EP0071376A1

EP0071376A1 - Fittings for anchoring elongate members to fixed structures

Info

Publication number: EP0071376A1
Application number: EP82303765A
Authority: EP
Inventors: Ernest Lancaster
Original assignee: Jw Raylor & Co (engineers) Ltd
Current assignee: Jw Raylor & Co (engineers) Ltd
Priority date: 1981-07-25
Filing date: 1982-07-19
Publication date: 1983-02-09
Also published as: GB2112439B; EP0071376B1; GB2112439A; DE3266033D1

Abstract

O A scaffold fitting for anchoring a scaffold tube to a wall has a bolt (2, 31) which can be secured into the wall and a gripping device (3, 20) which is connected to the bolt and can be clamped around the scaffold tube (19a, 28).

The gripping device can be adjusted, for example, rotated, around the bolt.

The gripping device may be formed from pivotably interconnected jaws (7, 12 or 21, 22) which can be fixed together with a clamping screw (13, 24).
In one embodiment the scaffold tube (19a) is at right angles to the bolt (2) and can be clamped onto the bolt to prevent further relative movement.
In an alternative embodiment the tube (28) is parallel spaced and laterally offset relative to the bolt (31).

Description

This invention relates to fittings for use in anchoring elongate members, such as scaffold tubes, to fixed structures particularly building structures of concrete brickwork or stone.
A known method of anchoring a scaffold tube to a fixed building structure involves the use of a large eye bolt which is screwed into a socket set into the building structure such that the end of the bolt having the eye projects freely from the building structure with the axis of the eye having a desired disposition (for example extending horizontally). A scaffold tube is inserted through the eye and is locked in position relative thereto by means of scaffold fittings (of the kind normally used to join scaffold tubes at right angles) mounted on the tube on opposite sides of the eye bolt.
With this known arrangement certain problems may arise. In particular, the mode of attachment of the scaffold tube relative to the eye of the bolt may be inconvenient and tends to leave play between the tube and the bolt; and, since tightening of the bolt in the threaded member necessarily involves rotation of the eye of the bolt, such tightening can only be effected conveniently when the scaffold tube is not engaged with the eye, and it may be difficult to tighten the bolt adequately whilst achieving a desired final disposition of the axis of the eye.
An object of the present invention is to provide a fitting with which the above mentioned problems can be avoided or at least appreciably reduced.
According to the invention therefore, a fitting for use in anchoring an elongate member to a fixed structure comprises a bolt adapted to be secured at one end relative to said fixed structure with the opposite end thereof projecting freely from the structure and a gripping device adapted to be tightened around said elongate member so as to grip same, said gripping device being mounted on said opposite end of the bolt so as to be positionally adjustable about the longitudinal axis thereof.
With this arrangement, in a secure yet convenient manner, the bolt can be anchored to the said fixed structure and the elongate member can be mounted relative to the bolt. Moreover, due to the adjustability of the gripping device, the bolt can be rotated, for example to tighten same in a socket in the fixed structure, without this necessarily preventing attainment of a desired final disposition for the gripping device and hence of the longitudinal axis of the elongate member.
Preferably the gripping device is mounted on the bolt so as to be freely rotatable about the axis of same at least prior to gripping of the elongate member. Preferably, also, said adjustability of the gripping device is restricted or prevented when the elongate member is gripped. Thus, the arrangement may be such that the elongate member when gripped is tightened against the bolt to restrain relative movement therebetween.
The gripping device may take any suitable form although conveniently such device may comprise pivotally interconnected jaw structures adapted to receive the elongate member between same, a fixing device such as a nut and bolt being provided for clamping the jaws tightly against the elongate member.
It is visualised that the fitting of the invention will find particular application in the context of the anchoring of scaffold tubes on fixed suitable building structures in which case the gripping device may be shaped and dimensioned to receive a conventional scaffold tube and the said one end of the bolt may be adapted to engage a conventional form of socket member set in such suitable building structure. It is however to be understood that the invention is not intended to be restricted to this field of application.
The invention will now be described further by way of example only and with reference to the accompanying drawings in which:-

Fig. 1 is a diagrammatic side view of one form of a fitting according to the invention;
Fig. 2 is an end view of the fitting as seen from the right of Fig. 1;
Fig. 3 is a diagrammatic side view of an alternative form of fitting;
Fig. 4 is an end view as seen from the left of Fig. 3 with the fitting pivoted downwardly; and
Fig. 5 shows a scaffold arrangement which can be constructed using the arrangement of Figs. 3 and 4.

The fitting of Figs. 1 and 2 is for use in anchoring a scaffold tube of circular cross-section to a fixed suitable building structure 1 (shown in section).
The fitting comprises a bolt 2 and a gripping device 3.
The bolt 2 is threaded at one end portion 4 and has a hexagonal head 5 at its opposite end. Between the head 5 and the threaded portion 4, the bolt has a smooth cylindrical surface 6 extending over a major part of the length of the bolt.
The gripping device 3 comprises a rigid metal U-shaped part 7 having spaced parallel side walls 8 joined by a curved base. Aligned semi-circular cut-outs 11 are provided in the side walls 8 extending downwardly from the top edges thereof.
A curved lug 12 is pivotally mounted at one end on a pin 13a between the side walls 8 at one side of the aligned cut-outs 11. At the opposite side of the cut-outs 11 the eye of an eye bolt 13 is pivotally mounted on a pin 14 between the side walls 8, the opposite, threaded end of the bolt 13 engaging a fork 15 at the end of the lug 12 opposite the pivotal mounting thereof and being provided with a nut 16.
A passage generally of U-shaped cross-section is defined in the part 7 between the side walls 8, and the smooth surfaced part 6 of the bolt 2 is passed through this passage. A first washer 17 is fixed around the bolt 2 adjacent the hexagonal head 5 and a second washer 18 js fixed around the centre of the bolt 2, and as shown in Fig. 1 the gripping device 3 is retained in position on the bolt 2 between these washers 17, 18, the top of the device 3 being closed by the pins 13a, 14. The clearance within the passage and between the washers 17, 18 is however sufficient to permit free rotation of the bolt 2 about its longitudinal axis relative to the gripping device 3, although it will be noted that the smooth surface 6 of the bolt 2 extends slightly above the curved bottom extremities of the cut-outs 11.
In use, the bolt 2 is fixed to a suitable building structure by screwing the threaded end portion 4 into a socket member 19 set in the structure 1. Such threaded member 19 may be an expansion device of conventional form which expands and tightly grips the surrounding material as the bolt 2 is screwed into same.
A scaffold tube 19a is fitted into the gripping device 3 after disengaging the bolt 13 from forked end 15 to permit pivotal displacement of the lug 12 away from the cut-outs 11. The scaffold tube is located within the cut-outs 11 and the curved lug 12 is then pivoted into position around the tube, the bolt 13 then being re-engaged with the forked end 15 and the nut 16 being screwed onto the bolt 13 to clamp the tube tightly between the lug and the peripheries of the cut-outs 11, said lug 12 and the part 7 thereby defining jaw structures to hold the tube. When the nut 16 is fully tightened, the scaffold tube is locked against the surface of the bolt 2 thereby to prevent rotation of the bolt 2 relative to the gripping device 3.
With the arrangement so far described, the scaffold tube can be anchored relative to the building structure 1 securely and reliably yet in a particularly quick and convenient manner in so far as this anchoring is achieved using a single fitting unlike the above described conventional procedure which requires the use of a number of separate fittings. Moreover, prior to tightening of the nut 16 it will be understood that the bolt 2 can be freely rotated to tighten same into the building structure whilst maintaining a desired disposition of the gripping device (e.g. with the axis of the generally cylindrical passage defined between the jaw structure and the cut-outs extending horizontally). This facilitates the anchoring operation and indeed even enables the bolt 2 to be tightened in the building structure with the scaffold tube in position in the gripping device 3.
With the embodiment of Figs. 1 and 2 the scaffold tube 19a runs parallel to the wall 1. It is however possible to construct a fitting according to the invention which is adapted to support a tube at right angles to the wall. A fitting of this latter kind is shown in Figs. 3 and 4.
The fitting of Figs. 3 and 4 has a gripping device 20 comprising a shaped solid bottom part 21, a curved lug 22 pivotably mounted at one end via a pivot pin 23 on the part 21, and an eye bolt 24 pivotably mounted at its eye on a pin 25 and adapted to be secured to a forked end 26 of the lug 22 with a nut 27. The lug 22 and the part 21 have mutually confronting curved surfaces between and in contact with which a scaffold tube 28 can be securely clamped.
The part 21 has a downwardly projecting extension 29 which is provided with a through bore 30 the axis of which extends parallel to the axes of the pins 23, 25. It will be noted that this bore is not disposed in the centre of the fitting but rather is located adjacent the pin 23.
A bolt 31 (shown in Fig. 3 but not Fig. 4) is passed through the bore 30, such bolt being of like form to the bolt of Figs. 1 and 2 and having a hexagonal head 32, integral washers 33, 34, a smooth surfaced body 35 and a threaded end 36. The washers 33, 34 retain the bolt relative to the gripping device 20 whilst permitting free rotation of such device around the bolt.
In use, as shown in Fig. 3, the threaded end 36 of the bolt 31 can be engaged with a threaded socket member 37 set into a building wall 38. The scaffold tube 28 can then be clamped in the gripping device 20 with such tube extending at right angles to the wall 38. In practice the end of the tube abuts the wall as shown. It will be noted that the tube 28 is not clamped against the bolt 31 and is therefore free to rotate with the gripping device 20 around the bolt even when tightly gripped by the device 20.
The fitting of Figs. 3 and 4 can be used in the construction of a scaffold arrangement as shown in Fig. 5. This arrangement involves upright scaffold tubes 39 positioned near to the wall 38, aligned upright tubes 40 spaced further from the wall, ledger tubes 41, 42 extending horizontally respectively alongside the tubes 39 and the tubes 40, and transom tubes (e.g. the tube 28 shown in Figs. 3 and 4 as well as Fig. 5) extending horizontally at right angles to the tubes 41, 42. These tubes are fixed together at the crossing points 43 by fittings of the well-known kind having two integral tube gripping devices at right angles to each other. The end of the transom tube abuts the wall 38 and is fixed relative thereto in the manner shown in Figs. 3 and 4. Scaffold boards 45 are supported on top of the horizontal tubes 28, 41 to define walkways, such boards butting up against the wall and resting on top of the lugs 22 of the gripping devices 20 as shown in Fig. 4, it being observed that such lugs have flat top surfaces thereto.
In assembling the arrangement of Fig. 5, the tubes 39 and 41 are first erected and a hole for each bolt 31 is drilled in the wall 38. As can be seen from Fig. 4, the bolt hole is located by alignment, approximately, with the top extremity of the ledger 41. The bolt 31 is then screwed into the wall and the end of the tube 28 is clamped securely in the gripping device 20. At this stage conveniently the tube 28 may be vertically above the bolt 31, as shown in Fig. 3. The tube 28 can then be pivoted downwardly with the gripping device 20 about the bolt 30 to the position shown in Fig. 4 in which the tube 28 can be fixed with fittings to the tubes 41, 42 at the pertaining crossing points 43. In this position the geometry of the fitting shown in Figs. 3 and 4 is such that the top surface of the lug 22 is horizontal when the vertical spacing of the bottom periphery of the tube 28 and the upper peripheries of the tubes 41, 42 (i.e. the gap 44 shown in Fig. 4) is just sufficient to accommodate the intermediate structure of the fittings used at the crossing points 43. In this way, it will be seen that the transom 28 can be accurately fitted in a particularly quick and convenient manner and when so fitted provides a secure, stable support for the board 45. In particular, the board 45 rests on the flat surface of the lug 22 clear of the bolt 24 and there is no play in the fixing of the transom 28 because the end of the transom is rigidly clamped by the gripping device 20 and bodily movement of the tube 28 with the device 20 is restrained by virtue of the attachment of the tube 28 to the tubes 41, 42. The security of the fixing of the transom 28 is such that an appreciable saving in components can be achieved. That is, it is not necessary to use two side-by-side transoms as is the case where an eye bolt fitting is used for attachment to the wall.
The ready pivotability of the gripping device 20 through an angle of 360° about the bolt 31 facilitates easy engagement of the gripping device with a scaffold tube in that the gripping device can be moved through an appreciable distance to pick up the tube.
It is of course to be understood that the invention is not intended to be restricted to the details of the above embodiments. For example, and with reference to the embodiment of Figs. 3 and 4 this may be modified: by use of the bolt 31 (or a sleeve for the bolt) as the pivot pin for the lug 22 in place of the pin 23; by provision of a side-tapped screw in the part 21 which can be moved into engagement with the bolt 31 to lock same against rotation; by use of a U-shaped pressing in place of the solid part 21.
With reference to the arrangement of Fig. 5 it will be appreciated that only part of the structure is shown. In particular it will be understood that multiple transom tubes 28 will be employed and boards will be positioned between and parallel to the ledgers 41, 42 resting on the transoms 28 (in accordance with conventional practice) in addition to the boards 45 which rest on the transoms 28 and wall-anchoring fittings behind the uprights 39 in abutment.with the wall and parallel to the ledgers. Other scaffolding arrangements, and indeed also other constructions, can also be erected using the fitting of the invention.

Claims

1. A fitting for use in anchoring an elongate member to a fixed structure comprising a bolt adapted to be secured at one end relative to said fixed structure with the opposite end thereof projecting freely from the structure and a gripping device adapted to be tightened around said elongate member so as to grip same, characterised in that said gripping device (3) is mounted on said opposite end of the bolt (2) so as to be positionally adjustable about the longitudinal axis thereof.

2. A fitting according to claim 1, characterised in that the gripping device (3) is mounted on the bolt (2) so as to be freely rotatable about the axis of same at least prior to gripping of the elongate member (19a).

3. A fitting according to claim 1 or 2, characterised in that said adjustability of the gripping device (3) is restricted or prevented when the elongate member (19a) is gripped.

4. A fitting according to claim 3, characterised in that the arrangement is such that the elongate member (19a) can be tightened against the bolt (2) to restrain relative movement therebetween.

5. A fitting according to any one of claims 1 to 4, characterised in that said gripping device (3) comprises pivotably interconnected first and second jaw structures (7, 12) adapted to receive the elongate member between same, a fixing device (13-16) being provided for clamping the jaws tightly against the elongate member, and said bolt (2) being passed through the first said structure (7).

6. A fitting according to any one of claims 1 to 5, characterised in that said gripping device (3) is adapted to grip said elongate member (19a) with the longitudinal axis thereof at right angles to the longitudinal axis of the bolt (2).

7. A fitting according to any one of claims 1 to 5, characterised in that said gripping device (20) is adapted to grip said elongate member (28) with the longitudinal axis thereof parallel to the longitudinal axis of the bolt (31).

8. A fitting according to claim 7 when dependent on claim 5, characterised in that said jaw structures (21, 22) of the gripping device (20) , are pivotably interconnected (at 23) at one end and the fixing device (24-27) is adapted for connection to said structures at the opposite end. and said bolt (31) is located in the said first structure at a position (bore 30) displaced away from the centre thereof as . considered with reference to the said ends.

9. A fitting according to claim 8, characterised in that the bolt (31) is located at or close to the said one end . of the said first structure (211.

10. A fitting according to claim 8 or 9, characterised in that the said second jaw structure (22) has a flat upper . surface thereto which is inclined downwardly in a direction towards the bolt.

11. A scaffold assembly comprising scaffold tubes at least some of which are anchored relative to a wall with fittings according to any one of claims 1 to 10.