Magnetic switches
AssigneeHermetic Switch, Inc.
InventorWilliam T. Posey
Life of this patent
Estimating the term…
Abstract
Apparatus for proximity magnetic switching wherein magnet assemblies are used in combination with magnetic reed switches by placement of the reed switch axis in a magnetic field null position which is shifted or unbalanced by proximation of certain magnetic materials to actuate the magnetic reed switch. In particular, such proximity magnetic switch is made weather proof and entirely sealed from its environment by molding the magnet assembly and reed switch assembly in fixed orientation within a potted compound which then exposes an actuating surface for sensing the presence of a magnetically permeable material.
Claims14
A magnetic switch actuatable by proximity of a permeable object, comprising:
- first and second bars of magnet material having interface surfaces joined in overlay with each having a mating groove formed longitudinally on the respective interface surfaces thereby to form a bore through the joined magnet material, said first and second bars forming a bar of magnet material having first and second ends and being oppositely polarized transversely through the first and second ends to form first and second axes of polarity and polarity neutral zone in alignment with said bore;
- and
- magnetic reed switch means having first and second ends aligned generally perpendicular to said axes of polarity and being normally open and disposed in said neutral zone;
- wherein said permeable object presence in said magnetic force field shifts the neutral zone to place the reed switch means in a magnetic force field sufficient to actuate the reed switch means closed.
A magnetic switch actuatable by proximity of a permeable object, comprising:
- first and second magnets of similar size and polarity joined at respective interface surfaces and positioned with said interface aligned with a switch axis, said magnets having respective north and south poles and defining respective axes of polarity while normally producing a magnetic force field having a polarity neutral zone;
- first and second reed contacts of selected magnetic permeability;
- and
- means defining an elongated switch axis and having first and second ends for securing said reed contacts, said switch axis being aligned generally perpendicular to said axes of polarity with said reed contacts normally open and disposed in said neutral zone;
- wherein said permeable object presence in said magnetic force field shifts the neutral zone to place the reed contacts sufficiently within a magnetic force field to actuate the contacts closed.
A switch as set forth in claim 5 wherein said at least one magnet means comprises:
- first and second magnets of dissimilar size and same polarity joined at an interface and positioned with said interface aligned with said switch axis whereby the magnetic force field is unbalanced to normally close the first and second reed contacts.
A sealed proximity switch comprising:
- an enclosed reed switch having first and second aligned reed contacts and external connecting leads;
- at least one magnetic means defining an axis of polarity disposed adjacent said reed switch with said axis of polarity perpendicular to said first and second aligned reed contacts and producing a magnetic force field having a neutral zone at the position of said reed switch;
- a molding compound enclosing said reed switch and magnet means to form a switch body extending said external connecting leads;
- and
- a switch arm of permeable material movably secured on said switch body for movement through the magnetic force field to control closure of said reed contacts.
A magnetic switch actuatable by proximity of a permeable object, comprising:
- magnet means defining an axis of polarity and normally producing a magnetic force field having a polarity neutral zone consisting of a bar of magnet material having first and second ends and being oppositely polarized transversely through the first and second ends, and having an axial bore formed longitudinally between said first and second ends;
- and
- magnetic reed switch means having first and second ends and being disposed in said axial bore aligned generally perpendicular to said axis of polarity, said switch means being normally open and disposed in said neutral zone;
- wherein said permeable object presence in said magnetic force field shifts the neutral zone to place the reed switch means in a magnetic force field sufficient to actuate the reed switch means closed.
Dependencies are inferred from the claim text.