EP1380229B1

EP1380229B1 - Coupling member for interconnecting parts of a frame

Info

Publication number: EP1380229B1
Application number: EP03076975A
Authority: EP
Inventors: Petrus Antonius Lauwrentius Van Bakel; Leonardus Hubertus Geertruda Van Der Steen
Original assignee: Koninklijke Ahrend NV
Current assignee: Koninklijke Ahrend NV
Priority date: 2002-07-12
Filing date: 2003-06-25
Publication date: 2010-06-09
Anticipated expiration: 2023-06-25
Also published as: EP1380229A1; ATE470371T1; NL1021073C2; ES2346963T3; DE60332897D1

Abstract

The invention relates to a coupling member for mutually coupling parts of a frame in which said member comprises at least two elements mounted on the respective parts to be coupled, said elements comprise complementary engaging surfaces and positioning elements for being able to position said complementary engaging surfaces in relation to one another are provided as well as clamping means for being able to clamp said engaging surfaces against one another. <IMAGE>

Description

The invention relates to coupling members for interconnecting a first and a second framepart in which the frameparts to be coupled are at an angle in respect of each other, said coupling members comprising apertures in said first framepart and cams on said second framepart, which cams can be brought into said apertures after which said frameparts are moved in respect of each other such that parts of said cams will engage the innerwall of said first framepart, means being present for clamping surfaces of several parts against each other.
Coupling members for connecting frameparts are shown in EP 0 398 014 A1 . In case of this known construction said first framepart is formed by a plate with at least a flat portion which is provided with two rows of apertures in the shape of longitudinal slots. Said second framepart is formed by an U-shaped plate, the legs of which are provided with hooked tongues.
When coupling said frameparts the tongues are brought into said slots and then the frameparts are moved in respect of each other such that the free end of said tongues is brought behind the wall of said first framepart.
To prevent that the frameparts will move in respect of each other, such that the tongues might come out off said slots, an insert is present between the two legs which are provided with said hooked tongues. Said insert is provided with pins which are received into slots in said legs and are running at an angle in respect of the longitudinal slots. By moving said insert by means of a bolt said insert is pressed against the outer surface of the plate provided with said slots.
A disadvantage of said known construction is that the tongues are shaped from the plate and so will have a limited thickness only. By moving said insert the force by which said tongues are pressed against the inner wall of said first framepart will be increased but the end of said second framepart will be pressed away from said first part. So the dimensions of the engaging surfaces will be decreased.
Further the parts are only held together by friction which depends on the surface properties of the materials.
Now the object of the invention is to provide a more simple construction in which the connection is not dependent on friction only.
This is obtained by the fact that said apertures are provided in a first engaging surface of said first framepart and said cams are provided on a second engaging surface of said second framepart such that said engaging surfaces will be pressed against each other in the mounted position of said frameparts, said means for clamping said engaging surfaces against each other being formed by a threaded hole in said first engaging surface in which hole a threaded bolt is received provided in said second engaging surface.
In this way a very stable connection between the two frameparts is obtained.
According to a further elaboration said cam is substantially circular in cross section and is having its largest diameter at the free outer end, the aperture for receiving said cam having an elongated shape with a diameter tapering in longitudinal direction.
By providing for that the cam has its largest diameter at the free outer end and the aperture for receiving the cam is of an elongate shape having a diameter tapering in longitudinal direction, it is achieved that on moving the cam from the first to the second position, it can not be taken from the aperture in a direction opposite to the first direction anymore. Therefore, immediately after inserting the cam or cams into the aperture or apertures, a coupling between the parts concerned is established, from which the exact appropriate position can be reached with ease. In this way, the positioning means form a guide to the appropriate position without the risk that the parts may easily disengage from one another.
Further, it can be provided for, that the cam and the aperture for the cam have such a shape, that on reaching the second, final position, the engaging surfaces have been moved towards one another or abut one another at least partly. This can be achieved e.g. by having the thickness of the material in which the aperture for the cam is provided increase in the direction of the second, final position, the larger diameter of the cam at the outer end having been realized with a plate-shaped element, for example.
The clamping means by which the engaging surfaces can be clamped to each other are preferably mounted in profiled portions of the respective engaging surfaces, in which the profiled portions are at an angle to the general plane or the plane parts of the engaging surfaces, in such a way that on clamping the engaging surfaces together, the complementary positioning elements are forced into the second, final position. Therefore, the clamping means are mounted in such a way, that the clamping force has a component perpendicular to the engaging surfaces as well as a component in the direction of the first to the second position of the cam in the aperture for the cam. Apart from clamping together the respective engaging surfaces of the parts in the appropriate position, said clamping means also serve as additional positioning member providing for that the second position of a cam in an aperture for the cam is actually reached.
Preferably, the clamping means and the positioning means have been mounted on the engaging surfaces in spaced-apart relationship, so that there is sufficient freedom of movement for being able to insert the cam or cams into the respective apertures first, before having the clamping means engage one another. Then, preferably, the positioning and clamping means have been mounted in such a way, that the clamping means can be reached easily from a normal working position.
Hereinafter, the coupling member according to the invention is further explained by way of the example given in the drawing, in which

fig. 1: shows a perspective view of a leg for a desk top with a first engaging surface of a coupling member mounted on it;
fig. 2: shows a perspective view of a portion of a horizontal top member with a second engaging surface to be coupled to said leg; and
fig. 3: shows a perspective view of said horizontal top member and said leg before these are coupled to one another.

Fig. 1 illustrates a leg 1 for a desk top, having a vertical post 2 and a horizontal carrier 3 on which the desk top can be secured. At the bottom side, the vertical post 1 is provided with a base not further illustrated in the drawing. Such a leg 1 is connected to at least one further leg with the help of a horizontal top member 13 (see fig. 2) in order to obtain a supporting entity.
At the crossing between post 2 and carrier 3, a first engaging surface 4 being part of said coupling member is provided. Here, the engaging surface 4 is a substantially cylindrical surface 5 having a raised edge 6. The plane mounts apertures 7 being part of positioining means 7, 8, 9, 16, 17, 18. The apertures 7 have a portion 8 of a first diameter and a further portion 9 of a second diameter, which is smaller than the first diameter.
At the top in engaging surface 4, a profiled part 10 protruding from the plane 5 is provided. The profiled part 10 has a first sloping clamping plane 11 in which a threaded hole 12 has been made, which is part of the clamping means.
Fig. 2 illustrates a top member 13 having its end provided with a second engaging surface 14 complementary to first engaging surface 4 on leg 1. The engaging surface substantially comprises a circular plane 15 intended to fall inwardly of the raised edge 6 of the first engaging surface 4.
The plane 15 mounts two cams 16 comprising a cylindrical part 17 being perpendicular to the plane 15 and a circular plate part 18, mounted at its outer end, and having a larger diameter than the cylindrical part 17. At the top of plane 15, a cavity 19 is provided, which is bounded by a sloping second clamping surface 20 intended for cooperation with first clamping surface 11 on first engaging surface 4.
A threaded bolt 21 is mounted perpendicular to the second clamping surface 20. The threaded bolt 21 is accomo-dated in an insert 22 which can be slid across and/or into the clamping surface and can engage it with a snap connection. This facility provides for that the threaded bolt 21 should be mounted at the time when the coupling between the respective parts is established. Therefore, during storage and transport, no measures need be taken for protecting the otherwise projecting portion.
In fig. 3, the parts to be coupled, leg 1 and top member 13, respectively, are illustrated in a position in which the cams 16 can be brought into the apertures 7. The circular plate parts 18 are inserted in the parts 8 having the largest diameter, whereupon the top member 13 can be moved downwards and the cylindrical parts 17 can be lowered into portions 9 of the apertures 7 of smaller diameter. Subsequently, the threaded bolt 21 is brought into the threaded hole 12 and tightened as a result of which, at the same time, the respective engaging surfaces 5, 15 can come to lie against one another and the cams 16 are forced to the lowermost position.
A series of tests has clearly shown, that, although the structure is relatively simple, the coupling which can be established by it does not show any play and can therefore be loaded to a high degree.

Claims

Coupling members for interconnecting a first and a second framepart (2,3) in which the frameparts to be coupled are at an angle in respect of each other, said coupling members comprising apertures (7) in said first framepart (2) and cams (16) on said second framepart (13), which cams can be brought into said apertures (7) after which said frameparts are moved in respect of each other such that parts (18) of said cams (16) will engage the innerwall of said first framepart (2), means (10,11,12;20,21,22) being present for clamping the engaging surfaces of said frameparts against each other, characterized in that said apertures (7) are provided in a first engaging surface (4) of said first framepart (2) and said cams (16) are provided on a second engaging surface (15) of said second framepart (3) such that said engaging surfaces (4,15) will be pressed against each other in the mounted position of said frameparts (2,3), said means for clamping said engaging surfaces (4,15) against each other being formed by a threaded hole (12) in said first engaging surface (4) in which a threaded bolt (21) provided in said second engaging surface (15) is received.
Coupling members according to claim 1, characterized in that said cam (16) is substantially circular in cross section and is having its largest diameter at the free outer end (18), the aperture (7) for receiving said cam (16) having an elongated shape with a diameter tapering in longitudinal direction.
Coupling members according to claim 1 or 2, characterized in that said threaded hole (12) and said threaded bolt (21) are provided in profiled portions (10,20) of the respective engaging surfaces (4,15), said profiled portions (10,20) running at an angle to the general plane of said engaging surfaces (4,15) in such a way that on clamping said engaging surfaces (4,15) against each other by means of said threaded bolt (21), the parts (18) of said cams (16) engaging the innerwall of said first framepart (2) will be moved along said innerwall of said first framepart (2).
Coupling members according to claim 3, characterized in that said threaded bolt (21) is received into an insert (22) which can be slid onto said second clamping surface (14) or can engage it by a snap connection.