Abstract:
A platform bed frame includes two frame segments connected by hinge connections, leg assemblies connected to the two frame segments, a rotating hook member pivotally secured to one of the frame segments; and a securing extension attached to the other frame segment, and the rotating hook and extension allow two bed frames to be secured together. Alternately, the frame may include an extension and T-slot to connect two frames. A related improvement is a suspension leg including telescoping sections and a compressible, resilient member controlling movement of the telescoping sections. Another related improvement relates to a frame structure with connected angled supports and slats connected thereto to form the mattress supporting surface.

Description:
TECHNICAL FIELD OF THE INVENTION 
     The present invention relates generally to the field of bedding products and, more particularly, to an improved support structure for a mattress. 
     BACKGROUND OF THE INVENTION 
     Platform type bed frames have been used for several years as an alternative to standard bed frames that lie closer to the floor and are designed with relatively open framing to accommodate a mattress foundation as well as a mattress. In contrast, platform bed frames are typically raised a greater distance from the floor, for example ten to fourteen inches, which allows for underbed storage. Platform bed frames are also typically provided with a horizontal framework that is specifically designed to fully support a mattress without the need for a foundation. An example of a known platform bed frame is described in U.S. Pat. No. 7,600,278. The platform bed frame described in the &#39;278 patent has the added benefit of having a folding design. More specifically, the bed frame is divided into two halves with the halves being connected at the midpoint of the frame by a hinge connection. 
     However, platform bed frames of the type described in the &#39;278 patent have a number of significant drawbacks. First, the folding design utilized in these frames requires a structurally complex middle hinge that is relatively expensive. Further, the prior art platform bed frames have a relatively limited weight capacity that can create issues for larger customers. Also, while these prior art frames do fold, they still require larger packaging and are difficult to place on to standard store display shelves. 
     In addition, when used in combination to support larger mattresses, the known prior art platform bed frames provide insufficient support for the middle of the mattress, which can result in sagging of the mattress, especially in the case of foam mattresses or lower profile innerspring mattresses. In particular, the prior art frames utilize connecting bars to connect two frames together, which allows the mattress to sag between the connecting bars. 
     Another drawback of prior art frames is the manner of construction, which requires a large number of welds and relatively expensive, extruded materials. A further drawback is the lack of a resilient base for the prior art frames. 
     Therefore, it would be advantageous to provide an improved platform bed frame having greater structural rigidity and weight capacity while being foldable into a smaller footprint to enhance packaging and display qualities. 
     SUMMARY OF THE INVENTION 
     One aspect of the invention generally pertains to an improved platform bed frame having increased structural rigidity, both when used alone and when multiple bed frames are combined to accommodate larger mattresses. 
     Another aspect of the invention pertains to an improved platform bed frame having an increased weight carrying capacity. 
     Yet another aspect of the invention is to provide a platform bed frame capable of being folded into a smaller footprint. 
     Another aspect of the invention is to provide an alternative construction arrangement for lower cost and easier assembly. 
     One additional aspect of the invention is to provide a resilient base for a platform bed frame. 
     In accordance with one or more aspects of the invention, a platform bed frame is provided that includes two frame segments connected by hinge connections, leg assemblies connected to the two frame segments, a rotating hook member pivotally secured to one of the frame segments; and a securing extension attached to the other frame segment, and wherein the rotating hook and extension allow two bed frames to be secured together. Alternately, the frame may include an extension and T-slot to connect two frames. A related improvement is a suspension leg including telescoping sections and a compressible, resilient member controlling movement of the telescoping sections. Another related improvement relates to a frame structure with connected angled supports and slats connected thereto to form the mattress supporting surface. 
     These aspects are merely illustrative of the innumerable aspects associated with the present invention and should not be deemed as limiting in any manner. These and other aspects, features and advantages of the present invention will become apparent from the following detailed description when taken in conjunction with the referenced drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Reference is now made more particularly to the drawings, which illustrate the best presently known mode of carrying out the invention and wherein similar reference characters indicate the same parts throughout the views. 
         FIG. 1  is a perspective view of a platform bed frame in its unfolded position according to a first embodiment of the present invention. 
         FIG. 2  is a perspective view of the platform bed frame of  FIG. 1  in a partially folded position. 
         FIG. 3  is a side view of the platform bed frame of  FIG. 1  in a fully folded position. 
         FIG. 4  is a detail view of a leg assembly of the platform bed frame of  FIG. 1 . 
         FIG. 5  is a detail view of a frame segment hinge connection of the platform bed frame of  FIG. 1 . 
         FIG. 6  is a perspective view of a platform bed frame according to another embodiment. 
         FIG. 7  is a perspective view of a folding platform frame incorporating a similar frame structure to that of  FIG. 8 . 
         FIG. 8  is a partial perspective view of a platform bed frame incorporating a similar frame structure to that of  FIGS. 6 and 7  and including structure to connect two such frames to one another. 
         FIGS. 9A and 9B  are partial perspective views of another embodiment with structure to connect two frames to one another. 
         FIG. 10  is schematic cutaway view of an embodiment of a suspension leg for a platform bed frame. 
         FIG. 11  is a schematic cutaway view of a second embodiment of a suspension leg. 
         FIG. 12  is a schematic cutaway view of a third embodiment of a suspension leg. 
         FIG. 13  is a schematic cutaway view of a fourth embodiment of a suspension leg. 
         FIG. 14  is a schematic cutaway view of a fifth embodiment of a suspension leg. 
     
    
    
     DETAILED DESCRIPTION 
     In the following detailed description numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be understood by those skilled in the art that the present invention may be practiced without these specific details. For example, the invention is not limited in scope to the particular type of industry application depicted in the figures. In other instances, well-known methods, procedures, and components have not been described in detail so as not to obscure the present invention. 
       FIGS. 1-5  illustrate an improved folding bed frame  10  according to one embodiment of the present invention. The folding bed frame  10  includes two frame segments  12 ,  14 . Each frame segment is composed of an outer frame member  18  and multiple cross-members  20 . The outer frame member  18  of each frame segment may be manufactured from a single piece of material, for example, steel, aluminum, or other suitable and well known materials, that is bent or otherwise formed into a generally rectangular shape. Alternately, separate pieces of material may be combined, for example by welding, to form the desired shape for each frame segment. 
     In a preferred embodiment, the outer frame member  18  of each frame segment  12 ,  14  differ slightly in their shape. For example, the distal ends of the frame segments  12 ,  14  may be provided with one or more rounded corners. These rounded corners generally match the peripheral shape of the mattress resting on the bed frame  10  and minimize protrusion of any portion of the bed frame beyond the mattress edge. In the case of bed frames  10  that are intended for use in multiple sets, as discussed in more detail below, only the outer, distal corners of the frame segments  12 ,  14  are rounded as the inner, distal corners will typically lie adjacent a matching frame  10  and be positioned underneath the middle portion of the mattress. 
     The cross-members  20  for each frame segment  12 ,  14  are linear pieces of material, in most cases the same material used for the outer frame member  18 , that are attached to the outer frame member  18 . In the illustrated embodiment, the cross-members  20  are welded to the outer frame member  18 , although those of skill in the art will recognize that any number of other connecting methods can be used. The cross-members  20  serve at least two purposes. First, they provide increased rigidity to the frame segment. Second, combined with the other cross-members  20  of the bed frame  10 , they form the primary components of the platform that supports a mattress placed on the bed frame  10   
     The frame segments  12 ,  14  may be further supported by multiple elongated support members  22 . These elongated support members  22  combine with the cross-members  20  to provide additional support to a mattress on the frame. In the illustrated embodiment, the elongated support members  22  are narrow diameter bars that extend from one end of each frame segment to the other. These support members  22  are connected at each end to the outer frame member  18 . The elongated support members  22  may be welded to the outer frame member  18 . In other embodiments, the elongated support members  22  may be provided with threaded end sections that are threaded into mating threaded holes in the outer frame member  18 . Those of skill in the art will readily recognize that a variety of connecting methods are suitable for attaching the elongated support members  22  to the outer frame member  18 . In addition, to further increase the rigidity of the structure, the elongated support members  22  may also be connected to one or more of the cross-members  20  by any known means. 
     Each frame segment  12 ,  14  is provided with a folding leg assembly  24 . In the illustrated embodiment, these leg assemblies include two legs  26  and a leg assembly support beam  28 . The leg assembly support beam  28  is connected to each of the legs  26  in a secure manner, for example by bolts, screws, welds, or similar means. In a preferred embodiment, the leg assemblies  24  also include one or more angled support brackets  30 . The angled support brackets  30  are connected at one end thereof to the support beam  28  or the legs  26  and at the other end to the frame segment. In alternate embodiments, the leg assemblies  24  may only include legs  26  that are connected by hinges, as discussed below, to their respective frame segment. 
     The leg assembly  24  is hingedly connected to the frame segment  12 ,  14 . In the illustrated embodiment, a hinge connection  32  is provided at the top of each leg  26  to facilitate a pivoting connection between the leg  26  and one of the cross-members  20  of the frame segment  12 ,  14 . Similarly, where support brackets  30  are utilized, a hinge connection  34  may also be provided at the connection of the bracket  30  and frame segment  12 ,  14 . While the leg assembly  24  is connected to one of the cross-members  20  rather than to the outer frame member  18 , the latter arrangement is contemplated within the scope of the present invention. 
     The frame segments  12 ,  14  are attached to one another by two lateral hinge connections  36 . The hinge connection may take many forms. In the illustrated embodiment, each hinge connection  36  comprises a pair of parallel hinge members  38  that are pivotally connected at each end with the outer frame members  18  of the frame segments  12 ,  14 . 
     In order to provide further support to the bed frame  10 , each hinge connection is provided with a leg  40  to support the middle portion of the bed frame  10 . In the illustrated embodiment, the leg  40  is rigidly connected to the parallel hinge members  38  to form a roughly “T” shaped structure. This arrangement positions the legs  40  between the frame segments  12 ,  14  when the frame  10  is placed into its folded position, as illustrated in  FIG. 3 . 
     In the embodiment illustrated in  FIGS. 1-5 , each frame segment  12 ,  14  is provided with similar length and width dimensions, thereby effectively making each frame segment generally one-half of the overall dimensions of the bed frame  10 . 
     It is contemplated that pairs of bed frames  10  may be used in combination to accommodate mattresses of larger size. For example, a single bed frame  10  may be provided with overall length and width dimensions to accommodate a twin size mattress. Two such frames can be combined to accommodate a full size mattress. Swivel hooks  200 , as shown for example in  FIG. 8 , may be used to secure the two frames together and prevent the frames from being slid apart until desired. The swing hooks  200  have a base end  202  and a hook end  204 . The base end  202  is pivotally attached to the outside surface of an outer frame member  18  of one of the frame segments  12 ,  14 , preferably near one side of the frame segment  12 ,  14  such that the swing hook extends beyond the side of the frame segment  12 ,  14  to which it is attached. 
     The other frame segment  12 ,  14  is provided with an extension  206  to which the hook end  204  of the swivel hook  200  may be attached. The extension  206  may be, for example, the head of a bolt that is screwed into or welded to the outside surface of the outer frame member  18  of the other frame segment  12 ,  14 . Preferably, the extension  206  is positioned near the side of the other frame segment  12 ,  14  that abuts the frame having the swivel hook  200 . The relative positioning of the swivel hook  200  on the first frame segment  12 ,  14  and the positioning of the extension  206  on the other frame segment  12 ,  14  may be advantageously arranged such that engaging the extension  206  with the swivel hook  200  maintains the two frames in an abutting relationship. 
     In a preferred embodiment, each frame  10  has a swivel hook  200  at one end and an extension  206  at the other end. This arrangement allows for each frame  10  to be manufactured in an identical manner but, by flipping one frame 180° relative to the other frame, the swivel hook  200  of the first frame will be in position to engage the extension  206  of the second frame, while the swivel hook  200  of the second frame will be in position to engage the extension  206  of the first frame, so that both ends of the frames are secured together to form a solid base structure. 
     In a preferred embodiment of the connection structure illustrated in  FIGS. 9A and 9B , an extension  102  is similar in form to a bolt having a stem and head wider than the stem. The extension may be screwed, bolted, or welded onto the frame. The extension mates with a T-slot  104  that is cut into the outer frame member  18  of a frame. To mate the two, the frame having the extension  102  is raised slightly so that the head of the extension  102  can be inserted in a vertical direction into the T-slot  104 . The T-slot includes a lateral opening that is narrower than the width of the slot. The lateral opening accommodates the stem of the extension  102  so that the first frame can be lowered to sit evenly with the second frame after insertion of the extension  102  into the T-slot  104 , while retaining the head of the extension  102  within the slot of the T-slot  104 . The extension  102  and T-slot  104  are preferably positioned along the side of the outer frame member  18  of each frame. 
     Various combinations of extensions  102  and T-slots  104  may be used with the frames, so long as each extension  102  on a frame has a mating T-slot  104  at the appropriate location on the other frame to allow the frames to align in an abutting relationship. In one version, each frame may have multiple extensions  102  on one side of the frame and T-slots  104  on the other side. Where the frame is folding and composed of two frame segments, it is preferred that each frame segment be provided with at least one extension and one T-slot. Alternatively, each frame may have at least one extension  102  and one T-slot  104  on each side of the frame. 
       FIGS. 6-8  illustrate embodiments of a folding platform bed frame  300  using a different set of components for construction of the frame segments  302 . In this embodiment, each frame segment  302  is composed of an outer frame member  304  formed by a series of angle supports  306  that are screwed, bolted, or welded together to form each rectangular frame segment  302 . Each angle support  306  has vertical and horizontal portions that are at right angles to one another. In one version of this embodiment, the angle supports  306  are made from pieces of angle iron formed by bending an elongated piece of metal lengthwise. 
     Cross members  308  are secured to two opposing angle supports  306  to span the space therebetween and provide a support surface for a mattress. In one embodiment, the cross members  308  are wooden slats that are screwed or bolted to the horizontal portions of opposing angle supports  306 . The foregoing embodiment allows for a frame that is extremely economical to produce. Notably, the swivel hook and extension connecting arrangement discussed with the preceding embodiment can be utilized with this low cost embodiment as well in the same manner as described above. Platform frames using this structure may be produced in a non-folding version or a folding version by incorporation of a pair of hinges to connect to identical frame segments constructed in the above described manner. 
       FIGS. 10-14  describe a feature that may be incorporated into either of the foregoing embodiments or in other platform frames. The feature is a dampened suspension leg that may be incorporated into the leg assemblies of a platform frame. The suspension legs provide resilient support for the frame to increase the overall comfort of the frame and/or to accommodate variations in the surface on which the platform frame rests. 
       FIG. 10  illustrates a first embodiment of a suspension leg  400  for a platform bed frame. In this embodiment, the suspension leg  400  is composed of two telescoping sections  402 ,  404 . The upper telescoping section  402  is mounted to the bed frame in a manner similar to the standard legs described above. The lower telescoping section  404  is provided with a foot, for example a rubber pad, at its lower end and is free to move up and down relative to the upper telescoping section  402 . However, in a preferred embodiment, the upper telescoping section  402  and lower telescoping section  404  are each provided with mating lips or other engagement structures that prevent the lower telescoping section  404  from falling out of the upper telescoping section  402  after assembly. 
     A spring  406  is provided within the space defined by the two telescoping sections  402 ,  404  to bias the two telescoping sections apart and toward their maximum combined length. The spring  406  is advantageously provided with sufficient strength to be compressible in response to a significant weight being placed on the frame without “bottoming out” by compressing to an extent that the telescoping sections reach their shortest length. In this manner, except where a weight in excess of a maximum recommended amount is placed on the frame, the suspension leg remains in a position to provide resilient support to the bed frame. 
     In a preferred version of this embodiment as shown in  FIG. 11 , the spring  406  may be provided with a fabric sheath  408  to muffle any noise produced by the spring or the spring making contact with the inside walls of the telescoping sections. Alternately,  FIG. 12  illustrates a spring  406  having a coating of rubber or other elastomeric material  410  used for the same purpose. 
     In an alternate version of the suspension leg shown in  FIG. 13 , a compressible rubber insert  412  is used in place of the spring  406  to provide the resilient force to the suspension leg. 
     In yet another version shown in  FIG. 14 , an air cylinder  414  is used in a similar manner for the resilient force. In this version, the air cylinder  414  may be used in combination with the above described telescoping sections  402 ,  404 , or the air cylinder itself may form the structure for the suspension leg. 
     The preferred embodiments of the invention have been described above to explain the principles of the invention and its practical application to thereby enable others skilled in the art to utilize the invention in the best mode known to the inventors. However, as various modifications could be made in the constructions and methods herein described and illustrated without departing from the scope of the invention, it is intended that all matter contained in the foregoing description or shown in the accompanying drawings shall be interpreted as illustrative rather than limiting. Thus, the breadth and scope of the present invention should not be limited by the above-described exemplary embodiments, but should be defined only in accordance with the following claims appended hereto and their equivalents.