Security system with membrane switches to detect binary code on mechanical key

Security system for access control of vehicle doors, chamber doors, and enclosed areas, and further providing vehicle ignition circuit control and in car door and trunk control, said system comprising:

• (a) a key the same in all respects as a conventional key with the exception that all cuts are of the same depth and all connecting slopes are alike, wherein said cuts are on both serrated edges and represent binary bits of a digital code;
• (b) a mating structure configured to receive said key, said structure containing tumblers actuated by the insertion of said key;
• (c) switches mounted adjacent to and operated by said tumblers through a deformable elastic membrane seal, said switches providing a pattern of ON and OFF positions which translate the said key code into its electrical equivalent;
• (d) digital logic circuits which recognize said digital code by comparison with a preset code and output a control signal upon said recognition, said preset code formed by a set of mechanical switches or a programmable electronic memory;
• (e) additional logic and output circuits responsive to said output control signal that provide electrical locking, unlocking, vehicle ignition circuit control and in car door and trunk control;
• (f) said membrane seal which serves to totally enclose the contacts of said switches for protection against outside contamination;
• (g) each of said switches adjacent to said tumblers operably connected to the first input of a first digital logic circuit, with a second input of said first digital logic circuit connected to a logic one or zero as determined by said preset code, and with an output of said first digital logic circuit when the two inputs are the same;
• (h) a second digital logic circuit having inputs that are all of the outputs of the said first digital logic circuit, said second digital logic circuit providing a summation of the said inputs and producing an output that indicates said key recognition when all of the code positions of the said key match the corresponding binary code bits of the said preset code;
• (i) a master key, capable of unlocking and enabling of the ignition circuit and in car door and trunk controls, cut to one binary code, which can alternately enable and disable a second key, referred to as a valet key, said valet key cut to a different binary code, and capable of unlocking and ignition circuit control only;
• (j) a said first digital logic circuit with preset code matched to said master key and a said second digital logic circuit;
• (k) a said first digital logic circuit with present code matched to said valet key and a said second digital logic circuit;
• (l) a switch used simultaneously with insertion of said master key to cause the alternate enabling and disabling of said valet key;
• (m) a NOR digital logic circuit inputting the output of said second digital logic circuit of said master key and said switch and outputting a signal, when both inputs are present, to a toggle flip-flop circuit which alternately turns ON and OFF the digital logic circuits of the said valet key;
• and
• (n) an AND digital logic circuit inputting the output of either said second digital logic circuit of said valet key or said second digital logic circuit of said master key and outputting a signal to flip-flop circuits that cause unlocking and ignition circuit enabling for either the said master key or the said valet key, but only the said master key has a bypass of said AND circuit that enables the in car door and trunk controls.