US3057495A

US3057495A - Scoop for an implement

Info

Publication number: US3057495A
Application number: US748194A
Authority: US
Inventors: Clyde E Wren; Danuser Henry
Original assignee: Danuser Machine Co Inc
Current assignee: Danuser Machine Co Inc
Priority date: 1958-07-14
Filing date: 1958-07-14
Publication date: 1962-10-09
Anticipated expiration: 1979-10-09

Description

Oct. 9, 1962 c. E. WREN ETAL 3,057,495

SCOOP FOR AN IMPLEMENT Filed July 14, 1958 5 Sheets-Sheet 1 INVENTORS CLYDE E. WREN HENRY DANUSER MM, M

ATTORNEYS Oct. 9, 1962 c. WREN ETAL 3,057,495

SCOOP FOR AN IMPLEMENT Filed July 14, 1958 3 Sheets-Sheet 2 INVENTORS YDE E. WREN NRY DANUSER 64m M47 Mee ATTORNEYS Oct. 9, 1962 c. E. WREN ETAL 3,057,495

SCOOP FOR AN IMPLEMENT Filed July 14, 1958 s Sheets-Sheet s 7O 75 8O 76 66 65 25 L W i 73; T 1 I V r I M FIG. 5

4] CLYDE E. WREN HENRY DANUSER 3o 11 BY v 3 M4, M [Qty-(Le FIG. 4

:ATTORNEYS This invention relates generally to improvements in a scoop for an implement, and more particularly to improved control mechanism for moving and retaining the bucket in various desired positions.

It is an important objective to provide a control means operatively interconnecting the stop means for retaining the bucket and the valve means for controlling operation of the hydraulic system incident to rotating the bucket to the different positions, so that the stop means is operated in response to the valve means.

An important object is achieved by the improved mechanism interconnecting the stop means and the valve means of the assembly previously described.

Another important objective is to provide a valve means that operates a hydraulic means to rotate the bucket in a predetermined sequence to various positions, and that includes means for actuating a pair of pins hydraulically in response to mechanism actuating the hydraulic means which causes operative engagement of stop members selectively with stop abutments on the bucket in the different positions.

Still another important objective is realized by the provision of a rock shaft rotatively mounted on the scoop frame alongside of the bucket, the shaft having means interconnecting the valve means and having stop means adapted to engage the periphery of the bucket and selectively to engage stop abutments upon actuation of the shaft responsively to operation of the valve means.

Yet another important object is to provide an implement scoop that is simple and durable in construction, economical to manufacture, efficient in operation and capable of ready operation by anyone.

The foregoing and numerous other objects and advantages of the invention will more clearly appear from the following detailed description of a preferred embodiment, particularly when considered in connection with the accompanying drawings, in which:

FIG. 1 is a perspective view of the implement scoop;

FIG. 2 is a schematic drawing of the hydraulic system and the control mechanism connecting such system to the bucket;

FIG. 3 is a cross sectional view of the sequence valve;

FIG. 4 is an enlarged cross sectional view of the top portion of the hydraulic cylinder shown at the left in FIG. 2, and

FIG. 5 is an enlarged cross sectional view of the top portion of the right hand cylinder shown in FIG. 2,

Referring now by characters of reference to the drawings, and first to FIG. 1, it is seen that the implement scoop includes a frame generally indicated at 113 having end members 11 interconnected and attached by tubular brace 12 extending therebetween. Rotatively mounted at journals 13 on end frame members 11 is a bucket referred to at 14. A bracket 15 is fastened to the cen ter of tubular frame brace 12 and is adapted to be attached to the hydraulic lift mechanism of a conventional tractor or like implement.

The bucket 14 consists of an elongate trough member 16 closed at opposite ends by plates 17 that are journalled at 13 to the end frame members 11.

The hydraulic system of the operating tractor or prime mover must have a pump 20 shown in the schematic drawing of FIG. 2, and a normal control valve 21 capable of directing a flow of oil through either of the flow lines 3,357,495. Patented Oct. 9, 1952 22 and 23 leading to the hydraulic system of the scoop. These flow lines 22--23 are connected to a sequence valve 24, the details of which are disclosed in FIG. 3. The sequence valve 24 is operatively connected by

lines

25 and 26 to hydraulic cylinders indicated at 27 and 28.

The

cylinders

27 and 28 are pivotally attached to the end frame members 11 by pivot bolts 18. The end frame members 11 each have a horizontal portion provided with an aperture 29 through which a

cylinder

27 or 28 extends, such aperture 29 being of a size to permit pivotal move ment of the cylinder therein.

The piston 30 of hydraulic cylinder 27 is pivotally attached at 31 to a plate 32 fixed to the bucket end plate 17. Similarly, the piston 33 of hydraulic cylinder 28 is pivotally attached at 34 to plate 35 attached to the opposite bucket end plate 17. It will be noted that the cylinders 27 :and 28 are operatively connected to the bucket 14 so that the pistons 3i and 33 respectively act on opposite sides of the bucket pivot axis 13 so as to give the effect of a double-acting cylinder.

Rotatively mounted on and between the end frame members 11 is a transverse rock shaft 36. As will be seen from FIGS. 1 and 2, the shaft 36 is journalled in the housing of sequence valve 24, the shaft extending longitudinally of bucket 14 to the opposite end frame members 11.

Fixed on each end of shaft 36 is a stop member 37 consisting of a U-shaped arm having a pair of

rollers

40 and 41 adapted to engage the periphery of the adjacent end bucket plate 17.

Each of the end bucket plates 17 is provided with three stop abutments indicated in FIG. 2 and referred to hereinafter in the terminology of the position of the bucket which :they determine, such as load stop abutment 42, carry stop abutment 43 and dump stop abutment 44. The cooperation and coaction of the stop abutments 42-44 inclusive with the stop members 37 will be described in detail subsequently.

Located Within the housing of sequence valve 24 and attached to the rock shaft 36 is a valve follower 45 consisting .of a U-shaped member having a pair of

rollers

46 and 47. A pair of

slide pins

50 and 51 are mounted in the sequence valve 24 and are operatively intercounected and actuated by valve 24 in a manner subsequently described, the

slide pins

50 and 51 engaging the

rollers

46 and 47 respectively of the valve follower 45 so as to rotate the shaft 36 in response to operation of sequence valve 24, and hence cause actuation of the stop members 37. The sequence valve 24 coordinates the movement of the bucket stop members 37 with bucket movements caused by the

hydraulic cylinders

27 and 28, or with cylinder movements caused by external forces acting on the bucket 14, provides a certain amount of automatic bucket position control, and provides a bucket locking feature.

The

bucket control cylinders

27 and 28 are shown with their head ends greatly expanded in FIGS. 4 and 5 to show the detailed construction. Each cylinder has a stepped throttling plug 52 and 53 respectively extending down from the head. These plugs 52-53 are engaged by rings 54 and 55 respectively on the ends of the

pistons

31 and 33 to obtain a braking action as the bucket rotates toward positive mechanical stops (not shown). Because the bucket 14 can be removed from the pivot brackets to which it and the cylinders attach, and reversed for some special conditions, the functions of the cylinders are interchanged.

In order to adjust for this condition, throttling plug 52 has two

lands

56 and 57, while plug 53 has lands on and 61.

The cylinder 27 is provided with a passage 62 downwardly through the center of plug 52 communicating with 3 line 25, is provided with a passage 63 in plug 52 communicating with the interior of the cylinder between the plug lands 5657, and is provided with another passage 64 communicating with feed line 25 and with the interior of the cylinder above the plug land 56.

A valve member 65 is provided between the passage 63 and feed line '25, the valve member 65 being attached to a screw 66 to permit adjustment. A valve member 67 and coacting valve ball 68 is disposed in passage 64. A screw 70 is attached to pin 67 to enable adjustment.

The cylinder 28 is provided with a passage 71 extending downwardly through plug 53 and opening at its bottom, the passage 71 communicating with the feed line 26. Another passage 72 places the feed line 26 in communication with the interior of the cylinder above the plug land 60. Another passage 73 places the feed line 26 in communication with the interior of the cylinder at the region between the

plug lands

60 and 61. Another passage 74 places passage 73 in communication with the interior of the cylinder above the plug land 60.

A screW-pin-ball valve combination 75 is disposed in passage 72 to control flow therethrough. A similar screwpin-ball valve combination 76 is disposed in passage 73 between the feed line 26 to control flow through passage 73. Another screw-valve member 77 is disposed between

passages

73 and 74 to control flow through passage 74.

In the schematic view of FIG. 2, the left hand view of both bucket end plates 17 is shown. In normal operation, the bucket will be moving toward the left relative to the surface on which it is working and the reaction of both the material being loaded and the material in the bucket will tend to cause counterclockwies rotation of the bucket. To prevent unwanted rotation, in various desired positions, the three stop abutments 4243-44 are provided at three points on the periphery of the bucket.

When the rear stop roller 41 is contacting the load stop abutment 42 as is shown, the bucket is in the correct position to gather a load of material. When rear stop roller 41 is positioned against the carry-stop abutment 43, the bucket is tipped up so that a greater bulk of loose material can be retained. If scarifier teeth 78 (FIG. I) are attached, such teeth will penetrate the ground when the bucket is lowered. When the front stop roller 40 is positioned against the dump-stop abutment 44, the bucket is in a position such that all material will fall from it.

Fixed stops (not shown) provided between the frame 10 and the bucket 14 prevent the bucket from rotating counterclockwise past the dumping position or clockwise past the carrying position.

For normal forward operation, the cylinder adjusting screws are adjusted so that valve member 65 is open, valve member 68 is open slightly but will greatly restrict oil flowing upwardly through it, valve member 76 is open to the point that there is only a slight spring force on the ball 80 to restrict the oil flow, valve member 77 is open but also restricts oil flow, and valve member 75 is open to the point where there is only slight spring force on ball 81 to restrict the oil flow.

The drawings of FIGS. 2, 3, 4 and show all parts of the hydraulic system in the position they would assume when the bucket is rotated clockwise into loading position and the roller 41 is moving just past stop abutment 42. Oil flows from the pump 20 through the valve 21, through line 22 and into the sequence valve 24. As a result, pressure is exerted through restriction 82 to the upper end of spool 83 slidably mounted in the sequence valve 24, and is exerted on both sides of valve ball 84 and against valve ball 85. When the spool 83 is located in its lowermost position as shown in FIG. 3, the reduced upper portion of spool 83 places one side of the valve ball 85 and both sides of valve ball 84 in communication with the restriction 82, that is in turn in communication with line 22.

In addition, pressure from line 22 is exerted through passage 86 and past the valve 87 at a slightly reduced value to the side of valve member 88 by way of passage 90. This same slightly reduced pressure is transmitted to the lower end of spool 83 through passage 91 com-,

municating with passage 90. Because of gravity and slightly lower pressure at the bottom end, the spool 83 stays down in its lowermost position as shown in FIG. 3. In this position, the passage is placed in communication with the passage 86 and hence passage 22 by the annular recess 92.

The oil flows down through line 22, through port 93, by the reduced valve portion 94 formed in valve member 88, through port 95, and hence through line 96. It will be particularly noted and understood that passage 96 is not connected to slide

pins

50 and 51 in any way.

Passage 97, in communication with passage 96, is placed in communication with cylinder line 26 by valve pin 98 and valve ball 100. Screw 101 is provided to effect adjustment of the valve means 98100. The oil flows from passage 96 through passage 97, causing the valve pin 98 to raise and open valve ball 100. When the valve pin is raised, it seats against a valve seat and stops flow from passage 97, and maintains the valve ball in an open position.

Valves

102 and 103 are safety valves only, and never operate except when the system is overloaded.

As stated previously, the oil flows through passage 96 to the cylinder line 25, and hence passes to the cylinder 27. From FIG. 4, it is seen that the oil pressure closes the valve ball 68 and the oil flows through

passages

62 and 63 to cause the piston 30 to extend and rotate the bucket clockwise as seen in FIG. 2.

Clockwise rotation of bucket 14 causes a retraction of piston 33 of cylinder 28, and thus causes a return flow through

passages

71 and 72 past valve ball 81. It Will be noted that the valve ball 80 prevents return flow upwardly through

passages

73 and 74 as seen in FIG. 5. This return oil flows through line 26 into the sequence valve 24 past the valve ball 100 (held in an open position by pressure on valve pin 98), and hence flows into passage 104 and is discharged into the sump through line 23.

A small amount of pressure caused by fiow friction is exerted against valve ball 85, the upper side of valve member 88 through port 105, the left end of valve member 88 through port 106, and the lower side of valve member 88 through the port and restriction 107. However, this pressure is too slight to cause any effect at these points.

Oil that is under pressure in line 22 flows through restriction 108 and exerts force against the slide pin 50 causing it to move to the right as shown in FIG. 3, to rotate the valve follower 45 clockwise, and hence causing the stop roller 41 to move down into the depression 110 (FIG. 2). The only purpose of the restriction at passage 108 is to restrict oil flow to and from the slide pin 50 and so damp any rapid and undesirable reciprocation of the slide pin 50 and oscillation of the valve follower 45 and of rollers 40-41. The depressions 110 and 111 (FIG. 2) are considerably deeper and allow stop roller 41 to drop farther and allow follower 45 to rotate farther than any other points on the bucket periphery contacted by the stop rollers 40-41.

This additional travel of stop roller 31 allows slide pin 50 to move to the right (FIG. 3) forcing slide pin 51 and valve member 88 to the extreme left end of the bore in which the valve member 88 operates. In this position, the valve member '88 closes ports 93 and 95, and opens

ports

105, 107 and 113 to the common groove 94 provided in valve member 88. Further, the spring 114 is compressed. The restriction at port 107 is such that sufficient pressure is maintained in line 22 and at port 112 to force valve member 88 far enough to the left to keep port practically fully open.

This action of valve member 88 stops the flow of oil through passage 96 to the cylinder 27, releases the valve pin 98 allowing the valve ball 100 to close and hence stop the oil flow from cylinder 28, and stops the bucket 14 in the loading position.

The entire oil flow through line 22 is now passing through port 113 to port 135, through passage 104 andv hence back to the sump through line 23. The only exception is a small amount or" oil passing from line 22 through valve member 87, to port 112, through the small passage 115 in valve member 88, through port 106 back to the sump, and a small amount of oil passing through port 107 and back to the sump.

This condition will continue to exist as long as there is oil flowing through line 22 because any tendency of movement of valve member 83 to the right because of spring 114 will restrict oil flow through port 105, increase pressure in line 22 through valve 87 to the port 112, and thus tends to move the valve member 88 to the left, reestablishing the original condition.

The events just described automatically stop the scoop bucket 14 in the correct position to load and so relieve the operator, who energizes the hydraulic system to return the bucket from dumping position to loading position, of the responsibility of stopping the bucket at the correct position.

At this point it is assumed that the operator, seeing that the bucket is in loading position, neutralizes the tractor hydraulic system by stopping all oil flow in either

line

22 or 23. When this occurs, the spring 114- forces the valve member 88 toward the right until it strikes the slide pin 51 and stops in a position such that

ports

113, 93, 11 and 95 are interconnected by the groove 94 in valve member 88. The oil which was trapped between the valve member '88 and the slide pin 51 is disposed of in two ways.

The majority of this oil passes through port 112 to spool 83. Because oil cannot pass to the right through valve 37 there is an increase in pressure which, acting on the bottom of spool 83 by way of passage 91, forces the spool 83 upwardly to close ports 116 and 117. After port 117 is closed, any oil trapped above spool 83 is released by passing through valve 84 and restriction 82, thence to the line 22 and the sump. Any oil remaining between the valve member 88 and the slide pin 51 slowly passes back through the small axial hole 115 in valve member 88 to help fill the space vacated by the valve member 88 as it moves to the right.

It is now assumed that the operator lowers the bucket 14 to the ground to fill it. For best operation, the entire machine will be tilted so that the weight of the scoop will be resting on the bucket cutting edge 118. Under ideal conditions, cutting edge 113 will immediately penetrate the material to be loaded, creating a counterclockwise torque on the bucket.

Because in actual operation, the bucket did not stop instantly when stop roller 41 dropped into depression 11%, there is a slight gap between roller 41 and the load stop abutment 42. When loading is commenced, the torque mentioned above will cause the load stop abutment 42 to move toward the stop roller 41, thus shortening cylinder 27 and extending cylinder 28. Oil displaced from cylinder 27 passes through line 25, ports 95 and 93 to line 22. The only open port from line 22 is passage 108 to a slide pin 50. Pressure on slide pin 50 stops any tendency it may have to move to the left and thereby allow stop roller 41 to disengage the load stop abutment 42. The remaining volume of oil displaced from cylinder 27 passes from the valve member 88 through the port and restriction 107 and into the passage 104. A considerable amount of pressure is required to open valve 85 so that the oil opens the valve 100 instead and passes to cylinder 28 through line 26, through valve 80 and through

passages

71, 73 and 74 to provide the volume required by cylinder 28 as it extends.

In the event that the material to be loaded is very hard and the cutting edge 118 cannot penetrate its surface,

there is a clockwise torque exerted on the bucket 14 because of its weight resting on cutting edge 118. This causes cylinder 28 to attempt to contract by forcing oil up through passage 72 through valve 81 and through passage 71 to the line 26, but this is prevented by valve which is closed. This action causes the scoop weight to continue to rest on the cutting edge 118, thus aiding penetration.

When the bucket is filled it is assumed that it is raised by the operator and tipped into carrying position. To do this, the operator energizes the tractor control valve 21 so that pressure is again applied to line 22, and line 23 is again open to the sump. Because the spool 83 is raised, ports 116 and 117 are closed and the only outlets are through

ports

108, 113, 93 and through port and restriction 107. Pressure applied through port 108 acts on slide pin 53 but causes no reaction. Pressure at

ports

113 and 93 causes flow past the valve member 88 through port 95 through passage 96, and thus causes the valve pin 98 to be raised and valve ball 1% to be opened. Because of its restriction, only a very small amount of oil passes through port 137.

In addition, oil flows to cylinder 27 through line 25, through

passages

62 and 63 to extend the piston 30 and cause the bucket 14 to rotate clockwise. Stop roller 41 passes from the load-stop abutment 42 to the carry-stop abutment 43. As stop roller 41 is passing over the carry step abutment 43, the ring 55 of cylinder 28 is passing over land 61) of the throttling plug 53. Oil trapped in this area can leave only through the restriction in line 72 and by valve 31 and through line 71, through the restriction caused by needle valve 77, down through line 73 and up through line 71, all of which brakes the rotation to a gentle stop against positive mechanical stops on the bucket. Safety valves in the tractor hydraulic system or possibly valve 102 opens to return oil to the tractor sump until the operator again neutralizes the tractor hydraulic system.

When the stop roller 41 falls into the depression and engages carry stop abutment 43, the rock shaft 36 causes a corresponding adjustment of

followers

46 and 47 which causes a slight adjustment in position of slide pin 51 andv of spool 38 so that ports and 107 are closed.

To empty the bucket, the operator energizes the tractor control valve 21 to apply pressure to line 23 and to open line 22 to the sump.

When this is done, oil entering through line 23 opens valve 35 to force the spool 83 down as far as possible. A

small amount of oil continues to pass through valve 85, port 117 and restriction 32 back to the line 22 and the sump. With the stop roller 41 against carry-stop abutment 4-3, ports 1115 and 1117 are closed, but oil passing;

from line 1614 through port 1% forces the valve member 83 and the slide pin 51 to the right rotating the follower 45 counterclockwise to disengage the stop roller 41 from the carry stop abutment 43, and hence frees the bucket When the valve member 88 has moved a maximum amount to the right, ports 105,-

to turn counterclockwise.

113, 1117, and 112 are closed While ports 93 and 95 are opened and connected. The oil flowing through passage 1% passes through valve 1011, through line 26 to cylinder 23, through passage 71, valve 84 and

lines

73 and 74 to extend the piston 33, and hence rotate the bucket counterclockwise.

As the follower 45 is rotated, the stop rollers 40 engage the plates 17, and as the bucket is rotated counter. clockwise, the rollers 41 roll over the abutments 43 and

sages

62, 63 and 64 to line 25, through passage 96 of the sequence valve, through ports 95 and 93 to line 22 and back to the sump. As ring 64 of cylinder piston 30 passes over land 57 of the throttling plug 52, there is no braking I [In action because of the relatively open set of needle valve 65. However, as the stop roller 40 is passing over the dump stop abutment 44, ring 54 meets land 56, and the oil trapped above ring 54 can pass only through valve 68 which restricts the flow to provide braking action.

As the stop roller 40 passes over the dump stop abutment 44, pressure is exerted through port 106 to valve 88, thus forcing valve member 88 and the slide pin 51 to the right, rotating the valve follower 45 counterclockwise and moving the stop roller 40 down to the right of the dump stop abutment 44 so as to lock the bucket 14. Any further counterclockwise rotation of bucket 14 is prevented by fixed mechanical stops. Until the operator neutralizes the tractor hydraulic system, oil will pass through the tractor safety valve 21 to the sump or through line 23, valve 100 and valve 103, to line 25 and passage 96 back to the sump.

To return the bucket 14 to the loading position the tractor hydraulic system is energized to apply pressure to line 22 and to open line 23 to the sump. The hydraulic system is now in practically the same state that it was at the beginning of this explanation and the flow follows the same passage.

As stop roller 41 approaches the load stop abutment 42, the ring 55 of cylinder piston 33 will contact land 61. Oil trapped above ring 55 cannot pass through

passages

73 or 74 because of valve 80, and the restriction in passage 72 as well as valve 81 will restrict the flow through passage 71 and line 26, and so provide braking action to the bucket rotation.

Under some conditions it is desirable to reverse the bucket 14 so that it can be loaded with the scoop moving to the right as viewed in FIG. 2. To accomplish this, the bucket can be removed from the scoop frame and cylinders 2728, by removing

bolts

120 and 121 on one bucket end plate 17 and bolts at 122 and 123 on the 0pposite bucket end plate. The bucket is then turned about its vertical axis so that when in loading position, the cutting edge 118 is toward the right.

The hydraulic system is then adjusted as follows: Screw valve 66 of cylinder 27 is closed and valve 70 is slightly opened. Screw valve 7576-77 of cylinder 28 are all opened. Screw 101 on the sequence valve 24 is closed to hold valve pin 98 up and valve ball 100 permanently open.

Operation in reverse is much the same as forward operation except that to obtain automatic stopping at the loading position, the bucket is rotated as far as possible counterclockwise to the carrying position and then rotated clockwise. As stop roller 41 leaves the carry stop abutment 43, it is forced into depression 111 which serves the same purpose for reverse operation as depression 110 does for forward operation, and at this point bucket rotation will stop automatically. When loading is begun oil flow from cylinder 28 will cause counterclockwise rotation of the valve follower 45 and force the stop roller 40 into engagement with the load stop abutment 42.

The drawings of FIGS. 2, 3, 4 and 5 show all parts of the hydraulic system in the position they would assume when the bucket is rotated clockwise into loading position and the roller 41 is moving just past carry stop abutment 43. Oil flows from the pump through the valve 21, through line 22 and into the sequence valve 24. As a result, the oil flows down through line 22, through port 93, by the reduced valve portion 94 formed in valve member 88, through port 95, and hence through line 96 to the cylinder line and consequently to the cylinder 27. From FIG. 4, it is seen that the oil pressure closes the valve 68 and the oil flows through passage 62 to cause the piston 30 to extend and rotate the bucket clockwise.

Clockwise rotation of the bucket 14 causes a retraction of piston 33 and cylinder 28, and thus causes a return flow through the

passages

71, 72, 73 and 74. This return oil flows through the line 26 into the sequence valve 24 past the ball valve 100, and hence flows into passage 104 and is discharged into the sump through line 23.

Oil that is under pressure in line 22 flows through the restriction 108 and exerts force against the slide pin 50 causing it to move to the right, as shown in FIG. 3, to rotate the valve follower 45 clockwise, and hence causing the stop roller 41 to move down into the depression 111. Upon movement of stop roller 41 into the depression 111, the slide pin 59 is moved to the right (FIG. 3) forcing slide pin 51 and valve member 83 to the extreme left end of the bore in which the valve member 88 operates. Similar to the operation previously described, this action of valve member 3% stops the flow of oil through passage i=6 to the cylinder 27 and stops the bucket 14 in the loading position. The entire oil flow through line 22 is now passing through port 113 to port 105, through passage 104 and hence back to the sump through line 23. As stated previously the only exception is a small amount of oil :1 from line 22 through valve member 87, to port through the small passage 115, through port 106 back to the sump, and a small amount of oil passing through port 167 and back to the sump.

At this point, the operator neutralizes the hydraulic system by stopping all oil flow in either

line

22 or 23. When this occurs, the spring 114 forces the valve member 38 toward the right until it strikes the slide pin 51 and stops in a position such that

ports

113, 93, 107 and are interconnected by the groove 94 in valve member 88.

The operator now lowers the bucket to the ground to fill it. Because in operation, the bucket stopped in depression 111, there is a slight gap between roller 41 and the load stop abutment 42. When loading is commenced the torque will cause the load stop abutment 42 to move clockwise. Oil from cylinder 28 flowing back into the sequence valve 24 causes a pressure on slide pin 51 that rotates the follower 45 counterclockwise and forces the stop roller 45) into engagement with the load stop abutment 42.

Although the invention has been described by making detailed reference to a single preferred embodiment, such detail is to be understood in an instructive, rather than in any restrictive sense, many variants being possible within the scope of the claims hereunto appended.

We claim as our invention:

1. A scoop for an implement comprising a frame, a bucket pivotally mounted on said frame, hydraulic means operatively connected to said bucket for rotating the bucket about the pivot axis of said bucket, valve means connected to said hydraulic means for controlling operation, the bucket being provided with stop abutments spaced about the pivot axis of said bucket, a shaft rotatively mounted on said frame, stop elements attached to said shaft and selectively engaging said spaced abutments in predetermined positions upon rotation of the bucket about its pivot axis, and means operatively interconnecting said shaft and said valve means for controlling operation of said stop elements, said valve means causing the hydraulic means to retain the bucket selectively in said predetermined positions upon engagement of said stop elements selectively with said abutments.

2. A scoop for an implement comprising a frame, a bucket pivotally mounted on said frame, hydraulic means operatively connected to said bucket for rotating the bucket about the pivot axis of said bucket, valve means connected to said hydraulic means for controlling operation, stop means on the bucket spaced about the pivot axis of said bucket, a shaft rotatively mounted on the frame, a follower attached to the shaft and operatively connected to the valve means for actuation of the shaft, and means operatively interconnecting the shaft selectively with the spaced stop means in predetermined positions upon rotation of said bucket about its pivot axis, the valve means causing the hydraulic means to retain the bucket selectively in said predetermined positions.

3. A scoop for an implement comprising a frame, a bucket pivotally mounted on said frame, hydraulic means operatively connected to said bucket for rotating the bucket about the pivot axis of said bucket, valve means connected to said hydraulic means for controlling oper ation, the bucket being provided with stop abutments spaced about the pivot axis said bucket, a shaft rotatively mounted on said frame, stop elements attached to said shaft, one or the other of said stop elements selectively engaging said abutments in predetermined positions upon rotation of the bucket about its pivot axis, a follower attached to the shaft and operatively connected to the valve means for actuation of the shaft and said stop elements, said valve means causing said hydraulic means to retain said bucket selectively in said predetermined positions upon engagement of the stop elements selectively with said abutments.

4-. A scoop for an implement comprising a frame, a bucket pivotally mounted on said frame, a hydraulic means including a cylinder connected between the frame and each end of the bucket, one cylinder being connected to and acting on one side of the pivotal axis of the bucket, and the other cylinder connected to and acting on the opposite side of the bucket axis, valve means connected to said hydraulic means for controlling operation, stop means mounted on the frame and engaging the bucket in predetermined positions, and means operatively interconnecting the stop means and valve means for controlling operation of said stop means, said hydraulic means rotating said bucket to said predetermined positions, said valve means causing said hydraulic means to retain the bucket selectively in said predetermined positions.

5. The combination and arrangement of elements as recited above in claim 4, but further characterized in that said hydraulic cylinders include hydraulic passages having valve elements for selectively opening and closing the passages for braking the rotative action of the bucket in one limitof each cylinder operation.

6. A scoop for an implement comprising a frame, a bucket pivotally mounted on said frame, hydraulic means operatively connected to said bucket for rotating the bucket about the pivot axis of said bucket to different predetermined positions, valve means connected to said hydraulic means for controlling operation, the bucket having its periphery provided with a plurality of stop abutments spaced about the pivot axis of said bucket, stop means mounted on the frame and engaging the periphery of said bucket and selectively engaging said stop abutments in said predetermined positions upon rotation of the bucket, and means operatively interconnecting said stop means and said valve means for controlling operation of said stop means, the valve means being conditioned upon engagement of said stop means selectively with said stop abutments so that said hydraulic means retains said bucket in each of said predetermined positions.

7. A scoop for an implement comprising a frame, a bucket pivotally mounted on said frame, hydraulic means operatively connected to said bucket for rotating the bucket about the pivot axis of said bucket, valve means connected to said hydraulic means for controlling operation, the bucket being provided with a plurality of stop abutments spaced about the pivot axis of said bucket, a rock shaft rotatively mounted on said frame, stop members attached to said rock shaft, and means operatively interconnecting said rock shaft and said valve means to move one or the other of said stop members selectively into engagement with said stop abutments in predetermined positions of the bucket upon rotation of the bucket about its pivot axis, the valve means being conditioned upon engagement of said stop members selectively with said stop abutments so that said hydraulic means retains said bucket in said predetermined positions.

8. The combination and arrangement of elements as recited above in claim 7, but further characterized in that said stop members consist of a U-shaped arm extending outwardly from said rock shaft, one end or the other of said U-shaped arm engaging the periphery of the bucket and selectively engaging the said stop abutments.

9. The combination and arrangement of elements as recited above in claim 7, but further characterized in that lb the said means interconnecting the rock shaft and said valve means includes a follower attached to said rock shaft and extending on opposite sides of said shaft, and valve elements engageable by said follower and operable by said valve means, the follower oscillating said rock shaft in response to the valve means.

10. A scoop for an implement comprising a frame, a bucket pivotally mounted on said frame, hydraulic means operatively connected to said bucket for rotating the bucket about the pivot axis of said bucket, valve means connected to said hydraulic means for controlling operation, the bucket including opposite end members each provided with peripherally spaced stop abutments about the pivot axis of the bucket, a rock shaft rotatively mounted on said frame and extending along said bucket, each end of the rock shaft having a plurality of stop r embers, one or the other of said stop members engaging the bucket periphery, a follower attached to said rock shaft, and valve elements engageable by said follower and operable by said valve means, the follower oscillating said rock shaft in response to the valve means so as to move one or the other of said stop members at each end of the shaft selectively into engagement with said stop abutments in predetermined positions of the bucket upon rotation of the bucket about its pivot axis, the valve means being conditioned upon engagement of the stop members selectively with said stop abutments so that said hydraulic means retains the bucket in said predetermined positions.

11. A scoop for an implement comprising a frame, a bucket pivotally mounted on said frame, hydraulic means operatively connected to said bucket for rotating the bucket about the pivot axis of said bucket to various desired positions, valve means connected to said hydraulic means for controlling operation, the bucket being provided with a plurality of stop abutments spaced about its periphery and about its pivot axis, a rock shaft rotatively mounted on said frame, stop members attached to said rock shaft, said stop members consisting of a U-shaped arm extending outwardly of said rock shaft, one end or the other of said U-shaped arm selectively engaging the periphery of the bucket, a follower consisting of a U-shaped arm attached to and extending outwardly from said rock shaft, valve elements engageable by said follower and operable by said valve means, the follower oscillating said rock shaft in response to the valve'means so as to actuate said stop members selectively into engagement with said stop abutments in predetermined positions of the bucket upon rotation of the bucket about its pivot axis, the valve means beingconditioned upon engagement of the stop members selectively with said stop abutments so that the hydaulic means retains the bucket in said predetermined positions.

12. A scoop for an implement comprising a frame, a bucket pivotally mounted on said frame, hydraulic means operatively connected to said bucket for rotating the bucket about the pivot axis of said bucket to various desired positions, valve means connected to said hydraulic means for controlling operation, the bucket including opposite end portions each provided with peripherally spaced stop abutments about the pivot axis of said bucket,

a shaft extending along said bucket and rotatively mounted on said frame, stop members consisting of a U-shaped arm attached to and extending outwardly from said shaft, one end or the other of said U-shaped arms of said stop members selectively engaging the periphery of the bucket, a follower consisting of a U-shaped arm attached to and extending outwardly from opposite sides of said shaft, valve elements engageable by said ends of the U-shaped arm of the follower and operable by said valve means, the follower oscillating said shaft in response to the valve means so as to bring the ends of the U-shaped arms of the stop members selectively into engagement with said stop abutments in predetermined positions of the bucket upon rotation of the bucket about its pivot axis, the valve means being conditioned upon engagement of the stop members selectively with said stop abutments 11 so that the hydraulic means retains the bucket in said predetermined positions.

13. A scoop for an implement comprising a frame, a bucket pivotally mounted on said frame, the bucket being provided with a plurality of stop abutments spaced about the pivot axis of said bucket, a shaft rotatively mounted on said frame, stop members attached to said shaft and adapted selectively to engage the stop abutments in predetermined positions of the bucket, hydraulic means operatively connected to said bucket for rotating the bucket about the pivot axis of said bucket, valve means connected to said hydraulic means for controlling operation, the valve means including a pair of slide pins one on each side of said shaft, follower means attached to each side of the shaft and engaging said pins upon oscillation of said shaft so as to actuate said valve means upon engagement of the stop members selectively with said stop abutments so that the hydraulic means retains the bucket in said predetermined positions, and the valve means including means for operating said pins to cause operative engagement of the stop members selectively with the stop abutments in the predetermined positions of the bucket.

14. A scoop for an implement comprising a frame, a bucket pivotally mounted on said frame, the bucket being provided with a plurality of stop abutments, a shaft rotatively mounted on said frame, stop members attached to said shaft and selectively engaging the stop abutments in predetermined positions of the bucket, hydraulic means operatively connected to said bucket for rotating the bucket, valve means connected to said hydraulic means for controlling operation, control means having a pair of hydraulic lines to said valve means, the valve means including a pair of slide pins, follower means attached to the shaft and engaging said slide pins for shaft actuation, a valve member adapted to engage the first of said pins and adapted to control flow to said hydraulic means, means for exerting hydraulic pressure on the second pin upon feed through one line so as to bring one of said stop members against one abutment in a predetermined load position of said bucket, and means for exerting hydraulic pressure against the valve member and said first pin upon feed through the other said line so as to bring another said stop member against another said abutment in a predetermined dump position of said bucket, the valve means causing said hydraulic means to retain said bucket in said load and dump positions.

15. The combination and arrangement of elements as recited above in claim 14, but further characterized in that the said valve means includes means for moving the valve member away from the said first slide pin to stop flow to the hydraulic means after the bucket has been rotated to the load position, resilient means urging the valve member against the said first slide pin upon stopping of hydraulic feed to reopen the flow passage to the hydraulic means, and the said means for exerting hydrau lic pressure against the said second slide pin upon feed through the said one line causing the stop member to engage another said stop abutment as the bucket is rotated to another position by the hydraulic means upon resuming hydraulic feed through the said same line, the valve means causing said hydraulic means to retain said bucket in the last said position.

16. A scoop for an implement comprising a frame, a bucket pivotally mounted on said frame, the bucket being provided with a plurality of stop abutments spaced about the pivot axis of said bucket, a shaft rotatively mounted on said frame, stop members attached to said shaft and selectively engaging the stop abutments in predetermined positions of the bucket, hydraulic means operatively connected to said bucket for rotating the bucket about the pivot axis of said bucket, valve means connected to said hydraulic means for controlling operation, the valve means including a pair of slide pins, follower means attached to the shaft and engaging said pins for actuation of said valve means upon engagement of the stop members selectively with said stop abutments, the valve means including means for operating said hydraulic means in a predetermined sequence to rotate the bucket about the pivot axis of said bucket from loadto-carry-to-dump positions and to retain said bucket in said positions, the valve means including means for actuating said slide pins hydraulically so as to operate said follower means and cause operative engagement of the stop members selectively with the stop abutments in the different positions of said bucket.

References Cited in the file of this patent UNITED STATES PATENTS 2,008,178 Harrison July 16, 1935 2,196,690 Barrett Apr. 9, 1940 2,293,636 Berner et a1 Aug. 18, 1942 2,445,260 Brimhall July 13, 1948 2,463,675 Beyerstedt Mar. 8, 1949 2,488,699 Anthony Nov. 22, 1949 2,760,284 Cook Aug. 28, 1956