US3175712A - Material handling equipment - Google Patents

Description

Mm'ch 30, 1965 w. A. HERPICH ETAL 3,175,712

MATERIAL HANDLING EQUIPMENT 4 Sheets-Sheet 1 Filed June 6, 1961 INVENTOR 5 ATTORNEYS 4 Sheets-Sheet 2 W. A. HERPICH ETAL MATERIAL HANDLING EQUIPMENT March 30, 1965 Filed June 6, 1961 March 30, 1965 w. A. HERPICH ETAL 3,175,712

MATERIAL HANDLING EQUIPMENT 4 Sheets-Sheet 5 Filed June 6, 1961 INVENTORS ATTORNEYE' arch 1965 w. A. HERPICH ETAL 3,175,712

MATERIAL HANDLING EQUIPMENT 4 Sheets-Sheet 4 Filed June 6. 1961 BY M 0 M M, 74,1 4:-

ATTORNEY 3,175,712 MATEL HANDLING EQUIPMENT William A. I-Ierpich, Gallon, Ohio, and Neil F. Wender and Glenmore G. Garrett, Knoxville, Tenn, assignors to Dempster Brothers, inc, Knoxville, Tenn, a corporation of Tennessee Filed .lune 6, 1961, Ser. No. 115,177 5 Claims. (Cl. 214-303) This invention relates to improvements in material handling equipment of the character involving containers and vehicle-mounted container hoisting apparatus. This equipment frequently is used in collecting and transporting loose material such as refuse, for example.

A satisfactory way of handling loose material is to provide containers of suitable size into which the material may be deposited. In the collection of refuse, for example, several suitable containers may be placed at convenient locations and emptied from time to time as they are filled. These containers are of relatively large size and the handling of these containers requires a power actuated mechanism.

One type of mechanism used to service such containers is generally referred to as a front end loader or front end loading equipment. This container handling equipment employs a pair of lifting arms which are pivotally connected to the vehicle and extend to the front of the vehicle where a connection may be established between the lifting arms and a container. The vehicle is provided with a body of such a character that the contents of the container may be emptied into the body upon proper actuation of the hoisting equipment.

One front end loader device is shown, for example, in Patent No. 2,900,096 issued August 18, 1959, and includes, in addition to a pair of lifting arms, a front torque tube extending across the vehicle for connecting the lifting arms, and a pair of fork arms mounted on the torque tube and serving to establish a detachable connection between the container and the lifting arms.

In this front end loading equipment the fork arms extend along the outside of the container and fit into pockets or sleeve assemblies at the ends of the container. Actuation of the lifting arms and the fork arms by suitable power devices is effected to lift the container, from the ground or other supporting surface, over the cab of the vehicle to a position above the body of the vehicle so that the contents of the container may be dumped through a hopper opening into the body. The empty container may then be swung back to the ground in front of the vehicle.

When containers are emptied by front end loading equipment, it is not necessary to transport the containers themselves to a distant location for dumping. A vehicle equipped with this type of front end loader, and with a suitable body, is driven from point to point where various containers are located. One after another, the full containers may be emptied into the body of the vehicle and, once the body is full, the vehicle can be driven to the dumping area and the contents emptied from the body. In this manner, it is not necessary to remove the containers from the filling location, and the number of trips which the vehicle must make to a dumping location can be minimized.

In equipping a vehicle with a front end loader, it is desirous that the hoisting apparatus be actuated by power devices under the control of the operator located within the cab of the vehicle, or at a suitable position outside the cab. A convenient Way of actuating the hoisting apparatus is to provide fluid under pressure for actuating suitable cylinder and piston assemblies. It is desirous that the operation of the hoisting equipment be as simple I aten ice as possible and that the container dumping operation be completed rapidly.

The body of the vehicle customarily is provided with a door or cover for the hopper opening. When the hoisting apparatus is actuated to dump the contents of a container into the body, it is necessary, of course, that the cover be open. In providing simple and rapidly operating container handling apparatus, it is necessary that the hopper cover be actuated to its open and close positions in proper sequence in connection with the actuation of the lifting arms which hoist the container into position above the hopper. It is desirous also, that the actuation of the hopper cover be automatic, that is, that it be operated without the need for the operator to give his attention to opening or closing the hopper cover.

Accordingly, one object of this invention is to provide vehicle mounted container handling apparatus for dumping the contents of a container.

Another object of this invention is to provide a hydrau lic system for actuating and controlling vehicle-mounted container hoisting equipment.

Another object of this invention is to provide a hydraulically actuated hopper cover for the body of a vehicle.

Another object of this invention is to provide a system for automatically opening and closing a hopper cover in sequence with the actuation of container handling apparatus.

These objects may be accomplished according to one embodiment of this invention by providing, in connection with vehicle-mounted front end loading equipment, a hydraulically actuated and controlled system wherein the hoisting apparatus is operated manually by an operator, and a hopper cover is opened and closed automatically in response to movement of the hoisting apparatus.

The hoisting apparatus includes a pair of lifting arms pivotally mounted to the vehicle through a rear torque tube. Fork arms are provided at the front of the lifting arms for establishing a connection with a container which is to be hoisted above the body of the vehicle. The body is provided with a hopper opening through which material from the container may be dumped into the body. The hopper cover is pivotally mounted adjacent the hopper opening and swung between open and close positions by a cylinder and piston assembly. Additional cylinder and piston assemblies are provided for actuating the hoisting apparatus as well as a packer device within the vehicle body.

In the control system, fluid is supplied under pressure by a pump to a bank of manually actuated valves which control the flow of fluid to the container hoisting apparatus and the packer device. There is included in the control system a valve which is positioned adjacent the hoisting apparatus to be actuated thereby when the hoisting apparatus has moved a certain distance during a container dumping operation. Another valve is located adjacent the rear of the hopper cover to be actuated thereby when the cover is opened. These two valves aid in controlling the opening and closing of the hopper cover.

This embodiment of the invention is illustrated in the accompanying drawings, in which:

FIG. 1 is a side elevation view of a vehicle equipped with front end loading equipment, and showing in full lines and broken lines the hoisting equipment and the container in various positions;

FIG. 2 is an enlarged plan view of a hopper cover for the body of the vehicle;

FIG. 3 is a side elevation view corresponding with FIG. 2;

FIG. 4 is an enlarged fragmentary elevation view showing the relationship of one of the valves of a control system in association with the rear torque tube of the hoisting apparatus;

FIG. is a fragmentary front elevation view of part of the structure shown in FIG. 4;

FIGS. 6 and 7 are diagrammatic views showing a manner of actuating a valve of the control system by a cam on the rear torque tube; and

FIG. 8 is a diagrammatic view of the control system of the front end loading equipment.

In FIG. 1 there is illustrated a container It which is of relatively large size and which is capable of receiving loose material such as trash, or the like. The container 10 normally rests upon the ground, or other supporting surface, at a convenient location, and is provided with suitable openings at its top portion through which material may be deposited. The container 10 must be emptied from time to time as it becomes full, and this may be accomplished by inverting the container so as to dump the contents through an opening in the top wall.

A suitable vehicle is selected for receiving the hoisting apparatus which may handle the container 10. The vehicle is indicated in FIG. 1 by the reference numeral 12. The vehicle 12 has a chassis 13 and is self propelled under the control of an operator located within a cab 14.

A body 16 is provided on the vehicle chassis 13 behind the cab 14 and may be of any suitable type for receiving the particular material to be handled. For example, the body 16 may be built up of plates and strengthened as necessary by a series of reinforcing ribs 17. The interior of the body 16 provides ample room for receiving the material to be transported; however, it is often desirable that the interior of the body 16 be equipped with a packer mechanism for compressing material within the body. The packer mechanism may include a slidable packer head actuated by a hydraulic cylinder for compressing the material.

The top portion of the front of the body 16 is provided with a hopper opening 18 through which material may be dumped into the body 16. Side plates 19 extend along each side of the hopper 18 and cooperate with an angled front plate 20 (FIGS. 2 and 3) for guiding the material through the hopper opening 18 as the material is dumped from the container 10. A door 21 is provided at the rear of the body 16 so that the material may be emptied from the body 16 under the assistance of the packer mechanism. The door 21 normally is latched closed.

The hopper opening 18 in the body 16 is equipped with a cover 22 which may be built up of plates 2 and strengthened as necessary by a longitudinal central rib 26, a lateral rib 28, and suitable cross bracing 30. Framing 31 around the sides of the cover 22 supplies additional rigidity and ensures a tight fit between the cover and the plates 19 and 20. The cover 22 is hinged or otherwise pivotally connected at 32 to the top of the body 16, rearward of the opening 18, so as to be movable between a closed position (FIGS. 2 and 3) or an opened position (FIG. 1).

The opening and closing of the cover 22 is effected by actuation of a power device 36, which may be, for example, a conventional hydraulically actuated cylinder and piston assembly, including a cylinder 33 and a piston rod 40. The cylinder 38 is pivotally mounted at 42 to a pair of brackets 46 which extend upwardly from a plate 48 fixed to the top of the body 16. The free end of the piston rod 40 is pivotally connected at 50 to a pair of brackets 52 which extend upwardly from the juncture of the central rib 26 and the lateral rib 28 of the cover 22.

The power device 36 is preferably of the double acting type which permits fluid under pressure to be introduced at either end of the cylinder 33 so as to move the piston rod 40 inwardly or outwardly of the cylinder 38. Thus, the cylinder device 36 may be retracted to swing the cover 22 upwardly about the pivotal connection 32 from its closed position to its opened position, and the power de vice 36 may be extended to swing the cover downwardly from its opened position to its closed position.

The front end loading equipment or hoisting apparatus used in connection with the vehicle 12 is indicated in FIG. 1 by reference numeral 60, and includes a pair of lifting arms 62 spaced apart a distance corresponding substantially with the width of the cab 14. The lifting arms 62 may be of gooseneck shape or inverted U-Shape, for example, so as to extend over the top and downwardly in front and back of the cab 14, as illustrated in FIG. 1.

At the back of the cab 14 the lower end of the lifting arms 62 are fixed on a horizontally extending rear torque tube or rod 64 which extends substantially from one side of t e vehicle 12 to the other. The torque tube 64 is journaled in bearing blocks 66 (FIGS. 4 and 5) which are fixed to the vehicle chassis 13. In this manner, the lifting arms 62 are pivotally mounted to the vehicle 12 through the rear torque tube 64 and the bearing blocks 66.

A pair of lever arms 70 are attached to each opposite end of the torque tube 64 and extend downwardly therefrom. A power device 72, for example, a conventional hydraulically actuated cylinder and piston assembly, including a cylinder 74 and piston rod 76, is provided at each side of the vehicle 12 adjacent each pair of lever arms 76. The rear of each cylinder 74 is pivotally connected at 78 to brackets 80 fixed to the chassis 13. The free end of each piston rod 76 is pivotally connected at 82 to the free end of adjacent lever arms 71).

At the front of the vehicle 12, the lifting arms 62 are connected by a horizontally extending front torque tube or rod 94 which is journaled in bearing boxes secured to the forward ends of lifting arms 62. On each outside end of the torque tube 94 there is fixed a pair of lever arms 96. A power device 93, for example, a conventional hydraulically actuated cylinder and piston assembly, including cylinder and piston rod 102, is mounted on each of the lifting arms 62 by means of a bracket 104- so that the power device 98 extends along the corresponding arm 62. The free end of each piston rod 102 is connected at 106 with the free end of corresponding lever arms 96. A pair of fork arms 110 are rigidly mounted on opposit ends of the torque tube 94 adjacent the lifting arms 62.

On opposite end walls of the container 10 there is securely attached a sleeve assembly 112 which receives one of the fork arms 11% of the lifting mechanism 60. When the container 10 and the vehicle 12 are in the positions i1- lustrated in FIG. 1, the fork arms 110 may be inserted into or removed from the sleeve assemblies 112 in order to establish a detachable connection between the hoisting apparatus 60 and the container It).

The hoisting apparatus 60 may be operated as follows in order to dump the contents of the container 10 into the body 16 through the hopper opening 18. The power devices 100 may be actuated under the force of hydraulic pressure to rotate the lever arms 96 which in turn rotate the torque tube 94 so as to properly align the fork arms 110 for entrance into the sleeves 112. The lifting arms 62 may be pivoted about the axis of the rear torque tube 64 by operation of the power devices 72. In order to establish a connection between the lifting mechanism 6t) and the container 10 while it is on the ground or other supporting surface in front of the vehicle 12, the vehicle is maneuvered into proper position, and the power devices 72 and 98 are operated so that the fork arms 110 will enter the sleeves 112.

The power devices 72 may be operated further to swing the lifting arms 62 upwardly so that the container 19 is hoisted over the cab 14 and into dumping position at the top and front of the body 16 above the hopper opening 18. During the raising of the container lit, the fork arms 110 may be actuated by the power devices 98 to rotate slightly in a counterclockwise direction with reference to FIG. 1 so that the container 11) may be kept slightly tilted toward the vehicle but substantially upright. Once the container 10 is above the hopper opening 18, the fork arms 119 may be actuated to rotate in a clockwise direction far enough so that the container 10 is inverted to dump the contents from the top of the container 11), through the hopper opening 18 and into the body 16. This latter position of the lifting apparatus 60 and container is illustrated in broken lines in FIG. 1.

After the contents of the container 10 are dumped in this manner, the power devices 98 may be actuated to rotate the fork arms 110 so that the container 10 will be returned to a generally upright position. The lifting arms 62 then may be lowered by proper actuation of the power devices 72 to swing the container 10 to the front of the vehicle 12. Lifting apparatus of similar nature is illustrated and described in detail in Patent No. 2,900,096, issued August 18, 1959.

Normally, the cover 22 is closed over the hopper opening 18; however, when the lifting apparatus 60 is actuated to swing the container 10into dumping position, the cover 22 automatically swings to its open position illustrated in FIG. 1. Then, when the hoisting apparatus 60 is actuated to lower the container 10, the cover 22 is actuated to swing to its closed position. A hydraulic system for actuating the hoisting apparatus 69 and the cover 22 is illustrated diagrammatically in FIG. 8. The hoisting apparatus 60 is under the control of the operator while he is located within the cab 14, but the opening and closing of the cover 22 is effected automatically without the attention of the operator. The hydraulic system includes a storage tank or reservoir 120 which may be mounted on the chassis 13 of the vehicle 12 and which contains fluid needed for use throughout the system. Suitable fluid conduits or lines are illustrated diagrammatically in FIG. 8 and such lines may be employed as necessary in connection with the several members of the control system. All lines, however, for the sake of clarity, have not been illustrated throughout the drawings.

Fluid from the reservoir 120 is supplied through a line 104 containing a manually operated valve 106 to a pump 108. This pump 108 may be of any suitable type neces sary for providing the needed fluid under pressure and may be driven by the power take off mechanism of the vehicle 12.

Fluid under pressure from the pump 108 is supplied to a relief valve 111. Excess fluid may return from the relief valve 111 through a line 112 and a line 114 back to the reservoir 120. Normally, however, fluid will pass from the relief valve 111 through a line 116 to a normally open cam operated valve 120, through a line 122, into a line 124 containing a check valve 126, through a line 128, and into a bank of control valves 130. The bank of control valves 130 may be located within the cab 14 in convenient reach of the operator. If desired, a similar bank of control valves may be located outside the vehicle 12, but this arrangement is not illustrated in FIG. 8.

The fluid under pressure will flow as previously described when the lifting arms 62 of the hoisting apparatus 60 are in the position illustrated in FIG. 1, for example, as when a container 10 is about to be hoisted to dumping position. The bank of control valves 130 contains separate valves 132, 134 and 136 for controlling the flow of fluid to the power devices 72 which raise and lower the lifting arms 62, to the power devices 98 which rotate the fork arms 110, and to a cylinder device 140 which actuates a packer mechanism within the body 16.

When fluid flows under pressure into the valve bank 130, the valve 132 may be moved to one position to allow fluid to pass into a line 142 and then into the rear of the cylinders 74 to raise the lifting arms 62, or, the valve 132 may be moved to another position to allow fluid to pass into a line 144 and then into the forward end of the cylinders 74 to lower the lifting arms 62.

The valve 134 may be moved to one position to allow fluid under pressure to pass through a line 146 and into the rear of cylinders 100 to rotate the fork arms 110 in a clockwise direction with reference to FIG. 1, or, the valve 134 may be moved to another position to allow fluid to pass through a line 148 into the forward end of the cylinders to rotate the fork arms in a counterclockwise direction.

The valve 136 may be moved to one position to allow fluid to pass through a line 150 and into the cylinder 149 to extend the packer mechanism toward the rear of the vehicle to pack the contents within the body 116, or, the valve 136 may be moved to another position to allow fluid to pass through a line 152 and into the cylinder to retract the packer mechanism towards the front of the body 16 so that material may be dumped into the body.

Fluid under pressure passing into the cylinder 140 through either the line 150 or the line 152 may overflow into either line 156 or 158 and then through a return valve 160. This fluid, instead of returning to the reservoir 120, may be returned to the cylinder 140 in order to keep the cylinder 140 full of fluid at all times. Excess fluid not needed to keep the cylinder full will be returned to the reservoir 120. A manually actuated valve 162 is provided in the line 150 for additional control of the flow of fluid to the cylinder 140.

The cam operated valve 120 is normally opened under the force of a spring within the valve to allow fluid to pass therethrough when the lifting arms 62 are in a lowered position. The valve 120 is actuated by a cam device to control the opening of the cover 22. The cam device 170 is located on the rear torque tube 64, as illustrated in FIGS. 4-7.

The valve 120 is mounted on the body 16 above the rear torque tube 64 between the lever arms 70 by a bracket 166. The cam member 170, which for example may be a curved plate member, is mounted between the pair of lever arms 70 in the manner illustrated in FIGS. 6 and 7. The cam 170 is positioned about the torque tube 64 so as to rotate with the torque tube 64.

The valve 120 has an actuating arm 172 equipped with a cam follower 174 which may engage the cam 170. The cam 170 and the cam follower 174 are positioned so that when the lifting arms 62 are lowered, the cam follower 174 is not engaged by the cam 170 (FIG. 7), and the valve 120 is open to allow fluid pressure to flow freely to the valve bank 130.

After the lifting cams 62 have been raised a short distance at the beginning of a dumping operation of the container 10, the torque tube 64 will be rotated and in turn the cam 170 will be moved into position to engage the cam follower 174 of the valve 120 (FIG. 6). The cam 1'70 and the cam follower 174 are positioned so that the cam 170 pushes in on the arm 172 of the valve 120 after the lifting arms 62 have been raised to a position wherein the container 10 has completed only part of its movement to its dumping position, for example, to a position above the cab 14. The free flow of fluid under pressure through the valve 120 will be stopped. Fluid under pressure, instead of flowing into the line 122, will be backed up and flow through a line into the forward end of the cylinder 38 of the power device 36.

This flow of fluid under pressure into the forward part of the cylinder 38 retracts the piston rod 40 into the cylinder causing the cover 22 to swing to its opened position. t this time, fluid will not flow through the line 122 to the valve bank 130. Movement of the lifting arms 62 will stop, even though the valve 132 is open. Similarly, the fork arms 110 may not be rotated even though the valve 134 is open. Under this condition the check valve 126 in the line 124 serves an important function by preventing a backward flow of fluid out of the cylinders 74 and 100 of the power devices 72 and 98. Thus, the lifting arms 62 are held in their partially raised position and the fork arms 110 are held motionless while fluid flows from the pump 108 through the line 180 into the forward end of the cylinder 38 to open the cover 22. During the time that the valve 120 is closed under action of the cam 170, excess fluid not flowing through the line 180 is returned to the reservoir 120 through a line 192 and the line 114.

A shut off valve 186 is mounted on top of the body 16 adjacent the power device 36 and immediately to the rear of the cover 22. This valve is provided with an arm 1-53 which is in position to be contacted and moved inwardly of the valve 136 when the cover 22 is moved upwardly to its completely opened position. Normally, the arm 183 extends outwardly from the valve 186 and the valve is closed under the force of a spring within the valve.

As fluid under pressure continues to flow through the line 18% into the forward end of the cylinder 38, the cover 22 continues its upward swinging movement until it strikes the arm 188 of the valve 186 thereby opening the valve 186. This opening of the valve 186 allows fluid to flow from the line 180 through a line 192, into the line 128, and then into the valve bank 130. With fluid pressure now being supplied from the pump through the valves 11% and 188 and to the valve bank 130, the power devices 72 are again supplied with fluid under pressure to continue moving the lifting arms 62 upwardly. The valves 132 and 134 may be actuated as necessary to swing the container to dumping position above the hopper opening 18. The cover 22 will be opened and the hopper opening 18 will be free to receive the material from the container 10. The valve 134 may be controlled to actuate the power devices 98 to rotate the fork arms 110, so that the container 10 will be inverted as illustrated by broken lines in FIG. 1. In addition, fluid can be supplied through line 150 or 152 under control of the valve 136 to the packer cylinder 140.

After the power devices 98 have been actuated to invert the container 10 to dump the contents through the hopper opening 13 into the body 16, the systemmay be actuated as follows in order to lower the lifting arms 62 to return the container 10 to the ground in front of the vehicle 16, during which time the cover will close automatically.

While fluid is flowing from the pump 108 through the lines 180, 192 and 123 to the valve bank 13f), the cylinder devices 98 can be actuated under control of the valve 134 to return the container 10 to a generally upright position. Then the power devices 72 can be actuated to begin swinging the lifting arms downwardly After the lifting arms 62 have traveled a predetermined distance downwardly, for example to a position where the container 11) is over the cab 14, the cam 170 and cam follower 174 will break contact, and the spring within the valve 120 will then move the valve to its opened position. With the valve 129 open again, fiuid is free to flow from the pump 103 through the valve 120, through lines 122, 124 and 128 to the valve bank 130.

Fluid under pressure in the line 122 divides and part flows into the line 124 and part flows into a line 1% to the rear of the cylinder 38. Fluid under pressure in the rear of the cylinder 38 extends the piston rod 49 causing the cover 22 to swing downwardly to its closed position. At this time, the lifting arms 62 have moved downwardly far enough to move the container 10 away from the hopper opening 18 and out of the way of the cover 22.

After the cover 22 has moved downwardly slightly, the arm 188 breaks contact with the cover 22 and the valve 186 is closed under the action of the spring within the valve thereby shutting off the flow of fluid through the line 192. All of the fluid flowing through the line 180 will go into the front of the cylinder 38. As fluid under pressure continues to flow through the line 196 into the rear portion of the cylinder 38, the cover 22 will continue to close. The rear face of the piston in the cylinder 33 has an effective area larger than the effective area of the front face thereby allowing fluid within the rear of the cylinder 38 to overbalance the fluid pressure within the front so as to force the piston rod 40 to its extended position. This keeps the cover 22 closed tightly.

With fluid flowing freely from the pump 108 through the valve 120 to the valve bank 130, the manually ac- 8 tuated valves 132, 134 and 136 may be controlled as desired to actuate the cylinder devices 72, 98 or 140. The fork arms and the lifting arms 62 can be actuated to disconnect the lifting apparatus 61) from the container 10 and the packer mechanism may be actuated to compress the material within the body 16. The vehicle 12 is ready to be driven to a new location where another full container such as the container 10 is located, and another dumping operation may be carried out in the same man ner. The vehicle 12 may continue from container to container until the body 16 is full. As necessary, the packer cylinder 141! may be actuated to compress the material within the container 16. After the body 16 is full, the vehicle may be driven to a dumping location where the rear door 21 may be unlatched, and the material dumped from the body 16 under the assistance of the packer mechanism by actuating the packer cylinder 140.

The control system gives the operator complete control over the dumping operation in a simple and effective manner. The operator may direct his full attention to the movement of the lifting arms and fork arms because of the automatic control of hopper cover. The timing of the opening and closing of the cover with respect to the position of the container is determined safely and positively due to the positional relationship of the cam and cam operated valve 120.

While the invention has been illustrated and described in one preferred embodiment, it is recognized that other variations and changes may be made therein without departing from the invention as set forth in the claims.

We claim:

l. in container handling equipment; including a body having an opening, arms for moving a container over the opening and away from the opening, control means for moving the arms, and a cover for the opening; a system for opening and closing the cover including a source of fluid pressure, cylinder means for moving the cover, means for conducting a flow of fluid from the source to the control means, means for changing the flow of fluid from the control means to the cylinder means to open the cover before the arms move the container over the opening, and second means for conducting a flow of fluid from the source to the control means after the cover is open.

2. In container handling equipment; including a body having an opening, arms for moving a container over the opening and away from the opening, control means .for moving the arms, and a cover for the opening; a system for opening and closing the cover including a source of fluid pressure, cylinder means for moving the cover, means for conducting a flow of fluid from the source to the control means, means for changing the flow of fluid from the control means to the cylinder means to open the cover before the arms move the container over the opening, second means for conducting a flow of fluid from the source to the control means after the cover is open, and means for conducting a flow of fluid from the source to the cylinder means to close the cover after the arms move the container away from the opening.

3. In a control system for a front end loader including a body mounted on a vehicle, said body having an opening in the top thereof; lifting arms pivotally mounted to the vehicle for vertical swinging movement; fork arms operatively mounted on the lifting arms for vertical rotational movement with respect thereto, the lifting arms and fork arms cooperating to lift a container above the opening and dump the contents thereof into the body; and a cover for the opening; the combination of fluid pressure means for controlling movement of the lifting arms and the fork arms; a cylinder assembly for moving the cover to open and close positions with respect to the opening in the body; a reservoir for fluid; a first, normally open valve; a pump for supplying fluid under pressure through the first valve to said fluid pressure means; a second. normally closed valve; means for closing the first valve in response to upward movement of the lifting arms to cause fluid to flow to the cylinder for opening the cover, the second valve positioned to be opened by the cover after the cover is open to allow fluid to flow from the pump through the second valve to said fluid pressure means; and means for opening the first valve in response to d-ownward movement of the lifting arms to allow fluid to flow through the first valve to the cylinder assembly for closing the cover.

4. In a control system for a front end loader including a body mounted on a vehicle, said body having an opening in the top thereof; lifting arms pivotally mounted to the vehicle for vertical swinging movement; fork arms operatively mounted on the lifting arms for vertical rotational movement with respect thereto, the lifting arms and fork arms cooperating to lift a container above the opening and dump the contents thereof into the body; and a cover for the opening; the combination of a first cylinder assembly for swinging the lifting arms; a second cylinder assembly for rotating the fork arms; a third cylinder assembly for moving the cover to open and close positions with respect to the opening in the body; a valve bank including separate valves for controlling the flow of fluid to the first and second cylinder assemblies; a reservoir for fluid; a first, normally open valve; a pump for supplying fluid under pressure through the first valve to the valve bank; a second, normally closed valve; and means for closing the first valve after predetermined upward swinging of the lifting arms to cause fluid to flow from the pump to one end of the third cylinder assembly for opening the cover, the second valve positioned to be opened by the cover after the cover is open to allow fluid to flow from the pump through the second valve to the valve bank, said means opening the first valve after predetermined downward swinging of the lifting arms to allow fluid to flow through the first valve to the other end of the third cylinder assembly for closing the cover.

5. In a control system for a front end loader including a body mounted on a vehicle, said body having an opening in the top thereof; lifting arms pivotally mounted to the vehicle for vertical swinging movement; fork arms operatively mounted on the lifting arms for vertical rotational movement with respect thereto, the lifting arms and fork arms cooperating to lift a container above the opening and dump the contents thereof into the body; and a cover for the opening; the combination or" a first cylinder assembly for swinging the lifting arms; a second cylinder assembly for rotating the fork arms; a third cylinder assembly for moving the cover to open and close position with respect to the opening in the body; a valve bank including separate valves for controlling the flow of fluid to the first and second cylinder assemblies; a reservoir for fluid; a first, normally open valve; a check valve; a pump for supplying fluid under pressure through the first valve, through the check valve, to the valve bank; a second, normally closed valve; and a cam movable with the lifting arms for closing the first valve after predetermined upward swinging of the lifting arms to cause fluid to flow from the pump to one end of the third cylinder assembly for opening the cover, the second valve positioned to be opened by the cover after the cover is open to allow fluid to flow from the pump through the second valve to the valve bank, the cam opening the first valve after predetermined downward swinging of the lifting arms to allow fluid to flow through the first valve to the other end of the third cylinder assembly for closing the cover.

References Cited by the Examiner UNITED STATES PATENTS 1,851,502 3/32 Ferris et a1. 2l4-16.l2 X 1,922,851 8/33 Howard 214-303 X 1,953,579 4/34 Zeuthen 214-302 X 2,101,067 12/37 Howard 214-303 X 2,170,932 8/39 Venema 214-303 X 2,826,318 3/58 Beasley 214-302 X 2,873,872 2/59 Zoller 214-303 2,877,910 3/59 Nelson 214-302 2,951,600 9/60 Dempster et a1 214-302 X FOREIGN PATENTS 1,229,167 9/60 France.

HUGO O. SCHULZ, Primary Examiner. MORRIS TEMIN, Examiner.

Claims (1)

1. IN CONTAINER HANDLING EQUIPMENT; INCLUDING A BODY HAVING AN OPENING, ARMS FOR MOVING A CONTAINER OVER THE OPENING AND AWAY FROM THE OPENING, CONTROL MEANS FOR MOVING THE ARMS, AND A COVER FOR THE OPENING; A SYSTEM FOR OPENING AND CLOSING THE COVER INCLUDING A SOURCE OF FLUID PRESSURE, CYLINDER MEANS FOR MOVING THE COVER, MEANS FOR CONDUCTING A FLOW OF FLUID FROM THE SOURCE TO THE CONTROL MEANS, MEANS FOR CHANGING THE FLOW OF FLUID FROM THE CONTROL MEANS TO THE CYLINDER MEANS TO OPEN THE

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