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RELATED APPLICATIONS 
     The present invention was first described in Disclosure Document No. 491,345 filed on Mar. 20, 2001. There are no previously filed, nor currently any co-pending applications, anywhere in the world. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to concrete screeds and, more particularly, to a portable, oscillating grade determinant apparatus incorporating laser signal receiver. 
     2. Description of the Related Art 
     As anyone who performs a lot of physical work will attest, nothing beats having the proper tool for a job. The proper tool can save time, save money, produce a higher quality job, reduce damage to equipment, and provide for the increased safety of the worker. Each field of physical work has its own type of specialty tools, each performing a specialized task. The field of concrete finishing is no different. Screed pipes and boards are used to get the wet concrete to the proper elevation. These screed devices are often used with a tripod-mounted laser transmitter to determine when the proper elevation is reached. However, this system relies on tamping down the concrete, checking the elevation, tamping again, then checking again in a trial and error process. Of course if one goes too far, more concrete must be added. This process, while functional, takes a great deal of time, which translates into lost revenue for the professional contractor. 
     Accordingly, there is a need for a means by which concrete can be finished in an accurate manner which is quick, easy and effective. The development of the portable, oscillating grade determinant apparatus incorporating laser signal receiver fulfills this need. 
     A search of the prior art did not disclose any patents that read directly on the claims of the instant invention; however, the following references were considered related. The following patents disclose a screeding apparatus and method incorporating an oscillating attachment: U.S. Pat. No. 6,183,160 issued in the name of Tapio et al.; and U.S. Pat. No. 6,152,647 issued in the name of Tapio et al. 
     The following patents describe a laser-guided portable screed: U.S. Pat. No. 5,288,166 issued in the name of Allen et al.; and U.S. Pat. No. 4,4,752,156 issued in the name of Owens. 
     U.S. Pat. No. 6,129,481 issued in the name of Tapio et al. discloses a screed assembly and oscillating member kit therefor. 
     U.S. Pat. No. 6,089,787 issued in the name of Allen et al. describes a transformable two-person floating screed with automatic grade control. 
     U.S. Pat. No. 5,328,295 issued in the name of Allen discloses a torsional automatic grade control system for concrete finishing. 
     U.S. Pat. No. 4,930,935 issued in the name of Quenzi et al. describes an apparatus and method for pivoting a screed assembly. 
     U.S. Pat. No. 4,655,633 issued in the name of Somero et al. describes a self-propelled screeding apparatus and method. 
     Consequently, a need has been felt for providing a device which allows for the finishing of concrete in a manner which ensures floors are at the correct slope or completely level with a minimal amount of effort and time, which translates into increased revenue for the concrete contractor. 
     SUMMARY OF THE INVENTION 
     Therefore, it is an object of the present invention to provide a concrete grade determinant device which aids in the finishing of concrete. 
     It is another object of the present invention to provide a concrete grade determinant device which replaces the use of screed pipes or lumber. 
     It is still another object of the present invention to provide a concrete grade determinant device which works faster than conventional methods and which saves time and money. 
     It is still another object of the present invention to provide a concrete grade determinant device which provides a one shot operation, thus alleviating trial and error. 
     It is another object of the present invention to provide a tamping plate which forces concrete down to the proper level. 
     It is another object of the present invention to provide a tamping plate which is located at the base of the invention. 
     It is another object of the present invention to provide a metal plate with a triangular void which is rotated by an electric motor. 
     It is another object of the present invention to provide a metal plate with a triangular void which produces an oscillating or vibrating motion. 
     It is another object of the present invention to provide an electric motor powered by rechargeable batteries. 
     It is another object of the present invention to provide an electric motor controlled by a depressible ON/OFF switch. 
     It is another object of the present invention to provide a laser receiver located at the top of the present invention which operates in a conventional manner. 
     It is another object of the present invention to provide a laser receiver which receives signals from a conventional rotating laser transmitter mounted on a tripod. 
     It is another object of the present invention to provide a laser receiver having a speaker for generating an audible beeping sound when proper elevation is reached. 
     Briefly described according to one embodiment of the present invention, a portable, oscillating grade determining apparatus incorporating laser signal receiver is provided to aid in the installation and leveling of poured concrete floors. The present invention is placed upon poured concrete and activated via a depressible ON/OFF switch. An electric motor, powered by a rechargeable battery pack, turns a metal plate that is unbalanced by the removal of a pie-shaped section therefrom. This unbalanced nature produces an oscillating motion, which forces the tamping plate down into the wet concrete. Finally, when a laser receiver located at the top of the present invention receives a laser signal from a separate but conventional laser transmitter mounted on a tripod, the laser receiver beeps, indicating the concrete is now at the proper elevation. At this point, the present invention is removed and the remainder of the concrete can be finished to the same elevation. 
     The use of the present invention allows for the finishing of concrete in a manner which ensures floors are at the correct slope or completely level with a minimal amount of effort and time, which translates into increased revenue for the concrete contractor. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The advantages and features of the present invention will become better understood with reference to the following more detailed description and claims taken in conjunction with the accompanying drawings, in which like elements are identified with like symbols, and in which: 
     FIG. 1 is a perspective view of a portable, oscillating grade determinant apparatus incorporating laser signal receiver according to the preferred embodiment of the present invention; 
     FIG. 2 is a partial right-side elevational view of the portable, oscillating grade determinant apparatus incorporating laser signal receiver according to the preferred embodiment of the present invention; 
     FIG. 3 is a partial left-side elevational view thereof; and 
     FIG. 4 is a bottom side view of the tamping plate according to the preferred embodiment of the present invention; 
     FIG. 5 is a bottom side view of the metal plate according to the preferred embodiment of the present invention; 
     FIG. 6 is side elevational view of the handle and battery housing according to the preferred embodiment of the present invention; and 
     FIG. 7 is a perspective view of the portable, oscillating grade determinant apparatus incorporating laser signal receiver shown in-use. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     1. Detailed Description of the Figures 
     Referring now to FIGS. 1-4, a portable, oscillating grade determinant apparatus incorporating laser signal receiver  10  is shown, according to the present invention, comprised of an elongated grade post  20 , an A-shaped base bracket  30 , a tamping plate  40 , an electric motor  50 , and a laser signal receiver  60 . 
     The grade post  20  is of an elongated, hollow, rectangular configuration telescopically received within a grade post receiving member  24 . The grade post receiving member  24  is of an elongated, hollow, rectangular configuration welded perpendicularly to an upper tier  32  of the A-shaped base bracket  30  (to be described in greater detail below). A posterior end  22  of the grade post  20  telescopes inside the grade post receiving member  24 , and is held in a desired vertical position via a pin assembly  70 . 
     The pin assembly  70  includes a removable, handled pin  72  designed so as to cooperate with a plurality of holes  26  vertically aligned along the posterior end  22  of the grade post  20 . The handled pin  72  is shown located along an outer sidewall of the grade post receiving member  24 , positioned laterally, and extends through a hole  25  formed therein. The handled pin  72  is designed so as to cooperate with a desired plurality of holes  26  formed in the grade post  20 , thus providing a grade post  20  having various vertical lengths. Once a desired vertical length has been chosen, the grade post  20  is held in such position via a clamping pin  74  inserted through a hole  73  formed within an end of the handled pin  72 . The grade post  20  and the grade post receiving member  24  are preferably fabricated of an aluminum metal material. 
     The A-shaped base bracket  30  is fabricated preferably of an aluminum metal material and includes a middle tier  34  for supporting a 12 volt electric motor  50  suitably mounted thereto. 
     The A-shaped base bracket  30  has a pair of legs  36  perpendicularly welded centrally to an upper surface  42  of the tamping plate  40 . The tamping plate  40  is of a generally rectangular configuration having an angularly-oriented, raised lip  45  defining a periphery thereof. The tamping plate  40  has a lower surface  44  with a plurality of elongated ridges  46  welded perpendicularly in a series thereto. The ridges  46  serve to provide some degree of cohesion between the lower surface  44  of the tamping plate  40  and freshly-poured concrete  100  during operation of the present invention. The tamping plate  40  is preferably fabricated of an aluminum metal material. 
     Referring now to FIGS. 1,  2 ,  3 ,  5 , and  6 , rotatably mounted in a perpendicular fashion via a drive arm  52  to the electric motor  50  is a metal plate  54 . The metal plate  54  is designed with a triangular void  55  formed therein, whereupon actuation of electric motor  50  facilitates oscillatory rotation by the metal plate  54 . Actuation of the electric motor  50  is controlled by a depressible ON/OFF switch  56 , electrically connected thereto, mounted along a lower external sidewall of a generally rectangular, elongated handle  57 . The handle  57  is perpendicularly mounted along a linearly elongated centerline of the external sidewall of the grade post  20 . The handle  57  facilitates ease in transportability of the present invention. The electric motor  50  is powered by a rechargeable battery  58 . The rechargeable battery  58  resides within a square-shaped battery housing  59  mounted to an outward end of the handle  57 . 
     Referring now to FIGS. 1 and 7, the laser signal receiver  60  is adapted for receiving laser leveling signals  61  produced by a separate laser transmitter  90 . The laser signal receiver  60  is suitably attached to a rectangular bracket  62  mounted for vertical movement to the grade post  20  above the handle  57 . In order to secure the rectangular bracket  62  to the grade post  20 , a thumb screw  63  is threadedly engaged within a threaded bore  64  of the rectangular bracket  62  until reaching the external sidewall of the grade post  20 , thus allowing for various vertical orientations of the rectangular bracket  62 . The laser transmitter  90  is suitably mounted on a tripod  92  and produces a planar leveling signal throughout an angular reference plane, thus requiring the need for only a single laser signal receiver  60 . 
     In use, the laser transmitter  90  is placed in a desired location and laser leveling signals  61  are generated therefrom. The portable, oscillating grade determinant apparatus incorporating laser signal receiver  10  is placed upon freshly-poured concrete  100 , and the electric motor  50  is turned on via the depressible ON/OFF switch  56 . The metal plate  54  rotates in a vibratory manner so as to produce an oscillating motion which forces the tamping plate  40  downward into the freshly-poured concrete  100 . Upon laser signal receiver&#39;s  60  reception of laser leveling signals  61  transmitted by the laser transmitter  90 , an audible beeping sound is generated from a speaker  65  located on the laser signal receiver  60 , thus indicating the freshly-poured concrete  100  is at proper elevation. At this point, the portable, oscillating grade determinant apparatus incorporating laser signal receiver  10  is removed from the area of freshly poured concrete  100  and the remaining concrete is screeded to the previously determined elevation. The present invention provides a means for determining proper cement elevation in a single attempt, thus alleviating any trial and error process previously required for rechecking elevation levels. 
     Therefore, provided that the laser transmitter  90  remains stationary so as to transmit laser leveling signals  61  being transmitted in a precisely level reference plane, freshly poured concrete  100  can be screeded in a manner which ensures a completely level surface. 
     2. Operation of the Preferred Embodiment 
     To use the present invention, the user places the laser transmitter  90  in a desired location for generating laser leveling signals  61 . The user then places the portable, oscillating grade determinant apparatus incorporating laser signal receiver  10  upon an area of freshly-poured concrete  100 , and turns the electric motor  50  on via the depressible ON/OFF switch  56 , thereby actuating rotation by the metal plate  54  in a vibratory manner so as to produce an oscillating motion which forces the tamping plate  40  downward into the freshly-poured concrete  100 . Upon laser signal receiver&#39;s  60  reception of laser leveling signals  61  being transmitted by the laser transmitter  90 , an audible beeping sound is generated from the speaker  65  which indicates the freshly-poured concrete  100  is at proper elevation. At this point, the user removes the portable, oscillating grade determinant apparatus incorporating laser signal receiver  10  from the area of freshly poured concrete  100  and screeds the remaining concrete to the previously determined elevation. 
     The use of the present invention allows for the finishing of concrete in a manner which ensures floors are: at the correct slope or completely level with a minimal amount of effort and time, which translates into increased revenue for the concrete contractor. 
     Therefore, the foregoing description is included to illustrate the operation of the preferred embodiment and is not meant to limit the scope of the invention. As one can envision, an individual skilled in the relevant art, in conjunction with the present teachings, would be capable of incorporating many minor modifications that are anticipated within this disclosure. Therefore, the scope of the invention is to be broadly limited only by the following claims.

Summary:
A portable, oscillating grade determinant apparatus incorporating laser signal receiver is provided for determining proper cement elevation or slope. The apparatus has an electric motor, powered by a rechargeable battery, and actuated by a depressible switch, which turns a metal plate that is unbalanced by the removal of a pie-shaped section therefrom. This unbalanced nature produces an oscillating motion which forces a tamping plate down into freshly-poured concrete. A laser receiver receives a laser signal from a separate laser transmitter mounted on a tripod. The laser receiver includes a speaker which generates audible beeps to indicate the concrete is at proper elevation.