US2701007A

US2701007A - Folding armrest

Info

Publication number: US2701007A
Application number: US299265A
Authority: US
Inventors: Glenn G Hickok
Original assignee: IONIA Manufacturing Co Inc
Current assignee: IONIA Manufacturing Co Inc; IONIA MANUFACTURING COMPANY Inc
Priority date: 1952-07-16
Filing date: 1952-07-16
Publication date: 1955-02-01
Anticipated expiration: 1972-02-01

Description

Feb. 1, 1955 G. G. HICKOK 2,701,007

FOLDING ARMREST Filed July 16, 1952 2 Sheets-Sheet l /m/en for mm Feb; 1, 1955 G. G. HICKOK 2,701,007

FOLDING ARMREST Filed July 16, 1952 2 Sheets-Sheet 2 /n Men fol M United States Patent FOLDING ARMREST Glenn G. Hickok, Ionia, Mich., assignor to Ionia Manufacturing Company, Inc., Ionia, Mich., a corporation of Michigan Application July 16, 1952, Serial No. 299,265

4 Claims. (Cl. 155-445) The present invention provides an arm rest for a folding chair. Preferably, the present invention is used in conjunction with a folding chair mechanism of the type shown and described in the Burnham Patent Number 2,568,269, but is not limited to use with that mechanism.

The superior comfort characteristics of a chair provided with adequate arm rests are well known, and the primary reason that every folding chair is not so equipped is the fact that an arm rest having adequate strength characteristics is usually sufficiently complicated, or of heavy enough structure, as to bring the cost too far above a plain chair. The tendency of an occupant to place a large portion of his weight upon the arm rest of a chair as he is entering and leaving it, coupled with the fact that a considerable degree of side load is often applied to these members, makes it necessary to devote careful attention to the strength of the arm rest. Further, it is necessary that these forces be resisted by the arm rest without a substantial amount of deflection. Even though the chair be capable of carrying a loading assigned to it, any large amount of resiliency will give the occupant a feeling of insecurity. The positioning of the arm rest must therefore be positive, and as free from deflection as possible-both vertically and laterally.

These fundamental design problems are very troublesome due to the relative movement existing between the various parts to which the folding arm mechanism is connected. It is very difficult to assure a positive positioning of the arm when the remainder of the chair is not solidly fixed together. This is particularly true with regard to lateral forces, since the vertical positioning of the arm can be accomplished through a co-planar linkage system. Stabilizing the arm against side forces is another matter, however, since there is no practical way to position a diagonal brace for this purpose. The resistance of the arm against lateral displacement is largely similar to the action of a cantilever beam. Having in mind that the arms and operating linkage are pivotally connected, it is understandable why adequate lateral rigidity in an arm is difficult to incorporate without the use of excessively heavy journal and bearing structures. The present invention provides for the lateral stiffening of an arm without relying upon the alignment of the pivot bearings to any great extent. In this mechanism, bearings function entirely as pivot points, and are not utilized to position the arm in a plane parallel to the axis of the ivot. P In the preferred form of the present invention, an arm rest is pivotally connected to the front leg assembly of the chair, and a link extends between a forward point on the arm rest and a point upon the rear leg assembly. During the folding of the chair, a considerable amount of movement takes place on the part of this link in a direction parallel to the front leg. The normal position of the link is transverse to the front leg, and the movement along the front leg permits the link at an intermediate point to engage and disengage a fixed abutment secured to the front leg assembly. A very positive coupling action takes place at this engagement; and with the chair in the fully erected position, the link is therefore secured to the rear legs (by the pivot connection) and fixed with respect to the front legs at the engaged abutment. The link member actually becomes a rigidly mounted cantilever beam, the outer end of it forming the pivot con nection with the outer end of the arm rest. This link becomes the primary stiffening factor enabling the arm to resist side loads. A preferred form of the cross- 2,701,007 Patented Feb. 1, 1955 ice section of the supporting link is provided by the present invention, and which naturally facilitates the engagement with the fixed abutment.

The several features of the present invention will be discussed in detail through an analysis of the particular embodiments illustrated in the accompanying drawings. Referring to the drawings:

Figure 1 is a perspective view showing a chair embodying the present invention, with the chair in the fully erected position.

Figure 2 is a side elevation showing the chair illustrated in Figure 1, with the chair in the fully erected position.

Figure 3 is a view of the chair illustrated in Figures 1 and 2, but in the folded position.

Figure 4 shows an enlarged section taken through the folding arm mechanism.

Figure 5 is a view taken on the plane 5-5 of Figure 4. (Figure 5 also indicates more clearly the plane of the view of Figure 4.)

Figure 6 is a section taken on the plane 6-6 of Figure Referring to Figure 1, a folding chair is shown having a seat 10, a back 11,

front legs

12 and 13, and

rear legs

14 and 15. Arm rests 16 and 17 are positioned by the mechanism to be discussed hereinafter.

Referring particularly to Figures 4 and 5, a bracket 18 is shown firmly secured to the front leg 12 by the

bolts

19 and 20. Similar structure is provided on opposite sides of the chair. The upper end of the bracket 18 is provided with an offset portion 21 establishing a spaced relationship between the bracket and the leg 12 in this area. The arm-rest 16 is pivotally connected to thei lgaper portion of the bracket 18 by the rivets 22 an A U-shaped bracket 24 is fixed with respect to the arm rest 16 (see Figure 6), and the arms of this member are pivotally connected to the link 25 by the

rivets

26 and 27. The lower end of the link 25 is pivotally connected to the rear leg 14 at 28.

The lower end of the bracket 18 is provided with an offset indicated at 29 establishing a cantilever projection 30 at this point having the primary function of providing a firm abutment which the link 25 engages as the chair approaches the fully erected position. The cross-section of the link 25 is generally channel-shaped. The form of the depending projection 30 on the bracket 18 is such as to closely engage the walls of this channel and thereby effect a firm lateral positioning of the link 25 at this point. It will be noted that the link 25 generally maintains a transverse relationship with the front leg 12, and that the folding movement of the chair causes the link to move along the front leg while generally maintaining this transverse position. This movement causes the channel-shaped cross-section of the link 25 to engage and disengage itself from the depending projection 30. A comparison of Figures 3 and 4 will indicate the extremes of the movement of the link 25 between the folded and erected chair positions. The drawings referred to herein illustrate a chair of the type shown in the Burnham Patent Number 2,568,269. In this chair, the seat 10 is pivotally connected to the front legs as indicated at 31 in Figure 2, and to the rear legs substantially coaxially with the pivot connection 28. The upper end 32 of the rear legs is connected to the front legs by the link 33.

The particular embodiments shown in the accompanying drawings and disussed herein are for illustrative purposes only, and are not to be considered as a limitation on the scope of the appended claims. In these claims, it is my intention to claim the entire invention except as I am limited by the prior art.

I claim:

1. In a folding chair having front legs, rear legs, a seat pivotally connected to said front and rear legs, and a link connecting the upper portion of each of said rear legs to the front leg associated therewith, said links extending upwardly along said front legs from the points of connection thereto when said chair is in erected condition, folding arm-rest means comprising: opposite brackets fixed with respect to said front legs respectively and each having a downwardly-extending projection at the lower end thereof spaced from said front legs; op-

posite arm-rest members pivotally connected respectively to said brackets; and arm-rest supporting links pivotally connected respectively to said arm-rest members at points in front of said front legs and to said rear legs, said armrest supporting links having an upwardly-opening channelshaped cross section adapted to engage said projections respectively with said chair in erected condition.

2. In a folding chair having front legs, rear legs, a seat pivotally connected to said front and rear legs, and a link connecting the upper portion of each of said rear legs to the front leg associated therewith, said links extending upwardly along said front legs from the points of connection thereto when said chair is in erected condition, folding arm-rest means comprising: opposite brackets fixed with respect to said front legs respectively; opposite arm-rest members pivotally mounted for rotation on axes fixed with respect to said front legs; and arm-rest supporting links pivotally connected respectively to said armrest members at points in front of said front legs and to said rear legs, said arm-rest supporting links being adapted to engage said brackets respectively at an intermediate point on said arm-rest supporting links with said chair in erected condition.

3. In a folding chair having front legs, rear legs, and a seat pivotally connected to said front and rear legs, folding arm-rest means comprising: opposite brackets fixed with respect to said front legs respectively; opposite arm-rest members pivotally mounted for rotation on axes fixed with respect to said front legs; and arm-rest supporting links pivotally connected respectively to said arm members at points in front of said front legs and to said rear legs, said links being adapted to engage said brackets respectively at an intermediate point on said links with said chair in erected condition.

4. In a folding chair having front legs, rear legs, and a seat pivotally connected to said front and rear legs folding arm-rest means comprising: a bracket fixed with respect to one of said front legs; an arm-rest rfiember pivotally mounted for rotation on an axis fixed with respect to said one of said front legs; and, an arm-rest supporting link pivotally connected to said arm-rest member at a point in front of said one front leg and to one of said rear legs, said link being adapted to engage said bracket at an intermediate point on said link with said chair in erected condition.

References Cited in the file of this patent UNITED STATES PATENTS