Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02263007 1999-02-25
SAFETY EDGE FOR AN ELECTRICALLY OPERATED DOOR
FIELD OF THE INVENTION
The present invention relates to a safety edge for connection to a surface
such as an electrically operated door.
BACKGROUND OF THE INVENTION
Electrically operated doors, especially overhead doors, are inherently
dangerous. During their downward travel mode, overhead doors are capable of
trapping and exerting extreme force upon any object obstructing their path of
travel.
Therefore, a triggering device is placed upon the lower lead edge of the door
which
serves to reverse the direction of travel of the overhead door should an
object obstruct
the door's path of travel. These triggering devices are known as safety edges,
although
they are also referred to as reversing systems or reversing bars.
One common type of safety edge is a pneumatic system. A gum-hose is
used to force air to a diaphragm operated switch. The diaphragm, when aroused
by the
force of said air, touches a set of electrical points together. Pneumatic
systems have a
number of inherent problems. The diaphragm operated switch is hidden from view
and is, therefore, difficult to inspect for routine maintenance. The gum-hose
has a
tendency to crack, rot and leak; thereby rendering the system ineffective.
Should the
door encounter a narrow obstruction during downward travel, a pneumatic
reversing
system does not always transmit sufficient air through said gum-hose to
operate the
diaphragm switch. The longer the hose used (i.e. for larger or wider doors),
the less
effective pneumatic systems become, due to outward deflection of the longer
gum-hose,
reducing airflow to said diaphragm. This is especially evident when the gum-
hose is
compressed furthest from said diaphragm switch. On very slow moving doors, the
operating capabilities of this switch are extremely limited, due to a reduced
force of
airflow to said diaphragm.
A more reliable and widely used system is the mechanical safety edge
system. Mechanical safety edge systems consist of a metal rail attached to the
lead edge
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of a door section by a hinged attachment system. The mechanical safety edge
relies
upon gravity to disengage one or more electric switches fastened to the inner
face of a
bottom section of door. The metal rail pivots upwardly about its hinges upon
striking
an object in its path of travel. The switches are positioned to be struck by
the metal rail
or its linkages as it pivots. Although mechanical systems are far more
reliable than
pneumatic systems, they also have inherent drawbacks. The weight of the metal
rail
makes it difficult to attach to new lightweight doors and also causes
counterbalancing
problems. T'he linkages tend to wear or come out of alignment with the
switches they
are supposed to contact, thus causing the safety edge to malfunction.
A third style of safety edge is the compressible electrical contact system.
This system consists of thin ribbons of copper tape, separated by foam rubber
strips.
The foam rubber strips are uniformly perforated, and when compressed allow the
ribbons of copper tape to contact, sending an electrical signal. As with the
other
systems described above, this system has inherent defects. The system is
housed in a
canvas and/or rubber sheath. If the sheath becomes torn, cracked or
perforated, the
incursion of moisture creates a short in the electrical system. This type of
reversing bar
is also extremely expensive, and has to be manufactured to suit the length of
each
individual door size on which it is to be used. This presents stocking
problems, as well
as marketing concerns. For these reasons the compressible electrical contact
system is
not as widely used a system as either the pneumatic or mechanical safety
edges.
A fourth style of safety edge is similar to both the pneumatic and
compressible electrical contact systems described above, and consists of a
deformable
member positioned along the bottom edge of the door. The deformable member
carries
an electrical contact which engages a second electrical contact mounted on the
bottom
of the door when the door encounters an obstruction and the deformable member
is
deformed. One disadvantage of this system is that the deformable member, which
is
often made from plastic or rubber, is prone to cracking, rotting and leaking
(as in the
pneumatic system), with the result first, that the deformable member may cease
to
function properly and second, that the electrical contacts may become exposed
to dirt
and moisture and thus become fouled. A second disadvantage of this system is
that the
size and configuration of the deformable member is limited by the requirement
that it
must provide for the electrical contacts to be separated when the deformable
member is
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not deformed and also provide for the electrical contacts to be engaged when
the
deformable member is deformed. This disadvantage is particularly significant
in
circumstances where the deformable member also serves to provide a seal
between the
door and the floor when the door is closed.
SUMMARY OF THE INVENTION
What is required is an alternative safety edge that obviates some or all of
the problems present in the prior art.
According to the present invention there is provided a safety edge which
includes a female housing strip and a male actuator strip. The female housing
strip has
an interior cavity in which is positioned at least one of a first electrical
contact means.
The male actuator strip has at least one of a second electrical contact means.
The male
actuator strip is telescopically received in the female housing strip. In a
preferred
embodiment of the invention, the male actuator strip is telescopically
received in the
interior cavity of the female housing strip. The male actuator strip is
movable between
a first position in which the second electrical contact means is spaced from
the first
electrical contact means and a second position in which the second electrical
contact
means engages the first electrical contact means to close or complete a
normally open
circuit.
Means is provided for attaching the safety edge to a surface. In the
preferred embodiment of the invention, means are provided for attaching the
female
housing strip to the surface. Alternatively, the male actuator strip may be
attached to
the surface. The surface may be the edge of a door, window, shutter, wall,
gate, panel
or any other surface which may cause injury or damage if it is permitted to
move
without regard to obstructions that may be in its path. In the preferred
embodiment,
the safety edge is intended to be used in conjunction with an automatically
closing
door.
The means for attaching the safety edge to the door may be integral with
the safety edge or may be comprised of a separate component or components.
Where
the means for attaching the safety edge to the door are integral with the
safety edge, the
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means may be comprised of an integral attachment flange which extends from and
is
formed as part of either the female housing strip or the male actuator strip.
Where the means for attaching the safety edge to the door is comprised of
a component or components separate from the safety edge, the means may be
comprised of a separate attachment flange which can be mounted on the edge of
a door
or other surface and can also be attached to either the female housing strip
or the male
actuator strip. Preferably, the separate attachment flange and the female
housing strip
comprise an attachment lug and a complementary attachment groove to facilitate
attachment of the separate attachment flange to the female housing strip. In a
preferred
embodiment, the separate attachment flange comprises the attachment lug and
the
female housing strip comprises the attachment groove.
The separate attachment flange may be of any shape and size as long as it
facilitates attachment of the safety edge to the edge of the door or other
surface.
Preferably, the female housing strip is compatible with a variety of shapes
and sizes of
separate attachment flange in order to maximize the versatility of the safety
edge.
Preferably the safety edge includes both an integral attachment flange and a
separate
attachment flange and preferably the integral attachment flange can be severed
from
the safety edge if its use is not required.
In the preferred embodiment, each female housing strip and male actuator
strip together comprise a safety edge unit, and a plurality of safety edge
units are
connected together to form a complete safety edge. In this embodiment, the
safety edge
further comprises a connector comprising at least one connective member for
connecting adjacent safety edge units together both structurally and
electrically. More
particularly, in the preferred embodiment, each female housing strip of the
plurality of
safety edge units has opposed ends, adjacent female housing strips have
adjacent
opposed ends, and the connector connects the adjacent opposed ends of the
adjacent
female housing strips.
Each female housing strip may have an interior wall, an exterior wall and
a plurality of channels disposed between the interior wall and the exterior
wall, and the
connector may comprise at least one connective member insertable into at least
one of
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the plurality of channels at the adjacent opposed ends of the adjacent female
housing
strips. Preferably the channels extend between the opposed ends of the female
housing
strip and preferably the connector comprises at least one connective member
for
connecting the safety edge units together structurally and comprises at least
one
connective member for connecting the safety edge units together electrically.
The structural connective member may be comprised of any shape or size
which is compatible with the corresponding channels in the female housing
strips to
provide a firm connection between adjacent female housing strips while
permitting
limited flexure of the joint between adjacent female housing strips. In a
preferred
embodiment, the structural connective member is comprised of two pairs of
tines, with
each pair of tines being insertable in a channel of a female housing strip for
engagement
with a locking pin which extends across the channel.
The first electrical contact means may extend the full length of the female
housing strip or may be positioned intermittently along the female housing
strip.
Preferably, however, the first electrical contact means preferably comprises a
pair of
first electrical contacts. Preferably, one of the pair of first electrical
contacts is
positioned at one of the opposed ends of the female housing strip and another
of the
pair of first electrical contacts is positioned at another of the opposed ends
of the female
housing strip, and preferably the pair of first electrical contacts is
electrically connected
by using conductive material such as wiring, metal strips or by other means
known in
the art.
The first electrical contact means may comprise a positive electrical
contact and a negative electrical contact in spaced relation, and the second
electrical
contact means may comprise a bridge contact so that when the male actuator
strip is in
the second position the bridge contact spans between the positive electrical
contact and
the negative electrical contact to close the normally open circuit. The second
electrical
contact means may extend the full length of the male actuator strip or it may
be
positioned intermittently along the male actuator strip as long as the second
electrical
contact means can engage the first electrical contact means when the male
actuator strip
is in the second position.
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Preferably, one or both of the first electrical contact means and the second
electrical contact means is pivotable so that an electrical connection can be
made
between the first and second electrical contact means when the male actuator
strip is in
the second position even when the male actuator strip does not telescope
evenly along
the length of the female housing strip. Most preferably, the second electrical
contact
means are pivotable relative to the male actuator strip. In a preferred
embodiment, the
second electrical contact means are mounted on the male actuator strip such
that they
"float" relative to the male actuator strip. The second electrical contact
means preferably
"float" relative to the male actuator strip as a result of being connected to
the male
actuator strip with a biasing device, which in the preferred embodiment is
either a
spring or an elastomeric material. The biasing device may be located in a
cavity defined
by the male actuator strip.
In the preferred embodiment, the female housing strip is a "C" channel in
cross section and the male actuator strip is telescopically received within
the "C"
channel. The safety edge may also comprise a stop means to prevent the male
actuator
strip from being withdrawn from the female housing strip. In the preferred
embodiment, the stop means comprises internal shoulders in the interior cavity
of the
female housing strip which are adapted to engage external shoulders on the
male
actuator strip when the second electrical contact means is spaced from the
first electrical
contact means by a predetermined distance. Other forms of stop means may,
however,
be utilized in the invention.
The safety edge may also comprise biasing means to bias the male
actuator strip toward the first position. In the preferred embodiment, the
biasing means
comprise springs such as coil springs or leaf springs which are positioned
between the
male actuator strip and the female housing strip in the interior cavity of the
female
housing strip. In the preferred embodiment where coil springs are used, the
coil
springs are received in pockets located on the male actuator strip. Other
forms of
biasing means may, however, be used in the invention as long as they provide
the
specified biasing function. Such alternative biasing means may include other
types of
springs or other resilient material such as foam rubber or may even comprise a
form of
pneumatic or hydraulic dampening system.
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The safety edge units of the present invention may be fabricated in any
length and may then be cut and assembled to create a safety edge as required
for a
specific application. As a result, the various components of the safety edge
are
preferably designed to be easily assembled in the field so that manufacturing
of the
components can be standardized.
In particular, preferably the structural and electrical connective members
may be inserted and removed from the channels of the female housing strip
without
causing damage to any components of the safety edge. In addition, preferably
removable endblocks are provided at both ends of each safety edge unit. These
removable endblocks add strength to the safety edge and assist in maintaining
the
orientation of the male actuator strip in the female housing strip. They also
provide a
conduit for conductive material such as wiring which pass through the female
housing
strip and the endblocks.
The removable endblocks preferably fit snugly in the ends of the female
housing strips and accommodate the conductive material which is extending
along the
female housing strips. The removable end blocks may be held in place in the
ends of
the female housing strips by any device or means, but preferably may be
inserted and
removed without the use of fasteners which may cause damage to components of
the
safety edge.
In a preferred embodiment, the removable endblocks are held in place in
the ends of the female housing strips by a plunger which engages the female
housing
strip and by engagement with two locking pins which extend into the interior
of the
female housing strip. In the preferred embodiment the plunger is biased
towards the
female housing strip, preferably with a spring or an elastomeric material.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features of the invention will become more apparent from
the following description in which reference is made to the appended drawings,
wherein:
CA 02263007 1999-02-25
FIGURE 1 is a pictorial view of a safety edge constructed in accordance
with the teachings of the invention.
FIGURE 2 is a pictorial view of a female housing strip for the safety edge
illustrated in FIGURE 1.
FIGURE 3 is a pictorial view of a male actuator strip for the safety edge
illustrated in FIGURE 1.
FIGURE 4 is a pictorial view of a first electrical contact means assembly
for the female housing strip illustrated in FIGURE 2.
FIGURE 5 is a pictorial view of a second electrical contact means assembly
for the male actuator strip illustrated in FIGURE 3.
FIGURE 6 is a partially cut-away pictorial view of the safety edge
illustrated in FIGURE 1, with the endblock removed.
FIGURE 7 is a pictorial view of an endblock for the safety edge illustrated
in FIGURE 1.
FIGURE 8 is a pictorial view of an electrical connective member for use
between two adjacent safety edge units of the safety edge illustrated in
FIGURE 1.
FIGURE 9 is a pictorial view of an end cover plate for the safety edge
illustrated in FIGURE 1.
FIGURE 10 is a pictorial view of a dust plug for the safety edge illustrated
in FIGURE 1.
FIGURE 11 is a pictorial view of the safety edge illustrated in FIGURE 1
with end cover plate, dust plug and weather strip attached.
FIGURE 12 is a pictorial view of the safety edge illustrated in FIGURE 10
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attached to a typical electrically operated overhead door.
FIGURE 13 is a partially cut-away detailed pictorial view of the safety
edge as illustrated in FIGURE 11.
FIGURE 14 is a side view of a plastic alignment plug for the safety edge
illustrated in FIGURE 1.
FIGURE 15 is a pictorial view of a preferred embodiment of a separate
attachment flange for the safety edge illustrated in FIGURE 1.
FIGURE 16 is a pictorial view of an alternate embodiment of a separate
attachment flange for the safety edge illustrated in FIGURE 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The preferred embodiment of safety edge, generally identified by
reference numeral 20, will now be described with reference to FIGURES 1
through 16 as
a safety edge for an overhead door.
Referring to FIGURES 1 to 3, the key components of safety edge 20
include an elongate female housing strip 22 and an elongate male actuator
strip 24.
Referring to FIGURE 12, the length of female housing strip 22 and male
actuator strip 24
can be equivalent to the width of any overhead door. In actual practice,
female housing
strip 22 and male actuator strip 24 will be made in safety edge units of
standard lengths
with a plurality of safety edge units being joined to make up any required
width of
safety edge 20, as will hereinafter be further explained. Female housing strip
22 is
separately illustrated in FIGURE 2. Male actuator strip 24 is separately
illustrated in
FIGURE 3. It will be understood that the following description of safety edge
20 as
employed on an overhead door bottom section is by way of example only, as the
safety
edge of the present invention may also be advantageously employed in other
applications, such as, rolling steel door bottom rails, rolling shutter door
bottom bars, as
well as gates, windows, shutters, sliding panels and the like.
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Referring to FIGURE 12, each female housing strip 22 has opposed ends
26. Referring to FIGURE 2, each female housing strip 22 has a "C" channel body
28
which defines an interior cavity 30. "C" channel body 28 has both an
integrally formed
vertically extending integral attachment flange 32 and an integrally formed
attachment
groove 33.
Referring to FIGURE 13, integral attachment flange 32 serves as one
means for attaching female housing strip 22 to an edge 34 of a door 36 and may
be
severed from the safety edge 20 by cutting or by some other method if the use
of the
integral attachment flange 32 is not required.
Referring to FIGURES 2, 15 and 16, the attachment groove 33 facilitates a
second means for attaching the female housing strip 22 to an edge of a door 36
using a
separate attachment flange 35 which comprises an attachment lug 37.
Alternatively, the
integral attachment flange 32 and/or the attachment groove 33 may be formed
with or
otherwise connected to the male actuator strip 24 so that the male actuator
strip 24 may
be attached to an edge 34 of a door 36. In addition, the attachment groove 33
may be
formed as part of the separate attachment flange 35 and the attachment lug 37
may be
formed as part of either the female housing strip 22 or the male actuator
strip 24.
The attachment groove 33 and the attachment lug 37 are complementary
in order to provide a connection between the separate attachment flange 35 and
the
female housing strip 22. The separate attachment flange 35 may be any shape or
size as
may be required in order to mount the safety edge 20 to an edge of a door 36
or some
other surface. Referring to FIGURE 15, a preferred separate attachment flange
35 is
illustrated in which the flange 35 is vertically extending. Referring to
FIGURE 16, an
alternate separate attachment flange 35 is illustrated in which the flange 35
is
horizontally extending and includes an attachment channel 39 for engaging an
edge of
the female housing strip 22 to provide a more positive attachment of the
separate
attachment flange 35 to the female housing strip 22.
In the preferred embodiment, the attachment groove 33 extends along the
top of the female housing strip for the entire length of the female housing
strip. The
attachment groove 33 may however be located at any position on the female
housing
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strip 22 or the male actuator strip 24.
Referring to FIGURE 2, "C" channel body 28 has an interior wall 38, an
exterior wall 40, and a plurality of channels 42, 44 and 46 disposed between
interior
wall 38 and exterior wall 40. Each of channels 42, 44, and 46 extend between
opposed
ends 26. Channels 46 have longitudinally extending slots 47, the purpose of
which will
hereinafter be further described. Integral attachment flange 32 and exterior
walls 40
have longitudinally extending exterior reinforcing ribs 48. It is preferred
that female
housing strip 22 and, in particular, integral attachment flange 32 be
constructed of a
lightweight plastic material. This enables portions of integral attachment
flange 32 to be
cut away, to accommodate a variety of obstacles, while still maintaining
adequate
support for female housing strip 22. Interior cavity 30 of female housing
strip 22 has
internal shoulders 50. Separate attachment flange 35 is also preferably
constructed of a
lightweight plastic material.
Within interior cavity 30 is positioned first electrical contact means 52.
First electrical contact means 52 can take a variety of forms, as long as it
is compatible
with a second electrical contact means 54 to complete a normally open circuit,
as will
hereinafter be further described.
In the preferred embodiment, first electrical contact means 52 includes a
pair of first electrical contacts, each of the first electrical contacts
comprising a positive
electrical contact 52a and a negative electrical contact 52b in spaced
relation. Positive
electrical contact 52a and negative electrical contact 52b are separately
illustrated in
FIGURE 4. One of the pair of first electrical contacts is positioned at each
of the
opposed ends of the female housing strip 22.
Each of the pair of first electrical contacts comprising positive electrical
contact 52a and negative electrical contact 52b consists of two copper strips
to which are
connected insulated conductive wires 56. These conductive wires 56 extend
along the
length of the female housing strip 22 to connect the pair of first electrical
contacts
electrically. When placed in position, positive electrical contact 52a and
negative
electrical contact 52b are accessible for electrical contact from both
interior cavity 30 and
from channels 42.
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Referring to FIGURE 12, male actuator strip 24 is generally elliptical in
transverse section and has opposed ends 64. Referring to FIGURE 3, male
actuator strip
24 has a top edge 66 and external shoulders 68 which are spaced toward top
edge 66.
Top edge 66 has second electrical contact means 70 at each of opposed ends 64.
Second
electrical contact means 70 is a "bridge" contact that spans between positive
electrical
contact 52a and negative electrical contact 52b when the male actuator strip
24 is in a
second position, as hereinafter will be further described.
Referring to FIGURE 6, male actuator strip 24 is telescopically received
within the interior cavity 30 of female housing strip 22. Male actuator strip
24 is
movable between a first position in which second electrical contact means 70
is spaced
from first electrical contact means 52 and a second position in which second
electrical
contact means 70 engages first electrical contact means 52 to close a normally
open
circuit. Leaf-type springs (not shown) serve to bias male actuator strip 24
toward the
first position and are positioned in the interior cavity 30 between the female
housing
strip 22 and the male actuator strip 24 . External shoulders 68 on male
actuator strip 24
engage internal shoulders 50 within interior cavity 30 of female housing strip
22 to
prevent male actuator strip 24 from being withdrawn from female housing strip
22
when in the first position. Male actuator strip 24 moves to the second
position to cause
second electrical contact means 70 to come into contact with first electrical
contact
means 52 when an obstruction is encountered in its path of travel. Having
first
electrical contact means 52 at each of opposed ends 26 of female housing strip
22 and
second electrical contact means 70 at each of opposed ends 64 of male actuator
strip 24
enables each safety edge unit comprising the safety edge 20 to operate in a
safe manner
even when struck at one end only.
Preferably, one or both of the first and second electrical contact means
52,70 are pivotable about an axis that is perpendicular to the longitudinal
axis of the
male actuator strip 24 so that the normally open circuit can be closed even
when only
one end of the male actuator strip 24 is in the second position due to uneven
telescoping
of the male actuator strip 24 in the female housing strip 22. This pivoting
function can
be achieved in any manner such as by mounting the first and/or second
electrical
contact means 52,70 on a pivoting axis. In the preferred embodiment, the
second
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electrical contact means 70 are mounted so that they "float" relative to the
male actuator
strip 24 and are thus pivotable. This "floating" function is achieved in the
preferred
embodiment by mounting the second electrical contact means 70 on the male
actuator
strip 24 with a biasing device. Although any type of biasing device may be
used, in the
preferred embodiment the biasing device is comprised of an elastomeric
material 75
which is contained in a cavity 77 in the upper surface of the male actuator
strip 24, and
the second electrical contact means 70 are mounted on the elastomeric material
75 using
a wire 79 which extends around both the second electrical contact means 70 and
the
elastomeric material 75 and is held in place with a block 80 which is inserted
in the male
actuator strip 24.. Alternatively, the first electrical contact means 52 may
pivot in
addition to or instead of the second electrical contact means 70.
Referring to FIGURE 7, a removable endblock 78 is illustrated. Preferably
each safety edge unit includes an endblock 78 at each of the opposed ends of
the female
housing strip 22 to provide strength to the female housing strip 22 and to
assist in
maintaining the male actuator strip 24 in its proper orientation within the
interior cavity
30 of the female housing strip 22. The endblocks 78 also provide a conduit for
conductive material which extends through the female housing strip 22.
Referring to FIGURES 1 and 7, each endblock 78 is attached to the female
housing strip 22 in three separate locations which eliminate the use of screws
or other
fasteners in the attachment of the endblocks 78. Each endblock 78 is attached
to the
female housing strip 22 at one location with a plunger 81 associated with the
endblock
78 which plunger 81 engages a discontinuity in the female housing strip 22. In
the
preferred embodiment, the plunger 81 is biased towards engagement with the
female
housing strip 22 by an elastomeric material 82, but other forms of biasing
device may be
used.
Referring to FIGURE 1, in the preferred embodiment each end of each
female housing strip 22 is equipped with a pair of locking pins 83 which
extend from
the exterior of the female housing strip 22 through the channels 44 on both
sides of the
female housing strip 22 and protrude into the interior cavity 30 of the female
housing
strip 22. Referring to FIGURE 13, in the preferred embodiment each endblock 78
includes a lower endblock cavity 78a. Each endblock 78 is attached to the
female
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housing strip 22 at second and third locations by engaging the lower endblock
cavity
78a with the locking pins 83 which protrude into the interior cavity 30 of the
female
housing strip 22. Further alignment and support for the endblocks 78 is
achieved by
complementary notches and flanges 84 on the endblock 78 and the female housing
strip
22.
Referring to FIGURE 12, the electrical circuit is formed by connecting
conductive wires 56 to the electrical door opener 86 by means of an electrical
cord 88.
In the preferred embodiment, the conductive wires 56 for each safety edge unit
extend
between and terminate at each first electrical contact means 52 comprising the
pair of
first electrical contacts, except as may be required to facilitate the
formation of the
electrical circuit between the safety edge 20 and the electrical door opener
86, in which
case the conductive wires 56 also extend through an endblock 78 and through an
access
port 85 which can be drilled or cut into the female housing strip 22 on-site,
where they
may be connected to the electrical cord 88 which in turn is connected to the
electrical
door opener 86.
As indicated, safety edge 20 is preferably modular and is preferably
comprised of a plurality of safety edge units connected together both
structurally and
electrically. Referring to FIGURE 12, two or more substantially identical
safety edge
units when coupled together can achieve a required length of safety edge 20 to
correspond to the length of an edge 34 of door 36 on which they are to be
installed.
Each safety edge unit is constructed in such a manner so as to allow its use
individually
for door sections of small length or in a plurality of safety edge units
connected together
for use on door sections of greater length.
Referring to FIGURES 1, 8 and 14, structural and electrical connection
between two identical safety edge units is in the preferred embodiment
accomplished
using a connector comprising copper interlocks 90 and plastic alignment plugs
92 as
connective members. Copper interlocks 90 extend through a gasket 94 into
channels 42
of female housing strip 22 where they make an electrical connection with
electrical
contacts 52a and 52b. In order to prevent copper interlocks 90 from going
completely
into channels 42, the copper interlocks 90 are provided with a discontinuity
91 which
limits the distance that copper interlocks 90 can be extended into channels
42. Copper
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interlocks 90 are preferably made of copper.
Referring to FIGURE 14, plastic alignment plugs 92 similarly extend into
channels 44. Plastic alignment plugs 92 provide a structural connection
between
adjacent safety edge units which helps to maintain the alignment of a female
housing
strip 22 of one safety edge unit with a female housing strip 22 of a next
adjoining safety
edge unit. The plastic alignment plugs 92 may be comprised of any shape or
size which
is compatible with the corresponding channels 44 in the female housing strips
22 to
provide a firm connection between adjacent female housing strips 22 while
permitting
limited flexure of the joint between adjacent female housing strips 22. In a
preferred
embodiment, each of the plastic alignment plugs 92 is comprised of two pairs
of tines
93, with each pair of tines 93 being insertable in a channel 44 of a female
housing strip
22 to surround and engage the locking pins 82 which extend through channels 44
with a
locking pin engagement surface 95.
Referring to FIGURE 9, an optional end cover plate 96 is illustrated. End
cover plate 96 preferably has protruding plugs 98 that are adapted to be
received in
channels 44 of female housing strip 22. Referring to FIGURE 11, when
connection to an
adjacent safety edge unit is not required, end cover plate 96 may be used to
complete
the terminal end of a female housing strip 22. The end cover plate 96 is
preferably
attached to the safety edge 20 with a screw 97 which fastens the end cover
plate 96 to an
endblock 78.
Referring to FIGURE 10, an optional foam rubber dust plug 100 is
illustrated. Referring to FIGURE 11, dust plug 100 may be used to complete any
or all
of the opposed ends 64 of a male actuator strip 24. Dust plug 100 may be
attached to
the safety edge 20 by pressing one end of the dust plug 100 into the lower
endblock
cavity 78a of the endblock 78.
Referring to FIGURE 11, it is preferred that a rubber weatherstrip 102 be
attached to female housing strip 22 so that it covers male actuator strip 24.
This
weatherstrip 102 prevents debris from entering into interior cavity 30 of
female housing
strip 22 and may also function to provide a seal between the door edge 34 and
the floor
when the door 36 is closed. Weatherstrip 102 is retained in channels 46 and
extends out
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CA 02263007 1999-02-25
through slots 47. Weatherstrip 102 is easily slid into position by sliding
along slot 47
from one of opposed ends 64.
The use and operation of safety edge 20 will now be described with
reference to FIGURES 1 through 16. Referring to FIGURE 12, a plurality of
safety edge
units are secured in end to end relation along edge 34 of door 36 using
connectors as
depicted in FIGURES 8 and 14 to form a complete safety edge 20. Referring to
FIGURE
13, each safety edge unit is secured to edge 34 of door 36 by inserting screws
104 either
through integral attachment flanges 32 or through separate attachment flanges
35.
Attachment flanges 32,35 may be cut away as required to avoid obstacles, such
as
bottom lifting fixture 106. If separate attachment flanges 35 are used, the
female
housing strips 22 may be attached to the separate attachment flanges 35 either
before or
after the flanges 35 are secured to the edge of door 36. Integral attachment
flange 32
may be severed from the safety edge 20 if a separate attachment flange 35 is
to be used.
Referring to FIGURE 1, the end to end connection of adjacent safety edge
units is accomplished using connectors by extending copper interlocks 90 into
channels
42 of female housing strip 22 where they make an electrical connection with
electrical
contacts 52. Plastic alignment plugs 92 similarly extend into channels 44 to
provide a
structural connection and to add stability. Removable endblocks 78 are also
inserted in
each end of each female housing strip 22 and are secured to the female housing
strip 22
with the plunger 81 and the locking pins 82. Gaskets 94 are provided between
copper
interlocks 90 on adjacent endblocks 78. Preferably the ends of the safety edge
where a
female housing strip 22 is not attached to an adjacent female housing strip 22
are
equipped with an end cover plate 96 and a dust plug 100. An access port 85 may
be
drilled or otherwise provided in the female housing strip 22 adjacent to the
end cover
plate 96 to facilitate connection of the safety edge 20 to a power supply.
Referring to FIGURE 6, male actuator strip 24 moves to the second
position to cause second electrical contact means 70 to come into contact with
first
electrical contact means 52 when an obstruction is encountered in its path of
travel. The
engagement of the second electrical contact means 70 and the first electrical
contact
means 52 completes a previously open electrical circuit which includes the
electrical
door opener 86, the electrical cord 88, the conductive wires 56 and the first
electrical
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CA 02263007 1999-02-25
contact means 52. The electrical contact between second electrical contact
means 70 and
first electrical contact means 52 can be made at either of opposed ends 64 and
26,
respectively, which enables each safety edge unit to operate independently and
in a safe
manner even when struck at one end only. Positive contact between the first
and
second electical contact means 52,70 is enhanced by the floating action of the
second
electrical contact means 70 relative to the male actuator strip 24.
Referring to FIGURE 12, using a plurality of safety edge units in the safety
edge 20 also assists in improving the seal between the door edge 34 and the
floor when
the door 36 is closed by virtue of the independent action of each male
actuator strip 24
in each safety edge unit. This independent action also better accommodates an
angular
drainage slope on a floor because the telescoping movement of a relatively
short length
of male actuator strip 24 will more easily follow an angled floor line when
deflected by
the closing of the door 36.
It will be apparent to one skilled in the art that modifications may be
made to the illustrated preferred embodiment without departing from the spirit
and
scope of the invention as hereinafter defined in the claims. For example and
as
discussed above, the safety edge 20 may be configured so that the male
actuator strip 24
includes means for attaching the safety edge to a door and the female housing
strip 22 is
movable relative to the male actuator strip 24 between a first position in
which the
second electrical contact means 70 is spaced from the first electrical contact
means 52
and a second position in which the second electrical contact means 70 engages
the first
electrical contact means 52 to form a complete electrical circuit.
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