GB2093900A

GB2093900A - Safety device for metal scaffolding

Info

Publication number: GB2093900A
Application number: GB8137823A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1981-03-03
Filing date: 1981-12-15
Publication date: 1982-09-08
Also published as: DE3108020C2; CH657888A5; GB2093900B; FR2501269A1; DE3108020A1; DK155958C; DK510081A; ATA499981A; FR2501269B1; DK155958B; AT390108B

Abstract

A safety device, for preventing the falling of objects and to protect workers on scaffolding, comprises outer metal frames 1 each of which extends over the length of a scaffold panel, and the height of which corresponds to half the height of a scaffold storey. Each outer frame 1 carries or encloses a screen 17 made of wire netting which spans the entire area of the frame 1. Bottom member 11 of the frame 1 is in the form of a downwardly-open channel member, and side members 13 have lugs, 18, 19 for mounting the panel in place. <IMAGE>

Description

SPECIFICATION Safety device for metal scaffolding This invention relates to a safety device intended for use with metal scaffolding, more especially metal scaffolding having vertical scaffold elements designed as adjustable or vertical frames, and by which safety device the falling of objects, for example a tool or building material, is prevented and the safety of personnel working on the scaffolding or therebelow, is guaranteed.

Protective walls for metal scaffolds, for example so-called roofers' protective walls, have already become known in which wooden panels, for example scaffold-framed panels, are used on a supporting structure consisting of metal strip members (see Swiss Patent No. 524 036).

However, safety devices of this kind on the one hand have the disadvantage of being complicated in construction and on the other hand, apart from in the topmost storey of a scaffold, are not usable universally, since they effectively obstruct the access of light to the lower storeys. In addition, this construction involves a considerable increase in the weight; moreover, because they may be subject to very high wind pressures which have to be absorbed by appropriately-strong anchorage of the scaffolding e.g. to a building.

The problem of the invention is to provide a safety device which is simple to erect and is usable for all storeys of a scaffolding structure; and which is effective to prevent the falling of objects or articles such as tools or building materials as well as to protect workers on the scaffolding.

To solve this problem in accordance with the invention a safety device as above discussed comprises metal outer frames which each extend over the length of a scaffold panel or bay and correspond in height to half the height of a scaffold storey, each said frame carrying a screen of wire netting, which spans substantially the entire area of the frame.

In a development of the invention each said frame comprises a lower frame member in the form of a downwardly-open U-profiled or channel strip; said outer frame preferably comprises an upper frame member and two lateral frame members each in the form of a scaffold tube. All of the frame members are advantageously connected to one another by welding.

The vertical lateral frame members are provided with fastening elements which are designed to correspond with the respective scaffolding system. Two such frames are, then, provided for each storey of the scaffolding, so that the upper member of the lower frame forms a handrail, whilst the upper frame engages, by its lower frame member, which is U-shaped in section, over the upper limb of the lower frame.Because of this construction, one obtains satisfactory protection against falling of any objects, whilst at the same time the additional advantage is obtained that the incorporation of the device renders unnecessary both the use of an edge board or wind board, and of a knee ledge; and generally also the use of a diagonal strut is superfluous, since the wire screen, which is clamped firmly in the inner frame, in its entirety achieves an equivalent stiffening action to that available from a diagonal strut.

Of course, any suitable section, for instance an I-section or an angle section, can be used for the lower frame member of each outer frame.

Since, in scaffolding constructed from adjusting frames, no adjusting frame is employed in the upper most storey, but use is generally made only of so-called handrail posts, which have only half the height of a scaffolding storey. As a result, a special scaffolding element has to be provided for the mounting thereon of a safety device, which special element corresponds in its conception basically indeed to the handrail posts, but has the necessary height and fastening means for the mounting of the two frames, to be arranged one above the other, of the safety device.In further development of the invention, such a supporting element for the uppermost storey, is designed in such a way as to comprise, welded to a vertical tube corresponding to the normal storey height, at the lower end of said vertical tube and at right angles to it, a rectangular tube which serves as a masking above the claws, which engage in the Uprofile forming the upper termination of an adjusting frame, of the scaffold frame panels.

Provided at the building end of this rectangular tube, corresponding in its length to the scaffold depth, is then a short scaffold tube socket which serves to establish connection thereto, of the adjusting frame present thereunder, by means of its tube connector.

An exemplified embodiment of the safety device of the invention is illustrated in the accompanying drawings, in which: Fig. 1 is a view of the frame of the said preferred embodiment of the safety device fallen perpendicular to the longitudinal extent of its scaffolding structure (not shown); Fig. 2 is a section through the lower frame member of the device, the section being taken as indicated by the line A-A in Fig. 1; and Fig. 3 is a view of a supporting element for the mounting of the safety device in the topmost storey of a scaffolding structure, considered in the longitudinal direction of the scaffolding.

The preferred embodiment of the safety device in accordance with the invention as illustrated in Figs. 1 and 2 comprises an outer frame 1, lower frame member 11 of which consists of a downwardly-open U-profile. Two side members 13, as well as the upper frame member 12 extending parallel to the lower member 11, each consist, for example, of round scaffolding tubes which are welded at the upper corners of the outer frame 1, to one another, and, at the lower corners of the frame 1 , to the lower member 11. The outer frame 1 is provided with tongue-shaped fastening lugs 1 6 which are fixed securely on its frame members and which point towards the interior 1 4 of the outer frame 1.These lugs 1 6 provide for an inner frame 1 5, consisting of narrow metal strips 1 5', 15" to be fastened within the outer frame 1.

This inner frame 1 5 serves as a support for a wire screen 17, for example in the form of a wire mesh or netting, which is ciamped into the inner frame 15. In order to be able to fasten the wire mesh to the inner frame 15, for example the limbs 1 5' and 15" of this inner frame 1 5 may be in the form of narrow strips of a flat metal, the elasticity of which makes it possible to thread these metal strips through the outer meshes of the wire mesh alternately to the one and the other side and, after introduction of the strips, to join them together at the four corners of the inner frame 1 5 for example by screw connections. Then, the inner frame 1 5 with the wire screen 17, is secured to the fastening lugs 16, for example with the aid of screws (not shown).In this way the possibility exists, in the event of damage to the wire screen 1 7, of dismantling the inner frame 1 5 with the wire screen 1 7 thereon without difficulty and of replacing it by another one. The fastening of the wire screen 1 7 to the inner frame 1 5 is, naturally, also possible in other ways, for example by clamping the outermost meshes between two strips 15', 15" which are bolted or rivetted to one another.

To fasten the safety device to adjusting frame of a scaffolding structure (not shown), at the upepr end of each side member 13 of the outer frame 1 are hook-shaped fastening brackets 1 8 which engage downwards into transoms or transverse stays (not shown) designed as upwardly-open Uprofiles, of the adjusting frames in a way similar to the claws of the scaffolding frame panels serving as bearing and working surface. Mounted approximately at half the height of each of the side limbs 13, or at the height of the fastening elements, for example wedge boxes, which are normally provided for the fastening of the knee strips, are fastening straps 1 9 which are similarly appropriately angled.Of course, where applicable, the shape of the fastening or connecting straps 18, 1 9 is governed by the respective scaffolding system in which the safety device is intended to be used, that is to say, instead of a hook-shaped or an angled embodiment, for example also straps made from flat metal can be provided, in which bores for the slipping onto rocking pins or similar devices are introduced.

In order to instal a safety device in accordance with the illustrated example,chosen here, on a metal scaffolding, for each panel or bay two of the frames 1 are arranged one above the other, the lower frame being secured by means of the fastening elements 18, 1 9 in the wedge boxes of the two adjusting frames bounding the panel or bay whilst the outer frame of the upper safety device, as already indicated, is suspended by means of the fastening elements 1 8 into the Uprofiles forming the upper transoms of the adjusting frames and is held in its position by the lower transoms or cross stays, masking these Uprofiles, and consisting of a rectangular tube, of the adjusting frames forming the next storey.The angled straps 1 9 can either be introduced into wedge boxes of the adjusting frame, if wedge boxes are provided at this level on the adjusting frame; otherwise, the fastening elements 19 can remain free. The upper frame 1 engages, with the U-profile forming its lower member 11, over the upper limb 12 of the lower frame 1, so that a connection which ensures the stability of the safety device exists between the upper and the lower frame members.

Since, as has already been stated above, in the uppermost storey of scaffolding erected with adjusting frames, no adjusting frame is installed, but normally handrail posts are used, which have only half the height of a scaffolding storey, for the mounting of safety devices occupying an entire storey height special safety grid or guard grid supports have to be provided, which are installed instead of the handrail posts. Such a safety grid support 2 is shown in Fig. 3. It comprises a vertically-extending supporting tube 21 the length of which corresponds to the overall height of a scaffolding storey.Welded to the lower end of this supporting tube 21, at right angles to it, is a rectangular tube 22, which serves to mask the transom or transverse stay, profiled in U-shaped configuration and opening upwardly, of the adjusting frame present thereunder and in so doing to protect the fastening claws, suspended therein, of the scaffolding frame panels of the topmost storey against lifting off. Mounted at the building end of the rectangular tube 22, parallel to the supporting tube 21, is a tube socket 23 which is slipped onto the tube connectors of the adjusting frame present thereunder. Designated by the numeral 24 are, in each case, the horizontal bores which are intended for the securement of the respective scaffold tubes 21, 23 on the tube connectors of the adjusting frame, present thereunder, by means of pins or cotters (not shown).As a precaution, additionally a bolt 25 is provided, which allows an edge board to be inserted if necessary.

Provided along the supporting tube 21, in the arrangement of the two frames 1 forming the safety device, in the chosen example, are wedge boxes 26 into which the frames can be suspended in the manner already shown above, in which respect also the upper hook-shaped fastening elements 18 are secured by a wedge connection.

The securing of the frames 1 takes place with the aid of the wedges 27 arranged non-detachably in the wedge boxes 26. In the example shown here it is the wedge boxes 26 and wedges 27 are of a form already known from German Offenlegungsschrift No. 27 57 189. It is, however, of course readily possible to provide any suitable form of a wedge connection, or even instead of a wedge connection to provide for fastening by means of bolts and rocking pins or in any other suitable manner.

Claims

1. A safety device for preventing the falling of objects and for protecting workers, on metal scaffolding more especially on metal scaffolding having adjustable or vertical frames, characterised in that it comprises metal outer frames which each extend over the length of a scaffold panel or bay, and correspond in height to half the height of a scaffold storey, each said frame carrying a screen of wire netting which spans substantially the entire area of the frame.

2. A safety device as claimed in claim 1, characterised in that each said outer frame comprises a lower frame member in the form of a downwardly open U-profiled strip.

3. A safety device as claimed in claim 2, characterised in that each said outer frame comprises an upper frame member and two lateral frame members each in the form of a scaffold tube.

4. A safety device as claimed in claim 1, 2 or 3 characterised in that the wire screen is fastened to an inner frame which comprises narrow flat metal strips and which is mounted, by appropriate fastening means on or in the outer frame.

5. A safety device as claimed in claim 1, chracterised in that each metal outer frame comprises lateral frame limbs having fastening elements which correspond, in their shape, to the fastening arrangement of the respective scaffolding.

6. A safety device for preventing the falling of objects anad the protection of workers, on metal scaffolding, substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.