Chairs and seats – Bottom or back – Framework
Reexamination Certificate
1995-10-31
2001-11-27
Cranmer, Laurie K. (Department: 3507)
Chairs and seats
Bottom or back
Framework
C297S452130, C297S452300
Reexamination Certificate
active
06322147
ABSTRACT:
BACKGROUND
The present invention relates to chairs for use in offices and in institutional settings such as patient care facilities.
Special purpose patient chairs are disclosed, for example, in U.S. Pat. No. 4,555,139 to the above-identified inventor. Similar chairs having broader application are disclosed in U.S. Pat. No. 4,784,435 to the same inventor, both patents being commonly owned with the instant invention, the disclosures thereof being incorporated herein by this reference. Disclosed therein are laterally spaced seat and back-supporting members that are formed of high-strength spring material and having a flexible member extending therebetween for forming seat and back portions of the respective chairs. The seat and back-supporting members, which are rigidly spaced apart by a plurality of cross-members, have reverse curvature for providing lumbar support by the back portion. The above chairs are adapted for facilitating cleanliness in that the flexible members are thin, perforate and non-absorbent, having imperforate margins that enclose upper extremities of the seat and back-supporting members in a shape having low plan surface area at the top of the chairs to avoid collecting food or other waste matter.
The '139 patent discloses a chair having arms extending forwardly of the seat and having rigid front supports, the seat and back-supporting members being connected to the front supports for imparting significant springiness to the chair seat and back to enable infirm patients to easily rise from the seat while grasping the arms proximate the front supports. The '435 patent discloses a chair having arms extending forwardly to rigid supports that are approximately even with the seat front, the seat and back-supporting members being attached to the rigid front supports with resilient mountings for preserving a desired degree of springiness with the seat and back-supporting members being significantly foreshortened as compared with the '139 disclosure. In applications not requiring extreme ease of egress, the '435 disclosure provides a chair that is significantly more compact and inexpensive to produce. However, in some related applications the springiness of the above chairs is actually excessive, being potentially distractive to occupants of the chairs and persons nearby. Also, the seat and back-supporting members of the '435 chair remain undesirably expensive to produce, and they require critical quality assurance and monitoring.
Inexpensive, rigid chairs are known, and tensile sling chairs also include “director's chairs”, “butterfly” lawn-type chairs, and outdoor folding chairs. None of the sling chairs is believed to be particularly comfortable, because the supporting structure fails to provide a desired combination of shaping and tensioning of the material of the sling components. It is believed that none of the chairs of the prior art offers a desired combination of comfort, compactness, and compatibility with institutional environments. Thus there is a need for a chair that is suitable for institutional environments, that is particularly comfortable, yet is inexpensive to produce, using a small number of component parts.
SUMMARY
The present invention meets this need by providing a chair that combines extraordinary comfort, sturdiness, cleanliness and simplicity that is inexpensive to produce and particularly suitable for institutional environments. In one aspect of the invention, the chair includes a base having (I) first and second leg members, each leg member being formed as an inverted U-shaped front and rear leg pair, and (ii) a rigid bar rigidly connecting the rear leg pairs at respective medial locations thereon; an elongate seat frame; a connector structure; a non-rigid tensile member for supporting an occupant of the chair; and a horizontally disposed spreader bar engaging the back segments and extending behind the tensile member. The term “non-rigid” as applied to the tensile member means that the tensile member is flexible in bending, but not necessarily flexible in tension (stretching). The seat frame has a U-shaped plan and front elevational configuration including a horizontal cross segment, rearwardly extending seat segments, and a generally L-shaped side elevational profile including the rearwardly extending seat segments and upwardly extending back segments. The connector structure joins the seat frame to the base with the front legs supporting the seat segments near the horizontal cross segment. Seat and back portions of the tensile member, engaging respective portions of the seat segments and the back segments of the seat frame, are tensioned by (I) the cross segment of the seat frame rigidly extending between and spacing front extremities of the seat segments; (ii) the spreader bar being spaced above the back legs for spacing the back segments of the seat frame; and the back segments extending rigidly from the back legs to above the spreader bar.
The connector structure can also include back leg connections between the rear legs of the base to the back segments of the seat frame near the seat segments; and the back leg connections can augment the tensioning by rigidly spacing the back legs at those connections. The connections can include respective frame fasteners: a pair of seat fasteners connecting respective seat segments of the frame proximate the cross segment to a corresponding front leg, and a pair of first back fasteners connecting respective back segments of the seat frame proximate the seat segments to a corresponding rear leg. Each back fastener can include a pair of fixedly spaced head members and a shank element that extends through adjacent walls of the respective leg members and the seat frame with the head members bearing against interior surfaces of the respective walls. Each back fastener can include a pair of threadingly engaged fastener elements, each head member being formed on one of the elements, a head member including an axially disposed engagement surface, the seat frame having wrench clearance openings formed therein concentric with the respective fasteners for passing a portion of a wrench from outside the seat frame to the engagement surface, the wrench clearance openings being for appearance sake not more than approximately 110 percent of a shank diameter of the fastener. Also, there can be a pair of second back fasteners that are vertically spaced from the first ones, for augmenting the strength of the connector structure without enlarging the fasteners.
The engagement of the flexible member with the seat frame can include the flexible member enclosing portions of the seat and back segments, the frame connections including spacers for rigidly spacing the leg members from the seat frame, thereby providing clearance for the flexible member, the flexible member having openings for enclosing the spacers. The engagement of the at least one flexible member with the seat frame can include the flexible member having a pair of back pockets enclosing upper extremities of the back segments, each back segment being formed with front and rear side walls thereof in facing contact at the respective upper extremities, each of the back segment extremities compressively engaging upper closures of the back pockets for vertically tensioning the at least one flexible member.
Preferably a front wall of each back segment is uniformly spaced from a tube centerline of the seat frame to a point proximate each upper extremity, an opposite rear wall of each back segment being formed smoothly converging into contact with the front wall proximate the upper extremity from a point below the contact for facilitating a smooth front contour of the back segments, and for limiting plan area exposure of the back pockets proximate the upper extremities of the back segments; thus the upper closures of the back pockets can be closure seams.
The seat segments of the frame can extend downwardly and rearwardly by an angle &phgr; from horizontal, the angle &phgr; being from approximately 5° to approximately 15°. Preferably t
Cranmer Laurie K.
Sheldon & Mak
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