Abstract:
An article of seating furniture is provided with a lift mechanism. The article can be a chair with a base and a seat that is pivotally connected to the base. A back is coupled to the seat and may be either fixed to the seat or rotatably coupled to the seat. An actuator is mounted to the base extending towards the rear of the chair. The actuator is pivotally coupled to the base on one end and is pivotally coupled to the seat on the other end. The actuator moves the seat between a generally horizontal position and a raised position. With the back rotatably mounted to the seat, a linkage bar can be added that extends from base front to a bracket that mounts the back to the seat. The linkage bar reclines the back as the seat is raised from horizontal position to the raised position.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation-in-part of prior application number Ser. No. 11/379,665 filed on Apr. 21, 2006. 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not applicable. 
    
    
     BACKGROUND 
     Lift chairs are now well known in the art. These lift chairs extend beyond chairs to all types of seating furniture, including sofas, chairs and sectionals. A lift chair is designed to assist a user both in sitting down in a chair and in getting up from a chair. A wide variety of lift chairs now exist in the marketplace. All of these lift chairs achieve the basic function of raising some portion of the chair to assist the user. Some chairs raise just the arms, while others raise the seat, back and arms together in one unit. People need and use lift chairs for a variety of reasons, most of which relate to the health and strength of the user. 
     While lift chairs currently exist, they suffer certain drawbacks. Most lift chairs utilize relatively complex lifting mechanisms. This complexity leads to increased weight, cost and repair concerns. A relatively simple lift chair mechanism is needed. Additionally, lift chair mechanisms offer limited, if any, flexibility to the manufacturers. If a lift mechanism is used, the chair manufacturer may not have the flexibility needed to configure the lift chair as desired. In some instances, it may be desirable to lift the seat and back together in one unit, maintaining the orientation of the back relative to the seat. In other instances, it may be desirable to position the back more vertically as the seat is lifted. A lift mechanism that offers manufacturers and users the flexibility to configure a lift chair for both instances is needed. Lift chairs also exist that offer a reclining back feature in addition to the lift feature. However, these mechanisms suffer from the complexity concern noted above. A lift mechanism offering a reclining back feature is needed that is simple in construction. 
     Thus, while lift chairs are known, there remains a need for a lift chair and lift chair mechanism that are of relatively simple construction, that offer flexibility in configuration and that can accommodate a reclining back feature, while not limiting the furniture styling. 
     BRIEF SUMMARY OF THE INVENTION 
     Accordingly, the present invention provides an article of seating furniture with a lift mechanism. The article of seating furniture can be a chair with a base and a seat that is pivotally connected to the base. A back is coupled to the seat and may be fixed with respect to the seat in one embodiment and rotatably coupled to the seat in another embodiment. An actuator is mounted to the base, preferably in the middle of the base and extending towards the rear of the chair. The actuator is pivotally coupled to the base on one end and is pivotally coupled to the seat on the other end. In use, the actuator is used to move the seat from a generally horizontal position of normal use, to a raised assisted position that allows the user to more easily exit the chair. In the embodiment where the back is rotatably mounted to the seat, a linkage bar can be added that extends from the front of the base to a lower portion of the bracket that mounts the back to the seat. The linkage bar functions to recline the back as the seat of the chair is raised from the seated position to the assisted position. 
     In yet another embodiment a second actuator can be mounted below the connection point of the first actuator to the seat. This second actuator is coupled on the other end to the back brackets. The second actuator can be used to selectively recline the back from an upright position to a reclined position. 
     In yet another embodiment, a four bar linkage is used to couple the seat to the base. In this embodiment, the seat is not directly pivotally coupled to the base at a single point. Instead, the four bar linkage is used to control the motion of the seat as the actuator of the seat is engaged. The four bar linkage raises the rear of the seat relative to the front of the seat, but also raises the front of the seat relative to the base of the chair. 
     As will be seen from the detailed description that follows, the lift mechanism utilizes fewer working parts than the previous embodiments contained in the prior art. Additional advantages, and novel features of the invention, will be set forth in part in a description which follows and will become apparent to those skilled in the art upon examination of the following, or may be learned by practice of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       In the accompanying drawings which form a part of the specification and which are to be read in conjunction therewith, and in which like reference numerals are used to indicate like parts in the various views: 
         FIG. 1  is a side cross-sectional view of an article of seating furniture with certain parts removed for clarity; 
         FIG. 2  is a view similar to  FIG. 1 , showing the seat in a raised position; 
         FIG. 3  is a partial, enlarged, cross-sectional view taken along the line  3 - 3  of  FIG. 1 ; 
         FIG. 4  is a partial perspective cross-sectional view of the article of  FIG. 1 ; 
         FIG. 5  is a side cross-sectional view of a different embodiment of an article of seating furniture with certain parts removed for clarity; 
         FIG. 6  is a view similar to  FIG. 5 , showing the seat in a raised position; 
         FIG. 7  is a perspective view of the embodiment of  FIG. 5 , again with parts removed for clarity; 
         FIG. 8  is a side cross-sectional view of a different embodiment of an article of seating furniture with certain parts removed for clarity; 
         FIG. 9  is a view similar to  FIG. 8 , showing the back in a reclined position; 
         FIG. 10  is a view similar to  FIG. 8 , showing the seat in a raised position; 
         FIG. 11  is a perspective view of the embodiment of  FIG. 8 , again with parts removed for clarity; 
         FIG. 12  is a perspective view of a different embodiment of an article of seating furniture with certain parts removed for clarity; 
         FIG. 13  is a side elevation view of the embodiment of  FIG. 12 ; 
         FIG. 14  is an enlarged view of the area indicated by circle  14  of  FIG. 13 ; 
         FIG. 15  is a view similar to  FIG. 13 , showing the back in a reclined position; 
         FIG. 16  is a view similar to  FIG. 13 , showing the seat and back in an elevated position; 
         FIG. 17  is an enlarged view of the area indicated by circle  17  of  FIG. 16 ; 
         FIG. 18  is a perspective view of a different embodiment of an article of seating furniture with certain parts removed for clarity; 
         FIG. 19  is a side elevation view of the embodiment of  FIG. 18 ; and 
         FIG. 20  is a view similar to  FIG. 19 , but showing the seat and back in an elevated position. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to the drawings in greater detail and initially to  FIG. 1 , a lift chair  10  is shown and designated generally by the numeral  10 . Chair  10  includes a base  12 , a number of legs  14 , a seat  16  and a back  18 . Chair  10  is shown with certain parts removed, such as the seat fabric, cushioning, etc, for the sake of clarity in the explanation that follows. It should be understood that chair  10 , in use, is a fully-finished chair. The base  12  typically sits on the legs  14  providing the appearance of an ordinary chair. Base  12  includes left and right side panels  20  and front and back panels  22 . Panels  20  and  22  form a frame for attachment of the seat, arms and other components of the finished chair. As best seen in  FIG. 3 , front frame panel  22  can be a two-piece construction, as shown, but could also be a one-piece construction. 
     As best seen in  FIGS. 1-4 , a lift frame bracket  24  is attached to the front panel  22 . Frame bracket  24  has a front section  26  and a side section  28  that transitions to a back section  30 . The front section  26  has a pair of mounting holes  32  (as seen in  FIG. 4 ) that are used to couple the bracket  24  to the front panel  22 . For example, bolts or screws could be used to connect these two elements. Other mounting mechanisms could also be used. The side section  28  also has a number of holes. The upper-most hole  34  is used to couple the bracket  24  and the seat  16 , as is further described below. The lower-most holes  36  are used to couple an articulating link to the back  18 , as will be described below with reference to  FIGS. 5-7 . The back section  30  also has a pair of mounting holes  38  that are used to couple bracket  24  to side panels  20 . Again, bolts, screws or other mounting mechanisms could be used to achieve this end. 
     Seat  16  is supported on chair  10  with a seat frame  40 . Seat frame  40  is preferably made from a sturdy material, such as square steel tubing. It should be understood that other materials with similar characteristics could be used as well. Seat frame  40  is shaped with a perimeter matching that of seat  16 . The front portion of seat frame  40  is pivotally coupled to base  12 . More specifically, the front portion of seat frame  40  is pivotally coupled to side section  28  of bracket  24  using the upper-most hole  34 . This can be achieved with a pin, rivet, or other attaching mechanism that couples the seat frame  40  to the bracket  24  in a manner that allows the seat frame to pivot with respect to the base  12 . As best seen in  FIG. 4 , a seat suspension system is typically provided, such as through the use of sinuous wire springs  42 . The use of springs  42  is well known in the art, as are other suspension methods. The particular manner of support is not of particular importance, and any of the known methods are acceptable. In use, additional padding and covering material would be used, as is clearly understood by those in the art. 
     Returning to  FIG. 1 , a back bracket  44  is mounted on seat frame  40  near the rear of chair  10 . One back bracket  44  is mounted to each side of frame  40 , such that a left and right back bracket are used. In the embodiment shown in  FIGS. 1-4 , the bracket  44  is fixedly coupled to the frame  40 . To achieve this coupling, a pair of mounting holes  46  is located in a middle section of the bracket  44 . Holes  46  are both used in this embodiment to fix bracket  44  in place with respect to frame  40 . The upper section of bracket  44  is fixedly coupled to the seat back  18 . As best seen in  FIG. 4 , back  18  is shown without the usual padding material, upholstery or other covering for the sake of clarity. The lower section of bracket  44  extends below and beside the frame  40 , and will be discussed in more detail with respect to  FIGS. 5-7  below. 
     Returning now to the front of chair  10 , a mounting tube  48  is coupled to the front section of  26  of bracket  24 . The tube  48  can be attached to bracket  24  in any way that provides a long-lasting attachment. Tube  48  extends between brackets  24  and forms a mounting location for a u-shaped yoke  50  as best seen in  FIG. 4 . Yoke  50  is attached to tube  48  such as by weldment, bolts, screws or the like. Yoke  50  has a pair of spaced apart legs  52  with a mounting hole  54  through each leg  52 . Mounting holes  54  are used to pivotally couple an actuator  56  to the yoke  50 . Actuator  56  can be a motorized actuator, as shown, or could be another device that operates to linearly extend a rod  58  or other element from a main body. Gas cylinders and electric actuators are some of the devices suitable for use. The actuator  56  should be capable of moving seat  16  when a person is seated within chair  10 . While not shown, it should be understood that actuator  56  has a corresponding control associated with the chair  10  such that a user of the chair can control the actuator  56 . For example, the control could be physically mounted to the chair  10  in a convenient location, such as on the arm, or could be a control wand arrangement. The end of actuator  56  opposite tube  48  is also coupled to a u-shaped mounting yoke, labeled as  60 , having a pair of mounting holes  62 . Yoke  60  provides a pivotal coupling between actuator  56  and a mounting bridge  64 . A pin or other element is placed through holes  62  and the extending rod from actuator  56  to achieve the pivotal coupling. Yoke  60  is fixedly attached to the mounting bridge  64 . The mounting bridge  64  is, in turn, coupled to the seat frame  40 , extending from one side to the other. As an example, bridge  64  can be welded to seat frame  40 , although other rigid mounting arrangements could be used as well. 
     In use, the chair  10  can be used as a normal chair, as shown in  FIG. 1 . In this position, the chair functions as any other chair. The chair can be moved, by controlling the actuator, to the position shown in  FIG. 2 . In this position, the user of the chair is assisted in exiting the chair. To achieve this position, the user uses the control associated with the actuator  56 . The actuator extends rod  58  to exert an upward force on seat  16 . The pivot mounting of actuator  56  at yokes  50  and  60  allows the actuator to pivot as needed. The seat  16  is allowed to pivot upwardly due to its coupling to bracket  24  at hole  34 . In this embodiment, the back is fixed relative to the seat, such that the back and seat orientation remain the same throughout the motion of the seat. 
     Another embodiment of chair  10  is shown in  FIGS. 5-7 . Many of the components are the same as that described above with respect to  FIGS. 1-4 , as evidenced by the same reference numerals. The embodiment shown in  FIGS. 5-7  adds a linkage bar  66 . Bar  66  is coupled proximate the front of chair  10 . More specifically, bar  66  is pivotally coupled to bracket  24  using one of lower holes  36 . The location at which bar  66  is coupled to bracket  24  determines the motion of back  18 , as is further discussed below. A number of holes  36  are provided to allow the desired motion to be achieved. The opposite end of bar  66  is pivotally coupled to the lower end  68  of back bracket  44  using a hole  70  in the back bracket. As best seen in  FIG. 7 , it is preferable that a linkage bar  66  be provided on each side of chair  10 . 
     The other change in the embodiment shown in  FIGS. 5-7 , compared with that of  FIGS. 1-4 , is that back bracket  44  is rotatably coupled to seat frame  40 . To achieve this coupling, only one hole  46  is used. As shown in  FIGS. 5-7 , only the rear-most hole  46  is used. 
     The addition of bar  66  allows and forces the back  18  to recline, or pivot rearwardly, as the actuator rod  58  is extended. In use, the chair functions as a normal chair when the actuator is not extended, as shown in  FIG. 5 . In this position, a user would notice no difference between the chair of  FIG. 1  and the chair of  FIG. 5 . If the user desires to exit the chair  10  and to have assistance, the user can use the control for the actuator  56  to extend the rod  58 . As the rod  58  extends, the seat  16  is forced upwardly, pivoting about the attachment point at hole  34 . As the seat frame pivots upwardly, bar  66  exerts a rotating force on back bracket  44  (counter-clockwise as viewed in  FIG. 6 ). Back bracket  44  pivots about the attachment point at hole  46 . Because the back  18  is fixedly coupled to back bracket  44 , the back  18  is forced into a reclining motion, pivoting rearwardly away from seat  16 . This allows the back  18  to move away from the occupant as the seat  16  rises. Certain users may find this more comfortable, as the back will allow the user to maintain a different posture when exiting the chair. 
     The addition of bar  66  is a simple operation, and can be done by a manufacturer prior to sale or even in a post-sale, retrofit environment. The coupling of back bracket  44  to seat frame  40  is changed from a fixed coupling to a rotatable coupling, and the bar  66  is pivotally coupled to back bracket  44  and lift frame bracket  24 . In this way, the same basic components can be used to achieve two entirely different motions, based on the desire of the chair manufacturer and chair user. 
     Yet another embodiment of chair  10  is shown in  FIGS. 8-11 . In this embodiment, many of the same components are used, as evidenced by the use of the same reference numerals for the same components described above. In the embodiment of  FIGS. 8-11 , the connection between the actuator  56  and the back  18  is different. A different yoke  72  is attached to mounting bridge  64 . Yoke  72  has holes  74  that are used to pivotally couple the yoke  72  to the actuator  56 . However, yoke  72  also has a pair of depending legs  76 . Legs  76  extend downwardly from bridge  64  and extend toward the front of chair  10 . Each leg  76  has a hole  78  extending through it. A second actuator  80  is coupled between legs  76 , using holes  78 . Actuator  80  extends toward the rear of chair  10 . Actuator  80  can be a gas cylinder or other device that operates to retract and extend a rod  82 . While not shown, the actuator  80  also has a control associated therewith that allows the user to engage the actuator  80  when desired, as is more-fully described below. The rod  82  is attached to a coupling block  84 , which is in turn pivotally coupled to a yoke  86 . Yoke  86  is rigidly coupled between back brackets  88  as is more-fully described below. Bracket  88  differs from bracket  44  in the lower portion. Bracket  88  is fixedly coupled to back  18  and rotatably coupled to seat frame  40 , as in the embodiment shown in  FIGS. 5-7 . Bracket  88  has a mounting leg  90  that extends inwardly from the side of chair  10 . Leg  90  is used to rigidly couple bracket  88  to a cross tube  92 . Cross tube  92  and legs  90  thus serve to connect the brackets  88 . Cross tube  92  serves as the mounting base for the yoke  86 , as best seen in  FIG. 11 . 
     In use, the chair  10  can function as a normal chair, just as the embodiments shown in  FIGS. 1 and 5 . In contrast to the chairs described above with respect to  FIGS. 1-7 , the chair of  FIGS. 8-11  allows the user to recline the back  18  with the user in a seated position, as shown in  FIG. 9 . To recline the back, the user must engage the actuator  80 . Actuator  80  functions to retract rod  82 , which in turn exerts a forward motion on the lower end of bracket  88 . The bracket  88  pivots about the connection point to seat frame  40 , which in turn reclines the back  18 . 
     The chair  10  of  FIGS. 8-11  also allows the user to move the chair to the assist position shown in  FIG. 10 . To achieve this position, the user engages actuator  56 , as with the embodiments of  FIGS. 1-7 . As shown in  FIG. 10 , the user can engage only actuator  56 , in which case the back  18  of chair  10  will remain fixed relative to the seat  16 . The user could also first engage actuator  80 , in which case the back  18  will be reclined relative to seat  16  with the seat in the assisted position. 
     Yet another embodiment of chair  10  is shown in  FIGS. 12-17 . Many of the components are the same as that described above with respect to  FIGS. 8-11 , as evidenced by the same reference numerals. The embodiment shown in  FIGS. 12-17  adds a linkage mechanism  100  to connect the base  12  to the seat  16 , the importance of which will be discussed in greater detail below. 
     Linkage  100  is coupled on one end to lift frame bracket  24 . More specifically, linkage  100  includes a first link  102  and a second link  104 , each having one end pivotally coupled to lift frame bracket  24 . Bracket  24  is slightly different in this embodiment and includes a pair of mounting holes  106  that allow the pivotal coupling of links  102  and  104 . As best seen in  FIG. 14 , a third link  108  is pivotally connected to link  102  on the end opposite bracket  24  as indicated by number  110 . Link  108  is also pivotally coupled on the opposite end to seat frame  40  at pivot point  112 . A third pivotal connection exists between the two ends of link  108  to the second link  104  as indicated at pivot point  114 . Linkage  100  also has a fourth link  116  that is pivotally connected on one end to second link  104 , as indicated by pivot point  118 , and on the other end to seat frame  40 , as indicated by pivot point  120 . As further described below, linkage  100  serves as the connection between the base  12  and the seat frame  40 . Seat frame  40  is not pivotally connected to bracket  24  at its front end, as noted with respect to the embodiment of  FIGS. 1-11 . As best seen in  FIG. 12 , each side of chair  10  has a linkage  100  coupling the base  12  to the seat  16 . 
     The embodiment of  FIGS. 12-17  is shown with a slightly different yoke  122  pivotally connecting the actuator  56  to the bridge  64 . Yoke  122  also serves to pivotally connect the yoke  122  to the second actuator  80 . As with the embodiment shown in  FIGS. 8-11 , actuator  80  is pivotally connected on its opposite end to a yoke  86 , which is in turn coupled to the cross tube  92 . As best seen in  FIG. 15 , the embodiment of  FIGS. 12-17  allows the back of the chair to recline. The position of the back is held in place through actuator  80 . While not shown, it should be understood by those of skill in the art that actuator  80  is provided with a control mechanism that, when engaged, controls the actuator  80  to move the back of the chair. 
     In use, the actuator  56  can be used to lift the seat  16  and back  18 , as best seen in  FIGS. 16 and 17 . Linkage  100  operates to lift and rotate the seat frame  40  as the rod  58  of actuator  56  extends. In contrast with the embodiments described with reference to  FIGS. 1-11 , linkage  100  not only rotates the seat frame  40 , but also lifts the seat frame  40 , including the front end. This arrangement provides more of a vertical lift assist to the chair occupant as compared to the embodiments of  FIGS. 1-11 . 
     Yet another embodiment of chair  10  is shown in  FIGS. 18-20 . Many of the components are the same as that described above with respect to  FIGS. 12-17 , as evidenced by the same reference numerals. The embodiment shown in  FIGS. 18-20  is simplified as compared to that of  FIGS. 12-17 . In the embodiment of  FIGS. 18-20 , the second actuator  80  and cross tube  92  are removed. Additionally, the back brackets  88  are coupled to the frame  40  and are not allowed to rotate. As best seen in  FIG. 19 , back brackets  88  can be secured with two bolts  124  extending through mounting holes  46 . Linkage  100  operates in this embodiment as described above with respect to  FIGS. 12-17 , as can best be seen by comparing  FIGS. 16 and 20 . 
     The present invention has been described in relation to particular embodiments, which are intended in all respects to be illustrative rather than restrictive. Alternative embodiments will become apparent to those skilled in the art to which the present invention pertains without departing from its scope. 
     It will be seen from the foregoing that this invention is one well adapted to attain the ends and objects set forth above, and to attain other advantages, which are obvious and inherent in the device. It will be understood that certain features and sub-combinations are of utility and may be employed without reference to other features and sub-combinations. This is contemplated by and within the scope of the claims. It will be appreciated by persons skilled in the art that the present invention is not limited to what has been particularly shown and described hereinabove. Rather, all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not limiting.