Patent Application
20070267225
Referring to
Referring also to
Loading apparatus 30 may include a chute 38 having a first end 32 positioned outside of bowl 18, and a second end 33 through which work material may be conveyed during loading and/or unloading bowl 18. Chute 30 may further include an apron 39 extending from a material feed opening 42 outwardly toward cutter 20. Thus, work material removed from a work surface by cutter 20 may be guided via apron 39 toward and into material feed opening 42, and thenceforth discharged out of a material discharge opening 36 into bowl 18.
Loading apparatus 30 may still further include at least one auger 34 having an axis of rotation A. The at least one auger 34 is configured to feed work material in a feed direction between first and second ends 32 and 33 of chute 38. The at least one auger 34 may include first and second augers 34a and be 34b positioned in parallel. In one embodiment, augers 34a and 34b may comprise counter-rotating augers having blades 35a and 35b with overlapping peripheries. The augers are positioned in parallel, and configured to feed work material through chute 38 during either loading or unloading of bowl 18. An approximate feed direction for loading is shown via arrows B in
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In another embodiment of a loading apparatus 130, shown schematically in
Referring to the drawing Figures generally, during a typical loading operation, machine 10 will be driven across a work surface at as first work area, and cutter 20 and hence cutting edge 22 lowered to a desired vertical position such that cutting edge 22 will pass through work material, dislodging material from the work surface. Continued forward motion of machine 10 will result in additional material dislodged by cutter 20 being pushed upward and backward from cutting edge 22 and into chute 39, capturing the work material and beginning to load the same. Prior to or upon beginning to move cutter 20 through the work material, rotation of augers 34a and 34b in first and second directions may be initiated. Because augers 34a and 34b will typically be counter-oriented, e.g. having respective “left-handed” and “right-handed” helical configurations, they will typically be rotated in opposite directions during loading of bowl 18, but each urging work material in approximately the same feed direction, toward bowl 18 from cutter 20.
Work material pushed upward and rearward toward and into chute 38 will typically flow generally in two paths defined by curving surfaces 39a and 39b toward left and right sides of material feed opening 42. Approximately one half of the work material captured via cutter 20 will generally be fed toward first auger 34a, and one half fed toward second auger 34b. At material feed opening 42, rotation of augers 34a and 34b will generally rotate a cutting edge 53a and 53b at the loading ends 37 of each respective auger 34a and 34b against work material, and the work material will begin being conveyed through the portion of chute 38 defined by peripheral walls 50. Conveying of work material with augers 34a and 34b will tend to reduce the power necessary to continue to move machine 10 forward through the work material as compared to certain other designs. In particular, rotation of augers 34a and 34b performs a substantial portion of the loading work, rather than relying solely or mostly upon forward motion of the machine to push the work material into bowl 18.
When bowl 18 is relatively empty, work material will tend to be discharged via a portion of material discharge opening 36 that is located relatively close to front side 29 and bottom side 28 of bowl 18. As filling of bowl 18 progresses, material discharge opening 36 will tend to become partially blocked by deposited work material, and additional work material will be discharged relatively more upward and backward in bowl 18. This phenomenon results at least in part from the relative positioning of loading apparatus 30 in front of bowl 18, and its relative inclination. In one embodiment, the axis of rotation A of augers 34a and 34b may be oriented diagonally, for example at approximately a 45° angle, relative to articulation axis J. It is contemplated that an angle of approximately 45° may provide a desired balance between upward lifting force and backward loading force on work material conveyed by loading apparatus 30. For certain applications, and for certain machine designs, a different angle of inclination of axis A relative to axis J may be appropriate, and the augers may not be oriented in parallel. Where bowl load volume is to be maximized for a particular machine design or size, a loading apparatus 30 may be configured such that augers 34a and 34b are relatively more vertical, whereas when available power for pushing work material backward in bowl 18 is sought to be maximized, for example, for a relatively less powerful or lighter machine, a relatively more horizontal inclination of axis A may be appropriate.
When bowl 18 has been filled to a desired extent, cutter 20 may be lifted to substantially close bowl 18, and machine 10 will typically be driven to a second work area, for example, where work material is to be deposited. To deposit work material, cutter 20 may be lowered to a height corresponding to a desired lift thickness for deposited material. Machine 10 may then be driven across a work surface at the second work area, and augers 34a and 34b rotated in opposite directions to those used for loading bowl 18, to convey work material from bowl 18, through chute 38, and onto the work surface. During deposition of work material with machine 10, ejector apparatus 24 may be used to push work material toward front side 29 of bowl 18. Unloading of bowl 18 may thus take place in a manner generally the reverse of that occurring during loading. In other words, when bowl 18 is at least partially filled, work material may block a portion of material discharge opening 36, and thus material initially discharged via material discharge opening 36 will tend to be material that is positioned at relatively higher vertical positions in bowl 18. As unloading progresses, work material that is positioned progressively lower in bowl 18 will be discharged.
The presently disclosed design for a loading apparatus 30, 130 for use in a scraper or other material capturing machine 10 improves operating efficiency over known designs such as open bowl scrapers and auger scrapers wherein the augers are positioned within the bowl and thus reduce potentially available bowl volume. Rather than distributing work material within the bowl as in conventional auger-scraper designs such as Carston, augers 34a and 34b are used to convey work material into and out of the bowl without sacrificing bowl volume. This approach also allows easier loading, as the conveying power provided by augers 34a and 34b reduces the force necessary to move material into the bowl. Augers 34a and 34b can also carry material relatively higher into the bowl than conventional designs, as they do not have to overcome remolding forces associated with surrounding work material. In other words, in a design such as Carston, work material once distributed by the auger will tend to move back around the auger as bowl filling progresses, resisting efforts to pile material higher in the bowl, and also providing resistance to rotation of the auger.
With regard to conventional elevator scrapers, the present disclosure provides still other advantages. The present disclosure provides a system wherein the work material is better confined during conveying to the bowl, and may thus produce less airborne dust than elevator scraper systems. Moreover, expense, complexity and maintenance problems associated with elevator scraper designs are obviated, as machine 10 and loading apparatus 30, 130 may use a relatively smaller number of parts than elevator scrapers having track or chain driven paddles and the like.
The present description is for illustrative purposes only, and should not be construed to narrow the breadth of the present disclosure in any way. Thus, those skilled in the art will appreciate that various modifications might be made to the presently disclosed embodiments without departing from the full and fair scope of the present disclosure. For example, while the present disclosure is discussed primarily in the context of mobile scraper machines, it is not thereby limited. Those skilled in the art will appreciate that other types of material capturing and/or transfer apparatus such as are used in mining, agriculture and other activities may benefit from the teachings of the present disclosure. It should also be appreciated that while material discharge opening 36 is shown as an elongate, generally rectangular opening, and openings 136 are shown as spaced apart squares, the present disclosure is not thereby limited and slots, circular openings or some other configuration or positioning might be used. Other aspects, features and advantages will be apparent upon an examination of the attached drawings and appended claims.
