US2404949A - Adjustable drafting stand - Google Patents

Description

July 30, 1946. H L DE LlSLE 2,404,949

ADJUSTABLE DRAFTING STAND Filed Sept. 17, 1942 5 Sheets-Sheet 2 JAW- (mll

/ Heol 1. P50516 DICE/9550 l nu L/,sw H Maemyf/rfcame July 30, 1946. H L DE LlsLE 2,404,949

ADJUSTABLE DRAFTING STAND Filed Sept. 17, 1942 3 Sheets-Sheet 5 fyi f@ 0" Patented July 30, 1946 ADJUSTABLE DRAFTIN G STAND Harold L. De Lisle, deceased, late of Sheboygan, Wis., by William H. Murphy, executor, Chicago, Ill.

Application September 17, 1942, Serial No. 458,634

Claims. l

This invention relates to adjustable drafting stands of the class in which the drawing board is adjustable both vertically and angularly and. more particularly, of the type wherein the dra-v ing board is maintained in its adjusted inclined position by friction, and, in its adjusted vertical position, is balanced by a spring adapted to be adjusted to exert a controllable tension.

Among other objects, the present invention aims to provide an improved and simplied construction of this type including a novel gripping mechanism for the inclination of the drawing board which may be released by a manual movement by the draftsman, and, similarly, novel tension means for the vertical adjustment of the board which may be operated by a movement of the foot through a pedal device.

These and other objects and advantages will be apparent from the following description, taken together with the accompanying drawings, in which Figure 1 is an end elevational view of a drafting stand embodying the present invention, showing in full lines an inclined selected position of the drawing board, and, inbroken lines, a horizontal position thereof;

Figure 2 is an enlarged front elevational View of the structure of Fig. 1, parts being cut away for clearness of description; f

Figure 3 is an enlarged partial cross-section taken on the line 3 3 of Fig. 2, and also being a similar section on the line 3 3 of Fig. 4;

Figure 4 is a fragmentary view on the scale of Fig. 3 of the left-hand side of Fig. 2 but with parts in cross-section taken on the line 4 4 of Fig. 3;

Figure 5 is an enlarged partial plan View taken on the line 5 5 of Fig. 2;

Figure 6 is a similar View taken on the line 6 6 of Fig. 2;

Figure 7 is a partial vertical section on the scale of Fig. 5, taken on the line 1 1 of Fig. 5;

Figure 8 is a. similar View taken on the line 8 8 of Fig. 6; and

Figure 9 is a detail section taken on the line 9 9 of Fig. 2 somewhat enlarged.

Referring in detail to the illustrative construetlon shown in the drawings, the numeral I9 indicates in general a base for the drawing board indicated generally by the numeral l I. The base III may be in the form of a table or desk having a working top I2, front legs I3 and I4 and rear legs I5. The table may be reinforced along its.

top ends by panels I6 and along its lower ends by cross-pieces I'I, the latter being connected by a longitudinal runner I8, thus providing a suitable supporting structure for the board. The top I2 of the table may be used as one working surface, accessible from one side of the table I0, which is here referred to as the rear side, namely the side opposite that at which the drawing board I I is pivoted as next described. The drawing board I I provides another working surface in the usual way.

In accordance with the present invention, the table ID at its -front side carries for simultaneous vertical adjustment, as later more particularly explained, a pair of hollow posts I9 and l2|) having their free lower ends 2I slidingly passed through a casing 22 carried at the front of the desk I il by and between the legs I3 and I4 thereof. rI'his casing is here shown of about the width of the legs and extending vertically thereof about onethird of the height of the legs, but preferably a little nearer their tops than their feet. Bolts 23 may so secure the casing to the legs I3 and I 4. It will be noted that the table top I2 terminates at the front of the table adjacent the posts I9 and 2B short of the legs I3 and I4 so as to accommodate the posts in the plane of the legs.

Adjacent their tops, there is shown pivoted to each of the vertically movable posts I9 and 20, as at 24, a yoke-like or inverted U-shaped` bracket 25, which as best shown in Fig. 4, may be formed or two angular sector-shape plates 25a and 25h having their flanges welded together as at 2G, one of the latter being extended as at 21 to be secured as by screws 28 to the under face of the drawing board I I, the board and brackets being reinforced adjacent thereto by the cross-cleats 29 also on the under face of the board.

With the drawing board so arranged for angular movement on the pivots 24, frictiona1 or gripping means are provided for holding the board at a selected angular adjustment whereby the board may be disposed either vertically or horizontally or at any intermediate angle therebetween. For this purpose, there is shown secured to each of the posts i9 and 2Q, between the plates 25a and `25h of each of the yoke-like brackets 25 respectively, a segment plate 33 along the arcuate periphery of which is suitably secured an arch rail 3! having corrugations thereon, as by the screw threads 32. A frictional mating member such as the half-nut 33 rides on each of the arch rails 3l, the half-nut 3 3 beine, here shown secured between the sides of an inverted channel bar 34. The threads in the half-nut mesh with the screw threads 32 on the arch rails, the bracket 25 also straddling the channel bar 34.

Each of the channel bars 34 is secured to a nger 35 which is keyed to a rock shaft 39 journalled at each end in the cleats 29, the ends oi the rock shaft 35 which pass through the cleats and through the iingers 35 being conveniently reduced, as best shown in Fig. fl, to prevent longitudinal movement of the rock shaft. Between each of the inverted channel bars 34 and the flanges 26 of the brackets 25 is inserted a compression coil spring 31. which normally biases the channel bars 34 into position to cause the gripping members 33 to frictionally engage the arch rails 3I, and, in this instance, to intermesh the threads 33a on the half-nut 33 with the threads 32. One of the inverted channel members 34, in this instance the one at the left-hand end of the drawing board is conveniently extended outwardly as at 38 to form a hand lever by which the common rock shaft 3S may be partially rotated against the action of the springs 31 to release the gripping members 33 from the arch rails 3l and thus permit angular adjustment oi the drawing board, as suggested in Fig. l.

The end of the lever 38 may terminate in a wooden handle 39 for convenience in grasping this lever and moving it toward the board to effect the release just described. Upon letting go of the lever 38, the springs 31 again urge the gripping members 33 into engagement with the arch rails 3l to retain the board in its selected angular position until its position is again desired to be changed. Stop members 49 carried at the top of the posts I9 and 20 limit backward rotative movement of the pivot brackets 25 on the posts to inhibit rotation of the drawing board in this direction beyond the horizontal position as shown in broken lines in Fig. l, and other stops 4I at the lower ends of the arch rails 3| may limit the rotation of the drawing board in the opposite direction, by also contacting with the pivot brackets 25.

Turning now to the means for eiecting the vertical adjustment of the drawing board, and further in accordance with the present invention, the casing 22 receives the posts I9 and 2U therethrough by means of apertures 42 and 43 in the upper and lower walls respectively of the casing, these apertures affording a sliding fit for the posts therein. Aflixed to each of the free ends 2| of the posts, as at 44, are flexible members such as, in this instance, the cable 45 for the post I9 and the cable 46 for the post 2U. These cables run upwardly parallel with the posts and into the casing 22 where they are supported as next described. It will be noted that the openings 43 in the lower wall of the casing are enlarged sufciently to pass the cables therethrough with the posts, the cables being here shown upon the outside of the posts in contact therewith.

The cable 45 for the post I9 in this instance passes over an idler pulley 41 journalled within the casing on a pair of uprights -48 riveted as at 48a to the inner faces of the casing, and thence to one end of a relatively heavy expansion coil spring 49, to which the cable 45 is hooked as at 59. The other end of this expansion coil spring is hooked as at I to a cord 52, the other end of which is wound on a spindle 53 journalled within the casing 22 adjacent its end opposite the post I9. The cable 48 for the post 29 passes upwardly into the casing 22 similarly to the cable 45 and over an idler pulley 54 journalled within the casing on uprights 55 riveted as at 55a to the inner faces of the casing. The cable 45 thence travels longitudinally of the casing 22 to pass over the same pulley 41 upon which the cable 45 is entrained, and thence the cable 46 travels from the pulley 41 with the cable 45, to the coil spring 49 where it is also connected, as at 59, to the coil spring. The spindle 53 has its bearing in the casing walls advantageously reinforced by extensions h of the uprights 55.

Tension on the spring 49 may be varied by means of a crank 55 on the exterior of the casing which is keyed to the spindle 53, as at 51, and has a handle 58. By rotating the crank 5B in a clockwise direction, looking at Fig. 2, the tension of the spring 49 may be increased and by turning the crank counter-clockwise, the tension may be decreased. The face of the casing may have radially arranged holes 59 therein into which a nib Bil at the inner end of the handle 58 may be sprung to hold the crank in selected adjusted positions against the pull of the spring 49. The handle 58 may be constructed as shown in Fig. 9 in which the nib 50 is shown integral with a spring plunger 69a threadedly connected as at 59h with the exterior shell 69o of the handle, A coil spring 99d surrounds the plunger 60a and presses at one end against the flange 99e of the plunger 69a and at its other end `against the crimped endlf of a spring barrel 99g. By pulling outwardly on the exterior shell 90C of the handle, the nib is retracted, the spring being further compressed, so as to be again urged toward the face of the casing upon release of the handle.

Thus the entire weight of the posts I9 and 2D and with them the drawing board II and its langular adjustment mechanism may be counterbalanced by the spring 49. In practice, almost the entire weight is counterbalanced so that vertical adjustment of the drawing board may be effected by relatively slight manual effort on the part of the draftsman, to raise or lower the drawing board as desired. A brake mechanism, as next described, is provided to maintain the board in such selected vertical adjustment.

Following the present invention, the brake mechanism just referred to comprises, as here shown, a pair of jaws 6I and G2 which, by their somewhat wedge-shape mouths IDI), partially receiving the posts i9 and 20 respectively, are arranged to jam. the posts between themselves and the opposite margins of the casing apertures 42 and 43 and thus to frictionally clamp the posts against vertical movement therein. The jaws 6I and 52 are shown carried integrally at the upper ends of bifurcated arms 93 and 54 respectively. The arm 93 is conveniently pivoted on the pivot 55 of the idler pulley 41 and the arm 64 is pivoted similarly on the pivot of the idler pulley 54. Loosely connected to the jaw El, as by a somewhat ball and socket connection, is a short cylindrical hollow bar` 51, a nib Gla on the jaw projecting into the interior of the bar, and connected to the jaw 62 is a similar hollow bar 68 which has a relatively long extensible section 59. A nib 62a on the jaw 62 projects loosely into the interior of the bar 68. These bars may be conveniently in the form of pipes or tubing. The bar sections 53 and 69 are left and right-hand threaded as at 98a and 69a respectively lwhere they are connected by a threaded coupling 13 by which the combined length of the bar sections 68 and 59 may be shortened or lengthened.

Adjacent the left-hand end of the casing 22, in this instance, the uprights 48 are extended as at 1I to provide a bearing as at 12 for a pintle 13 extending across the casing. Upon the pintle 'I3 is pivoted centrally a pair of parallel brake links 14 and 14a. The links 14 and 14a are exf tended .in :opposite .i-.directions :from their pivot 11.3. Theotherwisefree ends .of the bars .61 :and .69 are pivotedlas 'at .l5 .and :1 6 respectively .to `the adjacent .ends .of the .brake rlinks 1A and l14d. The link 'I4 iis ,further extended -in `both Idirec.- tions of ythe pivot v'13, in one 4direction .as at 'H lto `have hooked thereto as at -18 va wire l y.which has its other end hooked as at 80 to an expan- :sion -coilrspringanchored as vat 82 to a .clip 83, Weldedfas `at `84 fto -the lower wall .of the casing, The 1extremity of fthe extension 'L1 of .theilink M may be offset outwardlyfas at i85 to :be fclear `of :the bar 69. The .otherend `86of the .link L4 has articulated therewith as v:at ,8.7! a -wire rod 8B which .extends :downwardly `throueha slot .89 in ,the'lower wall of:the.oafsingto .be articulated as at .90 mithra .-foot lever or pedal 9| gplvoted as at 92 `on "an inverted Ueshape bracket 93 suitably fsecured .tothe Aunder face of the .desk ,runner v|23.

Since in the .normal gposition '.-of vthe bars (Sl and69,.a line connecting .the pivots T5 -and 'f6 of .the bars .61 and 69 yon .the .links V'M -'lila ris subzstantially .aligned with atheaxesfof .these bars, .the .bars vare .at substantially their maximum dista-nce apart andthe jaws 6l .and .62 are `pressed outwardly toclamp the posts @I9 yand .20 -respectively .against vertical movement. When, now, the .pedal :9| depressed, the rod 88 Ais reciprocated rdownlwardlyand the brake links .T4-14a Iare .frotated counter-clockwiseontheir pivot lf2 against :the force .of .the fexpansion spring ill. Rotation yof the fbrake links .draws :the ends of the .bars 51 .and 69 towardeach other or at least toward .a .-verticalline passingsthroughthe pivot l2, thus `reduoingthe overallflength of the -barsrBiL-B-ES ,anjdrelaxing the pressure of the jaws 6I and `62 on the posts I9 and 20 respectively. This movement need be -only very slight and the --articulated connections provided by the -nibs 64a .and '62a I(somewhat .in the nature -of universal joints) .with :the bars .accommodate -this movement ol :the brakelinks. 'Thereimay .beat the l same time .a slight inward movement toward -each :other of :the arms 93 and 64 on theirpivots :and 6 Yduring 'the icontractual movement :of the bars dust .-described. lThus, lthe -posts :I'S "and 2i! .are released for 'vertical Imovement :andare Arendered subjcctito .theipullof thespring 4.9, and counter- -balanced thereby, so that :the :drawing `'board may be either depressed or elevated by alight pressure iolD ithe hand. Thereupon the pedal s! may :be .released aand the "drawing board .again secured at its desired elevation. The extension 1| carries a brake stop lug 'Ha Iwhich limits clockwise rotation of the links 'i4--14a under the influence of the expansion spring 8l to a point where a line connecting the pivots I5 and 'I6 is substantially coincident with the axis of thebars (il-69. The stop lug 'Ha acts by engagement With the extension 86 of the link 14.

Intermediate the casing 22, the bar 69 may carry a pair of wooden hangers 94 and 95 somewhat loosely thereon. The hanger 94 at its lower end has a pair of vertically spaced apart screws 96 between which and between the open sides of the hanger pass the cables and 46, thus providing a guide for these cables. Similarly, the hanger 95 has a pair of vertically spaced apart screws 91 between which and between the open sides of this hanger slidingly passes the cord 52 to guide this cord in its movement. The hangers 94 and 95 also assist in maintaining the spring 49 in transverse position in the casing but are adapted to slide on the bar 69 to accommodate longitudinal expansion or contraction of the spring, ,the spring 4.9 being thus what .is com monlylknownas oating.

It is `to .be .understood that the invention isnot intended .to .be limited to .details -of construction here .shown `for `illustrative purposes. 'Other .modications will ysuggest vthemselves to :those skilled inthe art and having y,the ,benefit of ,the vpresentdisclosure. Furthermore, it is notintend- `ed that it be .understood that .allffeatures `of .the present disclosure must .be used .conjointly, :since 'it will lbe apparent to workers in the .art .that various combinations .or l.sub-combinations may at .times he advantageously employed.

The invention having been described, .what is `claimed is.:

l. In a drafting standjincluding ,a pair .of ver- ;tically movable pests, the combination including, a Acasing having spaced apertures, said posts pass- A.ing .through `the apertures andslidable with respect vto ,the casing, a ,pair of brake members 'hinged in .the .casing and ,adapted ,to rctionally .engage the .posts .to clamp :them .against movement, a pair .of .aligned movable .bars supported within `the casing .by Asaid 'brakemembers .respec- .-tively, a link intermediallypivoted in the casing Iand articulated ait Aeach end with lsaid 'bars `respectively, a spring anchored in said casing, means connecting ,the spring and link, said spring means urging ,thelink in .a direction `to press the Abars .apart whereby to urge the ybrake Vmembers Sinto frictional engagement with said ,postsand a manually `operable lever secured tosaidllink .in said casing and adapted `to rotate thelinkin ,the .opposite direction ,against the force of said spring tofreleaselthebrakemembers.

2. In 'a ydrafting-.stand of the .type .comprising a'base .and apar'of vertically reciprocable spaced .apart `upright .members .adjustably .supporting a .drawing board on .the base, the combination ,including, .a ycasing .having `spaced apertures ,in which .said .upright members .are yslidably .arranged, a vpair .of .brake vmembers hinged .in the ,casing andadaptedto frictionally engage the .up .right members yand press ,them against the :sides of -the .casing rapertures to v1clamp them against movement, a pair .of .aligned Amovable vbars engaging said `brake .members respectively, a :link

intermedially pivoted -in the .casing and articulated at each end with said bars respectively, spring lmeans `connected to 'the link, :said spring -means urging thelink in `.a rotative direction to urge the `bars whereby ,to -urge the brake members into-clamping engagement with-said .upright members, and a manually operable lever secured to said link in said casing and adapted to rotate the link in the opposite direction against the force of said spring to release the brake members.

3. In a drafting stand of the type including a base and a pair of upright spaced apart members vertically reciprocable relative to the base, the combination including, a casing having spaced apertures in which said members are slidably arranged, friction brake means in and cooperating with said casing to hold the members in vertically adjusted positions relative to said casing, said brake means including a pair of movable friction pieces located between the members and engageable with the members, and means for ,simultaneously and selectively drawing the friction pieces together to effect disengagement thereof from the members and moving them apart to eifect engagement thereof with the members.

4. The structure of claim 2 wherein the combined length of the bars is adjustable.

'tically reciprocable on the base, and a drawing board supported by said members, the. combination including, a casing mounted on the base and "having a pair of spaced apart apertures movably receiving the upright members, and friction brake mechanism located within said casing for holding said upright members in adjusted vertical positions, said brake mechanism including a pair of movable friction pieces pivotally mounted in said casing, between the members and engageable with the members, and mechanism including means operable from the exterior of the casing for selectivelydrawing the friction pieces together to effect disengagement thereof from the upright members and moving them apart to effect engagement thereof with the members.

` 7. In a drafting stand, a base structure, a pair of board supporting members slidably supported in horizontally spaced` relationship for vertically reciprocable movement on and relative to said base' structure, a drawing board mounted on said board supporting members at the upper ends thereof, means including a spring connected to said base structure and both of said board supporting members for urging said board supporting members and said drawing board upwardly, a'pair of brake members each movably secured to said base structure adjacent one of said board supporting members for movement toward each other and away from the respective board supporting members and for movement away from each other toward the respective board supporting members, said 'brake members being frictionally engageable with said board supporting members when moved away from each other and disengageable from said board supporting members when'moved toward each other, and toggle means mounted on the base structure and interconnecting said brake members for moving the latter toward each other to disengage the same from said board supporting members and for moving said brake members away from each other into frictional engagement with said board supporting members. Y 8. I n a drafting stand as set forth in claim 7 a casing carried by said base structure, having spaced apertures in which said board supporting members are slidably arranged and housing said members, said spring and the toggle means for the brake members, said apertures having sides cooperating with said brake members when ,the latter are moved away from each other into frictional engagement with said board supporting members for holding the board supporting members and the drawing board in vertically adjusted position.

9. In a drafting stand, a base, a casing mounted on said base and having horizontally spaced apertures therein, a pair of board supporting members slidably arranged in spaced upright positions for vertically reciprocable movement in said apertures, a drawing board mounted on said board supporting members at the vupper ends thereof, means connected to said board supporting members and said casing for urging said board supporting members and said drawing board upwardly, a pair of brake members each movably mounted in said casing adjacent one of said board supporting members for movement from and to engagement therewith, said brake members being frictionally engageable with said board supporting members when the brake members are spread apa-rt and disengageable therefrom when moved toward each other, toggle means including a spring supported in said casing between said brake members and resiliently urging them apart into frictional engagement with the respective board supporting members for holding said board supporting members and drawing board in vertically adjusted positions relative to said casing, and manually operable means for operating the last said means to move said brake members toward each other out of holding engagement with said board supporting members. y

l0. A friction brake mechanism for holding in selected vertical adjustment a pair of spaced apart members supporting a drafting board for vertical movement on a base, said brake mechanism including a pair of movable friction pieces pivotally mounted on the base and engageable with the members when said friction pieces are moved apart and disengageable therefrom when drawn together, and means including a single cable connection and a single cam actuated through said connection for simultaneously drawing the friction pieces together or moving them apart.

. WILLIAM H. MURPHY. Executor of the Estate of Harold L. DeLisZe, De-

ceased.

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