Abstract:
A system and method of facilitating excavating a below grade opening at a construction site in a parcel of land includes a first vehicle having a motor operably connected to at least a pair of traction members and a second excavating vehicle. The motor is operably connected to a first receiver for receiving a signal from a remotely controlled transmitter to actuate the motor. Upon actuation of the motor, the motor rotates the traction members for maneuvering the first vehicle within the opening. The first vehicle has a graduated measurement device mounted generally vertically thereon for remotely controlled vertical telescopic movement. A second beam receiver is mounted to the graduated measurement device for receiving a laser beam from a laser transmitter to facilitate precise determination of the depth of the floor of the opening.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The invention relates generally to a method and apparatus for excavating a basement or like below grade opening. 
   2. Related Art 
   At a construction site, a basement is typically constructed by excavating a portion of a parcel of land. Typically, the excavation must be continually monitored to determine how much more earth needs to be excavated. In a conventional process, an elevation survey is performed utilizing a transit and a target. Commonly, the transit is a laser transmitter used on the ground area surrounding the opening and the target is a laser receiver attached to a grade stick. The grade stick, and thus the laser receiver, is placed into the opening area and as the excavation proceeds, the elevation differential between the target and bottom of the excavation is determined. With this information, the necessary additional excavation can be performed to achieve the desired elevation for the floor of the opening. 
   The conventional crew typically includes a surveyor or transit man and a rod man. The rod man carries the grade stick to the points selected by the surveyor and holds the grade stick in a generally upright or vertical orientation so that the desired data related to elevation can be obtained as the hole is excavated. Excavation is performed and continues intermittently between excavations until the desired elevation is obtained. This measuring and excavating process is repeated until the excavation floor is at the desired elevation and level. 
   The conventional surveying techniques described above can be slow and tedious, since a rod man is needed to move the grade stick to various locations. In addition, the rod man can be subjected to difficulties, such as pests, weeds, brush, and ultimately dangerous situations that may result from depths at the excavation site presenting a risk of cave in. Additionally, the requirement for a rod man increases the possibility for miscommunication between the surveyor and the rod man and the need for two people to accomplish excavation adds inherent costs in the excavation process. 
   SUMMARY OF THE INVENTION 
   An apparatus for use in excavating adds a remotely controlled vehicle having a motor operably connected to at least a pair of traction members. The motor is operably connected to a first receiver for receiving a signal from a remotely controlled transmitter to actuate the motor. Upon actuation of the motor, the motor drives the traction members for maneuvering the vehicle along the floor of the excavation. The vehicle has a graduated measurement device mounted generally vertically thereon with a second receiver mounted to the graduated measurement device. The second receiver receives a laser beam from a laser transmitter to communicate the elevation of the depressed area. 
   Another aspect of the invention relates to the method of excavating and to the method of construction of the system. The method of excavating steps include providing a laser transmitter for emitting a laser beam signal at a predetermined elevation. Next, providing a first vehicle and arranging the first vehicle for remote control operation. Further, mounting a laser receiver to the first vehicle. Further, providing a second vehicle separate from said first vehicle and having an excavator for excavating the opening. Next, maneuvering the second vehicle to at least partially excavate the area in the parcel. Next, maneuvering the first vehicle by remote control within the area of the parcel being excavated to position the receiver on the first vehicle for receipt of the laser beam signal being sent from the laser transmitter. Next, obtaining an elevation measurement from the first vehicle and then, maneuvering the first vehicle by remote control within said area of the parcel being excavated, and lastly, maneuvering the second vehicle to further excavate the area if further excavation is needed to obtain the desired elevation. 
   One advantage of the invention provides a method for excavating a below grade opening that reduces the cost of excavation. 
   Another advantage of the invention provides a reduced possibility for miscommunication and error in obtaining elevation measurements while excavating the opening. 
   Another advantage of the invention provides a method and apparatus for excavating a parcel of land that eliminates the risk of harm to a rod man. 
   Another advantage of the invention provides an economical and efficient method and apparatus to excavate a parcel of land. 
   Another advantage of the invention provides an excavation system that is of relatively simple design and manufacture. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     These and other objects, features and advantages of this invention will become readily apparent from the following detailed description of the preferred embodiments, appended claims and accompanying drawings, in which: 
       FIG. 1  is a schematic side elevational view of a vehicle constructed according to one presently preferred embodiment of the invention; 
       FIG. 2  is a bottom plan view of the vehicle of  FIG. 1 ; 
       FIG. 3  is a perspective elevational view of a transmitter for remotely controlling the vehicle of  FIG. 1 ; 
       FIG. 4  is a schematic perspective view of a parcel of land being excavated with the use of the vehicle of  FIG. 1 ; and 
       FIG. 5  is a schematic electrical control system which may be employed. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Referring in more detail to the drawings,  FIGS. 1 and 2  illustrate one presently preferred embodiment of a elevation measurement vehicle, referred to as a first vehicle  10  for facilitating excavating a basement or other opening O in a parcel of land  14  ( FIG. 4 ). The first vehicle  10  is arranged for remote control operation so that a remote control transmitter  12  ( FIG. 3 ) can send a signal to a first receiver  16  on the first vehicle  10  for maneuvering the first vehicle  10  within the opening O being excavated. The first receiver  16  is a radio frequency or other such commercial device having a microprocessor  17  either integrally formed therewith or separate therefrom and is typically obtainable from a laser equipment retailer. Once the first vehicle  10  is in the desired floor area of the opening O, an elevation measurement may be obtained from a vertically disposed graduated measurement device  18  on the first vehicle  10 . Once the elevation measurement is obtained, the first vehicle  10  may be maneuvered via the remote control transmitter  12  from the immediate area of the opening O being excavated so that additional excavation may be performed by a excavation vehicle, referred to as a second vehicle  20 , represented here as a backhoe  20  ( FIG. 4 ) having an excavator, shown here as a bucket  22 , from which the first vehicle  10  may be controlled. As a result of the first vehicle  10  being operable via the remote control transmitter  12 , the first vehicle  10  eliminates the need to have two persons present to obtain the elevation measurement. Accordingly, the process of excavating the parcel of land  14  is made more efficient, more economical and safer, among other advantages, which are discussed in more detail hereafter. 
   The first vehicle  10  has a pair of front wheels  24  and a pair of rear wheels  26 . Desirably, a pair of endless treads  28 ,  30  are received about the front wheels  24  and the rear wheels  26  for rotation therewith. The treads  28 ,  30  preferably have studs  32  extending outwardly therefrom to facilitate maintaining traction in use. 
   As shown in  FIG. 2 , generally a pair of actuators, represented here as electric motors  34 ,  36  are operably connected to the rear wheels  26 , wherein the motors  34 ,  36  are operable to rotate the rear wheels  26  independently of one another. The electric motors  34 ,  36  are preferably connected to a battery system, represented here as a pair of batteries  38 ,  40 . Desirably, the batteries  38 ,  40  are rechargeable as is known in the art. It should be recognized that any suitable mechanism may be used to couple the motors  34 ,  36  to the rear wheels  26 , for example and without limitation, a pair of chains  42 ,  44  operably connecting a drive gear  46  extending from each motor  34 ,  36  to a driven gear  48  operably connected to a pair of drive shafts  52 ,  52 . Accordingly, actuation of each motor  34 ,  36 , either separately or together, causes respective fore or aft movement of the chains  42 ,  44 . As such, the respective driveshafts  50 ,  52  are caused to rotate the respective rear wheels  26 , thereby driving the respective treads  28 ,  30 . It should be recognized that the chains  42 ,  44  may be replaced with belts, shaft linkages, or the like. It should also be recognized that the electric motors  34 ,  36  could be replaced with hydraulically driven motors, fuel combustion motors, or the like. In addition, the motors  34 ,  36 , though shown operably connected to the rear wheels  26 , could instead be operably connected to the front wheels  24 , or to both the front and rear wheels  24 ,  26 . 
   As shown in  FIG. 2 , the first receiver  16  is shown mounted to a bottom surface  54  of the vehicle  10 . The first receiver is generally powered by a DC battery  55 , though any suitable source of power can be used. It should be recognized that the first receiver  16  could be mounted in any desired location on the vehicle  10 , and that it need not be mounted on the bottom surface  54  as shown here. The first receiver  16  is operably connected to the motors  34 ,  36 , and is shown here to be connected by a pair of wires  56 . Accordingly, the actuation of the motors  34 ,  36  can be controlled via the remote control transmitter  12  by sending a signal from the transmitter  12  to the first receiver  16 , as represented schematically in  FIG. 5 , and disclosed generally in U.S. Pat. No. 5,135,427 to Suto et al., and U.S. Pat. No. 5,882,241 to Mullaney et al., incorporated herein in their entirety by reference. 
   As shown in  FIG. 1 , the first receiver  16  is also operably attached via a wire  58  ( FIG. 2 ) to the graduated measurement device  18 . The graduated measurement device  18  has a grade stick  60  in operable connection with the motor  62  of an actuator  64 . Actuator  64  may incorporate a conventional ball nut and screw actuator device for example. Upon receiving a signal from the first receiver  16 , as shown schematically in  FIG. 5 , the actuator  64  operates to move the plunger  62  between an extended position and a retracted position. As the actuator  64  moves the plunger  62  toward its extended position, the grade stick  60  moves conjointly with the plunger  62 . An enumerated scale  66 , preferably marked in inch or metric units, is marked along the length of the grade stick  60  so that an operator excavating the opening can readily read the number indicia of scale  66  to determine the relative vertical position of the lower surface of the treads with respect to a laser beam emitted from a laser transmitter  72  ( FIG. 4 ), a constant in terms of elevation, the excavator can determine the depth of the floor of the opening from reading the scale and perform any further excavation necessary. The operator preferably maneuvers the first vehicle  10  and adjusts the axial position of the plunger  62 , and thus grade stick  60  between the retracted and extended positions while remaining in the cab or seat of the second vehicle  20  via the remote controlled transmitter  12 , discussed in more detail hereafter. 
   To facilitate obtaining an elevation reading from a level surface, preferably the first vehicle  10  has a debris member or blade  68  operable between a raised position and a lowered position via an actuator  70 . The double acting fluid pressure actuator cylinder  70  is operably connected, generally by a wire  71 , to the first receiver  16  so that the operator can remotely raise and lower the blade  68  by sending a signal from the remote control transmitter  12  to the first receiver  16 . Upon maneuvering the first vehicle  10  to the area of the opening O being excavated, the operator can lower the blade  68  to engage the blade  68  with the floor surface of the opening O being excavated to remove any debris, such as rocks or the like, that may be present on the surface and which would interfere with level determination. Therefore, the first vehicle  10  can be positioned on a generally flat surface in the excavation so that the operator can obtain an accurate elevation reading from the graduate measurement device  18 . 
   As shown in  FIG. 4 , in operation and with an opening O partially excavated, an operator sets up the laser transmitter  72  on transit base  72   a  for emitting a laser beam signal at a predetermined elevation above the floor of the opening O to a second receiver, represented here as a laser target  78 . The laser system illustrated may be one commercially purchased from Spectron Precision, Inc. of Dayton, Ohio such as the 1242. Typically, U.S. patents disclosing suitable laser systems which are incorporated herein by reference include U.S. Pat. Nos. 6,055,046 and 6,292,258. With the laser transmitter  72  emitting a laser beam signal, the operator can maneuver the vehicle  10  into the opening O by maneuvering a joy stick  74  on the remote control transmitter  12 , as shown in  FIG. 3 . Then the operator can lower the blade  68  by actuation of a switch  76  on the remote control transmitter  12  and remove any debris, such as rocks, that may be present in the area where the elevation measurement is to be taken. With the first vehicle  10  in position, the operator can depress another switch or button  79  to extend or retract the graduated measurement device  18  so that target  78  receives the laser beam signal being sent from the laser transmitter  72  and thereby obtain an elevation measurement of the floor of the opening O. Upon the second laser receiver  78  being positioned to receive the laser beam signal, the operator can read the measurement on the grade stick  60  to determine what additional excavation is required. Once the operator obtains the elevation measurement, the first vehicle  10  can be maneuvered away from the area to be further excavated, again through the use of the remote control transmitter  12  by manipulating the joy stick  74  to send a signal to the first receiver  16  and thus, to maneuver the rear wheels  26  and the treads  28 ,  30 , as desired. 
   The operator of the backhoe  20  can continue the excavation process and the measurement process through utilization of the first vehicle  10  until the desired elevation of the area being excavated is obtained. With the operator being able to maneuver the first vehicle  10  via the remote control transmitter  12 , the previous requirement for a second operator to hold the grade stick  60  is no longer necessary. Accordingly, associated costs, time expenditures, risks and the like are eliminated. 
   Preferably, the first vehicle  10  is of a size such that the vehicle  10  can be maneuvered in tight areas. As shown in  FIG. 4 , a common size bucket  22  on a backhoe has a width of about two feet ( 2 ′), and thus, the treads  28 ,  30  on the first vehicle  10  are arranged so that their outer edges are laterally spaced a distance (d) to fit within a two foot ( 2 ′) wide trench. Generally, the distance (d) is just less than two feet ( 2 ′). 
   It should be recognized that the above description represents a currently preferred embodiment, and that modifications can be made to the construction without departing from the scope of the invention. The above is meant to be exemplary and not limiting. The invention is defined by the claims that follow.