US607814A - Alexander aigner - Google Patents

Description

No. 607,814. Patented July .26, I898. A. AIGNER.

PARALLEL MOTION FOR DRAWING BOARDS.

(Application filed Sept. 25, 1897.)

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Nrre Tarps ALEXANDER AIGNER, OF BUDA-PESTH, AUSTRIA-HUNGARY.

PARALLEL MOTION FOR DRAWING-BOARDS.

SBFCIFICATION forming part of Letters Patent No. 607,814, dated July 26, 1898.

Application filed September 25,1897. Serial No. 653,060. (No model.)

To all wholn it may concern:

Be it known that I, ALEXANDER AIGNER, a subject of the King of Austria-l lnngary, residing at Buda-Pesth, Austria-Hungary, have invented certain new and useful Improvements in Parallel Motions for Drawing- Boards, of which the following is a specification.

The object of this invention is to provide an appliance for the parallel guiding of rulers on drawingboards.

The appliance can be attached to any kind of drawing-boards.

The invention is designed to prevent the inaccuracies resulting from the unevenness of the drawing-board sides and the ledge of the T-square by the application of a simple mechanism easy to handle. This result is obtained without interfering in any manner with the independent use of the drawingboard and without influence upon its dimensions, either in height or width.

By means of this appliance more rapid and accurate drawing is facilitated, and hence a saving of work and time are brought about.

In the accompanying drawings the invention is illustrated, in which Figure 1 shows a drawing-board provided with the new appliance in a view from below. Fig. 2 represents the clip or dog appliances employed. Fig. 3 is a lateral View of the rollers applied in pairs at three corners of the drawing'board. Fig. 4 is a lateral view of the adjustable pair of rollers attached to the fourth corner of the drawing-board. Fig. 5 is a view taken sectionally through the drawingboard. Fig. 6 shows another form of the clip or dog attachment for the Tsquare, and Fig. 7 shows such appliance for the rollers. Fig. 8 shows still another modification of the clip or dog attachments.

As shown in Fig. 1, four corner-pieces I, II, III, and IV are attached in a permanent stationary manner to the four corners on the back of the drawing-board R. Of these the ones designated I, II, and III are of even'size.

They consist, as appears from the lateral view Fig. 3, of a plate a and'two strap-pulleys Z), which roll easily. The corner-pieces I and III are attached lengthwise, halving the right angle, while corner-piece II is placed broadside. Oorner -piece IV, which serves for tightening the cable and at the same time for the insertion of the ruler, consists, as shown in the lateral view Fig. 4, of an angle-plate a and the guide for the rollers or pulleys, these being adjustable in the arms of the angle-plate by means of the ti ghtenin g-screws c. A thin supple cable E is stretched over the eight rollers of the four corner-pieces in the rotation designated by the numbers of the various rollersnamely, 1, 2, 3, 4, 5, 6, 7, and 8and the two ends are spliced or joined together. The tightening-screws c are tight ened sufficiently to allow the cable to glide easily over the rollers. The cable is guided over the rollers or pulleys in such a manner that the corresponding outer and inner cable parts on opposite sides ofthe frame move in the same direction, as shown by the arrows in Fig. 1. the ruler T in any manner desired in accordance with the height or width of the drawingboard by the assistance of the clips or dog attachments described hereinafter.

For the protection of the tightened cable a guard-ledge F, Figs. 1 and 5, is provided at the four edges of the drawing-board. This guarding-ledge reaches as faras the cornerpieces, leaving the latter open, so that the cable can be renewed easily whenever such contingency becomes necessary.

IVhile the drawin g-board must be supplied with the cable-rollers or strap-pulleys and with the endless cable for the employment of the new apparatus, the draftsman will only require two clips or dogs, which he can use on any drawing-board, owing to their construction. These clips or dogs serve for thetemporary attachment of the ruler to the cable.v

The clip or dog represented in Fig. 2, A, B, and 0, consists of a jaw or holder d, adapted to receive the'ruler,which is held by means of the screw 6 when laid on the drawing-board R. A square pin f is attached to the holder.

This pin points downward, and a catch-piece g 011 this pin holds the cable. This catch- This makes it possible to employ.

ing screws are turned toward the draftsman, whether the 'board is used lengthwise or broadside. The ruler is laid on the lower edge of the drawing-board in such a manner that both ends of the same overreach the drawing-board. Then the one clip or dog is pushed from below on the ruler at the edge of the drawing-board while the cable-holder g is entirely open, and the clip is fastened to the ruler by the screws. After this the cable-holder is attached to the cable by the screw. The same operation is performed with the second clip or dog at the other side of the ruler; but to allow of an easier movement a play of about one millimeter must be allowed between the two clips and the edges of the drawing-board.

Should the ruler be set to a line already drawn beforehand, it can be set sharply on the line by means of the cable-tightening screws,

as atightening or loosening of the same effects a displacement of the ruler attached to the cable.

These clips, Figs. 6, A B O, consist only of the holder m with the tightening-screw 12 means of the lower nut r the two arms of the holding-spring are pressed together, and the cable is caught accordingly. Moreover, the clips can be further simplified for school use in that they may be bent out of one piece, Fig. 8, and adapted for a normal dimension of drawing-board and ruler. In Fig. 8, d shows an elastic vise or holder, e the screw for fastening the ruler, and f an oblique angle, on the lower arm g of which a little plate 72/ and a screw 7; are adapted to hold the cable between the side g and the plate It. The cable-rollers for this apparatus, as shown in Fig. 7, are stamped out of two round'sheet plates Z, which are connected by clasps u, stamped out at the same time. The clip shown in Fig. 8 consists of the holder d", into which the tightening-screws e, intended for the fastening of the ruler, are screwed from above.

I claim In combination in a drawing-board of rectangular form, a pair of pulleys arranged at each corner of the board, two of said pairs being arranged with their axes on the hypotenuse of the right angle at the corner while the pulleys of the other two pairs have their axes on lines dividing the right angles, the cable extending around said pulleys and having its outer portions running in the same direction while its inner portions run in the opposite direction, the ruler and the clamps for attaching the same to the cable and the means for adjusting the cable, substantially as described.

I11 witness whereof I have hereunto set my hand in presence of two witnesses.

ALEXANDER AIGNER. v

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