GB2090785A

GB2090785A - Book binding ploughs

Info

Publication number: GB2090785A
Application number: GB8200980A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1981-01-14
Filing date: 1982-01-14
Publication date: 1982-07-21

Abstract

A bookbinders plough for use in trimming the edges of a book held firmly clamped between the jaws of a vice with the edge to be trimmed protruding slightly, comprises a blade 11 attached to a carriage 10 movable transversly along a guide or guides 3 adapted to be maintained at right angles to the face of the book. The guides are mounted in a member 2. The description also discloses several ways of mounting the transverse guides, and means for obtaining incremental transverse movement and also, when needed, the lifting of the cutter during the return stroke automatically. <IMAGE>

Description

SPECIFICATION An improved bookbinder's plough A bookbinder's plough is a tool used for trimming the head, tail and foredge of a book after the signatures have been assembled. In commercial bookbinding this job is done by a guillotine; but the plough is the traditional tool and is still used in hand bookbinding. In order that the nature of the proposed improvements shall be clear it is necessary first to described the traditional plough and its method of use.

Such a plough (Figure 1 ) consists of two slabs of wood - the cheeks - which are maintained roughly parallel to each other by two guide rods which are fixed in one cheek and slide through holes in the other. Between these two guide bars is a screw, working in a threaded hole in one cheek and located axially in the other, through which it projects and is fitted with a handle. Rotation of this handle therefore moves the slabs towards or away from each other.

The book is clamped vertically in a wooden press with the edge to be trimmed standing slightly above the tops of the jaws.

The cheek of the plough in which the screw works in a threaded hole is guided by a channel formed on the top surface of one jaw of the press parallel to the vertical face. The other cheek has a dagger-shaped blade or knife mounted in its lower edge projecting away from the handle (i.e. towards the threaded cheek). Since the threaded cheek is maintained at a constant distance from the book rotation of this handle moves the point of the blade towards (or away from) the book.

In use the plough is moved to and fro along the length of the press the handle being rotated before the beginning of each stroke so that the point of the knife moves a small distance towards the book. Once the point has reached the book this incremental rotation of the screw results in a few pages being cut at each stroke.

The knife cannot be moved forward during the course of trimming an edge without leaving a visible ridge or ripple in the cut face, nor can the side piece of the plough be allowed to slide on the trimmed edge for fear of marking it. The effect of these two retraints is that the separation of the cheeks of the plough at the start of a trim will be at least twice the thickness of the book plus the distance from the edge of the jaw of the press to the inner face of the guided cheek (2T + D in Figure 1); and the total length of the plough excluding the handle must be at least twice the thickness of the thickest book it is intended to trim plus the thickness of the two cheeks plus D; 2(T + W) + D (Figure 1). Moreoverthe knife must project from the moving cheek by a distance at least equal to the thickness of the book to be trimmed.A plough capable of trimming thick books is therefore long and more important, the blade has a long overhang from its support which, combined with the tilting of the cheek, allows considerable vertical movement of the tip. Finally, since the cheek carrying the blade moves across the upper surface of one jaw of the press, any unevenness in this surface is repeated (often magnified) in the trimmed edge of the book. The invention now to be described overcomes all these disadvantages.

The essential difference from the traditional plough is that, instead of moving towards each other, the cheeks remain at the same distance apart during a trim. This distance need be only just enough to span the book. The blade is mounted on a carriage that moves on a guide or guides spanning the distance between the cheeks. Two embodiments are illustrated in Figures 2 & 3. In both the numbering of functionally equivalent parts is the same.

It will be apparent on inspection that with this arrangement the length of the plough depends on the thickest book to be trimmed instead of on twice this thickness, that the width (Figure 1) of the outer jaw of the press does not limit the thickness of the books that can be trimmed and most important of all, that, since the blade is short and stiff the trajectory is determined by the guides, instead of the top surface of a laying press: the trimmed edge of the book is bound to be flat.

Referring now to Figures 2 & 3 the cheeks (1) & (2) are connected by the guide bars (3) & (4) in Figure 2, or by the tube (5) in Figure 3. By slackening the clamping screw (or screws) (6), the separation of the cheeks can be adjusted to span the book being trimmed. Either cheek may be extended downward or have a downwardly projecting tongue (13) to fit a groove in one of the jaws of the press in which the book is clamped so as to constrain the plough to move parallel to the edge of the jaw. Alternatively the guidance of the plough can be achieved by a groove (14), in the bottom edge of the cheek which fits over a tongue projecting from the upper surface of one of the jaws of the press. The feed-screw (7) is free to rotate in both cheeks but is restrained axially in one of them, as, for example, by the two collars (8) & (9).A carriage (10), riding on the guide bars and moved by the feed-screw (7) supports the blade (11).

Rotation of the handle (12) therefore moves the blade towards cheek (2).

If the screw is quite straight and the nut a good fit it may be aliowed to guide the blade, itself. But the arrangement just described is better.

The blade may be inclined downward towards the point, as in Figures 2 & 4 so that the remainder of it is clear of the trimmed work. If the blade is horizontal it may be extended backward to pass through a guide formed in the lower edge of one cheek (or the cheek when, as in Figure 4, only one is used). This gives the guidance of the tip of the blade additional rigidity but is seldom needed.

The second cheek (2) of the plough serves no purpose except to support the outer end of the tube (5) or guide bars (3) & (4) and can be dispensed with altogether if cheek (1) is made wide enough to prevent the plough tilting sideways in use or is prevented from tilting by means such as that at (14) shown in Figures 4 & 5. A plough made in this way is supported by one jaw of the press or may be permanently attached to a track (15) which is not part of a press. Such a combination can be used without one being clamped by any conventional means, over a book resting on a table.

Claims

CLAIMS 1. A bookbinder's plough made according to this invention is similar to the traditional, known forms in that it is a tool that travels to and fro parallel to the jaws of a vice or press in which the book to be trimmed is clamped, whilst a cutter, carried by the plough, is advanced in a direction at right angles to this to-and-fro travel so as to cut progressively deeper into the edges of the book. But it differs from the known design in that the cutter is not fixed to one of the side members but travels on guides that span the width of the book. For ease of description it is assumed that the book is held vertically between the jaws of a press with the edgeto be trimmed projecting above their upper surfaces which will normally, but not necessarily, be horizontal. But this is not an essential condition of the invention. The book may be clamped in the horizontal plane or at any intermediate angle. It is only necessary to imagine the book rotated into the vertical plane, and the other co-ordinates rotating with it to transform any actual configuration into that assumed here.

1. The invention claimed is, then, a bookbinder's plough consisting of one or more side members capable of being traversed parallel to the edge of the book and carrying guides on which a cutter can be traversed at right angles to this longitudinal movement; the transverse travel of the cutter being sufficientto span the widest bookto be trimmed.

2. The bookbinder's ploug as claimed in Claim I, having two side members, one on each side of the book. One side member, it does not matter which, runs in or on guideways in or on the upper surface of the press in which the book is clamped and parallel to the clamping faces in a longitudinal direction.

Between the two side members there are one or more guides parallel to the surface on which the plough rests. The cutter is carried by a carriage sliding on the guide or guides and advanced in small and accurately reproducible increments by a screw or other means. Advance' means a movement such that the depth of the cut increases; it may be towards or away from the guided side of the plough.

3. A plough as claimed in Claim 2 in which the guide for the carriage consists of two bars, either or both of which may be circular or rectangular, fixed in one side member (or cheek) and sliding through holes in the other. A clamping screw in the slideable cheek bears on one of the bars to maintain the separation of the two side members when correctly set to span the book. The carriage in which the cutter is clamped slides on these bars. One bar passes through a closely-fitting hole in the carriage, the other through a slot in the opposite side of the carriage which touches only the top and underside of the bar thus constraining this side of the carriage vertically but not horizontally so that if the separation of the bars should change the guidance of the carriage would not be affected.A screw passing through a nut in the carriage and axially located in one of the side members has secured to it a handle or other means by which it may be rotated.

4. A plough as claimed in Claim 2 in which the two sides of the plough are connected by a single member such as a tube - which forms the guide for the carriage in which the cutter is clamped. This guide being of such cross section - e.g. square, triangular, dovetail, circular with a longitudinal groove - as will prevent the carriage rotating about it or within it and guide the cutter along a straight line.

5. A plough as claimed in Claim 4 in which the guide is a slotted tube. The carriage may ride on the outside of this tube or slide within it. The screw and nut by which the carriage is advanced are, in either case, within the tube. In the first a tongue attached to the nut passes through the slot in the tube to engage and transmit motion to the carriage; in the second, where carriage and nut are both inside the tube, the slot faces downward and an arm, attached at its upper end to the carriage, projects through it and has a cutter attached to its lower end.

6. A bookbinder's plough as claimed in Claim 1 having only a single side member, or, alternatively two on the same side of the book, from which the guide along which the carriage travels projects horizontally, extending as a cantilever over the whole width of the book, the single side member being wide enough, or the two sufficiently widely spaced, to provide suitable support for the guide, or being prevented from overturning by other means for instance by a projection on the side remote from the blade running between the upper and lower sides of a channel attached to the press in which the book is clamped.

A bookbinder's plough as claimed in Claim 6 in which the guides consist of two rods and the means of advancing the carriage along them is a screw as claimed in Claim 3 except that the guides are supported at one end only.

8. A bookbinder's plough as claimed in Claim 6 in which the guide is a single member such as a tube as claimed in Claims 4,5 except that this guide is supported at one end only.

9. A plough as claimed in any of the foregoing claims in which the blade extends backward from its clamp in the carrier and slides in a guide formed in the lower edge of one of the cheeks or in the cheek if there is only one.

10. A bookbinder's plough as claimed in any of the foregoing claims in which the screw advancing the carriage is fitted with click stops so that the user can tell through what part of a complete revolution he has rotated the screw by counting the clicks.

11. A bookbinder's plough as claimed in any of the foregoing claims in which the blade is advanced automatically at one or both ends of the stroke.

12. An embodiment of the plough as claimed in the previous claim would be a plough as claimed in any of the Claims 2 to 10 in which the blade is advanced by a screw which is fitted with a toothed wheel lying close to or recessed into the side of the plough in which the screw has its bearing. This toothed wheel can be moved through part of a revolution by one or more pawls engaging the teeth in its periphery. Moveable shrouds which prevent the pawls from engaging the teeth they cover are interposed between the pawls and the wheel. By adjusting the position of a shroud the proportion of the movement of the corresponding pawl that is transmitted to the wheel can be varied from none at all to the total angular movement of the pawl.Each pawl is moved, through a linkage, by plungers projecting from one end of the plough encountering a stop in the guideway in which the plough moves to and fro along the press holding the book. If there are two pawls there is a plunger at each end of the plough and a stop at each end of the guideway. It will be obvious that by adjustment of the shrouds it is possible to arrange for the screw to be rotated through any angle from zero up to that subtended by the movement of the pawl at either one or both ends of the travel of the plough.

13. A bookbinder's plough as claimed in Claim 1 in which the blade automatically rises clear of the work for the return stroke.

14. A bookbinder's plough as claimed in Claim 13 in which as well as rising forthe return stroke the blade is automatically advanced by a preset distance before the beginning of the next stroke.

15. An embodiment of the bookbinder's plough claimed in Claim 14 would be one with side members on each side of the book to be trimmed connected by guides spanning between them, or one with a single side member from which the guides project as cantilevers; in both of which main guide is the screw used for advancing the carriage which is rigidly fixed in one side member (or the side member) and about which the carriage can rotate through an angle sufficient to lift the cutter clear of the work. In its lowered position the end of the carriage remote from the screw rests upon a second guide bar which determines the position of the blade during the forward, cutting stroke. The nut which advances the cutter is held between projections on the carriage and is provided with ratchet teeth around its periphery.A pawl on the carriage can engage these teeth but may be prevented from doing so by a moveable shroud as in Claim 11. The carriage is biassed to rise by a spring, but during the cutting stroke is held down in contact with the secondary guide bar by a latch. This latch is released at the end of the forward stroke by a plunger at the front of the plough striking a stop at the end of the guideway on the press in which the book is clamped.

The carriage lifts. At the end of the return stroke and before beginning the next cutting stroke the carriage may be pressed down into contact with the secondary guide bar by the operator or may be returned to this position by a plunger at the rear end of the ploug striking a stop at the end of the guideway in the press. During this movement the pawl engages the teeth on the periphery of the nut and so advances the carriage for the next cut. The distance advanced can be altered by altering the position of the shroud.

At the end of the downward movement the latch engages automatically holding the carriage down in contact with the secondary guide bar until is is released by the stop at the end of the forward stroke.

Alternatively by a simple change in the position of the pawl the carriage can be advanced as it rises at the end of the forward stroke, but the arrangement described isto be preferred.

16. A bookbinder's plough as claimed in any of the foregoing claims, except Claim 9, in which the cutter uses a knife or dagger-shaped blade like those of most traditional ploughs but which, instead of being horizontal as these are, slopes down towards the cutting tip so that its rear end is clear of the trimmed surface.

17. A bookbinder's plough as claimed in any of the foregoing claims which uses a high-speed rotary cutter in place of the traditional blade.

18. A bookbinder's plough as claimed in any of the foregoing claims in which the distance between the cutter and the guides is adjustable.

19. A bookbinder's plough as claimed in Claims 1,6,7,8,9,10,11,12,16,17,18,whichhasitsown longitudinal guide, independent of any press, which guide can be clamped down on a book on the edge of a bench or table to bring the plough into play for trimming.