Abstract:
A seating unit comprising a base configured to be positioned on a floor, a torsional energy unit connected to the base, a back connected to the torsional energy unit and a seat rotatably connected to the torsional energy unit. The torsional energy unit biases the back to a forward position. The torsional energy unit further limits angular rotation of the seat between a substantially horizontal seating position and a substantially vertical seating position.

Description:
CROSS REFERENCE TO RELATED APPLICATION  
       [0001]     This application claims priority to U.S. Provisional Patent Application No. 60/579,107, entitled SEATING UNIT, which was filed on Jun. 12, 2004, the entire disclosure of which is incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The present invention concerns a seating unit.  
       BACKGROUND OF THE INVENTION  
       [0003]     Modern chairs often have backs and seats that move upon recline of a person seated in the chairs. More sophisticated chairs include motion control mechanisms to provide sliding and pivoting motions that move in a particular way relative to the seated user so as to provide an optimally comfortable and adjustable chair motion. However, these mechanisms tend to be sophisticated with rigid pivot end slide elements which can result in complex control mechanisms that have many pieces and are difficult to assemble. In turn, the chair becomes expensive. Further, the mechanisms take up space and can become structurally large in size, which is unacceptable for chairs requiring a thin profile or otherwise requiring a clean unobstructed area under their seat. Also, design of these mechanisms is a complex task, with substantial time required to understand and work out competing functional requirements and physical relationships.  
         [0004]     Accordingly, a seating unit with motion control mechanism is desired having the aforementioned advantages and solving the aforementioned problems, including having a relatively small, compact mechanism that is flexible and adaptable for different circumstances, and yet that provides a comfortable motion. Also, a motion control mechanism is desired that is easier to incorporate into chair designs without substantial design time, prototyping, and testing. Moreover, a seating unit that is easy to stack or nestle with another similar seating unit is desired.  
       SUMMARY OF THE INVENTION  
       [0005]     An aspect of the present invention is to provide a seating unit comprising a base configured to be positioned on a floor, a torsional energy unit connected to the base, a back connected to the torsional energy unit and a seat rotatably connected to the torsional energy unit. The torsional energy unit biases the back to a forward position. The torsional energy unit further limits angular rotation of the seat between a substantially horizontal seating position and a substantially vertical seating position.  
         [0006]     Another aspect of the present invention is to provide a seating unit comprising a base configured to be positioned on a floor, a pair of connection devices connected to the base, a back connected to the connection devices and a seat rotatably connected to the connection devices. The connection devices bias the back to a forward position. The connection devices further limit angular rotation of the seat between a substantially horizontal seating position and a substantially vertical seating position. Each connection device allows sides of the back to rotate independently, thereby allowing a first side or a second side of the back to be rotated rearward relative to the other side of the back. The base includes a front area and a rear area, with the front area having a different configuration than the rear area such that a pair of the seating units can be positioned next to each other when the seat is in the vertical stacking position. The seat of a rear one of the seating units abuts the back of a second one of the seating units.  
         [0007]     Yet another aspect of the present invention is to provide a torsional energy unit for a seating unit having a base, a seat and a back. The torsional energy unit comprises a base member configured to the base of the seating unit, with the base including at least one arcuate slot and a notch. The torsional energy unit also includes a torsional spring engaged with the base member and having an end and a pin engaged with the end of the torsional spring and located within the notch of the base member, thereby limiting movement of the end of the torsional spring. The torsional energy unit further includes a rotating member rotatably connected to the base member and connected to the pin, with the rotating member being configured to be connected to the back of the seating unit. The torsional spring biases the rotating member such that the pin will abut a first end of the notch and bias the back to a forward position when the rotating member is connected to the back. The pin abuts a second end of the notch when the rotating member is connected to the back and the back is forced rearward against the bias of the torsional spring to prevent further rearward movement of the back. The at least one arcuate slot is configured to accept a flange of the seat of the seating unit therein for limiting movement of the seat.  
         [0008]     These and other aspects, objects, and features of the present invention will be understood and appreciated by those skilled in the art upon studying the following specification, claims, and appended drawings. 
     
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0009]      FIG. 1  is a perspective view of a seating unit of the present invention.  
         [0010]      FIG. 2  is a side view of the seating unit of the present invention.  
         [0011]      FIG. 3  is a front side view of the seating unit of the present invention with a seat in a vertical position.  
         [0012]      FIG. 4  is a top view of a base and a yoke of the seating unit of the present invention.  
         [0013]      FIG. 5  is an exploded front view of a seat of the seating unit of the present invention.  
         [0014]      FIG. 6  is an exploded view of a connection device of the seating unit of the present invention.  
         [0015]      FIG. 7  is a partial perspective view of the yoke and a first assembly step of the connection device of the seating unit of the present invention.  
         [0016]      FIG. 8  is a partial perspective view of the yoke and a second assembly step of the connection device of the seating unit of the present invention.  
         [0017]      FIG. 9  is a partial perspective view of the yoke and a third assembly step of the connection device of the seating unit of the present invention.  
         [0018]      FIG. 10  is a partial perspective view of the yoke and fourth assembly step of the connection device of the seating unit of the present invention.  
         [0019]      FIG. 11  is an exploded perspective view of the parts of the connection device of the seating unit of the present invention.  
         [0020]      FIG. 12  is a first side partial perspective view of the yoke and fifth assembly step of the connection device of the seating unit of the present invention.  
         [0021]      FIG. 13  is a second side partial perspective view of the yoke and fifth assembly step of the connection device of the seating unit of the present invention.  
         [0022]      FIG. 14  is a perspective view of the seat of the seating unit of the present invention.  
         [0023]      FIG. 15  is an exploded perspective view of a seat support and a base plate of the connection device of the seating unit of the present invention. 
     
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0024]     For purposes of description herein, the terms “upper,” “lower,” “right,” “left,” “rear,” “front,” “vertical,” “horizontal,” and derivatives thereof shall relate to the invention as orientated in  FIG. 1 . However, it is to be understood that the invention may assume various alternative orientations, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification are simply exemplary embodiments of the inventive concepts defined in the appended claims. Hence, specific dimensions and other physical characteristics relating to the embodiments disclosed herein are not to be considered as limiting, unless the claims expressly state otherwise.  
         [0025]     The reference number  10  ( FIGS. 1-3 ) generally designates a seating unit of the present invention. The seating unit  10  includes a base  12 , a seat  14  and a back  16 . The seat  14  and the back  16  are connected to the base  12  by a connection device  18  (see  FIG. 6 ).  
         [0026]     In the illustrated example, the base  12  ( FIGS. 1-4 ) includes a bottom X-shaped support  20  having casters  22  at ends of the bottom X-shaped support  20  for movably supporting the base  12  on a floor. A vertically extending support  24  extends upwardly from the bottom X-shaped support  20 . It is contemplated that the vertically extending support  24  can have a first telescoping section  26  and a second telescoping section  28  as is well known to those skilled in the art, thereby allowing the vertically extending support  24  to be selectively and vertically adjustable. A yoke  30  is connected to the top of the vertically extending support  24 . The yoke  30  includes a pair of end receiving sections  32  (see  FIG. 4 ) configured to be connected to the connecting device  18 . As illustrated in  FIG. 2 , a front portion of the bottom X-shaped support  20  is lower than a rear portion of the bottom X-shaped support  20 , thereby allowing the front portion of the bottom X-shaped support  20  of a first rear seating unit  10  to slide under the rear portion of the bottom X-shaped support  20  of a second front seating unit  10 . It is contemplated that the base  12  could comprise a pair of inverted V-shaped support legs having casters on a lower end thereof and a yoke extending between the top of the inverted V-shaped support legs. Furthermore, it is contemplated that any base having the receiving sections  32  could be used.  
         [0027]     The illustrated seat  14  includes a seat tray  34  and a seat support frame  36 . The seat support frame  36  is connected to the seat tray  34  and supports the seat tray  34 . As discussed in more detail below, the seat support frame  36  is connected to the connection device  18 , which allows the seat tray  34  to rotate between a horizontal seating position ( FIGS. 1 and 2 ) and a vertical stacking position ( FIG. 3 ).  
         [0028]     In the illustrated example, the back  16  includes a seat back  38  ( FIG. 4 ), a right inside connection device cover  40 , a left inside connection device cover  42 , a right outside cover  44  and a left outside cover  46 . As discussed in more detail below, the seat back  38  is connected to the connection device  18 , which biases the seat back  38  forward.  
         [0029]     The illustrated connection device  18  ( FIG. 6 ) rotatably supports the seat  14  for rotation between the horizontal seating position and the vertical stacking position and supports the back  16 . The connection device  18  includes an L-shaped base plate  50  (see  FIG. 7 ) connected to at least one of the end receiving sections  32 . The L-shaped base plate  50  includes a base portion  52  having a pair of fastener holes  54  therein for being connected to the end receiving section  32  of the yoke  30  with fasteners. The L-shaped base plate  50  also includes an upwardly extending support portion  56 . Preferably, the upwardly extending support portion  56  of two L-shaped base plates  50  connected to the yoke  30  are parallel. The upwardly extending support portion  56  of the L-shaped base plate  50  includes a pair of arcuate slots  58 , a top notch  60  and a center opening  62 . The L-shaped base plates  50  are connected to the yoke  30  such that the upwardly extending support portions  56  are facing inward.  
         [0030]     In the illustrated example, the connection device  18  includes an energizer plate  64  (see  FIGS. 6 and 10 ) connected to the L-shaped base plate  50  and biased relative thereto by a torsion spring  66 . The energizer plate  64  is U-shaped and includes a leg portion  68 , an annular back connection portion  70  and a spanning portion  72  connecting the leg portion  68  and the annular back connection portion  70 . The torsion spring  66  is shaped in a spiral and includes an inner end  71  and an outer hook end  74 . Although the torsion spring  66  is illustrated as being a single flat piece of metal or other resilient material shaped into a spiral, it is contemplated that the torsion spring  66  could comprise a plurality of pieces of material shaped into a spiral. The connection device  18  can be constructed by placing the torsion spring  66  adjacent an outside face of the upwardly extending support portion  56  of the L-shaped base plate  50  such that the outer hook end  74  of the torsion spring  66  is generally aligned with the top notch  60  in the upwardly extending support portion  56  of the L-shaped base plate  50  (see  FIGS. 8 and 9 ). Thereafter, a spring anchor  76  is placed into the center of the torsion spring  66 , capturing the inner end  71  of the torsion spring  66  and preventing the torsion spring  66  from rotating as discussed below (see  FIG. 9 ).  
         [0031]     The illustrated energizer plate  64  is placed into the connection device  18  with the spanning portion  72  being located within the outer hook end  74  of the torsion spring  66 , the leg portion  68  being located adjacent the inner side of the upwardly extending support portion  56  of the L-shaped base plate  50  and the annular back connection portion  70  being located adjacent the torsion spring  66  (see  FIG. 10 ). Furthermore, a washer  78  is preferably located between the leg portion  68  of the energizer plate  64  and the inner side of the upwardly extending support portion  56  of the L-shaped base plate  50  (see  FIG. 6 ).  
         [0032]     In the illustrated example, the L-shaped base plate  50 , the torsion spring  66  and the energizer plate  64  are connected by inserting an inside axle  80  having a rectangular inner end  82  through an annular opening  84  in the leg portion  68  of the energizer plate  64 , through an annular opening  33  in the washer  78 , and through the center opening  62  in the upwardly extending support portion  56  of the L-shaped base plate  50  (which is also shown as being rectangular) (see  FIG. 6 ). The spring anchor  76  also preferably includes a rectangular boss  86  that is inserted into the center opening  62  in the upwardly extending support portion  56  of the L-shaped base plate  50 , thereby preventing the spring anchor  76  and the inner end  71  of the torsion spring from rotating. A spring anchor tandem member  90  includes a cylindrical portion  92  that extends through a center opening  88  in the annular back connection portion  70  of the energizer plate  64  and abuts against the spring anchor  76 . It is contemplated that the spring anchor  76  and the spring anchor tandem member  90  could having mating projections (such as the slot  31   a  and opening  31   b  with mating extending members  31   c  shown in  FIG. 11 ) to rotatably lock the spring anchor tandem member  90  with the spring anchor  76 . Finally, a pin  98  is inserted through center openings in the spring anchor tandem member  90 , the spring anchor  76  and therefore the center of the spring  66 , the center opening  62  in the upwardly extending support portion  56  of the L-shaped base plate  50 , the washer  78  and into the inside axle  80  to connect the above elements together.  
         [0033]     The illustrated spring  66  biases the back  16  in an upright position. As illustrated in the figures, the outer hook end  74  of the spring  66  captures the spanning portion  72  of the energizer plate  64  therein. The spring  66  therefore biases the spanning portion  72  towards the front of the seating unit  10 . In other words, the right side spring  66  biases the energizer plate  64  in a clockwise direction and the left side spring  66  biases the energizer plate  64  in a counterclockwise direction (as the left side connection device  18  is a mirror image of the left side connection device  18 ). Furthermore, the energizer plate  64  is configured to rotate on circular surfaces of the spring anchor tandem member  90  (the outside surface of the cylindrical portion  92 ) and the inside axle  80 . The annular back connection portion  70  of the energizer plate  64  is connected to the back  16 .  
         [0034]     In the illustrated example, the seat back  38  of the back  16  includes bottom legs  100  having circular ends  102  (see  FIG. 14 ). The circular ends  102  have a plurality of holes  104  therein. As illustrated in  FIGS. 6, 10  and  12 , the annular back connection portion  70  of the energizer plate  64  also has holes  106  therein. The seat back  38  is connected to the connection device  18  by placing the circular ends  102  of the seat back  38  over an outside of the annular back connection portion  70  of the energizer plate  64  and aligning the holes  104  in the circular ends  102  of the seat back  38  with the holes  106  in the annular back connection portion  70  of the energizer plate  64 . Fasteners  108  (see  FIG. 5 ) are then inserted through the holes  104  and  106  to connect the circular ends  102  of the seat back  38  to the annular back connection portion  70  of the energizer plate  64 . Accordingly, the seat back  38  with be connected to the energizer plate  64  and rotate therewith. Therefore, the spring  66  will bias the seat back  38  in an upright position. In the illustrated embodiment, the right outside cover  44  and the left outside cover  46  are placed over the circular ends  102  of the seat back  38  after the fasteners  108  have been connected thereto.  
         [0035]     The illustrated connection device  18  includes a seat back limiting device for limiting rotation of the seat back  38 . The connection device  18  includes a limiting pin  120  inserted through aligned openings in the leg portion  68  and the annular back connection portion  70  of the energizer plate  64 . The limiting pin  120  is also located in the top notch  60  of the upwardly extending support portion  56  of the L-shaped base plate  50 . The top notch  60  includes a first end  130  and a second end  132  (see  FIG. 7 ). The limiting pin  120  is configured to slide within the top notch  60  between the first end  130  and the second end  132 . As the energizer plate  64  rotates the seat back  38  forward under the bias of the spring  66 , the limiting pin  120  will abut against the first end  130  of the top notch  60 , thereby preventing the seat back  38  from rotating any more forward. Similarly, as a person sits in the seating unit  10  and rotates the seat back  38  backwards against the bias of the spring  66 , the limiting pin  120  will eventually abut against the second end  132  of the top notch  60 , thereby stopping rotation of the seat back  38  rearward.  
         [0036]     In the illustrated example, the seat support frame  36  includes a pivot rod  300  having a pair of circular plates  200  on ends thereof. The circular plates  200  include a central opening  202  and an arcuate flange  204  extending outwardly. The seat support frame  36  is connected to the connection device  18  by inserting the inside axle  80  into the central opening  202  of the circular plates  200  of the seat support frame  36 , thereby allowing the seat support frame  36  to rotate about the inside axle  80 . In the illustrated embodiment, the arcuate flanges  204  of the circular plates  200  of the seat support frame  36  are inserted into one of the arcuate slots  58  in the upwardly extending support portion  56  of the L-shaped base plate  50 . The upwardly extending support portion  56  of the L-shaped base plate  50  preferably includes a pair of arcuate slots  58  such that only one configuration of the L-shaped base plate  50  can be used as mirror images in each side of the yoke  30 , with a pair of arcuate slots  58  being aligned. The arcuate flanges  204  are allowed to slide within the arcuate slots  58  of the extending support portion  56  of the L-shaped base plate  50  between a top end  210  and a bottom end  212  of the arcuate slots  58 . When the arcuate flanges  204  abut the top end  210  of the arcuate slots  58 , the seat support frame  36  is in the vertical stacking position. Moreover, when the arcuate flanges  204  abut the bottom end  212  of the arcuate slots  58 , the seat support frame  36  is in the horizontal seating position. The illustrated pivot rod  300  is not aligned with an axis of rotation of the seat support frame  36 . Furthermore, the left side of the seat back  38  and the right side of the seat back  38  can independently rotate, thereby allowing the left side or right side of the seat back  38  to be rotated backward relative to the other side of the seat back  38 .  
         [0037]     It is to be understood that variations and modifications can be made on the aforementioned structure without departing from the concepts of the present invention, and further it is to be understood that such concepts are intended to be covered by the following claims unless these claims by their language expressly state otherwise.