Electric switches
First Claim
1. An electric switching device comprising two separate relatively movable parts, a first one of said parts including a housing having operative face means, at least two Hall effect devices fixed in the housing adjacent said operative face means and reversed in physical relationship to each other so as to be actuated by magnetic poles of opposite polarity presented against said face means, an electrical circuit including said Hall effect devices and electronic switching means having a normally conducting or non-conducting state and connected electrically to said Hall effect devices to change from said normal state to the opposite state only when all the Hall effect devices are actuated simultaneously, the other part of the device including operative face means adapted to cooperate with the face means of the first part, and a plurality of magnetic pole means fixed in position with respect to said face means for actuating respective Hall effect devices in said one part when said two parts are placed together in close proximity and with said face means cooperating with each other in predetermined spatial relationship.
1 Assignment
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Accused Products
Abstract
An electrical switching device for use on machinery to prevent machine operation unless safety guards or the like are correctly positioned comprises two separate parts one part including at least two Hall effect devices which respond to magnetic poles of opposite polarity and electronic switching means which is actuated only when all the Hall effect devices are triggered simultaneously, and the other part including a corresponding number of magnets positioned to actuate the respective Hall effect devices when the two switch parts are placed in close proximity and predetermined orientation. The switch is substantially tamper proof and a control circuit can detect any unauthorized attempt to override the switch.
91 Citations
9 Claims
- 1. An electric switching device comprising two separate relatively movable parts, a first one of said parts including a housing having operative face means, at least two Hall effect devices fixed in the housing adjacent said operative face means and reversed in physical relationship to each other so as to be actuated by magnetic poles of opposite polarity presented against said face means, an electrical circuit including said Hall effect devices and electronic switching means having a normally conducting or non-conducting state and connected electrically to said Hall effect devices to change from said normal state to the opposite state only when all the Hall effect devices are actuated simultaneously, the other part of the device including operative face means adapted to cooperate with the face means of the first part, and a plurality of magnetic pole means fixed in position with respect to said face means for actuating respective Hall effect devices in said one part when said two parts are placed together in close proximity and with said face means cooperating with each other in predetermined spatial relationship.
Specification