GB2415663A

GB2415663A - Folding blackboard drawing aids

Info

Publication number: GB2415663A
Application number: GB0414750A
Authority: GB
Inventors: Jeremy Gordon Lawson
Original assignee: Helix Ltd
Current assignee: Helix Ltd
Priority date: 2004-07-01
Filing date: 2004-07-01
Publication date: 2006-01-04
Anticipated expiration: 2024-07-01
Also published as: GB2439466B; GB2439466A; GB0414750D0; GB0712838D0; GB2415663B

Abstract

A set square 10 has two symmetrical panels foldable joined by a hinges 16, 18. Each panel has front and back surfaces arranged so that, when the drawing aid 10 is in an unfolded condition, the front and back surfaces of the panels are coplanar. Each hinge has a cylindrical inner and a hollow bearing (60, 66 figure 2). Parts of each hinge are formed separately from the panels so that when the drawing aid is unfolded no part of either panel extends forward of the front surface or rearward of the back surface. Handle 20 has two T-section securing projections (30, 32, figure 2) which may pass through apertures (40, 42 figure 2) in the panels. The handle may be slid towards the right angles corner of the set square to retain the panels in position. A blackboard ruler has panels 102, 104, 106 with handle sections 108, 110 having T-section securing projections 120,122,124. Alternatively, the ruler may be formed from two panels joined by a hinge.

Description

STATIONERY ITEMS

The present invention relates to stationery items, particularly but not exclusively, to drawing aids for use with a blackboard or whiteboard.

Stationery items such as drawing aids for use with a blackboard or whiteboard are quite large and are often provided in foldable or modular form. Foldable stationery items sometimes include a hinge which projects from a flat plane of the rest of the stationery item when it is unfolded.

Often such stationery items require some form of marking which can be seen when they are unfolded.

Modular stationery items for use on blackboards or whiteboards can be quite long e.g. 1 metre long rulers. It can be difficult to securely attach different panels making up each item securely together.

The present invention provides a stationery article comprising a first member and a second member foldably joined by a hinge, each member having respective front and back surfaces arranged such that, when the article is an unfolded condition, the front surfaces are substantially coplanar with each other and the back surfaces are substantially coplanar with each other, wherein at least part of the hinge is formed separately from the two members such that, when the article is in the unfolded configuration no part of either of the members extends forward of the front surface or rearward of the back surface.

This can enable the surface decoration of the members to be applied easily, for example by a printing process, since they are flat and can be laid on a flat surface and printed.

The stationery article may by a drawing aid, which may form part of a geometry set.

The present invention further provides a stationery article comprising a first segment, a second segment, and a handle arranged to cooperate with the first and second segments to maintain them in a desired position relative to each other.

The segments may comprise panels or sections.

Preferred embodiments of the present invention will now be described by way of example only with reference to the accompanying drawings in which: Figure 1 is a perspective view from the front of a geometry article according to a first embodiment of the invention; Figure 2 is a detailed perspective view from the rear of part of the article of Figure 1; Figure 3 is a perspective view of the article of Figure 1 in a folded state; Figure 4 is a detailed perspective view from the front of part of the article of Figure 1 in a fully dismantled state; Figure 5 is a detailed perspective view from the front of part of the article of Figure 1 in a partially assembled state; Figure 6 is a detailed perspective view from the front of part of the article of Figure 1 in a further partially assembled state; Figure 7 is a perspective view of a geometry article according to a second embodiment of the invention; Figure 8 is a perspective view from the rear of part of the article of Figure 7 in a partially assembled state; and Figure 9 is a detailed perspective view from the rear of part of the article of Figure 7 in a partially dismantled state.

Referring to Figure 1, a set square 10 comprises a body 11 formed in two symmetrical panels 12, 14 joined together by two hinges 16, 18 so that they can be folded about a fold axis X-X between an unfolded condition, as shown, and a folded condition. The set square 10 further comprises a handle 20 that can be removably secured to the two panels 12, 14. The body is in the shape of a right angled triangle having a long side lla and two equal length short sides lib. The folding axis extends from the right angled corner to the centre of the long side lla, so that the two panels 12, 14 are equal in size and also in the shape of right angled triangles.

Referring to Figure 2, the handle 20 comprises a narrow rectangular base 22 having a flat underside 24, a central rib 26 extending upwards from the longitudinal centre line of the base 22 perpendicular to the plane of the underside 24, and a flat grip portion 28 that is parallel to the underside 24 of the base and extends from both sides of the central rib 26. Two T-section securing projections 30, 32 project from the underside 24 of the handle 20, one towards each end. Each securing projection comprises a stem 34 in the form of a rib extending perpendicularly from along the centre line of the underside 24 of the handle, and a foot 36 extending across the end of the stem 34 parallel to the underside 24 of the handle, and projecting from either side of the stem 34.

As can best be seen in Figure 2, the body 11 of the set square has two apertures 40, 42 through it, when it is in its unfolded condition. Each of the apertures 40, 42 is formed on the folding axis X-X, between the two panels 12, 14. Each aperture 40, 42 has a wide portion 44 nearest to the long side 11a of the set square, and a narrower slot portion 46 nearest the right angled corner of the set square. The wide portions 44 are slightly larger than the foot 36 of the projections 32 on the handle 20, and are symmetrical about the folding axis X-X. The slots 46 are also each symmetrical about the folding axis X-X and open into the wider portions at a point on the folding axis. The slots 46 are narrower than the feet 36 of the projections, but just wider than the stems 34. The wider portions 44 extend through the whole thickness of the panels 12, 14, which is substantially the same as the total height of the projections 32 on the handle, i.e. the height of the stems 34 plus the thickness of the feet 36.

The slots 46 are each formed in a thinner area 48 of the panels 12, 14 that is adjacent the wider openings 44 and the same size is the wider openings.

These thinner areas 48 are formed by a recess 50 in the rear of the panels 12, 14 which is equal in depth to the thickness of the feet 36 on the projections 30, 32. The slots 46 are therefore substantially as deep as the stems 34. As the apertures 40, 42 are symmetrical about the fold line X-X one half of each of the apertures 40, 42, including one half of the wide portion 40, one half of the slot 46, and one half of the thinner area 48 is formed in each of the panels 12, 14.

When the handle 20 is removed, the panels 12, 14 can be folded against each other so that their top surfaces are in contact as shown in Figure 3.

In order to assemble the set square, the body 11 is unfolded so that the two panels are parallel to each other and co-planar with each other. This forms the apertures 40, 42 by aligning the adjacent sides of the panels 12, 14 that define them. The handle 20 is then placed adjacent to the top surface of the body 11, and the feet of the projections passed into the wide parts 44 of the apertures 40, 42 until the underside 24 of the handle rests on the top surface of the body 11. The handle is then slid towards the right angled corner of the set square, so that the stems 34 of the projections move into the slots 46 and the feet 36 of the projections move into the recesses 50, until the ends of the feet 36 rest against the ends of the recesses 50. The handle is retained in this position by friction. In this position the underside 24 of the handle rests against the top surface of the two panels in the region around the apertures 40. The upper surface of the feet 36, that faces the underside 24 of the handle, rests against the underside of the thinner regions 48 of the panels 12, 14. Therefore the two panels are both gripped between the feet 36 and the underside of the handle 20, which holds them in position parallel to each other and in a common plane. As the hinge axis X-X is level with the top surface of the body 11, the edges 52, 54 of the two panels 12, 14 abut against each other when the set square is in the flat unfolded condition, and therefore also serve to retain the panels 12, 14 in the correct relative position, preventing them from being folded past the fully open position.

If the set square is to be folded again, the handle is simply slid along the top surface of the panels 12, 14 toward the long side of the set square, until the feet 36 are aligned with the wide parts 44 of the apertures 40, 42. The handle 20 is then removed. The panels 12, 14 can then be folded back to their folded condition as shown in Figure 3.

Referring to Figure 4, each of the hinges 16, 18 comprises a cylindrical inner 60 and a hollow bearing 62. The inner 60 is formed from a first semi-cylindrical half 64 that is formed integrally with one of the panels 12 and a second separate semi-cylindrical half 66. The bearing 62 is formed from a first integral bearing half 78 formed in the other of the panels 14 and a separate bearing half 80.

The integral inner half 64 is formed such that its flat surface 68 is level with the front surface of the panel 12, and its longitudinal axis is aligned with the edge 52 of the panel 12. The radius of the hinge inner 60 is less than the thickness of the panels 12, 14 so that the rounded side 70 of the integral inner half 64 does not pass through the plane of the rear surface of the panel 12. The separate inner half 66 has two projections 72 that locate in cooperating recesses 74 in the integral inner half 64 with an interference fit so that the two halves of the hinge inner portion can be pushed together. The integral inner half 64 is connected to the rest of the panel 12 at either end, and an aperture 76 is formed between the side of the integral half 64 and the rest of the panel 12.

The integral bearing half 78 is formed as a semi-cylindrical recess 82 in the front surface of the panel 14. Its centre line is level with the edge 54 of the panel 14, and one half of it is therefore formed by a projecting portion 80 of the panel 14 that projects beyond the edge 54. Two slots 84 are formed in the front surface of the panel 14, parallel to, and on either side of, the recess 82. The separate bearing half 80 comprises a semi- cylindrical cover portion 86 and a pair of legs 88 with inwardly projecting ribs 90 on them. The legs are resilient and fit into the slots 84 and the ribs 90 snap fit into undercut grooves 92 in the sides of the slots 84 to retain the two halves 78, 80 of the bearing 62 together.

As can be seen in Figure 4, the projecting portion 80 of the panel 14 and the integral hinge inner half 64 are each formed entirely between the front and rear surfaces of the respective panels 14, 12, whereas the separate hinge inner half 66 and bearing half 80 project above, or in front of, the front surface of the panels when the hinge is assembled. The advantage of this is that the panels 12, 14 can be printed with a simple printing process before the hinges are assembled, since they are both completely flat.

In order to assemble the hinges, the separate hinge inner half 66 is fitted onto the integral hinge inner half 64, the integral hinge inner half 64 is placed in the integral bearing half 62. The set square is then in a semi- assembled state as shown in Figure 5. The separate bearing half is then placed over the hinge inner and its legs 88 fitted into the slots 84 and snapped into place, as shown in Figure 6. This serves to hold the two halves 64, 66 of the hinge inner together, and to secure the hinge inner inside the bearing 62, thereby securing the two panels 12, 14 together.

The two panels 12, 14 can then be folded together about the fold axis, with the hinge inner rotating in the bearing 62. The aperture 76 in the panel 12 accommodates the projecting portion 80 on the panel 14 when the set square is in the un-folded condition.

Referring to Figure 7 a blackboard ruler 100 according to a second embodiment of the invention comprises three panels 102, 104, 106 and two handle sections 108, 110. The panels 102, 104, 106 are arranged to be placed end to end to form the main body 112 of the ruler 100. Each handle section 108, 110 is arranged to span the join between one of the end panels 102, 106 and the central panel 108 to secure them together.

Each of the handle sections 108, 110 is similar in section to the handle 20 in the set square of Figures 1 to 6. One of these 108 will now be described. The handle section 108 comprises a base 112 with a flat underside 114, a central rib 116 extending upwards from the longitudinal centre line of the base 112 perpendicular to the plane of the underside 114, and a flat grip portion 118 that is parallel to the underside 114 of the base and extends from both sides of the central rib 116. Three Tsection securing projections 120, 122, 124 project from the underside 114 of the handle section 108, one 120, 124 towards each end, and one 122 in the centre. The end securing projections 120, 124 are identical to those 30, 32 of Figure 2, and the central one 124 is of the same cross section but twice as long. Each of the end panels 102 106 has one aperture 126 in it which is the same shape as those 40, 42 of Figure 2, having its wider portion 128 towards the inner end 130 of the panel 102, 106 and its slot 132 and recess 133 towards the outer end 134. At the inner end 130, that is arranged to abut against the middle panel 104, each of the end panels 102, 106 has a slot 138 formed in a recess 140. These are the same size and shape as the slots 132 in the apertures 126, but open at the inner end of the panel 102, 106. The central panel 104 has, at each end, a slot 142 and recess 144 the same size and shape as those in the ends of the end panels 102, 106, and spaced from each end, an aperture 146 of the same size and shape as those 126 in the end panels 102, 106.

To assemble the ruler 100, one end of one of the handle sections 108, 110 is attached to one of the panels 102, 104, 106 by passing one of its smaller projections through the wider part of the aperture 126, and then sliding it along the panel so that the end projection 120, 124 moves into the slot in the appropriate aperture 126, 146 and half of the rib and foot of the central projection 122 move into the slot 142 and recess 144 in the end of the panel 102, 104, 106. The other end of the handle section 108, 110 is then secured to another of the panels in the same way. The other handle section is then secured to the other end panel and the central panel 104 in the same way.

When the ruler is assembled, the three panels 102, 104, 106 are all held parallel to each other, end to end, with their upper surfaces in a common plane in contact with the undersides 114 of the handle sections 108, 110.

The undersides of the securing projections 120, 122, 124 on the handle sections are flush with the undersides of the panels 102, 104, 106, so that the underside of the assembled ruler can be held flat against a flat surface such as a blackboard.

It will be appreciated that features from the two embodiments could be combined in a number of ways. For example, the ruler could be made in two sections hinged together by a hinge or hinges similar to those in the set square. Also the handle on the set square could be turned so that is was parallel with the long side of the set square, and attached using a combination of projections and apertures similar to that in the ruler described above. Also clearly other shapes of geometry articles can be made in a similar manner, including protractors and other shaped set squares.

Claims

1. Stationery article comprising a first member and a second member foldably joined by a hinge, each member having respective front and back surfaces arranged such that, when the article is an unfolded condition, the front surfaces are substantially coplanar with each other and the back surfaces are substantially coplanar with each other, wherein at least part of the hinge is formed separately from the two members such that, when the article is in the unfolded configuration no part of either of the members extends forward of the front surface or rearward of the back surface.

2. An article according to claim 1, in which the hinge is arranged to allow folding of the article such that the front surfaces are substantially parallel to, and facing, each other when the article is in a folded configuration.

3. An article according to claim 1 or claim 2 in which the hinge defines a hinge axis that is substantially in, or in front of, the plane of the front surfaces when the article is in the unfolded configuration.

4. An article according to claim 3 in which the hinge defines a hinge axis that is substantially in the plane of the front surfaces when the article is in the unfolded configuration.

5. An article according to any foregoing claim wherein the hinge comprises an inner part rotatably supported in an outer part.

6. An article according to claim 5 wherein an integral section of the inner part is formed on one of the members.

7. An article according to claim 6 wherein a separate section of the inner part is formed separately from the members and attached to the integral section.

8. An article according to claim 7 wherein each section of the inner part is substantially semi-circular in section, such that the inner part is substantially circular in section.

9. An article according to claim 7 or claim 8 in which engagement means is provided between the sections of the inner part to correctly align them with each other.

10. An article according to claim 9, in which the engagement means comprises a projection provided on one of said sections and a corresponding recess provided in the other of said sections.

11. An article according to any of claims 5 to 10 wherein an integral section of the outer part is formed on one of the members.

12. An article according to claim 11 wherein a separate section of the outer part is formed separately from the members and attached to the integral section.

13. An article according to claim 12 wherein the outer part has in inner surface, supporting the inner part, that is substantially circular in section.

14. An article according to claim 12 or claim 13 wherein the separate section of the outer part is provided with securing means to join it to the integral section of the outer part.

15. An article according to claim 14, in which the securing means comprises resilient catch engageable within a recess provided in the integral section of the outer part.

16. An article according to claim 14 or claim 15, in which the securing means is arranged to secure the hinge outer part around the hinge inner part to securely retain the sections of the inner part together.

17. An article according to any preceding claim, which is a blackboard stationery article.

18. A stationery article comprising a first segment, a second segment, and a handle arranged to cooperate with the first and second segments to maintain them in a desired position relative to each other.

19. An article according to claim 18, in which securing means is arranged to secure the handle to at least one of the segments.

20. An article according to claim 18 or claim 19, in which the securing means comprises a friction fit aperture and projection arrangement between the handle and at least one of the segments.

21. An article according to claim 20, in which the securing means comprises a T-section projection, having a stem and a foot, extending from the handle, and a slot defined by at least one of the segments the stem being slightly longer than the depth of the slot and the foot being wider than the slot such that the foot can be slid along the slot portion to secure the handle against the first and second segments.

22. An article according to claim 21 wherein the slot forms part of an aperture which further includes a wide portion that is wider than the foot, such that the foot can be passed through the wide portion before the stem is slid along the slot.

23. An article according to claim 21 or claim 22 wherein the handle includes bearing portions arranged to bear against the two segments when the handle is secured to them, thereby to maintain the segments in their desired positions.

24. An article according to claim 23 wherein the bearing portions each comprise at least part of a planar surface arranged to bear against a planar surface on the respective segment.

25. An article according to any of claims 19 to 24 wherein the securing means comprises two securing mechanisms, each arranged to secure the handle to a respective one of the segments.

26. An article according to any of claims 18 to 25 in which the first and second segments are foldably joined to each other along a fold axis and the handle is arranged to maintain the first and second segments in an unfolded configuration.

27. An article according to claim 26, in which the handle has a planar surface arranged to bear against planar surfaces of the first and second segments in the unfolded configuration to prevent undesired folding movement of the first and second segments.

28. An article according to claim 26 or claim 27 including stop means arranged to inhibit folding of the segments past the unfolded configuration.

29. An article according to any of claims 24 to 28 in which the aperture is defined partly by each of the segments.

30. An article according to claim 29 when dependent on claim 26 in which the aperture is defined such that it extends symmetrically about the fold axis.

31. An article according to any of claims 19 to 25, in which the first and second segments each have a respective planar surface and the handle is arranged to join the first and second segments together such that the planar surfaces are arranged in a coplanar relationship.

32. A stationery item according to claim 31, in which the handle has a planar surface on the handle arranged to bear against the planar surfaces on the two segments to prevent movement thereof.

33. A stationery item substantially as hereinbefore described with reference to Figures 1 to 6 or Figures 7 to 9 of the accompanying drawings.

34. A set square substantially as hereinbefore described with reference to Figures 1 to 6 of the accompanying drawings.

35. A ruler substantially as hereinbefore described with reference to Figures 7 to 9 of the accompanying drawings.