Abstract:
The present invention is directed generally to trenching devices, and more particularly to a trenching device optimized for basement water proofing and other application where it may be preferable to trench near and along a vertical surface. The trenching device has been designed for ease of portability and commercial shipping.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Patent Application No. 61-464918, filed Mar. 11, 2011, the disclosure of which is incorporated herein by reference in its entirety. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention is directed generally to trenching devices, and more particularly to a trenching device optimized for basement water proofing and other application where it may be preferable to trench near and along a vertical surface. 
       BACKGROUND 
       [0003]    Trenchers that use digging chains have long been known in the prior art. Generally, a trencher includes a carriage and a trencher boom that carries a digging chain having a series of digging blades. Typically, the digging chain is carried by a motor driven sprocket wheel and an idler pulley wheel, which are mounted to a frame that can be moved into a digging position. Generally, the frame that carries the digging chain pivots at its base to tilt into contact with a working surface of soil or clay so that the digging chain can excavate a trench as the trencher moves across the working surface. 
         [0004]    U.S. Pat. No. 4,483,084 by Caldwell et al. is exemplary of the prior art. Caldwell&#39;s trencher includes a boom that pivots relative to a carriage so that it can dig at various angles and depths. If a shallow trench is desired, an operator of Caldwell&#39;s trencher would pivot the trencher boom by a shallow angle. If a deeper trench is desired, an operator would pivot the trencher boom of the Caldwell trencher until it reaches a steeper angle. 
         [0005]    One disadvantage of prior art trenchers arises when an operator wishes to dig a curved trench. For example, relatively shallow, circular trenches are needed for receiving the concrete footing of the foundation of a circular structure such as a grain bin or a tank. Trenches of greater depth that are excavated for water or electric power lines must often be dug around obstacles. Because the digging chains of prior art trenchers must generally pivot into a digging position, the digging chain of a prior art trencher contacts a work surface at a shallow angle when it is digging a shallow trench and often penetrates a work surface at a moderate angle when digging a deeper trench. If the trench is to be circular or curved, it becomes very difficult if not impossible to guide a shallow angled digging chain around a curved path while it is digging. A digging chain penetrating a working surface at a shallow or moderate angle will interfere with the walls of the trench if a curved section of trench is attempted. Moreover, in a prior art trencher, the digging chain is cantilevered away from the trencher carriage so that the center of the digging chain will swing through an arc as the carriage turns. Because it is not practical to turn a prior art trencher along a tightly curved path while it is digging a trench, intersecting trench sections must be dug to make a trench around an obstacle. Generally, significant amounts of material will accumulate where sections of the trench intersect. Material that accumulates at these intersections must be removed by hand digging. What is needed is a trencher that can easily dig circular or curved trenches and which can also smoothly transition from digging a straight trench to digging a curved trench when an obstacle is encountered. 
         [0006]    Another prior art trencher device in the prior art includes a mobile, powered base including a boom assembly. The boom assembly includes a first boom member pivotally mounted to the powered base, and a second boom member pivotally mounted to the opposite end of the first boom. A digging chain is looped along the second boom, and a drive shaft transfers power to the digging chain via a ninety-degree drive positioned adjacent the pivotal interconnection of the first and second booms. In use, the first boom is rotated downwardly to a position approximately parallel to the ground surface, and the second boom and chain are oriented approximately vertical. To transport the trencher, the first boom is rotated upwardly to about a forty-five degree angle, and the second boom is rotated upwardly about the pivotal connection to the first boom to raise the digging chain above the ground surface, thereby permitting movement of the mobile base. However, the driveshaft interconnecting the powered base and the ninety-degree drive unit has a single universal joint at each end. Because the universal joints are only operable within a relatively small angular range of motion, the upward rotation of the first boom relative to the powered base is limited. Further, in this type of trencher the ninety degree drive unit rotates with the second boom, such that the universal joint connecting the ninety degree drive unit to the drive shaft is placed at an angle when the second boom is rotated upwardly for transport of the trencher. The range of allowable rotation of the first boom relative to the powered base is limited, as is the rotation of the second boom relative to the first boom such that the overall length of the second boom is necessarily quite short to permit movement of the digging chain above the level of the soil surface for transport. These limited rotational ranges, and the relatively short second boom and digging chain necessarily limits this type of trencher to a relatively shallow trenching capability. 
         [0007]    Accordingly, there existed a need for a durable trencher capable of digging trenches. 
       SUMMARY OF THE INVENTION 
       [0008]    One embodiment of the present invention describes a trencher device comprising a digging bar to excavate material, a motor to activate the digging bar, tires to facilitate relocating the trencher device, a braking assembly to immobilize the device while excavating material, and an auger to displace the excavated material laterally. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    The invention may be more completely understood in consideration of the following detailed description of various embodiments of the invention in connection with the accompanying drawings, in which: 
           [0010]      FIG. 1  shows a schematic representation of one embodiment of the present invention depicting an oblique view of a trencher device. 
           [0011]      FIG. 2  shows a head-on view of the trencher device depicted in  FIG. 1  highlighting the lateral offset of the digging bar. 
           [0012]      FIG. 3  shows a side view of the trencher device depicted in  FIG. 1 . 
       
    
    
       [0013]    While the invention is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit the invention to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims. 
       DETAILED DESCRIPTION 
       [0014]    In general, the present invention is directed to trenching devices, and more particularly to a trenching device optimized for basement water proofing and other application where it may be preferable to trench near and along a vertical surface. 
         [0015]    One embodiment of the present invention is depicted in  FIG. 1  wherein a trenching device  10  is shown at an oblique view. The trenching device  10  is energized by a user via engaging the electrical activation switch  12  located on the distal end of the adjustable handle  14 . Once the electrical activation switch  12  is turned on, an internal motor and drive shaft assembly (not shown in  FIG. 1 ) will engage the digging bar  16 . During operation, an internal chain assembly circulates in a counterclockwise motion from the proximal end  18  to the distal end  20  of the digging bar  16 . In this configuration, dirt  22  excavated during the digging process may be directed away from the digging bar  16  in the direction depicted in  FIG. 1 . 
         [0016]    In a preferred embodiment of the present invention, the digging bar  16  may be offset laterally from the main physical components of the digging device  10  as depicted in  FIG. 2 . In this configuration, while digging a linear trench along a vertical wall, the digging bar  16  may be kept in close proximity to the wall for the entire span of the trench. This feature is a significant improvement over prior art devices. For example, prior art devices typically have the digging bar placed near the centerline of the trencher. In this centerline configuration, while digging a linear trench along a vertical wall, these devices would leave a significant amount of dirt unearthed near the wall structure, which would typically require a follow-on hand dig to expand the trench proximate to the vertical wall. This feature of the present invention enabling a single-pass proximate trench to a vertical wall is highly beneficial when digging a trench as part of a procedure to “water proof” a residential basement or other structure to generate a water barrier near a vertical wall. 
         [0017]    Returning to  FIG. 1 , during the “digging” operation of the trenching device  10 , the trencher may be mechanically constrained to a particular location by brakes prohibiting the rotation of the trencher&#39;s tires  24 . This braking assembly, internal to the trenching device  10  and not shown in  FIG. 1 , may be either mechanically or electronically activated disc brake devices. Also, during the “digging” operation of the trenching device  10 , the counterclockwise motion of the chain assembly in the digging bar  16  naturally tends to pull the trenching device  10  forward. Given that the trenching device  10  is designed to dig a trench in the backward direction, it is highly desirable that the trencher&#39;s tires  24  have a large surface area to overcome the natural forces tending to pull it forward while digging. 
         [0018]      FIG. 1  of the present invention depicts the trencher device  10  configured as a left-side trencher. The left-side auger device (not viewable in  FIG. 1 ) is encased within the auger shroud  26 . The trencher device  10  can be reconfigured as right-side trencher by first disengaging the digging bar  16  and auger shroud  26  from the trencher device  10 . Right-side auger  28  may be removed from its&#39; storage location as shown in  FIG. 1 , and mounted onto the right-side drive shaft assembly on the trencher device  10 . The auger shroud  26  and same digging bar  16  may then be attached to the right-side auger  28  for device operation. The left-side auger may then be placed in the same location where the right-side auger  28  was originally stored. 
         [0019]    The present invention should not be considered limited to the particular examples described above, but rather should be understood to cover all aspects of the invention as fairly set out in the attached claims. Various modifications, equivalent processes, as well as numerous structures to which the present invention may be applicable will be readily apparent to those of skill in the art to which the present invention is directed upon review of the present specification. The claims are intended to cover such modifications and devices.