US2893126A - Drawing instrument - Google Patents

Description

July 7, 1959 M. COALLIER DRAWING INSTRUMENT Filed Nov. so, 1956 7 1 Jfawzkg/aallzkr United States Patent '0 DRAWING INSTRUMENT Maurice Coallier, Montreal-Nord, Quebec, Canada Application November 30, 1956, Serial No. 625,277

3 Claims. (Cl. 33-103) The invention relates to drawing instruments and more particularly to so-called T squares.

.nates the use of expensive slidable T squares as well as the usual drawing board.

It -is.still.another object of the present invention to provide a T square of the above type which includes an adjustable blade whichmay be used in drawing oblique parallel-lines and wherein .the head of .thesquare may be used .as -.a scale, the device being easy to use and inexpensive to manufacture.

For other objects and for a better understanding of the invention, reference may be had to the following detailed description taken in connection with the accompanying drawing, in'which:

Figure l isa perspective view of a preferred embodiment of ,the present invention;

Figure .2;is an enlarged fragmentary perspective view 0110118 end of .the head member shown partly broken :away and showing the same in operative engagement with the drawing paper;

Figure 3 is a vertical sectional view taken along the line *3-3' of Figure .1;

:Figure 4 is a fragmentary end elevationa'l view of the device; v

Figure 5 is perspective view shown along the slide .forminga part of the invention;

' Figurez is afragmentarytop plan view of a modified .:form of the present invention shown without the head member;

Figure '7 is a vertical sectional view taken along the line 7-7 of Figure 6; and

Figure 8 is 'a fragmentary end elevation view of the a modified form of Figures 6 and 7.

Referring now more in-detail to the drawing, 10 represents 'an elongated rectangular head member formed of an elongatedmetalplate folded longitudinally upon itself so as to provide a member of substantially U-shaped cross section having a relatively widebottom portion 11,

the rounded central portion 12 and the relatively narrow top portion 13, substantially as illustrated. The top portion 13 is provided 'with an elongated, longitudinally extending slot 14 and along the longitudinal edge remote from the central portion 12 is integrally formed with the downwardly and outwardly extending portion 15. The downwardly and outwardly extending portion 15 along its lower longitudinal edge is integrally formed with the vertical portion 16 which terminates in the plane of the bottom member 11 and is integrally formed with the inwardly extending portion 17 which is bent upwardly along its inner edge as at 18 and continues inwardly across the top of the bottom portion .11 in engagement therewith as .at 19. The overlying portion 19 along its inner edge is integrallyformedat right angles thereto with the .vertical. support 20 on which rests the inclined portion drawing paper 21 in true relationship with the head so that the longitudinal edge thereof is parallel to the slot 14, as will be obvious.

In order to open the head member to position and release the drawingpaper, an elongated rectangular bar 23 is secured to the undersurface of the top portion 13 while a second rectangular bar 24 is similarly secured to the top surface of the bottom portion 11, the bars 23 and 24 extending substantially the length of the head member. The bar 23 is provided with an elongated longitudinally extending slot 25 which is aligned vertically with the slot 14 and the top portion 13. The bars 23 and 24 at their central portions .are integrally formed with lateral extensions or handles 26 and 27, respectively, which are vertically aligned with each other .and which extend outwardly through the vertically aligned slots 28 (Figure 1) provided in the upper and lower edges of the central portion 12 whereby upon squeezing the handle members 26 and 27, the bars 23 and 24 will open the head member, and upon releasing the handle members 26 and 27, the resilience of the head member will again close the edges thereof. It will be noted that the slots 28 which are aligned vertically with each other serve as fulcrums for thehandles 26 and 27 which act as levers for the spring .clip head 10.

The downwardly and outwardly extending portion 15 of the head memberis provided with a scale 29. Thus, the inclined portion 15 may also serve as a rule for measuring distances longitudinally thereof on the drawing paper.

A blade 30 of elongated rectangular shape is provided alongthe opposite edges with the downwardly and outwardly sloping portions 31 and 32 which are provided with the scales 33 and 34 respectively.

The scale or blade 30 .at one end is integrally formed with or fixedly mounts the upwardly inclined portion 35 which slidably abuts theinclined portion 15 of the head member and which terminates in the L-shaped extension 36 which is adapted to slidably abut the top portion 13 of the headmember, as shown in Figure l. The longitudinally extending portion of the L-shaped member 36 along its undersurface is integrally formed with a depending ridge v317 imparting a T-shaped cross section and which is slidablyreceived within the grooves 14 and 25 in the top .of the head member whereby to permit the sliding movement of the blade 30 at right angles to and longitudinally of the head member to permit the drawing of parallel lines on the paper at right angles to its edge which is received within the head member.

In operation, the instrument itself is placed on a flat supporting surface. Upon pressing the handles 26 and 27 together, the jaws of the head member are opened for insertion of the edge of the drawing paper 21, which edge enters and stops at the stops 22 in order to properly align the paper with the head member. When the paper is properly set within the head 10, the slide 36, 37 is placed within the slots 14, 25 whereupon the blade 30 may then be used to draw parallel lines on the paper 21, which latter is held firmly and is capable of being displaced with the blade and head without requiring the wardly extending stud 41.

edge of the drawing board or table. It will be noted that the underlying part 17 which lies in the same plane as the bottom portion 11 of the head will lie flat on the supporting surface and will thereby prevent the pencil or pen from making holes in the paper, since the paper then also lies flat on the supporting surface. Such holes are possible when the paper is not lying flat, and the present invention prevents this. The instrument can be used as a triangle with other triangles for tracing parallel lines.

Referring now particularly to Figures 6 through 8, there is shown a modified'form of the present invention wherein the blade 30a may be used for drawing parallel oblique lines at angle other than ninety degrees to the head member. Inthis case the blade 30a is formed at one'end with the semi-circular end portion 40 and is 'integrallyformed with the externally threaded, upwardly extending stud 41 which extends upwardly above the top plane of the blade (Figure 7). The blade 30a at this end is provided at its upper surface with a circular groove 42, concentric with the stud 41 and which rec'eives therewithinthe circular plate 43 integrally formed a horizontal plane at the lower end of the upwardly inclined portion 35a of the slide,'the plate 43 having a central opening which receives therethrough the up- A cylindrical nut 44 is screwed downwardly onto the upper end of the stud 41 whereby to lock the blade 30a relative to the plate 43 and slide member 3541.

A In other respects the form of the invention shown in Figures 6 through 8 is the same as that shown in Figures 1 through 5, and like reference numerals identify like parts throughout the several views, the slide 35a being used with the head member 10 interchangeably with the blade 30, previously described.

By means of the lock nut 44, the blade 30a may be set at any angle relative to thehead 10 to permit the drawing of oblique parallel lines, the slide 35a, 36, 37 connected thereto moving longitudinally within the head member and more particularlyswithin the slots 14, 25

thereof, a

While various changes may be made in the detail construction, it shall be understood that such changes shall 'be within the spirit and scope'of the present invention as defined by the appended claims.

What I claim' is: l. A T square comprising an elongated rectangular head member of U-shaped cross section of resilient material having a bottom portion, a rounded central portion and a top portion, said top portion having a longitudinally extending slot, said top portion being of less width than said bottom portion, said top portion along the longitudinal edge thereof remote from said rounded central portion being integrally formed with a straight,

downwardly and outwardly extending portion terminating along its lower longitudinal edge in an inwardly extending base portion lying in the same plane as said bottom portion, said inwardly extending base portion along its inner longitudinal edge being integrally formed with an upwardly bent portion passing over the longitudinal edge of said bottom portion and continuing inwardly in an overlying portion in abutment with the outer portion of said bottom portion whereby to provide a pair of cooperating jaws adapted to receive therebetween the edge member to the end of said blade comprising said blade of a sheet of drawing paper, said overlying portion along its inner longitudinal edge being integrally formed at right angles thereto with a vertical portion supporting said downwardly and outwardly extending portion, 1ongitudinally spaced stop means provided on the upper surface of said bottom portion adapted to align the edge of the drawing paper with said slot, handle means for separating the bottom and top portions of said head member so as to permit the insertion of the edge of the drawing paper into engagement with said stop means, a slide of substantially T-shaped cross section having a depending portion received within said slot for sliding movement therewithin and a horizontal portion in sliding engagement with said top portion, a downwardly and outwardly extending member connected to one end of said slide and in sliding engagement with said downwardly and outwardly extending portion of said head member, an elongated rectangular blade, and means connecting one end of said blade with said downwardly and outwardly extending member whereby to secure the paper to said head member and to permit the movement of said blade longitudinally thereof for drawing parallel lines on the paper.

2. A T square according to claim 1, said handle means comprising a first elongated, rectangular bar secured to the undersurface of said top portion and having an elongated second slot aligned vertically with said first slot, a second elongated rectangular bar secured to the upper surface of said base portion and in vertical alignment with said first bar, said first and second bars at their central portions being provided with laterally extending,

vertically aligned tongues, the central portion of said head member being provided with longitudinally extending vertically aligned slots at the top and bottom thereof receiving said tongues outwardly therethrough and serving as a fulcrum upon moving said tongues together whereby to separate said overlying portion from said base portion. r

3. A T square according to claim 2, said means for connecting said downwardly and outwardly extending having a semicircular end portion, said blade on its upper surface at said semicircular end portion having a circular groove, said 'blade at the center of said groove being provided with an upwardly extending, externally threaded stud extending upwardly above the top plane of said blade, a circular plate secured to the lower end of said downwardly and outwardly extending member in a horizontal plane adapted to rotate within said groove, said plate having a circular central opening receiving said stud upwardly therethrough, and lock nut means screwed onto the upper end of said stud for locking said plate to said blade at any desired angle ofsaid blade relative to said head member for drawing oblique parallel lines.

References Cited in the file of this patent UNITED STATES PATENTS 522,227 McDonald t July 3, 1894 571,252 Walkinshaw et a1, Nov. 10, 1896 703,235 Camden June 24, 1902 1,623,117 Holland Apr. 5, 1927 1,849,493 Larkin Mar. 15, 1932 2,442,870 Flynn June 8. 194

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