GB2396137A

GB2396137A - Pivoted multi arm drawing instrument with apertures.

Info

Publication number: GB2396137A
Application number: GB0404370A
Authority: GB
Inventors: Sally Werner
Original assignee: Individual
Current assignee: Individual
Priority date: 1999-11-18
Filing date: 2000-11-20
Publication date: 2004-06-16
Anticipated expiration: 2020-11-20
Also published as: GB0404370D0; GB2396137B

Abstract

The invention provides a pivoted drawing instrument which comprises at least two straight arms 1,2 joined by a pivot pin 3. Each of the arms has one or more series of apertures 4,4' in it. Through these a writing point such as a nib or pencil may be used to mark a sheet, etc. A pair of arms may be used to mark a circle. If three arms 1,2,2' are connected using three pivot pins 3 to form a triangle, suitably placed apertures on pairs of sides of the triangle may be used to define pairs of points which lie on parallel lines, thus facilitating the drawing of such. Where more than a single series of apertures is provided on an arm, the spacing between the apertures may be different, and/or the apertures of different series may be suitable for different types of marker, such as thick pen nib and fine pointed marking instrument.

Description

Improved Drawing Instruments Field of the 'nvention

5 The present invention relates to improved drawing instruments that may serve as a divider to define regular mark spacings and which is particularly useful for marking out parallel or radiating lines or may, for example, serve as a simple compass.

Background to the Invention

C:a!!inranhers, designers and technical draughtspers^ns lo.!!! be a!! t^^ fam.i'.a. ^:ith the frustration involved in accurately ruling or marking up a sheet of paper where regular marks or divisions are required.

15 When ruling a sheet of paper for calligraphy, even with a drawing board fitted with a T-square and set-square, the process is tedious and time consuming, involving measuring millimetre after millimetre along a ruler, and by virtue of this may often lead to errors arising.

20 For calligraphers in particular the construction lines must be precise. Even the tiniest variations will be seen in the finished works. They usually work with X number of lines to be fitted into a required area. The spacing between the parallel lines more often than not will involve fractions of a millimetre.

25 For the present inventor the conventional process represented a major problem to be resolved which was inadequately addressed by existing drawing instruments, all of which have their own respective limitations. It is accordingly a general objective of the present invention to provide apparatus to avoid the need for repetitive measurements when preparing a sheet of paper for calligraphy or other formal 30 graphic work and which, furthermore, is simple, economical, accurate and efficient in use and which may be used in a wide range of different situations.

Summary of the Invention

According to a first aspect of the present invention there is provided a drawing instrument which comprises an elongate substantially flat and substantially rigidly 5 straight arm that is adapted to be placed flat on to a sheet of paper and that is combined, at least in use, with a pivot pin means that projects from the arm, suitably through an aperture in the arm, to be able to pin the drawing instrument to the paper while allowing the instrument to pivot thereabout, the arm having a first plurality of apertures therein, in series, at spaced intervals there along, through 10 each of which apertures a tip of a writing instrument may be inserted to mark the peae beneath and a.cecond such plurality of apertures, in series there a!cng, the apertures of the second series being for one particular type of writing instrumenVmarker such as, for example, a thick pen nib while the apertures of the other series are for a different marker such as, for example, a finer pointed marking 1 5 instrument.

Preferably the plurality of apertures of each series are provided at regularly spaced intervals. 20 Preferably the second series of apertures is substantia!!y,oara!!e! to the fi,st se,ies of apertures.

Preferably a pivot pin aperture is provided at or near to a first end of each series of apertures to allow pivot pin means to be projected there through.

Particularly preferably each series has at least two pivot pin apertures at one end that are spaced apart by less than the regular interval of the marker apertures to enable use of the device to define distances that are not integer multiples of the marker aperture interval.

Suitably the drawing instrument provided in combination with the pivot pin means is an elongate pointed instrument having a form similar to a pencil but with a sharp pointed tip to pin the drawing instrument to the paper.

In another embodiment of the drawing instrument, the drawing instrument comprises at least a pair of substantially flat and substantially rigidly straight arms having, in use, a pivot pin means projecting substantially perpendicularly from one of the arms and through an aperture in the other of the arms by means of which the 5 arms are fastened together and one arm may be pivoted to a desired orientation relative to the other, wherein each arm has a plurality of apertures therein, in series, at regularly spaced intervals therealong through each of which a pencil lead or pen tip or other marker may be inserted to mark a page placed beneath the instrument.

10 Preferably the pair of arms are fastened together with an end of one arm n\!erianning an adjacent end of the ^the, armm.

Particularly preferably the arms are flexible relative to the plane of the paper while remaining substantially rigidly straight in order that an upper one of the arms that 15 overlaps the arm that is placed against the paper may be pressed into close contact with the paper for substantially the whole of its length.

Suitably the pivot pin means co-operatively engages with a cap or nut to securely fasten one arm of said pair of arms to the other arm of said pair of arms.

2Q The pivot pin means is advantageously readily Remountable and positionable at a range of different locations along the length of each respective arm.

The pivot pin means preferably may be inserted through any one of the plurality of 25 apertures in each of the arms.

Suitably each arm has more than one series of apertures running along its length and suitably substantially parallel to each other, the apertures of one series being spaced apart by one fixed interval and the apertures of another series being at a 30 different fixed interval and/or the apertures of one series being for one particular type of marker such as, for example, a thick pen nib, while the apertures of another series are for a different marker such as, for example, a finer pointed marking instrument.

Suitably more than two arms are provided and whereby three arms may be linked together to form a triangle or four arms linked together to form a parallelogram using an appropriate number of pivot pin means, one at each joint.

5 Preferably each of the arms is of transparent material.

Suitably the apertures on each arm are spaced apart at the same intervals as the apertures on each other arm.

10 Preferably the series of apertures to receive a marker on each arm are at substantia!!y the serge distance f,^r.. a straight edge of the, especLive aril, as the corresponding series of apertures on the other arm.

Markings may be provided on each arm to indicate distance measurement with 15 respect to the distance along the series of apertures.

Additional position fixing means may be further provided to fix the pair of arms at a desired angular spacing apart, if the pivot pin means securing cap, nut or the like is inadequate. Brief description of the drawings

Preferred embodiments of the present invention will now be more particularly described, by way of example, with reference to the accompanying drawings 25 wherein: Figure 1 is a plan view of a preferred embodiment of drawing instrument of the first aspect of the present invention; 30 Figure 2 is a plan view of a preferred embodiment of drawing instrument of the second aspect of the present invention; Figure 3 is a transverse sectional view through the drawing instrument along the line Ill- n in Figure 2;

Figures 4A and 4B are schematic diagrams illustrating deployment of the preferred embodiment of drawing instrument for drawing of parallel lines; Figure 5 is a schematic view similar to that of Figures 4A and B but illustrating use 5 of the instrument to draw radiating lines; Figure 6 is a schematic plan view of a drawing instrument formed of three arms for use to draw a triangle or parallel lines; and 10 Figure 7 is a schematic plan view of a drawing instrument comprising four arms linked to form a para!!elogram.

Description of the Preferred embodiments

15 Referring firstly to figure 1, the illustrated drawing instrument comprises an elongate substantially flat and substantially rigidly straight arm 10 of transparent plastic material. It is illustrated here as being a straight edged strip in the form of a rule. It may be of other shapes and may be wholly rigid or may be somewhat flexible provided that this does not affect its being substantially rigidly straight.

A distinctive feature of the drawing instrument is that it has more than one series of spaced apart apertures 40 extending there along.

Running along the length of the arm 10 close to a first edge thereof is a first series 25 11 of apertures 40 at regularly spaced intervals. Each of the apertures 40 is of a size to accommodate a marking tip of a fine felt tip pen 18. At one end of the arm 10 there is a pivot pin aperture 14 to receive a sharp tip of a hand held pivot pin instrument 15 that resembles a pencil with a rigid, suitably metal, pointed tip. The pivot pin instrument 15 is a convenient means of releasably pinning the arm 10 flat 30 to a piece of paper while enabling the arm 10 to pivot about the tip of the pivot pin 15. Running parallel to the first series 11 of apertures 40 is a second series 12 of apertures 40' the apertures 40' being at regularly spaced intervals, but intervals 35 which are different from the intervals of the first series of apertures 11 and in which

the apertures 40', are substantially larger than the apertures 40 of the first series 11. This second series 12 of apertures 40' is suited for use of a much larger tipped marking instrument - e.g. a substantially more blunt felt tip. Equally, the first series 11 could be suited for use of a pencil whereas the second series 12 is suited for use 5 of a conventional felt tip or other relatively larger tipped marking instrument.

The second series 12 of apertures has its own pivot pin aperture 16 at one end ( or for that matter at either end).

10 A further series 13 of spaced apart apertures 40" is provided running the length of the arm 10 along the other side edge of the arm 10. In this third series 13 of apertures 40" the apertures 40" are a very fine bore and suited only to the finest tip marking instrument. This third series 13 also has its own pivot pin aperture 17.

15 The pivot pin apertures 14, 16, 17 of each series are all small apertures of uniform size. Furthermore, there is for each case, suitably an alternative pivot pin aperture 14b, 16b, 17b aligned with the series of apertures immediately next to the initial pivot pin aperture, 14a, 16a, 17a that is at a spacing to allow adjustment of the centre point of the circle to within, for example, a half spacing or quarter spacing 20 relative to the normal spacings between the apertures 40 of the respective series.

The independent pivot pin instrument 15 can be inserted through any of the pivot apertures 14, 16, 17 for use of the selected series 11, 12, 13 of marker apertures 40. This drawing instrument 10 is useful to serve as a divider to define regular mark spacings or may, for example, function as a simple compass. It is extremely compact, simple to use and versatile as well as being very cheap to manufacture in contrast to conventional compasses or dividers.

Referring now to Figures 2 and 3, the drawing instrument of the second aspect of the invention comprises a pair of substantially flat and substantially rigidly straight arms 1, 2 of transparent plastics material and which are pivotally fastened together at one end by a pivot pin 3. These arms could be 30 or 45 cm or more in length for 35 some uses.

Each of the arms 1, 2 has a series of apertures 4, 4', preferably twenty or more or even more than 100 extending along its length but close to one longitudinal edge.

These apertures 4, 4' are intended to receive the tip of a marker such as a pen or 5 pencil to mark paper placed beneath the drawing instrument. Although such markers could be integrally built into the drawing instrument this is generally undesirable since the markers would be difficult to monitor, control and, indeed, maintain. 10 The apertures 4, 4' in each series are spaced substantially equidistantly apart, suitably of the order of 2 to 2.5 mm apart for use with 0.5 mm diameter pencil leads.

Although each arm 1, 2 is illustrated with only one series of apertures 4, 4', respectively, further series of apertures may be provided on each arm 1, 2 suitably parallel to the first series and spaced apart by lesser or greater intervals or which 15 have larger or smaller aperture sizes to suit different types of marker.

The pivot pin 3 that pivotally links the arms 1, 2 is illustrated in Figure 3. This is suitably a short metal pin having a head 5 at one end and the shank of which passes through an aperture in one arm 1 and through a corresponding aperture in 20 the other arm 2 and is secured in place by a cap 6. Cap 6 suitably is pointed to serve as a pivot point or may, for example, be replaced by an annular collar or a small nut. In principle, the pivot pin could hold the two arms 1, 2 together purely by its friction fit into the apertures of the arms 1, 2 but since there must be generally sufficient play for the arms 1, 2 to pivot apart to any desired angle, it is preferable to 25 provide some means of securing the pivot pin 3 in place, holding the two arms 1, 2 together and which is tightenable to enable the selected angle to be fixed during use. The sizes of the apertures 4 should closely accommodate the marker to be used 30 therewith, for precision. The edges of the apertures 4 are suitable bevelled.

Furthermore, the straight longitudinal edges of the arms 1, 2 are suitably bevelled in order to, for example, assist in their use with ink pens on finished artwork.

Although each of the arms 1,2 is substantially rigidly straight it is preferred that they 35 are relatively thin and flexible relative to the plane of the paper on which the drawing

instrument is to be used. This enables an upper one of the two arms 1, 2 to overlap the lower arm that is placed against the paper in order that the upper arm may be pressed into close contact with the paper for substantially the whole of its length.

Furthermore, the arms 1, 2 may be pivoted substantially through 360 relative to 5 each other.

The nature of the pivot pin 3 is suitably such that it may be demounted at will to enable the arms 1, 2 to be used independently of each other, if desired.

Furthermore, the position at which the pivot pin 3 pivotally links together the arms 1, 10 2 is suitably variably adjustable between any of a number of different positions.

Indeed, the pivot pin 3 is most conveniently insertable through any of the a,nerh!res 4, 4' that may be used for the marker. This is particularly useful where three or more arms 1, 2 are to be joined together as a triangle or parallelogram to enable different sizes or angles to be selected.

Turning now to Figure 4, use of the device to enable drawing of parallel lines will shortly be described.

Firstly it will be noted that use of either of the arms of the instrument for marking 2Q marks at regularly spaced apart intervals on a piece of paper is straightforward and seif-expianatory. A single arm 1, 2 on its own may be used for this purpose, by simply marking the page through each one or selected ones of the apertures 4 of the arm 1 or 2. This can be of use when, for example, defining the equidistant spacing apart of parallel lines or, for example, the spacing apart of concentric 25 circles to be drawn with a compass. The act of drawing parallel lines may be achieved by a number of different approaches using the device of the invention.

In one mode of use to define parallel lines, the device comprising the two arms 1, 2 linked together by the pivot pin 3 may be fixed at a desired angular position through 30 tightening of the cap or nut 6 of the pivot pin 3.

The drawing instrument with the desired angle set is then placed with one longitudinal edge of one arm 2 against a tri-square or similar fixed straight edged device. A series of vertical or diagonal parallel lines may then be drawn across the 35 page simply by drawing along a longitudinal edge of the other arm 1 of the

instrument remote from the base line defined by the tri-square; and then shifting the instrument to the led or right and drawing a further line along the same longitudinal edge of the instrument. The angle of slope of the parallel lines is dictated by the angle between the arms 1, 2 of the instrument. Furthermore, simply by tilting the 5- whole instrument about the pivot pin 3 until the other arm 2 rests against the base line defined by the tri-square it is possible to draw parallel lines that slope to the left rather than to the right. Similarly, by moving the tri-square to a position above the defined base line and placing the instrument below it, it Is possible to define lines in any chosen direction through 360 . Indeed, the use of a tri-square or the like is not 10 essential but preferable for specific tasks.

The ability of the instrument of the present invention to define mark spacings to the right and left of a notional Y axis is not only useful for drawing parallel lines. It also enables lines to be drawn radiating from a focal point with considerable ease. This 15 is illustrated in Figure 5. For this the user marks a series of dots with the instrument in the position illustrated in Figure 4A and then shifts the instrument along to the position illustrated in Figure 4B to define an inverted "V" shape in dots, ensuring that the second series of dot marks is arranged so that at least one of the dot marks coincides with a dot mark of the first series of dots. By then simply drawing a 20 perpendicular line from the apex point to the base this will define the [ecus, and the remaining radiating lines may be drawn in from the focal point to each of the marked dots.

The drawing instrument of the present invention may also be used as a compass to 25 draw circles and is particularly good for large circles.

In the context of drawing parallel lines, there are a number of different ways of doing this beyond that described above and particularly usefully these can dispense with the need for a drawing board and T-square.

By linking together three arms 1, 2, 2' as illustrated in Figure 6 to form a triangle, a respective pivot pin 3 is provided at each apex of the triangle as the link and fastening means between each arm 1, 2, 2'. By virtue of the ability to insert the pivot pin 3 through any of the series of apertures 4, 4' it is possible to select 35 between a wide range of different sizes and shapes of triangle. The ability to form

the drawing instrument into a triangular configuration is not simply a convenient means of drawing triangles. More importantly, it enables the user to mark out the writing paper for drawing of parallel lines without need for any base surface such as a T-square along which to slide the instrument. Provided that the sides of the 5 triangle form are of equal length then the apertures 4, 4' of each arm 1, 2 will be aligned with each other such as to enable dot marks made through apertures 4 of one arm 1 to be joined to dot marks formed in the apertures 4' of the other arm 2 to provide the required parallel lines.

10 To assist in this it is convenient to have numbering or other labelling at intervals along the length of each arm 1, 2 so that the corresponding labelled anerh!re I' on the second arm 2 can be found for the aperture 4 of the first arm 1.

This same process can be used when configuring the drawing instrument as a 15 parallelogram using four arms 1, 2, 2', 2". Such a configuration has the further benefit that it can be used for drawing of grids, i.e. intersecting sets of parallel lines, with ease rather than simply parallel lines in one direction. Any of the pivots pins 3 may be used as a pivot for rotating the parallelogram about an apex. Furthermore, the parallelogram may be extended or collapsed about the pivots 3.

T he device of the invention need not simply be used to draw equidistantly spaced parallel lines but can, of course, be used to draw unevenly spaced parallel lines or grouped/multi-spaced parallel lines such as, for example, musical staves simply by selecting appropriate groups of holes along each arm when marking the paper.

25 Adjustment of the space between parallel lines can be achieved simply by adjusting the angle between the first and second arms 1, 2 or by the selection of the apertures 4 on each arm 1, 2 to be used.

Grouped parallel lines such as staves can, of course, also be formed by marking 30 the dot marks for the stave through the selected group of apertures 4 and then shifting the device vertically upwardly or downwardly e.g. by moving the T-square down-wardly to mark out the next stave.

The drawing instrument of the second aspect of the present invention may be sold as a kit of parts. Preferably the kit has several interchangeable and inter-

connectabie arms.

5 Suitably at least 4 arms 1, 2, 2", 2"' are provided in a set, so that the first pair can be joined and used joined together. When the angle required for the spacing is different to that required for the slope of the lines the other two arms can be joined to each other and both pairs can be used, ie. one for marking the spaces and the other for drawing the lines. Then in each pair the angle can remain fixed or stored 10 and the need to re-set the angle is eliminated. This is very advantageous when the same spacing or parallel lines are to be repeated later and elsewhere Although we have described and illustrated the arms as being simply straight, they may be formed with tangential extensions to have an Lshape, for example. Where 15 the arms are supplied in kit form there is suitably at least one arm that is L-shaped.

Other shapes may also be useful.

Claims

Claims

1 A drawing instrument which comp,ises an elongate substantially fiat and substantially rigidly straight arm that is adapted to be placed flat on to a 5 sheet of paper and that is combined, at least in use, with a pivot pin means that projects from the arm, suitably through an aperture in the arm, to be able to pin the drawing instrument to the paper while allowing the instrument to pivot thereabout, the arm having a first plurality of apertures therein, in series, at spaced intervals there along, through each of which apertures a tip 10 of a writing instrument may be inserted to mark the page beneath, and a second such plurality of apertures; in series there along, the apertures of the second series being for one particular type of writing instrumenVmarker such as, for example, a thick pen nib while the apertures of the other series are for a different marker such as, for example, a finer pointed marking 1 5 instrument.

2. A drawing instrument as claimed in Claim 1, wherein the plurality of apertures of each series are provided at regularly spaced intervals.

20 3. A drawing instrument as claimed in Claim 1 0! 2, wherein the second series of apertures is substantially parallel to the first series of apertures.

4. A drawing instrument as claimed in Calim 1, 2 or 3, wherein a pivot pin aperture is provided at or near to a first end of each series of apertures to 25 allow pivot pin means to be projected there through.

5. A drawing instrument as claimed in Claim 4 wherein each series of apertures has at least two pivot pin apertures at one end that are spaced apart by less than a regular interval of the marker apertures to enable use of the device to 30 define distances that are not integer multiples of the marker aperture interval. 6. A drawing instrument as claimed in Claim 1, 2, 3 or 4 or 5 in combination with a pivot pin means that is an elongate pointed instrument having a form

similar to a pencil but with a sharp pointed tip to pin the drawing instrument to the paper.

5 7. A drawing instrument as claimed in any preceding claim, which comprises at least a pair of substantially flat and substantially rigidly straight arms having, in use, a pivot pin means projecting substantially perpendicularly from one of the arms and through an aperture in the other of the arms by means of which the arms are fastened together and one arm may be pivoted to a 10 desired orientation relative to the other, wherein each arm has a plurality of apertures therein! in series at reaulariv spaced intenie!s ther;ea!^ng thrcuyh each of which a pencil lead or pen tip or other marker may be inserted to mark a page placed beneath the instrument.

15 8. A drawing instrument as claimed in Claim 7 wherein the pair of arms are fastened together with an end of one arm overlapping an adjacent end of the other arm.

9. A drawing instrument as claimed in Claim 8, wherein the arms are flexible 20 relative to the plane of the paper while remaining substantially rigidly st, eight in order that an upper one of the arms that overlaps the arm that is placed against the paper may be pressed into close contact with the paper for substantially the whole of its length.

25 10. A drawing instrument as claimed in any of claims 7 to 9 wherein the pivot pin means co-operatively engages with a cap or nut or the like to securely fasten one arm of said pair of arms to the other arm of said pair of arms.

11. A drawing instrument as claimed in any of Claims 7 to 9, wherein the pivot 30 pin means is readily Remountable and positionable at a range of different locations along the length of each respective arm.

12. A drawing instrument as claimed in Claim 11, wherein the pivot pin means may be inserted through any one of the plurality of apertures in each of the 35 arms.

13. A drawing instrument as claimed in any of Claims 7 to 12, wherein each arm has more than one series of apertures running along its length and suitably substantially parallel to each other, the apertures of one series being spaced 5 apart by one fixed interval and the apertures of another series being at a different fixed interval and/or the apertures of one series being for one particular type of marker such as, for example, a thick pen nib, while the zpe,ures of another series are for a different marker such as, for example, a finer pointed marking instrument.

14. A drawing instrument as claimed in any of Claims 7 to 1-9 Wherein more than two arms are provided and whereby three arms may be linked together to form a triangle or four arms linked together to form a parallelogram using an appropriate number of pivot pin means, one at each joint.

15. A drawing instrument as claimed in any of Claims 7 to 14 wherein each of the arms is of transparent material.

16. A drawing instrument as claimed in any of Claims 7 to 15 wherein the 20 apertures on each arm are spaced apart at the same inten!a!s es the apertures on each other arm.

17. A drawing instrument according to any of Claims 7 to 16 wherein the series of apertures to receive a marker on each arm are at substantially the same 25 distance from a straight edge of the respective arm as the corresponding series of apertures on each other arm.

8. A drawing instrument as claimed in any of Claims 7 to 17 wherein markings are provided on each arm to indicate distance measurement with respect to 30 the distance along the series of apertures.

19. A drawing instrument according to Claim 10 wherein the cap or nut or the like is adjustable to tighten one arm against the other to selectively fix the angle between the arms.

20. A drawing instrument according to any of Claims 7 to 19 wherein position fixing means independent of the pivot pin means are further provided to fix the pair of arms at a desired angular spacing apart.

5 21. A drawing instrument as hereinbefore described with reference to any suitable combination of the accompanying drawings.

22. A drawing instrument according to any preceding claim, wherein the second series of apertures has its apertures at different intervals to the apertures of 10 the first series of apertures.

Amendments to the claims have been filed as follows 1. A drawing instrument which comprises at least a pair of substantially flat and substantially rigidly straight arms having, in use, a pivot pin means projecting 5 substantially perpendicularly from one of the arms and through an aperture in the other of the arms by means of which the arms are fastened together and one arm may be pivoted to a desired orientation relative to the other, wherein each arm has a plurality of apertures therein, in series, at regularly spaced intervals therealong through each of which a pencil lead or pen tip or 10 other marker may be inserted to mark a page placed beneath the instrument 2. A drawing instrument as claimed in Claim 1, wherein the pair of arms are fastened together with an end of one arm overlapping an adjacent end of the 15 other arm.

3. A drawing instrument as claimed in Claim 2, wherein the arms are flexible relative to the plane of the paper while remaining substantially rigidly straight in order that an upper one of the arms that overlaps the arm that is placed 20 against the paper may be pressed into close contact with the paper for substantially the whole of its length.

4. A drawing instrument as claimed in any of claims 1 to 3, wherein the pivot pin means co-operatively engages with a cap or nut or the like to securely 25 fasten one arm of said pair of arms to the other arm of said pair of arms.

5. A drawing instrument as claimed in any of Claims 1 to 3, wherein the pivot pin means is readily Remountable and positionable at a range of different locations along the length of each respective arm.

6. A drawing instrument as claimed in Claim 5, wherein the pivot pin means may be inserted through any one of the plurality of apertures in each of the arms.

7. A drawing instrument as claimed in any of Claims 1 to 6, wherein each arm has more than one series of apertures running along its length and suitably substantially parallel to each other, the apertures of one series being spaced apart by one fixed interval and the apertures of another series being at a 5 different fixed interval and/or the apertures of one series being for one particular type of marker such as, for example, a thick pen nib, while the apertures of another series are for a different marker such as, for example, a finer pointed marking instrument.

10 8. A drawing instrument as claimed in any of Claims 1 to 7, wherein more than two ari-,-'s are provided and whereby three arms may be linked together to form a triangle or four arms linked together to form a parallelogram using an appropriate number of pivot pin means, one at each joint.

15 9. A drawing instrument as claimed in any of Claims 1 to 8, wherein each of the arms is of transparent material.

10. A drawing instrument as claimed in any of Claims 1 to 9, wherein the apertures on each arm are spaced apart at the same intervals as the 20 apertures on each other arm.

11. A drawing instrument according to any of Claims 1 to 10, wherein the series of apertures to receive a marker on each arm are at substantially the same distance from a straight edge of the respective arm as the corresponding 25 series of apertures on each other arm.

12. A drawing instrument as claimed in any of Claims 1 to 11, wherein markings are provided on each arm to indicate distance measurement with respect to the distance along the series of apertures.

13. A drawing instrument according to Claim 4, wherein the cap or nut or the like is adjustable to tighten one arm against the other to selectively fix the angle between the arms.

lid

14. A drawing instrument according to any of Claims 1 to 13, wherein position fixing means independent of the pivot pin means are further provided to fix the pair of arms at a desired angular spacing apart.

5 15. A drawing instrument as hereinbefore described with reference to any suitable combination of the accompanying drawings.

16. A drawing instrument according to any preceding claim, wherein the second series of apertures has its apertures at different intervals to the apertures of 10 the first series of apertures.