GB2068499A - Releasable joint for railings - Google Patents

Abstract

The end of a rail 5 is received in a hole 15 in a cap 14 placed over the top of post 1 so that the lower part of a head 10, 11 on the end of the rail is located in an annular groove 12 in the head 3 of the post. The cap and rail are clamped in position by means of an externally threaded nut 15 which is screwed up inside the internally threaded cap until it engages beneath a flange 4 on the head 3. <IMAGE>

Description

SPECIFICATION Releasable connection This invention concerns a releasable connection between a stem and one or more branch members.

It is envisaged that connections in accordance with the invention may be employed in many structures including furniture and particularly for use in a barrier eg for the convenient marshalling of people in queues.

Barriers are commonplace which comprise chains or ropes strung between free-standing posts. These barriers are versatile in that they can easily be moved from one position to another and of course succesive lengths of rope or chain can be disposed at any desired relative angle.

However, such barriers are prone to unauthorised interference and vandalism.

Also known in a barrier system comprising a number of free-standing posts each having a head portion which is of square section in plan view. In one or more of the faces of the head there is provided a key-hole slot. Rails are provided having a spigot at each end, of a form which can pass into the keyhole and lock in the slot with the end of the rail held firmly against the head. This system can provide a rigid barrier which is less prone to interference than the more commonplace system previously mentioned. However, it suffers from certain other disadvantages, particularly in that the head can be subject to considerable strain resulting from stresses imposed on the barrier structure, so that the head needs to be of relatively massive construction in order to resist such stresses-and may nevertheless still be subject to accidental or deliberate damage.The large mass of the head makes necessary also the provision of a more massive foot to the post for stability, which is both more costly and less convenient in use. It is further possible with this known design that the spigot can be dislodged from the keyhole either accidentially or deliberately by unauthorised persons.

The present invention seeks to provide a robust connection which is secure and relatively free from unauthorised interference yet which is versatile and easily releasable by authorised persons.

According to the present invention there is provided a releasable connection between a stem and one or more branch members comprising a head portion adapted to be connected to a stem and provided with a lip; one or more branch members, each provided at its end with a spigot having an enlarged portion remote from the said end, said enlarged portion having at least one shaped face engageable with the lip to prevent movement of the spigot in at least one direction; and clamping means which can restraim the movement of the spigot so as to prevent disengagement of the shaped face from the lip.

In one convenient arrangement the lip is provided so as to define an edge of a recess in the head portion within which the enlarged portion can be located so that the shaped face of the spigot can engage the inner face of the lip.

The lip may conveniently be annular to allow the branch members to be disposed around the stem at any of a variety of desired angles at least in one plane.

The clamping means may be a cylindrical cap in which holes are provided to receive the ends of the branch members. A plurality of interchangeable caps may be provided with a.

different number of holes and at different orientations.

Conveniently the cylindrical cap has an internal screw thread and there is further provided as part of the clamping means an externally threaded locking ring which is engageable with the said cap.

Preferably there is provided on the head portion a flange against which the locking ring may be tightened to firmly secure the cap.

Each branch member may have a flat end face engageable with a side of the head portion to prevent inward movement of the branch member.

Preferably the shaped face and the portion of the lip with which the shaped face is engageable are of complementary shape.

In a convenient embodiment the shaped face and the portion of the lip with which it is engageable may each be of similar spherical form, in order to facilitate efficient engagement of the shaped face and the corresponding lip. The load between the shaped face on the lip is then transmitted over a finite area, rather that through point or line contact, even though the relative orientation of stem and branch may be varied. The possibility of damage between these mating faces is thus very much reduced.

One embodiment of the invention will now be described by way of example only with reference to the accompanying drawing, which is a sectional elevation of a portion of a barrier, incorporating a connection in accordance with the invention.

The barrier portion as illustrated comprises a vertical tubular stem 1 with a heavy base 2 of circular cross section, and a head portion 3 firmly located at the end of the stem remote from the base 2. The head portion is inserted into the stem 1 until a flange 4 extending from the head portion engages with the end of the stem, and the head portion is secured in position, eg by soldering or brazing.

Two tubular branch members 5 rest on the flange 4 each with a plug 6 firmly located in the end thereof. Each plug 6 has a rim 7 such that a flat face 8 of the rim can engage with the side of the head portion 3 above the flange 4 so as to limit movement of the branch member 5 inwards.

The plugs 6 may be secured to the tubular branch members 5 in a similar manner to that used in securing the head portion 3 in the stem.

-Extending from each of the plugs 6 is a cylindrical spigot 9 the end portion of which is enlarged and has formed thereon on its rearward side a shaped face 10 of spherical form, and on its Forward side a tapered face 11.

The enlarged portion of the spigot is received in an annular recess 12 bounded by an annular lip 1 7 on the head portion 3 so that the spherically shaped face 9 can engage a complementary face 13 of lip 17. In this way movement of the branch members radially outward of the head portion 3 may be resisted.

Clamping means are provided comprising a hollow cylindrical cap 14 having one closed and one open end of an internal diameterjust greater than that of the flange 4. The cap 14 fits over the head portion 3 with the closed end of the cylinder uppermost. Adjacent the open end of the cylinder there is provided an internal screw thread with which there is engageable an externally threaded locking ring 1 5 constituting the remainder of the clamping means of an internal diameter greater than the stem 1 but smaller than the flange 4.

Holes 1 6 are provided in the cylindrical wall of the cap 14, snugly to receive the ends of the branch members 5.

in use the cap is placed over the head portion and the branch members inserted through the holes in the cap until the shaped face 9 of the spigot engages with the complementary face 13 of the recess 12, and the flat face 8 of the rim 7 engages with the side of the head portion 3. The locking ring is subsequently engaged with the internal screw thread of the cap 14 and turned until it is firmly against the flange 4, hence pulling the cap 14 firmly downwards on to the two branch members 5 so as positively to retain the enlarged portion of the spigot 9 located in the recess 1 2 with the faces 9, 1 3 held in contact with each other and the face 8 held in contact with the side of the head portion 3.

Outward radial movement of the branch members is thus prevented by the enforced engagement of the shaped face 9 of the spigot with the complementary face 13 of the recess, while inward radial movement of the branch members is prevented by the enforced engagement of the flat face 8 of the rim and the side of the head portion 3. Vertical movement of the branch members is prevented by the cylindrical cap bearing down thereon. In this way relative movement of the branch members 5 and the head portion 3 is restrained whilst easy removal of the locking ring 1 5 provides a releasable connection.

It will be apparent to those skilled in the art that numerous changes can be made to the embodiment described without departing from the scope of the invention.

Thus, for example, although in the embodiment described the cap has two holes directly opposite one another it will be readily appreciated that a different number of holes and different orientations may be employed.

Furthermore it is conceivable that the clamping means other than the cylindrical cap 14 and locking ring 15 may be employed. For example the clamping means 14, 1 5 might conceivably be replaced by a disc which is clamped over the spigots 9 by means of a central bolt received in a threaded axial bore in the upper portion of the head 3. Such an arrangement would permit the branches 5 to be disposed at any desired relative angle at least in a horizontal plane. Also, conceivably the lip 1 7 and/or recess 8 might be formed in the lower surface of such a disc, or in the lower surface of the disc closing the cap 14, instead of or as well as in the head portion 3.

Other possible modifications within the scope of the invention will be apparent from the foregoing disclosure.

Claims (9)

1. A releasable connection between a stem and one or more branch members comprising a head portion adapted to be connected to a stem and provided with a lip; one or more branch members, each provided at its end with a spigot having an enlarged portion remote from the said end, said enlarged portion having at least one shaped face engageable with the lip to prevent movement of the spigot in at least one direction; and clamping means which can restrain the movement of the spigot so as to prevent disengagement of the shaped face from the lip.

2. A releasable connection according to claim 1 wherein the lip is annular.

3. A releasable connection according to claim 1 or claim 2 wherein the shaped face and the portion of the lip with which the shaped face is engageable are of complementary shape.

4. A releasable connection according to claim 3 wherein the shaped face and the portion of the lip with which the shaped face is engageable are of spherical form.

5. A releasable connection according to any of claims 1 to 4 wherein the lip defines the edge of a recess in the head portion within which the enlarged portion can be located, the said shaped face engaging the radially inner face of the lip.

6. A releasable connection according to any one preceding claim wherein the clamping means comprises a cylindrical cap provided with holes to receive the ends of the branch members.

7. A releasable connection according to claim 6 wherein the cylindrical cap has an internal screw thread and there is further provided as part of the clamping means an externally threaded locking ring which is engageable with the said cap.

8. A releasable connection according to claim 7 wherein there is provided on the head portion a flange against which the locking ring may be tightened to firmly secure the cap.

9. A releasable connection according to any one preceding claim wherein each branch member has a flat end face engage able with a side of the head portion to prevent inward movement of the branch member.

1 0. A reieasable connection substantially as hereinbefore described, with reference to the accompanying drawing.