Knock down table

The invention relates to a knock down table suitable for food preparation that includes extension legs and terminal legs that are interconnected with a threaded connector and threaded receiving plugs in the connecting ends of the extension and terminal legs. One of the receiving plugs in each connection protrudes from the end of its legs and is configured to extend into the connecting leg and abut with the receiving plug in the other leg.

FIELD OF THE INVENTION

The invention relates to tables that exhibit a configuration that can be disconnected for shipping or transporting the table in a conventional corrugated box and form a stable work surface when reassembled.

BACKGROUND OF THE INVENTION

Stainless steel and similar sterilizable tables are important for the food preparation industry. Such tables provide the necessary work surfaces for cleaning, cutting and assembling foods served to customers. Open table supports provide space for storage of materials used in the food preparation. Models with an undershelf provide additional storage space for bowls and containers. A typical commercial kitchen has use for both open and undershelf tables.

The basic version of an open table uses legs of a tubular or rectangular cross sectional shape that are inserted into mating sockets connected or welded to the underside of the table top. A set screw for each socket provides lateral pressure in the inserted table leg portion to hold the leg within the socket and provide a measure of stability. Greater stability for the table is provided with a support frame made of rigid tubes or bars that are welded between the legs. Similarly, an undershelf can be welded between the legs and serve as the lower support for the table legs.

Metal food preparation tables having all welded connections make for a very stable work surface but at increased cost and difficulty of transporting the unit from manufacturer to customer. Such tables must be shipped in a fully assembled state by large pallets or crates using special equipment that can handle the weight of the fully assembled table unit.

For convenience, transport to offsite events, or reduced shipping costs prep tables have been offered that can be disassembled for transport and reassembled on site. Such tables use an open socket and set screw to attach the legs to the table top. The open table models use a lower support frame in an “H” frame or “C” frame construction and pass-through ferrules of circular or rectangular shape at each corner. Lateral set screws on each ferrule are used to hold the leg in place.

The conventional undershelf for a prep table uses a connection configuration that is similar to those of the open support frame. In particular, the typical undershelf unit would exhibit a pass-through ferrule connection on each corner of the undershelf and set screws to hold the shelf in position on the legs. Unfortunately, the use of set screws and pass-through ferrules for either the open or undershelf models can loosen over time and commercial use so that the table becomes less stable and requires adjustments to all set screws.

The National Sanitation Foundation (NSF) a number of regulations regarding food preparation tables. The currently approved materials are certain types of stainless steel and aluminum alloys. The NSF regulations also mandate that there be no gaps over 1/32″ to prevent the growth of bacteria.

It would be desirable to have a knock down prep table that complies with the applicable NSF regulations and which can be readily disassembled for transport and still form a stable work surface when reassembled.

A number of published applications and patents have described connections for tubular joints. For example, U.S. Pat. No. 2,647,000 describes a transverse, permanent connection using a deformed, internally threaded, metal washer or rivet within the joining tube. A bolt extends through aligned openings in the joined tube and into the internally threaded connection of the deformed washer. The washer is initially deformed using a deformation tool that uses a compression anvil around an extended bolt. The anvil engages the edges of the walls of the deformable rivet and, upon advance of the threaded bolt, compresses the rivet walls until they engage and become secured by internal grooves of the joining tube. The tool is then removed leaving the rivet in place ready to receive the connecting bolt during assembly.

U.S. Pat. No. 2,799,519 also describes the use of transverse bolts and an internal rivet to connect tubular members with T-joints.

U.S. Pat. No. 2,950,015 describes a joint system for knock down racks made of joined tubular members. The connections use some members that are spot welded and others that employ frictional fits between tube sections having larger and smaller diameters. One disclosed set of such frictional fits provide an expanded member having an internal, recessed bolt that engages a nut recessed in the member of reduced diameter.

U.S. Pat. No. 4,444,125 describes a knock down work table made with tubular legs having external grooves at increments over the length of each leg. The lower shelf and optional C-shaped support rail have pass-through ferrules at the corners. A frustoconical collar washer having an internal rib engages a leg groove and supports the shelf or support rail by the interaction of the leg groove and internal collar washer rib. U.S. Pat. No. 6,068,143 uses a similar leg groove/collar washer ridge system for upright shelf systems.

U.S. Pat. No. 4,786,203 relates to a connector assembly for food preparation equipment. The assembly is designed to minimize the formation of exposed gaps with a series of threaded connector elements and a locking collar that secure the joining tube to a mating connector that is transversely bolted to the joined tube.

U.S. Pat. No. 4,952,092 describes a system for permanently connecting vertically aligned metal tubes and metal cross-member rails that uses a threaded bolt passing through the vertically aligned tubes and connects the cross-member rails with round plugs forced into bosses protruding from the rails. The rail ends are then welded to the vertical tubes.

It would be desirable to have a joint system for a knockdown table that would allow for assembly into a highly stable work surface that would remain stable over extended time and which is suitable for use in food preparation.

It would also be desirable to have a knockdown food preparation table that can be shipped in a compact, disassembled state and readily re-assembled by the customer to form a highly stable work surface that is suitable for use in food preparation.

SUMMARY OF THE INVENTION

It is an object of the invention to provide a knockdown food preparation table that can be shipped to customers without the need for pallets or crates.

It is further an object of the invention to provide a knockdown food preparation table that can be readily assembled to form a sturdy working surface that complies with all applicable regulations for food preparation or disassembled to a more compact size for shipping.

In accordance with these and other objects of the invention that will become apparent from the description herein, a knock down food preparation table according to the invention comprises: (a) a rectangular table top with a top side, an underside and four corners, (b) four receiving sockets secured to the underside of said table top and located near each corner thereof, (c) four tubular, extension legs of the same length and external dimensions, wherein each extension leg exhibits: (i) a first leg portion end that fits into one of the receiving sockets on the underside of said table top, and (ii) a second leg portion end having a first plug that is secured within said second leg portion end, each said first plug exhibiting an axially-extending, threaded, central bore, and (d) a lower support frame comprising four, tubular, terminal legs that extend from front and back of a top side of said frame to a lower side of said frame, wherein each top end of each terminal leg comprises a second plug fit therein and that exhibits an axially-extending, threaded, central bore to receive a threaded rod so that a second leg portion end of an extension leg can be secured together with said threaded rod, whereby the second leg portion of an extension leg abuts a corresponding top side of a terminal leg, wherein one of said first plug or said second plug protrudes into a tubular leg segment of the other leg when fully twisted together.

The table of the present invention provides a structurally stable support system and a working surface that all comply with the applicable regulations for food preparation while also providing the advantages of ready disassembly for transport without pallets or crates for the assembled table unit.

DETAILED DESCRIPTION OF THE INVENTION

The invention is conveniently described with reference to the attached drawing figures. In each drawing, similar parts are designated with the same reference numerals.

As shown inFIG. 1, rectangular table top1is supported by upper stiffening channels2that extend along the long dimensions of the table top. The specific length of each upper channel2is subject to some variation but is preferably in a supporting relationship along substantially the entire length of table top1. Optionally, table top1can have an integrated or integral backsplash14(FIG. 2) and may be made of stainless steel, hard wood suitable for a cutting surface, an open frame for receiving cutting surface inserts, and coated steel with straight, rounded or chamfered edges.

Open leg sockets3are attached, preferably welded, to each end of the underside of channels2. Each socket is made of the same shape type as legs4, e.g., hollow square or round shapes. Importantly, the inside dimensions of socket3are configured to receive the upper end of extension leg4in a snug, friction fit.

The lower end of leg4and the top end of terminal leg6are fitted with connector plugs generally designated as5having a threaded central bore13to receive threaded bolt11. In each connection, one of the plugs5is recessed into its tubular leg and the other plug protrudes from the end of its legs so that, when connected, one of the plugs spans the connection between extension leg4and terminal leg6with bolt11securing the leg portions together. Bolt11may be permanently connected to first plug5′ with an adhesive, spot weld or solder.

As shown inFIG. 4, extension leg4can have first plug5′ recessed while second plug5″ in terminal leg6can protrude.FIG. 5illustrates the reverse connection in which first plug5′ protrudes from extension leg4while second plug5″ is recessed into terminal leg6. Plug5′ is also shown as having a central, threaded bore13′ that extends into plug5′ but does not extend all the way through plug5′ as well as chamfer15that can facilitate assembly of extension leg4and terminal leg6. Central, threaded bore13in plug5″ is shown as extending all the way through plug5″ and, inFIG. 6, all the way through both plugs5′ and5″. It will be understood that either of plugs5″ and5″ can be used in extension leg4or terminal leg6for the preferred connection of the invention.

Plugs5′ and5″ preferably have a shape to fit firmly within extension leg4and terminal leg6by friction fit, with or without welding, spot welding or adhesive. Round shapes are preferred to facilitate a connection by twisting. The outer circumference17of either of plugs5′ or5″ can exhibit a friction-enhancing textured or surface feature to facilitate a firm connection inside the respective leg segment. Such surface features can include knurling, cross-hatching or grooves that are not parallel to leg axis16.

Preferably, plugs5are tightly friction fit or spot welded inside its respective tube so as to provide substantially rigid connections. Bolts11can be provided as loose parts for insertion at the point of assembly or secured within a plug5preferably within the plug which is then inserted into extension leg4, so that twisting extension leg4can advance bolt11into the plug of terminal leg6until a tight connection is formed.

The connection between extension leg4and terminal leg is straight, i.e., along leg axis16, by twisting extension leg4with bolt11into the second threaded plug5′ in terminal leg6so that the twisting action draws the protruding plug into the other leg to occupy the space of the recess of the other plug. Preferably, the advance of the first plug causes the first and second plugs5′,5″ to become abutted and thereby provide a substantial contact surface to prevent loosening of the connections during lateral movement or forces on the table top. SeeFIG. 6. It will be understood, as noted above, that either of plug5′ or plug5″ may be configured to protrude from its leg segment but that both are preferably not protruding (for visual aesthetics and structural rigidity) or recessed in the same connection.

Rectangular undershelf7is preferably welded to each of terminal legs6at the corners of undershelf7. The rigid connection of terminal legs6to undershelf7and its vertically folded edges form a rigid support for extension legs4and terminal legs6. Undershelf7can be in the form of: (a) a solid metal shelf (seeFIGS. 1 and 2) suitable for industrial use; (b) a cross tube support comprising one or more welded and interconnected metal cross tubes24that extend parallel to a working edge of the table top and between welded tubes connecting front and back terminal legs4(seeFIG. 10); (c) a wire shelf25(FIG. 11) of the type shown in U.S. Pat. No. 6,068,143, which is hereby incorporated by reference, that are adapted in terminal connections to be welded and secured to terminal legs6at each end; or (d) an open frame of three metal tubes of round or rectangular cross section that are welded at each end to form a rigid, open, C-shaped frame23(FIG. 9) that allows boxed products to be stored under the assembled table. Preferably, all metal parts used in the undershelf are made of stainless steel. Braking casters9and/or rolling casters10can be installed into the lower ends of terminal legs6(FIG. 1) or adjustable feet12.

Undershelf7is preferably reinforced along its central length against flexure from the weight of product containers stored thereon with at least one lower support channel8.

FIGS. 7 and 8show greater details of legs4and terminal legs6before an undershelf7is welded to terminal legs7. Adjustable foot12having externally threaded post18that has been twisted into internally threaded sleeve19is press fit into terminal end20of terminal leg6until sleeve shoulder21abuts the edge of terminal end20.

Leg4is connected to terminal leg6by way of bolt11that is secured in inset plug5′. Bolt11is then twisted into central bore13of protruding lower plug5″. As shown, first connecting end21of terminal leg6abuts second connecting end22of extension leg4.