GB1598187A - Method for positioning work element/s for movement towards work piece/s - Google Patents

Description

(54) METHOD FOR POSITIONING WORK ELEMENT/S FOR MOVEMENT TOWARDS WORK PIECE/S (71) We, THE FURNITURE INDUSTRY RESEARCH ASSOCIATION, a British Company, organised under the laws of Great Britain, of Maxwell Road, Stevenage, Hertfordshire SGI 2EW, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- The present invention relates to a method of positioning at least one work element on a member, along which the or each element can be moved and releasably fixed thereto in a required position, in a work system in which the or each work element is moved towards at least one workpiece whereby the or each work element can be brought into working engagement with the or each workpiece at a required position. The method is suitably applicable in positioning saws or drill heads in woodworking machines.

On woodworking machines, the setting of the various saws, cutter blocks, and drill heads is generally facilitated with the use of graduated scales, vernier scales and. of latter years, with expensive mechanical and electronic devices with digital read-outs. At the same time, many machines are without any form of aid to setting and sets are achieved by a trial and error process.

Dial indicator gauges are universsaly used to effect controlled and accurate movements in many industries but the working range of such instruments is invariably restricted to a maximum of about 100 mm.

The method of the present invention may employ a simple but accurate dial gauge indexing system, in which the measuring range of a dial indicator can be substantially extended to provide a positioning system of any desired length.

According to the present invention there is provided a method of positioning at least one work element on a member, along which the or each work element can be moved and releasably fixed thereto in said position, in a work system in which the or each work element is moved towards at least one workpiece in a predetermined position, whereby the or each work element can be brought into working engagement with the or each workpiece at a required position, comprising providing and positioning a strip of material along said member in a known relative position to said workpiece, containing a plurality of equally spaced locating means of known spacing thereby forming an incremental system, providing a measuring means mountable on said strip having means to co-operate with the locating means, said measuring means being adapted to measure distances at least up to and equal to the distance between each locating means, positioning the or each work element along the member with said measuring means and strip so that the or each work element can be placed into working engagement with the or each workpiece at the required position.

Such a strip indexing system can be made by employing a length of steel strip through which pairs of round and elongated holes are pierced at precise intervals.

It is normally engisaged that the measuring means is in the form of a dial gauge, and the remainder of the following description refers to such a measuring means. However, other forms of measuring means may be used such as a micrometer head or linear transducer.

As previously mentioned holes are used to locate accurately the dial gauge, e.g. by means of ball ended feet fixed firmly to the dial gauge, where it may be retained in position by a permanent magnet. For example the dial gauge spindle has a total indicated travel of 20mm and each numbered graduation represents a spindle movement of Imm. Sub divisions giving a resolution of 0.1 mum are included on the scale.

The method of the invention is further explained with reference to the accompanying drawings in which: Figure I is a diagrammatic view of the dial gauge and indexing strip: Figure 2 is a front elevation of the dial gauge in the direction of arrow A in Figure 1; Figure 3 is a diagrammatic illustration of the method of the invention; Figure 4 is another diagrammatic illustration of the method of the invention.

Referring to Figure I, there is shown a strip of steel 1 having a plurality of holes 2a and 2b equally spaced on either side of the strip 1. In this embodiment the holes are spaced 20mm apart along the strip and hole 2a is of circular construction and hole 2b is in the form of an elongated slot. Placed along side the strip is a tape member 6 having markings thereon of 20mm intervals. A dial gauge 3 may be positioned in said holes 2a and 2b, the relative positioning of the dial gauge being indicated by the arrow 5 thereon adjacent the number on the tape 6. A spindle on the dial gauge 4 is adapted to read distances between the holes 2a, 2b, in the embodiment 20mm.

Referring to Figure 2 there is shown a view of the dial gauge in the direction of arrow A in Figure 1, which illustrates the method the dial gauge can be positioned on the strip. The base of the dial gauge includes two ball feet 7a and 7b spaced apart so as to fit respectively into holes 2a and 2b of strip 1. The balls 7a and 7b are held in screw members 8a and 8b screwed into the base of the dial gauge. A third foot 9 is provided to maintain the base of the dial gauge 3 parallel to the plane of the strip I and which simply rests on the strip 1. The dial gauge 3 includes a permanent magnet 10 which holds it in position on the strip 1.

It will be seen that the dial gauge 3 can be readily moved along the strip 1 into engagement with the holes 2a, 2b.

As mentioned above the strip 1 will normally be mounted on a member of the work system along which the or each work element is movable. By correctly positioning the strip on said member relative to said workpiece, the distance the or each work element should be placed along said member can be accurately measured using the strip and dial gauge.

An example of the present invention is described with reference to Figure 3. Figure 3 shows a method for accurately positioning a number ofdrilling heads I Ia. I lb, and 1 lc along their support member (not shown) and where the workpiece end stop 13 is permanently fixed in position.

In operation of the apparatus shown in Figure 3, the or each drilling head is supported and laterally positioned by the support beam member and lowered towards the workpiece 12 once the drill heads lla. 1 lb and 11 c have been positioned. Figure 3 diagrammatically illustrates such a situation where a typical task requires the drilling of holes at distances of 175, 927 and 1320mm from the end face of a component. In setting the machine, the dial gauge is initially positioned at position 160 on the strip, and the first head I Ia moved along until the gauge dial 3 indicates 15.0mm.

Similarly, the second head I Ib is set by locating the gauge 3 at positon 920 and moving it until the gauge 3 reads 7.0mm and the final head 1 lc with the gauge 3 at position 1320 with a zero reading on the dial gauge.

It will be appreciated that the strip must be positioned relative to the workpiece, i.e. the system has to be zeroed when it is initially fixed to the machine. The illustration indicates that the gauge strip I is fixed to the horizontal beam with the dial gauge 3 positioned to the right of each head. Although at first it may seem necessary to provide dial gauge spindle abutment faces directly in line with the axis of the drill spindles, it is found in practise that virtually any face of the drill head can be utilised.

However, it is unlikely that a feature common to all heads will be precisely the same distance away from the true axis of the drill spindles so zero adjust screws 14, typically standard 6mm set screws with lock nuts, are provided so that the distances can be adjusted to be equal.

Although, as will be apparent, numerous ways to zero the system can be adopted one method will be illustrated.

The simplest way to zero the system is to select a piece of timber with squared off ends and to mark on it lines at distances of say 200, 400 and 600mm from the work stop 13 on the left hand edge of the workpiece. With true running drill bits in the spindles, the drill heads are transversely adjusted to allow holes to be bored in the timber approximately in line with the markings. The precise positions of these holes are then determined with an appropriate measuring instrument which could result in values of 201.9; 339.7 and 600.8mm respectively. Starting with the first boring head, the dial gauge 3 is located in a suitable pair of holes and the strip 1 moved to the left or right until the gauge (with its spindle touching the zero-adjust screw 14) registers approximately 1 .9mum.

The strip 1 may then be secured in position, e.g. with countersunk head screws, and a final adjustment made to the zero adjust screw to allow the gauge to read I .9mm precisely. The numbered strip is then fixed in position so that the gauge arrow, adjacent to the ball ended feet, points to position 200. The numbering is then extended along the rest of the strip 1. The dial gauge 3 is then transferred to position 380 where the zero-adjust screw 14 on the second head is adjusted to cause the gauge 3 to read exactly 19.7mm and finally, with the gauge 3 in position 600, the zero-adjust screw 14 on the third head is adjusted to allow the dial gauge to register 0.8mm. It will be seen that after positioning the strip 1 relative to the workpiece 12, the drill heads can be accurately positioned on the support beam member to drill holes in the workpiece at any required distance from the work stop.

In systems where it is desirable to move the work stop, dial location strips can be effectively employed to enable their accurate positioning, so making the system more flexible. Figure 4 illustrates a similar set up to the previous example except that two workpiece stops 13a and 13b are employed and, for illustrative purposes, positions of 100 (mm) and 750 (mm) have been selected.

Depending upon machine configurations.

In this embodiment two strips la, lb are employed, one on the support beam member and one on the workpiece bench, and the two strips positioned relative to one another for example in a similar manner to the method described above.

To set the workpiece stops 13a, 13b in their required positions, the dial gauge 3 would be located at positions 100 and 740 and the stops moved, in turn, towards the dial gauge 3 until dial readings of zero and 1 Omm are achieved respectively.

In determining the positions of the various drill heads, the offset position of the work stops has to be added to the drawing dimensions. For instance the position of the first drilling head used to bore a hole at 120mm from the end face, require a setting position of 100 + 120 (mm). Likewise the position of the three other boring heads require settings of 400, 930 and 1075 (mm) respectively.

It will be appreciated that whilst spacings of 20mm between the locating means have been described, any increment of spacing may be used provided the dial gauge can measure at least the distance between each locating means. Furthermore whilst the locating means are preferably holes which receive the ball feet of the gauge, any suitable form of locating means can be used.

Whilst it is engisaged that the strip will normally be screwed to the member, any alternative fixing method may be used. In particular it may be an advantage to mount the strip in a casing containing magnets whereby the strip can be removeably attached to the member. Such an arrangement would only be possible if the member was of a magnet attracting material.

It will also be appreciated that whilst a numbered tape is preferably provided to be placed adjacent the strip, numbers may be printed or engraved on the strip itself.

WHAT WE CLAIM IS: 1. A method of positioning at least one work element on a member, along which the or each work element can be moved and releasably fixed thereto in said position, in a work system in which the or each work element is moved towards at least one workpiece in a predetermined position, whereby the or each work element can be brought into working engagement with the or each workpiece at a required position, comprising providing and positioning a strip of material along said member in a known relative position to said workpiece and containing a plurality of equally spaced locating means of known spacing thereby forming an incremental system, providing a measuring means mountable on said strip having means to co-operate with the locating means, said measuring means being adapted to measure distances at least up to and equal to the distance between each locating means, positioning the or each work element along the member with said measuring means and strip so that the or each work element can be placed into working engagement with the or each workpiece at the required position.

2. A method according to claim 1, wherein said locating means comprises a plurality of equally spaced pairs of holes in the strip.

3. A method according to claim 1 or 2, wherein said means to co-operate with said locating means comprises ball feet.

4. A method according to claims 1, 2 or 3, wherein said measuring means includes a magnet and said strip is metal to which said magnet is attracted thereby fixing the measuring means to said strip.

5. A method according to any preceding claims wherein said strip is positioned and a point on said strip is selected such that said point is relative to a fixed point on said workpiece, whereby the or each work element is placed a distance along said member corresponding to the distance of the required position from said fixed point on the workpiece.

6. A method according to claim 5, further comprising providing markings on or adjacent said strip by each pair of holes representing the distance of each pair of holes from said point on said strip whereby the distance the or each work element is to be moved along said member from said point can be measured.

7. A method according to any of claims 1 to 4, wherein two or more workpieces and work elements are provided, further comprising providing a second strip indentical to said first mentioned strip adjacent said workpieces, positioning a point on said first strip relative to a point on said second strip, positioning a fixed point on each workpiece a distance from said point on said second strip,

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (12)

**WARNING** start of CLMS field may overlap end of DESC **. where the zero-adjust screw 14 on the second head is adjusted to cause the gauge 3 to read exactly 19.7mm and finally, with the gauge 3 in position 600, the zero-adjust screw 14 on the third head is adjusted to allow the dial gauge to register 0.8mm. It will be seen that after positioning the strip 1 relative to the workpiece 12, the drill heads can be accurately positioned on the support beam member to drill holes in the workpiece at any required distance from the work stop. In systems where it is desirable to move the work stop, dial location strips can be effectively employed to enable their accurate positioning, so making the system more flexible. Figure 4 illustrates a similar set up to the previous example except that two workpiece stops 13a and 13b are employed and, for illustrative purposes, positions of 100 (mm) and 750 (mm) have been selected. Depending upon machine configurations. In this embodiment two strips la, lb are employed, one on the support beam member and one on the workpiece bench, and the two strips positioned relative to one another for example in a similar manner to the method described above. To set the workpiece stops 13a, 13b in their required positions, the dial gauge 3 would be located at positions 100 and 740 and the stops moved, in turn, towards the dial gauge 3 until dial readings of zero and 1 Omm are achieved respectively. In determining the positions of the various drill heads, the offset position of the work stops has to be added to the drawing dimensions. For instance the position of the first drilling head used to bore a hole at 120mm from the end face, require a setting position of 100 + 120 (mm). Likewise the position of the three other boring heads require settings of 400, 930 and 1075 (mm) respectively. It will be appreciated that whilst spacings of 20mm between the locating means have been described, any increment of spacing may be used provided the dial gauge can measure at least the distance between each locating means. Furthermore whilst the locating means are preferably holes which receive the ball feet of the gauge, any suitable form of locating means can be used. Whilst it is engisaged that the strip will normally be screwed to the member, any alternative fixing method may be used. In particular it may be an advantage to mount the strip in a casing containing magnets whereby the strip can be removeably attached to the member. Such an arrangement would only be possible if the member was of a magnet attracting material. It will also be appreciated that whilst a numbered tape is preferably provided to be placed adjacent the strip, numbers may be printed or engraved on the strip itself. WHAT WE CLAIM IS:

1. A method of positioning at least one work element on a member, along which the or each work element can be moved and releasably fixed thereto in said position, in a work system in which the or each work element is moved towards at least one workpiece in a predetermined position, whereby the or each work element can be brought into working engagement with the or each workpiece at a required position, comprising providing and positioning a strip of material along said member in a known relative position to said workpiece and containing a plurality of equally spaced locating means of known spacing thereby forming an incremental system, providing a measuring means mountable on said strip having means to co-operate with the locating means, said measuring means being adapted to measure distances at least up to and equal to the distance between each locating means, positioning the or each work element along the member with said measuring means and strip so that the or each work element can be placed into working engagement with the or each workpiece at the required position.

2. A method according to claim 1, wherein said locating means comprises a plurality of equally spaced pairs of holes in the strip.

3. A method according to claim 1 or 2, wherein said means to co-operate with said locating means comprises ball feet.

4. A method according to claims 1, 2 or 3, wherein said measuring means includes a magnet and said strip is metal to which said magnet is attracted thereby fixing the measuring means to said strip.

5. A method according to any preceding claims wherein said strip is positioned and a point on said strip is selected such that said point is relative to a fixed point on said workpiece, whereby the or each work element is placed a distance along said member corresponding to the distance of the required position from said fixed point on the workpiece.

6. A method according to claim 5, further comprising providing markings on or adjacent said strip by each pair of holes representing the distance of each pair of holes from said point on said strip whereby the distance the or each work element is to be moved along said member from said point can be measured.

7. A method according to any of claims 1 to 4, wherein two or more workpieces and work elements are provided, further comprising providing a second strip indentical to said first mentioned strip adjacent said workpieces, positioning a point on said first strip relative to a point on said second strip, positioning a fixed point on each workpiece a distance from said point on said second strip,

positioning each work element a distance along said member corresponding to the distance of the required position from said fixed point on each workpiece.

8. A method according to claim 7, further comprising providing markings on or adjacent each pair of holes on both strips representing the distance of each pair of holes from said points on said strips, whereby the distance of the workpiece fixed points to the point on said second strip and the distance each work element is to be moved along said member from said point on said first strip can be measured.

9. A method according to any of claims 5 to 8 wherein said fixed point on the workpiece is a work stop.

10. A method according to any preceding claims wherein the or each work element comprises drill heads, the or each workpiece is wood, and said member is a drill head support beam of a woodworking machine.

II. A method according to any preceding claim wherein said measuring means is a dial gauge, micrometer head, or linear transducer.

12. A method of positioning at least one work element on a member, substantially as hereinbefore described, with reference to the accompanying drawings.