Abstrict A fluid flow meter having a transparent housing and a piston movable
within the housing for indicating the rate of flow of fluid through
the housing in accordance with the position of the piston relative
to a scale on the housing. Fins are disposed within the housing
to receive the fluid entering the housing and to induce the fluid
to have a steady and laminar flow and thus present a steady force
on the piston for accurate flow readings. A spring urges the piston
toward the inlet, and a spring seat is adjustably disposed within
the housing so that the spring force on the piston can be readily
calibrated and thus the spring will exert the desired force on the
piston so that accurate flow readings can be obtained. The entire
meter is made of only a minimum number of parts but there is required
accuracy and also opportunity to observe the flow through the transparent
meter housing.
Claims What is claimed is:
1. In a fluid flow meter comprising a housing of a transparent
material and having a fluid inlet and a fluid outlet and having
a cylindrical wall defining a hollow interior, a conical member
secured on the interior of said housing, a piston movably disposed
in said housing and slidable along said cylindrical wall of said
housing and having a central opening piloted on said conical member
for movement of said piston in accordance with the rate of flow
of fluid through said housing and toward said outlet, a spring for
urging said piston toward said inlet, a scale on said housing and
matched with said piston for indicating the rate of flow of fluid,
the improvement comprising a plurality of fins extending between
said housing and said conical member adjacent said fluid inlet and
in the path of the flow of fluid into said housing and toward said
piston, to direct the fluid to flow in a laminar flow pattern as
contrasted to a turbulent flow pattern and to direct the laminar
flow onto said piston and thereby create steady flow-sensing positions
for said piston.
2. The fluid flow meter as claimed in claim 1 wherein said piston
and said fins are adjacent each other and at one end of said conical
member when there is no flow through said housing.
3. The fluid flow meter as claimed in claim 1 or 2 wherein said
fins are disposed in contact with said piston, when there is no
flow through said housing, and said fins thereby present an end
stop for said piston in the no-flow position.
4. The fluid flow meter as claimed in claim 1 or 2 wherein said
fins are affixed to both said housing and said conical member for
mounting said conical member on the cylindrical axis of said housing.
5. The fluid flow meter as claimed in claim 1 or 2 wherein said
spring extends along the cylindrical axis of said housing, a spring
seat disposed in said housing and located at the end of said spring
opposite said piston and being movably disposable for adjustably
applying the spring force onto said piston and thereby calibrate
the force in accordance with the flow of fluid.
6. The fluid flow meter as claimed in claim 1 or 2 wherein said
piston has a planar surface at the end thereof toward said outlet,
for alignment of said planar surface with said scale to reveal the
rate of flow of fluid through said housing.
7. In a fluid flow meter comprising a housing of a transparent
material and having a fluid inlet and a fluid outlet and having
a cylindrical wall defining a hollow interior, a conical member
secured on the interior of said housing, a piston movably disposed
in said housing and slidable along said cylindrical wall of said
housing and having a central opening piloted on said conical member
for movement of said piston in accordance with the rate of flow
of fluid through said housing and toward said outlet, a spring for
urging said piston toward said inlet, means operatively associated
with the position of said piston for indicating the rate of flow
of fluid, the improvement comprising a plurality of fins extending
between said housing and said conical member adjacent said fluid
inlet and in the path of the flow of fluid into said housing and
toward said piston, to direct the fluid to flow in a laminar flow
pattern as contrasted to a turbulent flow pattern and to direct
the laminar flow onto said piston and thereby create steady flow-sensing
positions for said piston, said spring extending along the cylindrical
axis of said housing, and a spring seat disposed in said housing
and located at the end of said spring opposite said piston.
8. The fluid flow meter as claimed in claim 7 wherein said spring
seat is movably disposably engaged with said housing for adjustably
applying the spring force onto said piston and thereby calibrate
the force in accordance with the flow of fluid.
9. The fluid flow meter as claimed in claim 7 or 8 wherein said
piston and said fins are adjacent each other and are at one end
of said conical member when there is no flow through said housing.
10. The fluid flow meter as claimed in claim 7 or 8 wherein said
fins are disposed in contact with said piston, when there is no
flow through said housing, and said fins thereby present an end
stop for said piston in the no-flow position.
11. The fluid flow meter as claimed in claim 7 or 8 wherein said
fins are affixed to both said housing and said conical member for
mounting said conical member on the cylindrical axis of said housing.
12. The fluid flow meter as claimed in claim 7 or 8 wherein said
piston has a planar surface at the end thereof toward said outlet,
for alignment of said planar surface with said scale to reveal the
rate of flow of fluid through said housing.
Description This invention relates to a fluid flow meter, and, more particularly,
it relates to a flow meter of a transparent housing type which permits
direct reading of the rates of flow of fluid through the meter.
BACKGROUND OF THE INVENTION
Fluid flow meters are well known in the prior art and they exist
in various forms and constructions. The prior art flow meters commonly
have a piston which is displaced in accordance with the rate of
flow through the meter, and it is old to have the housing of a transparent
material so that the position of the piston can be observed and
thus the rate of flow determined. Examples of such prior art are
found in British Pat. No. 928319 and in U.S. Pat. Nos. 2311181
and 2370634 and 2439614 and 2655041 and 3196673. However,
those prior art patents are of structures significantly different
from the one disclosed herein, in that the prior art structures
have their so-called piston members floating, rather than spring-urged
and operating over a fixed cone, as in the present invention.
The prior art is also aware of flow meters which utilize a remote
type of indicator, such as a pointer and dial or the like, and U.S.
Pat. Nos. 1499839 and 2325884 and 2574866 and 3398305 show
that type of flow meter structure and it differs from the present
invention which utilizes a spring-urged piston which can be seen
through a transparent housing for determining the rate of flow.
Still another group of prior art patents is U.S. Pat. Nos. 2638582
and 3218853 and 3554031 shows meters or valves which have pistons
slidable in a conical housing, but they do not relate the piston
to a transparent housing through which the position of the piston
can be seen and thus the rate of flow determined.
All of the aforementioned prior art patents differ from the present
invention in that the present invention has the spring-urged piston
slidable in a cylindrical housing of transparent material and there
are fins on the upstream side of the flow in the housing so that
the flow can become steady and laminar and thus create a steady
force on the piston for the desired accurate reading. Further, the
present invention has an adjustable seat for the spring which urges
the piston, and thus the spring can be put under proper tension
and therefore it is in the nature of calibrating the spring for
the particular meter installation and characteristics of that individual
spring, and thus, again, an accurate flow rate reading can be obtained
by this means which differs from the prior art. Still further, the
present invention differs from the aforesaid prior art in that it
is made of only a minimum number of pieces and thus there is no
requirement for elaborate interfitting of parts and there is no
requirement for extensive assembly proceedings as there is with
the prior art structures such as those mentioned above. Still another
prior art patent is U.S. Pat. No. 3805611 which employs a spring-urged
movable piston operating on a conical member and having a cylindrical
housing interior and with the position of the piston itself indicating
the rate of flow through the meter. However, for the reasons mentioned
in this paragraph, the present invention also distinguishes over
U.S. Pat. No. 3805611 that is, the present invention has the
flow fins, the adjustable spring seat, and the minimal number of
parts. That prior art flow meter has twenty-two pieces compared
to five pieces required for the present flow meter, for example.
Therefore, the present meter is less subject to failure of parts,
and there is significantly less requirement for fitting the parts
one to another and thus the meter can be an accurate meter with
less manufacturing expense and attention, and, significantly, the
present meter does not rely upon the use of a magnet, as with U.S.
Pat. No. 3805611 for the reading of the position of the piston
within the housing.
There are other objects and advantages, and those will become apparent
upon a reading of the following description in light of the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a longitudinal sectional view through a preferred embodiment
of a flow meter of this invention.
FIG. 2 is a left end elevational view of the meter shown in FIG.
1.
FIG. 3 is a right end elevational view of the meter shown in FIG.
1.
FIG. 4 is an enlarged sectional view of the piston shown in FIG.
1.
FIG. 5 is a right end elevational view of a fragment of the piston
shown in FIG. 4.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The improved flow meter of this invention has a housing 10 which
is of a transparent material, such as suitable plastic, and an inlet
11 and a fluid outlet 12 and an intermediate chamber 13 extending
between the inlet 11 and the outlet 12 and all are in fluid flow
communication. There is a cylindrical interior wall 14 extending
throughout the length of the housing 10 and the inlet end and the
outlet end of the housing 10 have threaded lengths 16 and 17 respectively,
for connecting to fluid flow lines directing the flow to and from
the meter shown.
It will be therefore understood that the housing 10 is transparent
and the parts that are on the interior of the housing can be readily
seen, even when fluid is flowing through the meter. Thus, FIG. 1
shows the fragmentary section with the housing exterior surface
or wall 18 extending over a frontal portion of the meter as shown,
but, it will be seen that the interior of the housing 10 can still
be seen beneath that housing wall fragment 18. A plurality of triangularly
shaped fins 19 are disposed within the housing interior at the inlet
11 and are disposed also in the longitudinal plane of the housing
10 and thus they extend planarly in the direction of the flow through
the meter. That is, fluid entering the inlet 11 will encounter the
fins 19 which are in the path of the incoming fluid and which are
planar and disposed in the direction of the fluid flow. With that
arrangement, the flow entering the meter will encounter the plurality
of fins 19 and six fins are shown equally spaced around the interior
of the housing 10 and the fluid will therefore be directed longitudinally
of the housing 10 rather than in turbulence or swirling toward
the cylindrical wall of the housing 10. The fins serve to calm any
turbulent flow and to create a steady or laminar flow directed in
the longitudinal direction of the cylindrical housing 10.
A conical member 21 is coaxially disposed in the housing 10 and
has its larger end 22 adjacent the fins 19 and thus the conical
member 21 tapers downwardly toward the outlet 12. The housing 10
and fins 19 and conical member 21 can all be molded in one plastic
mold so that they constitute one unitary piece and thus there is
no need for assembly or interfitting or adjustment of the respective
parts mentioned. Of course the smaller end of the conical member
21 is not open but is actually blocked, as shown in FIG. 2 and
thus the flow does not go through the conical member 21 but instead
goes around the conical member 21 after passing the fins 19.
A cylindrical and hollow piston 23 is movably disposed within the
housing 10 and the outer circumference 24 of the piston 23 is fluid
tight with the cylindrical surface or wall 14 of the housing 10
but slides therealong. The piston 23 has its head 26 adjacent the
fins 19 and, in the arrangement shown, the piston 23 actually has
a circular ridge 27 in abutment with the adjacent edges 28 of the
fins 19 which present those six edges 28 on one transverse plane
across the housing 10 as shown. It will of course be understood
that fluid entering the inlet 11 will pass the fins 19 and will
encounter the piston head 26 and, depending upon the rate of flow
of fluid at that time, the piston 23 will be urged to the left,
as viewed in FIG. 1. Of course the inner circular surface 29 of
the piston 23 is in fluid tight contact with the outer conical surface
31 of the conical member 21 when the piston 23 is in the position
of FIG. 1 that is, when there is no flow through the meter. However,
flow through the meters moves the piston 23 to the left, as mentioned,
and thus the piston circular surface 29 is moved out of fluid sealing
relationship with the conical member 21 and the degree of movement
of the piston 23 is determined by the rate of flow and of course
by the angle of the cone on the conical member 21 all as will be
fully understood by anyone skilled in the art.
With that arrangement, the fins 19 are in contact with the piston
23 in the commencement position shown in FIG. 1 and thus the incoming
flow is produced as steady or laminar flow and is immediately directed
onto the piston head 26 so that the piston 23 receives a steady
force for an accurate reading of the rate of flow. The reading is
accomplished by provision of a scale 30 which is affixed to the
housing 10 and which itself is transparent and which of course has
graduations thereon, such as those shown ranging from zero to six
in the drawing. The piston 23 has its planar end surface 32 aligned
with the zero position in the "no flow" condition shown
in FIG. 1 and then additional readings taken as the piston 23 moves
to the left will be made by observing the position of the piston
leading or planar surface 32 with respect to the scale 30. Actually
the scale 30 can either be a transparent piece, with the graduations
thereon, affixed to the exterior of the housing 10 or it can be
printed or engraved on the housing 10 or any other manner. In any
event, the point is that both the scale 30 and the housing 10 are
transparent, and thus the piston leading planar surface 32 can be
readily seen and thus its position can be accurately observed during
the course of flow of fluid through the meter.
A compression spring 33 is disposed in the housing 10 and has one
end 34 abutting the piston 23 and it has its other end 36 abutting
a spring seat 37. Thus the spring 33 urges the piston 23 to the
right, as viewed in FIG. 1 and that of course is in the direction
against the force applied by the flow through the meter. Of course
with the appropriate graduations on the scale 30 and with the appropriate
spring force applied to the piston 23 the accurate readings can
be obtained.
In addition to the provision and location of the fins 19 relative
to the piston 23 as described above, another important feature
is the provision of the spring seat 37 and that is important because
the seat is readily adjustable in that it is in the nature of a
clip of a cylindrical configuration with retaining teeth 38 in contact
with the housing interior wall 14 so that the spring seat 37 is
held against movement to the left, under normal actions in the meter,
but the seat 37 can be readily slid to the right, all as viewed
in FIG. 1 and thus the seat 37 is adjustable and therefore the
force created by the spring 33 can be adjusted or calibrated as
desired. FIG. 2 shows the elevational view of the spring seat 37
and it shows that the projections 38 are in the nature of spring
prongs which secure themselves against the housing interior wall
14 especially when the housing 10 is made of a plastic material
which permit the prongs 38 to somewhat embed themselves in the material
to the degree necessary to retain the seat 37 in the desired longitudinal
position along the housing 10. Of course the adjustable seat 37
is basically a ring member having the radially projecting prongs
38 so it in no way interferes with flow through the meter, and
it is not moved by flow itself. FIG. 2 also shows the end view of
the conical member 21 as mentioned above, and it shows the 6 fins
19 and that view therefore is only of the body part 10 and the
spring seat part 37 and the spring 33 and the piston 23 are removed.
Likewise, FIG. 3 shows the end elevational view of the body 10
only, and there is no showing of the piston 23 and the spring 33
nor is there any showing of the spring seat 37.
FIGS. 4 and 5 show the details of the piston 23 including ring
27 which abuts the fins 19 which therefore serve as a stop for the
piston 23 and FIGS. 4 and 5 also show the hollow interior of the
piston 23. Further, FIGS. 1 2 and 3 show that the body 10 has
a hexagonal section designated 39 and thus a wrench can be used
for connecting the housing 10 with fluid flow lines which would
be at opposite ends of the housing 10 but which are now shown herein.
The entire arrangement is for a simplified but yet adjustably accurate
flow meter, and this is accomplished by means of having only five
pieces constituting the entire meter. Further, the fins 19 and piston
23 are immediately adjacent each other, and thus the steady and
laminar flow is directed immediately to the piston 23 and the adjustable
spring seat 37 permits the desired calibration so that the steady
flow can be utilized and the force of the spring can be arranged
to provide for the accurate flow readings desired. |