Patent Publication Number: US-6655732-B1

Title: Multiple position leg rest mechanism for a reclining chair

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates generally to reclining chairs and, more particularly, to a three-position leg rest mechanism for a reclining chair. 
     Traditionally, reclining chairs are equipped with an actuation mechanism which is operatively interconnected between a prefabricated chair frame and a stationary base assembly. The actuation mechanism is typically a combination of various mechanical linkages operable for providing various comfort features such as independent reclining movement of a seat assembly as well as actuation of an extensible leg rest assembly and associated tilting of the chair frame. 
     While many conventional reclining chairs operate satisfactorily, furniture manufacturers are continually striving to develop improved frames and actuation mechanisms for reducing system complexity and smoothness of operation as well as occupant comfort. Furthermore, there is a continuing desire to develop improved fabrication and assembly techniques which will result in reduced costs while promoting increased efficiency and improved product quality. 
     SUMMARY OF THE INVENTION 
     In accordance with the principles of the present invention, an improved leg rest mechanism is disclosed which is more simple and less costly to manufacture, which is more durable and which is easier to maintain than conventional leg rest mechanisms. The improved leg rest mechanism is readily adaptable for use with conventional actuation mechanism 
     In accordance with a preferred embodiment, a reclining chair is provided to include an improved multiple position leg rest mechanism which can be positioned in a retracted position, a first intermediate or partially extended position, a second intermediate position and a fully extended position. 
    
    
     Additional objects, advantages, and features of the present invention will become apparent from the following description taken in conjunction with the accompanying drawings. 
     DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an exploded perspective view of a wall proximity reclining/tilt chair in accordance with the present invention; 
     FIG. 2 is a perspective view of the internal frame of the wall proximity reclining/tilt chair shown in FIG. 1; 
     FIG. 3 is an enlarged prospective view of the actuation mechanism shown in FIG. 2; 
     FIG. 4 is an enlarged prospective view of the improved three-position actuation mechanism shown in FIG. 3; 
     FIG. 5 is an exploded prospective view of the improved three-position actuation mechanism shown in FIG. 4; 
     FIG. 6 is an enlarged prospective view of an alternate embodiment of this improved three-position actuation mechanism shown in FIG. 3; 
     FIG. 7 is an enlarged view of the alternate embodiment of FIG. 6; and 
     FIG. 8 is an enlarged prospective view of the ratchet sector plate shown in FIG.  7 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In accordance with the teachings of the present invention, an improved actuation mechanism for use in single and multi-person articles of furniture (i.e. chairs and sofas or loveseats) is disclosed. A general understanding of the art to which the present invention pertains is disclosed in U.S. Pat. No. 3,325,210, Adjustable Leg Rest Locking Device, and U.S. Pat. No. 5,570,927, Modular Wall Proximity Reclining Chair, which are commonly owned by the assignee of the present invention and the disclosure of which is expressly incorporated by reference herein. As will be described, the pre-assembled actuation mechanism is uniquely suspended in a “fixed” three-pivot-point arrangement from pre-upholstered box-like frame components so as to provide precise mechanical alignment and superior structural rigidity while concomitantly facilitating application of highly efficient fabrication and assembly processes. 
     With reference to FIG. 1, the article of furniture shown is a combination wall proximity recliner and tilt chair, hereinafter referred to wall proximity reclining/tilt chair  10 , which includes a pre-assembled actuation mechanism  12  and various upholstered frame components that can be quickly and simply assembled as a modular seating unit. Such “modular” construction provides a significant advancement over conventional furniture fabrication and assembly techniques since manipulation of heavy and cumbersome “unitized” chair frames during upholstery installation is no longer required. As such, each frame component or frame sub-assembly can be upholstered prior to modular assembly with actuation mechanism  12  so as to improve individual component quality as well as overall system quality and production efficiency. Moreover, since actuation mechanism  12  of the present invention is relatively compact in size, the use of loose upholstered cushions, which is an important feature in marketing various styles of chair, sofa or loveseat furniture, is also possible. It should also be understood, however, that the improvements now incorporated into actuation mechanism  12  are not limited to use with reclining/tilting chair  10 , but rather are applicable for use in virtually any type of single or multi-person article of furniture. As such, the particular structure of the various sub-assemblies and components which, when assembled, define reclining/tilting chair  10  is merely intended to illustrate but one furniture application to which the present invention is applicable. 
     In accordance with the primary design features of the present invention, the various pre-assembled and upholstered frame components provided for operably suspending actuation mechanism  12  within reclining/tilt chair  10  will now be described. FIG. 2 shows the various pre-assembled frame components with their upholstery, padding, springs, etc. removed to better illustrate the interdependency of the frame components construction which can be rapidly and rigidly assembled in a relative easy and efficient manner. As such, all of the frame components can be individually fabricated or sub-assembled to include the requisite brackets, springs, padding and upholstery on an “off-line” batch-type basis. Thereafter, the various pre-assembled and upholstered frame components are assembled for totally integrating actuation mechanism  12  therein. As noted, while the disclosure is primarily directed hereinafter to wall proximity reclining/tilt chair  10 , it will be appreciated that the novel modular construction and method of assembly taught by the present invention can be readily incorporated into wall proximity sofas, loveseats and the like. 
     As best seen in FIG. 2, actuation mechanism  12  of wall proximity reclining/tilt chair  10  is integrated into and operably suspended from chair frame  20  and, in particular, from left and right side frame assemblies  24 . In addition to side frame assemblies  24 , chair  10  also includes a front rail assembly  26  and a rear rail  28  which, when interconnected, define a rigid “box-like” chair frame. Preferably, most of the structural frame components such as side frame assemblies  24 , front rail assembly  26 , and rear rail  28 , are each constructed in a manner which enables them to support springs, padding, upholstery, etc. in order to complete a decorative and stylish reclining/tilt chair  10 . As previously noted, each frame component is individually pre-assembled for subsequent modular assembly into wall proximity reclining/tilt chair  10 . However, it is to be understood that the specific construction shown for each frame component is merely exemplary in nature. 
     With reference to FIGS. 2 and 3, actuation mechanism  12  is shown to include a drive rod  30  and front support shaft  32 , both of which are spatially oriented to be precisely located and “suspended” from left and right side frame assemblies  24 . In the preferred construction, drive rod  30  is an elongated square shaft having a manually-operable handle  38  (shown in FIG. 1) secured thereto adjacent an upholstered exterior portion of one of side frame assemblies  24  and which can be easily reached by a person seated in chair  10  for convenient actuation thereof. In addition, leg rest assembly  16  as shown in FIG. 1, is supported for extensible movement on actuation mechanism  12 . More specifically, leg rest assembly  16  includes left and right pantograph linkages  34  and a spring-assisted toggle assembly  36  which are operably associated with drive rod  30  and front support shaft  32  for permitting the seat occupant to selectively actuate leg rest assembly  16  in response to rotation of drive rod  30  via the handle. 
     Leg rest assembly  16  is supported and moved by identical left and right hand pantograph linkages  34 . Conventional pantograph linkages  34  are operably suspended about the second set of “fixed” suspension points defined by support shaft  32 . The extensible action of leg rest assembly  16  takes place simultaneously for both the left hand and right hand pantograph linkages  34  when there is sufficient angular rotation of drive rod  30  via handle  38 . With reference to FIG. 3, an exemplary construction for spring-assist toggle assembly  36  is shown which works coactively with leg rest pantograph linkages  34  for securely holding leg rest assembly  16  in a fully retracted position against front rail assembly  26 . Toggle assembly  36  is also operable to supply a spring force for biasingly urging leg rest assembly  16  toward one of its extended and retracted positions. Further details concerning the pantograph linkages  34  and toggle assembly  36  can be found in U.S. Pat. No. 5,570,927, the disclosure of which has been expressly incorporated by references herein. 
     According to the particular embodiment shown in FIGS. 4 and 5, a ratchet-type detent mechanism  40  interconnects drive rod  30  and support shaft  32  for providing various locked positions for leg rest assembly  16  between its “stowed” or retracted and “extended” positions. Generally, detent mechanism  40  provides three distinct locking positions for leg rest assembly  16  that can be established independent of the reclined/tilted position of chair  10 . 
     Detent mechanism  40  includes a sector assembly  44  having a square aperture  46  formed therethrough to receive drive rod  30  so as to be supported for rotation thereon. An incline link  42  extends generally between drive rod  30  and front support shaft  32  in a manner as hereinafter described. Sector assembly  44  includes a pair of sector plates  48  having an arcuate peripheral edge  50  defining a first cam  52 , a pair of locking recesses  54   a ,  54   b , a second cam  55  and an aperture  56  formed therethrough. Sector assembly  44  further includes a spacer plate  58  interposed between the pair of sector plates  48 . A pivot pin  60  extends through the rearward end of incline link  42  and is received in apertures  56  such that the sector plates  48  are pivotally supported on the incline link  42 . A L-shaped guideway  62  having a longitudinal leg  62   l  at a transverse leg  62   t  is formed in incline link  42  forward of pivot pin  60  and receives a floating detent pin  64 . 
     When assembled, as best seen in FIG. 4, the sector assembly  44  is supported for rotation therewith on the drive rod  30  and the incline link  42  is pivotally coupled to the sector assembly  44  through pivot pin  60 . The floating detent pin  64  engages the arcuate peripheral edge  50  of the sector plates  48 . A biasing mechanism or pair of tensioning springs  66  extend between pivot pin  60  and detent pin  64  to bias the detent pin  64  rearwardly towards the pivot pin  60 . 
     The forward end of incline link  42  has an aperture  68  formed therethrough. A wire hanger element  70  extends from front support shaft  32  and has a free end which is received in aperture  68  of incline link  42 . A position locking element  72  extends through the front support shaft  32  for locating and retaining the wire hanger element  70  on front support shaft  32 . A similar retaining element  74  is utilized to locate and retain the sector assembly  44  on the drive rod  30 . 
     In operation, actuation mechanism  12  and leg rest assembly  16  are in a retracted position and detent pin  64  is positioned into longitudinal leg  62   l  by first cam  52 . When the drive rod  30  is rotated to extend the leg rest assembly  16 , from the retracted position the sector assembly  44  is also rotated causing the detent pin  64  to traverse the peripheral edge  50  of the sector plates  48 . When recess  54   a  is encountered, the tension spring  66  in combination with the longitudinal leg  62   l  permits the detent pin  64  to seat within the recess  54   a . Counter-rotation of the drive rod  30  is resisted such that actuation mechanism  12  is positioned in a first intermediate position which is approximately one-third extended. Further rotation of the drive rod  30  overcomes the biasing force of the tension springs  66  causing the detent pin  64  to ratchet out of recess  54   a  and into recess  54   b . Counter-rotation after drive rod  30  is again resisted such that leg rest assembly  16  is positioned in a second intermediate position which is approximately two-thirds extended. Further rotation of the drive rod  30  moves the detent pin  64  out of recess  54   b  until it engages second cam  55 . In this position, the leg rest assembly  16  is fully extended and second cam  55  urge detent pin  64  forwardly and upwardly into transverse leg  62   t  of L-shaped guideway  62 . In this manner, detent pin  64  is disengaged from the peripheral edge  50  of the sector plates  48  such that counter-rotation of the drive rod  30  is not inhibited by detent pin  64  acting on recesses  54   a,b  formed in the peripheral edge  50 . Counter-rotation of drive rod  30  will return leg rest assembly  16  to its fully retracted position. As leg rest assembly  16  returns to its retracted position, sector assembly  44  rotates relative to incline link  42  and first cam  52  engages detent pin  64  to reset its position into longitudinal leg  62   l . Tension springs  66  urge detent pin  64  rearwardly within guideway  62  into a bias with peripheral edge  50  of sector plates  48 . In this manner, the detent mechanism  40  is reset. 
     From the above description, it will be appreciated that when the detent pin  64  is lockingly biased to one of the recesses  54 , the leg rest assembly  16  is releaseably locked into a corresponding elevated position against inadvertent retraction by the detent mechanism  40 . Furthermore, the leg rest assembly  16  can only be returned to its retracted position from an intermediate position by first fully protracting the leg rest assembly  16 . 
     Detent mechanism  40  is designed to fail prior to any other members of actuation mechanism  12  due to misuse or overloading. Replacement of detent mechanism  40  requires partial disassembly of the chair and removal of drive rod  30 . Thus, an alternate embodiment of detent mechanism  40  is illustrated in FIGS. 6,  7  and  8  which is adapted for use with actuation mechanism  12  and which facilitates replacement of detent mechanism  40  without disassembly of the chair or removal of drive rod  30 . 
     Referring now to FIGS. 6,  7  and  8 , detent mechanism  40 ′ is substantially similar to detent mechanism  40  with modifications relating to the attachment of sector plates  48 ′ to drive rod  30 . More specifically, square aperture  46 ′ of sector plates  48 ′ extends away from the peripheral edge  50 ′ that engages detent pin  64  to form a cut out  76  in sector plates  48 ′. Spacer plate  58  is replaced with a spacer plate  58 ′ to maintain the proper spacing between sector plates  48 ′ and to couple the drive rod  30  to the sector assembly  44 ′. Spacer plate  58 ′ includes locking edges  80  that slidably engage retainer notches  82  of sector plates  48 ′ and retain sector plates  48 ′ on drive rod  30 . Retaining element  74 ′ is used to locate sector assembly  44 ′ on drive rod  30 . Operation of alternate embodiment detent mechanism  40 ′ is substantially similar to operation of detent mechanism  40 . 
     The foregoing discussion discloses and describes exemplary embodiments of the present invention. One skilled in the art will readily recognize from such discussion, and from the accompanying drawings and claims, that various changes, modifications and variations can be made therein without departing from the spirit and scope of the invention as defined in the following claims.