EARTH MOVING APPARATUS AND METHOD CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority from U.S. Provisional Patent Application Nos. 60/691,724 filed June 17, 2005; 60/723,485 filed October 4, 2005; 60/736,886 filed November 15, 2005; and 60/800,172 filed May 13, 2006. STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH

[0002] Not Applicable. APPENDIX

[0003] Not Applicable.

BACKGROUND OF THE INVENTION FIELD OF THE INVENTION

[0004] The present invention is in the field of earth moving. RELATED ART

[0005] Excavation and earth moving remain a constant need in all types of development. Traditionally, excavating the earth and transporting it were done by two separate machines. Typically a bulldozer or a backhoe would separate earth from the ground substrate and deposit it in a truck or other transportation. There exists in the industry a need for a single unit capable of both excavating and transportation to increase speed, efficiency and economy.

[0006] Preexisting equipment capable of both excavating and transporting material, principally road graders, have shortcomings in both their ability to excavate and transport material economically. Additionally, road graders have a simple, single cutter bar to be driven through the earth directly, requiring higher amounts of power. There is a need in

the art for a device capable of skimming or grading a layer of earth more efficiently and economically.

SUMMARY OF THE INVENTION

[0007] The present invention is a vaned conveyor combined with a cutter bar and deployed to cut or excavate a layer of earth and convey it upwards into a hopper or truck. In one aspect of the invention, the invention comprises a self-loading truck.

[0008] Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:

[0011] Fig. 1 is a side view of a first embodiment.

[0012] Fig. 2 is an end view of a first embodiment.

[0013] Fig. 3 is a partially cutaway side view of a first embodiment.

[0014] Fig. 4 is another partially cutaway side view of a first embodiment.

[0015] Fig. 5 is an alternate partial cutaway side view of a first embodiment.

[0016] Fig. 6 is a side view of a self-loading truck embodiment.

[0017] Fig. 7 is a detailed cutaway side view of a self-loading assembly of the self-loading truck.

[0018] Fig. 8 is a partial cutaway side view of an excavating assembly.

[0019] Fig. 9 is a cutaway side view of an alternate excavating assembly.

[0020] Fig. 10 is a cutaway side view of an alternate excavating assembly.

[0021] Fig. 11 is a cutaway side view of an alternate excavating assembly.

[0022] Figure 12 is a detailed side view of an elevation adjustable excavating assembly.

[0023] Figure 13 is a perspective close up of the elevation adjustable excavating assembly.

[0024] Figure 14 is a perspective close up of the elevation adjustable excavating assembly in a different position.

[0025] Figure 15 is a side view of a cleat and fin assembly.

[0026] Figure 16 is a perspective view of a fin.

[0027] Figure 17 is a perspective view of an individual cleat.

[0028] Figure 18 is a side view of an individual fin.

[0029] Figure 19 is an end view of an individual fin.

[0030] Figure 20 is a side view of a excavating assembly including sectioning fins.

[0031] Figure 21 is a perspective view of a releasable throat and sectioning fin assembly.

[0032] Figure 22 is a perspective view of releasable throat and sectioning fin assembly having one released throat section.

[0033] Figure 23 is a front view of an excavating assembly including a guard rail.

[0034] Figure 24 is a side view of an excavating assembly including a guard rail.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0035] The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.

[0036] Referring now to the figures wherein like reference numbers correspond to like elements, Fig. 1 depicts a first embodiment of the self-loading excavator transporter of the present invention. An excavating assembly 2 is mounted on a trailer 4 comprising a hopper 6 having a goose neck 8 and hitch 10. The trailer 4 and excavating assembly 2 are mounted to transport and ride on a wheel 12. The excavating assembly 2 is driven by a drive device 14 which may be one of a gasoline or diesel engine, an electric motor or, in the depicted embodiment, a hydrostatic drive. In the case of a hydrostatic drive, power may be transferred from an engine of the tractor or other machine hauling the implement of the invention with hydraulic hoses.

[0037] In Fig. 2 a rear view of the trailing implement incorporating the present invention shows the wheels 12 in relation to the hopper 6 and the excavating assembly 2. The excavating assembly 2 is further comprised of side walls 20 between which are maintained sections or panels 22. The sections or panels may be movable or slideable, as for example along a groove assembled or fabricated into the inner aspects of side walls 20. The panels are maintained in a first position with pressure from a maintenance device 24. In the depicted embodiment, maintenance device 24 is a hydraulic cylinder. A hydraulic cylinder is selectively set at a level of pressure corresponding to a desired trip force. That is, when a first panel of the implement encounters an obstruction in the earth, such as a rock, after a preselected amount of force is exerted against the obstruction without movement of the obstruction, the preselected trip pressure of the position maintenance device 24 is overcome and the device yields. In the case of hydraulic cylinder, the cylinder is compressed. Consequently, the movable panels 22 slide away from the obstruction and along the groove in

the inner aspect of the side walls 20 into a retracted position along a continuum of potential retracted positions. Thus, the machine passes over the obstruction without damage.

[0038] As viewed in Fig. 2, behind the sliding panels 22 and position maintenance device 24, is a conveyor 26. The conveyor 26 in the depicted embodiment would be attached to and driven by a drive chain as described in greater detail below. Attached to the conveyor 26 are a plurality of vanes 28 which move with conveyor 26 relative to the excavation assembly 2 as a whole and section earth for excavation, as described more fully below. The drive unit 14 is mounted to a drive wheel which is at an upper aspect of the excavation assembly 2 as depicted in Fig.2.

[0039] Fig. 3 is a partially cutaway view of the trailer implement embodiment of the present invention showing a hopper emptying device comprised of a moving wall 30 and a hydraulic cylinder 32 mounted on goose neck 8 and deployed to advance and retract the moving wall 30 through the hopper 6 in order to push out a full load of dirt by advancing and create a space for a new load by retracting.

[0040] Also depicted in Fig. 3 is an excavator mounting device 40, which in the depicted embodiment is a hydraulic cylinder. It is pivotably attached to the hopper at 42 and pivotably attached to the side walls of the excavating unit 2 at 44. Upon expansion of the hydraulic cylinder 40, the excavating unit rotates away from engagement with the ground around pivot 46. Thus, the unit is disengaged and ready for transportation of the excavated earth.

[0041] Fig. 4 again depicts a cutaway side view of the trailer embodiment of the present invention further comprising a thrower 50. As described more fully below, the excavating assembly 2 conveys excavated earth upwards over the rearmost aspect of the excavating assembly 2 and deposits it over the hopper 4 at an uppermost aspect of the excavating unit 2. In order to promote a more even distribution of the excavated earth

through the hopper, the thrower unit 50 is deployed underneath the deposit verge of the forward aspect of the excavator assembly 2. In the depicted embodiment, the spreader is a rotating axle, which may further comprise a drum cylinder, having fins mounted radially to the axle. When the excavated earth falls on the spreader 50 from the upper aspect of the excavator assembly 2, the spreader spins and throws the descending portions of earth forward into the hopper.

[0042] Figure 5 depicts an alternative embodiment having a moving floor 60.

[0043] Figure 6 depicts a self-loading truck embodiment of the present invention. In addition to the excavating assembly 102 being mounted on truck 104, Figure 6 also illustrates use of a thrower 150 and/or a moving floor 160 for distributing material excavated through a hopper 106, which is co-extensive with a truck bed. Beneath the chassis of the truck Figure 6 also shows a shear bar 110 and a ripple coulter 112. The shear bar serves the purpose of cutting and lifting sectioned material upwards into the excavating assembly 102. The ripple coulter disks or sections the earth being excavated as the unit moves forward over it.

[0044] Figure 7 depicts one version of an excavating assembly. After earth to be excavated is disked and sectioned by ripple coulter 112, it is cut at a pre-selected depth by shear bar 110 and guided into a gap 114 between a first cleated belt 116 and a second cleated belt 118. Each of the cleated belts has a plurality of vanes 120 on it. Each cleated belt is configured to rotate in an opposing, complementary fashion such that excavated earth will be drawn into an advanced through gap 114 between the two belts. As depicted in Figure 7, the direction of rotation would be counterclockwise for the upward cleated belt 116 and clockwise for the lower cleated belt 118. Either or both belts may be straight or include an angle 122 as depicted in Figure 7. The two belts 116 and 118 together also create an exit aperture 124 from which excavated and conveyed earth exits the assembly for loading into

the hopper or truck be d 106. Alternatively, distribution of the loaded material can be enhanced with the use of a rotating spreader or paddle 150.

[0045] Figure 8 depicts a conveyor vane assembly. A plurality of vanes are attached to a conveyor 202. A conveyor is disposed to rotate partially around each of an upper and a lower wheel 212. Either or both of the wheels 212 may be a drive wheel. Either wheel may also be an undriven return wheel. Either or both wheels may be controlled and maintained by tensioning devices. Structural support for the upper aspect of the moving conveyor 202 is provided by a linear upper slide 208 over which the conveyor 202 travels. Similarly, a lower slide 211 provides support for the flexible conveyor on its underside return path. Slides may be supported by tensioning devices 209, 210.

[0046] Disposed to work in close cooperation with the vanes 202 at their lowermost and deepest penetration into the material is a substantially horizontal cutter blade 204. The cutter blade 204 is positioned and maintained by a lower support structure 205. The lower support structure 205 is also integrally formed or assembled with a lifting throat providing a surface disposed to work in close cooperation with the outer edge of each of the plurality of vanes. The lower support structure 205 extends upwards and rearwards relative to the direction of travel (arrow A). The lower support structure extends above a hopper or truck bed, as does the upper and rearward portion of the conveyor vane assembly. Extending the length of the lower support unit and, optionally, above it is a side shield 214. The side shield may be disposed in close cooperation with the sides of the vanes 202.

[0047] In operation, the conveyor rotates in a clockwise direction as depicted in Figure 8 such that each vane in turn as the unit moves forward is brought into contact with the material being excavated. As rotation of the conveyor continues, the vane, driven by the conveyor and supported by the weight and pressure of the unit above it, cuts into the bottom material as indicated at vane 202A. Substantially at a vertical position, each vane in its

lowermost position (202A) presents a laterally sectioned portion of material to the cutting blade 204. The cutting blade cuts under the section of material. As the conveyor continues to rotate, the material is urged upwards and rearwards on the throat, which is comprised of the lower support structure 205. A left and right side shield 214 at its lowermost portion 214A cuts the bottom material along its side, thus completely separating a section of bottom material from the rest of the continuous bottom. The forward motion of the dredge and continued rearward clockwise rotation of the conveyor and vanes urges each fully cut and section portion of bottom material rearwards from the cutting blade and therefrom upwards onto the lower support structure and into the lifting throat. As illustrated by the arrows in Figure 8, continued rotation of the conveyor continuously urges sectioned material upwards and rearwards until it is lifted above a hopper and to a position roughly proximate to the upper rearward wheel 212. At that point a discharge chute 215 guides the sectioned material into the hopper. It is within the scope of the present invention that the structure receiving the sectioned and lifted material may be any suitable material handling structure including without limitation a hopper, a truck bed, a standing conveyor, a moveable conveyor, a deposit and transport assembly configuration.

[0048] In a second version of the present invention, a third wheel is used to configure the conveyor vane assembly into a wedge, see Figure 9. Again a plurality of vanes 301 are attached to a conveyor 302 which is supported by an upper slide in its upper aspect 303. As depicted in Figure 10, three wheels 307 orient the conveyor 302 such that a portion of it 302 A is placed flat along the bottom surface for a length defined by the distance between lead wheel 307A and trailing bottom wheel 307B. Any single one or any combination of wheels 307 may be a drive wheel. The conveyor 302 is further supported by an upper slide 303, lower slide 309 and back slide 308. The two slides in turn are structurally supported by tension devices 310.

[0049] Similar to the previous embodiment, a cutting blade 306 is disposed horizontally and beneath the surface of the material being excavated in order to cut and separate sections of material presented to the cutter blade by the advancing conveyor/vane assembly. The cutting blade 306 is backed by the lower support structure 304 and, as before, flanked by a shield 305 on either side. A discharge chute 315 again is oriented to deposit the cut and lifted sections of bottom material into a receiving structure.

[0050] In operation, as before, the conveyor 302 rotates around the wheels and translates between them in a clockwise direction as depicted in Figure 9 so that each of the plurality of vanes 301 in turn cuts into the bottom material as it rotates around lead wheel 307A. In this embodiment, as the excavator and wedge conveyor assembly move forward, each vane, having cut into the bottom material, remains relatively stationary to the bottom material as the excavator and conveyor wedge moves forward over it. Upon reaching the lower rear wheel 307B, each vane in turn rotates around it and, again in close cooperation with the lower support structure, and sides 304 and side shields 305, which together form the lifting throat, urges a cut and sectioned portion of bottom material upwards and rearwards along the throat. As before, the upper portion of the throat and upper rearward wheel 307C are above the surface of the water, such that when a section of bottom material reaches a discharge chute 315, it drops into the receiving structure.

[0051] Figure 10 depicts an alternative excavation assembly 1102 that may be mounted on any embodiment. It includes a tensioning roller 1150. The tensioning roller 1150, together with wheels 1152 deploy the excavation conveyor 1154 in a path that becomes entirely inverted over a hopper or truck bed, thus facilitating the ejection of excavated material from the vanes 1156 and onto a hopper. The tensioning roller 1150 may be further mounted either rigidly or on a moveable mount 1160 such as a shock absorbing, sprung or hydraulically controlled shaft such that tension of the conveyor 1154 may also be controlled

and/or extraordinary stresses on the conveyor may be absorbed without damage or work interruption.

[0052] The embodiment as depicted in Figures 7, 8, 9, 10 or 11 may be mounted otherwise than on a truck or trailer. As such, the chain, belts and other apparatus as disclosed herein as the invention may be applied for use in a wide variety of applications, including without limitations those that are not submerged such as dry land, and loose earth, hard packed earth, loose rock, gravel, sand, oil sand, waste fills, trash, refuse, quarried products, or other mixed uses that are neither purely dry land nor submerged, such as swamps, bogs, peat, tundra or taiga.

[0053] In the embodiment depicted in Figure 11 the overall apparatus 500 moves in the direction indicated by arrow A. The belt, drive chain and vanes rotate clockwise as shown in Figure 11 or, in the direction indicated by arrow B. Apparatus 500 is comprised of a side panel 501 onto which are mounted drive and idling wheels 502. Any combination of gears 502 may be drive wheels, but in the depicted embodiment the lower two wheels are drive wheels. Any drive system may be employed to generate drive, including without limitation engines and motors, but in the depicted embodiment hydrostatic drive is used, hi the depicted embodiment, upper wheel 502A is deployed as an idling wheel. Accordingly, tensioning device 506 is used for an operator to maintain an optimal tension on the drive chain/belt/vane assembly.

[0054] The drive chain 503 engages with the teeth of the drive gears 502 in order to rotate the chain. Attached to the chain is belt 505, which provides a continuous surface from one side wall 501 to a second side wall (obscured in the side view of Figure 12). Belt 505 also provides a continuous, substantially uninterrupted top surface for a section of sediment, earth or other material to be lifted as belt 505 proceeds along a top surface of the earth 512 to be lifted. A plurality of vanes 504 are structurally attached to drive chain 503 in

the depicted embodiment and along belt 505. Together the drive chain 503, belt 505 and vanes 504 comprise a conveyor assembly. This conveyor assembly may be mounted in a variety of manners without departing from the scope of the present invention, including without limitation a truck, trailer, tracked device, amphibious device, a static conveyor, a moveable conveyor, or other earth moving apparatuses.

[0055] In operation, as the drive chain 503 and belt 505 rotate clockwise, each successive vane 504 is driven by the weight of the dredge into the bottom material 512 in the vicinity of leading drive wheel 502. This earth or sand material is also being penetrated by the leading edge of the substantially vertical side wall 501. As the excavator moves forward, a section of earth is cut by the combination of each successive vane 504 with a first and second side wall 501. Simultaneously, the pressure of at least one vane being driven rearward against the earth or other material 512 drives the excavator forward. In the depicted embodiment, four vanes 504 are fully engaged with the bottom material at all times, providing propulsion.

[0056] Thus, the belt 505, sidewalls 501, and vanes 504 cut the earth to be lifted into a section having a top (with belt 505) side (at side plates 501) front and back (successive vanes 504). The section of material to be lifted is completed by a substantially horizontal cut into the bottom material by cutter bar 510 at level 513. As the excavator advances, a section of material 514 is cut by the cutter bar 510, which cut comprises the sixth and final side of the section of material to be lifted. Immediately behind cutter bar 510 are a plurality of transverse plates 508 which together comprise a lifting throat. After the cutter bar 510 has completed a section, the continuing rotation of the chain/belt/vane assembly lifts each section against the curvilinear contour of the throat 508 and around the trailing drive wheel 502. After a sufficient degree of rotation, gravity holds the section of material 514 against the belt as it rises upwards.

[0057] In the depicted embodiment, at the upper extent of the drive chain/belt/vane assembly, this assembly is angled such that as it rounds wheel 502A, the force of gravity causes each sediment section to fall from the assembly into a receiving device such as any of those described hereinabove, for example a conveyor or hopper.

[0058] In order to accommodate travel over possible buried objects, the cutter bar 510 and partitioned throat 508 assembly is designed to retract. The cutter bar 510 and each transverse section 508 of the throat are disposed to be held in place by and slide along guide rails 509. The guide rails are attached to the side walls 501. An upper terminal transverse throat panel 508 is in contact with the piston of hydraulic arm 507. The pressure exerted by this arm is selectable by an operator, in order to maintain a selected pressure for cutting the material being worked upon and also for maintaining a selected "break away" pressure at which the cutter bar and panels will retract when brought into contact with a buried object such as a large rock, tree, debris or otherwise. When encountering such an obstruction, the transverse panels of the throat 508 and cutter bar retract upwards and rearwards along the guide tracks 509 and are retained therein until such time as the obstacle has been traveled over by the excavator 500. At that time, the pressure of the hydraulic arm 507 acts to return the throat downwards and forwards repositioning the throat and also the cutter bar 510 in reestablishing cutting engagement with the bottom material.

[0059] In Figure 12, additional details of the excavator are shown. Conveyor assembly 401 is comprised of a cleated belt 430. Rollers 432 and conveyor frame components 443 support the conveyor. One or more of top roller 432a, bottom front roller 432b or bottom back roller 432c may be powered for driving the conveyor. In the depicted embodiment, the preferred direction of travel is to the left of Figures 12 - 14. The conveyor would rotate counterclockwise in Figures 12 - 14. In the depicted embodiment, the

movement of the conveyor and the engagement of its cleats or vanes with the bottom material provides drive to the entire excavating apparatus. Depth control is by cleat length.

[0060] Efficient operation of the excavator is optimized if engagement surface

411 remains level, or at least substantially parallel with the slope or grade of the top surface of the bottom material of the body of water. Operating problems will include maintaining this flat engagement of bottom engagement surface 411 with the bottom material when the angle of the earth changes. Another problem is meeting and overcoming without damage, delay, or unnecessary failure to dredge a portion of the bottom when an obstruction is met. In the depicted embodiment, adjustable tensioners provide for flexible and user selectable adjustment of the angle and position of the overall excavator 401 and conveyor in order to meet these and overcome these operational problems.

[0061] In the depicted embodiment, at least one of formed portions 433 are mounted such that they can move relative to the earth and/or to the chassis on which they are mounted. In particular, front member 433a may be pivoted, substantially around pivot point

412 to extend forward of the rest of the overall excavator assembly 401 or towards the front of the unit by extension of telescoping arm 450. Likewise, front bottom roller 432b may be extended or retracted through the use of telescoping arm 437 on which it is mounted. Telescoping arms 437 may be further mounted on a pivot point 452 in order to accommodate a change angle between bottom engaging surface 411 and front frame member 433 a and the conveyor riding on it. Alternatively or additionally, additional adjustments in depth, elevation of the bottom engaging surface or the angled relationship between back frame member 433b, the conveyor riding on it and bottom engaging surface 411 may be made by extending or retracting rear bottom roller 432c through the use of telescoping arm 438. In the depicted embodiment, telescoping arm 438 is mounted at a bottom end of rear support frame

element 433b and extends or retracts substantially parallel to the long dimension ot rear frame element 433b.

[0062] Figure 13 depicts the overall assembly of the excavator 401 and the cleated conveyor engaging a bottom surface in a first position. In this position the difference between front bottom roller 432b and the rear frame portion 433b with the conveyor riding on it is relatively narrow through dimension C (telescoping adjustment arms have been omitted from Figures 13 and 14 for clarity and illustrating the variability of the position of the components). In Figure 14, dimension C has been expanded, by extending telescoping arm 437 (again omitted from Figure 14 for clarity). It is anticipated that in the position shown in Figure 13, the entire excavator assembly 401 can further be adjusted rearwardly relative to the hull by allowing for such pivoting, as for example at schematically depicted mount 460, which would essentially pivot around the axis of top roller 432a. Accordingly, it is anticipated that a rearward pivoting of the overall assembly 401 and narrowing of dimension C would allow optimized contact with the bottom of bottom engaging portion 411 in a shallower depth. For a deeper depth, the components would be adjusted more as depicted in Figure 14. That is, the overall assembly 401 would be rotated in direction D and dimension C would be expanded. Accordingly, bottom engaging portion 411 would continue to maintain substantially full contact with the surface of the earth, allowing for efficient excavating of it.

Cleat and Fin Combination

[0063] A novel cleat and fin arrangement is disclosed in Figs. 15 through 19. For some applications a broad belt segmenting broad rectangles of earth for raising may be divided into subsections transverse to the belt. It is also advantageous to bolster the strength of transverse vanes or cleats. Accordingly, in Figs. 15-19 a combination of interacting cleats and fins are disclosed. As previously described, a chain 806 rotates around the drive wheels

and carries with it a belt 804. On top of the belt are cleats 802 which serve the same function vanes depicted in previous embodiments of sectioning mud or sediment to be lifted. Each cleat 802 has a foot 803 which attaches to the belt 804 and/or chain 806 underneath it. Interacting and/or with each cleat 802 is a fin 808. The fin 808 is aligned longitudinally with the belt 804 and chain 806 as depicted in Figure 18. Each vane is comprised of a side 820 which is longitudinally aligned and an angled base comprised of a fin foot 812 and a fin lead face 810. As depicted in Figure 16, a perspective view, the fin base 806 is transverse to the belt 804 and is mounted on it. The fin face plate 810 is disclosed to abut an adjacent cleat 802 when the belt 804 is flat. In the depicted embodiment, each fin 808 further has a notch 816 in its leading edge and a extension 818 in its tailing edge. The notch of each fin aligns and closely cooperates with the extension of the next adjacent fin.

[0064] As can be seen in Figure 17, a perspective view and Figure 19, an end view, each cleat or vane has a vertical member 802 which serves to section the mud as described above. Each cleat or vane also has a foot 803 for mounting onto the belt 804. Each cleat also has a notch 822 dimensioned and positioned to interact with the extension 818 of each fin. These components interact and combine to provide strength to the cleats as they section mud or earth. They also divide sections of mud into smaller volumes for ease of cutting and lifting. The notch and extension arrangement for interaction between each cleat and the adjacent fin promotes unloading of earth as each cleat and fin rounds the upper wheel.

[0065] Figures 20 through 22 depicts a wedge conveyor, and excavator employing the cleat and fin assembly. As depicted in Figure 20, the belt rotates counterclockwise for a direction of travel for the overall excavator to the left in Figure 20. Each fin trailing edge rotates away from the belt at each rotation of the belt around a wheel. At a top wheel 830 this rotation promotes the ejection of a section of earth from the belt. On a bottom contact plane

832 the fins may advantageously exceed the cleats in depth. This will promote the contacting and driving away from the belt and other operational components of the excavator any buried obstructions. The fins 802 further provide reinforcement to keep loading forces from pulling the cleats backward or out of vertical with the belt and thereby warping the belt and/or drive chains away from the drive wheels and sprockets.

[0066] Figure 21 is a perspective view of an assembly including support fins 802. In the depicted embodiment, the support fins subdivide a transverse section between cleats 802 into four sections. The outermost section edges are defined by the sidewalls 834 of the dredge. As fins 808 rotate around trailing wheel 836 they advance between the adjacent edges of an assembly of adjacent trip bottom throats 838. This construction further allows the fins 808 to be a greater depth than the cleats 802 in order to provide protection from submerged and buried objects. Each adjacent throat section 838 is mounted to a side wall 834 of the excavator at pivoting mount 844 and to a frame portion 840 with mounting rods 842. Each throat section 838 is configured to release or "trip" in the event that its leading edge, which is the cutting edge 846, hits a buried obstacle. Each throat section 838 is biased into its down and engaged cutting position for normal operation and maintained there at a preconfigured pressure. In the depicted embodiment, hydraulic rams 848 apply this pressure. The pressure is preconfigured to be overcome when it exceeds a threshold and that threshold is anticipated to be set at the degree of resistance corresponding to the cutting edge 846 meeting buried obstruction that would otherwise break the throat component 838.

[0067] Figure 22, another perspective view of the sectioned assembly with fins depicts one of the throat sections 838 in its released or tripped position, which allows a buried obstruction to pass.

[0068] Depicted in Figure 23 and Figure 24 are a guard rail 1002. In a depicted embodiment it is centered underneath the conveyor and its vanes. The guard rail 1002

descends into the earth or other material to a depth (C). This depth is deeper than a depth (D) at which side rails 1004 operate. The depth of vanes 1006, attached as before to a drive chain and/or belt (obscured) may alternately penetrate to a depth of the side plates 1004, or be more shallow than the side plates 1004. In any event, any depth of vane penetration or side wall penetration shallower than a penetration depth of the guard rail 1002 is within the scope of the present invention.

[0069] In Figure 24, a side view of the guard rail is shown 1002 including a mount assembly 1008 attaching the guard rail 1002 to the side rails. Otherwise, the excavation conveyor operates as previously described, with conveyor 1010 conveying vanes 1006 around wheels 1014 to section and lift earth.

[0070] The guard rail 1002 may be disposed to present only an edge to the direction of travel, thereby minimally impeding forward progress and the power needed to attain it. The leading edge of guard rail 1002 may optionally extend ahead of the leading edge of the side walls 1004, with a direction of travel being in either direction. In operation, buried obstructions contact the leading edge of the guard rail 1002 and, as the excavator moves forward, the guard rail and dredge rise and/or the obstruction sinks, thereby allowing the excavator assembly to travel over the obstruction.

[0071] As various modifications could be made to the exemplary embodiments, as described above with reference to the corresponding illustrations, without departing from the scope of the invention, it is intended that all matter contained in the foregoing description and shown in the accompanying drawings shall be interpreted as illustrative rather than limiting. Thus, the breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims appended hereto and their equivalents.