Apparatus For Embossing Concrete

Technical Field

The present invention relates to an improved em- bossing tool for patterning an impressionable surface material such as freshly poured concrete or other similar plastic surfaces. While the technique of imprinting a design such as a brick or Spanish tile motif on a concrete or similar surface is known, see for example U.S. Patent Nos. 3,406,618 and 4,231,677, the prior art tools principally used to effect a design on a suitable surface are fraught with limitations the sum of which make their use both inordinately laborious .and expensive.

Background Art

In the past, embossing tools for patterning con¬ crete, also known as walking tools, have essentially comprised a platform or grid capable of supporting at least one workman and a plurality of blades formed on the bottom surface of the platform, the arrangement of which defined a particular pattern. On the top surface of the platform, enlarged striking areas were formed above the intersections of the blades as well as above other strategic points along the blades, which when hammered would transmit a driving force to the blade edges.

A prior art embossing tool which does not require hammering is described in U.S. Patent No. 4,231,677 to Roming which is incorporated herein by reference. The structural design of the Roming embossing tool is such that it accomodates only one person, whose weight, when standing with both feet on the platform is suffi¬ cient to provide an effective driving force to the

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pattern blades, hence eliminating the "striking areas" and the need for a supplemental driving or hammering ^' force. The structural design and dimensions of that embossing tool enabled a workman to symmetrically position his weight on the top surface of the tool, thereby causing his weight (driving force) to be evenly distributed along all of the embossing pattern blade edges. The structural design and dimensions of the Roming embossing tool also combined to eliminate flotation, permitted the use of any concrete mix and particularly the standard and more economical mix com¬ prising 3/4 inch aggregates, and facilitated a quick and essentially mistake proof embossing operation.

The platform in the Roming tool is made either of solid metal or formed of solid metal with a plurality of openings. The solid metal design even with the plurality of openings made the tool heavy and awkward to handle. In addition the Roming tool was limited in size to not more than 18 inches square. Because of the size limitation the Roming tool was not capable of covering a large surface area in one application.

Disclosure of Invention

The principal object of the present invention is to provide a tool which eliminates the aforesaid dis¬ advantages of the prior art. According to the present invention, the embossing tool, like those known in the prior art, broadly comprises a metal rectangular platform member, the bottom surface of which is rigidly formed with a plurality of blades arranged in a predetermined pattern. The metal platform has either a solid design or prefer¬ ably is formed with a plurality of openings, the metal platform having a hollowed out channeled structure. It is preferred to have a plurality of openings in the plat- from in order to provide a view of the impressionable surface below the tool to be embossed. The center of the

platform is formed with an opening designed to receive a shaft member, the upper end of which is fitted with a grip. By locating the shaft member in the center of the platform, a workman can uniformly position his feet on the platform to render foolproof the even distribu¬ tion of weight along the edges of the blades.

As a further feature, the platform is formed with at least one recess on each of two adjacent sides of the platform and at least one protrusion on each of the two remaining adjacent sides of the platform. The recess and protrusion are designed to selectively communicate or interlock, respectively, with a protru¬ sion and recess of the platform member of a second identically designed embossing tool. It is further contemplated that the recesses and protrusions are of the same thickness as the platform member and hollowed out in the same manner as the platform.

The platform member and recesses and protrusions formed on the sides thereof are cast so as to have an accentuated draft. Preferably the draft of the platform member is from about six to eight degrees (6°-8°) , principally to facilitate the alignment of the tool with a second cool through respective mating recesses and protrusions. So designed, the embossing tool per- mits an essentially mistake-proof embossing operation. The tool is also designed so that the upper plat¬ form can accommodate one workman who when standing on both feet and in any parallel position on the platform effects a transfer of his weight substantially evenly along the embossing blade edges.

The novel embossing tool is fabricated in accor¬ dance with conventional aluminum, sand casting techni¬ ques. The cast or sand mold is preferably made in two sections in order to impart a double draft to the embossing tool, i.e. a first draft being imparted to

the blade portion by the mold section therefor. The mold for the platform member is designed so as to form hollowed out channels throughout the platform structure. The two mold sections are joined and the resulting casting is of course in one piece. Any durable cast aluminum alloy is suitable for use in the manufacture of the embossing tool of the present invention.

It has been discovered that the embossing tool molded with the hollowed out channeled design has in- crease strength over prior art tools such as Roming which are molded as solid aluminum. The increased strength in the tool is believed to be due to the in¬ creased strength of the aluminum which is due to the hollowed out channeled design of the platform and the method of molding the platform. It is believed that the strength of aluminum is effected by the size and arrangement of crystalline grains in the aluminum. The more uniform the size and distribution of the grain, the stronger tha aluminum casting. During the process of casting aluminum in molds, the grains in the aluminum form* nuclei as the aluminum cools. It is believed that the hollowed out channeled design of the mold for this tool affords a larger surface area for the solidification of the aluminum. The larger surface area allows grains to form in the aluminum which, are smaller and more uni¬ formly sized as well as more uniformly oriented through¬ out the aluminum mold. It is believed that these molding conditions create an embossing tool with significantly greater strength and resistence to warping under pressure. Because of the increased strength the tool is less likely to warp during use and allows for the molding of embossing tools with larger surface dimensions.

The structural design of the novel embossing tool contemplates a hollowed out channeled platform member having the dimensions from about eighteen to thirty-six inches square or about 324-1296 square inches total surface

area. Preferably, however, the dimensions of the hollowed out channeled platform member should be about twenty-four inches square (576 square inches) since these dimensions best accommodate the standard brick and tile patterns. The weight of the platform member is about 15-40 pounds with the weight of the preferred 24" x 24" tool being about 16-17 pounds.

The blade portion of the embossing tool is rigidly connected to the bottom surface of the platform. The perimeter of said blade portion essentially conforms to the overall rectangular dimensions of said platform member so that the total number of square inches of the pattern laid down by impressing the tool into a suitable surface is about equal (depending on the blade pattern) to the total surface area of the platform. V7ithin the foregoing parameters, it is further contemplated that the total number of ineal inches of blade rigidly formed on the bottom of the platform member is between about 98 (inches) to ^" about 300 (inches) . The ^* depth of the blades range from about one to one and a half inches, with a preferred depth being one and one eighth inches. Moreover, the embossing blades are of a generally V- shaped construction, the included angle of which is from about 10° to 30°, but preferably is about 22°. Reference is made to the accompanying drawings which illustrate a preferred embodiment of the novel embossing tool. It should be understood, however, that the invention is not limited to the precise arrangements and structures shown in the drawings.

Brief Description of Drawings

Figure 1 is a three-quarter top view of the embossing tool;

Figure 2 is a three-quarter bottom view of the embossing tool;

Figure 3 is a cross-sectional view of the platform taken along line 3-3 of Figure 1;

Figure 3A is a cross-sectional view of the pre¬ ferred embodiment showing a.deep hollowed out channel;

Best Mode for Carrying Out the Invention

With reference to the foregoing Figures and par¬ ticularly Figures 1-3A, the embossing tool 11 comprises a rectangular weight supporting platform 13, in this instance intended to be a twenty-four inch square, having an upper surface 15, having hollowed out channels 16; an essentially flat bottom surface 17, and essen¬ tially flat interior and exterior side portions, respectively 19 and 21. The upper frame 13 is further formed with a plurality of symmetrical openings 23, defined by a plurality of hollowed out channeled arms 25 which radiate from a center frame portion 27 and which terminate at the interior side 19 and interior corners 29 of frame 13. An opening is formed in the center of the frame portion 27 and is adapted to receive shaft 33, the terminal end of which is fitted with a grip 35. Two adjacent exterior sides of frame 13 are formed with recesses 37 and the remaining two adjacent sides of frame 13 are formed with protrusions 39. Said recesses and protrusions are of the same thickness of frame 13, have hollowed out channels 16 and are designed and located so as to mate, respectively, with corresponding protrusions and recesses of a second embossing tool. The bottom surface 17 of platform 13 is rigidly connected to a plurality of V-shaped blades 41, which in this instance are intended to have an included angle of about twenty-two degrees. Said blades 41 are arranged in a predetermined pattern shown in the drawings as a conventional brick pattern. The blades 41 extend down¬ wardly from the bottom surface of 17 of frame 13 to a depth of about 1 h inches.

Although the various features of the new and im¬ proved embossing tool have been shown and described in detail to fully disclose one embodiment of the invention, it will be evident that changes may be made in such details and certain features may be used without others without departing from the principles of the invention.