Single frame sling chair

A sling chair includes a back frame member having side rails held in substantially parallel relation by a pair of cross bar members. In one embodiment, the cross bar members are generally curved so as to extend away from the back faces of the side rails, forming a concave back structure which can receive a sling member and, eventually, a seated occupant. The cross bar members are adapted to retain the sling member in secure fashion through upper and lower backrest assemblies, resulting in better support and more efficient assembly. This also facilitates separate provisioning of decorative features to improve the chair's aesthetic qualities.

FIELD OF THE INVENTION

The present invention relates to chair constructions, and more particularly relates to a chair construction employing a sling-type backrest which promotes chair stability, comfort and a variety of design alternatives.

BACKGROUND OF THE INVENTION

Various types of sling chairs have been known which provide a somewhat concave and/or giving backrest. Such chairs generally include a back portion and a seat portion, and may optionally include armrest portions. The back portion generally includes a back frame and a flexible yet supportive backrest made of fabric or other suitable material and mounted to the back frame. Different mechanisms have been employed for securing the backrest to the back frame, and these prior art mechanisms have suffered from several deficiencies. First, these prior art mechanisms often fail to provide a secure connection, which can result in the backrest being unsupportive of the seated individual. Further, the sling backrest for these chairs is frequently retained along the chair side rail supports, creating side-to-side sling tension, restricting the potential to add decorative chair features, and complicating assembly.

SUMMARY OF THE INVENTION

The present invention provides a connection assembly for a sling chair which allows for efficient chair assembly and results in a comfortable yet sturdy chair. The present invention includes a back frame member having side rails held in substantially parallel relation by a pair of cross bar members. In one embodiment, the cross bar members are generally curved so as to extend away from the back faces of the side rails, forming a concave back structure which can receive a sling member and, eventually, a seated occupant. The cross bar members are adapted to retain the sling member in secure fashion through upper and lower backrest assemblies. In this way, the sling member is not secured to the side rails, but rather to the cross bar members, resulting in better support, a more secure connection and more efficient assembly. The method of securing the sling member using a detachable support bar having a scaffold support element ensures that the sling member is efficiently and securely retained. The present invention also facilitates separate provisioning of decorative features to improve the chair's aesthetic qualities.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

As shown inFIGS. 1 through 6, the present invention provides a single frame sling chair10, having a rigid frame12.FIG. 1shows an overall, right side view of one embodiment of a chair according to the present invention, including monolithic welded frame12comprising frame rails14, seat16, armrests18and leg portions20. A backrest assembly22is also shown, including upper backrest assembly portion24and lower backrest assembly portion26. Upper backrest assembly portion22includes top cross bar28and detachable support bar30, described more completely hereafter. Top cross bar28may be integrally formed with top element32and connective fascia34, or may be secured to elements32and34as separate members. Top cross bar is secured to, and acts as a spreader between, frame side rails14, as shown inFIG. 2.

As further shown inFIGS. 1 and 2, lower backrest assembly portion26includes bottom cross bar38which is secured to frame rails14and acts as a spreader to hold frame rails14apart. Bottom cross bar38cooperates with top cross bar28to hold frame rails14in substantially parallel relation. A backrest33, such as a sling fabric member, is secured to the upper24and lower26backrest assembly portions to provide body support to individuals using the chair of the present invention.

In the embodiment as shown inFIG. 2, top and bottom cross bar members are provided in substantially parallel relation. The crossbars28,38are provided of a curved or concave shape generally, and can be solid or hollow. As shown inFIGS. 1 and 2, the crossbars28,38project at least partially outwardly away from respective back faces15of side rails14. The crossbars28,38can be any of a variety of section shapes, and can be adapted to accept a decorative casting34as part of or an attachment to crossbar, as shown in the exemplary embodiment ofFIG. 2. Decorative side castings35can also be provided as shown inFIG. 2so as to flank sling member33. The sectional shape of side rails14as well as that of support bar30can be circular, oval, square, or other shape, for example. Further, support bar30and side rails14can be solid or hollow.

The remainder of the chair frame can have any arrangement for a seat bottom, it may have arms or no arms, and it may have any number of legs, or a pedestal instead of legs, and may be a rocker, swivel chair, swivel-rocker, swivel-glider, or a rigid monolithic frame.

The method of securing top28and bottom38cross bar members to back frame rails14can be by conventional means, such as by welding or by providing the frame rails with open interior slots for receiving respective ends of cross bar members28,38(not shown). The method of securing backrest33to top and bottom cross members involves upper24and lower26backrest assemblies. Upper backrest assembly24comprises at least top cross bar member28and detachable support bar30. As shown inFIGS. 2,3and5, detachable support bar30is provided with a base portion41and a scaffold portion42, wherein scaffold portion can be “c”-shaped as shown for receiving a substantially rigid rod50. As shown inFIG. 5, rod member50is placed through a loop40in sling member33, wherein the sling loop40and rod50rest in the channel created by scaffold portion42. Loop40can be formed, for example, by bending sling member edge back upon itself and securing the sling member to itself, such as via a hem or similar method. A portion of sling member33thus rests in the gap43created by the base portion41and cross bar member28. The support bar30can be secured to the bottom face45of top cross bar28using screws46mating with internal threads47in base portion41and cross bar28, for example. Alternative means of fastening support bar30to top cross bar28can be employed, such as sheet metal screws, hook and loop fasteners, clamps, or malleable plug members extending from support bar30into openings in cross bar28, for example.

As shown inFIGS. 2,4and6, lower backrest assembly26comprises at least bottom cross bar38and rod member60. As shown inFIGS. 2 and 6, bottom cross bar38can include an upper portion52and a lower portion53which join together at respective ends38aand38b, and which have respective inside walls54aand54b, outside walls55aand55band interior facing walls56aand56b. Cross bar member38can be formed as a unitary, monolithic piece or can be formed by securing respective portions52and53together at ends38aand38bthrough welding or other attachment means. Regardless of how formed, the interior facing walls56aand56bcooperate to form a through-and-through slot44. As shown inFIG. 2, slot44can extend for substantially the length of upper52and lower53portions. As shown inFIG. 6, the end of fabric sling33opposite the end secured to upper bracket assembly is provided with a loop58for receiving rod member60. Loop58can be formed in a manner similar to that described for forming loop40. Rod member and sling loop portion58are then retained against outside walls55aand55b, which are respectively provided with inwardly extending portions57aand57bfor such purpose. In one embodiment as shown inFIG. 6, inwardly extending portions57aand57bare arcuate in cross-section. Portions57aand57bassist in providing the back assembly22with a low profile, minimizing the extent of rod and sling extension outside of the plane formed by outside walls55aand55b, which in turn minimizes sling member exposure to unnecessary wear and tear. As shown inFIGS. 4 and 6, the securing of sling member33within lower bracket assembly26can be optionally enhanced through the employment of one or more machine screws64extending through openings66in lower cross bar member and mated with hollow receiving screw65or other similar securing element. In one embodiment of the invention, a screw receiving member such as a nut having an interior threaded surface is maintained within walls of cross bar38so as to receive screw64while not extending outwardly of the upper portion52of cross bar38. In this way, minimum visibility of attachment elements such as nuts and bolts can be maintained, which enhances the aesthetic qualities of the present invention.

It will be appreciated that the shape of top28and bottom38cross bar members can be adapted to suit particular chair requirements in accordance with the present invention. For example, the top cross bar member28can have a rounded rectangle cross-sectional shape, as shown inFIG. 5, or can have a square, hexagonal, octagonal or other polygonal shape. Bottom cross bar member38can have a primarily rectangular shape with arcuate interior wall segments57aand57bas shown inFIG. 6and described earlier. Alternatively, bottom cross bar member38can have a square, hexagonal, octagonal or other polygonal shape. In one embodiment, bottom cross bar member38has an octagonal shape and adjacent edges establish a receiving channel for retaining rod member58and looped hem60, again minimizing the outward extension of the sling fabric loop and rod member beyond the lower backrest assembly. In a further embodiment, a metal frame member (not shown) can be secured to upper52and lower53portions of bottom cross bar member38to conceal and protect sling member33and loop60.

By placing the sling entrapment at the top and bottom in the cross members, rather than in the side rails, the invention facilitates the creation of a comfortable concave shape to the back rest. Also, the invention thereby allows for shorter looped hems and dowels than would exist if the sling were attached to the side rails. The invention also permits sturdier and more rigid frame construction and leaves open more design possibilities for accessory items.

The method of assembling the backrest22to the frame12according to the present invention can occur in several ways. In one exemplary way, chair frame12is provided with top cross bar member28and bottom cross bar member38secured to side rails14as shown inFIG. 2. Sling member33is provided with looped hems40and58at two ends thereof. Looped end58is manipulated through slot44in lower cross bar member so as to be positioned somewhat adjacent to wall portions57aand57b. Rod member60is then manipulated through looped end58such that any tension applied to the remainder of sling member, such as pulling on sling member from a location on the interior of lower cross bar member, will result in looped hem58contacting wall portions57aand57b. Machine screws and nuts or equivalent attachment means can assist in retaining sling member in place with respect to bottom cross bar member38.

Next, rod member50is placed through looped hem portion40of sling member33, and this arrangement is positioned over base portion41of support bar30and within scaffold portion42. Support bar30is then raised so as to align with the under face45of top cross bar member28. Threaded bolts46or similar attachment means can then be manipulated through base portion41, sling member33and top cross bar member28to securely maintain support bar and sling to top cross bar member28.