Pendent liquid level alarm apparatus
First Claim
1. An apparatus for providing an indication when liquid in a vessel has risen to a pre-determined level comprising:
- a. a sensor having (i) an elongated hollow cylindrical housing, (ii) an elongated cylindrical float axially slidable within said housing, (iii) means for limiting upward and downward axial motion of said float within said hollow cylindrical housing, (iv) means permitting ingress and egress of liquid into said cylindrical housing, and (v) means responsive to upward movement of said float a pre-determined distance in closing an electrical circuit, said means comprising in combination a solid permanent magnet fastened to the upper surface of said float with its magnetization axis parallel to the longitudinal axis of said float and a reed switch having at least two contact bars mounted within said sensor in the vicinity of said means for limiting upward axial motion of said float, the longitudinal axis of said reed switch being substantially colinear with the magnetization axis of said magnet, said reed switch thereby being responsive to upward motion of said permanent magnet in closing said contact bars of said reed switch, andb. means for suspending said sensor in said vessel with the longitudinal axis of said sensor being oriented in a generally vertical direction
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Accused Products
Abstract
A liquid level electrical alarm apparatus includes a perforated hollow cylindrical sensor housing having upper and lower cup-shaped caps. A cylindrical float contained within the sensor housing contains a permanent magnet near its upper end, effective in closing the contact bars of a reed switch element mounted in the upper cap when the float rises a pre-determined level. The sensor body is suspended by a flexible electrical cable connected to the upper cap. Means are provided for adjusting the length of cable from which the sensor is suspended into a vessel, thereby permitting adjustment of the liquid level which trips the alarm.
51 Citations
24 Claims
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1. An apparatus for providing an indication when liquid in a vessel has risen to a pre-determined level comprising:
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a. a sensor having (i) an elongated hollow cylindrical housing, (ii) an elongated cylindrical float axially slidable within said housing, (iii) means for limiting upward and downward axial motion of said float within said hollow cylindrical housing, (iv) means permitting ingress and egress of liquid into said cylindrical housing, and (v) means responsive to upward movement of said float a pre-determined distance in closing an electrical circuit, said means comprising in combination a solid permanent magnet fastened to the upper surface of said float with its magnetization axis parallel to the longitudinal axis of said float and a reed switch having at least two contact bars mounted within said sensor in the vicinity of said means for limiting upward axial motion of said float, the longitudinal axis of said reed switch being substantially colinear with the magnetization axis of said magnet, said reed switch thereby being responsive to upward motion of said permanent magnet in closing said contact bars of said reed switch, and b. means for suspending said sensor in said vessel with the longitudinal axis of said sensor being oriented in a generally vertical direction - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. An apparatus for providing an indication when liquid in a vessel has reached a pre-determined level comprising:
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a. an elongated sensor body having a hollow interior and means permitting the flow of liquid into and out of the interior of said sensor body from the exterior of said sensor body, b. a float longitudinally slidably contained within said sensor body, the longitudinal position of said float being responsive to the level of liquid within the interior of said sensor body, c. means responsive to the longitudinal position of said float within said sensor body in closing an electrical switch, thereby providing an indication when liquid in said vessel has reached a predetermined level, said means comprising. (i) a permanent magnet fastened to said float near an upper end of said float, and (ii) a switch responsive to sufficiently close approach of said permanent magnet in closing said switch, and (d) means for flexibly suspending said sensor body in said vessel, said means comprising a flexible cable which is more readily bendable about axes transverse to the longitudinal axis of the cable then about axes normal to the longitudinal axis of the cable. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24)
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Specification