An outrigger arm assembly to prevent a would-be intruder from successfully climbing over a fence. The outrigger arm assembly is mounted on top of the fence. Each hollow fence post is interconnected to a hollow outrigger arm by a replaceable collar which breaks when a load in the range of 20 to 30 pounds is applied to the outrigger arm, resulting in the downward movement of the outrigger arm, and the fall of the climber. The assembly also includes a movement sensor, within the hollow arm, which is activated and provides an alarm signal, when the outrigger arm is moved more than a predetermined number of degrees, such as the downward movement of the outrigger arm. The assembly further includes a coiled spring, positioned within the hollow fence post and extending into the hollow outrigger arm, by which the arm is automatically returned to its original defensive position, after the load is removed.

BACKGROUND OF THE INVENTION 
This invention relates to fences and, more particularly, to an outrigger 
arm assembly adapted for use with hollow upright fence posts. 
It is well-known in the fence art, as well as in the security field, that 
an extension (i.e., outrigger arms) mounted on top of, and angularly 
inclined and outward from, fence structures constitutes a psychological 
obstacle, rather than a real physical obstacle, to a would-be intruder who 
is intent on climbing the fence upon which the extension is mounted. This 
is so, even if the fence is chain-link fabric (or barbed wire), and if the 
extension is stranded transversely by and with barbed wire, and also if 
the fence is eight feet or more in height (i.e., a height which 
necessitates that a would-be intruder must be off the ground before he 
reaches the outrigger arms). In fact, it is equally well-known that the 
outrigger is actually used by skilled climbers as a tool to climb over the 
fence. 
Therefore, what is needed in the art, and is not presently available, is 
structural means to enhance the effectiveness of an outrigger in deterring 
a determined fence climber. 
I have invented such a structural means (which I refer to herein as a 
"break-away outrigger" or as "an outrigger arm assembly"); and, thereby, I 
have significantly advanced the state-of-the-art. 
SUMMARY OF THE INVENTION 
My invention, as adapted for use with a fence structure, is a break-away 
outrigger, i.e., an outrigger arm assembly which will break away from the 
fence structure when a load of preselected quantity is applied (e.g., the 
pulling action of a climber holding on the outrigger arm and/or the 
transversely positioned barbed wire connected thereto), whereby the 
climber, most probably, will fall off the outrigger and/or the fence, or 
at the very least will become entangled in the barbed wire of the 
outrigger. 
Accordingly, the principal object of this invention is to teach the 
structure of such a unique break-away outrigger (i.e., outrigger arm 
assembly). 
Another object of this invention is to provide means for the self-return of 
the outrigger defensive position or posture (i.e., angularly inclined and 
outward from the fence), after the outrigger has broken away from the 
fence and the load is removed from the broken-away outrigger. 
Still another object of this invention is to provide means for sensing 
movement of the break-away outrigger, whether the outrigger is broken away 
or not, whereby an alarm will result from the movement, and thereby 
alerting others, such as security personnel, of the movement and of the 
attempt of the climber to scale the outrigger. 
These objects, as well as other related objects, of this invention will 
become readily apparent after a consideration of the description of my 
invention, together with reference to the contents of the drawing.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
With reference to the drawing, shown therein in simplified form, is a side 
elevation view of a preferred embodiment 10 of my inventive outrigger arm 
assembly. To better orient and assist the reader the directional 
designations "front-outside," "back-inside," "up" and "down" are shown, 
together with their respective arrows. 
As shown in the drawing, the preferred embodiment 10 comprises: a hollow 
outrigger arm 11 in the form of an upright portion 12 and an inclined 
portion 13, wherein the upright portion 12 has a top end 12A and a bottom 
end 12B, and the inclined portion 13 has a first end 13A second end 13B, 
an upper external surface 13C, and a lower external surface 13D; means, 
generally designated 20, connected to the lower external surface 13D of 
the inclined portion 13 of the hollow outrigger arm 11, for holding and 
supporting a plurality of wires (preferably barbed wires), such as 
representative wires 21A, 21B and 21C, that are strung transverse to the 
inclined portion 13; means, generally designated 30, associated with the 
inclined portion 13 of the hollow outrigger arm 11, for sensing movement 
of this inclined portion 13; means, generally designated 40, associated 
with hollow upright fence post 100 and with the hollow outrigger arm 11, 
for maintaining the hollow outrigger arm in a preselected positional 
relationship with and to the hollow upright fence post (i.e., angularly 
inclined and outward from and to the front of the fence post 100); and, 
means, generally designated 50, for releasably holding together and 
supporting the top end portion 100A of the hollow upright post 100 and the 
bottom end 12B of the upright portion 12 of the hollow outrigger arm. 
The wires holding and supporting means 20 may comprise, and preferably 
does, a plurality of hooks, one hook for each wire, such as representative 
hooks 22A (for wire 21A), 22B (for wire 21B) and 22C (for wire 21C). The 
hooks 22A, 22B and 22C are connected, in spaced-apart relationship, to the 
lower external surface 13D of the inclined portion 13 of the hollow 
outrigger arm. 
The movement sensing means 30 comprises, and preferably is, either one of 
two types of commercially readily available movement sensors, either 
electric or electronic. The sensor, such as 31, is positioned within the 
inclined portion 13 of the hollow outrigger arm 11, and is so disposed 
that it is activated when the inclined portion 13 is moved a predetermined 
number of degrees, .theta., from the normal (i.e., usual) angular 
inclination of the inclined portion 13. One type of such a commercially 
available movement sensor will ring a loud, sound alarm, thereby alerting 
security personnel and others. Another type of commercially available 
sensor is linkable to a display device, with or without connecting wires, 
which can be positioned at a central security or surveillance facility, 
and when this type of movement sensor is activated, a sight (video) and/or 
sound (audio) alarm signal is provided at the display device. 
The hollow outrigger arm-hollow upright fence preselected positional 
relationship maintaining means 40 may comprise, and preferably is, a 
coiled spring 41 disposed within the hollow outrigger arm 11 and within 
the top end portion 100A of the hollow upright fence post 100. 
The releasable holding (together) and supporting means 50 for the top end 
portion 100A of the hollow upright fence post 100 and the upright portion 
12 of the hollow outrigger arm 11 may comprise, and preferably is, a 
collar 51 that is fitted over and holds together the top end portion 100A 
of the hollow upright fence post 100 and the upright portion 12 of the 
hollow outrigger arm 11. The collar 51 is made of material that breaks 
when a load, such as "L," a preselected quantity (preferably in the range 
of 20 to 30 pounds) is applied to the inclined portion 13 of the hollow 
outrigger arm 11 (or to any of the transversely stranded wires 21A or 21B 
or 21C). It is here to be noted that this easily breakable collar 51 is 
equally easily replaceable. 
MANNER OF OPERATION OF THE PREFERRED EMBODIMENT 
The manner of operation of the preferred embodiment 10 of my inventive 
break-away outrigger (i.e., outrigger arm assembly) can be ascertained 
very easily by a person of ordinary skill in the art from the foregoing 
description, together with reference to the contents of the drawing. 
For others, it is sufficient to say in explanation, that what occurs, in 
sequence, is as follows: A climber-intruder climbs the fence having a 
plurality of fence posts, such as 100, and mounted upon the fence, a 
plurality of my outrigger arm assemblies, such as 10, one for each fence 
post; and, at some time during the climb, the would-be intruder must reach 
one of my outrigger arm assemblies 10. When he grabs the inclined portion 
13 of the arm 11 and/or the wires 21A, 21B or 21C, the collar 51 breaks, 
and he is unable to climb over the outrigger. In addition, when the collar 
51 breaks, and the arm 11 is pivoted, or is otherwise moved downwardly, 
the movement sensor 31 is activated and gives off the alarm. After the 
climber lets go of the inclined portin 13 and/or of the wires 21A, 21B or 
21C, the coiled spring 41 returns the outrigger to the defensive posture 
(i.e., the original position, as shown in the drawing). The broken collar 
51 may be easily replaced thereafter. 
CONCLUSION 
It is abundantly clear from all of the foregoing, and from the contents of 
the drawing, that the stated and desired principal object, as well as the 
other objects, of my invention, have been attained. 
It is to be noted that, although there have been described the fundamental 
and unique features of our invention as applied to a particular preferred 
embodiment, various other embodiments, adaptations, substitutions, 
additions, omissions, and the like may occur to, and can be made by, those 
of ordinary skill in the art, without departing from the spirit of my 
invention.