WO2000003849A2

WO2000003849A2 - Corner joint connector for furniture

Info

Publication number: WO2000003849A2
Application number: PCT/US1999/016072
Authority: WO
Inventors: William B. Callahan
Original assignee: Callahan William B
Priority date: 1998-07-17
Filing date: 1999-07-16
Publication date: 2000-01-27
Also published as: AU5458799A; WO2000003849A9; WO2000003849A3

Abstract

An assembly for joining pieces of furniture together into a finished furniture unit. Each assembly has a pair of plates (fig. 5), each of which is formed with face and butt elements (fig. 9). Openings are formed through each face for receiving fasteners which join the plates to horizontal rails or other furniture pieces. Other openings are formed through each butt for receiving fasteners which join the butt to vertical pieces such as furniture legs (fig. 10). The openings in the butt are positioned in spaced-apart relationship so that the fasteners are enabled to extend through the leg piece without interference.

Description

FURNITURE CONSTRUCTION

This is a continuation-in-part of provisional application serial no. 60/093,252 filed July 17, 1998.

BACKGROUND OF THE INVENTION

1 . Field of the Invention

This invention relates to the construction of decorative and durable furniture.

2. Description of the Related Art

In building furniture there are several types of joints. There are primary structural joints that form the overall structure of furniture and there are secondary joints used in various component parts and generally provide sub-structure support to other furniture components, such as doors, shelving, and drawers. The furniture assembly of this invention is about designing and building primary structural furniture joints.

How joints are formed depends on the joint design and the joining materials. Some joints are constructed wholly from primary component parts (legs and rails) with no secondary joining materials (a hardware fastener for example). This type is known as mortise and tenon joint. The tenon, a projection is cut on the end of a piece of wood (rail) and shaped for insertion into a hole (mortise) cut into the leg to form the joint. Secondary joining materials are most often individual wooden pins, pegs, screws, staples or nails. Sometimes it's a combination of these materials plus an interior bracket such as an internal table leg bracket. In the case of most bed frames, metal bed fasteners (one male, one female) are used to construct the joint. The rail holds the male part and the bed post holds the female part. These types of fasteners are for the most part structural and provide no decorative element. The problem with most furniture with traditional joints like those mentioned above is that when they fail the furniture is no longer useful. Joint failure can be caused over time by extreme stress in and around a joint, seasonal and climatic conditions, and deterioration of the wood surrounding metal screws, often leaving metal fastening hardware loose, unstable, and most saddening is, it may still have natural and delightful qualities, but it has lost its usefulness.

OBJECTS AND SUMMARY OF THE INVENTION

The type of joint of this invention is a primary structural joint. The furniture assemblies of this invention are used to connect legs or posts of furniture to cross-members (also known as rails, aprons or skirts), to form a primary furniture structure, which results in a furniture structure from which other component parts are added, such as a table top, bed slats, or a chair seat. Figures 1-4.

With the furniture assemblies of this invention the integrity of the joint is more reliable and more enduring because the assembly hardware is not secured by simply embedding itself into the wood, and/or the use of metal screws to fasten parts, sometimes directly into the end grain of a rail, generally considered one of the worse places to put a nail, screw or pin.

Like most all traditional furniture construction methods mentioned previously, durability of the joint and not necessarily its remaining part, is significantly lessened as use and time pass. With the present invention the wooden rail is partially clad externally on a minimum of two surfaces (the butt, and one of the two broad sides), with an assembly plate of the invention and having one or more sets of bolts running through one or more sides of the assembly plate and the wood it secures. The nuts, bolts, studs and sleeves parts used are either male or female (interconnecting), and having either an internal or external thread. The fastener(s) are then engaged by screwing them together and through a furniture assembly of this invention, which firmly secures and joins it to the rail. At the butt end of the furniture assembly of this invention, where it connects to a leg or post, there are two or more fastening connections that fasten to its joining member (e.g. a carriage bolt) Figure 32, originating from the joining leg or post, and completing the joint (the furniture assembly of this invention). The tightening of all securing ArtUnion Assemblies fasteners is accomplished with the aid of one simple tool.¹

Bolts Figures 32, 33, 34, 35, 36 Nuts Figures 36 Sleeves Figure 37 Studs Figure 38

A furniture assembly of this invention produces a binding so strong and

All male bolts and female cap nuts are torx or hex driven. Using one of these simple tools is similar to using a screw driver. so enduring it will survive the most destructive seasonal and climatic conditions including severe flood conditions. Although a severe flood could cause some wood mold or discoloration from dirt embedded in the grain of the wood, a mild cleaning solution can make the furniture as good as new. If there would be any shrinkage after drying, a simple tightening of the assembly bolts will make it solid again. Even a piece of Arts & Culture furniture completely destroyed by fire, the ArtUnion Assemblies could be salvaged and with some new or recycled wood and a wire brush one could put things happily back together again - and possibly add some new character to the furniture.

There are no standards for the size of an ArtUnion Assembly (AUA), nor are there any standards for placement of holes in the face, back or side of any AUA design. The only requirement for positioning of holes is the offsetting of holes (either square or round) on the butt of the ArtUnion Assembly, where it connects to the furniture leg.² This offsetting distance from the top hole from the top of the buttplate in comparison to the distance of the bottom hole to the bottom of the plate, allows two ArtUnion Assemblies to intersect at a corner and not have their joining bolts in conflict with one another. This also allows for the two corner plates to be positioned at the same height as one another.

Also, there is no standard nut and bolt size (width or length), although a 1/4-20 inch and 5/16-18 inch threaded diameters appear to be the proper scale for most furniture. Additionally, not having standardized sizes for ArtUnion Assemblies or placement of holes in the faceplate and backplate of an ArtUnion Assembly depends on the type and size of the furniture being designed, the thickness and width of wood used for the

when addressing furniture legs, this can also refer or mean furniture "posts," for example "bed post." connecting rails,³ as well as the size and placement of any design embellishment in the ArtUnion Assembly.

Depending on the furniture theme and supporting ArtUnion Assembly design, the face of an ArtUnion Assembly may or may not have any exposed fasteners on any of its surfaces. Where no fastener head is visible, this is called a blind/anchored connection, and where the head of a cap nut or carriage bolt is visible, this is called a through-hole connection because the nut or bolt can be passed through the hole.

Blind/anchored connections - A blind/anchored connection is accomplished by having either a stud or sleeve permanently secured to a faceplate/bs (faceplate backside) by way of a spot weld. A cap nut is used in conjunction with a stud, and a button head screw is used in conjunction with a sleeve. Tightening of the nut or bolt is accomplished with the aid of one simple tool.¹

Through-hole connections - Exposed connecting bolts used on the faceplates of ArtUnion Assemblies are shaped or sculpted to fit the design theme of the furniture and design of the ArtUnion Assembly. Two examples of this might be a square headed bolt with beveled or tapered sides, giving the appearance of a projected tenon, or a bolt head in the shape of a five pointed star. In all cases where an exposed bolt head is used, the hole in which the bolt is placed will be square to accept the square neck of a carriage bolt. Like the blind/anchored connections above, the exposed through-hole connection requires the same simple tool for easy assembly or disassembly. The cap nut can be tightened from the backplate side of the ArtUnion Assembly without the

3

Rail - a piece of lumber connecting one furniture leg or post to another, also known as an apron. need for a tool to hold the faceplate bolt (possibly a decorative bolt) in place as the female cap nut is turned and tightened from the back.

Connecting ArtUnion Assemblies (furniture assemblies of this invention) to the posts or legs of furniture. There are three primary methods for accomplishing this. The first is an exposed female cap nut that screws from the exterior of a leg to the end of a male bolt having a square neck that fits through both the square hole on the buttplate of an ArtUnion Assembly and the leg.

The other is a blind connection (no exposed cap nut appearing on the furniture leg) where a hanger bolt is screwed into the wood with its pointed end and a female cap nut is screwed and tightened from the inside the of the ArtUnion Assembly, before the rail is installed. In this situation the holes on the buttplate of the ArtUnion Assemblies are round, rather than square. Where a blind connection of an ArtUnion Assembly and a leg is called for (using a hanger type bolt) the holes on the buttplate will be round regardless of the type of plate used. In most cases the ArtUnion Assembly will be butted directly against the furniture leg. In some cases where a design calls for it, a mortise will be cut into the leg and the ArtUnion Assembly will be inserted into the mortise and then secured. This method, although more labor intensive produces a more finely crafted joint.

An alternative decorative method (third method) like the exposed through-hole connection method above, has male bolt with sculpted head and a female cap nut securing ihe ArtUnion Assembly to the furniture leg.

Furniture assemblies of this invention and their designs. U-Plate design - Figures 6-10 and 12-14.

The purpose of this design is to provide a decorative assembly that provides the maximum all around strength.

The U-Plate ArtUnion Assembly is a single plate design in the form of a letter "U." The U-Plate design has three external sides; faceplate, backplate and buttplate. The faceplate is the side that receives design elements and the buttplate is the side that connects to the leg of furniture. Depending primarily upon the esthetic design needs of a particular furniture, the bolts used to tighten an assembly to a rail can be entered and tightened from either the front or back of an ArtUnion Assembly. This esthetic choice of which side the bolts are fastened from is something that must be designed into the furniture from the very beginning.

Connecting a U-Plate assembly design to the legs of furniture.

There are three methods for assembly of a U-Pate design and its connection to the legs of a furniture piece.

Assembly design option #1 - no connecting bolts showing on the exterior of furniture legs.

1. The furniture legs are pre-drilled with a single drill bit having two different diameters to receive both the hanger bolt and a cap nut (the smaller diameter is for receiving the.pointed screw end of the hanger bolt and is drilled first and followed by the larger diameter that receives the cap nut).

2. Hanger bolts are screwed into the furniture leg. When complete, the hanger bolt will protrude no more than 1/8⁴ of an inch beyond the joining surface of the leg.

3. A "U-Plate design" assembly is secured to the furniture leg by placing its butt side (round holes) over and onto the projecting hanger bolts, and fully securing it with two female cap nuts.

4. One end of a connecting rail is slid into the opening of the U-Plate and fastened with two carriage bolts placed through the square from the faceplate (square holes) and two female cap nuts from the backplate (round holes).

Assembly design option #2 - connecting bolts showing on the exterior of furniture legs are non-decorative.

1 . The furniture legs are pre-drilled all the way through the leg to the diameter of a female cap nut.

2. Carriage bolts are placed through the square holes of the U-Plate from the inside. Their square neck, directly under the head fits squarely into the square holes of the U-Plate.

3. The U-Plate with its carriage bolts in place are then fitted in and through the holes of the leg, and fully secured with two female cap nuts from the exterior of the leg.

4. Step four, follow step #4 above. _

based upon thickness of plate, in this example plate thickness is 0.125 inches. Assembly design option #3 - connecting bolts showing on the exterior of legs are decorative or sculpted.

2. Two decorative or sculpted bolts are place through the pre-drilled holes from the exterior side of the leg.

3. A U-Plate design assembly is secured to the furniture leg by placing its butt side holes (round) over and onto the threaded end of sculpted bolts projecting from the furniture legs, and fully securing it with two female cap nuts.

3. A U-Plate design assembly is secured to the furniture leg by placing its butt side holes (round) over and onto the hanger bolts projecting from the furniture legs, and fully securing it with two female cap nuts.

4. Step four, follow step #4 above.

L-Plate design - Figures 15-1 7

The purpose of the L-Plate is to produce an assembly that is quite strong but of lighter weight than the U-Plate.

The L-Plate ArtUnion Assembly is a single plate design in the form of a letter "L." The L-Plate design has two sides, face and butt. The face is the side that receives design elements and the butt, is the side that connects to the leg of a furniture piece. Since there is no backing plate called for in this design, there are two options for meeting special structural needs. One is using standard washers between the head of the bolt or nut and the wood rail, and second using a Universal Back-Plate (exhibit "I") designed exclusively for use with ArtUnion Assembly plates.

Assembly

See U-Plate assembly instructions above for connecting the L-Plate to the furniture legs.

1. The L-Plate is fully secured to the leg using one of the three bolting methods (blind, exposed female cap nut or sculpted bolt head).

2. A wooden rail is fully secured to the backside of the faceplate, using one of the two fastening methods (blind or exposed).

|-Plate design - Figures 26-28

The purpose of the J-Plate is to produce a slightly stronger assembly than the L-Plate, but less weight of the U-Plate.

The J-Plate ArtUnion Assembly is a single plate design in the form of a letter "J." The J-Plate design has three sides; face, butt and an abbreviated backplate. The face is the side that receives design elements and the butt, is the side that connects to the leg of a furniture piece. The abbreviated backplate provides some additional support for situations requiring additional structural support. Since there is no backing plate called for in this design, there are two options for meeting special structural needs. One is using standard washers between the head of the bolt or nut and the wood rail, and second using a Universal Back-Plate (exhibit "I") designed exclusively for use with ArtUnion Assembly plates.

Assembly - See U-Plate assembly instructions above for connecting the L-Plate to the furniture legs.

1 . The J-Plate is fully secured to the leg using one of the three bolting methods (blind, exposed female cap nut or sculpted bolt head).

2. A wooden rail is fully secured to the backside of the faceplate by slipping it under the abbreviated backplate and then securing it using one of the two fastening methods (blind or exposed).

M-Plate design - Figure 23

The purpose of the M-Plate design is to offer another level of increase strength by binding two furniture rails with a single assembly rather than two as is the process shown above.

The M-Plate design is a two part assembly consisting of a four sided outer plate ("M" shape) and a backplate. The backplate can be a three sided backplate like the one shown in exhibit G or it could also be a two side L shaped plate, depending on the thickness of the wood rails being used. Like all other plate designs the outer plate is the plate that receives any design applications. Fastening the wood furniture rails to the M-Plate uses the same processes used in all other ArtUnion Assembly plate designs, that is, either visible or invisible fasteners as viewed from the exterior or face of the ArtUnion Assembly plate.

The M-Plate does not necessarily require an interior backplate, it depends primarily on the type and size of furniture and the thickness, density and overall strength of the wood used in the furniture rails. If no interior plate is used, washers are used in its place like the L-Plate assembly.

Also the size of the M-Plate, and the dimension of the "step" is determined by the furniture piece and size, as well as the thickness of the of the rails and legs of the furniture piece.

Assembly

1. The faceplate is attached to a furniture leg using the assembly methods #1 or #2 as described for the U-Plate design above.

2. Both wooden rails are then put in place from the backside of the faceplate.

3. A backplate if any, is then put in place and male button head screws are inserted and fully tightened.

Corner Back-Plate - Exhibit H

The purpose of the Corner Back-Plate is for the construction of case goods (cabinets and chests). With case goods, flat horizontal surfaces (shelves or the bottom of a chest) need to be secured to the furniture piece.

Assembly Installation of a Corner Back-Plate is no different than attaching a backplate. Once the furniture frame is complete, surface materials can just be dropped into place. No additional fastening is required.

M-Plate Design - Figures 20, 21 , 22 and 25

The purpose of the M-Plate is to provide additional strength by joining two "L-Plates" to form one plate.

Universal Backplate - Figures 29-31 , also, 18, 19, 22, 23, 24, 25 The purpose of the Universal Backplate is to serve as an all purpose backplate, and to provide additional support and strength for the J- and L-Plates that have no backplate.

Universal Back-Plate can also serve as additional structural support, in addition to a backplate where called for.

Interfacing ArtUnion Assembly plates to furniture legs

Most ArtUnion Assemblies can be connected to furniture legs by butting them directly up to the leg or have a recessed connection (mortise cut into the leg), where the ArtUnion Assembly is actually inserted into the leg making for a more crafted look and connection. Most all ArtUnion Assembly plate designs support the mortise inset design except for Hinge-Plate and Key-Plate design where a blind faceplate is used. Another recessed method is the rabbet. Here instead of having a hole cut into the furniture leg, a hole with two sides is cut from the corner of a furniture leg. The side that butts to the AUA plate is longer and the side that butts to the backplate is shorter. The rabbet also provides a more crafted look and connection.

While the foregoing embodiments are at present considered to be preferred it is understood that numerous variations and modifications may be made therein by those skilled in the art and it is intended to cover in the appended claims all suςh variations and modifications as fall within the true spirit and scope of the invention.

Claims

What is claimed is:

1 . An assembly for joining first, second and third pieces of furniture together to form a structural joint, the assembly comprising the combination of first and second plates, each plate having a face and a butt, each face being formed with a first opening centered along a first axis which is orthogonal with the first piece for receiving a first fastener to secure the first piece to the first plate, the butt being formed with a second opening, said second opening of the butt of the first plate extending into the third piece along a second axis for receiving a second fastener, said second opening of the butt of the second plate extending into the third piece along a third axis for receiving a third fastener, and said second and third axes being positioned in spaced-apart relationship to enable the second and third fasteners to extend into the third piece without interference.

2. An assembly as in claim 1 in which the first and second plates each further comprising a back, each butt holding the respective back and face in spaced-apart relationship to form respective first and second slots in each plate, the slots of the first and second plates being adapted for seating the respective first and second pieces.

3. An assembly as in claim 1 in which the butts of the first and second plates are joined together along a common edge to form an L- shaped cavity for receiving the third piece.

4. An assembly as in claim 3 and further comprising an L-shaped backup plate having walls which are joined together along a common joint which is aligned with the common edge.

5. An assembly as in claim 4 in which the common joint comprises an edge.

6. An assembly as in claim 4 in which the common joint comprises a flat plate.

7. An assembly as in claim 1 in which at least one of the fasteners comprises a bolt.

8. An assembly as in claim 1 in which at least one of the fasteners comprises a stud.

9. An assembly as in claim 1 in which at least one of the fasteners comprises an internally threaded sleeve together with a hanger bolt that is adapted for fastening into the sleeve.

10. An assembly as in claim 1 in which the third piece comprises an upright leg of the furniture.

1 1 . An assembly as in claim 10 in which at least the second piece comprises a horizontal rail of the furniture.