Patent Publication Number: US-6209262-B1

Title: Obstruction sensing system for a gate

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates in general to a sensing system for a gate and more specifically to a sensing system that is applied to the vertical leading edge of a gate. 
     2. Description of the Prior Art 
     There are many devices on the market that sense an object being in the path of a closing gate or closing garage door that will take corrective action. The requirement for the above stems from the a 1995 Federal mandate that governs the parameters of safety devices installed on residential garage doors which must be fail-safe, therefore, the automatic garage door must reverse itself without producing a force that would injure. Recently, the same requirement has been imposed on automatic gates. Some of the patents on sensing edges are: 
     1. U.S. Pat. No. 5,066,835 to Miller et al. This patent has a sensing edge with a switch assembly positioned thereon. 
     2. U.S. Pat. No. 5,027,552 to Miller et al. This patent includes a proximity sensing switch that detects a change in capacitance to actuate the device that controls a door. 
     3. U.S. Pat. No. 5,299,387 to Miller et al describes a sensing edge for a gate. Two layers of conducting material are spaced apart such that a force on the gate edge will cause the conducting material to contact and close a circuit. 
     4. U.S. Pat. No. 5,964,058 to Richardson describes an electrosensing edge for a garage door. A cable on the bottom edge is moved when the bottom edge strikes an object and thereby actuates switches attached to the ends of the cable. 
     U.S. Pat. No. 5,079,417 to Strand describes a photocell beam shining through the door edge and if an object blocks the beam, the photo switch provides a signal to reverse the motion. 
     What is needed, is an inexpensive device that uses mechanical means to activate a switch whereby the force can be multiple directional. 
     From the foregoing, the need should be appreciated for an inexpensive and simple gate sensing system. Accordingly, a fuller understanding of the invention may be obtained by referring to the Summary of the Invention, and the Detailed Description of the Preferred Embodiment, in addition to the scope of the invention defined by the claims taken in conjunction with the accompanying drawings. 
     SUMMARY OF THE INVENTION 
     It is the object of the present invention to provide a novel sensing edge for an automatic gate. 
     It is another object of the present invention to provide a sensing edge that can be activated in multiple directions. 
     It is yet another object of the present invention where the activation of the sensing edge will provide a signal to be transmitted to the gate mechanism. 
     It is still another object of the present invention where the activation of the sensing edge will directly provide an input signal to the gate mechanism. 
     Briefly, in accordance with the present invention there is providing a sensing edge that is mounted on the vertical edge of a powered gate. If the gate edge encounters an object in its path, a pressure of three to five pounds on the gate edge will activate the gate mechanism. The edge is designed such that any object in the gate path on the front, right or left side will activate the gate mechanism. 
     The novel features which are believed to be characteristics of the invention, both as its organization and its method of operation, together with further objects and advantages thereof, will be better understood from the following description in connection with the accompanying drawings in which a presently preferred embodiment of the invention is illustrated by way of example. It is to be expressly understood, however, that the drawings are for purposes of illustration and description only, and are not intended as a definition of the limits of the invention. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     In the drawings which illustrate the best mode presently contemplated for carrying out the present invention: 
     FIG. 1 shows a partial view of a gate with the sensing system attached to the leading edge of the gate. 
     FIG. 2 shows a switch box including the switch mechanism required to control the movement of the gate. 
     FIG. 3 shows the principle behind the gate sensing system. 
     FIG. 4 shows an alternate way to send a signal to the gate control mechanism. 
    
    
     These and other objects, features and advantages of the present invention will become more readily apparent upon detailed consideration of the following Description of the Preferred Embodiment with reference to the accompanying drawings. 
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Turning now to FIG. 1 there is seen a gate generally described as  10 . The gate has an opening and closing mechanism (not shown) that is powered. Attached to the leading edge  12  of the gate  10  is a plate  14  fastened by any acceptable fastening means. Fastened to the plate  14  are lower ball retaining members  16  and  18  held by fastening means  17  and  19 . On the top of the lower ball retaining members  16  and  18  are round balls  20  and  22 . The balls  20  and  22  may be made from any hard material such as metal or plastic. A rectangular tube  24  is used to conform to the shape of the leading edge of the gate. Fastened inside of the tube  24  are upper ball retaining member  26  and  28 . The fastening members are shown as  30  and  32 . The tube  24  is held in place on balls  20  and  22  by gravity. On the top of tube  24  is fastened a plate  34  which is more clearly seen in FIG.  2 . 
     FIG. 2 shows the plate  34  which is fastened to the top of tube  24 . Also seen in FIG. 2 is a switch box  36  that is fastened to plate  14  by fastening means  38  and  40 . As seen in the cut away of FIG. 2, the switch box contains a snap action switch  42  that operates when plate  34  moves in an upward direction. Roller  43  moves on top of plate  34  when plate  34  moves in an upward direction. FIG. 2 also shows a waterproof cover  37  fixed on the top of switch box  36 . 
     FIG. 3 shows the principle utilized in the sensing system in the present invention. As the force  44  is applied to an upper ball retaining member, either  26  or  28 , since the lower ball retaining members are fastened to the gate through plate  14  and the upper ball retaining members  26  and  28  are fastened to the tube  24 , the upper ball retaining members  26  and  28  will ride up the balls  20  and  22  and move the upper ball retaining members  26  and  28  in an upward movement. Since the upper ball retaining members  26  and  28  are fastened to tube  24 , the plate  34  fastened to the top of tube  24  will move upward and activate switch  42 . The action of switch  42  will complete a circuit and send a signal through wires  46  and  48  to transmitter  50  as seen in FIG.  1 . The transmitter  50 , in turn, will send a signal to the gate control mechanism (not shown) and the signal will either stop the gate control mechanism or reverse the gate control mechanism depending on how the gate control mechanism is configured which in turn depends on the safety requirement of the gate installation. 
     FIG. 4 shows an alternate method to send a signal to the gate control mechanism. The hard wire  54  directly sends a signal to activate the gate control mechanism. The hardwire can either be a curly wire or be in a spring retraction reel (not shown). As an option the leading edge of the tube  24  may have a rubber channel  25  fixed thereon. 
     Thus, it is apparent that there has been provided in accordance with the invention, a sensing edge for a gate that fully satisfies the objectives, aims, and advantages set forth above. While the invention has been described in conjunction with specific embodiment thereof it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the aforegoing descriptions. Accordingly, it is intended to embrace all such alternatives, modifications, and variations that fall within the spirit and scope of the appended claims.