US2935890A - Control apparatus - Google Patents

Description

May 10, 1960 Filed llay 10, 1956 D. L. HALL CONTROL APPARATUS 2 Sheets-Sheet 1 IN VENTOR.

D. L. HALL May 1960 D. L. HALL 2,935,890

' CONTROL APPARATUS Filed May 10, 1955 2 Sheets-Sheet 2 PIC-3.3

IN VEN TOR.

D. L. HALL CONTROL APPARATUS Daniel L. Hall, Duhnqne, Iowa, assignor, by mesne assignmenm, to Deere & Company, a corporation of Delaware Application May 10, 1956, Serial No. 584,053

11 Claims. (Cl. 74-471) This invention relates to control apparatus and particularly to a multiple control means for selectively regulating a pair of control members, such as valve spools in a hydraulic control system.

The invention finds particular utility in a hydraulic control system of the type in which a pair of single acting valves are selectively operated to control a double acting cylinder, the theory of operation being that one valve spool is moved in one direction and the other in the opposite direction to exend a hydraulic cylinder, for example, the valves being moved respectively in the opposite directions to retract the cylinder. Heretofore, this result has been achieved by the use of a pair of independent control levers, particularly in those cases in which the system required the shifting of both valve spools in the same direction to achieve a float status in the cylinder. According to the present invention, the control is simplified by the provision of a single main control lever which carries an auxiliary lever normally locked thereto, the auxiliary lever being releasable for movement independently of the main lever when the float positions of the valves are required. The invention featuresa simple and economical dual-lever arrangement including a novel form of latch and means for biasing the latch into both its locked and released positions. It is a feature of the invention to adapt the novel dual-lever arrangement to a hydraulic system of the character referred to above; although, the principles of the invention have wider application.

The foregoing and other important objects and desirable features inherent in and encompassed by the invention will be come apparent as 'a preferred embodiment thereof is disclosed, by way of example, in the ensuing specification and accompanying sheets of drawings, the

several figures of which will be described immediately below.

Fig. 1 is a view, partly in section and partly'in elevation, showing centrally positioned control levers related to neutrally positioned control valves.

'Fig. 2 is a similar view, showing the two levers moved in unison to move the valves simultaneously but respec tively in opposite directions. I

Fig. 3 is a similar view showing the auxiliary lever released and the main lever so positioned'that both con trol valves are moved simultaneously in the same direction.

Fig. 4 is a rear elevation of the control levers.

Fig. 5 is a plan view, partly in section as seen along the line 5-5 of Fig. 4. a

The basic control means chosen for the purposes of illustration comprises a valve housing 10 having lower and upper or first and second fore-and- aft valve bores 12 and 14 in. which valve spools 16 and 18 are respectively shiftable fore-and-aft or axially. In this respect, it should be noted that here as well as in the claims the expressions upper, lower, front etc. are used in'the interests of convenience and not as words oflimitation, since the parts may be obviously otherwise arranged.

The housingli) has at an upper portion thereof an 2,935,890 Patented May 10, 1960 22 via intermediate valve housing passages 28 and 30..

In this position of each spool, associated check valves 32 and 34 are biased to closed positions. As will be apparent from the description to follow, the check valves are respectively under control of ramped lands 36 and 38 on the spools l6 and 13.

The spools are respectively centered or maintained in their neutral positions by centering springs 40 and 42,"respectively. These are of conventional construction and need not be elaborated.

The valve housing 10 includes a pair of motor lines 44 and 46 which are connected respectively to opposite ends of a cylinder 48 within which is contained a piston 50. When the valve spools 16 and 18 are in their neutral positions (Fig. l) the check valves 32 and 34 are closed and fluid in the cylinder 48 is hydraulically locked therein; and fluid pumped through the valve housing via 20, 30, 28, 22v is isolated from the motor lines by the valve spool lands 36 and 38.

The neutrally positioned valve spools 16 and 18 also isolate the motor lines, via the check valves 32 and 34, from the reservoir ports 52 and 54 which are connected in common to a reservoir line 56 that leads ultimately to the reservoir outlet 22.

The valve spool arrangement is such that when the upper spool 18 is shifted to the right, or forwardly, and the lower spool 16 is shifted to the left, or rearwardly, the land 38 on the upper spool exposes the upper check valve 34 to inlet pressure from the line 20, which pressure of course opens the check valve so that fluid flows through the motor line 46 to the left or rear end of the cylinder 48. As the piston 59 moves to the right, the fluid exhausted therefrom passes through the motor line as and past the check valve 32, which has been positively opened by the ramp on the lower spool land 36, to the reservoir port 52 and thence via the lines 56 and 22 to the reservoir. When the spools are shifted respectively in the opposite directions, the upper spool land 38 positively opens the upper check valve 34 and the lower check valve 32 is opened by pressure from the line 20, the fluid flowing via the passage 30 to the lower valve bore 12 to the left of the land 36, which land is now in a ,position just to the right of the Fig. 1 position so that fluid flowing from 30 follows the path indicated rather than crossing over to the passage 28. In this position of the valve spools, the piston 50 will move in the opposite direction.

It will be noted from the description thus far that each valve is of the one-way or single-acting type; yet, the motor 4850 is of the double-acting type. Consequently, the valve spools 16 and 18 are normally tied together in such manner that as one moves in one direction the other simultaneously moves in the opposite direction. In conventional arrangements of this character, any linkage that controls the valve spools is made interchangeable as between the spools so that the opposite directions -of movement of the spools can be suited to the desired According to the present invention, this disadvantage is eliminated, as will be outlined below.

The basic part of the improved control apparatus resides in a main control lever 58 and an auxiliary lever 60. The main lever is fulcrumed on a transverse pivot or fulcrum 62 and is located behind the control valve, housing 16, in which respect it should be noted that the expression behind, like other expressions previously explained, is used merely for the purposes of convenience.

The lever 58 has a lower end 64 below the fulcrum 62 and an upper end 66 above the fulcrum 62, the upper end being conveniently provided with a knob 68 for facilitating the manipulation of the lever by an operator.

Because of the fulcrum mounting at 62, the lever 53 is rockable'fore-and-aft from a central position (Fig. 1), to either a forward position (Fig. 2) or to a rearward position (not shown). The lower end 64 of the main lever 58 is pivotally connected at 715 to the rear end of lower link means '72 which is pivotally connected at "74 at its front end to the lower valve spool 16. Accordingly, fore-and-aft rocking of the main control lever will incur fore-and-aft shifting of the spool 16 from its neutral position of Fig. l. Specifically, the centering means 49 normally yieldingly maintains the valve spool 16 in its neutral or Fig. 1 position and thus acts through the link means '72 to maintain thecentral or upright position of the main lever 58. When the upper end of the lever 58 is moved forwardly, to rock the lever in a clockwise direction, the link means 72 is operative to move the spool 16 to the rear or to the Fig. 2 position, at which time the centering spring means 40 is loaded so that when manual force on the lever 58 is released the centering spring will return the valve spool 16 to its neutral position and will accordingly return the lever 58 to its central position. The same results, but in reverse fashion, follow from movement of the main lever 58 to the rear of its central position, the spool 16 in this case moving forwardly and loading the centering spring 40 in the opposite direction.

By means that will be presently described, the auxiliary lever 60 is normally connected to the main lever 58 so that the spool 18 is caused to move simultaneously with the spool 16 but in an opposite direction in each case. Part of this result flows from the connection to the lower end 76 of the auxiliary lever 60 of the rear end of upper link means 78, the connection being effected by a pivot 80. The forward end of the link means is pivotally connected at 82 to the rear end of'the upper spool 18. When the two levers are interconnected for movement in unison, forward movement of the lever 58 incurs forward movement of the upper spool 16, since the pivotal connection 80 is above the main lever fulcrum 62. Hence, as the lower spool 16 moves rearwardly, the upper spool will move forwardly (Fig. 2). Conversely, when the lever 58 is moved rearwardly from its central position, the lower spool 16 will move forwardly and the upper spool 18 will move rearwardly. The action of the upper centering spring 42 is similar to that of the lower means 49 as previously described.

Normal interconnection of the two levers for movement in unison is effected by the combination of an auxiliary fulcrum 84 and releasable lock means indicated as a whole by the numeral 86. As will be seen, the fulcrum 84 is intermediate the lower end 76 of the lever 60 and an upper end 88 of that lever. Accordingly, the fulcrum 84 is above the main lever fulcrum 62, as is the pivotal connection 80 for the upper link means 78. As already described, the pivotal connections '70 and 80 are at opposite sides of the fulcrum 62 which, therefore, results in simultaneous fore-and-aft movement of the valve spools 16 and 18 but in opposite directions. The lock means 86 comprises a latch 90 pivoted on a transverse axis at 92 to a forwardly projecting integral ear 94 on the auxiliary lever 60. The latch extends rearwardly alongside of and past the main lever 58 and terminates in a rear handleportion 9 6. v The latch 90 depends below the pivot 92 and is connected at 98 to the upper end of blas lever, the valves would have only extend and retract po- 4 ing means in the form of a coiled tension spring 100. The lower end of the spring 100 is connected at 102 to an ear or lug 104 integral with the lower end portion of the main lever 68. The line of force exerted by the spring 100 in Figs. 1 and 2, or when the lock means 86 is locked, is rearwardly of the pivot 92 but forwardly of the auxiliary lever fulcrum 84. The tendency of the spring 160 is therefore, as respects the latch 99, to rotate the latch downwardly and rearwardly about the pivot 92. However, such rotation is normally prevented'by means of a stop in the form of a transverse pin 106 carried by the main lever 58 rearwardly of the pivot 92. The latch 96 is notched at 108 to engage the stop pin 166 from above, the shape of the notch affording front and rear portions 110 and 112 which respectively engage the pin from in front and from behind.

The spring 100 has a further tendency, since it is connected to the latch and the latch in turn is connected to the auxiliary lever 60 at the pivot 92, to rock the auxiliary lever 60 about the fulcrum 84, which rocking would normally occur in a forward or clockwise direction. As already stated, however, the latch when locked by the pin 106 as received in the notch 188, is immobilized.

From the foregoing description it follows that when the latch 9il-is locked by the combined action of the spring and stop pin 106, the auxiliary lever 60 is prevented from rocking forwardly or rearwardly except in unison with the main lever 58. Moreover, when both levers are interconnected and are in their central position, the valve spools 16 and 18 are in their neutral positions, which neutral positions are yieldingly maintained by the centering springs 40 and 42. Even during movement of both levers in unison to the rear, for shifting the spool 18 rearwardly and the spool 16 forwardly, the spring 1% is sufliciently stronger than the upper centering spring 42 so as not to be abnormally displaced. Accordingly, when the levers are interconnected for operation in unison, normal movement of the valve spools 16 and 18 may be expected for retracting and extending the cylinder and piston assembly 48--50.

As shown in Fig. 3, the releasable lock 86 may be released and the main lever 58 moved forwardly to incur the rear position of the lower spool 16. At the same time, the released latch will allow the spring 100 to rock the auxiliary lever 60 in a clockwise direction so as to swing its lower end 76 rearwardly, acting through the upper link means 78 to move the upper valve spool 18 also rearwardly. Hence, both valve spools are in their rear positions and occupy'these positions simultaneously,

incurring in the valvehousing 10 a float position enabling free hack and forth floating movement of the piston 50in the cylinder 46. This result follows from the fact that both check valves 32 and 34 are positively opened by the ramped lands 36 and 38 respectively on the spools. At the same time, the high pressure inlet 20 is communicated directly with the reservoir outlet 22 via the passages 30 and 24, and fluid flows freely past the reduced spool portions 24 and 26. In short, the pump delivers directly to the reservoir and opposite ends of the cylinder 48 are connected via the motor lines 44 and 46 through the positively opened check valves 32 and 34. Thus, there is accomplished a simple multiple lever arrangement in which the valve spools 16 and 18 have, in effect, three positions in addition to their neutral positions, whereas, without the releasable auxiliary sitions. V

In the released position of the auxiliary lever 60 (Fig. 3) for reasons that will appear below, the tendency of the latch 90 will still be to rock in a counterclockwise direction about the pivot 92}, but this is prevented by an abutment .portion 114, a somewhat triangular portion of the latch 90 that is bent inwardly and ahead of the upper end 88 of the auxiliary lever 60, the latch being slit at 116 to afford material for the abutment 114.

Best operation of the releasable lock means 86 will be achieved after the two levers are moved simultaneously to the Fig. 2 position, at which time, it will be noted, the lower valve spool 16 has moved to therear to positively open the lower check valve 32. This is normally the position ocupied by the valve spools to supply fluid under pressure to the left hand end of the cylinder 48 for causing the piston 50 to move forwardly or to the right. With the levers in this position, the operator may lift the rear end of the latch 90, via the handle 96, freeing the notch 108 from the pin 106. As

already noted, the line of force exerted by the spring 100 is ahead of the auxiliary lever fulcrum 84. Thus, the spring 100 acts through the latch 90 and via the pivot 92 on the forward end of the auxiliary lever 60 to rock the auxiliary lever in a clockwise direction, or to the position of Fig. 3. The spring 100 is designed so that it is stronger than the upper centering spring 42 and will therefore overcome the spring 42 in accomplishing movement of the upper spool 18 to the rear. line of force exerted by the spring 100 on the latch 90 is still rearwardly of the latch pivot 92 and therefore tends to rock the latch in a counterclockwise direction, which is limited, because the abutment portion 114 on the latch engages ahead of the upper end 88 of the auxiliary lever 60. A tthe same time, the tendency of the spring is to continue rotating the auxiliary lever 60 in a clockwise direction. However,-this cannot occur. For one thing, the centering spring 42 is'now substantially solid and therefore imposes a rearward limit on movement of the upper spool 18; Hence, the latch 90 is in effect immobilized and the abutment 114 is still engaged ahead of the forward edge of the upper end 88 of the auxiliary lever.

The multiple lever arrangement is a simple and economical construction and may be readily adapted to valve spools or other controllable components already in existence and is therefore effective to produce in such valve spools or equivalent element a third control function.

An additional feature of this control system is that, the auxiliary lever and the valve spools being in the float position as shown in Fig. 3, movement of the main lever to the rearward position will automatically return the auxiliary lever and the latch to the locked position; and then, the main lever being subsequently released, the valve spoolswill both be returned to the neutral position as shown in Fig. 1.

In Fig. 3, it is apparent that the centering spring 42, being solid or nearly so, restrains the valve spool 18 and the upper link 78 from further rearward movement; therefore, rearward rocking of the main lever 58 causes the auxiliary lever 60 to rotatecounterclockwise about the pivot 84. Simultaneously, the abutment 118 engaging the pin 106 raises the latch 90 against spring 100 until the notch 108 engages pin 106, thus interlocking the auxiliary lever 60 and the main lever 58.

Features and objects of the invention not categorically enumerated will undoubtedly occur to those versed in the art, as will many modifications and alterations in the preferred embodiment disclosed, all of which may be achieved without departure from the spirit and scope of the invention.

What is claimed is:

l. Actuating mechanism for controlling a pair of separate controllable devices comprising: a generally upright main lever operatively connected to one device and having upper and lower ends and a fulcrum intermediate said ends to mount said lever for fore-and-aft rocking; an auxiliary lever alongside the main lever and operatively connected to the other device and having an upper end proximate to the main lever upper end, a lower end spaced above the main lever fulcrum, and an auxiliary fulcrum intermediate said upper and lower ends of said InFig. 3, the

6 auxiliary lever and mounting said auxiliary lever on the main lever above the main lever fulcrum for fore-and-aft rocking of said auxiliary lever relative to the main lever; releasable coupling means cooperative between the levers and having a normal condition effecting an interconnection of the levers for fore-and-aft rocking in unison to control both devices in unison and releasable to enable fore-and-aft rocking of the auxiliary lever relative to the main lever to control only said other device; and biasing means acting to yieldably retain said normal condition of the coupling means and effective to rock the auxiliary lever relative to the main lever upon release of the coupling means.

2. Actuating mechanism for controlling a pair of separate controllable devices, comprising: a generally upright main lever operatively connected to one device and having upper and lower ends and a fulcrum intermediate said ends to mount said lever for fore-and-aft rocking; an auxiliary lever alongside the main lever and operatively connected to the other device and having an upper end proximate to the main lever upper end, a lower end spaced above the main lever fulcrum, and an auxiliary fulcrum intermediate said upper and lower ends of the auxiliary lever and mounting said auxiliary lever on the main lever above the main lever fulcrum to enable foreand-aft rocking of said auxiliary lever relative to the main lever to control only said other device; a latch carried on the auxiliary lever on a pivot parallel to and forwardly of and above the auxiliary fulcrum, said latch extending rearwardly and alongside the main lever; a stop on the main lever below the latch; biasing means acting on the latch and reacting on the main lever to exert a downward force on the latch intermediate the latch pivot and the auxiliary fulcrum and thereby tending to act. through the latch to rock the auxiliary lever about said auxiliary fulcrum so that the upper end of said auxiliary lever moves forwardly relative to the'main lever; and retainer means on the latch and engaging the stop from above and behind for preventing said rocking of the auxiliary lever by the biasing means, said latch being liftable about its pivot to disengage the retainer means from the stop. 7

3. The invention defined in claim 2, including: abutment means on the latch engageable with the stop from ahead of the stop, after the latch is lifted to release the retainer means, for preventing rearward and downward movement of the latch by the biasing means.

4. The invention defined in claim 3, including: means interengageable between the latch and the auxiliary lever, upon release of the retainer means and forward rocking of the auxiliary lever by the biasing means, to limit said forward movement of said auxiliary lever.

5. The invention defined in claim 4, in which: the interengageable means comprises a forward edge portion of the auxiliary lever and an ear portion on the latch projecting laterally into the path of said edge portion.

6. Actuating mechanism for controlling a pair of separate controllable devices, comprising: a generally upright main lever operatively connected to one device and having a fulcrum about which said lever is rockable fore-andaft; an auxiliary lever operatively connected to the other device and having a fulcrum on the main lever parallel to the main lever fulcrum to enable fore-and-aft rocking of said auxiliary lever relative to the main lever; releasable coupling means having a normal condition effecting an interconnection of the levers for fore-and-aft rocking in unison about the main lever fulcrum to control both devices in unison; and biasing means acting to yieldably. retain said normal condition of the coupling means and effective to rock the auxiliary lever in one direction relative to the main lever upon release of the coupling means so as to control only said other device. 1

7. The invention defined in claim 6, including: abutment means operative upon release of the coupling means to limit said relative movement of the auxiliary lever.

8. Actuating mechanism for controlling a pair of separate controllable devices, comprising: an actuating member movable selectively back and forth along a defined path and operatively connected to one device; a lever operatively connected to the other device and having a fulcrum on the member transverse to said path for mounting the lever for rocking back and forth relative to the member; releasable coupling means having a normal condition efiecting an interconnection of the lever and memher for movement in unison along said path for controlling both devices inunison; and biasing means acting to yieldably retain said normal condition of the coupling means and eliective to rock the lever in one direction relative to the member upon release of the coupling means so as to control only said other device.

9. Actuating mechanism for controlling a pair of 'sep-, arate controllable devices, comprising: an actuating member movable selectively back and forth along a fore-andaft path and operatively connected to one device; a lever operatively connected to the other device and having a fulcrum on the member transverse to said path for mounting the lever for rocking back and forth relative to the member; a latch carried by the lever on a pivot ahead of the fulcrum; a stop on the member for preventing rotation of the latchin one direction about its pivot; biasing means acting on the lever and reacting on the member for pivoting the latch in one direction relative to the lever and into engagement with the stop, said biasing f m'eans exerting a force on a line ahead of the fulcrum so as to act through the latch to urge the lever to' swin'g forwardly about its fulcrum and to carry the latch forwardly therewith; and retainer means on the latch and engaging the member from behind to prevent forward movement of the latch and thus to prevent forward movement of the lever whereby the member and lever are effective to control both devices in unison, said latch being forcibly movable against the biasing means and away from the stop to release the retainer means for effectuating the biasing means to swing the lever forwardly and to carry the latch forwardly therewith so that the lever is effective to control only said other device, and saidlatch having means thereon engagement with the stop, after release of the retainer means and forward movement of the latch with the lever, to limit said relative pivoting of the latch in the aforesaid one direction by the biasing means.

10. The invention defined in claim 9, including: means interengageable between the lever and latch, upon release of the retainer means and forward rocking of the lever, to limit said forward rocking of a predetermined extent.

11. Actuating mechanism for controlling a pair of separate devices, comprising: an actuating member movable selectively back and forth along a defined path and operatively connected to one device; a lever mounted to swing" on a fulcrum transverse to said path for rocking back and fourth at times relative to the member and operatively connected to the other device; releasable coupling means having a normal condition effecting an interconnection of the lever and member for movement in unison along said path for controlling both devices in unison; and biasing means acting to yieldably retain said normal condition of the coupling means and efiective to rock' the lever in one direction relative to the member upon release of the coupling means to control only said other device.

References Cited in the file of this patent

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