Note: Descriptions are shown in the official language in which they were submitted.
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094/05918 PCT/GB93/01682
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BEAM FIXING DEVICE
This invention relates to a fixing device for use in
clamping together two overlapping plates, such as the bottom
flange plate of an upper I-section beam and the top flange
plate of a lower I-section beam extending under and supported
from the upper beam.
In the construction of buildings, it is often necessary
to clamp together metal beams, which usually extend
perpendicular to each other, and the clamping can be carried
out by drilling through the overlapping flanges of the beams
and then fitting threaded fasteners through aligned holes.
Alternatively, if it is required to provide a fastening
system which does not need any hole drilling to take place,
it is known to use LINDAPTER (registered trade mark) fixings,
which can be used to clamp together overlapping flange edges
of two beams.
LINDAPTER fixings have been used for many years for
joining together flanged metal beams, and for other uses, and
remain widely used by customers for many different fixing
applications. An example of existing use of LINDAPTER
fixings is shown in Figure 1 of the accompanying drawings, to
which reference will now be made. This shows the use of
threaded fastener clamps to join together overlapping I beams
50 and 51, with the bottom flange 52 of beam 50 overlying the
top flange 53 of beam 51 and extending perpendicular thereto.
The fasteners are designated by reference 54, and each
comprises bolt 55, nut 56 and a pair of opposed gripping
saddles 57 which have ribbed gripping noses 58 to engage
respective flange edges. However, as can be seen in Figure
1, a feature of use of the fixings 54 to join together two
overlapping flanged beams is the need for a separation plate
59 to be provided, sized according to the dimensions of the
flanges of the overlapping beams, and which is positioned
between the bottom flange 52 of the upper beam S0 and the top
flange 53 of the lower beam 51. Further, the specially sized
plate 59 also requires formation of drilled holes 60 at
corner locations to suit the particular combination of flange
W~94/05918 2~ ~3 ~ 4 ~ PCT/GB93/01682
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plates to be joined together.
This separation plate is an essential component of the
known fixing system, in conjunction with suitable LINDAPTER
type threaded fasteners.
This has been, and still is acceptable to many
customers, but can give rise to inconvenience during assembly
on sites which have a number of different beam pr~ofiles, and
which overlap at certain positions on site, in that the
plates have to be manufactured for each individual
application and the assemblers will have to make sure that an
appropriate separation plate is used at each beam overlapping
position, and time is involved in the selection of the
appropriate separation plates for any particular location,
and further time can be involved in reselecting separation
plates when a wrong selection has been made, and all of which
add to labour costs in the assembly operation, in addition to
the cost of the fixings and plates themselves.
Accordingly, a need is no'w becoming recognised for a
fixing device which can be used to clamp together two
overlapping plates, and more particularly overlapping flange
plates of one beam overlying another beam, and which is
readily adjustable for use with different widths of flange
plate, so as to provide economies in labour costs of assembly
of overlapping beams on site. This need is being recognised
particularly in factories into which conveyor systems are to
be installed e.g. car assembly lines, where there are many
locations at which different sized support beams intersect
and require to be clamped together at such intersections.
According to the invention there is provided a fixing
device for clamping together first and second overlapping
plates havinq respective first and second pairs of opposed
connecting edges which intersect at four corner regions, said
fixing device being operative to clamp the second plate to
said connecting edges of the first plate and to clamp the
first plate to said connecting edges of the second plate, and
said fixing device comprising:
a set of four elongate clamping plates each
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WO94/0591X PCT/GB93/01682
positionable along a respective one of said connecting edges
of one of said plates and of a length to project axially
beyond the opposed connecting edges of the other of said
plates whereby each end of each clamping plate is
positionable over a respective one of said corner regions;
slots formed through each clamping plate and extending
generally parallel to the axis thereof so as to overlie said
corner region; and,
a set of four threaded fasteners each being capable of
being taken through a slot of one clamping plate at one
corner region and through a slot of an underlying clamping
plate at the same corner region, each fastener being
adjustable along.the length of the respective slot until it
reaches a required position in the respective corner region
and then being tightenable in order to clamp the clamping
plates together, whereby a respective threaded fastener is
positionable and then tightenable at each corner region in
order to clamp together the overlapping plates via the four
clamping plates.
The invention therefore provides a fixing device which
is adjustable to suit different widths of overlapping plates
(width being measured between opposed connecting edges), and
which therefore can readily be operated on site to meet
differing requirements. The fixing device of the invention
is therefore "universal" in the sense that a common design
can be utilised with a range of plate widths.
A particularly preferred arrangement of overlapping
plates to be clamped together by a fixing device of the
invention comprises an overlapping arrangement of flanged
beams, such as I-beams.
When the overlapping beams intersect at right angles to
each other, the four corner regions at which the threaded
fasteners are located will be at the corners of a rectangular
area. However, it is not essential to the invention for the
beams to intersect at right angles to each other, and they
may be arranged skewed, in which case the area of overlap
will be a parallelogram. The fixing device of the invention
W O 94/05918 2143 ~ ~ 4 PC~r/GB93/01682
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is just as capable of clamping together two overlapping
plates in such an arrangement.
During assembly, each threaded fastener will be
adjusted along the length of a respective slot until the
fastener projects downwardly closely adjacent to an
underlying connecting edge, and is then tightened up. To
provide a clamp assembly which is resistant to possible
loosening by vibration, which may occur when a sup~rting
structure of beams is used to support conveyor systems, it is
preferred that there are surrounding gripping formations
arranged alongside each slot, and engageable by clamping
elements forming part of the threaded fasteners, and which,
upon tightening, make gripping engagement and thereby resist
any tendency for the fasteners to move thereafter along the
length of the respective slot.
The threaded fasteners preferably include "washers"
which fit around the threaded shanks of the fasteners, and
each of which can make gripping engagement with gripping
portions along the slots of the clamping plates.
A fixing device according to the invention is
particularly suitable for joining together the flanges of
beams having flange thicknesses which are approximately
constant throughout their width, but this is not essential to
the invention. A fixing device according to the invention
can be used also to clamp together flanged I-beams of
tapering flange thicknesses as used particularly on the US
market, provided that the threaded fasteners are located
closely adjacent to each corner region, and with sufficient
overlap of the clamping faces of the clamping plates which
engage the flange edges, so that a rigid and shake proof
clamped assembly can be obtained.
For economies of manufacture, it will be preferred that
each clamping plate in the set of clamping plates for each
fixing device of the invention may be of identical design.
However, this is not essential to the invention, provided
that each clamping plate fulfils the requirements of the
fixing device of the invention as defined above.
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One embodiment of fixing device according to the
invention will now be described in detail, by way of example
only, with reference to the accompanying drawings, in which:
Figure 2 is a diagrammatic illustration of two
overlapping plates which can be coupled together by a fixing
device according to the invention;
Figure 3 is a side view showing part of a preferred
embodiment of fixing device according to the invention, being
used to join together the flange plates of two overlying I-
section beams,
Figure 4 is a plan view of one of a set of four
coupling plates forming part of the fixing device of the
invention;
Figures 5a to 5c are, respectively, plan, side and end
detail views of a washer type clamping element for use with
each of a set of four threaded fasteners also forming part of
the fixing device of the invention; and
Figure 6 is a view, similar to Figure 3, of a modified
embodiment of the invention.
Referring first to Figure 2 of the drawings, this is a
schematic illustration of first and second overlapping plates
which can be clamped together by a fixing device according to
the invention, and these plates may comprise, for example, a
bottom flange of an upper I-section beam, and a top flange of
a lower I-section beam which overlap at a perpendicular point
of intersection between them.
The first and second overlapping plates are designated
by references 10 and 11, and first plate 10 has a first pair
of opposed connecting edges 12, and second plate 11 has
opposed connecting edges 13. The connecting edges 12 and 13
intersect at right angles at four corner regions 14, and it
is at these corner regions, as will be described in more
detail below, at which threaded fasteners are positioned in
order to clamp together the overlapping plates.
The embodiment of fixing device according to the
invention comprises a set of four elongate clamping plates
which will be described in more detail below with reference
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to Figure 3, and each clamping plate can be positioned along
a respective one of the connecting edges of one of the plates
e.g. along connecting edge 12 of first plate 10, and will be
of a length sufficient to project axially beyond the opposed
connecting edges (13) of the second plate 11, whereby each
projecting end of each clamping plate is posit;onable over a
respective one of the corner regions 14. ^
Referring now to Figure 3 of the drawings, this shows a
top flange plate 11a of a lower I-section beam 15, and a
bottom flange plate 1Oa of an upper I-section beam 16, of
which only part of the web 17 is shown. In the illustrated
arrangement, the web 17 of upper beam 16 extends
perpendicular to the web of lower beam 15. It should further
be noted that flange plate 1Oa rests directly on the upper
surface of flange 11a. (Flange plates 1Oa and 11a are
examples of the overlapping plates 10 and 11 shown
schematically in Figure 1).
As referred to above, a sét of four elongate clamping
plates is provided, three of which are shown in Figure 3, and
each being designated generally by reference 18.
Each clamping plate 18 is positioned along a respective
one of the connecting edges, as described a~ove in connection
with the pairs of edges 12 and 13 shown in Figure 2, and the
two clamping plates 18 shown below flange plate 11a extend
generally parallel to the axis of the beam 15, whereas the
upper clamping plate shown above the flange plate 11a in fact
sits flush on the upper surface of flange plate 1la, and
extends parallel to the axis of upper beam 16.
Although not clearly apparent from each of the two
upper clamping plates 18 engages over the upper surface of
the connecting edge of top flange plate 1Oa, in generally
similar manner to the way in which nose portions 18a of the
two lower clamping plates 18 press against the underside of
bottom flange plate 11a.
Figure 4 is a plan view of a clamping plate 18, and
nose portion 18a is illustrated, which comprises the "toe",
and reference 18b defines the "heel", which will engage the
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094/05918 P~T/GB93/01682
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surface of the adjacent clamping plate proper.
As can be seen in Figure 4, each clamping plate 18 has
a pair of axially extending slots 19, and which are of
sufficient length to allow adjustment along the length of the
slots to suit the particular width of underlying flange
plate. Thus, in use, the slots 19 will extend sufficiently
far so as to overlie the corner regions 14.
A set of four threaded fasteners is provided,
designated generally by reference 20, and each being capable
of being taken through slot in one of the two upper clamping
plate 18 shown in Figure 2, at one corner region 14, and
through a slot in the underlying clamping plate at the same
_ corner region.
Each fastener 20 will be adjusted along the length of
its slot 19 until it is located beyond the connecting edge of
the underlying flange plate, and then is tightened in order
to clamp the two clamping plates together. Accordingly, a
respective threaded fastener 20 can be adjusted until it is
positioned at a respective one of the four corner regions 14,
and is then tightened in order to clamp together overlapping
flange plates 1Oa and 11a via the set of four clamping plates
as a rigid assembly.
In the illustrated arrangement, the beams extend
perpendicular to each other, but it will be readily
appreciated that the fixing device of the invention can be
used readily in order to couple together a skewed junction of
overlying beams.
In order to provide restraint against any tendency for
the fasteners 20 to move longitudinally along the slots 19,
after tightening, grooved gripping surfaces 21 are provided
along the edges of the slots 19, and radiused washers 22, 22a
(see Figure 3) are fitted on the shanks of the threaded
fasteners and make gripping engagement with the surfaces 21
once the required positions of the fasteners have been taken
up. Then, upon tightening, a very rigid assembly is
obtained, which will resist any tendency for the fasteners to
shake loose, or move along the slots 19. This will be of
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particularly advantage when a fixing device according to the
invention is used to join together beams which form part of
supporting structure for conveyors or other installations
which may generate substantial vibration in use. The washers
are shown by references 22 and 22a in Figure 3, and are also
shown in more detail in Figures 5a to ~c, which illustrates
complementary gripping formations.
The lower radiused washer 22a shown in Figure 3 is able
to allow the associated clamping plate 18 to rock until nose
18a engages the underside of the flange 11a and the heel 18b
engages the other clamping plate, while still maint~in1ng the
shank of the fastener vertical, and being restrained from
moving along the slot 19 by the grooved surface 21. In this
way, the clamping plate can readily be adjusted to suit
different plate (flange) thicknesses.
Referring now to Figure 6 of the drawings, this shows
modification to the fixing device, and this figure generally
corresponds with Figure 3, and corresponding parts are given
the same reference numerals, and will not be described in
detail again.
The main modification concerns provision of an
additional constructional element on each clamping plate 18,
in the form of an extra protrusion or leg to prevent the
clamping plates sliding out of engagement with each other
when they are being used at the extremity of their
adjustment. As shown in Figure 6, the tail portion 18b of
each clamping plate 18 has an additional leg or protrusion
18c, and Figure 6b shows the clamping plates 18 at the limit
of their adjustment, and in which leg 18c of one of the
underlying clamping plates is closely adjacent to leg 18c of
the overlying and perpendicularly extending clamping plate.
Further, to assist in correct installation of the
clamps, Figure 6 shows application of markings 23 which
assist in installation, with appropriate marking being
determined by experiment for any particular combination of
flange plates to be joined together. A central marking 24 is
also provided.
