Vibrator for screed boards

#Power screed boards and similar apparatus presently are commercially available, and the use of them for and in leveling, settling and/or compacting materials such as concrete is well known. Most, if not all, of the commercially available units are designed and constructed for heavy duty use by, for example, contractors who do a large volume of business. As a result, these units are generally expensive and are far too costly for the contractor who is called upon for an occasional job of laying a concrete patio or the like, and particularly, the handyman who wants to do his own work.

#In U.S. Pat. No. 4,073,593 there is disclosed apparatus which can be easily and quickly removably secured to a length of board to convert or adapt the length of board to a power screed board so as to provide a relatively lightweight, inexpensive power screed board. The disclosed apparatus, while successful in the marketplace, is not entirely satisfactory and a demand for a similar but yet improved, more durable apparatus was created. In particular, many contractors realize the advantages of the disclosed apparatus, especially the portability and the lightweight features associated with it, but found the apparatus to be too spartan.

#Accordingly, the disclosed, do-it-yourself apparatus has been completely redesigned to satisfy the needs of the many contractors who rejected it for one or another reason, and to provide an improved, portable, lightweight vibrator which these contractors now consider a valuable tool of the trade for concrete work. In particular, the vibrator of the present invention is an integral unit which is easily and quickly removably secured to a screed board to vibrate it, and only requires a source of electrical power to operate it. Virtually any 2.times.4, 2.times.6 or larger boards of wood or metal such as aluminum or magnesium up to 20 feet in length can be used as the screed board. When properly installed on the screed board, the vibrator will walk or pull the screed board toward the rough pour, to save time and labor in leveling concrete. Numerous other advantages are provided, as will be apparent from the description below.

#For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description, taken in connection with the accompanying drawings, in which:

#FIG. 1 is a perspective view generally illustrating the portable, lightweight vibrator of the invention removably affixed to a screed board;

#FIG. 2 is a side-plan view of the vibration element of the vibrator;

#Referring now to the drawings, in FIG. 1 a portable, lightweight vibrator 10 exemplary of the present invention is illustrated affixed to a screed board 12. As illustrated, the vibrator 10 is used to vibrate the screed board 12 to level the concrete 16 contained between the forms 14 and 15. With the portable, lightweight vibrator 10, a pour can be leveled faster and easier than seesawing a screed board back and forth by hand. The vibrator 10 is designed to do any concrete job that normally would be done by hand, and it eliminates the hard work of screeding and jitterbugging. No longer do forms need to be hammered to settle the concrete, and it brings finishing paste to the surface without hand troweling.

#More particularly, the portable, lightweight vibrator 10 is formed as an integral unit and includes a U-shaped housing 18 having a top wall 20, a pair of side walls 22 and 24, a bottom wall 26, which is longer in length than the top wall 20 and the side walls 22 and 24, and a pair of depending walls 28 and 30 below the bottom wall 26 and extending the length thereof. The bottom wall 26 is disposed between the top wall 20 and the side walls 22 and 24 and provides a cavity for receiving therein a vibration element 32. The vibration element 32 which is described more particularly below, is supported within the cavity by means of a pair of bearing assemblies 42 and 44.

#The vibration element 32 includes a main drive shaft 34 to which is fixedly secured a weight element 36. A randomly adjustable weight 38 of a generally cylindrical shape is eccentrically secured about the main drive shaft 34 and is adjustably fixedly secured to the main drive shaft 34 by means of a set screw 40. The main drive shaft 34, as can be best seen in FIG. 4, has a punch mark 46 formed in it for providing indicia for adjusting the amplitude of vibration of the vibrator 10, as more particularly described below.