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US5021619A Expired / Lapsed US ⏱️ 0.0 years remaining

Flow responsive switch apparatus

Assignee: Harwil Corp
•
Filing: 1990-04-02
•
Granted: 1991-06-04
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Expires: 2010-04-02
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Abstract

Abstract A liquid flow switch apparatus is provided for connection to ducting wherein liquid flows forwardly. The apparatus comprises: a support body connectible to the ducting; a stem carried by the body to project into a liquid flow zone in the ducting, and a magnetically responsive switch in the stem; a cantilevered arm carried by the body to project into the flow zone upstream of the stem and to be deflected downstream into supported relation with the stem in response to flow impingement on the arm; and a magnet carried by the arm to be displaced by the stem deflection into sufficiently close proximity with the stem and the switch as to effect switch operation.

Inventors

  • 👤 Harold D. Hutchinson

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-29 10:47
CPC Classifications
H; H01; H01H; H01H35/00; H01H35/24; H01H35/40; H01H35/405

Claims Analysis

Total Claims: 12
Claim 1
Independent Claim 170 words
In liquid flow switch apparatus connected to ducting wherein liquid flows forwardly, the combination comprising a) a support body connectible to said ducting, b) a stem rigidly carried by the body and projecting therefrom into a liquid flow zone in the ducting, and magnetically responsive switch means in the stem, c) a thin cantilevered arm fixedly carried by the body and projecting into said flow zone upstream of said stem and deflectable downstream into direct contact with the stem in response to flow impingement on the arm, d) and magnetic means carried by the arm to be displaced by said stem deflection into sufficiently close proximity with the stem and said switch means as to effect switch operation, e) said arm itself being yieldably flexible to provide the only spring force acting to resist arm deflection, and f) the body supporting a stop shoulder limiting movement of the arm away from the stem, at an arm first position toward which it is yieldably urged in the absence of said flow.
Claim 2
Dependent Claim 170 words
In liquid flow switch apparatus connected to ducting wherein liquid flows forwardly, the combination comprising a) a support body connectible to said ducting, b) a stem rigidly carried by the body and projecting therefrom into a liquid flow zone in the ducting, and magnetically responsive switch means in the stem, c) a thin cantilevered arm fixedly carried by the body and projecting into said flow zone upstream of said stem and deflectable downstream into direct contact with the stem in response to flow impingement on the arm, d) and magnetic means carried by the arm to be displaced by said stem deflection into sufficiently close proximity with the stem and said switch means as to effect switch operation, e) said arm itself being yieldably flexible to provide the only spring force acting to resist arm deflection, and f) the body supporting a stop shoulder limiting movement of the arm away from the stem, at an arm first position toward which it is yieldably urged in the absence of said flow.
Claim 3
Dependent Claim 25 words
The combination of claim 1 wherein said arm has a substantially flat surface facing upstream away from the stem to receive direct flow impingement thereagainst.
Claim 4
Dependent Claim 18 words
The combination of claim 1 wherein the body and stem are unitary and consist of molded plastic material.
Claim 5
Dependent Claim 31 words
The combination of claim 1 wherein the body is hollow and the arm has a supported end in the body hollow, the arm tapering in width away from said supported end.
Claim 6
Dependent Claim 23 words
The combination of claim 4 wherein said arm supported end forms a bend, and including potting resin encapsulating said bend in said hollow.
Claim 7
Dependent Claim 26 words
The combination of claim 4 wherein said arm-supported end forms a bend, and including fastener means attaching said bend to said body, interiorly of the body.
Claim 8
Dependent Claim 23 words
The combination of claim 1 wherein the arm is metallic and comprises a flat spring which is yieldably bent in said second position.
Claim 9
Dependent Claim 13 words
The combination of claim 1 wherein said switch means comprises a reed switch.
Claim 10
Dependent Claim 42 words
The combination of claim 1 wherein the arm comprises a thin metallic member forming a through opening, and including molded plastic cup parts encapsulating said magnetic means and retained by the arm, at least one of said parts extending through said opening.
Claim 11
Dependent Claim 44 words
The combination of claim 1 wherein said stop shoulder is defined by two narrow members projecting downwardly in a hollow defined by the support body, and against which the arm, in the form of a flat spring, forcibly seats, in the absence of flow.
Claim 12
Dependent Claim 18 words
The combination of claim 1 wherein said ducting has a hollow tee to which the body is connected.

References Cited (Backward Citations)

US2421768A Cited
US4034174A Cited
US4074097A Cited
US4152688A Cited
US4282413A Cited
US4788534A Cited
US4827092A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1994-06-03 1994-12-03 1995-06-04 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1998-06-03 1998-12-03 1999-06-04 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2002-06-03 2002-12-03 2003-06-04 $7700.00 Window Closed / Lapsed

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