Magnetic differential pressure-responsive means

Claim 2

A magnetic pressure-responsive switch comprising, in combination, a housing; a partition extending across the housing dividing the housing into noncommunicating first and second chambers; first and second fluid passages communicating the first chamber with first and second sources of fluid pressure; a magnetic piston movably mounted in the first chamber and positioned relative to the first and second fluid passages so as to be exposed to pressure in both said passages, movable in said first chamber toward and away from the partition between first and second positions in response to a predetermined pressure differential between the two passages; an electrical switch mounted in the second chamber, said electrical switch having a pivoted, generally L-shaped magnetic lever arm for operation by pivoted movement between first and second positions, one portion of the lever arm being disposed adjacent to the partition so as to be magnetically attracted to the magnetic piston on the opposite side of the partition, the other portion of said lever arm being disposed generally perpendicularly to said partition; bias means engaging said other portion of the lever arm and urging said lever arm into said first position, whereby when the magnetic piston moves from the first to the second position, the lever arm on the opposite side of the partition is correspondingly moved from the first to the second position, to operate said electrical switch.

Claim 3

A magnetic pressure-responsive switch in accordance with claim 1 in which the electrical switch is a microswitch.

Claim 4

A magnetic pressure-responsive switch in accordance with claim 1, in which the lever arm is made of a magnetizable material and the magnetic piston includes a magnet.

Claim 5

A magnetic pressure-responsive switch in accordance with claim 1, in which the bias means engaging the switch lever arm is positioned adjacent a fulcrum of the lever arm.

Claim 6

A magnetic pressure-responsive switch in accordance with claim 1, in which the bias means engaging the lever arm is within the switch body.

Claim 7

A magnetic pressure-responsive switch in accordance with claim 1, in which the switch body is boxlike in shape and the lever arm is arranged to follow the shape of the switch body.

Claim 8

A magnetic pressure-responsive switch in accordance with claim 1, in which the second chamber closely encloses the electrical switch so as to permit movement of the lever arm but keep wasted space to a minimum.

Claim 9

A magnetic pressure-responsive switch in accordance with claim 1, in which the electrical switch in accordance with claim 1, in which the electrical switch is supported in the second chamber by a plastic-mounting block.

Claim 10

A magnetic pressure-responsive switch in accordance with claim 6, in which the mounting block has a shoulder which spaces the lever arm from the partition.

Claim 11

A magnetic pressure-responsive switch in accordance with claim 1, including filters across both the first and second fluid passages, to prevent passage of contaminants into the first chamber.

Claim 12

A magnetic pressure-responsive switch in accordance with claim 1, including magnetic means for manually resetting the electrical switch.

Claim 13

A magnetic pressure-responsive switch in accordance with claim 11, in which the magnetic means for manually resetting the electrical switch comprises a magnetic button positioned exteriorly of the second chamber but adjacent to a wall portion of the chamber in juxtaposition to the said other portion of the lever arm, said magnetic button being movable toward and away from the said wall portion of the second chamber so as to attract said other portion of the lever arm to set the electrical switch.

Claim 14

A magnetic pressure-responsive switch in accordance with claim 1, including means for holding the piston in its second position to prevent automatic resetting of the switch.

Claim 15

A magnetic pressure-responsive switch in accordance with claim 13 in which the means for holding the piston in its second position comprises catch means and means associated with the piston and positioned for engaging the catch means so as to be held by the catch means when the piston moves into its second position.

Claim 16

A magnetic pressure-responsive switch in accordance with claim 14 including means for automatically releasinG the catch means.

Claim 17

A compact magnetic pressure-responsive switch comprising, in combination, a housing made of a nonmagnetizable material; a partition extending across the housing dividing the housing into noncommunicating first and second chambers; first and second fluid passages communicating the first chamber with the first and second sources of fluid pressure; a piston assembly movably mounted in the first chamber, positioned adjacent the partition and relative the first and second fluid passages so as to be exposed to pressure in both passages, said piston assembly having a magnet associated therewith; a spring engaging the piston assembly and normally urging the piston assembly into a first position, said piston assembly being adapted to move in the first chamber into a second position closely spaced from the first position in response to a predetermined pressure differential between the two passages sufficient to produce a force on the piston assembly in excess of the force of the spring; an electrical microswitch mounted in the second chamber, said electrical switch having a generally boxlike body and having pivotally mounted thereon a generally L-shaped lever arm made of a magnetizable material for operating the electrical switch by pivotal movement between closely spaced first and second positions, one portion of the lever arm being disposed in close proximity to the partition so as to be magnetically attracted to the magnetic piston assembly on the opposite side of the partition, the other portion of said lever arm being disposed generally perpendicularly to said partition, said L-shaped lever arm being positioned to generally follow the shape of the microswitch body; a spring incorporated within said switch body and engaging said other portion of the lever arm, and urging said lever arm into a first position; a plastic-mounting block mounted in the second chamber and fixed to the microswitch in a manner to position the switch in the second chamber such that the lever arm is located at a predetermined short distance from the partition; whereby when the magnetic piston assembly moves the short distance from its first to its second positions the lever arm on the opposite side of the partition is correspondingly moved the short distance from its first to second positions to operate the electrical switch, and an electrical connector mounted on the housing in juxtaposition to the second chamber and electrically connected to the electrical switch.

Claim 18

A compact magnetic pressure-responsive switch comprising, in combination, a housing made of a nonmagnetizable material; a partition extending across the housing dividing the housing into noncommunicating first and second chambers; first and second fluid passages communicating the first chamber with the first and second sources of fluid pressure; a piston assembly movably mounted in the first chamber, positioned adjacent the partition and relative the first and second fluid passages so as to be exposed to pressure in both passages, said piston assembly having a magnet associated therewith; a spring engaging the piston assembly and normally urging the piston assembly into a first position, said piston assembly being adapted to move in the first chamber into a second position closely spaced from the first position in response to a predetermined pressure differential between the two passages sufficient to produce a force on the piston assembly in excess of the force of the spring; an electrical microswitch mounted in the second chamber, said electrical switch having a generally boxlike body and having pivotally mounted thereon a generally L-shaped lever arm made of a magnetizable material for operating the electrical switch by pivotal movement between closely spaced first and second positions, one portion of the lever arm being disposed in close proximity to the partition so as to be magnetically attracted to the magnetic piston assembly on the opposite side of the partition, the other portion of said lever arm being disposed generally perpendicularly to said partition, said L-shaped lever arm being positioned to generally follow the shape of the microswitch body; a spring incorporated within said switch body and engaging said other portion of the lever arm, and urging said lever arm into a first position; a plastic-mounting block mounted in the second chamber and fixed to the microswitch in a manner to position the switch in the second chamber such that the lever arm is located at a predetermined short distance from the partition; whereby when the magnetic piston assembly moves the short distance from its first to its second positions the lever arm on the opposite side of the partition is correspondingly moved the short distance from its first to second positions to operate the electrical switch, and an electrical connector mounted on the housing in juxtaposition to the second chamber and electrically connected to the electrical switch.

Claim 19

A compact pressure-responsive switch in accordance with claim 16, in which filters are provided across both the first and second passages to prevent passage of contaminants into the chamber.

Claim 20

A compact magnetic pressure-responsive switch in accordance with claim 16, including a magnetic switch reset button assembly mounted on the housing adjacent to said other portion of the magnetizable lever arm, said magnetic button assembly comprising a magnet biased normally away from said housing but movable toward said housing to attract and move said other portion of the lever arm out of its second position thereby resetting the switch.

Claim 21

A compact magnetic pressure-responsive switch in accordance with claim 16 including catch means for holding the magnetic piston assembly in its second position to prevent automatic resetting of the switch.

Claim 22

A magnetic pressure-responsive switch in accordance with claim 1 in combination with a filter assembly having a housing provided with an inlet and an outlet; a filter element in the housing positioned in the line of flow from the inlet to the outlet such that all flow through the housing must pass through the filter element; and passages in the housing communicating the upstream and downstream sides of the filter element with the first and second passages of the magnetic pressure-responsive switch so that when a predetermined pressure differential across the filter element is reached, the magnetic pressure-responsive switch is actuated.

Claim 23

The combination in aCcordance with claim 20 wherein the filter assembly includes a pressure relief valve adapted to permit fluid to bypass the filter element when a predetermined pressure differential is reached.

Claim 24

The combination in accordance with claim 20 including means for holding the piston of the switch in its second position comprising catch means, means associated with the piston and positioned for engaging the catch means when the piston moves into its second position, and means engaging the filter element in the housing and operatively associated with the catch means for automatically releasing the catch means when the filter element is removed from the housing for service.

Claim 25

A magnetic pressure-responsive device comprising, in combination, a housing; a partition extending across the housing dividing the housing into noncommunicating first and second chambers; first and second fluid passages communicating the first chamber with first and second sources of fluid pressure; magnetic differential pressure-responsive means movably mounted in the first chamber so positioned relative the two fluid passages as to be exposed to pressure in both fluid passages and arranged to move between first and second positions in the chamber in response to a predetermined pressure differential between the passages; signalling means mounted in the second chamber for signalling when the predetermined pressure differential is reached, said signalling means having a switch and a magnetic actuating member a portion of which is disposed adjacent to the partition so as to be magnetically attracted to the magnetic differential pressure-responsive means on the opposite side of the partition, and another portion of which is disposed along a wall of said second chamber, said actuating member being adapted to operate the said signalling means upon movement from a first to a second position such that movement of the magnetic differential pressure-responsive means from its first to its second positions results in movement of said actuating member from its first to its second position to operate the switch; and magnetic reset means positioned adjacent a wall of the second chamber in position to attract said another portion of the actuating member and movable toward and away from said chamber to move the actuating member from its second position back into its first position to reset said signalling means.

Claim 26

A magnetic pressure-responsive device comprising, in combination, a housing; a partition extending across the housing dividing the housing into noncommunicating first and second chambers; first and second fluid passages communicating the first chamber with first and second sources of fluid pressure; magnetic differential pressure-responsive means movably mounted in the first chamber so positioned relative the two fluid passages as to be exposed to pressure in both fluid passages and arranged to move between first and second positions in the chamber in response to a predetermined pressure differential between the passages; signalling means mounted in the second chamber for signalling when the predetermined pressure differential is reached, said signalling means having a switch and a magnetic actuating member a portion of which is disposed adjacent to the partition so as to be magnetically attracted to the magnetic differential pressure-responsive means on the opposite side of the partition, and another portion of which is disposed along a wall of said second chamber, said actuating member being adapted to operate the said signalling means upon movement from a first to a second position such that movement of the magnetic differential pressure-responsive means from its first to its second positions results in movement of said actuating member from its first to its second position to operate the switch; and magnetic reset means positioned adjacent a wall of the second chamber in position to attract said another portion of the actuating member and movable toward and away from said chamber to move the actuating member from its second position back into its first position to reset said signalling means.

Claim 27

A magnetic pressure-responsive device in accordance with claim 23, in which the magnetic reset means has a magnetic button biased normally away from said chamber by a spring.

Claim 28

A magnetic pressure-responsive device in accordance with claim 24, in which the magnetic reset button is mounted in a housing fixed to the wall of the second chamber.