WO2006024302A1

WO2006024302A1 - Scaffold board with hooks having inclining front edges

Info

Publication number: WO2006024302A1
Application number: PCT/DK2005/000558
Authority: WO
Inventors: Børge KROGSTRUP
Original assignee: Pf Management Holding Aps
Priority date: 2004-09-01
Filing date: 2005-08-31
Publication date: 2006-03-09
Also published as: CA2577081A1; EP1797256A1; US20080164099A1

Abstract

Method for mounting a scaffolding board and scaffolding board (1) including a section (2) with a substantially flat surface for persons staying upon this surface, and including a fitting with hooks (5) at the end of the section (2), where the hooks (5) are provided with downwards directed recesses for securing the assembled scaffolding board (1) on a transverse beam. The section (2) extends approximately to the centre (9) of the recess (8) to cover half of the transverse beam (7) when the scaffolding board (1) is placed on the beam (7).

Description

SCAFFOLD BOARD WITH HOOKS HAVING INCLINING FRONT EDGES Field of the Invention

The present invention concerns a scaffolding board comprising a section with a sub¬ stantially flat surface for persons staying upon this surface, and including a fitting with hooks at the end of the section, where the hooks are provided with downwards di- rected recesses for securing the assembled scaffolding board on a transverse beam, where the section extends approximately to the centre of the recess to cover half of the transverse beam when the scaffolding board is placed on the beam. The invention also concerns a method for mounting a scaffolding board.

Description of Prior Art

Scaffolding boards of metal, e.g. steel or aluminium, typically having a skid-proof board surface and hook fittings for fastening the board on a transverse beam, are prior art. The hook fittings vary depending on the application. An example used primarily in USA is shown in Fig. 1, where the board is provided with a set of hooks in continua- tion of the board. These boards are characterised in that by laying/mounting of the boards in continuation of each other, a hole appears between the board over the trans¬ verse beam. This hole may act as a stumbling edge when walking over it, or as an ob¬ stacle when using e.g. a wheelbarrow. With the other board shown lowermost on Fig. 1 , it has been attempted to cover the hole that may appear between the boards when disposed in continuation of each other. However, these boards are very defective in that they are not in any way skid-proof in relation to the transverse beam, but to the contrary easily slide off the beam, implying great danger while staying on the board.

The system with hook fittings projecting out from the board is commonly known and used, as it has to be possible to take up a single board disposed in a row of at least three succeeding boards, without dismounting the remaining boards. It has previously been attempted to circumvent this problem by mounting a crossing board after mount¬ ing the scaffolding boards. This, however, is cumbersome and time-consuming, and requires extra components. Alternatively, as shown on Fig. 1 , the boards can be made in two versions with hooks that differ so that the interspaces are covered. Such a sys¬ tem with different types of hooks is, however, disadvantageous when a uniform pro¬ duction is wanted. Furthermore, the boards with the hooks shown on Fig. 1 are far from skid-proof, and an upstanding edge of the size of the material thickness plus the drawing height still remains.

Previously, a board has been developed which only at one end continues the top flange/the drawing up beyond the hook fitting. During mounting, the end with the top flange is laid down over the end of the next board without any top flange, whereby the hole between successive boards is covered. This type of board has the drawback that all boards are to be mounted or dismounted from one end of the scaffolding run.

The above descriptions of boards all illustrate deficiencies in existing systems. There¬ fore there is need for improvements of existing systems.

An improvement of such systems is known from JP patent publication 2002-161636 by Kondo Atsushi. In this publication, scaffolding boards are provided with staggered rotatable hooks that may be put over the transverse beam. By lowering the scaffolding board down over the beam, the hooks are rotated and thereby pushed in between the succeeding board and the transverse beam. The disadvantage of this system is that the board, in order to be mounted, is to be lifted up at a level above the subsequent board and then forcibly lowered in order that the board is hooked securely onto the trans- verse beam. This lowering is difficult to perform during erection of scaffolding, where the board is to be held up while simultaneously only one end is acted on with a down¬ ward force. Besides, rotating hooks are a cost-increasing process which is unsuitable.

Description of the Invention It is the purpose of the invention to provide a secure scaffolding board with hook fit¬ tings that close the hole between succeeding boards, where the scaffolding board has a simple design and only few resources are required during the making of the scaffold¬ ing board.

This purpose is fulfilled by a scaffolding board that includes a section with a substan¬ tially flat surface for persons staying upon this surface, and including a fitting with hooks at the end of the section, where the hooks are provided with downwards di¬ rected recesses for securing the assembled scaffolding board on a transverse beam, where the section extends approximately to the centre of the recess for covering half of the transverse beam when the scaffolding board is placed on the beam, where the sec¬ tion extends approximately to the centre of the recess, e.g. a U-shaped recess, to cover half of the transverse beam when the scaffolding board is placed on the beam. As op- posed to the previously mentioned Japanese patent publication, the hooks are perma¬ nently mounted, particularly rotationally fixed, on the section.

This means that the scaffolding board according to the invention is much easier and cheaper to manufacture while at the same time easy to mount, safer in use and which does not entail holes between the boards disposed in continuation of each other. When driving a wheelbarrow over such boards, the transition between two succeeding boards is largely imperceptible. At the same time, uniform ends of the boards are achieved, meaning that they may be laid or taken up from an arbitrary end.

Typically, scaffolding boards in continuation of each other are provided so that two succeeding scaffolding boards are resting on the same transverse beam. As the metal section extend approximately to the middle of the recess in order to cover half of the transverse beam, one is to provide that the section itself on a corresponding scaffold¬ ing board mounted in continuation does not prevent access of the hooks to the beam. The hooks are therefore designed so that they without rotation fit with their front edge into the interspace between the top side of the beam and the underside of the corre¬ sponding board mounted in continuation thereof. In practice, this means that the verti¬ cal height A of the front edge is less than the height of the interspace between the top side of the beam and the underside of the section on the board mounted on the trans- verse beam in continuation thereof.

In that connection, the hooks may furthermore advantageously be provided with a bevelled front edge in order to, by pushing the end of the board towards an end of an¬ other board disposed in continuation on a transverse beam, to get it sliding up the bev- elled front edge in order thereby to lift this other board for inserting the scaffolding board with the hooks on the transverse beam. By using hooks with bevelled or sloping front edges that lift the adjacent board under pushing action, scaffolding boards may readily be disposed in continuation of each other by a single person, and the weight of the scaffolding boards mutually lock each other to the transverse beam. Typically, such a front edge may extend from the underside of the section and sloping down¬ wards in direction away from the section.

Such a sloping front edge that lift the subsequent scaffolding board during mounting, also enables the legs of the hook at each side of the transverse beam to be made so long that they extend to at least half of the diameter of the beam while simultaneously the distance of the centre of the transverse beam and the top side of the board may be kept within the relevant guidelines for scaffolding. Exactly the relation between the distance between the centre of the transverse beam and the top side of the board and the distance over which hooks are to extend downwards around the transverse beam, sets up strict rules for the dimensions of the hooks of the board. For example, the scaf¬ folding board according to the JP publication 2002 161636 mentioned in the introduc¬ tion with the rotatable hook does not comply with the guidelines used in USA, as the legs on the hooks do not extend far enough down on both sides of the transverse beam. The hook cannot be constructed in a simple way either with legs which are sufficiently long for that purpose, as elongation of the front leg on the hook will cause that prior to the mounting it will point away from the end of the subsequent board and no longer swing correctly forward during the mounting.

In order that the hooks on a board according to the invention may easily fit into the interspace between the transverse beam and the section on another board which is al¬ ready provided on the beam, the hooks may be designed with a front leg and a rear leg to form the downwards directed recess with a distance B between the upper edge of the recess and the underside of the section, where the front leg has a front edge with a height A, which is less than B, and a sloping front edge extending from the underside of the section to the front edge. This sloping front edge can be a straight edge, but may also be curving.

By mounting the board on the transverse beams, at first one board is laid with the hooks on the beam, whereafter the next board can be pushed in under the first board by pressing the sloping front edges of the hooks against the underside of the first board, which then is slightly lifted, but not enough to release engagement with the transverse beam, whereafter the board is pushed in, and both fall into place.

Advantageously, the scaffolding board has identical sets of hooks at both ends. In that way no allowance is to be made during mounting which end is to be disposed in con- tinuation of other boards already placed on the beam. For example, at both ends the scaffolding board may have identical sets with two hooks, where one of the two hooks have a different distance to the closest side of the scaffolding board than the other hook. This entails that the hooks on scaffolding boards disposed in continuation of each other do not block each other. The hooks may typically be designed with a sub- stantially flat profile. The hooks may possibly be assembled in pairs with a transverse profile for reinforcing the profile in boards with small material thickness and for rapid positioning when mounting hooks on the board.

The profile has e.g. a surface which is connected with L-shaped side members at a right angle to the surface in order thereby to constitute an edged C-section. Manufac¬ turing of such a scaffolding board is simple, as it can be made in long webs, e.g. by extrusion, and adapted to the correct length for scaffolding boards, succeeded by mounting hooks at the ends. Optionally, the scaffolding boards may be provided with a pattern of holes and elevations to reduce weight, to prevent water from collecting on the section and to safeguard people walking on the scaffolding board against sliding on the surface.

The invention primarily concerns a scaffolding board with hook fittings for the Ameri¬ can market - for substituting and improving prior art scaffolding boards on this market which put up other demands than e.g. the European market - but may naturally also be envisaged applied on other markets, particularly where American specifica¬ tions/standards are used.

Short Description of the Drawing The invention will be explained in more detail with reference to the drawing, where:

Fig. 1 shows scaffolding boards according to prior art;

Fig. 2 shows the ends of two scaffolding boards according to the invention; Fig. 3 shows two ends of scaffolding boards assembled around a beam; Fig. 4 shows a cross-section of Fig. 2; Fig. 5 shows Fig. 3 in perspective view from below; and Fig. 6 shows the dimensions of the hooks in relation to the scaffolding boards.

Detailed Description

On Fig. 1 is shown a draft of two scaffolding boards according to prior art, where the upper scaffolding board is provided with a kind of hooks, where the hole appearing when the boards are disposed in continuation of each other is not covered. With the other board shown at the bottom of Fig. 1 , it has been attempted to cover the hole ap¬ pearing between the boards when they are disposed in continuation of each other. However, these boards are very defective as they are not skid-proof in any way in rela¬ tion to the transverse beam, but on the contrary easily slide off the beam, entailing great hazard while staying on the board.

Fig. 2 shows ends of scaffolding boards 1 according to the invention. The board 1 has a metal section 2, e.g. of steel or aluminium, with two downwards facing L-shaped sections as side members 3 for constituting substantially an overall and more or less C-shaped cross-section. Typically, scaffolding boards 1 are provided with holes 4 so that dust and rain do not collect on the surface of the section 2, where the holes 4 addi¬ tionally are raised and provided with relatively sharp edges in order to safeguard against skidding on the board.

At each end of such a scaffolding board 1, by suitable fittings 6 there is fastened a set of hooks 5 engaging in over transverse scaffolding beams 7. The hooks 5 are provided with downwards directed recesses 8 for securing the entire scaffolding board 1 on a transverse beam 7. The section 2 extends approximately to the centre 9 of the recess 8 in order to cover half of the transverse beam 7 when the scaffolding board 1 is placed on the beam 7. This is more clearly seen on Fig. 3.

As shown on Fig. 2, the hooks 5 are provided a front edge 15 that fit into the inter¬ space between the top side of the transverse beam 7 and the underside of the section 2 on the subsequent on the transverse beam mounted board, the hooks 5 are provided with a sloping front edge 10. The end of the board 1 with the hooks 5 may thus be pushed in under the end of the other board 1', when this other board 1' is placed on a transverse beam 7. Due to this push, the second board 1' slides up the inserted front edge 10 and is thereby lifted sufficiently in order that the scaffolding board 1 with the hooks 5 may be pushed in over the transverse beam 7, however without lifting the other board 1' so much that the hooks 5 go free of the beam 7.

Fig. 3 and Fig. 5 show two board ends 1, 1' in continuation of each other with the hooks 5 disposed on the transverse beam 7. As it appears from Fig. 4, which is a cross- section of Fig. 2, the hooks 5, 5' at right and left sides, respectively, of the board 1 are staggered in relation to the closest side of the board. This entails that the hooks, when the boards are placed in continuation of each other, do not interfere.

In order to readily fit in the interspace 12 between the transverse beam 7 and the sec- tion 2 on a second board 1 ' which already has be placed on the beam, as shown on Fig.

6, the hooks 5 may be designed with a front leg 13 and a rear leg 14 for forming the downwards directed recess 8 with a distance B between the upper edge 9 of the recess and the underside of the section 2, where the front leg 13 has a front edge 15 with a height that is less than B and a sloping or bevelled front edge 10 that extend from the underside of the section 1 to the front edge 13.

By the invention there is thus provided a simple scaffolding board which does not have the disadvantages discussed in the introduction. Particularly, there is provided a scaffolding board with hook fittings that close the hole between to succeeding boards and which simultaneously may be mounted and dismounted in an arbitrary sequence. The latter only requires that adjacent ends of two boards are to be lifted up, until one is free of the other. It has simple design, and only few resources are required during manufacture, e.g. by using extrusion, or edge or roll bending, of the section and subse¬ quent mounting of a simple plate-like hook fitting.

The invention also provides for safety aspects, as not only the holes between the boards are covered, but a mutual locking of the hooks 5 is also achieved, as a board 1 in the shown embodiments cannot be dismounted without lifting the adjacent board 1'.

Claims

1. Scaffolding board (1) comprising a section (2) with a substantially flat surface for persons staying upon this surface, and including a fitting with hooks (5) at the end of the section (2), where the hooks (5) are provided with downwards directed recesses for securing the assembled scaffolding board (1) on a transverse beam (7), where the sec¬ tion (2) extends approximately to the centre (9) of the recess (8) to cover half of the transverse beam (7) when the scaffolding board (1) is placed on the beam (7), charac¬ terised in that the hooks (5) are mounted in fixed position, particularly rotationally fixed, on the section (2) and fit with their front edges (15) into the interspace between the top side of the beam (7) and the underside of the section (2) on a similar board mounted in continuation thereof.

2. Scaffolding board according to claim I₅ where the front edge (15) has a vertical height A which is less than the distance between the top side of the transverse beam

(7) and the underside of the section (2) when the board (1) mounted on the transverse beam (7).

3. Scaffolding board according to claim 2, characterised in that the hooks (5) are pro- vided with bevelled front edges (10) extending from the underside of the section (1) sloping downwards in direction away from the section (1) in order to, by pushing the end of the board (1) towards an end of another board (1') disposed in continuation on a transverse beam (7), to get it sliding up the bevelled front edge in order thereby to lift this other board (I¹) for inserting the scaffolding board (1) with the hooks (5) on the transverse beam (7).

4. Scaffolding board according to any preceding claim, characterised in that the hooks (5) have a front leg (13) and a rear leg (14) to form the downwards directed recess (8) with a distance B between the upper edge (9) of the recess and the underside of the section (1), where the front leg (13) has a front edge with a height A and a front edge (10) extending from the underside of the section (1) to the front edge, where A is less than B.

5. Scaffolding board according to any preceding claim, characterised in that the recess (8) is U-shaped.

6. Scaffolding board according to any preceding claim, characterised in that the scaf- folding board (1) has identical sets of hooks (5) at both ends.

7. Scaffolding board according to claim 6, characterised in that at each end, there is an identical set of two hooks (5), where one of the two hooks (5) has a another distance to the closest side of the scaffolding board than to the other (5').

8. Scaffolding board according to any preceding claim, where the section (2) has a surface connected with L-shaped side members (3) at a right angle from the surface in order to constitute an edged C-section.

9. Method for mounting a scaffolding board, where the scaffolding board includes a section (2) with a substantially flat surface for persons staying upon this surface, and including a fitting with hooks (5) at the end of the section (2), where the hooks (5) are provided with downwards directed recesses for securing the assembled scaffolding board (1) on a transverse beam (7), where the section (2) extends approximately to the centre (9) of the recess (8) to cover half of the transverse beam (7) when the scaffold¬ ing board (1) is placed on the beam (7), where the hooks (5) are mounted in fixed po¬ sition, particularly rotationally fixed, on the section (2) and fit with their front edges (15) into the interspace between the top side of the beam (7) and the underside of the section (2) on a similar board mounted in continuation thereof on the transverse beam (7), where the hooks (5) are provided with bevelled front edges (10) extending from the underside of the section (1) sloping downwards in direction away from the section (1), where the method is characterised by pushing one end of the board (1) towards an end of another corresponding board (1') disposed on a transverse beam (7), to get it sliding up the bevelled front edge in order thereby to lift this other board (V) for insert- ing the scaffolding board (1) with the hooks (5) on the transverse beam (7).

10. Method according to claim 9, where the hooks (5) have a front leg (13) and a rear leg (14) to form the downwards directed recess (8) with a distance B between the up- per edge (9) of the recess and the underside of the section (1), where the front leg (13) has a front edge with a height A and a front edge (10) extending from the underside of the section (1) to the front edge, where A is less than B.