Abstract:
A device and method is presented for adapting existing articulating bedframes to prevent lateral movement of the user while the bedframe is articulated.

Description:
FIELD OF THE INVENTION 
       [0001]    The invention concerns an adaptation for existing articulating bedframes to maintain the user&#39;s lateral head position while changing head elevation. 
       BACKGROUND OF THE INVENTION 
       [0002]    Articulating bedframes, that is, bedframes which allow adjustment of the user&#39;s head position, foot position, or mid-body position, or the angles of such zones relative to the horizontal, have been used for many years. Such bedframes are in common use in hospitals as well as homes. Tilting and repositioning mechanisms for such beds can be either manual or motorized. These mechanisms can also range from the simple to the very complicated, depending on the degree to which various sections of the bed may be set to move in conjunction with each other. 
         [0003]    With less complicated (and usually less expensive) mechanisms, elevation of the user&#39;s head and upper torso is usually accomplished by providing a pivot hinge to allow a section near the head of the bed to tilt upward. However, adjustment of such a section has the undesirable effect of also moving the user&#39;s head laterally at the same time the user is moved vertically. This combined motion means that anytime the user&#39;s position is adjusted, the user will also move relative to stationary objects adjacent the bed, such as lamps, bedtables, telephones, remote controls, etc. Thus, the convenience of being able to reposition one&#39;s head, often at the touch of a button, is offset by the inconvenience of having to either reposition or awkwardly reach for items which the user wants or needs near at hand. 
         [0004]    Various integrated bedframes have been developed to overcome this problem by moving the mattress laterally relative to the bedframe at the same time that the vertical position and tilt of a section is adjusted. With such a mechanism, the user&#39;s head can effectively remain stationary relative to a vertical plane, and thus the problems of access to bedside materials can be overcome. However, such mechanisms can be complex and expensive. Further, such integrated mechanisms do not benefit users with articulating beds of other designs. 
         [0005]    For example, U.S. Pat. No. 6,276,011 to Antinori (“the &#39;011 patent”) discloses an integrated bedframe with a lower frame section welded to slide rails. The slide rails are designed to allow rollers attached to the articulating bed mechanism to move together with the motion of the bed mechanism. A fixed-pivot lever attached to the backrest portion of the bed, in conjunction with the rollers moving down the slides, acts to maintain the horizontal position of the user&#39;s head while the backrest is raised or lowered. 
         [0006]    A further example is U.S. Pat. No. 6,216,295 to Pearson (“the &#39;295 patent”), which discloses a fixed-pivot mechanism to be attached to the backrest portion of an adjustable bed, and a two-part bedframe which uses rollers to allow one portion of the bedframe to move horizontally relative to the other part of the frame. This mechanism also serves to maintain the head in an essentially fixed horizontal position while the backrest is rotated. This function is accomplished by using multiple pivot arms which are rotationally linked to each other. 
         [0007]    Although these articulating beds provide their users with beds that can maintain the user&#39;s head position in an essentially stable lateral position, they do not provide such functionality for existing beds. It is desirable to provide an adaptor for existing articulating bedframes which will efficiently and inexpensively allow the user to reposition the bed without altering the lateral position of his or her head. 
       SUMMARY OF THE INVENTION 
       [0008]    The invention is an adaptor unit which is attachable to existing articulating bedframes. Once attached, when the user adjusts his or her head elevation, the adaptor acts to reposition the articulating bedframe so that the lateral position of the user&#39;s head remains essentially unchanged. Common articulating bedframes typically have a head elevation section, which alters the angle of the user&#39;s head and upper torso relative to the center section, and a foot elevation section, which alters the angle of the user&#39;s legs and feet relative to the center section. The head elevation section is typically pivotally mounted to the center section of the articulating bed 
         [0009]    The invention comprises a sub-frame on which the existing articulating bedframe will be placed. The sub-frame is an essentially rectangular framework comprising two side rails, an end base rail, and a headboard support rail. 
         [0010]    Existing articulating beds are usually mounted on wheels or casters so that they may be easily moved. The side rails of the sub-frame of the invention are spaced apart so that the wheels or casters of the articulating bed can roll on top of the side rails. Guide channels are provided on top of the side rails so that the articulating bed, once attached to the sub-frame, can only move parallel to, and on top of, the side rails. To maintain the ability to readily reposition the entire assembly of sub-frame and articulating bed, the sub-frame is preferably provided with casters to allow it to roll about. 
         [0011]    To control position of the articulating bedframe relative to the sub-frame when the user&#39;s head elevation is changed, a pivoting elevator linkage is provided. The elevator linkage is preferably of fixed length, and pivotally attached to both the sub-frame and the head elevation section of the articulating bed. 
         [0012]    When the position of the head elevation section of the articulating bed is altered (that is, by pivoting it up or down relative to the horizontal), the pivoting action of the elevator linkage forces the articulating bed to move relative to the sub-frame. Because the articulating bed&#39;s wheels are constrained by the guide channels, the articulating be can only move parallel to the side rails of the sub-frame. 
         [0013]    The pivoting action of the elevator linkage thus moves the articulating bed back and forth parallel to the sub-frame in such a way that the user&#39;s head is maintained in an essentially fixed position relative to items adjacent the articulating bed. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]      FIG. 1A  is a schematic side view of one embodiment of the invention. 
           [0015]      FIG. 1B  is a schematic top view of the embodiment of  FIG. 1A . 
           [0016]      FIG. 1C  is a section view of line A-A′ of  FIG. 1A . 
           [0017]      FIG. 2A  is a schematic side view of one embodiment of the invention with a partial bedframe mounted thereon. 
           [0018]      FIG. 2B  is a schematic side view of one embodiment of the invention with an articulating bedframe mounted thereon in a full reclining position. 
           [0019]      FIG. 2C  is a schematic side view of one embodiment of the invention with an articulating bedframe mounted thereon positioned so that the user&#39;s head would be elevated. 
       
    
    
     DETAILED DESCRIPTION 
       [0020]    Referring to  FIGS. 1A ,  1 B, and  1 C, the sub-frame  10  of the invention is shown schematically. Sub-frame  10  is shown first without an articulating bed in place to more clearly illustrate its construction. The sub-frame  10  comprises side rails  12 , a headboard support rail  14 , and a foot rail  16 , which are fastened together. Side rails  12 , headboard support rail  14 , and foot rail  16  may be constructed of square or rectangular extruded metal tubing, and may be fastened together by fasteners such as bolts, by welding, or by other means known to those skilled in the art to provide strength to the overall sub-frame  10 . 
         [0021]    Because the wheels or casters of the articulating bed will roll atop side rails  12 , those of skill in the art will recognize that the spacing between the side rails  12  (for example, the spacing denoted by dimension “d” of  FIG. 1B ) must be set to essentially match the side-to-side wheel spacing of the articulating bed. The sub-frame  10  may be sized to a particular articulating bed, or set of beds, or without departing from the spirit of the invention, the sub-frame  10  may be made so that the spacing “d” between the side rails  12  is adjustable. 
         [0022]    The sub-frame  10  may additionally comprise headboard brackets  20  to allow the attachment of a headboard for appearance or convenience. Preferably, the sub-frame  10  is mounted on wheels or casters  18  to allow relative ease in re-positioning. 
         [0023]    The sub-frame additionally preferably comprises front guide channels  22  and rear guide channels  24  that are used to constrain the rolling of the wheels or casters of the articulating bed (see description of  FIG. 2 , below) to be parallel to, and atop, the side rails  12 . Front and rear guide channels  22 ,  24  provide an essentially U-shaped channel, as shown in  FIG. 1C . The section view of  FIG. 1C  provides an example of an embodiment of one of rear guide channels  24 . Front and rear guide channels  22 ,  24  provide sides  25  which extend upward from side rail  12 . Front and rear guide channels  22 ,  24  may be formed by attaching pre-formed U-shaped stock atop side rails  12 , by attaching individual side plates to either side of side rails  12 , or by other means known to those of skill in the art. 
         [0024]    Those of skill in the art will recognize that front and rear guide channels  22 ,  24  need not be the same width as the side rails  12 . Because front and rear guide channels  22 ,  24  are used to constrain the motion of wheels or casters attached to an articulating bed (as described below), front and rear guide channels  22 ,  24  should be sufficiently narrow to constrain the motion of those wheels or casters so that they remain atop side rails  12 , and sufficiently wide to allow those wheels or casters to roll without binding. 
         [0025]    Further, those skilled in the art will recognize that many variations on such constraints are possible. For example, side rails  12  might be formed with a groove along their top surfaces to provide a channel for the wheels or casters of the articulating bed. Alternatively, guides could be attached to the articulating bed which extend downward from the articulating bed along the sides of side rails  12  in such a way as to prevent the articulating bed from rolling off of the sub-frame  10 . In other words, various means are available to constrain the rolling motion of the articulating bed. 
         [0026]    In a preferred embodiment, sub-frame  10  additionally comprises side support plates  26 . Side support plates  26  comprise connection points  28  to allow additional support and directional constraints for the articulating bed. 
         [0027]    Sub-frame  10  also comprises elevator linkages  30 , which comprise pivotal attach points  31 ,  32 . Elevator linkages  30  are pivotally attached to sub-frame  10  by connectors  34  inserted through pivotal attach points  32 . Those of skill in the art will recognize that a variety of connectors  34  may be used which will provide essentially freely pivoting motion for elevator linkages  30 . 
         [0028]    Referring to  FIG. 2 , specifically  FIG. 2A , a sub-frame  210  is shown schematically with a partial frame for an articulating bed attached thereto, to illustrate the interconnection between the sub-frame  210  and the articulating bed. For clarity, the elevator linkages ( 30  of  FIG. 1  are omitted from  FIG. 2A ) The articulating bed comprises a base frame  236 , which is supported on forward and rearward wheels or casters  244 ,  246 . Forward and rearward wheels or casters  244 ,  246  are fitted into front and rear guide channels  222 ,  224 , respectively, to constrain the rolling of forward and rearward wheels or casters  244 ,  246  to be along the top of sub-frame  210 . 
         [0029]    Additionally, guide  238  is preferably attached to base frame  236  of the articulating bed. Guide  238  comprises guide slot  240 , and is slidably attached to side support plate  226  of the sub-frame  210  by sliding connectors  242  inserted through side support plate  226  and guide slot  240 . Those of skill in the art will recognize that sliding connectors  242  may comprise a variety of materials, such as metal or teflon, and serve primarily to provide a sliding linkage between side support plate  226  and guide  238 . 
         [0030]    Referring now to  FIG. 2B , sub-frame  210  is shown schematically with an articulating bed, denoted generally as  235 , attached in a full reclining position. As in  FIG. 2A , the articulating bed  235  comprises base frame  236 , mounted on forward and rearward rear wheels or casters  244 ,  246 , which are respectively constrained in rolling motion by front and rear guide channels  222 ,  224 . 
         [0031]    Guide  238  is attached to base frame  236  and comprises guide slot  240 , thus allowing a further connection to sub-frame  210  via sliding connectors  242  inserted through side support plate  226  and guide slot  240 . 
         [0032]    Center support  258  is mounted atop base frame  236 , and is also attached to head elevator section  250  and foot elevator section  274 . (Those of skill in the art will recognize that the illustrated configuration is one of a large number of articulating bed configurations which are in use, and that this configuration is shown to illustrate the functioning of the invention. Accordingly, the illustrated configuration is not intended as limiting of the scope of the invention.) Head elevator section  250  pivots relative to center support  258  about a first pivot point  262 , allowing head elevator section  250  to raise and elevate the user&#39;s head and upper torso. Similarly, foot elevator section  274  pivots relative to center support  258  about a second pivot point  272 , allowing foot elevator section  274  to raise and elevate the user&#39;s legs and feet. 
         [0033]    Motion of the head elevator section  250  is accomplished by means of forward motor  254 , which is pivotally attached to center support  258  at forward motor pivot  260  via forward motor arm  256 , and which drives forward extendable arm  248 . Forward extendable arm  248  is pivotally attached to head elevator section  250  at head elevator pivot  252 . Thus, activation of forward motor  254  from the full reclining position shown will cause head elevator section  250  to pivot about first pivot point  262 , driving head elevator pivot  252  along arc D relative to the articulating bed  235 . 
         [0034]    Similarly, motion of the foot elevator section  274  is accomplished by means of rear motor  264 , which is pivotally attached to center support  258  at rear motor pivot  270  via rear motor arm  268 , and which drives rear extendable arm  278 . Rear extendable arm  278  is pivotally attached to foot elevator section  274  at foot elevator pivot  276 . Thus, activation of rear motor  264  from the full reclining position shown will cause foot elevator section  274  to pivot about second pivot point  272 , driving foot elevator pivot  276  along arc E relative to the articulating bed  235 . 
         [0035]    Elevator linkage  230  is pivotally connected to sub-frame  210  at first elevator linkage point  232 , and is also pivotally connected to head elevator section  250  at second elevator linkage point  231 . Those of skill in the art will recognize that the pivotal linkages at first and second elevator points  232 ,  231  will require appropriate hardware, such as spacers, to allow for the inset of the articulating bed  235  from the side of the sub-frame  210 . 
         [0036]    Elevator linkage  230  is preferably of a fixed length, but in any case is pivotally connected between sub-frame  210  and head elevator section  250  so that second elevator linkage point  231  is constrained to move along arc C relative to the sub-frame  210 . Thus, when forward motor  254  is activated to rotate head elevator section  250 , articulating bed  235  must move laterally relative to sub-frame  210  in such a way that second elevator linkage point  231  travels along arc C relative to sub-frame  210 . (Those of skill in the art will recognize that, as reflected in  FIG. 2B , arcs D and E are relative to the articulating bed  235 , and thus travel laterally with it, whereas arc C is relative to sub-frame  210 , and thus remains stationary while the articulating bed  235  traverses laterally relative to sub-frame  210 .) 
         [0037]    As head elevator section  250  rotates and articulating bed  235  moves relative to sub-frame  210 , it is maintained in position above sub-frame  210  because its wheels or casters  244 ,  246  are constrained by front and rear guide channels  222 ,  224 . 
         [0038]    It will be recognized that bedding, including a mattress, will be positioned on top of articulating bed  235 . Such bedding materials have been omitted for clarity in  FIG. 2 . A user reclining on such bedding will be positioned so that his or her head will be at approximately the lateral position of line B of  FIG. 2A , as indicated by outlines of the user&#39;s head  280  and torso  282 . 
         [0039]    Referring to  FIG. 2C , the articulating bed  235  is shown with the head elevator section  250  raised. Motor  254  has been used to extend forward extendable arm  248 , cause head elevator section  250  to pivot upward relative to center support  258 . However, the pivotal connection between elevator linkage  230  and head elevator section  250  at second elevator linkage point  231  requires the articulating bed  235  to shift laterally in the direction indicated by arrow Y from its initial position shown in  FIG. 2B , because second elevator linkage point is constrained to track along arc C. As a result, the wheels or casters  244 ,  246  of the articulating bed  235  roll forward atop sub-frame  210  in forward and rear guide channels  222 ,  224 . 
         [0040]    Guide  238 , attached to articulating bed  235 , has also shifted laterally, causing guide slot  240  to slide forward over sliding connectors  242  inserted through side support plate  226  and guide slot  240 . 
         [0041]    Due to the lateral shift of the articulating bed  235  relative to sub-frame  210  as the head elevator section  250  rotates, the user&#39;s head  280  and torso  282  are maintained in essentially the same position relative to stationary line B. Those of skill in the art will recognize that, as the process is reversed, the lateral shift of articulating bed  235  will also reverse, again maintaining the user&#39;s head  280  and torso  282  in essentially the same lateral position. 
         [0042]    The above examples are included for demonstration purposes only and not as limitations on the scope of the invention. Other variations in the construction of the invention may be made without departing from the spirit of the invention, and those of skill in the art will recognize that these descriptions are provide by way of example only.