Abstract:
A chair includes: a hollow frame including, on each lateral side of the chair, a front, a back, a bottom, a front bend arranged between the front and the bottom, and a back bend arranged between the back and the bottom; a seat attached to the front of the frame; a seat back attached to the back of the frame; at least one front stiffener insert arranged inside the frame at the front bend and extending along a partial length of the front and the bottom; and at least one back stiffener insert arranged inside the frame at the back bend and extending along a partial length of the back and the bottom. The front stiffener inserts and the back stiffener inserts stiffen the frame relative to a frame without such inserts. The seat back and the seat may be movable independently of each other relative to the bottom of the frame.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates generally to a chair and a method for forming a chair. More particularly, the present invention relates to a chair which allows a predetermined amount of deflection of a chair frame when a person sits in the chair, based upon stiffener inserts placed inside the frame.  
       BACKGROUND INFORMATION  
       [0002]     Many individuals who use chairs for long periods do not prefer to sit in a totally stiff chair. In response to this, manufacturers have produced adjustable chairs which provide individuals who use them with an added degree of comfort compared to stiff non-adjustable chairs. To accommodate these individuals, the adjustable chairs have numerous fine tuning adjustments. The adjustments can include devices for varying a height of the seating surface, varying the position of a seat back or adjusting the tension spring on a seat back for more or less support when an individual reclines.  
         [0003]     Chairs which use these current seating designs may have to be constantly readjusted to allow an individual to position him/herself to a desired position. This may require a user to dismount the chair and fine tune the chair position to a desired configuration. This fine tuning may lead to further discomfort, and can impact the stability of the chair. As a result, the user must fine tune the chair again to a new setting to overcome these shortcomings. Over time, these chair settings may vary, requiring the user to again reset the chair to a desired configuration. As there is a constant need to fine tune the chair components, most users ignore the shortcomings of the chair configurations and merely use the chair in a non-optimal configuration. Such use in a non-optimal configuration can lead to significant problems such as worker fatigue and/or medical problems.  
         [0004]     Another significant drawback of certain chair designs is that production of chairs which have numerous fine tuning adjustments is a complex procedure, increasing the overall production time and cost of the chair. Moreover, chairs which have numerous parts are more prone to fail, decreasing the overall service life.  
         [0005]     Certain conventional chairs are believed to have a seat and a seat back that are positionally affixed to each other by connecting frame elements and that are cantilevered relative to a bottom support portion of a frame so that the seat and seat back are constrained to move in unison with each other relative to the bottom support portion of the frame, i.e., to the floor. Due to, e.g., ergonomics, user comfort, etc., there is believed to be a need for a chair in which the seat back and the seat are movable independently of each other relative to supporting frame members and to the floor.  
         [0006]     There is believed to be a need for a chair which may provide a user with a supportive seating surface, but which remains flexible when a user shifts position, such as when the user rests against a chair back. There is also believed to be a need to maintain the amount of flexure for the chair such that a user may easily find a comfortable seated position.  
         [0007]     There is believed to be a need for a chair design which may alleviate a user from having to continually finely adjust a chair position to maintain a comfortable configuration over time.  
         [0008]     There is believed to be a further need to provide such a chair that may be inexpensive to manufacture and which may have a long service life.  
       SUMMARY  
       [0009]     In an example embodiment of the present invention, a chair may provide a user with a supportive seating surface, which may remain flexible when a user shifts position, such as when the user rests against a chair back.  
         [0010]     In an example embodiment of the present invention, a chair design may alleviate a user from having to continually finely adjust a chair&#39;s components while maintaining a comfortable seating position.  
         [0011]     An example embodiment of the present invention may provide a durable chair that is inexpensive to manufacture.  
         [0012]     In an example embodiment of a chair according to the present invention, the chair includes a support, a seat attached to the support, a frame attached to the support, the frame having a front, a bottom, and a back, and a seat back connected to the frame. The frame further has at least one front stiffener insert and at least one back stiffener insert, the front inserts and the back inserts configured to structurally stiffen the frame relative to a frame without inserts. The structural stiffening may be configured to provide a predetermined amount of flexibility of the front and/or back relative to each other and/or relative to the bottom and may provide such flexibility of the front independently of the back and vice versa.  
         [0013]     In an example embodiment of the present invention, a chair includes: a hollow frame including, on each lateral side of the chair, a front, a back, a bottom, a front bend arranged between the front and the bottom, and a back bend arranged between the back and the bottom; a seat attached to the front of the frame; a seat back attached to the back of the frame; at least one front stiffener insert arranged inside the frame at the front bend and extending along a partial length of the front and the bottom; and at least one back stiffener insert arranged inside the frame at the back bend and extending along a partial length of the back and the bottom.  
         [0014]     The frame may be tubular.  
         [0015]     The chair may include an arm rest connected to the frame, and the chair may include a grip arranged on an exterior of the arm rest. The grip may be ribbed. The grip may be made of rubber.  
         [0016]     The chair may include glides arranged on the bottom of the frame and configured to provide a contact surface for the chair to a floor. The glides may include a slip resistant surface to contact the floor.  
         [0017]     The chair may include a support connected to the frame and configured to support the seat.  
         [0018]     An inner diameter of the frame and an exterior diameter of the stiffener inserts may be substantially equal.  
         [0019]     The frame may be made of a single member, which may include a tube.  
         [0020]     The back of the frame and the front of the frame may be connected to each other only by the front bend, the bottom and the back bend.  
         [0021]     The front stiffener inserts and back stiffener inserts may be substantially solid.  
         [0022]     The front stiffener inserts and back stiffener inserts may be hollow tubes.  
         [0023]     The back stiffener inserts may have an upright length greater than the front stiffener inserts.  
         [0024]     The back stiffener inserts and the front stiffener inserts may extend in an upright direction an equal amount.  
         [0025]     The front stiffener inserts and the back stiffener inserts may be configured to provide a predetermined degree of stiffness to the frame at the front bends and back bends.  
         [0026]     The seat back and the seat may be movable independently of each other relative to the bottom of the frame.  
         [0027]     In accordance with an example embodiment of the present invention, a chair includes: a hollow frame including, on each lateral side of the chair, a front, a back, a bottom, a front bend arranged between the front and the bottom, and a back bend arranged between the back and the bottom; a seat attached to the front of the frame; a seat back attached to the back of the frame; means for stiffening the frame at the front bend; and means for stiffening the frame at the back bend.  
         [0028]     In accordance with an example embodiment of the present invention, a method for forming a chair includes: inserting a first stiffener insert into each of two hollow tubular members at a first location; inserting a second stiffener insert into each of two hollow tubular members at a second location; after the inserting steps, bending each tubular member and first stiffener insert in an area of the first location and bending each tubular member and second stiffener insert in an area of the second location to form a front, a bottom and a back of each lateral side of a frame of the chair; after the bending step, connecting a seat to the front of the frame; and after the bending step, connecting a seat back to the back of the frame. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0029]      FIG. 1  is a side view of an example embodiment of a chair according to the present invention.  
         [0030]      FIG. 2  is a bottom view of the chair of  FIG. 1 .  
         [0031]      FIG. 3  is a front view of the chair of  FIG. 1 .  
         [0032]      FIG. 4  is a back view of the chair of  FIG. 1 .  
         [0033]      FIG. 5  is a cut-away section of a front stiffener insert of a frame.  
         [0034]      FIG. 6  is a cut-away section of a back stiffener insert of a frame.  
         [0035]      FIG. 7  is a detailed view of an arm rest grip.  
         [0036]      FIG. 8  is a bottom view of an example embodiment of a support for a seat. 
     
    
     DETAILED DESCRIPTION  
       [0037]     Referring to  FIG. 1 , a chair  10  of an example embodiment of the present invention is illustrated. The chair  10  has a frame  12  which is constructed from a member which has sufficient structural load carrying capacity to accommodate a seated individual. In the present embodiment, the frame  12  is configured from a hollow tube, e.g., a structural pipe. The frame  12  may also be configured from structural tube as an additional non-limiting configuration. On each lateral side of the chair  10 , the frame  12  has a back  17 , a bottom  14  and a front  16 . The bottom  14  provides a contact surface which may be used to contact a flooring surface. The front  16  is connected to the bottom  14  a front bend  40 . The front  16  is connected to a support  18 . The front  16  may be angled with respect to the bottom  14  at a front bend  40  to extend back to the support  18 . The angle between the bottom  14  and the front  16  at the front bend  40  may be varied thereby increasing or decreasing the overall seat height of the chair  10  and the inclination of the seat  22  relative to the floor and relative to the remaining components of the chair  10 . As illustrated, the support  18  is connected to a seat  22 . The support  18  is configured to support the weight of an intended user. The support  18  may be made of pipe, as illustrated, or may be constructed from other structural member shapes, such as channels for example. The support  18  may be cantilevered from a connection with the front  16  of the frame  12 . An alternative embodiment allows the connection between the support  18  and the front  16  of the frame  12  to be centrally located to the support  18  such that cantilever spans extend in substantially equal distances from the connection point.  
         [0038]     The back  17  of the frame  12  may be arched from a back bend  38  to the seat back top  36 . The amount of arch between the back bend  38  and the seat back top  36  may be increased or decreased during fabrication of the chair  10 . The amount of arch may be specified to provide greater or reduced lumbar support for a seated individual. The amount of arch may also allow the seat rear  24  to extend past the adjacent portion of the frame  12  such that little or no gap is present between the seat rear  24  and the frame  12  when an individual uses the chair  10 . Alternatively, the back  17  of the frame  12  may be configured such that there is a gap between the seat rear  24  and the back  17  of the frame  12 . The back  17  of the frame  12  is configured to structurally support the seated individual enough to allow the back  17  of the frame  12  to bend a prescribed amount. The amount of bend permitted is controlled such that discomfort of the individual is prevented. The back  17  of the frame  12  may also be a straight design between the back bend  38  and the seat back top  36 . The seat  22  may be configured to move separately from the back  17  of the frame  12  and the seat back  32 , thus the seat  22  may be geometrically configured to avoid contact with the frame  12  which would limit overall movement of the seat  22 . The frame  12  may be configured from, e.g., aluminum pipe, steel, stainless steel, etc. The surface of the frame  12  may be highly polished.  
         [0039]     The seat  22  provides a surface upon which a person may sit on the chair  10 . The seat  22  is connected to the support  18  through seat connection  44 . The seat  22  may be a preformed unit, made of plastic for example, or may be a composite structure. The seat  22  may be covered with a variety of materials, including cloth, leather, etc., to provide a durable and attractive surface for the user. Covers for the seat  22  if used, may be flame retardant and/or stain resistant. If the seat  22  is made of plastic, the surface of the seat  22  may be formed such that slip of the user is resisted, through, for example, texturing the plastic seating surface. The seat  22  is configured with a seat front  20  and a seat rear  24 . The relative positions of the seat front  20  and the seat rear  24  may be altered such that the seating position of the individual may be moved forward or backward relative to the seat back  32 . In the configuration illustrated, the seat rear  24  may be positioned such that an overlap of the seating surface and the seat back surface occurs. The seat front  20  and/or the seat rear  24  may be configured such that the ends are blunt to prevent binding when a users body parts contacts these edges. As illustrated, the seat front  20  and seat rear  24  may be sloped to additionally protect the user from a sharp contact point.  
         [0040]     The seat  22  is configured such that the seat  22  may be moved independently of the seat back  32  relative to the bottom  14  of the frame  12 , i.e., and to the floor. For example, the seat  22  may move independently from the seat back  32  such that when a user leans back onto the seat back  32 , the user may force the seat  22  to move in a forward direction (i.e., a direction away from the seat back  32 ) when relaxing.  
         [0041]     The seat connection  44  may include mechanical arrangements, such as screws, bolts, other arrangements, etc., for example. Other mechanical arrangements may also be used such as rivets or welds. If the seat connection  44  is provided through a screw or bolt, for example, the screw or bolt may be countersunk into the seat connection  44  to limit the possibility of contact between the user and any potentially sharp components of the connection  44 . The seat connection  44  may also be configured to allow for snap insertion of the seat  22  onto the support  18 , thereby allowing the seat  22  to be easily removable.  
         [0042]     An arm rest  28  is connected to the back of the frame  12 , allowing the user to place an arm on the chair  10 . The connection  30  of the arm rest  28  to the frame  12  may be through a welded, bolted or other connection, etc. The arm rest  28  is cantilevered from the back of the frame  12  to provide a clear span under the length of the arm rest  28  allowing greater space for the user on the sides of the chair  10 . The arm rest  28  may be made of a pipe member as illustrated, for example, to provide sufficient structural support. Other structural members may be used, including channels, tubes, etc., as non-limiting examples. In the illustrated example embodiment, the arm rest  28  may be arranged substantially parallel to the seat  22  and the bottom  14  of the frame  12 . The arm rest  28  may be attached such that the arm rest  28  is placed in a non-parallel configuration to either the seat  22  and/or the bottom  14  of the frame  12 .  
         [0043]     The arm rest  28  is provided with a grip  26 . The grip  26  may extend down the entire length of the arm rest  28  or may be positioned along any portion of the arm rest  28 . The grip  26  may be configured such that a comfortable positioning of a users arm is encouraged along the arm rest  28 . The grip  26  may be configured with individual ribs, as illustrated. If configured with ribs, the ribs may be positioned along the entire grip  26  or along sections of the grip  26 . The grip  26  may be made of high density plastic, as another non-limiting example. The grip  26  may also be made of rubber for user comfort. The grip  26  can also be configured as a pair of arm pads connected to the arm rest  28 .  
         [0044]     The frame  12  extends from a back bend  38  to a top  36 . A seat back  32  is positioned on the frame  12  to provide a user with a surface to support the back of an individual when the individual assumes a seated position. The seat back  32  extends from a back bottom  34  to a back top  36 . The seat back  32  may be lengthened or shortened to provide a larger or smaller supporting surface.  
         [0045]     The seat back  32  is connected to the frame  12  through a back connection  48 . The back connection  48  may be established through bolts, screws, other mechanical connections, etc. The back connection  48  may be optionally covered to conceal any sections of the connection  48 . The back connection  48  may also be established by sliding the seat back  32  into channels in the frame  12 . The seat back  32  may be configured with ribs  50  so that a textured surface contacts the seated individual.  
         [0046]     The frame  12  is configured with a back bend  38  and a front bend  40 . A set of glides  46  are positioned on the bottom  14  between the back bends  38  and the front bends  40 . The set of glides  46  provides a contact surface between the chair  10  and the flooring surface. The set of glides  46  may be configured with a slip resistant bottom surface to prevent and/or limit the chair  10  from sliding upon the supporting surface. The set of glides  46  may be attached to the bottom through either a chemical connection, such as gluing, etc., or a mechanical connection, such as a machine screw, etc. The glides  46  may also be configured such that they are adjustable so that a height of the chair may be raised or lowered. The set of glides  46  may be replaced by casters to allow for the chair  10  to roll along the floor surface. The casters may be attached to the chair  10  through inserts placed in the bottom  14 .  
         [0047]      FIG. 2  illustrates a bottom view of the chair  10  illustrated in  FIG. 1 . The seat  22  is supported by a lower support  52  connected to a side support  54 . The lower support  52  is connected to a seat support member  58 . The seat support member  58  may be formed as part of the frame  12 , as illustrated, or may be a separate member. The surfaces of the seat support member  58 , the side support  54  and the lower support  52  contacting the lower surface of the seat  22  may fully contact the seat  22  along the full length of the respective members. Alternatively, selected spots of the respective members may contact to provide support for the seat  22 .  
         [0048]      FIG. 3  is a front view of the chair  10 . The seat back  32  of the chair  10  may be arched such that the upper edge of the seat back  32  is raised in relation to the ends of the seat back  32  which connect with the frame  12 . The back bottom  34  may also be arched such that the ends of the bottom  34 , which connect to the chair  10 , are lower than the center of the bottom  34 . The frame  12  may be configured such that the front bend  40  portion of the frame  12  flares outwardly as compared to the back of the frame  12 .  
         [0049]     Referring to  FIG. 4 , a back view of the chair  10  is illustrated. The seat back  32  is connected to the frame  12  through back connections  48 . Any number of connections may be used to secure the seat back  32  to the frame. The connection  48  may be countersunk into the seat back  32  such that the connections  48  do not protrude past an exterior of the seat back  32 . A back bend  38  is positioned on one end of the bottom  14  of the frame  12 . The seat back  32  may be configured with an additional lumbar support for a seated individual.  
         [0050]      FIG. 5  illustrates the front bend  40  of the frame  12 . A front stiffener insert  60  may be placed in the front bend  40  such that the relative stiffness of the frame  12  is enhanced compared to a non-stiffened frame. The front stiffener insert  60  may have an external diameter which snugly fits into the internal diameter of the front bend  40 . The front stiffener insert  60  may be inserted into the frame  12  before the creation of any bends in the frame, thereby allowing insertion of the front stiffener insert  60  prior to forming a final bent frame structure. The front stiffener insert  60  may be made of any material which provides a stiffer frame when the stiffener insert is positioned in the frame and which provides the desired degree of stiffening. The front stiffener insert  60  may be made of a material which has a relative stiffness greater than the stiffness of the frame  12  into which the stiffener insert  60  is placed. The front stiffener insert  60  may extend any desired length in an upright  62  or horizontal  64  direction, to provide stiffness. The front stiffener insert  60  may have a length in accordance with a desired degree of stiffness or flexibility. The front stiffener insert  60  may be a solid or hollow unit providing a greater of lesser degree of structural stiffness to the frame  12 .  
         [0051]      FIG. 6  is a partial cut-away cross section of the frame  12  in an area of the back bend  38 . A rear stiffener insert  70  is placed in the frame  12  such that it extends from the back of the frame  12  to the bottom  14 . The rear stiffener insert  70  may be configured such that it has a definable horizontal length  68  and an upright length  66 . The rear stiffener insert  70  may have an external perimeter or circumference which allows the stiffener insert  70  to be snugly placed in the frame  12 . The rear stiffener insert  70  may be made of any material which would allow a stiffer frame when the stiffener insert  70  is positioned in the frame  12 . The rear stiffener insert  70  may be made of a material which has a relative stiffness greater than the stiffness of the frame  12  into which the stiffener insert  70  is placed. The rear stiffener insert  70  may extend any desired length in an upright  66  or horizontal  68  direction, to provide stiffness. The stiffener insert  70  may be a solid or hollow unit providing a greater of lesser degree of structural stiffness to the frame  12 . Thus, the rear stiffener insert, by selection of length, height, material properties, etc., may provide a predetermined degree of stiffness or flexibility for the seat back  32  of chair  10 .  
         [0052]      FIG. 7  is a side view of the grip  2  of the chair  10 . The grip  26  may be formed with an exterior end  72  which may be inserted onto the frame portion of the armrest  28 . The grip  26  is configured such that the grip  26  will not rotate or slide along the frame portion of the armrest  28 . The grip  26  may be formed into a first section  82 , a second section  84  and a third section  86 . The first section  82  is configured with a set of ribs  74  which are separated by spaces  76 . The second section  84  is configured with a solid exterior body. The third section  86  is configured with a second set of ribs. An end cap  88  may be formed on the grip  26  such that the frame portion of the armrest  28  contacts the grip  26  to limit further travel. The grip  26  may also be configured as a solid piece, or entirely of ribs.  
         [0053]      FIG. 8  illustrates an example embodiment of the support structure underneath the seat  22  of the chair  10 . The seat support member  58  may have a first member  78  and a second member  80  positioned such that the bottom of the seat  22  is supported only by the first member  78  and the second member  80 . The first and second members  78 ,  80  may extend over the seat support member  58  such that the first and second members  78 ,  80  have substantially equal support lengths over a center line of the seat support member.  
         [0054]     The chair  10  may have a supportive seating surface, while remaining flexible to allow a user to shift position, such as when the user reclines toward a back of the chair  10 . The chair  10  may also provide a design which alleviates a user from having to continually finely adjust a chair while maintaining a comfortable seating position. The chair  10  may be easily manufactured due to minimization of moving parts. The minimization of moving parts may also decrease the cost to produce the chair.  
         [0055]     It should be appreciated from the foregoing description that the seat  22  and the seat back  32  may be moved, e.g., flexed from a rest position due to the flexibility, stiffness and resiliency characteristics of the frame  12 , independently of each other relative to the bottom  14  of the frame  12 , and to the floor.  
         [0056]     The chair  10  may be formed according to a method, which includes inserting the front stiffener insert  60  into each of two hollow tubular members at a location that will be bent to form the front bend  40  and inserting the back stiffener insert  70  into each of the two hollow tubular members at a location that will be bent to become the back bend  38 . After insertion, each tubular member and first stiffener insert  60  is bent and each tubular member and second stiffener insert  70  is bent to form the front  16 , the bottom  14  and the back  17  of each lateral side of the frame  12  of the chair  10 , with front bend  40  and back bend  38  being formed respectively between the front  16  and the bottom  14  and between the back  17  and the bottom  14 . After bending, the seat  22  is connected to the front  16  of the frame  12 , and the seat back  32  is connected to the back  17  of the frame  12 .