Note: Descriptions are shown in the official language in which they were submitted.
CA 02419583 2003-02-25 PCT/AU00/00943
='' . Received on 19 April 2002
- i/1 -
Title: Security Closure
Background
This invention relates to security screens which may be applied over windows
and/or
doorways for the purposes of enabling ventilation through the window or door
when
open but to prevent the access of insects past the screen. In addition the
closure
needs to be resistant to destructive forces to prevent unauthorised access
past the
screen.
Disclosure of the Invention
Accordingly the invention resides in a security closure comprising a frame
which
defines the perimeter of the closure where the frame is adapted to be mounted
across an opening, a metallic perforate sheet element supported by said frame
to
close the space defined by the frame, said perforate sheet element being
formed of
a non-expanded stainless steel sheet having a thickness sufficient to
withstand
penetration of impact by blunt objects and having a plurality of closely
spaced
apertures punched therein which are dimensioned to prevent insect access
through
the apertures and wherein the spacing of the apertures provides a
substantially
unrestricted view through the sheet element.
Accordingly the invention also resides in a security closure comprising a
frame
where the frame is adapted to be mounted across an opening, a perforate sheet
element supported at its side edges by the frame to close the frame wherein at
least
some of the side edges of the sheet element being formed with a lip, the frame
formed with a recess having an opening directed inwardly with respect to the
closure, the side edges of the sheet element being received within the recess
such
that the lip is located within the recess, an elongate locking member received
and
fixed in the recess outward of the lip, said locking member being clampingly
engaged with the sheet material and the recess.
According to an alternative feature of the invention the sheet element is
formed of
woven mesh.
AMENt~ED, SHE'T
IPEA/AU
CA 02419583 2003-02-25 PCT/AU00/00943
Received on 19 Apri12002
1/2 -
According to an alternative feature of the invention the sheet element is
formed of
expanded mesh.
According to one particular embodiment the engagement of the locking member in
the recess is, at least in part, frictional.
According to another particular embodiment the engagement of the locking
member
to the one side at least in part comprises the interengagement of
complementary
formations provided on opposed faces of the locking member and the recess.
1 '
A M E N D E : t;.~ IS hE-E
1PEA/AU
CA 02419583 2003-02-25
WO 02/12672 PCT/AU00/00943
-2-
According to a preferred feature of the embodiment the complementary
formations
comprise serration-like formations. According to another preferred feature of
the
invention the fixing of the locking member to the one side is at least in part
effected
by fixing elements between the locking member and the one side. According to
one
embodiment the fixing elements comprise rivets.
According to a preferred feature of the invention, the sheet element is formed
of
stainless steel. According to one embodiment the sheet element is powder
coated.
According to a preferred feature of the invention, the locking member
substantially
fills the space between the one side of the recess and the sheet material.
According
to one embodiment, the locking member clampingly retains the sheet element
against the other side of the recess.
According to a further preferred feature of the invention the locking member
is
formed of increasing thickness to be wedgingly engaged between the one side of
the
recess and the sheet element.
According to a further feature of the invention the sheet element is formed of
a non-
expanded sheet material having a plurality of closely spaced apertures punched
therein which are dimensioned to prevent insect access through the apertures.
According to a preferred feature of the invention the apertures have a
diameter of
between 1.6 mm to 3.6 mm. According to a preferred feature of the invention
the
spacing of the apertures center to center is between 2.0 mm and 3.5 mm.
According
to a preferred feature of the invention the thickness of the stainless steel
sheeting is
between 0.5 mm and 1.0 mm.
According to an alternative feature of the invention the sheet element is
formed of
woven mesh.
According to a preferred feature of the invention a layer of an electrical
insulator is
located between abutting surfaces of the sheet element and the locking member.
According to a further preferred feature of the invention a layer of an
electrical
insulator is located and between the abutting surfaces of the sheet element
and the
recess. According to one embodiment the electrical insulator comprises a strip
CA 02419583 2007-06-07
-3-
formed of a plastics material which is received over the lip and at least the
portion
of the sheet element closely adjacent the lip which are located in the recess.
According to a preferred feature of the invention each edge of the sheet
element is
formed with a lip.
According to a preferred feature of the invention the lip at each edge extends
for
the full length of the respective edge.
The security closure may comprise a closure which is fixed across a window or
alternatively may comprise a door which can be selectively moved between an
open and closed position across an opening.
In one aspect, the present invention resides in a security closure comprising
a
frame having an outer edge which defines the outer perimeter of the frame and
further having an inner edge which surrounds an open portion of the frame, the
outer edge of the frame being dimensioned such that in use the security
closure is
receivable across an opening to close the opening, a perforate rigid sheet
element
received in the open portion of the frame to close the open portion, the edges
of the
sheet element being formed with a lip extending from one face of the sheet
element, the inner edge of the frame formed with a recess having an entry
extending across at least a portion of the width of the inner edge, the recess
extending along the inner edge, the edges of the sheet element received within
the
recess such that the lip is located within the recess, an elongate locking
member
received within the recess outward of the lip, said locking member being
clampingly
engaged between the one face of the sheet element and the opposed face of the
recess.
In another aspect, the present invention resides in a security closure
comprising a
frame having an outer edge which defines the outer perimeter of the frame and
further having an inner edge which surrounds an open portion of the frame, the
outer edge of the frame being dimensioned such that in use the security
closure is
CA 02419583 2007-06-07
- 3a -
receivable across an opening to close the opening, a perforate rigid sheet
element
received in the open portion of the frame to close the open portion, the edges
of the
sheet element being formed with a lip extending from one face of the sheet
element, the inner edge of the frame formed with a recess having an entry
extending across at least a portion of the width of the inner edge, the recess
extending along the inner edge, the edges of the sheet element received within
the
recess such that the lip is located within the recess, an elongate locking
member
received within the recess outward of the lip, said locking member being
clampingly
engaged between the one face of the sheet element and the opposed face of the
recess and a layer of an electrical insulator received over the lip and
adjacent
portion of the sheet element to be received between opposed surfaces of the
sheet
element and the locking member and the opposed surfaces of the sheet element
and the recess.
In a further aspect, the present invention resides in a security closure
comprising a
frame having an outer edge which defines the outer perimeter of the frame and
further having an inner edge which surrounds an open portion of the frame, the
outer edge of the frame being dimensioned such that in use the security
closure is
receivable across an opening to close the opening, a perforate rigid sheet
element
received in the open portion of the frame to close the open portion, the edges
of the
sheet element being formed with a lip extending from one face of the sheet
element, the inner edge of the frame formed with a recess having an entry
extending across at least a portion of the width of the inner edge, the recess
extending along the inner edge, the edges of the sheet element received within
the
recess such that the lip is located within the recess, an elongate locking
member
received within the recess outward of the lip, said locking member being
clampingly
engaged between the one face of the sheet element and the opposed face of the
recess wherein the elongate locking member is fixed in the recess at least in
part
through the inter-engagement of complementary formations provided on the
opposed face of the recess and opposed face of the locking member and the
locking member substantially fills the space defined within the recess between
lip
CA 02419583 2007-06-07
- 3b -
and the entry between the one face of the sheet element and the opposed face
of
the recess.
The invention will be more fully understood in the light of the following
description of
several specific embodiments
Brief Description of the Drawings
The description is made with reference to the accompanying drawings of which:
Figure 1 is a schematic partial sectional elevation of a security closure
according to
the first embodiment illustrating the mounting of the sheet material to the
frame;
and
Figure 2 is a schematic partial sectional elevation of a security closure
according to
the second embodiment illustrating the mounting of the sheet material to the
frame.
Description of Several Specific Embodiments of the Invention
The first embodiment as shown at Figure 1 is directed to a screen closure
which
may comprise a screen which is applied across a window or alternatively may
comprise a screen door where the closure is required to permit air flow
through the
window or doorway but to prevent the access of insects through the closure and
to
prevent unauthorised entry through the accessway.
The screen closure according to the embodiment comprises a frame 11 which
defines the perimeter of the closure and which is configured to be received in
the
CA 02419583 2003-02-25
WO 02/12672 PCT/AU00/00943
-4-
window or door frame and is adapted to be fixed thereto in the most
appropriate
manner. The frame 11 is formed of a metal section formed of aluminium where
the
section is configured to support the. edges of a screen 13 which is formed of
perforated stainless steel sheet where the perforations are closely spaced and
are
dimensioned such as to prevent insect access through the apertures. The
apertures
are formed by punching. The screen material comprises a non-expanded sheet
material. The apertures are dimensioned to prevent the passage of insects such
as
house flies and mosquitoes through them and are spaced sufficiently closely to
provide a relatively unrestricted view through the screen when observed from a
distance. In addition the grade and thickness of the stainless steel sheeting
and the
spacing of the apertures is such that the sheet is capable of withstanding
significant
impact forces created by sharp and blunt objects.
The inner perimeter of the frame 11 is formed with an inwardly directed recess
15
defined between a pair of flanges 17 and 19. The edges of the screen material
13
are each formed with an upstanding lip 21 which is formed by bending the
screen
material at the edges to form the lip which is substantially perpendicular to
the plane
of the screen. In mounting the screen to the frame the edge of the screen 13
is
received within the recess 15 such that the lip 21 is closely adjacent the
base 23 of
the recess 15. The screen 13 is retained in position in the recess by means of
a
elongate locking member 25 which is received between one flange 17 and the
opposed face of the screen 13 such that the lip 21 is positioned between
locking
member 25 and the base 23. The opposed faces of the locking member and the
one flange are each formed with a serrated profile where the profiles are
complementary and each serration has an inclined face and an upright face and
the
serrations are arranged on each surface to permit movement of the locking
member
into the recess but to prevent movement of the locking member from the recess.
The locking member 25 is dimensioned such that it will fill the space between
the
one flange 17 and the screen 13 and as a result clampingly retain the screen
13
against the other flange 19. The inner face of the other flange 19 is also
formed
with a serrated profile of similar if not identical form to that of the one
flange 17. In
addition the serrated face of the locking member 25 is inclined with respect
to the
base of the locking member such that in use the side of the locking member
having
the lower profile is introduced into the recess first whereby with further
introduction
CA 02419583 2003-02-25
WO 02/12672 PCT/AU00/00943
-5-
of the locking member into the recess the locking member becomes wedgingly
engaged.
As a result of the first embodiment, a screen closure is provided which is
secure in
that the means of retaining the screen securely retains the screen in position
in the
frame without requiring any fixing or bolting of the screen material to the
frame. In
addition, the use of perforated non-expanded stainless steel sheet material
provides
a medium which can be more readily powder coated than screen materials which
have been used in the past such as mesh or expanded sheet material. In this
regard the powder coating which is applied to mesh sheet material and expanded
sheet material can be the subject of cracking and resultant separation from
the sheet
material as a result of localised deflection of the sheet material which
results in a
spoiling of the appearance of the sheet material and can result in corrosion.
In
addition it has been found that the perforated sheet material can be harder to
cut
with a knife or similar sharp instrument when compared to some mesh or
expanded
sheet materials. The perforated sheet material also provides an aesthetically
pleasing appearance.
The second embodiment as shown at Figure 2 is of similar form to the first
embodiment and as a result the same reference numerals have been used in
relation to corresponding elements of the second embodiment. The second
embodiment differs from the first embodiment in that it also includes a layer
27 of an
electrical insulator which overlies the lip 21 and extends over at least the
adjacent
portion of each face of the screen 13 which will be received in the recess 15.
The
layer 27 is formed of a strip formed of a suitable plastics material and is
preformed
tot the configuration of profile of the edge of screen. In assembly of the
closure the
preformed strip 27 is applied over the edge of the screen and the combination
of
edge and strip is introduced into the recess at which time the locking member
is
driven into place.
A first example of the second embodiment was constructed to provide a screen
door
870mm wide and 2040mm long. The screen was formed of stainless steel sheeting
0.71 mm thick of 304 grade and the frame was formed of an aluminium section as
shown at Figure 2. The spacing between the apertures in the stainless steel
sheet
was 3.1 mm and the diameter of the apertures was 2.06 mm. On testing the door
in
CA 02419583 2003-02-25
WO 02/12672 PCT/AU00/00943
-6-
accordance with the requirements of Appendix A of AS/NZS 2803.1:1994, "Method
of Test for Resistance to Forced Entry". The door held all required forces and
remained a closed deterrent.
A second example of the second embodiment was constructed to provide a screen
door 1250mm wide and 2100mm long. The screen was formed of stainless steel
sheeting 0.71mm thick of 304 grade and the frame was formed of an aluminium
section as shown at Figure 2. The spacing between the apertures in the
stainless
steel sheet was 3.1 mm and the diameter of the apertures was 2.06 mm. On
testing
the door in accordance with the requirements of Appendix B of AS 2803.2:-1995,
"Method of Test for Resistance to Forced Entry". The door held all required
forces
and remained a closed deterrent.
A third embodiment of the invention is of similar form to the first and second
embodiment with the exception that fixing of the locking member to the one
flange is
supplemented by the use of rivets which are used to fix the one flange to the
locking
member at spaced intervals along their length.
According to alternative embodiments of the invention the screen is formed of
a
stainless steel mesh of a suitable grade to provide apertures small enough to
prevent insect access through the screen or an expanded stainless steel sheet
material which provide apertures small enough to prevent insect access through
the
screen.
Throughout the specification, unless the context requires otherwise, the word
"comprise" or variations such as "comprises" or "comprising", will be
understood to
imply the inclusion of a stated integer or group of integers but not the
exclusion of
any other integer or group of integers.
It should be appreciated that the scope of the present invention need not be
limited
to the particular scope of the embodiment described above.
