Patent Application
20110299924
The present invention relates in general to concrete and masonry construction, and, more particularly, to an apparatus and method for introducing pigments, colorants and other additives to the surface of plastic concrete.
Concrete can be molded into a variety of shapes and configurations including driveways, decks, concrete masonry units (CMU), blocks, beams, columns, decorative stones, mosaics and facades as examples of decorative concrete applications. Many of these products include a colorant or pigment which provides color to the application. Concrete additives such as plasticizers, pigments, colorants or dispersants are added to concrete mixes in order to increase the plasticity of the concrete, which improves the workability of the concrete prior to hardening. Color pigments may be added to concrete mix in order to produce a certain color for aesthetic enhancement of the concrete.
The addition of concrete pigment and other admixtures or additives to concrete mix is known in the art. For example, U.S. Pat. No. 7,270,469 discloses an apparatus and method for adding pigmentation to a concrete mix by using a pigmentation dispenser with a hopper and two rotors wherein the pigment is dispensed onto concrete mix traveling on a conveyor. The concrete mix and dispensed pigment are then conveyed to a mixer which mixes them together. However, such methods require the addition of pigment to the entire batch of concrete to be mixed resulting in a monolithic coloring of the entire concrete mixture, some of which will never be seen or viewed as certain of the concrete structure surfaces after finishing will face the ground or other structures and remain hidden from view. As a result, there is a certain waste volume of pigment generated in such mixing and coloring regimes. Likewise, if a deeper color is required, then the entire batch of colored concrete must be reintroduced to the coloring and mixing system again resulting in the additional waste of colorant to color then entire batch of concrete to be manipulated into a slab, façade, or CMU. Moreover, these methods of adding color hardeners or additives to a concrete mix or slab are performed prior to finishing or shaping of the concrete, thereby increasing the time required to complete the process or project.
The addition of color additives to cast in place concrete has traditionally been by hand. As a plastic concrete slab is being finished, a worker will take a handful of powderized color hardener and disperse it over the slab, in effect flinging a handful of dry color hardener powder into the air which disperses and falls by gravity on to the wet or plastic concrete surface. A color hardener is a powder that is applied to the surface of plastic, cast in place concrete. It colors the concrete and acts to “harden” the concrete slab.
This method of color hardener application has serious drawbacks. For example, the color hardener powder is dispersed erratically in an uncontrolled amount and in variable concentration on to the concrete slab, which can result in a non-uniform color. Depending on prevailing environmental conditions (e.g. wind), a substantial amount of the color hardener is dispersed and deposited on other surfaces close to the slab and goes to waste, as well as potentially bleeding color undesirably on other surfaces. A more serious drawback is that the powder may be inhaled by the worker and other workers on the site, potentially leading to detrimental physiological effects (sneezing, asthma or other undesirable health conditions). As a result, a need exists for an apparatus and method which effectively and safely broadcasts concrete color hardener or other additives on to a plastic cast in place slab.
Therefore, one object of the present invention is to provide an apparatus and method for the controlled dispensation and application of concrete colorants or additives to concrete surfaces without the need to monolithically mix such colorants or additives prior to finishing or manipulation of the concrete into the desired shape or structure.
A further object of the present invention is provide an apparatus and method which provides a mechanism by which pigments or other additives may be introduced to the concrete mixture in specific areas in the discretion of the operator as the concrete is being finished.
A further object of the present invention is the provision of an apparatus and method for introducing color hardener or other additives to concrete mix which is efficient in operation and conserves the volume of additive required to complete the concrete treatment process.
In accordance with the present invention, a method and apparatus for broadcasting dry color hardener while finishing a concrete surface is provided as disclosed herein. The apparatus comprises a concrete float with a vibratory broadcaster assembly attached therewith. The broadcaster assembly is suspended above the plane of the finishing tool, such as a bull float or other finishing tool, with a vibratory source attached. The broadcaster assembly is filled with color hardener or other additive and the apparatus is placed on a wet, concrete surface which is to be treated and finished by a user. Actuation of a power switch activates the vibratory source resulting in the substantial broadcast of color hardener on to the plastic concrete surface at the desired location(s) as determined by the user. The color hardener or other additive is then integrated into the concrete by passage of the float or finishing tool over the concrete surface.
Other technical advantages of the present invention will be readily apparent to one skilled in the art from the following figures, descriptions and claims. While specific advantages and embodiments have been enumerated above, various embodiments may include all, some, or none of the enumerated advantages.
The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself, however, as well as a preferred mode of use, further objectives and advantages thereof, will be best understood by reference to the following detailed description of illustrative embodiments when read in conjunction with the accompanying drawings, wherein:
For purposes of teaching and discussion, it is useful to provide some overview as to the way in which the invention disclosed herein operates. The following information may be viewed as a basis from which the present invention may by properly explained. Such information is offered for purposes of explanation only and, accordingly, should not be construed to limit the broad scope of the present invention and its potential applications.
In one embodiment, the switch 10 may detachably secured on or about the person of user 2, such as clipped to the user's belt or suspended about the user 2 with a strap or button. This allows the user 2 to broadcast the color hardener 8 in areas on surface 12 as desired without the aid of additional persons. In another embodiment switch 10 may rest on the ground, along with variable control switch 32 or without, and be controlled by the user 2 or another person as desired. As shown in
Turning to
Broadcaster 28 includes screen 42 secured to screen frame 44. Screen 42 is comprised of a mesh or metal type screen with holes of punched therein to allow for additive flow through the screen 42 upon activation of the vibratory source 30 which imparts vibrations or shockwaves to the broadcaster 28 causing the dispersion of additive through the holes in screen 42. In one embodiment, screen 42 is made of 050 gauge aluminum metal with 3/32 inch diameter staggered holes punched therein. Screen frame 44 is constructed of aluminum metal or other suitable structural material. Screen frame 44 acts to support screen 42 and also as a containment wall around the perimeter of screen 42 for keeping the additive poured on to the screen 42 surface in place and ready for application. In one embodiment, screen frame 44 is made of aluminum metal tubing or channel of sufficient strength to contain and support screen 40 when loaded with additive for broadcast. In the embodiment shown, vibratory source 30 is attached to the broadcaster 28 by weld, bolt or other attachment means as known in the art.
Broadcaster 28 is secured to and supported by float plate 22 via upper supports 38 and lower supports 40. The upper supports 38 and lower supports 40 are secured to the float plate 22 via the float plate mount bracket 24 by weld, bolt or other attachment means as known in the art. Upper supports 38 and lower supports 40 are secured to the broadcaster 28 by weld, bolt or other attachment means as known in the art. Vibratory source 30 is detachably secured to the broadcaster 28 by weld, bolt or other attachment means as known in the art. Vibratory source 30 may be attached to the broadcaster 28 at any suitable attachment point and its position shown in the Figures herein is not to be construed as a limitation of the architecture disclosed herein.
With reference to
Turning to
In the depicted embodiment, vibratory source 30 is comprised of an electric motor with offset weights attached to a driveshaft dispensed therein so as to provide a source of vibrations or shock waves sufficient to induce the flow of additive resting on the top surface of screen 42 through the holes in the screen 42 and down on to the concrete surface being finished. A variable speed vibratory device may be utilized with the vibratory cycle speed controlled by the user via the control switch or a variable speed switch or both. As the cycle speed is increased, the amount of color hardener or additive broadcast increases, thereby resulting in a higher concentration of additive being applied to the concrete surface. As the vibratory cycle speed is lowered, smaller volumes of color hardener or additive are dispersed resulting in lower concentrations being applied to the concrete surface.
In application and with reference to the all of the figures herein described, a user can utilize the broadcast float apparatus 10 to selectively apply additives to the desired areas of a concrete slab which is being finished. For example, a spotted color pattern could be easily colored into the concrete using the apparatus and method disclosed herein. Additionally, the apparatus 10 allows a user to apply color hardener or other additives in areas of a plastic slab where traditional “hand throwing” techniques could not be utilized. The operator may simply add the requisite number of tool extension poles to position the apparatus 10 in the desired area for the broadcast of color hardener or other additives. Likewise, in other embodiments of the invention it may be desirable to use a plasticizer in select portions of the plastic slab being finished to alter or extend the curing time for a certain portion of the slab. This would facilitate light foot traffic on portions of the untreated slab and allow users to insert forms, columns or other objects in select areas of the slab which have remained in a plastic, uncured state.
While the invention has been particularly shown and described with reference to a various embodiments, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention.
