DRAWING AID

Abstract: A drawing aid for assisting in the marking of lines or other markings on sheet material incorporates a blade-like portion (2) which is connected with a location region (1A, 2A) which includes means (4, 5) deformable relative to the blade-like portion to be able to provide abutment surfaces which enable the aid to so co-operate with the actual edge of a sheet (8) of flexible or non-rigid material such as a sheet of paper as to use the edge (11) as the guide for the aid during the positional adjustment thereof to the location at which it is desired to draw lines or the like on the sheet (8). When the aid is engaged with a sheet edge (11) a part (1A, 2A) of the aid (1) presses on the sheet marginal edge (11A) to remove any buckles etc. and also to prevent any relative displacement of aid, and sheet.

Description: DRAUI NG AID This invention relates to drawing aids. In particular, the present invention is concerne uith an arrangement for facilitating the drauing, markin or scribing of coπtinous lines, series of dots or dashes or combinations thereof on a sheet of markable material such manner that the lines etc. , are aligned at a predetermined orientation uith respect to a reference direction, such as the edge of the sheet. In this specification the term markable material is intended to include paper, card, plastics, metal sheet or foil in extended area form and uhich is of such thickness or characteristic as to be flexible or non- rigid. It is knoun to provide aids for drauing lines or series of dots, dashes etc., at a predetermined angle uith respect to a reference direction. One such aid, commonly called a Tee Square, includes a uoodβn or other rigid material elongate stock defining a reference face or edge along the length thereo and an elongate blade of uhich at least one of the longer edges thereof is intended to provide a straight edge or guide face for a writing or marking implement, this straight edge or guide face being conventionally perpendicular to the stock reference face or edge. In use of the knoun Tee Square it is necessary for the stock reference edge to abut the side or end face of a raised platform such as a drauing board or drafting table upon uhich the sheet material to be marked has been previously secured in place. Iπ practice, the sheet of material is conventionally 'set' or oriented for the purposes of drauing thereupon by engaging the Tee Square stock uith one of the end faces of the board or table and then causing the louer edge of the sheet of paper to abut the Tee Square blade guide edge thereby to ensure that the louer edge of the paper sheet is parallel to the Tee Square blade guide edge. Follouiπg this alignment, the paper is firmly secured i.e., pinned or taped to the board or table so as to prevent any βubsequent movement . In using the Tee Square the latter is moved up or doun uhilst maintaining the stock against the board or table uith respect to the paper sheet and lines etc., are draun uhere required. Since the Tee Square stock needs to have considerable depth or thickness for the purposes of structural strength and rigidity it is, in practice, necessary positively to secure the sheet material on a platform ( i.e., board or table) uhich provides an accurately rectilinear reference edge of an adequate vertical depth for the effective use of the Tee Square. If this platform is not available it is not possible to use the Tee Square. Consequently, the use of a Tee Square or like drauing aid is uholly restricted to the availability of the support platform uith the requisite accuracy in construction for receiving and guiding the The Tee Square stock edge. In other uords. the knoun Tee Square constructions cannot be regarded as being suitable as a portable drauing aid. It is an abject of the present invention to provide a drauing aid uhich avoids the above mentioned difficulties such as the need for a platform type of sheet support uith an accurate guide edge ' . According to the presentinvention there is provide a drauing aid incorporating at least one guide edge for co-operation uith a material marking means, for facilitating the drauing of lines or other markings upon sheet material lying upon a support surface, characterised in that the drauing aid is adapted to utilise a marginal edge region of a sheet of material in such manner that the sheet edge is caused to provide a reference or direction guide for the drauing aid uhen operationally setting or positioning the aid uith respec to the sheet. Conveniently the adaptation is such that uhen the aid is in co-operation uiththe marginal edge region relative movement betueen the sheet and the aid and betueen the sheet and the support surface is simultaneously prevented. In a preferred construction the aid incorporates an elongate blade portion defining said at least one guide edge and in addition the aid includes a location portion adapted for co-operation uith an edge αf the sheet to set the guide edge at a predetermined direction uith respect to the edge of the sheet. For a better understanding of the invention and to shou hou to carry the same into effe.ct reference uill nou be made to the accompanying drauiπgs in uhich :- Figure 1 is a diagrammatic plan vieu of a first embodiment of a drauing aid for facilitating the production of lines or the like running perpendicular to an edge of a sheet of material, i.e., a sheet of paper; Figure 2 is a diagrammatic side vieu to a larger scale of a part of the drauing aid o ^ f Figure 1; Figure 3 is a section taken upon the line III-II of Figure 1, the section being to a larger scale than that of Figure 1; Figure 4 is a schematic vieu in three dimensional form of a detail of the drauing aid of Figures 1,2 and 3, the Figure 4 illustrating the drauing aid uhen operationally positioned uith respect to a sheet of paper of uhich only a fragment is shoun and to a larger scale than that of Figures 1 to 3; Figure 5 is a diagrammatic plan vieu of a part of a second embodiment of a drauing aid in uhich the angle at uhich lines may be draun is selectively variable; Figure 6 is a diagrammatic cross section of the drauing aid of Figure 5; Figure 7 is a diagrammatic three dimensional vieu of a part of a further embodiment of a drauing aid Figure 8 is a fragmentary sectional vieu on the line IX-IX of a further embodiment of a drauing aid shoun in Figure 9; and Figure 9 is a fragmentary plan vieu of the further embodiment of the drauing aid. - b- Referriπg nou to Figures 1,2,3 and 4 the drauing aid 1 shoun therein includes a main body 2 of an elongat blade like rectangular shape having at one end thereof lugs, arms,ears or other elements 4 and 5 uhich extend i opposite directions from the main body and generally in direction transverse to the length of the main body 2. The longitudinal edges 5 and 7 of the main body are parallel to each other, uith each edge being intende to provide a guide edge for a marking implement, such as a pencil, pen, scriber or the like (-not shoun) uhich is to be used to produce the requisite markings, i.e., cαπtinous lines, on a sheet of paper 8 (shoun in Figure In addition, the edges 9 and 10 of the elements 4 and 5 are precisely in line uith each other, and, in practice, effectively combine or co-operate to define a reference direction indicated by the dashed line R. This line R is accurately perpendicular to the direction of the guide edges 6 and 7. To use the drauing aid as so far described a shee 8 of paper having a straight edge 11 is placed upon a suitable support surface 8A of uhich only a fragmentary portion is shown. The surface 8A can be a table top, boo brief case of the flat type. As uill be explained hereinafter it is merely necessary to provide a flat surface for supporting the sheet 8 and, furthermore, it is not necessary for the sheet to be secured ' to the support surface. The aid is positioned upon the sheet 8 so that the element edges 9 and 10 are adjacent to and are able co-operate uith the edge 11 of the sheet 8. Since the pencil or the like marking implement guide edges 6 and 7 are perpendicular to the direction R it follou3 that the edges uill be perpendicular to the edge 11 uhen the edges 9 and 10 abut the edge 11 of the sheet 8. By displacing the drauing aid leπgthuise of the sheet edge 11 uhilst ensuring the contact uith the sheet edge it uill be possible to drau lines or to form series of dots or dashes perpendicular to the sheet edge at any desired position leπgthuise of the sheet edge 11. Returning πou to the further consideration of the Figures of the drauings a secondary extension, plate arm,ear,or element 12 projects from the element 4 in the lεngthuise direction of the main body. A similar secondary element 13 projects from t-he element 5. The element 12 includes a horizontally directed part 12A and an inclined part 128, the latter extending at 45 to the part 12A. The element 13 has similar parts 13A and 13B. User finger location means 14 are provided on the elements 4 and 5. These location means can comprise recesses; knurled or other roughened regions or raised parts. In the Figures 2 and 4 raised parts in the form of rims 15 have been shoun. If desired,a third finger locating means can be provided at the neck region 2A of the main body 2. This third location means is shoun in dashed lines at 14A in Figure 1. The thickness of the horizontal parts 12A and 13A of the elements 12 and 13 relative to the thickness of th elements' 4 and 5 and also the main body 2 is such that the louer surfaces of the parts 12A and 13A are each located above the plane ° ? the louer surface 16 of the main body 2 and the elements 4 and 5. Uith this arrangement a step or gap is produced of such height dimension relative to the plane of the louer surface 16 that the gap or step is able to accommodate uith clearance the maximum thickness of sheet material that can satisfactorily be used uith the drauing aid. As uill be seen from Figure 4 the formation of the element 13 produces the gap or step and in so doing produces a vertical surface 13C uhich is effectively an extension of the face or edge 10 of the associated element 5. A similar vertical surface 12C is produced by the formation of the element 12, the surface 12C forming effectively an extension of the face or edge 9. In other words the various surfaces and faces 9,10, 12C and 13C all co-αperate to provide the reference direction R. A centrally disposed cantilever arm 17 is provided at the end of the drauing aid that is adjacent to the elements 4 and 5. The arm 17 facilitates the general lifting of the aid, by facilitating the tilting of the main body 2 auay from the sheet 8. Two series of ribs 18 directed longitudinally of the main body project from the lower surface 16 of the main body. The ribs 18 of the two series are parallel to each other. The ribs have a triangular cross section so that they present a relatively sharp contact region uith the sheet. The major part of the main body 2 is stiffened in the longitudinal direction thereof by means of an inverted channel 19 uhich terminates short of the line R defined by the surfaces and edges 9,10,12C and 13Cy uhereby a region is established in uhich a higher flexibility is possible at the so-called neck region 2A of the main body 2. This enables the stiffened part of the main body slightly to flex up or dαun relative to the remainder of the drauing aid 1 in the vicinity of the elements 4 and 5. OMPI -S- A graduated scale is provided along each edge 6 and 7 of the main body, the nature of the scales being as required i.e., a metric distance scale. The general mode of use of the drauing aid 1 as so far considered uill nou be examined To recapitulate it has been mentioned that in use the sheet 8 of materi to be marked is laid upon a larger area support surface 8A (only a fragmentary portion of the surface 8A being shoun) and the drauing aid 1 of the-invention is caused to co-operate uith an edge 11 of the sheet 8. In practice, the sheet 8 is oriented uith respec to the support surface 8A such that the edge 11 is locat to the left hand side of the sheet and thus the user whe the latter is right-handed. In the case of a left-hande user the edge 11 would be located to the right hand side of the sheet and thus the user. Also for convenience of working the edge 11 is arranged in a generally uprigh setting uith respect to the position of the user. The mode of aligning or registering the drauing aid 1 uith respect to the edge 11 uill nou be examined in greater detail It uill be presumed that the edge 11 has been arranged for the benefit of a right-handed user upon the support surface 8A. The drawing aid is bodily moved by means of the cantilever arm 17 to a location closely adjacent to the sheet and such that the elements 4 and 5 are in the near vicinity of the edge 11 of the sheet 8. The user then engages the second finger and thumb of the left hand in the upstanding rims 15 and if thought useful the fore finger in the recess 14A. Also the third finger can be used to provide an additional steadying effect to the overall feel of placement situation- The user then exerts a sufficient pressure an the elements to establish a feel uhich is indicative that the elements 4 and 5 have been slightly depressed. This initial depression causes the elements to present the vertical surfaces and edges 9,10,12C and 13C touardβ the adjacent edge 11 of the sheet, and simultaneously causes the louer surfaces of the neck region 2A and the elements 12A, 13A in co-operation uith the support surface 8A to confine the marginal region 8B of the sheet 8 and thus prevent buckling, thereby ensuring that the actual edge 11 of the sheet forms a substanti¬ ally rectilinear guide for the vertical surfaces and edges 9,10,12C and 13C. Follouing this the user then positioπally adjusts the drauing aid touards the edge until the above mentioned surfaces contact the edge 11. During this movement the user uill use the right hand to restrain the sheet against displacement relative to the support surface 8A. The adjustment of the drauing aid vertical surfaces into the contact position uith the edge 11 of of the sheet 8 normally involves a rocking or to and fro movement of the aid 1 relative to the edge 11. It uill be noted that during the above mentioned stages of positional adjustment of the drauing aid to the edge 11 the parts 12B and 13B of the elements assist in guiding the elements 12 and 13 over the edge 11 and prevent the elements from entering beneath the sheet. Upon achieving the contact uith the edge 11 the elements 4 and 5 are further depressed until the louer surfaces thereof abut the support surface 8A. It uill be noted from the Figure 4 that uith the elements 4 and 5 fully pressed into contact uith the support surface 8A a clamping effect is produced across the uidth of the main body in the vicinity of the root ends of the elements 4 and 5, that is to say, the neck region 2A. In addition, the flexibility of the main body neck region 2A betueen the reference line R and the adjacent end of the stiffening channel 19 uill accommodate any tendancy far the main body to tilt or lift auay from the sheet. At this stage it uill be found readily possible to move the drauing aid lengthuise of the sheet 8 using the edge 11 as a guide, by slightly releasing the firm pressure upon the elements 4 and 5. The clamping action betueen the surface 16 and the support 8A is maintained by the resilience of the elements 4 and 5 and the neck 2A. During displacement of the drauing aid lengthuise of the edge 11 it uill be found necessary for the user to restrain the sheet 8 against displacement relative to the surface 8A by engaging the sheet uith the right hand. It has been found that the sheet tends to rotate about the user's right hand, due to the aid being pressed again3t the edge 11 uith a force not aligned uith the fulcrum formed by the right hand, such rotation making difficult precise positioning of the aid. The clamping action described substantially reduces the tendancy of the sheet to rotate, so that moderate pressure by the user's right hand is sufficient to immobilise the sheet 8. On reaching the required position the elements 4 and 5 are pressed firmly into contact uith the support surface 8A. It has been found that once the firm clamping action is effected by the pressure upon the elements 4 and 5 against the support 8A the sheet is also firmly held in place so that it is no longer necessary for the user to engage the sheet uith the OM right hand whereby marking of the sheet can be effected uithout relative displacement occuriπg betueen the drauing aid 1, the sheet 8 and support 8A. In addition the forefinger may be pressed on the location 14A (Fig.1), uhich action tends to prevent any change in the alignment during a marking operation, by holding th surfaces and edges 9,10,12C and 13C in contact uith edge The above mentioned step may be extended across the full uidth of the neck region In this case the depth of the step betueen edges 9 and 19 is less than the thickness of the material to be used uith the aid as the 3tep is only intended to engage only uith the upper regions of the material edge 11. Furthermore, as a result of the height dimension of the gap or slot the parts 12A and 13A do not contact the surface of the sheet This factor in conjunction uith the flexibility of the elements 4 and 5 makes it possible for the drauing aid to be used uith sheet material of differeing thicknesses. The basic constraint in this respect is that the engagement of the elements 4 and 5 uith the support surface 8A must not be prevented by the engagement of ' the parts 12A and 13A uith the surface of the sheet 8. It should also be noted that the flexibility of the elements 4 and 5 makes it possible for the drauing aid to conform to a support surface uhich is not accurately flat. n Since the drauing aid of the invention is intended for use uith single sheets of paper commonly available such as typing top copy paper, typing copy paper or similar papers having thicknesses of the order of 0t0033 inches ( °» 084mm ) such sheets uill clearly be highly flexible or non-rigid and easily distortable at the edge regions thereof uhereby any irregularity of the support surface 8A of the order of sixty microns would, if the elements 4 and 5 were non-flexible prevent the elements from co-operating uith the -edge 11 of a sheet at a location uhere an irregularity deeper than the sixty microns occursd. By providing the flexible elements 4 and 5 such difficulties arising from a non-flat support surface 8A do not arise. The previously mentioned series of ribs 18 serve a useful function during the setting or registration of the drawing aid relative to the sheet edge. As has been mentioned during the setting of the aid relative to the edge 11, the user by means of his left hand suiπgs the aid slightly uith a to. and fro movement. In the absence of the ribs 18 this motion uill involve moving the total surface area of the main body 2 relative to the sheet surface uhich uαuld then be in overall contact uith the main body. Because of such overall contact considerable frictional force uould need to be overcome in order to achieve the requisite suiπging action. In addition, the ensuing rubbing contact could induce electrostatic attraction betueen the main body louer surface and the sheet surface thereby increasing the resistance to the required movements. This in turn, causes the user to increase the force exerted to achieve the required setting or registration movements and thus impedes a smooth movement for the adjustments. OMPI The provision of the ribs 18 not only reduces t excessive resistance to movement difficulties mentioned above but also tends to reduce any tendancy for the ' = drauing aid to shift during use. This is thought to result from the increased loca pressures uhich occur betueen the ribs and the surface αf the sheet 11 as compared uith the overall pressure spread over the uhole area of the main body. Referring nou to Figures 5 and 6 these Figures illustrate a construction in uhich a protractor assembly 21 is provided. In this construction the main body is effectively pivotally connected to a stub main body part 22 having the elements 4 and 5 together uith the element 12 and 13 at one end thereof. The stub body part mount a screued member 23 onto uhich the main body is connect by a pivotal connection. An operating head 24 is provided for locking the main body in a desired setting. The stub main body part 22 is provided uith a protractor uhose calibration is such that the 90 mark lies on a line uhich is perpendicular to the reference line R defined by the edges 9 and 10 αf the elements 4 and 5. In use of the construction of Figures 5 and 6 the drauing aid will be positionally set aβ discussed in relation to the embodiment of Figures 1 to . In addition, the angle made by the main body edge 6 and 7 may be set as required. It should be noted that in theFigure 6 a support surface 8A is indicated. The section of the aid 1 to the left of the line R that is the reference surfaces and edges 9,10,12C and 13C and part of the neck region 2A can be conveniently regarded as a location region 1A, the latter including the elements 4 and 5. OMPI A further embodiment αf the invention is shoun in Figure 7. In this embodiment the flexible element arrangements have been replaced by a bracket arrangement 26 uhich is mounted to the main body 2 of the drawing aid 1. The bracket assembly 26 includes a plate 27 connected to the main body 2 by way of a transverse mounting block 28. The other and of this plate is divided into three side-by-side strips 29,30 and 31, uhich, in practice, produce a resilient cantilever effect. The inner one αf the strips 30 is longer than the two outer strips 29 and 31 and is connected at its free end to a transverse black 32 having an inner vertical face 33. An inverted U-shaped bridge member 34 is connected to- the two outer strips 29 and 31. The bridge member 34 bridges the main body 2 and includes tuo leg parts 35 uhich are generally in line uith the end region of the inner end of the main body and uhich have bottom faces 36 that lie in a common plane. In the Figure 7 fragmentary portions of the sheet 8 and the support surface 8A are shoun so that th relationship of the aid 1,uhen in use, to the sheet edge 11 and the surface may be seen. In use the aid is placed in co-operation uith the sheet so that the body can lie on the sheet uith the block 34 located above the marginal edge region 11A of the sheet and uith the inner vertical face 33 of the block adjacent to the sheet edge 11. The block 32 is depressed touards the surface 8A until a satisfactory feel is obtained betueen the vertical face 33 and the sheet edge 11. In vieu of the structure of the bracket arrangement 26 the dounuard o movement of the block 32 uill automatically pull the OMPI - bridge member 34 downwards into contact with the marginal region 11A of the sheet 8. The aid is the positionally adjusted as above described uith respect to the sheet to obtain the desired positional setting. Once this setting is obtained the block is pressed firmly into contact uith the support surface 8A. This operation uill automatically pull the bridge member 34 into a firmer contact uith the sheet marginal edge 11A, If desired the user can exert additional pressure upon the bridge member 34 by pressing thereupon uith a convenient finger. Referring now to Figures 8 and 9 in this embodiment of the aid a leaf spring arrangement 37 is provided for exerting pressure upon the marginal edge region 11A αf the main body 2 in addition tα those arising from the pressure exerted upon the elements 4 and 5 in the manner considered above. The leaf spring arrangement includes a post 38 upstanding from the main body. A spring member 39 is mounted cantilever fashion to the post and is secured thereto by a screu 40. The free end region 41 of the spring member 39 is deformed to provide a sheet engaging part 42 uhich projects through a bore 43 provided in the main body 2. As will be noted the initial set or positioning of the spring member 39 is such that the part 42 protrudes slightly below the plane of the lower surface 16 of the main body. The extent of the protrusion of the part 42 is such that the spring member 39 is able to exert a pressure on the marginal edge region 11A during the setting adjustments of the aid. The step uhich is formed by the elements 12 and 13 can be continued across the full uidth of the under¬ side of the drauing aid, as indicated at the dashed line 44 in Figure 9. The depth of the step 44 is less than the thickness of the sheet material to be used uith the aid as the step extension is intended to engage only uith the upper regions of the sheet edge 11. The aid is conveniently made from a transparent plastics material. In a variation of the construction of Figures 8 and 9 the leaf spring arrangement could be replaced or augmented by a press type of spring assembly (not shoun) uhich is depressible to exert pressure upon the sheet uhen it is required to prevent relative displace- ment between the aid and sheet and the sheet and surface

Claims: CLA I MS 1. A drauing aid incorporating at least one guide edge for co-operation uith a material marking means, for facilitating the drauing of lines or other markings upon sheet material lying wpoπ a support surfac characterised in that the drauing aid (1) is adapted to utilise a marginal edge (11,11A) of a sheet of material, of such thickness that the sheet is flexible or non-rigid, in such manner that the sheet edge (11 ) is caused to provide a reference or direction guide for the drauing aid uhen operationally setting or positioning the aid uith respect to the sheet (8). 2. A drauing aid as claimed in claim 1, and characterised in that uhen the aid is in co-operation uith the marginal edge (H,11A) relative movement betueen the sheet (8) and the aid (1) and betueen the sheet (8) and the support surface(8A) is simultaneously prevented. 3. A drauing aid as claimed in claim 1 or 2, and characterised in that the aid (1) incorporates an elongate blade-like portion (2) defining said at least one guide edge; and in that the aid (1) includes a location region. (1A) adapted for co-operation uith the edge (11) of the sheet to set the guide edge (6) at a predetermined direction uith respect to the edge (11). OMPI Z°. 4. A drauing aid as claimed in claim 3, and characterised in that the location region (1A ) incorporates resilient means (4,5; 32;37 uhich upon placing the blade-like portion over a sheet (8) are 5 co-αperable uith the support surface (8A)for the sheet (8) uhereby upon exerting a pressure or loading upon the location region (1A) so as to press the aid touards the support, buckling or other distortion of the sheet marginal edge 11A) any relative displacement betueen the 10. sheet and the aid and betueen the sliest and the support surface is prevented. 5. A drauing aid as claimed in claim 4, and characterised in that the location region (1A) includes means (4,5) deformable uith respect to the elongate 15 blade-like portion (2) in such manner that on deformatio the means (4,5) are able to present abutment means (9,10, 12C,13C) adapted to engage uith the edge (11) of the sheet. 6. A drawing aid as claimed in claim 5, and 0 characterised in that the abutment means is able to present to each side of the blade-like portion (2) reference surfaces or edges (9,12C;10,13C) adapted each to engage uith the edge (11) of the sheet (8). 7. A drauing aid as claimed in claim 6, and 5 characterised in that the deformable means includes a pair αf arms (4,5) extending transversely of the blade-like portion (2), each said arm (4,5) serving to define a reference surface or edge(9;10) for engagement uith the edge (11) of the sheet (8) on 0 deformation of the associated arm touards the support surface (8A) follαuiπg engagement αf the blade-like portion uith the sheet (8). 8. A drauing aid as claimed in claim 7, and characterised in that each said arm (4,5) is provided uith an extension part (12;13) extending lengthuise of the blade-like portion, and at such position relative to the associated arm as to overly the marginal edge (11A) of the sheet during the engagement of the associated reference surface or edge (9;1θ) uith the edge (11 ) of the sheet (80). 9. A drauing aid as claimed in claim 8, and characterised in that the formation of the extension parts (12;13) defines with the associated arm (4;5) said surfaces (12C;13C) for co-operation uith the edge (11) on deformation αf the associated arm touards the support surface (8A). 10. A drauing aid as claimed in any one αf claim 1 to 9, and characterised in that the aid is provided uith means (14;15;14A) for indicating preferred position for a user's fingers uhen using the drauing aid. 11. A drauing aid as claimed in any one of claims 1 to 10, and characterised in that the aid include includes resilient means for exerting pressure upon the marginal edge (11A) of the sheet (8) uhen the aid is co-operating uith the sheet and i3 being urged into co-operation uith the support surface (8A). 12. A drauing aid as claimed in claim 11, and characterised in that theresilient means includes a leaf spring arrangement (26) having a part (42) adapted to co-operate uiththe sheet (8) marginal edge (11A) on engaging the aid uith the sheet. 13. A drauing aid as claimed in any one of claims 1 to 12, and characterised in that.the portion of the aid incorporating the guide edge(6; 6,7) is • formed integrally uith the remainder of the aid. 14. A drauing aid as claimed in any one of claims 1 to 12, and characterised in that the portion of the aid incorporating the guide edge (6) or edges 6,7) is formed separately from the remainder of the aid whereby the guide edge or edges can be selectively set uith respect to said remainder as to enable selective variation of the direction of the guide edge or edges relative to the edge (11) of the sheet (8) 15. A drawing aid as claimed in claim 3 o in anyone of claims 4 to 14 as appendant to claim 3, and characterised in that the blade-like portion is provided uith stiffening means (19) extending lengthuise of the blade-like portion (2) betueen the free end of portion (2) and the neck region (2A) of the portion (2). 16. A drauing aid as claimed in claim 3 or in any one of claims 4 to 15 as appeπdent to claim 3, and characterised in that the louer surface (16) of the blade-like portion (2) is provided uith longitudinally directed ribs or the like (18) uhich are spaced along the length of the blade-like portion (2), the arrangement being such that the ribs(l8) provide contact regions betueen the blade-like portion (2) and the surface of the sheεt(8) during the use αf the drauing aid. 17. A drauing aid as claimed in claim 16, and characterised in that the ribs (18) are arranged as tuo lines running lengthuise αf the blade-like portion (2), uith each such line including a plurality αf ribs(l8). 18. A drauing aid as claimed in claim 17 r and characterised in that each rib has a generally triangular cross-section. 19. A drauing aid as claomed in claim 3 or any one of claims 4 to 9 as appendeπt to claim 3, and characterised in that the aid includes a cantilever arrangement incorporating a first part (32)adapted for engagement uith the support surface when the aid is in co-operation with a sheet (8), and a second part (34) adapted automatically to engage uith the marginal edge (11A) of the sheet on urging the first part into engagement uith the support surface. 20. A drauing aid as claimed in claim 19, and in that the cantilever arrangement includes a plate member mounted to the upper surface of the blade-like portion, the plate member serving to mount said first and second parts such that the first part is supported in such manner as to define means (33) adapted for engagement uith the edge (11) of the sheet(8) and such that the second part ( 34,35,36) is adapted for engagement uith the marginal edge (11A) at location adjacent tα the first part engagement uith the edge (11 OMPI

Inventors: GRIEW DAVID CHARLES LAMBERT, GRIEW, DAVID, CHARLES, LAMBERT
Applicants: GRIEW DAVID CHARLES LAMBERT, GRIEW, DAVID, CHARLES, LAMBERT
Application year: 1984
Main classification: B43L7
IPC codes: B43L7