US2280732A - Convertible rocking chair - Google Patents

Description

April 21, 1942.

M. THUM CONVERTIBLE ROCKING CHAIR Filed Jan. 31, 1940 Patented Apr. 21, 1942 UNITED STATES PATENT OFFICE CONVERTIBLE ROCKING CHAIR Martin Thum, Rochester, N. Y.

Application January 31, 19:10, Serial No. 316,645

4 Claims. (Cl. 15573) The present invention relates to rocking chairs, and more particularly to that class of chairs commonly referred to as convertible rocking chairs in that they are capable of use as a rock ing chair, a reclining chair, or as an ordinary chair, at the option of the user.

Many chairs of this character are so constructed that the rocker elements do not extend beyond the body, seat or legs of the chair, either at the front or rear of the chair, yet despitejthis fact the chair possesses stable equilibrium at all times whether occupied or unoccupied and whether the chair is used in the ordinary manner, as a rocker, or as a reclining chair.

The improved rocking chair comprising the present invention is no exception and likewise is so constructed that it is devoid of forwardly or rearwardly projecting rockers, yet it possesses the further advantage that it does not involve the usual common danger to objects positioned directly beneath the rocker assembly, to children, domestic animals or the like.

Furthermore, the rocker assembly is so constructed that the function of the chair as a rocking chair is not affected despite the fact that an obstacle such as the edge of a rug may be positioned directly beneath the chair.

The provision of such a rocking chair being the principal object of the invention, it is a further object thereof to provide a rocker construction or assembly for chairs in which the It is another object of the invention to pro vide such a rocker construction which still retains its convertible features in that it may be used either to permit rocking of the chair or to maintain it in its inclined or upright positions.

Yet another object of the invention is to provide a rocker construction or assembly which, unlike common rockers having shifting fulcrums, will not gradually creep forwardly or rearwardly on the supporting surface upon continued use of the rocking chair in its rocking capacity. A similar and related object of the invention is to provide a rocker construction which will prevent the rocking chair to which it is applied from leaping forwardly when the chair is rocked violently, this being a phenomenon common to most rocking chairs having shifting fulcrums.

A still further object of the invention, in a modified form thereof, is to provide a rocking chair construction in which the chair, despite its rocking features, is supported for voluntary shifting thereof on the supporting surface by casters, or at least by a semi-caster effect.

It is another object of the invention to provide a rocking chair of the character set forth above which, although it presents no shifting fulcrum on the supporting surface together with the dangers attendant thereon, at the same time presents the appearance of a rocking chair and is instantly recognizable as such.

It is still another object of the present invention to provide a chair having front legs and a rear supporting means in the nature of oppositely disposed fulcrum means arranged beneath the chair, forwardly of the back of the chair, at

points beneath the chair whereby the latter is easily moved or rocked from a normal position to a tilted position, the said rear fulcrum supporting means upon which the chair may be rocked or tilted functioning Within a very limited space beneath the chair body in contact with the supporting surface, and with the front legs providing a four-point chair supporting means. The result is that the major portion of the weight of the chair and its occupant is carried by the fulcruming means both in normal or reclined position of the chair and ease of rocking in either direction is made possible.

The provision of a rocking chair possessing the features indicated above in which the rocker construction possesses no parts that are movable relative to each other or to the chair body and which therefore is unlikely to get out of order; one which is rugged and durable; one which is comparatively inexpensive to manufacture; and one which is well adapted to perform the services required of it, are further desiderata that have been borne in mind in the development and production of the present invention.

Other objects and advantages of the invention, not at this time enumerated, will become apparent as the following description ensues.

In the accompanying single sheet of drawings:

'Figure 1 is a side elevational View of a chair to which one form of the improved rocker construction comprising the present invention has been applied, the full lines illustrating the chair in its normal upright position and the broken lines illustrating he same in its rec-lining position.

Figure 2 is a side elevational view similar to Figure 1 showing a modified form of the rocker construction.

Figure 3 is a fragmentary side elevational view of a chair showing a further modified form of the rocker construction applied thereto.

Figure 4 is a side elevational view similar to Figures 1 and 2 showing yet another modified form of the rocker construction.

Figure 5 is a fragmentary side elevational view similar to Figure 3 showing still another form of rocker construction.

Figure 6 is a sectional view taken substantially along the line ti5 of Figure 5.

Figure '7 is a fragmentary side elevational view similar to Figures 3 and 5 illustrating an additional modified form of rocker construction.

Figure 8 is a sectional view taken substantially along the line 3-8 of Figure '7.

Figure 9 is a perspective View of a base or support for a chair body having associated therewith convertible rocker features designed according to the principles of the present invention.

Referring now specifically to Figure 1, the improved rocker construction is shown for illustrative purposes as being applied to an upholstered chair ID having a seat 12, a back It, and arms 16 forming what may be considered the body of the chair Ill. The base of the chair body is provided with a pair of depending front legs or supports 18 and a pair of depending rear legs or supports 20, the latter if desired being inclined rearwardly.

Extending rearwardly from points medially of the height of the front legs i2 and only slightly elevated from the supporting surface are a pair of parallel extending members each being in the form of a rail or bar, and which preferably terminate at points well within the vertical projection of the chair body and which, when the front legs 18 are in contact with the floor or other supporting surface, extend substantially parallel to the latter. The members 22 are preferably of rectilinear design or substantially so.

The members 22 are secured adjacent their rear ends as at 24 to the rear legs or supports 2t! and underlie the same and extend beyond the I rear legs as at 25 a distance sufiicientonly to lend a degree of stable equilibrium to the chair as a whole when the latter is in its reclining position as shown in broken lines and whether the chair is vacant or occupied. By thus extending beyond the inclined legs 25! and projecting rearwardly therefrom in spaced relation to the supporting surface the members 22 give the general appearance of the usual rocker elements employed in conventional rocking chair constructions. If the rear legs 2i! are sufficiently inclined from the vertical, it is obvious that the members 22 may terminate at the inside of the legs 2? and the chair will still maintain a degree of stable equilibrium in its reclining position.

In order that the chair may be rocked from its full line upright position to its dotted line reclining position and vice versa, a sharply rounded protuberance 26 or rocker element is formed on the underneath side of each member 22 medially of the front and rear legs 18 and 2t respec tively, and preferably nearer the latter than the former. To insure accurate front and rear rocking movement of the chair and to prevent sidewise cantingof the same, the protuberances 26 are directly oppositely disposed on each side of the chair and their distance from the rear legs, and from the rear ends of the rocker elements 22, is a matter that may be determined by the specific character of the chair to which the rocker construction is attached and by the extent and nature of the rocking movement desired as will appear presently. The height of the protuberances 2'5, 1. e. the distance from the supporting surface to the lower edge of the rocker elements 22 at the protuberances, is preferably substantially equal to the distance that the front legs l8 project beneath the members 22, thus causing these latter elements to extend substantially parallel to the supporting surface when the chair is in its normal upright position as previously described.

The protuberances 26 are preferably located on the members 22 at points slightly rearwardly of the center of gravity of the chair body when occupied, or at least at a point very close to the calculated center of gravity of chair and its cccupant in order that the protuberances will jointly provide a stationary fulcrum for the chair on the supporting surface at a point sufficiently Well beneath the chair that the occupant may, with little difficulty, rock the chair to either of its two extreme positions. The chair will thus possess a degree of stable equilibrium and have a four point support both in its normal upright position and in its reclining position and, at any inclination between these two extremes, the chair will possess a degree of unstable equilibrium depending upon the weight and center of gravity of the combined chair and occupant. It will further be seen that by varying the distance of the protuberances 26 from the rear supporting legs 23, the character of the rocking action may be varied, while varying the distance the rear ends of the members 22 project rearwardly beyond the protuberances 26, the inclination of the chair when in its reclining position may be varied.

The location of the protuberances 26 on the members 22 is thus predetermined not only by the weight and location of the center of gravity of the chair body, but also by the extent and slope of the chair bottom [2 and by the height and slope of the chair back it, these latter factors being significant in determirdng the center of gravity of the chair and its occupant. These considerations are preferably adhered to in de signing the rocker construction for any particular chair even though the chair when not occupied is incapable of remaining stable in its reclining position.

In connection with the form of the invention just described and illustrated in Figure 1, it is to be noted that the members 22 are not to be confused with the usual runners employed in connection with the ordinary rocking chair. Such runners shift their point of contact with the supporting surface as the chair is rocked thus causing the chair to creep forwardly ppon continued use. Vifhere the chair is rocked violently it will, because of the shifting center of gravity of the chair body, leap forwardly, so to speak, sometimes damaging the chair and sometimes harming the occupant. In the present instance the center of gravity of the chair body is given little freedom to shift. At the most, it will shift from a point slightly forwardly of the protuberances 26 to a point slightly rearwardly thereof, thus placing the chair gently in either of its extreme positions when rocked from one to the other.

The members 22, being thus spaced from the supporting surface and being incapable of contacting the latter except at the extreme rear ends thereof when the chair is in its reclining position, there is little opportunity for articles positioned beneath the members 22 to become crushed and the always present danger of injuring children or domestic animals that exists in connection with other types of rocker constructions is eliminated. Furthermore, the rocking features of the rocker construction are not interfered with despite the presence of articles beneath the members 22. Thus the chair may straddle the edge of a rug or other obstacle and still function as a rocking chair without difficulty. When the chair is used for rocking purposes, no accumulated potential rocking energy can be stored in the rocker construction, and consequently no excessive momentum is encountered tending to upset the stable equilibrium of the chair or its occupant.

In Figure 2 a modified form of rocker construction involving substantially the same principles of operation as the rocker construction of Figure l is shown. In this form of the invention, for illustrative purposes, the chair body construction including the seat 12, back l4 and arms It remains substantially the same while the modifled rocker construction permits the chair to co cupy a position fairly close to the supporting surface, thus giving the appearance of the ordinary easy or Morris chair. The front legs or supports 28 are relatively short compared to the legs 18 and are entirely independent of the rocker elements 32. These latter elements are secured to the underneath side of the chair body at the rear corners thereof and are formed with downwardly projecting protuberances 3'? which, like the protuberances 25, are sharply rounded. The rocker elements 32 are formed with extensions 35 which project slightly beyond the rear edge of the chair bottom and control the inclination of the chair when the latter is in its reclining position. The extensions 35, however, do not project rearwardly beyond the vertical projection of the chair upon the supporting surface for reasons that are well understood in connection with. the extensions 25. The height of the protuberances 36 is substantially equal to the height of the front legs 28 and thus the chair, when in its upright position presents an underneath surface which is spaced from and substantiall parallel to the supporting surface.

In the form of the invention just described, the same advantageous features outlined in connection with the form of the invention shown in Figure l are attained while at the same time the elimination of rocker elements that are coextensive with the length of the chair causes the latter to take on the appearance of an easy chair despite the fact that the chair is capable of being used as a rocking chair.

In the form of the invention illustrated in Figure 3, the rocker construction remains substantially the same as in the form shown in Figure 1 with the exception that the protuberances 26 on the members 42 have been omitted and in their stead there has been substituted a traction roller 46 '(see also Figure 6) which is rotatably supported between a pair of ears 4'! formed on the underneath side of the members 42. The combined height of the rollers 46 and ears 4! is substantially equal to the distance that the front legs 48 project below the members 42 and thus, in addition to the advantageous features present in connection with the other forms of the rocker construction, a semi-caster effect is obtained whereby the chair may manually be shifted on the supporting surface with comparative ease.

In Figure 5 somewhat the same condition as that shown in Figure 2 obtains, but the rocker construction is modified to cause the chair to take on the appearance of a glider which ordinarily is mounted on runners. In this form of the invention, the members 52 are secured directly to the underneath side of the chair and extend from points adjacent the front thereof to points beyond the rear lower edge of the chair but well within the confines of the vertical pro jection of the chair on the supporting surface. The front legs 58 project downwardly from the members 52 at the front of the chair a distance equal to the combined height of the rollers 56 and their supporting ears 5! as in the form of the invention shown in Figure 3. Thus a semicaster effect is attained while the advantages set forth in connection with the other forms of the invention are preserved.

In Figure 4 the rocker construction is substantially the same as that shown in Figure 2 except for the substitution of the roller constructions 66, 61, for the protuberances 36 on the members 62, In this manner, the chair takes on the appearance of an easy or Morris chair while still possessing the same rocking features and the semi-caster gliding effect.

In Figures 7 and 8, a rocker construction designed for use on a soft or yielding supporting surface, as for example on a thick soft rug or on a lawn, is disclosed. The true rocking chair type of construction shown in Figures 1 and 3, rather than the easy chair or glider chair con struction of Figures 2 and 5, has been selected for illustrative purposes only. In this form of the invention, a pair of foot members 16 having foot portions 19 and web portions 8! have their latter portions pivoted between ears I! formed on the underneath side of the rocker elements 12. The combined height of the foot members and ears is substantially equal to the distance the front legs 18 project below the rocker elements 72 in order that the rocker elements will extend substantially parallel to the supporting surface when the chair is in its upright position. The foot portions 19 of the foot members 76 are of sufficient extent that they will not sink into the relatively soft supporting surface and thus the chair may be utilized as an outdoor rocking chair despite the condition of the ground.

In the form of the invention shown in Figure 9, the convertible rocking features of the present invention are incorporated in a chair frame or base which, if desired may be in the form of an integral casting to which the chair body (not shown) is secured or on which it is mounted in any suitable manner. The frame 90 includes a front rail 92, a pair of parallel side rails 94, and a curved rear rail which merges gently into the contour of the side rails 94. A pair of rocker elements 98, including protuberances similar to the protuberances 25 and 36 of Figures 1 and 2, depend from the side rails 94 and are designed for contact with the supporting surface at spaced points which are slightly rearwardly of the center of gravity of the combined chair body and frame. A limit stop Hill is formed centrally of the curved rear rail 96 and determines the inclination of the chair body in the reclined position thereof. Relatively short legs or supports I02 depend from the front corners of the frame 90 and are of a height corresponding to the height of the rocker elements 98 in order that the major portion of the side rails 94 will remain spaced from and parallel to the supporting surface ,when'the chair is in its'upright position.

The invention is not to be limited to the exact arrangements of .the rocker constructions shown in the accompanying drawing or described in the specification as various changes may be resorted to without departing from the spirit of the invention. For example, the foot construction shown in Figures '7' and 8 is capableof use in connection with rocker constructions designed along the lines of those shown in any of the preceding figures. Onlyinsofaras the invention has particularly been pointed out in the accompanying claims is thesame to be limited,

What is claimed is:

1. In a convertible chair construction, a chair body having a bottom, front and rearlegs depending from the bottom at-each side thereof, rails secured to each front leg at a point spaced upwardly'from the lower end thereof, said" rails extending rearwardly beneath the chair in par allelism and terminating within the vertical projection of the chair, and a pair of relatively short oppositely positioned protuberances depending from said rails at points slightly rearwardly of the center of gravity of the chair and for-- wardly of the rear ends of the; rails, said protuberances providing a substantially fixed fulcrum for the chair upon its supporting surfacem the height of said protuberances being substantially equal to the distance from the supporting surface to said upwardly spaced points whereby the rails are normal-lymaintained parallel to and spaced from the supporting surface, therear legs being connected tothe rails at-points located between the rear ends of the rails and the protuberances.

2. A rocker construction for chairs and the like comprising a'pairof elongated tiltab-le rail for contact with a supporting surface, and a relatively short depending leg formed on the forward end of each member and of an extent substantially equal to the extent of thefulcrum member whereby the majorportion" of the rail-like memher is normally maintained slightly elevated from the supporting surface, the extreme rear portion porting the side rails in spaced relationship from the surface for movement of the chair from a forward upright position to a rearwardly inclined position, a pair of spaced legs depending from the base structure at the front thereof and designed for contact with the supporting surface for limiting the forward rocking movement of the chair body and determining its forward upright position, said protuberances and legs being substantially of equal extent and serving to maintain the side rails slightly elevated from the supporting surface and substantially parallel thereto when the chair is in its forward upright position, and a limit stop mounted on the rear of the base structure and designed for contact with the supporting surface for limiting the rearward rocking movement of the chair body and determining its rearwardly inclined position.

4. In a convertible rocking chair construction, a chair body having a base structure including a pair of side rails, a relatively short protuberance depending from each side rail medially thereof at a region slightly rearwardly of the center of gravity of the chair, said protuberanc-es providing a substantially fixed horizontal fulcrum axis upon which the chair is pivoted for tilting movement, legs depending from the base structure in the forward regions thereof, said protuberances and legs serving to support the side rails and maintain the same spaced above the supporting surface on which the chair is mounted in the normal position of the latter, the portions of said rails rearwardly of the protuberances being adapted for contact with the supporting surface to limit the rearward tilting movement of the chair.

MARTIN THUM.

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