Patent GB-1038219-A (GB)
Title: Improvements in or relating to fluid flow regulators
IPC: F15C1/08
Filed: 1963-10-30
Abstract: 1,038,219. Hydrostatic transmission. H. TEVES, E. A. TEVES, and M. TAUSEND, [trading as ALFRED TEVES MASCHINENUND ARMATURENFABRIK KOMM. GES.]. Oct. 30, 1963 [Nov. 24, 1962], No. 42831/63. Heading F2D. [Also in Division G3] A pump 1, Fig. 1, is connected to a motor 2 or a tank 3 under the control of an oscillating valve 5 whereby the motor speed is controlled. The valve has opposed electromagnets 11, 12 alternately energized from a unit 6 comprising a power pack 13, a pulse generator 7, and a phase shifter 8. The latter may be used to vary the times of connection to the motor and tank and so vary the motor speed. An accumulator 4 is connected to the motor input which together with the piping smooths the ripple in the pulsed fluid pressure supplied to the latter. The ripple may be further reduced by an additional oscillating valve and accumulator. The oscillating valve may have only one electromagnet, the winding 30 (Fig. 3, not shown) of which, when energized by A.C. causes reciprocation of an armature 29 with or against the force of springs 34, 35; the fluid displaced from one chamber 31 or 37 by a channel, not shown, flows into the other chamber and assists the displacement of the armature, so that an inlet 20 is connected by a grooved-sliding closure-member 25 to the motor or tank outlets. The springs and moving parts are adapted to the A.C. frequency to provide an harmonically oscillating system which requires the minimum of electric power for actuation. The electromagnet casing 32 may be moved axially to alter the centre of oscillation and hence the distribution between the outlets. A restriction 41 (Fig. 5, not shown) may be, disposed in the pump output 40, the pressure difference across which is applied by lines 42, 43, across a pair of amplifiers 44, 45 connected by a manual stop valve 50. Each amplifier consists of a main channel 46, 47 (Fig. 5a, not shown) connected in the lines 42, 43 and an auxiliary channel 48, 49 connected to chambers 31, 37 (Fig 3, not shown), respectively, in place of the channel therebetween whereby the action of the electromagnet is assisted. Multi-stage amplification may be provided. In another form of oscillating valve the sliding closure-member 51 (Fig. 6, not shown) houses a tube 53 interconnecting chambers 31, 37, the tube being secured to the member 51 by a friction device 59; the reduced portion 25 of the member 51 embodies throttling steps 26a, 27a, inclined passages 60, 61 and a radial port 62 which port and passages co-operate with ports 65 and 63, 64 respectively. When the piston 51 nears the reversal point one of the steps 26a, 27a exercises a throttling action to produce a pressure difference between motor or inlet groove 19, 20 and the reduced portion 25 whereupon fluid from the inlet groove 20 enters the tube 53 and discharges therefrom by passage 60 so that piston 51 and tube 53 are urged to the right by reaction, which ceases when the groove 19 is closed; the piston 51 continues to move due to inertia until the tube 53 is stopped by an abutment 57, the piston 51 then overcomes the friction device 59 and aligns passage 64 and port 64 as groove 21 is opened. The spring 35 and the force imparted to the armature by the next electrical pulse cause the piston 51 to stop and then reverse. The process is repeated due to the pressure difference produced between the inlet and tank grooves 20, 21. The oscillating valve may be replaced by one of the constantly-rotating type having a closure member 69, (Fig. 7b, not shown) driven from a shaft through a clutch, the member incorporating a chamber 72, always open to the pump, and two opposed pairs of outlets connected to the tank and motor. Fluid from the chamber 72 discharges through a slot 73 to the adjacent outlet. A pair of segments 75, 76 is manually movable around the member 69 to adjust the areas of the tank outlets; similar means are associated with the motor outlets and comprise an element 78 (Fig. 8b, not shown) movable with the segments 75, 76. In this embodiment the closure member is rotated by the reaction forces caused by the fluid flowing to the outlets through tangential slits 81.