Patent GB-103483-A (GB)
Title: Improvements in or relating to Apparatus for Varying the Pump Stroke in Windmills and the like.
Inventor: JOSEPH SILVERTON EVERETT
IPC: F03D11/02
Filed: 1917-01-11
Abstract: 103,483. Everett, J. S., and Everett, W. S. Jan. 1'7, 1916, [Convention date]. Void [Published under Sect. 91 of the Act]. Driving and transmission mechanism, special application of. - Apparatus for varying the stroke of pumps driven by windmills &c. comprises a long narrow cylinder D inserted in the down-rod connecting the windmill crank to the pump plunger. The cylinder contains oil and a system of floating valves and pistons and ports, whereby the working parts are moved in the cylinder or prevented from moving according to the pressure of the wind on the windmill vanes. In Fig. 3, a general view of the apparatus is shown, comprising an external cylinder A mounted on a plate A<1> and a piston-rod B mounted on a plate B<1>, the plate A<1> being connected to a plate C by rods a passing through the plate B<1>, which is connected to a plate C' by rods b The plates C, C' are at right-angles to each other and carry members c for connexion to the upper and lower parts of the downrod. In the form shown in Figs. 4, 5 and 6, the cylinder D is connected by the lower link c to the lower part of the down-rod, the upper part of which is connected to the piston-rod E by the upper link c. The rod E is connected by a nut E<3> to a combined cylinder and piston G, provided with ports G<1> above the piston H and ports G<2 >below it. Below the ports G<2> is an enlargement G<3> enclosing an annular series of spaces G<4> within the cylinder wall. The lower end of the cylinder carries a piston G<5> having a fluted periphery, a valved perforation g<3> and two regulating set-screws g<1>, g<2>. Within the cylinder G is a piston valve, of which the parts J, J<2> make a piston fit with the cylinder, while the part J<1> is of smaller diameter and is hollow and provided with ports j. The part J<2> has ports j<1> adapted to be closed by a valve j<2>. A spring k<1> rests on a perforated partition K and presses the piston valve upwards. Below the partition K is a piston M pressed upwards by a spring m on the stem M<1>, which passes through the piston G<5> into a recess in the stem D<1>. The stem M<1> has a taper groove m<1>, into which the screw g<2> may be set to any required distance to regulate the travel of the piston and the area of the groove m<1>, through which the oil can escape from or enter the cylinder. As the load increases during the up-stroke of the downrod, the valve J is forced down by the oil pressure, thus connecting the ports G<1>, G<2> so that the piston H can move freely through the oil, and the rod E can rise and lengthen the down-rod by the same amount, thereby shortening the stroke of the pump plunger. During the down-stroke, the pressure below the piston H increases, and the valve J is forced to its highest position, thus connecting the ports G<1>, G<2>. The piston M is depressed, the oil below it escaping through the groove m<1> and passing up through the flutes in the piston G<5> into the space F. When the pressure above the piston M is removed by the escape of the oil through the space G<4> and ports G<2>, the piston M is forced up by the spring m as fast as it can draw oil through the groove m<1> and port g<3> into the cylinder G. In the modification shown in Fig. 7, the cylinder G is integral with the cylinder D and projects a little below the casing A in the plate A<1>. The piston H is replaced by a partition H<1>, and the piston G<5> is modified so that the screws g<1>, g<2> can be adjusted from outside. The piston rod is connected at one end to the plate B<1>, and at the other end to a hollow piston N, over which the cylinder D slides. In the wall of the cylinder D are ports d<1> for the passage of oil from the cylinder D to the casing A, and taper ports allowing the passage of oil between the casing A and the space above the piston N as the cylinder D rises and falls.