Adjustable Fence for a Saw Table or the Like

This invention relates to adjustable fences for saw tables or the like, particularly such fences which are movable sideways across the saw table or the like and are releasably clampable in a selected position.

Such a fence is disclosed in German Offenlegungsschrift No. 2,904,685 in which clamping is effected by means of screws provided in two clamping regions of the fence. Both these screws are tightened to ensure that the fence does not shift under the load exerted against it by the workpiece being guided thereby while the workpiece is being machined. The disadvantage of this fence is that the user has to fasten it at both ends in order to position and fix it, that is to say, for adjustment purposes, the user first has to loosen two screws and then has to tighten both of them again.

Furthermore, there is also disclosed in German Utility Model No. 7,239,236 a fence which is fastened only at one end by clamping. However, with this fence there is the risk that the free end of the fence may be pivoted or deformed by the load exerted on it by the workpiece.

The object of the present invention is to provide a fence for a saw table or the like which can be secured at both of its ends in a simple way be means of clamping.

A feature by which this object is achieved is by providing the fence with a pivotal end and a single operating device for effecting pivoting of that end to clamp both ends of the fence against the saw table or the like. This provides the advantage that only one operating device, e.g. a screw, has to be actuated to firmly secure both ends of the fence to the saw table or the like.

Another optional feature of the invention is the provision of an extension fence slidable over and along the main fence and also securable in position by said operating device. This provides the advantage that the position of the main fence relative to the saw table and the position of the extension fence relative to the main fence can both be simultaneously fixed by a single operation of said operating device.

Accordingly, therefore, the present invention provides an adjustable fence for a saw table, or the like, comprising an elongate main fence member defining a longitudinal direction and having a first clamping portion at one end; an auxiliary fence member pivoted to said main fence member about a pivotal axis at right angles to said longitudinal direction, said auxiliary fence member extending from the other end of said main fence member and having a second clamping portion spaced from said first clamping portion in said longitudinal direction; and means, connected between said main and auxiliary fence members and actuatable by one hand of an operator, for adjustably pivoting said auxiliary fence member relative to said main fence member to shorten the distance between said first and second clamping portions, whereby said first and second clamping portions can be clamped against opposite sides of said table with said main fence member extending over the surface of said table.

Preferably, the main fence member is hollow and the auxiliary fence member extends inside the main fence member.

The adjustably pivoting means preferably comprises a headed screw threadedly engaging the auxiliary fence member and extending at right angles to the pivotal axis with the head of the screw being supported by and bearing against the outside of the main fence member.

Both fence members may be provided with inwardly directed foot portions spaced below the main fence member and forming the first and second clamping members. These foot portions preferably engage in grooves along opposite sides of the table and below the surface thereof.

An extension fence may be slidably mounted on the main fence and be displaceable thereon in the longitudinal direction, the position of the extension fence relative to the main fence being adjustably secured by the adjustably pivoting means. This makes it possible to guide workpieces which exceed the dimensions of the saw table and also to prevent a cut-to-length workpiece part from becoming jammed between the saw blade and fence.

Other objects, features and advantages of the present invention will become more fully apparent from the following detailed description of the preferred embodiment, the appended claims and the accompanying drawings.

In the accompanying drawings:

FIG. 1 shows diagrammatically a perspective view of a saw table equipped with an adjustable fence according to the invention;

FIG. 2 is a longitudinal section through the adjustable fence on the line 2--2 of FIG. 1;

FIG. 3 is a plan view of the adjustable fence of FIG. 2, partly broken away and sectioned to show the interior thereof;

FIG. 4 is a section on the line 4--4 of FIG. 2 showing the clamping portion of the main fence member;

FIG. 5 is a plan view of the extension fence shown in FIG. 1; and

FIG. 6 is a section on the line 6--6 of FIG. 3 showing the engagement of the extension fence over the main fence member.

The preferred embodiment of the adjustable fence of the present invention is shown in FIGS. 1 to 6, and a saw table equipped according to the invention with this adjustable fence is shown in FIG. 1.

FIG. 1 shows the saw table 10, illustrated in simplified form, having a table surface 12 in which a slit 14 is provided for the passage of a conventional circular saw blade (not shown). In the edge region underneath the table surface 12 there is a continuous groove 16 serving as a guide device for the adjustable fence 18. This continuous groove 16 is made up of a groove along each of the four sides of the saw table, and the fence 18 is mounted in the grooves in two opposite sides, as shown the front and the back of the saw table.

The fence 18 consists essentially of a tubular main fence member 20 and a separate auxiliary fence member 22. Fastened immovably in one end of the main fence member 20 is a clamping portion 24 rigidly retained in the main fence member 20, for example by means of gluing. The lower part of the clamping portion 24 engages in the portion of the groove 16 not shown in FIG. 1 and located on the rear side of the saw table 10.

The auxiliary fence member 22 is inserted into the other end of the hollow main fence member 20 and is pivotally fastened therein. A knurled headed screw 26 adjustably pivots the auxiliary fence member 22 relative to the main fence member 20 to clamp the fence 18 to, or release it from, the saw table 10, as will be described more fully later. The auxiliary fence member 22 has integral therewith a clamping portion 28, which is similarly shaped to the clamping portion 24, and comprises a hooked portion extending downwardly and which terminates in a foot portion 30. The foot portion 30 extends at right angles to the longitudinal direction of the main fence member 20 and engages in the portion of the groove 16 in the front wall of the saw table 10.

An extension fence 32 in the form of an inverted channel of U-section and having a flange 34 extending from one side thereof, is engaged over the main fence member 20 and slidable longitudinal therealong. The extension fence 32 has a slot 36 along the top thereof and through which engages the screw 26 by which the extension fence 32 is clamped in position on the main fence member 20. The length of the slot 36 determines the extent to which the extension fence 32 can be adjusted in either direction along the fence 18 as will be described more fully later.

The saw table 10 is provided with pads 38 at its lower four corners and on which it can be supported on a workbench. Switches 40 are provided in the front of the saw table for switching on and off and controlling an electric motor (not shown) housed in the saw table for driving the saw blade when present.

Referring now mainly to FIGS. 2 and 3, the auxiliary fence member 22 can be seen extending inside the hollow tubular main fence member 20 and having a vertical screw threaded bore 42 adjacent its inner end, the screw threaded bore 42 being threadedly engaged by the threaded shank 44 of the screw 26. Towards the outer end of the auxiliary fence member 22 adjacent the hooked portion thereof and adjacent the open end of the main fence member 22 (i.e. the left end in FIGS. 2 and 3), a pivot pin in the form of a peg or spindle extends horizontally through the auxiliary fence member 22. The ends of the pivot pin 46 are secured in and terminate in opposite side walls of the tubular main fence member 20. The dimensions of the auxiliary fence member 22 are selected so that it can be pivoted to and fro about the pivot pin 46 to such an extent that the distance between the foot portion 30 of the auxiliary fence member 22 and the corresponding foot portion 48 of the main fence member 20 varies sufficiently to effect clamping and release from clamping of the foot portions 30 and 48 in their respective opposite portions of the groove 16. Between the pivot pin 46 and the screw threaded bore 42, the auxiliary fence member 22 is waisted at 50. As can be seen from FIG. 2, both foot portions 30 and 48 extend downwardly below the main fence member 20 approximately the same distance. As can be seen more clearly from FIG. 3, the two foot portions 30, 48 also extend parallel to each other in a direction at right angles to the longitudinal direction of the fence 18. Each end of the transversely extending foot portions 30, 48 is formed with an inwardly extending foot 52 which slidably engages in the groove 16. The pair of feet 52 on each foot portion 30, 48 are spaced apart as shown in FIG. 4. FIG. 3 shows the inverted channel sectioned extension fence 32 fitting over the main fence member 20 with the flange 34 extending to one side. FIG. 2 shows the screw threaded stem 44 extending through the longitudinal slot 36 in the top of the extension slide 32, the head of the screw 26 firmly engaging the top of the extension fence 32 when screwed downwards to pivot the auxiliary fence member 22 counterclockwise in FIG. 2 to effect clamping between the clamping foot portions 30 and 48.

FIG. 5 shows a full plan view of the extension slide 32 and showing the portion thereof broken away in FIG. 2.

FIG. 6 is a section on the line 6-6 of FIG. 3 and shows the pivot pin 46 in broken lines to more clearly illustrate the right angle relationship between the pivot pin 46 and the screw shank 44. The engagement of the extension fence 32 around the main fence member 20 can be clearly seen, as can a short wall portion 54 of the extension 32 extending downwardly from the outer end of the flange 34 and at right angles thereto. This wall portion 54 forms a low bearing surface which is advantageously used when sheet-like or board-like material of small thickness is being sawn. The extension fence 32 can be arranged, as required, on the main fence member 20, in such a way that the flange 34 is located either on the side nearest the saw blade (as shown in FIG. 1) or on the side away from the saw blade, depending on how the fence 18 is being used. Preferably, the flange 34 faces the saw blade, and by appropriately positioning the extension fence 32 lengthwise relative to the saw blade, it is possible to prevent parts severed from the workpieces during cutting operations from being jammed between the saw blade and the fence 18.

In use, the screw 26 is unscrewed sufficiently to release the clamping effect of the clamping foot portions 30,48, this also rendering the extension slide 32 free to slide along the main fence member 20. The fence 28 is then moved laterally in FIG. 1 with the feet 52 sliding in opposite sections of the groove 16. When the fence 18 has been located in the desired lateral position, then the extension fence 34 is slid along the main fence member 20, and possibly over the extending portion of the auxiliary fence member 24, until located in the desired longitudinal position. Thereafter, the head of the screw 26 is turned to screw the shank 44 into the inner end of the auxiliary fence member 22 to shorten the distance between the foot portions 30 and 48, until the feet 52 clamp firmly in the respective opposite portions of the groove 16 to firmly locate the fence 18 in position. At the same time, the head of the screw 26 is caused to engage and clamp the top of the extension slide 32 against the top of the main fence member 20, so also locking the extension fence 32 in position. To reset either the lateral position of the fence 18 or the longitudinal position of the extension fence 32, the screw 26 is loosened and the above procedure repeated.

It will be appreciated that the present invention provides an adjustable fence which can readily be clamped at both ends to the saw table simply by tightening a single screw with one hand. Further, any desired position of the extension fence can also be fixed simultaneously by the tightening of this single screw.

It will also be appreciated that because of the slot 36, the extension fence can be displaced beyond the dimensions of the saw table, in order thereby to form an extended fence for longer workpieces.

The above described embodiment, of course, is not to be construed as limiting the breadth of the present invention. Modifications, and other alternative constructions, will be apparent which are within the spirit and scope of the invention as defined in the appended claims.