Flow meter

Claim 2

A flow meter comprising a fluid-filled, fluidtight housing; at least one movable U-shaped tube mounted within indication housing and having an inlet and an outlet end and radially outwardly extending flanges at said ends, one surface of said flanges being in contact with said fluid; a fixed inlet tube and a fixed outlet tube having respectively open ends substantially aligned with and spaced from said inlet and said outlet ends of said movable U-shaped tube for feeding the fluid to be measured into and out of the latter; a pair of resilient joint means respectively connecting said fixed tubes to the outer periphery of said outwardly extending flanges, said inlet joint means being fluidtight and defining with its flange a pressure chamber so that the movable tube will tend to move in one direction in response to momentum changes of the fluid passing through the interior thereof and under the influence of the fluid pressure acting on said flanges; means to communicate the pressure of the measured fluid at said outlet end with the fluid in said housing, whereby the fluid pressure on said inlet flange will provide pressure compensation; counteracting means for providing a force counteracting the tendency of said movable tube to move in said one direction; and means for measuring said force as an indication of the amount of measured fluid flowing through the meter.

Claim 3

A flow meter as defined in claim 1, wherein said counteracting means comprise an iron core fixed to said tube for movement therewith and a stationary coil surrounding said core, and means for transmitting a force proportional to the pressure in said pressure chamber to said movable tube in a direction opposite to said one direction.

Claim 4

A flow meter as defined in claim 2, wherein only said resilient inlet joint means is fluidtight and the other is constituted by spring means opposing movement of said movable tube in said one direction and permitting passage of fluid between the respective end of the movable tube and that of the corresponding fixed tube into said housing, and wherein said force transmitting means comprise tube means communicating at one end with said pressure chamber formed by said one fluidtight joint means and at the other end with said fluidtight housing and a flexible membrane extending transverse through said tube means intermediate the ends thereof.

Claim 5

A flow meter as defined in claim 2, wherein only said resilient inlet joint means is fluidtight and the other is constituted by spring means opposing movement of said movable tube in said one direction and permitting passage of fluid between the respective end of the movable tube and that of the corresponding fixed tube into said housing, and wherein said force transmitting means comprise an auxiliary resilient fluidtight joint means in said housing connected at one end to said movable tube for movement therewith and a tube communicating at opposite ends with said one and said auxiliary fluidtight joint means.

Claim 6

A flow meter comprising a fluid-filled, fluidtight housing; at least one movable U-shaped tube mounted within said housing and having an inlet and an outlet end and radially outwardly extending flanges at said ends, one surface of the flanges being in contact with the fluid; a fixed inlet tube and a fixed outlet tube having respectively open ends substantially aligned with and spaced from said inlet and outlet ends of said movable tube for feeding the fluid to be measured into and out of the latTer; a pair of resilient joint means respectively connecting said fixed tubes to the outer periphery of said outwardly extending flanges, both of said joint means being fluidtight and defining with the respective flange a pressure chamber so that the movable tube will tend to move in one direction in response to momentum changes of the fluid passing through the interior thereof and under the influence of the fluid pressure acting on said flanges; means for sensing the movement of said tube; pump means responsive to said sensing means for maintaining a pressure in said housing which acts upon said flanges and tends to prevent movement of said movable tube; and means for sensing the pressure differences between the fluid in said housing and the measured fluid inlet pressure and between the fluid in said housing and the measured fluid outlet pressure as an indication of the fluid flow.

Claim 7

A flow meter comprising a fluid-filled, fluidtight housing; at least one movable U-shaped tube mounted within said housing and having an inlet and an outlet end and radially outwardly extending flanges at said ends, one surface of the flanges being in contact with the fluid; a fixed inlet tube and a fixed outlet tube having respectively open ends substantially aligned with and spaced from said inlet and outlet ends of said movable tube for feeding the fluid to be measured into and out of the latTer; a pair of resilient joint means respectively connecting said fixed tubes to the outer periphery of said outwardly extending flanges, both of said joint means being fluidtight and defining with the respective flange a pressure chamber so that the movable tube will tend to move in one direction in response to momentum changes of the fluid passing through the interior thereof and under the influence of the fluid pressure acting on said flanges; means for sensing the movement of said tube; pump means responsive to said sensing means for maintaining a pressure in said housing which acts upon said flanges and tends to prevent movement of said movable tube; and means for sensing the pressure differences between the fluid in said housing and the measured fluid inlet pressure and between the fluid in said housing and the measured fluid outlet pressure as an indication of the fluid flow.

Claim 8

A flow meter as defined in claim 5, and wherein said pressure difference sensing means comprise a pair of tube means each communicating at one end with the pressure chamber formed by the respective fluidtight joint means and at the other end with the interior of said housing, and a flexible membrane extending transversely through each of said tube means intermediate the ends thereof.