Non-contact switch for detecting the presence of operator on power machinery
First Claim
1. A computer-free, filterless engine cut-off switching circuit for controlling power machinery, the circuit adapted for continuously sensing the presence of an operator'"'"'s hands in the proximity of an operating zone without requiring actual contact between the operator and any portion of the machinery, the circuit of the type including an electrical power conditioner, a sensor connected to the conditioned power for activating a device operable to shut off the machinery, the switching circuit further comprising:
- a. an emitter means mounted on the machinery and emitting a broadly diffused light signal outside the visual spectrum from the machinery into an operating zone adjacent the machinery where the operator'"'"'s hand is to be positioned during operation of the machinery, said emitted light signal continuously reflected by the operator'"'"'s hand when the hand is positioned in the operating zone;
b. a modulator means connected to said emitter means modulating said emitted light signal;
c. detector means mounted on the machinery substantially adjacent said emitter means and mated electrically therewith for receiving and detecting only said modulated reflected, emitted light signal;
d. synchronizer means associated with said emitter means and said detector means for synchronizing said emitted light signal and said reflected, emitted light signal as received by said detector means;
e. non-surrounding barrier means made of radiation impervious material disposed between said emitter means and said detector means and terminating adjacent the operating zone acting only to prevent the detection of non-reflected signals; and
f. control means continuously responsive to the presence of a reflected signal for keeping the power machinery active and responsive to the lack of a reflected signal for deactivating the power machinery.
0 Assignments
0 Petitions
Accused Products
Abstract
A non-contact operator present engine cut-off switch includes an emitter for directing a radiated signal away from a control handle on power machinery and a detector positioned to receive the radiated, reflected signal from the hand of an operator in order to detect the operator presence in an operating zone to permit operation of the power machinery. The non-contact sensing circuitry may be hermetically sealed to protect the circuitry from adverse environmental conditions.
-
Citations
17 Claims
-
1. A computer-free, filterless engine cut-off switching circuit for controlling power machinery, the circuit adapted for continuously sensing the presence of an operator'"'"'s hands in the proximity of an operating zone without requiring actual contact between the operator and any portion of the machinery, the circuit of the type including an electrical power conditioner, a sensor connected to the conditioned power for activating a device operable to shut off the machinery, the switching circuit further comprising:
-
a. an emitter means mounted on the machinery and emitting a broadly diffused light signal outside the visual spectrum from the machinery into an operating zone adjacent the machinery where the operator'"'"'s hand is to be positioned during operation of the machinery, said emitted light signal continuously reflected by the operator'"'"'s hand when the hand is positioned in the operating zone; b. a modulator means connected to said emitter means modulating said emitted light signal; c. detector means mounted on the machinery substantially adjacent said emitter means and mated electrically therewith for receiving and detecting only said modulated reflected, emitted light signal; d. synchronizer means associated with said emitter means and said detector means for synchronizing said emitted light signal and said reflected, emitted light signal as received by said detector means; e. non-surrounding barrier means made of radiation impervious material disposed between said emitter means and said detector means and terminating adjacent the operating zone acting only to prevent the detection of non-reflected signals; and f. control means continuously responsive to the presence of a reflected signal for keeping the power machinery active and responsive to the lack of a reflected signal for deactivating the power machinery. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
-
-
13. An engine cut-off switching circuit for controlling power machinery, including an internal combustion engine power source of the type including a condenser coil and wherein the switching circuit is inserted in series between the condenser coil and the engine ground the circuit sensing the presence of an operator'"'"'s hand in the proximity of an operating zone without requiring actual contact between the operator and any portion of the machinery, the circuit of the type including an electrical power conditioner, a sensor connected to the conditioned power for activating a device operable to shut off the machinery, the switching circuit further comprising;
-
a. a light emitting diode mounted on the machinery and emitting a broadly diffused light signal outside the visual spectrum from the machinery into an operating zone adjacent the machinery where the operator'"'"'s hand is to be positioned during operation of the machinery, said emitted light signal continuously reflected by the operator'"'"'s hand when the hand is positioned in the operating zone; b. an optical light detector mounted on the machinery substantially adjacent said diode and electrically mated therewith for receiving and detecting only said reflected, emitted light signal; c. synchronizer means associated with said diode and said detector for synchronizing said emitted light signal and said reflected, emitted light signal as received by said detector; d. non-surrounding barrier means made of radiation impervious material disposed between said diode and said detector and terminating adjacent the operating zone acting only to prevent the detection of non-reflected signals; and e. control means continuously responsive to the presence of a reflected signal for keeping active the power machinery and responsive to the lack of a reflected signal for deactivating the power machinery. - View Dependent Claims (14, 15, 16, 17)
-
Specification