Abstract:
A back pad for a chair having a back defined by a shell, the back pad being fitted over the back shell and providing the back with a resilient padded feel while additionally providing styling flexibility with respect to the appearance of the chair back.

Description:
This application is a continuation-in-part of application Ser. No. 10/267,422 filed Oct. 9, 2002. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to a chair as typically used in offices and the like and, more specifically, to an improved back pad which can be optionally attached to the chair back to provide altered comfort and appearance. 
     BACKGROUND OF THE INVENTION 
     Chairs, and particularly office-type chairs, are conventionally provided with either a shell-like back or an upholstered back. In a chair with a shell-like back, the back is conventionally formed of a molded plastics material having limited resiliency or flexibility, and any aesthetics or decorative styling are typically achieved solely by coloration and shape. While chairs of this type are acceptable in some applications, nevertheless in many applications they do not provide the degree of cushioned resiliency frequently desired or expected. For this reason many office chairs employ a cushioned back wherein the back includes an inner supportive shell having a suitable deformable cushioning layer thereover, which cushioning layer is enclosed by a flexible covering such as fabric or vinyl. Such cushioned back construction provides a higher degree of cushioned comfort as desired in many use applications, but at the same time such construction is more expensive. 
     In an effort to provide increased manufacturing efficiency and flexibility with respect to providing a chair permitting use with both a shell back and a cushioned back, one prior chair as manufactured by Keilhauer and known as the “Tom” chair employs a back defined by a one-piece plastic shell having a large plurality of small openings therethrough disposed in a grid-like pattern, which shell back enables the chair to be used for direct supportive engagement with the chair occupant. In an effort to provide improved chair flexibility, the aforementioned chair can also be provided with a back pad which removably attaches to the back shell in overlying relationship to the front face thereof. This back pad employs a plastic shell with a foam layer thereover which in turn is enclosed within an outer covering. The back pad secures to the back shell by screws which extend through holes located in the corners of the back shell for engagement with aligned holes associated with the corners of the back pad. When the back pad is mounted on the back shell, there is provided a more resilient and deformable back construction for user comfort. The back pad does provide limited styling, except that the pad effectively covers only an upper portion of the back shell and provides no covering over the waist portion of the back shell. Furthermore, the securement of the back pad to the back shell by screws requires that the back shell have openings therethrough, and providing such openings is in many instances considered unacceptable from a styling standpoint, particularly when the chair is utilized without the back pad mounted thereon. 
     Accordingly, it is an object of this invention to provide an improved chair having a back defined by a back shell which can be utilized without an upholstered or cushioned covering thereover, but which can optionally be provided with an upholstered resilient back pad which can be readily and easily fitted over the back shell, either at the factory or retrofitted at the job site, so as to provide the back with a resilient padded feel while additionally providing styling flexibility with respect to the appearance of the back. 
     It is also an object of the present invention to provide an improved chair, as aforesaid, wherein the back pad incorporates as an integral part thereof an upward extension which, when the back pad mounts to the back shell, projects upwardly above the back shell to function as a head rest, thereby converting the chair from one having a normal height back to one having a higher height back. 
     It is also an object of the present invention to provide an improved chair back, as aforesaid, wherein the back pad can be readily fitted to the back shell by means of flanges on the back pad which overlie the top and side edges of the back shell so that the back pad can be effectively fitted downwardly over the back shell to effect secure engagement therewith, thereby permitting the back pad to be easily and securely mounted on the back shell without requiring use of threaded fasteners or the like, whereby the back shell at least throughout the principal visible portion thereof can be free of fastener openings and the like. 
     In the improved chair of this invention, the chair includes a back arrangement which projects upwardly from adjacent a rear edge of the seat. The back arrangement is defined principally by a one-piece back shell constructed of a thin plastics material so as to have the desired contour and preferably at least limited resiliency or flexibility, whereby the back shell can directly function as the exposed back of the chair for direct supportive contact with the chair occupant. The chair can optionally be provided with a preassembled back pad unit which can be provided on the chair at the time it is shipped from the factory, or can subsequently be retrofitted onto the chair, to provide the chair with a more conventional cushioned back covered with a fabric or covering. The preassembled back pad unit has its own thin shell, again preferably a thin plastic sheet of suitable shape and contour formed similar to the main back shell so as to be positionable directly over the front face of the main back shell. The pad shell has a thin cushioned layer overlying and secured to the front face thereof, and a flexible outer covering encloses the front side of the pad unit and wraps therearound for fixed securement to the back side of the pad shell. The flexible covering has a top flap portion which wraps around the upper edge of the pad shell and is sized sufficiently so as to define a downwardly opening pocket portion where the covering overlies the back side of the pad shell. The pad shell also has upper and opposed side mounting flanges, all positioned so as to be disposed under the upper fabric portion which defines the rear pocket, so that the pad unit can be fixedly secured to the back shell by being slidably inserted downwardly over the upper edge thereof so that the flanges of the pad shell securely engage and embrace the back shell along the upper and opposed side edges thereof, and the flap portion defining the rear pocket overlies the upper rear side of the back shell. 
     In the improved chair of this invention, as aforesaid, the pad unit in an alternate construction has the pad shell provided with an upper headrest extension which projects upwardly a selected distance above the upper mounting flanges. The cushioning layer and the covering layer all extend upwardly and enclose this upward extension such that the pad unit, when mounted on the back shell, effectively defines a headrest extension which projects upwardly above the upper edge of the back shell to convert the back arrangement into a high-height back. 
    
    
     Other objects and purposes of the invention, including structural and operational advantages thereof, will be apparent to persons familiar with constructions of this general type upon reading the following specification and inspecting the accompanying drawings. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of a chair having a back defined by an unupholstered back shell. 
     FIG. 2 is a perspective view of the chair shown in FIG.  1  and having a back pad unit optionally mounted on the back shell. 
     FIG. 3 is a rear perspective view of the chair shown in FIG.  1 . 
     FIG. 4 is a front view of the back pad unit shown detached from the chair. 
     FIG. 5 is a rear view of the back pad unit shown in FIG.  4 . 
     FIG. 6 is an enlarged fragmentary cross-sectional view taken generally along line  6 — 6  in FIG.  2 . 
     FIG. 7 is a front elevational view of the pad shell associated with the pad unit. 
     FIG. 8 is a top view of the pad shell shown in FIG.  7 . 
     FIG. 9 is a sectional view taken along line  9 — 9  in FIG.  7 . 
     FIG. 10 is a back elevational view of the pad shell shown in FIG.  7 . 
     FIG. 10 is a top view of the pad shell shown in FIG.  7 . 
     FIG. 11 is an exploded fragmentary view illustrating the manner in which the pad unit, adjacent the lower end thereof, attaches to the back shell. 
     FIG. 12 is a perspective view of a chair similar to FIG. 2 but illustrating a variation of the pad unit mounted on the back shell. 
     FIG. 13 is a front view of the pad unit of FIG. 12 but s own detached from the chair. 
     FIG. 14 is an enlarged fragmentary sectional view taken generally along line  14 — 14  in FIG.  12 . 
     FIG. 15 is a front elevational view of the pad shell associated with the pad unit shown in FIGS. 12-14. 
     FIG. 16 is a top view of the pad shell shown in FIG. 15 
     FIG. 17 is a sectional view taken along line  17 — 17  in FIG.  15 . 
     FIG. 18 is a back elevational view of the pad shell shown in FIG.  15 . 
    
    
     Certain terminology will be used in the following description for convenience in reference only, and will not be limiting. For example, the words “upwardly”, “downwardly”, “rightwardly” and “leftwardly” will refer to directions as appearing in the drawings, and will also refer to the same directions with respect to an occupant seated in the chair. The words “front” and “rear” will refer to directions with respect to an occupant seated in the chair. The words “inwardly” and “outwardly” will refer to the geometric center of the chair and designated parts thereof. Said terminology will include the words specifically mentioned, derivatives thereof, and words of similar import. 
     DETAILED DESCRIPTION 
     Referring to FIG. 1, there is illustrated a chair  11  of the type conventionally used in offices and the like. The chair  11  includes a seat  12  which projects forwardly from an upwardly projecting back  13 . A pair of arm rest assemblies  14  are movably supported on uprights  16  which project upwardly from adjacent opposite sides of the seat  12 . A conventional chair control arrangement (not shown), which typically defines a generally horizontal tilt axis, connects the seat  12  to the upper end of an upright pedestal  18 , the latter typically having a height adjusting air spring associated therewith. The pedestal  18  at its lower end couples to a conventional base  19 , the latter typically having a plurality of radially outwardly projecting legs provided with casters adjacent the outer ends thereof. 
     The back  13  in the illustrated chair  11  is defined principally by a monolithic one-piece back member or shell  21  which is typically formed of a synthetic resin material such as a plastics material. This one-piece back member  21  includes a main upright panel  22  which defines the dominant horizontal and vertical extent of the chair back for supportive engagement with the back of a seated occupant. The main panel  22  extends vertically from an upper edge  23  downwardly to a lower edge which is typically disposed in the vicinity of the rear edge of the seat  12 , and also extends horizontally between opposite side edges  24 . The back shell  21  in the illustrated chair also includes mounting sleeves  26  which are fixedly joined to and project outwardly from opposite sides of the main panel  22  for coupling, and more specifically slidably supporting, the back member  21  to the arm uprights  16 . A suitable latching mechanism is preferably provided for cooperation between the mounting sleeves and the arm uprights to permit height adjustment of the back member. 
     The construction of the chair  11  is described in grater detail in copending application Ser. No. 10/267,422, filed on Sep. 11, 2003, as owned by the assignee hereof and entitled “HEIGHT-ADJUSTABLE CHAIR BACK” (Atty. Ref. FSFG Case 21). The disclosure of this latter copending application is incorprated herein by reference. 
     According to the present invention, there is provided a preassembled pad unit  31  (FIGS. 2-6) which can be optionally mounted on the back shell  21  to provide the chair back with a more conventional upholstered appearance and feel. 
     The pad unit  31  has its own support panel or shell  32  which is preferably formed as a relatively thin plastic sheet of suitable shape and contour, and which is preferably formed similar to the shape and contour of the chair back shell  21  so that the pad shell  32  can be directly positioned over the front face of the chair back shell  21 . 
     The pad support shell  32  has a thin cushioning layer such as a foam layer  34  overlying the front side  33  and secured thereto as by an adhesive. An outer flexible covering  36  such as a flexible sheet of fabric or vinyl overlies the foam cushion layer  34  to totally enclose the front side of the pad unit. This covering  36  has side edge parts  39  and a lower edge part  41  which wrap around the side and bottom edges of the cushioning layer  34  and support shell  32  so as to overlie and are fixedly secured, as by stapling or the like, to the back surface of the support shell  32 . The flexible covering  36  also has a top portion  42  which wraps around the upper edge of the cushion layer  34  and support shell  32  and projects downwardly behind the back surface of the support shell  32 . This top edge portion or flap  42  of the flexible covering is sufficiently sized so that, when it wraps around the upper edge and overlies the back surface of the support shell, it defines a downwardly opening pocket  43  between the flap  42  and the rear surface of the support shell  32 , which pocket opens upwardly from the lower free edge  44  of the flap. The vertical sides of the folded over flap  42  are secured, as by stitching, to the main front covering panel  37  generally along the vertical sides of the pad unit. 
     The pad shell  32 , as illustrated by FIGS. 7-10, is a one-piece sheetlike member, such as a thin sheet molded of a plastics material, and extends vertically between respective upper and lower edges  51  and  52 , and horizontally between opposite edges  53 . The side edges  53  in the illustrated arrangement include upper side edge portions  54  which project downwardly from the upper edge  51  through a limited distance, and which in the illustrated arrangement are approximately parallel. These upper side edge portions  54  in turn join to lower side edge portions  56  which in the illustrated arrangement taper slightly inwardly in converging relationship with respect to one another as they project downwardly toward the lower edge  52 . 
     The pad shell  32  has a pair of rearwardly and downwardly projecting top securing flanges  57  disposed in spaced relationship along the top edge  51  thereof. A pair of similar opposed side securing flanges  58  are associated with the opposite side edge portions  54  and project rearwardly and inwardly of the panel shell  32  in opposed relationship to one another. The flanges  57  and  58  each cooperate with the back side of the pad shell  32  so as to effectively define a slot for accommodating therein an edge of the chair back shell  21 , as discussed hereinafter. These top and side flanges  57 - 58  are preferably formed as an integral and monolithic part of the shell pad  32 . The flanges  57 - 58  are also positioned so as to be associated with an upper portion of the pad shell  32  such that they are positioned upwardly from the lower free edge  44  of the pocket flap  42  so as to be covered by the pocket flap  42 . 
     The pad shell  32  on the back side thereof, in the vicinity of the lower edge  52 , has a protruding catch structure  69  (FIG. 11) which includes an opening  61  projecting through the shell and defining a clip receptor  62  internally thereof. This catch structure  69  is adapted to project into an opening  63  which is formed through the chair back shell  21  in the vicinity of the lower edge thereof, such as at an elevation generally corresponding to that of the chair seat, and a separate clip member  64  is used to secure the pad shell  32  to the chair back shell  21 . This clip member  64  has an enlarged platelike head  66  provided with a male clip part  67  protruding outwardly from one side thereof, which latter clip part  67  is inserted from the rear side of the chair back shell opening  63  into the clip receptor  62  to create a snug snap-like fit to securely connect the shells.  32  and  21  together. 
     The pad unit  31  defined by the support shell  32 , the intermediate cushioning layer  34  and the outer covering  36  is assembled as a fully integrated unit which can then be selectively and optionally attached in overlying relationship to the front face of a chair back shell  21 , either prior to shipment from the supplier, or retrofitted onto the back shell at the point of use. 
     The attachment of the pad unit  31  to the chair back shell  21  will now be briefly described. 
     The pad unit  31  is positioned adjacent the front face of the chair back shell  21  but is disposed in slightly raised relationship relative to the upper edge of the chair back shell. When so disposed, the pad unit  31  is then slidably moved downwardly along the front face of the chair back shell  21  so as to cause the upper edge of the chair back shell to initially be inserted into the pocket  43  defined by the folded over covering flap  42 . The continued downward movement of the pad unit  31  then causes the side securing flanges  58  to slidably engage around the upper portions of the side edges  24  of the chair back shell  21 , with the downward displacement of the pad unit  31  continuing until the top securing flanges  57  engage with and seat on the upper edge  23  of the chair back shell  21 . With the pad unit  31  properly seated on the chair back shell  21  as determined by engagement of the securing flanges  57  and  58  therewith, the protruding catch  69  associated with the lower part of the pad shell  32  aligns with and can be inserted into the opening  63  formed through the chair back shell  21 . The securing clip member  64  is then positioned adjacent the rear face of the chair back shell  21  and the male clip part  67  is then inserted into the clip receptor  62  to create a snap-like engagement therewith, whereby the lower portion of the pad unit  31  is hence secured to the lower portion of the chair back shell  21 . 
     With the pad unit  31  secured to the chair back shell  21 , substantially as illustrated by FIGS. 2 and 3, the pad unit covers substantially the entirety of the front face of the chair back, and the pad unit also projects downwardly throughout the waist portion of the chair back so that an occupant of the chair can, when leaning rearwardly, experience contact with the cushioned back pad throughout substantially the full vertical extent of the chair back. The pad unit  31  in the illustrated embodiment, however, has the lower portion thereof, namely that portion which extends through the waist portion of the chair back, of lesser width than the chair back so that opposite side waist portions of the chair back, as defined on opposite sides of the waist portion of the pad unit, are visible and hence provide the chair with a different appearance as illustrated in FIG.  2 . Since the pad unit is typically provided with some type of fabric or upholstery material as the outer covering, this configuration of the pad unit and the partial exposure of the chair back in the waist area thereof hence provides greater flexibility with respect to overall aesthetics of the chair. 
     Referring now to FIGS. 12-18, there is illustrated a variation of the preassembled pad unit  71  for a chair back according to the present invention. The preassembled pad unit  71  incorporates therein substantially all of the features associated with the pad unit  31  described above, and hence the parts of the modified pad unit  71  which correspond to the same parts of the pad unit  31  are designated by the same reference numerals, and will not again be described in detail. 
     The modified pad unit includes a main support panel or shell  72  which is also preferably constructed as a thin sheetlike member preferably of a plastics material and includes a main lower panel part  73  which is integrally joined to a smaller upper panel part  74 . The lower panel part  73  is normally sized and shaped so as to substantially identically correspond to the support panel or shell  32  associated with the pad unit  31  as described above. However, the upper panel part is integrally joined to and projects upwardly from the lower panel part  73  so that the support shell  72  hence is of greater vertical extent and terminates at an upper edge  76  as defined on the upper panel part  74 . 
     The upper panel part  74 , in transverse vertical cross section, has a generally forwardly protruding profile  77  which defines a forwardly protruding rounded convex surface on the front side thereof, with this profile  77  defining a rounded concave recess on the rear side thereof. One or more reinforcing ribs  78  extend vertically across the recess defined in the rear of the protruding profile  77  to increase the strength and rigidity of the upper panel part  74 . With the vertical upward extension of the support panel  72  caused by the inclusion of the upper panel part  74 , the pad shell  72  hence has the top securing flanges  57  thereof spaced downwardly from the free upper edge  76 , and in fact these securing flanges  57  are spaced vertically downwardly from the forwardly protruding profile  77  defined by the upper panel part  74 . 
     Since the vertical extent of the pad panel shell  72  is increased by the presence of the upper panel part  74 , the foam cushioning layer  34  is also vertically enlarged so as to overlie the full vertical extent of the front face of the panel member  72  as illustrated in FIG. 14, and the covering layer  36  is also enlarged so as to extend over the entire front face of the pad unit, with the size of the fold-over top flap  42  also being suitably enlarged so that the flap  42  when folded over so as to define the pocket  43  extends downwardly to an elevation at least below the side securing flanges  58 . 
     The modified pad unit  71  is secured to the back shell  21  of the chair in the same manner as described above with respect to the pad unit  31 . However, when the pad unit  71  is secured to the chair, the upper portion thereof as illustrated in FIG. 14 protrudes upwardly a substantial distance above the upper free edge  23  of the chair back shell  21 . The upwardly protruding portion of the pad unit is defined by the upper panel part  74  and the cushioning and fabric layers which extend thereover, and the forwardly protruding rounded profile  77  associated with the upper panel part  74  enables the upper portion of the pad unit  71  to define a head rest for the seated occupant, which head rest is defined above the upper edge  23  of the chair back shell  21 . In this manner the chair having a normal-height chair back shell  21 , by attachment of the pad unit  71  thereto, can be converted into a chair having a higher-height back so as to effectively define a head rest integral with and adjacent the upper portion of the chair back arrangement. 
     The modified pad unit  71 , like the pad unit  31  described above, can be easily fitted to the chair back either at the factory or retrofitted to the chair back at the work site. 
     If removal of the pad unit  31  or  71  from the chair is required for any reason, then the pad unit can be removed from the back shell by first removing the clip member  64 , and thereafter slidably displacing the pad unit upwardly so as to disengage it from the chair back shell. While removal of the clip member  64  may cause some destruction or damage to the clip member, it will be appreciated that the pad unit can be remounted to the chair shell merely by obtaining a replacement clip member  64  if necessary. 
     With the chair pad arrangement of the present invention, the basic chair back shell  21  can be maintained free of openings or perforations, except for the small catch opening  63  provided through the lower portion of the back shell, and hence the overall aesthetics and appearance of the back shell remains clean and unencumbered for desirable usage when the back pad is not mounted thereon, and at the same time the shell accommodates mounting of the back pad without resulting in a significant number of visible fasteners and the like which destroy the appearance or aesthetics of the back shell. 
     Although particular preferred embodiments of the invention have been disclosed in detail for illustrative purposes, it will be recognized that variations or modifications of the disclosed apparatus, including the rearrangement of parts, lie within the scope of the present invention.