GB2299644A

GB2299644A - Concealed releasable connecting fitting for furniture joints

Info

Publication number: GB2299644A
Application number: GB9607362A
Authority: GB
Inventors: Martin Heinze
Original assignee: BECKER KG FRITZ
Current assignee: BECKER KG FRITZ
Priority date: 1995-04-06
Filing date: 1996-04-09
Publication date: 1996-10-09
Anticipated expiration: 2016-04-09
Also published as: GB2299644B; DE19512884A1; GB9607362D0

Description

1 A connecting fitting 2299644 lle invention relates to a connecting

fitting for connecting two parts of a piece of furniture.

Connecting fittings are used to join furniture parts together. Here, the finmiture fitting is intended to guarantee that the parts connected are immovably fastened to one another and to take up the loads occurring during use of the piece of fizffiture.

From German Patent 43 16 058, a connecting fitting is known having a fitting body with a bolt opening for receiving a connecting bolt. In the known connecting fitting, the bolt opening and the connecting bolt have corresponding diameters so that the connect- ing bolt is guided on all radial sides in the bolt opening. The connecting bolt is secured within the fitting body by means of annular fastening elements that are supported on the fitting body and through which the connecting bolt is passed.

The fastening elements abut the connecting bolt clampingly so that the same is fixed in the axial direction. However, the connecting fitting has the drawback that only small forces can be taken up in the axial direction and that the connection cannot be released and restored.

It is an object of the present invention, to provide a connecting fitting for transmitting great forces, which is invisible from outside and is well to release and to install again.

llie object is solved, according to the invention, with the features of claim 1.

According to the invention, the fitting body of the connecting fitting is provided with an inner toothing extending substantially circumferentially and cooperating with the outer toothing of a connecting bolt inserted into the bolt opening. The two toothings, c 0 kept in mutual abutment by the pressing force of a threaded pin screwed in obliquely with respect to the bolt opening, provide for a non-positive and an interlocking connection by which great forces may be transmitted.

The connecting bolt has an outer diameter that is smaller than the inner diameter of the bolt opening so that it may be inserted into the bolt opening, thereby requiring no screwing operation. Thus, the connecting fitting provides for a fast connection of respective parts. Further, the connecting fitting requires only relatively coarse positional tolerances since the connecting bolt only has to protrude into the bolt opening.

Since the connecting bolt is secured in the bolt opening by means of a threaded pin provided in a threaded bore extending obliquely to the axis of the bolt opening, it becomes possible to arrange the access to the threaded pin in an edge between the furniture parts to be joined and to cover it by means of upholstery, if necessary. This arrangement of the access to the threaded pin offers the possibility of providing the entire connecting fitting invisibly.

When the fitting body is disc-shaped and the bold opening is disposed offset from the axis thereof, it is possible to compensate for irregularities when mounting the fitting body. A recess or profile extending along the outer circumference of the fitting body allows the fitting body to be securely anchored in a piece of furniture. The connecting fitting of the present invention may be produced with particular ease if the toothing provided in the bolt opening is an inner thread.

Further advantageous embodiments and developments of the invention are obvious from the dependent claims, as well as from the description in conjunction with the drawings. The following is a description of two preferred embodiments made with reference to the drawings.

n In the Figures:

Fig. 1 illustrates a chair with a first and a second joint, each having a connecting fitting according to the present invention, Fig. 2 is a sectional view of the chair in Fig. 1, taken along the line II-II, Fig. 3 is a sectional view of the joint in Fig. 2, taken along the line III-III, Fig. 4 is a exploded view of a connecting fitting with a connecting bolt to be inserted in the bolt opening, Fig. 5 is a sectional view of the chair in Fig. 1, taken along line V-V, and Fig. 6 is a sectional view of the connecting fitting in Fig. 5, taken along line VI-VI.

Fig. 1 illustrates a chair 10 comprising a wooden frame structure 16 of posts 12 and transversal frame parts 14. The structure 16 has an upholstered scat plate 18 and a back rest 20, also upholstered.

As can be seen from Fig. 2, the back rest 20 is mounted to the rear transversal frame part 14 of the structure 16 by means of a first embodiment of a connecting fitting 22.

The connecting fitting 22 has a disc-shaped fitting body 24, inserted into a circular opening 26 in the transversal frame part 14 with adhesive interposed. The fitting body 24, preferably made of brass or steel and having a profile 28 on its outer side, is provided with a bolt opening 30 extending eccentrically with respect to the axis of the fitting body 24 and having a metric M8 thread. Beside the bolt opening 30, the fitting body 24 has a threaded bore 32 with a M5 thread that extends obliquely with respect to the bolt opening 30 and opens into the same. The outer end of the bolt opening 30 and 4 the threaded bore 32, respectively, opens into the outer end face of the fitting body. 'Me angle enclosed by the axis of the bolt opening _3 0 and the threaded bore is smaller than 45" and is 30" in the case of the illustrated embodiment. In the threaded bore 32, a threaded pin 34 is disposed, the outer end of which is formed as a hexagonal socket opening 36 for receiving tools.

In order to join the back rest 20 with the transversal fi-ame part 14, a substantially U shaped bracket 3 8 is flirther provided which grips a supporting board 42 supporting the back pad 40. The bottom portion of the bracket extending in parallel to an edge of the supporting board 42 is provided with a bead 44 through which a M6 threaded bore 46 for a connecting bolt 48 passes. The connecting bolt 48 is a threaded pin, the M6 thread of which extends over the entire length of the connecting bolt 48.

For fastening the back rest 20 to the transversal frame part 14, the connecting bolt 48 protrudes into the bolt opening 30 of the fitting body 24. The connecting bolt 48 is secured in the fitting body 24 by means of the threaded pin 34 which is threaded into the threaded bore 32 such that its firont end presses the connecting bolt 48 against the thread of the bolt opening 30. In this state, the thread of the connecting bolt 48 is engaged in the thread of the bolt opening 30, whereby it is secured in a non-positive and interlocking manner.

To make the connection, the connecting bolt 48 situated on a ftuniture part is inserted into the bolt opening 30 of the fitting body situated on another furniture part by displac ing the former ftirniture part. In doing so, the connecting bolt 48 is not turned relative to the fimiiture part it is situated on, but it is merely moved together with the fim-dture part. Thus, it is not necessary to provide an access to the connecting bolt 48. When the connecting bolt 48 is inserted in the bolt opening 30, a suitable tool, e. g. a hexagonal box key, is set to the threaded pin 34 and the threaded pin 34 is screwed onto the connecting bolt 48. If necessary, an upholstery covering the access to the threaded pin 34 is pushed aside. Since the threaded pin 34 does not have a head, but only a tool receptacle, the tool used for turning the threaded pin 334 and the access to the threaded pin 3 34 may be of small dimensions.

By tightening the threaded pin 34, the external thread of the connecting bolt 48 is pressed against the internal thread of the bolt opening 30. However, the threads are not in a normal threaded engagement. Rather, the thread of the connecting bolt 48 is so small as to not mate with the thread of the bolt opening 3 W. The small diameter of the connecting bolt 48 permits an insertion of the connecting bolt 48 into the bolt opening without turning. Nevertheless, the threads are locked with each other, there possibly also occurring deformations of the threads. When such deformations happen, the ridges of the threads bury themselves into each other, so that a non-positive and interlocking connection is obtained with which very great axial forces may be transmitted. llus, the connecting fitting 22 provides a plugged connection for the ft=mission of great forces which is invisible despite being secured by the threaded pin 34.

In order to disengage the connection of back rest 20 and transversal fiame part 14, the back pad 40 may be pushed aside so that the access to the threaded pin 34 is exposed. By loosening the threaded pin 34, the locked position of the connecting bolt 48 in the bolt opening 30 is released. The connecting bolt 48 may then be withdrawn from the bolt opening 30.

Figs. 4 - 6 illustrate a second embodiment of an inventive connecting fitting 122, wherein parts corresponding to parts of the first embodiment are designated by a reference numeral increased by 100. The connecting fitting 122 serves to fasten a lateral frame part 14 to a post 12 and has a fitting body 124 corresponding in design to the fitting body 24. In contrast to the connecting fitting 22, the connecting fitting 122 25 has a connecting bolt 150 with a M6 nut thread 152 on the one end and a wood screw thread 154 on the other end. The connecting bolt 150 is screwed into the lateral frame 1..

6 part 14 by its wood screw thread 154. In order to relieve the connecting fitting, pegs 156 are provided to both sides of the connecting fitting that are anchored in bores in the post 12 or the lateral fime part 14. In order to secure the joint against being dislodged, the connecting bolt 150 is secured in the fitting body 124 by means of a threaded pin 1.3 A corresponding to the threaded pin 34.

7

Claims

1. A connecting fitting comprising a fitting body (24; 124) with a bolt opening (30; 130) and further comprising a connecting bolt (48; 150) insertable into said bolt opening (30; 130) without turning, characterized in that said bolt opening (30; 130) has an inner toothing extending substantial circumferentially, that said connecting bolt (48; 150) has a circumferentially extending outer toothing on its insertion end, and that a threaded pin (34; 134) is provided in a threaded bore (32; 132) extending obliquely to the axis of said bolt opening (30; 130), the outer end of said threaded pin having a tool receptacle (36; 136), the inner end of the threaded pin pressing the outer toothing of said connecting bolt (48; 150) inserted into said bolt opening (30; 130) against the inner toothing of said bolt opening (30; 130).

2. The connecting fitting of claim 1, characterized in that said fitting body (24; 124) is disc-shaped and that the bolt opening (30; 130) is disposed eccentrically to the axis of said fitting body (24; 124).

3 3. The connecting fitting of claim 1 or 2, characterized in that said fitting body (24; 124) has a recess or a profile (28; 128) extending along the outer circumference thereof.

4 8 4. The connecting fitting of one of claims 1-3, characterized in that said inner toothing of said bolt opening (30; 130) is an internal thread, the inner diameter of which is larger than the outer diameter of the toothing portion of said connecting bolt (48; 150).

5. The connecting fitting of one of claims 1-4, characterized in that said connecting bolt (150) has a nut thread (152) on the one end and a wood screw thread (154) on the other end.

6. The connecting fitting of one of claims 1 - 4, characterized in that said connecting bolt (48) is a threaded pin with a nut thread extending over its entire length.

7. A connecting fitting, substantially as hereinbefore described with reference to the accarpanying drawings.