GB2134619A

GB2134619A - Joint for tubular structures

Info

Publication number: GB2134619A
Application number: GB08329457A
Authority: GB
Inventors: Salvatore Mura
Original assignee: PONTEGGI DALMINE SOC
Current assignee: PONTEGGI DALMINE SOC
Priority date: 1983-02-02
Filing date: 1983-11-04
Publication date: 1984-08-15
Also published as: BE897424A; FR2540221A1; ATA207783A; NL8302667A; ES284534U; ES284534Y; DE3317190A1; SE8304179L; AT390485B; IT8320674V0; MX155777A; SE8304179D0; GB8329457D0

Abstract

The joint has a body 2 and a pair of caps 3, each cap having a curved central part the inner surface of which is shaped such as to engage a respective one of a pair of cylindrical tubes 6 to be connected by at least a quarter of its circumference, and having two end portions, one of which has a hammer- head 12 adapted to be particulately inserted in a corresponding hole of the body to allow rotation of the cap by approximately 90 DEG with respect to the body, and the other of which has an open slot to receive the shank of a locking bolt 7, said other end portion having a pair of wings bent at right angles, the edges of said wings being concave to engage the periphery of its respective tube. <IMAGE>

Description

SPECIFICATION Joint for tubular structures This invention relates to a joint for tubular structures.

More particularly, the invention relates to a right-angled joints formed in cold press sheet steel, of the type described in Italian Patent No.

1,002,461 of the same Applicant, improved to allow two bolt operation.

Joints for connecting tubular elements such as tubes used in scaffolding, at right-angles or at different angles known at present are generally formed of three elements, of which the central element or body is shaped on both its opposed surfaces to receive the tubes to be connected and two similar outer elements or caps are shaped on their internal surface to receive and lock each tube to the body. Each cap is connected to the body through two bolts, the tightening of which determines also the tightening of the joint on the tubes to be connected, by reason of which the joint thus requires four bolts.

There are further known two bolt type joints, in which each cap is attached to the body in an openable manner through hinge pins, latches or similar systems, and each cap is provided with a single bolt to effect connection of the cap to the body in the closed position of the joint, and locking of the joint on the tubes to be connected.

According to the present invention there is provided a joint for tubular structures comprising a body and a pair of caps, each cap having a curved central part the inner surface of which is shaped such as to engage a respective one of a pair of cylindrical tubes to be connected by at least a quarter of its circumference, and having two end portions, one of which has a hammer-head adapted to be articulately inserted in a corresponding hole of the body to allow rotation of the cap by approximately 900 with respect to the body, and the other of which has an open slot to receive the shank of a locking bolt, said other end portion having a pair of wings bent at right angles, the edges of said wings being concave to engage the periphery of its respective tube.

The connection of each cap to the body is effected through an articulated engagement of a suitably shaped head on the cap in a seat provided on the body. The head being adapted to allow rotation of the cap with respect to the body by approximately 900, the engagement of each cap on the body in the closed position and the tightening of the joint on the tubes to be connected being effected by a single bolt.

The cap of the joint is formed of a plate of rectangular sheet steel, shaped and cold formed such as to engage a cylindrical tube to be connected by at least a quarter of its circumference, with end portions formed respectively on the one hand with a hammer-head adapted to be inserted in an articulated manner in corresponding seats in the body to allow rotation of the cap by approximately 90 degrees with respect to the body, and on the other hand with an open slot for the introduction of the shank of the locking bolt, with right-angled bent-over wings for rigidity during tightening, part of the edges of which are concave to receive the periphery of the tube.

The body of the right-angled two bolt joint for tubular structures is in turn constituted by a quadrangular plate sheet, shaped and cold formed in order to have adjacent its vertices and on each of its faces, both one pair of arcuate projections for receiving the tubes, as well as a pair of indentations with holes in the bases thereof, suitably shaped, to allow the introduction of the hammer-head of each cap and a rotational play of the heads of the bolts and of the caps.

Each cap has two end portions oriented with respect to the central part of the cap with an inclination such as to determine, in combination with the concave edges of the right angled wings, in the closed position of the joint, the engagement of the cylindrical tube by at least one half of its circumference, the engagement contact being distributed along the length of the central plate and the winged arm, and in the open position of the joint the support guided by the horizontal tube.

The connection of each cap with the body is substantially without transverse play of the cap with respect to the body in the open position of the joint.

Each can is held attached to the body, as provided by the security standards, through simple connections consisting forming the wings of the hammer-head at right angles with successive flattening of the same after assembly or even during the operation of cold-heading or calking such as to form projections on the edge of the seat with holes for introduction of the head of the cap in the body. The two bolt right angled joint, in cold pressed sheet, is easily and rapidly made, and does not require special equipment, it has the required mechanical stress strength and has noticeable advantages in use for assembly and dismantling of tubular structuring.

In particular, the special shape of the caps and their connection to the body, in the open position of the joint, permits positioning and support of the horizontal tubular elements on joints already fixed to vertical structures, which greatly facilitates installation operations.

Embodiments of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which: Fig. 1 is a perspective view of an assembled joint made in accordance with the present invention; Fig. 2 is a front view of the joint mounted on a vertical structure; Fig. 3 is a side view of the joint of Fig. 2; Fig. 4 is a view corresponding to Fig. 3, but with one cap open; Fig. 5 is a view corresponding to Fig. 3 but showing part of one of the caps and part of the body in section taken generally along the line V-V of Fig. 2; Figs. 6 to 9 show a detail of a cap; Fig. 10 shows a blank from which a cap is made; Fig. 11 shows the cap in front view; Fig. 12 shows the cap in plan; Fig. 13 shows the cap in side view along arrow X of Fig. 5;; Fig. 14 shows the body in front view; Fig. 1 5 shows the body in plan.

With reference to Figs. 1 to 5 of the drawings a joint for tubular structures is indicated generally by the reference numeral 1 and is constituted by a body 2 and by a pair of identical caps 3. Each cap 3 is connected to the body 2 through the articulated engagement in a seat 4 formed in the body 2 of a hammer-head 12 formed on one end of the cap 3, and adapted to permit rotation of the cap 3, with respect to the. body 2 by approximately 900 from a joint-closed position as illustrated in Fig. 3 to a joint-open position as illustrated in Fig. 4. The caps are locked on the body and tightening of the joint on tubes 6 to be connected is effected by a pair of respective bolts 7.

As illustrated in Figs. 6 to 13 each cap 3 is constituted by a shaped and cold formed rectangular plate 8. The cap comprises a curved central part 9 from the ends of which there extends respective end portions 10 and 1 The inner surface of the central part 9 engages its respective cylindrical tube 6 by approximately a quarter of its circumference.

The end portion 10 has a hammer-shaped head 12 bent outwardly of the portion 10 and having wings 12'. The end portion 11 has an open slot 13 to receive a bolt 7 and has a pair of wings 14 bent over at right angles, edges 1 5 of which are concave with the same radius of curvature as the central part 9.

On the outer surface of the central part 9 there is provided a reinforcement and strengthening rib 16, whilst on the wings 14 there are formed respective protrusions 1 7 at the edge of the open slot 13, for the purposes of preventing slipping of the bolt 6 from the cap 3.

As illustrated in Figs. 14 and 15, the body 2 of the joint comprises a shaped and cold formed quadrangular plate 1 8 having on each of its faces both a pair of arcuate projections 1 9 for receiving a respective one of the tubes 6 to be connected as well as a pair of indentations 20. One of the indentations 20 of the pair having a hole 21 shaped to allow introduction of the hammer-head 12 of the caps 3 and the other of the indentations 20 having a hole 22 shaped to receive one of the bolts 7.

As can be seen in particular in Figs. 3 to 5, the end portion 11 of the cap 3 extends from the central part 9 such as to determine, in combination with the concave edges 1 5 of the right-angled wings 14, in the closed position of the joint, the engagement of the cylindrical tube 6 by at least half of its circumference, said engagement contact being distributed along the inner surface of the central part 9 and the edges 15 of the end portion 11.

As can be seen in particular in Fig. 4, in the open position of the joint, the cap 3 serves to support the horizontal tube 6, lying against the central part 9 and laterally engaged by the concave edges 1 5 of the wings 14 of the end portion 11. The cap 3, in said open position, is further sufficiently rigid due to the absence of transverse play in the connection with the body through the hammer-head 12 in the holes 21 of the body.

As appears from Figs. 6 to 9, to attach the cap 3 to the body 2 the wings 12' of the hammerhead 12 are first bent at right angles (Fig. 6) and then introduced in the hole 21 of the body 2 by rotation of the cap 3 (Fig. 7) to allow the passage of said wings 12' through the hole 21. Thereafter, the cap 3 is again rotated into its normal position and flattening of the two wings 1 2' (Fig. 8) is carried out so as to result in the shape shown in section in Fig. 9 which retains the cap 3 attached to the body 2.

Claims

1. A joint for tubular structures comprising a body and a pair of caps, each cap having a curved central part the inner surface of which is shaped such as to engage a respective one of a pair of cylindrical tubes to be connected by at least a quarter of its circumference, and having two end portions, one of which has a hammer-head adapted to be articulately inserted in a corresponding hole of the body to allow rotation of the cap by approximately 900 with respect to the body, and the other of which has an open slot to receive the shank of a locking bolt, said other end portion having a pair of wings bent at right angles, the edges of said wings being concave to engage the periphery of its respective tube.

2. A joint as claimed in claim 1, wherein the body is constituted by a plate shaped to present on each of its faces, both a pair of arcuate projections for receiving a respective one of the tubes, as well as a pair of indentations, one of said indentations having a hole to receive the hammerhead of one of the caps and the other indentations having a hole to receive the head of a locking bolt.

3. A joint as claimed in either preceding claim, wherein the winged end portion of each cap extend from the central part of the cap such as to determine, in combination with the concave edges of the right angled wings, in the closed position of the joint, engagement of its respective tube by at least one half of its circumference, said engagement contact being distributed along the inner surface of the central pair and the concave edges of the wings.

4. A joint as claimed in any preceding claim, wherein in the open position of the joint, the cap serves to support its respective tube.

5. A joint as claimed in any one of the preceding claims, wherein the connection of the cap to the body is, in the open position of the joint, substantially without transverse play.

6. A joint as claimed in any one of the preceding claims, wherein the hammer-heads of the caps have wings bent over at right angles, the successive flattening of which on the introduction of the heads in the respective holes of the body retains each cap attached to the body.

7. A joint for tubular structures substantially as hereinbefore described with reference to the accompanying drawings.