Abstract:
A combined wall treatment and bed, that is, a unit which resembles a decorative wall treatment, such as a painting, when in the upright and stowed position, but which can be lowered to provide a comfortable bed. When the unit is in the upright and stowed position its appearance is that of a thin (4½″) wall treatment, the thickness of a large painting, and thus consumes practically no living space. A fixed component can be attached to any standard wall construction without modification; it supports the lower edge of a movable portion and defines an axis about which the movable portion pivots to provide a functional and comfortable bed.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
   This application claims priority from provisional application Ser. No. 60/840,707, filed Aug. 29, 2006. 

   FIELD OF THE INVENTION 
   This present invention relates generally to a combined wall treatment and bed, that is, to a piece of furniture which can be readily converted from a thin, attractive wall treatment to a comfortable bed. 
   BACKGROUND OF THE INVENTION 
   Convertible furniture has long been known as a way to conserve floor and living space while providing temporary sleeping accommodations. It appears that William L. Murphy invented what is commonly known as the “Murphy bed” or the “wall bed” (these terms being used interchangeably herein) in the early 1900&#39;s, and versions of his design are still used today. The basic Murphy bed consists of a bed frame with a standard mattress. The bed frame pivots about an axis at or near the head of the bed from a stowed position in which the frame and mattress are juxtaposed to the wall to a horizontal sleeping position. To assist the user in raising and lowering the bed, these beds generally employ a system of torsion or extension springs to counterbalance the weight. Most of these beds are enclosed in a cabinet-type stationary furnishing enclosure that hides the bed, provides attachment to the floor and/or wall, and provides a structure from which to hinge the bed and the counterbalance system. 
   Although the basic concept of the Murphy or wall bed has not changed a great deal since the early versions, a number of patents listed below show that development has continued in two primary areas: First, since the beds to date are quite heavy many attempts have been made to find improved ways to suspend the weight of the bed as it is pulled down off the wall. Secondly, since the Murphy beds to date are relatively large pieces of furniture, numerous attempts have been made to convert them into more useful furnishings when in a stowed position. 
   The following patents are generally relevant to the subject matter of this invention: 
   U.S. Pat. No. 182,544 Sep. 26, 1876 D. Arnaud 
   U.S. Pat. No. 675,702 Jun. 4, 1901 Adams 
   U.S. Pat. No. 1,015,318 Jan. 23, 1912 Javins 
   U.S. Pat. No. 2,747,202 May 29, 1956 Driver 
   U.S. Pat. No. 3,999,245 Dec. 28, 1976 Bue et al. 
   U.S. Pat. No. 4,694,518 Sep. 22, 1987 Lukich et al 
   U.S. Pat. No. 4,766,623 Aug. 30, 1988 Beilhoffer et al. 
   U.S. Pat. No. 5,036,558 Aug. 6, 1991 Lameka et al. 
   U.S. Pat. No. 5,136,737 Aug. 11, 1992 Reppas 
   U.S. Pat. No. 5,446,932 Sep. 5, 1995 Voorhis 
   U.S. Pat. No. 6,405,392 Jun. 18, 2002 Schwalbe, Jr. 
   U.S. Pat. No. 6,508,526 Jan. 21, 2003 Reppas 
   Since, as noted, the design of Murphy or wall beds has not changed significantly through the years, certain fundamental limitations on the basic design of the Murphy bed, as generally exemplified by one or more of the patents listed above, remain as follows: (1) Existing wall beds still take up a significant amount of floor space, generally between 18″ to 24″ from the wall times the width of the bed, or between 6-8 square feet of living space. This is a substantial loss of valuable space in small apartments, for example. Furthermore, such bulky objects cannot be disguised as an attractive wall treatment, for example. (2) Most existing wall beds require fixation to the floor, leaving scars and holes in precious floor finishes or carpets; that is, the weight of standard wall beds makes it structurally impossible to attach them to standard walls without being supported on the floor or requiring modification of the wall structure. (3) Since the existing wall beds have full mattresses and heavy frames it is difficult to engineer counterbalancing systems to assist the lowering of these beds. (4) Since most of the Murphy style beds are 18-24″ off the wall and encased in a closet or cabinet structure, while lying in bed one&#39;s head is substantially enclosed, giving some a claustrophobic feeling. (5) Since most wall beds are stowed in an armoire/cabinet one needs to open the doors of the cabinet when in a sleep position. This requires space on both sides of the bed into which the doors can be opened. (6) Existing Murphy beds by and large do not have box springs, or if they have a suspension system it is usually a saggy, uncomfortable assembly of wire and springs. (7) Existing Murphy beds do not have a mechanism to slow the rise of the bed as it reaches the vertical, thus creating a situation where fingers could get pinched and the bed could slam against the back of the cabinet. This is especially true since most wall beds are being pulled back vigorously by the counterbalancing mechanism at the top of the pivoting movement. (8) Existing wall beds only rely on the built-in counter balancing system of weights or a spring system to hold the bed in the vertical closed position. If a spring, pulley, or attachment breaks the bed could come down in a dangerous manner. 
   Thus, there remain many deficiencies in the known wall or Murphy beds. 
   SUMMARY OF THE INVENTION 
   The present invention comprises a combined wall treatment and bed, that is, a unit which resembles a decorative wall treatment, such as a painting, when in the upright and stowed position, but which can be lowered to provide a comfortable bed. When the unit is in the upright and stowed position its appearance is that of a thin (typically 4½″) wall treatment, the thickness of a large painting, and thus consumes practically no living space. The unit can be attached to the surface of a wall of any standard construction without modification. A fixed portion of the unit is secured to the wall, supporting its lower edge about one foot off the floor and defining an axis about which the movable portion of the unit pivots to provide a functional and comfortable bed. A pair of legs, which are concealed in an upper frame element, automatically articulate out to support the foot of the bed as it reaches the horizontal position. A planar center member disposed between upper and lower frame elements supports and conceals the sleep system; its façade can be decorated with, e.g., wood, cloth, or painted treatments to taste. An adjustable spring system comprising a torsion spring, gas spring, or other like element for storing energy as the bed is lowered and releasing it as it is raised, supports the unit as it is lowered and holds it against the wall in the upright position. A hydraulic damper, preferably with three adjustable stages, may be provided to dampen motion of the unit as it pivots between upright and lowered position. A thin yet very comfortable bed is provided by a sleep system that utilizes a comfortable hybrid air and foam mattress. An electric air handling system automatically inflates the hybrid air and foam mattress as the bed begins its descent and deflates the mattress as the bed is pivoted to the vertical position, and preferably allows for pressure adjustment after the bed is down. The sleep system also uses thin flexible cambered slats to support the mattress, which take up very little space and provide maximum comfort. 
   More specifically addressing the noted prior art with respect to the advantages provided by the present invention: 
   As noted above, while existing wall beds save a considerable amount of space as compared to the standard beds which they replace, existing wall beds continue to take up considerable and valuable space (18-24 inches off the wall times the width of the bed, or 6 to 8 square feet). This is a lot of space to be consumed where living space is at a premium, i.e., in circumstances where a wall bed would be desired. This has motivated many inventors to combine wall beds with other useful furniture, in order to better utilize living space. For example, U.S. Pat. No. 675,702 issued to Adams Jun. 4, 1901 and U.S. Pat. No. 5,136,737 issued to Reppas Aug. 11, 1992 combine a wall bed and a sofa. U.S. Pat. No. 2,747,202 issued to Driver May 29, 1956 combine a faux fireplace and a folding bed. U.S. Pat. No. 6,508,526 issued also to Reppas Jan. 21, 2003 combines a wall bed with a computer workstation. 
   Similarly, in the early invention of D. Arnaud, U.S. Pat. No. 182,544, Sep. 26, 1876, the bed pivots up to create a deep “wardrobe”. In U.S. Pat. No. 5,036,558, Aug. 6, 1991, Lameka et al. combined his wall bed with an “imitation fire place” to enhance the wall bed furnishing when it is in the stowed position. Beilhoffer et al., in U.S. Pat. No. 4,766,623, issued Aug. 30, 1988, addresses this problem by designing a suspension system which allows the Murphy bed to be installed in a recess in a wall; of course the recess consumes space instead. 
   The concern of the floor space consumed by conventional wall beds even when in the closed position was cited in U.S. Pat. No. 5,446,932 entitled “Folding Wall Bed” issued to Voorhis Sep. 5, 1995. Voorhis attempted to reduce this distance from the wall by pivoting the bed frame off the headboard and creating concealing sideboards that hinge down. However, a requirement remains for enough space from the wall for a headboard, counterbalance mechanism, a full mattress, and the façade. 
   In contrast, the combined wall treatment and bed of the invention is comparatively thin, typically extending only 4½″ or less from the wall when in a stowed position, the same dimension as a large painting. Further, as the slim unit of the invention is secured to the wall, not the floor, the floor space around and under the unit is usable. Accordingly, as in the case of a large painting, one need not navigate around this unit when in the stowed position. 
   As detailed further below, the innovations which allow for the slimness of the combined wall treatment and bed of the invention include a strong, light-weight frame and a sleep system comprising a hybrid foam and air mattress which can be compressed by application of vacuum to approximately 2½″ when in a stowed position and inflated to a comfortable 7″ when in a sleep position. This air mattress lies atop a thin flexible cambered slat system. Legs hidden in the top frame open automatically as the bed comes down to support the foot of the bed from the floor. Another aspect of the design that allows for the slenderness of the unit of the invention is disposition of the counterbalance mechanism, provided to allow the unit to be easily lowered and raised as desired, behind a concealing frame. The counterbalance mechanism preferably comprises a compact assembly of adjustable gas or torsion springs, and an adjustable damper if needed. The bed when closed appears as an attractive wall treatment by covering the frame with a light, thin, durable panel of suitable design; for example, the panel might comprise an attractive material, such as wood veneer, or support a decorative fabric, painting, poster, or the like. 
   As noted, known wall beds are often made to be used as, or to resemble, a large piece of furniture, e.g., a sofa, computer workstation, wardrobe, or cabinet. In contrast, the unit of the present invention is not and does not resemble a conventional piece of furniture; it does not rest on the ground or appear at all like a piece of furniture, nor take up floor or practical living space as would a piece of furniture. In the upright position, the unit of the invention appears as a wall treatment, for example, finished wood or painted wall panels, or a framed painting or tapestry which one can change at will to match the general decor. The top frame, concealing the articulating legs, and the bottom frame, concealing the counterbalance mechanism, damper system, air handling system and leg-articulating mechanism, together frame the center of the wall-treatment, which can be decorated in any way imaginable. Thus when one looks at the unit in its upright and stowed position there is nothing mechanical to give away the fact that the unit also functions as a comfortable bed, and the appearance of the desired wall treatment is in no way compromised. 
   As noted above, the weight of standard wall beds makes it structurally impossible to attach them to standard wall constructions, necessitating that they be supported on the floor, or requiring modification of the wall structure. Securing conventional wall beds to the floor leaves scars and holes in precious floor finishes and carpets. The combined wall treatment and bed of the invention is readily secured to standard wall construction and avoids the scarring of the floor. Walls can much more easily be repaired when moving the unit of the invention than can a floor after movement of the conventional wall beds. 
   Since existing Murphy beds are designed with heavy frames and heavy full mattresses, elaborate counterbalancing mechanisms are typically provided to assist with this weight during raising and lowering of the bed. Several of the patents noted above relate to solving this problem of providing sufficient counterbalance. For example, Beilhoffer et al., in U.S. Pat. No. 4,766,623, Aug. 30, 1988, addressed this problem by assisting tension springs using a water-filled counterweight and extension springs to counter-balance the significant weight of the bed. 
   According to the present invention, the frame is made of light weight materials, and the hybrid air/foam mattress is light in weight, as is the cambered slat system; these expedients all reduce considerably the work that the counterbalance mechanism must do. In one embodiment, fully adjustable torsion springs are utilized as energy storage elements of the counterbalance mechanism. In this embodiment a damper is preferably provided to control the motion of the bed as it is raised and lowered, preventing possible injury and ensuring that the bed does not hit the floor loudly when coming down, nor bang into the wall when being lifted. In another embodiment gas springs are used as the energy storage and damping elements; in this case a separate damper is unneeded. 
   Since numerous of the Murphy beds extend 18-24″ from the wall and are encased in a cabinet or wardrobe, while lying in bed one&#39;s head is inside the cabinet, giving some a claustrophobic feel. This problem is eliminated according to the invention since the unit need not be concealed or housed in a cabinet of any kind. Further, the fact that this wall bed is not encased in a cabinet allows one to clip on side tables, to hold the guest&#39;s necessities. Similarly, because the unit of the invention is not enclosed in a cabinet the sides of the bed are completely open and no space is required to allow cabinet doors to open. 
   Existing wall beds typically use a common rigid surface to support the mattress, or, if they do incorporate a flexible mattress support, a saggy and uncomfortable wire and spring support is usually provided. In contrast, the combined wall treatment and bed of the invention uses state of the art thin flexible cambered slat technology, as used in most modern European sleep systems. The slats flex to follow movement and the pressure contours of one&#39;s body. A combined hybrid inflatable air mattress, preferably including foam in the air bladder with an additional foam topper, provides comfort while being light weight and compactly stored. 
   Existing Murphy beds do not have a mechanism to slow the rise of the bed as it reaches the vertical stored position, thus creating a situation where fingers could get pinched and the bed could slam against the back of the cabinet. This is especially true since most wall beds are being pulled back vigorously by the counterbalancing mechanism at the top of the pivot arc. The unit of the present invention can be provided with a damper, for example a hydraulic rotary damper, to control the rate of pivoting as the unit rotates toward the vertical stowed position. If gas springs are used as the energy storage element they provide the damping function. This provides a great deal of safety in contrast to existing wall beds, which typically rely on a built-in counter-balancing system comprising sash-type vertically sliding weights or a spring system. If a spring, pulley, or attachment breaks the bed could come down in a dangerous manner. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will be better understood if reference is made to the accompanying drawings, in which: 
       FIG. 1  is a perspective view of the present invention of the combined wall treatment and bed of the present invention in a vertical stowed position; 
       FIG. 2  is a perspective view of the combined wall treatment and bed of the present invention as the bed is being lowered from a vertical stowed position; 
       FIG. 3  is a perspective view of the combined wall treatment and bed of the present invention in the lowered or sleep position with the mattress inflated, and with side tables attached; 
       FIG. 4  is an elevational view of the bed frame in the vertical stowed position, with the outer façade removed showing the frame, hinge plate with leg articulating mechanism, axle, bearings, torsion springs, and damper; 
       FIG. 5  is a partial plan view of the unit in the lowered sleep position, showing a portion of the frame, the bearings, and torsion spring mechanism; 
       FIG. 6  is an elevation view of the wall attachment plates as attached to a standard stud wall construction, showing the studs, and of the mechanical hinge plate secured to the wall attachment plates and supporting the pivoting axle, bearings, torsion springs, leg deployment mechanism, and damper; 
       FIG. 7  is a cross-sectional view along line  7 - 7  of  FIG. 6 ; 
       FIG. 8  is a side view of the torsion spring cone centered on the axle with adjusting slots, adjusting lever and setscrews; 
       FIG. 9  is an elevational view, comparable to  FIG. 4 , showing the damper and 90 degree right angle joint in additional detail; 
       FIG. 10  is an end view of the sleep system assembly, showing the slats and foam/air hybrid mattress, wherein the inflatable portion of the mattress is shown in full as inflated for use and in dotted lines as deflated for storage; 
       FIG. 10   a  is a detail of the assembly of  FIG. 10 ; 
       FIG. 11  is a cross-section on line  11 - 11  of  FIG. 4 , showing the rubber cambered slat receivers with attaching screws and bed frame; 
       FIG. 12  is a perspective view showing the overall arrangement of one embodiment of the leg actuation mechanism; 
       FIG. 13 , comprising  FIGS. 13   a  and  b , shows a detail of a cam assembly employed to cause the legs to retract upon raising the movable portion of the unit from the sleep position, as in  FIG. 13   a , to the upright and stowed position, as in  FIG. 13   b;    
       FIG. 14  shows the assembly of one of the legs to the frame of the unit; 
       FIG. 15  is a cross-sectional view taken along line  15 - 15  of  FIG. 14 ; 
       FIG. 16  is a view comparable to  FIG. 4 , illustrating an alternative mechanism for articulating the legs; 
       FIG. 16   a  shows a further alternative thereto; 
       FIG. 17  is a partial plan view corresponding to the adjacent portion of  FIG. 16 ; 
       FIGS. 18 and 19  show a portion of the leg articulation mechanism of  FIG. 16 , with the bed in the stowed and partially-deployed positions, respectively; and 
       FIG. 20  shows a perspective schematic view of another embodiment of the leg actuation mechanism. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Referring now to the drawings and in particular to  FIGS. 1 ,  2 , and  3 , these show overall views of the combined wall treatment and bed of the invention (sometimes “the unit” hereafter) in several positions. Specifically,  FIG. 1  shows the unit in its raised and stowed position, in which it appears as a wall treatment. In this embodiment, the outer face or façade  20  of the unit, which forms the underside of the unit when lowered for sleeping, is shown as a paneled face. All manner of flat surface treatments may be applied to façade  20 , including, without limitation, wood paneling, artwork, fabrics, bulletin boards, black- or white-boards, and the like. It is also within the invention to provide means for readily replacing one form of surface treatment with another, to enable easy redecoration.  FIG. 2  shows the combined wall treatment and bed of the present invention in an intermediate position, as it is being lowered to the sleep position or raised to the stowed position.  FIG. 3  shows the combined wall treatment and bed of the present invention in the lowered or sleep position, with the preferred hybrid foam/air mattress  134  in inflated position and optional side tables  16  clipped onto side rails  14 , the structure of which is detailed below. 
     FIGS. 1-3  show that the unit comprises a fixed portion  22 , comprising a bottom frame  24  and headboard  26 , which are fixed to the wall W, and a movable portion  30 , comprising a platform section  32 , the outer surface of which is façade  20 , legs  34 , and a top frame  36 . Movable portion  30  pivots around a horizontal axis defined by a mechanism (detailed below) comprised by the bottom frame  24 . As illustrated in  FIG. 2 , the legs  34  swing out as the movable portion is lowered, pivoting about longitudinal axes near the sides of the platform section  32 , to support the outer or foot end of the platform section  32  in the lowered position, and retract likewise when it is raised. More specifically, the overall effect as illustrated in  FIG. 1  is to completely conceal the mechanical components of the unit of the invention, disguising the legs  34 , which move out of the plane of the façade  20 , and the bottom frame  24 , which remains essentially stationary as the movable portion of the bed is pivoted downwardly into the sleep position, as part of the wall treatment. 
   As illustrated by  FIG. 1 , when the platform section  32  is raised to the vertical closed position, legs  34  are aligned with top frame  36 ; preferably the legs have a treatment  35  so that legs  34  and top frame  36  are finished similarly, and so that the legs  34  appear to be part of the top frame  36 , so that together with the bottom frame  36  they form a decorative “frame” or “border” for the façade. Façade  20  may be provided with vertical side members  18 , which cooperate esthetically with the bottom frame  24 , legs  34  and top frame  36  to effectively provide a complete visual frame for the internal portion of façade  20 . The top frame  36  cooperates with the legs  34  when the platform  44  is in its raised position, while the remaining mechanism is concealed in the bottom frame  24  and in the platform  32 , concealed beneath the façade  20 . In this way, the owner is given freedom to choose whatever decorative treatment he or she likes for the façade  20 , with the legs  34 , side members  18 , and top and bottom frames  36  and  24  forming part of the design or framing it, as desired. For example, the façade  20 , legs  34 , side members  18  and top and bottom frames  36  and  24 , respectively, can all be finished identically, e.g., in wood veneer, giving the appearance of a paneled wall. The clearance necessary to allow movement of the various components can be provided by narrow decorative gaps or “reveals” between the members. As illustrated in  FIGS. 2 and 3 , the legs may be rotated out from behind concealing panels, or, as shown in  FIG. 1 , the entire leg assembly may rotate as one. 
   The overall visual effect is that when one looks at the unit in the vertical position there is little to give away that it is also a comfortable bed. 
     FIG. 4  shows an elevational view of the principal components of one embodiment of the mechanism, as if looking at the unit in the vertical position, with the façade removed, and with the slat assembly which supports the sleep system shown partially cut away.  FIG. 5  shows a more detailed view, in plan, of the torsion spring system, which counterbalances the weight of the unit, easing the work of raising and lowering it between upright and stowed and sleep positions. In another embodiment, discussed in detail in connection with  FIG. 20  below, the torsion spring arrangement shown can be replaced by one or more gas spring(s); implementation of the gas spring, or another mechanical device for storing energy as the bed is lowered and releasing it as the bed is raised, is considered to be within the skill of the art. In each case the energy-storing device need simply be connected between the fixed and moving portions of the bed of the invention so as to store mechanical energy, as by compressing a gas, tensioning a spring, lifting a weight, or the like, as the bed is lowered, and releasing the stored energy as the bed is raised, easing this task. All manner of mechanisms for doing so are considered within the claims of this application where not specifically excluded. 
   As illustrated in  FIG. 4 , in one embodiment of the invention the movable portion  30  of the unit comprises a frame  40 , comprising side rails  42 , a central rail  44 , and top and bottom members  46  and  48  respectively. Typically, and without limiting the invention, these will be fabricated of steel or aluminum angle stock, tubing, an aluminum extrusion or the like, provided (apart from central rail  44 , which is unseen) with wood veneer concealing members or the like. The fixed portion  22  of the unit comprises a wall plate  50 , secured to the wall as described below, which supports an axle  52  mounted in pillow blocks  54 . The axle  52  is secured to lower member  48  of frame  40  by brackets (or additional pillow blocks)  55 , such that the movable portion  30  of the unit and the axle  52  pivot together with respect to fixed portion  22  about the axis defined by axle  52 . In the embodiment shown, but to which the invention is not to be limited, torsion springs  56  fitting concentrically over axle  52 , and detailed further below, counterbalance the weight of the unit. 
   More specifically (see  FIG. 5 ), one end  56   a  of each torsion spring  56  is secured to the wall plate  50  by a bracket  64  and a cone  62  fitting over the axle  52 , allowing the torsion spring  56  to rotate freely around axle  52 . The other end  56   b  of the torsion spring  22  is secured to the axle  52  by a second cone  66 , secured to the axle  52 . Thus, because one end  56   a  of the torsion spring is fixed to the wall plate  50 , and the other end  56   b  of the torsion spring  56  rotates with the movable portion of the unit, the torsion spring is twisted tighter, creating resistance (storing energy) as the frame is lowered, and the energy is released as the bed is raised, easing the work of doing so. The torsion spring assembly thus effectively counterbalances the weight of the unit. 
   The precise amount of counterbalancing desired can be obtained by adjusting the relative position of the end  56   b  of the torsion spring with respect to the axle  52 , effectively adjusting the amount of preload applied to the spring. The adjustment should be such that the unit can be lifted with ease by a slight person, for example, so that about ten total pounds of force are required, and so that the unit is held upright against the wall by the torsion springs. 
   The preload applied by the springs  56  can be adjusted as shown in  FIG. 8 , an end view showing axle  52  and cone  66 , to which end  56   b  of spring  56  is affixed. The preload is effected by turning cone  66  with respect to axle  52 , e.g., employing a spanner wrench or like tool  68  fitting into bores  69  in cone  66  to exert torque on cone  66 , and locking cone  66  to axle  52  where desired using setscrews  70 . Another possibility would be a ratcheting system, which can be easily adjusted and released. These particular embodiments are not meant to limit the torsion spring adjustment systems useful in implementation of this invention. 
   A damper system  58  mounted to the wall plate  50  and secured to axle  52  limits the rate of rotation of the axle  52  with respect to the wall plate, thus controlling the motion of the unit between the upright and stowed position and the sleep position.  FIG. 9  shows the damper system  58 , which controls the rate of descent as the bed is being lowered and also slows its ascent as the bed approaches the upright position. In this embodiment, a known hydraulic rotary damper  80 , typically employed as a door closer, is used; in order to accommodate the existing hydraulic damper in the space available, the axis of rotation of the axle  52  must be redirected though 90.degree., e.g., using a pair of bevel gears  82 . The damper  80  used in this embodiment has three adjustment screw valves  84 ,  86 ,  88  which, when the unit is used as a door closer, control the door to prevent slamming while ensuring reasonably rapid opening, and so on. As used herein, valve  84  controls the descent of the unit as it descends to a horizontal position, while valve  86  controls the rate of descent as the unit approaches the floor, beginning about 18 inches from the horizontal. Wall approach valve  88  controls rate of rotation of the unit as it is being lifted and approaches the vertical, starting about two feet before it approaches the wall in the upright position; that is, as the work required to be done by the torsion springs is reduced as the unit approaches the vertical, i.e., as the springs have less work to do per degree of rotation, the damper prevents the unit from moving too fast, which could lead to, e.g., fingers getting caught in the mechanism, and might be noisy. Thus, wall approach valve  88  controls the movement of the bed as it approaches the wall. Provision of the damper  80  thus adds safety and control both when the bed is being lowered, keeping it from dropping too quickly, hitting the floor hard, or slamming up against the wall as it is moving upright. 
   In the preferred embodiment of the invention, legs  34 , which support the foot end of the unit in the sleep position, are deployed automatically as the unit is lowered and are similarly retracted as it is raised. As shown in  FIG. 4 , legs  34  are mounted to the top frame member  46  at pivots  59 . Their automatic deployment and retraction can be accomplished in a wide variety of ways within the scope of the invention. In one preferred embodiment shown and detailed further below one or more tension cables retract the legs when the unit is raised, while springs urge the legs outwardly as it is lowered. Thus, as the unit is raised or lowered, the legs are retracted or deployed accordingly. Preferably, the mechanism is over-center in that the legs are moved beyond the vertical when deployed, such that they cannot be retracted without lifting the unit and will not buckle and collapse inwardly when loaded. 
     FIGS. 6 and 7  show the preferred method of attaching the bottom frame and headboard to the wall W. In this embodiment, and assuming a standard stud-and-drywall wall construction, one or more wall attachment plates  100  are first secured to the structural elements in the wall W, that is, to wooden or metal studs  106 , and a hinge plate  104 , which carries the pillow blocks and other components discussed above, is then secured to the wall attachment plates  100 . This is preferred for reasons of ease of installation, although it is within the scope of the invention to secure the hinge plate  104  directly to the wall W. The wall attachment plates  100  are attached along a straight line a given dimension, typically one foot, off the floor, such that the head of the bed is parallel to the floor when open. In a further option, the wall attachment plates  100  could comprise first members to be secured to the studs and second members to be attached thereto, to which the hinge plate is in turn attached; the second members could be made vertically adjustable with respect to the first members, for ease in leveling the hinge plate. Likewise, the wall attachment plates  100  should be securable to the hinge plate  104  at any position therealong, to ensure secure mounting even if the studs are not evenly spaced. In the embodiment shown, the lower edge of the hinge plate  104  is lowered into a J-shaped channel  110  formed integrally with or fixed to wall attachment plates  100 . The upper edge of the hinge plate  104  is then secured to the wall plates  100  with screws  108  and clips  112 . A headboard  26  can be provided to conceal the wall attachment plates. 
     FIGS. 10 ,  10   a , and  11  show the cambered slat sleep suspension system, which provides comfort by absorbing movement and pressure, following the contours of the body. In this embodiment, cambered slats  120  are made of thin (⅜) inch hardwood plywood laminated over curved forms to have a camber of ⅜ inch over the length of the slat. The slats are about 3″ wide in this embodiment. The slats  120  could also be made of other flexible materials such as fiberglass, metals, or plastics, and could be of differing dimensions. As illustrated in  FIGS. 4 ,  10 , and  11 , rubber strips  122  are molded to define receptacles to receive the ends of the slats  120  while allowing the slats to move and flex somewhat, absorbing the shifting pressure when the bed is in use. The molded rubber strips are held in place by screws  124  extending into the side rail  42  (see  FIG. 11 ). As shown in  FIG. 10   a , the frame may comprise a metal member  127  for strength, concealed by a wooden molding  129 . 
     FIG. 10  also shows the preferred combined air/foam mattress  134 , in dotted lines in the deflated condition and in full as inflated when in a sleep position. This mattress  134  is made of an airtight bladder filled with a compressible fiber/foam material  135  with a thinner layer (e.g., one inch thick)  136  of foam forming a topper. This creates the feel of a natural foam mattress, without the uncomfortable “roll” encountered with conventional air mattresses. Preferably the mattress  134  is automatically inflated as the unit is operated to take the sleep position and deflated, by applying a vacuum to the interior of the mattress, as the unit is raised. Deflating the mattress by application of vacuum compresses the fiber and foam components within the air bladders of the mattress. Thus the mattress, which can be as much as seven inches thick and very comfortable when inflated, is compressed to about 2½ inches thick when deflated, reducing the overall thickness of the bed of the invention, as is critical to its appearance as an attractive wall treatment when in the vertical position. Inflation and deflation can be accomplished using a bi-directional air pump  138 , connected to the mattress  134  and arranged to be operated automatically upon motion of the movable portion of the unit with respect to the fixed portion. While this embodiment uses the hybrid fiber/foam inflatable component with a foam topper, one could use a simple air mattress to accomplish the same thing. Further, of course, while this embodiment uses an electric air handling system one could use a foot pump or other means of inflation and deflation. 
     FIGS. 12-15  show one preferred embodiment of a mechanism for automatically lowering the legs  34  as the movable portion of the unit is lowered to the sleep position, and for retracting the legs as it is raised. In this embodiment, the legs are spring-biased toward the deployed position, and are pulled back to the retracted position against the spring bias when the movable portion of the unit is raised. Other arrangements for providing similar automatic operation of the legs are within the skill of the art. 
   As noted above,  FIG. 12  is a perspective view showing the overall arrangement of one embodiment of the leg actuation mechanism, in which a cam  176  mounted on axle  52  controls a cable  174  which retracts the legs against the spring bias.  FIG. 13 , comprising  FIGS. 13(   a ) and ( b ), shows a detail of the cam assembly, wherein  FIG. 13(   a ) shows the cam assembly when the unit is in the sleep position, and  FIG. 13  ( b ) shows the position of the cam assembly with the unit in the upright and stowed position.  FIG. 14  shows the assembly of one of the legs to the frame of the unit, and  FIG. 15  is a cross-sectional view taken along line  15 - 15  of  FIG. 14 . Legs  34  are shown as solid members, for simplicity, but of course the invention is not to be thus limited. The structural loads applied to legs  34  could be carried by extruded aluminum members sheathed in a ornamental treatment to match or complement the treatment of the underside of the bed. For example, the legs could be sheathed in veneered composite material. The sheathing applied could also be made readily removable, so that the appearance of the bed could be conveniently altered as desired. 
   As shown, the legs  34  pivot about axes running generally along the sides  42  of the frame; a bolt  59  (one leg assembly being shown in  FIGS. 12 ,  14 , and  15 ; the other being minor-imaged) secures each leg  34  to the frame  40 , e.g., being threaded into a block  150  welded to the side frame  42 . A bushing  152 , e.g., of high-density plastic material, spaces the leg  34  from block  150 , provides low-friction pivoting of the leg, and provides a pivot about which hairpin spring  154  is retained. Spring  154  is arranged to exert an outward bias on leg  34 , that is, to rotate it clockwise in  FIG. 15 , by exerting bias between a pin  156  fixed to leg  34  and an ear  160  on a bracket  162  fixed to frame  40 , e.g., by screws  164  extending into block  150 . 
   It is desirable to limit the degree to which the leg  34  pivots outwardly responsive to the bias of spring  154 , to ensure that the leg solidly supports the foot end of the unit when in the sleep position. One way to accomplish this is shown in  FIGS. 14 and 15 . A first pin  168  extends between mating bores in bushing  152  and block  150 , preventing rotation of bushing  152 , and a second pin  170  extends from a bore in leg  34  into an arcuate recess  172  in bushing  152 , limiting the degree of rotation permitted to leg  34 . 
   As noted, a cable  174  is provided to retract the legs  34  against the bias of spring  154  when the movable portion of the unit is raised to the vertical stowed position. As illustrated, one end of cable  174  is secured with respect to the wall plate  50 , so that as the movable portion is raised, rotating axle  52 , cable  174  is wound upon a cam  176  secured to axle  52 . The opposite end of cable  174  is bifurcated, as indicated at  178 , and passes over sheaves  180  secured to the top member  46  of frame  40  so as to simultaneously control the motion of both legs  34 . A spring  182 , of higher spring value than spring  154  (after consideration of the various mechanical advantages provided), but having its travel limited, is disposed along cable  174  to keep positive tension on cable  174 , so that the legs are securely retained when the movable portion of the unit is in its upright position. 
     FIGS. 16-19  show an alternative mechanism for automatically deploying and retracting the legs as the bed is lowered and raised, respectively. In this case the legs are operated by a rigid rod member  200 . Member  200  is driven in push-pull fashion by a mechanism shown in  FIGS. 18 and 19 . Motion of member  200  is communicated to the legs by flexible slide members  202 , which are fabricated of a flexible material capable of exerting force without buckling in both tension and compression, such as strips of fiberglass, and by further rigid members  208 , secured to slide members  202  at  210 . Flexible members  202  slide within guides  204 , while rigid members  208  are constrained to back-and-forth movement by headed bolts extending through slots  208   a  in members  208 . Members  208  are then pivotally secured to legs  34  by bolts  212 . Thus, as member  200  is urged back and forth, legs  34  are pivoted in and out; legs  34  may again be provided with springs biasing them to the deployed position, to ensure that that any slack in the mechanism does not result in the failure of the legs to fully deploy. 
   One method of providing back and forth motion to member  200  as the bed is raised and lowered is shown by  FIGS. 18 and 19 . The axis about which bed frame pivots as it raised and lowered is defined by axle  52 , located with respect to the wall by a first bearing (or set of bearings)  54  and with respect to the bed frame by a second bearing  55 . A bracket  216  secured to the sliding member  200  at  222  pivots with respect to a bolt  218 , fixed with respect to the wall, as the bed frame is raised and lowered. As the pivot point defined by axle  52  is not collinear with the pivot point defined by bolt  218 , as the bed is lowered the sliding member  200  is forced outwardly, away from axle  52 , causing the legs to be deployed; as the bed is raised the opposite occurs, pulling the legs back into their inactive position. 
   A further mechanism for automatically deploying and withdrawing the legs is shown by  FIG. 16A ; here bevel gears  230  on either end of axle  52  simply drive a mating pair of gears  232  mounted on shafts  234  running along the outer edges of the bed frame, and arranged to operate the legs  34  as desired. 
     FIG. 20  shows schematically a further mechanism for automatically deploying and withdrawing the legs as the bed is lowered and raised. (The decorative sheathing that would normally be provided on the frame members and legs is omitted from this view for clarity.) In this design, as illustrated, individual leg-lifting cables run from the legs to respective actuating mechanisms on the opposite side of the bed. The actuating mechanisms comprise cams, generally similar to that shown in  FIGS. 13   a  and  b , while the energy-storage and damping functions are both provided by one or more gas springs, effecting a further simplification. 
   More specifically, in this embodiment the bed pivots about an axis defined by a continuous axle or two stub axles  252  supported by bearing brackets  258 , which would typically be mounted on a wall plate  248  secured to a wall (not shown). Left and right legs,  240  and  242  respectively, are pivoted about axes  243  and  247 , and are operated by cables  262  and  274  confined in sheaths  260  and  272 . One end of each cable is fixed to the corresponding leg and the other end is fixed with respect to the wall plate  248  and hence the wall by a bracket  266 . Cables  274  and  262  are tensioned by cams  270  and  264  as the bed is raised from its lowered position in  FIG. 20  to the vertical position, pulling legs  240  and  242  into the plane of the bed frame comprising side frames  247 ,  246  and foot member  244 . If the axles  252  are spaced sufficiently from the wall plate  248  it may be possible to dispense with the cams. Conversely, as the bed is lowered, tension in the cables is released, and hairpin springs  241 ,  245  (the complete leg attachment mechanism possibly being as shown in  FIGS. 14 and 15 ) urge the legs to their deployed position. 
   In the  FIG. 20  embodiment, as the bed is lowered energy is stored in one or more gas springs  276 ,  250  (a pair being shown), connected between crank arms  278 ,  254  fixed to pivot axles  252  and brackets  255 ,  256  fixed to wall plate  248 ; this energy is released as the bed is raised, easing the work of doing so. Gas springs suitable for this application and in which the rate of travel is controlled are commercially available, so that the gas springs can also be used to limit the rate of motion of the bed, eliminating the need for a separate damper as shown in other embodiments discussed above. 
   Other suitable mechanisms for thus automatically deploying and withdrawing the legs as the bed is lowered and raised are within the skill of the art and are intended to be included within the scope of this invention. 
   A further improvement that is within the scope of the invention is to provide a further mechanism for lowering the decorative façade covering the portion of the unit that is fixed to the wall as the movable portion is pivoted toward the sleep position, and raising it correspondingly; this would allow the sections of the decorative façade covering the fixed and movable portions of the unit to fit closely to one another, which would be esthetically desirable. This could be accomplished in the  FIG. 20  embodiment by mounting this portion of the façade for vertical sliding motion over a range of up to a few inches, and actuating its motion by a mechanism operated by rotation of axles  252 . 
   It is also within the invention to employ the mechanical design of the unit of the invention into a stowable bed intended for use where space-conservation is important but esthetics are less so, such that the unit need not comprise a decorative façade. For example, the unit of the invention could be incorporated in a hospital-room cabinet, to provide temporary accommodation for patients&#39; visitors and the like. 
   While a preferred embodiment of the invention has been described in detail, this is exemplary only and the invention is not to be limited thereby.