[0001] The invention relates to a beam/floor board combination for system scaffolds having
beams, mostly cross girders, for supporting floor boards, the extremities of the floor
boards being provided with hitching means which will hitch across a portion of the
beam.
[0002] Traditionally, in scaffolding one often employs the standardized scaffold pipe having
an outer diameter of 48.3 mm. Also, this pipe is often used in system scaffold elements
like frames, posts and beams, because then it is easy to establish connections to
standard scaffold couplings, for small adaptations. For this reason, beams serving
to support floor boards are made using this pipe. System floor boards are then provided
with hooks that fit across said pipe and are mounted in offset relationship to provide
space for the adjacent floor board. The designer has the task to find a best possible
balance between hooks as narrow as possible, for keeping the offset as small as possible,
and hooks as wide as possible, to make the hooks as strong as possible. Especially
for narrow floor boards, this is a difficult task, also because the difficulty arises
at two opposite angles. Thus, practice has shown that the hook means of the floor
boards on the market are very vulnerable, which causes problems during mounting and
requires much maintenance.
[0003] There are solutions on the market which require less maintenance, in which the cross
girder of the system scaffold is designed as an inverted T-profile, so that system
floors can be put onto the supporting planes thus provided, which require no hooks
and therefore do not have the above-mentioned difficulties. However, to my knowledge,
it has turned out to provide a practical and robust solution for the problem of floor
board getting blown up by the wind. Further, the solution has the difficulty, that
the floor boards can not be under strain of tension and thus are not part of the complete
supporting construction of the scaffold, as a result of which usually additional beams
have to be mounted at both sides of the floor.
[0004] A considerable improvement was achieved with the
German patent application P 23 41 176.8 of Bera Berlin in 1973. There, the cross girder is designed as a U profile, in which
hook-shaped means are hitched across both raised edges of the U-profile. The hitching
means can be made considerably more compact and robust than the members mentioned
earlier; however, the hitching means will remain vulnerable during rough treatment
on the building site. Since this concerns a closed frame system, the floor boards
are prevented from blowing away in that the hitching means are covered by the upper
scaffold frame. Such locking does not exist in a system scaffold having modular posts
and beams. This would require an additional cross profile, which is difficult to realize
in existing modular post systems.
[0005] The object of the present invention is to provide a solution for the difficulties
mentioned above by which a suitable beam/floor board combination can be put on the
market in a labour technically and economically sound way.
[0006] To this end, the beam/floor board combination according to the invention has been
developed further, c.q. modified, in a novel way, characterized in that the cross-section
of said beam is provided with a lower flange having raised edges at the extremities,
with said hitching means hitching across the raised edges, said cross-section of the
beam also being provided with a narrow upper flange, in which the intermediate distance
L1 between two successive upper flanges of the beams is smaller than the total length
L2 of the floor board plus hitching means and the length L2 in turn is smaller than
the length L3 between the webs of the beams.
[0007] The advantage is that the floor board can be mounted to and be demounted from the
beam in a smooth way and that if the floor board is blown up by the wind, this will
only be possible at one side and across a small height, and that subsequently the
floor board will be locked to the beam at the other side. Further, the cross-section
of the beam allows the use of various profiles, such as an inverted T-profile, a rectangular
or a U-shaped profile and transverse profile and the like, said transverse profile
being provided with raised edges and a narrow upper flange.
[0008] Further, the beam/floor board combination according to the invention has been developed
such, that said hitching means at the extremities of the floor board for hitching
across the raised edges of the beam are fastened to the floor board by means of shock
absorbing intermediate layers.
[0009] The advantage is that on demounting the floor boards, parts will be thrown to the
ground from the scaffold and will hit the hitching means, which will then be able
to absorb the shock without getting damaged.
[0010] Then, the beam/floor board combination has been developed further, characterized
in that the resulting transverse profile of the beam is a hollow web having a narrow
upper flange and a U-shaped bottom flange for receiving the hitching means at the
extremities of the floor boards.
[0011] The advantage is a relatively low cross girder having a relatively large stiffness
against bending and torsion and allowing for easy insertion of the hitching means.
[0012] Further, the beam/floor board combination has been developed further, characterized
in that said hitching means have an H-shaped transverse profile.
[0013] The advantage is that the floor boards can also be mounted and demounted in inverted
positions.
[0014] Then, the beam/floor board combination has been developed further, characterized
in that said hitching means have an inverted U-shaped transverse profile.
[0015] The advantage is that the hitching means can be designed in a more robust cross-section,
however, the floor boards can only be mounted in one position.
[0016] Hereinafter, the invention is explained further by way of the preferred embodiments
illustrated in the drawing, in which:
figures 1A-1D show a mounting diagram of the beam/floor board combination in the system
scaffold;
figures 2A-2D show a demounting diagram of the beam/floor board combination in the
system scaffold;
figure 3 shows a locking of the beam/floor board combination on getting blown up by
the wind;
figures 4A-4C show a hitching means having an H-shaped transverse profile at the extremity
of the floor board; and
figures 5A-5B show a hitching means having an inverted U-shaped transverse profile
at the extemity of the floor board.
[0017] Figures 1A through 1D illustrate the mounting diagram of the floor board 1 in the
mutually parallel beams 2 having e.g. a roughly inverted T-shaped cross-section. The
lower flange of the inverted T-shaped cross-section of the beams 2 have raised edges
3 at the lower flange 4 and a narrow upper flange 5. The length L1 between upper flanges
5 is smaller than L2 being the complete floor board 1 having the hitching means 6,
7, 8, 9, 10 (see figures 4A-4C and 5A-B) and in turn smaller than L3 being the distance
between the webs 11 of beam 2 having the inverted T-shaped cross-section (see also
figure 3). Sliding in or mounting the floor board 1 is indicated by arrows and can
therefore be deducted from figures 1A through 1D.
[0018] Figures 2A through 2D show the opposite, namely, demounting, and the complete proces
can be deducted from these figures too.
[0019] Figure 3 shows locking of the beam/floor board combination. At one side of the floor
board, the beam 1 can be inserted completely, then the other side of the floor board
1 can be blown up by the wind past the narrow upper flange 5, causing the floor board
1 to be at an angle α briefly, and then the hitching means 6, 7, 8, 9, 10 will be
fixedly clamped between web 11 and the raised edge 3 of the lower flange 4. when the
gust of wind disappears again, the end brought up will, with its hitching means, fall
back onto the raised edge 3, etc.
[0020] Figures 4A through 4C show a hitching means 6, 7, 8 having an H-shaped transverse
profile. Then, the floor boards 1 can also be used in the opposite direction, which
can be important when the floor boards are dirty. Between the hitching means 6, 7
of figurens 4A and 4B and the floor boards 1, a shock absorbing intermediate layer
12, 13 is mounted in order to protect edges 13 of the hitching means 6, 7 against
excessive permanent distortion during rough treatment (floor boards 1 falling from
the scaffold onto the ground) of the floor boards 1. In figure 4C, the entire hitching
means 8 is designed in shock absorbing material 14.
[0021] In figures 5A and 5B, the hitching means 9, 10 is designed with a U-shaped transverse
profile. In figure 5A, a shock absorbing intermediate layer 15 is mounted and in figure
5B, the shock absorbing intermediate layer 16 is combined with a hook 17. Here, floor
board 1 is designed as metal plate 18 having edges 19 all round.
[0022] Finally, it should be stated clearly, that preferred embodiments of the beam/floor
board combination have been described above and that obviously further modifications
and the like are possible, without departing from the scope of this patent.
1. Beam/floor board combination for system scaffolds having beams, mostly cross girders,
for supporting floor boards, the extremities of the floor boards (1) being provided
with hitching means (6, 7, 8, 9, 10) which will hitch across a portion of the beam,
characterized in that the cross-section of said beam (2) is provided with a lower flange (4) having raised
edges (3) at the extremities, with said hitching means (6, 7, 8, 9, 10) hitching across
said raised edges, said cross-section of the beam (2) also being provided with a narrow
upper flange (5), in which the intermediate distance L1 between two successive upper
flanges (5) of the beams (2) is smaller than the total length L2 of the floor board
(1) plus hitching means (6, 7, 8, 9, 10) and the length L2 in turn is smaller than
the length L3 between the webs (11) of the beams (2).
2. Beam/floor board combination according to claim 1, characterized in that said hitching means (6, 7, 8, 9, 10) at the extremities of the floor board (1) for
hitching across the raised edges (3) of the beam (2) are fastened to the floor board
(1) by means of shock absorbing intermediate layers (12, 13, 15, 16).
3. Beam/floor board combination according to claim 1, characterized in that said hitching means (14) are made entirely of shock absorbing material.
4. Beam/floor board combination according to claims 1-2, characterized in that the hitching means (14) of the floor board (1) have one or more cavities at the side
facing the floor board, in which said cavities have an overlap of ample clearance
with protrusions (20) at the floor board (1) and in which the cavities thus formed
are filled with a shock absorbing plastic (12), which plastic furthermore allows for
the connection between the hitching means (12) and the floor board (1).
5. Beam/floor board combination according to claim 4, characterized in that said cavities have been filled with a shock absorbing material (12) by an injection-moulding
method.
6. Beam/floor board combination according to claim 1, characterized in that the resulting transverse profile of the beam (2) is a hollow web (11) having a narrow
upper flange (5) and a U-shaped lower flange (4) for receiving the hitching means
(6, 7, 8, 9, 10) at the extremities of the floor boards (1).
7. Beam/floor board combination according to claims 1-4, characterized in that said hitching means (6, 7, 8) have an H-shaped transverse profile.
8. Beam/floor board combination according to claims 1-4, characterized in that said hitching means (9, 10) have an inverted U-shaped transverse profile.