Patent Application
20180216301
This invention relates to an apparatus and method for cutting non-linear trenches into concrete decks and floors in walk-behind fashion to make the resulting concrete resemble natural stone or flagstone pavers.
Concrete is one of the most common building materials in the world. It is used for sidewalks, foundations, roads and numerous other applications. One common application of concrete is as a material for flooring, both indoors and outdoors, e.g., by pouring concrete into a preformed shape by use of forms fabricated from wood or other suitable materials. Over time, horizontal concrete surfaces (concrete ground surfaces), especially outdoors, suffer from deterioration due to aging, freeze-thaw cycles and other environmental factors. In particular, freeze-thaw cycles and the resultant thermal expansion/contraction create cracks in outdoor concrete surfaces such as sidewalks and roads, and cause it to crumble. Various approaches have been devised to repair these cracks in the hope of prolonging the useful life of these outdoor concrete surfaces. For example, cracks can be cleared of debris, e.g., using hand-held electric grinders and the like, and then filled with caulk or other flexible fillers. Such repairs, however, tend to be unsightly and the caulk tends to dry out and require periodic replacement.
Other attempts to prolong the life of outdoor concrete surfaces involve using conventional grinders to make linear cuts in the concrete to form joints that allow for expansion and that provide a controlled crack direction (following the joint which makes the concrete thinner along its length). However, conventional grinders used for this purpose, namely, for making fresh cuts in concrete without following pre-existing cracks, tend to be limited to cutting straight lines. Conventional handheld grinders also tend to be difficult to operate for extended periods of time, forcing the user to be hunched over in close proximity to the cutting wheel.
Moreover, the foregoing approaches produce surfaces with obviously repaired cracks and linear cuts of limited aesthetic appeal. Thus, a need exists for a system and method for restoring concrete surfaces that addresses the aforementioned issues.
In an aspect of the present invention, a walk-behind apparatus for cutting non-linear trenches in concrete includes a frame supported by at least three ground engaging wheels, including one or more fixed direction wheels at a front end portion of the frame disposed to rotate on a fixed axis of rotation, and one or more multi-directional wheels at a rear end portion of the frame disposed to rotate on one or more movable axes of rotation, to permit the frame to rotate about a substantially vertical axis passing through the frame normal to the ground. A handle at the rear end portion of the frame is engageable by a user walking behind the frame for pushing the apparatus forward and/or for steering the apparatus by pushing the handle left or right. A motor-driven ground-engaging cutting wheel has a cutting wheel axis of rotation, a diameter D in a range of from about 5 inches to about 20 inches, and a cutting portion having a width w in a direction parallel to the cutting wheel axis of rotation within a range of from about 0.5 inches to about 1.5 inches. The cutting wheel axis of rotation is substantially parallel to the fixed axis of rotation and extends notionally through the fixed direction wheels.
The cutting wheel is disposed within a disc-shaped protective shroud sized and shaped to contain a majority of the cutting wheel therein during operation. The protective shroud is disposed in view of the user to permit the user to visually align the shroud and cutting wheel with a non-linear path on the ground while pushing and/or steering, to guide the cutting wheel along the non-linear path.
In particular embodiments, an additional aspect of the present invention includes the cutting wheel having circumferentially spaced metallic segments, the segments each having a cutting surface of convex cross-section in a plane parallel to the cutting wheel axis of rotation, so that during operation, the metallic segments are configured to cut a kerf in a concrete ground surface while the convex cross-section permits the cutting wheel to ride up and/or into side walls of the kerf while steering to avoid binding.
In another aspect of the invention, a method for restoring a concrete ground surface by forming portions resembling natural stone, pavers or flagstone, includes use of the apparatus of either of the foregoing aspects, in which a user engages the handle to steer the apparatus to a desired location on the concrete ground surface. While engaging the handle, the user visually aligns the shroud and cutting wheel with a non-linear path on the concrete ground surface, and actuates the cutting wheel to rotate about the cutting wheel axis of rotation. The cutting wheel is then engaged with the concrete ground surface to cut a kerf, while the user walks behind and steers the apparatus to guide the cutting wheel along the non-linear path.
The features and advantages described herein are not all-inclusive and, in particular, many additional features and advantages will be apparent to one of ordinary skill in the art in view of the drawings, specification, and claims. Moreover, it should be noted that the language used in the specification has been principally selected for readability and instructional purposes, and not to limit the scope of the inventive subject matter.
The present invention is illustrated by way of example and not limitation in the figures of the accompanying drawings, in which like references indicate similar elements and in which:
In the following detailed description, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration, specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized. It is also to be understood that structural, procedural and system changes may be made without departing from the spirit and scope of the present invention. In addition, well-known structures, circuits and techniques have not been shown in detail in order not to obscure the understanding of this description. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims and their equivalents.
As used in the specification and in the appended claims, the singular forms “a”, “an”, and “the” include plural referents unless the context clearly indicates otherwise. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation. All terms, including technical and scientific terms, as used herein, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs unless a term has been otherwise defined. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning as commonly understood by a person having ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and the present disclosure. Such commonly used terms will not be interpreted in an idealized or overly formal sense unless the disclosure herein expressly so defines otherwise.
In particular embodiments, a method and apparatus is provided for allowing an operator to cut non-linear trenches (kerfs) into concrete decks and floors in walk-behind fashion to make the resulting concrete resemble natural stone or flagstone pavers. In particular embodiments, the apparatus include a relatively large diameter segmented grinding wheel configured to produce kerfs of various depths with generally arcuate or concave cross section of various radii. These kerfs and the configuration of the apparatus serves to provide relatively low transverse forces on the grinding wheel to help prevent the wheel from binding in the kerf as the apparatus is steered to produce the non-linear cuts, while the grinding wheel is configured to accommodate remaining transverse forces. These aspects enable the grinding wheel to be relatively large diameter, for enhanced efficiency and relatively long useful life, while still being able to efficiently cut along non-linear paths. A handle-actuated depth gauge allows the operator to move the grinding wheel into and out of the concrete at various predetermined depths. Particular embodiments also include an integrated dust collector.
The present inventor has recognized that when concrete surface repair may be necessary or desirable for structural or aesthetic purposes, it may be desirable to do so in manner that changes the surface shape, and optionally color, to one that resembles natural stones or pavers. Since natural stone and pavers typically have irregular sizes and shapes with non-linear edges, it would be desirable to cut irregular and non-linear patterns into the surface of the concrete in order to achieve the desired resemblance. The inventor further recognized that prior to the invention there was no wheel-supported (walk-behind) or otherwise useful device available that would allow the operator to make these non-linear cuts in a consistent and operator-friendly manner.
For example, it was recognized that one type of commercially available device is a walk-behind floor cutting saw made for straight cuts, such as to cut contraction/control joints. These cuts are relatively deep and narrow requiring relatively large diameter, thin blades, e.g., ⅛″ wide by 20″ in diameter. One skilled in the art would recognize that deviations from a straight cut would tend to bind the blade against the walls of the kerf, potentially damaging and/or shattering the blade. Conventional hand-held floor cutting saws are similarly configured for straight cuts.
Conventional specialty saws may allow a user to follow pre-existing (e.g., non-linear) cracks. However, these saws are generally not adapted for cutting new non-linear trenches. It was further recognized that conventional hand-grinders would generally be incapable of providing desired levels of efficiency in a high volume and/or large scale application, as the operator would quickly tire of holding and operating the grinder.
The instant inventor recognized that in order to cut kerfs in concrete ground surfaces of consistent depth along non-linear paths, without binding and/or shattering the grinding wheel, at least two issues had to be overcome:
Referring now to the Figures, embodiments of the present invention will be described in detail. Turning initially to
In this regard, as shown in
In light of the foregoing, it will be recognized that an aspect of embodiments of the present invention is the provision of relatively large diameter cutting/grinding wheels that are capable of being steered during operation to produce non-linear kerfs.
As shown in
In particular embodiments, the frame 20 is foldable to facilitate storage and transportation, e.g., the frame includes articulating members configured to alternately move the rear end portion 25 away from the front end portion 23 into an operational position, and to move the rear end portion 25 toward the front end portion 23 into a closed, storage position. Referring to
In the embodiment shown, multi-directional wheels 24 are held by free spinning (swivel) castors that permit the wheels' axes of rotation to be rotated 360 degrees about a vertical (z) axis. As best shown in
As best shown in
As also shown in
Moreover, while motor 34 may take any of a number of conventional configurations, in particular embodiments, motor 34 may take the form of a conventional handheld grinder which is removeably supported by frame 20 as shown. In these embodiments, motor 34 and the cutting wheel 26 driven thereby form a substantially conventional unitary assembly that may be easily fastened to the frame for use as shown and described herein, while being easily removed therefrom to facilitate maintenance and/or replacement. For example, this unitary assembly may take the form of a commercially available handheld grinder of the type configured to use grinding wheels of approximately 7″ diameter.
Referring now to
Moreover, while particular embodiments include the aforementioned segmented grinding wheel, it should be recognized that cutting wheels of conventional rectilinear cross-section, such as shown in
As best shown in
It is also noted that the resulting concave shape of the kerf 42 may be sized and shaped to resemble the concave shape of a conventional grout or mortar line. This aspect enables the kerf to be colored and/or coated with a thin layer of grout or mortar once cutting is complete, as will be discussed in greater detail hereinbelow.
Turning back to
Thus, the operator adjusts the total weight of the apparatus by adding or removing weights (ballast plates 62) to or from the receptacle 60. Adjusting the total weight in this manner helps ensure that the cutting wheel 26 penetrates the concrete surface to the desired depth, while being limited by a limit stop, according to different levels of workability (e.g., compressive strengths) of the various concrete mixes that are encountered, and while minimizing the weight that the operator has to push.
In particular embodiments, the cutting wheel 26 is moveable to the desired depth by cutting depth adjuster 66 (
As best shown in
Referring now to Table I, a method 100 for restoring a concrete ground surface by forming portions resembling natural stone, pavers or flagstone is described.
The method 100 includes providing 102 the apparatus shown and described with respect to
While engaging the handle, the user visually aligns, at 108, the shroud 32 and cutting wheel 26, with the non-linear path. Optionally, the visually aligning 108 includes looking 109 along a clear line of sight s extending from handle 30 through the frame 20 to the shroud 32. The cutting wheel 26 is then actuated 110 with motor 34. At 112, the user engages actuator 68 of the depth adjuster 66 to engage the rotating cutting wheel 26 with the concrete ground surface to cut a kerf 42. At 114, the user walks behind and steers the apparatus to guide the cutting wheel along the non-linear path, so that the kerf extends along the non-linear path. The orientation of the grinding wheel between the fixed direction front wheels as well as the multi-directional rear wheels, keep the grinding wheel in the center of z-axis rotation. The convex shape of the grinding wheel allows for smooth turns along the cut path as the operator turns the machine left or right, without binding in the kerf, e.g., by effectively permitting the cutting wheel to ride up and/or into the side walls of the kerf while turning. Once cutting is complete, the operator releases the actuator 68 at 116 so that the spring bias of depth adjuster 66 lifts the cutting wheel 26 out of the kerf.
Referring now to Table II, additional option aspects of method 100 include placing one or more ballast plates 62 on a ballast receptacle 60 of the frame at 122, prior to said actuating depth adjuster 112. At 126, grout or mortar is optionally applied to the kerf, and at 128, color in the form of paint, stain and/or dye is applied to the concrete ground surface and/or to the grout or mortar. It should be recognized that the term ‘concrete ground surface’ refers to the concrete surface forming the ‘ground’ upon which users walk with the walk-behind apparatus 10. The application of color to the concrete ground surface at 128 may thus help make the portions of the concrete bordered by the kerfs resemble flag stones and the like. At 130, the color application 128 includes applying a base color substantially uniformly to the concrete ground surface including the grout or mortar, and then selectively applying a secondary color to portions, e.g., peaks, of the concrete surface texture, in an irregular and/or selective manner, to produce a color distribution resembling natural stone pavers and flagstones.
The present invention has been described in particular detail with respect to various possible embodiments, and those of skill in the art will appreciate that the invention may be practiced in other embodiments. First, the particular naming of the components, capitalization of terms, the attributes, or any other structural aspect is not mandatory or significant, and the mechanisms that implement the invention or its features may have different names, formats, or protocols. Also, the particular division of functionality between the various system components described herein is merely exemplary, and not mandatory; functions performed by a single system component may instead be performed by multiple components, and functions performed by multiple components may instead performed by a single component.
Finally, it should be noted that the language used in the specification has been principally selected for readability and instructional purposes, and may not have been selected to delineate or circumscribe the inventive subject matter. Accordingly, the disclosure of the present invention is intended to be illustrative, but not limiting, of the scope of the invention, which is set forth in the following claims. It should be further understood that any of the features described with respect to one of the embodiments described herein may be similarly applied to any of the other embodiments described herein without departing from the scope of the present invention.
This application claims the benefit of U.S. Provisional Patent Application Ser. No. 62/499,484, entitled MACHINE FOR GRINDING NON-LINEAR TRENCH INTO CONCRETE—501, filed on Jan. 27, 2017, and claims the benefit of U.S. Provisional Patent Application Ser. No. 62/600,566, entitled APPARATUS FOR CUTTING LINE PATTERNS INTO CONCRETE—EXTENDED, filed on Feb. 24, 2017, and the contents of which are incorporated herein by reference in their entirety for all purposes.
| Number | Date | Country | |
|---|---|---|---|
| 62499484 | Jan 2017 | US | |
| 62600566 | Feb 2017 | US |
