초록 ▼

A float switch for sensing a liquid level and switching between “on”and “off”states in response to the same. Overall, the device is carried within a hollow housing, with its movement restrained by the tethering action of a power cord. “Snap action”switching is achieved by the interaction between an

A float switch for sensing a liquid level and switching between “on”and “off”states in response to the same. Overall, the device is carried within a hollow housing, with its movement restrained by the tethering action of a power cord. “Snap action”switching is achieved by the interaction between an actuator having camming surfaces formed on its exterior, and a spring-loaded switch mechanism. The switch mechanism includes a thin, flexible E-shaped snap member, having two legs bowed to form a leaf spring and having a bearing point located on the central leg. The actuator is carried in a tube within the housing and the switch mechanism is positioned adjacent the actuator\s path of travel, so that a camming surface of the actuator can make contact with the bearing point. As the water level rises, an increasing proportion of the actuator\s weight is carried by the bearing point, until the vertical component of the actuator weight exceeds the spring resistance of the snap member. The characteristic operation of the spring is such that it yields only suddenly and completely rather than gradually, providing a desirable snap action operation.

대표청구항 ▼

An improved float switch for controlling electrically powered devices by sensing a liquid level and switching from an “on”position to an “off”position in response to changes in the same, comprising: hollow housing means adapted to float on liquid, including upper and lower housing shells, said shell

An improved float switch for controlling electrically powered devices by sensing a liquid level and switching from an “on”position to an “off”position in response to changes in the same, comprising: hollow housing means adapted to float on liquid, including upper and lower housing shells, said shells being hermetically joined to prevent the entry of liquid; an electric cord extending from said lower housing shell, said cord being secured at a tether point below the liquid level to permit free movement of said housing means on the liquid surface, wherein a change in liquid level results in a change in orientation of the transverse axis of said hollow means; spring-loaded switch means for completing electrical circuit across said electrical cord, said switch being biased toward an open condition, electrically connected to said cord and carried within said lower housing shell, said switch means including a bearing point means for moving said switch from said open condition to a closed condition in response to an application of pressure on said bearing point; including a pivot terminal, having generally parallel arms extending from base member to define a generally U-shaped portion thereof, mounted within said lower shell with the open end of said U-shaped portion aligned transverse to the axis of travel of said actuator means; a snap member, formed of a thin, flexible electroconductive material, generally E-shaped with three generally parallel legs extending from a transverse bar, having the central leg thereof extending beyond the outer legs, said snap member being joined to said pivot terminal by having said snap member central leg extended into said U-shaped portion of said pivot terminal, with the distal end there of affixed to said pivot terminal base member, with each of said snap member outer arms being affixed to the termination of said pivot terminal arms, such that said outer legs are bowed in the same direction in the same direction, forming a leaf spring; and said bearing point means, carried on said snap member central leg; actuator means, generally cylindrical in form, carried adjacent to said switch means in said housing for gravitationally-induced movement between first and second positions in response to said orientation of said housing means, said actuator means having a camming surface formed on the surface thereof, divided into a plurality of camming portions circumferentially around said actuator means, each said camming portion adapted to interact with said bearing point means for operating said switch means; said camming portions including: a dwell portion adapted to make no contact with said bearing point, a snap portion flaring outward from said dwell portion sufficient to make contact with said bearing point and to move the same a distance greater than the distance required to operate said switch means; and a detent portion, having a circumference less than the circumference of the distal end of the snap portion; wherein the weight of said of said actuator means is selected such that the force exerted by actuator means, applied at said snap portion to said bearing point as the transverse axis of said housing means moves from horizontal toward the vertical, to overcome the resistance of said spring loading of said switch means at a preselected angle of said housing, providing a snap action closing of said switch.