PROCEDE D'ECRASEMENT D'UN TUBE

METHOD OF CRUSHING A TUBE

Abrégé français

La présente invention concerne un tube (10) comprenant une partie centrale écrasée (18) en vue de recevoir un élément de fixation (22) et des zone latérales non écrasées (20) disposées de part et d'autre de la région écrasée (18) procurant ainsi une solidité structurelle additionnelle au tube.

Abrégé anglais

A tube (10) includes a central crushed region (18) for receiving a fixing
element (22) and lateral non-crushed regions (20) disposed either side of the
crushed region (18) which provide additional structural strength to the tube.

Revendications

5
THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:-
1. A method of crushing a tube, the method including:-
pressing together opposed portions of the tube such that the opposed
portions abut to define a land which is adapted to receive a fixing element,
wherein opposed lateral portions of the tube adjacent the land do not abut but
rather define sub-tubes which straddle the land and which extend lengthwise of
the tube.
2. A method of forming a flattened region in a tube, the method including
pressing together opposed portions of the tube, whilst not pressing together
lateral opposed portions of the tube.
3. A method of forming a flattened region in a tube, the method including
selectively pinching opposed portions of the tube together such that the
opposed portions of the tubes abut at a central location and such that lateral
sub-tubes are defined which straddle the pinched portion.
4. A method of forming a land on a tube, the method including:-
compressing opposed peripheral portions into abutment to define the
land, such that lateral ribs extend along either side of the land, the ribs
being
formed by the portions of the tube adjacent the abutting portions which define
the land.
5. A method of crushing a tube, the method including:-
crushing the tube between a pair of opposed crush members, at least
one of the crush members being substantially narrower than the corresponding
dimension of the tube and engaging the tube in a substantially central
location
whereby a central crushed region is defined between a pair of lateral non-
crushed regions, said crushed region being adapted to receive a fixing
element.
6. A tube formed according to the method of any one of claims 1 to 5.

6
7. A tube including a crushed region wherein opposed portions of the tube have
been crushed together to abut and define a land which is adapted to receive a
fixing element, the tube further including longitudinally extending non-
crushed
regions located laterally either side of the crushed region.
8. A tube including:-
a land at an end of the tube formed by compressing opposed peripheral
portions of the tube into abutment, and
ribs extending along either side of the land and formed by the portions of
the tubular member adjacent the abutting peripheral portions.

Description

CA 02386364 2002-04-04
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1
"METHOD OF CRUSHING A TUBE"
TECHNICAL FIELD
This invention relates to a method of crushing a tube.
The invention has particular, but not exclusive, application in preparing
the end of a tube for connection with another member via a conventional fixing
element such as a bolt.
The invention has particular utility in crushing the end of a web. As used
herein "web" is used to refer to a strut or bracing element which extends
between the upper and lower chord of a roof truss.
DISCLOSURE OF INVENTION
According to one aspect the invention resides in a method of crushing a
tube, the method including:-
pressing together opposed portions of the tube such that the opposed
portions abut to define a land which is adapted to receive a fixing element,
wherein opposed lateral portions of the tube adjacent the land do not abut but
rather define sub-tubes which straddle the land and which extend lengthwise of
the tube.
According to another aspect the invention resides in a method of forming
a flattened region in a tube, the method including pressing together opposed
portions of the tube, whilst not pressing together lateral opposed portions of
the
tube.
According to another aspect the invention resides in a method of forming
a flattened region in a tube, the method including selectively pinching
opposed
portions of the tube together such that the opposed portions of the tubes abut
at
a central location and such that lateral sub-tubes are defined which straddle
the
pinched portion.
According to another aspect the invention resides in a method of forming
a land on a tube, the method including:-

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compressing opposed peripheral portions into abutment to define the
land, such that lateral ribs extend along either side of the land, the ribs
being
formed by the portions of the tube adjacent the abutting portions which define
the land.
According to another aspect the invention resides in a method of
crushing a tube, the method including:-
crushing the tube between a pair of opposed crush members, at least
one of the crush members being substantially narrower than the corresponding
dimension of the tube and engaging the tube in a substantially central
location
whereby a central crushed region is defined between a pair of lateral non-
crushed regions, said crushed region being adapted to receive a fixing
element.
According to another aspect the invention resides in a tube including a
crushed region wherein opposed portions of the tube have been crushed
together to abut and define a land which is adapted to receive a fixing
element,
the tube further including longitudinally extending non-crushed regions
located
laterally either side of the crushed region.
According to another aspect the invention resides in a tube including:-
a land at an end of the tube formed by compressing opposed peripheral
portions of the tube into abutment, and
ribs extending along either side of the land and formed by the portions of
the tubular member adjacent the abutting peripheral portions.
BRIEF DESCRIPTION OF DRAWINGS
Reference will now be made to the accompanying Figures which
illustrate preferred embodiment of the invention and in which:-
FIG 1 is a plan view of a tube having a crushed or flattened end;
FIG 2 is a frontal elevation of the tube of FIG 1;
FIG 3 is a right side elevation of the tube of FIG 1 with a bolt head
present;
FIG 4 is a right side elevation of the tube of FIG 1 with the bolt head
absent; and

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FIG 5 is a right side elevation of the tube of FIG 1 with the nut and bolt
present and with the tube fastened to a planer surface.
BEST MODE
Referring firstly to FIG 1, there is shown in plan a metallic tube 10. Tube
may be, for example, a web which in use extends between the upper and
lower chords of a roof truss.
Tube 10 is originally formed from a planer sheet of material which is
10 folded about a longitudinal axis to define the tube with an overlapping
longitudinal seam 12 as best shown in FIG 2.
The seam may be welded, riveted, glued or fixed by any known means.
However, the preferred embodiment utilises an integral stitching method which
swages together material in the overlapping seam region.
With reference to FIG 2, it will be noted that the end of the tube is tapered
in frontal elevation. Furthermore, referring to FIG 1, a substantially
triangular
region 14 is more aggressively tapered and is pressed together into an
abutting
relationship adjacent the end of the tube.
Referring to FIG 3, it will be noted that in a central region 18 the opposed
peripheral portions of the tube are crushed together so as to be abutting and
planer. In contrast, open sections 20 are defined either side of the central
crushed region 18. Each of the open sections 20 defines a sub-tube or rib
which extends longitudinally of the tube 10 either side of the central crushed
region 18.
The central crushed region 18 is adapted to receive a fixing element by
virtue of one or more punched holes 16. As shown in FIG 3, the punched hole
16 receives a fixing element in the form of a nut and bolt arrangement 22.
The central crushed region 18 provides a flattened land which is adapted
to receive a conventional fixing element such as nut and bolt arrangement 22.
In contrast, the lateral non-crushed regions 20 provide additional structural
strength as compared to a tube in which the entire end of the tube is pinched
into an abutting relationship.

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Referring now to FIG 5, it will be noted that when the tube is fastened a
planer surface (eg the upper or lower chord of a truss), the end of the tube
is
deformed in that ribs or sub-tubes 20 are deformed upwardly in a wing-like
manner by virtue of the engagement of the underside of the tube with the
planer
surface of the chord. It will be appreciated that upward wing-like deformation
of
the sub-tubes 20 occurs under load, ie. the bolt is under tension as it is
tightened. This results in a secure joint between the tube and chord.
It will, of course, be realised that the above has been given by way of
illustrative example of the invention. Any variations, modifications, or
omissions,
as would be apparent to persons skilled in the art, are deemed to fall within
the
broad scope of this invention.

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