However, the placement of the leg supports relative to the side rails is often dependent on the overall width of the cross-rail support。 It would be advantageous to have across-rail  support  system with an adjustable overall width to fit varying sizes of mattresses and adjustable leg supports where the placement of the leg supports along the support system is independent from the overall width of the support system。 This would allow for the placement of the leg supports to be determined not based on the width of the mattress but rather for support and comfort or other considerations such as possible obstructions underneath the bed。 Furthermore。 it would be advantageous if the support system was easy to use and required a minimal number of parts。

         BRIEF SUMMARY OF THE INVENTION

   The present invention addresses the above needs and achieves other advantages by providing a cross-rail support system having a number of adjustable support leg assemblies attached to two parallel and adjacent elongate beams。 The overall width of the support system is adjustable by sliding the elongate beams relative to each other along their lengths。  The placement of the support leg assemblies is also adjustable by sliding the assemblies along the elongate beams and is independent from the total width of the support system。 In addition。 the leg assemblies maintain the parallel alignment of the elongate beams to each other and provide

support to the mattress。

  In one embodiment, the present invention includes across-rail support system for use with a bed frame to support a mattress。 The cross-rail support system has a pair of elongate beams and at least two leg assemblies。 The elongate beams are in a parallel alignment to each other and together define an overall width between their outer ends that extends across the bed frame。 The leg assemblies maintain the parallel alignment between the beams and provide support to the mattress。 Each assembly includes an elongate tube and a leg structure。 Each elongate tube defines at least one interior space for holding the elongate beams side by side and allowing the sliding of the elongate beams along the lengths of each other thereby adjusting the overall width of the cross-rail support system。 Each leg structure depends from the elongate tube of its respective leg assembly and has a height that extends generally perpendicular to the elongate beams。 Also, the leg assemblies are slide able along the lengths of the elongate beams relative to each other and independently from the overall width of the elongate beams so that the positions of the leg assemblies and overall width of the cross-rail support system are independently adjust-

able。

  In other embodiments。 the cross-rail support system has one or more leg assemblies。 Each leg assembly also may have at least one locking member for inhibiting each leg assembly and the elongate beams from sliding when the locking member is engaged。 Also。 the height of each leg structure may be adjustable。 For example, the leg structures may comprise a series of telescoping extensions。 Further。 A locking member may be included on the leg structure such that when engaged the height of the leg structure is fixed。 The elongate beams and elongate tubes may be rectangular in shape。 In another aspect, each leg structure depends from its respective elongate tube at a position closer to an outer end of that elongate tube。 Brackets may also be affixed to the outer ends of each elongate beam for engaging the side rails of a bed frame

  Another embodiment of the invention includes a bed frame assembly for supporting a mattress。 The bed frame assembly includes a pair of side rails, a pair of ends, and at least one of the cross-rail support systems。 The sliding guide confines the movement of the sliding element,the inferior end of which is hingedly linked to the sliding element。The pair of side rails and the pair of ends are interconnected forming a rectangular frame。 The cross-rail support system or systems are connected to the side rails between the ends。