Abstrict A device for recording the flow rate through a flow meter over
a period of time is provided for use in conjunction with a flow
meter having a rotatable member, the rotational position of which
is indicative of the fluid flow rate through the flow meter. The
recording device comprises a housing in which a recording medium
is mounted and rotatably driven at a predetermined. rate. An elongated
scribe arm is pivotally secured at one end to the housing and, at
its other end, has a writing instrument which engages the writing
medium and produces a visible mark thereon. Similarly, an elongated
actuating arm has an axle which is pivotally mounted to the housing
and this axle in turn is connected to the flow meter rotatable member.
The actuating arm and scribe arm are in turn connected together
by a connecting arm which is pivotally connected to the actuating
arm at one end and pivotally connected to the scribe arm at its
other end. Moreover, the pivotal connection between the connecting
arm and both the scribe arm and the actuating arm are radially spaced
from their respective pivotal mounting points so that pivotal movement
of the actuating arm causes a like and proportional pivotal action
of the scribe arm.
Claims I claim:
1. For use in conjunction with a fluid flow meter having a rotatable
member the rotation of which is indicative of the fluid flow rate
through the flow meter, a device for recording the flow meter flow
rate over a period of time, said device comprising:
a housing;
a recording medium and means for substantially continuously moving
said recording medium in a predetermined direction, said writing
medium and said moving means being mounted in said housing;
an elongated scribe arm having a writing means secured to one end,
said writing means engaging said writing medium and producing a
visible mark thereon;
means for pivotally securing the other end of the scribe arm to
the housing so that, as the scribe arm pivots, said writing means
moves substantially transversely across said writing medium with
respect to the direction of movement of the writing medium; and
linkage means for connecting said flow meter rotatable member to
said scribe arm so that said scribe arm pivots in unison with the
rotation of said rotatable member, said linkage means including
adjustment means for varying the proportion between the rotation
of said rotatable member and the pivotal movement of said scribe
arm.
2. The invention as defined in claim 1 and further comprising means
for selectively holding said writing means in a position spaced
from said recording medium.
3. The invention as defined in claim 1 and further comprising means
for limiting the pivotal movement of said scribe arm between two
rotational positions.
4. The invention as defined in claim 1 and further comprising an
indicia scale positioned on said housing, wherein said linkage means
including an actuating arm a portion of which swings across said
indicia scale upon rotation of the rotatable member.
5. The invention as defined in claim 1 wherein said writing medium
is circular in shape and wherein said moving means rotates said
writing medium around its axis.
6. The invention as defined in claim 5 wherein said writing medium
comprises a paper disc.
7. The invention as defined in claim 1 wherein said linkage means
further comprises an actuating arm secured to and extending radially
outwardly from the flow meter rotatable member and an elongated
connecting arm pivotally secured at one end to said scribe arm at
a point radially spaced from the pivotal connection of said scribe
arm with said housing, and means for pivotally connecting the other
end of the connecting arm to said actuating arm at a point radially
spaced from the axis of rotation of the flow meter rotatable member.
8. The invention as defined in claim 7 wherein said adjustment
means comprises means for adjusting the pivotal connection of said
other end of said connecting arm longitudinally along said actuating
arm.
9. The invention as defined in claim 1 and further comprising spring
means for urging said writing means against said recording medium.
10. The invention as defined in claim 9 wherein said spring means
further comprises an elongated spring band secured to and forming
a part of the scribe arm, said writing means including a housing
having a portion through which the spring band extends.
11. For use in conjunction with a fluid flow meter having a rotatable
member the rotation of which is indicative of the fluid flow rate
through the flow meter, a device for recording the flow meter flow
rate over a period of time, said device comprising:
a housing;
a recording medium and means for substantially continuously moving
said recording medium in a predetermined direction, said writing
medium and said moving means being mounted in said housing;
an elongated scribe arm having a writing means secured to one end,
said writing means engaging said writing medium and producing a
visible mark thereon;
means for pivotally securing the other end of the scribe arm to
the housing so that, as the scribe arm pivots, said writing means
moves substantially transversely across said writing medium with
respect to the direction of movement of the writing medium; and
wherein said linkage means further comprises an actuating arm secured
to and extending radially outwardly from the flow meter rotatable
member and an elongated connecting arm pivotally secured at one
end to said scribe arm at a point radially spaced from the pivotal
connection of said scribe arm with said housing, and means for pivotally
connecting the other end of the connecting arm to said actuating
arm at a point radially spaced from the axis of rotation of the
flow meter rotatable member.
Description BACKGROUND OF THE INVENTION
I. Field of the Invention
The present invention relates generally to recording devices and,
more particularly, to a recording device adapted for connection
with a fluid flow meter and which produces a visible record of the
flow rate through the flow meter over a period of time.
II. Description of the Prior Art
Several types of fluid flow meter, such as a vane fluid flow meter,
include a rotatable shaft of the rotational position of which is
indicative of the flow rate through the flow meter. Conventionally,
this shaft is directly connected to an indicator needle which swings
across a scale in unison with the rotation of the flow meter rotatable
member. The scale includes suitable indicia which correlates the
rotation position of the flow meter rotatable member, and hence
the position of the indicator needle, with the flow rate through
the flow meter so that the fluid flow rate through the flow meter
can be visually determined exteriorly of the flow meter.
These previously known flow meters, however, have not included
means for recording the flow rate through the flow meter over a
prolonged period of time. Thus, transient fluctuations and long
term variations of the fluid flow rate through the flow meter will
be missed entirely unless the fluid flow meter is viewed continually.
Continual viewing of the fluid flow meter, however, is an impractical
and expensive solution for detecting transient fluctuations or long
term variations in the fluid flow rate through the flow meter.
There have, however, been a number of previously known recording
devices for recording the fluid flow rate through a flow meter.
These previously known devices, however, are not only expensive
in construction but also delicate in operation and thus unsuitable
for industrial purposes.
SUMMARY OF THE PRESENT INVENTION
The present invention overcomes the above mentioned disadvantages
of the previously known devices but providing a device for recording
the fluid flow rate through a flow meter over a period of time and
which is inexpensive and of a durable construction.
In brief, the recording device according to the present invention
comprises a housing which is secured to the fluid flow meter. A
suitable recording medium, such as a circular sheet of paper, is
mounted to the housing and rotatably driven at a constant rate.
Any suitable means, such as a simple and inexpensive clock mechanism,
can be employed to rotatably drive the recording medium.
An elongated scribe arm is pivotally connected at one end to the
housing and, at its other end, includes a writing instrument which
engages and produces a visible mark on the writing medium. Moreover,
the length of the scribe arm and its pivotal connection with the
housing is selected so that as the scribe arm pivots, the writing
instrument is moved substantially radially across the writing medium.
Thus, the radial position of the visible mark on the writing medium
caused by the writing instrument is proportional to the pivotal
position of the scribe arm.
The recording device further comprises an actuating arm secured
to an axle which in turn is rotatably mounted to the housing. The
actuating arm axle is connected by any suitable means to the flow
meter rotatable member so that the rotational position of the actuating
arm is proportional to the rotational position of the flow meter
rotatable member.
The actuating arm and scribe arm are connected together by means
of an elongated connecting arm pivotally secured at one end to the
actuating arm and at its other end pivotally secured to the scribe
arm. Moreover, the pivotal connection of the connecting arm with
both the actuating and scribe arms is radially spaced from their
respective pivotal connections with the housing so that pivoting
of the actuating arm causes a like and proportional pivoting of
the scribe arm thus radially displacing the writing instrument across
the writing medium.
BRIEF DESCRIPTION OF THE DRAWING
A better understanding of the present invention will be had upon
reference to the following detailed description when read in conjunction
with the accompanying drawing, wherein like reference characters
refer to like parts throughout the several views, and in which:
FIG. 1 is a front plan view illustrating the recording device according
to the present invention;
FIG. 2 is a fragmentary side view illustrating the recording device
according to the present invention and its connection with a fluid
flow meter;
FIG. 3 is a fragmentary view taken substantially along line 3--3
in FIG. 1 with parts removed and enlarged for clarity;
FIG. 4 is a fragmentary view illustrating a portion of the recording
device of the present invention;
FIG. 5 is a fragmentary view taken along line 5--5 in FIG. 1 and
enlarged for clarity; and
FIG. 6 is a fragmentary sectional view taken substantially along
line 6--6 in FIG. 1 and enlarged for clarity.
DETAILED DESCRIPTION OF THE PRESENT INVENTION
With reference first to FIGS. 1 and 2 the recording device 10
according to the present invention is thereshown for use with a
flow meter 12 having a rotatable member 14 the rotational position
of which is indicative of the fluid flow rate through the flow meter
12. As illustrated, the flow meter 12 is a vane type flow meter
of the type more fully described in U.S. Pat. No. 3776037 which
issued on Dec. 4 1973. The flow meter 12 however, forms no part
of the instant invention and, for that reason, will not be further
described.
Still referring to FIGS. 1 and 2 the recording device 10 further
comprises a housing 13 having a back wall 15 side walls 16 (only
one shown) and top and bottom walls 18 and 20 respectively. The
front of the housing 13 moreover, can be closed by a door 22 (shown
in FIG. 2 in an open position) which is pivotally secured to one
side wall 16 of the housing 13 by a hinge 24. The back wall 15 of
the housing 13 is secured to the flow meter 12. Latch members (not
shown) are provided around the housing 13 to retain the door 22
in its closed position when desired. Moreover, with the door 22
in its closed position, the door in conjunction with the housing
defines an interior chamber 28 which is generally rectangular in
cross section. A window 30 on the door 22 however, permits the
interior chamber 28 to be viewed exteriorly of the housing 13 even
when the door 22 is shut.
Referring to FIGS. 1 2 and 6 the recording device further comprises
a generally rectangular plate 34 secured to the back wall 15 of
the housing by bosses 36 and screws 38 so that the plate 34 lies
in a plane generally parallel to the door 22 when closed. As is
best shown in FIG. 6 a shaft 40 is rotatably mounted in a bearing
assembly 42 secured to the rear face 44 of the plate 34 so that
the shaft 40 has a portion 46 which protrudes outwardly from the
front face 48 of the plate 34. The opposite end of the shaft 40
is secured to the flow meter rotatable member 14 by means of a collar
50 (FIG. 2) so that the shaft 40 rotates or pivots in unison with
the flow meter rotatable member 14.
Referring now to FIGS. 1 and 5 a motor assembly 52 having an output
shaft 54 is secured by any suitable means to the rear face 44 of
the plate 34 and so that the shaft 54 protrudes outwardly from the
front face 48 through an aperture 56 in the plate 34. The motor
52 may be of any conventional construction but, in the preferred
form of the invention, is a spring wound motor which rotatably drives
its output shaft 54 at a constant rate, for example, one revolution
per day.
The output shaft 54 from the motor 52 includes a transverse slot
58. A circular sheet of paper 60 or other suitable writing medium,
includes a pair of central half-moon shaped aperture 62 which fit
over the motor output shaft 54 and so that a portion 64 of the paper
sheet 60 is positioned within the shaft slot 58. By this construction,
rotation of the shaft 54 in turn rotatably drives the paper sheet
60. A pair of holddown members 66 (FIG. 1) are also preferably secured
to the plate 34 and extend slightly over the outer edge of the paper
sheet 60 in order to maintain the sheet 60 flat against the plate
34.
Referring now to FIGS. 1 3 and 4 a scribe arm shaft 70 is rotatably
mounted in a bearing assembly 72 which is secured to the rear face
44 of the plate 34 and so that a portion 76 of the shaft extends
outwardly from the front face 48 of the plate 34 through an aperture.
A limit member 78 having a pair of upwardly protruding ears 80 is
secured to the rear end of the shaft 70 by a set screw 82. The ears
80 cooperate with protruding bosses 84 on the bearing assembly 72
and limit the rotation of the shaft 70 between two pivotal positions
as shown in phantom in FIG. 4 for a reason to be subsequently described.
Referring now particularly to FIGS. 1 and 3 an elongated scribe
arm 86 is secured at one end to the outwardly extending portion
76 of the shaft 70 by a set screw 88. The scribe arm 86 further
includes an elongated spring member 90. The spring member 90 extends
through a portion 92 of a writing implement 94 having a writing
tip 96 and the spring member 90 is biased so as to urge the writing
tip 96 against the paper sheet 60. As illustrated, the writing implement
94 is a so-called felt tip pen although any conventional writing
implement could alternatively be used. In addition, the limiting
member 78 (FIG. 4) limits the pivotal action of the scribe arm 86
between an inner radial and outer radial position with respect to
the circular sheet 60 and the scribe arm 86 is longitudinally dimensioned
so that it sweeps substantially across the circular sheet 60.
Referring now particularly to FIGS. 1 and 6 an elongated actuating
arm 100 is secured to the outwardly extending portion 46 of the
shaft 40 by a set screw 102 so that the actuating arm 100 rotates
in unison with the shaft 40 and thus in unison with the flow meter
rotatable member 14. One end of the actuating arm 100 forms a pointer
104 which sweeps across an indicia plate 106 upon rotation of the
shaft 40. Indicia plate 106 includes a scale indicative of the fluid
flow rate through the flow meter 12 and both the pointer 104 and
indicia plate 106 can be viewed through the window 30 on the front
door 22. The actuating arm 100 also includes a portion 110 which
extends radially outwardly from the shaft 40 opposite from the pointer
104 and has an elongated slot 112 formed through it.
Referring now to FIGS. 1 3 and 6 an elongated connecting arm
114 is pivotally connected at one end 116 to the actuating arm 100
and along the slot 112. As best shown in FIG. 6 the pivotal connection
between the connecting arm 114 and the slot 112 comprises a threaded
member 118 which lockingly engages a nut 120. Moreover, the screw
118 and nut 120 can be adjustably secured to the actuating arm 100
along the slot 112 without interfering with the pivotal connection
of the connecting arm 14.
As shown in FIG. 3 the other end 128 of the connecting arm 114
is similarly pivotally connected to the scribe arm 86 by a pivot
pin 130 at a position radially spaced from the axis of rotation
of the shaft 70.
In operation the actuating arm 100 connecting arm 114 and scribe
arm 86 together form a linkage means so that the rotational position
of the actuating arm shaft 40 in turn controls the pivotal position
of the scribe arm 86. For example, when the actuating arm 100 is
in a position indicating zero fluid flow through the flow meter,
the connecting arm 114 pivots the scribe arm 86 toward its radially
innermost position. Conversely, as the actuating arm 100 is rotated
in a counterclockwise direction (as viewed in FIG. 1) to its maximum
fluid flow rate, the actuating arm 100 pivots the scribe arm 86
to its radially outermost position via the connecting arm 114. Since
the circular sheet 60 is continually rotatably driven by the motor
52 the writing implement 94 on the scribe arm 86 produces a chart
on the circular sheet 60 indicative of the fluid flow rate through
the flow meter over a period of time.
As best shown in FIGS. 1 and 5 a lifting member 140 is pivotally
secured at 142 to the plate 34 and includes a portion 144 which
extends underneath the writing implement 94 and the lifting member
140 is pivotaly between a lifting position (illustrated in phantom)
and a nonlifting position (illustrated in solid line). In its lifting
position, the portion 144 of the lifting lever 140 engages and picks
the writing implement 94 up from the sheet 60 for example, when
replacement of the writing sheet 60 is desired. When a new sheet
60 is installed over the motor shaft 54 in the previously described
fashion, the lifting lever 140 is again returned to its lower or
nonlifting position and the tip 96 of the writing implement 94 again
contacts the writing sheet 60.
It can, therefore, be seen that the recording device 10 according
to the present invention is advantageous in that it provides a written
record of the flow rate through a flow meter over a predetermined
period of time, for example, a one day period. Moreover, the entire
recording device can be relatively inexpensively constructed and
is virtually maintenance free in operation. In addition, since the
rotational or pivotal movement of the flow meter rotatable member
14 varies from one flow meter to another, the longitudinal adjustment
slot 112 in the actuating arm 100 insures that the scribe arm 86
can swing entirely radially across the circular sheet 60 for different
rotational displacements of the actuating arm 100.
Having described my invention, however, many modifications thereto
will become apparent to those skilled in the art to which it pertains
without deviation from the spirit of the invention as defined by
the scope of the appended claims. |