Patent GB-190926034-A (GB)
Title: Improvement in Means for Imparting Stability to Unstable Bodies.
Inventor: BRENNAN LOUIS
IPC: G01C21/18
Filed: 1909-11-10
Granted: 1911-01-10
Abstract: 26,034. Brennan, L. Nov. 10. [Cognate Application, 29,391/09.] Gyroscopic apparatus. - Devices are arranged upon a body carrying one or more gyrostats so that when equilibrium is distributed there is derived from the precessional movement of the gyrostat, or from a relative swinging movement or tendency to movement of the gyrostat frame and its support, or from both, the proper force to control powerful auxiliary forces adapted to influence either precession of the gyrostat or the relative position of the centre of gravity of the body and its support, or both, whereby maintenance of equilibrium is attained. This controlling-force may be a combination of forces depending in magnitude upon the sum of a function of the disturbing moment and a function of the time integral of the disturbing moment, or it may depend upon one only of these functions. There may be added a further component of the controlling-force derived from a solidfriction coupling to balance the unavoidable friction in the precessional movement. In Figs. 1 and 2 is shown a device in which equilibrium is maintained by acceleration of precession. Frames c in which heavy wheels b rotate, carry racks d engaging a double rack e capable of being moved longitudinally by pistons f moving in cylinders g arranged co-axially on opposite sides of the gyrostats. The admission and exhaust of working fluid from cylinders g to turn the gyrostats about vertical axes are controlled by valves k, such as are described in Specification 7177/02, [Class 135, Valves &c.], connected to the cylinders by pipes p; these valves give pressure in the working cylinders g proportional to the pressure exerted on the valve spindle to operate the valve. The valves k are operated by an actuating-lever o operated by three separate forces, all of which originate in the precessional movement of the gyroscope; one force is due to the spring 6 and is proportional to the displacement of the gyrostats from their central position; a second force is due to a viscous coupling s, which causes to be transmitted to the valves k a force substantially proportional to the velocity of precession; and a third force is obtained from a solidfriction coupling 2 on the gyroscope spindle, which balances the friction in the precessional movement. The effect of these forces acting on the valve k is simply multiplied to the required extent by the fluidoperated cylinders g and caused to act directly on the gyrostats through a rack e and toothed sectors d operating to turn the gyrostats about vertical axes. In a modification, a force proportional to the reaction between the frame of the gyrostat and its support may be substituted for the force proportional to the velocity of precession, as both are proportional to the disturbing-couple. The modifications in which equilibrium is obtained by effecting shifts of the centre of gravity have the same valves k similarly controlled by three forces, but they control the supply of working fluid to cylinders arranged to slide the body of the vehicle across the under carriage. Further devices described, Figs. 13, 14, and 15, comprise means for reducing and damping oscillations in apparatus, such as that described in Specification 27,212/03. The means for accelerating precession are so arranged that the commencement of acceleration can take place before the gyrostat arrives at the central position on its return thereto after having been disturbed. The motion of the gyrostat is retarded on its return to the central position when the acceleration has ceased, the retardation being arranged to cease before the gyrostat reaches the central position, whereby oscillations of the body are damped out. When the vehicle tilts on one side, the accelerating surface 30 comes into contact with a rotating roller 25 geared to the spindle of the gyrostat; precession takes place, and a pin 22 on a sliding piece 21 on the frame c supporting the gyrostat moves round in a circular groove 26, the corresponding pin on the other side being moved inwards by a spiral camsurface 27 along a ledge 28. When the position of equilibrium has been passed and the gyrostats are returning to their central position, the pin on the farther side moves in a circular path on the surface 28 so that the return movement is frictionally retarded until the circular movement of the pin causes it to leave the ledge 28 and drop into the slot 29, when the roller 25 and surface 30 can come into contact and the precession is accelerated on that side; thus oscillations of the vehicle are quickly damped. A spring 36 arranged on arms of the frames c accelerates the precession away from the central position, and retards it in the other direction. In a modification, the rotating roller is carried by the vehicle and the accelerating surface by the gyrostat frame. Specifications 27,212/03 and 29,579/09, [Class 103 (vi), Railway &c. vehicles, Undercarriage &c.], are referred to.