US2308285A - Hydraulic control valve - Google Patents

Description

Jan. 12, 1943. R. K. JEFFREY ETAL 2,308,285

HYDRAULIC CONTROL VALVE Original Filed March 18, '1939 2 Sheets-Sheet l l/v l/EN TOES 1 ROBERT KJEFF'EEY,

AND

5TERU G C. MOON,

' HTT'Y.

Jan. 12,1943.

use, l5

R; JEFFREY a-rm. 2,308,285

HYDRAULIC CONTROL VALVE Original Filed March 18, 19:59 Z SheetS-Sheet 2 W//// IOS/ jj'sleuhlcs C. MooN,

//v vsN o/es:

Patented Jan. 12, N43

HYDRAULIC CONTROL VALVE Robert K. defirey and Sterling C. Moon, Columbus, Ohio, assignors to The .l'efirey Manufacturing Company, a corporation of Ohio Original application March 18, 1939, Serial No. 262,764. Divided and this application Decemher 5, 1940, Serial No. 368,676

2 Claims.

This invention relates to an improved hydraulic control valve particularly adapted for use in an improved hydraulic control system for a mining machine.

An object of the invention is to provide an improved power operated hydraulic control valve.

Still another object of the invention is to provide a solenoid operated hydraulic control valve which is adapted to control the rate of fluid flow therethrough in accordance with the current flowing in an electrical circuit.

Another object of the invention is to provide a combined solenoid and mechanically operated hydraulic controlling valve adapted to vary progressively the rate of flow of hydraulic liquid therethrough.

Other objects of the invention will appear hereinafter, the novel features and combinations being set forth in the appended claims.

In the accompanying drawings,

Fig. 1 is an elevational view of the automatic volume control valve of our invention showing its mounting on a mining machine frame shown in section;

Fig. 2 is a plan view of the valve of Fig. 1;

Fig. 3 is a sectional view taken on the line 3-3 of Fig. 1 looking in the direction of the arrows;

Fig. 4 is a sectional view taken on the line 4-4 of Fig. 1 looking in the direction of the arrows;

Fig. 5 is a sectional view taken on the line 5--5' of Fig. 1 looking in the direction of the arrows;

Fig. 6 is an enlarged sectional elevational view taken on the line 6-6 of Fig. 2 looking in the direction of the arrows;

Fig. 7 is a sectional view taken onthe line l-=-'l of Fig. 6 looking in the direction of the arrows, and also showing the manual operating mechanism partly in section; and

Fig. 8 is an enlarged detail view taken on the line 88 of Fig. 6 looking in the direction of the arrows..

This application is a division of our application Serial No. 262,764, filed March 18, 1939, for an improvement in 9. Mining machine.

As is pointed out in our parent application above identified, it is desirable to regulate automatically the feeding movement of the kerf cutting mechanism, and this is preferably done in inverse proportion to the ampere load ,on the driving motor. It is also preferred that this inverse proportion be limited to less than the entire range of ampere variation. In practice, the mechanism is preferably adjusted so that the cutter mechanism is driven at full speed until the current reaches approximately of its full 55 M8, sealed together load rating, whereupon the feed rate of the kerf cutting mechanism is progressively decreased as the current of the driving motor increases until it is finally shut off at approximately 115% of its full rated value. It is, of course, to be understood that the above is merely illustrative of the preferred range and the range may be extended in either direction to any extent desired.

It is,'of course, evident that with this automatic system the kerf cutting mechanism is operated at the maximum rate possible without undesirable overloading of its driving motor so that when easy cutting is encountered, the feed rate is increased and when hard cutting is encountered the feed rate is reduced. Furthermore, when the driving motor for the cutting mechanism is not operated at all, or is merely runing light as when no cutting operation is being performed, the feed rate for adjusting the various hydraulic piston motors is at a maximum thus providing for a high rate of adjustment to position the cutter mechanism for kerf cutting.

Th apparatus which provides for this automatic control as above set forth, is disclosed in detail in the drawings, which will now be described.

As a general description, it may be stated that the automatic control valve, designated generally by the number 90, is operative to control the volume of fluid delivered to the operating hydraulic motors of the hydraulic system in accordance with the current flowing in an electric motor such as that for driving the cutter chain of a mining machine as disclosed in our parent application.

It is to be seen that the automatic control valve comprises a main casting or body I of nonmagnetic material which has an integral downwardly extending cylindrical portion I06 formed with-spaced integral flanges I01, I08 upon which cylindrical portion I06 and between which flanges I01 and I08 is mounted an operating solenoid I09 contained within an insulating casing H0.

Removably attached to the top of the casting I05 is a valve casting or body I l I of non-magnetic material which has a bottom integral flange I41 by which it is attached to casting I05 by screws by seal wires I49 and which is provided with a central longitudinally extending cylindrical bore IIZ. Substantially midway of the casting H l is a chamber, orifice or passageway H3 which isformed by the bore H2 extending through a centrally disposed web H4. Above the web I I4 there i a circumferential port H5 communicating with the chamber H3 and provided with a threaded opening H6 to which is threadedlpressure pipe or conduit 88.

It is thus manifest that port I I is the inlet or pressure port for delivering fluid under pressure to the chamber, orifice or passageway H3 which, it may be stated, is adjusted as to effective size so that the pressure drop across the same regulates a by-pass control valve, as described in our parent application, to control the volume of fluid flow delivered to the pressure pipe 88 and 92 and thence to the hydraulic piston motors of the hydraulic control system. The structure of this port H5 and the connection to it is illustrated in detail in Fig. 4 of the drawings. Directly below the web II4 there is a circumferential port III communicating with the chamber H3 and provided with a threaded opening to which is threaded pressure pipe or conduit 92. It is thus manifest that the port H1 is the outlet or receiving port for receiving fluid under pressure from the chamber, orifice or passageway I I3.

To provide an adjustment of the effective size of the chamber, orifice or passageway II3 there extends into the bore H2, a slidable piston H8 of non-magnetic metal, the upper part of which is preferably, but not necessarily, uniformly tapered at H9 and the extreme upper portion I of which is generally cylindrical and is provided with oil seal grooves I2I to reduce the liquid flow past said upper portion I 20. The central portion of the piston H8 is formed as a shank I22 of reduced diameter which is normally positioned centrally of the chamber H3 thereby providing a maximum efiective opening of said chamber H3 when the valve 90 is in its normal position of adiustment.

Directly below the shank I22 is a generally cylindrical portion I23 of the piston H8 which is provided with oil seal grooves I24 to restrict the flow of oil through the lower portion of the bore H2 designated II2'. Extending downwardly from the cylindrical portion I23 is a shank I25 which, at its bottom, is pivotally attached to a plunger I26 of magnetic material by a loose connecting pivot pin I21, which plunger extends downwardly into a central opening I28 in the casting I05 within which opening I28 is a helical spring I29, the upper end of which abuts an inattracts the plunger I 26 to pull it downwardly against the action of the spring I29 which, after a predetermined movement, progressively reduces,

the effective size of the chamber, orifice or passageway H3 by the progressive movement of the tapered portion H9 of piston I I8 therethrough.

It is further manifest, that the effective size of said opening or passageway H3 is inversely pro portional to the amount of current flowing in the solenoid I09 once the tapered portion H9 of piston II8 has entered said orifice or passageway H3. As previously suggested, in practice it is preferred that a current of substantially 85% of the rated current for the motor will be required before any appreciable reduction of the effective size of chamber, orifice or passageway H3 is effected, and'that said passageway will be completely closed when the current reaches approximately 115% of the rated value; the complete closing, of course, being effected whenever the upper portion I 20 of said piston I I8 enters the orifice or passageway H3, for it substantially completely fills it.

To provide for the manual adjustment of the automatic control valve so that an operator may vary the action theerof, to reduce the feed rate but, preferably, not to increase the feed rate, without regard to its tendency to operate automatically, said valve mechanism is provided with manually operable mechanism including an operating handle I32 which is pivotally attached to a stub shaft I33 supported upon the valve casting III by a Journal bearing I34 and journal bearing I35, the latter of which is formed in a removable cap I36 which is attached to said casting III by screws I31. A packing I38 is provided to prevent loss of hydraulic fluid from. the valve about the shaft I33. Keyed to said shaft I33 is an operating shipper I39 which cooperates with a groove I40 in a thrust collar I which bears against the top of the plunger I28. It is manifest that by moving the handle I32 upwardly the control piston H8 may be positively moved in a downward direction to reduce the feed rate as hereinafter pointed out. If desired, collar I may be rigidly attached to shank I25 in which case the feed rate may be either increased or reduced manually and this may be either with or without the automatic control provided by solenoid I09.

It may be stated that the forces acting on the piston H8 by virtue of the spring I29 and the solenoid I09 are relatively small as compared with the strength of an operator and may be at the maximum of the order of fifteen pounds. Consequently, an operator will have no difficulty in adjusting the piston I I8 manually by the handle I32 without regard to the tendency of the automatic mechanism to adjust said piston II 8.

As disclosed in our parent application, the automatic control valve 90 is mounted adjacent the forward lefthand portion of the mining machine platform and is carried on a horizontal plate I42 by virtue of a flange I43 formed as an integral part of the casting I05, which flange is attached to the plate I42 as by screws I44. The handle I32 extends forwardly through a slot in an upright plate I45 of said platform so that said handle I32 is readily operable by the operator.

As seen by reference to Fig. 6 of the drawings, the central portion of the automatic control valve 90 provides a chamber I46 which will be filled with hydraulic fluid at all times due prim cipally to seepage, which hydraulic fluid will act as a lubricant for the moving parts therein and in the opening I28.

In the top of the casting III there is formed a chamber I50 which communicates with the chamber I40 by way of passageway I5I.' Excess hydraulicfluid'is drained from the top of the chamber I50 by a return pipe 83 (see Fig. 5).

To dampen somewhat the action of the piston .I I8 we provide in association with the upper portion I20 thereof a dash-pot, the structure of which is-best seen by reference to Figs. 6 and 8 of the drawings. Said dash-pot is formed by a cylindrical bore I52 in the top of said upper portion I20 into which projects a piston I53 which is slightly less in diameter than the diameter of the bore I52, said piston I53 being formed as an integral portion of a plug I54 having enlarged portion I55 which is adapted to extend into and close the bore I I2 formed in the extreme top portion of the casting III. The plug I54- additional- 157 has a top cylindrical portion I56 which is rigidly attached to a removable top plate I51, for example as by having a press fit therewith, which plate I5! is removably attached to the casting I l I as by screws I58.

To provide a control pressure conduit leading from the valve 90 toa high pressure relief valve which is responsive to the pressure in the pressure pipe or conduit 92 which, of course, is the same as the pressure in the port Ill, I provide a conduit which is formed by a vertical bore I59 seen by reference to Fig. 5 of the drawings, the

bottom of which communicates with said port I ii. The vertical bore I59 communicates with a transverse bore ISO to which is connected a pipe or conduit IIiI which leads to the pressure relief valve. As illustrated in Fig. 5 01' the drawings, the top of the vertical bore I59, which communicates with chamber I50, is closed by a threaded plug I62.

As was above set forth, there is a predetermined position for the piston N8 of said control valve 90 for each current value between 85 percent and 115 percent of the rated load of motor connected in series with winding IDS. This, of course, means'that orifice H3 has a predetermined eflective size for every current value between the mentioned limits. The pressure drop across orifice H3 is proportional to its effective size and the volume of hydraulic fluid flowing through it and entirely independent of the pressure of the hydraulic fluid. This drop in pressure across orifice 3 may be employed to control the by-passing of hydraulic fluid as disclosed in our parent application, or otherwise employed.

Obviously those skilled in the art may make scope of the invention as defined by the claims hereto appended, and we therefore wish not to be restricted to the precise construction herein disclosed.

Having thus described and shown an embodi-' ment of our invention, what we desire to secure by Letters Patent of the United States is:

1. A control valve comprising a body having a pressure chamber through which hydraulic fluid is adapted to flow, movable valve mechanism in said body for controlling the effective size of said chamber, an additional chamber in said body separated from said first chamber by said valve mechanism and positioned below it and adapted to receive the hydraulic fluid which'leaks from said pressure chamber past said valve mechanism, electrical power operated means within said second chamber for operating said movable valve mechanism, said means being lubricated by various changes in the details and arrangement of parts without departing from the spirit and the hydraulic fluid which leaks into said additional chamber, and manually operable means for operating said valve mechanism including mechanismwithin said additional chamber lubricated by said leaking hydraulic fluid.

2. A control valve comprisinga body having a pressure chamber-through which hydraulic fluid is adapted to flow, movable valve mechanism in said body for controlling the effective size of said chamber, an additional chamber in said body separated from said first chamber by said valve mechanism and positioned below it and adapted to receive the hydraulic fluid which leaks from said pressure chamber past said valve mechanism, and electrically operated means within said second chamber'tor operating said movable valve ROBERT K. JEFFREY. smanme c. MOON.

Images