Multiple switch control system

• US 4,785,194 A
• Filed: 03/12/1987
• Issued: 11/15/1988
• Est. Priority Date: 04/02/1986
• Status: Expired due to Term

• Current Assignee: Izumi Corporation Industries Incorporated
• Original Assignee: Izumi Corporation Industries Incorporated
• Inventors: Gottlieb, Morton S.
• Primary Examiner(s): Shoop, Jr., William M.
• Assistant Examiner(s): IP, SHIK LUEN PAUL
• Application Number:
  US07/025,190
• Time in Patent Office: 614 Days
• Field of Search: 307/9, 307/10 R, 307/115, 74/552, 74/558, 74/484 R, 74/484 H, 74/473 SW, 364/424, 340/22, 340/572, 340/573, 340/51, 340/52 R, 340/52, 200/61.54, 200/61.55, 200/61.56, 200/61.57, 200/56 R, 200/61.35
• US Class Current: 307/10.1
• CPC Class Codes: B60R 16/027 between relatively movable parts of the vehicle, e.g. between steering wheel and column devices for measuring, signalling or controlling tyre pressure or temperature specially adapted for mounting on vehicles B60C23/00
• CPC Class Codes: H01H 2239/012 Decoding impedances

Abstract

A plurality of control switches are located in the hub of a steering wheel of a vehicle. The switches are connected to a remote control distribution terminal by a single lead connector. Actuation of each switch creates a switching voltage identifiable with that switch by a control circuit in the remote control distribution network. Reference voltages of predetermined values are applied selectively to individual control circuits in a circuit network. A control circuit in the network identifies the actuation of its associated switch by comparing the value of the switch created voltage with a predetermined threshold voltage or reference and the effect of the switch created voltage value on the adjacent control circuit. Switch components are actuated for control of selected vehicle accessories.

Claims

1. A control system for controlling accessory equipment in a motor vehicle wherein control switches are located in the hub of a steering wheel of said motor vehicle remote from a control circuit network, said control system including:

(a) a source of power and a return;

(b) a first voltage divider including at least a first resistance and a common junction between said source of power and said return;

(c) a second voltage divider including at least a plurality of resistors in series connection between said source of power and said return;

(d) a plurality of substantially identical parallel circuits connected sequentially between said source of power and said return, each circuit of said plurality of circuits including a first input, a second input, a comparator, a logic gate, a switch and a load;

(e) said first input of each said circuit connected to said common junction for applying a first voltage to said comparator of each said circuit;

(f) said second input of each said circuit connected to said second voltage divider for applying a second voltage to said comparator of each circuit such that the value of said second voltage applied to the respective comparator is different from the value of that voltage applied to adjacent comparators as a function of the sequential position of the circuit along said second voltage divider;

(g) each said circuit of said plurality of circuits, except the first circuit of said plurality of circuits positioned along said second voltage divider further including one inverter, said inverter connected between the output of said comparator and one of the inputs of said logic gate of the parallel circuit in the higher adjacent position along said second voltage divider;

(h) a plurality of resistance elements equal in number to the number of circuits in said plurality of circuits and connected in parallel connection to each other and each resistance element of said plurality of resistance elements connected in series connection between said common junction and said return for changing the value of said first voltage when one or the other of said resistance elements is electrically inserted between said common junction and said return;

(i) said switch of each said circuit having a normally open condition and a closed condition, driven to a closed condition in response to an output from a logic gate of the circuit of which each component is a part, said switch for electrically closing an electric circuit to at least one acessory of said accessory equipment of said motor vehicle when said switch is in said closed condition; and

,

(j) a plurality of switch means equal in number to the number of resistance elements in said plurality of resistance elements and connected in parallel with each other and each switch of said plurality of switch means connected in series with at least one of said resistance elements of said plurality of resistance elements and each said switch of said plurality of switch means connected to said return for electrically inserting a different resistance element each into said first voltage divider for driving one circuit of said plurality of substantially identical, parallel circuits for controlling at least one accessory of said accessory equipment.

2. A control system as in claim 1 and in which said logic gate is an AND gate and said switch is a set of relay contacts, said relay contacts being driven to a closed condition by energization of a relay coil.

3. A control system as in claim 1 and in which said logic gate is an AND gate and said switch is a transistor, the output of said AND gate being applied to the base junction of said transistor for driving said transistor into a conductive state.

4. A control system as in claim 1 and in which said logic gate is a NAND gate and said switch is a semi-conductor switching element normally in an open circuit condition and driven to a closed circuit condition in response to an output from said NAND gate.