FIELD OF THE INVENTION

The present invention relates generally to shelving systems. More specifically, it relates to free-standing, modular shelving units that may be assembled by hand without tools.

BACKGROUND OF THE INVENTION

Free-standing, modular shelving units are available in a variety of types. Assembling shelving units, however, is often a time-consuming task that requires various parts and tools.

A simple common shelving unit design consists of rectangular wood planks separated by steel shelf risers that are attached to the planks by screws or bolts. Although structurally stable, this type of shelving system requires tools to assemble and disassemble. Another common design is a boltless steel rack shelving unit that has four tall steel vertical support bars with holes and horizontal bars with rivets. These units may be assembled by hand to create a frame for holding multiple wood shelves. Although this design may be assembled by hand, it is typically not modular, and it does not disassemble to form a compact kit.

Another common modular shelf design is to simply stack wood boxes vertically and horizontally to create the desired size shelving unit. The boxes, however, need to be fixed to each other, typically using tools and additional hardware, to provide overall stability. Moreover, the boxes are bulky and typically are not designed to disassemble into more compact form.

Common wire rack shelves snap together by flexing a vertical support bar of one level of the shelf so that a lip at the foot of the bar snaps into a loop at the top of the level below, for example, as shown in Fig. 4 of US 5035335. This type of modular shelving system is easily hand-assembled, but the vertical supports and horizontal shelves are permanently fixed to each other, so that when disassembled it remains bulky. In addition, because the vertical legs are designed to horizontally flex, the resulting structure lacks stability and is not suitable for heavy duty use. In view of the above, there is still a need in the art for improved shelving units that do not suffer from the limitations in the prior art.

SUMMARY OF THE INVENTION

In one aspect, the invention provides a shelving unit that is self-supporting, freestanding, structurally stable, rigid, modular, and stackable. Moreover, the shelving unit may be easily assembled and disassembled by hand without tools, and it is compact when disassembled. Specifically, to form a structurally stable shelving unit, no screws, bolts, nails, or other attachment members are required in addition to the shelves and risers themselves. In one aspect, a free-standing shelf system includes an upper shelf with an upper pair of slits at opposite ends, a lower shelf with a lower pair of slits at opposite ends, an upper pair of vertical supports, and a lower pair of vertical supports. Each of the vertical supports is made of a rigid metal bar shaped to form a top horizontal loop portion, two slanted vertical portions and two bottom horizontal portions, and has a slanted L profile. The upper pair of vertical supports are positioned at the opposite ends of the upper shelf, such that the top horizontal loop portions of the upper pair of vertical supports pass through the slits of the upper shelf to form an upper pair of protruding loops. Similarly, the lower pair of vertical supports are positioned at the opposite ends of the lower shelf, such that the top horizontal loop portions of the lower pair of vertical supports pass through the slits of the lower shelf to form a lower pair of protruding loops. The bottom portions of the upper pair of vertical supports passes through the protruding loops of the lower pair of vertical supports to lock the lower pair of vertical supports in place, i.e., to secure the lower pair of vertical supports to the lower shelf. The shelf unit may further include a pair of U-shaped metal locking bars that pass through the protruding loops of the upper pair of vertical supports to lock the upper pair of vertical supports in place. The shelf unit may also include additional shelves and corresponding pairs of vertical supports, and a pair of U-shaped metal locking bars that pass through protruding loops of a top level pair of vertical supports.

The shelf unit may further include a ground-level shelf and a pair of U-shaped metal loop bars that pass through slits of the ground-level shelf to form a lower pair of protruding loops. The bottom portions of the lower pair of vertical supports pass through protruding loops of the U-shaped metal loop bars to lock the U-shaped metal loop bars in place.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a perspective view of a shelf component of a shelving system according to a preferred embodiment of the invention.

Fig. 2 is a perspective view of a riser that serves as a vertical support for a shelving unit according to a preferred embodiment of the invention.

Fig. 3 is a perspective view of an assembled shelving unit having three shelves, each with a pair of risers, according to an embodiment of the invention.

Fig. 4 is a front profile view of a riser, showing its slanted L-shaped profile, according to an embodiment of the invention.

Fig. 5 is a side profile view of a riser, showing a top loop portion just above a widening portion and two vertical portions that are tapered downward, according to an embodiment of the invention.

Fig. 6 is a bottom view of a riser, showing its tapered bottom portions, according to an embodiment of the invention.

Fig. 7 is a perspective view of a U-shaped locking attachment bar, according to an embodiment of the invention.

Fig. 8 is a perspective view of a metal starting loop, according to an embodiment of the invention.

Fig. 9 is a perspective view of a locking bar loop and starting loop interlocked with a riser, according to an embodiment of the invention. Fig. 10 is a perspective view detailing the ends of two levels of a shelving unit according to an alternate embodiment of the invention.

DETAILED DESCRIPTION

An overview of an embodiment of a shelving system according to the present invention is illustrated in Figs. 1-3. This shelving system uses modular shelves (Fig. 1) and risers (Fig. 2) that are easily hand-assembled to form a shelving unit (Fig. 3). The shelves and risers combine in a sequential, interlocking fashion as levels are stacked up during assembly. The system is extensible, allowing any number of levels to be stacked to form a stable unit. In the case of a single level, it may be used as a bench, coffee table or similar. Each level has one shelf (Fig. 1) and a pair of risers (Fig. 2), and the height of each pair of risers determines the vertical spacing between shelves. Use of riser pairs having different heights allows the shelving unit to have shelves with different vertical spacing. Once assembled, the entire shelving unit is stable and can be moved and even flipped upside down for a different aesthetic appearance.

Fig. 1 shows a shelf component of the shelving system according to a preferred embodiment of the invention. The shelf 100 is a single rectangular wood board with rectangular slits 102, 104 positioned at opposite ends of the shelf. The board length is preferably at least twice the width and at most ten times the width. The slits are preferably oriented perpendicular to the length of the board, or more generally within 30 degrees of being perpendicular, and extend 60% to 90% of the width of the board. Preferably, the slits are between 1 cm and 3 cm in width. Each slit is preferably 2 cm to 20 cm cm from an end of the board. In alternate embodiments, the corners of the board may be rounded, even to the point of forming a complete semi-circle or semi- oval at each end of the board.

Each shelf 100 may be made of solid wood, such as plywood. The shelf 100 can also be made of metal reinforced particleboard, or various other structures of wood, metal and/or plastic. The shelves may be coated, treated, or covered with another material to enhance their function and/or increase their visual appeal. For example, a simple felt pad cut to conform to the shape of the shelf, including slits, can provide padding useful if a single level is used as a bench. Wood shelves may be varnished, and aluminum boards may be brushed. Colored formica may also be used as a finish. Fig. 2 shows a riser that serves as a vertical support for the shelving unit, according to a preferred embodiment of the invention. The riser 200 is made of a single rigid metal bar (solid or hollow), such as a bent steel rod, forming a rigid vertical support. The riser may also be made of multiple bent steel rods welded together, aluminum rods, bent steel sheet metal, or cast metal (aluminum or steel). Various techniques such as metal bending, metal casting, extrusion, and welding may be used. The risers can be powder coated using any of a variety of different colors.

The riser 200 has a top horizontal loop portion 202, two slanted vertical portions 204, 206, and two bottom horizontal portions 208, 210. In the context of the present description "loop" is defined as a curved shape, such as an open U shape, Ω shape, or closed O shape. In this embodiment, each riser 200 is formed as a steel rod shaped in a closed ring, with the bottom portions 208 and 210 joined. As shown in the profile view of Fig. 4, the riser 200 has a slanted L-shaped profile. For example, the slanted vertical portion 204 and bottom horizontal portion 208 form a slanted L shape (as do the slanted vertical portion 206 and bottom horizontal portion 210). The L shape is preferably designed so that the top horizontal loop portion 202 of the riser is directly above the center of the horizontal portion 208 of the L, thereby creating a slanted L shape. This alignment above the center is not a requirement in all embodiments, and the L shape is not necessarily slanted (i.e., vertical portion 204 and bottom horizontal portion 208 may be perpendicular). Figs. 5 and 6 show side and top views of the same riser. The bottom horizontal portions 208, 210 are tapered inward, as clearly shown in Fig. 6, such that the separation between the bottom portions 208, 210 at the point that is directly below the top loop portion 202 is equal to the with of the top loop portion 202, thereby allowing the bottom horizonal portions to slide into the top loop portion 202 of another riser of an immediately lower level of the shelving unit. A shelving unit, as shown in Fig. 3, may be hand-assembled by sequentially stacking levels, where each level has a shelf and a pair of risers. The unit in Fig. 3, for example, has three levels with respective shelves 300, 302, 304. Shelf 300 has risers 306 and 308, shelf 302 has risers 310 and 312, and shelf 304 has risers 314 and 316. Each level provides a base for the next higher level of the shelf. When the next level is added, it serves to lock the lower shelf risers in place. First, a bottom level is assembled by inserting the top horizontal loop portion of two risers 306, 308 into the slits at opposite ends of shelf 300. The top horizontal loop portions of the risers 306 and 308 are shaped so that when inserted through the slits in the shelf 300, it creates a loop of metal protruding above the surface of shelf 300. The shape of the riser widens just below the loop portion passing through the slit of the shelf so that the riser supports the shelf (as shown in Fig. 5). The risers 310, 312 for the next level of the unit rest on shelf 300 of the first level, and the bottom portions of these risers 310, 312 slide horizontally into the horizontal loops of risers 306, 308 that protrude above the surface of shelf 300. Consequently, the second-level risers 310, 312 lock the first- level risers 306, 308 in place so that they can not slide vertically out of the slots in the shelf 300. The slots of the second-level shelf 302, in turn, prevent the second-level risers 310, 312 from sliding horizontally out of the loops of risers 306, 308. Because each level of the shelving unit locks the portion of the metal loop protruding from the previous shelf, the system locks together as it is assembled.

To terminate the top shelf 304 of the shelving unit, a pair of U-shaped riser terminating components may be used, such as the locking attachment bar 700 shown in Fig. 7. These locking bars have a shape similar to the bottom portion of a riser, and they are used in the same way as a pair of risers, by sliding them horizontally through the horizontal loops protruding through the top shelf slits. Fig. 9 illustrates a locking bar 700 interlocked with a riser 900. For clarity, the shelf is not shown.

If a ground-level shelf is desired below the risers of the lowest level of a unit, then a metal starting loop 800 may be used, as shown in Fig. 8. These locking bar loops have a shape similar to the top horizontal loop portion of a riser, and they are used by sliding them vertically through the ground-level shelf slits at the very beginning of the assembly process. The bottom portions of the first level risers then slide into the loops protruding from the ground level shelf. Fig. 9 illustrates a locking bar loop 800 interlocked with a riser 900. For clarity, the ground-level shelf is not shown. To disassemble the shelving unit of Fig. 3, the top locking bars are removed from the horizontal loops of the top level risers 314, 316 protruding from the top shelf 304. This allows the top shelf 304 to be lifted vertically off its pair of risers 314, 316. With the top level risers no longer locked horizontally in place by the top shelf slits, they may slide horizontally out of the protruding horizontal loops of the risers 310, 312 below. This allows the next shelf 302 to be lifted vertically off its risers 310, 312, which frees those risers to slide horizontally out of the loops of the risers 306, 308 below, and so on. The components of a disassembled shelving unit forms a compact and packable kit including a stack of boards, nested risers, and terminating elements. Fig. 10 illustrates one end of two levels of a shelving unit according to an alternate embodiment of the invention. Similar to the embodiment shown in Fig. 3, each level of the unit has a shelf with slits and a pair of rigid metal risers having slanted L profiles. In this embodiment, however, each end of the shelf has two co linear slits instead of just one slit, and each riser has two top horizontal loop portions instead of just one. In the example shown in Fig. 10, shelf 1000 has two co linear slits 1008 and 1010 at the same end of the shelf, and loop portions 1004 and 1006 of a single riser protrude through these two slits. Similarly, shelf 1002 has a pair of co linear slits at the same end of the shelf, and two loop portions of a single riser protrude through the slits. For example, loop 1012 protrudes through slit 1014. Additionally, each riser is not a closed ring. The bottom horizontal portion of each riser has two parallel arms instead of a tapered loop. For example, the riser shown for shelf 1002 has bottom horizontal portions 1018 and 1020. The bottom parallel arms of each riser are designed to slide through the top loops of the riser below it. For example, bottom arm 1016 slides through the loop 1012 of the riser below it. In some embodiments, a small spacer, such as a piece of felt, rubber, or plastic, may be attached to the bottom of a horizontal portion 1016 near the joint with the vertical portion to tighten the fit of the horizontal portion within the loop portion 1012 and help secure the lock. Alternatively, the portion 1016 itself could be wedge-shaped. Similarly, bottom portions 208, 210 (Fig. 2) could be wedge-shaped or have a small spacer near the joints with vertical portions 204, 206, respectively.

Despite the variation in design specifics, the principle of this embodiment is the same as that of the embodiment described in relation to Fig. 3. In both cases, the top horizontal loops are inserted through the slits in the shelf, forming loops protruding through to the other side of the shelf. The bottom portions of the risers of the next level above then slide through the protruding loops, locking the risers and shelf of the lower level together. The next level shelf is then placed on its risers such that the riser loops pass through the slits in the shelf, locking the risers from sliding horizontally. The shelving unit is thus assembled with the interlocking risers and slits creating a stable shelving unit. Specifically, the placement of the top horizonal loop of a riser through the shelf slits prevents the riser from horizontal movement, and the placement of the bottom portion of a riser from the next level through the top horizontal loop of the riser prevents the shelf from vertical movement off its riser. The risers and shelves thus form a sequentially interlocking and stable shelving unit.

In summary, the present invention provides shelving units that may be easily hand- assembled and are structurally stable. The shelving system can create shelving units having one or more levels, and it can be disassembled into a compact kit. The risers and shelves are secured to each other using an interlocking mechanism without being permanently attached to each other. Specifically, loops at the tops of the risers slide vertically through slits in the shelves, and these are locked vertically together by bottom portions of risers from the level above that slide horizontally through the loops. These risers, in turn, are locked horizontally into place when their loops are placed vertically through the slits of its shelf. The alternating horizontal-vertical interlocking mechanism creates a stable shelving unit without the use of any tools or additional hardware or other attachment components.