US2034350A - Drafting apparatus - Google Patents

Description

March 17, 1936. EL MARIO 2,034,350

DRAFTING APPARATUS Filed April 21, 1934 s Sheets-Sheet 1 A T T ORNE Y5.

March 17, 1936. E. MARIO DRAFTING APPARATUS 3 Sheets-Sheet 2 Filed April 21, 1934 INVENTOR. -1" 91 6414140 ATTORNEYS.

March 17, 1936. 5 MARK; 2,034,350

DRAFTING APPARATUS Filed April 21, 1934.

3 Sheets-Sheet 3 JNVENTOR.

M 972741010, BY M A TTORNEYS.

Patented Mar. 17, 1936 UNITED STATES -ATENT OFFICE 8 Claims.

This invention relates to a drafting apparatus and while it is particularly adapted for use by v topographical draftsmen when making maps and charts, it may also be used by architects and engineers when drawing plans.

One object of the invention is to provide a device of this character which can be used for laying off straight or arcuate lines at any angle desired and also as a pr-otractor and thus permit a map or plan to be very accurately drawn.

Another object of the invention is to so construct the device thata base bar thereof may be firmly secured upon a drafting table and adjusted to extend exactly horizontal, with a supporting rod or bar projecting therefrom at right angles to the base bar or at a slight incline towards the upperor rear side of the table and thereby permit straight -or arcuate lines to be accurately plotted and drawn.

A still further object of the invention is to'provide for detachably mounting a ruler under the base bar and permit a protractor or straight edged ruler to be selectively connected with the supporting rod.

Another object of the invention is to provide a protractor of such construction that either 'an arcuate line or entire circle may be drawn and also provide a straight edged ruler so associated with a circular scale that it may be turned within the confines of the scale with its axis coinciding with the center of the scale when the protractor is in use.

Still another object of the invention'isto permit the device to be swung vertically into and out of position over the drawing table and also allow the circular scale to be shifted without danger of smearing a drawing.

Still a further object of the invention resides in providing a device which is simple and durable in construction, inexpensive to manufacture and one which will be very efficient in application.

With these and numerous other objects in view, my invention consists in the novel features of construction, combination and arrangement of parts as will be hereinafter referred to and more particularly pointed out in the specification and claims.

In the accompanying drawings forming a part of this application;

Figure l is a top plan view showing the improved drafting device applied to a table with a circular scale in use;

Figure 2 is a sectional view taken along the line 2-2 of Figure 1;

Figure 3 is a fragmentary view of the circular scale partially in top plan and partially in section;

Figure 4 is an enlarged sectional View taken along the line -44 of Figure 3;

Figure 5 is a view in elevation looking from the 5 front of the table;

Figure -6 is a transversesection taken-along the line 6-5 of Figure 1;

Figure 7 is a fragmentary View showing a mounting forming part of the device, principally 10 in elevation and partially in section along the line l-i of Figure 8 Figure 8 is a section taken along the line 8-8 of Figure 7;

Figure 9 is a sectional view taken horizontally through Figure 7;

Figure 10 is a section taken along the line it-lii of Figure 5 with portions of a securing clamp shown in section and other portions thereof inelevation; V 20 Figure 11 is a section through the clamp taken along the line l'l-Il of Figure 10;

Figure 12 is a section taken horizontally through the clamp along the line I2l2 of Figure 10;

Figure 13 is another sectional view taken horizontally through the clamp along the line l3-l3 of Figure 10;

Figure 14 is a top plan view showing straight edged rulers in use;

Figure 15 is a sectional view taken along the line iii-l5 of Figure 14;

Figure 16 is a perspective view showing the improved drafting device applied to a table and equipped with the straight edged rulers.

This improved drafting implement has been shown applied to the top i of a drafting table formed with a slot 2 through which an edge portion of the paper 3 is to project as shown clearly in Figures 2, l5 and 16, but it is to be understood that this merely illustrates one conventional form of drawing table to which the device may be applied and also that it may be applied to a drawing board instead of directly to a table top.

The base bar 4 is formed of strong angle metal and has a lower horizontal flange '5 from which projects an upstanding vertical flange 6 formed with a longitudinally extending slot 1. At its ends the base bar is formed with enlargements constituting feet 8 which support the base bar I in an elevated position as shown clearly in Figure 2 and from these enlarged ends of the base bar project arms '9 having clamps l0 pivoted to their outer ends. These clamps normally extend in depending relation to the arms with their stationary jaws II in position to bear against the 5'5 upper face of the table top I and their adjusting screws l2 below the table top. When the adjusting screws are rotated in a direction to move them upwardly into position to engage the under face of the tabletop and are then tightened, the table top will be firmly gripped and the base bar will be securely held in operative relation to the drawing table but since its arms are pivoted to the clamps, it may be swung vertically towards or away from the table. In view of the fact that the paper 3 extends under the base bar, the paper will be prevented from curling or slipping out of place. Threaded rods or bolts I3 extend upwardly from the jaws I l near their free ends and carry springs I4 against which the arms 9 rest when the arms are in position over the table with the rod or threaded stem engaged through the oval opening l5 formed in the arms. Nuts K5 are threaded upon the projecting upper end of the bolts l3 to limit upward movement of the arm and base bar or hold the feet 8 of the base bar firmly against the paper if the securing nuts are sufficiently tight. 'It will thus be seen that the base bar may normally have its feet spaced slightly from the paper or firmly held in contact therewith and that when the feet of the base bar are slightly out of contact with the paper, this paper may be readily slid along the table top and through the slot 3. By removing the nuts from the upper ends of the rods or bolts l3, the base bar and its arms may be swung upwardly and then downwardly to a position in which the base bar and mechanism carried thereby will be suspended from the table adjacent an edge thereof, where it will be out of the way when not needed. As the openings l5 are oval when viewed in top plan the arms 9 may move vertically without binding upon the bolts l3 but will be prevented from having side play.

In order to detachably and adjustably connect a scale or ruler with the base bar, a bracket I1 is employed which is formed of angle metal and has a lower horizontal flange l8 and an upstanding vertical flange l9. The horizontal flange of the bracket rests upon the flange 5 of the base bar 4 and the flange H] has flat face-to-face contact with the flange 6 and carries a threaded stem 20 which is passed through the slot 1 and has threaded upon its free end portion a winged nut 2| which when tightened firmly secures the bracket in a set position. When this nut is loosened, the bracket may be slid longitudinally upon the base bar to a desired position where it will be again secured by tightening the nut. Openings 22 are formed through the upstanding flange of the bracket in such position that they are exposed through the slot 1 as shown clearly in Figures 5 and 7, thereby permitting a person to pass his fingers through these openings and easily slide the bracket to an adjusted position. A mounting rod 23 extends transversely of the bracket at substantially right angles thereto and at one end carries a cross-head 24 which rests upon the horizontal flange I 8 of the bracket where it is secured by bolts 25 and by referring to Figure .9, it will be seen that one of these bolts is passed through a circular opening 26 formed near one end of the cross-head while the other bolt passes through a slot 21 extending trans- -versely of the cross-head adjacent the other end thereof. By this arrangement, the supporting bar or rod 23 may be disposed exactly at right angles to the bracket and base bar and the two bolts 25 then tightened or the supporting bar may be set slightly out of a position at right angles to the bracket and secured in this position by tightening the bolts.

This improved drafting implement is to be used by topographical draftsmen when making maps or charts and by architects and engineers when drawing plans. I have, therefore, provided a protractor which may be applied to the supporting rod 23 and includes in its makeup a circular scale 28 and straight edge ruler 29 and have also provided a straight edged ruler 30 to be connected with the supporting rod in place of the protractor and a second straight edged ruler or scale 3| which may be mounted under the base bar when either the scale 30 or the protractor are in use. It will be understood that the ruler or scale 30 may be used without the scale 3| and also the protractor and in addition, that the scale 3| may be used without the protractor or scale 30 in which case the bracket H can be detached from the base bar and thereby allow full length use of the scale 3|.

The circular scale 28 of the protractor is formed of xylonite or celluloid metal and has its upper face marked with appropriate scale markings as shown in Figure 1. A bridge 32 consisting of a metal rod having its ends turned downwardly and secured to the circular scale by screws 33 passed upwardly through the circular scale, is disposed above this circular scale and extends across the same as shown in Figure 6 and by referring to Figure 1, it will be seen that this bridge or yoke does not extend diametrically of the circular scale in order that a zero mark 34 provided at the center of the straight edged rule or scale 29 may be visible.

A lug or bearing 35 which is firmly fixed to the bridge 32 at its center extends downwardly therefrom and is formed with an opening slidably receiving the mounting rod 23 and the circular scale carries a block or bearing 36 through which the mounting rod is also passed. This block 36 is equipped with a set screw 3! which when tightened will firmly hold the protractor in an adjusted position longitudinally of the supporting rod. It will thus be seen that the protractor or circular scale can be adjusted longitudinally of the supporting rod and by loosening the winged nut 2|, the circular scale together with the rod and bracket may be adjusted longitudinally of the base bar. Therefore, this protractor may be adjusted longitudinally and transversely of the sheet of paper and disposed in a desired position relative to a map or plan being drawn.

The straight edged rule or scale 29 extends diametrically of the circular scale within confines of its inner periphery and at its ends carries metal shoes 38 which are arcuate longitudinally and project from opposite sides of the rule. Referring to Figure 4, it will be seen that each shoe is secured to the rule or scale by a counter-sunk screw 39 and that the outer marginal edge portion of the shoe is bevelled from its upper and lower faces, thereby providing a tapered marginal portion 40 which engages in a groove 4| of similar configuration formed in the inner marginal edge face of the circular scale. By this arrangement, the ruler or straight edged scale 29 will be held diametrically of the circular scale but may be turned the full circumference of the circular scale about an axis coinciding with the center of the circular scale and indicated upon the rule by the zero mark 34. Scale markings upon the upper face of the ruler increasingly progress from the zero mark towards the two ends of the ruler and as the zero mark is exposed and may be in the form of a small opening, if so desired, it will be very easy to find a center upon a map or plan and also the straight edged rule or scale may be accurately set to extend at any angle desired, where it will be held due to frictional binding between the shoes 38 and walls of the groove 4|. The openings 39 formed in ends of the scale 29 to receive the screws 39 are elongated longitudinally of the scale as shown in Figure 4 and, therefore, when contacting faces of the marginal portions 46 and Walls of the groove 4| become worn, the screws can be loosened to permit the shoes to be slid longitudinally of the scale until they again fit snugly within the groove 4| and the screws retightened. Therefore, wear can be compensated for.

When the straight edged scale or ruler 3B is to be used in place of the protractor, the protractor is removed by sliding it longitudinally off of the rod 23 after first loosening the screw 42 and removing the washer 43 from the end of the rod. The rod is then slid through openings formed in the bearing blocks 44 and 45 which are firmly held upon the ruler by screws 46 passed upwardly through the same and since the bearing block 44 carries a set screw M, the ruler 30 may be firmly secured in a set position and prevented from slipping longitudinally of the rod. This ruler and the protractor may rest fiat upon the sheet of paper when in use but by properly adjusting the nut It the spring l4 may yieldably support the base bar in a sufficiently elevated position to permit shifting of the scale across the paper without danger of blotting. While the rulers or scales 3 and 3| may be used by engineers or architects, they are primarily intended for use for laying off or determining longitude and latitude by map makers and topographical draftsmen.

When this improved drafting apparatus or implement is in use, the clamps ID are applied to the table top or drawing board with the jaws II and securing screws l2 engaging upper and lower faces thereof. Care should be taken to have the base bar 4 extend parallel to the slot 2 or the adjacent edge of the table top. When so secured, the base bar will extend over the sheet of paper and if a map is being drawn, a line extending horizontally across the paper and indicating latitude may be brought into proper parallel relation to a side edge of the lower flange 5 of the base bar and the paper secured in a stationary position upon the drawing table by contact or the nut [6 may be tightened sufficiently to force the feet 8 of the base bar into clamping engagement with the sheet of paper. It is preferred, however, to have the feet of the base bar spaced slightly above the paper in order that the scale or rulers may be moved across the paper, without danger of smearing and then brought into contact with the paper by pressure applied to the base bar which will compress the spring l4 and move the scale and feet of the base bar into contact with the paper. If the ruler or straight edge scale 3| is to be used, it is secured against the under face of the base bar by the screws shown in dotted lines in Figure 15. When this ruler is in place and the ruler or scale 30 is in use, the scale will be applied to the mounting rod 23 with one end contacting with an edge of the ruler 3| or the ruler or scale 30 may be slid along the rod 23 and releasably secured in any desired position thereon. The protractor or circular scale may be used either with or without the rule 3| and by properly adjusting this scale along the rod 23 and moving the bracket I! along the base bar, the circular scale may be shifted into any desired position for drawing arcuate or circular lines and also for drawing straight lines at a desired angle through the medium of the scale 29. By moving the protractor into position over a compass rose provided upon the drawing table or the sheet of paper, the scale 29 may be accurately set to extend at a desired angle and then moved into position for drawing. When the device is not in use, the bracket can be easily and quickly detached from the base bar and together with the rod 23 and the scale put away and the clamps It] may then be loosened to permit removal of the base bar from the table or left in engagement therewith and the nut l6 unscrewed in order to permit the base bar to be swung from a position over the table to a depending position at one side thereof where it will be out of the way.

From the foregoing description of the construction of my improved device, the operation thereof and the method of use will be readily understood. It will be seen that I have provided a simple, inexpensive and efficient means for carrying out the objects of the invention and while I have particularly described the elements best adapted to perform the functions set forth, it is obvious that various changes in form, proportion and in the minor details of construction may be resorted to, without departing from the spirit or sacrificing any of the principles of the invention.

Having thus described the invention, what is claimed is:

1. A drafting implement comprising a mounting including a bar supported in an elevated position, a circular scale disposed beneath said bar and suspended from the same, a ruler extending diametrically of said scale, and arcuate shoes at ends of said ruler detachably connected therewith and slidably engaged in a circumferentially extending seat formed in the inner marginal edge face of the scale for movement about the inner peripheral edge thereof whereby the ruler may be turned about an axis coincident with the center of the scale.

2. A drafting implement comprising a mounting including a base bar and means for connecting the base bar with a drawing board and mounting the base bar for swinging movement towards and away from the upper face of the drawing board, depending feet at the ends of the base bar to support the base bar spaced above the drawing board, a supporting bar extending transversely of said base bar and connected therewith for adjustment longitudinally of the base bar, a scale extending longitudinally of said base bar beneath the same between the feet and detachably connected with the base bar, said scale having a portion projecting forwardly from the base bar to present an edge spaced forwardly therefrom in parallel relation thereto and another scale disposed beneath said supporting bar longitudinally thereof and detachably connected therewith and extending at right angles to the front edge of the first mentioned scale.

3. A drafting implement comprising a mounting including a base bar and means for connecting the base bar with a drawing board and mounting the base bar for vertical swinging movement towards and away from the upper face of the drawing board, means for cushioning movement of the base bar towards the drawing board and yieldably holding the base bar spaced above the drawing board, a bracket carried by said base bar and adjustable longitudinally thereof, a supporting bar extending at substantially right angles to said base bar and having one end detachably connected with said bracket, and a scale carried by said supporting bar.

4. A drafting implement comprising a mounting including a base bar, depending feet at ends of said bar to support the bar spaced above a drawing board, arms extending from ends of the bar, clamps pivoted to said arms and having jaws beneath the arms, bolts rising from said jaws and passing through openings in the arms, springs between the arms and jaws yieldably resisting downward movement of the arms, nuts carried by said bolts and engaging the arms to hold the arms against said springs, a supporting bar extending transversely from said base bar, a scale detachably carried by said supporting bar and a second scale detachably secured under said base bar between said feet.

5. A drafting implement comprising a mounting including a horizontal base bar adapted to have a scale associated therewith, arms extending from the outer longitudinal edge of said bar, clamps pivoted to outer ends of said arms and depending therefrom for engaging a drawing board and mounting the base bar for vertical swinging movement towards and away from the drawing board, means to cushion downward movement of the base bar towards a drawing board and'urge the base bar upwardly and yieldably hold the base bar spaced above the drawing board, and means for controlling upward movement of the base bar by the yieldable means.

6, A drafting implement comprising a mounting including a base bar adapted to have a scale associated therewith, arms extending from said bar, clamps pivoted to said arms for engaging a drawing board and mounting the base bar for vertical swinging movement towards and away from the drawing board, springs between the arms and portions of said clamps to yieldably hold the base bar spaced above a drawing board, and means to hold the arms in engagement with the springs.

'7. A drafting implement comprising, a mounting including a bar supported in an elevated position, a circular scale disposed beneath said bar and suspended from the same, a ruler extending diametrically of said scale'and having its end portions reduced from its under face to form seats, and shoes detachably secured in the seats at ends of said ruler and projecting from opposite sides thereof, the inner marginal edge face of the scale being grooved to form a circumferentially extending track and said shoes having tapered edge portions engaged in the track to slidably connect the ruler with the scale for turning about an axis coincident with the center of the scale. 7

8. A drafting implement comprising a mounting including a base bar formed of angle-material and having a horizontal flange and a vertical flange extending upwardly therefrom and formed with a longitudinally extending slot, means for detachably securing said base bar upon a drawing board, a bracket formed of angle-material and having a horizontal flange resting upon the horizontal flange of said base bar and an upwardly extending vertical flange provided with a fastener engaged through the slot to detachably connect the bracket with the vertical flange of the base bar and mount the bracket for adjustment longitudinally of the base bar, openings being formed in the vertical flange of the bracket and aligned with the slot whereby fingers may be engaged through the openings and the bracket slid along the base bar, a supporting bar detachably secured at one end to the horizontal flange of said bracket and projecting therefrom transversely of the base bar, and a scale carried by the supporting bar.

EMILIO MARIO.

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