Patent Publication Number: US-6338172-B1

Title: Polymeric length and width adjustable bed frame system

Description:
RELATED APPLICATIONS 
     This application is a continuation-in-part of application Ser. No. 08/950,960, filed Oct. 15, 1997, now U.S. Pat. No. 5,996,145 the content of which is incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention is related to bed supports, and, more particularly, to an all polymeric adjustable bed frame system. 
     BACKGROUND OF THE INVENTION 
     Conventional beds that consist of a mattress and box springs are commonly supported by a bed support consisting of two longitudinal bed rails attached to the corner posts of a headboard or extending between the corner posts of a footboard and a headboard to support the box springs from both lateral sides. Each bed rail is typically an elongated angle member that includes two downwardly directed hooks or fingers or, alternatively, a bracket with attachment holes at each end. In this arrangement, the footboard and headboard actually support the bed rails and therefore the mattress. A plurality of wooden slats generally extend between the side rails for providing additional mattress support. 
     Conventional bed rails of the type described above are typically formed of stamped metal. Stamped metal bed rails are relatively expensive to manufacture because of the costs of the raw materials (typically steel), the metal forming processes, and a separate painting step. Moreover, the metal bed rails are heavy, substantially increasing the costs of shipping and handling the bed rails. A particular disadvantage in this regard is that known metal bed rails/frame system components cannot be shipped by regular parcel shippers without significant extra cost. Accordingly, when a customer requests a single metal bed frame from a bed retailer, the retailer may well be delayed in his ability to fill the order while he waits for the delivery of a large shipment via common carrier. This situation can cause great customer dissatisfaction. 
     Mattresses of different sizes (e.g., twin size, full size, queen size, king size, and California king size) have different lengths. Commonly available metal bed rails as described above typically come in a single standard length and cannot easily be adjusted for length. Therefore, a retailer who sells beds of different sizes and wishes to provide bed rails for each such size must carry an inventory bed rails of appropriate length for each bed size. Moreover, even if the corresponding size bed rail is available, it often does not provide a close length fit. In which case a gap may be left between the mattress and the headboard or footboard or, if no footboard is used, the frame may protrude beyond the end of the mattress. Attempts have been made to provide length adjustable bed rails as described in U.S. Pat. No. 1,080,577 to Pascale et al., U.S. Pat. No. 2,539,933 to Silverman, U.S. Pat. No. 3,161,894 to Short, and U.S. Pat. No. 4,679,261 to Stanley et al. However, each of the bed rails disclosed therein suffers from one or more drawbacks in manufacture, assembly, or effectiveness. 
     Generally, and particularly in the case of larger mattress sizes, transverse slats are provided extending between the bed rails. Typically, the ends of the slats are supported by the flanges of the bed rails which also support the edges of the mattress. The slats are often ¾ inch or more thick. The slat thickness projects upwardly into the mattress so that the mattress is not uniformly supported. As a result, the mattress may be unstable and may have uncomfortable ridges or bulges. 
     Mattresses of different sizes have different widths. Thus, slats of different lengths are required for different size mattresses. Typically, the provided slats are simply wooden boards which are cut to one of three standard lengths corresponding to the width of the mattress. Attempts have been made to provide length adjustable slats as disclosed in U.S. Pat. No. 1,080,577 to Pascale et al, U.S. Pat. No. 1,504,897 to Brotherton Jr., et al., U.S. Pat. No. 2,452,808 to Tucker, U.S. Pat. No. 2,886,832 to Mitchell, et al., U.S. Pat. No. 3,984,884 to Spitz, and U.S. Pat. No. 4,679,261 to Stanley, et al. Each of these slat designs suffer from one or more drawbacks in manufacture, installation, or use. 
     Another problem encountered by bed retailers is the growing popularity of California king size mattresses. California king size mattresses are 4 inches longer and 6 inches narrower than conventional king size mattresses. Because the mounting slots of the headboard and footboard of a king size bed are typically preformed to fit a standard king size mattress, conventional bed rails do not properly fit the California king size mattress. 
     Yet another problem encountered by consumers who purchase beds relates to the step of bolting bed frames side rails to headboards and footboards. Metal bed frame side rails typically are provided with mounting brackets that include two horizontal slots that ideally have a spacing of 2.5 inches center line to center line. Moreover, the lower of the two slots should be positioned approximately 5.5 inches above the floor. These guidelines have been established by the International Sleep Products Association (ISPA) in its Sleep Products Voluntary Dimensional Guideline. Nevertheless, our study of a large number of headboards indicates that the borings or threaded studs provided in wooden headboard vary considerably from these standard dimensions. As a result, it can be very difficult to align a metal bed frame side rail to the corresponding mounting position on even a industry accepted “standard” wooden headboard or footboard. 
     Thus, there is a need for a bed frame system having bed rails which are cost effectively manufactured, shipped and inventoried. Further, the bed rail should have relatively light weight components sized to be shipped by known parcel shippers. 
     There is a need for a bed rail which is conveniently length adjustable and which also provides effective and substantially uniform support for a mattress. In particular, there exists a need for a bed frame system which may be assembled to custom fit and support mattresses of substantially all commonly available sizes. This bed frame should be conveniently assembled without the need for tools. 
     Further, there exists a need for a bed rail which allows the provision of transverse support slats but which reduces or eliminates the irregularities in mattress support caused by the thickness of the slats used on known metal bed frames. 
     SUMMARY OF THE INVENTION 
     The present invention is generally directed to a bed frame system that provides a number of advantages over known metal bed frames. The bed frame system includes the characteristic of being length and width adjustable so as to properly support a variety of mattress sizes using a small number of components. No component exceeds 48 inches in length. The present invention is further generally directed to bed support devices, including length adjustable bed rails and length adjustable bed slats, which are formed substantially of polymeric material. Bed frames and components thereof according to the present invention may be cost-effectively manufactured and provide substantial savings in weight. They offer more options for shipment to the customer. 
     The present invention relates to an all polymeric bed frame, comprising opposing laterally spaced apart, elongated side rails, each of the side rails having first and second ends and comprised of a substantially vertical wall and a horizontal support ledge extending laterally from a lower edge of said substantially vertical wall; an end cap positioned at least one of the side rail first or second ends, the end caps being adapted for connection to a conventional bed headboard, and being positioned substantially perpendicular to the longitudinal dimension of the side rails; at least two spaced apart slats attached to the horizontal support members between the side rail first and second ends. The side rails and the at least two slats are comprised of a polymeric material selected from the group consisting of polyethylene, polyethylene copolymers, polypropylene, and acrylonitrile butadiene styrene. 
     These and other aspects of the present invention will become apparent to those skilled in the art after a reading of the following description of the preferred embodiments when considered in conjunction with the drawings. It should be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention as claimed. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate one embodiment of the invention and, together with the description, serve to explain the principles of the invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The above and other objects, features, and advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: 
     FIG. 1 is an isometric view of the bed frame system of the present invention; 
     FIG. 2 is a perspective view of the detail of the connection of a length adjustable slat according to the present invention to the side rail of the bed frame of the present invention; 
     FIG. 3 is a perspective view showing the details of the connection of a length adjustable slat according to the present invention to the male and female members making up the side rail of the present invention; 
     FIG. 4 is a perspective view of the details of the connection of a length adjustable slat according to the present invention to an opposing end of the side rail of the present invention from that shown in FIG. 2; 
     FIG. 5 is a partial perspective view showing the details of the connection of the additional support foot to the pair of separable elongated slat portions of the present invention; 
     FIG. 6 is an isometric view of the male and female side rail members of the present invention showing the interaction between the female member alignment rail and the male members alignment slot; 
     FIG. 7 is a partial cross-sectional perspective view taken along  7 — 7  in FIG. 5 showing the nesting relationship between the pair of separable elongated slat portions of the present invention; 
     FIG. 8 is a partial perspective view taken from the underside of the connection between the length adjustable slat and the side rail of the present invention; 
     FIG. 9 is a partial cutaway perspective view taken from underneath the length adjustable slat of the present invention showing the connection of the additional support put thereto; 
     FIG. 10 is a cross-sectional view taken along line  10 — 10  in FIG. 1 showing the cross-sectional profile of either the male or female members of the length adjustable side rail of the present invention at a point outside either one of the inwardly or outwardly offset meeting sections of those members; 
     FIG. 11 is an exploded sectional view taken along line  11 — 11  in FIG. 3; and 
     FIG. 12 is a sectional view taken along line  12 — 12  in FIG.  3 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIG. 1, the polymeric length and width adjustable bed frame according to the present invention, indicated generally at  10 , includes opposing laterally spaced apart, elongated side rails  12  having first and second ends. Each side rail  12  has end cap  50  which permits attachment to a standard headboard. The bed frame further includes at least two spaced apart slats  14  secured at opposing ends thereof to the side rails  12 . In a preferred embodiment three slats  14  are provided. The side rails  12  and the slats  14  are length adjustable. It will be appreciated that adjusting the length of the slats  14  also adjusts the width of the bed frame  10 . 
     Referring now to FIGS.  1 , 6 , and  10 - 12 , each length adjustable side rail  12  is comprised of a male member  12   a  and a female member  12   b . The male member  12   a  is comprised of a substantially vertical wall  40  and an integrally formed horizontal support ledge  42  that extends laterally from a lower edge of the first side of the vertical wall  40 . The horizontal support ledge is provided with a plurality of fastener openings  46  which, as is illustrated in FIG. 1, are provided in spaced apart groups. The male member vertical wall  40  has a curvilinear shape in this preferred embodiment and may be provided with a serious of stiffening members  45  for structural rigidity. Given the all polymeric construction of the bed frame  10 , the curved shape also serves to enhance the structural rigidity and load bearing capability of the bed frame. Other shapes may be used as desired as will be readily appreciated by one of ordinary skill. 
     The male member further includes an inwardly offset mating section  60  positioned at one end thereof (See FIG.  3 ). As best illustrated in the exploded cross sectional view of FIG. 11, the portion of the vertical wall  401  in the mating section  60  has a wall thickness less than that at a point outside the mating section. In a preferred embodiment, the wall portion  41  in the mating section has a thickness of about half that shown in FIG.  10 . The wall portion  41  is recessed so as to be offset inwardly from the outside edge of the vertical wall  40 . This recess  43  is continued into the horizontal support ledge  42 . A longitudinal alignment slot  44  extends along the length of the mating section in the recessed portion  43  of the substantially vertical wall  41 . It should be noted that, in a preferred embodiment, one of the groups of fastener openings is located in the reduced thickness, offset region  60  of the horizontal support ledge  42 . As will be explained in more detail below, this recessed portion permits the male member  12   a  to be received by the female member  12   b  while maintaining the outside edges and the horizontal support ledges  32 , 42  of each of those members in coplanar alignment. 
     Referring again to FIG. 3, the female member  12   b  includes a outwardly offset mating section  62  for receiving the male member mating section. A cross sectional view of this mating section taken along  12 — 12  in FIG.  1  and looking towards the end of the bed frame  10  is illustrated in FIG.  12 . It will be appreciated that, because this view is taken looking towards the end of the bed frame  10 , the orientation of the horizontal support ledge  32  is reversed from that shown in FIG.  11 . The female side rail member  12   b  includes a substantially vertical wall  30  and a horizontal support ledge  32 , which extends from a lower edge of a first side of the substantially vertical wall  30 . In a preferred embodiment, the female member vertical wall  30  has a curvilinear shape. Similar to the male member, the thickness of the portion  31  of the vertical wall  30  located in the outwardly offset mating section  62  is less than, and preferably, about half that in the remainder of the female member. This portion  31  is recessed and thus offset from the inside edge of the female member. The thickness of the horizontal support ledge  32  is similarly reduced in thickness and is similarly offset. The horizontal support ledge  32  includes a plurality of fastener openings  36  positioned in spaced apart groups along the length of the support ledge  32 . Preferably, one of these groups of fastener openings  36  is contained in the outwardly offset portion  31  of the female member  12   b . A longitudinal alignment rib  34  projects laterally from the first side of vertical wall  30  and extends along the length of the inwardly offset wall portion  31 . The female member vertical wall  30  may further be provided with stiffening members  35  to provide additional strength and stability to the bed frame. In this embodiment these members are formed as side-by-side, X-shaped members. It will be appreciated that any suitable design of stiffening member may be used and that many different approaches may be taken to their design so long as the function of increasing the overall load carrying ability of the side rails  12  is met. 
     The offset mating sections  60 , 62  are positioned at one end of each of the male and female members  12   a ,  12   b  and have a length about 12 and about 20 inches. Thus, up to about 20 inches of the length of the male member  12   a  will be received by about 20 inches of the length of the female member  12   b.    
     The cooperation of the male and female side rail members  12   a ,  12   b  is illustrated in FIGS. 3,  6  and  11 . The male and female members are brought together such that the inwardly offset mating section  60  of the male member is received in the outwardly offset mating section  62  of the female member. Thus, female member alignment rib  34  engages with the male member alignment slot  44  so as to increase the stability and promote the proper alignment of the two side rail members  12   a ,  12   b . The recessed portion of the male member horizontal support ledge  32  will rest on the recessed portion of the female member horizontal support ledge  42  so as to align the fastener openings  46 , 36 . It will be readily appreciated that, given the cooperating nature of each recessed portion  31 ,  41  the horizontal ledges  32 ,  42  of the female and male side rail members will be substantially coplanar. This feature is an advantage over prior art metal bed frames using wooden slats positioned on metal angle iron frames. A near continuous, one level support surface is provided along the entire length of each side rail. No portion of the side rail extends above the level of the horizontal support ledges  32 ,  42 . 
     The male and female members may be adjusted to a desired length by sliding the male and female members so as to lengthen or shorten the side rails  12  as desired. It will be appreciated that a number of different bed rail lengths may be created through such adjustment. Desirably, male and female side rail members having a length of about 48 inches can be used to adjust the side rail length from about 75 inches to about 84 inches so as to accommodate mattresses in sizes ranging from twin to king. 
     In a preferred embodiment each of the side rails  12  includes an end cap  50  positioned at least one end thereof. As shown in FIGS. 2 and 4, the end caps  50  extend perpendicularly from the longitudinal dimension of the side rails so as to define a mounting surface  51  suitable for connection to conventional headboards and footboards. The term “conventional” refers to headboards and footboards conforming to standards published by the well known International Sleep Products Association. The end caps  50  include at least one pair of vertically oriented mounting slots  50   a ,  50   b . Each slot in the pair lies on a common vertical axis  50   c . In this preferred embodiment each end cap is provided with two pairs of mounting slots and is integrally formed with the side rails  12 . Although a headboard  80  and footboard  82  are shown in dotted line in FIG. 1, a headboard  80  may be used alone without the footboard  82 . 
     If desired a decorative cover  54  is provided and snaps into place in the mounting slots  50   a ,  50   b  as needed. These covers  54  provide a finished appearance if no headboard and/or no footboard will be used with the bed frame. 
     Referring now to FIGS. 1,  5 ,  7  and  9 , the length adjustable slats  14  include first and second elongated U-shaped slat portions  14   a ,  14   b  each of which has a U-shaped first end  70  and a flat second end  72 . The U-shaped first ends have a nesting relationship such that the U-shaped end of slat portion  14   a  is received within the slightly larger and corresponding U-shaped second slat portion  14   b . The smaller of the two slat portions may include with stiffening members to provide additional strength to the bed frame. Each of the slat portions includes laterally projecting flanges  15   a ,  15   b  (FIG.  7 ). It will be readily appreciated from FIG. 7, that, when the slat portions  14   a ,  14   b  are in a nested position, the horizontally projecting flanges are stacked atop each other vertically. Desirably, each slat portion  14   a ,  14   b  is formed from a single piece of polymeric material so that a smooth, continuous transition is made from the U-shaped end  70  to the flat end  72 . 
     Each slat portion further includes an integrally formed downwardly extending support leg  16   b . Each support leg  16   b  extends from the flat end  70  of each slat portion and, desirably, is positioned inboard of the outside edge of the slat. The term “inboard” refers to a spacing between the outside edge of the slat and the center line of support foot of between about 2 inches and about 6 inches, preferably between about 3 inches and about 5 inches. It is believed that this positioning increases the resistance of the bed frame assembly to “racking.” This term refers to the tendency of the bed frame to sway or tilt responsive to the application of a sideways, horizontal force. 
     The portion of the slat flat end  70  positioned between the support foot and the outside edge of the slat is recessed. As best illustrated in FIG. 3, the depth of this recess  17  is such that the side rail  12  may be received therein so as to position the horizontal support ledges  32 , 42  of the male side rail members  12   a ,  12   b  in the same plane as the upper surface  14   c  of the slat. The slat flat end provides a wide-load bearing area for carrying the weight of the mattress and box spring supported by the bed frame. 
     The length adjustable slat further includes a third support foot that clamps the slat portions  14   a ,  14   b  to each other securely at a point between the first and second integrally formed support feet  16   b . As illustrated in FIG. 5, the third support foot  18  includes an anchoring portion  19  which is secured to the horizontally extending flanges  15   a ,  15   b  of each slat portion. In this preferred embodiment the anchoring portion includes a flat platform  19   a  on either side of which are provided upwardly extending lugs  19   b  whose function is to grip and hold the horizontally extending flanges  15   a ,  15   b  in place. 
     Assembling the length adjustable slat for a particular size mattress/box spring combination is straightforward and does not require tools. First, the slat portions  14   a ,  14   b  are nested together so as to define a width corresponding to the mattress size, i.e., full, queen, or king. This step may be facilitated by the provision of indicia  22  (See FIG. 1.) on the upper surface  14   c  of the innermost slat portion  14   a . Next, one of the anchoring lugs  19   b  is fitted onto one set of the horizontally extending flanges  15   a ,  15   b . The support foot is then rotated under the slat so that the opposing lug  19   b  snaps into place on the opposing horizontally extending flanges  15   a ,  15   b . It will be appreciated that, given the resiliency of the all polymeric construction of the bed frame, the lugs  19   b  will spread slightly as needed to fit over the stacked flanges  15   a ,  15   b.    
     The connection of the side rails  12   a ,  12   b  to the slats  14  is illustrated in FIGS. 2-4. As discussed above, each slat end section  72  includes a recess  17  located near the outside edge of each slat portion. It will be appreciated that, when the male side rail member  12   a  is received in the female side rail member  12   b , the corresponding horizontal support ledges  32 , 42  of each member are stacked one atop the other and define a combined thickness substantially equal to the depth of recess  17 . However, it will be further appreciated that, for the slats connected closest to the ends of the side rails  12 , the thickness of the support ledges equals the depth of the recess. The relative position between the two side rail members is then adjusted such that the fastener openings  36 ,  46  of each are aligned so as to create a desired length side rail. The thus aligned side rail members  12   a ,  12   b  are then positioned in the recess  17  such that at least two of the fastener openings in the side rail are lined with at least two of the fastener openings in the slat portion flat end. The side rail is then secured to the slat with fasteners  20 . In a one preferred polymeric “push-in” fasteners are used. Desirably, at least two fasteners per connection are used although the scope of the present invention includes using a larger or smaller number of fasteners. In an alternative embodiment, the fastener may be molded integrally as part of either the male or female side rail members  12   a ,  12   b . It will be appreciated that the procedure just described for connecting the slats  14  to the side rails  12  applies to the center slat as illustrated in FIG.  3 . Referring to FIGS. 2 and 4, the slats positioned near the first or second ends of the side rails  12  will be connected using a similar approach. 
     As discussed above, each of the components of the bed frame of the present invention is comprised of a polymeric material. Desirably, these components may be constructed using known thermoplastic manufacturing techniques to include injection molding. Suitable polymeric materials include thermoplastics including polyethylene, polyethylene copolymers, polypropylene, polypropylene copolymers, polystyrene, polystyrene copolymers, styrene acrylonitrile copolymers, polycarbonate and polycarbonate blends. A particularly preferred material is acrylonitrile butadiene styrene (ABS). ABS has high rigidity and impact strength and excellent abrasion resistance. ABS combines toughness with stress-cracking and creep resistance and may be thermoformed with excellent mold detail with most known equipment. 
     The bed frame system of the present invention offers a number of advantages over known metal bed frame systems and plastic bed frame systems. First, the system uses a single set of components that cooperate so as to be length and width adjustable and thus configurable to accommodate mattress/box spring sets that range in size from double to king. It follows that a bedding retailer need not worry about maintaining an expensive inventory of complete sets of different-sized bed frame components. This is because individual components may be ordered on as-needed basis to make up a complete set. 
     Another advantage stems from the all-polymeric construction of the bed frame. This construction offers substantial weight saving which reduces shipping costs while providing the structural integrity of known metal bed frame systems. In fact, it is believed that the strength of a properly engineered all-polymeric bed frame system according to the present invention will have the physical characteristics approaching or exceeding that of known metal bed frame systems. 
     Another advantage lies in the cost savings when bed frames according to the present invention are shipped in a knocked-down condition using known package shippers such as United Parcel Service®. In a preferred embodiment the length of the side rail male and female members  12   a ,  12   b  is between about 40 inches and about 48 inches. The length of each slat portion  14   a ,  14   b  is between about 40 inches and about 48 inches. Each of these dimensions are within the maximum allowable to permit the bed frame assembly to be shipped by UPS without an expensive surcharge. Shippers must pay more to ship conventional metal bed frame systems in this fashion because the components making up those systems typically require a surcharge given the length of their components. The benefits of this situation are numerous. First, if a bedding retailer needs a single bed frame assembly, the single assembly may be shipped overnight on demand at a cost competitive price. Conversely, with known metal bed frame systems, shipping a single unit has proven to be impractical. This because of the high minimum charge for a common carrier and the high extra fees associated with regular parcel shippers. It follows that a retailer must stock a large number of complete metal bed frame systems and thus tie up valuable resources in inventory that may not match demand at a given point in time. 
     It should be noted that even if the bed frame system of the present invention is shipped via common carrier, its preferred maximum dimension of 48 inches corresponds to the 48 inch standard pallet size used by common carriers. 
     Another substantial advantage of the all polymeric bed frame system according to the current invention is the substantial weight savings over an all-metal bed frame design. Polymeric components can be engineered to provide strength characteristics that meet or exceed those of all metal bed frames at potentially substantial weight savings. This advantage permits bed frames according to the present invention to be shipped at lower cost and enables the bed frames to be handled with ease during set up. 
     Yet another advantage lies in the ability to readily incorporate color into a bed frame assembly. Known metal bed frames are nearly universally provided in a dark brown or near black color. The typical paint finish is not of high quality and has proven to be prone to damage during shipment, thus detracting from the appearance of the frame. The bare exposed metal resulting from this damage is susceptible to rust. Consequently, consumers go to great lengths to hide plain metal frames with bed coverings. On the other hand, a wide variety of colorants may be added to the polymeric material used to make the bed frame assembly of the present invention is created. Thus, the bed frame may be color coordinated with the decor in a given room. The bed frame of the present invention is free of rust problems. 
     A potentially significant safety issue with metal bed frames lies in the sharp edges usually found on the metal frame side rails. Consumers have suffered scrapes and cut from the sharp edges which often are hidden beneath bed covers. Moreover, metal bed frame components are know to pinch fingers and cause cuts during assembly. The rounded parts of the bed frame of the present invention avoid those problems. 
     Although the present invention has been described with preferred embodiments, it is to be understood that modifications and variations may be utilized without departing from the spirit and scope of this invention, as those skilled in the art will readily understand. Such modifications and variations are considered to be within the purview and scope of the appended claims and their equivalents.