US 5,120,915 A · Pressure-actuated pump control switch

Abstract

A pressure switch according to the invention combines a pressure chamber with diaphragm, plunger, spring-loaded switch mechanism and electrical contacts in a single compact assembly. According to one aspect of the invention, the terminal board of the pump motor is incorporated into the control switch housing, eliminating the need for wiring from the switch to the terminal board and enabling the switch to be mounted inside the wiring compartment of the motor. According to another aspect of the invention, a pair of opposing blades are used in the switch mechanism to eliminate side forces and decrease friction, improving accuracy and life of the switch. A simple set screw may be used with one of the switch blades, in cooperation with a stop associated with the other blade, to adjust the spring force and thereby control the pressure control differential.

Claims15

Dependent claims

A pressure switch, comprising:

a base;
a pressure chamber assembly secured to said base, including a diaphragm which moves in response to changes in pressure within a chamber and an inlet for admitting a pressure fluid to said chamber;
a plunger in abutment with said diaphragm for movement therewith;
a terminal board secured to said base, including an electrically insulating board, first, second and third pairs of terminals mounted on an outer surface of said insulating board, first electrical contacts mounted on an inner surface of said insulating board and electrically connected to said first pair of terminals, second electrical contacts mounted on an inner surface of said insulating board and electrically connected to said third pair of terminals;
and
a switch mechanism mounted on said base and disposed to open and close by establishing and interrupting electrical contact between said first and second pairs of contacts in response to movement of said plunger.

3 more elements

A pressure switch, comprising:

a housing;
a pressure chamber assembly secured to said housing, including a diaphragm which moves in response to changes in pressure within a chamber and an inlet for admitting a pressure fluid to said chamber;
a plunger in abutment with said diaphragm for movement therewith, including a pair of diverging notches formed on opposite sides of said plunger, which notches form a pivot point;
a switch mechanism including a lever engaged for movement with said plunger and pivotally mounted to said housing at one end of said lever, a main spring which biases said lever and said plunger against said diaphragm, a pair of opposed switch blades having inner ends which pivotally engage said notches on opposite sides of said plunger, a pair of contacts disposed proximate the outer end of each switch blade, an electrical connector spanning said pair of contacts, means for securing said connector and contacts to each respective switch blade, means for retaining said main spring on the end of said lever opposite said pivotally mounted end, and a switch spring mounted on said switch blades which biases said switch blades against said plunger for pivoting about the pivot point;
and
pairs of terminals secured to said housing and disposed to engage the contacts of each switch blade, respectively, upon pivoting of said blades against said plunger to a closed position as said plunger moves in response to movement of said diaphragm due to a change in pressure in said pressure chamber.

3 more elements

Dependencies are inferred from the claim text.

Pressure-actuated pump control switch

Life of this patent

Pressure-actuated pump control switch

Life of this patent

Abstract

Claims15