US2757715A - Folding chair - Google Patents

Description

1956 s. B. HENDRICKSON 2,757,715

FOLDING CHAIR Filed May 18, 1955 2 Sheets-Sheet 1 Fig. I

IN VEN TOR. SEVERIN B. HENDRICKSON ATTORNEYS s. B. HENDRICKSON 2,757,715

Aug. 7, 1956 FOLDING CHAIR 2 Sheets-Sheet 2 Filed May 18, 1955 I H 3 III INVENTOR.' SEVERIN B. HENDRICKSON M0 1 him/Mid ATTORNEYS United States Patent FOLDING CHAIR Severin B. Hendrickson, Templeton, Mass., assignor to Heywood-Wakefield Company, Gardner, Mass., a corporation of Massachusetts Application May 18, 1955,.SerialNo. 509,267

9 Claims. (Cl. 155-142) This invention relates to folding chairs, and more particularly to folding chairs which collapse automatically when lifted.

In the construction of folding chairs a number of important considerations should be :borne ,in mind. In the first place, it is highly desirable to provide a chair that may be folded for stowage, or set up-for use in .a simple manner. Many conventional forms of chair require :either .two hands or a hand and a foot to fold up, and in many instances they unfold inadvertently while .being carried. Other forms of chair require additional hand .operationfor setting up. In this connection :one of the principal objects of my invention :is to provide a folding :chair that will fold .up automatically when its back is lifted up by a single hand. .In addition, it is an object of my invention to provide such a chair that may be car- .ried in the folded position with one .hand without-risk of having the chair opening up inadvertently, but which may also be set up for use simply by lowering the chair to the floor.

Another important consideration relates to ,the interrelationship of the elements of the folding chairduring use. Many forms of conventional folding chairs have exposed operating elements that produce a scissors .or pinching action, and when using such chairs .it is necessary to be careful to avoid pinching the fingers or other portions of the body. In this connectionit is an object of my invention to provide a folding c'ha'irlin which there is virtually no danger of pinching the user.

Still another design problem relates to the freedom of movement of the operating elements ,of the chair. Many conventional forms .of folding chairs employ pins sliding in tracks or channels, and frequently such tracks or channels become clogged with dirt or other obstructions such that the sliding elements of the .chair do not work smoothly and efficiently. Therefore, it isa further object of my invention to .provide a folding chair in which the relative motion between closely spaced elements is arranged in such a way that there is little danger of their becoming clogged, jammed or otherwise obstructed.

'It will also be understood, of course, that it is-highly desirable to construct folding chairs of as light a material as may be consistent with the safety of occupants of the chairs, and in this connection it is an important object of my invention to arrange the operative elements: of'the chair of my invention in such a way as toemploy'the maximum support characteristics of these various elements so that the over-all weight of the chair may be reduced to a minimum while still maintaining an adequate strength-safety margin.

In the accomplishment of'theseand other objects of my invention, I employ a tubular frame construction in which the principal forces act longitudinally .of the tubular elements of the frame. Inthis way -.theh igh.-strength -.of tubes in compression islernployed to.its best advantage. .A further feature of my invention ,isthat the elements which serve to bear the principal forces -.of vthe weight '2 of occupants are so completely hidden within the structure of the chair that there is virtually no chance of the chair pinching an occupant. Still another feature of my inven tion is that the operative elements are so weighted that the chair collapses automatically when it is lifted from the top, but these elements are also positioned in an offset relationship in such a way that the chair returns to the set-up position when it is lowered to the floor.

These and other objects and features of my invention will best be understood and appreciated from a detailed description of a preferred embodiment thereof, selected for purposes of illustration, and shown in the accompanying drawings, in which: 7

Fig. l is a view in perspective of the chair of my invention set up for use; i I

Fig. 2 is a view in side elevation of the chair of Fig.1; and

Fig. 3 is a view in side elevation showing the chair in the folded position.

The preferred embodiment of my invention herein shown comprises a tubular metal base frame indicated at 10, having a pair of front legsv 12, joined by a cross brace 14 in the lower portion thereof. In the upper portion of the frame 10, the tubular elements are bent into a loop across the topof the chair to which a back .rest element 16 is secured. At an intermediate point 18 on the frame .10, I pivot a seat element 20 which may be of conventional covered tubular form or other suitable construction. The s'eatp20 has a portion extending rear wardly of the chair from the pivots 18 and tubular rear 7 legs 22 are pivoted to the seat 26 at 24 in the said rearthe chair, I provide a pair of links 28 pivoted to the main frame 10 at a point substantially above the vpivots 1,8; The links 28 extend downwardly to the rear of the chair and enter the upper open tubular ends of the rear legs 22, It will be noted that the links 28 are not truly conventional links in that they are not pivoted at both ends to operative elements. The links 28 are only ,piv- ,oted to the frame 10 at their upper portions, but they enter the tubular legs 22 and remain in telescoping sliding operative vrelationship thereto.

When the chair islset up for use, the seat 2% is pivoted downwardly in the front and upwardly in the rear. While this pivotal motion is taking place the rear .legs .22 swing outwardly, and the links 28 slide downwardly into theupper ends .of the legs 22. At the pointin which :the chair is in the fully erect or set-up position, the links .28 comeup against the pivots 25% in the legs 22. In this position it will be seen that the weight .of the chair is borne primarily by theseat operating through the pivots 18.and 24 and the lower portions of the legs 1?. and 2.2.

.However, other forcesbacting about these pivot points and against'the .back rest ,16 Will tend to move the'baek rest rearwardly and downwardly, and this latter-mentioned force is taken-up by the links/28 resting against the pivots 24. It should be .noted also in this connection .thatrthe thrust of;the linksZS is directly parallel and in line with the rear legs, 22 such'that very little "bending abutting each other with any force are the pivots 24, and the lower ends of the links 28 which are completely hidden within the legs 22. Thus there is no danger of the operative elements of my invention pinching the occupant of the chair when the chair is set up for use. Of course, when the chair is folded up as may be seen in side elevation in Fig. 3, there is a possibility that the link 28 closing against the frame could catch a finger and pinch the same. However, this is not considered to be a substantial disadvantage because it will be understood that there are no substantial weights or forces acting on the elements of the chair in the said collapsed position.

When the chair of my invention is collapsed or folded, the only action necessary is to lift the main frame 10 from the top in the area of the back rest 36. When this is done the weight of the legs 22 and the portion of the seat to the rear of the pivots 18 substantially overbalances the weight of the portion of the seat 20 forward of the pivots 18, and since the links 28 slide freely within the upper portions of the legs 22, the chair simply collapses with the seat 20 assuming a substantially vertical position with the rear legs 22 dropping a short distance below the front legs 12. When this happens as may be seen in Fig. 3, the links 28 pull outwardly of the rear legs 22, but the links 28 and the portions of the rear legs 22 extending above the pivots 24 are sufficiently long to prevent a complete separation of these elements even when the seat 20 is substantially parallel to the frame 10.

It should be noted that the rear legs 22 are substantially directly behind the front legs 12 so that when the chair is folded up, the rear and front legs come up substantially flush against each other, and for this reason the seat 20 does not arrive at a truly vertical position parallel to the frame 10. The links 28 are also directly behind the related elements of the frame 10, and they are joined thereto by means of forwardly extending ears 30 which enter small slots in the rear of the frame 10, and the cars 30 are actually pivoted to the frame 10. In this way it will be seen that there is a slight offset between the front and rear legs of the chair such that lowering the chair to the floor in the folded state causes the lower ends of the rear legs 22 to reach the floor first, and thereafter further downward forces on the chair acting through the aforementioned ofiset relationship between the elements causes the seat 20 to pivot outwardly and bring the chair to the fully set-up position.

An additional feature of my invention, seen more clearly with reference to Fig. 2, is that the forward corner of the seat does not extend outwardly over the extremities of the front legs and thus a person may stand or a child may sit on the forward corner of the seat 20 without running any risk of tipping the entire chair forward. In order to overcome forces acting downwardly on the said forward corner of the seat 20, the legs 12 absorb most of the force by a direct weight through the frame 10. However, it is also to be understood that a substantial portion of these forces is likewise transmitted through the pivots 24 and the links 28 to the upper portion of the frame 10 thereby causing a bending force in the frame 10 in the neighborhood of the pivots 18. While it might be considered that such a bending force in the frame 10 would be a disadvantage in the chair as shown, I have found in actual practice that the tubular frame 10 is adequately strong to resist the weight of a 200 pound man without 'any sign of distortion whatsoever.

Since numerous minor variations of this preferred embodiment of my invention will now be apparent to those skilled in the art, it is not my intention to confine the invention to the precise form herein shown, but rather to limit it in terms of the appended claims.

Having thus described and disclosed a preferred embodiment of my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

l. A folding chair comprising, a tubular frame, front legs integral with said frame, a seat pivoted to said frame,

tubular rear legs pivoted to said seat and having portions extending upwardly from said seat, and links pivoted to said frame at a point above the pivot point between said seat and frame, said links extending downwardly to the rear of said frame entering the said upwardly extending portion of said rear legs, and sliding therein in telescoping relation.

2. A folding chair comprising, a tubular frame, front legs integral with said frame, a seat pivoted to said frame, tubular rear legs pivoted to said seat and having portions extending upwardly from said seat, links pivoted to said frame at a point above the pivot point between said seat and frame, said links extending downwardly to the rear of said frame entering the said upwardly extending portion of said rear legs and sliding therein in telescoping relation, and stop mechanism in said rear legs limiting the travel of said links therein when said chair is set up for use.

3. The folding chair defined in claim 2 further characterized by said links and upwardly extending portions of said rear legs being sufficiently long to remain engaged in telescoping relation when said seat is pivoted to a position substantially parallel with said frame.

4. A folding chair comprising, a base frame, a pair of front legs and a back integral with said base frame, a seat pivoted to said base frame at an intermediate point, a portion of said seat extending rearwardly of said chair from said frame, rear legs pivoted to said portion, mechanism for pivoting said rear legs from a downwardly and rearwardly extending position relative to said chair when said chair is set up for use to a position parallel to said frame when said chair is folded for stowage, a link operatively associated with said mechanism pivoted to said frame at a point above the pivot point between said seat and frame, means for retaining said link substantially parallel to said rear legs when said chair is set up for use, and means including said link for limiting upward pivotal motion of the rear portion of said seat when said chair is set up for use.

5. A folding chair comprising, a base frame, a pair of front legs and a back integral with said frame, a seat pivoted to said base frame at an intermediate point between said front legs and said back, a portion of said seat extending rearwardly of said chair from said frame, rear legs pivoted to the portion of said seat which extends rearwardly of said frame, a link pivoted to said frame at a point above the pivot point between said seat and frame, means for maintaining said link and said rear legs in parallel relation while said seat is pivoted relative to said chair, and means including said link for limiting upward pivotal motion of the said rear portion of said seat in a relatively horizontal position when said chair is ready for occupancy.

6. A folding chair comprising, a frame, a seat pivoted to said frame, rear legs pivoted to said seat at a point on said seat to the rear of the pivot between said seat and frame, links pivoted to said frame at a point above the pivot between said seat and frame, and means including said links for limiting upward pivotal motion of the rear of said seat relative to said framewhen said chair is set up for use.

7. A folding chair having in combination, a frame, a seat pivoted to said frame, a tubular rear leg pivoted to a rear portion of said seat and having an upwardly extending portion with an opened end, a link pivoted to said frame above said seat and fitting in telescoping rela tion into the said upwardly extending portion of said rear leg, and stop means in said rear leg limiting the travel of said link therein when said seat is set up for use.

8. A folding chair comprising, a tubular frame, a seat pivotally connected to said frame, a pair of rear legs pivotally connected to said seat at the rear thereof and to said frame at a point above said seat, free sliding telescoping means for increasing the length of said rear legs between the pivotal connection thereof to said seat and said frame, and the total efiective weight of said rear legs and seat to the rear of the pivot between said seat and frame substantially exceeding the eifective weight of said seat to the front of the pivot between said seat and frame.

9. The folding chair defined in claim 8 further characterized by said rear legs lying directly to the rear of said frame whereby said rear legs will remain oifset slightly to the rear of said frame.

References Cited in the file of this patent UNITED STATES PATENTS Adler July 7, 1931 Schermerhorn June 18, 1935 Mains Aug. 25, 1942 OConnor et a1. Aug. 29, 1944 Hickok Oct. 19, 1954

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