US1401299A

US1401299A - Meter

Info

Publication number: US1401299A
Application number: US201412A
Authority: US
Inventors: Wohlenberg Walter Jacob
Original assignee: Individual
Current assignee: Individual
Priority date: 1917-11-10
Filing date: 1917-11-10
Publication date: 1921-12-27
Anticipated expiration: 1938-12-27

Description

W. J. WOHLENBERG.

METER.

APPLICATION FILED NOV.10,1917- RENEWED NOV. 17.1921.

1,401 ,299, Patented Dec. 27, 1921.

6 SHEETS-SHEET I.

W. J. WOHLENBERG.

METER.

APPLICATION FILED NOV. 10, 1917. RENEWED NOV. 17.1921.

1,401,299, Patefited Dec. 27, 1921.

w. J. WOHL ENBEBG.

METER. APPLICATION FILED NOV. 10 1917- RENEWED NOV. 17.192].

1,401,299. Patented Dec. 27, 1921.

6 SHEETS-SHEET 3- IIII/I/III/I/ W. J. WOHLENBERG.

METER.

7 APPLICATION FILEDYNOV. 10. 1917. RENEWED NOV. 17.1921. 1,401,299.

Patented Dec. 27, 1921'.

6 SHEETS-SHEET 4.

W. J. WOHLENBERG.

METER. APPLICATION-FILED NOV. 10, 1917. RENEWED NQV. 17.1921.

1,401,299. I Patented Dec. 27, 1921.

6 SHEETSSHEET 5- J6 go'lg. 6 9 I P W. J. WOHLENBERG.

METERK APPLICATION FILED NOV-10, 1917- RENEWED NOV. 17.1921- 1,401,299. Patented Dec. 27, 1921. 6 $HEET3$HEET 6- LL unit. Ki m qS v m on UNITED STATES PATENT OFFICE.

WALTER JACOB WOHIiENBERG, OF NEW HAVEN, CONNECTICUT.

METER.

Application filed November 10, 1917, Serial No.

To all whom it may concern:

Be it known that, I, WALTER JAooB WOHL- ENBERG, a citizen of the United States, and a resident of New Haven, in the county of New Haven and State of Connecticut, have invented new Improvements in Meters, of which the following is a full, clear, and exact description.

- y invention relates to meters for determining the quantities of fluid or' energy flow.

An object of my invention is to have the means of having the fluids direction of flow deflected by a displaceable surface whereby the displacement of said displaceable surface may be a measure of the rate of flow at given fluid densities. I

A second object of my invention is to have the said deflecting surfaces supported at said point of said system of arms, displaceable in a straight line, whereby said deflecting surfaces will be displaced, by variations in the rate of flow, in straight line directions.

A third object of my invention is to have the means of having the mechanism respond automatically to variations of density of the fluid being metered, whereby the indications, rates of registering or records will'be accurate measures of the weight flow of the I accomplish these and other objects of my invention by the structures conventionally disclosed in the accompanyingdrawings, in which similar characters of reference denote corresponding parts.

Figures 1, 2, 3, 3 4 and Pare diagrammatic representations of the fluid flow existing in the vicinity of the deflecting surface above mentioned and they are included as an aid to the theoretical discussion disclosing the principle of operation.

Fig. 5 represents a longitudinal cross section disclosing certain features of the in vention.

Figs. 6 6 and 6 are diagrammatic illustrations used in connection with the explanation of the suspension mechanism shown in Fig. 5.

' Fig. 6 shows a special distribution of the suspension points 18 of this mechanism.

Fig. 7 illustrates the mechanism by means of which the magnitudes of the measuring displacements are corrected automatically for variations of the fluid density.

Specification of Letters Patent.

201,412. Renewed November 17, 1921.

conditions of the measuring displacements are caused to take place.

Fig. 9 represents a special form of the deflecting surface against which the fluid motion acts.

Fig. 10 shows how the deflecting surface may be supported between rollers instead of by the suspension mechanism disclosed in Fig. 5, and Fig. 11 is a cross section showing an assembled view of the principal elements involved in the construction of the meter.

Referring now to Fig. 5, 5 represents the fluid inlet and 7 the outlet from the otherwise leakage proof meter casing 9. The fluid is guided from 5 into 7 by means of the semicircular tube 6 which has inits straight portions holes or vents 8 whereby Patented Dec. 27, 1921.

Serial No. 515,971.

the static pressure within the space Q will these are in turn supported by means ofpins 19 respectively by

arms

13, 14 and 15 and 17. These arms are supported by stationary or fixed pins 18. The joints at 18, 19, 20 and 21 are all hinged and such that the parts fastened together thereby are free to rotate with respect to each other about the in axes as centers. It follows that the who e arm system is free, within given limits, to oscillate about the pins 18.

f now the arms 13, '14, 15 and 17 are of equal lengths and their points of suspension 18 are in parallel lines z-z and z'2' and if furthermore the links 12 are equal in length to links 16 then points 20 and 21 may be so located that the points 21 will be c0nstrained to move very nearly in the straight line m-w. This is more readily seen by reference to Figs. 6 and 6'. Referring first now to F ig. 6, there is represented the arrangement of the

arms

13 and 14 as shown in the suspension mechanism. Consider that both of these arms may be turned successively about their points of support 18 through equal angles 6, 6 In each position let the point p bisect the line joinmg their extremities. It will in each case fall in the straight line w-w.

' Consider now that the

arms

13 and 14 are connected by a link as 16 Fig. 6". If under these conditions, the arm 13 is rotated through an angle 6 then the arm 14 will be rotated through an angle 6 6 because, for displacement parallel to ww of the points 19 of the arms the distance between them increases. Consequently, if the distance is to remain constant, then the point 19 of the lower arm must be displaced a greater amount horizontally. This will operate to cause the mid point p, of the link 16 to be displaced a small amount below the line wm in its new position p',. There will, however, be a point p, which is again on this line in the displaced position p,. This point will move a very small amount above the line wac in the early part of the displacement as will any point p, to the left of 12 It is obvious now that the arms and link may be chosen of such a length that when properly located a point will move virtually away from the line ww.

along the straight line w-w. This elementary system of arms as here described is exactly a Watts straight line motion and was invented by James Watt.

A still nearer approximation is afforded by the suspension mechanism .of Fig 5 which is diagrammatically disclosed in Fig. 6.

In these figures the solid lines show the mechanisms in the central position in which now the

arms

14, 12 and 13 and 15, 16 and 17 may be mutually at right angles. It is readily seen that the system of arms 141213 is exactly equivalent to the system -15-16 17 turned 180 about the same axis w-w. The linkage system A is connected to the inverted linkage system B at points 20 by means of link 11 having on it a pin of support at 21.

These

points

10 or 20, will be located on the

links

16 and 12 of the fundamental elements of the mechanism, as previously explained. Then for a displacement of the systems A and B such that 6 :6 and 6 :0 the one point 10 will be displaced above the line a2a2 just as much as the other will be displaced below this line. If new the points p are connected by a third link as 11 then the displacement angles 6, and 0 can not be quite equal respectively to 6' and 6, and consequently a point 21 located on 11 as p, was located on 16 and 12 will move slightly However, just as the displacement of'p from w-w is but a small fractional part of that of-the points 19, just so that of 21 will be but a small fractional part of that of p, and consequently the variation from the straight line motion may be reduced to a negligibly small amount. If a still closer approximation is desired then it is obvious that the points 21- of two inverted combination systems as described might be connected to a common link and on it would be a point having a motion departlows that the mechanical friction to such a motion can be reduced to a negligible amount by making the arms of said suspension mechanism'of such lengths that the motion in the joint is very small.

vAs shown in Fig. 5 the rod 10 has a collar 23 against which the spring 24 presses. The tension in this spring may be adjusted by means of tension screw 26 having at its end the collar 25 supporting the other end of said spring.

The tube are 6 has preferably very thin walls so that its inside area is very nearly equal to that of the pipe ends 5 and 7. For such a condition there will be practically constant velocity and uniform flow of the fluid over the path shown. The tubular arc will be perfectly balanced as to static pressure and the only force F existing will be due to the velocity of the fluid, or rather due to the deflection from the straight line direction which is caused in its motion by the curved path imposed. by the are. This force will cause the arc to be displaced to the left compressing the spring 24 and the displacements may be transmitted to a shaft 30 rotated by means of lever 29 which has slot 28 into which the pin 27 fits and hence causes the rotation of said lever when the rod 10 is displaced.

These displacements will for a given resistance be governed by the force F which is proportional to the product 7V The volume of the elementwill be equal to 'rdB- (11' if its depth is unity and its mass will then be equal to rd0dr-6 where 8 represents the fluid density and g the acceleration due to gravity. It follows constant on a circular arc of that the radialforce dF exerted by the particle because of its curvilinear motion will be equal to grda gg v da 3 The component of this force in a direction 02-03 will obviously be equal to tween limits 6 and 6 dF,= (sin sin 9 5 57 5. 5

Now for ideal conditions of flow the further assumption may be made that .zV for obviously with zero friction and zero pressure change this condition will result. Substituting this condition and multiplying by g where n represents the number of such arcs of elementary radial depth, there results,

in which the product 'n d 7' is exactly a the radial depth of the sector i j is Land is exactly 8 the mean density of this sector. It follows that for this flow as described the force F exerted by a sector z j is Z will, be exactly equal to sin 0 2; v a e We have now to find the relation between the mean density 8 in the tube are and that in the straight portion of the pipe.

Referring to Fig. 3 there is represented a section of a tube in which now the fluid is at rest. We will consider some of the particles m falling on the concentric arcs continued into parallel lines. Obviously now all of the particles in the tube will fall on some one of such lines and a given are section z" y" is Z will contain a given number of such particles or molecules. Consider now that each line of particles possesses a uniform linear velocity V as shown in Fig. 3 Obviously -now in the curved partofthe tube these lines of particles will V cos 0d0 (4) To find the total force F x the circular arcs of fluid as 1, 2, n of a given are of fluid i j is Z of Fig. 2 it is merely necessary to sum up the forces of the arcs of elementary radial depth. Consider this fluid arc to be divided intoarc sectors each of elementary depth (ll' and that the density of arc Z isx of 2, B etcu-to 8 Then obviously any arc sectors as 3 for instance will exert the force exerted by all of (1F (sin 0; sin eg gvga and the arc sectors n will exert the force (11 7 F n n j is Z will exert the dF (sin 6 sin 0 Whence the total sectors 71 force become closer together near the outer surface and farther apart near the inner surface and a small element as (a) will have acting on it the centrifugal force 03F and a force aZF in the opposite direction due to the inward rate of variation of pressure. For steady flow these forces will be such that pressure existing in the fluid.

Now obviously for ideal conditions of flow each line of these particles will maintain its uniform velocity V about the curve and although the radial space distribution of the successive lines varies there will still be the same number of total lines passing through the sector z' j 70', Z as there are through the sector 2" j is Z wherein the fluid is at rest. Furthermore, the resultant forces aZF and dF atany point'of any line are exactly at right angles to the direction of the line and for ideal flow there is at no point on any line a force between the particles in the direction of the line. Consequently in any given line there is no tendency to alter the distances between the particles on that line although the distances between neighboring particles in the direction of the line may be altered by one line of particles so to speak tending to telescope with a line which in the stationary conditional number of particles occupy the space i j" n Z! on the CHI-V6, as an equal Spac i 3'1. 1' cut out of the straight portion w1ll contain, provided that the cross-sectional areas are equal and that the volume cut out in the curved section is a sector as c y is" Z" containing the whole cross sectional area of flow. In other words the same total mass and weight is contained in each volume so cut out whence.

F,= (sin o sin 0,)A-%V26 7 where A has been substituted for the product Z. r which is obviously the cross sectional area.

Consider now a condition of imperfect flow in which the velocity V may undergo a considerable variation. Referring to Fig. 4 u represents a straight section of pipe through which the fluid is flowing with a velocity V. If while the fluid is flowing this pipe be bent into the form of an are as shown bymm; .of Fig. 4, then possibly both the velocity V and thedensity 8 willbe a variable in an arc line. The tendency will obviously be to'crowd more particles into the circular are than existed in the straight pipe length. The mean density would thereby be increased and the mean velocity decreased.

These variations would operate to changethe magnitude of F in op osite senses but since this force varies as 2 and only di rectly as 6 it follows that the actual force would be, due tosuch imperfections, somewhat smaller than the force F above arrived at. For good conditions of flow this variation will however be very small and negligible.

Equation now may be expressed as F =KV B (8) ments of rod 10 and lever 29 may directly indicate the weight flow of fluid, for, with 8 constant therewillbe only one value of V6 for each value of the product V 8. If, however, 6 is not constant, that is if the pressure much fluid is flowing as in the other.

and temperature of the fluid vary during the flow, then the magnitude of V 8 will not be a conclusive indication of the magnitude V8 for the flow. In other words for this condition there may be any number of values V8 for a given product V 6. For instance I; if V22 and 8:4. We

have V 3=16 and 73:8 and II; if V24 and 5:1 then 7 8216 but V5=4.

Now obviously both conditions I and II will cause the same displacement to the above mechanism but in the one case only half as t is necessary therefore to take account of the fluid density when this varies during the flow. This is accomplished as follows:

In Fig. 7 the rod l0is represented as transmitting its displacement through pin 27 to lever 31. In the slot of this lever the bar 34 is adapted to slide and its longitudinal position Within the slot is controlled by the diaphragm 42. This diaphra functions exactly as the diaphragm 31 in ig. 1 of my application for fluid meters Serial Number 198,895. It is a fluid density responsive mechanism and may, as such, be replaced by the other forms of density responsive mechanisms described in said application. As in the former invention, the diaphragm or envelop surrounding the density cell 43 is surrounded by the fluid being metered, and the density fluid contained within the cell may be of the same kind as that being metered, so that at all times the volume 43 will be directly proportional to the specific volume of the surround ing fluid and inversely proportional to the density of the said surrounding fluid. It

follows that the displacements of the wall 41 means of coupling 48 and the ratio of magnitudes of longitudinal displacements of 33 to those-of 41 maybe adjusted by changing the pin 39 to other holes 37 provided for the purpose. v

The point 33 now is in the shown arrangement at all times exactly the fulcrum about which the lever 31 is displaced by means of rod 10, so that the arm length Z, will be inversely proportional to the fluid density surrounding 42.

To the other end of the sliding bar 34, at 35,'is pinned the rod 44 which may transmit the displacements of the point '35 through lever 46 and axle 47 to the outside, if so desired.

Suppose now' that the rod 10 causes a dis- The displacements of the placement AS of the pin 27, the displacement system to axle 47 which may project through of pin 35 caused thereby will obviously be equal to i As gf Now 1 is proportional to where 5 is the fluid density and if the displacement of rod 10 is caused from a deflecting flow are as 6 of Fig. 5 then AS, cc V 6 whence 12 AS, =V 6 1 Z V a But Z is practically constant for small displacements AS, whence for such, the displacements AS will be proportional to the quantity Obviously for each value of- [V8] there is only one value V6 whence the displacements AS will be an exact measure of the rate of weight flow'of the fluid. They-will be proportional to the squares of the weight flow of the fluid.

As shown in this system the fulcrum is between the power and resisting connections of the levers. This however is not necessary for the same result will be attained if for instance the fulcrum 33 were interchanged with the resisting connection 35 of the link or if the power and resisting connections were interchanged. The relation in which the displacements AS of the resisting connection are proportional to (V8)? will be true as long as the sliding bar or link is provided with the fulcrum and either the resisting or power connections, said remaining connection being'provided on the member 31 or guide.

These displacements may, as before shown. be transmitted through a linkage e casing. In a speclal 'caseit might be desired to have the work of displacement of the force F instead of being stored in a spring as 24 be stored in a gravity mechanism as shown in Fig. 8. The rod 10 has a roller 54 pressing against the arm 55 of the pendulum suspended from 56 and having at its other end the Weight 57 held in place by the nut 58. If now the rod 10 is displaced an amount a as shown then the pendulum will be. displaced to the right. The following equation willbe true,

in which F represents the force with which the roller 54 presses horizontally to the left on the pendulum arm in displacing the pendulum. W represents the weight of the pendulum, a the horizontal distance which the center of gravity of the pendulum system is from its point of support 56 and h the vertical distance between the line of action of F and the point of support 56. For small angles 6 a will be proportional to s whence where S represents the horizontal distance of the displacement of the roller 54 from the position it has when in contact with the pendulum arm when the latter hangs vertically. The density mechanism may be applied as before. This arrangement will be particularly advantageous where the resisting mechanism is to be exposed to high temperatures in that its accuracy will not be affected by such. high temperatures whereas a spring will lose its temper under such conditions.

Fig. 9 shows a special arrangement of the deflecting surface. In this arrangement t are the surfaces causing the fluid to assume a curved path. The fluid enters through inlet "5 having a definite velocity V. The deflecting tube 6' has a constant total cross sectional area, perpendicular to the direction of flow, at all parts and hence within this tube 6'. This condition may be attained by means of an equalizing pipe as 8'. After leavin 6 the fluids velocity Wlll be d1ssipated and the kinetic. energy of flow w1ll be returned to the fluid at the pressure existing in Q. The fluid temperature will thereby be raised and we have from the source region Q, for the velocity V in 5 to the chamber Q' exactly a free expansion of the fluid dur ng which its heat. content remains constant. The density fluid of the density correcting mechanism now should for accuracy obviously be exposed to the pressure and temperature conditions of the fluid flowing 1n the passage 5'. This can be accomplished by providing a chamber as Q" with an opening as 8" to 5. The density chamber and compensatin cylinder may then be located within this 0 amber. For all ordinary "rates of flow, however, there will be very small difbe located in either. The advantage of this arrangement is that it reduces the necessary has in it the curved elements 72 tangential to the direction of flow at entrance and then curving-as shown so that fluid motion will cause a force F to be exerted on 73. The suspending linkage is as shown suspended and connected by

pins

77 and 76, so that the' links 75 may freely rotateabout pins 77 as centers. .The element 71 may thus bendis placed across the fluid path against small frictional resistance, and if the arms 75 are of sufficient length the relatively small displacements will be virtually in the line w-w. The displacements of. the element 71 are caused to store energy in a conservative resisting medium such as the spring 111 by means of collari 110 fixed to rod 73. The other end of the spring is supported against the pedestal 112 which is shown bolted to the pressure casing and havin opening 113 through which the rod 73 is ree to move.

This displacement of the flow deflecting element is as before, transmitted to a lever 79 containing a slot 80 inwhich the bar 81 slides. The position of this bar is controlled by the density responsive diaphragm 42. In-

stead of a rod 36 with holes 37 as in Fig. 7, this is now shown as a slotted bar 84 in whose slot 85 the block 87 is adapted to slide,

so that the position of the fulcrum at 87 may be controlled from the outside by means of bolt head 108 on screw bar 104:. This screw bar is fixed longitudinally by means of collars 106 and turns in the threaded base of the diaphragm mechanism at points 103. As the head 108 is turned the diaphragm is moved horizontally and hence the fulcrum 87 is moved longitudinally in the slot 85. At 107 packing is provided to prevent leakage. Some of the fluid being metered enters the chamber 109 through the openings 74 so that at all times the diaphragm 42 is surounded by the pressure and temperature conditions of the fluid being metered. 1

The pin 82 in the bar 81 is the movable fulcrum ,controlled by the density mechamsm about which the lever 79 is displaced by the flow deflecting element. The. pin- 83 on the bar 81 may have attached a linkage sys-' tem 88-89 for the the displacements A to a wire or'thin rod 93. 91 represents a guiding bearing for the rod which has the wire 93 attached or fixed at the end 92.

purpose of transmitting This wire 93 now is held in tension by means of a weak spring 96, as the only purpose of this spring is to hold said wire 93 in tension. The wire passes through the meter casing in the holeprovided in plug95 and may be fixed in the head 99 by means of screw 100. The head 99 has a threaded stem over which the adjusting collar 97 screws whence the distance between the spring holding shoulders on 95 and 97 may be adjusted and likewise the initial spring tension may be adjusted.

It follows now that since the wire 93 is continually in tension that it may be very small and still be strong enough to transmit all forces causing displacements AS If the wire 93 is very small then the hole in-plug 95 through which the wire passes may likewise be very small. Then evenwith a small clearance area about the wire such a small opening will exist that'the fluid leakage therethrou'gh will be negligible. This system therefore providesa mean of transmitting mechanical displacements involving small forces through a wall between spaces ofdifierent fluid pressures and with small leakage of the fluid from the one space to the other. These displacements may be transmitted from head 99 through rod 101 guided in bearing 102 to and indicating registering or recording mechanism.

It is obvious that many changes other than those shown may be made in the arrangement and construction of this apparatus without departing from the spirit and scope of the invention, and therefore I do not wish to limit my invention to the exact 1. In fluid flow meters, the combination,

with an element responsive to the flow im pulse of the fluid, of an element proportionally responsive to variations of the fluids density and a lever composed of two members movable lengthwise relatively to each other, said lever being provided with a fulcrum, a resisting connection and a power connection, one of said members, called the link,

being provided with the fulcrum and one of said connections, the other member, called the guide, belng provided with the other of said connections, said link having its'position relatively to said guide mechanicall controlled by the element responsive to variations of the fluid density, said lever having one end mechanically connected with the element responsive to the fluid flow impulse, as and for the purpose set forth.

2. In fluidflow meters, the combination,

with an element responsive to the flow impulse of the fluid, of an element responsive to variations of the fluids density and a lever composed of a guide and a link movable lengthwise relatively to said guide, said lever being provided with-a fulcrum a resisting connection and. a power connection, said link being provided with the fulcrum and one of said connections, said guide being provided with the other of said connections, said link being mechanically connected at the fulcrum with said element responsive to variations of the fluids density, 'and said lever having one end me"hanically connected to the element responsive to the flow impulse of the fluid, as and for the purpose shown. I

3. In fluid flow meters, the combination, with an element responsive to the flow impulse of the fluid, of an element responsive to variations of the fluidsfdensity and a lever composed of a guide and a link movable lengthwise relatively to said guide, said lever being provided with a fulcrum, a resisting connection and a power connection, said link being provided with the fulcrum and one of said connections, said guide .being provided with the other of said connections, said link being mechanically connected at the fulcrum with said element responsive to variations of the fluids density, said element responsive ,to the flow impulse comprising a flow deflecting surface mounted in the fluid stream on a carriage displaceable by the flow impulse on said surface, said carriage beingconnected so as to mechanically transmit its displacements to a mechanically COIISGI'VatiX G resisting medium and to one end of said lever, as and for the purpose set forth.

4. In fluid flow meters, the combination, with an element responsive to the flow impulse of the fluid, of an element responsive to variations of the fluids density and a lever composed of a guide and a link movable alengthwise relatively 'to said guide, said lever being provided with a fulcrum, a resisting connection and a power connection, said link being provided with the fulcrum and one of said connections, said guide being provided with the other of said connections, said link being mechanically connected at the fulcrum with said element responsive to variations of the fluids density, said element responsive to the flow impulse comprising a curved flow deflecting surface in the fluid flow path, said curved deflecting surface being at flow entrance tangential to the fluid stream, said curved deflecting surface being mounted on a carriage displaceable by the flow impulse on,

said deflecting surface, said carriage being connected so as to mechan'icall transmit its displacements to a mechanically cont servatiye resisting medium and to one end of saidlever, as and for the purpose shown. 5. In fluid flow meters, the combination,

with an element responsive to the flow im-.

pulse of the fluid, of an element responsive to variations of the fluids density and a lever composed of a guide and a link movable lengthwise relatively to said guide, said lever being provided with a fulcrum, a resisting connection and a power connection, said link being provided with the fulcrum and one of said connections, said guide being provided with the other of said connections, said link being mechanically connected at the fulcrum with said element responsive to variations of the fluids density, said element responsive to flow impulse comprising a flow deflecting element in the flow path, said deflecting eleinent having curved surfaces which are at flow entrance tangential to the fluid stream, said curved portions terminating in straight portions, said deflecting element forming a channel of constantcross sectional area normal to the direction of flow, said deflecting element being mounted on a carriage displaceable by the flow impulse on said deflecting surfaces, said carriage being connected so as to mechanically transmit its displacements to a mechanically conservative resisting medium and to one end of said lever, as and for the purpose set forth.

'6. In fluid flow meters, the combination, withan element responsive to the flow impulse of the fluid, of an element proportionally responsive to variations of-the fluids density and a lever composed of a guide and a link movable lengthwise relatively to said guide, said lever being provided with a fulcrum, a resisting connection and a power connection, said link being provided with the fulcrum and one of said connections, said element responsive to variations of the fluids density confining a quantity of an elastic fluid-within an envelop adapted to be placed in the fluid being metered, said envelop beingimpervious to the surrounding and confined fluids but being adapted both to conduct heat readily between them and to undergo, becauseof the forces acting on it due to variations of the surrounding fluids density, relative displacements of its parts allowing equalization of the internal pressure with the external pressure, said envelop having a displaceable part mechanically conguide, said lever being provided with a fulcrum, a resisting connection and a power connection, said link being provided with the fulcrum and one of said connections, said element responsive to variations of the fluids density confining a quantity of an and confined fluids but being adaptedboth to conduct heat readily between them and to 7 undergo, because of the forces acting on it due to variations of the surrounding fluids density, relative displacements of its parts allowing equalization of the internal pressure with the external pressure, said envelop havin a displaceable part mechanically connecte to the link at the fulcrum, said element responsive to the flow impulse comprising a flow deflecting surface mounted in the fluid stream on a carriage displaceable by the flow impulse on said surface, said carriage being connected so as to mechanically transmit its displacements to a mechanically conservative resisting medium and to one end of said lever, as and for the purpose set forth.

8. In fluid flow meters, the combination,

with an element res onsive to the flow impulse of the fluid, 0 an element PIOPOItlOIlally responsive to variations of the fluids density and a lever composed of a guide and a link movable lengthwise relatively to said guide, said lever being provided with a fulcrum, a resisting connection and a power connection, said link being provided with the fulcrum and one of said connections, said element responsive to variations of the fluids density confining a quantity of an elastic fluid of the same kind as the surrounding fluid within an envelop adapted to be placed in the fluid being metered, said envelop being impervious to the surrounding and confined fluids but being adapted both to conduct heat readily between them and to undergo, because of the forces acting on it due to variations of the surrounding fluids density, relative displacements of its parts allowin equalization of the internal pressure with t e external pressure, said envelop having a displaceable part mechanically connected to the link at the fulcrum, said lever having one end mechanically connected to the element res onsive to the flow im ulse of the fluid, as and for the purpose set orth.

9. In fluid flow meters, the combination, with an element responsive to the flow impulse of the fluid, of an element proportionally responsive to variations of the fluids density and a lever composed of. a guide and a link movable lengthwise relatively to said guide, said lever being provided with a fulcrum, a resisting connection and a power connection, said link being provided with the fulcrum and one of said connections, said element responsive to variations of the fluids density confining a quantity of an elastic fluid of the same kind as the surrounpling fluid within an envelop adapted to be placed in the fluid being metered, said envelop being impervious to the surrounding and confined fluids but being adapted both to conduct heat readily between them and to undergo, because of the forces acting on it due to variations of the surrounding fluids density, relative displacements of its parts allowing equalization of the internal pressure with the external pressure, said envelop having a displaceable part mechanically connected to the link at the fulcrum, said element responsive to the flow impulse comprising a flow deflecting surface mounted in the fluid stream on a carriage displaceable by the flow impulse on said surface, said carriage being connected so as to mechanically transmit its displacements to a mechanically conservative resisting medium and to one 2nd lpf said lever, as and for the purpose set ort 10. In the fluid flow path of meters, a flowplacements to a mechanically conservative resisting medium.

12. In the fluid 'flow path of meters, a curved flow deflecting surface, said curved deflecting surface being at flow entrance tangential to the fluid stream, said curved portion terminating in a straight portion, said curved deflecting surface being mounted on a carriage displaceable by the flow impulse on said deflecting surface, said carriage being connected so as to mechanically transmit its displacements to a mechanically conservative resisting medium.

13. In the fluid flow path of meters, a flow deflecting element, sald deflecting element having curved surfaces which are at flow entrance tangential to the fluid stream, said curved portions terminating in straight portions, said deflecting element forming a channel of constant cross sectional area normal to the direction of flow, said deflecting element being mounted on a carriage displaceable by the flow impulse on said deflecting surfaces, said carriage being connected so as to mechanically transmit its displacements to a mechanically conservative resisting medium.

14. In meters, the combination with a fluid flows, of'a flow deflecting surface in chamber to and from which the metered the path of the inflowing fluid, said deflecting surface beingmou'n'ted on a carriage displaceable by the flow impulse on the deflecting surface, said carriage being connected so as to mechanically transmit its displacements to a mechanically conservative resisting medium, the conduit surrounding said fluid stream Within said chamber having an opening in the surface tangential to the flow lines, as and for the purpose set forth.

15. In meters, the combination with a chamber, having inlet and outlet passages for the metered fluid, of a flow deflecting channel in the path of-the inflowing fluid, said inlet and outlet passages being of the same cross sectional area, said deflecting channel being at all sections of substantially the same area as the inlet and outlet passages to the chamber, and being curved from tangency with the inlet passageinto the outlet passage, said deflecting channel being mounted on a carriage displaceable by the flow impulse and reaction on said channel, said carriage being connected so as to mechanically transmit its displacements to a me chanically conservative resisting medium, the conduit surrounding said fluid stream within said chamber having an opening in the surface tangential to the flow lines, as and for the purpose set forth.

\VALTER J ACOB WOHLENBERG.