US2023168A - Control mechanism for hydraulic devices - Google Patents

Description

Dec. 3, 1935. R, ERLING I YCONTROL MEGHANsM FOR HYDRAULIC DEVICES A Filed Aprilvle, 1954- 2 sheets-sheet 1 )Trrl 1 lll/1 ATTOR EY Dec. 3, 1935. R. ERLING CONTROL MECHANISM FQR HYDRAULIC DEVICES Filed April 16, 1954 2 Sheets-Shea?, 2

INVENTOR RALPH ERL l N G ATTQRNEY Patented Dec. 3, 1935 UNITED STATES PATENTv GFFICE CONTROL MEonANisM Fon HYDRAULIC nEvIcEs I l Ralph Erling, Alexandria, Va. Application April 16, 1934, Serial No. 720,840 7 Claims. (Cl. 60-52) (Filed but not issued In the drawings:

Fig. 1 illustrates one form of the present invention, the pump being shown in section along the axis of rotation thereof;

Fig. 2 is a section through the pump transverse to its axis of rotation;

Fig. 3 is an enlarged detail view of one of the adjustable connecting means;

Fig. 4 shows a hydraulic system wherein is included another form of my invention;

Fig. 5 is a detail view of to the pump controls;

Figs. 6 and 7 are fragmentary plan views showing the interrupted gear in two different positions;

Fig. 8 is a sectional elevation through Fig. 7 on line 8 8.

The invention forming the subject of the present. app ication 1s 1n many respects similar to the device disclosed piston type of variable delivery pump, and another form in connection with an axial piston pump, equally satisfactory results will be had from either control apparatus if used with either type of pump.

The rudder post 9 is connected by means of tiller l0 to ram l l which thas its opposite ends disposed to operate as pistons in cylinders l2 and i3 that are respectively connected to pump i4 by under the act of March 83, as amended April 3 pipes l5 and I6. Manually operable wheel I1 is connected to sun pinion I8 of diierential gear i9 by worm 20, gear v2| and shaft 22. The planet on rotatable shaft 29 and has at its other end 1.0 teeth 30 that may be meshed with teeth 21 on the differential member, the stops 3| being provided to limit the swing of sector 28. A roller 32 is rorides up on the edge of flange 26 and prevents retrograde movement of the sector until member 25 vhas been rotated back in the opposite direction to bring depression 33 into such position that the 25 roller can move into it.

from rod 31 and carry a pivot 40 lying substantially at right angles to the arms. Rods 4| pass through aperatures in abutment 42 and are connected to the arms 39 by means of externally 35 threaded sleeves 63 which are retained on the rods by heads 44, loading springs 45 being disposed around the rods 4| between abutment 42 and heads 46 on the rods to restrain piston 36- magnitude.

Movement 1nder 35 is limited by the arm 50 mounted on shaft 29 extending into the S101; 49 and a pin 5| named bysector 5,2 that 55 is pivotally mounted on guide 38 being disposed in the slot 48. The teeth 53 on sector 52 are engaged with a pinion 54 on shaft 55 to which is fixed the pinion 56 also, the latter pinion being meshed with a rack 51 connected to piston valve 58 in the servo motor that controls immediately the stroke of the pump I4. Inasmuch as servo motors of this type are well known for the purpose herein mentioned and as the servo forms no part of the present invention, it will not be further described.

An auxiliary pump 59, driven by motor 68 which operates pump I4, supplies fluid under pressure through pipe 6I to actuate the servo motor, any excess of fluid being passed through relief valve 62 to a tank 63 connected to pump 59 by return pipe 64.

Rudder post 9 actuates differential I9 through follow-up mechanism comprising pinions S5, 66, shaft 61, pinions 68, 69 and shaft 18 to which is xed arm 95. Upon an extension of shaft 61 is a pinion 1I meshed with pinion 12 that is secured on shaft 13 to which is iixed a rudder angle index 14 movable over an angle scale 15. The wheel angle is shown on the same scale by index 16 on gear wheel 11 that is meshed with gear 18 on shaft 22. The index 16 is disposed to contact adjustable stops 19 to prevent further rotation of wheel I1 when the wheel has been moved to a position that will put the rudder hard over, the springs 88 on the stops serving to augment the eiiert required to turn the wheel and to warn the helmsman that the hard-over position is being approached. It is to be understood that gear 11 is not connected to shaft 13, but acts independently of the shaft.

When wheel I'I is turned, the diierential I9 is acted upon and, since the rudder post and follow-up hold the planet pinions 23 and 24 stationary, the member 25 is compelled to rotate, which swings the sector 28, rotates shaft 29 and, by means of arm 58, swings lever 81 on its pivot. This movement of lever 41 constrains sector 52 to rotate on its pivot and through the teeth 53, gear 54, shaft 55, gear 56 and rack 51 the pump I4 is put on stroke and caused to begin to deliver i'luid to one or the other of the cylinders I2 and I3. As soon as ram II begins to slide, the follow-up mechanism acts through differential I9 upon sector 28 to swing lever 81 and take stroke off the pump. However, the sector 28 will not be moved until member 25 has been turned suiiiciently so to position the depression 33 that roller 32 may move thereinto and sirnultaneously to engage teeth 21 with teeth 38. It is thus apparent that full stroke is kept on the pump until substantially the end of movement of the rudder and, likewise, that while a relatively small rotation of wheel I1 suices to put the pump on iullstroke, nevertheless, continued turning of wheel I1 in no way aects the operation of the pump except to define the extent of operation of the follow-up necessary to take the stroke off the pump. Since shifting the position of pivot 48 varies the relative length of the lever arms cooperating with sectors 28 and 52, respectively, that position may be changed to increase the stroke put on the pump by a given degree of actuation of wheel I1 to compensate for leakage due to wear of the pump parts.

, It will be observed that when the pressure rises to the point that the resistance of springs 45 is overcome, the piston 36 is moved outwardly, the fulcrum 40 of lever 41 is moved4 away from the center of rotation of arm 58, thereby changing the lever arm between iulcrum 48 and arm 58 and also 48 and pin 5I, whereby the effect upon the pump stroke of any given angular extent will be made dependent upon pres ure conditions in the 5 system. If arm 58 remains in fixed position while the fulcrum shifts, the lever 41 is rotated to change the setting of control spindle 55, thus varying the stroke of the pump to alter the rate 10 tially at the maximum pressure permitted by springs 45. It is obvious that there will be no shifting of the fulcrum except when the pressure is in the vicinity of the predetermined maximum. The form of my invention shown in Fig. 4 is 15 the same as that above described except for diferences in mechanism employed to transmit movement from sector 28 to control spindle 55' and for omission of a torque equalizer from Fig. 4. The shaft 8l upon which sector -28 is carried 20 serves no purpose other than supporting that Extending upwardly from sector 28 is a pin 82 having one end disposed in a slot 83 in y lever 84 having a second slot 85 in its other end.

A slidably mounted rod 86 has both ends down- 25 turned, the one of them being disposed in slot 85 and the other being disposed in a slot 81 in an arm 88 fixed to control spindle 96. Lever 84 is pivotally carried by a bracket 88 having in it elongated holes 89 through which securing means 30 are passed to nx the bracket to a support, the purpose of elongating the holes being to make provision for shifting the bracket in the direction of the length of lever 84 whereby the effective arms of the lever on opposite sides of its 35 pivot may be changed to vary the degree of actuation of control spindle 55 for any given movement of sector 28 and so to compensate for wear in the pump.

Fig. 5 shows in detail a device for transmitting 40 movement from sector 28 to arm 88 on ,control spindle 55' which eliminates the sliding rod 86 shown in Fig. 4 by having lever 84 act directly upon a pin 98 secured to arm 88. It is obvious that the sliding rod 86 in Fig. 4 can be connected 45 directly to the piston valve of the servo motor shown in Fig. 1 or connected immediately to the pump elements whereby the stroke is changed.

The invention herein described may be manufactured-and used by or for the Government of 50 the United States of Americay for'governmental purposes without the .payment of any'royalties thereon.

I claim:

1. The combination with hydraulic mechanism 55 that includes a pump having means to control the delivery of iiuid thereby, means driven by such delivered uid, a diierential gear device having two input elements and an output element, a follow-up connecting said driven means G0 and one of said input elements, and manual operating means connected to the other input element, of means connecting said output element to said control means comprising' a cylinder, means placing said cylinder always in communi- 65 cation with the pressure side of said plunger operable in said cylinder, a guide for the outer end of said plunger, an abutment member adjacent that end of s'aid cylinder into which said plunger passes, a lever pivotally mounted 70 on said plunger intermediate the ends of said lever, means slidably engaged with the lever connecting an end of said lever to .the output element of the differential whereby limited swing may be imparted to said lever by operation of said differential, means slidably engaged with the lever connecting the other end of said lever to the said control means, headed spring supporting rods slidable in said abutment, a loading 5 spring on each of said rods between the head thereof and said abutment to restrain outward movement of said plunger, and adjustable means connecting said rods to the plunger to vary the position of the pivot of said lever when the force in said cylinder acting on said plunger is less than the force exerted thereon by said springs.

2. The combination with hydraulic mechanism that includes a pump having means to control the delivery of fluid thereby, means driven by such delivered fluid, a differential gear device having two input elements and an output element,

a follow-up connecting said one of said input elements, and manual operating means connected to the other input element,

of means connecting said output element to said control means comprising a cylinder, means placing said cylinder always in communication with the pressure side oi said pum a plunger operable in said cylinder, a guide for the outer end of said plunger, an abutment member adjacent that end of said cylinder into which said plunger passes, a lever pivotally mounted on said plunger intermediate the ends oi' said lever, means slidably engaged with the lever of said lever to the output means slidably engaged with the lever connecting the other end of said lever to said control means,

headed spring supporting rods slidable in said abutment, a laterally extending arm fixed to each side of said plunger, a sleeve on each of said rods adjustably engaged with said arm adjacent thereto and having a face adapted to contact said abutment tov limit the movement of said plunger into said cylinder, and a loading spring on each of said rods between a head thereof and said abutment to restrain outward movement of said plunger.

3. The combination with hydraulic mechanism that includes a pump having means to control the delivery of uid thereby, means driven by such delivered iluid, a diierential gear device having two input elements and an output element, a follow-up connecting said driven means is pivotally mounted, said bracket being adjustable longitudinally of the lever on the bracket support,

lever and to said control means.

4. 'I'he combination with hydraulic mechanism that includes a pump having means to control the delivery of fluid thereb means driven by 5 such delivered uid, a diierential gear device having two input elements and an output element, a follow-up connecting said driven means and one of said input elements, and manual operating means connected to the other input element, of a lever, a bracket on which said lever is pivotally mounted, said bracket being adjustable longitudinally of the lever on the bracket support, means slidably engaged with the lever connecting one end of said lever to'said output element whereby actuation of the output element driven means and imparts limited swing to said lever, and means slidably engaged with the lever connecting the other end of said lever to said control means.

5. 'I'he combination with hydraulic mechanism that includes a pump having means to control 5 the delivery of iiuid thereby, means driven by such delivered iiuid, a diiierential gear device having two input elements and an output element, a follow-up connecting said -driven means and one of said input elements, and manual op- 10 erating means connected to the other input element, of means connecting said diierential to said control means including a torque equalizer having a cylinder connected to receive iluid under pressure from said pump and a plunger slid- 15 able in said cylinder, a lever pivotally mounted swing to said lever, means slidably engaged with the lever connecting the other end of said lever to said control means, and adjustable means to vary the limit of movement of said plunger into said cylinder. f

6. The combination with hydraulic mechanism that includes a pump having means to control the delivery of fluid thereby, means driven by such delivered fluid, a differential gear device having two input elements and an output ele- 30 ment, a follow-up connecting said driven means and one of said input elements, and manual operating means connected to the other input element, of means connecting said differential to said control means comprising a lever pivotally 35 mounted intermediate its ends, means slidably engaged with the lever connecting one end of said lever to said output element whereby actuation of the diierential imparts a limited swing to said lever, means slidably engaged with the 40 lever connecting the other end of the lever to said control means, and adjustable means to vary semi-permanently the position of the pivot of the lever with respect to both of said connecting means independently of the action of any 45 other parts of the mechanism.

7. The combination with hydraulic mechanism that includes a pump having means to control the delivery of iluid thereby, means driven by such delivered iluid, a diierential gear device having two input elements and an output element, a follow-up connecting said driven means and one of said input elements, and manual operating means connected to the otherinput ele- 55 ment, of means connecting said output element to said control meanscomprising means responsive to pressure in said pump above a predetermined magnitude, means to restrain responsive movement of said pressure responsive means unytil said pressure reaches said magnitude, a lever pivotally mounted intermediate its ends on an element of said responsive means to be moved translationally therewith, means slidably engaged with the lever connecting one end of said lever 5 to said output element whereby there is imparted to the lever a limited swinging movement when the differential is actuated, means slidably engaged with the lever connecting the other end of 7o said lever to said control means and means adl justable -to vary the position of the pivot of said lever with respect to a xed element of said pressure responsive means.

RALPH* ERLING.

Images