US2080792A - Scale section liner - Google Patents

Description

May 18, 1937. B. SIMMONS SCALE SECTION LINER Filed Sept. 15, 1936 I \lHIIlllllllll HUMP)? 1IlllldllllyllllllALhlllJlJI111111:..1

H11 lllllljlllllllllllll Patented May 18, 1937 UNITED STATES PATENT OFFIC Application September 1 Claim.

(Granted under the act of amended April 30,

This application is made under the act of March 3, 1883, as amended by the act of April 30, 1928, and the invention herein described and claimed may be manufactured and used by or for the Government for governmental purposes without the payment to me of any royalty thereon.

My invention relates to improvements in devices for producing accurate work in drafting and more particularly to improvements in that class of instruments known as section liners.

The objects of my invention are to provide a device of the character mentioned, simple in construction and cheaply made, while at the. same time capable of producing accurate work and being conveniently operated.

Another object is to provide an instrument which may be used, in addition to its primary purpose, as a protractor, adjustable triangle and straight edge.

My invention differs from and is an improvement over existing patents that use a segment of toothed rack which is moved along a rack which is secured to a straight edge. This requires the lifting of the triangle to which it is attached from point of use to point of use, whereas, my invention, employing a spring for engaging the teeth on the rack enables the operator to slip the triangle from point to point with greater ease and speed without lifting the triangle.

Other patents employ a ruler arm attached to the spacer bar, whereas, in my invention, the adjustable triangle which serves the same purpose as the ruler arm is not attached to the spacer unit, thereby permitting its removal from the surface of a drawing without disturbing the spacer rack and so changing the adjustment of the device. This actioncan not be accomplished by prior patents. This also enables the operator to use my triangle alone as a protractor or as a triangle which is adjustable to various angles. My straight edge may also be used as a straight edge without the triangle. Thus, my invention has several uses other than its primary one.

I am also aware that other patents employ a ruling arm which is adjustable to various angles with the base. Since the scale in each instance for setting the ruler arm at the required angle is small and near the end at which the ruler arm is attached to the spacer mechanism, a slight error in the setting is greatly increased at the far end of the ruler arm. My invention overcomes this possible inaccuracy by having the scale settings farther from the pivot points of the arms. The ruling arms of the prior patented devices are fastened at the desired angleat or near their 15, 1936, Serial No. 100,861

March 3, 1883, as 1928; 370 o. G. 757) point of pivot. As all material possesses some amount of flexibility it becomes necessary when ruling to gauge the pressure against the arm at its outer extremity to a nicety, otherwise'the pressure exerted against the arm will cause a slight bow or spring which will render the ruled lines slightly curved, unevenly spaced, and inaccurate. I overcome the foregoing serious objections in my invention byhavingthe arm-whichis in use braced at or near its outer end by being securely clamped to the arm not in use. I also employ a special spring to engage and disengage the rack, thereby making my device much simpler in operation when it is used in either direction.

These objects of my invention are obtained by a simplified form of device as illustrated in the drawing, wherein a special form of triangle with adjustable arms is moved along a straight edge and a special spring mounted on said triangle is held in contact with the teeth of a spacer rack mounted on said straight edge, thereby definitely controlling the location of the ruler arms of the said triangle with relation to the plane surface upon which it is desired to rule lines, as will hereinafter more fully appear.

Referring to the drawing, it will be seen that: 2

Figure 1 shows a plan view of my device in position for ruling lines with the left hand side of the triangle;

Figure 2 is a section taken on the line 2-2 of Figure 1 and looking in the direction of the arrows;

Figure 3 is a section taken on the line 3-3 and looking in the direction of the arrows;

Figure 4 is a section taken on the line 4-4 and looking in the direction of the arrows;

Figure 5 is a section of the straight edge taken on the line 5-5 and looking in the direction of the arrows; and,

Figure 6 is a section taken on the line 66 and looking in the direction of the arrows.

Referring again to the drawing; a triangle base I, of transparent celluloid, bakelite, or other suitable materials, has cemented or otherwise attached upon its upper surface an upright arm 7, of like material. Into a flat metal piece 8, a slot 9 has been cut. This metal piece 8 pivots on a screw In which is of sleeve bolt type as shown at [0 in Figure 4. The narrower end of said metal piece 8, is bent upwardly at right angles to itself and has attached to said bent-up end a short section of steel spring II, by means of two bolts l2, which thread into the metal piece 8, as shown. As the base I, of the triangle is slipped in the direction of the arrow I 3, the spring ll, springs over the teeth of the spacer rack I4, any number of spaces required. The base I, is then backed up against the desired tooth, thereby holding the triangle rigidly in the predetermined position. A bolt I5, has a milled head nut which may be loosened, thereby allowing the position of the metal plate 8, and with it the spring II, to be changed so that the triangle may be moved in the opposite direction. A ruler arm I6 of transparent celluloid, bakelite, or other suitable mate rial, is secured to the under part of upright arm I, by means of the sleeve bolt I1, and in such amanner as to pivot easily. A slot 29, is cut through said arm in the shape as shown in section in Figure 2. A bolt I8, Figure 6, with an oblong head slides in said slots 29 and 21. arm I9, of transparent celluloid, bakelite orother: suitable material, is secured to the upper face of the base I, with a sleeve bolt 20, in such a manner as to pivot easily. A slot 21, is cut through said arm I9, in the shape as shown in section in Figure 3. The bolt I8, protrudes through this slot. A small flat head bolt 2|, with left hand thread is threaded into the end of bolt I8. By loosening the nut 22, thereby allowing the bolt I8 to slip in the slots 21 and 29, the arms I6 and I9, may be placed at diflerent angles with reference to the base. The arms may then be clamped in the desired angles by tightening the nut 22. The face of the arm I9, isprotected from the action of the nut 22, by thewasher 23. The scales represented by 24 enable the operator to set either arm at a, predetermined angle with the straight edge 25. In Figure 1, those figures written on the ruling arms across the graduation lines refer to the setting of the arm I9, while those figures written below the graduation lines refer to the setting of the arm I6. In the working model said figures and graduations should be stamped in two different colors. A ruling edge 26, of the same material as the arm I9, is cemented or otherwise secured to arm I9, on its under face. A toothed rack I4, of steel or other suitable material is secured to the straight edge 25, by sleeve bolts in the manner shown in Figure 5. The rack and straight edge comprise a separate unit and are in no way attached to the triangle. This rack I4, has two sets of differently spaced teeth as shown and may be removed and placed so that the other set of teeth may be put into use. The valleys between the teeth are marked as shown at 28 to facilitate counting the spaces when lines are being drawn. Said rack I4, is set back from the edge of the straight edge 25, so as not to interfere with its use as a ruler or straight edge. The straight edge 25, which may be constructed of hardwood, bakelite, celluloid or any other suitable material, is greater in length than the rack I4, on the right hand end, the. end broken away in A ruler' on their points of attachment to the base I, and upright arm I, until the mark at the end of one of the'arms coincides with the angle setting required. The nut 22, is then tightened, clamping the arms in position.

The triangle is now placed with its base I, against the edge of the straight edge 25 and. with one end of the spring engaging the teeth of the spacer rack I4, with the fingers of one hand placed upon the base .I, the triangle is slipped along the straight edge 25, until the desired position is reached. A slight pressure inthe opposite direc-, tion now forces the end of'the spring II, against a tooth of the spacer rack I4. The triangle is held firmly in this position by one hand-while a line is ruled with the other hand against the'ruler arm. The pressure is now reversed and the triangle slipped the required number of teeth and the operation repeated. In the drawing, the ruler arm I6; is set for an angle of approximately 42 with the base, as indicated by the line near its end being between 40and 45 mark on arm I9. The spring is set so the triangle may be slipped from left to right. It is quite evident from the drawing and the description that by loosening the milled head nut on bolt I5, the

position of the spring I I, may be reversed so that its other end will engage the teeth on the spacer rack I4, thus allowing the triangle to be moved in an opposite direction while lines are drawn along ruler arm l9:

Having thus described my invention, what I claim for Letters Patent is:

3 The combination of an adjustable triangle and a straight edge, the triangle comprising a base, an uprightarrn secured at one end of said base, ruler armsfpivotally attached to said base and said arm, graduations on said ruler arms, means for adjusting and holding said ruler arms at different angles, a ruling edge secured to the under face of one of said ruler arms, a plate pivotally mounted on said upright arm, a ratchet spring demountably attached to said plate, the straight edge comprising a ruler, a rack detachably mounted thereon, said triangle adapted to be moved along said straight edge with either end of said spring adapted to engage the teeth of said rack, and means for setting said spring to engage and disengage said rack.

BERNARD L. SIMMONS.

Images