US2911006A - Hydraulic distributor - Google Patents

Description

Nov. 3, 1959 R. VOGEL HYDRAULIC DISTRIBUTOR Filed Oct. 29. 1957 INVENTOR: RICHARD VOGEL Y AGENT to loud ll l l Un t S t s P wn OT v 2,911,006 T h 7 HYDRAULIC DISTRIBUTOR Richard Vogel, Nordhausen, Har'z, Germany, assignor to VEB Schlepperwerk Nordhausen, Nordhausen, Harz,

7 Germany, a corporation of Germany Application October 29, 1957, Serial No. 693,075 I Claims priority, application Germany June 25, 1957 7 Claims. (Cl. 137-622) My 'present invention relates to a hydraulic distributor for'power lifters and the like and has for its principal object the provision of improved means for selectively controlling the flow of a motive fluid to a number of discharge ports and for varying the operating pressure of thefluid.

Known distributors be used on tractors or similar equipment, are set to a predetermined operating pressure and, therefore, must be employed together with separate valve means to vary the pressure of the conveyed fluid. Accordingly, these prior-art arrangements are relatively complex, occupy considerable'spa'ce and, owing to the independent actuation of their controls, require a great deal of attention from the operator; avoidance of these drawbacks is, therefore, another object of my invention. p

A further object of the invention is to provide a distributor of the character set forth above which jis simple, compact in form and size, and adapted to be 'n-ian u factured as a standard article for use withmany typesof hydraulic apparatus.

A still further object of the, invention is to provide a distributor having means for selectively switchingfa source of motive fluid from one discharge port to another and for simultaneously varying the pressure of said fluid.

A hydraulic distributor according to a preferred em bodiment of the instant invention has a tubular casing provided with an intake port and a plurality of discharge ports, and a hollow valve member in the form of a sliding piston with an axial bore and transverse apertures which, upon suitable axial and/or angular displacement in the casing, may-be brough into a position to permit or preventpassage of fluid from the intakeport through the piston'and'into selected discharge ports. A single operating member is provided for selectively placing one or more piston apertures in communicative position with respect to the intake and discharge ports in the casing, and a safety valve is installed directly in the sliding piston in such manner that a predetermined (e.g. axial)- displacementof the piston automatically brings about a concurrent adjustment of the safety valve to a higher or a lower operating pressure.

uThe discharge ports through which the fluid at higher on lower pressures 'is permitted to leave thecasing in difierent'positions of to-t he same or to different loads,.such as hydraulic jacks orfurther distributors connected in tandem with-the first one, depending' on whether it is desired to. actuatea single controlled device or a-plurality of suchdevices -at:difier-v ent operating pressures. v v

The invention will be described in greater detail with reference to the accompanying drawing in which:

,Fig. 1 is a 1: 1 of Fig. 5, through-a distributor embodying thein vntion;

Fig. 2 is a similar sectional view of the distributor,

showing its piston in a different axial position;..

Fig. 3 is a transverse section taken on line 33 of Fig. l with the valve piston turned through about 45 deg e h Fig. 4 \is a transverse section taken on line 4- 4 of Fig '2' with the piston rotated through another 45 ,de; bish o for hydraulic hoists, adapted to the piston may be-connectedeither "{FFig. '5 ,is an enlarged right-hand end viewof the. dis& tribu tor'showing two additional operative positions ofjthe piston actuating member indot-dash lines. v In Figs. 31 and 2. there i s shown a tubular casing 11 which is'fixed'ltoa supporting wall by means of four bolts 12, the la'tter also holding a square retaining frame 13.] The frame 13, serves as a bearingfor a hub 14who'se working position slot 14g accommodates an' actuating 'lever 15 swingable about al 'pi vot 16.. The bifurcatelower end of 'levi- 1 5 straddles a pin 17 which spans theslottedend 18a of a piston 18, the latter being slidably received in' the bore 1 1a of the valve casing ih s'uch-manner as tqfpefi mitaxial displacement of the piston when, the lever-{15 is swung about pivot 16', between the'limiting' positions shown'in Figs. 1 and 2, as well as angular'displacement of the piston upon rotation of lever 15 between'a normal 7 h and several alternative positions shown at" 15',"15 "(dot-dash lines) iiifFig. 5, thehub 14'rotating withthe piston; T heextent of axial displacement of thepistori' in'the direction-of arrow A (see'Fig. I) is controlled by a ring 19 'which abuts against a sealing ring 59,'a radial shoulder 20 determining the extent of axial movement of the piston in the opposing direction of arrow B (see Fig. 2). A stud 21, "projectingfrom the hub 14, controls the 'extentof angular movement of the pi sto'n in the' direct ion' ofarrowC (Figs; 4 andf 5 abutting against suitable' stops,-j one ofwhichfis'showrl,

' l 26 is provided in a at 22in Fig. 5 ""Conventionalindexing means" com prising a ball 23 and a spring z tfprevent unintentional rotation: of the'h'ub 14 with respect toZthe valve casing 11', andasimil'ar detent comprising a ball 25"andaspring; I tubular member- ZT n-the hub 14 (see Fig. 5')- for the purposeof frictionally holding t he piston against undesirable axial displacement. i "Piston 18 has an axial bore 28which isopenfat one; end and-.'communicates with the interior 'lla of easing 11 via entrance apertures 29a, 29b. In Figi lythe 'aper-z ture 29a is showhin communication withthe'intakepoit- 30 provided in the casing 11. Port 30 isconnected with "a source (not shown) of fluid under pressure, such as a hydraulic pump drawing from an'oil sump; whereby'such fluid isfree to passthrough inlets-30' and 29a into the piston bore 28 and thence throughexit apertures"31, 32 in the piston and aligned dischargepo'rts 33, 34 in'the cas -i ing to respective controlled devices-designated in the drawingas'Loadl and Load II. Inthis position of the piston,its secondpair of exit apertures-35,36 are oif-f set .fromv discharge ports 37, 38 iii-the valve casing,- the latter two'ports b'eing' respectively connected withLoad" II (in parallel with port 33) and with a'further controlleddevice designated as Load III. 'When the pistim 18 is moved in the direction of arrow B into the position of Fig. 2, the casing-11 closes the apertures 31,- 32 while" the, fluid is freeto pass through aligned outlets; 35, '37 and;36, 38. It will be noted that peripheral cutouts"29'a-,.- 29b in communicationfwith apertures 29a, 29b permitentry of the fluidjinto piston-bore 28 in and between both extreme axialpositions of the piston. The flow of fluid" longitudinal axial section, taken on line-v largedcutout 51 on piston .18 and a discharge port 39;

into the bore 28 may be reduced or fully out 01f upon ro-L tation of lever 15 in the; direction of arrow 0 wherebytheinlets 29a, 2% are closed by easing ligand the piston. bore 28 communicates with the oil sump through an en provided in the casing (see Figs. 3 and 4) end-of piston bore 28 We. tubular plug '42. Sleeve 41'de-S 'finesan axial channel 43 slidably receiving a valve rod;

44 whose perforated head 44a is urgedtoward'the inner-.5 (right-hand) endof this channel by .a spring 5.0 within:

= arage arger??? muaisa gmti t- raneairet relieforifices 47a, 47b and 48a, 48b in the piston 18. The enlarged left-hand end 44b of the valve rod 44 abuts against a sliding bolt 49a which forms the movable anchor of spring 50, its other anchor being a fixed stud 49b. In the position of Fig, 1, the reduced portion. 44a of the valve rod 44 is out of register with openingsv 45a, 45b, 46a, 46b as the rod occupies its extreme position corresponding to the lowest pressure of fluid in the piston bore 28; 'thus, the safety valve 40 is closed andno fluid can escape through any of orifices 47a, 47b, 48p, 48b

until the pressure within piston bore 2 8 has risen sufllcient- 1y to align the portion 44c with the right-hand valve openings 45a and 45b.

In Fig. 2, with the piston 18 withdrawn to the right to have the casing 11 obstruct the orifices 47a and 47b, the spring 50 is almost totally com pressed under still higher fluid pressure and the fluid is free to flow through the perforated head 44a, around the reduced portion 44c of thevalve rod and thence through the aligned passages 46a, 48a and 46b, 48b back to the oil sump. Thus, thelever 15 controls the safety valve 40 and hence the fluid pressure in piston bore 28 simultaneously with the selection of outlets in the valve casing 11 to lead the fluid toward certain controlled devices (Loads I and II) under relatively low pressure, e.g, of atmospheres, and toward the same or other devices (Loads Hand III) under relatively high pressure, .eg. of 109 atmospheres. i Safety valve will also operate when the lever 15 is in an axial position intermediate those shown in Figs. 1 and2 while occupying the angular position shown in full lines in Fig. 5, all the discharge ports in the distributor casing 11 being then closed.- Fig. 3 shows the piston 18 turned through about 45 degrees in the direction of arrow C. Actuating lever 15 is then in the position 15' (see Fig. Cutout '51 communicates with the discharge port 39 whichleads the fluid back to the oil sump. Upon further rotation of the lever in the same direction into its position 15" shown in Fig. ,5, longitudinal grooves 53, 54 on the periphery of piston 18 together with cutouts 51, 52 provide a path from either or both pairs of discharge ports 33, 34 and 37, 38 to the central port 39 (see Fig. 4) to permit the return of fluid from the associated loads to the oil sump. The triangular cross-sections of the grooves 53, 54 permit flow control between these ports through variation of the eflective width of the fluid path by slightly rotating the piston 18. By turning the lever 15 back into the position shown in full lines in Fig.- 5, Le. into the position of Figs. 1 and 2, the cutouts 51, 52 are closed by the casingll and the distributor may supply fluid 'to the discharge ports 33, 34 or 37, 38 upon axial displacement of the piston to the left or to the right, respectively, in the previously described manner.

,It will thus be seen that I have provided a device for thechanneling of oil or some other hydraulic fluid over a plurality of different paths into and out ;of the inte rioi' of a valve member, represented by piston 18 in the embodiment specifically described, the shift from; one operating position to another being accompaniediu cer tain instances by the blocking or the unbloeking of a pressure-relief orifice (such as the one indicated'at 47a) inord'er to vary the critical pressure at which the safety valve '40 will open. If the orifices 48a and 43b Were omitted, then the safety valve would be completely dis abled in the axial piston position of Fig.2. Moreover, this change-ever in the response threshold of the safety valve need not necessarily coincide with a switching articularly illustrated forjLead operation, as has been II which in either of the positions shown in Figs. -1 and 2 will receive fluid via intake port 30 and 'dis'charge port 33 or 37-, the latter two ports efiectively consume ing a single outlet in view of their interconnection by a common discharge duct shown in dot-dash lines at v rater f 'f thejiistofi, on the other en lcs the @W 56 51651513 $3167 63" erasing iiffiiiid 1 3155 ou t any readjustment in the mode of operation of the safety valve.

My invention is, of course, not limited to the various structural and operational details specifically disclosed herein but may beembodied in numerous modifications and adaptations without departing from the spirit and scopeof the appended claims.

- Ielairir:

1. A distributor for a motive fluid under pressure, comprising a casing, a hollow valve member displaceably mounted in said casing, actuator means for displacing said valve member between a first and a second operating position, inlet means on. said casing and on said valve member for admitting. fluid into said valve member in each of said operating positions, and outlet means on said casing and on said valve member for discharging said fluid from the interior of said valve member in at least one 'of said positions; said valve member being provided with safety means including a portion of said member provided with a plurality of pressure-relief orifices, blocking means on said casing positioned to obstruct one of said orifices in said second position but not in loaded closure means in said valve member normally stopping the flow of fluid from .said interior through said orifices, said closure means being adapted to yield under increasing fluid pressurefor progressively uncovering first said one and then the other of said orifices whereby the fluidwill be allowed to escape from said interior by way of said safety means at a relatively low pressure in said first operating position and at a relatively high pressure in said second operating position of said valve member. 7 I

2.- -A distributor according to claim 1, wherein said valve member is an axially slidable piston, said orifices being axially spaced on said piston.

3. A distributor according to claim 2, wherein said piston is provided with an extremity projecting from said casing, said one orifice being withdrawn into said casing in said second operating position.

4. A distributor according to claim 2,,wherein said exit aperture registers with respective ones of saiddis-' chargeports.

5. A distributor according to claim 2, wherein saidoutlet means comprises a plurality of axially spaced discharge ports on said casing and at least one exit aperture on said piston, said piston being selectively 1 rotatable in said casing under the control of said actuatormeans into a plurality of angular positions, said exit aperture registering with one of said ports in one of said angular positions and with both of said ports in another of said angular positions.

6. A distributor according to claim 2, wherein said' outlet means comprises a plurality of axially spaced discharge ports on said casing and a-peripheral groove on said piston, said piston being axially and angularly displaceable bysaid actuator means into a position in which said groove bridges said discharge ports.

7 A distributor according to claim 6, wherein said groove is of tapering cross-section, 'thereby establishing between said discharge ports a path width in different angular positions of said piston.

References Cited in the file of this patent UNITED STATES PATENTS 2,297,026 Sanford et al. Sept. 29, 1942 2 549, 21 vre11 Apr 24, 195.; 2,655,167 Dunkelow Oct. .1 3,l1 9 2, 57,641. Medd k Aug 7. 1956 said first position, and spring- 7 of different effective I

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