Materials handling machine

Claim 2

A materials handling machine, comprising a flexible endless bucket train for digging, elevating and dumping loose materials, said bucket train including a plurality of spaced buckets with flexible tension elements therebetween, first, second, third and fourth wheels engaging and supporting said bucket train which passes over said first wheel, under said second wheel, over said third wheel and over said fourth wheel, said bucket train hanging freely along a catenary curve in a substantially vertical plane between said fourth and first wheels, said fourth and first wheels being spaced apart horizontally in planes closely similar to the plane of said catenary curve, and means for driving at least one of said wheels to circulate said bucket train in a direction to travel upwardly along said catenary curve to said first wheel, downwardly between said first and second wheels, upwardly between said second and third wheels, over said third and fourth wheels, and downwardly from said fourth wheel along said catenary curve, said bucket train being effective to dig any loose material disposed along said catenary curve, said first and third wheels being generally opposite each other and in different planes closely similar to the plane of said fourth wheel, said second wheel being in a plane extending at a considerable angle to the horizontal and transversely to the planes of said first and third wheels to produce dumping of said buckets between said first and second wheels.

Claim 3

A machine according to claim 1, in which said buckets are circular in cross section and disposed axialLy along said bucket train, said tension elements comprising flexible cable elements extending axially between said buckets.

Claim 4

A machine according to claim 1, in which said first and third wheels are generally at the same elevation and are in generally vertical planes converging at the locality of said fourth wheel.

Claim 5

A machine according to claim 1, in which said first and third wheels are in generally vertical planes which are generally parallel but converging at a small angle so as to meet in the locality of said fourth wheel.

Claim 6

A machine according to claim 1, in which said second wheel is in a generally vertical plane generally perpendicular to the planes of said first and third wheels.

Claim 7

A machine according to claim 1, in which said first and third wheels are generally at the same elevation and in generally vertical planes converging at a small angle, the plane of said third wheel being substantially the same as the plane of said fourth wheel, the plane of said first wheel being substantially the same as the plane of said catenary curve.

Claim 8

A machine according to claim 1, including a boom for supporting said fourth wheel, said boom being swingable about a generally horizontal axis to change the elevation of said fourth wheel relative to said first and third wheels.

Claim 9

A machine according to claim 7, in which said boom is swingable about an axis in the locality of said first and third wheels.

Claim 10

A machine according to claim 7, including mean for raising and lowering said boom by swinging said boom about said axis thereof.

Claim 11

A machine according to claim 1, including a boom for supporting said fourth wheel, said boom being swingable about a generally horizontal axis in the locality of said first and third wheels, and means for raising and lowering said boom by swinging it about said axis thereof to change the elevation of said fourth wheel.

Claim 12

A machine according to claim 10, in which said first and third wheels are in planes converging at a small angle so as to meet in the locality of said fourth wheel, said second wheel being in a generally vertical plane generally perpendicular to the planes of said first and third wheels.

Claim 13

A machine according to claim 10, in which said second wheel is on the remote side of said first and third wheels from said fourth wheel.

Claim 14

A machine according to claim 1, in which said second and fourth wheels are displaced in opposite directions from the position of said first and third wheels.

Claim 15

A machine according to claim 1, including means for collecting and conveying the material dumped from said buckets as said bucket train travels between said first and second wheels.

Claim 16

A materials handling machine, comprising a support, a boom having generally horizontal pivot means connecting the inner end of said boom to said support to provide for swinging movement of said boom in a generally vertical plane, a flexible endless bucket train for digging, elevating and dumping loose material, said bucket train including a plurality of spaced buckets and a plurality of flexible tension elements extending between said buckets, at least a first generally vertical wheel rotatably mounted in the locality of said pivot means, an additional wheel rotatably mounted on the outer end portion of said boom, said bucket train passing over said additional wheel and said first wheel and hanging freely along a catenary curve between said additional wheel and said first wheel, said first wheel and said additional wheel being disposed in generally vertical planes corresponding closely to the vertical plane of said catenary curve, and means for driving at least one of said wheels to circulate said bucket train in a direction to travel over said additional wheel, downwardly and then upwardly along said catenary curve to dig and elevate any loose material along said catenary curve, said bUcket train then travelling over said first wheel to dump the loose material from the buckets, said bucket train then travelling back to said additional wheel, said boom being swingable in a generally vertical direction about said pivot means to change the elevation of said additional wheel and thereby change the elevation of the bucket train along said catenary curve.

Claim 17

A materials handling machine, comprising a support, a boom having generally horizontal pivot means connecting the inner end of said boom to said support to provide for swinging movement of said boom in a generally vertical plane, a flexible endless bucket train for digging, elevating and dumping loose material, said bucket train including a plurality of spaced buckets and a plurality of flexible tension elements extending between said buckets, at least a first generally vertical wheel rotatably mounted in the locality of said pivot means, an additional wheel rotatably mounted on the outer end portion of said boom, said bucket train passing over said additional wheel and said first wheel and hanging freely along a catenary curve between said additional wheel and said first wheel, said first wheel and said additional wheel being disposed in generally vertical planes corresponding closely to the vertical plane of said catenary curve, and means for driving at least one of said wheels to circulate said bucket train in a direction to travel over said additional wheel, downwardly and then upwardly along said catenary curve to dig and elevate any loose material along said catenary curve, said bUcket train then travelling over said first wheel to dump the loose material from the buckets, said bucket train then travelling back to said additional wheel, said boom being swingable in a generally vertical direction about said pivot means to change the elevation of said additional wheel and thereby change the elevation of the bucket train along said catenary curve.

Claim 18

A machine according to claim 15, including suspension means on the upper portion of said support for suspending said support from a crane or the like.

Claim 19

A machine according to claim 15, including swivel suspension means connected to the upper portion of said support for suspending said support for swiveling movement about a generally vertical axis.

Claim 20

A machine according to claim 15, including a second rotatable wheel adjacent said first wheel for guiding said bucket train downwardly and then under said second wheel after passing over said first wheel, said second wheel causing the loose material to be dumped from said buckets.

Claim 21

A machine according to claim 15, including second and third rotatable wheels adjacent said first wheel, said bucket train being threaded over said first wheel, under said second wheel, over said third wheel, and then back to said additional wheel, the loose material being dumped from said buckets as they travel downwardly from said first wheel and under said second wheel.

Claim 22

A machine according to claim 19, in which said first and third wheels have rotary axes which in the locality of the pivot axis of said boom, said second wheel being disposed in a generally vertical plane transverse to the planes of said first and third wheels.

Claim 23

A material handling machine, comprising a flexible bucket train for digging and lifting loose materials, said bucket train including a plurality of buckets having a generally circular cross section, said bucket train including a plurality of flexible tension elements extending axially between said buckets, dumping means including first, second and third generally vertical wheels engaging and supporting said bucket train which passes over said first wheel, under said second wheel, and over said third wheel, a fourth generally vertical wheel spaced horizontally a considerable distance from said first wheel relative to the spacing between the buckets in the bucket train, said bucket train extending between said third and fourth wheels, over said fourth wheel, and then hanging freely along a catenary curve between said fourth and first wheels, means for driving at least one of said wheels to circulate said bucket train in a direction to travel downwardly and then upwardly along said catenary curve between said fourth and first wheels to dig and elevate any loose material engaged by said buckets along said catenary curve, over said first wheel and downwardly to said second wheel to dump the loose material from said buckets, under said second wheel and upwardly to said third wheel, and over said third wheel to said fourth wheel, said first and third wheels being generally opposite each other in different planes converging at a small angle so as to meet in the locality of said fourth wheel, said second wheel being in a generally vertical plane extending transversely to the planes of said first and third wheels, the plane of said second wheel intersecting the planes of said first and third wheels along the lines traversed by said bucket train in travelling between said first and second wheels and then between said second and third wheels, said second wheel being positioned on the opposite side of the position of said first and third wheels relative to the position of said fourth wheel whereby the buckets are dumped remotely from said catenary curve.

Claim 24

A material handling machine, comprising a flexible bucket train for digging and lifting loose materials, said bucket train including a plurality of buckets having a generally circular cross section, said bucket train including a plurality of flexible tension elements extending axially between said buckets, dumping means including first, second and third generally vertical wheels engaging and supporting said bucket train which passes over said first wheel, under said second wheel, and over said third wheel, a fourth generally vertical wheel spaced horizontally a considerable distance from said first wheel relative to the spacing between the buckets in the bucket train, said bucket train extending between said third and fourth wheels, over said fourth wheel, and then hanging freely along a catenary curve between said fourth and first wheels, means for driving at least one of said wheels to circulate said bucket train in a direction to travel downwardly and then upwardly along said catenary curve between said fourth and first wheels to dig and elevate any loose material engaged by said buckets along said catenary curve, over said first wheel and downwardly to said second wheel to dump the loose material from said buckets, under said second wheel and upwardly to said third wheel, and over said third wheel to said fourth wheel, said first and third wheels being generally opposite each other in different planes converging at a small angle so as to meet in the locality of said fourth wheel, said second wheel being in a generally vertical plane extending transversely to the planes of said first and third wheels, the plane of said second wheel intersecting the planes of said first and third wheels along the lines traversed by said bucket train in travelling between said first and second wheels and then between said second and third wheels, said second wheel being positioned on the opposite side of the position of said first and third wheels relative to the position of said fourth wheel whereby the buckets are dumped remotely from said catenary curve.

Claim 25

A materials handling machine, comprising a flexible bucket train for digging and lifting loose materials, said bucket train including a plurality of buckets having a generally circular cross section, said bucket train including a plurality of flexible tension elements extending axially between said buckets, dumping means including first, second and third generally vertical wheels engaging and supporting said bucket train which passes over said first wheel, under said second wheel, and over said third wheel, a fourth generally vertical wheel spaced horizontally a considerable distance from said first wheel relative to the spacing between the buckets in the bucket train, said bucket train extending between said third and fourth wheels, over said fourth wheel, and then hanging freely along a catenary curve between said fourth and first wheels, means for driving at least one of said wheels to circulate said bucket train in a direction to travel downwardly and then upwardly along said catenary curve between said fourth and first wheels to dig and elevate any loose material engaged by said buckets along said catenary curve, over said first wheel and downwardly to said second wheel to dump the loose material from said buckets, under said second wheel and upwardly to said third wheel, and over said third wheel to said fourth wheel, said first and third wheels being generally opposite each other in different planes converging at a small angle so as to meet in the locality of said fourth wheel, said second wheel being in a generally vertical plane extending transversely to the planes of said first and third wheels, said second wheel being positioned on the opposite side of the position of said first and third wheels relative to the position of said fourth wheel whereby the buckets are dumped remotely from said catenary curve.

Claim 26

A materials handling machine, comprising a flexible bucket train for digging and lifting loose materials, said bucket train including a plurality of buckets having a generally circular cross section, said bucket train including a plurality of flexible tension elements extending axially between said buckets, dumping means including first, second and third generally vertical wheels engaging and supporting said bucket train which passes over said first wheel, under said second wheel, and over said third wheel, a fourth generally vertical wheel spaced horizontally a considerable distance from said first wheel relative to the spacing between the buckets in the bucket train, said bucket train extending between said third and fourth wheels, over said fourth wheel, and then hanging freely along a catenary curve between said fourth and first wheels, means for driving at least one of said wheels to circulate said bucket train in a direction to travel downwardly and then upwardly along said catenary curve between said fourth and first wheels to dig and elevate any loose material engaged by said buckets along said catenary curve, over said first wheel and downwardly to said second wheel to dump the loose material from said buckets, under said second wheel and upwardly to said third wheel, and over said third wheel to said fourth wheel, said first and third wheels being generally opposite each other in different planes converging at a small angle so as to meet in the locality of said fourth wheel, said second wheel being in a generally vertical plane extending transversely to the planes of said first and third wheels, said second wheel being positioned on the opposite side of the position of said first and third wheels relative to the position of said fourth wheel whereby the buckets are dumped remotely from said catenary curve.

Claim 27

A materials handling machine, comprising a flexible bucket train for digging and lifting loose materials, said bucket train including a plurality of buckets having a generally circular cross section, said bucket train including a plurality of flexible tension elements extending axially between said buckets, dumping means including first, second and third generally vertical wheels engaging and supporting said bucket train which passes over said first wheel, under said second wheel, and over said third wheel, a fourth generally vertical wheel spaced horizontally a considerable distance from said first wheel relative to the spacing between the buckets in the bucket train, said bucket train extending between said third and fourth wheels, over said fourth wheel, and then hanging freely along a catenary curve between said fourth and first wheels, means for driving at least one of said wheels to circulate said bucket train in a direction to travel downwardly and then upwardly along said catenary curve between said fourth and first wheels to dig and elevate any loose material engaged by said buckets along said catenary curve, over said first wheel and downwardly to said second wheel to dump the loose material from said buckets, under said second wheel and upwardly to said third wheel, and over said third wheel to said fourth wheel, said first and third wheels being generally opposite each other in different planes converging at a small angle so as to meet in the locality of said fourth wheel, said second wheel being in a generally vertical plane extending transversely to the planes of said first and third wheels.

Claim 28

A materials handling machine, comprising a flexible bucket train for digging and lifting loose materials, said bucket train including a plurality of buckets having a generally circular cross section, said bucket train including a plurality of flexible tension elements extending axially between said buckets, dumping means including first, second and third generally vertical wheels engaging and supporting said bucket train which passes over said first wheel, under said second wheel, and over said third wheel, a fourth generally vertical wheel spaced horizontally a considerable distance from said first wheel relative to the spacing between the buckets in the bucket train, said bucket train extending between said third and fourth wheels, over said fourth wheel, and then hanging freely along a catenary curve between said fourth and first wheels, means for driving at least one of said wheels to circulate said bucket train in a direction to travel downwardly and then upwardly along said catenary curve between said fourth and first wheels to dig and elevate any loose material engaged by said buckets along said catenary curve, over said first wheel and downwardly to said second wheel to dump the loose material from said buckets, under said second wheel and upwardly to said third wheel, and over said third wheel to said fourth wheel, said first and third wheels being generally opposite each other in different planes converging at a small angle so as to meet in the locality of said fourth wheel, said second wheel being in a generally vertical plane extending transversely to the planes of said first and third wheels.

Claim 29

A materials handling machine, comprising supporting means, a boom having generally horizontal pivot means connecting the inner end of said boom to said supporting means to provide for swinging movement of said boom in a generally vertical plane, generally vertical swivel means connected to said supporting means and extending upwardly therefrom to support said supporting means for swiveling movement about a generally vertical swivel axis, a flexible endless bucket train for digging, elevating and dumping loose material, said bucket train including a plurality of spaced buckets of generally circular cross secTion and a plurality of flexible tension elements extending axially between said buckets, dumping means disposed adjacent said pivot means and including first, second and third generally vertical wheels engaging and support said bucket train which passes over said first wheel, under said second wheel, and over said third wheel, a fourth wheel rotatably mounted on the outer end portion of said boom, said fourth wheel being spaced a remote distance from said first wheel relative to the spacing between the buckets in the bucket train, said bucket train passing between said third and fourth wheels, over said fourth wheel, and hanging freely along a catenary curve between said fourth and first wheels, said fourth wheel being generally parallel to the vertical plane of swinging movement of said boom, said first and third wheels being generally opposite each other and in different generally vertical planes converging at a small angle so as to meet in the locality of said fourth wheel, said second wheel being in a generally vertical plane extending transversely to the planes of said first and third wheels, means for driving at least one of said wheels to circulate said bucket train in a direction to travel downwardly and then upwardly along said catenary curve between said fourth and first wheels to dig and elevate any loose material along said catenary curve, said bucket train then travelling over said first wheel and downwardly to said second wheel to dump the loose material from the buckets with the aid of the centrifugal force developed as the buckets travel around said second wheel, said bucket train then travelling under said second wheel, upwardly to said third wheel, over said third wheel, between said third and fourth wheels, and over said fourth wheel to said catenary curve, and means for swinging said boom about said pivot means for raising and lowering said fourth wheel and thereby raising and lowering said bucket train along said catenary curve, said second wheel being positioned on the opposite side of the position of said first and third wheels from the position of said fourth wheel whereby the buckets are dumped remotely from said catenary curve.

Claim 30

A materials handling machine, comprising supporting means, a boom having generally horizontal pivot means connecting the inner end of said boom to said supporting means to provide for swinging movement of said boom in a generally vertical plane, generally vertical swivel means connected to said supporting means and extending upwardly therefrom to support said supporting means for swiveling movement about a generally vertical swivel axis, a flexible endless bucket train for digging, elevating and dumping loose material, said bucket train including a plurality of spaced buckets of generally circular cross secTion and a plurality of flexible tension elements extending axially between said buckets, dumping means disposed adjacent said pivot means and including first, second and third generally vertical wheels engaging and support said bucket train which passes over said first wheel, under said second wheel, and over said third wheel, a fourth wheel rotatably mounted on the outer end portion of said boom, said fourth wheel being spaced a remote distance from said first wheel relative to the spacing between the buckets in the bucket train, said bucket train passing between said third and fourth wheels, over said fourth wheel, and hanging freely along a catenary curve between said fourth and first wheels, said fourth wheel being generally parallel to the vertical plane of swinging movement of said boom, said first and third wheels being generally opposite each other and in different generally vertical planes converging at a small angle so as to meet in the locality of said fourth wheel, said second wheel being in a generally vertical plane extending transversely to the planes of said first and third wheels, means for driving at least one of said wheels to circulate said bucket train in a direction to travel downwardly and then upwardly along said catenary curve between said fourth and first wheels to dig and elevate any loose material along said catenary curve, said bucket train then travelling over said first wheel and downwardly to said second wheel to dump the loose material from the buckets with the aid of the centrifugal force developed as the buckets travel around said second wheel, said bucket train then travelling under said second wheel, upwardly to said third wheel, over said third wheel, between said third and fourth wheels, and over said fourth wheel to said catenary curve, and means for swinging said boom about said pivot means for raising and lowering said fourth wheel and thereby raising and lowering said bucket train along said catenary curve, said second wheel being positioned on the opposite side of the position of said first and third wheels from the position of said fourth wheel whereby the buckets are dumped remotely from said catenary curve.

Claim 31

A materials handling machine, comprising supporting means, a boom having generally horizontal pivot means connecting the inner end of said boom to said supporting means to provide for swinging movement of said boom in a generally vertical plane, generally vertical swivel means connected to said supporting means and extending upwardly therefrom to support said supporting means for swiveling movement about a generally vertical swivel axis, a flexible endless bucket train for digging, elevating and dumping loose material, said bucket train including a plurality of spaced buckets of generally circular cross section and a plurality of flexible tension elements extending axially between said buckets, dumping means disposed adjacent said pivot means and including first, second and third generally vertical wheels engaging and supporting said bucket train which passes over said first wheel, under said second wheel, and over said third wheel, a fourth wheel rotatably mounted on the outer end portion of said boom, said fourth wheel being spaced a remote distance from said first wheel relative to the spacing between the buckets in the bucket train, said bucket train passing between said third and fourth wheels, over said fourth wheel, and hanging freely along a catenary curve between said fourth and first wheels, said fourth wheel being generally parallel to the vertical plane of swinging movement of said boom, said first and third wheels being generally opposite each other and in different generally vertical planes converging at a small angle so as to meet in the locality of said fourth wheel, said second wheel being in a generally vertical plane extending transversely to the planes of said first and thiRd wheels, means for driving at least one of said wheels to circulate said bucket train in a direction to travel downwardly and then upwardly along said catenary curve between said fourth and first wheels to dig and elevate any loose material along said catenary curve, said bucket train then travelling over said first wheel and downwardly to said second wheel to dump the loose material from the buckets with the aid of the centrifugal force developed as the buckets travel around said second wheel, said bucket train then travelling under said second wheel, upwardly to said third wheel, over said third wheel, between said third and fourth wheels, and over said fourth wheel to said catenary curve, and means for swinging said boom about said pivot means for raising and lowering said fourth wheel and thereby raising and lowering said bucket train along said catenary curve.

Claim 32

A materials handling machine, comprising supporting means, a boom having generally horizontal pivot means connecting the inner end of said boom to said supporting means to provide for swinging movement of said boom in a generally vertical plane, generally vertical swivel means connected to said supporting means and extending upwardly therefrom to support said supporting means for swiveling movement about a generally vertical swivel axis, a flexible endless bucket train for digging, elevating and dumping loose material, said bucket train including a plurality of spaced buckets of generally circular cross section and a plurality of flexible tension elements extending axially between said buckets, dumping means disposed adjacent said pivot means and including first, second and third generally vertical wheels engaging and supporting said bucket train which passes over said first wheel, under said second wheel, and over said third wheel, a fourth wheel rotatably mounted on the outer end portion of said boom, said fourth wheel being spaced a remote distance from said first wheel relative to the spacing between the buckets in the bucket train, said bucket train passing between said third and fourth wheels, over said fourth wheel, and hanging freely along a catenary curve between said fourth and first wheels, said fourth wheel being generally parallel to the vertical plane of swinging movement of said boom, said first and third wheels being generally opposite each other and in different generally vertical planes converging at a small angle so as to meet in the locality of said fourth wheel, said second wheel being in a generally vertical plane extending transversely to the planes of said first and thiRd wheels, means for driving at least one of said wheels to circulate said bucket train in a direction to travel downwardly and then upwardly along said catenary curve between said fourth and first wheels to dig and elevate any loose material along said catenary curve, said bucket train then travelling over said first wheel and downwardly to said second wheel to dump the loose material from the buckets with the aid of the centrifugal force developed as the buckets travel around said second wheel, said bucket train then travelling under said second wheel, upwardly to said third wheel, over said third wheel, between said third and fourth wheels, and over said fourth wheel to said catenary curve, and means for swinging said boom about said pivot means for raising and lowering said fourth wheel and thereby raising and lowering said bucket train along said catenary curve.

Claim 33

A materials handling machine, comprising supporting means, a boom having generally horizontal pivot means connecting the inner end of said boom to said supporting means to provide for swinging movement of said boom in a generally vertical plane, a flexible endless bucket train for digging, elevating and dumping loose material, said bucket train including a plurality of spaced buckets of generally circular cross section and a plurality of flexible tension elements extending axially between said buckets, dumping means disposed adjacent said pivot means and including first, second and third generally vertical wheels engaging and supporting said bucket train which passes over said first wheel, under said second wheel, and over said third wheel, a fourth wheel rotatably mounted on the outer end portion of said boom, said fourth wheel being spaced a remote distance from said first wheel relative to the spacing between the buckets in the bucket train, said bucket train passing between said third and fourth wheels, over said fourth wheel, and hanging freely along a catenary curve between said fourth and first wheels, said fourth wheel being generally parallel to the vertical plane of swinging movement of said boom, said first and third wheels being generally opposite each other and in different generally vertical planes converging at a small angle so as to meet in the locality of said fourth wheel, said second wheel being in a generally vertical plane extending traversely to the planes of said first and third wheels, means for driving at least one of said wheels to circulate said bucket train in a direction to travel downwardly and then upwardly along said catenary curve between said fourth and first wheels to dig and elevate any loose material along said catenary curve, said bucket train then travelling over said first wheel and downwardly to said second wheel to dump the loose material from the buckets with the aid of the centrifugal force developed as the buckets travel around said second wheel, said bucket train then travelling under said second wheel, upwardly to said third wheel, over said third wheel, between said third and fourth wheel, and over said fourth wheel to said catenary curve, and means for swinging said boom about said pivot means for raising and lowering said fourth wheel and thereby raising and lowering said bucket train along said catenary curve, said second wheel being positioned on the opposite side of the position of said first and third wheels from the position of said fourth wheel whereby the buckets are dumped remotely from said catenary curve.

Claim 34

A materials handling machine, comprising supporting means, a boom having generally horizontal pivot means connecting the inner end of said boom to said supporting means to provide for swinging movement of said boom in a generally vertical plane, a flexible endless bucket train for digging, elevating and dumping loose material, said bucket train including a plurality of spaced buckets of generally circular cross section and a plurality of flexible tension elements extending axially between said buckets, dumping means disposed adjacent said pivot means and including first, second and third generally vertical wheels engaging and supporting said bucket train which passes over said first wheel, under said second wheel, and over said third wheel, a fourth wheel rotatably mounted on the outer end portion of said boom, said fourth wheel being spaced a remote distance from said first wheel relative to the spacing between the buckets in the bucket train, said bucket train passing between said third and fourth wheels, over said fourth wheel, and hanging freely along a catenary curve between said fourth and first wheels, said fourth wheel being generally parallel to the vertical plane of swinging movement of said boom, said first and third wheels being generally opposite each other and in different generally vertical planes converging at a small angle so as to meet in the locality of said fourth wheel, said second wheel being in a generally vertical plane extending traversely to the planes of said first and third wheels, means for driving at least one of said wheels to circulate said bucket train in a direction to travel downwardly and then upwardly along said catenary curve between said fourth and first wheels to dig and elevate any loose material along said catenary curve, said bucket train then travelling over said first wheel and downwardly to said second wheel to dump the loose material from the buckets with the aid of the centrifugal force developed as the buckets travel around said second wheel, said bucket train then travelling under said second wheel, upwardly to said third wheel, over said third wheel, between said third and fourth wheel, and over said fourth wheel to said catenary curve, and means for swinging said boom about said pivot means for raising and lowering said fourth wheel and thereby raising and lowering said bucket train along said catenary curve, said second wheel being positioned on the opposite side of the position of said first and third wheels from the position of said fourth wheel whereby the buckets are dumped remotely from said catenary curve.