) downwardly. The first portions have formations, (inner rebates) affording positive edge location for copy paper. Corner posts (24) terminate the inner rebates. Outward flanging (20) may terminate the edges for anchoring the trays during copying. The dishing has formations (26, 28) effectively subdividing the dishing for smaller paper sizes, though the formations do not reach the normal bed depth but are merely visible through the bed material. The trays will stack closely with side formation (32, 34) in register but stack with spacing at least equal to desired bed depth when those formations (32, 34) are not in register. <IMAGE>

Description

SPECIFICATION Duplicator trays The invention relates to duplicator trays for holding gelatinous beds from which copies can be taken in accordance with print or patterns laid on and/or partially absorbed into the bed as dyes typically from suitable ink masters.

The basic process is very well adapted to cheap and reliable inplementation and is inherently capable of multi-colour printing at least for small runs of up to about 100 copies. Furthermore, the bed can be reused from another master after the print or pattern from the previous master has been fully absorbed, or "sunk", below the surface of the bed. Some inks, however, have a very slow absorbtion into the preferred gelatinous material and may be wiped off with a damp cloth so that the tray is ready virtually immediately for reuse.

Masters are conveniently made on paper by suitable pens or pencils, or by typing onto paper from the rear of suitable carbon paper.

Such masters are then laid onto the gelatinous bed for about half a minute, usually after moistening the bed, to transfer dye onto the bed. The bed is then ready for printing off onto paper, cotton or the like.

This invention has particular application to the provision of a simple and advantageous tray for the gelatinous bed material and to this end proposes a moulded plastics tray dished to a depth appropriate for the bed material with edge portions that extend firstly away from the dishing and then secondly turn towards the base level of the dishing, the first extension of said edge portions having a formation that defines a positive copy sheet edge location for a said copy sheet in predetermined registration with the bed.

Preferably, the formation is on each of the edge portions and comprises an inner rebating of lesser width than the adjacent surrounding parts of those edge portions.

Other advantageous further features include: (a) formation of the second extensions of the edge formations readily to allow anchoring of the tray during copying, for example by termination in outwardly directed flanging.

(b) formation of the bottom of the dishing to define visible sub-divisions of that dishing to suit smaller paper sizes but without interruption with the desired depth for bed material, for example as double parallel ridges; (c) formation of the first extension(s) of the edge portions in registration with the dividing formation(s) of (b); (d) formation of opposed second extensions of the edge portions in dissimilar manner to allow close stacking at one registering relative orientation for the trays and define a spacing therebetween to at least the bed depth at another relative orientation thereof.

The term "moulded" as used herein is intended to have a general scope and particularly to include vacuum forming of sheet material.

One preferred embodiment of the invention will now be described specifically, by way of example, with reference to the accompany drawings, in which: Figure 1 is a plan view of a duplicator tray; and Figure 2 is a section on the line A-A of Fig.

1.

In the drawing, duplicator tray 10 is centrally dished at 1 2 to define a rectangular well for a particular paper size, e.g. A4, plus at least normal tolerances, with sides 14 of a depth, preferably at least 6mn, suitable to receive a bed of gelatinous material.Edge portions 1 6 of the tray extend firstly away from the sides 1 4 and then are returned at 1 8 to a depth at least equal to that of the dishing or well 1 2. As shown, those returned edge portions 1 8 are further turned outwards to afford an exterior flange 20 on which the tray will rest in use, preferably with the bottom of the dishing or well 1 2 also in contact with an underlying support surface, say of a table, desk or bench.

The flange 20 can serve in securement of the tray to an underlying support, for example by sticky tape, drawing pins, etc. Furthermore, the flange 20 could be on only one end or its function performed by localised tabs, etc.

The first extensions of the edge portions 1 6 of the tray are shown to have inner rebatings 22A to 22D sized more closely in width to said particular paper size and enabling accurate registration of successive copy sheets.

Clearly, the intended function and purpose each of the rebatings 22 could equally well be performed by a raised rib at what is shown as the boundary of the corresponding rebating.

Such registration aids are shown on all four sides of the tray, which is of substantial advantage in convenience of use by affording full choice of which end or side of the copy is to be used as the basis of registration.

It is, of course, envisaged that masters used to put copy onto the gelatinous bed will normally be of the same size as paper on which copies are to be made. For a given maximum size of paper, say A4, that, of course, means that a narrow margin is required at one side or end but the dishing of the tray will nonetheless match the paper size.

If desired, though less advantageously, the registration aids at opposed pairs of sides of the tray could suit unrelated different paper sizes, e.g. foolscap and A4 say with the dishing of the tray underize relative to the particular paper size concerned.

Overall, of course, the four rebatings 22A to 22D also afford the advantage of what are, in effect, post-like corner formations 24 obtruding slightly into the dishing or well 1 2 usefully to improve structural strength and integrity of the trays.

The dishing or well 1 2 has, in its bottom, formations 26, 28 that subdivide the area thereof, actually quarter it, to suit other copy sizes, e.g. A6. Each of the dividing formations 26, 28 is shown as comprising raised double parallel beads subscripted A and B and centrally spaced at C. Obviously, the positions of formations such as 26 or 28 will correspond to desired sub-sizes of copies, but the presence of perpendicularly directed such formations is preferred in usefully stiffening the tray.

In practice, it has been found that introduction of hot gelatinous materials for the tray as illustrated can sometimes lead to the tray twisting or otherwise deforming unsatisfactory. That is solved if the subdividing formations 26, 28 stop short of intersection and/or meeting sides of the dishing 12, preferably both as shown, with substantially equal shortfalls to the sides at about half the central gaps.

It will also be noted that the rebatings 22 have medial depressions or grooves 30A to 30D registering with the spacings C of the formations 26, 28 that run theretowards. That is a substantial advantage after a gelatinous bed has been used several times when the base formations 26, 28 may become obscured by absorbed or "sunk" dyes residual from previous copied material.

The returned portions of 1 8 of the edge portions 1 6 at opposed sides of the tray are shown as locally indented 32A, 32B and 34A, 34B, respectively at differently spaced positions there along. Thus, if another tray is superposed on the tray illustrated in the same orientation, the indentations 32, 34 will register and the trays will stack closely, especially given the slightly convergent sloping of the sides 14 and return edge portions 1 8 as shown in Fig. 2. The depth 36 of the indentations 32, 34 is such that when trays are superposed with 180 rotated relative orientations, their engagement of the edge portions 1 6 will secure a spacing of tray dishings or wells that exceeds the desired bed depth, e.g.

of 6mm or more. Nonetheless, such indentations 32, 34 end above the bottom flanging 20 and so secure a degree of relative stacking and close location of loaded trays.

Obviously, the indentations 32, 34 may be differently spaced, additionally or alternatively located in ends of the tray, and/or replaced by alternative formations for the same purpose.

Sides of the indents 32, 34 actually converge downwardly and inwardly with a slightly shallower downward slope on those sides nearest the middle of the tray, the further to facilitate stacking and unstacking.

It will be appreciated that the tray illustrated readily permits the use of one imprint for the largest size (A4) of copy, two separate imprints for half that size of copy, and four ..aparate imprints for one quarter that size.

That substantially increases utilisation possibilities at the smaller sizes of paper. For the largest size, the capability of partial stacking of the trays when loaded with gelatinous beds greatly facilitates package of two or more trays together for users who may wish to make double-sided or different copies at the same time, i.e. without waiting for the dyes to sink and allow re-use of one and the same bed.

Claims (14)

1. A duplicator tray for holding a gelatinous bed from which copies can be taken in accordance with print or patterns laid onto the bed as dyes or inks, comprising a moulded plastics tray dished to a depth appropriate for gelatinous bed material with edge portions that extend firstly away from that dishing and then secondly turn towards the base level of the dishing, the first extension of said edge portions having a formation that defines a positive copy-sheet-edge location with a said copy sheet in predetermined registration with the bed.

2. A duplicator tray according to claim 1, wherein the formation is on edge portions and comprises an inner rebating of lesser width than the adjacent surrounding parts of those edge portions.

3. A duplicator tray according to claim 1 or claim 2, of oblong shape with said formations on opposite pairs of sides terminated substantially at corners of the tray substantially in register with the dishing of the tray.

4. A duplicator tray according to claim 3 with claim 2, wherein said terminations comprises post-like corner formations of the tray.

5. A duplicator tray according to any preceding claim, wherein the second edge extensions reach at least the bottom of the dishing.

6. A duplicator tray according claim 5, wherein the second edge extensions terminate, in an outwardly directed flange by which the tray is anchorable.

7. A duplicator tray according to any preceding claim, wherein the bottom of the dishing has, internally to be visible through a gelatinous bed, formations terminating below the desired depth of bed material indicating subdivisions to suit smaller paper sizes.

8. A dupticator tray according to claim 7, wherein the subdividing formations comprise doubie ridges along a cruciform shape.

9. A duplicator tray according to claim 7 or claim 8, wherein perpendicular subdividing formations stop short of meeting each other.

10. A duplicator tray according to claim 7, 8 or 9, wherein the subdividing formations stop short of the edges of the dishing.

11. A duplicator tray according to any one of claims 7 to 10, wherein the edge portions have further formations at positions corresponding to the subdividing formations.

1 2. A duplicator tray according to claim 11 with claim 2, wherein the further formations comprise indentations of the rebatings.

1 3. A duplicator tray according to any preceding claim, wherein the second extensions are formed in dissimilar manners on different sides of the tray so that two trays will stack closely in one registering relative orientation of the trays and stack with a spacing therebetween to at least desired bed depth in another orientation of the trays.

14. A duplicator tray according to claim 1 3 wherein the dissimilar formations comprises indents with corresponding interior protrusions.

1 5. A duplicator tray according to any preceding claim formed by vacuum moulding.

1 6. A duplicator tray substantially as herein described with reference to and as shown in the accompanying drawings.