US415691A - Drawing-table - Google Patents

Description

(No Modell) 3 Sheets--Sheet 1. J. A. E. SVBNSON. ADRAWING- TABLE.

110.415,691. Patented Nov. 19, 1889.

lll/lll) (11:0 Model.) V s sheets-sheet 2.

J. A. F. SVENSON.

DRAWING TABLE.

110.415,691. Patented Nov. 19, 1889.

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(No Mfkdel.) 3 Sheets-Sheet. J. A. P. SVENSON.

DRAWING TABLE.

QU@ @JWM UNITED STATES PATENT EEICE.

eIOIIN AXEL FERDINAND SVENSON, OF SCRANTON, PENNSYLVANIA.

DRAWI NG-v-TABLE.

SPECIFICATON forming part of Letters Patent No. 415,691, dated November 19, 1889.

Application led .Tune 4, 1889. Serial No. 313,088. (No model.)

To all whom it may concern:

Be it known that I, J oHN AXEL FERDINAND SVENSON, having declared my intention of becoming a citizen of the United States, residing at Scranton, in the county of Lachawanna and State of Pennsylvania, have invented certain new and useful Improvements in Drawing-rlables; 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.

The object of myinvention is to produce a drawing-table which shall combine all the useful properties of the older devices,wherein the working-surface of the board was always held horizontal, with the more recent improvements upon these, which only oered a vertical drawing-board surface. Closely depending on this greater range of utility, my improvement embraces a new and superior parallel-ruling device.

Figure l is an elevation of my improved drawing-table. Figs. 2 and 3 are sectional views of the same. In Figs. l., 2, and the drawing-board is removed in order to show more clearly the essential mechanism. Fig. 4t is a detached plan of the movable frame which carries the drawing-board, showing the parallel-ruling device. Figs. 5 and 6 are sectional elevations of the same. Figs. 7 and 8 are detached views showing in detail the arrangement of fastening the ruler to the cords. Fig. 9 is amodificatou of the parallelruling device.

The following is a full description of my improvement:

a is the frame upon whose lower member the board rests when in place. This frame moves in slides l) b', and is balanced by a weight w through two cords and t', which are secured to the frame and carried over pulleys c c d e f, and finally fastened at their opposite ends to the table T. Each of the pulleys d, e, and f has, of course, two grooves in the rim. The counter-weight is suspended from the center pin of the movable pulley f.

The slides b ZJ are, near their upper ends, united by the cross-piece g, to which the support h is hinged. rlhe slides b b are also hinged at their lower ends to a projection built up from the stationary part of the drawing-table. The object of all these hinges is to allow the parts to take the positions they occupy in Fig. 3. y

It is seen in Fig. 2 that the strain in the cords 'i t" tends to force the lower ends of support 7i into recesses formed for this purpose in pieces k, thus making impossible any accidental slip of said lower ends of support h. In' effecting the change from position of board Vin Fig. l to that in Fig. 2 the draftsman pulls with one hand the support h forward as far as indicated by dotted lines h in Fig.2. l'Iis other hand, which had previously grasped the upper side of frame a., can noW gradually lower the system down to rest upon the posts l, which have pegs a?, that penetrate the slides l) b and tit into holes made for this purpose in the edges of frame a. The small wheels m facilitate the descent by rolling down the curved incline It. lVheu'placed in the position of Fig. 3, the frame a is prevented from moving out of slides l) h by the pegs on, described above. The mere lifting upward of frame a suffices to restore the systeinte the position of Fig. 2, all the movable parts adjusting themselves automatically to this position. The pulley d performs a very imlportant function in this change of the board from one position to the other; in fact, it is the Very thing which makes this change practicable. This will become apparent from an examination of Fig. 3. Here it is seen that the strain in the cords t' t" between pulley d and pulley e has been made to take a direction nearly opposite to that in the cords between pulley c and pulley CZ, the effect of which is to neutralize the downward pull caused by the heavy counter-weight w, which, were it not for this disposition of pulley d and cordsz' i', would very seriously oppose any attempt at raising the system to the position of Fig. 2. From the foregoing description it becomes evident that when the `drawing-board occupies the position of Fig. 2 it can be moved up or down at will to accommodate the draftsman in a standing or sitting position. Besides, he can while sitting move the frame and board so high up as to leave a sufficiently open space over the table T,

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whereby this is converted into a very convenient writing-desk. Add to this the position in Fig. 3, and it cannot fail to be noticed that my invention can well lay claim to superiority, the various positions of the drawing-board, so easily changed from one to the other, affording greatconvenience and rest to the draftsman.

Before explaining my improved parallelruling device it will be well to remark that in heretofore-existing devices for operating the ruler on a vertical drawing-board the weight of this ruler was counteracted by a vbalance-weight attached in such a manner that the board could not be placed in a horizon tal position without disturbing the proper relation between them. Therefore in order to accommodate the above-described changes in the" position of the drawing-boardI have invented a new device, which in all positions shall give the ruler a perfect motion.

In Fig. 4, o is the ruler, which at s and s is fastened to the cords ,e a. vThese cords, running over pulleys q q q2 Q3, constitute in combination with the ruler o the parallelruling device. RR are the balance-weights, which at all times hold the ruler in equilibrium. The cordal is placed in position in the following manner: Beginning, for instance, at the balance-weight R, it is led in the direction of the arrows in dotted lines upward and over pulley q, then down to s, where it takes a turn around the square projection of the bar u, which in larger scale is shown hy Figs. 7 and S. Further, the cord runs down and around the pulley qi, then to the right and around pulley q2, ascending from thence to balance-weight R. The other cord runs from R', as indicated by arrows in full lines, over pulley q to s and around the square at s', then over pulley q2 to the left and over pulley Q3 to balance-weight R. The two pulleys q2 and g3 are double-grooved to accommodate the two cords. `The arrows also indicate the path of two corresponding points of the cords when the ruler is moved toward the lower edge of the board, and it is then evident that since the two points s and s always move in the same direction and to the same extent the device must produce a perfect parallel motion. The simplicity of my improvement and on this score its superiority over previous contrivances is at once apparent when it is considered that no separate vpulleys are needed for the balanceweights. Moreover, my arrangement of pulleys and cords is such that the balanceweights secured to the latter slide on the surface of frame a, which important feature secures a perfect equilibrium between ruler and balance-weights'in all positions of the drawing-board, since they always move in t-he same plane.

As shownin Figs. 7 and 8, the bar a has at Si 'a projection which is partly round and partlysqua're. The round part moves in the guides y. (Shown by Figs. 4 and 5.) The 'square is a fastening for the cord, as previously described. The bar is at u formed -into a socket resting on the washer u2 and j Listing the ruler to any thickness of drawing-board.

In Figs. 4, 6, 7, and 8, P is a shelf attached to the ruler and designed for holding instruments when the drawing-board occupies its vertical position. lVhen the board is horizontal, this shelf can be folded fiat against the ruler by means of hinges o. I

In the modification shown in Fig. 9 the cords are crossed between the pulleys q2 and Q3 instead of running parallel. The operation is the same in all respects.

Vhat I claim isV l. An adjustable drawing-table comprising a frame to hold a drawing-board hinged at one edge, a support hinged at or near the opposite edge of said frame, and a weight suspended from said frame and hinged support, the lower end of said hinged support being free, whereby said frame and support may be folded together and the frame thereby adjusted to different angles, substantially as set forth.

2. An adjustable drawing-table comprising a frame to hold a drawing-board hinged at one edge, a support hinged at or near the opposite edge of said frame, a weight suspended by a cord from said frame and hinged support, and a fulcrum d on said IOO IIO

support, over which said cord passes, the lower end of said support being free, whereby said frame may be folded together and the frame thereby adjusted and held at diiierent angles, substantially as described.

3. In an adjustable drawing-table, the combination of the following elements: a table T, an adjustable frame to hold a drawing-board hinged at one edge to said table, a support hinged to said frame and having its free end resting and movable upon said table, a cord secured at one end to said frame near its lower edge, passing over pulleys on said support, and secured at its other end to said table, and a weight suspended by said cord below the table, all substantially as set fort-11.

4. In a drawing-table, the combination of the following elements: a table T, having a vertical standard 7a, one edge of whichforins an inclined track, a frame-hinged to said table, a support hinged to said frame and having its free end resting upon said track, acord connected at one end to 'said frame and at the other to said table and having an intermediate f ulcrum upon said support, and a Weight suspended by said cord below the table, all substantially as and for the purposes set forth.

5. The combination, Withthe table T, of a frame hinged thereto, a support hinged to said frame and having a rolling bearing on the table, and a system of counterbalancing devices for holding and permitting the adjustment of said frame and support, substantiallyr as set forth.

6. The combination, with the table T, having the standard 7.-., with its curved and inclined track, of the support 71 havinga roller resting and movable upon said track, and the cords t' t" and Weight w, all substantially as set forth.

7 The combination, with the table T', having the standard Zand pin :r at its rear, of the frame a l), hinged to the front of said table, substantially as set forth.

S. In a drawing-table, the combination, with the table T, of the hinged frame a b, the auxiliary supporting-fralne 7L, hinged thereto, the cords te, secured at one end to said frame and at the other to said table, the guide-pul leys c c e, the fulcrum-j'mlley d, and the Weight w, suspended on the cord, all substantially as described.

9. The combination, with the table T, of the grooved Ways l) D', hinged thereto, and the sliding frame a, said ways and frame forming an adjustable holder for a drawing-board, substantially as set forth.

IO. The combination, in a drawing-table, of

a parallel-ruler, balanced cords for sliding the same, and a yielding connection between said ruler and cords, substantially as set forth.

ll. The combination, With a drawing-table, of balanced cords running on pulleys, sub- 4o stantially as set forth, a parallel-ruler, and the bar u, connected to said ruler and cords, substantially as set forth.

l2. The combination, With the table having the pulleys q q and double-grooved pulleys q2 g3, of the cords z z', the sliding balance- Weights R R, and the adjustable ruler o,sub stantially as set forth.

13. The combination of a table having guides y, the ruler o and cords for movingit, and the arms u, connect-ed to such cords and having a guide-roller, substantially as set forth.

14. The combination, with the ruler 0, of the arm u, having' hook vu', and the clamping- 5 5 nut fu, substantially as set forth.

l5. The combination, with the cords ze and With the ruler 0, of the arms a, having square projections to serve as fastenings for a turn of the cords, substantially as set forth.

IG. The combination, with the ruler, of a hinged shelf, as P, substantially as and for the purposes set forth.

In testimony whereof I have aflixed my signature in presence of two Witnesses.

JOHN AXEL FERDINAND SVENSON.

IV itn ess es:

JAS. I-I. TORREY, JNO. P. ALBRo.

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