US2228615A

US2228615A - Flowmeter

Info

Publication number: US2228615A
Authority: US
Inventors: Frank W Thomas
Original assignee: Allen Electric and Equipment Co
Current assignee: Allen Electric and Equipment Co
Priority date: 1937-08-12
Filing date: 1937-08-12
Publication date: 1941-01-14
Anticipated expiration: 1958-01-14

Description

J an.14,1941.

F. W. THOMAS FLOWMETER Filed Aug. 12, 1957 3 Sheets-Sheet 1 65 i 100 110 (oz 55 1 12 5.; a L I 1 f F? 5 e 54 5 a KI BY IN VENTOR.

' ATTORNEY .5

1941- F; w. THOMAS FLOWMETER Filed Aug. '12, 1957 3 Sheets-Sheet 2 1N VENTOR. Fran/r W. 7/70/7746 BY Q ATTORNEYJ.

W 4 \af, m 2/2 I r n U10 6 4 mm W Jan. 14, 1941.

F. w. THOMAS 2,2

FLOWMETER Filed Aug. 12, 1937 3 Sheets-Sheet 3 Mar/706 ATTORNEYS Patented Jan. 14, 1941 UNITED STATES FLOWMETER Frank W. Thomas, Pasadena, Calif., usignor to Allen Electric & Equipment 00., Kalamazoo,

Mich.

Application Auguit 12, 19:1, sci-n1 No. 158,713

. 2: Claims. (Cl. 73-209) This invention relates to improvements in fiowmeters. 1

This invention relates to flowmeters primarily for use in measuring the flow of fuel to internal 5 combustion engines when employed in their various uses. It hasfor its objects:

First, to produce a new and improved flowmeter.

Second, to produce such a device which is suit- 10 able for use in internal combustion engine work to determine the amount of fuel employed over a given period of time.

Third, to produce such a device which is extremely accurate and which may be made quite 1 inexpensively.

Fourth, to provide such a device in which the flow of the fluid to the internal combustion engine provides all the essential power for operation without substantially interfering with the regular flow of the fuel and which can be operated with a minimum amount of said fuel, so thatthe operation of the engine in starting will not be interfered with..

Fifth, to provide such'an apparatus in which 25 the flow of fuel to the engine is utilized through diaphragm means. 8

Sixth, to provide such a device in which reductions in the eifective area of the diaphragm are compensated for.

Seventh, to produce a spring means suitable for use in opposing the action of the diaphragm and for compensating for reduction in eflective area of the diaphragm as it advances which de- 35 vice is substantially free from friction.

Further objects and advantages pertaining to details and economies of construction and operation will appear from the description to follow. Preferred embodiments of my invention are illus- 40 trated in the accompanying, drawings, in which:

Fig. 1 is a front elevational view of my improved apparatus.

Fig. 2 is a front elevational view of the working portion of my apparatus partly in section to show certain of the working mechanism.

' Fig. 3 is abottom plan view of'the apparat taken on line 8-3 of Fig. 2. I Fig. 4 is a detail sectional view taken on line 50 H Of Fig. 2.

Fig. 5 is a detail sectional view of the apparatus taken on line 5-5 of Figs. 2 and 3.

Fig. 6 is a fragmentary view taken from the right hand side of Fig. 2, portions beingbroken 55' away to show the operating mechanism and suitable screw fastening means 1.

showing the variable orifice of the meter in open position. i

Fig. 7 is a detail sectional view taken on line 1-1 of Figs. 2, 4 and 5.

Fig. 8 is a detail sectional view taken on the 5 line 8-8 of Fig. 6.

Fig. 9.is a perspective view of the working mechanism of my device with the outer covering and the dial removed.

Fig. 10 is a rear view of my apparatus with 10 the outer covering removed and with the back of the casing removed to show the arrangement of the diaphragm and the spring which opposes the movement of the diaphragm.

Fig. 11 is a detail perspective view of a portion of the indicator mechanism.

Fig. 12 is a. detail perspective view showing more of said indicator operating mechanism.

Fig. 13 is a detail sectional view showing a modified form of toggle joint for use in connection with the spring mechanism for opposing movement of the diaphragm, showing the apparatus in full line in one position and in dotted lines in one of its other positions.

Referring to the drawings, I is an outer covering having a handle 2 for transporting the same. The working parts of the mechanism are enclosed within this outer covering to permit ease in transportaion and to protect the operating parts and to improve the appearance of the device. The operating mechanism of the device consists of a casing 3 formed of two

halves

4 and 5 which are sealed together with a gasket 6 and v A main fuel passage for the fuel to be metered is indicated generally at 8. At the up-stream end of this passage 8 is an inlet 9 which is provided with a suitable nipple Ill and a rubber hose connection H- for connection to the gasoline pump or source of supply for operating an internal combustion engine to be tested. A suitable filter I80 is disposed in the inlet 8 to strain the dirt, lint, etc. from the gasoline. I prefer to use for this tubing a synthetic rubber material sold commercially under the trade name Duprene." The outlet I! at the down-stream end of passage 8 is provided with a nipple i8 and a tube l4 similar to the tube II which connects the apparatus with the fuel line leading to the carburetor of the internal combustion engine to be tested.

Disposed in the passage 8 is a variable orifice i8 consisting of a let it screw threaded at I] in the passage 8 and having a taper extended with the restricted end in the passage 8. A ball I8 passage through the jet |6 so that a slight jet.

amount of fuel may always pass through the Disposed within the casing 3 is a diaphragm 28 made of any suitable flexible material. The diaphragm is formed of a very thin substantially friction-less material sold commercially as Neoprene. This is very thin. aeroplane cloth treated with the synthetic rubber product Duprene above referred to. In my device, I have found that a diaphragm five inches in diameter is substantially the proper size for the purpose intended. The diaphragm 28 divides the chamber 3 into an up-stream chamber 2| and a down-stream chamber 22. A restricted passage 23 extends from the portion of passage 8 up-stream from the jet l6 to the up-stream chamber 2|. The down-stream chamber 22 communicates directly at 24 with the jet l6 downstream from the ball l8. The passages 23 is restricted to dampen the movements of the diaphragm which might result from uneven operation of a fuel pump, road vibrations or any other reason and in running a road test with.my ap- 'paratus the fuel is preferably admitted to the chamber 2| only through sage 23.

In operating my device on the floor for testing stationary engines or for testing automobile engines or the like, or where dampening is not necessary, I admit fuel to the chamber 2| the restricted pasthrough an additional passage 25 which is controlled by a needle valve 26 having an outlet 21,

a valve seat 28, a valve body 29 screw threaded at 38 to the valve casing 3| and provided with a knurled knob 32. When this valve is open, additional fuel may be admitted to the up-stream chamber 2| thereby eliminating the dampening eifect and making the instrument more responsive to very slight variations.

The chambers 2| and 22 are restricted and are kept as small as possible for a purpose to be later explained.

The rear half 5 of the casing 3 is provided with a flat portion 33 disposed as close to the diaphragm 28 as is possible without interfering with the operation thereof and close enough to serve as a stop limiting the movement of the diaphragm. Raised portion 34 is provided on the rear half 5 01' the casing 3 to accommodate spring mechanism 35 for opposing the movement of the diaphragm into the the chamber 22. In the form of invention shown in Figs. 1-12, this mechanism consists of a toggle 36 having a first arm 31 and a secondarm 38. The joint of the toggle consists of a cam surface 39 on the toggle arm 31 and a cam surface 48 on the toggle arm 38 connected by a flexible strap 4| which is fastened at 42 at one end of cam 39 and extends between the

cams

39 and 48 and is fastened at 43 at the opposite end of cam 48. The strap 4| is so disposed that it connects the toggle arms and makes the spring pressure exerted on the toggle arms effective to oppose movement of the diaphragm 28 into the chamber 22. The free end 44 of toggle arm 38 is held by a strap 45 clamped by a screw 46 thereto and clamped by end 44 of toggle arm 38 toward and away from the pivot point of the toggle arm 31 and still holds the end 44 against any rotary movement about the pivot point of the toggle arm 31.

The toggle mechanism and the mechanism for controlling the size of the variable orifice are closely tied together. A lever 48 is provided extending through the chamber 22 and opposite the diaphragm 28. The resilient wire I9 carrying theball- I8 is fixed to the end of this lever and is movable thereby. The lever has a pivot point 49 which serves also as the pivot point for the toggle arm 31 which is fastened by screws 58 to the lever 48. An arm 5| extends from the toggle arm 31 and a tension spring 52 is connected by a metal strap 53 to the end of the arm 5|. end of the spring to the toggle arm 38. The metal straps 53 and 54 are substantially twothousandths of aninch thick and the strap 45 is made of similar material. It will be apparent that this mounting is substantially friction-less because the bending of the

straps

45, 53 and 54 offers substantially no frictional resistance.

In the -preferred construction, the free' end 44 of the toggle arm 38 is bent upwardly as shown in Figs. 5 and 6 and the strap 54 is fastened to the toggle arm 38 at the point 55 which is disposed to one side of the axis of the toggle arm 38 which passes between the extreme end of the toggle arm 38 and the point of contact of the cam 48 with the cam 39. This point 55 is disposed between the axis and the diaphragm 28 and the result is that when the toggle arm 38 is moved in a counter-clockwise direction, as

are so shaped that as the toggle moves in either direction the distance between the free ends of the

toggle arms

31 and 38 is controlled with a consequent control on the stretching of the spring.

A thrust member 56 extends from the diaphragm 28 to the toggle arm 38; This member is provided with a reduced end 51 extending through an aperture in the toggle arm 38. A metal diaphragm plate 58 is riveted to the diaphragm with rivets 59 and the thrust member 56 is riveted to said plate at the point 68.

The lever 48 is provided with a novel pivot means which permits the end of the lever to extend out of the down-stream chamber 22 to provide means for actuating the indicating mechanism, as will be later explained. A fork 6| is provided on the end of the lever provided with adjustablepivot bearings 62, riding in suitable seats 63 mounted on the casing 3. I prefer to make these seats as friction-less as possible and prefer to use ball bearing or jewel mountings which are not shown in detail since they do not form any part of this invention. The fork. 6| is mounted on the end of the lever 48 which passes through an aperture 64 in the wall of the down-stream chamber 22. By providing the fork member 6| on the end of the lever 48, I cause the pivot point 49 of the lever 48 to fall in the aperture. ,A diaphragm 65 is sealed to the lever 48 and extends across the A metal strap 54 connects the other 4 viewed in Fig. 5, the point 55 moves toward the aperture and is sealed by a suitable ring 66 with screws 61 extending into the casing, providing a seal against loss of fluid from the chamber 22 and permitting substantially friction-less movement of the lever 48 and the transmission of the movement of lever 48 to the outside of the casing 3.

Mounted on the outer end of the lever 48 is an arm 88 having at its end a ball 88 to form a universal connection with the indicating mechanism. An arm 18 extends from the other side of the lever and is provided with a set screw 1| forming a stop against the casing 3. A counterweight I1| is mounted on the outermost end of lever 48.

The indicating mechanism consists of a dial 12 which has on it indicia 13 indicating gallons per hour flow through the meter. These indicia are indicative of gallons per hour, but it will be apparent that when I refer to gallons per hour I have reference to any unit of measure for any unit of time and that gallons per hour are merely illustrative. Indicia 14 are provided to indicate the miles per gallon obtained in an automobile or the like which is being tested by my apparatus, and by properly adjusting the indicating mechanism it is possible to obtain a direct reading in miles per gallons for any given speed of operation of the vehicle. It will be apparent that the reference to miles per gallon is illustrative only and that when I refer to miles per gallon I do not necessarily limit myself to these particular units of measure.

The dial is provided with a hand 15 which is mounted on 'a shaft 18 bearing a pinion 11 and having a watch spring 18 thereon to reduce vibration of the hand in the operation by; eliminating lost motion in the gearing. A curved rack 18 is pivoted on a shaft 88 in engagement with the pinion 11. An arm 8| extends from the rack 18 to engage a connecting link 82. The connecting link 82 is a metal strap bored at 83 to provide a seat for the ball 88.. The end of the strap is turned back as at 84 to clamp the ball 88 to the seat 83 providing a universal connection, and a member 88 is provided to prevent dislodgment of the link from engagement with the ball 88. The link 82 is provided with a slot 88 fitting over the lever 8|. A notch 81 is provided in the end of the link 82 and a spring 88 is fastened to the rack 18 fits in the notch 81 to hold the link 82 and the lever 8| in contact, as indicated in detail in Fig. 11.

The hand operating mechanism is mounted on a cross strap 88 which is pivoted on a screw 88. Adjustment is' provided with the slot 8| and screw 82 at one end of the strap and with a slot 83 and a cam 84 provided with a slotted head 85 'at the other end of the strap, permitting the mechanism to be adjusted to or away from the arm 88 of the lever 48. Movement of the lever 88 to or away from the hand operating mechanism causes the hand to rotate on the dial through the action of the lever 8| and the spring 88 on the end of the link 82. A curved portion 88 is provided on the upper surface of the lever 8| and the end of the slot 88 rides on this curved portion. The curve of the curved portion 88 is a radius equal to the length of the link 82 between the ball 88 and the top end of slot 88. This provides for a shifting of the link 82 along the lever 8| without causing any movement of the pointer over the-dial. This permits the ratio of movement between the lever 88 and the pinion 11 and the hand 15 borne thereby to be varied so that the indicating apparatus can be adjusted to read miles per gallon at any given rate of speed. Means are provided for adjusting the position of the link 82 along the lever 8|. These consist of a tension spring 81 anchored on an arm 88 at one end and fastened to the link 82 at 88. A connetting member I88 on the other side of the link 82 connects to the end |8| oi. the arm I 82 of bell crank lever I83 which is pivoted at I84 and the arm 88 is pivoted to the same end I8I. The

other arm I85 of the bell crank lever hasacam follower portion I88 which engages a cam I 81. A worm gear I88 is provided in operative engagement with the cam I81 and a worm I88 in engagement with the worm gear I88 is mounted on a shaft 8 which is provided with an adjusting knob II I. A dial I I2 is mounted on the shaft I I3 which carries the cam I81 and indicia H4 indicate in miles per hour the relative position of the link 82 and the arm 8|. It will be apparent that miles per hour is merely illustrative and that I do not intend to be limited to the particular units of measurements selected. A spring H5 is provided connected to the arm I82 of bell crank lever I83 and to the casing at I I8 to assist in the 28 movement of and-the holding of the link 82 in adjusted position.

In Fig. 13 I show a modification of the joint'of the toggle '38. The toggle arm I38 corresponds to the arm 38 'of the toggle shown'in Figs. 1-12. The-toggle arm I 31 corresponds to'the toggle arm 3,1. On the toggle arm I31 I provide a circular member I38 corresponding to the cam 38. A

flexible strap I is fastened to the member I38, extends therearound and between the member I38 and the end of thetoggle arm I38, and is fastened at I43 to the end of the toggle arm I38. This arrangement of parts serves as a toggle joint operated substantially the same as the toggle joint shown in Figs. 1-12. A member II1 is mounted adjacent the member I38. The strap meter is connected in the fuel circuit of the in-' ternal combustion engine to be tested. The up- -stream tube I I is'conneoted to thefuel supply and the tube I4 is connected to the line so that it will communicate with the carburetor and the engine. The engine is then started and the fuel flows through the inlet 8 through the jet I8 and out at the outlet I2. -A small amount of fuel passes through the passage 23 to the up-stream chamber 2|. Fuel also flows into the chamber 22, filling it. It will be noted that when the device is operated some air willbe trapped in the chamber 2I- because the passage 23 opens into the chamber at a point below the top of the chamber 2|. This is not only not objectionable, but is very desirable in smoothing out pump pulsations and the like.-

The diaphragm 28 is made purposely of such size that it will be able to provide suflicient force for moving the toggle mechanism 38 against the action of spring 82 to thereby move the-lever 48 which moves the ball I8 to the right to open up the jet I8- to permitfuel toflowtherethrough. Sufiicient power is also provided to actuate the indicating mechanism. The actuation of the device is brought about by the difierence in pressure between the up-stream and down-stream sides of the jet l8. A slightly higher pressure exists on the up-stream side of-the Jet I8 and tends to move the diaphragm 28 to the right, as shown in Fig. 5, to a position comparable with the position shown in Fig. 6, depending upon the amount of fluid that is actually flowing to satisfy the demands of the internal combustion engine sulting from the application of pressurevin the tip-stream chamber 2| is reduced. Consequently it is desirable to reduce the force exerted by the spring 52 in opposition to the diaphragm. This -'is accomplished by the toggle mechanism which I employ. The spring 52 tends to pull the lever 31 toward the diaphragm 28. When the toggle is disposed so that the toggle joint is substantially to one side of a line between the pivot points of the free ends of the two toggle: arms, the spring also exerts a force through the arm 38 tending to force both arms toward the diaphragm. The downward and lateral offsetting of point of connection 55 of the spring to the toggle arm 38 of course decreases the pivotal moment exerted on that toggle arm by spring 52 as compared to the moment exerted on toggle arm. 37. As the diaphragm moves rearwardly from the position of Fig. 5 toward the position of Fig. 6, it is obvious that the toggle arm 38 approaches parallelism with the spring, hence the eifect of spring 52 tending to rotate arm 38 in clockwise direction diminishes. Due to the greater lever arm provided by arm 5| on toggle arm 31, the predominant force on the diaphragm is always exerted by toggle arm 31. As the diaphragm moves rearwardly, the proportionate effect of the toggle arm 31 on the diaphragm becomes greater even though the total resultant force exerted on the diaphragm becomes less. Should the arm 38 become parallel with spring 52,, as pointed out above, the effect of arm 38 would be nil. Arm 3] continually urges the diaphragm to the left, but the connection of spring 52 to toggle arm 38 insures that the resultant of the forces exerted.

on the diaphragm by the two toggle arms decreases as the toggle joint is brokenaway from the diaphragms.

It will be apparent that the force exerted by the spring in opposition to the diaphragm must be very slight and that friction must be substantially eliminated from the operation of the device. I accomplish this by utilizing the strap members as the connections and thereby substantially eliminate all friction. The mechanism is entirely floating as will be apparent and exerts substantially no friction producing forces against the bearings. I

I make the chambers 2| and 22 restricted so that the device can be used practically in connection with the testing of the average internal combustion engine used in automobiles or the like. The restricted chambers 2| and 22 can be filled by the fuel supply system of the automobile before the supply of fuel in the carburetor is exhausted so that the apparatus can be simply and easily connected in the fuel line and the car started and the test made without the necessity for resorting to a filling of the device before testing. The restricted passage 23 dampens the action of the diaphragm and eliminates rapid fluctuations of the indicating device, which is particularly valuable when tests are being made on the open road. When testing on the floor where vibrations are at a minimum and where it may be desirable to have a more sensitive response, the valve controlled'by the knob 32 may be opened by turning that knob.

It will be apparent that the meter measures in reality the quantity of fuel flowing through the meter for a given period of time. I have so arranged the indicating device that in road testing a vehicle it is possible to determine and read directly the number of miles obtained for each gallon of fuel at a given speed. My adjusting device on the hand operated mechanism makes such a reading possible. By adjusting the cam I01 it is possible to adjust the position of the link 82 on the lever 8| so that if, for example, the fuel is flowing at the rate of four gallons per hour, the hand 15 at forty miles an hour will indicate that ten miles are obtained for each gallon of fuel used. If the speed happens to be twenty miles an hour, the mechanism is adjusted and the hand will indicate that five miles per gallon are being obtained.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. In an apparatus of the class described, the combination of a casing, a main fluid passage for the fluid to be metered, a variable orifice in said passage comprising a tapered jet with its restricted portion up-stream and a ball movable into and out of said tapered jet, said ball being mounted on a resilient wire member, an operating diaphragm dividing the casing into a restricted up-stream chamber and a restricted down-stream chamber, a restricted. passage extending from the main fluid passage up-stream from said variable orifice to said up-stream chamber, and a passage extending from the down-stream chamber to the main fluid passage down-stream from said variable orifice, said casing having an opening therethrough into said down-stream chamber, a pivoted lever having its pivot point lying in the plane of said opening and extending outside said casing, through said opening, through said down-stream chamber, and across said operating diaphragm, said lever carrying said resilient wire member, a second 'diaphragm closing the opening in said casing ment of the operating diaphragm into said down-stream chamber, and means operatively connecting said spring to said diaphragm so ar-' ranged that the effective force of the spring in opposition to the movement of the diaphragm is reduced during the movement of the operating diaphragm into the down-stream chamber, and indicating apparatus and means connecting said lever at a point outside said casing to said indicating apparatus, said operating diaphragm being of a size suflicient to permit utilization of the differential pressure of the flow of the fluid through said main fluid passage to permit direct operation of the variable orifice by said diaphragm without substantial pressure loss in the flow to be metered.

2. In an apparatus of the class described, the combination of a casing, a main fluid passage for the fluid to be metered, a variable orifice in .said passage, an operating diaphragm dividing ing from the down-stream chamber to the main fluid passage, down-stream from said variable orifice, -said casing'having an opening therethrough into said down-stream chamber, a'pivoted lever having its pivot point lying'in the plane oi said opening and extending outside said casing, through said opening, through said downstream chamber, and across said operating diaphragm, and means connecting said lever operatively to said variable orifice to control the size thereof, a second diaphragm closing the opening in said casing and sealed to said lever at its pivot point, means connecting said operating diaphragm to said lever whereby movement of said operating diaphragm intosaid down-stream chamber moves said lever to increase the size oi said variable orifice, and a spring tending to oppose the movement oi the operating diaphragm into said down-stream chamber, and means operatively connecting said spring to said diaphragm so arranged that the eflective force of the spring in opposition to the movement of the diaphragm is reduced during the movement of the operating diaphragm into the down-stream chamber, and indicating apparatus and means connecting said lever at a point outside said casing to said indicating apparatus, said operating diaphragm being of a size suflicient to permit utilization of the difierential pressure of the flow oi the fluid through said main fluid passage to permit direct operation of the variable orifice by said diaphragm without substantial pressure loss in the flow to be metered.

3. In an apparatus of the class described, the combination of a casing, a main fluid passage for the fluid to be metered, a variable orifice in said passage, an operating diaphragm dividing the easing into an up-stream chamber and a down-stream chamber, a passage extending from the main fluid passage up-stream from said variable oriflce to said up-stream chamber, and a passage extending from the down-stream chamber to the main fluid passage down-stream from said variable orifice, said casing having an opening therethrough into said down-stream chamber, a pivoted lever having its pivot point lying in the plane of said opening and extending outside said casing, through said opening, through said down-stream chamber, means connecting said lever operatively to said variable orifice to control the size thereof, a second diaphragm closing the opening in said casing and sealed to said lever at its pivot point, means connecting said operating diaphragm to said lever whereby movement of said operating diaphragm into said down-stream chamber moves said lever to increase the size of said variable orifice, and a spring tending to oppose the movement of the operating diaphragm into said down-stream chamber, and means operatively connecting said spring to said diaphragm so arranged that the eiiective force of the spring in opposition to the movement of the diaphragm is reduced during the movement of the operating diaphragm into the down-stream chamber, and indicating apparatus andmeans connecting said lever at a point outside said casing to said indicating apparatus, said operating diaphragm being of a size sufiicient to permit utilization of the diflerential main fluid passage to' permit direct operation 'ot'the variable orifice by said diaphragm without substantial pressure loss in the flow to be metered.

4. In an apparatus of the class described,"the combination of a casing, a main' fluid passage for the fluid to be metered, a variable orifice in said passage, an operating diaphragm dividing 1 the casing into a restricted lip-stream chamber and 'a restricted down-stream chamber, a restricted passage extending from themain fluid passage up-stream from said variable orifice to said up-stream chamber, and a passage extending from the down-stream chamber to the main fluid passage down stream from said variable orifice, a spring tending to oppose the movement of the operating diaphragm into said downstream chamber, and means operatively connecting said spring to said diaphragm so arranged that'the effective force of the spring in opposition to the movement oi. the diaphragm is reduced during the movement of the operating diaphragm into the down-stream chamber,.

and indicating apparatus, and means connecting said operating diaphragm to said variable orifice for controlling the size thereof and to said indicating apparatus whereby the amount 01 fluid flowing will be indicated, said operating diaphragm being of a size suflicient to permit utilization of the differential pressure of the flow of the fluid through said main fluid passage to permit direct operation of the variable orifice by said diaphragm without substantial pressure loss in the flow to be metered.

5. In an apparatus of the class described, the combination of a casing, a main fluid passage for the fluid to be metered, a variable orifice in said passage, an operating diaphragm dividing the easing into an up-stream'chamber and a down-stream chamber, a passage extending from the main fluid passage up-strea'm from .said variable orifice to said up-stream chamber, and a passage extending from the down-stream chamber to the main fluid passage down-stream from said variable orifice, a spring tending to oppose the movement of the operating diaphragm into said down-stream chamber, and means operatively connecting said spring to said diaphragm so arranged that the efiective force of the spring in oppositionto the movement of the diaphragm is reduced during the movementof the operating diaphragm into the down-stream chamber, and indicating apparatus and means connecting said operating diaphragm to said variable orifice for controlling the size thereof and to said indicating apparatus whereby the amount of fluid flowing will be indicated, said operating diaphragm being of a size suiflcient to permit utilization of the difierential pressure of the flow of the fluid through said main fluid passage to permit direct pressure of th flow the mud through the casing intoa-restrictedup-stream chamber I and a restricted down-stream chamber, a restricted passage extending from the main fluid passage up-stream from said variable orifice to said up-stream chamber, and a passage extending from the down-stream chamber to the main fluid passage down-stream from said variable orifice, said casing having an opening thereplane of said opening and extending outside said casing, through said opening, through said downstream chamber, and across said operating dia-. phragm, means connecting said lever operatively,

to said variable orifice to control the size thereof, a secondfdiaphragm closing the opening in said casing and sealed to said lever at its pivot point, means connecting said operating diaphragm to said lever whereby movement of said operating diaphragm into said down-stream chamber moves said lever to increase the size of said variable orifice, and a spring tending to oppose the movement of the operating diaphragm into said downstream chamber, and means operatively connecting said spring to said diaphragm, and indicating apparatus and means connecting said lever at a point outside said casing to said indicating apparatus, said operating diaphragm being of a size sufilcient to permit utilization of the differential pressure of the flow of the fluid through said main fluid passage to permit direct operation of the variable orifice by said dia hragm without substantial pressureloss in the flow to be metered.

7. In an apparatus of the class described, the combination of a casing, a main fluid passage for the fluid to be metered, a variable orifice in said passage, an operating diaphragm dividing the easing into an up-stream chamber and a down-stream chamber, a passage extending from the main fluid passage up-stream from said varia le orifice to said up-stream chamber, and a passage extending from the down-stream chamber to the main fluid passage down-stream from said variable orifice, said casing having an opening therethrough into said down-stream chamber, a pivoted lever having its pivot point lying in the plane of said opening, and extending outside said casing, through said opening, through said down-stream chamber, means connecting said lever operatively to said variable orifice to control the size thereof, a second diaphragm closing the opening in said casing and sealed to said lever at its pivot point, means connecting said operating diaphragm to said lever whereby movement of said operating diaphragm into said down-stream chamber moves said lever to increase the size of said variable orifice, and a spring tending to oppose the movement of the operating diaphragm into said down-stream chamber, and means operatively connecting said spring to said diaphragm, and indicating apparatus and means connecting said lever at a point outside said casing to said indicating apparatus, said operating diaphragm being of a size suflicient to permit utilization of the differential pressure of the flow of the fluid through said main fluid passage. to permit direct operation of the variable orifice by said diaphragm without substantial pressure loss in the flow to be metered.

8. In an apparatus of the class described, the combination of a casing, a main fluid passage for the fluid to be metered, a variable orifice in said passage, an operating diaphragm dividing, the casing into a restricted up-stream chamber and a restricted down-stream chamber, a restricted passage extending from the main fluid passage up-stream from said variable orifice to said upstream chamber, anda passage extending from the down-stream chamber to the main fluid -passage down-stream from said variable orifice,

a spring tending to oppose the movement of the operating diaphragm into said down-stream chamber, and means operatively connecting said spring to said diaphragm. and indicating apparatus and means connecting said operating diaphragm to said variable orifice for controlling the size thereof and to said indicating apparatus whereby the amount of fluid flowing will be indicated, said operating diaphragm being of asize sumcient to permit utilization of the differential pressure ofthe flow of the fluid through said main fluid passage to permit direct operation of the variable orifice by said diaphragm without substantial pressure loss in the flow to be metered.

9. In an apparatus of the class described, the combination of a main passage for the fluid to be metered, a casing, a diaphragm dividing the casing into an up-stream chamber and a down-stream chamber, a variable orifice in said main passage, a connection from said upstream chamber to said main fluid passage up-stream from said variable orifice, a connection from said down-stream chamber to said main fluid passage down-stream from said variable orifice, means for exerting spring pressure opposed to movement of said diaphragm into the down-stream chamber, said spring pressure decreasing as the diaphragm advances into said chamber whereby the diminishing of the effective area of the diaphragm is compensated for, comprising a toggle having the free end of its first arm pivoted on a fixed pivot and having the free end of its second arm fastened to means disposed to hold said end against movement around the pivot of the free end of the first toggle arm but permitting movement of the free end of the second toggle arm to or away from said pivot point, an arm extending from the side of one of said toggle arms opposite to the side of the toggle from which its force is exerted, a

and a spring connected to ,the other of said toggle arms at a point spaced from the joint of the toggle and to said extending arm at a point spaced from its toggle arm, means connecting the toggle and the diaphragm whereby the force exerted by the spring may be transferred to the diaphragm in opposition to movement of the diaphragm toward the toggle under the force of fluid flowing through the apparatus, and means for operatively connecting said toggle to said variable orifice to control the variations thereof, an indicating apparatus, and means for operatively connecting said toggle to said indicating apparatus whereby the rate of fluid flow through the apparatus will be indicated by said indicating apparatus.

10. In an apparatus of the class described, the combination of a main passage for the fluid to be metered, a casing, a diaphragm dividing the casing into an up-stream chamber and a downstream chamber, a variable orifice in said main passage, a connection from said up-stream chamber to said main fluid passage up-stream from said variable orifice, a connection from said down-stream chamber to said main fluid passage down-stream from said variable orifice, means for exerting spring pressure opposed to movement of said diaphragm into the downstream chamber, said spring pressure decreasing as the diaphragm advances into said chamber whereby the diminishing of the effective area of the diaphragm is compensated for, comprising a toggle having the free end of its first arm pivoted on a'flxed pivotand having the free end of its second arm fastened to means disposed to hold said end against movement around the pivot of the free end of the first toggle arm but permitting movement of the free end of the second toggle arm to or away from said pivot point, an arm extending from the side of one of said toggle arms opposite to the side or the toggle from which its force is exerted, and a spring connected to the other of said toggle arms at a point spaced from the joint of the toggle and to said extending arm at a point spaced from its toggle arm, means connecting the toggle-and the diaphragm whereby the force exerted by the spring may be transferred to the diaphragm in opposition to movement of the diaphragm toward the toggle under the force of fiuid'flowing through the apparatus, and means to control the variations of the variable orifice under control of the position of the diaphragm, an indicating apparatus and means for controlling said indicating apparatus under control of the position of the variable orifice whereby the rate of fiow oi! fiuid through the apparatus will be indicatedby said indicating apparatus.

11. The combination of a movable member, means for exerting spring pressure against said member, said spring pressure decreasing as said member advances toward said means for exerting spring pressure, comprisinga toggle having the free end of its first arm pivoted on a fixed pivot'and having the free end of its second arm fastened to means disposed to hold said end against movement around the pivot of the free end of said first toggle arm but permitting movement of the free end of the second toggle arm to or away from said pivot point, an arm ex tending from the side of one of said toggle arms opposite from the direction in which the toggle exerts its force, and a spring connected to the other of saidtoggle arms at a point spaced from the joint of the toggle and spaced from the axis of said toggle arm on the side of the toggle opposite from said extending arm and to said extending arm at a point spaced from its toggle arm, whereby the efiective length of the spring is controlled as the toggle positions change, and means connecting the toggle and the movable member whereby the force exerted by the spring may be transferred to the movable member.

12. The combination of a movable member, means for exerting spring pressure against said member, said spring pressure decreasing as said member advances toward said means for exerting spring pressure, comprising a toggle having the free end of its first arm pivoted on a fixed pivot and having the free end of its second arm fastened to means disposed to hold said end against movement around the pivot of the free end of said first toggle arm but permiting movement of the free end of the second toggle arm able member whereby the iorce exerted by the spring may be transferred to the movable member.

13. In an apparatus of the class described, means for exerting spring pressure against a movable device the force produced by the movement of which varies as it advances, said spring pressure varying as the device advances, whereby the variable force exerted by the device is compensated for, comprising a toggle having the free end of its first arm pivoted on a fixed pivot and having the free end of its second arm .fastened to means disposed to hold said end against movement around the pivot 01 the free end of the first toggle arm but permitting movement of the free end of the second toggle arm to or away from said pivot point, an. arm extending from the side of one of said toggle arms opposite the device, and a spring connected to the other of said toggle arms at a point-spaced from the joint of the toggle and to said extending arm at a point spaced from its toggle arm, and means connecting the toggle and the device whereby the force exerted bythe spring may be transferred to the device in opposition to movement of the device toward the toggle.

14.In an apparatus of the class described, means for exerting spring pressure against a movable device the force exerted by the movement of which varies as it advances, said spring pressure varying as the device advances, whereby the variable force exerted by the device is compensated for, comprising a toggle having the free end of its first arm pivoted on a fixed pivot and having the free end of its second arm fastened to means disposed to hold said and against movement around the pivot of the free end of the first toggle arm but permitting movement of the free end of the second toggle arm to or away from said pivot point, an arm extending from the side of one of said toggle arms opposite the device, and a spring connected to the other of said toggle arms at a point spaced from the joint of the toggle and located between the device and a line connecting the free ends of said toggle arms and to said extending arm at a point spaced from its toggle arm whereby the effective length of the springis controlled as the toggle positions change, and means connecting the toggle and the device whereby the force exerted by the spring may be transferred to the device in opposition to movement of the device toward the toggle.

15. The combination of a movable member, means for exerting controlled spring pressure against movement of said member, comprising a toggle having the free end of its first arm pivoted on a fixed pivot and having the free end of its second arm fastened to means disposed to hold said end against movement around the pivot of the free end of said first toggle arm but permitting movement of the free end of the second toggle arm to or away from said pivot point, an arm extending from the side of one of said toggle arms, and a spring connected to the other of said toggle arms at a point spaced from the joint of the toggle and to said extending arm at a point spaced .from its toggle arm, the joint of the toggle comprising a curved member on one toggle arm lying in contact with the other toggle arm and a flexible member fastened on said curved member and extending therearound and between said member and the adjacent toggle arm and fastened to the other toggle'arm, and means connecting the toggle and movable member whereby the force exerted by the spring may be transferred to the movable member.

16. The combination of a movable member, means for exerting controlled spring pressure against movement of said member, comprising a toggle having the free end of its first arm pivoted on a fixed pivot and having the free end of its second arm fastened to means disposed to hold said end against movement around the pivot 01' the free end of said first toggle arm but permitting movement of the free end of the second toggle arm to or away from said pivot point. an arm extending from the side of one of said toggle arms, and a spring connected to the other of said toggle arms at a point spaced from the joint of the toggle and to said extending arm at a point spaced from its toggle arm, the joint of the toggle comprising a cam member on one toggle arm lying in contact with the other toggle arm and a flexible member fastened on said cam member and extending therearound and between said member and the adjacent toggle arm and fastened to the other toggle arm, and means connecting the toggle and movable member whereby the force exerted by the spring may be transferred to the movable member.

17. The combination of a movable member, means for exerting controilled spring pressure against movement of said member, comprising a toggle having the free end of its first arm pivoted on a fixed pivot and having the free end of its second arm fastened to means disposed to hold said end against movement around the pivot of the free end of said first toggle arm but permitting movement of the free end of the second toggle arm to or away from said pivot point, an arm extending from the side of one of said toggle arms opposite said movable member, and a spring connected to the other of said toggle arms at a point spaced from the joint of the toggle and to said extending arm at a point spaced from its toggle arm, the joint of said toggle comprising a pair of opposed cam surfaces shaped to control the spring pressure against the movable member, and a flexible member fastened at the end of one cam and extending between the cams and fastened to the opposite end of the opposed cam in a manner to transmit the force of the spring, and means connecting the toggle and the movable member whereby the force exerted by the spring may be transferred to the movable member.

18. In an apparatus of the class described, a toggle joint and spring mechanism for opposing the movement of a movable member comprising a first toggle arm having aflxed pivot, a second toggle arm having its free end anchored against movement about the pivot of the first toggle arm by a thin metal strap which permits movement of the free end of the second toggle arm to or away from the pivot of the first toggle, an arm extending from one of said toggle arms, and a spring connecting said extending arm and the other toggle arm and connections between the spring and the extending arm and toggle arm comprising thin metal straps.

19. In an apparatus of the class described, a toggle joint and spring mechanism for opposing the movement of a movable member comprising a first toggle arm having a fixed pivot, a second toggle arm having its free end an chored against movement about the pivot of the first toggle by means permitting movementof the free end of the second toggle am to or away from the pivot of the first toggle, an arm extending from one of said toggle arms, and a spring connecting said extending arm and the other toggle arm and connections between the spring and the extending arm and toggle arm comprising thin metal straps.

20. In an apparatus of the class described, a toggle joint and spring mechanism for opposing the movement of a.v movable member comprising a first toggle am having a fixed pivot, a second toggle arm having its free end anchored against movement about the pivot of the first toggle arm by a flexible member which permits movement of the free end of the second toggle arm to or away from the pivot of the first toggle,

an arm extending from one of said toggle arms,

and a spring connecting said extending arm and the other toggle arm and connections between the spring and the extending arm and toggle arm comprising flexible members.

21. In an apparatus of the class described, the combination of a casing, a main fluid passage for. the fluid to be metered, a variable orifice in said passage, an operating diaphragm dividing the casing into an tip-stream chamber and a downstream chamber, said operating diaphragm being of a size suflicient to permit utilization of the differential pressure of the flow of the fluid through said main operation of the variable orifice by said diaphragm without substantial pressure loss in the fiow to be metered, a passage extending from the main fluid passage up-stream from the variable orifice to said up-stream chamber, and a passage extending from the down-stream chamber to the main fluid passage down-stream from said variable orifice, spring means tending to oppose movement of the operating diaphragm into said down-stream chamber comprising a toggle having the free end of its first arm, pivoted on a fixed pivot and having 'the free end of its second arm fastened to means disposed to hold said end against movement around the pivot of the free end of said first t'oggle arm by permitting movement of the free end of the second toggle arm to or away from said pivot point, an arm extending from the side of one of said toggle arms and a spring connected to the other of said toggle arms at a point spaced from the joint of the toggle and to said extending arm at a point spaced from its toggle arm, and means connecting the diaphragm and said toggle in such a manner that the action of the spring opposes the movement of the diaphragm into the down-stream chamber and compensates for the decrease in the effective area of the diaphragm as it advances into said chamber, and means controlled by said diaphragm for controlling said variable orifice.

22. In an apparatus of the class described, the combination of a main passage for the fluid to be metered, a casing, a diaphragm dividing the casing into an up-stream chamber and a downstream chamber, a variable oriflce in said main passage, a connection from said up-stream chamber to said main fluid passage up-stream from said variable orifice, a connection from said downstream chamber to said main fluid passage down... stream from said variable orifice, means for exerting spring pressure opposed to movement of said diaphragm into the down-stream chamber, said spring pressure decreasing as the diaphragm advances into said chamber whereby the diminishing of the effective area of the diaphragm is com, pensated for, comprising a toggle having the free end of its first arm pivoted on a fixed pivot and having the free end of its second arm fastened to means disposed to hold said end against movement around the pivot of the free end of the first toggle arm but permitting movement of the free end of the second toggle arm to or away from said pivot point, an arm extending from the side of one of said toggle arms opposite to the side of the toggle from which its force is exerted, and a spring connected to said extending arm at a point spaced from its toggle arm tending to force said fluid passage to permit direct toggle toward said diaphragm, means connecting the toggle and the diaphragm whereby the force exerted by the spring may be transferred .to the diaphragm in opposition to movement of the diaphragm toward the toggle under the force of fluid flowing through the apparatus, and means to control the variations of the variable orifice under control of the position of the diaphragm,

an indicating apparatus and means for controlling said indicating apparatus under control of the position of the variable orifice whereby the rate of flow of fluid through the apparatus will be indicated by said indicating apparatus.

23. In an apparatus of the class described, the' combination of a main passage for the fluid to be metered, a casing, a diaphragm dividing the casing into an up-stream chamber and a downstream chamber, a variable orifice in said main passage, a connection from said up-stream chamber to said main fluid passage up-stream from said variable orifice, a connection from said down stream chamber to said main fluid passage downstream from said variable orifice, means for exerting spring pressure opposed to movement of said diaphragm into the down-stream chamber, said spring pressure decreasing as the diaphragm advances into said chamber whereby the diminishing of the effective area of the diaphragm is compensated for, comprising a toggle having the free end of its flrstarm pivoted on a fixed pivot and having the free end of its second arm fastened to means disposed to hold said end against movement around the pivot of the free end of the first toggle arm but permitting movement of the free end of the second toggle arm .to or away from said pivot point, and a spring tending to force said toggle toward said diaphragm, means connecting the toggle and the diaphragm whereby the force exerted by the spring may be transferred to the diaphragm in opposition to movement of the diaphragm toward the toggle under the force of fluid flowing through the apparatus, and means to control the variations of the variable orifice under control of the position of the diaphragm, an indicating apparatus and means for controlling said indicating apparatus under control of the position of the variable orifice whereby the rate of flow of fluid through the apparatus will be indicated by said indicating apparatus.

24. The combination of a movable member, means for exerting spring pressure against said member, said spring pressure decreasing as said member advances toward said means for exerting spring pressure, comprising a toggle having the free end of its first arm pivoted on a fixed pivot and having the free end of its second arm fastened to means disposed to hold said end against movement around the pivot of the free end of said first toggle arm but permitting movement of the free end of the second toggle arm to or away from said pivot point, an arm extending from the side of one of said toggle arms opposite from the direction in which the toggle exerts its force, and a spring connected to said extending arm at a point spaced from its toggle arm tending to force said toggle toward said movable member, whereby the effective length of the spring is controlled as the toggle positions change, and means connecting the toggle and the movable member whereby the force exerted by the spring may be transferred to the movable member.

25. In an apparatus of the class described, means for exerting spring pressure resisting movement of. a. pressure actuated device the force of whose movement decreases as the device, advances, said spring pressure decreasing as the device advances whereby the diminishing of the force exerted by the device is compensated for, comprising a toggle having the free end of its first arm pivoted on a fixed pivot and having the free end of its second arm fastened to means disposed to hold said end against movement around the pivot of the free end of the first toggle arm but permitting movement of the free end of the second toggle arm to or away from said pivot point, and a spring tending to urge said toggle against said device, and meansconnecting the toggle and the device whereby the force exerted by the spring may be transferred to the device in opposition to movement of the device toward the toggle.

26. The combination of a movable member, means for exerting controlled spring pressure against movement of said member, comprising -a toggle having the free end of its first arm pivoted on a fixed pivot and having the free end of its second arm fastened to means disposed to hold said end against movement around the pivot of the free end of said first toggle arm but permitting movement of the free end of the second toggle arm to or away from said pivot point, and a spring tending to force said toggle in opposition to movement of said movable member, the joint of the toggle comprising a curved member on one toggle arm lying in contact with the other toggle arm and a. flexible member fastened on said curved member and extending therearound and between said member and the adjacent toggle arm and fastened to the other toggle arm, and means connecting the toggle and movable member whereby the force exerted by the spring may be transferred to the movable member.

27. In an apparatus of the class described, means for opposing movement of a device movable with varying force in a' given direction in such manner that the opposition to movement likewise varies as the device moves in said direction, comprising a pair of toggle arms having adjacent ends thereof connected for movement with the device and the remote ends thereof restrained and provided with extension members on the opposite side of the toggle arms from the device, resilient tension means connected between said extension members, said tension means being connected to one of said extension members at a point farther removed from its toggle arm than the point of connection of the tension means to the other member is removed from its toggle arm, whereby said tension means exerts a greater moment on one of said toggle arms than on the other, and means for connecting said device to said toggl arms for actuation of the latter in response to movement of the device, at least one of said toggle arms approaching parallelism with said tension means during said actuation to vary the resultant effort exerted by said arms on the device in accordance with the varying force exerted by the device.

28. In an apparatus of the class described, means for opposing movement of a device movable with varying force in a given direction in such manner that the opposition to movement likewise varies as the device moves in said direction, comprising a pair of toggle arms having extension members to exert a" greater moment on one of said toggle arms than on the other;

and means for connecting said device to mid toggle arms for actuation or the latter in re- 5 spouse to movement of the device, at least one or said toggle arms during said actuation ap- FRANK W. THOMAS.