Fluidic clinometer control apparatus

Abstract

Disclosed herein is a fluidic clinometer for automatically operating servomechanisms according to the angular displacements of a structure on which the inclinometer is fixedly mounted for integral movement therewith. It includes a substantially U-shaped tube having enlarged chambers of equal size at the free ends of its vertical legs which are open to the atmosphere, the walls of said chambers being formed of micropous material of a porosity to permit the passage of air, or similar gaseous fluid, but inhibit the escape of mercury, or other analogous liquid, therethrough; mercury, or other such liquid, partially filling the tube, up to about the middle of said chambers when the tube is in normal upright position; a substantially U-shaped casing concentrically surrounding said tube in airtight relation and providing an annular air space there-between; an air inlet medially of the horizontal or connecting part of said casing and an air outlet in each of the vertical legs of the casing; fluidic amplifying means having fluid communication with said outlets; fluid lines leading from the output side of the amplifying means for operating servomechanisms; and other fluid lines leading from the amplifying means to a differential pressure gauge indicating the angle and direction of inclination of said tube and casing, and hence of a structure on which the latter are to be mounted, in relation to a horizontal plane of reference. While this apparatus is capable of a variety of application, it is especially adapted for use in U.S. Pat. No. 3,689,953, Sept. 12, 1972, to the present co-inventor Costas E. Markakis, to control the amount and direction of the air needed to maintain the floating structures therein in stable or upright position.

We claim: 
     
       1. A fluidic clinometer for automatically controlling the operation of servomechanisms, comprising a substantially U-shaped tube with its legs terminating in chambers of equal size, which are open to the atmosphere and are formed of microporous material, of a porosity permitting the passage of air, or other similar fluid, therethrough but inhibiting the escape of liquid from within the chambers; a suitable liquid partially filling the tube up to about the middle of the height of the chambers when the leg connecting part of the U-shaped tube is horizontal and the legs are vertical; a substantially U-shaped, fluidtight casing of greater diameter than the tube concentrically enclosing said tube throughout, thus forming an annular air passage between said tube and said casing, and said casing being provided with a fluid inlet medially of its connecting part and with a fluid outlet in each of its legs, the outlets being adapted to communicate with and control servomechanisms. 
     
     
       2. A fluidic clinometer according to claim 1 wherein the liquid in the tube is mercury. 
     
     
       3. A fluidic clinometer according to claim 1 wherein the porosity of said chambers is of the order of 50 microns. 
     
     
       4. A fluidic clinometer according to claim 1 wherein each leg of the casing is constricted between its juncture with the connecting part of the casing and its said outlet. 
     
     
       5. A fluidic clinometer according to claim 1 wherein the connecting part of the U-shaped tube and casing are substantially rectilinear and longer than the height of their vertical legs. 
     
     
       6. A fluidic clinometer according to claim 1 including fluidic amplifying means connected to said fluid outlets of said casing for amplifying the pressure of the air issuing therefrom therefrom. 
     
     
       7. A fluidic clinometer according to claim 6 wherein the amplifying means comprise a fluidic proportional amplifier connected to the outlets of the legs of said casing; two fluidic monostable amplifiers having fluid connection with the outlets of said proportional amplifier; and fluid lines extending from the outputs of said monostable amplifiers adapted to communicate with and control servomechanisms. 
     
     
       8. A fluidic clinometer according to claim 7 including a differential pressure gauge bridging the fluid connections between the proportional and the monostable amplifiers, providing a visual indication of the angles of inclination of the tube and casing, and hence of a structure on which they are to be fixedly mounted. 
     
     
       9. A fluidic clinometer according to claim 1 wherein the liquid is mercury, each leg of the casing is constricted between its juncture with the connecting part of the casing and its said outlet, and fluidic amplifying means connected to the fluid outlets of said casing for amplifying the pressure of the air issuing therefrom. 
     
     
       10. A fluidic clinometer according to claim 9 wherein the amplifying means comprise a fluidic proportional amplifier connected to the outlets of the legs of said casing; two fluidic monostable amplifiers having fluid communication with said proportional amplifier; and fluid lines extending from the outlets of said monostable amplifiers, adapted to communicate with and control servomechanisms. 
     
     
       11. A fluidic clinometer according to claim 10 including a differential pressure gauge connected across the output lines of the proportional amplifier and calibrated in degrees in opposite directions from a zero reference point, thereby providing a ready visual indication of the angle and direction of inclination of the clinometer, and hence of a structure on which it is to be fixedly mounted. 
     
     
       12. A fluidic clinometer comprising a substantially U-shaped tube with its legs terminating in chambers of equal size, which are open to the atmosphere and are formed of microporous material, of a porosity permitting the passage of air, or other similar fluid, therethrough but inhibiting the escape of liquid from within the chambers; a suitable liquid partially filling the tube up to about the middle of the height of the chambers when the leg connecting part of the U-shaped tube is horizontal and the legs are vertical; a substantially U-shaped, fluidtight casing of greater diameter than the tube concentrically enclosing said tube throughout, thus forming an annular air passage between said tube and said casing and said casing being provided with a fluid inlet medially of its leg connecting part and with a fluid outlet in each of its legs; and means communicating with said outlets for indicating the pressure differential there-between in terms of the angles of inclination of the tube and casing about an axis transversely thereof. 
     
     
       13. A fluidic clinometer according to claim 12 wherein the legs of said casing are constricted between said outlets and the juncture of the legs of the casing with the leg connecting part of the latter. .Iadd. 14. A fluidic clinometer control apparatus comprising a substantially U-shaped tube with its legs terminating in chambers of equal size, which are open to the atmosphere and are formed of microporous material, of a porosity permitting the passage of air, or other similar fluid, therethrough but inhibiting the passage of liquid from within the chambers; a suitable liquid partially filling the tube up to about the middle of the height of the chambers when the leg connecting part of the tube is horizontal and its legs are vertical; a fluidtight enclosure surrounding each of said microporous chambers in spaced relation to said chambers, thus forming an air space therebetween, .Iadd.said air space between said chamber and said enclosure being substantially equal in both legs, each enclosure being provided with a fluid inlet, to be connected to a source of pressurized fluid, and with a fluid outlet; and pressure responsive means connected to said fluid outlets and adapted to control the operation of servomechanisms..Iaddend..Iadd. 15. A fluidic clinometer control apparatus according to claim 14 wherein the porosity of said microporous chambers is of the order of 50 microns..Iaddend. .Iadd. 16. A fluidic clinometer control apparatus according to claim 15 wherein the liquid in the tube is mercury..Iaddend..Iadd. 17. A fluidic clinometer control apparatus according to claim 14 wherein the pressure responsive means includes fluidic amplifying means to said outlets for amplifying the pressure of the fluid issuing from the outlets of said enclosures..Iaddend..Iadd. 18. A fluidic clinometer control apparatus according to claim 17 wherein said fluidic amplifying means comprises, a fluidic proportional amplifier connected to said outlets, two fluidic monostable amplifiers having fluid communication with the outlets of said proportional amplifier; and fluid lines extending from the outputs of said monostable amplifiers adapted to communicate with and control servomechanisms..Iaddend..Iadd. 19. A fluidic clinometer control apparatus according to claim 18 including a differential pressure gauge bridging the fluid connections between the proportional and the monostable amplifiers, providing a visual indication of the angles of inclination of the tube, and hence of a structure on which the tube is to be mounted..Iaddend..Iadd.20. A fluidic clinometer control apparatus according to claim 18 wherein the porosity of the microporous chambers is of the order of 50 microns and the liquid in the tube is mercury..Iaddend.