Float controlled switch mechanism
United States Patent 2084051

This invention relates to a new and improved float-controlled switch mechanism and has for its principal object to provide an improved mechanism of this character for opening and closing a switch in accordance 'with predetermined changes in the liquid level within a container. Other objects...

Vulpen, John Van
Russell, Edward A.
Parks, Paul B.
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335/239, 335/261
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This invention relates to a new and improved float-controlled switch mechanism and has for its principal object to provide an improved mechanism of this character for opening and closing a switch in accordance 'with predetermined changes in the liquid level within a container.

Other objects and advantages of the invention will be apparent from the following detailed description of one approved form of apparatus constructed and operating according to the principles of this invention.

In the accompanying drawing: The figure is a vertical section through the float operated switch mechanism, and a portion of a tank for containing a liquid.

In the drawing, 24 designates a container for receiving water from a source of supply, for example, water of condensation from a steam heating system. The said container is preferably closed so that compressed air or other fluid pressure can be introduced into the tank above the liquid level (by suitable means not shown) to forcibly discharge .the liquid from the tank.

The switch mechanism herein shown comprises a thimble 41 which is mounted at its lower end in the closure plate 48 which is secured to and forms a portion of the top of container 24. This thimble is open at its lower end but is closed at its top 49 so as to prevent the escape of fluids from the container. Thimble 47 is surrounded by the coil 50 of an electromagnet. This coil 50 is constantly energized through a continuously closed circuit. A movable core 51 is slidable vertically within thimble 47 so that it may 85 be partially withdrawn from coil 50 as shown in solid lines in the drawing or may be elevated into the coil as shown in dotted lines. The float 46 is adapted to move vertically within a suitably perforated guide casing 52 suspended from the top of container 24, and a rod 53'depending from core 51 projects downwardly through a guide opening 54 in the bottom of casing 52.

The rod 53 projects loosely through a central passage 55 in float 46. Upper and lower stop projections 56 and 57 are secured on rod 53 in the path of movement of float 46. When a predetermined maximum liquid level has been reached in container 24, the float 46 will be elevated so as to engage the stop 56 and lift the core 51 into its dotted line position within coil 50.

After the core has been so elevated, the magnetic attraction of coil 50 is sufficient to hold up the core 51 and rod 53 while the float 46 is being lowered as the water is forced out of the container. When a predetermined lower liquid level is reached, the float 40 will engage the lower stop 57, and the weight of the float is sufficient to withdraw core 51 from coil 50 and pull the core down to the solid line position with stop 57 resting on the bottom of casing 52. The core and rod will remain in this position until the float 46 has again been elevated into engagement with the upper stop 56 by the accumulated condensate within container 24. The 'switch arm or armature 58, pivoted at 59, carries movable contacts 60 adapted to engage with the fixed contacts 61. A spring 62 tends to hold the armature 58 in the elevated position shown in the drawing with contacts 60 out of engagement with contacts 61. When core 51 has been projected upwardly into coil 50, the magnetic attraction of the electromagnet is increased sufficiently to draw down the arm 58 against the resistance of spring 62 and thereby bring the contacts 60 and 61 for the purpose of closing an electric circuit. When core 51 is drawn downwardly out of coil 50, the magnetic attraction is decreased so that spring 62 will pull up the arm 58 and separate the contacts 60-61.

Under normal conditions the switch will be open and the interior of container 24 will be under atmospheric pressure so that the condensate from a radiating system can drain by gravity into the container when a certain predetermined amount of liquid has accumulated in the container 24, the float will be elevated sufficiently to lift the rod 33 and core 51 thus causing the electro-magnetic device to close the switch.

When most of the liquid has been discharged from the tank, the float will engage stop 57 and 85 partially withdraw the core 51 from the electromagnet thus permitting the switch to open the contacts 60-61.

We claim: In combination, a closed container for a liquid, an electro-magnetic device comprising a thimble mounted in the top of the container, the thimble being closed at its upper end and opening at its lower end into the container, a normally energized coil surrounding the thimble, a core guided for vertical movement within the thimble, a switch mechanism positioned adjacent the coil and comprising an operating arm that is attracted to one position when the core is elevated within the coil, means for moving the arm to a second position when the strength of the magnet is diminished by lowering the core to a partially withdrawn position, the core when elevated within the coil being retained in that position by the magnetic attraction of the coil, a member 2 2,084,051 suspended from the core, a float within the con- means within the container to support said sustainer adapted to cooperate with said member to pended member when the core is in withdrawn elevate the core within the coil when the float position. is raised to a predetermined level, and to with- JOHN VAN VULPEN. draw the core from the coil when the float is EDWARD A. RUSSELL. 5 lowered to a second predetermined level, and PAUL B. PARKS.