US3638982A

US3638982A - Magnetic catch

Info

Publication number: US3638982A
Authority: US
Inventors: Howard D Chapman; Vincent A Panico
Original assignee: CLARIN CORP
Current assignee: CLARIN CORP
Priority date: 1968-08-15
Filing date: 1968-08-15
Publication date: 1972-02-01
Anticipated expiration: 1989-02-01

Abstract

Magnetic catch in which a magnet is sandwiched between pole pieces to form a magnet assembly held in a molded plastic housing including sidewalls and a rearwall, the rear wall having opening means therein facilitating coring for molding of formations on the sidewalls to provide means for retaining the magnet assembly in the housing. In one arrangement, the molded formations are in the form of integral pins projecting into openings in the pole pieces and preferably receive the ends of a pin extending through the magnet and pole pieces. Abutment means, preferably in the form of integral molded flanges, are provided for engaging the rearward surface of a panel in which the catch is mounted, such flanges being engageable by a resilient tabs are provided on the rear wall of the housing for engagement by a second panel to assist or to operate in place of the wire spring.

Description

United States Patent Chapman et al.

1 1 CHAIR WITH TILTABLE SEAT [72] Inventors: Howard D. Chapman; Vincent A. Panico,

both of Highland Park. 111. [73] Assignee: C1arinCorp.,Chicago 111. [22I Filed: Aug. 15.1969 1211 Appl. No.: 850,529

[52] U.S.Cl 1 1 1 1 1 297/332, 335.56

151 1 Int. Cl 1 1 1 1 1 1 1 A47c 4/20 [58] Field ofSearch 297/332. 335,33156302333;248/384.387;5/1h4 56) References Cited UNlTED STATES PATENTS 523,287 7/1894 Kollenberg 297/332 1.057.256 3/1913 McCarry 5/164 1,726,030 8/1929 Kurasch et a1 297/333 2.136.058 11/1938 Peppas 1. 297/333 21164 116 6/1939 Lincoln 1 1 1. 297/335 1451 Feb. 1,1972

2.843.186 7/1958 Spencer 297/335 3,001.816 9/1961 (lurin .1 297/56 3.158398 11/1964 Stryker 297/337 3.194.601 7/1965 Hoven et a1 .1 297/333 FOREIGN PATENTS OR APPLICATIONS 20.872 5/1906 Sweden 1. 297/332 229132 2/1959 Australia 1 1 1 1. 297/335 Primary EXUHI/Htf- Francis K. Zugel AIIr!I'I|t 1'.\'- Fitch. Even. Tahin and Luedeka I 57 1 ABSTRACT A spring device for lifting a chair seat into an upright position when not in use The spring is an elongate flat strip of metal attached at one end to the chair frame. The opposite free end of the spring is in sliding pressure contact with the underside of the chair seat so as to cause the seat to move to an upright position in a smooth motion.

6 Claims,4 Drawing Figs PATENTED rm 11972 3.638.982

SHEI 2 [1F 2 INVENTOR HOWARD D. CHAPMAN vmcnrr A. umco g %l/mz h ifcw rl CHAIR WITH TILTABLE SEAT The present invention relates to chairs of the tiltable seat variety. More particularly, it is directed to an improved chair having an automatically tiltable seal which can also be folded for storage.

it is common in the chair making art to spring load an auditorium seat so that the seat is automatically tilted into an upright position when not in use. The particular type of chair which incorporates this feature is normally referred to as an opera chair. The mechanism by which the seat is shifted into the upright position has taken many forms throughout the years, such as the mounting of coil springs at the sides of the seat and onto the frame of the chair. or mounting tension springs between the frame and the seat of the chair to pull downward on the rear of the seat and force the seat to pivot about a fixed pivot point. The prior art mechanisms for causing the seat to tilt toward the upright position suffer the limitations that they are not easily incorporated in a folding type of chair and they are a safety hazard in the folding of the chair due to the possibility of having the fingers pinched in the action of the spring at the corner of the frame. In addition, the spring action of prior art chairs is often harsh due to the designs of the springs incorporated therein.

The main objects of the present invention are to provide an improved folding chair having an automatically tiltable seat; to provide a spring biased tiltable seat for a chair in which the spring is not fixed to the seat member; and to provide a safe spring-loaded tiltable chair seat having gentle spring movement to an upright position when the occupant rises from the chair.

These and other objects and advantages of the present invention will become apparent in connection with the following description and drawings, in which:

FIG. 1 is a perspective view of a folding chair embodying the present invention having the seat in its in-use position.

FIG. 2 is an enlarged fragmentary sectional elevational view of a portion of the chair taken along line 2-2 of FIG. 1.

FIG. 3 is a perspective view of a folding chair embodying the present invention and having the seat in its upright position.

FIG. 4 is an enlarged fragmentary sectional elevational view of a portion of the chair taken along line 4-4 of FIG. 3.

While the present invention will be described in connection with the illustrated embodiment showing what is commonly referred to as an X-type of folding chair construction, it should be understood that the principles of operation of the tiltable seat disclosed and claimed herein are equally applicable to any other type of chair frame construction whether foldable or fixed.

In the construction illustrated, an improved seat-lifting spring unit 1 is applied to a folding chair 2 comprising a metal frame 3 of the X-type which supports a hinged seat 4 which is normally urged upwardly into its raised or storage position by the improved spring unit I.

The X-type frame, which is similar to that shown in Patent No. 3,026,144 dated March 20, 1962, comprises a front leg structure 5 and a rear leg structure 6 pivotally connected together by pivot pins, as at 7, so as to permit the chair to be folded for storage purposes.

The front leg structure Sis of inverted -shape so as to provide a pair of front supporting legs 8 and an upper bight 9 in which the usual backrest 10 is secured. Extending between the front legs 8 of the structure 5 is the usual reinforcing cross brace 11, which supports the improved spring unit 1, and a pair of diagonal reinforcing struts 12 for strengthening the frame.

The rear leg structure 6, which is hinged to the front leg structure 5 by the pivot pins 7, comprises a pair of rear supporting legs [3 connected together in spaced relation to each other by parallel cross braces 14 and 15. The legs 13 project upwardly beyond the pivot pins 7 to form supporting arms 16 having cushion pads 17 for supporting the seat 4 when the seat is in its lowermost or body-supporting position. Extending between the arms 16 and rigidly secured thereto is a U-shaped reinforcing bracket 18.

As will be apparent. the seat 4 may be of any desired construction. it may be made of a single sheet or panel of wood or metal or, as illustrated in FIGS. 1 and 2, it may comprise a plate 19 which is upholstered with suitable padding 20. In the construction shown. the hinged seat is pivotally connected to the front leg structure 5 by means of pivot pins 2| carried by beating plates 22 mounted on the inner faces of the front legs 8. As shown in FIG. 3, the hinge axis ofthe seat is positioned above that of the leg structures 5 and 6.

In the illustrated embodiment. the spring unit 1 comprises a strip of spring steel 23 having a width of approximately two inches and a thickness of approximately one sixteenth of an inch. As illustrated in FIG. 4, the lower end ofthe spring 23 is offset to form a bearing flange 24 which is rigidly secured to the cross brace 11 of the leg structure 5 by means of rivets 25 or by any other suitable means.

The main body of the spring has a permanent set so that, when not under stress, the spring has the general contour of an S-curve providing a pair of oppositely disposed

bumps

26 and 27, as best illustrated in FIG. 4. When the hinged seat is being raised, the hump 26 is positioned so as to slidably engage the bottom face of the seat which, in the embodiment illustrated, is the plate 19.

The outer free end 28 of the spring is offset downwardly and forwardly so as to form a bearing ridge 29 in sliding engagement with the seat plate 19. With this improved construction and arrangement of parts, when the seat is lowered, the spring is placed under stress so that the bearing ridge 29, exerting a firm continuous pressure against the central region of the bottom of the seat will immediately flip the seat upwardly and rearwardly from the position shown in FIG. 1 to the fully retracted position shown in FIG. 3 as soon as the seat occupant rises.

With this improved construction, the action of the spring is smooth, as distinguished from the jerking movement which would result if the outer end of the spring were anchored to the seat.

In the specific embodiment illustrated, as an added safety feature to avoid possible snagging of the free end of the spring on the clothing of a person using the chair. the free end of the spring is housed within a guard or shield 30 mounted on the lower face of the seat. The shield is made of sheet metal bent to form a rectangular channel having outwardly offset flanges 31 (FIG. 3), side walls 32, a bottom wall 33, a closed forward end 34, and an open rear end 35 for receiving the free end of the spring. The guard or shield 30 is of sufficient width to allow free movement of the spring within the channel without binding. The channel itself is only three or four inches in length, as the sliding movement of the spring relative to the tltair seat is relatively small No contact is made with the shield itself by any portion ofthe spring during the movement of the chair seat. An additional value of the shield results when the ridge 29 and the underside of the chair are lubricated to facilitate the sliding contact. The shield thereby acts to prevent soiling of the clothes or hands of the person utilizing the chair.

The present invention has resulted in an improved chair having a hinged seat which is tilted upwardly when not in use, as the result of the novel spring unit employed.

Although but one specific embodiment of the invention is herein shown and described, it will be understood that details of the construction illustrated may be altered without departing from the spirit ofthe invention as defined by the following claims.

We claim:

I. A chair comprising a frame having supporting legs. a seat mounted on said frame intermediate its forward and rearward ends for pivotal movement between a horizontal operating position and a substantially upright position, and an elongated spring having one of its ends rigidly fixed to said frame and having a portion adjacent the other of its ends in continuous sliding pressure contact with the bottom surface of said seat in an area located forwardly of the pivotal axis thereof effective to urge said seat toward said upright position throughout the range of movement of said seat, and means on said spring intermediate the ends thereof adapted to move into sliding pressure engagement with the bottom surface of said seat in an area located rearwardly of the pivotal axis thereof after said seat has moved from said operative position and before it reaches said upright position so as to conterbalance the force applied to said seat by said other end of said spring while said seat is in motion.

24 A chair as defined in claim 1 comprising further a housing mounted on the bottom of the hinged seat and positioned so as to encompass the slidable free end of said spring 3. A chair as defined in claim 1 wherein said spring is offset in a direction away from the bottom surface of said seat adjacent the other of its ends to provide a transversely disposed bearing ridge which slidably engages the bottom surface of said seat 4. A chair in accordance with claim I, wherein said means on said spring intermediate its ends adapted to move into sliding pressure contact with the bottom surface of said seat in an area located rearwardly of the pivotal axis thereof comprises a portion of said spring defining a hump adjacent the fixed end thereof.

5. A chair in accordance with claim I. wherein said spring is formed so that the portion adjacent one of its ends in continuous sliding pressure contact with the bottom surface of said seat in an area located forwardly of the pivotal axis thereof and the means on said spring adapted to move into sliding pressure engagement with the bottom surface of said seat in an area rearwardly of the pivotal axis thereof is continuously maintained out of contact with the bottom sur face of said seat.

6. A chair in accordance with claim I, wherein said frame includes a front leg unit providing a pair of front legs and a rear leg unit providing a pair of rear legs, said front and rear leg units being pivotally interconnected so as to permit the chair to be extended for use and collapsed for storage. and wherein said seat is pivotally mounted on one of said leg units and wherein said one end of said spring is rigidly fixed to a cross member extending between the legs of said one of said leg units in such a manner that pivotal movement of said front and rear leg units relative to each other does not cause flexing of said spring.

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