Patent Publication Number: US-6698831-B2

Title: Adjustable chair

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority from U.S. Provisional Patent Application Serial No. 60/219,747, filed Jul. 20, 2000, which is hereby incorporated by reference. 
    
    
     FIELD OF THE INVENTION 
     The invention relates to an adjustable chair for supporting a person while receiving body-working therapy, particularly back and/or neck massage. 
     BACKGROUND OF THE INVENTION 
     Massage is often performed on a person who sits in a chair so that the person&#39;s back faces the therapist. These types of chairs typically employ a chest rest and a face rest so that the person can sit in a relaxed forward-leaning position during a body working procedure. Examples of such chairs are shown in U.S. Pat. Nos. 4,746,167, 5,401,078, 5,762,402, and 6,065,808. Each of these patents is incorporated here by reference. 
     It is important for body-working chairs to be highly adjustable because of variability in body size and anatomy, and because of variations in the types of procedures that may be carried out. Some chest supporting chairs for massage have insufficient degrees of adjustability to accommodate a wide range of body sizes, positions, and procedures. 
     Another problem with prior chairs is that they require the therapist to work in an awkward, unstable, or unhealthy position. Thus, proper adjustment of the chair is important for the therapist as well as for the massage recipient. 
     Another problem with prior chairs is that sometimes the adjustment mechanisms are overly complex so that it is difficult to figure out how to change the orientation of the chair to suit the particular situation. 
     Another problem with prior chair designs is that some chairs may become unstable when they are adjusted into certain positions. 
     Further, it is desirable to address the problems mentioned above in a chair design that is lightweight and collapsible so that it can be easily transported and stored. 
     SUMMARY OF THE INVENTION 
     The invention provides an adjustable lightweight chair for supporting a person in a position that presents a person&#39;s back for conducting a massage or other type of therapy. The chair has a seat supported by a rear leg framework. A front leg structure has an upper portion. A first transverse axis is defined substantially perpendicular to the upper portion of the front leg structure. A clamp device connects a substantially planar padded chest rest to the front leg structure. The clamp device has a lock position and an unlock position. When the clamp device is in the lock position the chest rest is free to move longitudinally and rotationally relative to the transverse axis. Movement of the chest rest relative to the transverse axis is prevented when the clamp device is in the lock position. 
     In a preferred embodiment of the invention the clamp device is operated between the lock and unlock positions by operating a single cam lever or handle. The handle is symmetrically located along the transverse axis relative to the chest rest. An adjustable face rest is connected to the chest rest. A slide mechanism permits alteration of the distance between the chest rest and the face rest. A second clamp device permits adjustment of the face rest in accordance with U.S. Pat. No. 5,427,436, and U.S. patent application Ser. No. 09/599,290, filed Jun. 21, 2000, each of which is hereby incorporated by reference. 
    
    
     BRIEF DESCRIPTION OF THE FIGURES 
     FIG. 1 is a perspective view of a chair. 
     FIG. 2 is a side view of the chair shown in FIG.  1 . Alternative chair positions are shown in dashed lines. 
     FIG. 3 is a rear view, from the perspective of line  3 — 3  in FIG. 2, of the chest rest shown in FIGS. 1 and 2. 
     FIGS. 4 and 5 are partial cut-away views of the clamp mechanism used to provide adjustability for the chest rest. FIG. 4 shows the clamp mechanism unlocked. FIG. 5 shows the clamp mechanism locked. 
     FIG. 6 is a partial cut-away view of a chest rest clamp illustrating how the clamp locks longitudinal movement. 
     FIG. 7 is a bottom view, from the perspective of line  7 — 7  in FIG. 2, of a detachable knee support according to a preferred embodiment of the invention. 
     FIG. 8 shows a series of three perspective views of a detachable knee rest, illustrating a mechanism for locking the knee rest onto a cross support. 
     FIGS. 9A-C are side views of a chair in setup, partially collapsed, and collapsed positions. 
     FIG. 10 shows an alternate embodiment of the invention connected to an edge of a table. 
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION 
     The invention includes numerous design features that may be combined in different ways to produce lightweight collapsible chairs that are easily adjusted into different positions for different applications. Examples of preferred embodiments of the invention are shown in the figures and described below. 
     FIG. 1 shows a chair including numerous adjustment mechanisms allowing configuration of the chair to be customized for a particular person. Chair  20  is particularly well suited for supporting a person who is receiving massage or other body-working therapy on the back, upper shoulders, or neck. 
     Chair  20  is generally supported by a lightweight primary frame  22 . Frame  22  supports seat  24 , a pair of detachable knee rests  26 , arm rest  28 , chest rest  30 , and face rest  32 . 
     Frame  22  is partially stabilized by front cross support  40 . Front cross support  40  has a central front pivot section  42  that is rigidly connected to diagonal support member  44 . A pair of parallel front leg members  48  extend upward from front cross support  40 . Each of front leg members  48  have an inside slot or groove  50  that engages opposite sides of coupling member  52 . 
     When chair  20  is set up, coupling member  52  is locked in a central location in slots  50 , as shown in FIG.  1 . Manipulation of toggle  53  unlocks coupling member  52  with respect to leg members  48  so that it can slide within slots  50 , thereby allowing chair  20  to be collapsed, as shown in FIGS. 9A-C. 
     A pair of parallel transverse supports  56  connect coupling member  52  to diagonal support member  44 , and to rear cross support  58 . Rear cross support  58  has a rear pivot section  59  that rotates relative to rear leg members  60  when chair  20  is collapsed. A pair of wheels  70  are provided at distal ends of extension members  61  of rear leg members  60 . Wheels  70  are raised above the ground when chair  20  is set up. As shown in FIGS. 10A-C, wheels  70  contact the ground for easy transport when chair  20  is collapsed and leaned forward. When chair  20  is collapsed aperture  72  behind chest rest  30  may be used as a handle to pull the collapsed chair in an orientation that causes the chair to ride stably on wheels  70 . 
     FIG. 2 shows a side view of chair  20 . Arrows and dashed lines are used to illustrate various adjustment mechanisms provided on chair  20 . Rear leg members  60  may be extended by telescoping action so that wheel  70  moves in direction  76  to an extended position as shown in FIG.  2 . 
     Seat  24  may be leveled by moving seat  24  around pivot  79  and securing strut  80  in an appropriate slot. FIG. 2 shows seat  24  in a second adjusted position  82 . 
     Knee rest  26  may be removed by a mechanism described below, so that a person can place their feet on the floor. Knee rest  26  includes two components, namely, pad  84  mounted on top of planar rigid base  86 . 
     Armrest  28  may be rotated in direction  90  to position  92  by manipulating handle  93  to an unlocked position. Once armrest  28  is adjusted to the desired position, further movement is prohibited by manipulating lever  93  to the locked position. 
     Chest rest  30  is free to move longitudinally in direction  94 , and rotationally in direction  96  when lever  100  is in the unlocked position. Accordingly, chest rest  30  may be adjusted to an infinite number of different positions, such as position  102 . 
     Face rest  32  may be moved longitudinally in direction  110 , and rotationally in direction  112 , when lever  116  is in the unlocked position. The face rest adjustment mechanism employed in chair  20 , as shown in FIG. 2, is described in further detail in U.S. Pat. No. 5,427,436, and U.S. patent application Ser. No. 09/599,290, filed Jun. 21, 2000, both of which are hereby incorporated by reference. 
     Extension members  61  telescope from rear leg members  60 , and may be locked into position by operation of push pin  62 . 
     FIGS. 3-6 illustrate details of the clamp mechanism used to provide adjustability for chest rest  30 . Aspects of the chest rest clamp device are generally symmetrical with pairs of components being provided on opposite sides of the chest rest. For simplicity, reference numbers and discussion may be limited to one side of the clamp. The drawings clearly indicate which of the described components have undescribed counterparts, and which components are singular. For example, it will be noted that most of the clamp devices employed in chair  20  are operable by manipulating a single lever or handle. 
     FIG. 3 shows a rear view of chest rest  30 . The adjustable clamp device is secured to rigid base plate  120 . Rod  122  from face rest  32  is secured to base plate  120  through guide  124 . Lever  126  can be manipulated to prevent movement of rod  122  relative to guide  124 . Alternatively, lever  126  can be manipulated to free movement of rod  122  in guide  124 . On the other side of chest rest  30  rod  127  is moveable in guide  128 . A leaf spring (not shown) secures rod  127  in guide  128 . 
     Mounting brackets  130  are bolted onto the face of base plate  120 . Mounting brackets  130  each have a longitudinal slot as shown in FIGS. 1 and 2. Clamp housing  132  contains the clamp device. Aperture  140  is provided in housing  132 . Anti-rotation bar  142  has a portion that protrudes from aperture  140 . 
     FIG. 4 shows details of the chest rest clamp that are contained inside housing  132 . Rod  150  extends through housing  132 . Nuts  152  secure rod  150  relative to mounting brackets  130 . Steel washers  154  and nylon washers  156  are positioned on the outside of mounting brackets  130 . Flanged washers  160  are provided on the insides of mounting brackets  130 . Two pairs of locking discs are arranged with opposing teeth configurations so that engagement and disengagement of each pair of locking discs provides rotational locking, and freedom, respectively. Each pair of discs has an outside locking disc  162  that is rotationally fixed relative to a respective mounting bracket  130  by a tab engaging a slot in bracket  130 . Spring  164  separates outside locking disc  162  from inside locking disc  166  so that the discs are urged apart when lever  100  is in the unlocked position. Cam followers  170  are configured so that movement of lever  100  between unlocked and locked positions causes each inside locking disc  166  to engage and disengage the respective outside locking disc  162 . Movement of cam followers  170  toward outside locking discs  162  causes anti-rotation bars  142  to move from the inside portion of aperture  140  to the outside portion of aperture  140 . In FIGS. 4 and 5 the aperture in housing  132  is shown in dashed lines. FIG. 5 shows the same view of the clamp as shown in FIG. 4 except in the locked position. Lateral movement of anti-rotation bar  142  relative to aperture  140  as the clamp is engaged, can be seen in FIGS. 4 and 5. Anti-rotation bar  142  prevents rotation of cam follower  170  and locking disc  166  relative to housing  132 . 
     FIG. 6 shows locking discs  162  and  166  engaged in solid lines, and disengaged in dashed lines. Movement of the clamp longitudinally relative to mounting brackets  130  is prevented when locking discs  162  and  166  are engaged and applying pressure in opposition to washers  156 ,  154 , and nuts  152 . Alternatively, when the clamp is unlocked, allowing disengagement of locking discs  162  and  166 , the clamp is free to move longitudinally relative to mounting bracket  130 . Nylon washer  156  minimized friction providing smooth adjustability when the clamp is unlocked. The distance between opposing nylon washers  156  on the outside of brackets  130  remains substantially constant through clamp operation so that chest rest  30  can be moved smoothly and squarely. Opposing nuts and washers are adjusted so that the chest rest does not fall or become loose when the clamp is unlocked, however the chest rest is easy to push or pull in a desired direction. 
     FIG. 7 shows the bottom side of knee rest  26  of FIG.  2 . Knee rest  26  has a rigid planar base member  86 . Base member  86  has a hand-sized aperture  180  which may be used to carry the chair when it is collapsed. A pair of flanges  182  are provided on a side of base member  86 . Each flange  182  has a key-hole shaped slot  184  which has a variable width, i.e., a wide-width portion, and a narrow-width portion. FIG. 8 shows how knee rest  26  can be secured to transverse support member  56 . Transverse support member  56  has a pair of T-shaped posts  190  and  192 . T-shaped posts  190  and  192  are dimensioned so that they can be inserted through respective wide-width portions of apertures  184 . Depressible spring biased pin  194  is then pushed down by the solid portion of flange  182  so that flanges  182  can slide in direction  196  until T-shaped posts  190  and  192  are registered with respect to narrow-width portions of slots  184 , and pin  194  reemerges on the outside of flange  182 . Knee rest  26  can be detached from transverse support member  56  by reversing the steps illustrated in FIG.  8 . 
     FIGS. 9A-C illustrate how chair  20  is collapsed. In FIG. 9A chair  20  is set up for use. In FIG. 9B chair  20  is partially collapsed. In FIG. 9C chair  20  is completely collapsed. Chair  20  can be transported by leaning chair  20  forward so that wheels  70  are deployed in contact with the ground. Handle  72 , as shown in FIG. 1, can be used to transport chair  20  by pulling the chair in a forward orientation so that it rolls on wheels  70 . Alternatively, chair  20  may be carried in a sideways orientation by using one of the handles provided in knee rests  26 , as shown in FIG.  7 . 
     FIG. 10 shows an alternate embodiment of the invention. Chest and face rest support apparatus  200  includes adjustable chest rest  202  connected to adjustable face rest  204 . Apparatus  200  is designed to clamp onto an edge of a rigid planar structure such as a tabletop  206 . An adjustable chest rest clamp  210  is essentially the same as described previously and shown in FIGS. 3-6. Face rest  204  employs an adjustable clamp device  212  according to the details described in U.S. Pat. No. 5,427,436, and U.S. patent application Ser. No. 09/599,290, filed Jun. 21, 2000. Apparatus  200  may be used in conjunction with a standard chair (not shown). 
     Although the invention has been disclosed in its preferred forms, the specific embodiments thereof as disclosed and illustrated herein are not to be considered in a limiting sense, because numerous variations are possible. As used herein, singular terms do not preclude the use of more than one of the associated element, and embodiments using more than one of a particular element are within the spirit and scope of the invention. Applicant regards the subject matter of his invention to include all novel and nonobvious combinations and subcombinations of the various elements, features, functions, and/or properties disclosed herein. No single feature, function, element or property of the disclosed embodiments is essential. The following claims define certain combinations and subcombinations of features, functions, elements, and/or properties that are regarded as novel and nonobvious. Other combinations and subcombinations may be claimed through amendment of the present claims or presentation of new claims in this or a related application. Such claims, whether they are broader, narrower, equal, or different in scope to the original claims, also are regarded as included within the subject matter of applicant&#39;s invention.