US2555575A - Adjustable and foldable desk and drawing board - Google Patents

Description

June 5, 1951 CRAYTON 2,555,575

ADJUSTABLE AND FOLDABLE' DESK AND DRAWING BOARD Filed Nov. 17, 194'? 3 Sheets-Sheet l 4 INVENTOR.

June 5, T, B CRAYTQN ADJUSTABLE AND FCLDABLE DESK AND DRAWING BOARD Filed Nov. 1'7, 194'? 3 Sheets-Sheet 2 BY 1 L21 21W 3 MW June 5, 1951 T. B. CRAYTON ADJUSTABLE AND FOLDABLE DESK .AND DRAWING BOARD Filed Nov. 17, 1947 3 Sheets-Sheet 3 INVENTOR. 2 4 212 Patented June 5, 1951 UNITED STATES PATENT OFFICE ADJUSTABLE AND FOLDABLE DESK AND DRAWING BOARD 8 Claims.

My present invention has for its object to provide an improved article of furniture serving the dual purpose of a desk and drawing board which is capable of adjustment when used in either capacity, both in height and angularity, the parts thereof being so constructed that they may be readily collapsed and folded into a small compass.

A further object of my invention is to provide a portable desk structure comprising a series of jointed or foldable legs forming a support carrying the desk proper which may be conveniently adjusted to accommodate a person who may wish to work either in a sitting or standing position, said legs and the desk connections cooperating therewith being so disposed as to enclose the desk when the parts are in the knock down or collapsed position.

To these and other ends my invention comprises further improvements and advantages as wili be further described in the accompanying specification, the novel features thereof being set forth in the appended claims.

In the drawings:

Figure l is a side elevation showing the furniture piece constructed in accordance with my invention.

Figure 2 is a rear view thereof.

Figure 3 is a view showing in side elevation the parts in a partly collapsed position.

Figure 4 is a side elevation showing said parts completely folded together.

Figure 5 is a top plan view as seen when looking downwardly on the furniture piece depicted in Fig. 1.

,Figure 6 is a detail sectional view taken on the line 66 of Fig. 2 showing the device for releasing the desk strut, said device being in the locked or secured position.

Figure 7 is a similar view, the device being shown in the unlocked position.

Figure 8 is an end view of the locking device illustrated in Figs. 7 and 8.

Figure 9 is a detail view of the claw having a serrated edge against which the flexible strut release is clamped when the releasing device is in the locked position shown in Fig. 6.

Figure 10 is a horizontal sectional view taken on the line llll0 of Fig. 1, and

Figure 11 is a bottom plan view (corresponding to Fig. 4) showing the parts folded for transportation.

Similar reference numerals, in the several figures, indicate similar parts.

In carrying out my invention I construct a tripod, somewhat in the nature of an easel, composed of lateral or forward legs A and B which are spaced apart and parallel. These legs extend upwardly and rearwardly at an angle of approximately 55 to the horizontal and are rigidly held in this inclined position by a rear vertical leg C. Each of the forward legs is composed of pieces In and l of unequal length, the shorter pieces comprising the lower ends and being hinged to the lower ends of the longer pieces as indicated at l2. These hinges are at the rear sides or edges of the legs and the meeting ends of one or the other of the pieces Hi and H, in line with the hinge pintle diverges at a slight angle so that the lower ends of the legs extend ahead of their upper ends. This arrangement provides a slightly bent knee at the point of the hinge which adds to the stability of the joint.

The parts ll) of legs A and B are held in spaced relation at their lower ends by a cross bar D and their upper ends are likewise connected at their rear edges by a cross piece It. The upper portion I l of these legs are connected at their lower ends by cross pieces hi and by a cross piece E located substantially midway of the sections. Cross piece E is preferably ametal strap having fingers it at its ends which overlie the outer faces of the sections ii and hold it spaced from the rear edges of the section H. In the rear edges of the leg sections It will be seen notches E for the reception of the strap E when said sections are folded upon each other.

Rear leg C at its upper extremity is forked or bifurcated and each of these two parts is hinged, as indicated at I6 to the strap E to add lateral stability to the leg. The lower end of the latter is braced against the legs A and B but as the rear leg is located centrally of legs A and B the brace calls for a special arrangement of parts. The brace, indicated by F comprises parallel metal straps 202| (Fig. 5) spaced apart the thickness of leg C and united at their rear ends by a rivet or bolt 22 lying in a slot 25 at the lower end of the leg and retained therein by a plate 26 which spans the slot. The cross piece D connecting the lower ends of the forward pair of legs is made of two pieces 21-48 the proximate ends of which are spaced apart, as shown in Fig. 10, which are rigidly connected by a strap 29 on the outer side and on their inner side by a V- shaped metal band 3ft having laterally extending fingers 3|, the depressed portion of the band delining the width of the slot in which the outer end of brace F lies and to which its straps 20-2I are pivoted as indicated at 32 (Fig. 1).

It will be seen that the brace F being rigid holds the rear leg properly spaced and the length of slot 25 allows sufiicient play to accommodate the movement of the brace when the several legs are folded. To further accomplish this action leg C is formed of upper and lower sections (IE-3i? hingedly connected at their forward edges, as by a hinge 31. The latter is normally locked or held against breaking into its open position by a brace which I make in the form of a shelf 38 which extends between the inner faces of the legs A and B and is pivoted to the upper edge of the cross bar it by hinges 39. I notch the forward edge of this shelf so as to embrace the two sides of leg C which not only stabilizes the leg but also adds to the area of the shelf. The latter is held in horizontal position by pins 40 on the leg which are received in slight depressions on the lower side of the shelf.

As a further means of securing leg C and adding to the stability of the frame work in its open or erected position and yet permit it to be easily collapsed I employ chains 50 extending from a point near the lower end of leg C to points near the upper ends of the lower sections it) of legs A and B which limit their separation. I also employ retractile coil springs 51 connected to the aforementioned points of said legs which tend to draw the lower end of leg C inwardly and hold it in tight engagement with the end of brace arm F. In practice I enclose the chains within the springs, as shown in Fig. 1, which has the advantage of preventing entanglement of the chains, due to their looseness when the parts of the structure are folded together since the springs being connected to the central leg and of a firmer nature will naturally form symmetrical loops at each side thereof.

The element comprising the desk or table top is mounted for both vertical and angular adjustment on the legs A and B and to this end I provide on the inner faces of the legs at their forward edges a series of spaced notches 55 located in both the members It! and H. Similar notches are provided in the inner faces of the upper members H at their rear edges. Observing Fig. 1 it will be seen that both sets of notches are cut at an angle to the front and rear edges of the members It! and H so that when the supporting frame is erected they extend in horizontal planes to facilitate the insertion and withdrawal of pins by means of which the desk is secured in position.

The table or desk preferably comprises a rectangular box 69 fitting between the legs A and B and having a cover iii of an overall length approximately equal to that of the leg members H. The depth of the box may exceed slightly the depth of the leg members H and its bottom is tapered upwardly at its outer end, as indicated at 62 to accommodate the cross bar I4 when the several parts arefolded together. Adjacent the rear or inner end of the box is a vertical partition 63 which forms a pencil compartment which is normally closed by a lid 5 3'. The latter and the cover 6| may each be hinged to the partition 63, as indicated at 65, or otherwise movably secured to the box. On the lower rear corners of the latter are laterally extending pins H3 adapted to be engaged respectively with one or another of the corresponding recesses 56 of the legs A and B.

The desired working position of the desk element, either horizontal or inclined, is obtained by means of a strut G hinged at its upper end, as indicated at 1-5, to spaced points located at a '4 mid point on the bottom of box 60 and comprising laterally extending arms 16 carrying at their extremities pins ll which are adapted to engage in corresponding apertures 55 on the respective legs A and B.

It being essential that the desk element be secured rigidly in any position as determined by the selected notches 55 in which the pins 10 are engaged and the notches 55 in which the pins H are located I provide a novel form of locking device as will be now set forth. Attached to a mid point on the strut G is a flat belt 80, such as a strip of webbing, which extends rearwardly and is trained around a pulley 8| on the lower rear end of box 6 From these the belt extends forwardly beneath the box to a clip H, the details of which are illustrated in Figs. 6 to 9. The clip comprises a plate 82, which is rigidly secured to the lower side of the forward end of the box, having depending flanges 33 having at their inner ends ears 86 provided with inwardly extending embossures 85. On the outer end of plate 82 are dentures 86 the tips of which are bent downwardly slightly. Pivoted between the outer ends of flanges 83 is a rectangular tubular member 87 the center opening of which is of a size to accommodate the belt and permit it to pass freely therethrough when the member 87 is in alinement with the plate on which it is mounted, as shown in Fig. 7. Conversely when the member Bl is rotated into the position shown in Fig. 6 it places a crimp in the belt, as indicated by 8%! and forces the upper surface of the belt into engagement with the denturestfi. At such times member Si is retained in looking position by the embossures from which it may readily be disengaged by applying a little force on the free end 88 of the belt.

The dismantling or collapsing of the furniture piece described will be readily understood. Irrespective of the position occupied by the desk element it is first released by unlocking the belt 80, or releasing it in the clip II. If the desk is in the position shown in Fig. l slack in the belt will permit its movement rcarwardly to disengage the pins F8 from notches 56 whereupon its rotation on hinges l5 and rotation of strut G on its pins ii, in a direction toward legs A and B, will bring said parts into parallelism with and nest them between the sections H of said legs. The next stepis to free the joint 3'! of the rear leg C by lifting the shelf or brace 33 which then folds between the forward legs against the .desk strut G. Folding of leg C occurs coniointly with the folding of the parts it and ii of legs A and B .on their joints 52. Breaking of hinge 3! permits the section 35 of leg 0 to ultimately fit in contact with the rear face of box 66 above the cross piece E. This movement contracts the section 36 drawing upwardly the brace F and the latter in turn causes sections it of the legs A and B to break their joints 52 so that they may be folded with their rear edges in contact with the rear edges of the other members I! of said legs. In the closed position of these parts the cross piece E fits into' the recesses E and the center opening in cross piece I) accommodates the part 36 of rear leg C. By reason of the points of connection of the ends of the two sets of spring-chain retention members til-5i it will be seen that as section 36.01? leg C is collapsed that they form two loops which lie in engagement against the underside of the shelf 38 as shown in Fig. 11.

For the purpose of securing the parts in collapsed position I employ two sets of fastening devices. One of these comprises two butterfly latches 90 on the bottom of the box 60 (see Fig. 11) which when rotated engage over the cross brace E and secure the box within the sections ll of the forward pair of legs. The other fastenings may be simple hooks 9| on the exterior faces of sections ll near their free ends which are arranged to engage studs Or eyes 92 on the free ends of the sections II when these parts are folded together.

The furniture piece herein set forth is especially adapted for use by engineers in temporary quarters in the field whose duties vary from paper work which may be expedited in a sitting position and to the making of drawings which can be more comfortably made when standing. The desk in which ever position it may be mounted may be secured either horizontally or inclined and when collapsed within its supporting framework is sufficiently light in weight to permit it to be readily transported by hand.

I claim:

1. A furniture piece having a supporting frame comprising spaced side parallel members of given depth forming a pair of forward legs, means for supporting said legs in an inclined plane, said legs being provided on their proximate faces with spaced horizontal notches at their rear and forward edges, a desk element fitted between the legs, laterally extending pins on the rear end of said element for engagement with the rear notches of said legs and a brace arm pivotally attached to a midpoint on the underside of the desk having laterally extending arms the extremities of which lie within the side members of the frame, pins extending laterally from said arm extremities for engaging in the notches on the forward edges of the frame members, a pulley on the rear edge of the desk, means connected to said arm and extending rearwardly from the rear side of said brace around said pulley thence forwardly beneath the desk and a releasable locking device on the forward edge of the desk for securing said means to hold the pins on said two parts from being disengaged from the respective notches.

2. A furniture piece having a supporting frame comprising a pair of parallel forward legs each composed of upper and lower open rectangular frames havin parallel side pieces of given depth and connecting cross bars, one of the latter on the upper frame being a metal strap offset rearwardly from the sides of said frame and located at a mid point thereof, said frames having notches in their forward and rear edges, hinges connecting the rear edges of said two frames permittin one to be folded against the other, a desk comprising a covered box of a depth equal to that of the upper frame plus the offset distance of said strap, pins on the rear lower corners of the box extending laterally for engagement with the notches on the rear side of the supporting frame and a supporting strut on the bottom of the box also provided with laterally extending pins for engagement with the notches on the forward edges of the supporting frame, latch members on the bottoms of the box for securing it when in folded position within said frame by engagement with said strap, a third leg composed of upper and lower sections, the former being hinged to said strap, a hinge connectin said sections located on the side of the leg which faces the forward legs, and a strut in the form of a hinged shelf carried on the up per supporting frame member for locking the hinge of said third leg.

3. A furniture piece having a supporting frame comprising a pair of parallel forward legs each composed of upper and lower open rectangular frames having parallel side pieces of given depth and upper and lower connecting cross bars, hinges uniting said frames permitting them to be folded together, a rear leg composed of an upper member hinged to a cross bar of said upper frame and a lower member pivotally connected to said upper member, said lower member having a floor engaging end, a strut pivotally connected to said lower member near its floor engaging end and the lower cross piece of the lower front le frame and collapsible completely within the latter when it is folded upon its upper frame, a desk member fitting within said upper frame and cooperative means on said upper frame and desk member for removably supporting said desk member.

4. A furniture piece composed of a pair of forward parallel legs of given depth made in two pieces forming upper and lower sections, hinges connecting the rear edges of said sections permitting them to be folded against each other, a cross bar uniting the upper sections at their mid point, another cross bar connecting the lower portions of the lower sections which is notched at its rear edge, a third leg comprising an upper section hinged to the first mentioned cross bar and a lower floor engaging section pivotally connected to said third leg upper section, said last mentioned section having a floor contacting end, a strut pivotally connecting the floor contacting end of the floor engaging section and within said notch of the second mentioned cross bar which is collapsible lengthwise of said floor section when the several parts are folded together, a desk member, said desk being collapsible within said upper leg sections when the upper and lower sections are folded together and cooperative means on said upper sections of the forward legs and desk member for adiustably supporting said desk member.

5. A furniture piece composed of a pair of forward parallel legs of given depth made in two pieces forming upper and lower sections, hinges connecting the rear edges of said sections, a cross bar uniting the upper sections at their mid point and offset from the rear edges of said sections, said lower sections being notched on their rear edges to accommodate the cross bar when the leg sections are folded against each other, another cross bar connecting the lower portions of the lower leg sections having a central notch at its rear edge, a third leg comprising an upper section hinged to the offset cross bar and a lower centrally located floor engaging portion pivotally connected to said third leg upper section, said last mentioned portion having a floor contacting end, a strut pivotally connected to the floor contact-ing end of said floor section, and within said central notch of the last mentioned cross bar which is collapsible lengthwise of the floor member when the several parts are folded together, a desk member and cooperative means on said upper sections of the forward legs and desk member for adjustably supporting said desk member.

6. A furniture piece having a supporting frame comprising side members forming front legs, each composed of upper and lower pieces hinged for folding one upon the other and cross bars connecting said pieces in spaced relation to form upper and lower .leg sections, a rear leg hinged to the cross bar of the upper pieces and 00111- posed of two pivotally connected sections foldable upon each other and arranged to lie within the lower section of the forward legs when the latter are folded upon the upper section of said legs, said rear leg having upper and lower ends, a strut pivoted to the lower end of the third leg and the lower pieces of the forward legs, a spring likewise extending between the last mentioned parts yieldingly holding the third leg against the strut, a desk member and cooperative means on said upper section of the forward legs and desk member for 'adjustably supporting said desk member.

7. A furniturepiece having a supporting frame comprising side members forming front legs, each composed of upper and lower pieces hinged for folding one upon the other and cross bars connecting said pieces in spaced relation to form upper and lower leg sections, a rear leg hinged to the cross bar of the upper pieces and composed cf two pivotally connected sections foldable upon each other and arranged to lie within the lower section of the forward legs when the latter are folded upon the upper section of said legs, said rear leg having upper and lower ends, a strut pivoted to the lower end of the third leg and the lower pieces of the forward legs, a spring likewise extending between the last mentioned parts yieldingly holding the third leg against the strut, a flexible limiting member likewise extending between the third leg and each of said front legs acting to remove strain on the strut by reason of attempted movement of the third leg beyond the limit set by the strut, a desk member and cooperative means on said upper section of the forward legs and desk memher for adjustably supporting said desk member.

3. A furniture piece having a supporting frame 8 comprising side 'members forming front legs, each composed of upper and lower pieces hinged for folding one upon the other and cross bars connecting said pieces in spaced relation to form upper and lower leg sections, a rear leg hinged to the cross bar of the upper pieces lying centrally of the front legs and composed of two hinged sections the upper one of which is pivoted to the cross bar of the upper forward leg sections and the lower one has an end engaging the floor, a strut extending from the lower forward leg sections to the floor engaging end of the lower section of the third leg, chains likewise extending between the last mentioned parts connected to the upper portions of lower side pieces of the front legs and the lower section of the third leg to limit movement thereof in a direction away from the front legs, springs surrounding the chains and serving to draw the third leg into yielding engagement with said strut, a desk member and cooperative means on said upper section of the forward legs and desk member for adjustably supporting said desk member.

THOMAS B. CRAYTON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 519,655 Atzert May 8, 1894: 697,639 Lindner Apr 15, 1902 826,805 Scheibner July 24, 1906 1,242,151 DeGroot Oct. 9, 1917 2,196,044 Tyrrell Apr. 2, 1940 FOREIGN PATENTS Number Country Date 673,445 France Oct. 8, 1929

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