US1569090A - Drafting board - Google Patents

Description

Patented a... 12, 1926.

UNITED STATES FRED D. JOHNSON, OF MOLINE, ILLINOIS.

DRAFTING BOARD.

Application filed June 23, 1924. Serial No. 721,885.

To all whom it may concern:

Be it known that I, FRED D. JOHNSON, a citizen of the United States, residing at Moline, in the county of Rock Island, State of Illinois, have invented a new and useful Drafting Board; and I do hereby declare the following to be a full, clear, and exact description of the invention, such 'as will enable others skilled in the art to which it appertains to make and use the same. 7

The invention relates to drawing boards,

and has for its object to provide a device of this character preferably formed from a reetangular shaped frame, ,and provided with a relatively large sheet of glass, thereby forming a hard smooth surface on which paper rests during drawing or tracing.

A further object is to provide a board adjacent its sides with channeled members, in which heavy bolts are mounted, and which heavy bolts extend through clamping bars adapted to engage opposite sides of a sheet of drawing paper for securely clamping the same to the board; also to provide the clamping bars on their under side with strips of rubber for frictionally engaging and holding the sheet of paper on the board.

A further object is to provide a .bar adjacent one side of the board, and on which bar is slidably and adjustably mounted a bracket, and to which bracket a strai ht edge is pivotally mounted and adjustafiy connected in a manner whereby the straight edge can be positioned at various angles on the board for drawing lines at an angle and for guiding a conventional form of drawing angle during a drawing operation.

With the above and other objects in view the invention resides in the combination and arrangement of parts as hereinafter set forth shown in the drawing, described and claimed it being understood that changes in the precise embodiment of the invention may be made within the scope of what is claimed without departing from the spirit of the invention.

In the drawing:

Figure 1 is a top plan view of the drafting board.

Figure 2 is a view in elevation of one end of the drawing board.

Figure 3 is a detail sectional view taken on line 33 of Figure 1. 1

Figure 4 is a detail perspective view of a portion of one of the clamping bars.

Referring to the drawing, the numeral 1 designates a rectangular shaped frame, in a rabbet 2 of which a sheet of relatively thick glass 3 is disposed. The glass 3 forms a hard smooth surface on which a sheet of paper rests and is held, therefore tracing can be easily done or drawing. Ifdesired,- while tracing, a light may be disposed beneath the glass 3 for facilitating the ti acing operation. Imbedded in the channels 4 in opposite sides of the frame 1 are channel bars 5, the upper sides ofwhich are provided with slots 6, in which slots the shanks 7 of the headed bolts 8 are disposed.

The headed bolts 8 are longitudinally adjustable in the slots 6, and consequently the bolts may be adjusted towards and away from each other according to the size of sheet of paper being clamped on the board. Shanks 7 of the bolts extend upwardly through the ends of clamping bars 9, which bars extend across the board at right angles to the channeled member 5, and have their under sides provided with rubber strips 10, which strips, when the nuts 11 are tightened on the bolts 8, are forced into frictional and binding engagement with the sheet of paper on the board and prevent slipping of the paper, therefore it will be seen that thumb tacks are obviatedand a sheet of paper may be easily and quickly placed in position and clamped on the board.

Extend ng transversely of the drawing board adjacent one side thereof and in parallel relation to one of the channel members 5 is a guide rod 12, which guide rod has its ends mounted in brackets 13 carried by the frame 1. Slidably mounted on the guide rod 12 is a sleeve 14, which sleeve is held in vari ous adjusted positions by means of the set screw 15, and formed'integral with the sleeve 14 is a downwardly offset horizontally disposed disc 16, to which disc is pivotally connected at 17, the upwardly offset arm 18 of the straight edge 19 which extends across the glass '3 of the board; Straight edge 19 may be used in a similar manner to a T-squarefor drawing lines, and a conventional form of drawing implement may be placed in engagement therewith in the usual manner;

By pivotally mounting the straight edge 19, it will'be seen that it may be placed in various angular positions in-a plane parallel to the plane of the glass 3 when desired, therefore it may be used as a protractor, in combination with the scale 20 on the disc 16. The clamping bars 9 and the straight edge 19 may be provided with graduations for facilitating operation, :and if desired, a scaled oration. It will also be seen thatthe straight edge may be easily and quickly positioned in various positions on the drawing board, and clamping bars are provided for securely clamping and holding a sheet of paper in any position desired on the board, and the use of thumb tacks, which is now the common practice is obviated.

The invention having been set forth what is claimed as new and useful is The combination with a drawing board, means for clamping a sheet of paper on said drawing board, of a strai ht edge extending across said drawing boar an upwardly ottset disc carried by one end of said straight edge, a guide bar carried by the drawing board, a bracket longitudinally adjustable on the guide bar, a downwardly ofi'set disc carried by said bracket, and means pivotally connecting said discs and operable to secure them together in adjusted position.

In testimony whereof I have signed my 35 name to this specification.

FRED D. JOHNSON.

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