Housing contained fluid flow switch and indicator

Information

  • Patent Grant
  • 6635836
  • Patent Number
    6,635,836
  • Date Filed
    Friday, January 10, 2003
    21 years ago
  • Date Issued
    Tuesday, October 21, 2003
    21 years ago
Abstract
A fluid flow indicator including a disk and spring assembly positioned within a fluid conduit whereby the pulsing force a fluid input biases the disk and spring against an electrical contact thereby completing an electrical circuit and illuminating a visual indicator.
Description




BACKGROUND OF THE INVENTION




The present invention relates to fluid flow indicators and specifically to an indicator that provides a visual indication of a pulsating fluid flow.




It is common to include lubrication devices in the design of industrial machinery. Specifically, lubricant may be provided to bearings, journals, chains, sprockets and other machine components. The lubrication devices may include pumps that meter lubricant to the machine at a predetermined level or at predetermined time intervals. The lubricant is typically stored in a lubricant supply source, such as a tank and then delivered by a conduit to a pump. The amount of lubricant in the tank or other supply source may be monitored by a sight gage, float gage, or similar device. A second conduit directs the lubricant from the pump either to the machine or to a lubricant manifold where it may be subsequently sent to multiple locations on the machine.




In most applications if the supply tank is full, it is assumed that lubricant is being delivered to the machine component. However, if the supply conduit breaks or the pump malfunctions, there is typically no indication of lack of lubricant flow until a machine component fails. There is a need for a device that monitors fluid flow downstream of the lubricant pump and provides a confirming signal that fluid is flowing from the pump outlet.




SUMMARY OF THE INVENTION




The present invention relates to a device for monitoring fluid flow from a pressurized fluid output, such as the output from a pump or metering device. The fluid flow indictor activates an indicator, such as a light emitting diode, in response to a predetermined increase in the pressure of the fluid flowing through a conduit. Specifically, a pulse is generated by an increase in fluid pressure across a specified plane within a cavity or chamber, followed by a pressure drop across the plane, and then equalization of the pressure across the plane. This pulse translates into instantaneous force acting on the plane. A disk is placed in the plane causing the pulse to be amplified. The disk is then unidirectionally linearly dampened with a conical spring, resulting in displacement of the disk along a linear axis from an initial position to a second position.




The invention utilizes a power supply, such as one or more button cell batteries, and a visual indicator, such as a light-emitting diode (LED), in a closed loop circuit with the spring and the disk. The spring and disk assembly functions as switch, closing the circuit when the fluid pressure reaches a predetermined level. This results in illumination of the indicator. Thus, as pressurized fluid flows through the conduit, the device allows for a continuous visual monitoring of the fluid flow in a display on the LED.











DESCRIPTION OF THE DRAWINGS





FIG. 1

is a perspective view of the fluid flow indicator of the present invention;





FIG. 2

is an exploded perspective view of the fluid flow indicator;





FIG. 3

is a side elevational view of the indicator assembly installed in a typical fluid flow circuit.





FIG. 4

is a cut-away side elevational view of the indicator with no fluid flowing; and





FIG. 5

is a cut-away side elevational view of the indicator during fluid flow.











DETAILED DESCRIPTION




Referring to the drawings, the fluid flow sensor assembly of the present invention is designated generally by the reference numeral


10


. A housing


11


has a longitudinal through bore


12


extending from the housing


11


top surface


13


to its bottom surface


15


. A pair of counter bores


23


is formed inwardly from both the top surface


13


and the bottom surface


15


. The counter bore


23


at the top surface is preferably provided at its inlet end with threads


17


engageable with a threaded pipe nipple


20


. The counter bore


23


at the lower end of the bore


12


is provided with threads


18


engageable with an outlet pipe nipple


21


. (See

FIGS. 4 and 5

.) The nipples


20


and


21


are threaded to a conduit


14


located in a fluid flow line emanating from a tank of fluid to be sensed by the sensor assembly


10


(not shown).




An elongated milled slot


26


is formed in the front face


16


of the housing


11


. Two large counter-bores


30


and


31


are sized to each hold a pair of batteries


19




a


and


19




b


, and are further configured to define the slot


26


. The respective axes of the counter-bores


30


,


31


preferably lie substantially perpendicular to the axis of the longitudinal bore


12


.




Referring next to

FIG. 2

, a smaller diameter counter-bore


34


is formed parallel to and between the aforementioned larger counter-bores


30


,


31


and is arranged to retain a light-emitting diode (LED)


36


. Within the uppermost larger counter-bore


30


, there is a centrally located small diameter bore


38


(see FIG.


4


). The small diameter counter-bore


38


extends diametrically across the longitudinal bore


12


to intersect with the shoulder


24


formed at the junction of counter bore


23


and the bore


12


. The bore


38


is arranged to receive a wire lead


40


emanating from the battery


19




a


and having a flat contact portion


40




a


resting on the shoulder


24


and lying transversely across the diameter of the counter bore portion


23


of the bore


12


. The housing


11


is preferably fabricated from acetyl or other non-conducting material.




A contact disk


42


is secured to a conical spring


44


and the assembly is inserted into the upper opening or fluid inlet end of the bore


12


in the housing


11


. The disk


42


and spring


44


are preferably fabricated from brass and stainless steel, respectively. The electrically conductive wire battery lead


40


provides a stationary contact for electrically mating with the contact disk


42


through spring


44


during fluid flow pressing against the disk


42


. The lead


40


is inserted within the bore


38


in the upper battery pocket


30


, extending across the counter bore


23


to rest on the shoulder


24


. The end of the push wire lead


40


is bent over allowing a battery


19




a


to be inserted into the battery pocket


30


. The light emitting diode


36


has two leads


46


,


47


. Lead


46


is known as the anode and lead


47


is known as the cathode. The anode lead


46


is trimmed to a length of {fraction (21/32)} inches. The cathode lead


47


is trimmed to a length of {fraction (5/16)} inches and then bent at substantially right angle as shown in

FIGS. 1

,


4


and


5


. The LED


36


is inserted into the LED counter bore


38


. In a preferred embodiment ,the LED


36


is a high efficiency green at


45


degrees cone angle LED that is daylight visible.




The batteries


19




a


and


19




b


supply power to the indicator assembly


10


. In the preferred embodiment, the batteries are conventional silver oxide button cell batteries having a predetermined power rating. Each battery


19




a


,


19




b


is placed into its respective battery pocket, or counterbore


30


and


31


. The counter-bores


30


and


31


are each dimensionally contoured to accommodate a respective button cell battery


19




a


and


19




b


. An electrically conductive battery jumper tab


22


retains the batteries


19




a


,


19




b


. The tab


22


is placed over the batteries


19




a


,


19




b


and is retained by a pair of drive mounting studs


25


(See FIG.


2


). The studs


25


engage with a friction fit into openings


27


formed in the housing


11


. It should be noted that the tab


22


has a central opening


29


formed therein. The LED


36


passes through the central opening


29


when the tab or jumper


22


is installed.




Finally, a conventional, epoxy-based potting compound


49


is mixed and poured into the milled slot


26


and over the above-described components. Care must be taken to insure that the potting compound


49


does not coat the LED


36


or overflow from the slot


26


. The potting compound


49


cures in approximately 12 hours, during which time the indicator assembly


10


should remain on a flat surface.




As best seen in

FIGS. 4 and 5

, the helical spring


44


, push wire lead


40


, contact disk


42


, LED


36


, batteries


19




a


,


19




b


and jumper tab


22


form an electrical circuit. The batteries


19




a


,


19




b


are connected in series by the jumper tab


22


. The push wire lead


40


connects the upper battery


19




a


to one end of the helical spring


44


. The helical spring


44


, coupled to the contact disk


42


forms a switch in conjunction with lead wire


46


of the LED


36


. The other lead wire


47


(cathode), emanating from LED


36


, is connected to the other battery


19




b


. When the disk


42


contacts the anode lead


46


of the LED


36


, the electrical circuit is closed thereby illuminating the LED


36


. When the disk


42


retracts under the force of spring


44


, the circuit is opened and the LED


36


is no longer illuminated.




Again referring to

FIGS. 4 and 5

, the indicator assembly


10


is installed between a fluid inlet


48


and a fluid outlet


50


. Fluid flows under a predetermined pressure into the indicator


10


from a source, such as a PURGEX® metering pump, manufactured by OIL-RITE® CORPORATION of Manitowoc, Wis. As the fluid contacts the disk


42


, the fluid pressure overcomes the resistance of the spring


44


attached to the disk


42


. The disk


42


is displaced from its initial position to a second position where it contacts the lead wire


46


as shown in

FIG. 5

, thereby completing the electrical circuit. When the electrical circuit is closed, the LED


36


illuminates. As the pressure from the pulse of the fluid diminishes, the spring force overcomes the fluid force and the disk


14


moves back to its initial position as shown in FIG.


4


. When the metering pump expels the next fluid pulse, the electrical circuit will be completed again and the LED


36


will be illuminated. The illuminated LED


36


provides a visual indication that fluid is flowing through the indicator assembly


10


.




The foregoing is considered as illustrative only of the principles of the invention. Furthermore, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described. While the preferred embodiment has been described, the details may be changed without departing from the invention.



Claims
  • 1. A fluid flow indicator assembly for monitoring the flow of pressurized fluid through a conduit, said assembly comprising a self-contained unit including a housing having a longitudinal through bore extending from a fluid inlet end to a fluid outlet end of said housing;said housing containing an electrical indicator circuit comprising a light emitting diode, a first and a second lead wire, each of said lead wires being axially spaced apart and each extending transversely across said longitudinal through bore, a battery power source for illuminating said diode and being, supported within said housing and being connected to said first lead wire, said second lead wire being connected to said diode, and a normally open electrical switch comprising a fluid pressure operated movable contact, said movable contact being axially movable within said bore and arranged to electrically contact said first lead wire responsive to fluid pressure exerted against said movable contact, and electrically conducting biasing means supporting and restraining said movable contact against movement towards said second lead wire extending across said bore.
  • 2. The indicator assembly of claim 1 wherein said biasing means comprises a conically wound spring contained within said longitudinal bore, said spring having a first end supported from and in electrical connection with said first lead wire, and said movable contact being suspended from and in electrical connection with the opposite end of said spring, and said movable contact being axially movable against the bias of said spring under the influence of fluid flow in said longitudinal bore and towards electrical contact with said second lead wire to complete the electrical circuit for energization of said diode from said battery.
  • 3. The indicator assembly of claim 1 wherein said housing includes a pocket defined by a counter-bore configured to receive a button cell battery.
  • 4. The indicator assembly of claim 3 wherein said housing includes a pair of longitudinally spaced pockets, each pocket being defined by a counter-bore and being respectively configured to receive a pair of electrically connected button cell batteries.
  • 5. The indicator assembly of claim 4 wherein the electrical connection for said button cell batteries comprises an overlying electrically conducting jumper tab, said tab further including fastener means for securing each of said batteries within a respective housing pocket.
  • 6. The indicator assembly of claim 1 wherein said movable contact comprises a disk positioned in a plane intersecting the longitudinal axis of said longitudinal bore and having a diameter of sufficient dimension to be responsive to fluid flow in said longitudinal bore.
  • 7. The indicator assembly of claim 5 wherein the batteries and jumper tab are covered with a cured layer of an electrical insulating potting compound.
  • 8. A method of indicating fluid flow in a conduit containing fluid, said method comprising the steps of:providing a housing having a through bore with a fluid inlet at one end and a fluid outlet at the opposite end of said bore: providing laterally spaced stationary electrical conducting elements within said bore and a movable contact axially movable within said bore, said movable contact being in electrical connection with electrically conducting biasing means and being arranged to intercept fluid flow within said longitudinal bore, said biasing means being in electrical and mechanical connection with one of said stationary conducting elements arranged to conduct electrical current from one of said stationary conducting elements to the other of said elements to via said movable contact and further being arranged to bias said movable contact in an axial direction away from electrical connection with said other of said elements in the absence of fluid flow effecting closure of said movable contact with the other of said stationary contact elements; counter-boring said housing to provide a receptacle for receiving a light-emitting diode arranged to indicate presence of fluid flow in said longitudinal bore, counter-boring said housing to provide a pocket for receiving at least one button cell battery, and providing electrical conducting leads for completing an electrical circuit from said battery to said diode responsive to fluid flow in said longitudinal bore.
  • 9. The method of claim 8 including the step of counter-boring a pair of longitudinally spaced pockets for respectively receiving a pair of said button cell batteries, providing a jumper tab mechanically securing and electrically connecting said pair of batteries.
  • 10. The method of claim 9 including the step of applying a curable electrically insulating composition to said housing contents including said batteries and said jumper tab, and curing said composition therein.
PRIORITY APPLICATION

This application claims the benefit of prior application Ser. No. 60/373,729, filed Apr. 18, 2002.

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Number Date Country
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Provisional Applications (1)
Number Date Country
60/373729 Apr 2002 US