Patent Publication Number: US-2012030973-A1

Title: Earth mover which continuously excavates a trench and simultaneously clears the excavated trench of spoils

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to trench excavating and more particularly, to an earth mover which continuously excavates a trench and simultaneously clears the excavated trench of spoils and deposits the spoils alongside the excavated trench. 
     BACKGROUND OF THE INVENTION 
     In pipeline operations where a pipeline is buried below the ground surface it is necessary to form a trench in the ground either during the process of laying the pipeline or to acquire access to a buried pipeline for service. In either of these instances, during trenching, the top soil must be removed from the underlying soil layers and stored separately to prevent contamination of the top soil. Further, it is desirable to form such a trench with low impact soil disturbance to minimize the amount of top soil that is stripped, and thus reduce the environmental impact caused by forming the trench. 
     Accordingly, an earth mover of an improved construction allowing for controlled depth trench excavation for stripping and separating top soil from underlying soil layers is desired. 
     SUMMARY OF THE INVENTION 
     The preferred embodiments of the present invention addresses this need by providing an earth mover which continuously excavates a trench and simultaneously clears the excavated trench of spoils and deposits the spoils alongside the excavated trench with low impact soil disturbance is provided. 
     To achieve these and other advantages, in general, in one aspect, an earth mover is provided. The earth mover includes a chassis supported for transport across a ground surface in a travel direction in either a ground engaging position and a non-ground engaging position. The chassis is positioned in the ground engaging position during a trenching process. A cutter configured to form a rectilinear trench is supported by the chassis in a rotatably drivable fashion about a cutter axis of rotation that is fixed relative to the chassis. The earth mover further includes a spoils collector and a stripping blade having a stripping edge disposed at a following position relative to the cutter and having a transport surface contiguous with the spoils collector, wherein spoils cut by the cutter during the trenching process are transported along the transport surface and into the spoils collector. A spoils transfer assembly is supported by the chassis and includes a conveyor configured to remove spoils received in the spoils collector and to deposit the removed spoils along the side of a trench formed during the trenching process. 
     There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood and in order that the present contribution to the art may be better appreciated. 
     Numerous objects, features and advantages of the present invention will be readily apparent to those of ordinary skill in the art upon a reading of the following detailed description of presently preferred, but nonetheless illustrative, embodiments of the present invention when taken in conjunction with the accompanying drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of descriptions and should not be regarded as limiting. 
     As such, those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention. 
     For a better understanding of the invention, its operating advantages and the specific objects attained by its uses, reference should be had to the accompanying drawings and descriptive matter in which there are illustrated preferred embodiments of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are included to provide further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate preferred embodiments of the invention and together with the description serve to explain the principles of the invention, in which: 
         FIG. 1  is a side elevation of the earth mover, constructed in accordance with the principles of the present invention; 
         FIG. 2  is a top plan view of the earth mover attached to a vehicle; 
         FIG. 3  is a front elevation view of the earth mover in the non-ground engaging position; 
         FIG. 4  is a bottom plan view of the earth mover, illustrating the cylindrical drum, stripping blade, and stripping edge; 
         FIG. 5  is a bottom plan view of the earth mover, illustrating the adjustable length of the stripping edge; 
         FIG. 6  is a side elevation view of the earth mover, illustrating the earth mover from the opposite side of  FIG. 1 , with the side surfaces removed, in operation; and 
         FIG. 7  is a top plan view of the earth mover in operation. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     As a preliminary matter, it should be noted that in this document (including the claims) directional terms, such as “above”, “below”, “upper”, “lower”, “forward”, “behind”, etc., are used for convenience in referring to the accompanying drawings. Additionally, it is to be understood that the various embodiments of the present invention described herein may be utilized in various orientations, such as inclined, inverted, horizontal, vertical, etc., without departing from the principles of the present invention. 
     In  FIGS. 1-3 , there is representatively illustrated an earth mover  10  for continuously excavating a trench at a controlled depth to separate earth layers, for example, a top soil layer from underlying clay, and simultaneously clearing the top soil from the excavated trench and depositing the top soil alongside the excavated trench in a windrow  76 . The earth mover  10  is particularly useful in pipeline operations where a trench must be formed with low soil impact disturbance and where the top soil needs to be separated from the underlying earth. It is important to note here, while the following description may be specific to excavating a trench, the earth mover  10  could be used in other applications including, but not limited to, soil reclamation, stripping and mulching peat moss, removing top soil for sidewalks and the like, among others. 
     Still referring to  FIGS. 1-3 , the earth mover includes a chassis  12  supporting a cutter  20 , a stripping blade  50 , a spoils collector  40  and a spoils transfer assembly  70 . A wheel support assembly  90  is mounted at one end of the chassis  12  and supports the chassis  12  on wheels  120 . At an end opposite the wheel support assembly  90 , the chassis  12  is provided with a hitch  132  or the like coupling for engaging the chassis to a vehicle  130  that tows or pushes the earth mover  10 . Hitch  132  can be configured to engage the chassis to a towing ball, a hitch pin, a three-point hitch or the like of the vehicle  130 . Further, the vehicle  130  could be, but is not limited to, a skid steer loader, an excavator, a front loader, a bulldozer or any other suitable vehicle. 
     Cutter  20  is supported by the chassis  12  in a rotatably drivable fashion on axel  28  about an axis of rotation  30 . Cutter  20  is attached to axel  28  for conjoined rotation therewith. Opposite ends of the axel  28  are rotatably supported by bearing assemblies  27  mounted on opposite sides of chassis  12 . A drive motor  38  is operatively coupled to axel  28 , for example, by a chain drive assembly  29  for rotatably driving the axel  28  and thus the cutter  20  about axis  30 . The drive motor  38  could be a hydraulic motor, an electric motor or a combustion engine. One of ordinary skill in the art will appreciate the chain drive assembly  29  could be substituted with any number of drive assemblies for operatively connecting the drive motor  38  with axel  28  to rotatably drive the axel, and should not be limited to the chain drive assembly  29  as illustrated. As a non-limiting example, the axel  28 , and thus cutter  20  could be driven by a power-takeoff of vehicle  130 . 
     Cutter  20  is configured to form a rectilinear trench  74  when moved into an earth engaging position where the cutter  20  is plunged into the ground surface  118  and the earth mover  10  is moved along a trenching path. Cutter  20  comprises a cylindrical drum  22  having a circumferential exterior surface  23 . A plurality of cutting teeth  24  are interspersed across the exterior surface  23  in a regular or irregular pattern. As illustrated, each cutting tooth  24  is a fixed carbide tooth. However, a person of ordinary skill in the art will appreciate the cutting teeth  24  can be of any suitable excavating tooth points, and should not be limited to fixed carbide teeth. 
     It is preferred the axis of rotation  30  to be generally normal to a travel direction  26  of the earth mover  10  during a trenching operation. However, it is contemplated the axis of rotation  30  could be swept forward or rearward relative to the travel direction  26 . 
     Still referring to  FIGS. 1-3 , the earth mover  10  may further include a cutter shield  32 , which partially encloses the cutter  20  and provides protection for an operator, or other person proximate to earth mover  10 , from the cutter and/or excavating debris. In one configuration, the cutter shield  32  substantially encloses the cutter  20  except a lower portion thereof permitting the cutter  20  to be engaged with the ground surface  118 . 
     The earth mover  10  may further include a pair of sleds  34 ,  35  one located on each side of the chassis  12  below a respective bearing assembly  27 . Sleds  34 ,  35  provide a depth stop to the chassis  12  to prevent lowering the chassis into the ground surface beyond a predetermined depth that otherwise may cause damage to the earth mover  10 , and particularly to the bearing assembly  27 . Sleds  34 ,  35  are configured to engage the ground surface along opposite sides of the earth mover  10  and an excavated trench. Sleds  34 ,  35  provide sliding support to the chassis  12  across the ground surface in the instance the chassis  12  is lowered beyond the predetermined depth. Sleds  34 ,  35  can be attached to the chassis  12  in a manner such that the sleds are vertically adjustable relative to the chassis. Additionally, sleds  34 ,  35  can be lowered to engage a ground surface to support the chassis  12  of the earth mover  10  when not operating. 
     Referring to  FIGS. 1 and 6  the inclined stripping blade  50  is supported by the chassis  12  for conjoint movement therewith. In other words, as the chassis  12  is lowered or raised, so is the stripping blade  50 . Generally, the stripping blade  50  operates to plane the spoils from the excavated trench  74  and into the spoils collector  40 . The stripping blade  50  includes a stripping edge  52  that is disposed in a following position  114  relative to the cutter  20 , and in a trenching operation, the stripping edge  52  strips the spoils from the bottom surface of the excavated trench. The stripped spoils are then transported along a transport surface  60  of the stripping blade  50  and into a spoils collector  40 . In an embodiment, the transport surface  60  is contiguous with the spoils collector  40 , such that the spoils are directed by the stripping blade  50  directly into the spoils collector as the earth mover  10  is moved forward in a trenching operation. 
     With reference to  FIGS. 4 and 5 , in an embodiment, the stripping edge  52  may be removably attached to a lower portion of stripping blade  50  by a bolted connection to permit replacement of a worn stripping edge  52 . Further, the stripping edge  52  may be adjustably attached to the stripping blade  50  adjusted to a desired depth relative to the circumference of the cutter  20 . As illustrated, the stripping blade  50  includes a plurality of parallel and spaced slots  56 , and the stripping edge  52  includes an equal number of cooperatively aligned through holes  55 . A bolt  54  extends each slot  56  and through hole  55  pair and is secured by a nut  57 , thus securing the stripping edge  52  to the stripping blade  50 . The position of the stripping edge  52  can be adjusted by loosening bolts  54 , repositioning stripping edge  52  by sliding bolts  54  along the slots  56 , and then subsequently retightening the bolts  54 . The stripping edge  52  can be replaced by completely removing the bolts  54 . The stripping blade  50  and/or stripping edge  52  substantially extends the entire the length of cylindrical drum  22 , thereby planning the entire width of the trench excavated by the cutter. In this configuration, the spoils collector  40  receives substantially all of the spoils. It is contemplated, in other embodiments, the stripping blade  50  and/or stripping edge  52  may extend less than the entire length of the cylindrical drum  22  as desired. Additionally, in embodiments, the stripping blade  50  may include lips (not pictured) extending along the transport surface  60  in a direction from the cutting edge  52  towards the spoils collector  40  to guide and retain spoils on the transport surface to minimizing spilling back into the excavated trench  74 . 
     In alternate configurations, the stripping blade  50  could be comprised of multiple blades. In embodiments, multiple smaller blades could be staggered to cover the same surface areas as one larger stripping blade. Alternatively, multiple blades could be placed in series, with each blade following the previous blade, at a uniform or asymmetrical depth. 
     With reference to  FIGS. 1 and 6 , spoils collector  40  is supported by chassis  12  and is located generally rearwardly of stripping blade  50 . Spoils collector  40  operates to receive and collect spoils planed by stripping blade  50  and/or stripping edge  52 , and thus transported along transport surface  60 . Spoils received by spoils collector  40  are cached in a spoils receiving bay  71 , an area of spoils collector  40  located behind the stripping blade  50  and operatively configured to receive and temporarily contain spoils awaiting transport from the conveyor  72 . 
     Spoils collector  40  may further include a collector shield  68 , which partially encloses spoils collector  40  such to contain the spoils received from the stripping blade  50 . In one configuration, the collector shield  68  substantially encloses the spoils collector except for a collector mouth  69 , located at the lower portion of the spoils collector  40  for receiving spoils from the transport surface  60 . 
     Referring to  FIG. 6 , the spoils transfer assembly  70  operates to remove spoils received by spoils collector  40  and deposit the spoils alongside the excavated trench  74  in a windrow  76 . The spoils transfer assembly  70  is supported by chassis  12  of the earth mover  10 , and is located generally rearwardly of the spoils collector  40 . Additionally, in embodiments, the spoils transfer assembly  70  further operates to mulch the spoils as they are removed from the spoils collector  40  and deposited. 
     The spoils transfer assembly  70  includes a conveyor  72 , further comprised of a receiving end  75  and a depositing end  77 . The receiving end  75  is located within the spoils collector  40 , positioned such to collect and remove the spoils contained within the spoils receiving bay  71  of spoils collector  40  and deposits such spoils into windrow  76 . The spoils enter conveyor  72  at the receiving end  75  located inside of spoils receiving bay  71 , from which they are transferred to along conveyor  72  to the depositing end  77 . As illustrated, conveyor  72  is further comprised of a fixed section  84  and an articulated section  85 , connected at an articulated joint  86 . In this configuration, the articulated section  85  may be positioned at varying angles as required by the job performed. In one example, the articulated section  85  may be raised when creating a deep trench, thus accommodating the amount of spoils created. 
     As illustrated, the conveyor  72  further includes an elongated auger  80  that is disposed within and along a trough  73 . Auger  80  contains a universal joint  82  at approximately the same location as the articulated joint  86  of conveyor  72 , allowing auger  80  to operate as articulated section  85  is angularly repositioned. The auger  80  is operated to transport the spoils from the spoils collector  40  along the trough  73  to depositing end  77 , and to simultaneously mulch the spoils as they are transported along the trough  73 . However, a person of ordinary skill in the art will realize alternative conveyors can be used to relocate spoils while remaining within the scope of the invention. 
     Conveyor  72  may be driven by a conveyor motor  78 . The conveyor motor  78  could be a hydraulic motor, electric motor, or a combustion engine. Alternatively, conveyor  72  can be operatively coupled and driven by drive motor  38 . 
     Trough  73  encloses the sides of conveyor  72 , connecting to the lower portion of conveyor  72  and extending vertically. Inclusion of trough  73  provides containment of the spoils transported by conveyor  72 , prevents spillage. In an alternate configuration, trough  73  may completely enclose conveyor  72 . 
     With continued reference to  FIGS. 2 and 3 , the wheel support assembly  90  rests on the ground via wheels  120 , supporting earth mover  10  as it moves in the travel direction  26 . A drive axel  94  connects wheels  120 , rotating within an axel sleeve  96 . Right and left wheel support arms  92 A and  92 B attach to axel sleeve  96  at right and left support arm hubs  93 A and  93 B, respectively. Wheel support arms  92 A and  92 B pivot about wheel support pivot axis  122 , further connected to the chassis  12  via support arm braces  91 . 
     A hydraulic cylinder  105  is connected to the axel sleeve  96  via a hydraulic hub  95 . Right and left hydraulic pivot braces  98 A and  98 B are attached to the hydraulic hub  95 , allowing a hydraulic axel  97  to connect between the pivot braces  98 A and  98 B. A first end of the hydraulic cylinder  100  connects to hydraulic axel  97 , allowing the hydraulic cylinder  105  to pivot about a first hydraulic axis  124 . Similarly, a second end of the hydraulic cylinder  101  is connected to the chassis  12  via right and left hydraulic braces  102 A and  102 B, allowing hydraulic cylinder  105  to pivot about a second hydraulic axis  125 . By allowing the hydraulic cylinder  105  to pivot about first and second hydraulic axes  124  and  125 , the hydraulic system is able to adjust the trenching height of earth mover  10  by adjusting the length of which hydraulic piston extends from hydraulic cylinder  105 . 
     In another embodiment, earth mover  10  could be self-propelled by an engine, drivetrain, and/or other required machinery known in the art, operatively attached to drive connector  18  of chassis  12 . The self-propelling machinery would be composed of an internal combustion, electric, or other machine. 
     In operation, earth mover  10  is capable of trenching and forming pipeline right-of-ways in areas where low impact soil disturbance is required. Earth mover  10  can remove topsoil, clay, frozen ground, rock, or other earth compositions from below the ground surface  118 . Additionally, earth mover  10  is capable of performing all required processes necessary to move the earth in one pass. First, earth mover  10  breaks up the earth at the cutter  20 , creating spoils ready for collection. Second, earth mover  10  collects the loosened spoils via the stripping blade  50 . Third, earth mover  10  relocates the collected spoils to a convenient position within the spoils collector  40 . Finally, the spoils transfer assembly  70  removes the spoils from the spoils collector  40 , creating a windrow  76  of spoils. 
     Earth mover  10  can be set to ground engaging or non-ground engaging positions  110  and  112 , respectively. During transportation or storage, earth mover  10  will generally be in the non-ground engaging position  112 . Alternately, earth mover  10  will be in the ground engaging position  110  while creating trenches and moving earth. Since the height of cutter  20  is adjustable, earth mover  10  can be easily transported to and from different jobs. By altering the hydraulics on wheel support assembly  90 , the operator can raise the cutter assembly  20  from the ground engaging position  110  to a sufficiently elevated non-ground engaging position  112 , such that earth mover  10  may be safely pushed or pulled to a new location. 
     From the non-earth engaging position  112 , an operator initiates the apparatus by starting rotation of cutter&#39;s  20  cylindrical drum  22  to a speed sufficient to loosen the earth desired, such as 1000 RPM. At this time, the operator will also initiate conveyor  72  to allow the relocation of spoils to a convenient windrow  76 . After initializing, the operator enters the ground engaging position  110  by lowering the cutter  20  to the desired cutting depth. 
     In the first stage of the trenching process  111 , cutter assembly  20  engages the ground surface  118 . The cutting teeth  24  of cutter  20  break up the earth as earth mover  10  moves forward in the travel direction  26 . The operator may select which layers of earth (topsoil, subsoil, clay, etc.) he or she desires to remove by adjusting the cutting depth, via the hydraulics on the wheel support assembly  90 . 
     Once the earth has been broken into spoils by cutter  20 , the spoils encounter stripping blade  50 . The stripping edge  52  of the stripping blade  50  planes the newly loosened spoils from the bottom of the trench  74 . These spoils move up the inclined transport surface  60  of the stripping blade  50 . Although the cutter  20  propels some spoils up the transport surface  60  through its rotating momentum, most spoils are taken by the stripping blade  50  as earth mover  10  travels forward in the travel direction  26 . The force the newly loosened spoils push the remaining spoils across the transport surface  60   
     Next, spoils are received by the spoils collector  40 , where they gather in the spoils receiving bay  71 . The spoils remain here temporarily, until they are removed by conveyor  72  of the spoils transfer assembly  70  and dropped into a windrow  76 . Additionally, spoils removal by the spoils transfer assembly  70  prevents clogging of the spoils collector  40  that could be caused by to excessive spoils in the spoils receiving bay  71 . 
     If the operator desires to refill a trench  74  with the spoils of a previously formed windrow  76 , he or she would simply drive earth mover  10  over windrow  76 . Stripping blade  50  would receive the already loosened spoils, delivering the spoils to spoils collector  40 . Since the distance between the windrow  76  and the trench  74  would be unchanged, earth mover  10  effectively relocates the spoils from the windrow  76  back into the trench  74 . 
     A number of embodiments of the present invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. Accordingly, other embodiments are within the scope of the following claims.