US2567554A - Straightedge construction - Google Patents

Description

p 11, 1951 c. P. DAVEY STRAIGHTEDGE CONSTRUCTION Filed June 11, 1947 I CZczrazzcePDadg 19%; W, W S

Patented Sept. 11, 1951 UNITED STATES PATENT OFFICE STRAIGHTEDGE CONSTRUCTION tion of Delaware Application June 11, 1947, Serial No. 753,990

be and preferably is transparent, in order that the surface being worked upon may be viewed through such transparent edge portion. Strips of transparent plastic material are commonly used for this purpose. The transparency of plastic material of the sort commonly used for edge strips in T squares depends to some extent upon the maintenance of absolute smoothness and the avoidance of even microscopic scratches on the opposite faces thereof. The occurrence of sur- 7 face scratches imparts a frosted condition im-.

pairing visibility therethrough.

It has heretofore been the practice to apply such transparent edge portions to the usually opaque body of the device by gluing, orotherwise cementing, the transparent edge strip to the body which in T squares usually comprises a wooden slat. After the edge strip has been attached to the body of the straightedge, itis the practice to retain the assembly in suitable clamps until the glue or cement has set. Thereupom the opposite faces of the device are buffed, honed, scraped or otherwise finished to remove the excess glue that may have been squeezed out along the joint between the body and the transparent edge strip. Finally, the surface may be polished or varnished, or both.

Considerable difilculty has been encountered in the past in applying transparent working, edge strips, in' devices of the character mentioned.

because of the difiiculty of restoring transparency 40,,

to the edge strip after the same has been scraped or honed for the removal of excess glue at the joint, and polished to impart a smooth finish in the surfaces of the device. It is almost impossible to restore the transparency of plastic strips, by any polishing operation for the removal I 6 edge of the device with respect to the body thereof inwardly of said edge, in order to avoid contact of the device with a surface on which used, at the working edge, thereby facilitating the ruling of 8 Claims. (Cl. 33-107) contact of any portion of the straightedge with the inked line before the same becomes dry. Undercutting the edge of the strip in this fashion also serves to prevent the scratching of the surface of the strip, at the undercut portions thereof, since said surface, when the device is in use, is not in contact with a surface on which the device is applied and over which it is slidingly moved when in use.

An important object of the present invention is to provide improved means for attaching transparent edge strips at and along the working edges of straightedge devices while preserving the original surface finish and consequent transparency of the edge strips; a further important object being to mount edge strips on a straightedge body with at least one and preferably both surfaces of the edge strip oiiset inwardly of the surface of the body.

Another important object is to provide novel means for and method of mounting edge strips on a supporting body without the employment of glue or cement, thereby avoiding the necessity of scraping and polishing the device and marring the suriace of the edge strips in finishing the device.

Another important object is to provide improved means for and method of mounting edge strips on a supporting body whereby the body may be fabricated in finished condition prior to the mounting of the edge strips thereon, thereby accomplishing manufacturing economies without in any way sacrificing the finished appearance of the straightedge device.

Another important object is to provide means for mounting edge strips in a straightedge device whereby the edge strips may be readily removed and replaced by new strips, in the event that they should become nicked, marred or otherwise injured in service.

Another important object resides in providing novel clip means for mounting edge strips in straightedge devices; a further object being to provide a channel-like clip adapted for interlocking engagement with an edge strip and with a body on which the strip is to be mounted, to secure the strip to the body, substantially entirely throughout the length of the mounted strip; a further object being to form the channel-like clip as a substantially fiat element providing oppositely opening clip channels for the respective reception of the mounting edges of the strip and of the body in abutting relationship; a still further object being to utilize a substantially ink lines without danger of smearing through flat clip having overall width slightly greater than the vertical distance between the opposed faces of the strip to be mounted therein.

Another important object is to provide mounting clip means of the character mentioned adapted for assembly on a member having dovetailed sectional configuration along an edge thereof for interlocking engagement with the clip.

Another important object is to proyide mount ing clip means adapted for assembly on the dovetailed edge portions of the member either by. relative longitudinal sliding movement of the" clip and member, or by snappingthemember. and clip together by relative transverse assembly thereof.

Another important object is to provide a straightedge device comprising a medial base slat or body member and edge i'str'ipscf. trans.- parent material clipped to the opposed longitudinal edges of said body, member including one or more transverse anchor strips extending between and securedto theedge-strips; saidanchcr strips extending each in a slot formed in' the edge strips and through thebody member therebetween; a further object being" to provide a transverse anchor strip ateach' of the-opposite ends of the straightedge device; a still further object being to provide-a transverseenchcr strip intermediate the'ends of'the devioe'whereoy to aid in securing the edge strips'against longitudinal movement on the'body member:

The foregoing and numerous other important objects, advantages, and inherent functions of r Fig. 4 and Fig; respectively, are perspective views showing modified forms of mounting clips. To illustrate the invention,"the-drawings show a straightedge device H comprisinga T square blade having'a body portion l2 and" strips E of transparent material mounted along edges the body portion E2 to provide line drawing working edges it along the outer or body reins edges of the strips:

The present invention, of course, is not nee-es sarily limited'to T square blades'but may be:

applied in any device having a working ed As shown, however, the body portion lfi'ma comprise a slat or strip, preferably of, wood, although other suitable material than wood may be employed if desired. The edge strips comprise any suitableorpreferred edge strip material, including plastic material, it being par ticularly desirable to utilize transparent plastic material in blades for T squares and other line ruling straightedge devices in order to reveal to view therethrough the'portions of a surface being worked on adjacent and behind the linebeing ruled when the device is in use;

In accordance with the present invention the edge strips l3 are secured to the body portion 12, each by means of a mounting clip it which preferably comprises a relatively flat elongated member providing a pair of oppositely opening channels 56, E8, the opposed walls, defining said channels, being preferably curved inwardly to the outer end edges, and said outer end edges being turned inwardly to provide locking lips H, H. The clips may be made of any suitable preferably resilient material such as springy metal, although the present invention is not necessarily limited to metal clips but con templates the possibility of using a resilient clip material including plastic material. Accordingly, the,,.clips ,may be produced in any preferred manner as by casting, moulding, machining or stamping: In the interests of manufacturing economy, 'it is-preferable to make the clips of sheet'm'etal by bending, stamping or rolling op'erationse- As shown more particularly in Figs. 2 and 3, each clip' 15 may comprise a strip of sheet metal bent at its medial portions to provide a central longitudinally extending partition l8,- the sheet metal strip on'opposite sidesof the partition 18 being. bent to form spaced inner walls I9 of the channel. lB-and being rebent to form the locking lips I! and outer wall portions 29 of the channel l6, said outer Wall portions extending past and outwardly of the partition l8to-form WallsZEJ of the channel IS, themarginal edges of the strip being bent inwardly-to form the locking lips 17; Ifdesired, the strip portions Hand 20' may be attached to the underlying opposed edges of the partition portion l8- as by spot or roll welding 2|.

As shown in Fig. 4, the clip-iSmaycomprise a pairof channel membersZZ- and 22, each formed from a sheet metal stripbent to provide medial or partition forming portions 23 and 23 and spaced wall portions and 24- terminating in the locking lips I! and l'i' at the'outer edges of said spaced channel forming wall portions. The

1: channels-22- and 22 may be'assembled in back to-back relationship-with -their medial partition portions 23- and 23" in registering'engagement, and said medial portions may be welded together as by spot or strip welding 25-in'order to provide the clip [5;

As-indicated in Fig. 5 oft-he drawings, the clip l5 may be formed as an integral member as by die-casting, moulding or machining operations,

and the clip may thus be made of metal or plastic in" vertical registration on the opposite sides' thereof, said grooves-preferably alsoextending longitudinally throughout the lengths o f-the-parts' and being disposed inwardly'of the-'mounting edges of said parts that are to-be joined.

The grooves also preferably each comprise a shoulder 21 facing the mounting edge of the part in which formed, said shoulder 21 being preferably disposed in a' plane extending at right angleswith respect to the opposed faces or surfaces of the part in which formed. Each groove also p'referablycomprises a flat bottom surface 28 extending at right angles with respect to theshoulder 21, and an inclined groove surface 29 preferably lying in a plane making an angle of about l35- with the plane of the groove bottom 28, saidimc1ined groove surface 29 sl0plng toward the mounting edge of the part, in which formed, which is to be connected with the other part.

It will be noted that the clip channels [6 are sized to receive the mounting edges of the strips I3; .and' each clip may be applied to its edge strip either by inserting the mounting portion of the strip into the end of the channel l6 of the clip and then relatively sliding, the parts together, with the clip lips I 1 extending in locking engagement in the strip grooves 26, or the strip may be assembled in the clip by spreading the walls of the channel It sufficiently to receive the mounting edge of the strip therebetween and then snapping the mounting portion of the strip into position in the clip to receive the lips I! in interlocking engagement in the strip grooves 26. After a strip l3 has thus been interlockingly assembled in its clip l5, the strip and clip may be mounted on the body I 2 either by moving the clip and the body 12 relatively in ailongitudinal direction with the clip lips l1 riding, in interlocking engagement in the grooves, 26, or the parts may be. assembled by spreading the walls 26 of the clip sufficiently to allow the mounting portion of the member l2 to be inserted between the locking lips I1 and to be pressed inwardly into the clip into position allowing the locking lips H to snap into interlocking engagement with the grooves 26 of the body member I 2.

Edge strips [3 may thus be firmly anchored on the support body I2. If desired, the body, at the central portions thereof between the spaced mounting grooves '26, may have its opposite surfaces 3i! extending in planes common to the outer surface of the clips l5 or, if desired, said surfaces may be cut back as at 30' to lie in planes common to the planes defining the opposite surfaces of the clip mounting portions of the member l2. The surfaces 30 thus may form a continuation of the sliding surfaces of the clips l5 and may thus rest upon and aid in supporting the straightedge on any surface upon which it is used. Where the surfaces of the body l2 are cutback as at 30', they will, of course, not engage any surface on which the straightedge is used, but the straightedge will be supported entirely on such surface by the outer surfaces of the clips l5. The cut back arrangement of the surfaces, as indicated at 30', affords a manufacturing advantage in that body stock material need only be formed with the locking grooves,

whereas in fabricating the body member l2 with flush faces 30, it is not only necessary to form the groove 26 but also to undercut the opposite surfaces of the body at the clip mounting portions thereof. In either case, however, the opposite faces of the body stock material may be finished to final condition prior to the cutting of the grooves 26' and the undercutting of the faces of the clip mounting portions where the flush surface construction is employed.

It will be seen also that by merely forming locking grooves 26 in edge strip stock, and without otherwise cutting, honing, bufling or polishing the strip, it may be mounted on the finished body member ii in position with the opposite faces of the edge strip offset inwardly with respect to the opposite faces of the mounting clip.

Accordingly, when mounted the surface of the Consequently, the original smooth, unmarred' urfa fin 9 h dg strip mem erwi l preserved not only during the fabrication of the straightedge device, but also throughout its service life.

If desired, transverse anchoring strips 3| may be applied in order to permanently secure the edge strips in mounted position on the straightedge device. These transverse strips 3|, if desired, may comprise material similar to the material of which the edge strips are fabricated. These transverse strips may be applied at each end of the straightedge device where the same is of the blade type, or the transverse anchor strips may be applied intermediate the ends of the device. The anchor strips preferably are mounted in slots or grooves 32 cut transversely through the edge strips and the body member i2, the medial portions of the anchor strips extending through the body portion 12, and the ends thereof extending through and being cemented or otherwise attached to the edge strips. Where anchor strips are thus attached as at the opposite ends of a straightedge device in the form of a T square blade, the grooves 32 may comprise saw cuts formed in the end edges of the blade element. The anchor strip mounting grooves 32, of course, may be formed through the partition .portions 18 of the mounting clips, or the mounting clips may terminate short of the anchor strips.

It is thought that the invention and its numerous attendant advantages will be fully understood from the foregoing description, and it is obvious that numerous changes may be made in the form, construction and arrangement of the several parts without departing from the spirit or scope of the invention, or sacrificing any of its attendant advantages, the form herein disclosed being a preferred embodiment for the purpose of illustrating the invention.

The invention is hereby claimed as follows:

1. A ruler construction comprising a body member having oppositely facing substantially parallel surfaces and a support edge at and along a side of said member, said surfaces of said member being undercut at and inwardly of said support edge to form a tongue of lesser thickness than the spacement between said surfaces, an edge strip having opposite edges respectively forming a ruling and a mounting edge, and being of substantially uniform thickness not greater than the thickness of said tongue, and a relatively fiat enlongated clip for securing said edge strip on said tongue, said clip providing a pairof spaced side walls and a medial partition web normal to and extending between said side walls to form a pair of oppositely opening channels respectively adapted to receive and resiliently grip said tongue and the mounting edge of said strip, whereby to support the clip and edge strip on said body member entirely between the spaced planes of the surfaces of said body member.

2. vA ruler construction comprising a body member having oppositely facing substantially parallel surfaces and a support edge at and along a side of said member, said surfaces of said member being undercut at and inwardly of said support edge to form a tongue of lesser thickness than the spacement between said surfaces, an edge strip having opposite edges respectively forming a ruling and a mounting edge, and being of substantially uniform thickness not greater than the thickness of said tongue and a relatively fiat elongated clip for securing said edge strip on said tongue, said clip comprising a pair of sheet metal channel members having flattbottom' walls:securedrvtogether toirprovide a for:securingsaidredgeastriponsaidtongue; said painpfgoppositelyiopeningachannels in'said clip clipI-providing'ra pairr-of'spaced side wallsend and adapted respectively to receive said tongue a medial partition web extending between said and 2 the mountingtedgeof'said strip. therein, side wallsetoifo'rmapair of-op'positely opening whereby to secure said'edge striptand said-iclipv channelsadapted' -respectively to" receive said-- on said; body. member in: position: disposed-1 entongue-'r'and--"the m'ounting edge of said'= strip tirely .between the spaced planes 50f the surfaces therein, said spacecl'sideiwa'l'ls havingiinwardly of said body member. oifs'et'portions forresilientiinterlocking engage 3r A vruler construction r comprising a body ment in said locking and" anchoring grooves,- member: having oppositely facing-substantially 10.;wherebytowsupport:sai'd'clipon saidtongue in parallelsurfaces and a support edge at and alongposition entirely, betweenthe spaced planes ofa .sideuof' said member, saidsurfaces of i said the surfaceseotsaid body member," and to supmemberlbeingrundercut-at and inwardly of said port said strip-withl-its opposite faces in'ofiset support edge to form'a tongue coilesserthickness relationship inwardly-of saidspaced planes." thanithe spacement between:saidssurfacesya 15 SKA: ruler construction "comprising a :body" edgeilstrip. having: opposite Jedgese respectively member? having--;oppositely:facing substantiallyforminga ruling and amounting edgeZLand being parallel sur-faces-i-definin'g the'substantially uniofrosubstantially uniform thicknesslnot greater form-thiekne sqof id ember, n apsupporfin than the thickness-of said tongue; and'a relaedge at and alonguaxside oi'said member, the" tively flat elongated clip for securing-i-said edge goi said surfaces of saidvmember-rbeing-undercutto-- strip on said tongue, said l pmp in a p r form a tongue of lesserthickness-than the space of spaced apart sheet metal plates and a medial incnt between said surfaces at and along saidpartition extending between andnormal of said support edge, said tongue-on its opposite sides plates and integrated therewith at and alongbeing formed with registering docking groovesthe opposite edges. of said partition, thereby-gatherein, van'edge'rstrip'sof substantially uniform forming .a pair of oppositelyopen channelsin thickness not greater than the thickness of said said-clip and adapted respectivelyto receive and tongue-and having opposite edges respectively resiliently grip. said tongue and the 'mounting i'orming a ruling'and'a mountingiedge, said edge edge of said strip to secure saidstrip: and thestriprbeing-iormedwith anchor grooves inthe clip .on said body member in position disposed 30-ropposite sides thereof 'andinwardly of and inentirely between the spaced planes of the surparallelism with respeotto said mounting edge, faces of said bodyl'member; and a'relatively flat elongated clip of sheet metal 4. A ruler construction comprising a body 1 for-securing said edge stri-p'omsaidtongue,- said member havingtoppositely-..facing substantiallyv clip providing a pair of spaced side walls and parallel surfaces :and' a: support edge at and 5a medial partition webextending between said along a side of said member, said surfacesof'said side walls to form apair of oppositely opening 7 member being undercut at andinwardly of said channels adapted respectively to receive said support edge to form a tongue of 'lesserthickness tongue and the' mounting edge' of said strip than the spacement between-said -suriaces; an therein, *said spaced'side walls having inwardly edge; strip. havingopposite i edges respectively 40 offset lips for resilient interlocking engagement forming a ruling and a mounting edge, and in said looking'and anchoring grooves; whereby being of substantially uniform thickness not tosupport said *clip on said tongue in position greater than the thickness of said tongue; and disposed entirely between the spaced planes of a relatively flat elongated clip for securing saidthe-surfaces-ofsaid body member;- and to.sup-- ed e strip on said tongue, said clip compri ing a 1 port said strip: with its opposite faces in ofiset integral strip of metal bent longitudinally to rel ationship 'inwardly of said "spaced planes; provide spaced side walls anda bottom wall, in 7. A rulerconstruction comprising a body the medial portions of the strip of metal,- said memberi'ha-ving goppositely facing substantially strip of metal having marginal portions rebent parallel facesandasubstantially straight supupon said side walls, in spaced parallel relation,- 50 port'edge at andalong a side of said memb'er,-: in position overlying said side walls and projecti g. the said surfaces of said member being under on the side or" said bottom wall remote from said cut-to form a tongue of lesser thickness than side walls, to form a pair of opp i y opening the -Spa'cement between'said surfacesy'at and channels in the clip on opposite sides of said botalong said support," d e, aid tongue on it to wall an a apte sp v to receive and s a te Sides being formed with looking grooves!- resiliently grip said tongue and the mounting therein-at the baseof said tongue, an edg'estrip e e of said strip whereby u t the clip and of substantially uniform'thickness not greater ed e strip upon said ongue imp i i n di p se than the thickness-pf 'saidtongue" and having e y between h p c p n f the urstraight opposite edges respectively forminga faces of said body member.- g lullng and a mounting ledge, said edge strip hav 5. A ruler construction comprising a body, ingregistering'j anchor *grooves'iormedin tha mem having pp y facing stan ially opposite sides thereof and: in'parallelism with parallel surfaces and'a support edgerat'and along respect to said mounting edge, and a relatively aside ofsaid member, the saidsurfa'ces' of said" flatielongated-clip" of sheet ''metalforl-securing member being undercut'at-and inwardly of said rdy d s t ipio i t ue; Said 1 p pport edge to form n 'pilesser thickprisiiig a pair of spaced side walls and a medial ness than the spacement'b'etwe'en" said surfaces," partitiom extending between said side walls'to said tongue on its opposite side -being forme i'orm a air of oppositely-opening channels- W t ook n v th i fi y and? adapted-respectively'to receive said'tongue and parallelto said support edge; an edge strip havthe mounting edgeof said'strip thereir'rand'to ing opposite edges respectiVely -Torminga ruling hold the' same in edge to edge facing relation-'- and'a' mountingedge and' anohor grooves for-med" sh Men-- opposite -sides "oi -said" partition, with on the opposite sides" thereon inwardly oi and said cli'p disposed entirely between the spaced in parallelism with respect to said mounting edge, planes-rifthesurfaiees of said" body membrfisai d andarelatively flat eloh'g-ated clip o-fshet metal -u spaced-sidewalls having"inwar dly onset igiortions for resilient interlocking engagement in said locking and anchoring grooves.

8. A ruler construction comprising a body member having oppositely facing substantially parallel surfaces and a support edge at and along a side of said member, said surfaces of said member being undercut at and inwardly of said support edge to form a tongue of lesser thickness than the spacement between said surfaces, an edge strip having opposite edges respectively forming a ruling and a mounting edge, and being of substantially uniform thickness not greater than the thickness of said tongue, and a relatively flat elongated clip for securing said edge strip on said tongue, said clip providing a pair of spaced side walls and a medial partition web normal to and extending between said side walls to form a pair of oppositely opening channels respectively adapted to receive and resiliently grip said tongue and the mounting edge of said strip, whereby to support the clip and edge strip on said body member entirely between the spaced planes of the surfaces of said body CLARENCE P. DAVEY.

REFERENCES ori'rED The following references are' of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,216,468 Lee Feb. 20, 1917 1,398,852 Gilbert Nov. 29, 1921 1,768,679 Gasstrom July 1, 1930 1,818,404 Kaufman Aug. 11, 1931 1,984,273 Kuechenmeister Dec. 11, 1934 2,366,449 Keuffel et a1. Jan. 2, 1945 2,379,179 Peterson June 26, 1945

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