|Publication number||US329392 A|
|Publication date||Oct 27, 1885|
|Filing date||Dec 1, 1884|
|Publication number||US 329392 A, US 329392A, US-A-329392, US329392 A, US329392A|
|Inventors||Edmund Joed An|
|Export Citation||BiBTeX, EndNote, RefMan|
|Referenced by (5), Classifications (1)|
|External Links: USPTO, USPTO Assignment, Espacenet|
No. 329,392. Patented Oot. 27, 1885.
N. Pneus. Pnmumognpm. wnmngm n.c.
EDMUND JORDAN, OF BROOKLYN, NEV YORK.
SPECIFICATION forming part of Letters Patent No. 329,392, dated October 27, 1385.
Applicairin filed December 1, 1884.
To @ZZ whom it may concern.-
Beit known that I, EDMUND JORDAN, of Brooklyn, Kings county, New York, have invented certain new and useful Improvements in Drawing-Boards, of which the following is a specification.
My invention aims to provide a strong, light, and durable drawing-board, which will remain constantly true and square at the edges, and proofto the changes of shape due to warpage or shrinkage, as continually occurs with the common wooden board.
Another object of my invention is to enabie the head of the T` square to be held firmly to the straight edge of the board and prevented from tilt-ing or wabbling out of place and yet be free to be shifted when desired. To these ends I construct a drawing-board with a continuous marginal frame of cast metal having its center filled in with wood or its equivalent, so that the wood forms a supportingsurface for the paper while the edges of the metal frame are planed to form true and unalterable straight and square edges to the board. I also provide this metal frame or margin on one or more sides and on the top surface with longitudinal grooves parallel with the outer straight edges of the frame, and I form the head ofthe T-square with aledge to fit into said groove, said groove and ledge being straight on the inner side and beveled on the outer side, whereby the weight of the T-square or the pressure of the hand thereon will cause the head to be wedged up against the straight edge of the groove and thus kept firmly in a true and square position and prevented from wabbling out of place at the same time that it is left free to be slid or shifted to a new position when desired. I also construct the metal frame with an underlying barred rim perforated with slots, on which rim the wood filling rests, while the screws pass through the slots into the wood, so as to hold the wood firmly on the frame yet allow the shrinkage thereof.
My invention therefore consists, mainly, in the features above outlined, as hereinafter fully set forth.
In the drawings, Figure l presents a plan view of my improved board with the wood partly broken away to show the under part of the metal frame. Fig. 2 is a central cross- Serial No. 149,223. (No model.)
} section on x x. Fig. 3 represents an end view of the head of the T-squarc on an enlarged scale, and Fig. 4 gives an edge view of the head on the inner side, and Fig. 5 an edge view on the outer side. Fig. (i represents a modiiication.
Referring to Figs. l and 2, A indicates the metallic frame of the board, and B the wooden center or filling. The metallic frame A is a continuous rectangular frame cast in one piece, preferably of iron, and formed with upright marginal sides a, which embody the straight edges of the boaid, and also having an inner base-rim, b, on which the wooden center B is supported so that the surface of the wood is flush with the top of the sides a, as well shown in Fig. 2. A central bar, d, extends from one side of the frame to the other under the middle of the wooden filling B, this bar being flush with and a continuation of the base-rim b, and being cast integral with the frame it stiffens the same and gives a good central support to the wood. Upon the top of the bar d, and also upon the base-rim b on the sides parallel with the bar, bosses e @are cast, which bosses are perforated with short parallel slots t', while the tops of the bosses are planed off level, and on these bosses the wooden iilling B rests, as shown in Fig. 2. Screwsff, as best shown in Fig. 2, pass up through the slots i and screw into the wood, while the heads of the screws are countersunk into washers g, which span the slots in recesses h beneath the bosses, so that the screws and washers are raised above the base-surface of the metallic frame, as will be readily understood from Fig. 2, hence the screws f firmly hold the wooden filling B in its metallic frame A, and prevent the curling up or warping of the wood, while the slots t' and recess la allow the screws sufficient play to freely permit the shrinkage or expansion of the wood due to changes in weather or to the gradual drying and contraction of the wood.' At the same time the metallic frame A forms the true or straight edges of the board, as its outer uprising edges, k k, are planed true and square relatively to each other, while the top surface of the frame is planed level and flush with the wooden filling B, as fully shown in Figs. 1 and 2; hence by this construction a light, cheap, and absolutely' durable and true board will be IOO produced, for, as the marginal edges of the board consist of a rigid` continuous metallic frame planed true and square, the board is proof to allchanges of Weather, and will not warp or get out of truth, and its edges are alwayssmooth and regular andfree from protuberances to catch against the T-square, which advantages render my inventionamost important improvement in drawingboards,`as will be readilyappreciated.
It Will be noted by referring to Fig. l that the outer edges of the frameAare planed with a true edge, lo, for a short distance only near the top and sufficient to receive the head of the T-squarc,"as shown on the right of Figs. 1 and 2, the lower portion of the edge being shaped with a retreating curve or ogee profile, whichis left unfinished. This form, as will be appreciated, imparts a more agreeable appearance to'the frame, reduces the amonntifof metal therein, and renders the frame light, and at the same time reduces the amount of planing necessary to produce `true edges on the frame, Whichare important points inthe practical construction. It will now be observed thatthe straight edges 7c on the exterior of the frame adapt the board to be used with common T-squares in the usual Way, with the edge of the headabutting directly against the edge of the board, as illustrated on the left in Figs. l and 2. In addition tothis,
however, I provide the board with a second series of straight edges adapted to receive a special form of T-square, as illustrated on the left of Figs. land 2, which presentsimportant advantages and forms one of the features of my inventionwthat is, I prefer to plane into the top of the frame on each side a longitudinal groove, m, running the full length of the side, as shown in Fig. l, the grooves being of course true or square with each other. The inner wall of each groove is straight and forms a second straight edge, being parallel with the outer or ordinary edge, 7c, while the outer Wallv of the groove is inclined or beveled, as shown best in Fig. 2. Now, the head of the T-square is formed with adownwardlyprojectingange or web, n, which is adapted to fit into said groove, as shown on the left of Figs. l and 2. The straight side of the web n forms the inner or square edge of the head of the T-square, and is thus adapted to fit either against the outer straight edge, 7c, as shown on the right of Figs. land 2, or against the straight edge of the grooves m, as shown on the left in Figs. l and 2. It will be seen, however,-that when the improved T-square is placed on the board with its flange n in one of the grooves m m the iiange will 'tend to wedge itself in the grooves and force thestraight edge oi the head up against the straight edge of the groove, thus acting to hold the square iirmly on the board and prevent its tilting or wabbling out of place, as is likely to occur with the ordinary square when used on the edges of ordinary boards; hence by this means a slight downward pressure of the hand on the head of the squarewill hold it with absolute steadiness in anyfposition required, and at the same time when the pressure is relaxed the square may be slid freely along the board to any other position required, which advantages of truth and steadiness are obviously of great importance in drawing. I prefer .to form the head of the square of cast metal in one piece,r as best shown in Figs. 3, 4, and 5, and also to form the blade p of thin steel, the flange n being notched at the middle beneath the blade, while the head is mortised above thenotch (see Figs. 4 and 5) to snugly receive the end of 'the blade,whieh is riveted in said mortise, as indicated in Figs. 1 and 2. An arch or upright, o, is cast on the top of the head over Vthe notch in the lflange n, so as to neutralize the weakening caused by the.` notch, and at the same time forma convenient handle, whereby the headmay be grasped in moving the square.
It will be readily understood from the description already given, and by the illustration in Figs. 1 and 2, that the novel T-square described may be used either with the common board or with myimprovedboard in either of two positions, and, on` the other hand, either common T-.sqnares or the novel squares de scribed may be used with my improved board in different positions.
It will be readily understood that the wedging groove or grooves-m may be used on one side only of the board; but I of course prefer to employ them on all sides, as shown.
The wooden filling B, as seen in Figs. 1 and 2, is preferably made, as usual, of a number of parallel sections glued together at the edges, and it will be noted that by means of the metallic frame the wood ofthe board may be made much thinner than usual, as sufficient strength will be secured by the frame, so that while in this Way all the permanent advantages of a metalboard are secured, yet the board may be made as light, if' notlighter, than an ordinary Wooden board, and at the same time its cost will be but little or no greater than that of wooden boards of the best class. I do not, however, confine myself to a lling of wood, as paper or any other fibrous or non-metallic substance may be used, or any other suitable material, as the filling in itself is not an essential feature of myinvention.
It will be understood that it is not necessary that both the groovem and flange n each have a beveled or wedging face, as it is only necessary that there be a wedging action between the two to force the edge of the square against the true edge of the groove, which may be accomplished by having an inclined face on one' of the parts, as indicated in Fig. 6; but I do not recommend that modification.
I am aware of the Patent No. 308,040, showing a dovetailed groove in one of the edges of the board, in which the dovetailed edge of the T-square head is locked or engaged; but this is distinct from my invention, in which a Wedging groove is employed on the top surface IOO IIO
of the board, which acts to wedge the head of the square up to the straight edge of the board, and yet leave the heads free to be lifted off at any point.
I am also aware of the Patent No. 161,982; but its features are distinct from my invention, and I disclaim them.
Vhat I claim as my invention isl. A drawing-board formed of a marginal frame of cast metal, having its edges planed true and square, adapted to receive the T- square head, with afilling of wood or its equivalent, substantially as set forth.
2. A drawing-board formed of a continuous marginal metallic frame cast in one piece, with its edges planed true and square, adapted to receivethe Tsquarehead, and filled with wood or other supporting material, substantially as set forth.
3. A drawing-board having one or more of its margins made of metal, having the lower portion of its edge formed with a retreating curve, and the upper portion plaiied to a true straight edge, substantially as shown and described.
4. A drawing board having a wedging groove sunk in the top thereof longitudinally along the margin of the board, onewall of said groove forming a straight edge, and adapted to receive a flanged T-square head, substantially as and for the purpose set forth.
5. A drawing-board having one or more of its sides provided with a metallic margin, having its outer face planed to a true edge, and a Wedging groove sunk in its top surface parallel with the said edge, whereby the board is adapted to receive T-squares of different kinds in different positions, substantially as set forth.
6. A drawing board formed with a marginal metallic frame' having its outer and upper edge planed true with an inwardly-projecting baserim, b, and a central lling resting on said rim, substantially as set forth.
7. The combination, with the metallic frame A, trued at the edges, with the internalpbaserim, b, the bosses g, and slots i, of the filling B and screws f, substantially as herein shown and described. Y
8. A drawing-board formed by the coinbination of the metallic frame A, trued on the upper and outer edges, with bar d, and baserim b, and a central filling, B, supported on said rim and bar, substantially as set forth.
EDMUN D JORDAN.
J No. E. GAviN, Crus. M. HIGGiNs.
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