Abstract:
An extension and retraction system for an article of furniture, such as a storage unit, includes a mounting structure for securement to the storage unit, a base arrangement for mounting to a floor or other supporting surface, and a cantilever-type extension and retraction arrangement interposed between the mounting structure and the base arrangement. The extension and retraction arrangement is in the form of a plurality of slide assemblies, each of which includes a stationary inner guide member mounted to the base arrangement mounted to each stationary guide member for telescoping inward and outward movement. Each extension member is connected to the mounting structure, and exertion of a pull-out or push-in force on the article of furniture is transferred through the mounting structure to cause extension and retraction of the extension members, to provide movement of the article of furniture between an extended position and a retracted position. The extension and retraction system is particularly well suited for applications such as high density shelving or storage, in which a number of similarly constructed units are assembled in a closely spaced relationship, such that movement of one of the units to an extended position provides access to the contents of the unit. The number of slide assemblies may be varied according to the load requirements for the article of furniture, to provide flexibility in manufacture and installation while maintaining the same basic design for the extension and retraction system.

Description:
BACKGROUND AND SUMMARY OF THE INVENTION 
     This invention relates to furniture such as shelving or the like, and more particularly to a pull-out system for providing movement of furniture such as high density shelving between a retracted position and an extended position. 
     Various systems are known for providing pull-out movement of an article of furniture, such as a shelf, bookcase or the like, between a retracted position and an extended position. Systems of this type are useful for providing high density storage, in that there is no aisle between adjacent units. Access to a unit is obtained by pulling the unit outwardly to its extended position while leaving the adjacent units in the retracted position. This enables a user to access stored items from the front or rear of the unit. 
     Several types of known systems provide movement of a storage unit via engagement with a supporting surface such as a floor. In one form, the unit is mounted to a base having a set of wheels which provides movable support for the unit as it is moved between its extended and retracted positions. Another construction involves a hidden track system which is movable along with the unit and which includes spaced support members which engage the supporting surface as the unit is pulled outwardly to its extended position, and which are moved upwardly out of engagement with the supporting surface as the unit is returned to its retracted position. While these systems function satisfactorily to provide movement of a storage unit between extended and retracted positions, each is disadvantageous in certain applications in that the unit engages the floor as it is moved between its extended and retracted positions. In some usage environments, the unit will be mounted to or adjacent a floor having a wearable floor covering such as carpet, and repeated movements of the unit between its extended and retracted positions results in wear of such floor coverings. 
     To overcome this drawback, it is known to mount a stationary base to the floor, and to provide a telescoping frame assembly between the base and the storage unit. The telescoping frame assembly is adapted to provide cantilevered movement of the storage unit between its extended and retracted positions, without engagement with the floor or other supporting surface. This type of system functions generally satisfactorily, but the telescoping frame assembly is complex, heavy and difficult to manufacture and assemble in a cost-effective manner. 
     It is an object of the present invention to provide a cantilevered extension and retraction system for use in combination with an article of furniture, to provide movement of the article of furniture between an extended and retracted position without engagement with a supporting surface such as a floor. It is a further object of the invention to provide such a system which is relatively simple in its components and construction, yet which provides highly satisfactory and easy movement of the storage unit between its extended and retracted positions. It is a further object of the invention to provide such a system which involves a novel application of conventional components in an extension and retraction system. A still further object of the invention is to provide such a system which is easy to install and to interconnect with conventionally constructed storage units. A still further object of the invention is to provide such a system which can be differently configured to accommodate varying load requirements for the article of furniture. 
     In accordance with one aspect of the invention, a cantilevered pull-out system for an article of furniture, such as a storage unit, includes a base arrangement for mounting to a supporting surface such as a floor. One or more extendible and retractable slide members are adapted for interconnection with the base arrangement, and each slide member includes a stationary portion mounted to the base arrangement and an extendible and retractable portion movably mounted to the stationary portion. The article of furniture is adapted to be mounted to a support structure, which is secured to the extendible and retractable portion of each slide member. The slide members are constructed and arranged to provide movement of the support structure and the article of furniture between a retracted position in which the support structure and the article of furniture are located over the base arrangement, and a cantilevered extended position in which the support structure and the article of furniture are moved outwardly relative to the base without engagement of the support structure with the supporting surface. 
     The base arrangement is preferably in the form of two or more base members, each of which includes a slide member mounting section and a floor-mounting section for securement to the supporting surface. The stationary portion of each slide member is adapted for mounting to the slide member mounting section of each base member. The base members are separate from each other, and the floor-mounting section of each base member is secured to the supporting surface separately from that of the other base members. The stationary portions of the slide members span between and are supported above the supporting surface by the slide member mounting sections of the base members. The number of extendible and retractable slide members is selected according to the load requirements for the article of furniture, and the configuration of the slide member mounting section of each base member can vary according to the number of slide members to be mounted to the base members. The floor-mounting section of each base member is preferably in the form of a floor-engaging member which extends substantially transversely to the direction of movement of the support structure and the article of furniture between its extended and retracted positions, and the slide member mounting section of each base member is in the form of a series of slide mounting members extending upwardly from the floor-engaging member. Each floor-engaging member includes a floor-engaging flange adapted to receive one or more fasteners for engagement with the floor or other supporting surface, and an adjustable elevation member spaced from the floor-engaging flange. In a preferred form, each floor-engaging member defines a wall spaced vertically above the floor-engaging flange, and the adjustable elevation member includes a foot located below the wall and engageable with the supporting surface, and a threaded shank extending upwardly from the foot. The threaded shank is engaged with threaded structure associated with the wall of the floor-engaging member, such that turning of the threaded shank results in adjustment of the elevation of the foot to provide leveling of the floor-engaging member. 
     The one or more extendible and retractable slide members are preferably in the form of a series of substantially identically constructed slide members interposed between the base arrangement and the support structure. Each slide member may be a telescoping slide assembly, and the stationary portion of each slide assembly includes an axially extending guide member mounted to the base arrangement along its length. The base arrangement includes a pair of slide member mounting sections spaced along the length of the guide member of each slide assembly, and each guide member is mounted to the spaced slide member mounting sections. The extendible and retractable portion of each slide member is in the form of an extension member adapted for inward and outward telescoping movement relative to the guide member. The support structure is secured to the extendible and retractable portion of each slide member by means of an axially extending support member mounted to each extension member and engaged with the support structure. 
     The support structure preferably includes a releasable engagement arrangement for providing releasable mounting of the article of furniture to the support structure. In a preferred form, the support structure includes a rigid frame section for securement to the article of furniture, and a series of support members interposed between the rigid frame section and the extendible and retractable portions of the slide members. The support members are preferably in the form of elongated structural support members, each of which is mounted to an extension member of one of the slide members. In a preferred form, an outer pair of support members are interconnected with a pair of spaced cross-members, to make up the rigid frame section. Each support member may include a pair of spaced, upwardly extending projections which extend through a pair of openings formed in a transverse wall associated with the spaced crossmembers of the rigid frame section. A spacer arrangement may be interposed between the transverse wall and selected ones of the support members, for ensuring that the support members and the slide assemblies are equally loaded. 
     The invention further contemplates a method of assembling a pull-out mechanism for an article of furniture, such as a storage member. The method involves the steps of securing the article of furniture to a mounting structure, and providing a base arrangement adapted for securing to a supporting surface. The method further includes connecting a series of substantially identically constructed extendible and retractable slide assemblies between the base arrangement and the mounting structure. The number of slide assemblies is selected according to the load requirements for the article of furniture. The slide assemblies are interconnected with the mounting structure and the base arrangement, and provide movement of the mounting structure and the article of furniture between retracted and extended positions. The base arrangement is preferably in the form of a series of base members, each of which is adapted for separate mounting to the supporting surface. The step of interconnecting the slide assemblies with the base arrangement is carried out by securing a fixed inner portion of each slide assembly to one of a series of mounting areas associated with each base member. The method further includes the step of varying the configuration of the base member according to the selected number of slide assemblies, to provide the required number of mounting areas for the selected number of slide assemblies. Each base member preferably includes a floor-engaging member, and the step of varying the configuration of the base member is carried out by securing a series of slide mounting members to the floor-engaging member in configurations adapted to mount varying numbers of fixed inner slide assembly portions. 
     Various other features, objects and advantages of the invention will be made apparent from the following description taken together with the drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The drawings illustrate the best mode presently contemplated of carrying out the invention. 
     In the drawings: 
     FIG. 1 is an isometric view of a number of storage members or units incorporating the extension and retraction system of the present invention, showing the units in a retracted position; 
     FIG. 2 is a view similar to FIG. 1, showing movement of one of the units to an extended position to provide access to items stored on the storage unit; 
     FIG. 3 is a section view taken along line  3 — 3  of FIG. 1; 
     FIG. 4 is a section view taken along line  4 — 4  of FIG. 2; 
     FIG. 5 is an isometric view of the extension and retraction system incorporated into the storage units of FIGS. 1 and 2, shown in a retracted position; 
     FIG. 6 is a section view taken along line  6 — 6  of FIG. 5; 
     FIG. 7 is a partial section view taken along line  7 — 7  of FIG. 6; 
     FIG. 8 is a top plan view of the extension and retraction system of FIG. 5; 
     FIG. 9 is a section view taken along line  9 — 9  of FIG. 8; 
     FIG. 10 is a partial section view taken along line  10 — 10  of FIG. 8; 
     FIG. 11 is a partial section view taken along line  11 — 11  of FIG. 8; 
     FIG. 12 is a partial section view taken along line  12 — 12  of FIG. 8; 
     FIG. 13 is an enlarged view of an end portion of FIG. 12; 
     FIG. 14 is a view similar to FIG. 9, showing the configuration of an extension and retraction system for use with a storage unit having a lesser load capacity; 
     FIG. 15 is a partial section view taken along line  15 — 15  of FIG. 14; 
     FIG. 16 is a view similar to FIGS. 9 and 14, showing the configuration of an extension and retraction system for use with a storage unit having a greater load capacity; and 
     FIG. 17 is a partial section view taken along line  17 — 17  of FIG.  16 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1 illustrates a series of storage units or assemblies  20  mounted adjacent a wall  22  and supported by a floor or other supporting surface  24 . In FIG. 1, each storage assembly  20  is shown in a retracted position, in which a side of each storage assembly  20  is located adjacent wall  22 . Storage assemblies  20  are located immediately adjacent each other, and are typically installed in a row of numerous similarly constructed storage assemblies  20 , to provide high density storage along wall  22 . 
     Each storage assembly  20  is movable between a retracted position and an extended position. Storage assemblies  20  of FIG. 1 are shown in the retracted position, and the endmost one of storage assemblies  20  in FIG. 2 is illustrated as being moved to its extended position. 
     Each storage assembly  20  is in the form of a storage cabinet  26  mounted to a base or mounting structure  28 , in a manner to be explained. Storage cabinet  26  is of conventional construction, including a pair of spaced sides  30 ,  32 , a top  34 , and a bottom  36  which cooperate to define an internal storage space  38  which may be subdivided using a series of shelves  40 . Storage cabinet  26  has an open front which provides access to internal storage space  38 , and is preferably closed at its rear. When one of storage cabinets  26  is in its extended position as shown in FIG. 2, internal storage space  38  is fully exposed so as to provide access to items stored on shelves  40 . When retracted, storage cabinets  26  are located immediately adjacent each other without aisles therebetween, such that the front of each storage cabinet  26  can only be accessed by moving the storage cabinet  26  to its extended position. 
     While each storage assembly  20  is illustrated as including an open front storage cabinet  26 , it is understood that other types of storage members, such as file cabinets or storage cabinets with doors, may be incorporated into storage assembly  20 . 
     Each storage cabinet  26  extends along a longitudinal axis, along which the storage cabinet  26  is movable between its extended and retracted positions, in a manner to be explained. The open front of each storage cabinet  26  opens in a direction transverse to the longitudinal axis. 
     Referring to FIGS. 3-5, mounting structure  28  of each storage assembly  20  is connected to a cantilever-type extension system  42  for providing movement between an extended position as in FIG. 2 and a retracted position as in FIG.  1 . Generally, extension system  42  includes a base arrangement in the form of a series of base members  44 , in combination with a series of identically constructed self-contained slide assemblies  46  interconnected between base members  44  and mounting structure  28 . 
     Base members  44  are substantially identical in construction, and include an outer base member  44  positioned under the outer end of cabinet  26  when storage assembly  20  is in its retracted position, as shown in FIG.  3 . An intermediate storage member  44  is positioned approximately midway along the length of storage cabinet  26  when storage assembly  20  is in its retracted position, and an inner base member  44  is located between the intermediate storage member  44  and the inner end of storage cabinet  26  adjacent wall  22 , when storage assembly  20  is in its retracted position. 
     Each base member  44  includes a floor-engaging member  48  and a series of slide mounting members  50  extending upwardly from each floor-engaging member  48 . Referring to FIGS. 6 and 7, each floor-engaging member  48  defines spaced ends which are located outwardly of the sides of mounting structure  28 , and slide mounting members  50  are located along the length of floor-engaging member  48  between its ends. 
     Each floor-engaging member  48  is in the form of an inverted channel defining a top wall  52 , a front wall  54  and a rear wall  56 . A flange  58  extends rearwardly from the lower end of rear wall  56 , and is adapted to engage floor  24 . Flange  58  includes one or more openings for receiving fasteners  60 , which may be in the form of bolts adapted to engage anchors mounted in floor  24  at the location of each opening in flange  58 . In this manner, fasteners  60  function to securely mount each base member  44  to floor  24 . 
     Referring to FIG. 9, at least a pair of leveling members  62  is mounted to each floor-engaging member  48  at spaced locations along its length. Leveling members  62  are preferably located inwardly of the ends of each floor-engaging member  48 . Each leveling member includes a foot  64  and a threaded shank  66  extending upwardly from foot  64 . A nut  68  is mounted within an opening formed in top wall  52  of floor-engaging member  48 , for receiving the threads of shank  66 . The top of shank  66  includes a transverse slot, which is adapted to receive the end of a screwdriver or other satisfactory tool to enable shank  66  to be turned by a user and to thereby adjust the elevation of foot  64 , to provide leveling of base member  44  in a transverse direction. Leveling members  62  are also operated to provide longitudinal leveling of base members  44 , in a manner to be explained. 
     Slide mounting members  50  are in the form of endwise-mounted channel members, as shown in FIGS. 6 and 7. Each slide mounting member  50  includes a pair of spaced flanges  70  extending from a web  72 . A series of aligned, spaced slots  74  are formed in top wall  52  of each floor-engaging member  48  adjacent each side of top wall  52 , and a series of spaced transversely extending slots  76  are formed in top wall  52 , extending outwardly from the centerline of top wall  52 . The lower end of each flange  70  includes a tab adapted for engagement within one of slots  74 , and the lower end of each web  72  includes a tab for engagement within one of slots  76 , so as to locate slide mounting members  50  on top wall  52  of floor-engaging member  48 . Slots  74  and  76  are configured such that, when the tab of a web  72  is received within one of slots  76 , the tab of each flange  70  is received within an end area of one of slots  74 . As shown in FIG. 7, two of slide mounting members  50  may be placed in a back-to-back relationship to form a rectangular section, and the adjacent ends of flanges  70  may be welded together to form a tubular mounting structure extending upwardly from floor-engaging member  48 . In addition, the bottom edge of each slide mounting member  50  is preferably welded to the upper surface of top wall  52 , such that slide mounting members  50  and floor-engaging member  48  are connected in a weldment adapted to be secured to floor  24 . 
     As shown in FIG. 7, one end of each floor-engaging member  48  includes a tab  78  extending from top wall  52 , and the opposite end of each floor-engaging member  48  includes a recess  80  formed in top wall  52 . This construction provides a mating configuration, in that the tab  78  of one of floor-engaging members  48  may be received within the recess  80  of an adjacent floor-engaging member  48 , to provide alignment of a series of base members  44  when installing a number of adjacent storage assemblies  20 . 
     Referring to FIG. 4, each slide assembly  46  includes a stationary or fixed-position inner guide member  82 , an outer extension member  84 , and an intermediate slide member  86  interposed between guide member  82  and extension member  84 . Each slide assembly  46  is of conventional construction, and may representatively be that such as is available from Jonathan Manufacturing Corp. of Fullerton, Calif. under its Model No. 432. Extension member  84  is slidably mounted for telescoping inward and outward movement relative to intermediate slide member  86 , which in turn is slidably mounted for telescoping inward and outward movement relative to guide member  82 . In this manner, slide assembly  46  provides a range of inward and outward movement defined by the limit of extension of intermediate member  86  relative to guide member  82  and outer extension member  84  relative to intermediate slide member  86 . 
     Each guide member  82  includes a vertical wall  88 , which is adapted for placement against the outer surface of web  72  of one of slide mounting members  50 , as shown in FIGS. 6 and 7. A fastener, such as a screw  90 , extends through an opening in vertical wall  88  into engagement with an aligned threaded opening in web  72 , for mounting guide member  82  to one of slide mounting members  50  of each base member  44 . Base members  44  are positioned such that the slide mounting members  50  of each base member  44  are in alignment with each other in a front-to-rear direction. In this manner, a series of slide assemblies  46  are mounted to each base member  44  by engagement with one of slide mounting members  50  of each base member  44 . The alignment of base members  44  ensures that, when slide assemblies  46  are mounted in this manner, the direction of extension and retraction of each slide assembly  46  is parallel to that of the other slide assemblies  46 , which normally is perpendicular to the plane of wall  22 . 
     Referring to FIGS. 3-5 and  8 , mounting structure  28 , to which storage cabinet  26  is mounted, generally includes a rigid frame assembly or section  92  in combination with a series of inner support members  94 ′ which are interposed between rigid frame assembly  92  and the outer extension member  84  of the inner ones of slide assemblies  46 . A pair of outer support members  94 ″ form a part of rigid frame assembly  92 , and each outer support member  94 ″ is engaged with outer extension member  84  of one of the outer slide assemblies  46 . 
     Rigid frame assembly  92  includes a pair of mirror image upper cross-member assemblies  96  interconnected by outer support members  94 ″. Each upper cross-member assembly includes an inverted shallow channel member  100  defining a top wall  102  and a pair of depending side walls  104 . An inner flange  106  extends inwardly from the inner one of side walls  104 , and an outer flange  108  extends outwardly from the outer one of side walls  104 . A series of slots  110  are formed in inner flange  106 , and a series of openings  112  are formed in outer flange  108  in alignment with slots  106 . 
     A mounting member, shown generally at  114 , is secured to channel member  100 . Mounting member  114  includes a pair of mounting tabs  116  which extend through slots formed in channel member top wall  102 . Each mounting tab  116  extends upwardly from a side wall  118  which is located within the internal space defined by channel member  100 . A bottom wall  120  extends between and interconnects side walls  118 . A weld is provided between mounting member  114  and top wall  102 , such as at the location where each tab  116  protrudes from the upper surface of top wall  102 , to secure mounting member  114  and channel member  100  together. Mounting member tabs  116  define slot structure which is adapted to releasably engage a locking rod  122 , the ends of which overlap a pair of lower frame members  124  of storage cabinet  126 . Engagement of locking rods  122  within the slot of each tab  116  functions to clamp storage cabinet  26  against the upper surface of top wall  102 , to firmly secure storage cabinet  26  to rigid frame assembly  92 . The details of the manner in which mounting tabs  116  and locking rod  122  interact to secure storage cabinet  26  in place are set forth in copending application Ser. No. 09/328,478 filed Jun. 9, 1999, the disclosure of which is hereby incorporated by reference. 
     A series of studs  124  are mounted to top wall  102  of channel member  100 , and are positioned to locate the comers of storage cabinet  26  relative to rigid frame assembly  92 . A pair of openings  126  are formed in channel member top wall  102 , for providing access to the slots in the top ends of threaded shanks  66  of leveling members  62 , to provide the user with access to threaded shanks  66  to level extension system  42  upon initial installation. 
     A pair of side cover members  98  span between upper cross-member assemblies  96 . Side cover members  98  conceal the sides of mounting structure  28 , and each includes a side wall  128  and an upper lip  130  extending inwardly from the upper end of side wall  128 . Upper lip  130  overlaps the outer end of each channel member top wall  102 , and includes a lateral projection  132  which is mounted to channel member top wall  102  via a fastener  134 . 
     Support members  94 ′ and  94 ″ are generally L-shaped, defining a vertical web  136  and a horizontal flange  138  at the lower end of web  136 . A projection  140  having a relatively short length is formed at both the outer and inner end of each support member  94 ′ and  94 ″, and a pair of projections  142  having a length longer than that of each projection  140  is formed on each support member  94 ″ inwardly of each projection  140 . Projections  140  are adapted to be received within openings  112  in each channel member outer flange  108 , and projections  142  are adapted for engagement within slots  110  formed in each channel member inner flange  106 . As shown in FIG. 4, a series of fasteners  144  are employed to connect webs  136  of support members  94 ′ and  94 ″ to outer extension member  84  of each slide assembly  46 . This functions to interconnect each slide assembly  46  with mounting structure  28 , to enable movement of mounting structure  28  inwardly and outwardly relative to base members  44  and guide member  82 . 
     Engagement of projections  140  within openings  112  and projections  142  within slots  110  functions to fix support members  94 ′ and  94 ″ to upper cross-member assemblies  96 , such that support members  94  and upper cross-member assemblies  96  are movable inwardly and outwardly as a unit. 
     A series of L-shaped brackets  145  are provided for interconnecting each channel member  102  with outer support members  94 ″, such that channel members  102  and outer support members  94 ″ cooperate to define rigid frame section  92 . Each outer support member  94 ″ includes an extended projection  146 , and each bracket  145  includes a vertical leg  148  attached to extended projection  146  via a screw  150 . Each bracket  145  further includes a horizontal leg  152  which overlies channel member inner flange  106  and is secured thereto by a pair of screws  154 . With this arrangement, outer support members  94 ″ function to structurally interconnect upper cross-member assemblies  96 , to form a rigid framework which is interconnected with the outer slide assemblies  46  via connection of outer support members  94 ″ with outer extension members  84  of the outer slide assemblies  46 . 
     In the illustrated embodiment, the rigid framework of mounting structure  28  is made up of channel members  102  in combination with outer support members  94 ″. Alternatively, the rigid framework could be made up of a pair of cross-members welded or otherwise rigidly interconnected with a pair of longitudinal frame members, separate from the support members such as  94 ″. The separate rigid framework may be connected to outer extension members  84  in any satisfactory manner, such as in the same manner as support members  94 ′ are interconnected with channel members  102 . 
     A front cover member, shown generally at  156 , functions to conceal the front of mounting structure  28 . Front cover member  156  includes a top wall  158  which overlaps and is engaged with channel member top wall  102 , and a depending front wall which is bent rearwardly at its ends to form a pair of front side walls  160 . With this arrangement, the exposed portions of mounting structure  28  are concealed by side cover members  98  and front cover members  156 , to finish the external appearance of mounting structure  28  and to prevent access or damage to internal components. 
     Referring to FIG. 10, base members  44  are leveled in both directions to ensure even movement of each storage assembly  20  between its extended and retracted position. Such leveling is accomplished by manipulating anchor bolts  60  and leveling members  62 , to adjust the elevation of each base member  44  at the location of each leveling member  62  in both a longitudinal direction and a transverse direction, so as to provide a level condition for each guide assembly  46 . 
     Referring to FIG. 11, inner support members  94 ′ are set at an elevation lower than that of outer support members  94 ″. Each projection  140  of each inner support member  94 ′ extends upwardly from an upper edge  164 , and a series of shims  166  are interposed between upper edge  164  and the underside of channel member outer flange  108  to ensure that each slide assembly  46  carries a share of the load of storage assembly  20 . Each projection  140  has a width less than that of each opening  112 , and has a length only slightly less than that of opening  112 . In this manner, each support member  94 ′ is capable of “floating” side-to-side movement while the relative longitudinal movement between each support member  94 ′ and outer flange  108  is restricted by engagement of projection  140  with the front and rear edges of opening  112 . Upon installation, the user simply varies the number of shims for each inner support member  94 ′ according to the elevation of each support member  94 ′ to ensure that support members  94 ′ are equally loaded. 
     Referring to FIG. 12, the projection  142  of each inner support member  94 ′ is received within its respective slot  110 . Again, slots  110  each have a width greater than that of projection  142 , to accommodate lateral “floating” movement between support members  94 ′ and channel member inner flange  106 . Screws  150 , which secure brackets  144  to the extended flange  146  of each outer support member  94 ″, functions to transfer a proportionate share of the load of storage assembly  20  to outer support members  94 ″. FIG. 13 shows lateral movement of a projection  146  of one of supporting members  94 ″ within slot  110  and slight deflection of vertical leg  148  of bracket  145  to accommodate such lateral movement. 
     In operation, storage assemblies  20  are movable from the retracted position of FIG. 1 to the extended position of FIG. 2 by means of the user exerting an outward, pull-out force on a desired one of storage assemblies  20  using a handle  162 . Application of such a pull-out force is transferred from storage cabinet  26  to mounting structure  28  and thereby to slide assemblies  46  through support members  94 . The outward force causes extension of outer extension member  84  relative to intermediate slide member  86 , and outward movement of intermediate slide member  86  relative to guide member  82 . Slide assemblies  46  each include stop structure for preventing outward movement beyond a predetermined location, which is sufficient to provide full access to storage cabinet internal base  38  when moved to an extended position, as shown in FIG.  2 . When it is desired to return storage assembly  20  to its retracted position of FIG. 1, the user exerts a push-in force on the extended storage assembly  20 , which is transferred to slide assemblies  46  in the same manner as described above for retracting each telescoping assembly  46  and enabling movement of the extended storage assembly  20  back to its retracted position. 
     FIGS. 14 and 15 illustrate a lower-capacity version of an extension system  42 ′ for interposition between supporting structure  28  and base members  44 . The version of FIGS. 14 and 15 differs from that described previously in that only three slide assemblies  46  are employed. In this version, only three slide mounting members  50  are secured to each floor-engaging member  48 . None of the slide mounting members  50  are back-to-back, and each slide mounting member supports only a single slide assembly  46 . Slide mounting members  50  are positioned on floor-engaging member  48  such that slide assemblies  46  are substantially evenly distributed across the width of mounting structure  28 . Only selected ones of slots  74 ,  76  are employed to locate slide mounting members  50 , and slide mounting members  50  are mounted to floor-engaging member  48  by welding, as discussed previously. Each slide assembly  46  is mounted to one of slide mounting members  50  and support members  94 ′ and  94 ″ are engaged with mounting structure  28  and slide assemblies  46 , all as described previously. 
     FIGS. 16 and 17 illustrate the configuration of an extension system  42 ″ having a greater capacity than that illustrated in FIGS. 1-13. In this version, each slide mounting member  50  is oriented in a back-to-back relationship with another slide member  50 , and a slide assembly  46  is mounted to the mounting wall of each slide mounting member  50 . In this embodiment, each slot  74  and  76  is used to locate one of slide mounting members  50 , which are welded both to floor-engaging member  48  and to each other to form rigid tube assemblies extending upwardly from floor-engaging member  48 . Again, slide assemblies  46  are mounted to slide mounting members  50  and support members  94 ′ and  94 ″ are engaged with mounting structure  28  and slide assemblies  46 , all as described previously. 
     In the versions of FIGS. 14,  15  and  16 ,  17 , the configuration of the slots in channel member flanges  106  and  108  is varied according to the number of slide assemblies  46  employed for each version of extension system  42 . 
     It can thus be appreciated that any number of slide assemblies  46  can be employed according to the load requirements of storage cabinet  26 . In this manner, the same basic design of mounting structure  28  and base members  42  can easily be adapted to vary the capacity of storage assemblies  20 , according to user or manufacturer requirements. 
     The invention thus provides a highly efficient and effective mechanism for providing movement of a storage cabinet between extended and retracted positions. The invention utilizes conventional slide assemblies in a novel application, and provides a simple and efficient system for interconnecting the slide assemblies with a storage cabinet and for mounting the slide assemblies to a floor. 
     Various alternatives and embodiments are contemplated as being within the scope of the following claims particularly pointing out and distinctly claiming the subject matter regarded as the invention.