Sensing edge for a door including a switch and flexible protruding sensing members

A sensing edge for causing a closing door to open by actuation of a device upon force being applied to the sensing edge includes an elongate outer sheath for being attached to a door. The sheath is fabricated of a material which is compressible upon application of an external pressure. An interior surface of the sheath defines an area for receiving a portion of a switch means. A pair of flexible members extend from the exterior surface of the sheath away from the door and toward one another. Mounting walls extend from a different portion of the exterior surface of the sheath for receiving an edge of the door.

FIELD OF THE INVENTION 
The present invention relates to a sensing edge for a door and more 
particularly, to a sensing edge for a door that is easily mounted to an 
edge of the door and includes additional flexible members for providing 
enhanced sensitivity to the sensing edge. 
BACKGROUND OF THE INVENTION 
The use of sensing edges on doors is generally known. Sensing edges 
generally include a sheath having an area therein where at least a portion 
of a switch means is located. The sensing edge is attached to an edge of a 
door such that the sensing edge completely fills the gap between the edge 
of the door and an adjacent surface which is engaged by the door. Upon 
application of an external pressure to the sheath, such as by an 
obstructing article, the switch means is activated and operates to actuate 
suitable door control circuitry. The door control circuitry causes the 
door to open to prevent the obstructing article from being damaged by 
further closing of the door. 
Generally, prior art sensing edges of this type require a localized 
deflection to operate the switching means. A substantial force or weight 
may not be sufficient to actuate the switching means if the force or 
weight is distributed over a large area of the sensing edge. In an attempt 
to overcome this problem, such switches often include internal protrusions 
for locally enhancing internal forces reacting to an external force. 
However, if the sensing edge is not properly mounted to the edge of the 
door, i.e., if the activation mechanism of the sensing edge is too close 
to the adjacent surface, the sensing edge will be mechanically actuated by 
the adjacent surface when the door is in a closed position even though the 
control circuitry prevents the door from opening. For instance, if the 
switching mechanism within the sensing edge is comprised of a pair of 
opposed flexible electrically conductive contacts, the contacts deflect 
toward each other each time the door closes. This causes the contacts to 
wear and decreases the life of the sensing edge. 
In addition, many prior art sensing edges comprise a switch means located 
within an outer sheath which is sealed off by two end walls. Electrical 
wires are attached to the switch means and extend through a hole in one of 
the end walls to a power source. The exposed portion of the electrical 
wires are usually encased in an insulating sheath. The electrical wires 
are typically loosely mounted within the end wall thereby increasing the 
probability of the wires being ripped away from the switch means. In 
addition, because the wires are loosely mounted they did not form a tight 
seal with the outer sheath. Thus, moisture and small particles tended to 
enter the sensing edge, thereby lowering the sensitivity of the switch 
means. 
Consequently, a need has arisen for a sensing edge which is highly 
sensitive to obstructing articles, but which is not sensitive to an 
adjacent surface when the door is in a closed position. There further 
exists a need for a sensing edge which can be adjustably mounted to the 
edge of a door such that the sensing edge completely fills the gap between 
the edge of the door and an adjacent surface despite irregularities in the 
adjacent surface. With respect to sensing edges that include a pair of 
opposed flexible electrically conductive contacts, a need has arisen for 
preventing the contacts from deflecting when the door is in the closed 
position and yet allows the sensing edge to fill the gap between the edge 
of the door and the adjacent surface engaged by the door. 
The present invention is directed to a sensing edge for causing a closing 
door to open by actuation of a device upon force being applied to the 
sensing edge. The sensing edge of the present invention includes flexible 
members which prevent the switching means from being actuated when the 
door is a closed position, but which do not inhibit switching sensitivity 
when the sensing edge encounters an obstructing article. The flexible 
members also allow the sensing edge to completely fill the gap between the 
door edge and the adjacent surface engaged by the door without actuating 
the switching means within the sensing edge. Further, the sensing edge of 
the present invention comprises a mounting wall which allows the sensing 
edge to be adjustably mounted onto an edge of a door such that the sensing 
edge completely fills the gap between the edge of the door and the 
adjacent surface engaged by the door. 
SUMMARY OF THE INVENTION 
Briefly stated, the present invention comprises a sensing edge for causing 
a closing door to open by actuation of a device upon force being applied 
to the sensing edge. The sensing edge comprises an elongate outer sheath 
having a first wall and a second wall. The first and second walls each 
have a first end and a second end. The first end of the first wall is 
connected to the first end of the second wall. The second end of the first 
wall is connected to the second end of the second wall. Each of the walls 
include an interior surface and an exterior surface such that the interior 
surfaces of the walls define an area for receiving a portion of a switch 
means. The first wall includes a first portion fabricated of a first 
material and a second portion fabricated of a second material. The second 
material is less flexible than the first material. The first wall includes 
a first protruding means and a second protruding means extending from the 
exterior surface thereof for receiving the edge of the door. The second 
wall is compressible upon application of an external pressure and 
fabricated of a flexible air impervious material. Switch means are 
positioned within the area for actuation of the device upon application of 
external pressure to the outer sheath. 
Preferably, a pair of flexible members extend from the exterior surface of 
the sheath away from the door and toward one another. Each flexible member 
has an inner surface, an outer surface, a first end and a second end. 
An additional embodiment is directed to a method for attaching such a 
sensing edge to an edge of a door. The method comprises the steps of 
providing such a sensing edge and positioning the sensing edge on the edge 
of the door such that the portion of the exterior surface of the sheath is 
in facing engagement with the edge of the door and the door is positioned 
proximate the protruding means. A fastener is positioned through at least 
one of the slots into engagement with the door such that the sensing edge 
can move with respect to the door edge. The door is positioned in a 
generally closed position such that the door edge is proximate a surface. 
The position on the sensing edge is adjusted relative to the door so that 
a portion of the exterior surface of the sheath is in complementary 
engagement with the surface. The position of the fastener is adjusted with 
respect to the door such that the position of the sensing edge with 
respect to the door is fixed. 
A further embodiment is directed to a sensing edge for causing a closing 
door to open by actuation of a device upon force being applied to the 
sensing edge. The sensing edge comprises an elongate outer sheath having a 
first end and a second end for being attached to an edge of a door. The 
sheath is fabricated of a material which is compressible upon application 
of external pressure. The sheath has an interior surface and an exterior 
surface. The interior surface of the sheath defines an area for receiving 
a portion of a switch means. The switch means is positioned within the 
area of the sheath for actuation of the device upon application of 
external pressure to the exterior surface of the sheath. The switch means 
has a first end and a second end and is positioned within the area of the 
sheath such that a gap is formed between the first end of the switch means 
and the first end of the outer sheath. Electrical conducting means is 
attached for controlling the actuation of the device in response to the 
application of force to the outer sheath. At least one end plug is 
complementarily positioned within the gap between the first end of the 
switch means and the first end of the outer sheath for sealing the first 
end of the outer sheath. The plug has a passageway formed therethrough. 
The electrical conducting means extends through and is positioned within 
the passageway such that the electrical conducting means is securely 
retained within the passageway.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Certain terminology is used in the following description for convenience 
and is not limiting. The words "right," "left," "lower," and "upper" 
designate directions in the drawings to which reference is made. The words 
"inwardly" and "outwardly" refer to directions toward and away from, 
respectively, the geometric center of the sensing edge and designated 
parts thereof. The terminology includes the words above specifically 
mentioned, derivatives thereof and words of similar import. 
Referring to the drawing in detail, wherein like numerals indicate like 
elements throughout, there is shown in FIG. 1, a building wall 10 having a 
doorway 12 provided with a door 14. While the door 14 illustrated is an 
overhead door having a sensing edge 16 in accordance with the present 
invention along its lower side or leading edge 18, it is within the spirit 
and scope of the invention to incorporate the sensing edge 16 described 
hereinafter along any edge of any door structure, such as vertically 
disposed or horizontally movable doors (not shown), as desired. 
Referring now to FIG. 2, the sensing edge 16 extends substantially along 
the entire leading edge 18 of the door 14. The sensing edge 16 is 
comprised of an outer casing or sheath 20 of an elongate, generally 
constant cross-sectional outline configuration, extending closely along 
the leading edge 18 of the door 14. That is, the sheath 20 extends along 
an axis extending generally parallel to the leading door edge 18. In the 
presently preferred embodiment, the sheath 20 is generally of oval or 
elliptical cross-section, but may be of any other suitable cross-sectional 
shape, such as circular, semicircular, rectangular or square (not shown). 
The sheath 20 includes a first wall 24 and a second wall 26 which is 
generally U-shaped in cross-section. The first wall 24 has a first end 24a 
and a second end 24b. The second wall 26 has a first end 26a and a second 
end 26b. In the preferred embodiment, the first end 24a of the first wall 
24 is connected to the first end 26a of the second wall 26, and the second 
end 24b of the first wall 24 is connected to the second end 26b of the 
second wall 26 to form a generally continuous sheath. However, it is to be 
understood by those skilled in the art that any number of walls could be 
used to make up the sheath, such as, but not limited to, one or three or 
more walls. The ends of the first and second walls may be integrally 
connected to one another, such as by soldering or the sheath can be formed 
as one unit, such as by injection molding or blow molding. 
The first wall 24 includes an interior surface 150a and an exterior surface 
150b. The second wall 26 also includes an interior surface 152a and an 
exterior surface 152b. The interior surfaces 150a, 152a of the first and 
second walls 24, 26 at least partially define an area 28 for receiving at 
least a portion of a switch means 30, described hereinafter. The first 
wall 24 includes a first portion 32 fabricated of a first material and 
second portion 34 fabricated of a second material. The first material is 
preferably more flexible than the second material. In the preferred 
embodiment, the first material is preferably a flexible air impervious 
material, such as Santoprene 101-55 made by Monsanto. The second material 
is preferably Santoprene 103-50 also made by Monsanto. The second wall 26 
can also fabricated of the first material such that it is compressible 
upon application of an external pressure, such as engagement with an 
obstructing article. However, it is to be understood by those skilled in 
the art that the second wall could be fabricated out of a different 
material than the first portion 32 of the first wall 24. 
The first wall 24 further includes first and second protruding means which 
extend from the exterior surface of the first wall 24 for receiving an 
edge 18 of the door 14. In the preferred embodiment, the first protruding 
means is a first mounting wall 36 and the second protruding means is a 
second mounting wall 38. The first and second mounting walls 36, 38 are 
preferably fabricated of the second material. In the preferred embodiment, 
the first mounting wall 36 extends further away from the second wall 26 
than the second mounting wall 38. The first mounting wall 36 is preferably 
generally parallel to and spaced apart from the second mounting wall 38 a 
sufficient distance for complementarily receiving the door edge 18. As 
discussed above, the first and second mounting walls 36, 38 can be 
received by any edge of the door, depending upon the type of door upon 
which the sensing edge 16 is being mounted. 
The first mounting wall 36 extends outwardly from the first wall 24 for 
engagement with the door 14. In the present embodiment, the first mounting 
wall 36 abuts one surface, preferably the interior surface, of the door 
14. The first mounting wall 36 includes at least one slot 42 such that a 
fastener 44 can be adjustably positioned through the slot 42 and into 
engagement with the door 14 for adjustably mounting the sensing edge 16 on 
the door edge 18. In the preferred embodiment, the slot 42 which is best 
shown in FIG. 4, is preferably generally oblong in shape, but may be of 
any other suitable shape, such as circular, square, rectangular or 
hexagonal (not shown). The fastener 44 is preferably a screw, but can be 
any type of suitable fastener, such as a bolt, nail or tack. 
Preferably, a plurality of slots 42 are equally spaced along the entire 
length of the sheath 20. It is understood by those skilled in the art, 
that the present invention is not limited to any particular number or 
spacing of slots 42 in the first mounting wall 36. It is further 
understood that the present invention is not limited to locating the slots 
42 in any particular configuration or any particular orientation in the 
first mounting wall 36. For instance, the slots 42 could be located such 
that the length of the slot is perpendicular to the first wall 24 or the 
slot 42 could be orientated such that the length of the slot 42 is 
parallel with the first wall 24. Further, the slots 42 could be located in 
both the first mounting wall 36 and the second mounting wall 38 without 
departing from the spirit and scope of the invention. Likewise, the slots 
42 could be located only in the second mounting wall 38. 
Further referring to FIG. 2, a pair of flexible members 46 extend from the 
exterior surface of the second wall 26 away from the door 14 and toward 
one another. In the present embodiment, the flexible members 46 are 
preferably fabricated of the first material. Each flexible member 46 has 
an inner surface and outer surface, a first end connected to the exterior 
surface of the second wall 26 and a second end. 
In the preferred embodiment, the flexible members 46 gradually decrease in 
thickness from the first end adjacent to the second wall 26 to the 
opposite, second end. However, the flexible members could alternatively 
increase in thickness from the first end to the second end or could be 
uniform in thickness. It is to be understood by those skilled in the art 
that the flexible members are directed toward one another either in a 
generally arcuate manner or the flexible members 46 could be straight and 
angled toward one another. The flexible members 46 are preferably 
constructed to be sensitive enough to allow the sensing edge 16 to detect 
an obstructing article but flexible enough to abut an adjacent surface 
(not shown) when the door 14 is in a closed position without actuating the 
sensing edge. 
When the door 14 is in a closed position, the flexible members 46 bend 
toward one another as illustrated in FIG. 5 and form a seal between the 
sensing edge and the adjacent surface. The seal prevents air currents from 
entering or exiting through the gap created between the door edge 18 and 
the surface. This is desirable to the owner in terms of energy costs and 
efficiency by preventing the escape of heated or cooled air. In addition, 
the flexible members 46 are capable of forming a tight seal beneath the 
sensing edge 16 without causing the switch means to be actuated. That is 
the flexible members 46 apply minimal pressure to the sensing edge 16 when 
the door is in a closed position. This results in increasing the life of 
the sensing edge because the switching means is not mechanically actuated 
each time the door is placed in the closed position. 
At least one groove 48 is positioned each of the flexible members 46 to 
increase the flexibility of each flexible member 46. In the present 
embodiment, the groove 48 is positioned on the inner surface or facing 
surfaces of the flexible members 46. However, it is understood by those 
skilled in the art, that the grooves 48 may be eliminated or that the 
grooves 48 may be positioned on the outer surface of the flexible members 
46 if desired. 
It is understood by those skilled in the art, that the present invention is 
not limited to any particular number of grooves 48 in the flexible members 
46. It is further understood that the grooves 48 can be of any particular 
shape, such as V-shaped, semicircular shaped or any other suitable shape 
without departing from the spirit and scope of the invention. 
Now referring to FIGS. 2 and 3, an end wall 50 (only one shown) closes and 
seals each end of the sheath 20 to thereby form the enclosed area 28 for 
receiving at least a portion of a switch means for actuation of a device 
(not shown) upon application of external pressure to the sheath 20. 
Alternatively, it is to be understood by those skilled in the art that an 
end plug could be used instead of the end wall 50 to seal each end of the 
sheath 20. 
The switch comprises a first sheet of resiliently compressible material 52 
which is positioned within the area 28 and includes a first face and a 
second face. The first face of the first sheet of resiliently compressible 
material 52 is in engagement with the interior surface of the first wall 
24. 
In the present embodiment, it is preferred that the first sheet of 
resiliently compressible material 52 and succeeding layers and sheets 
described hereinafter, be generally sized to complement the internal 
configuration of the area 28. However, it is understood by those skilled 
in the art, that the first sheet of resiliently compressible 52 and 
succeeding layers and sheets can be sized as wide or narrow as desired, 
and may be of any desired length for accommodating different structures 
and uses. 
In the present embodiment, it is preferred that the first sheet of 
resiliently compressible material 52 be constructed of generally soft foam 
rubber. It is understood by those skilled in the art, that the first sheet 
of resiliently compressible material 52 can be constructed of either 
closed or open-cell foam rubber or other material having similar 
properties. 
Just below (when viewing FIGS. 2 and 3) the first sheet of resiliently 
compressible material 52 is a first sheet of flexible electrically 
conductive material 54, engaged therewith, and having a first face and a 
second face. The first face of the first sheet of flexible, electrically 
conductive material 54 is in engagement with the second face of the first 
sheet of resiliently compressible material 52. In the present embodiment, 
it is preferred that the first sheet of flexible, electrically conductive 
material 54 be generally thin and preferably be constructed of aluminum or 
aluminum foil. However, it is within the spirit and scope of the invention 
to construct the first sheet of flexible, electrically conductive material 
54 of other conductive materials, such as copper, brass or an alloy 
thereof. 
As shown in FIG. 3, an electrical conductor or wire 56 is electrically 
connected to the first sheet of flexible, electrically conductive material 
54 preferably by soldering at one end thereof. The electrical conductor 56 
is used in connection with a circuit (not shown) for controlling the 
actuation of the device, as it is understood by those skilled in the art, 
in response to the application of force to the sheath 20, as described 
hereinafter. 
The first sheet of flexible, electrically conductive material 54 is in 
engagement with a layer of non-conductive material 58 having a first face 
and a second face for spacing apart the first sheet of flexible, 
electrically conductive material 54 and a second sheet of flexible, 
electrically conductive material 60. The layer of non-conductive material 
58 has a least one opening extending therethrough between the first and 
second faces thereof. As shown in FIG. 3, the layer of non-conductive 
material 58, preferably includes a plurality of openings 62 interspersed 
therealong for allowing the actuation of the switch (not shown) by 
applying pressure thereto, as described hereinafter. In the present 
embodiment, it is preferred that the openings 62 be generally oval shaped 
in cross-section. However, it is within the spirit and scope of the 
invention to configure the openings 62 to be of any geometric shape, such 
as square or circular. 
The layer of non-conductive material 58 is preferably constructed of 
generally soft foam rubber. It is understood by those skilled in the art, 
that the layer of non-conductive material 58 can be constructed of either 
closed or open-cell foam rubber or other materials having similar 
properties, so long as the function of the switch is achieved, as 
described hereinafter. 
The layer of non-conductive material is in engagement with the second sheet 
of flexible, electrically conductive material 60 having a first face and a 
second face. The first face of the second sheet of flexible, electrically 
conductive material 60 is in engagement or corresponding facing 
relationship with the second face of the layer of non-conductive material 
58. 
In the present embodiment, it is preferred that the second sheet of 
flexible, electrically conductive material 60 be constructed of the same 
material and configuration as the first sheet of flexible, electrically 
conductive material 54. Similarly, the second sheet of flexible, 
electrically conductive material 60 is connected to an electrical 
conductor or wire 64 for connection with the circuit for controlling the 
actuation of the device in response to the application of force to the 
sheath 20. 
In engagement with the second sheet of flexible, electrically conductive 
material 60 is a second sheet of resiliently compressible material 66 
having a first face and a second face. The first face of the second sheet 
of resiliently compressible material 66 is in engagement or corresponding 
facing relationship with the second face of the second sheet of flexible, 
electrically conductive material 60. The second face of the second sheet 
of resiliently compressible material 66 is in engagement with the inner 
surface of the lower portion of the second wall 26. 
The second sheet of resiliently compressible material 66 is preferably 
constructed of the same material and configured generally identically to 
the first sheet of resiliently compressible material 52. However, it is 
apparent to those skilled in the art, that the first and second sheets of 
resiliently compressible material 52, 66 can differ in configuration, size 
and/or material. 
As shown in FIG. 3, the first and second sheets of flexible, electrically 
conductive material 54, 60, are spaced apart by the layer of 
non-conductive material 58 and present equal portions to each other 
through the openings 62. Upon the application of force to the sheath 20, a 
portion of at least one of the first and second sheets of flexible, 
electrically conductive material 54, 60 deflects into at least one of the 
openings 62 in the layer of non-conductive material 58, and makes 
electrical contact between the first and second sheets of flexible, 
electrically conductive material 54, 60 to thereby close or open an 
electrical circuit to actuate the device. 
The sensing edge 16, described above, is preferably attached to the edge 18 
of the door 14 in the following manner. The sensing edge 16 is positioned 
on the edge 18 of the door 14 such that a portion of the exterior surface 
of the sheath 20 is in a facing engagement with the edge 18 of the door 
14, and the door 14 is positioned between the mounting walls 36, 38, 
respectively. In the preferred embodiment, the exterior surface of the 
first wall 24 is in facing engagement with the edge 18 of the door 14 and 
the width of the sensing edge generally corresponds to the thickness of 
the door so that the protruding mounting walls 36, 38 engage the 
corresponding interior and exterior door surfaces. However, it is 
understood by those skilled in the art, that any exterior surface of the 
sheath 20 could be in facing engagement with the edge 18 of the door 14. A 
fastener 44 is positioned through at least one of the slots 42 (and 
preferable in multiple slots) and into engagement with the door 14 such 
that the sensing edge 16 can move at least slightly up and down with 
respect to the door edge 18. That is, it is preferred that the fastener be 
mounted in the door 14 such that the first mounting wall 36 can be 
adjustably positioned with respect to the door. The door 14 is then 
positioned in a generally closed position. The sensing edge 16 is adjusted 
along the length of the door edge 18 so that the sensing edge 16 fills any 
gap between the door edge and an adjacent surface (not shown). Typically, 
the gap formed between the door edge 18 and the adjacent surface is not 
uniform in width along its length because the adjacent surface is not 
always level. This can be caused by the surface being located on an 
inclination or by the surface being uneven. It is understood by those 
skilled in the art that the surface is preferably the ground, that can be 
a floor or any other suitable surface. The position of the sensing edge 16 
is adjusted relative to the door 14 so that the flexible members 46 are in 
complementary engagement with the surface along the entire length of the 
door. In the preferred embodiment, the flexible members 46 fold under the 
sensing edge 16 such that any gap between the surface and the door edge 18 
is completely filled without actuating the sensing edge 16. In some 
situations, it may be necessary to adjust some portions of the sensing 
edge 16 downwardly and in other situations upwardly depending upon local 
variations in the height of the adjacent surface. After the height of the 
sensing edge 16 has been adjusted along its entire length, the fastener 44 
(or plurality of fasteners) is then adjusted with respect to the door 14 
so that the position of the sensing edge 16 with respect to the door 14 is 
fixed. In the present embodiment, it is preferred that there not be 
excessive pressure on the flexible members 46 by the surface when the door 
14 is in a closed position so that the sensing edge 16 is not actuated 
when engaging the surface. 
Referring to FIGS. 6 and 7, there is shown a sensing edge 16 in accordance 
with an alternate embodiment of the present invention in which an end plug 
70 is used to seal a first end 23 of the outer sheath 20. The end plug 70 
is complementarily positioned within a gap (not shown) formed between a 
first end 51 of the switch means and the first end 23 of the sheath 20. 
The end plug 70 is shaped so that its outer periphery conforms with the 
interior surface of the first wall 24 and the second wall 26 of the outer 
sheath 20. It is to be understood by those skilled in the art that the 
shape of the end plug 70 is dictated by the shape formed by the interior 
surfaces of the first and second walls 24,26 of the outer sheath 20 and 
can be designed to fit any shaped gap. The end plug 70 is sized and shaped 
to completely fill the gap so that a tight seal is formed to prevent 
fluids from passing therethrough. 
In the preferred embodiment, the plug 70 is retained within the gap by 
applying an adhesive (not shown) to the exterior surfaces of the top 
portion 72 and the bottom portion 80 of the end plug 70. The end plug 70 
is preferably fabricated of a generally flexible material, such as a PVC, 
but can also be fabricated of Santoprene made by Monsanto or a combination 
of PVC and neoprene. Accordingly, it is understood by those skilled in the 
art that the end plug can be constructed of many different materials, 
including non-polymeric materials, such as wood or metal, without 
departing from the spirit and scope of the invention. 
The end plug 70 comprises a top portion 72 having a first face 74 which is 
placed in facing engagement with the interior surface of the first wall 24 
of the outer sheath 20. A second face 76 of the top portion 72 of the end 
plug 70 includes a main groove 78 which is generally parallel with the 
longitudinal axis of the sheath 20 and extends the entire length of the 
top portion 72. In the preferred embodiment, the main groove 78 includes 
two additional grooves 78a (only one is shown) which intersect the main 
groove 78 and extend in opposite directions from the main groove 78. The 
two additional grooves 78a and the main groove 78 are generally 
semi-circular in cross-section and form generally semi-circular openings 
in the side surfaces 75, 77 of the end plug 70. It is to be understood by 
those skilled in the art that the openings formed by the main groove 78 
and the additional grooves 78a can be constructed to have many different 
cross-sectional shapes such as, but not limited to being triangular or 
rectangular in cross-section without departing from the spirit and scope 
of the invention. 
The end plug 70 also includes a bottom portion 80 having a first face 82 
which complementarily engages the interior surface of the second wall 26 
of the outer sheath 20. A second face 84 of the bottom portion 80 of the 
end plug 70 has a main groove 86 which is complementary to the main groove 
78 in the top portion 72 of the end plug 70. The second face 84 of the 
bottom portion 80 also includes two additional grooves 86a, 86b which 
intersect the main groove 86 and extend in opposite directions therefrom. 
The grooves 86, 86a, 86b are generally semi-circular in cross section. 
When the end plug 70 is assembled, the top portion 72 and the bottom 
portion 80 are secured together such that the grooves 78, 78a in the top 
portion 72 are placed in facing engagement with the grooves 86, 86a, 86b 
of the bottom portion. When the top portion 72 and the bottom portion 80 
of the end plug 70 are engaged as shown in FIG. 6, the complementary main 
grooves 78, 86 form a passageway 88 which extends through the end plug 70 
and forms a generally circular opening 90. It is to be understood by those 
skilled in the art that the opening 90 may be formed in any portion of the 
end plug 70 including the side surfaces 75, 77 of the end plug 70. 
The top portion 72 and the bottom portion 80 of the end plug 70 are 
preferably secured to one another by an adhesive. It is understood by 
those skilled in the art that the top portion 72 and the bottom portion 80 
of the end plug 70 can be secured to one another by other means such as a 
standard fastener or cooperating interlocking elements which permit the 
top and bottom portions 72, 80 to be snapped together. 
Referring now to FIG. 7, electrical wires 56, 64 are connected to the 
switch means and extend through the passageway 88 formed within the end 
plug 70. In the preferred embodiment, the electrical wires 56, 64 are 
connected to the first sheet of electrically conductive material 54 and 
the second sheet of electrically conductive material 60 by standard crimp 
connectors 96 which clamp onto the sheets. It is to be understood by those 
skilled in the art that the electrical wires 56, 64 can be attached to the 
switch means in any conventional manner, including, but not limited to, 
being soldered onto the sheets or by means of a clamp. A portion of the 
electrical wires 56, 64 are encased in a cable 94 which is complementarily 
sized so as to be fixably received within the passageway 88. In the 
preferred embodiment, the cable 94 is adhesively secured to the bottom 
portion 80 of the end plug 70, however, the cable 94 can be secured within 
the passageway 88 by any suitable means, such as, a snap fit or by 
friction. 
As discussed above, the cable 94 extends through the passageway 88 and is 
connected to a power source (not shown). An insulating ring 98 acts as a 
sealing means to provide a tight seal at the point where the cable 94 
extends through the opening 90 of the passageway 88. The insulating ring 
98 acts to form a seal between the cable 94 and the passageway 88 to 
prevent the entry of water and small particles, such as dust, into the 
passageway 88 of the end plug 70 which could affect the switch means. The 
insulating ring is seated in an indent 97 in the end plug 70 which is 
located proximate to the opening 90 of the passageway 88. 
As discussed above, in addition to the main passageway 88, there exist four 
additional grooves 78a, 86a, 86b which form two auxiliary passageways 
which extend in opposite directions from the main passageway 88. In a case 
such as described above, the cable 94 extends through the main passageway 
88 and opening 90 of the end plug 70. However, the cable 94 can also 
extend through one of the auxiliary passageways (not shown). For instance, 
in the event that there is not enough space between the edge of the door 
14 and the doorway 12, the cable 94 will not be able to exit from the main 
passageway 88. If an auxiliary passageway is used, a hole equal to the 
size of the opening of the chosen passageway must be made in a portion of 
the outer sheath 20 corresponding to the position of the auxiliary 
passageway opening. In the preferred embodiment, the auxiliary passageway 
facing the inner surface of the door 14 would be chosen to prevent 
tampering with the electrical wires 56, 64 of the sensing edge 16 by a 
possible intruder. 
In order to prevent the entrance of liquids and small particles into the 
auxiliary passageways of the end plug 70, a blocking means in the form of 
a stopper 104 is placed in the opening of each unused passageway. The 
stopper 104 is sized so as to be fixedly received by the opening of the 
auxiliary passageway. An insulating ring 98 is securely placed around the 
outer circumference of each stopper 104 in order to provide a tight seal 
within the auxiliary passageway. The insulating ring 98 is seated in an 
indent 97 which is located proximate to the opening of each auxiliary 
passageway. 
The end plug 70 is assembled and attached to the sensing edge 16 in the 
following manner. The switch means 30 is placed within the outer sheath 20 
such that a gap is formed between the first end of the switch means 51 and 
the first end of the outer sheath 23. A pair of electrical wires 56, 64 
are attached to the switch means 30 by crimp connectors 96. The electrical 
wires are partially encased in an insulated cable 94. An insulating ring 
98 is placed around the outer circumference of the cable 94. An adhesive 
is applied to a portion of the cable 94. The cable 94 is secured within 
the main groove 86 of the bottom portion 80 of the end plug 70 such that 
the insulating ring 98 is received by an indent 97 located within the plug 
70. The cable 94 is secured within the main groove 78 by a friction fit. 
A stopper 104 is placed in the opening of each auxiliary groove 86a, 86b of 
the bottom portion 80 of the end plug 70. An adhesive is applied to the 
second face 76 of the top portion 72 of the end plug 70 and is attached to 
the second face 84 of the bottom portion 80 of the end plug 70 such that 
the grooves 78, 86 are complementarily aligned to form a passageway 88. An 
adhesive is applied to the outer surfaces of the end plug 70. The 
assembled end plug 70 is inserted within the gap such that the outer 
surfaces of the end plug 70 are adhered to the inner surfaces of the first 
wall 24 and the second wall 26 of the outer sheath 20. 
The end plug 70 acts to secure the electrical wires 56, 64 to the switch 
means 30 so that the wires 56, 64 cannot easily be removed such as by 
tugging at the wires 56, 64 or cable 94. The end plug 70 also ensures that 
contaminants, such as fluids or small particles, do not enter the sensing 
edge 16. The end plug 70 further prevents tampering with the switch means 
30. 
From the foregoing description, it can be seen that the present invention 
comprises a sensing edge for causing a closing door to open by actuation 
of a device upon force being applied to the sensing edge. The presence of 
slots in the protruding walls which extend from the sheath allows the 
sensing edge to be adjustably positioned with respect to the door edge. In 
addition, the presence of one or more flexible members, extending from the 
sheath provide a door seal and prevent the sheath from being accidentally 
actuated when the door is in a closed position. It will be appreciated by 
those skilled in the art, that changes could be made to the embodiment 
described above without departing from the broad inventive concepts 
thereof. It is understood, therefore, that this invention is not limited 
to the particular embodiment disclosed, but is intended to cover all 
modifications which are within the scope and spirit of the invention as 
defined by the appended claims.