US3321094A

US3321094A - Control for materials handling apparatus

Info

Publication number: US3321094A
Application number: US463216A
Authority: US
Inventors: Daniel B Shore
Original assignee: International Harverster Corp
Current assignee: Dresser Industries Inc
Priority date: 1965-06-11
Filing date: 1965-06-11
Publication date: 1967-05-23
Anticipated expiration: 1984-05-23
Also published as: GB1152022A

Description

y 3, 1967 D. B. SHORE 3,321,094

CONTROL FOR MATERIALS HANDLING APPARATUS Filed June 11, 1965 55 7ZiZ/8hfi7f jam/'66 15. Share United States Patent Ofilice 3,321,094 Patented May 23, 1967 This invention relates to control means and in particular to control means for controlling apparatus such as materials handling apparatus.

In one form of materials handling scraper apparatus an elevator conveyor is provided for elevating scraped materials such as earth materials upwardly and rearwardly into a collecting bowl. Such elevator type scrapers provide an improved operational efficiency in eliminating the need for the scraper itself to force the scraped materials rearwardly through the bowl as the scraper is dragged through the surface of the terrain. When the bowl is filled, it may be suitably delivered to a point of discharge whereupon an ejector is moved forwardly from the rear of the bowl to the open front end thereof thereby pushing the collected earth material outwardly from the bowl. As the elevator conveyor, in its operative position, extends across the front end of the bowl, it is necessary to remove the elevator conveyor from this position when the ejector is moved forwardly. In one form of such scraper apparatus, the conveyor is elevated by a hydraulic motor to a retracted position to permit the desired free forward movement of the ejector, the movement of the ejector being similarly effected by a hydraulic motor. The present invention comprehends an improved control means for use with such hydraulic motors, providing a positive synchronization of the disposition of the conveyor and ejector so as to preclude interferring movement therebetween while yet providing facilitated operation of the materials handling apparatus.

Thus, a principal feature of the present invention is the provision of a new and improved means for controlling a plurality of hydraulic motors, such as for use in -a ma terials handling apparatus.

Another feature of the invention is the provision of such a control means arranged to control the operation of a pair of hydraulic motors in a novel and simple manner effectively precluding interference between the elements driven by the motors.

A further feature of the invention is the provision of such a control means which is extremely simple and economical of construction while yet providing positive foolproof operation of the apparatus.

Still another feature of the invention is the provision of such a control means comprising an improved simplified hydraulic control system.

Another feature of the invention is the provision of such an improved control system in a materials handling apparatus including conveyor means for moving materials,

first hydraulic means for selectively disposing at least a portion of the conveyor means at a first, materials mov ing position and a second, retracted elevated position,

ejector means for moving materials, second hydraulic means for selectively moving at least a portion of the ejector means between a third, retracted position and a fourth, eject position, and a source of pressurized hydraulic fluid.

A yet further feature of the invention is the provision of such a control means for use in such a materials handling apparatus including first control means for conducting pressurized fluid from the source to the first hydraulic means to move the conveyor means from the first position to the second position, second cam operated hydraulic control means for sensing the disposition of the conveyor means, third control means for conducting pressurized fluid from the source to the second hydraulic means to move the ejector means to the fourth position, the third control means permitting movement of the ejector means to the fourth position only in the event that the second cam operated hydraulic control means senses disposition of the conveyor means at the second position, fourth cam operated hydraulic control means for sensing the disposition of the ejector means, and fifth control means for releasing the first hydraulic means to permit the conveyor means to move from the second, elevated position to the first position, the fifth control means permitting movement of the conveyor means to the first position only in the event that the fourth cam operated hydraulic control means senses disposition of the ejector means at the third position.

Still another feature of the invention is the provision of a materials handling apparatus including first means for moving materials, second means for selectively disposing at least a portion ofthe first means at first and second positions, third means for moving materials, and fourth means for selectively disposing at least a portion of the third means at a third position and at a fourth position, means for controlling operation of the apparatus comprising, first control means for causing operation of the second means to move the first means from the first position to the second position, second control means for sensing the disposition of the first means, third control means for causing operation of the fourth means to move the third means to the fourth position, the third control means permitting movement of the third means to the fourth position only in the event that the second control means senses disposition of the first means at thesecond position, fourth control means for sensing the disposition of the third means, and fifth control means for causing operation of the second means to move the first means from the second position to the first position, the fifth control means permitting movement of the first means to the first position only in the event that the fourth control means senses disposition of the third means at the third position.

Other features and advantages of the invention will be apparent from the following description taken in connection with the accompanying drawings wherein:

FIGURE 1 is a fragmentary schematic elevation of a materials handling apparatus provided With a control means embodying the invention;

FIGURE 2 is a fragmentary schematic elevation gen erally similar to that of FIGURE 1, but illustrating the arrangement of the conveyor in a retracted position with the ejector at a forward ejecting position; and

FIGURE 3 is a combination mechanical-schematic illustration of the control means.

In the exemplary embodiment of the invention as disclosed in the drawing, a materials handling apparatus generally designated 10 is shown schematically to include a bowl 11 movably carried on a wheel 12 and provided with a scraper blade 13 for scraping dirt upwardly and rearwardly into the bowl 11 as the bowl is moved forwardly along the ground G by a suitable tractor having a rear portion 14 connected to the bowl by a gooseneck 15 of conventional construction.

Apparatus may be further provided with an elevator conveyor generally designated 16 of conventional construction arranged to convey upwardly and rearwardly into the bowl 11 the earth material scraped by the scraper 13 from the surface of ground G. As shown in FIGURE 1, the conveyor 16 includes a first portion 17 which is disposed closely adjacent the scraper 13 in the operative position of the conveyor. When the bowl is filled with the collected material and moved to a suitable discharge location, the earth material is removed from the bowl by means of an ejector 18 which is moved from a rearward retracted position, as shown in FIGURE 1, to a forward ejecting position, as shown in FIGURE 2. As further shown in FIGURE 2, the conveyor 16 is repositioned at this time in an upper retracted position so as to preclude interference with the ejector 18 as it moves to the ejection position. Upon completion of the ejecting operation, the ejector 18 moves rearwardly from the position of FIGURE 2 to the retracted position of FIGURE 1. Upon restoration of the ejector 18 to the retracted position, the conveyor 16 may then be lowered to the conveying position of FIGURE 1 to reestablish the apparatus for further scraping operation.

In the illustrated embodiment, the conveyor 16 is moved from the conveying position of FIGURE 1 to the retracted position of FIGURE 2 by means of a hydraulic motor 19 connected to the conveyor by a suitable linkage generally designated 20. Herein the hydraulic motor 19 comprises a piston and cylinder device. The ejector 18 is moved between its retracted and forward positions by means of a second hydraulic motor 21. As discussed briefly above, the present invention comprehends an improved control means for synchronized operation of the

hydraulic motors

19 and 21 to provide the above discussed selective positioning of the conveyor 16 and ejector 18 in a novel and simple manner.

More specifically, as shown in FIGURE 3, the hydraulic motor 18 comprises a cylinder 22 defining a chamber 23 in which is movably disposed a piston 24 provided with a piston rod 25 extending slidably outwardly through the cylinder 22. A control valve 26 of conventional construction is provided for controlling the delivery of pressurized hydraulic fluid to the cylinder chamber 23. The source of the pressurized hydraulic fluid herein may comprise a conventional pump 27 for pumping the hydraulic fluid from a return 28 through a conduit 29 to the valve 26. The valve 26 may include a conventional relief valve 30 for recirculating the'pressurized fluid back to the return 28 in the event that other deliveries of the fluid from the valve are blocked. The valve includes a conventional actuator 31 for selectively directing the pressurized hydraulic fluid from conduit 29 to a conduit 32 connected to an inlet chamber 33 of a slave valve 34. The slave valve includes a housing 35 defining in addition to chamber 33 a check valve chamber 36 in which a check valve 37 is provided being biased to a closed position against a valve seat 38 by means of a coil spring 39. The valve seat 38 defines a passage 40 communicating with the inlet chamber 33. The chamber 36 is connected in fluid communication with the cylinder chamber 23 by a conduit 41. Thus, when valve 26 is positioned to permit flow of pressurized fluid from pump 27 to conduit 32, the fluid may normally flow from conduit 32 through inlet chamber 33 past check valve 37 and through conduit 41 into the lower end of cylinder chamber 23, thereby moving the piston 24 upwardly as shown in FIGURE 3 and raising the conveyor 16 from the position of FIGURE 1 to the position of FIGURE 2. Hydraulic fluid above the piston 24 is delivered through a return conduit 42 to the return 28 during this operation.

The ejector hydraulic motor 21 comprises a cylinder 43 defining a chamber 44 in which is movably disposed a piston 45 carried on the inner end of a piston rod 46 extending slidably outwardly through the cylinder 43 and connected to the ejector 18 at its outer end for movement of the ejector with the piston. Movement of the piston 45 to the left, as seen in FIGURE 3, is caused by the introduction of pressurized hydraulic fluid into the righthand end of chamber 44 through a conduit 47 connected to a chamber 48 in slave valve 34. A passage 49 interconnects chamber 48 with inlet chamber 33 of the slave valve. The passage is normally closed by a spool valve member 50 having one end slidably receivable in passage 49 and biased to this position by a coil spring 51 received in a well 52 in the slave valve housing 35 at the opposite side of inlet chamber 33. An actuator 53 is provided on the opposite end of the valve 50 being connected thereto by a stem 54 passing through the chamber 48 so as to have an outer end 55 of the actuator disposed exteriorly of the slave valve housing 35. Attached to the piston rod 25 is a cam 56 which bears against the actuator portion 55 and which includes an enlarged portion 57 moving the actuator to the left, as seen in FIGURE 3, when the piston 24 is in an uppermost position, as shown in FIGURE 2. Such movement of the actuator to the left as shown in FIGURE 3, repositions valve member 50 to provide communication between chambers 33 and 48 and thereby provide communication between the righthand end of ejector cylinder chamber 44 and conduit 32.

Under these circumstances, pressurized fluid in cylinder chamber 23 maintains the conveyor in an elevated position or check valve 37 prevents the elevator from dropping if the pressure in chamber 33 is less than the pressure required to elevate the conveyor. Concurrently, the pressurized fluid is delivered to the righthand end of ejector cylinder chamber 44, thereby causing the piston 45 to move to the left as shown in FIGURE 3, and correspondingly move the ejector 18 from the retracted position of FIGURE 1 to the ejecting position of FIGURE 2. Thus, in effect, actuator portion 55 comprises a sensing means which cooperates with the valve 50 to permit a movement of the ejector 18 to the ejecting position adjacent the scraper 13, as shown in FIGURE 2, only when the conveyor 16 is in the elevated, retracted position.

Upon completion of the ejecting operation, the operator may return the ejector to the retracted position by suitably actuating valve operator 31 to connect the conduit 29 to a conduit 58, in turn connected to the lefthand end of ejector cylinder chamber 44 by a distribution conduit 59. Thus, the piston 45 is moved to the right by the introduction of the pressurized fluid to the lefthand end of the chamber 44, the fluid at the righthand end of the chamber being returned to the conduit 32 as the valve 50 is maintained in the open position wherein communication is provided through passage 49 from chamber 48 to chamber 33. V

In addition to positively precluding movement of the ejector 18 to the lefthand ejecting position of FIGURE 2 in the event that the conveyor 16 is not suitably removed from the conveying position, it is desirable to preclude lowering of the conveyor 16 to its operating position as shown in FIGURE 1 in the event that the ejector is not suitably removed from the ejecting position shown in FIGURE 2. The lowering of the conveyor 16 [is prevented under these conditions by the closed check valve 37 as the hydraulic fluid in chamber 23 below piston 24 cannot flow reversely through passage 40 into chamber 33. When the ejector 18 is in the fully retracted position, however, it is desirable to automatically effect the return of the conveyor to the operating position. For this purpose, a valve 60 is provided having a housing 61 defining an inlet chamber 62 connected to conduit 58 by a second distribution conduit 63. The housing further defines an outlet chamber 64 and a passage 65 connecting chambers 62 and 64 and normally closed by a valve memher 66 which is biased to the closed position by a suitable coil spring 67 received in a well 68 in the lower end of the housing 61. An actuator 69 is connected to the valve by a stem 70 and is provided with an outer end portion 71 engaging a cam 72 carried on the outer end of the piston rod 46 and having an enlarged end portion 73. When the piston 45 is in its righthand-most position with the ejector inthe fully retracted position as shown in FIGURE 1, the cam portion 73 depresses actuator portion 71 sufliciently to move valve member 66 downwardly from passage 65 and permit fluid flow between chamber 62 and chamber 64. The fluid may then flow outwardly from chamber 64 through a conduit 74 to a chamber 75 in slave valve housing 35 in which is received a cup-shaped spool valve member 76 provided with a finger 77 extending across inlet chamber 33 to adjacent check valve 37. Delivery of pressurized fluid to within the internal space 78 of the cup-shaped member 76 urges the cup-shaped member to the right as seen in FIGURE 3 and causes finger 77 to move check valve member 37 from the valve seat 38 and thereby permit fluid flow from the lower end of chamber 23 back to conduit 32 and thereby permit piston 24 to move downwardly under the urging of the weight of conveyor 16. Thus, the conveyor is automatically restored to the operating position of FIGURE 1 upon the completion of the movement of the ejector 18 to the retracted position of FIGURE 1. The cup-shaped member 76 may be provided with suitable ports 79 to return the pressurized fluid to conduit 32 from conduit 74 once the finger -77 is moved to the position wherein it holds check valve 37 open.

Thus, in effect, the actuator portion 71 comprises sensing means which cooperates with the valve 66 to permit movement of the piston 24, and thus conveyor 16, to the lower position of FIGURE I automatically only when the ejector is removed from the ejecting position of FIGURE 2 to the noninterferring retracted position of FIGURE 1.

Thus, apparatus comprehends an improved materials handling apparatus wherein hydraulic motor means are controlled in a novel and simple manner to provide improved synchronized functioning of mechanisms such as conveyor and ejector mechanisms with undesirable interference between the mechanisms being effectively positively precluded and including means for automatically repositioning the mechanisms in certain stages of the operation thereof. The apparatus is extremely simple and economical of construction while yet providing long-lived foolproof and trouble-free functioning as discussed above.

While I have shown and described one embodiment of my invention, it is to be understood that it is capable of many modifications. Changes, therefore, in the construction and arrangement may be made without departing from the spirit and scope of the invention as defined in the appended claims.

I claim:

1. Ina materials handling apparatus including conveyor means for moving materials, first hydraulic means for selectively disposing at least a portion of said conveyor means at a first, materials moving position and a second, retracted elevated position, ejector means for moving materials, second hydraulic means for selectively moving at least a portion of said ejector means between a third, retracted position and a fourth, eject position, and a source of pressurized hydraulic fluid, means for controlling operation of said apparatus by said pressurized fluid comprising:

first control means for conducting pressurized fluid from said source to said first hydraulic means to move said conveyor means from said first position to said second position;

second cam operated hydraulic control means for sensing the disposition of said conveyor means;

third control means for conducting pressurized fluid from said source to said second hydraulic means to move said ejector means to said fourth position, said third control means permitting movement of said ejector means to said fourth position only in the event that said second cam operated hydraulic control means senses disposition of said conveyor means at said second position;

fourth cam operated hydraulic control means for sensing the disposition of said ejector means; and

fifth control means for releasing said first hydraulic means to permit said conveyor means to move from said second, elevated position to said first position, said fifth control means permitting movement of said conveyor means to said first position only in the event that said fourth cam operated hydraulic control means senses disposition of said ejector means at said third position.

2. The materials handling apparatus of claim 1 wherein said first hydraulic means comprises a hydraulic motor and said first control means comprises a check valve for conducting pressurized fluid from said source to said motor and normally precluding reverse flow therefrom, and said fifth control means comprises operator means for selectively holding said check valve open to permit reverse flow from said motor.

3. The materials handling apparatus of claim 1 wherein said second hydraulic means comprises :a hydraulic motor and said third control means comprises a valve for conducting pressurized fiuid from said source to said motor, means biasing said valve closed, and means responsive to said second cam operated hydraulic control means for selectively overcoming said biasing means to open said valve.

4. The materials handling apparatus of claim 1 Wherein said first hydraulic means comprises a hydraulic motor, said first control means comprises a check valve for conducting pressurized fluid from said source to said motor and normally precluding reverse flow therefrom, said fifth control means comprises operator means for selectively holding said check valve open to permit reverse flow from said motor, said second hydraulic means comprises a second hydraulic motor, said third control means comprises a valve for conducting pressurized fluid from said source to said second motor, means biasing said valve closed, and means responsive to said second cam operated hydraulic control means for selectively overcoming said biasing means to open said valve, and said means for controlling operation of said apparatus further includes means defining an inlet chamber for receiving pressurized fluid from said source and opening to each of said check valve and said third control means valve.

5. The materials handling apparatus of claim 1 wherein said source of pressurized fluid includes means for bypassing said second hydraulic means in the event said third control means is acting to prevent operation of said ejector notwithstanding delivery of pressurized fluid. thereto.

6. The materials handling apparatus of claim 1 wherein said first hydraulic means comprises a hydraulic motor and said first control means comprises :a check valve for conducting pressurized fluid from said source to said motor and normally precluding reverse flow therefrom, and said fifth control means comprises operator means for selectively holding said check valve open to permit reverse fiow from said motor, said operator means further including a pressure responsive actuator and a valve for selectively conducting pressurized fluid from said source to said actuator, means biasing said valve closed, and means responsive to said fourth cam operated hydraulic control means for selectively overcoming said biasing means to open said valve.

7. The materials handling apparatus of claim 1 where in said second hydraulic means comprises a hydraulic motor and said third control means comprises a valve for conducting pressurized fluid from said source to said motor, said valve including means responsive to said sec- 0nd cam operated hydraulic control means for selectively disposing said valve in open and closed positions.

8. The materials handling apparatus of claim 1 wherein said first hydraulic means comprises va hydraulic motor and said first control means comprises a check valve for conducting pressurized fluid from said source to said motor and normally precluding reverse flow therefrom, and said fifth control means comprises operator means for selectively holding said check valve open to permit reverse flow from said motor, said operator means further including a pressure responsive actuator and a valve for selectively conducting pressurized fluid from said source to said actuator, said valve including means responsive to 0 said fourth cam operated hydraulic control means for selectively disposing said valve in open and closed positions.

References Cited by the Examiner UNITED STATES PATENTS 2,379,536 7/1945 Mackenzie 911'89 2,956,353 10/ 1960 Hanner et a1 37- 8 3,244,078 4/1966 Kibble et -al. 91-189 X GERALD M. FORLENZA, Primary Examiner.

ROBERT G. SHERIDAN, Examiner.

Claims

1. IN MATERIALS HANDLING APPARATUS INCLUDING CONVEYOR MEANS FOR MOVING MATERIALS, FIRST HYDRAULIC MEANS FOR SELECTIVELY DISPOSING AT LEAST A PORTION OF SAID CONVEYOR MEANS AT A FIRST, MATERIALS MOVING POSITION AND A SECOND, RETRACTED ELEVATED POSITION, EJECTOR MEANS FOR MOVING MATERIALS, SECOND HYDRAULIC MEANS FOR SELECTIVELY MOVING AT LEAST A PORTION OF SAID EJECTOR MEANS BETWEEN A THIRD, RETRACTED POSITION AND A FOURTH, EJECT POSITION, AND A SOURCE OF PRESSURIZED HYDRAULIC FLUID, MEANS FOR CONTROLLING OPERATION OF SAID APPARATUS BY SAID PRESSURIZED FLUID COMPRISING: FIRST CONTROL MEANS FOR CONDUCTING PRESSURIZED FLUID FROM SAID SOURCE TO SAID FIRST HYDRAULIC MEANS TO MOVE SAID CONVEYOR MEANS FROM SAID FIRST POSITION TO SAID SECOND POSITION; SECOND CAM OPERATED HYDRAULIC CONTROL MEANS FOR SENSING THE DISPOSITION OF SAID CONVEYOR MEANS; THIRD CONTROL MEANS FOR CONDUCTING PRESSURIZED FLUID FROM SAID SOURCE TO SAID SECOND HYDRAULIC MEANS TO MOVE SAID EJECTOR MEANS TO SAID FOURTH POSITION, SAID THIRD CONTROL MEANS PERMITTING MOVEMENT OF SAID EJECTOR MEANS TO SAID FOURTH POSITION ONLY IN THE EVENT THAT SAID SECOND CAM OPERATED HYDRAULIC CONTROL MEANS SENSES DISPOSITION OF SAID CONVEYOR MEANS AT SAID SECOND POSITION; FOURTH CAM OPERATED HYDRAULIC CONTROL MEANS FOR SENSING THE DISPOSITION OF SAID EJECTOR MEANS; AND FIFTH CONTROL MEANS FOR RELEASING SAID FIRST HYDRAULIC MEANS TO PERMIT SAID CONVEYOR MEANS TO MOVE FROM SAID SECOND, ELEVATED POSITION TO SAID FIRST POSITION, SAID FIFTH CONTROL MEANS PERMITTING MOVEMENT OF SAID CONVEYOR MEANS TO SAID FIRST POSITION ONLY IN THE EVENT THAT SAID FOURTH CAM OPERATED HYDRAULIC CONTROL MEANS SENSES DISPOSITION OF SAID EJECTOR MEANS AT SAID THIRD POSITION.