ARTICULATED FRONT LOADER ARM MECHANISM FOR USE WITH A CONVENTIONAL REFUSE COLLECTION EXTENDED CAB CHASSIS

Abstract

An articulated front loader arm structure is provided for use with a conventional refuse collection vehicle having a conventional cab chassis. The articulated arm structure is controlled by a programmed logic controller (PLC) which for monitors and controls the movement of the front loader articulated arm structure. The PLC communicates with various cylinders and sensors to control the extension/retraction of the various cylinders associated with the various arm sections of the front loader arm structure during movement through both its container dump cycle and its container return cycle. The articulated arm structure allows the present front loader arm mechanism to both extend over a conventional cab chassis as well as to be stored on top of the refuse vehicle under the current legal height restriction of 13 feet, 6 inches.

Claims

1. An articulated front loader arm structure for use with a refuse collection vehicle having a conventional cab compartment and a storage compartment, the articulated front loader arm structure being engagable with a dumpster for emptying the contents of the dumpster into the storage compartment of the vehicle, the articulated front arm loader structure comprising: a forklift assembly including a pair of forklift arms for engaging a dumpster; a pair of front arm sections pivotally attached to said forklift assembly; a pair of forklift cylinders attached to said forklift assembly and to said front arm sections for pivotally moving said forklift assembly relative to said front arm sections; a pair of rear arm sections pivotally attached to said front arm sections such that one of said pair of rear arm sections is attached to one of said pair of front arm sections, and the other of said pair of rear arm sections is attached to the other of said pair of front arm sections; a pair of arm hinge cylinders attached to said pair of front arm sections and to said pair of rear arm sections for pivotally moving said pair of front arm sections relative to said pair of rear arm sections; and a pair of arm lift cylinders attached to said pair of rear arm sections and to said refuse collection vehicle for pivotally moving said pair of rear arm sections relative to said refuse collection vehicle; said front loader arm structure being movable between a first position where a dumpster is engaged with the forklift assembly on a support surface at or near ground level and a second position where a dumpster is located over the storage area of the vehicle in a dump position; movement of said pair of front and rear arm sections and said forklift assembly being controlled by said arm hinge cylinders, said arm lift cylinders, and said forklift cylinders.

2. The articulated front loader arm structure of claim 1 wherein said forklift cylinders, said arm hinge cylinders, and said arm lift cylinders each include a position sensor for monitoring the extension and retraction of each of said respective cylinders during articulation of the front loader arm structure.

3. The articulated front loader arm structure of claim 1 including a programmable logic controller for monitoring and controlling the extension and retraction of said pair of arm lift cylinders, said pair of arm hinge cylinders, and said forklift cylinders relative to each other as the front loader arm structure moves during both a container dump cycle and a container return cycle.

4. The articulated front loader arm structure of claim 3 wherein said programmed logic controller monitors the extension and retraction of each respective cylinder during movement of the front loader arm structure through the use of sensors associated with each respective cylinder, said program logic controller being programmed to control movement of the front loader arm structure such that the front loader arm structure and any dumpster engaged therewith will not hit or otherwise make contact with the cab compartment associated with the refuse collection vehicle during both its container dump cycle and its container return cycle.

5. The articulated front loader arm structure of claim 1 including an angular position sensor attached to a terminal end portion of at least one of said pair of front arm sections and to said forklift assembly for measuring the angular position of said forklift assembly relative to said pair of front arm sections.

6. The articulated front loader arm structure of claim 5 including a programmed logic controller coupled to said angular position sensor, said programmed logic controller storing in its memory the angular position of said forklift assembly relative to said pair of front arm sections after said forklift assembly engages a dumpster at or near ground level.

7. The articulated front loader arm structure of claim 1 wherein said front loader arm structure can be positioned and oriented for road travel over the storage area of the refuse collection vehicle at a height which is below 13 feet, 6 inches.

8. The articulated front loader arm structure of claim 1 wherein said forklift assembly includes a pair of forklift arms, one of said pair of forklift arms being attached to one of said pair of front arm sections, and the other of said pair of forklift arms being attached to the other of said pair of front arm sections.

9. The articulated front loader arm structure of claim 8 wherein one of said pair of forklift cylinders is attached to one of said pair of forklift arms and to one of said pair of front arm sections and the other of said pair of forklift cylinders is attached to the other of said pair of forklift arms and to the other of said pair of front arm sections.

10. The articulated front loader arm structure of claim 1 wherein one of said arm hinge cylinders is attached to one of said pair of front arm sections and to one of said pair of rear arm sections and the other of said pair of arm hinge cylinders is attached to the other of said pair of front arm sections and to the other of said pair of rear arm sections.

11. The articulated front loader arm structure of claim 1 wherein one of said pair of arm lift cylinders is attached to one of said pair of rear arm sections and to said refuse collection vehicle and the other of said pair of arm hinge cylinders is attached to the other of said pair of rear arm sections and to said refuse collection vehicle.

12. A system for controlling an articulated front loader arm structure for use with a refuse collection vehicle having a conventional cab compartment and a storage compartment, the articulated front loader arm structure being engagable with a dumpster for emptying the contents of the dumpster into the storage compartment of the refuse collection vehicle, the system comprising: an articulated front loader arm structure comprising: a forklift assembly including a pair of forklift arms for engaging a dumpster; a pair of front arm sections pivotally attached to said forklift assembly such that one of said pair of forklift arms is attached to one of said pair of front arm sections, and the other of said pair of forklift arms is attached to the other of said pair of front arm sections; a pair of forklift cylinders attached to said forklift assembly and to said pair of front arm sections such that one of said pair of forklift cylinders is attached to one of said pair of forklift arms and to one of said pair of front arm sections, and the other of said pair of forklift cylinders is attached to the other of said pair of forklift arms and to the other of said pair of front arm sections, and at least one position sensor associated with at least one of said pair of forklift cylinders for monitoring the extension and retraction of at least one of said pair of forklift cylinders during articulation of the articulated front loader arm structure; a pair of rear arm sections pivotally attached to said pair of front arm sections such that one of said pair of rear arm sections is attached to one of said pair of front arm sections, and the other of said pair of rear arm sections is attached to the other of said pair of front arm sections; a pair of arm hinge cylinders positioned and located between said pair of front arm sections and between said pair of rear arm sections such that one of said pair of arm hinge cylinders is positioned and located between one of said pair of front arm sections and one of said pair of rear arm sections, and the other of said pair of arm hinge cylinders is positioned and located between the other of said pair of front arm sections and the other of said pair of rear arm sections, and at least one position sensor associated with at least one of said pair of arm hinge cylinders for monitoring the extension and retraction of at least one of said pair of arm hinge cylinders during articulation of the articulated front loader arm structure; a pair of arm lift cylinders positioned and located between said pair of rear arm sections and said refuse collection vehicle such that one of said pair of arm lift cylinders is positioned and located between one of said rear arm sections and between a first fixed point associated with said refuse collection vehicle, and the other of said pair of arm lift cylinders is positioned and located between the other of said pair of rear arm sections and between a second fixed point associated with said refuse collection vehicle, and at least one position sensor associated with at least one of said pair of arm lift cylinders for monitoring the extension and retraction of at least one of said arm lift cylinders during articulation of the articulated front loader arm structure; and a programmable logic controller (PLC) coupled in communication with said respective pairs of arm hinge cylinders, said arm lift cylinders and said forklift cylinders, and respectively with the at least one position sensor associated with said pair of arm hinge cylinders, said pair of arm lift cylinders, and said pair of forklift cylinders for monitoring and controlling the extension and retraction of each of said respective cylinders during articulation of the articulated front loader arm structure, said PLC controlling movement of the articulated front loader arm structure between a first position where a dumpster is engaged with said pair of forklift arms on a support surface at or near ground level and a second position where a dumpster is positioned and located over the storage area of the refuse collection vehicle in a dump position.

13. The system of claim 12 including an angular position sensor positioned and located between the terminal end portion of at least one of said front arm sections and said forklift assembly for measuring the angular position of at least one of said forklift arms relative to at least one of said front arm sections, said angular position sensor being in communication with said PLC.

14. The system of claim 13 wherein said PLC includes memory for storing the measured angular position of at least one of said pair of forklift arms relative to at least one of said pair of front arm sections when a dumpster is initially engaged on a support surface at or near ground level.

15. The system of claim 12 wherein the PLC continuously monitors and adjusts the extension and retraction of the pair of arm hinge cylinders relative to the extension and retraction of the pair of arm lift cylinders to ensure that the position of the respective cylinders stay within a pre-determined range programmed into the PLC during articulation of the articulated front loader arm structure, both from its first position to its second position and from its second position to its first position.

16. The system of claim 15 wherein the PLC will either slow down the retraction of the arm hinge cylinders or slow down the retraction of the arm lift cylinders as needed so as to keep the position of the respective cylinders within the pre-determined range programmed into the PLC during movement of the articulated front loader arm structure, both from its first position to its second position and from its second position to its first position.

17. The system of claim 12 wherein at a predetermined location during movement of the articulated front loader arm structure from its first position to its second position, the PLC will send a signal to the pair of forklift cylinders to further extend so as to keep a dumpster somewhat level with the ground during at least a portion of its movement towards its second position.

18. The system of claim 12 wherein an operator can control movement of the articulated front loader arm structure and can activate the PLC through any one of a control panel, a joy stick or other control mechanism located in the cab compartment.

19. The system of claim 12 wherein when said pair of arm lift cylinders and said pair of arm hinge cylinders reach full retraction, the articulated front loader arm structure will be located at its second position and a dumpster engaged with said forklift assembly will be located above the refuse collection vehicle and over the storage compartment.

20. The system of claim 19 wherein when the front loader arm structure reaches its second position, the PLC will send a signal to the pair of forklift cylinders to retract the forklift cylinders thereby rotating a dumpster located above the storage compartment so as to dump the contents of a dumpster into the storage compartment.

21. The system of claim 20 wherein after a dumpster is emptied, the PLC will send a signal to said forklift cylinders to initially extend said forklift cylinders a pre-determined amount to partially rotate a dumpster away from its dump position, and the PLC will also send a signal to partially extend the arm hinge cylinders a pre-determined amount while leaving the arm lift cylinders retracted.

22. The system of claim 21 wherein the initial extension of said forklift cylinders to a pre-determined amount is such that the angular orientation between at least one of said pair of forklift arms and the terminal end portion of at least one of said front arm sections will be the same as the angular orientation of at least one of said pair of forklift arms and the terminal end portion of at least one of said front arm sections when said fork assembly initially engaged a dumpster on a support surface at or near ground level.

23. The system of claim 21 wherein once said arm hinge cylinders extend a pre-determined amount during its extension after a dumpster has been emptied, the PLC will send a signal to said arm hinge cylinders to continue to extend while likewise sending a signal to said arm lift cylinders to begin their extension thereby starting movement of the articulated front loader arm structure from its second position to its first position.

24. The system of claim 12 wherein the articulated front loader arm structure can be positioned and oriented for road travel on top of the refuse collection vehicle and over the storage area at a height which is under 13 feet, 6 inches.

25. The system of claim 12 wherein communication between the PLC and the at least one position sensor associated with each of said pair of forklift cylinders, said pair of arm hinge cylinders and said pair of arm lift cylinders is a wireless communication.

26. The system of claim 12 wherein said pair of arm hinge cylinders reach full extension prior to said pair of arm lift cylinders reaching their full extension when the articulated front loader arm structure is moving from its second position to its first position.

27. The system of claim 12 wherein after the articulated front loader arm structure has completed its movement from its second position to its first position, the PLC is activated to signal the and lift cylinders, the arm hinge cylinders, and the forklift cylinders all to retract at a pre-programmed rate to a pre-determined position.

28. The system of claim 27 wherein said pre-determined position is a road travel stowed position on top of the refuse collection vehicle and over the storage compartment at a height which is under 13 feet, 6 inches.

29. The system of claim 28 wherein when the articulated front loader arm structure is in its road travel stowed position, all cylinders are fully retracted, and said pair of rear arm sections are positioned and located at the side of the storage compartment and below the top edge portion thereof.

30. The system of claim 12 including a user interface for enabling an operator to initiate movement of the front loader arm structure between its first position and its second position, and between its second position and its first position.

31. The system of claim 12 wherein communication between the PLC and the respective pairs of arm hinge cylinders, said arm lift cylinders and said forklift cylinders is a wireless communication.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0024] For a better understanding of the present invention, reference may be made to the accompanying drawings.

[0025] FIG. 1 is a side elevational view of a typical refuse collection vehicle having an COE cab compartment and being equipped with a typical known prior art front loader arm structure.

[0026] FIG. 2 is a perspective view of a typical refuse collection vehicle utilizing the present articulated front loader arm mechanism constructed in accordance with the teachings of the present invention.

[0027] FIG. 3 is a side elevational view of the refuse collection vehicle of FIG. 2 showing the present articulated front loader arm mechanism engaged with a refuse container at the beginning of its dump cycle.

[0028] FIG. 4 is a schematic diagram of one embodiment showing the operation of the PLC, position sensor, control panel and joystick for controlling and monitoring the movement of the lift, hinge and forklift cylinders and the present articulated front arm mechanism.

[0029] FIG. 5A is a partial side elevational view showing a first embodiment of the present position sensor associated with the terminal end portion of at least one front arm section and the forklift arms.

[0030] FIG. 5B is a partial side elevational view showing a second embodiment of the present position sensor associated with the terminal end portion of at least one front arm section and the forklift arms.

[0031] FIG. 6 is a partial side elevational view of FIG. 3 showing the present articulated front loader arm mechanism moving through a portion of the dump cycle.

[0032] FIG. 7 is a partial side elevational view of FIG. 3 showing the present articulated front loader arm mechanism moving through a further portion of the dump cycle.

[0033] FIG. 8 is a partial side elevational view of FIG. 3 showing the present articulated front loader arm mechanism at its dump position.

[0034] FIG. 9 is a partial side elevational view of FIG. 3 showing the present articulated front loader arm mechanism at the beginning of its return cycle.

[0035] FIG. 10 is a partial side elevational view of FIG. 3 showing the present articulated front loader arm mechanism moving through a portion of its return cycle.

[0036] FIG. 11 is a partial side elevational view of FIG. 3 showing the present articulated front loader arm mechanism moving through a further portion of its return cycle.

[0037] FIG. 12 is a partial side elevational view similar to FIG. 3 showing the present articulated front loader arm mechanism at its returned ground level position.

[0038] FIG. 13 is a side elevational view similar to FIG. 3 showing the present articulated front loader arm mechanism in its stowed road travel position.

DETAILED DESCRIPTION OF THE INVENTION

[0039] FIG. 2 illustrates a refuse collection vehicle 30 having a chassis including a conventional operator or cab compartment 32 and a storage compartment 34 in which refuse is dumped and collected during the refuse collection process described below. The storage compartment 34, which is substantially similar to storage compartment 16 described above, is generally rectangular in shape, though in alternative embodiments the storage compartment 34 could take on a different shape. The refuse collection vehicle 30 includes on its front portion the present articulated front loader arm mechanism 36. The construction and operation of the articulated front loader arm mechanism 36 allows the present mechanism to extend over a conventional refuse collection cab compartment such as cab compartment 32, rather than a COE, an LCOE or other modified cab compartment. In addition, the articulated front loader arm mechanism 36 can be positioned and oriented for road travel on top of the refuse vehicle 30 and over the storage compartment 34 at a height under the current legal height restriction of 13 feet, 6 inches for refuse collection vehicles as will be hereinafter further explained.

[0040] FIG. 3 illustrates the refuse collection vehicle 30 and the present articulated front loader arm mechanism 36 from a side elevational view, thus showing only one side of the collection vehicle 30 and one side of the articulated front loader arm mechanism 36. Because of their symmetrical construction, the opposite side of collection vehicle 30 and the opposite side of the articulated front loader arm mechanism 36 not illustrated in FIG. 3 are substantially similar to the sides shown in FIG. 3. FIG. 2 illustrates this symmetry.

[0041] The front loader arm mechanism 36 includes a pair of front arm sections 38 positioned and located on either side of vehicle 30. The front arm sections 38 are pivotally attached to a pair of rear arm sections 40 via a pair of first pivot arm assemblies 42. The pivot arm assemblies 42 pivotally attach the arm sections 38 and 40 to one another and also allow for the angular rotation of arm sections 38, 40 relative to one another. A pair of arm hinge cylinders 44 positioned and located between the front arm sections 38 and the rear arm sections 40 allow the front arm sections 38 to angularly move relative to the rear arm sections 40 when the front loader mechanism 36 is in operation as will be described below. The arm hinge cylinders 44 may be hydraulically or pneumatically operated as well known and understood in the art.

[0042] The rear arm sections 40 are pivotally attached to the storage compartment 34 or to any other portion of the refuse collection vehicle 30 via a pair of second pivot arm assemblies 46. The rear arm sections 40 are further attached to a pair of arm lift cylinders 52. One end portion of the respective arm lift cylinders are attached to the refuse collection vehicle 30 at a first fixed point 48 and their opposite end portions are attached to the rear arm sections 40 at a second fixed point 50. The arm lift cylinders 52 operate to allow rear arm sections 40 to rotate toward the rear of the vehicle 30 during operation of the loader mechanism 36. Like the arm hinge cylinders 44, the arm lift cylinders 52 may be hydraulically or pneumatically operated as well known and understood in the art.

[0043] A forklift assembly 54 is likewise pivotally attached to the terminal end portion of the front arm sections 38 via a pair of third pivot arm assemblies 56. The forklift assembly 54 includes a pair of forklift arms 60 which can be positioned and maneuvered to engage a refuse container or dumpster 62 (as shown in FIGS. 3 and 6-12) so that refuse material contained within the dumpster 62 can be transferred to the storage compartment 34 associated with the refuse collection vehicle 30 via operation of the present articulated front loader arm mechanism 36. Movement of the forklift assembly 54 and its forklift arms 60 relative to the front arm sections 38 is controlled by a pair of forklift cylinders 64. The forklift cylinders 64 each have one end portion attached to a respective front arm section 38 and each have their opposite end portions attached to a respective flange 58 associated with the respective third pivot arm assemblies 56. Like cylinders 44 and 52, the fork cylinders 64 may also be either hydraulically or pneumatically operated.

[0044] In this regard, the present articulated front loader arm mechanism 36 is movable between a first position where a dumpster such as dumpster 62 engaged with the forklift assembly 54 via engagement means 66 on the dumpster 62 is resting on a support surface 68 at or near ground level, such as shown in FIG. 3, and a second position where the dumpster 62 is located over the storage compartment 34 of the vehicle 30 in a dump position, such as shown in FIG. 8. Movement of present arm mechanism 36 between its first and second positions is hereinafter referred to as the container dump cycle, and movement of the arm mechanism 36 from its second position back to its first position is hereinafter referred to as the container return cycle.

[0045] The schematic diagram of FIG. 4 illustrates the interaction and communication between the arm lift cylinders 52, the arm hinge cylinders 44, the forklift cylinders 64 and a programmed logic controller (PLC) 70 which measures, monitors, and controls the extension and/or retraction of the arm lift cylinders 52, the arm hinge cylinders 44, and forklift cylinders 64 as the present front loader arm mechanism 36 moves during both its container dump cycle and its container return cycle, The PLC 70 may be of the type commonly known or understood in the art, and thus should act as a digital computer used for automation. As an alternative to the PLC 70, any system controller or processor means which is able to monitor or control the extension and retraction of the cylinders 52, 44, 64 relative to each other may be used.

[0046] The PLC 70 or other system controller monitors and/or adjusts the position of the arm lift cylinders 52, the arm hinge cylinders 44, and forklift cylinders 64 during movement of the front loader arm mechanism 36 via its communication with an arm lift sensor 72, an arm hinge sensor 74, and a forklift sensor 76 as well as communication with the respective cylinders. The sensors 72, 74, and 76 may be of any type suitable for measuring the relative extension and retraction positions of the arm lift cylinders 52, the arm hinge cylinder 44 and the forklift cylinders 64 as well as the relative positions of the arm sections 40, 38 and/or the forklift assembly 54. The communication between the PLC 70 and the sensors 72, 74, and 76 via conductive paths 90, 92 and 94 and communication between the PLC 70 and the respective cylinders 52, 44 and 64 via conductive paths 91, 93 and 95 may be either of wired or wireless communication. The PLC 70 may be physically located in a number of different locations on the vehicle 30, such as in the cab compartment 32, where a user can operate the PLC 70. The sensors 72, 74, 76 are illustrated as associated with the cylinders 52, 44, 64 in FIG. 4, but in other embodiments, the sensors 72, 74, 76 may be built into the cylinders 52, 44, 64 or otherwise associated with the cylinders 52, 44, 64.

[0047] The sensors 72, 74, 76 ensure that the cylinders 52, 44, 64 do not retract and/or extend too quickly and thus cause uncontrolled and potentially dangerous movements of any of the rear arm sections 40, front arm sections 38, or the forklift assembly 54. The sensors 72, 74, 76 also measure the relative positions of the rear arm sections 40, front arm sections 38, and/or forklift assembly 54, and using a predetermined algorithm, the PLC 70 continuously monitors the cylinders 52, 44, 64 to ensure that the front arm sections 38 and the forklift assembly 54 and any refuse container or dumpster such as dumpster 62 engaged therewith do not hit or otherwise make contact with the hood area or the cab chassis 32 associated with the refuse vehicle 30 during its cycle movements.

[0048] The PLC 70 is also used to initiate and otherwise operate the arm mechanism 36 and its cylinders 52, 44, 64 during its dump cycle and its return cycle. PLC 70 may be operated to initiate the dump cycle, return cycle, or the operation of any of cylinders 52, 44, 64 by way of a user interface such as a control panel 78, a joystick 80 and/or other control mechanism compatible with the operation of the arm mechanism 36 as described herein (the schematic diagram of FIG. 4 illustrates this relationship). The control panel 78, joystick 80 and/or other control mechanism used to control the PLC 70 and the arm mechanism 36 are operatively connected to the PLC 70 via conductive paths 96 and/or 98 and are of a type known or foreseeable in the art able to be in electrical and/or data communication with the PLC 70. The control panel 78, joystick 80 and/or other control mechanism are preferably located in the cab chassis compartment where an operator is seated when operating the front loader and mechanism 36. The PLC 70, through user interfaces 78, 80 or other mechanisms, controls the respective cylinders 52, 44 and 64 via conductive paths 91, 93, 95 or some other known mechanism.

[0049] The PLC 70 also monitors and measures the angular position of the forklift arms 60 relative to the terminal end portion of at least one front arm section 38 through the use of a position sensor 82 associated with the forklift assembly 54 as shown in FIG. 5A. The position sensor 82 is illustrated in FIG. 5A as a rotary sensor 82. An alternative position sensor 84 is also illustrated in FIG. 5B as a linear sensor 84. Either of the position sensors 82 or 84 are in communication with the PLC 70 via conductive path 100 and either sensor may be any type so long as it is able to monitor and measure the angular position of the forklift arms 60 relative to the terminal end portion of at least one front arm section 38. Position sensors 82 or 84 and their relative functions during the operation of the articulated arm mechanism 36 are discussed in detail when further describing the operation of the articulated arm mechanism 36 below.

[0050] FIG. 3 illustrates a side elevational view of the loader arm mechanism 36 at the start of its container dump cycle. The container dump cycle starts with the present articulated front loader arm mechanism 36 being maneuvered and positioned by the vehicle operator using the control panel 78, the joystick 80, or some other interface mechanism to operate the PLC 70 such that the forklift arms 60 are at a height for engaging the engagement means 66 associated with a typical refuse container such as dumpster 62.

[0051] When the dumpster 62 is engaged with the forklift arms 60 via engagement means 66 in a manner known, the arm lift cylinders 52 are at or near full extension, the arm hinge cylinders 44 are at or near full extension, and the forklift cylinders 64 are extended so that the forklift arms 60 are engaged with the dumpster 62. After the dumpster 62 is engaged with the forklift assembly 54, the position sensor 82 or 84 (illustrated in FIGS. 5A and 5B) associated with the forklift assembly 54 measures the angular position of the forklift arms 60 relative to the terminal end portion of the front arm sections 38 and sends a signal to the PLC 70 via conductive path 100 including that angular position measurement, which the PLC 70 stores in a memory (not illustrated). The angular orientation measurement of the forklift arms 60 relative to the terminal end portion of the front arm sections 38 will again be used after the dumpster 62 has been dumped and the front loader arm mechanism 36 is maneuvered to start its return cycle.

[0052] When activated, the PLC 70 will first send a signal via conductive path 91 to retract the arm lift cylinders 52. The retracting of arm lift cylinders 52 allows front loader arm mechanism 36 with dumpster 62 attached thereto to initiate its movement upward towards its dump position. The dumpster 62 having begun its upward ascent is illustrated in FIG. 6, where arm lift cylinders 52 are shown in a partially retracted position. In this position, the arm lift cylinders 52 have reached a pre-determined location which coincides with the dumpster 62 being lifted to a pre-determined position such as just over the hood area of the vehicle 30. This pre-determined location which is read and measured by sensors 72, 74, 76 is sent to the PLC 70 via conductive paths 90, 92 and 94 which then will signal via conductive paths 93 the arm hinge cylinders 44 to start their retraction. The arm lift cylinders 52 beginning their retraction prior to the arm hinge cylinders 44 ensures that the front arm sections 38 and the refuse container 62 do not hit or otherwise make contact with the hood area of the vehicle 30 thus potentially damaging vehicle 30.

[0053] At the same time, when the refuse container 60 is at a position such as just over the hood area of the vehicle 30 or a different position and location pre-programmed into the PLC 70, the PLC 70 will send a signal via conductive path 95 to the forklift cylinders 64 to extend a pre-determined amount so as to keep the refuse container 62 somewhat level with the ground during this portion of its movement towards the dump position. If the forklift cylinders 64 did not extend as set forth above, the refuse container 62 would be angled inwardly toward the vehicle 30 to the point of risking dumping refuse prematurely onto the cab compartment or other parts of the vehicle 30 during its ascent to the dump position rather than in the storage compartment 34. This not only could defeat the purpose of the entire dump cycle, but it also could pose a danger to the operator within cab compartment 32 or cause damage to the vehicle 30.

[0054] Continuously throughout the duration of the container dump cycle, as the arm lift cylinders 52 and arm hinge cylinders 44 are retracted, the PLC 70 will monitor the location of the arm hinge cylinders 44 relative to the location of the arm lift cylinders 52 via conductive paths 90 and 92 to ensure that the respective positions of the cylinders are within a pre-determined range programed within the PLC and to further ensure that the cylinders are not retracting too quickly. If cylinders 52, 44 are moving too quickly or too slowly relative to one another, the dumping cycle could take place prematurely prior to reaching the storage compartment 34. This continuous monitoring is also necessary to ensure that the front arm sections 38, the forklift assembly 56, and the refuse container 62 engaged therewith will likewise clear the cab chassis 32 and any cab shield (not illustrated) positioned above the cab chassis during movement of the present articulated front loader arm mechanism 36 during the remainder portion of its travel toward the dump position as best illustrated in FIG. 7. FIG. 7 is a partial side elevational view showing the present arm mechanism 36 and attached dumpster 62 clear of the cab compartment 32 and moving through a further portion of the dump cycle.

[0055] In order to avoid the aforementioned undesirable scenarios, if the arm hinge cylinders 44 are not retracting within the pre-determined range programmed into the PLC 70 during the dump cycle, the PLC 70 will either slow down the retraction of the arm hinge cylinders 44 or slow down the retraction of the arm lift cylinders 52 as needed. That way the respective front and rear arm sections 38, 40 remain within a pre-determined range so that no portion of the front loader arm mechanism 36 or the dumpster 62 will contact and/or damage any portion of the refuse vehicle 30. It is the articulation between the front and rear arm sections 38, 40 of the present front loader arm mechanism 36 that allows the present mechanism 36 to be fabricated such that it is able to extend over a conventional refuse collection cab chassis such as cab chassis 32.

[0056] After some time of retracting, the arm lift cylinders 52 and the arm hinge cylinders 44 reach full retraction, and the refuse container 62 is located above the refuse vehicle 30 and over the storage compartment 34, as shown in FIG. 8. It is at this moment that the PLC 70 sends a signal to the forklift cylinders 64 via conductive path 95 to retract the forklift cylinders 64 thereby rotating the dumpster 62 toward the rear of the vehicle. The contents of the refuse container or dumpster 62 are then dumped into the storage compartment 34 as illustrated in FIG. 8.

[0057] After the refuse container is emptied, the PLC 70 will again send a signal to the forklift cylinders 64 to extend the forklift cylinders 64 to initiate the rotation of the refuse container 62 away from its dump position. The PLC 70 will also simultaneously send a signal to the arm hinge cylinders 44 via conductive path 93 to begin extending, while leaving the arm lift cylinders 52 retracted. This allows the front arm section 38 to clear itself away from the top of the refuse vehicle 30 before the container return cycle is initiated, as shown in FIG. 9.

[0058] Next, the PLC 70 further instructs the forklift cylinders 64 via conductive path 95 to extend to the same angular position between the forklift arms 60 and the terminal end portion of the front arm sections 38 measured by the position sensor 82 or 84 previously stored in the PLC at the initiation of the dump cycle. The forklift arms 60 having returned to the stored angular position relative to the front arm sections 38 shown at the start of the dump cycle in FIG. 3 is again shown in FIG. 9. In this angular position, the dumpster 62 will be substantially parallel to the ground surface when the dumpster 62 is returned to its starting position as illustrated in FIG. 12. Depending on how the PLC 70 is programmed, the forklift cylinders 64 may extend such that the forklift arms 60 are completely returned to the stored angular position relative to the front arm section 38 before the arm hinge cylinders 44 extend rather than the arm hinge cylinders 44 extending at the same time as the forklift cylinders 64.

[0059] After the arm hinge cylinders 44 reach a pre-determined location which is stored in the PLC 70 during extension after the dump cycle has been completed, the PLC 70 will signal the arm hinge cylinders 44 via conductive path 93 to continue to extend while likewise signaling the arm lift cylinders 52 via conductive path 91 to initiate their extension. These signals from the PLC 70 initiate the return cycle of the front loader arm mechanism 36. FIG. 10 is a partial side elevational view showing the present arm mechanism 36 moving through a portion of its return cycle.

[0060] As with the dump cycle, the PLC 70 continuously monitors the location of the arm lift cylinders 52 and the arm hinge cylinders 44 relative to one other during its return cycle. This continuous monitoring allows the PLC 70 to again ensure that the correct relationship between the cylinders 52, 44 is maintained throughout the entire return cycle. If necessary, the PLC 70 can instruct one or both of the cylinders 52, 44 to extend at an increased or decreased rate in order to prevent the dumpster 62, forklift assembly 54 and/or the front arm sections 38 of the present arm mechanism 36 from contacting and/or causing damage to any portion of the vehicle 30 including its cab compartment 32 during the return cycle.

[0061] Preferably, the arm hinge cylinders 44 will reach full extension when the refuse container 62 is generally over the hood area of the vehicle 30, prior to the arm lift cylinders 52 reaching their full extension. The arm hinge cylinders 44 having reached full extension prior to the arm lift cylinders 52 having reached full extension is shown in FIG. 11.

[0062] FIG. 12 shows completion of the return cycle, with the arm lift cylinders 52 continuing to extend until the refuse container 62 is on the ground. At this moment the vehicle 30 is able to reverse away from the dumpster 62 such that the forklift arms 60 disengage the dumpster 62 and its engagement means 66. The PLC 70 may then signal the arm lift cylinders 52, arm hinge cylinders 44, and forklift cylinders 64 via conductive paths 91, 93 and 95 to all retract at a preprogrammed rate to a pre-determined position after the return cycle has been completed. One such position can be a road travel position located on top of the refuse vehicle and over the storage area 34 as best illustrated in FIG. 13. The cylinders 52, 44, and 64 retract at a rate which prevents the front arm sections 38 and/or forklift assembly 56 from making contact and/or damaging the hood or cab compartment 32 of vehicle 30. Thus, the arm lift cylinders 52 preferably retract first such that the front arm sections 38 and forklift assembly 56 are lifted upwardly away from the cab chassis 32. Movement of the front loader arm mechanism 36 to its road travel position can also be accomplished by activating the dump cycle with no dumpster engaged, with the front loader arm mechanism 36.

[0063] Once the articulated front loader arm mechanism 36 is in its fully stowed position, the vehicle 30 is prepared for road travel. FIG. 13 illustrates the articulated front loader arm mechanism 36 in its fully stowed position. In the fully stowed position, all cylinders 52, 44, and 64 are fully retracted, and the rear arm sections 40 are positioned and located at the side of the storage compartment 34, and below the top edge portion of the storage compartment 34. In the stowed position, the front arm sections 38 and forklift assembly 56 are positioned and located just above the storage compartment 34. The front arm sections 38 as well as the forklift assembly 54 are stowed on top of the refuse vehicle 30 and over the storage compartment 34 at a height which is under the current legal height restriction of 13 feet 6 inches for refuse collection vehicles such as vehicle 30.

[0064] It is because of the articulation between the front and rear arm sections 38 and 40 the present arm mechanism 36 can both extend over a conventional cab chassis and retract to a storage position on top of the vehicle for road travel and still stay below the current legal height restriction of 13 feet 6 inches for refuse collection vehicles. It is the arm hinge cylinders 44 that allow for the novel articulation of the arm mechanism 36 as explained above.

[0065] From the foregoing, it will be seen that the various embodiments of the present invention are well adapted to attain all the objectives and advantages hereinabove set forth together with still other advantages which are obvious and which are inherent to the present structures. Since many possible embodiments of the present invention may be made without departing from the spirit and scope of the present invention, it is to be understood that all disclosures herein set forth or illustrated in the accompanying drawings are to be interpreted as illustrative only and not limiting. The various constructions described above and illustrated in the drawings are presented by way of example only and are not intended to limit the concepts, principles and scope of the present invention.

[0066] Thus, there has been shown and described several embodiments of a novel articulated front loader arm mechanism. As is evident from the foregoing description, certain aspects of the present invention are not limited by the particular details of the examples illustrated herein, and it is therefore contemplated that other modifications and applications, or equivalents thereof, will occur to those skilled in the art. The terms “having” and “including” and similar terms as used in the foregoing specification are used in the sense of “optional” or “may include” and not as “required.”

[0067] Many changes, modifications, variations and other uses and applications of the present constructions will, however, become apparent to those skilled in the art after considering the specification and the accompanying drawings. All such changes, modifications, variations and other uses and applications which do not depart from the spirit and scope of the invention are deemed to be covered by the invention which is limited only by the claims which follow.