US2116887A - Drafting device - Google Patents

Description

y 1933- w. J. GREENLEIAF AL v DRAFTING DEVICE Filed June 18, 1934 .WIIIIIIIIIIIIIIIIIIIIIJ \\1 Patented May 10, 1938 UNITED STA-TE s rATENr orr cs 2J16.88'I

' Walter J. (ii-miles: Lewis Skecl, Meadville,

Application June 18, 1934, Serial No. 781,968 I 6 Claims. -(CI. 3379) A further object isto provide an apparatus of v the indicated clfaracter which includes a simple protractor unit consisting of a verticalscale or' ruling edge and a horizontal scale or ruling edge,

a protractor, a lock clamp for locking the scales orruling edges at any angle, a knob to facilitate the movement of said protractor unit to any desired position on the board, and a, conventional paralleling mechanism, attached to aboard or drawing surface, to keep the rulinfg edges always :0 parallel to a line or group of lines.

A further object is to provide an apparatus of this character in which the vertical andhorizontal scales or ruling edgesv and the bracket for the locking clamp are ailstamped or cut from a single piece, thereby insuring that the rulin edges are always in the same relation to each other, as well as simplifying the cost of manufacture.

A further object is to provide a simplified and" m positive type of locking clamp adapted to lock the 'scales or ruling edgesat any definite anglein relation to the protractor. This locking clamp grips the outer edge of the protractor in such a manner as to prevent the movement or slippage 35 of the ruling edges from any angle at which they might. be set. v

A further object is to provide a construction of this character in which an eyelet is used to fasten the scale unit to the protractor so that 40 the eyelet functions as a bearing on which the scale unit may rotate to any desired angular position as indicated by the marking on. th outer edge of the protractor.

A further object is to provide apparatus of'the 45 stated character in which the protractor is circular on one side, concentric with the bearing on which the scale unit rotates, has lines or mark.- ings indicating equal divisions of a circle converging toward the centeroi' the bearing from 50 the outer edge of the circular side of the pro-.

tractor, with one. side of the protractor being extendedto form an anchorage for ,the paralleling levers.-

Q .A further object is to provide a construction 3 55 of this character inwhich a knob is fastenedto the top side of the protractor, having a shape". and size that will permit its use for moving the entire protractor head from one position to t another on the board.

A further object is to provide a construction 5 of this character in which a paralleling mechanism is attached to the protractor head and to the boardfin such a manner as to insure the ruling edges being kept parallel at all timesandat any position on the board. 1

A further object is to provide a construction of this character in which a U-shaped bracket is used to fastenthe paralleling mechanism to the top left-hand corner of the board, with its closed side at the edge of the board in such a 5 manner as to allow the vertical ruling edge to pass under the top side of the bracket, thereby reaching all sectionsof the board. I A further object is to provide a construction of this character in which paper clamps are at-- tached to the board in-such a manner as to clamp securely either a single sheet of paper or I an entire pad by tightening rubber covered nuts against the bottom of the board thereby pullin the clamps down on to the paper. 1 A further object is to provide a mechanical V drafting mechanism having means operable from beneath the board instead of from above for securing paper to the board thereby permitting the a vertical scale or ruling edge to pass over the paper clamps giving the ruling edges free access to any part of thedrawing paper which is held by these clamps. V

A further object is to provide a construction of i this character in which rubber covered paper clamping nuts, extending beneath the board, act as feet or pads tosupport or tilt the backside .of the board thereby allowing better visionwhen locating the ruling edges for drawing. Other objects will appear. in the course of the 0 following description.

Referring to the accompanying drawing which illustrates one practical construction of our in vention, Fig. '1 is a plan view of the drawing board and mechanism; Fig. 2 is a front elevation of the drawing board and mechanism; Fig. 3 a vertical section of the protractor-unit taken on line A-A. of Fig. 1; Fig. 4 the combination scale unit in perspective disassembled from the protratbml'ig. 5 a vertical section taken through "line .B'-B of Fig. 1; Fig. 6 shows the U-shaped bracket in perspective, by means of which the mechanism is attached to the board; Fig. '7 a perspective view of the assembled paper clamp ing unit; Fig. 8 the vertical section of paper 56 clamping unit taken on line C-C of Fig. 1; Fig. 3 the center piece member showing a P rspective section taken on line D-D of Fig. 1; Fig. 10 a disassembled view of the clamping bolt; and Fig. 11 a fragmentary vertical section taken through a joint of the paralleling mechanism.

Referring to the accompanying drawing which illustrates one typicalembodiment of our invention:

In Fig. 1, the drawing surface or board I, the paper clamps 2, thebracket l3, the long levers i5, ii, the center piece l3, the short levers ll, II, the protractor head 23, 25, 26, 33, the combination scales 25, andthe locking clamp 32, 33, constitute theessentials of the apparatus.

In Fig. 3 we show a vertical section of the protractor unit taken on line 'A-A'Fig. 1, in which 23 is the protractor with equal divisions of a circle scribed around a portion of its. outer edge 24' which is concentric with bearing 35, as shown in Fi 1.

The combination scale unit 25 shown, in perspective in Fig. 4 is attached to the protractor 23 by means of an eyelet 35 which serves as a bearing between the protractor 23 and the combination scale 25 and permits the combination scale 25 to be rotated to any angular position in relation to protractor 23. The eyelet 35 serves both .into locking tractor 23.

as a bearing and to hold protractor 23 and combination scale 25 together.

The protractor 22, 23, 24 is stamped or cut from a single piece of material, which is "ordinarily relatively thin but strong metal. The outer.edge 23 of the protractor 23 forms a perfect circle which is concentric to the bearing 35, but is extended and offset on one side to form the anchorage 22 to which the levers H, II are attached. The circular side 24 is scribed, marked, or indentedwith lines indicating equal divisions of a circle and converging toward the center of the bearing 35.

Knob 26, as best seen in Fig. 3, is fastened directly to the protractor 23 by means of screws 4i and is used to facilitate the movement of the protractor head to any position on the board, the ruling edges being part of the protractor head, as hereinafter described.

The combination scale unit 25, as seen in Fig. 4, is cut or stamped froin a single piece of thin strong material, such as metal, and has a vertical ruling edge 2| and a horizontal ruling edge, 28 at right angles to each other, a bearing hole 43, and a clamp bracket 3i which is bent in a. U-shape with suflicient opening to admit the edge of the protractor 23. A hole 33 is machined through both sides of clamp bracket 3| of proper size to admit clamp bolt 33 (as shown in Fig. 3) to sufiicient depth, so that the shoulder 33 will come engagement with the edge of pro- The locking clamp bolt 33, best shown in Fig. 3, (also shown in detail in Fig. 10) is made of a piece of bar stock with,slot 31 wide enough to admit the edge of the protractor 23 and milled. to sumcient depth so that the shoulder 33 will lock the protractor23 against the inner side of the:

g the bearing hole 43 so as to clear the outerfige line or mark 33 (see Fig.

amass? scale 25 and the protractor 23'are assembled, as

shown in Fig. 3, Fig. 1 and Fig.

i 5. The inner edge of the rise 23 is in the proper spaced relation to of the protractor 23 when the combination 1e 25 and the protractor 23 are assembled (see Fig. 1

5). The top of'the rise is provided with a single guide for locating the combination scales 25 at any desired angle in relation to the protractor 23 when the combination scales 25 are rotated 'on bearing 35. 'By making the division marks on the protractor as degrees of a circle, it will be recognized that the combination scales 25 can be set at any angle in degrees or other equal divi sions ofa circle. The rise 23, as shown in Fig. 1, Fig. '4 and Fig. 5, eliminates an extra piece of material and reduces construction costs.

The paralleling mechanism shown in Fig. 1 consists of two levers l1, ll of equal length .which are pivotally fastened at one end to the extended side '22 of the protractor 23. 'The oppo-' site ends of the levers I1, I 1 are pivotally his-- 1) which serves as a tened to the center piece iii. The center piece l8 (Fig. 9) is so constructed that it has two pairs of holes l3, l3 and 23, 23, the center lines of which are at right angles to each other. Each pair of holes is on a different plane so that'the levers ll, l'l attached to the holes 23, 23 do not interfere with the levers i3, i6 which are attached to holes l3, l3; as shown in Fig. 1. Fig. 9 shows the center piece iii in perspective, but cut on line D-D of Fig. 1, and aptly illustrates the manner in which it'is bent or formed to put holes i3, -l3on a different plane than holes 23, 23.

The levers i5, iii are pivotally attached to the holes i3, i 3 in the center piece l8, and the opposite ends of the levers are fastened to holes ll,

I 4 in the bracket l3, it in turn being fastened-to board i, as for example, in the upper left-hand corner 15 by suitable means, suchas eyelets 43 (see Fig. 6). e

The means for providing bearings between the protractor 23 and levers i1, ll,'center piece I3 and levers l6, l6, and the bracket I 3 and levers i 6, i5 forms an important part of our inventive concept. We have found that eyelets i2, as illustrated in Fig. 11, provide an inexpensive but rugged bearing which is substantially free of wear and play even afterlong use of the apparatus which is essential to the accuracy thereof.

The U-shaped bracket I 3, as shown in Fig. 1 and Fig. 6, is used to attach the paralleling mechanism to the board i and is assembled with the closed side i3 toward the outer edge i5 of the board i. This permits the vertical scale or ruling edge 21' to be usedclose to the edge l5 at the top of the board i as is shown in broken lines in Fig. 1 before being stopped by the closed side 13' of bracket i3.

The bracket it, as above statedis secured to the board by means of eyelets 23 which extend through the lower side 42 of the bracket and into the board :3. Holes it may be provided in the upper arm of the bracket over the eyelets which holes are of suificient size to admit punch er eyelet set or other assembly tool. Holes ll in the bracket III are used to attach the paralleling mechanism to the bracketby eyelets as will be understood.

In Fig. 8 the paper clamp 2 is shown in vertical section taken on line C of Fig. 1. Clamp 2 an anchor when inserted in a hole 4 in the board I, i {see Fig. 8) thus keeping the clamp 2 from turning when being tightened or loosened.

A clamp screw 6 is attached to the bottom of the clamp 2 in the same spaced relation to the anchoring projection 3 as a hole I provided in the board'i is to the hole 4. Thus when assembled,

the projection 3 drops intothe hole 4 and screw 6 passes through the hole (see Fig. 8). The

screw 6 is ofsufllclent length to extend through the board i and'receives a clamping nut] which can be screwed up against the bot tomb! the board I to produce a gripping action at edge"! for holding either a single sheet of paper, an entire pad of paper, or other material on which lines are to be drawn.

The nut I, as shown inFig. 8, has a rubber.

covering or pad 9 which serves as a foot or support for the board, as will be clearly seem in Fig. 2. These feet or pads I also prevent the clamp nuts from marring or scratching any surface upon which the board might be laid.

Fig. 7 shows a perspective view of clamp I and shows more clearly the formand assembly orthe unit.

While in accordance ,with the patent statutes one embodiment of our invention has been illustrated and described in detail, it should be underst od that our invention is not limited thereto Y or thereby but is defined in the ap'pendedclaims.

We claim: V i 1. Apparatus oi the character described comprising a protractor unit, a bracket adapted to be mounted, for example, on a drawing board, a pair I of levers connected pivotally to the bracket, a .second pair or levers connected plvotally to the unit, a centerpiece formed with offset portions so that the two bearing holes for one, 'pair of levers come on a dillerent plane to a second pair oi bearing holes, and means pivotally securing the levers to the centerpiece.

' 2. A parallel linkage type of drafting mecha nism including a U-shaped bracket to be-us'ed to attach the mechanism to a drawing board. said,

bracket having two or more holes in the bottom side for attaching to the board and having an equal number of holes through-the top side in a i 2. 3 m the bottom side through line with the holes which a punch or other assembly tool may be bracket so situated in the upper left hand corner of the drawing board with its closed side on the outer left edge so that it will admit the vertical scale into its open side and thus permit the scale to be moved over substantially the entire surface of the board.

4. Drafting apparatus including a protractor unit having, a scale arm, a bracket adapted to be secured to a drafting board and having an arm portion spaced in parallel relation with such a board, parallel linkage, means pivotally securing the linkage to the protractor unit, and means pivotally securing the other endfot the linkage to the arm portion of the bracket so as to' allow the scale arm of the protractorunit to be moved between the arm portion of the bracket and the board to which the bracket may besecured.

5. In combination, a one piece square having a hole therethro'ugh, a disc having a hole therethrough, a sleeve eyelet extending through the holes and having its ends crimped outwardly to' pivotally secure the square to the disc, prothe square can be moved'to and from the bracket without changing the angular relation of the square and the bracket.

6. In combination, a one piece square, a disc, means plvotally securing the square to the disc, protractor markings associated with the square and disc, means for locking the square in any desired angular relation with the disc, a U-shaped bracket having one leg portion adapted to be secured to a board and another leg adapted to be held iii-spaced relation to the first leg, and means securing tbe disc tothe last-named leg of the bracket so that the disc may be moved to and from the bracket without changing the angular relation oi. the disc and bracket and so the square can be moved between the legs of'the bracket.

waimm J. omen.

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