Anti-thief security sensor assembly

#1. Field of the Invention

#The present invention generally relates to an anti-thief security sensor assembly and, more particularly, to the anti-thief security sensor assembly that is used to form a part of a security system for detecting an intruder when he or she traverses across the path of travel of a detecting wave, for example, an infrared beam.

#2. Description of the Prior Art

#In any event, the present invention will become more clearly understood from the following description of a preferred embodiment thereof, when taken in conjunction with the accompanying drawings. However, the embodiments and the drawings are given only for the purpose of illustration and explanation, and are not to be taken as limiting the scope of the present invention in any way whatsoever, which scope is to be determined by the appended claims. In the accompanying drawings, like reference numerals are used to denote like parts throughout the several views, and:

#FIG. 1 is a perspective view showing a beam projecting device, which forms a part of an anti-thief security sensor assembly, according to a first preferred embodiment of the present invention, the beam projecting device being shown with a front cover removed;

#FIG. 2 is an exploded view of one of beam projectors employed in the beam projecting device shown in FIG. 1;

#Hereinafter, an anti-thief security sensor assembly according to preferred embodiments of the present invention will be described in detail.

#Referring first to FIG. 1, there is shown a beam projecting device P forming a part of an anti-thief security sensor assembly according to a first preferred embodiment of the present invention, with a front cover removed. As shown therein, the beam projecting device P is made up of a sensor casing which includes a generally rectangular mounting base 1 adapted to be fixedly secured to a support surface such as a wall of a building with its longitudinal axis oriented upwardly and downwardly, i.e., in a vertical direction, and a front cover 3 removably fitted to the mounting base 1 through a plurality of fixture holes 2 of the mounting base for protecting a sensor circuit arrangement.

#A terminal carrier casing 4, which is formed as a device body, having a plurality of terminal elements 5 is mounted on a portion of the mounting base 1 generally intermediate of the length of the latter and encloses therein an electronic circuit such as a circuit necessary to generate a beam signal to be projected. Upper and lower beam projectors 7 are mounted on respective upper and lower ends of the terminal carrier casing 4 for rotation about a vertical pivot axis (not shown) in a direction shown by the arrow h. The upper and lower beam projectors 7 are positioned in a fashion inverted relative to each other. For each of the upper and lower beam projectors 7, a respective horizontal angle adjustment knob 8 having its outer peripheral surface knurled to provide surface indentations is rotatably mounted on the corresponding end (an upper or lower end) of the terminal carrier casing 4 so that as the horizontal angle adjustment knob 8 is manually turned in a right or left direction, the respective beam projector 7 can be turned in a direction leftwards or rightwards about the vertical pivot axis to adjust the horizontal angle (the angle defined in the direction shown by the arrow h) of the corresponding beam projector 7.