US2278568A - Foldable frame - Google Patents

Description

April 7, 1942.

M. SEGRE 2,278,568

FOLDABLE FRAME Filed Dec. 28, 1939 2 Sheets-Sheet 1 3 INVENTOR "Fuss L F164} April 7, 1942. M.. SEGRE I FOLDABLE FRAME 7 Filed Dc. 28, 1939 7 2 ShGQtS-Shet 2 Massimo Sqgre INVENTOR.

Patented Apr. 7, 1942 UNITED STATES PATENT OFFICE FOLDABLE FRAME Massimo Segre, New York, N. Y.

Application December 28, 1939, Serial No. 311,268

4 Claims.

This invention relates to foldable frames to be used especially as camp chairs, stools, or tables, and particularly to a four-legged frame which can be folded into a small space and which, when opened, is sufficiently sturdy and stable to support a person or another relatively heavy load without tending to collapse under it.

The primary object of my invention is to provide a frame of the type described which is very simple, practical and safe and has several ad vantages which will fully appear from the following description. A particular object of my invention is to provide a four-legged foldable frame which, when folded, has its four legs close to each other and which can be opened or folded by acting only on two of said legs.

An embodiment of my invention is illustrated in the appended drawings, in which:

Fig. 1 is a perspective view of my frame in its normal position.

Figs. 2, 3, and 4 are elevational views of the same frame folded.

Fig. 5 is an elevational view, partly in section, and Fig. 6 is a plan view, partly in section, of a detail thereof, to wit, of the locking device.

Fig. 8 is a perspective view of a frame according to my invention adapted for use as a foldable chair; and Fig. 7 is an elevational view of the same modified frame folded.

Referring to the drawings, it is seen that the frame comprises two pairs of legs, I -3 and 2-4, made of metal or other suitable material; in the embodiment shown the legs are hollow, but this is not an essential feature of my invention. The two legs of each pair are pivoted together at a point intermediate their ends, as at II and I2. A pair of braces 9Ill, pivoted together at I5, is connected to legs 3 and 4, the connections thereof being arranged as follows. The upper end of brace 9 is pivoted to leg 3 and the upper end of brace I is pivoted to leg 4; the lower ends of the braces are pivoted to sleeves I3 and I4 respectively and said sleeves are slidable along the legs. Two links I and 8 are pivoted to the same sleeves and to legs I and 2 respectively.

The load which the frame is to support is directly borne by bars and 6, which may be hollow too. When the frame is used as a stool a strip of canvas 33 may be secured to said bars to provide a seat, as shown in Fig. 8, and when it is used as a table a removable rigid or foldable board may be laid thereon. When the frame is used as a chair, two of the legs are extended upwardly and a strip of canvas 34, Fig. 8 is secured to these extensions so as to provide a back, and the inclination of these legs will be such that the chair may be comfortable and restful.

In this case, when the chair is folded the strip of canvas forming the back thereof will be folded with it, and the person who carries the chair may put his arm under this strip of canvas 34 and thus use the same as a sleeve to carry the chair with greater ease.

Bars 5 and 6 are hinged to the pairs of ears 2? and 28, secured to the upper ends of legs 3 and 4, and are connected to legs I and 2 respectively by means of a linkage which is shown in detail in Figs. 5 and 6. Each of the legs I and 2 has a longitudinal slot and through these slots, denoted by numerals 29 and 30, extend pins I9 and 20,.which are bent twice at a right angle and are pivoted in bars 5 and 6. Each of the hollow legs ,I and 2 has a small block slidable therein; block 25 is secured to pin I9 and block 26 to pin 2!]. The length of slots 29 and 33 is not less than the length of the portion of bar 6 comprised between legs 2 and 4, or of the portion of bar 5 comprised between legs I and 3. By this arrangement, when the two legs of each pair are drawn together, pins I9 and 20 slide in the slots which they engage and bars 5 and 6 swing downwardly about their hinges 27 and 28 so that in the folded position of the frame they will be parallel to the legs.

The stability of the frame in its normal position is assured by a locking device consisting of the three links I8, I! and I8. This locking device is shown in Figs. 5 and 6. The three links are assembled as follows: I6 is pivoted to leg I at 3| and to l1; I7 is pivoted to I6 and I8; I8 is pivoted to leg 2 at 32 and to H. Link I8 is provided with two small brackets 23 and 24 consisting in strips of metal bent at a right angle and riveted to link I8 or otherwise secured thereto. When the frame is in the normal position of Fig. 1 bracket 23 engages links I6 and I! from below and bracket 24 engages link I6 from above, so that the three links are forced to remain parallel to each other in the positioned relationship shown in Figs. 5 and 6 and to behave like one rigid bar, thus assuring the stability of the frame under the load. The links however have a considerable lateral elasticity due to their shape so that it is easy to slightly bend them laterally and to force them out of engagement with said brackets when the frame is to be folded.

Thenumerals 2| and 22 denote two lugs whose purpose is to cooperate in preventing lateral motions of the bars 5 and B in the normal position of the frame.

When the frame is used as a chair and legs I and 2 extend upwardly from the plane of bars 5 and 6 to provide the back of the chair, slots 29 and 30 may be extended in the upward extensions of said legs so that bars 5 and 6 will swing upwardly during the folding of the frame and not downwardly as in the embodiment here illustrated; and a simple well known type of locking device may be used, consisting, for example, of two members pivoted together and to legs I and 2, one of these members having a notch and the other an offset lug engaging said notch and allowing both members to swing upwardly but not downwardly.

When the frame is in its normal position; as in Fig. 1, and has to be folded, two legs, such as I and 2 or 3 and 4, will be grasped and drawn toward each other. Then the X-braces 9-l0 are closed and force sleeves l3 and I 4 to slide downwards. links 1 and 8 to slant drawing the lower half of legs I and 2 nearer to the corresponding part of legs 3 and 4, thereby causing a relative rotation of the two legs of each pair about the connecting pivot thereof to take place. The motion described is rendered possible by the linkage between legs I and 2 and bars 5 and 6 already described, whereby said bars swing downwardly about their hinges 21 and 28, and tend to assume a position parallel to that of the legs.

Meanwhile the locking device goes through the following motions. As legs I and 2, or 3 and 4, are drawn together, link 15 tends to swing about pivot 31 but is kept in place by brackets 23 and 24. However, thanks to its lateral elasticity, alight pressure is sufficient to free it fromengagement with said brackets. Then the whole locking device collapses, as l8 swings downwardly about pivot 32, ll swings about the pivot that connectsit to l8, and thus causes It to complete its downward swinging motion about pivot 3!. The three links assume therefore a position at right angles to one another, as shown in Figs. 2 to 4.

In the final folded position the elements of the frame are in the positioned relationship illustrated in Figs. 2 to 4, which can m described as follows.

Legs I, 2, 3 and 4 and bars 5 and ii are parallel to each other and so close that the total volurne of the folded frame is very small, although or" there is no actual contact between any of said six members. Links 1 and B are also parallel thereto and braces il -l are on one side of the frame and their relative inclination is very small.

Links l6 and [8 of the locking device are pa'r alr.

lel to the legs, while the intermediate I! is perpendicular thereto. If a canvas is secured to bars and 6, it will of course be folded with the frame; if, instead of a flexible material or a series of articulate slats, a board is used, this latter will be removed before folding the frame. On opening the frame the inverse motions take place: it is sufiicient to separate two legs in order to completely unfold the frame, which, once unfolded, is stable and cannot accidentally collapse adapted for other similar purposes in" away which will be apparent to those skilled in the art;

This motion of the sleeves causes I therefore do not intend to limit my invention to the exact details herein set forth, as many changes can be made in the construction and arrangement of the various parts without departing from the spirit of the invention or exceeding the scope of the appended claims.

I claim:

1. A foldable frame comprising two pairs of legs, the legs of each pair being pivotally connected together; in each pair a slidable member on one leg thereof and a link pivoted to said slidable member and to the other leg of the pair; a pair of X-braces connecting on of the legs of a pair to one of the legs of the other pair and having the upper ends thereof pivoted to said legs and the lower ends pivoted to said slidable members; two bars, each bar being pivoted to a member fixed to the upper end of one of the legs of a pair and pivoted to another member slidable with respect to the other leg of the same pair; and locking means to hold the bars in horizontal position whereby the frame is prevented from accideritally folding when opened.

2. A foldable frame comprising two pairs of legs, the legs of each pair being pivotally con-' nected together and one of the legs of each pair being hollow and having a slot on a side thereof; in each pair a slidable member on one leg thereof and a link pivoted to said slidable member and to the other leg of the pair; X-braces connecting one of the legs of a'pair to one of the legs of the other pair and having the upper ends thereof pivoted to said legs and the lower ends pivoted to said slidable members; two bars, an end of each bar being pivoted to a member fixed to the upper end of one of the legs of a pair and the other end having an attachment engaging one of said slots on a side of a hollow leg, said attachment having an enlargement within said hollow leg; and locking means to hold the bars inhorizontal position whereby the frame is prevented from accidentally folding when opened.

3. A foldable frame comprising two pairs of legs, the legs of each pair being pivotally connected to each other; in each pair a slidable memher on one legthereof and a link pivoted to said slidable member and to the other leg of the pair; X-braces connecting one of the legs of a pair to one of the legs of the other pair and having the upper ends thereof pivoted to said legs and the lower ends thereof pivoted to said slidable members; two bars, each bar being pivoted to a merriber fixed to the upper end of one of the legs of a pair and pivoted to another member slidable with respect to the other leg of the same pair; and locking means to hold the bars in horizontal position comprising three members pivotally connected together, the first of said members being pivoted to a leg of a pair and the third of said members being pivoted to the adjacent leg of the other pair, one of said members having attachments engaging the other members in the extended position of the frame so that they are kept in a rigid horizontally positioned relationship therewith thus preventing accidental folding of the frame.

4. A foldable chair comprising two pairs of legs; the legs of each pair being pivotally connected to each other and one leg of each pair being longer than the other; in each pair a slidable member on one leg thereof and a link pivoted to said slidable member and to the other leg of the pair; X-braces connecting one of the legs of a pair to' one of the'legs of the other pair and having the upper ends thereof pivoted to said legs and the lower ends pivoted to said slidable members; two bars, each bar being pivoted to a member fixed to the upper end of one of the legs of a pair and pivoted to another member slidable with respect to the other leg of the same pair; a 5

strip of flexible material secured to said bars to provide a seat; a second strip of flexible material secured to the upper part of said two longer MASSIMO SEGRE.

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