GB2177653A

GB2177653A - Worktables

Info

Publication number: GB2177653A
Application number: GB08611635A
Authority: GB
Inventors: Bengt Axel Andersson
Original assignee: Waco Jonsereds AB
Current assignee: Waco Jonsereds AB
Priority date: 1985-05-13
Filing date: 1986-05-13
Publication date: 1987-01-28
Also published as: SE8502363D0; DE3615977A1; DE3615977C2; FR2581576A1; GB2177653B; SE444403B; GB8611635D0

Abstract

An insert member or plate (20) is insertable in an opening (15) for an undercutter or the like in the worktable (10) of e.g. a woodworking machine for closing the opening (15) or changing its dimensions. To allow simple, rapid and accurate positioning of the plate (20) in the opening (15), two opposing boundary surfaces (14) of the opening (15) each have a rack-like means (17, 18) inserted therein. Similarly, the member (20) is provided in two edge surfaces (31) with rack-like means (24, 25) the teeth (25) of which fit into the tooth spaces of the rack-like means of the opening (15). In this manner, outer edge surfaces of at least an upper portion of the insert member (20) will be located close to the opposing edge surfaces (14) of the opening and the top face of said upper portion will be flush with the top face of the worktable. Each boundary surface (14) and each edge surface of the member (20) may have a recess parallel to the rack-like means, these recesses being located opposite each other when the member (20) is placed in the opening (15), so as together to form a channel in which a locking bar is insertable. <IMAGE>

Description

SPECIFICATION Device for closing or changing the dimensions of an opening for an undercutter or the like in the worktable especially of a woodworking machine The present invention relates to a device for closing or changing the dimensions of an opening for an undercutter or the like in the worktable especially of a woodworking machine, comprising an insert member which has at least one portion with a planar top face and is insertable in the opening to such a depth, which is limited by underlying stop means, that said planar top face is flush with the top face of the worktable.

In woodworking machines, workpieces are processed for instance by means of undercutters acting through openings in the worktable. Sometimes it is desirable to cover such an opening, for instance for allowing the workpiece to pass without being affected by the undercutter or for safely exchanging an overcutter. In some cases, the undercutter is also exchanged for a cutter having other dimensions. In such cases, the new cutter may require for its operation an opening having other dimensions than the first opening. In order to cover an opening of this type, use has hitherto been made of plates with grooves and projecting parts, such as tongues and grooves. Such plates must be laid or moved in place, adjusted and anchored by bolts or clamping means which must not project from the surface of the plate or the surface of the worktable.The application of such plates is time-consuming and requires great accuracy.

The object of the present invention is to provide a new device which allows changing plates accu rately and rapidly. According to the invention, this object is achieved in that the opening of the workt able is provided along at least two opposite boundary surfaces with rack-like means the teeth of which project into the opening parallel to the top face of the worktable and at a distance therefrom, and that the insert member has outer edge surfaces spaced the same distance from each other as said boundary surfaces and, inwardly thereof, inner edge surfaces which also have rack-like means with projecting teeth which are insertable from above in the tooth spaces of the rack-like means of the opening of the worktable for fixing the insert member in the intended position therein.

The invention will be described in greater detail hereinbelow with reference to the accompanying drawings which highly schematically illustrate one embodiment of the invention and in which: Figure 1 is a vertical section of a portion of a worktable having an opening and a plate for clos ing the opening; Figure 2 illustrates a device for locking the insert plate in the opening of the worktable; and Figure 3 is a top plan view illustrating the use of plates according to the invention for defining a cut ter opening in a worktable.

In the drawings, 10 designates a worktable in a woodworking machine. The worktable 10 com prises plates 12 which are fixed on a part 11 of a machine frame by means of bolts (not shown) and which have a planar top face 13 and a boundary surface 14 which extends at right angles thereto and which, together with other surfaces, defines an opening 15. An undercutter is intended to operate through the opening 15. The boundary surface 14 has a rectangular groove 16 which is open towards the opening 15 and in which an elongated rack-like means 17, 18 is fixed by means of locking pins 19 extending through the plate 12 and the rack-like means 17, 18. The rack-like means has a body 17 filling the groove 16, and teeth 18 which project into the opening 15 and the bases of which are flush with the plane of the boundary surface 14.

The rack-like means 17, 18 are preferably made of plastic but may of course also be made of metal.

The teeth 18 may have any desired shape, although a saw-tooth or trapezoidal shape is preferable for reasons of manufacture.

In the drawings, rack-like means 17, 18 are disposed in two opposite parallel surfaces 14 of the opening 15, but such means may of course also be disposed in other surfaces defining the opening.

In order to close or bridge the opening 15, use is made of an insert member which in Figures 1 and 2 is in the form of a plate 20 having a planar top face 30 and opposite edge surfaces 31, 31 extending at right angles thereto. The distance between the edge surfaces 21 on opposite sides of the plate corresponds to the distance between the boundary surfaces 14 of the opening 15 while the distance between the edge surface portions 31 is less because of a stepped portion 22 provided at some distance from the top face 30 of the plate 20. As appears from Figure 1, the stepped portion forms a right-angled recess at each edge surface of the plate. In the edge surface portion 31, as in the boundary surfaces 14 of the opening 15, there is provided a rectangular groove in which a rack-like means 24, 25 is secured by means of locking pins 26.The rack-like means 24, 25 is of the same design as the rack-like means 17, 18, i.e. it has a body 24 and projecting teeth 25. The recess 23 has such a depth that the crests of the teeth 25 are located in the plane of the surface portion 21, as appears from Figure 1.

When the opening 15 is to be closed, the plate 20 is placed in the intended position over the opening and is allowed to descend therein, such that the teeth 25 of the rack-like means 24, 25 of the plate will pass into the spaces between the teeth 18 of the rack-like means 17, 10 of the opening and vice versa, whereby the plate 20 is immediately correctly positioned. In the instant case, the plate 12 of the worktable 10 has the same thickness as the plate 20 and since the bottom member 11 extends slightly beyond the plate 12 towards the centre of the opening and thus forms stop means for the plate 20, the top face of this plate will be positioned exactly flush with the top face of the work-table. Other types of stop means may of course be used for determining the depth of insertion of the plate 20 in the opening 15.

Mostly, the plate 20 is retained in the opening 15 because of its own weight but, in some cases it may be desirable to use special locking means. In such a case, the surface 14 of the plate 12 may be provided with a right-angled recess 27 and the plate 20 provided with a corresponding right-angled recess 28. As illustrated in Figure 2, the recesses 27, 28 are located opposite each other when the plate 20 has been inserted in the opening 15. In the illustrated embodiment, the recesses 27, 28 are provided immediately above the grooves 16, 23 of the plates 12 and 20, respectively. The grooves 27, 28 together form a channel which at the bottom in Figure 2 is defined by the two rack-like means 17, 18; 24, 25. In this channel, a locking bar 29 is insertable which safely retains the plate 20 in the opening 15.The recesses 27, 28 may of course be designed otherwise and in other locations in the surfaces facing each other.

Figure 3 is a schematic top plan view illustrating the use of the invention for defining a cutter opening. As in the previous case, the worktable has an opening 15 between plates 12 and is provided, at the top of the drawing, with a guide bar 40 along which a workpiece 43 to be processed is guided by feeding means (not shown). In the opening 15, there is provided a cutter 41 which is mounted on a drive shaft 42 and projects upwardly from the surface of the worktable for processing the workpiece 43. In order to support the workpiece 43 during processing, the opening 15 must be bridged, which can be achieved by means of a plate 20 which covers the entire opening15 and has an opening for the part of the cutter projecting from the worktable. However, the embodiment shown in Figure 3 using two narrow plates 20 on either side of the cutter 31 for defining an opening 44 for the cutter is sufficient for providing adequate support for workpieces 43 having a width as illustrated. As shown in Figures 1 and 2, the mutually facing edges of the plate 20 and the plates 12 are provided with rack means 17, 18; 24, 25 with teeth 18, 25 engaging in each other, and locking bars 29 may be provided.

By the invention, it is possible to modify an opening in a worktable in respect of its dimensions or safely and accurately close the opening by means of an insert member in a fraction of the time hitherto required for taking such a measure.

Claims

1. A device for closing or changing the dimensions of an opening (15) for an undercutter or the like in the worktable (10) especially of a woodworking machine, comprising an insert member (20) which has at least one portion with a planar top face (30) and is insertable in the opening to such a depth, which is limited by underlying stop means, that said planar top face (30) is flush with the top face (13) of the worktable (10), characterised in that the opening (15) of the worktable (10) is provided along at least two opposite boundary surfaces (14) with rack-like means (17, 18) the teeth (18) of which project into the opening (15) parallel to the top face (13) of the worktable (10) and at a distance therefrom, and that the insert member (20) has outer edge surfaces (21) spaced the same distance from each other as said boundary surfaces (14) and, inwardly thereof, inner edge surfaces (31) also having rack-like means (24, 25) with projecting teeth (25) which are insertable from above in the tooth spaces of the rack-like means (17, 18) of the opening (15) of the worktable for fixing the insert member (20) in the intended position therein.

2. Device as claimed in claim 1, characterised in that the boundary surfaces (14) of the opening (15) extend at right angles to the top face (13) of the worktable (10), that the outer edge surfaces (21) of the insert member (20) extend at right angles to the planar top face (30) thereof and merge by a stepped portion (22) parallel to said top face, into the inner edge surface (31) which extends throughout the remainder of the height of the member (20), that the rack-like means (17, 18) of the boundary surfaces (14) are disposed in rectangular grooves (16) in said surfaces (14) with the bases of the teeth (18) located in the plane of the boundary surface (14), and that the rack-like means (24, 25) in the inner surfaces of the insert member are inserted in rectangular grooves (23) to such a depth that the crests of the teeth (25) are located in the plane of the outer edge surface (21).

3. Device as claimed in claim 1 or 2, characterised in that each boundary surface (14) and the inner edge surface (31) of the insert member have a recess (27 and 28, respectively) parallel to the racklike means, said recesses being located opposite each other when the insert member is disposed in the opening (15), so as to form together a channel in which a locking bar (29) is insertable for locking the insert member (20) in the opening (15).

4. Device as claimed in claim 3, characterised in that the recesses (27, 28) for the locking-bar channel consist of a right-angled recesses directly above the grooves (16, 23) for the rack-like means (17, 18; 24, 25) and in the insert member (20) im- mediately below the upper edge surface (21), such that the rack-like means (17, 18; 24, 25) form one side of the locking-bar channel.

5. A device for closing or changing the dimensions of an opening for an undercutter in the work table of a machine, substantially as herein described with reference to the accompanying drawings.