Patent Publication Number: US-2005140183-A1

Title: Reclining chair with foot and leg rest

Description:
CONTINUATION DATA  
      This application hereby claims the benefit under Title 35, United States Codes § 119(e) of any U.S. application Ser. No. 60/526,789 filed Dec. 1, 2003, and is hereby incorporated by reference. 
    
    
     BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates to chairs and similar furniture, and, more particularly, to an improved reclinable chair having a foot and leg rest.  
      2. Description of the Related Art  
      Conventional arrangements for actuating movement of leg rests in chairs include a scissor-type mechanism. Notable deficiencies of this scissor-type configuration include multiple bearing points, the lack of a facility to lubricate the scissor links at the joints, and its susceptibility to collapse. Additionally, the mechanism is marked by instability that may cause the user to experience a tendency to be shifted or tilted to one side of the chair or the other. Moreover, a chair incorporating such a mechanism is typically characterized by a side-to-side wobble or other such undesirable movement.  
     SUMMARY OF THE INVENTION  
      According to the present invention there is provided an actuator assembly for use with a chair to actuate movement of the chair leg rest in response to recline of the backrest. The backrest drives translational motion of an actuator rod that is pivotingly connected at its upper end to the backrest. The rod passes through a linear slide bearing block that is pivotingly connected to the rear end of the seat. The rod is connected at its lower end to a linkage mechanism that actuates movement of the leg rest. The pivot point for the slide bearing block is off-center or offset relative to a central location thereof. This offset pivot connection produces an asymmetrical pivoting action in the slide bearing block. The block serves as a moving, floating fulcrum that follows its own independent arc of motion in response to a cam-like frictional urging that takes place as the rod travels through the bearing space formed in the block. Each side of the chair is equipped with an identical arrangement of actuating-related components to provide a stable system.  
      One advantage of the present invention is that the invention replaces the scissor-type mechanism otherwise used in conventional chair arrangements, while improving upon the stability and ease of use of the chair.  
      Another advantage of the present invention is that the invention enables the construction of a highly stable, body balanced recliner.  
      Another advantage of the invention is that the underside of the chair has now been freed of the arrangement of scissor links found in conventional chairs, since the invention employs an actuator assembly configured at the back of the chair.  
      A further advantage of the invention is that the invention employs the backrest as the driver unit to initiate, impart, and otherwise control the recline activity.  
      Another advantage of the invention is that the invention employs an actuator assembly that offers an enhanced mechanical advantage due to the configuration of parts, namely, the use of an actuating rod having a variable-length moment arm that powers displacement of a slide bearing block.  
      Another advantage of the invention is that the slide bearing block is adapted to have an asymmetrical (e.g., offset or off-center) pivot point, such that the block effectively acts as a moving, floating fulcrum that moves forward in response to progressive backrest recline to assist in extension of the leg rest. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of multiple embodiments of the invention taken in conjunction with the accompanying drawings, wherein:  
      FIGS.  1 A-C show respective side views of a chair configured in different illustrative and progressive states of recline and incorporating an apparatus for actuating a foot-leg rest, according to one form of the invention;  
       FIG. 2  shows a perspective rearward view of the chair illustrated in FIGS.  1 A-C;  
       FIG. 3  is a simplified free-body diagram showing in consecutive progressive relationship the position and orientation of the foot and leg rest actuator assembly of FIGS.  1 A-C at different levels of recline;  
      FIGS.  4 A-B show respective side views of a chair configured in different illustrative progressive states of recline and incorporating an apparatus for actuating a foot-leg rest, according to another form of the invention;  
       FIG. 5  shows an exploded view of the chair assembly shown in FIGS.  1  A-C and  FIG. 2 , according to another form of the invention;  
       FIG. 6  is one simplified representative side view of the chair assembly of FIGS.  1  A-C and  FIG. 2  that depicts in sequential detail the manner in which the chair is reconfigured as the reclining motion progresses;  
       FIG. 7  is another simplified, fragmentary representative side view of the chair assembly of FIGS.  1 A-C and  FIG. 2  that depicts in sequential detail the manner in which the chair is reconfigured as the reclining motion progresses;  
       FIG. 8  shows a fragmentary sectional view of an optional locking mechanism for use with the slide bearing block of the invention; and  
       FIG. 9  shows a fragmentary sectional view of an optional hold/clamp mechanism for use with the slide bearing block of the invention. 
    
    
      Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrates at least one preferred embodiment of the invention, in one form, and such exemplifications are not to be construed as limiting the scope of the invention in any manner.  
     DETAILED DESCRIPTION OF THE INVENTION  
      Referring now to the drawings and particularly to FIGS.  1 A-C, there is shown a series of lateral views of a chair  10  incorporating a foot and leg rest actuator assembly (generally illustrated at  12 ), according to one form of the invention. The views depict progressive levels of recline and corresponding extension of the leg rest. In particular, the views depict the cooperating relationship of the parts of actuator assembly  12  and chair  10  (and the corresponding changes in configuration and/or orientation) in different and progressive states of recline.  
      Reference should also be made to  FIG. 2 , which depicts a rear-side perspective view of chair  10 . It should be apparent that the components illustrated in FIGS.  1 A-C are but one set of a pair of matching corresponding configurations each located at respective sides of chair  10 , as shown in  FIG. 2 . In particular, the same assembly of parts as shown in FIGS.  1 A-C are also located in identical manner at the opposite side of chair  10 , as clearly evident in the view of  FIG. 2 .  
      The illustrated chair  10  includes, in conventional form, a seat cushion (seat panel) and seatboard combination  14 , a backrest or panel  16 , and a foot-leg rest or panel  18 .  
      Chair  10  is generally considered a reclinable chair. In particular, as known to those skilled in the art, the general reclining operation of chair  10  involves a user sitting down in chair  10  at seat  14 , and then leaning backwards against a forward portion of backrest  16  to a degree sufficient to reposition leg rest  18  to a desired location amenable to resting the feet and/or legs thereon. The reclining motion actuates movement leg rest  18 . According to the invention, actuator  12  constitutes the mechanism for actuating controlled movement of leg rest  18  in response to (and commensurate with) the reclining activity. Leg rest  18  is capable of movement between a fully retracted position to a fully extended position and to all intermediate points therebetween.  
      The illustrated actuator assembly  12  (and related connecting parts) includes, in combination, a bracket, stanchion, or backrest driver  20 ; a hinge or pivot connection  22 ; a translatable actuating bar or rod  24  (having upper end  26  and lower end  32 ); a pivotable slide block, linear block, and/or bearing block  28 ; a hinge or pivot connection  30 ; a pivot connection  34 ; and a linkage assembly  36 .  
      The illustrated bearing block  28  is a suitable device having an annular passageway formed therethrough to slidingly receive, carry, and otherwise support rod  24  that extends therethrough. Bearing block  28  is pivotingly attached to seat  14  (e.g., the seatboard) by hinge or pivot connection  30 , which is secured to seat  14  in a known manner.  
      According to one preferred aspect of the invention, the attachment point between bearing block  28  and hinge  30  is off-center or offset relative to the center of bearing block  28 . In this manner, bearing block  28  acts as a pivotable floating fulcrum that is capable of movement in its own independent arc during operation. In particular, as discussed further, as rod  24  slides or passes through bearing block  28  during reclining of backrest  16 , the interfering frictional contact or relative sliding motion between rod  24  and bearing block  28  initiates and then continues to impart a cam-like action to bearing block  28  (but without an actual cam device). In response, bearing block  28  undergoes an angular, rotational, and/or arcuate pivoting motion that further actuates extension and relocation of footrest  18 . The off-center hinge point feature of the pivoting fulcrum (i.e., bearing block  28 ) acts to change the center of motion of bearing block  28  to thereby amplify its motion.  
      The illustrated actuating rod  24  is pivotingly connected at the terminus of its upper end  26  to hinged attachment  22  located on operationally fixed bracket support or stanchion  20 . This joint between stanchion  20  and one terminal end of rod  24  constitutes an articulating connection therebetween. Stanchion  20  is fixedly secured to a rear-side portion of backrest  16 . The location of stanchion  20  along the vertical length of backrest  16  may be selectably chosen during assembly to accommodate different types of recline-induced driving activity, namely, to facilitate a different powering or driving influence exerted by backrest  16  on rod  24  (via stanchion  20 ) as the seatback is reclined. Different height levels for stanchion  20  will require different appropriate lengths for elongate rod  24  according to the particular geometry of the assembled interconnections.  
      The illustrated actuating rod  24  is pivotingly connected at the terminus of its lower end  32  to hinged attachment point  34 , which serves to couple actuator  12  to the footrest linkage mechanism  36 . As shown, rod  24  passes through an appropriate passageway formed in the body of bearing block  28 .  
      The illustrated backrest  16  is preferably attached in hinging manner to seat  14  by an appropriate pivoting connection  50  located at a suitable position to facilitate a reclining or pivoting movement of seatback  16  relative to seat  14  about the axis formed through pivoting connection  50  (orthogonal to the drawing).  
      The illustrated linkage mechanism  36  includes, in combination, a leg rest rod  38 ; a vertical bar  40 ; and hinge or pivoting connection  42 . In one form, the entire arrangement of parts constituting mechanism  36  at both sides of chair  10  may be considered a  4 -bar linkage.  
      The illustrated leg rest rod  38  is connected at one end to actuator rod  26  (via articulating pivot connection  36 ) and connected at another end to leg rest  18  (via pivoting connection  42 ). Accordingly, actuator rod  26  and leg rest rod  38  can pivot relative to one another, while leg rest  18  and leg rest rod  38  can pivot relative to one another. As shown, leg rest  18  is also pivotably connected to seat  14  by hinge or pivoting attachment  44 , which is secured to the underside of the seatboard, for example.  
      The illustrated vertical bar  40  depends downwardly from seat  14  at an underside thereof in suspension-type fashion. In particular, vertical bar  40  is pivotably connected at one end to the underside of seat  14  by a suitable hinge or pivoting attachment  46 . Bar  40  is pivotingly secured to leg rest rod  38  at a lower end thereof. In one preferred feature, leg rest rod  38  can be attached to vertical bar  40  at any point along the length of bar  40  (as shown by the various attachment holes). In this manner, the range of elevation or height capable of being reached by leg rest  18  can be adjusted. In effect, the throw-out or degree of extension of leg rest  18  can be adjusted by changes in the connection point between leg rest rod  38  and vertical bar  40  along the length thereof.  
      Referring now to  FIG. 3  in conjunction with FIGS.  1 A-C, there is shown in  FIG. 3  an exaggerated simplified free-body diagram of certain components of chair  10 , actuator assembly  12 , and linkage mechanism  36  to illustrate the motion activity that occurs during operation, namely, seatback recline. In particular,  FIG. 3  progressively depicts, in an illustrative manner, several consecutive arrangements of the indicated components at different levels of recline, namely, as the seatback  16  is reclined relative to seat  14 .  
      For purposes of simplicity, not every element from FIGS.  1 A-C is shown in  FIG. 3 . For example, throughout the several positions, it should be apparent that leg rest  18  remains pivotably connected to seat  14  by a common hinge member. Only the lower end of actuator rod  24  is shown.  
      During operation, as a user seated in chair  10  exerts sufficient rearward force against the forward portion of backrest  16  (e.g., the user leans back), the backrest  16  will begin to pivot relative to seat  14 .  FIG. 1A , for example, may be considered to show a pre-recline state (i.e., backrest  16  fully forward) or an incipient recline condition.  
      As backrest  16  displaces rearwardly, this action induces a linear slide-type translation of actuating rod  24  through slide bearing block  28 . The upper end  26  of actuating rod  24  effectively serves and otherwise constitutes a moment arm whose length changes as backrest  16  progresses through its recline. In particular, the distance between the end of actuating rod  24  (i.e., the terminus located at the hinged attachment to backrest driver  20 ) and an imaginary line through the pivoting fulcrum (i.e., bearing block  28 ) changes during recline, namely, the distance shortens. In effect, the invention provides a moving moment arm that changes in length as the backrest reclines.  
      Referring to  FIG. 3 , the progressive states of extension of leg rest  18  (due to increased recline of backrest  16 ) are accompanied by the illustrated increases in the length of the lower end of actuating rod  24 , which follows from the progressive shortening of the moment arm at the upper end of actuating rod  24 .  
       FIG. 3  also illustratively depicts the range of arcuate pivoting motion of slide block  28  in response to the cam-like driving or urging influence of actuating rod  24  as rod  24  travels through block  28  during recline operation. The arc or curve  60  generally defines a trace of the movement of a center point of slide block  28  as block  28  progressively moves/pivots through the indicated positions. According to another feature of the invention, the asymmetric attachment of slide block  28  to its pivoting connection  30  (i.e., the offset or off-center pivoting relationship) facilitates a type of pivoting movement that pivots block  28  forward and toward the underside of seat  14  in a manner that favorably urges, assists and otherwise produces the action needed to extend leg rest  18 . At the full end of its travel, it may be considered that slide block  28  occupies a generally horizontal position. In some applications, by suitable adjustment of leg rest rod  38  to vertical bar  40 , it may be possible to create a configuration that allows slide block  28  to travel past a horizontal plane.  
       FIG. 1B  shows an intermediate position for the extension of leg rest  18 .  FIG. 1 C  may be considered to correspond to a state of full extension of leg rest  18 , which corresponds to a state of full recline of backrest  16 .  
      Referring again to the operation of chair  10 , once recline has begun and thereafter continues, the shortening of the moment arm (upper end  26  of actuator rod  24 ) causes a corresponding lengthening of the lower end  32  of actuator rod  24 . In turn, the downward translational movement of actuator rod  24  induces a forward and upward displacement of leg rest rod  38 . The horizontal orientation of leg rest rod  38  is maintained by vertical rod  40 , which pivots/swings forward and upward as the leg rest rod  38  is urged forward.  
      The forward displacement of leg rest rod  38  urges leg rest  18  to pivot about hinge attachment  44 , thereby elevating and raising leg rest  18  into a desired position. The recline operation continues until a desired backrest position and/or leg rest position is attained. The opposite series of events occur to withdraw/retract the leg rest and return the backrest to a more forward position, i.e., pivot forward. It should be apparent that the actuating rod  24  may be seen to slidingly reciprocate through slide block  28  as the chair configuration alternates between full recline and a fully upright condition.  
      Referring to FIGS.  4 A-B, there is shown a series of lateral views of a chair  100  incorporating a foot and leg rest actuator assembly (generally illustrated at  120 ), according to another form of the invention. The views depict progressive levels of recline and corresponding extension of the leg rest.  
      Chair  100  and actuator assembly  120  are similar in all substantial respects (operationally, configuration-wise and structurally) to chair  10  and actuator  12 , respectively, of FIGS.  1 A-C and  FIG. 2 . However, chair  100  does not have a pivoting connection between the backrest and seat; the backrest is attached to the chair structure by other suitable means. Additionally, actuator rod  24  is coupled at its upper end to a fixed pivot or fixed bearing block  102 .  
      Referring to  FIG. 5 , there is shown an exploded view of the chair assembly depicted in FIGS.  1 A-C and  FIG. 2 , according to another form of the invention.  
       FIG. 6  shows one simplified representative side view of the chair assembly of FIGS.  1 A-C and  FIG. 2 , which depicts in sequential detail the manner in which the chair is reconfigured as the reclining motion progresses.  
       FIG. 7  is another simplified, fragmentary representative side view of the chair assembly of FIGS.  1 A-C and  FIG. 2 , which depicts in sequential detail the manner in which the chair is reconfigured as the reclining motion progresses.  
      Various optional features may be added. For example, compressible springs  27  may be disposed about the actuator rods  24 , such as at the upper ends between the slide block  28  and pivoting attachment to the backrest  16 .  
      Referring to  FIGS. 8 and 9 , there are shown fragmentary sectional views of optional locking and/or clamping mechanisms applied to the slide bearing block.  FIG. 8  depicts a mechanism  104  having a selectable locking feature that applies a lock to the sliding bearing block  28  by gripping actuator rod  24  to thereby prevent relative movement between the slide block  28  and seatboard  14 , e.g., to prevent further movement of backrest/leg rest once a certain recline position is reached.  FIG. 9  shows a slide block hold/clamp mechanism  104 .  
      A further optional feature involves the use of a mechanism to enable the user to adjust the balance points of the chair. For example, a cam friction lock can be incorporated into the pivot on the backrest where it joins to the seat. This frictional joint, such as a conventional knuckle device, is adapted to provide some degree of resistance at the pivot/hinge connection between the seatboard and backrest. In this manner, a forward-biased resistance is offered that prevents the user from “slamming” back when seating. It may be considered that this feature also allows the user to more readily “tune” adjustment of the recline position.  
      The invention possesses several advantageous features. For example, the invention employs a sliding bearing block that serves as a pivoting fulcrum having an offset or off-center (e.g., asymmetrical) pivot point attachment to the seatboard.  
      Further, the invention employs a separate set of arms (i.e., the pair of actuating rods or bars) that are located anywhere up and down in back (i.e., behind the backrest) to create respective first moment arms that are movable and of variable length. This feature allows the manufacturer to tailor the motion, namely, by adjusting the vertical position of the fixed bearing block or backrest driver where the upper end of the actuating rod terminates. Accordingly, different types of recline-type driving influence/activity can be exerted to induce leg rest extension; for example, fast, slow, or powerful extension of the leg rest. This adjustment of the location of the fixed bearing block or backrest driver is easily accommodated by the appropriate increase or decrease in actuator rod length.  
      Additionally, adjustment of the connection point between the leg rest actuating rod and the vertical bar suspended from underneath the seatboard gives a greater or lesser lift to the footrest, depending upon the point of attachment along the length of the vertical bar. This feature enables variable elevation ranges for the leg rest.  
      In the invention, the backrest triggers and controls recline. In one form, it may be considered that the fixed bearing block on the backrest (e.g., backrest driver) articulates the actuator rod through the slide bearing block located proximal (e.g., intimately near) the bottom of the seatboard. Additionally, it may be considered that the actuator rod articulates and pushes the leg rest rod attached to the rear of the footrest.  
      The invention also provides a body balanced recliner. In particular, the leg rest can power the backrest; no levers are needed to set the degree of recline. By comparison, in conventional chairs, there is typically needed (1) a lever bar adapted to control the chair being moved from a seating to recline position or in between, or (2) a stop latch, catch or pin that is activated to allow the chair to simply move. In the invention, the user can set the balance points so that their body motion controls recline. For example, as the user sits in the chair and leans back to initiate recline and corresponding leg rest extension, the chair is caused to recline in a manner (e.g., fast or slow) and degree (e.g., amount of extension) that is in proportional and commensurate response to their weight, i.e., based upon their upper body mass. As evident from  FIG. 2 , the opposing symmetrical placement of the pair of actuator arrangements at respective sides of the chair provides a very stable configuration. Return of the chair to the vertical or upright position can be simply actuated, for example, by pressing down on the leg rest.  
      The invention may be applicable to any chair article. For example, the invention may be used in a stand-alone chair or a chair that constitutes part of another piece of integrated, compound or sectional furniture, such as a couch or sofa that includes the reclining chair as one of its units.  
      Any suitable materials known to those skilled in the art may be used to fabricate and manufacture the various parts of the chair assembly. For example, the actuating rod may be made of aluminum, steel, wood, or plastic.  
      While this invention has been described as having a preferred design, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.