US2800847A

US2800847A - Selective control mechanism for tractors

Info

Publication number: US2800847A
Application number: US586076A
Authority: US
Inventors: Bennett Francis
Original assignee: Individual
Current assignee: Individual
Priority date: 1956-05-21
Filing date: 1956-05-21
Publication date: 1957-07-30
Anticipated expiration: 1974-07-30

Description

Jul so, 1957 F. BENNETT 2,800,847

SELECTIVE CONTROL MECHANISM FOR TRACTORS 4 Sheets-Sheet 1 Filed May 21, 1956 JFZvenZvr 2 W; 623' 5622226513 A 9 72% 5m 2 7% J y 1957 F. BENNETT 2,800,847

SELECTIVE CONTROL MECHANISM FOR TRACTORS Filed May 21, 1956 4 Sheets-Sheet 2 B flancis @eizneZZ,

July 30, 1957 F. BENNETT SELECTIVE CONTROL MECHANISM FOR .TRACTORS 4 Sheets-Sheet 3 Filed May 21, 1956 jzvezzivr' F7" azczls 562220322 July 30, 1957 F. BENNETT 2,800,847

SELECTIVE CONTROL MECHANISM FOR TRACTORS Filed May 21, 1956 4 Sheets-Sheet 4 ram 055 3620x652 mm, M27W 0527i),

United es Patent SELECTIVE CONTROL MECHANISM FOR TRACTORS Francis Bennett, Kewanee, iii.

Application May 21, 1956, Serial No. 586,676

4 Claims. (Cl. 97--46.39)

This invention relates to a power actuated selective control mechanism for independently actuating cultivator rigs or similar'attachments for tractors and more particularly is concerned with an attachment for converting existing equipment to selective operation.

At present, many tractors aremanufactured with builtin selective control systems for actuating independently movable. implements carried on opposite sides of the tractor. This afliords the operator the opportunity of raising and/or lowering the implements on either side either individually or simultaneously as conditions re- 11116. q There are, however, many existing tractors with power driven raising and lowering apparatus thatmove the left and right hand cultivator rigs simultaneously only, and it is the principal object of the invention to provide a simplified attachment for converting such tractors to selective operation.

It is a further object to provide an attachment that is low in cost and that is capable of field installation, thereby avoiding the expense and inconvenience of factory servicing.

In the illustrated embodiments, the device is adapted to a tractor having a sourceof hydraulic fluid under pressure and includes selectivelypositiona'olecontrol valve means for directing the fluid to either or both of a pair of independently actuatable members which in turn-positionthe cultivator rigs. Theoperatingmechanism for the'control valve is tied'in with the control lever for the pressure source through suitable lostmotion connections such that movements that position the valve do not. affect the control lever and vice versa.

Other objects and advantages of the invention will be apparent during the course of the following description.

Inthe accompanying drawings forming a part of this specification and in which like numerals are employed to designate likeparts throughout the same,

Fig. l is a fragmentary elevational view of the left side of a tractor with the left wheel removed and illustrating one embodiment of the attachment of the present invention;

Fig. 2 is a sectional view taken on the line 22 of Fig. 1; l

Fig. 3 is a plan sectional view taken on the line 33 of Fig. 2;

Figs. 4 and S are similar to Fig. 2 but show the opcrating mechanism in its two limit positions;

Fig. 6 is a fragmentary perspective view representing another embodimento'f the attachment ofthe invention;

Fig. 7 is a rear elevational view of the control valve mechanism and operating mechanism of the embodiment of Fig. 6; and

Figs; 8 a'nd'9" are plan'sec'tional views through the control valve mechanism of the embodiment of Fig. 6 illustrating the limit positions of movement of the control valve.

I Referring now to the drawings and particularly to Fig.

The lever 22 controls a source of hydraulic fluid underpressure located in a power supplying box 23 carried at the rear end of the tractor for operating the implements carried by the tractor. By way of illustration the invention is shown applied to an existing tractor known as the Waterloo line of John Deere & Company, but this specific disclosure should not be construed as limiting the scope of the inventon and the appended claims should be construed as broadly as the prior art will permit.

In the John Deere tractor, the cultivating implements are mounted for rotation about a horizontal axis between raised and lowered positions under the influence of right and left hand reciprocable rods. A typical right hand rod of the John Deere tractor is shown at 24 and is actuated by a crank arm 25 carried on a rotatable rockshaft 26. The rockshaft 26 is actuated by a hydraulic piston and cylinder arrangement (not shown) that communicates with the power box 23 through suitable internal hydraulic connections and that is controlled by control lever 22. As presently constructed, the left hand reciprocable member is also tied in with rockshaft 26 such that both members move simultaneously and thus simultaneously raise' or simultaneously lower their associated cultivating implements.

It is helpful to an understanding of the ultimate operation of tractors modified with attachments in accordance with the present invention to explain the functioning of F control lever 22 in connection with the power box 23.

To raise a cultivating implement carried on the front of the tractor, lever 22 is pushed forwardly or to the left as viewed in Fig. 1 to supply fluid under pressure and drive rod 24 forwardly and thereby raise the implements. As this motion reaches its limit, pressure is built up in the hydraulic system and the control lever 22 automatically returns to its center position thus relieving the applied pressure. In this connection the power box 23 includes check valves that come into operation and trap the hydraulic fluid and retain the cultivator implement in its raised position.

Lowering of the implements takes place under the action of gravity'and for this operation it is merely necessary to push control lever 22 to its rearward position. In this position, the check valves are released and under the influence of gravity the cultivator implements lower and force rod 24 rearwardly, thereby pumping the hydraulic fluid back into a reservoir provided in the power box. At any desired point the control lever may be returned to center to trap the remaining fluid and limit downward movement of the cultivator implement.

According to the present invention, the left hand reciprocable rod 27 is disconnected from the rockshaft 26 and is provided with its own piston and cylinder arrange ment 28 which is pivotally supported from the tractor by means of a suitable mounting bracket 29. In addition, the invention contemplates a selective control valve mechanism 30 having an inlet 31 connected through a hydraulic input line 32 to the source of hydraulic pressure fluid in the control box 23. In making this connection to the control box 23, it is necessary, as should be obvious, to modify the control box such that it no longer supplies fluid under pressure directly to the piston and cylinder arrangement associated with rockshaft 26. The control valve mechanism also includes a pair of outlets 32 connected through a first hydraulic output line 33 that feeds the piston and cylinder arrangement associated with r 3 rockshaft 26 and to a second that feeds piston and cylinder arrangement 28.

As shown in Fig. 3, the control valve mechanism includes a casing 35 having a main supply passageway 36 feeding a pair of valved outlet passageways 37 controlled by spools 38. With this arrangement, the spools 38 in the control valve mechanism 30 may be positioned selec tively so that pressure fluid is supplied, only to hydraulic output line 33, or only to line 34, or to both lines simultaneously. I 1

An operating mechanism for the control valve mechanism 30 is designated generally as 40 and is connected by a suitable link 41 to the control lever 22 for actuating the same. As best seen in Fig. 2, the operatingmechanism includes a center member 42 pivotally mounted on a pin 43 suitably supported in a socket 44 of inverted U-shape that is secured to the casing 35 of the control valve mechanism 30. A pair of side members 45 are also pivotally mounted relative to casing 35 but for this purpose are connected to the spool valves 38 that shift up and down as the side members reciprocate in opposite directions. Each spool valve has an intermediate annular recess 46 that unblocks its associated passageway when in register therewith. In addition the spools are preferably provided with headed stops 47 for limiting their upward shifting movement.

The operating mechanism includes a handle 48 carrying a cross bar 49 that is pivotally connected at its opposite ends to the upper ends of the side members 45 for pivoting movement relative thereto about an axis extending at right angles to the pivot axis for the lower ends of the side members 45. The cross bar 49 is provided with a pin 50 that rides up and down in a slot 51 formed at the upper end of the center member 38.

The function of the operating mechanism is best understood by reference to Figs. 4 and 5. As the handle 48 is tipped to the left, as shown in Fig. 4, it pivots about the upper end of the left side member 45, this movement being accommodated as the pin 50 rides upwardly in its slot 51, and thus carries the right side member 45 and its associated spool valve 38 upwardly so that the right hand spool blocks its associated passage in the control valve casing. In a similar manner, tipping the handle towards the right as shown in Fig. 5, raises the left hand spool and causes it to seal its associated supply passage.

It should be apparent that these tipping movements of the handle 48 are freely accommodated by the center member 42 without any corresponding movement due to the lost-motion pin and slot connection between 'the handle and center member. Thus this degree of movement of the operating mechanism is effective to position the spool valves without disturbing the setting of the control lever 22. With the control valve mechanism properly positioned, the associated implements may be raised or lowered by then pivoting the handle 48 as indicated in Fig. 1. This latter degree of movement of the handle brings the linkage 41 into play and correspondingly controls the positioning of control lever 22 which in turn governs the power supplied to the reciprocable'

rods

24 and 27 and hence effects at raising or lowering of the cultivator implements. It will be seen that as the operating mechanism and control lever are pivoted back and forth as indicated in Fig. 1, the predetermined positioning of the spool valves is left undisturbed since the side members 45 merely pivot about their lower ends to accommodate such movement. 1

peration.To raise both sides of the cultivator simultaneously, handle 48 is centered asindicated in Fig. 2 such that both spools 38 are in their lowermost position and their associated supply lines are in operative communication with the power box 23. Handle 48 is then pushed forwardly or to the left as viewed in Fig.1 causing fluid under pressure from the supply system in the power box 23 to flow through the input hydraulic line 32 through thecontrol valvemechanism 30 and through hydraulic output line 34 the output

hydraulic lines

33 and 34 to act upon the piston and cylinder arrangements associated with

rods

24 and 27 and drive both rods forward, thereby raising the cultivator implements. The subsequent pressure build-up returns control lever 22 to center and closes the check valves of the power box 23 to maintain the raised position.

For purposes of explanation it will now be assumed that it is desired to lower the left side cultivator only. To accomplish this, handle 48 is tipped to the position shown in Fig. 4, thereby raising the right hand spool 38 and sealing its associated passageway to trap the pressure fluid in the piston and cylinder arrangement associated with rockshaft 26 independently of the check valves in power box 23. The handle is then pushed backwardly or to the right as viewed in Fig. 1 and this correspondingly forces lever 22 rearwardly to unseat the check valve in the power box 23 which then provides an exhaust for the fluid trapped in cylinder 28. Under these conditions the elevated left side cultivator, under the influence of gravity, is gradually lowered and this lowering action forces the fluid trapped in cylinder 28 to flow back into a fluid reservoir in the tractor.

It should be apparent that various combinations of movements may be controlled by means of the present attachment. For example, it is possible to raise either side individually, or to lower either side individually, or to raise or lower both sides simultaneously. The manner for accomplishing this is believed obvious to one skilled in the art in view of the foregoing disclosure.

An alternative embodiment of the attachment of the present invention is shown in Figs. 6 to 9, and while the general principle is identical, the physical arrangement is somewhat different. In this embodiment, the control valve mechanism is designated generally as and is again connected to a hydraulic input line 32 and a pair of

hydraulic output lines

33 and 34. In this instance, however, the valve element consists of a single spool 131 (see Figs. 8 and 9) having a pair of enlarged portions 132 adapted when in register with their associated internal passageways in the control valve mechanism to completely seal such passageways.

The spool 131 is selectively controlled 'between a first position shown in Fig. 8 wherein the left hand passageway is open and the right hand passageway is sealed, a second or center position, as, shown in Fig. 7, wherein both passageways are open, and a third position as shown in Fig. 9 wherein the right hand passageway is open and the left hand passageway is sealed. The positioning of the valve element iseflected by an operating mechanism including a handle 137 pivotally mounted through the medium of a universal joint, designated generally as 138, that is carried by a bracket 139 secured to the casing of the control valve mechanism 130. Thus the handle 137 is capable of two independent degrees of movement. One consisting of pivotal movement about the axis defined by a pin 140 and the other consisting of pivotal movement about the axis defined by a rod 141.

The handle 137 includes a rigid lower extension 143 sandwiched between and in close abutting relationship with a pair of shouldered portions 144 formed on an ex ternal extension 145 of the spool 131. Thus as the handle is pivoted about pin 140, its lower extension 143 eontols the positioning of the spool.

In addition, the handle is connected to control lever 22 by means of a rack 146 that is slotted as at 148 to provide a lost-motion connection between the control lever 22 and the handle 137 to accommodate pivotal movement of the handle about pin 140 without any corresponding movement of the lever 22. After the handle has properly positioned the spool valve, however, it then may be pivoted about rod 141, and during this motion, it moves lever 22 correspondingly. This last described movement is freely accommodated without affecting the positioning of the valve element since the lower extension of'the handle is provided with a lost-motion connection that accommodates a limited amount of movement normal to the axis of the spool.

It is believed that the operation of the embodiment of Figs. 6 through 9 requires no detailed explanation. Reference may be had to the functioning of the previous embodiment for this purpose. 3

It is important to note that the desirable selective control, which is permitted by the attachments of the present invention, maybe provided with but a minimum of revision of the arrangement of the existing tractor. It is a simple task to connect the'externalhydrauli'c lines to the power box 23 which delivers the hydraulic fluid under pressure for operating the cultivator implements and the only other change required is to disconnect the left rod 27 from the rockshaft 26 and provide a separate piston and cylinder assembly 28 for controlling this rod. These operations can be performed in the field thus avoiding the serious disadvantages associated With a factory conversion. The device is simple and fool-proof, and as shown, is particularly well adapted to the conversion of the Waterloo line of tractors of the John Deere Company though the principle is believed applicable to other tractors having a built-in source of power for controlling the cultivator rigs.

I claim:

1. For use in converting an existing tractor or the like to selective operation, said tractor including a pair of movable members, a source of hydraulic fluid under pressure for actuating said members, and a three-position control lever for said source operable in a first position to supply fluid under pressure for raising said members, in a second position to maintain a predetermined fluid pressure for holding said members in any given position, and in a third position to provide a fluid exhaust for lowering said members under the action of gravity; an attachment for selectively controlling said members and comprising a three-position selective control valve mechanism, an input hydraulic line connecting said control valve mechanism to said source, a pair of output hydraulic lines connecting said control valve mechanism to said movable members, and an operating mechanism having two degrees of movement connected to said control valve mechanism and having a lost-motion linkage connection to said control lever such that in one degree of movement of said operating mechanism said control lever remains stationary and said control valve mechanism is actuated between a first position wherein said input line is in open communication with one of said output lines, a second position wherein said input line is in open communication with both of said output lines, and a third position wherein said input line is in open communication with the other of said output lines, and in the other degree of movement of said operating mechanism said control valve mechanism remains in its last selected position and said control lever follows said operating mechanism.

2. For use in converting an existing tractor or the like to selective operation, said tractor including left and right movable members connected to pivotally mounted implements movable between raised and lowered positions, actuating means including a piston controlled rockshaft connected to one of said movable members for operating the same, a source of hydraulic fluid under pressure for said actuating means, and a three-position control lever for said source operable in a first position to supply fluid under pressure for raising said implements, in a second position to maintain a predetermined fluid pressure for holding said members against movement due to gravity, and in a third position to provide a fluid exhaust for lowering said members under the action of gravity; an attachment comprising a piston and cylinder mechanism connected to the other of said movable members for actuating the same, a three-position selective control valve mechanism, an input hydraulic line connecting said control valve mechanism to said source, a pair of output hydraulic lines connecting said control valve mechanism to said actuating means and to said piston and cylinder mechanism, and an operating mechanism having two degrees of movement connected to said control valve mechanism and having a lost-motion linkage con nection to said control lever such that in one degree of movement of said operating mechanism said control lever remains stationary and said control valve mechanism is actuated between a first position wherein said input line is in open communication with one of said output lines, a-S'e'cond position wherein said input line isin open communication with both of said output lines, and a third position :wherein said input'line is in open communication with the other of said output lines, and in the other degree of movement of said operating mechanism said control valve mechanism remains in its last selected position and said control lever follows said operating mechanism.

3. For use in converting an existing tractor or the like to selective operation, said tractor including a pair of movable members, a source of hydraulic fluid under pressure for actuating said members, and a three-position control lever for said source movable in a single plane and operable in a first position to supply fluid under pressure for raising said members, in a second position to maintain a predetermined fluid pressure for holding said members in any given position, and in a third position to provide a fluid exhaust for lowering said members under the action of gravity; an attachment comprising a control valve mechanism having an inlet, a pair of outlets, a pair of normally open valve members controlling communication between said inlet and said outlets, an input hydraulic line connecting said inlet to said source, and a pair of output hydraulic lines connecting said outlets to said movable members; and an operating mechanism comprising a center member pivotally mounted on said control valve mechanism for movement in a plane substantially parallel to the plane of movement of said control lever, reciprocable side members pivotally connected at one end to said valve members to raise the same to a closed position, a handle pivotally connected at one end to said valve members to raise the same to a closed position, a handle pivotally connected to the other ends of said side members and having a lost-motion connection to said center member and accommodating pivotal movement of said handle in a plane substantially normal to the plane of pivotal movement of said handle to raise one or the other of said side members and the valve member associated therewith, and a link connecting said center member to said control lever such that movement of said handle in a plane parallel to said plane of movement of said control lever moves said center member and said control lever While said valve members remain in their last selected position.

4. For use in converting an existing tractor or the like to selective operation, said tractor including a pair of movable members, a source of hydraulic fluid under pressure for actuating said members, and a three-position control lever for said source movable in a single plane and operable in a first position to supply fluid under pressure for raising said members, in a second position to maintain a predetermined fluid pressure for holding said members in any given position, and in a third position to provide a fluid exhaust for lowering said members under the action of gravity; an attachment comprising a control valve mechanism having an inlet, a pair of outlets, a three-position valve member movable between a first position wherein said inlet is in open communication with one of said outlets, a second position wherein said inlet is in open communication with both of said outlets, and a third position wherein said inlet is in open communication with the other of said outlets, an input hydraulic line connecting said inlet to said source, and a pair of output hydraulic lines connecting said outlets to said movable members; and an operating lever having two degrees of movement pivotally mounted on said control valve mechanism, a lost-motion connection between said operating lever and said valve member sueh that one degree of movement of said operating lever varies the positioning of said'valve member and the other degree of movement of said operating lever is freely accommodated without corresponding movement of said valve' member, said other degree of movement being in a plane substantially parallel to the plane of movement of said control lever and a lost-motion connection be tween said operating lever and said control lever such that said one degree of movement of said operating lever is freely accommodated without corresponding move ment of said control lever and such that said other' degree ofmovement of said operating lever varies the positioning of said control lever correspondingly.

References Cited in the file of this patent I UNITED STATES PATENTS 2,664,708 'Norelius, et al. Jan. 5,