Abstract:
A shelf stores items and provides for organized and attractive display with ease of item access. Conforming to a defined physical environment or variable storage space optimally requires the shelf to provide for both vertical and horizontal adjustment. Here this is accomplished by a pair of legs that are telescopic (to reduce size) and can be locked at a height (vertical adjustment) by use of a pawl, pin, screw or other fastener known in the art. The shelf includes a planar surface that is comprised of a shelf portion, which is supported on each distal end by a leg extension. The leg extensions are mounted to the upper area of the legs. The leg extensions are received by the shelf portion, being movably mounted thereto. This allows for horizontal (width) adjustment. An end cover can be used to provide a flat surface that is consistent with the upper surface of the shelf portion. Feet are added to provide a more solid footing, the feet being removable and providing a mounting tab at the end of the legs and a mounting tab receiver at the opposite end of the legs. This allows for multiple shelves to be securely mounted one on the other.

Description:
This application claims the benefit of Provisional Application No. 60/374,240, filed Apr. 19, 2002. 

   FIELD OF THE INVENTION 
   The present invention generally relates to storage and display items. More specifically, the present invention relates to shelving and even more specifically to adjustable shelving adapted to conform to a desired dimension. 
   BACKGROUND OF THE INVENTION 
   As our lifestyles become more and more complex, we desire devices that enable organization. This helps to bring our lives some sort of normality. Shelving products have evolved since the days of the uncovered “cup boards” in the late 18 th  century to the modern cabinets with decorator doors and movable shelving as seen today. Though the shelving is typically “movable” it is not easy to move. The shelves must be unloaded, some sort of stop or mounting on two or more corners must be removed, and repositioned, the shelf reinstalled and then the shelf can again be loaded. This is a time consuming and labor-intensive project. As such, it is usually only done when the shelving is installed and never moved again. Many people are unaware that their shelving is movable. 
   As far a width adjustment, there are very few choices. For the most part this is restricted to buying or building the shelf or bookcase at the desired width. That will never be changed. 
   There are some “cup rack” type supports that offer a width adjustment. These usually include a base with an extension on one side. One of the problems is since there is an extension on a side the upper surface now has two levels, one for the base and one for the extension. This uneven surface is not only unattractive, but does not lend itself well to stacking items. Also, these devices do not provide for vertical or height adjustment. 
   SUMMARY OF THE INVENTION 
   In one aspect, the invention features a shelf with an adjustable height first leg and an adjustable height second leg positioned adjacent to the first leg. A leg extension is mounted to the first leg and the second leg, and positioned substantially orthogonal thereto. Also, a shelf portion is used that is capable of being received by the leg extensions, the shelf portion being movably mounted thereon, whereby width adjustment is enabled by varying placement of the shelf relative to the leg extensions. The shelf portion and the leg extensions may be movably mounted one to the other by a tongue in groove. In the preferred embodiment the leg extension includes the groove and the shelf portion includes the tongue. 
   The system may also include the adjustable height first leg and adjustable height second leg as each being comprised of a first portion and a second portion, which are movably mounted one to the other. The two-part construction of the legs may also include a lock releasably securing the first portion to the second portion. The lock may be a device such as a pawl, a screw or a pin. The pawl can be pivotally mounted to the first portion, and may include a bias, such as a spring or more specifically a spring coil. The second portion would include a rack and the bias applies a force to enable engagement of the pawl and the rack. 
   The device may also include a comprising an end cover, which is capable of receiving the leg extension and end cover may be modifiable in length. This can be accomplished by providing a plurality of undercuts on the end cover. 
   The first leg and the second leg may include a foot positioned on a distal end thereof and opposite to the shelf portion, as a support on which the shelf may stand. The feet can be mounted to the legs by providing the first leg and the second leg each with a mounting tab positioned on a distal end thereof and opposite to the shelf portion. A mounting tab receiver is then positioned adjacent to the shelf portion on the leg opposite to the mounting tab. This also enables stacking of one shelf on the other by removing the feet and inserting the mounting tabs of one shelf in the mounting tab receivers of another shelf, thus releasably securing one to the other. 
   In another aspect, the invention includes a method of providing an adjustable shelf as described, placing the device in said specific area and adjusting the height of the first leg and the second leg to provide a preferred vertical position of the shelf portion. The horizontal adjustment is then provided by adjusting the placement of the first leg and the second leg, thereby allowing the shelf portion to move relative to, and yet be supported by, the leg extensions. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The foregoing and other objects of this invention, the various features thereof, as well as the invention itself, may be more fully understood from the following description, when read together with the accompanying drawings, described: 
       FIG. 1  is an isometric front, upper view of an adjustable shelf produced in accordance with the present invention. 
       FIG. 2  is an isometric rear, lower view of an adjustable shelf produced in accordance with the present invention. 
       FIG. 3  is an isometric front, upper view of an adjustable shelf with the end covers shortened to allow access to the tab receivers thus enabling stacking of multiple shelves, the shelves made in accordance with the present invention. 
       FIG. 4  is an exploded isometric front, upper view of an adjustable shelf produced in accordance with the present invention. 
       FIG. 5  is an exploded isometric upper view of the upper portion of a leg, a leg extension and a section of a shelf portion, showing the assembly, the shelf produced in accordance with the present invention. 
       FIG. 6  is an exploded rear isometric view of a leg and foot assembly produced in accordance with the present invention. 
       FIG. 7  is an exploded isometric view of a pawl and rack height adjustment lock produced in accordance with the present invention. 
       FIG. 8  is an isometric view of a leg and foot assembly with a pin lock, the device produced in accordance with the present invention. 
       FIG. 9  is an isometric view of a leg and foot assembly with a screw knob lock, the device produced in accordance with the present invention. 
       FIGS. 10   a  and  10   b  are side views of an adjustable shelf in retracted and vertically extended positions respectively, the device produced in accordance with the present invention. 
       FIGS. 11   a  and  11   b  are rear views of an adjustable shelf in a vertically retracted position showing both compact and extended horizontal positions respectively, the device produced in accordance with the present invention. 
   

   For the most part, and as will be apparent when referring to the figures, when an item is used unchanged in more than one figure, it is identified by the same alphanumeric reference indicator in all figures. 
   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   The present invention is an adjustable shelf that enables both vertical and horizontal adjustment. The fully assembled shelf  12  is shown in FIG.  1 . This is a front, side, upper view that shows the preferred legs  14  which are comprised of a first portion  16  and a second portion  18 . This two-part telescoping leg assembly allows for compact storage and an elegant appearance. A lock  20 , shown here as a pawl  22 , provides a set leg length that can be determined by the user. On the bottom of the second portion  18  of the leg  14 , is positioned a foot  24 . The foot  24  is optimally releasably mounted to the end of the second portion  18 , but can be permanently fixed thereto. The advantage of the releasable mounting will be discussed later. 
   The upper end of the first portion  16  supports a planar surface including a shelf portion  26  and may include one or more end covers  28 . The end covers  28  and the shelf portion  26  comprise the supportive surface on which items can be stored. 
   In  FIG. 2  the “under side” of the shelf  12  is shown from the back. Here in the preferred embodiment the shelf portion  26  is shown to be open from the bottom. Leg extensions  30  are supported to the upper portions of the legs  14  and extend toward the other leg. This provides a “track” that enables the shelf portion  26  to move with respect to, while being supported thereon. The inside edges of the leg extensions  30  can be moved closer to or further apart from each other thus enabling a variation in shelf width. 
   The height adjustment of the legs  14  is more clearly seen in this figure. In this, the preferred embodiment, the second portion  18  of the leg  14  includes a rack  32 . This rack  32  can be molded into the second portion  18 , as shown here or it can be a separate part that is mounted thereto. In either case, the rack includes teeth that provide a graduated vertical set of “steps” for attachment of the pawl to conditionally secure the first and second portions of the legs. This provides an easy and efficient method of adjustment of the vertical aspect of the shelf. 
   In  FIG. 3 , at the top end of the first portion  16  of the leg  14  is a leg base  34 . The leg base  34  has a primary function of providing a cap for the upper edge of the first portion  16  of the leg  14  as well as providing an attachment for the leg extension (item  30  shown in FIG.  2 ). The leg base  34  can be exposed by either shortening the end covers  28 , or by extending the legs  14  further away from one another. 
   The leg base  34  may include one or more mounting tab receivers  36 . These receivers  36  can take a variety of shapes and configurations, but are intended to mate with mounting tabs (not shown here) on the bottom end of the second portion  18  of the leg  14 . The foot  24  is releasably fastened to the second portion  18  by the foot also including tab receivers, similar to those in the leg base  34 . This combination allows the user to stack a second shelf on a first shelf by remove the foot  24  from the second shelf and placing the mounting tabs exposed by removing the foot  24 , and placing the tabs into the receivers  36  on the leg base  34  of the first shelf. This allows secure stacking of one shelf on the other. 
   An exploded view of the invention  12  is shown in  FIG. 4  to better shown the relationship between the parts. The leg extension  30  is shown here to be releasably secured to the leg base  34 . This is done to provide for a more efficient “knock down” of the product to reduce shipping costs. A locking tab  38  is used to articulate with a hole in the bottom of the leg extension  30  and they are supported together by the leg protrusions  40  that mate with the protrusion cavities  42  on the leg extension  30 . This is only one method of assembly of these parts and is not intended to limit the scope of the invention. The invention can also be manufactured such that the leg extensions and the leg base  34  are one part. 
   The shape of the leg extension  30  is shown here to mate with and allow movement of the shelf portion  26  relative thereto. The ability of the shelf portion  26  to slide against the leg extension  30  and yet be supported by the leg extensions  30 , allows for horizontal adjustment of the leg positions. 
   The vertical adjustment is provided by the second portion  18 , which is received by the first portion  16  of the leg  14 . The lock in the form of a pawl  22  is shown to also be exploded from the first portion  16 . The details of this and other locks will be discussed later. 
   At the lower distal end of the second portion  18  are more clearly shown the mounting tabs  44 . These tabs  44  are shown here to be substantially in the shape of a cylindrical pin, but this general shape and specific details are not critical to the novelty of the invention. The tab receivers  46  in the feet  24  are made to fit the tabs  44 , thereby releasably locking them together. In a similar manner each leg base  34  also includes a receiver  36  to allow for stacking of the shelves  12 , as previously noted. 
   Further detail of the function and assembly of the leg  14  via the leg base  34  to the leg extension  30  is shown in FIG.  5 . The leg protrusions  40  are received by the protrusion cavities  42  of the leg extension  30 . The locking tab  38  includes a pin  48  which extends downward from the underneath side of the tab  38 . This pin  48  also extends through a cavity  42  to be received by a hole in the bottom of the extension  30 . With the protrusions  40  positioned within the cavities  42  (as shown by the arrow  50 ) and the pin  48  securing them in place, the structure of the leg  14  with the leg extension  30  via the leg base  34  is functionally one rigid unit. 
   The shelf portion  26  is received by the leg extension  30  as shown by the second arrow  52 . Though the shelf portion  26  can take a variety of forms, what is shown is considered by the applicants to be the preferred embodiment. The bottom side of the shelf portion  26  is open except for the “C” shaped edges  54 . These “rails” run the length of the shelf portion  26  to provide for structural rigidity of the shelf portion  26  without excess material to cause potential part interference, added weight or cost. The shelf portion also includes a pair of tongues  56 . The tongue  56  has a multi-fold purpose. First the material placement adds to the section modulus of the shelf portion about the axis that would see flexion when the shelf is loaded. This adds to the strength of the shelf portion especially when the shelf is at an extended position where a minimal amount of contact is made between the shelf portion  26  and the leg extensions  30 . 
   The second purpose to the tongue  56  is as a tracking guide along the grooves  58  located within the leg extensions  30 . This tracking assistance reduces the likelihood for the shelf portion  26  to bind when moving along the leg extension  30  when the shelf width is being changed. 
   The third advantage to the tongue  56  and groove  58  combination is during the loading of the shelf. When items are placed on the shelf portion  26 , during its intended purpose of item storage, the weight of these items will cause the leg extensions  30  to flex slightly along an axis parallel to the long axis of the grooves  58 . This is due to the reduced section at the grooves due to the presence of the grooves  58 . The upper portion is open. When this happens the outside upper edges of the groove  58  will pinch together slightly, grabbing the tongue positioned there between. The friction due to the contact of the tongue and grooves acts as a “lock” to further stabilize the shelf and prevent it from moving from side to side when it is loaded. This eliminates the need for further locking of the shelf portion  26  to the leg extensions  30  when the shelf is in place. Under more extreme conditions, an additional lock mechanism may be used. 
   As such, it is understood that any form of locking mechanism known in the art can be added between the shelf portion  26  and the leg extensions  30 . 
   A single leg  14  is shown in FIG.  6 . Here the first portion  16  is shown with a pair of ears  60 , which hold the pawl  22  as it is pinned through the pawl hole  62  and the ear holes  64 . The pawl includes a pawl handle  66  and a pawl tip  68 . The handle acts to enable the user to manipulate the pawl tip  68  to disengage it from the rack teeth  32  in the second portion  18  of the leg. The mounting tabs  44  are received by the tab receivers  46  in the foot  24 . Also as previously noted, the mounting tabs  44  of another leg can be received by the receivers  36  in the leg base  34 . 
   A more detailed view of the locking mechanism is shown in FIG.  7 . The pawl  22  is shown as removed from the first portion  16  showing the rack window  70 . This window  70  allows access of the pawl tip  68  to the rack teeth  32 . The pawl  22  can be manufactured from an number of materials but is preferably made from a plastic. This is inexpensive and allows for good elastic properties. The elastic properties are relevant in that in the preferred embodiment the pawl also includes a spring coil  72 . This spring can be a separate item that is attached to the pawl  22  or as in this case a molded portion of the pawl  22 . The free end of the spring coil  72  is positioned on the ridge  74  located above the window  70  and on the first portion  16 . The spring then pushes the handle  66  of the pawl  22  out away from the rack  32 , about the pivot of the pawl hole  62  and the ear holes  64 , thus engaging the pawl tip  68  into the rack teeth  32 . To disengage the pawl tip  68  from the rack  32 , the handle  66  is pressed in toward the first portion  16 , pulling the tip away form the rack teeth  32 . This flexes the spring  72  so when the handle  66  is released by the user, the bias from the spring  72  reengages the tip  68  and the rack  32 , locking one to the other. 
   Another form of locking of the first portion  16  and the second portion  18  is accomplished by a pin  76  as shown in FIG.  8 . Here the pin  76  is shown as it would be assembled into a first hole  78  located in the first portion  16  and also one of a plurality of second holes  80  located in the second portion  18 . The first portion  16  is still able to move along the long axis of the second portion  18 , as previously noted, only the locking mechanism is comprised of the pin  76  positioned through a pair of properly aligned holes ( 78  and  80 ). 
   To achieve an infinite variety of height adjustments, a screw knob can be used for height adjustment. This is illustrated in FIG.  9 . Here a knob  82  with a pressure pin  84  mounted to the end also includes a threaded portion  86 . The threaded portion  86  is received by the mating threads  88  on a receiver  90 , which is mounted to the first portion  16 . A hole (not shown) is located within the receiver  90  to allow the pressure pin  84  access through the first portion  16  to contact the second portion  18 . The friction between the pin  84  and the second portion  18  is provided and varied by the amount of tightening of the knob  82 , thus pushing the pin  84  more firmly against the second portion  18 . 
   The height adjustment of the device is shown in a side view in  FIGS. 10   a  and  10   b . The minimum height of “Y 1 ” is shown in  FIG. 10   a  where the pawl  22  is at the bottom of the rack  32 . The highest position “Y 2 ” is shown in  FIG. 10   b . The difference being the relative positioning of the first portion  16  to the second portion  18  and as held in place by the pawl  22  and rack  32 . The rack  32  design is also shown here to be of a saw-tooth design. This provides a vertical slant upward followed by a substantially horizontal “ledge”. The pawl tip  68  includes a shape that nearly matches this “V”, thus providing a locking of the pawl  22  to prevent downward movement of the first portion  16 . In this application, this design is beneficial in that little resistance is offered to restrict vertical movement of the first portion relative  16  to the second portion  18 . This allows the user to lift the shelf portion  26 , and the weight of the second portion  18  and the feet  24  will allow the second portion to “fall” away from the first portion  16 , thus “ratcheting” out to fit the height needs of the user. When the user desires a lower height, the user needs only to press the handle  66  of the pawl  22  in, releasing the pawl tip and allowing the first portion  16  to freely move relative to the second portion  18 . 
     FIGS. 11   a  and  11   b  show the horizontal width adjustment provided by the device. The narrow position is shown by the dimension “X 1 ” in  FIG. 11   a  and the widest dimension is depicted by “X 2 ” in  FIG. 11   b . As can be seen here, the shelf portion  26  remains at a constant place in both positions. The relative position of the legs  14  and the gap between the leg extensions  30  increases from “Xa” to “Xb”. This provides the increased width. It is understood that both the height adjustment, as shown in  FIGS. 10   a  and  10   b , as well as the width adjustment, as shown here, can both be performed together in any combination allowed by the specific design of the elements of the device. Thereby providing both width and height adjustment in a single shelf to fit any of an infinite number of space requirements.