referring to fig1 - 15 , there is seen one embodiment of an adjustable trivet 10 of the present invention . the trivet 10 is well suited for retaining a hot cookware container , such as a plate , dish , pot , pan , baking stone or the like , on an underlying surface . the term &# 34 ; underlying surface &# 34 ; means any surface capable of supporting the trivet 10 in a substantially horizontal fashion , such as a table top , floor , sill , countertop and the like . referring now to fig1 trivet 10 is comprised of edge supports 12 and 18 , rods 14 and 20 , and middle supports 16 and 22 . assembled as shown in fig2 these elements form two substantially identical components which are slideably interlocked to one another . in the preferred embodiment , trivet 10 is constructed of a wood material , as shown in fig3 and 4 . naturally , other materials or combinations of materials such as wood , metal , metal alloy , graphite , plastic , polymers and the like may be used . first edge support 12 and second edge support 18 each have a support surface 24 . the edge support surface 24 of each edge support 12 and 18 is designed to engage a cookware container at its outermost edge , as shown in fig1 . the support surfaces 24 should be wide enough to engage a sufficient portion of the container and thereby provide support and stability to the container . additionally , each edge support 12 and 18 is provided with an affirmative retaining means . the retaining means is an element which restricts a hot container from being unseated from support surface 24 . in a preferred embodiment , this feature is accomplished by edge raised surface 30 ( see fig3 - 7 ). edge raised surface 30 of each edge support 12 and 18 is preferably an integral portion of the respective support surface 24 , as shown in fig3 and 4 . however , it is anticipated that a completely separate raised surface 30 may be connected in some fashion to support surface 24 to accomplish the same goals . by providing a raised surface 30 along the length of each support surface 24 the container placed on trivet 10 is partially &# 34 ; nested &# 34 ;. that is , the configuration restricts a container from accidentally sliding off the front or back ( relative to fig1 ) of each support surface 24 . another advantage of the edge raised surfaces 30 is that they may also be further extended to form handles 31 on each edge support 12 and 18 ( see fig5 - 7 ). the handles 31 may be used for carrying the trivet 10 in a horizontal position . this may be done with or without a container in place . however , the use of trivet 10 as a means for carrying containers should be done carefully and with great caution . other than the possibility of breaking the trivet 10 at the center , the trivet 10 may be accidentally expanded while carrying allowing the container to shift unexpectedly and fall from the trivet . the preferred use of handles 31 would be to move trivet 10 , with or without a container in place , over an underlying surface , preferably by sliding . this can be accomplished by lifting only slightly on both handles 31 and slowly applying enough lateral force with both hands to overcome the frictional force between the trivet 10 and the underlying surface . preferably , as shown in fig8 the bottom side of trivet 10 is substantially smooth causing less friction against an underlying surface . the second element of the two substantially identical components is the middle supports 16 and 22 ( see fig1 and 2 ). middle supports 16 and 22 provide the seated container with support between the outermost edges . each middle support 16 and 22 is comprised of a middle support surface 26 . middle support surface 26 is designed to engage the underside of the container , similar to edge support surface 24 . this support is important because some cookware may have a tendency to droop or sag in the middle when supported at the edges . it is preferred that middle support surface 26 be approximately the same height as edge support surface 24 . this configuration will provide the greatest stability for a seated hot container . each middle support 16 and 22 is also comprised of an affirmative retaining means . the retaining means serves to restrict a seated container from sliding off either side of trivet 10 . in a preferred embodiment , the retaining means is a raised surface 32 on each end of each middle support 16 and 22 . middle raised surfaces 32 restrict side - to - side shifting of a container while on trivet 10 . preferably raised surface 32 is integral to support surface 26 ( e . g ., see fig3 and 4 ), but may be a separate element attached by some method to support surface 26 . in combination with the edge raised surfaces 30 , the middle raised surfaces 32 allow a container placed on trivet 10 to be completely &# 34 ; nested &# 34 ; ( see fig1 ). that is , a seated container would be restricted from most substantial movement in all lateral directions . the final element of the two substantially identical components of trivet 10 is the extension rods 14 and 20 . in the present preferred embodiment , rods 14 and 20 are shown to have a circular cross - section , but it is anticipated that other geometric shapes would be possible . additionally , in the interest of stability and strength it is preferred that the extensions should be substantially rigid . rods 14 and 20 are preferably attached at one end to an edge support 12 or 18 , and at the other end to a middle support 16 or 22 . attachment is accomplished by any of the most effective means known to those skilled in the particular field . in a preferred embodiment , a hole is made in the face edge of the support structure , such as the edge support or middle support . the depth of the hole is dependent upon factors such as the method of attachment , the length of rods 14 and 20 , the desired adjustable length of the trivet 10 , and the like . the placement of the holes is the same for each of the two substantially identical components and should take into consideration the number of rods 14 and 20 to be used . the embodiment shown in fig2 uses two rods per support pair ( one edge support and one middle support ), and therefore two holes are made in edge support 12 and 18 . one hole should be approximately 1 . 5 to 3 times as far from the side as the other hole is from the opposite side ( e . g ., if the first hole is 2 inches ( 5 . 1 cm ) from the right side , then the other hole should be between about 3 inches ( 7 . 6 cm ) and about 6 inches ( 15 . 2 cm ) from the left side ). corresponding holes should be made in the complementary middle support 16 and 22 . in addition , on each middle support 16 and 22 , bore holes 34 should also be drilled . the diameter of the predrilled bore holes 34 should be greater than the diameter of the rods 14 and 20 to allow easy sliding . the placement of the predrilled bore holes 34 should be the mirror image of the opposing end . that is , using the previous example above , the side having the rod hole at 2 inches ( 5 . 1 cm ) will have a predrilled bore hole equal to the distance of the rod hole for the opposite side ( between about 3 to about 6 inches ( 7 . 6 to 15 . 2 cm )). bore holes 34 act as guide means for the adjustability of the two identical components , and also serve as the means for interlocking the two substantially identical components . the placement of rod holes and predrilled bore holes 34 can be more readily understood from fig2 . the length of rods 14 and 20 can be varied for customizing trivet 10 . where use is to be made with smaller containers , shorter rods would be suitable . use with larger containers would require longer rods . it is also preferred , but not required , that the length of rods 14 are equal to the length of rods 20 . once assembled , trivet 10 is capable of supporting containers of various sizes . by pushing edge support 12 and edge support 18 at handles 31 towards one another , trivet 10 will achieve its minimum size ( see fig9 - 13 showing all views of trivet 10 in a &# 34 ; closed &# 34 ; configuration ). alternatively , by pulling at handles 31 moving supports 12 and 18 in opposite directions , trivet 10 will achieve its maximum size ( see fig1 and 15 , showing the &# 34 ; open &# 34 ; configuration ). another feature of the present invention is more easily understood when comparing the configurations of fig9 and fig1 . in the top view of fig9 while the edge supports 12 and 18 are at a minimum distance apart , middle supports 16 and 22 are at a maximum distance apart . fig1 , also a top view , shows that when at a maximum distance apart for edge supports 12 and 18 , middle supports 16 and 22 are at a minimum distance apart . the general purpose of this feature is to provide greater support at the middle of longer containers , as this is the area that is most likely to droop or sag , possibly contacting and damaging the underlying surface . trivet 10 is designed such that middle supports 16 and 22 are moved toward the middle of a seated container , as edge supports 12 and 18 are drawn apart , until they meet ( fig1 ). conversely , as edge supports 12 and 18 are moved together , middle supports 16 and 22 move to provide greater support to the outermost edges , effectively doubling the edge support surface 24 when trivet 10 reaches minimum size ( fig9 ). another advantage of trivet 10 is that it may allow cooling of a hot container while seated . cooling is more readily accomplished when cooling air is able to continuously flow around a large portion of the surface area of the hot container . in a preferred embodiment of trivet 10 , cooling channels 40 are provided ( see fig8 , and 14 ). cooling channels allow air to flow not just over the seated container , but also below the container where the greatest surface area is located . according to the present invention , the number and size of the cooling channels 40 can be changed to suit the size of the seated container . for example , fig8 showing a partially open configuration , includes three narrow cooling channels 40 , while fig9 a closed configuration , has one large cooling channel . still another configuration , the completely open configuration used for the largest containers and shown in fig1 , has two large cooling channels 40 . the foregoing illustrates the general principles of this invention . however , since numerous modifications and changes will be readily apparent to those skilled in the art based on this description , it is not desired to limit the invention to the exact construction and operation shown and described . accordingly , the scope of this invention includes other modifications and equivalents that fall within the scope of the foregoing description and the following claims .
an adjustable trivet having two substantially identical components slideably interlocked to permit use with various size cookware is provided . each component is equipped with an edge support having a raised end surface , a middle support having a raised end surface , and an extension for connecting the complementing supports . the adjustability feature provides greater support in the central area of larger containers , while moving the support toward the ends of the container as the size decreases .