Note: Descriptions are shown in the official language in which they were submitted.
1046797
FUEL USE RATE METER FOR ENGINES
This invention relates to a meter for measuring the rate of
fluid flow such as for determining the rate of fuel usage in an
engine.
The efficient functioning of engines comprises an important
factor in the operational aspect of trucking firms, marine firms,
and other firms which use engine driven equipment. These engines
are tested periodically for output efficiency to determine whether
or not repair or overhaul is necessary. Various testing methods
are used, a common one employing a dynamometer. Another method
to determine whether the engine is to be repaired or overhauled
is merely ~y considering total miles run or hours operated. With
the use of a dynamometer, or other methods now used, a precise
analysis of engine condition is not altogether possible because of
variables which may exist from engine to engine such as ignition
condltions.
The most efficient method of determining engine condition is
to ascertain the amount of fuel consumed by the engine per unit of
time. Prior devices have not accomplished this method of testing
in a commercially feasible manner because the meters used, while
showing fuel usage, do not give a direct reading of the rate that
the fuel is used. In prior devices, it is thus necessary to make
computations from the meter reading, which of course is incon-
venient and many times inaccurate. Another disadvantage of prior
devices is that they do not compensate for the expansion or con-
traction of fuel due to variations in temperature, and thus the
' fuel is not accurately metered, particularly in slow flow systems
such as fuel feed systems for engines. Although temperature con-
version tables are available, based on a temperature constant, for
` determining volune of flow, such computing method is often in-
accurate and always inconvenient. In some cases the use of con-
version tables is also impractical.
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In view of the above, means heretofore used for determining
the condition of engines by ascertaining fuel consumption or miles
or hours logged are not considered to be adequate because such
means do not indicate with the necessary preciseness the condition
of an engine. This may result in overhaul or repair w~lich is not
necessary, or on the other hand engines may remain in operation
when in fact they should be overhauled or repaired.
It is therefore a primary objective of the present invention
to provide a meter for use in a fluid flow system which indicates
directly the rate of fluid flow. Such meter is particularly adapted
for use in conjunction with a vehicle engine to show the rate at
which fuel is being consumed and thus to indicate the mechanical
condition of the engine.
Other objects of the present invention are to provide a meter
of the type described which includes adjustment means compensating
for temperature variations; which has a structure wherein indicating
means forming a part thereof may be remotely located from the drive
means of the meter; which may be combined with other treating means
such as temperature control means and bubble removing means; and
which includes a lever-operated bypass valve capable of either
directing fuel through the meter or around the meter.
A principal object is to provide a fuel measuring system
arranged for use with an engine having fuel supply means and in
which a portion of fuel fed thereto is unburned and including a
return line from the engine arranged to recirculate unburned fuel
back to the engine, said fuel measuring system comprising measuring
means having a movable measuring member operated by the simultaneous
i admission and discharge of fuel, said measuring means having means
for connection prior to the combining of the recirculated fuel and
the fuel supply means, an electric circuit, electric sensor means
in said circuit sensing movements of said movable member, and means
responsive to said sensor means providing an indication of fuel
flowing through said measuring means.
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Additional objects will become apparent from the following
description taken in connection with the accompanying drawings.
Figure 1 is a diagrammatic view of a fuel system including
the present fuel use rate meter for engines;
Figure 2 is a vertical sectional view of the present meter,
taken on the line 2-2 of Figure 3;
Figure 3 is a horizontal secti.onal view taken on the line
3-3 of Figure 2, this view being reduced in size relative to Figure
2 and having some of the parts omitted;
Figure 4 is an enlarged, horizontal sectional view taken
on the line 4-4 of Figure 2;
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Figure 5 is an enlarged vertical fragmentary sectional view
taken on the line 5-5 of Figure 4;
Figure 6 is a fragmentary vertical sectional view taken on
the line 6-6 of Figure 2;
Figure 7 is an elevational view of a barrel cam which com-
prises a part of internal drive means for the meter and which is
shown apart from ot'ner structure for clarity;
Figure 8 is a face view of an indicating instrument which
forms a part of the present system;
Figure 9 is a rear view of the instrument of Figure 8 showing
adjustment means thereon;
Figures 10 through 14 comprise diagrammatic views of various
fuel systems incorporating the present rate meter;
Figure 15 is a fragmentary plan view of an electrically
operated pickup system between drive means of the meter and in-
dicating means;
Figure 16 is an elevational view, partly broken away, showing
a modified form of rate meter;
Figure 17 is a fragmentary bottom plan view taken on the line
17-17 of Figure 16;
Figure 18 is a fragmentary sectional view illustrating a
modified form of indicator drive means which may be associated with
the structure of Figure 16; and
Figure 19 is a fragmentary elevational view showing a modified
structure of the barrel cam means of Figure 7.
With particular reference to the diagrammatic view of
Figure 1, an engine is designated by the numeral 10 and conven-
tional fuel feed means therefor comprising a fuel tank and a fuel
. line are designated by the numerals 12 and 14, respectively.
Forming a part of the present invention is a fuel meter
apparatus 16 which upon being driven by fluid flow operates in a
manner to provide accurate information in a direct reading on an
instrument to indicate operating conditions of an engine, as will
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1~467~7
be more apparent hereinafter.
The meter 16 is structurally detailed in Figures 2 through
6. It comprises an outer casing 1~ of cylindrical shape. Casing
18 has a bot~om wall 20 with projections 21 thereon for a purpose
to be describe~. A sleeve 22, forming a cylinder, is disposed
within the casing 18. The casing has a head 26 removably fitted
therein.
As best shown in Figures 2 and 4, the casing 18 has an in-
let 32 and an outlet 34 disposed substantially in diametrical re-
lation. The meter apparatus is associated with a bypass valve 35to be described hereinafter which preferably is formed with the
casing 18 in a common casting. The housing for the meter and
bypass valve is ins~alled in the fuel line 14 by conventional means,
with cut ends of the fuel line engaging the bypass valve and outlet
34 in the casing 18 by suitable fittings 14a. A passageway 36 in
the head 26 leads from the inlet 32 and opens into the interior of
the meter casing, and a passageway 38 also in the head leads from
the outlet 34 and opens into the interior of the meter casing in
laterally spaced relation to the outlet of the port 36. A third
passageway 40 extends from a point of inlet interiorly of the
meter casing which is disposed between the outlet of passageways
36 and 38 to a side of the head beyond the sleeve 22, best seen
in Figure 4. The head 26 and the outer casing 18 are cut away
vertically in the plane of the outer end of the port 40 to provide
a vertical passageway 42, Figure 4. This recess establishes
communication between the passageway 40 and the bottom of the casing.
It will thus be seen that the passageway 36 leads from the inlet 32
to the top region of the casing, the passageway 40 leads from the
said top region to the bottom of the casing, and the passageway
1 '
38 serves as an exhaust passageway connected to the meter outlet.
Valve mechanism will now be described to cause the fluid to
flow alternately to the upper and lower cylinder regions and ulti-
mately be exhausted through the outlet 34 for driving plunger means
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1~46797
up and down in the cylinder. The head 26 has a depending, round
center guide post 44 projecting into the casing at about the center
thereof. This post projects integrally from the upper wall of a
recess 45 cut in the lower surface of head 26. Also depending
from the head 26 but at the sides, are two guide posts 46 and 48
disposed in diametrically opposed relation. Each of the posts 46
and 48 is formed with upper and lower flanges 50 and 52, respect-
ively, and a central horizontal projection 54 on each side thereof,
the flanges 50 and projection 54 being arranged to form horizontal
slots between them which function as guides. Such guide slots are
formed on two sides of the posts, namely, the front and rear,
considering the front to be toward the viewer in Figure 2.
The two posts 46 and 48 slidably support a valve support
plate 56 on the front side thereof, best seen in Figures 2 and 4.
Valve plate 56 has a pair of arms 58 on each end ~lidably received
within the slots formed on the front side of the respective posts
46 and 48, the valve plate and arms being of selected dimension as
to be reciprocatable horizontally a short distance within the casing.
The posts similarly mount a loader plate or slide 60 on the other or
rear side thereof, this plate also having spaced end arms 62, Fig-
ure 5, received in a similar fashion in the post slots as are arms
58 of valve plate 56 on the other side, the loader plate and its
arms also being dimensioned so as to be horizontally reciproca-
table a short distance. Washers 64, Figures 4 and 5, are provided
at the front and rear of the support posts and are held in place
by bolts 66 to maintain the plates 56 and 60 within their parti-
cular slots of the posts. The loader plate 60 has two spaced arms
68 which project substantially at right angles from the body of the
plate in a forward direction and forward beyond the body of the
valve plate 56 and below the latter. Attached to the portion of
the valve plate 56 between the arms on the loader plate 60 is a
trip element 70 projecting both to the front and rear of the valve
plate in parallel relation to the arms 68. A shaft 72 is supported
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10467~7
between the arms 68 and also passes slidably through the trip
element 70. A first compression spring 76 is supported on the
shaft 72 between the trip element 70 and one arm 68 of the loader
plate and a second compression spring 78 is supported on the shaft
72 between the trip element and the other arm 68.
Valve plate 56 has a forwardly extending right angle tab or
ear 80, Figures 2 and 6, disposed below the region of the outlets
of the three passageways 36, 38 and 40 into the casing, and mounted
on such ear is an inverted cup valve 82 having a bottom stem 84
freely received within an opening provided therefor in the ear.
A coil spring 86 is disposed between the ear and the cup valve
about the stem and holds the valve firmly against the underside
of the head 26. As illustrated, the valve diameter is such that
its hollow or recess portion bridges at one time both the outlets
from passageways 36 and 40 or alternatively both the outlets from
passageways 38 and 40, depending upon the position of the valve in
two limit positions.
Slidably mounted on the post 44 is a piston rod 88. This
rod has a box-like shape, Figure 6, which provides for slidable
connection on the post, and projecting rearwardly from the piston
rod at the upper end thereof is a drive pin or projection 90. Piston
rod 88 has a lower transversely extending cut-out portion 94, re-
spectively, and post 44 has a cut-out portion 96 which as will be
more apparent hereinafter is adapted for lateral alignment with
the cut-out portion 94 at a down position of the piston rod. Drive
pin 90 projects into an upright angled slot 98 in the loader plate
60, and upon up and down movement of the piston rod, the loader
:,.
plate is cammed first to one side and then to the other. Such
movement of the loader plate in one direction compresses one of
the springs 76 between one of the arms 68 and the trip element 70
and in the other direction compresses the other spring between the
other arm 68 and the trip element 70.
Integrally connected to the bottom end of the piston rod 88
is a piston 100, Figures 2 and 6, having a liquid tight engage-
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1046797
ment in a suitable manner at its peripheral edge with the inner
wall of the sleeve 22.
As to the operation of the meter, reference is first ~ade to
Figure 2 wherein the piston 96 is disposed at its lower position
and the valve 82 connects the passageway 36 with the passageway
40. Fluid at this time is directed to the bottom of the casing
through passageway 42 for lifting the piston. As the piston is
driven upwardly the fluid above the piston in the casing is dis-
charged through the outlet passageway 38. Also during the upward
travel of the piston, the loader plate 60 is caused to be shifted
to the right due to the camming action thereon by the drive pin
90, and this causes the spring 76 to be compressed since the valve
plate 56 is restrained from moving correspondingly by engagement
of its trip element 70 with the left side of the piston rod 88 in
the area above cut-out portion 94. Such upward travel of the
. piston continues with progressive compreqsion of the spring 76
until the bottom cut-out portion 94 of the piston rod reaches a
; height sufficient to allow the trip element 70 to pass therethrough,
such upper position of the piston being shown in phantom lines in
Figure 2. This releases the valve plate for quick movement to the
right under the action of the loaded spring 76. Since the cup valve
82 moves with the valve plate 56 it will then be disposed in a posi-
. tion connecting passageways 40 and 38. Fluid is then introduced
:: to the upper area of the casing through inlet passageway 36 and the
piston is driven downwardly, the exhaust flow of the fluid at the
bottom of the piston being driven up through the vertical passage-
way 42 and out the outlet passageway 38. As the piston moves
downward, it causes ~he loader plate 60 to be shifted to the left
due to the camming action thereof from drive pin 90 and this causes
the spring 78 to be compressed. Such downward travel of the pis~
ton continues until the trip element 70 passes over the top of
the piston rod 88. ~ovement of the trip element 70 over the piston
rod 88 allows the spring 78 to move the valve plate 56 to its other
1~46797
position and again cause the fluid to be directed under the piston.
At this point the piston is slightly spaced above the projections
21 of the bottom of the cylinder. The cycle described above is
repeated continuously as long as fuel is supplied to the meter.
Thus, as the piston reciprocates in its up and down movement,
the loader plate 60 reciprocates laterally. As a part of the present
invention, it is desired that the output of the meter be rotational
and the structure to be described and best shown in Figures 4, 5 and
7, is provided to convert the lateral reciprocal motion of such
loader plate to rotational movement for a purpose which will become
more apparent hereinafter. The drive pin 90 on the piston rod 88
projects beyond the loader plate 60 and is engaged in a sinuous type
slot 102 in the periphery of an upright barrel cam 104 disposed
adjacent to the rear side of loader plate 60. This cam has project-
ing shaft ends 106 for rotatable support in the caEing, the upper
shaft end extending into a bearing socket 108 in the casing and the
lower shaft end rotatably engaged in a bore 110 in a U-shaped
bracket 112 secured to the underside of head 26 as by screws 113.
The upper portion of the barrel cam 104 extends into a recess 114
in the head 26 to accomplish proper operation of the drive pin 90
in the cam slot. The cam slot 102 i.s of selected positioning and
- shape such that as the piston moves up and down, the drive pin 90
rotates the cam. The particular shape of the cam slot allows the
drive pin to move around the ends thereof so that even though the
pin is reversing direction in up and down movement, or vice versa,
the cam rotates at a smooth uninterrupted speed. Cam 104 has sur-
face projections 115 thereon disposed in spaced relation and having
peak portions ll5a. Engageable with the projections 115 is one or
more, preferably two in diametrical relation, spring pressed ball
assemblies 116 threadedly supported in the bracket. The spring
pressed ball assemblies and projections 115 are arranged such that
as the drive pin 90 is almost to an end or turn portion of the cam
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1046797
slot 102 the spring pressed ball thereof rides over the ridge 115to urge the barrel cam rotatably in its forward direction and in-
sure that the drive pin will turn the corner and continue into the
next segment of the cam slot.
The upper end of barrel cam 102 integrally supports a drive
gear 117 having meshing engagement with a driven gear 118 secured
on an output shaft 119 rotatable in the head 26. Shaft 119 is
secured to a coupling 120 which connects this shaft to a flexible
cable 122. Such coupling is contained within a fitting 124 having
a screw threaded mounting in the head 26.
With reference again to Figure 1, as well as to Figures 8 and
9, the cable 122 leads to a tachometer-like instrument 132 having
the usual indicating needle 134. This instrument is graduated in
units 136 which depict fuel usage such as gallons or pounds. With
proper calibration of the instrument 132 and lead angle of cam
slot 102, an indication is available directly on the instrument of
the fuel being consumed by an ~ngine per unit of time to determine
' with the utmost accuracy the rate of fuel usage. Such reading can
be used to determine the general condition of the engine under
specific load conditions. Units 136 may be graduated for reading
in volume of fluid per unit of time or volume of fluid per unit of
weight.
The tachometer-like instrument 132 includes counter means
138, Figure 8, for permanently recording the volume of fluid used.
This instrument may also have counter means 140 which similarly
shows the volume used per unit of time or per unit of weight but
which have reset means 142 for resetting the counter means 140 back
to zero. Such an instrument, which is of well known structure
except for the graduated marking thereof, will thus indicate the
j 30 rate of fuel usage and at the same time will record accumulated
fuel usage and individual tests of fuel usage. With reference to
Figure 9, which shows a rear view of the instrument 132, adjust-
ment means 144 are available for adjusting the operation of the
instrument for a specific purpose or to correct the accuracy thereof.
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~ 04679'7
For example, the specific gravity of fuel may vary and it may be
necessary to correct the accuracy of the instrument as related to
the particular specific gravity of the fuel.
The instrument 132 may be mounted closely to the meter 16 or
since it is operated by a flexible cable it may be mounted at a
remote location. The present fuel system has the advantage that
the meter apparatus 16 may be mounted in the engine compartment
and the instrument 132 mounted in the cab for easy viewing by the
driver or by test personnel.
Figure 10 shows a system somewhat similar to Figure 1 with
the exception that a treatment tank 146 is provided in a line 148
extending from the engine 10 and connected into the fuel line 14
on the engine side of the meter apparatus 16. The system of Fig-
ure 10 is used with an engine 10 of the type which returns un-
burned fuel, such as a Diesel engine. The tank 146 has means 150
against which incoming fuel impinges for removing air bubbles from
the return fuel i~ any. The tank is vented at 152 for dlscharge
of air. Tank 146 in addition to removing bubbles can be used to
cool the fuel in order that the fuel is fed back to the engine at
a proper temperature.
Figure 11 shows another system which includes a fuel tank
12, a fuel line 14, the metering apparatus 16 in the fuel line 14,
and an engine, not shown, together with a return line 148 as in
Figure 10. Line 148 may have a treatment tank, not shown, si.milar
to tank 146 in Figure 10, if desired. The system of Figure 11
differs from Figure 10, however, in that the fuel return line 148
frGm the engine is connected back into the fuel tank instead of
into the fuel line 14 and such return line includes a second fuel
meter 16a adapted to record the flow of fuel similar to the meter
16. Since unburned fuel is returned to the tank 12, the exact
amount of fuel consumed by the engine will comprise the differential
of readings between meters 16 and 16a. For this purpose, the out-
puts frorn the two meters 16 and 16a are fed to a proportioning
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1046797
gear box 153 the output of which is fed to the tachometer-like
instrument 132 by a flexible cable 154. The indication on instru-
ment 132 will thus give the rate of fuel consumption by the engine.
Figure 12 shows still another system which is si~ilar to
Figure 10, employing a fuel tank 12 and a fuel line 14 leading
between the tank and the engine 10. The system also employs a
return line 14~ having a treatment tank 146 therein. The system
of Figure 12, however, includes temperature control means 155,
which serves to admit fuel to the engine at a constant temperature.
Such unit has suitable cooling means controlled by a thermistor
156. In the system of Figure 12, great accuracy of engine per-
formance is determined from instrument 132 since the fuel is fed to
the engine at the most desirable conditions.
Figure 13 illustrates an arrangement wherein the fuel meter
16 drives a cable 122 as in previous embodiments but instead of
the cable 122 driving the instrument 132 directly said cable leads
to a gear box 158 having a dual output 122a and 122b in direct
ratio drive. The output 122a leads to the tachometer-like instru-
ment 132 and the output 122b leads to a recording mechanism 160.
The recording mechanism is of conventional construction, comprising
the usual clock driven circular chart on which is recorded by means
of a stylus the rotative operation of output 122b. By means of
this system, not only can personnel determine the volume of fuel
being used per unit of time or per unit of weight but in addition
a permanent record is made of the fuel used per unit of time or
per unit of weight.
Figure 14 shows a further extension yet of a concept of the
invention. Its purpose is to combine the output of a meter of the
type described which measures fuel usage per unit of time with the
output of a speedometer to get a resultant of fuel usage of dis-
tance or revolutions per gallon. For example, the output cable
122 from the meter 16 operates a sensor 170 and an output cable 172
from a speedometer 174 which is driven by the drive shaft of the
vehicle or, if used to designate boat engine operationS by the
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~ 0467~7
propeller shaft, operates a sensor 176. The output from sensors
170 and 176 are combined electrically in a voltage or pulse divi-
der 178 to get a resultant force on an electrically operated meter
180 depicting fuel usage per unit of distance. That is, by feed-
ing gallons per hour, for example, into sensor 170 from meter 16
and feeding miles per hour into sensor 176 from speedometer 174,
the resulting output from voltage divider 178 will designate miles
per gallon, or if for boat operation, knots per gallon. Meter
180 has an output for driving a recording mechanism 160 of a type
previously described.
Figure 15 shows a concept of the invention wherein a tachom-
eter-like instrument 132' comprises an electrically operated tachom-
eter of well known structure. For this purpose, the output shaft
119 supports and drives a gear 182 at the upper surface of head 26.
Mounted on the head 26 is an electro-magnetic pickup device 184
of well known structure connected electrically to the tachometer-
like instrument 132'. Rotation of the output shaft 119 is thus
transferred electrically to the instrument 132' and as in other
structures herein the instrument records directly the rate of fuel
consumption.
Referring particularly to Figures 2 and 3, the bypass valve
35 is cast as an integral part of meter 16. It has a hollow in-
terior including a bore 190 and upper and lower chambers 192 and
194, respectively, on opposite ends of the bore. Inlet 32 to the
meter leads from upper chamber 192 of the valve. Forming the
operative part of the valve is a stem 196 of considerably less
diameter than the bore 190 and movable axially therein. Secured
to upper and lower ends of the stem are diaphragms 198 and 200,
respectively, abutting against shoulder portions 202 in the housing.
The chambers 192 and 194 are closed at the ends by removable walls
204 and 206, respectively.
The diaphragms 198 and 200 have tapered hubs 208 and 210,
respectively, engageable with the end edges of the bore 190 to
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1~46797
control the flow of fuel through the valve. The arrangement of
the parts is such that the stem 196 and the hubs 208 and 210 are
movable axially a short distance, and the hubs in such axial move-
ment are arranged to have wedging sealing abutment against one or
the other of the respective end edges of the bore 190.
The valve housing has an outlet passageway 214 which extends
up from chamber 194 to one side and out of communication with bore
l90, and this passageway communicates with a passageway 216 extend-
ing around the valve housing and meter casing, Figure 3, to the
outlet 34 of the meter casing. An inlet passageway 218 extends
from an outer side of the valve housing between bore 190
and fuel line 14.
In the operation of the valve, flow from the inlet passage-
way 218 and bore 190 can flow through either the inlet 32 to the
meter and out outlet 34 or through outlet 214 to bypass passageway
216 and out outlet 34, depending upon the position of stem 206.
That is, in a down position of the stem as shown, fuel from fuel
; line 14 bypasses the meter by flowing through the latter route
mentioned above, namely, through passageway 218, bore 190, passage-
way 214, bypass passageway 216 and outlet 34 to the fuel line 14.
In the up position of the stem, fuel from fuel line 14 flows through
the meter 16, namely, through passageway 218, bore 190, passageway
32 and passageway 36.
The stem 196 is urged to an upper position by a compression
spring 220 between end wall 206 and the stem wherein normal flow
is through the meter. However, to position the stem to a down posi-
tion, a lever 222 is mounted pivotally between a pair of ears 224
on top of the valve housing, and this lever has a cam end 226 in
engagement with a vertical pin 228 extending slidably through the
top wall 204 and abutting against the top end of stem 196. In
normal metering flow, the lever 222 is thus positioned so as to
allow the spring 220 to raise the stem. ~f it should be desirable
that the fuel flow bypass the meter, the lever is positioned so
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1046797
as to lower the stem ~o the position s'nown in Figure 2.
Figure 16 shows a somewhat modified form of meter 16'.
This meter similar to the meter sho~n in Figures 206, has an outer
casing 18', a piston 100' and mechanism for operating the plunger
up and down in reciprocating motion which includes the piston rod
88 and the other structure which will not be repeated for this
embodiment~ including the fluid passageway means and valve means
for causing the reciprocating drive movement of the plunger.
In the structure of Figure 16, the piston or plunger 100'
comprises a nut 234 secured integrally to the bottom end of piston
rod, and this nut threadedly receives a shaft 236 which extends
through the bottom wall of the casing în a fluid seal 237. The
shaft also extends through the piston 100' and a pair of plates
238 disposed on opposite faces of the piston. These plates have
arcuate or bulbular portions 240 and are constructed of metal
having a high coefficient of expansion, whereby upon variation
in temperature the arcuate portions expand away from and eontract
toward the piston. The piston carries an outer gasket 242 to pro-
vide sealing engagement with the inside surface of the casing, and
the outer peripheral edges of the plates 238 extend between a flange
portion 244 of the gasket and the piston. The diameter of the
plates 238 is slightly less than the diameter of the piston to allow
for lateral adjustment of the peripheral edge of the plates upon
expansion and contraction.
Threadedly mounted on the shaft Z36 on the bottom side of the
piston and on the outside of the bottom plate 238 is a nut 246.
The two threaded portions of the shaft 236 which engage the respect-
ive nuts 234 and 246 have opposing thread in an arrangement such
that when the shaft 236 is turned in one direction the nuts draw
the plates inwardl~J toward each other and upon rotation of the
shaft 236 in the opposite direction the bulbular portions of the
plates are moved apart. Compression springs 243 maintain the bul-
bular portions of the plates outwardly against the respective
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adjusting nuts.
The projecting end of shaft 236 carries a knob 250 whichas best s~en in Figure 17 is associated with graduation marks 252
provided on the bottom of the casing 18'. Such graduation marks
indicate adjusted rotative positions of the shaft 236 in the posi-
tioning of the bulbular portions 240 of the plates 238 relative
to the piston 100' for a purpose to be described hereinafter.
As was described hereinbefore in connection with the structure
of Figures 2-5, the piston is operated by fluid in a reciprocating
motion for driving indicating or counter means. In such recipro-
cating action, it drives a selected amount of fluid from areas on
each side thereof. The structure of Figure 16 automatically adjusts
itself to meter accurately even though the volume of the fluid
therein changes due to a variation in temperature. That is, the
plates 238 have specific expansion and contraction characteristics
such that when the fuel is warmer than a set constant, they expand
away from the piston 100 to reduce the volume of the area in which
the stroke of the piston occurs. By correlating the expansion
characteristics of the plates 238 and the expansion characteristics
of the fluid, exact metering is accomplished. If the liquid should
cool below the constant, the plates 238 contract to enlarge the areas
in which the piston operates. The expansion characteristics of
fluids of different specific gravities may vary, and for this pur-
pose the shaft 236 may be rotatably adjusted by knob 250 to posi-
tion the plates 238 according to well known characteristics of
expansion and contraction of various liquids. ~ proper setting of
the knob 250 as determined by the specific gravity of the fuel
being metered will provide accurate results.
In the embodiment of Figure 16, the head 26' of the meter is
altered relative to the structure of Figure 1 to the extent that it
contains a counter mechanism 256 of conventional construction
operating on a shaft 258. One end of the shaft has a bevel gear
260 secured thereon and according to the present invention, the
~46797
output shaft 119 instead o~ projecting through the head as in
Figure 5, has a bevel gear 262 thereon in mesh with the bevel
gear 260 for driving the counter mechanism 256. The head 26' has
; a removable cover 264 with a transparent or window portion 266
for viewing the counter.
Figure 18 is a fragmentary section view of a portion of the
head 26' and shows an embodiment wherein an end of shaft 258' of
the counter mechanism 256 has a coupling 268 with a flexible shaft
assembly 270 which leads to a remote counter system or a tachom-
eter-like instrument 132 of the type previously described. By
means of the structures of Figure 18 remote counter means may be
made available in addition to the counter 256 so that even though
the meter is mounted in the motor well of a vehicle, the counter
can be located in the cab.
Figure 19 shows a modified structure of the barrel cam 104'.
The cam of this embodiment, while having the same slot structure
and operation as described in connection with Figure 7, employs
leaf springs 274 at the ends of the cam slot 102. These springs
are positioned to one side of the slot end, such positioning being
on the side in which the drive pin is advancing. They are arranged
such that when the pin has passed the spring, it is advanced around
the turn and cannot travel back in the same segment of the slot.
As the pin springs past springs 274, the cam is also urged for-
wardly so as to rotate smoothly and without interruption when the
drive pin is at the turn.
Summary
.
According to the present invention, a fuel system is provi-
ded which allows operators to not only operate an engine in the
most efficient manner but also to examine fuel usage to test the
condition of the engine. That is, by viewing on the instrument
132 the volume of fuel being used per unit of time or per unit of
weight under a particular load condition, a most efficient method
is available of directly ascertaining engine efficiency and con-
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~sequently whether or not the engine needs repair or overhaul.
Such method has important advantages over other types of engine
tests because an accurate knowledge of fuel consumption based on
a particular load gives a direct indication without variables
of the engine's condition.
The system of Figure 12 is even more accurate in that the
fuel is always fed to the engine at optimum conditions for greater
efficiency. The structure of Figure 16 wherein adjustment is made
for the temperature of the fuel provides for even greater effi-
ciency, and it is to be understood that such type of meter can beused with any of the systems disclosed herein. Adjustment of the
expansion means in the meter of Figure 16 according to the specific
gravity of the fuel is accomplished by adjusting knob 250. In
connection with the embodiment of Figure 16, the output shaft 258'
can drive a flexible cable assembly 122 as in the embodiment of
Figure~ 2-5 wherein the meter casing 18' can be placed in the motor
well and the indicator or counter means driven thereby can be
placed in the cab or other place which is convenient for inspection.
The present system may be used in conjunction with almost
any engine of the fuel burning type such automotive, marine or
stationary engines. The throttle of an engine may be set by use
of the present rate meter rather than by revolutions per minute.
It is to be understood that the forms of my invention here-
in shown and described are to be taken as preferred examples of the
same and that various changes in the ~hape, size and arrangement of
parts may be resorted to without departing from the spirit of my
invention or the scope of the subjoined claims.
i
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