Velocity flowmeter

Claim 2

A flowmeter for measuring the rate at which fluid flows in one direction through a duct, and which is of the type that comprises a turbine having helical vanes, mounted in the duct for free rotation with its rotational axis parallel to that of the duct, and sensing means mounted in proximity to the turbine and cooperating therewith to produce a signal that corresponds to the rotational speed of the turbine and hence to the rate of fluid flow, said flowmeter being characterized by: A. the turbine being mounted for limited free motion axially, as well as for free rotation; B. upstream and downstream clutch members coaxial with the turbine and constrained to partake of its axial and rotational motion, 1. the upstream clutch member facing oppositely to said one direction and 2. the downstream clutch member facing in said direction; C. a fixed clutch element in the duct at a location normally upstream from the upstream clutch member and engageable by the latter when the turbine propels itself upstream in consequence of its rate of rotation exceeding that corresponding to existing stream velocity, such exgagement resulting in deceleration of the turbine; D. A rotatable clutch element coaxial with the turbine at a location normally downstream from the downstream clutch member and engageable by the latter when the turbine drifts downstream in consequence of its rotational speed being lower than that corresponding to existing stream velocity; and E. drive means by which the rotatable clutch element is rotatably driven at a speed higher than is normally attained by the turbine so that the turbine is rotationally accelerated by engagement of the downstream clutch member with the rotatable clutch element.

Claim 3

mean providing a mounting for said holder by which the same is pivoted for swinging motion in directions substantially parallel to the rotor axis about a substantially horizontal swinging axis which is spaced a substantial distance from the rotor axis and is transverse thereto; and B. counterbalance means connected with said holder and disposed at the opposite side of said swinging axis from said holder, said counterbalance means substantially offsetting the effect of gravity upon the holder so that the rotor moves in its substantially axial directions only under the influence of fluid flow and is not affected by displacement of its axis from the horizontal.

Claim 4

mean providing a mounting for said holder by which the same is pivoted for swinging motion in directions substantially parallel to the rotor axis about a substantially horizontal swinging axis which is spaced a substantial distance from the rotor axis and is transverse thereto; and B. counterbalance means connected with said holder and disposed at the opposite side of said swinging axis from said holder, said counterbalance means substantially offsetting the effect of gravity upon the holder so that the rotor moves in its substantially axial directions only under the influence of fluid flow and is not affected by displacement of its axis from the horizontal.

Claim 5

In a flowmeter for measuring a function of the velocity of a fluid stream that flows in one direction, said flowmeter being of the type comprising a rotor and means mounting the rotor in a stream to be measured, with the rotor axis substantially aligned with the direction of stream flow, said mounting means providing for rotation of the rotor by the stream at a rate generally corresponding to stream velocity and also providing for limited substantially axial motion of the rotor in response to differences between prevailing rotor rotational speed and the rotor speed that accurately corresponds to prevailing stream velocity, means for effecting compensation of the rotational speed of the rotor to bring it into accurate correspondence with stream flow velocity at times when such differences exist, the last mentioned means comprising: A. a rotAtable clutch element coaxial with the rotor and facing in the axial direction opposite to that of stream flow; B. a motor for driving the rotatable clutch element at a rotational speed higher than the highest expectable speed of the rotor; C. a stationary clutch element fixed in coaxial relation to the rotor and spaced axially from the rotatable clutch element, said stationary clutch element facing in the axial direction of stream flow; and D. clutch element means constrained to coaxial rotation with the rotor and to axial motion therewith, said clutch element means having axially oppositely facing friction surfaces, one of which is engageable with said stationary clutch element upon axial upstream motion of the rotor to thus effect retardation of rotor speed, and the other of which is engageable with the rotatable clutch element upon downstream motion of the rotor to thus provide for augmentation of rotor speed.

Claim 6

In a flowmeter for measuring a function of the velocity of a fluid stream that flows in one direction, said flowmeter being of the type comprising a rotor and means mounting the rotor in a stream to be measured, with the rotor axis substantially aligned with the direction of stream flow, said mounting means providing for rotation of the rotor by the stream at a rate generally corresponding to stream velocity and also providing for limited substantially axial motion of the rotor in response to differences between prevailing rotor rotational speed and the rotor speed that accurately corresponds to prevailing stream velocity, means for effecting compensation of the rotational speed of the rotor to bring it into accurate correspondence with stream flow velocity at times when such differences exist, the last mentioned means comprising: A. a rotAtable clutch element coaxial with the rotor and facing in the axial direction opposite to that of stream flow; B. a motor for driving the rotatable clutch element at a rotational speed higher than the highest expectable speed of the rotor; C. a stationary clutch element fixed in coaxial relation to the rotor and spaced axially from the rotatable clutch element, said stationary clutch element facing in the axial direction of stream flow; and D. clutch element means constrained to coaxial rotation with the rotor and to axial motion therewith, said clutch element means having axially oppositely facing friction surfaces, one of which is engageable with said stationary clutch element upon axial upstream motion of the rotor to thus effect retardation of rotor speed, and the other of which is engageable with the rotatable clutch element upon downstream motion of the rotor to thus provide for augmentation of rotor speed.

Claim 7

the downstream clutch member facing in said direction; C. a fixed clutch element in the duct at a location normally upstream from the upstream clutch member and engageable by the latter when the turbine propels itself upstream in consequence of its rate of rotation exceeding that corresponding to existing stream velocity, such exgagement resulting in deceleration of the turbine; D. A rotatable clutch element coaxial with the turbine at a location normally downstream from the downstream clutch member and engageable by the latter when the turbine drifts downstream in consequence of its rotational speed being lower than that corresponding to existing stream velocity; and E. drive means by which the rotatable clutch element is rotatably driven at a speed higher than is normally attained by the turbine so that the turbine is rotationally accelerated by engagement of the downstream clutch member with the rotatable clutch element.

Claim 8

the downstream clutch member facing in said direction; C. a fixed clutch element in the duct at a location normally upstream from the upstream clutch member and engageable by the latter when the turbine propels itself upstream in consequence of its rate of rotation exceeding that corresponding to existing stream velocity, such exgagement resulting in deceleration of the turbine; D. A rotatable clutch element coaxial with the turbine at a location normally downstream from the downstream clutch member and engageable by the latter when the turbine drifts downstream in consequence of its rotational speed being lower than that corresponding to existing stream velocity; and E. drive means by which the rotatable clutch element is rotatably driven at a speed higher than is normally attained by the turbine so that the turbine is rotationally accelerated by engagement of the downstream clutch member with the rotatable clutch element.

Claim 9

The flowmeter of claim 2 wherein said rotatable clutch element and said stationary clutch element are at axially opposite sides of the rotor and facing the same, and said clutch element means has its said faces at axially opposite ends of the rotor, each in opposing relation to one of said clutch elements, further characterized by: A. said means mounting the rotor comprising