Dual Rotor Ride-on Surface Polisher

Abstract

A dedicated concrete surface polisher comprises a frame and powered chassis substantially resembling a twin rotor riding trowel, equipped with a plurality of diamond polishing pucks, and mounting apparatus for maintaining flat puck contact with the lower concrete surface. Each rotor supports an intermediate drive plate driven by a hydraulic motor. The intermediate drive plate comprises a circular ring plate that is reinforced by a substantially rigid, winged drive collar. Each drive plate supports a plurality of radially spaced apart polishing rotors that project into contact with the concrete surface being treated. Each polishing rotor is secured to the ring plate. The polishing rotors support a plurality of radially spaced apart, downwardly projecting, diamond-equipped pucks that frictionally bear against the concrete surface for polishing and abrading in response to rotor rotation.

Description

BACKGROUND OF THE INVENTION

I. Field of the Invention

The present invention relates generally to the treating and smoothing of concrete surfaces with modern diamond-equipped abrasive pucks. More particularly, the present invention relates to dual rotor, concrete riding polishers for finishing concrete surfaces such as floors and the like, of the type that resemble twin-rotor riding trowels. Dual rotor, riding finishers within the focus of this invention have traditionally been classified in USPC Class 404, Subclass 112, and analogous polishing art can be found in USPC Class 451, Subclasses 521-548, and CPC Class B24D, Subclasses 11/00, 13/00, and 99/005.

II. Description of the Prior Art

It is well recognized in the concrete finishing arts that wet or plastic concrete must be processed or finished soon after pouring and before significant hardening, to achieve desirable characteristics. Wet concrete may be discharged from above and poured between spaced-apart forms that may border and traverse regions to be paved, such as bridge decks and the like. Usually wet concrete is poured immediately in front of a concrete finishing machine that may be supported by spaced-apart concrete forms that function as supporting guide rails for the machinery. A variety of finishing devices such as strike-offs, screeds, vibrating screeds, roller screeds or pavers, and bridge deck pavers are known in the concrete arts for preliminary treatment of the exposed concrete. Various propulsion means may be employed for machine displacement over supports for travel along the deck length. It is preferred to vigorously vibrate green concrete after pouring to facilitate desirable concrete consolidation.

Surface treatment of concrete floors may begin soon after pouring and preliminary shaping and striking off. Often the surface treatment may begin with troweling. High power, multiple rotor, hydraulic riding trowels for finishing concrete are well recognized by those skilled in the art. Proper finishing insures that desired surface characteristics including appropriate smoothness and flatness are achieved. It is also important that delamination be minimized. High power, hydraulically driven riding trowels are capable of finishing large areas of plastic concrete quickly and efficiently, while insuring high quality surface characteristics. After ordinary troweling with conventional rotating blades occurs, the surface may be further treated with rotating pans secured to the trowel's rotors that smooth the concrete surface. It is typical these days to follow panning or preliminary surface treating with abrasive grinding and polishing. Many different types of machines for grinding and polishing exist, and these have evolved and improved over the years.

For example, motor-powered polishing or treating machines of the type comprising rotors that are fitted with surface treating devices for abrasively contacting the floor or surface under treatment are well known. Many abrasive-bearing accessories exist that can be mounted to the rotors of typical riding trowels, for example, to convert them into polishers. Successful floor treatments with known finishing machines typically start with an abrasive grit and cycle towards finer grits. For example, cycling from 30-grit to 40-grit metal bonded diamond to eighty-grit metal bonded diamond abrasive and then to 150-grit bonded diamond abrasive or something finer is typical. At this point in the process, a chemical hardener may be applied to the floor's surface to densify the concrete, and polishing begins thereafter. To start polishing, a 100-grit resin diamond bond, may be employed, followed by a 400-grit bond, then an 800-grit bond, concluding with the use of very fine grit ratings between 1500-level and 3500-level.

The following U.S. patents present trowels that may be retrofitted to various aftermarket grinding and abrasive accessories: U.S. Pat. Nos. 4,046,484, 3,936,212, 4,320,986, 4,676,691, 4,878,779, 4,977,928, 5,108,220, 5,613,801, 5,816,740, 5,890,833, 6,089,786, 6,053,660, 6,048,130, 5,816,739, 6,106,193, 6,857,815, 7,108,449, 7,114,876, 7,690,864, 8,388,264, and 8,708,598.

German Pat. No. G9,418,169.1 entitled “Concrete smoothing machine” issued Jan. 26, 1995 to Betontechnik Shumacher GmbH discloses a riding trowel.

As the concept of polishing has been added to the standard practices of panning and blading concrete surfaces, numerous prior art systems have evolved. For example, U.S. Pat. No. 7,147,548 to Mehrabi issued Dec. 12, 2006 discloses a grinding and cutting head used with a rotating disk driven by a grinding and cutting machine. The head supports a diamond cutting element for surface treatment.

U.S. Pat. No. 7,204,745 to Thysell issued Apr. 17, 2007 discloses a circular cleaning disk intended for rotation by a cleaning machine. A number of recesses distributed over the active cleaning surface includes elements containing industrial diamonds used for grinding stone and concrete floors.

U.S. Pat. No. 7,226,347 to Padgett issued Jun. 5, 2007 discloses a walk behind polisher and grinder. A drive motor mounted on a frame provides rotation.

U.S. Pat. No. 7,357,700 to Lundberg issued Apr. 15, 2008 discloses polishing and grinding machine for treating concrete, terrazzo, stone and similar surfaces. Gangs of polishing heads treat concrete and similar surface flooring. A vehicle with a front loader arm supports a module containing the polishing gangs. The vehicle is capable of raising and rotating the module to easily change the pads attached to the polishing heads. Each polishing head is individually powered by a motor and floats over the floor surface. The pads attached to the polishing heads are preferably diamond-impregnated polishing pads.

U.S. Pat. No. 7,481,602 to Lampley issued Jan. 27, 2009 discloses a diamond trowel blade with diamond particles that can attach to a power trowel for surface preparation of hardened concrete surfaces.

U.S. Pat. No. 7,506,644 to Park issued Mar. 24, 2009 discloses a rotatable grinding wheel, with abrasive segments detachably connected to a disc. Abrasive segments are connected to the disc by inserting the fixing protrusions into fixing recesses.

U.S. Pat. No. 7,530,762 to Reed issued May 12, 2009 and U.S. Pat. No. 7,775,741 to Copoulos issued Aug. 17, 2010 disclose methods and apparatuses for surface finishing cured concrete floors using a riding trowel to which large diameter pans are attached. Abraders are releasably secured to the undersides of the pans.

U.S. Pat. No. 7,815,393 to Snyder issued Oct. 19, 2010 discloses an assembly for rotatably mounting a surface processing tool holder on at least one motor-driven, rotatable arm of a surface processing apparatus.

U.S. Pat. No. 9,174,326 to Ahonen issued Nov. 3, 2015 reveals a rotatable floor conditioning device. The instrument essentially comprises a porous washing, polishing, and waxing disk for surface treatment.

U.S. Pat. No. 10,011,999 to Tchakarov issued Jul. 3, 2018 a floor finishing apparatus including a grouting pan configured to be affixed to the rotating head of a finishing machine. Grouting pans are rotated over a prepped surface such that the curved sidewalls trowel the mortar onto the rough composite surface and the bottom surface which is in contact with the prepped floor forces the mortar into the surface voids such that a grouted surface.

U.S. Publication No. 2013/0324021 published Dec. 5, 2013 discloses an abrasive pad for use on hard surfaces that includes a fibrous, non-woven body with an abrasive coating containing diamond-impregnated abrasive elements.

U.S. Publication No. 2018/0369981 published Dec. 27, 2018 discloses a concrete floor trowel machine with blades equipped with a floor polishing jacket or attachment. The attachment may comprise pucks attached with metallic hook-and-loop means.

Another polishing trowel, known as the “Velox T-2440” trowel, is revealed at: https://www.diamaticusa.com/products/grinding-polishing-machines/velo-x-power-trowel.

U.S. Pat. No. 10,370,863 issued Aug. 6, 2019 discloses another polishing arrangement involving the retrofitting of abrasive components to the spider arms of a rotatable spider assembly of a trowel. A rigid mounting bracket has a somewhat rectangular handle for removably attaching the adapter to the trowel spider arm. The generally planar main body of the bracket is circumferentially offset behind the handle for positioning friction disks behind the trailing side of the rotating spider arm. The friction disks support a plurality of usually rotatable “pucks” that contact and grind against the lower concrete surface for polishing. The whole purpose of the disclosed device is to retrofit conventional trowels, particularly motor-powered, multiple-rotor riding trowels, for use in the final stages of grinding and polishing concrete surfaces. U.S. Pat. Nos. 7,815,393, and 11,286,677 are also relevant prior art.

Other Allen Engineering patents of interest include U.S. Pat. No. 5,613,801, issued Mar. 25, 1997, that discloses a power riding trowel equipped with a separate motor for powering each of two rotors. Steering is accomplished with structure similar to that depicted in expired Allen Pat. No. 5,108,220. U.S. Pat. No. 5,890,833 entitled “Hydraulically controlled riding trowel” issued to Allen Engineering Corporation Apr. 6, 1999 discloses a high performance, hydraulic riding trowel using a joystick system that controls steering, propulsion, and blade pitch. U.S. Pat. No. 6,089,786 entitled “Dual rotor riding trowel with proportional electro-Hydraulic Steering” issued Jul. 18, 2000 and U.S. Pat. No. 6,053,660 issued Apr. 25, 2000 and entitled “Hydraulically controlled twin rotor riding trowel” disclose joystick-operated, twin rotor riding trowels. The joystick system therein discussed may be similar to that employed in the instant invention.

Allen Pat. No. 6,106,193 entitled “Hydraulically driven, Multiple Rotor riding trowel issued Aug. 22, 2000 discloses high performance, hydraulic riding trowels for finishing concrete. U.S. Pat. No. 6,857,815 entitled “Acoustic impedance matched concrete finishing” issued Feb. 22, 2005 discloses a method for matching the acoustic impedance of concrete treating equipment to the acoustic impedance of the concrete slab being treated. A twin rotor riding trowel is provided with circular finishing pans that are attached to the conventional rotor blades. Allen Pat. No. 7,114,876 entitled “Acoustically matched concrete finishing pans” issued Oct. 3, 2006 discloses improved acoustically matched pans for riding trowels. Allen Pat. No. 6,048,130 entitled “Hydraulically driven, multiple rotor riding trowel” issued Apr. 11, 2000 a hydraulically-propelled, multiple rotor riding trowel utilizing hydraulic motors and circuitry.

Prior U.S. Pat. No. 11,326,359 issued May 10, 2022 and assigned to Allen Engineering Corporation, discloses an adaptor for retrofitting to a conventional riding trowel rotor, enabling the trowel to function as a polisher. A large, rigid, circular adaptor disk supports a plurality of smaller, spaced-apart, polishing rotors that project into contact with the concrete surface being treated. A plurality of radially spaced apart, downwardly projecting, diamond-equipped pucks projecting from the polishing rotors frictionally bear against the concrete surface for abrading and polishing in response to the rotating trowel rotors. For purposes of disclosure, U.S. Pat. No. 11,326,359 is hereby incorporated by reference as if fully set forth herein. However, the puck mounting arrangement described therein, while functional, is presently thought to be too complex and expensive.

However, despite the efficacy of modern polishing accessories that may be retrofitted to existing finishing trowels, I have found it advantageous to provide a finishing machine specifically designed for polishing or grinding with multiple abrasive pucks, the mounting arrangements for which are not retrofitted to either concrete “walk-behind” trowels or riding trowels.

It is further a critical design characteristic that the mounting hardware for the abrasive pucks maintains the flatness of the pucks against the lower concrete surfaces being processed, even though vigorous bending moments are experienced naturally in response to the rotors. Tilting of the rotors enable trowel or polisher steering during operation, but extreme stresses may be encountered by the rotors and the “puck” assemblies controlled by them.

SUMMARY OF THE INVENTION

This invention provides a powered, twin-rotor, concrete finishing machine for highly polishing concrete surfaces, that somewhat resembles a prior art, twin-rotor riding trowel. However the instant polisher is specifically directed to polishing and abrading, and has no rotor spiders for attachment to polishing accessories. Due to the disclosed heavy duty construction, the dedicated polisher machine is capable of polishing relatively larger areas of concrete than prior art devices in a shorter amount of time. At the same time, damage to rotor spindles is reduced.

At least one relatively rigid, circular drive plate comprises a ring plate that is reinforced by a substantially rigid drive collar. Each drive plate supports a plurality of radially spaced-apart polishing rotors that project into contact with the concrete surface below. Each polishing rotor supports a plurality of radially spaced apart, downwardly projecting, diamond-equipped pucks that frictionally bear against the concrete surface for polishing or abrading in response to rotation. The drive ring is reinforced with a winged drive collar that promotes flat contact of the polishing rotors and their pucks against the lower concrete surface being treated.

Thus a basic object of my invention is to provide a dedicated machine for polishing and abrading concrete surfaces.

Another important object is to provide a powered polishing machine of the character described that is dedicated to optimal polishing. The invention has no complex rotor spiders, has no finishing blades driven by a rotor, and which has no blade pitch adjustment apparatus.

Thus an important object is to obviate the need for “quick change” after-market modifications for riding trowels adapting them for polishing or abrading concrete surfaces.

Another object is to provide a concrete polishing system of the character described that allows for free-floating over the floor.

Another object is to provide a concrete polishing system of the character described that minimizes the number of heads or “pucks” required.

For labor-saving purposes it is an object to provide a concrete polishing machine of the character described that is highly reliable and which is relatively easily repaired or serviced.

Another important object is to provide a riding polisher characterized by reliable, precision steering characteristics.

Further it is an object to maintain optimal puck flatness during operation.

It is also an object to provide a high speed concrete surface polisher that accommodates numerous grinding pucks.

These and other objects and advantages of the present invention, along with features of novelty appurtenant thereto, will appear or become apparent in the course of the following descriptive sections.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following drawings, which form a part of the specification and which are to be construed in conjunction therewith, and in which like reference numerals have been employed throughout wherever practicable to indicate like parts in the various views:

FIG. 1 is a frontal, isometric view of a twin-rotor riding polisher for treating concrete surfaces, constructed in accordance with the invention;

FIG. 2 is a fragmentary, frontal isometric view of the polisher, with the driver's seat, neighboring shrouds and supportive frame structure removed for clarity;

FIG. 3 is a fragmentary, isometric view of the polisher, with upper substructure removed for clarity;

FIG. 4 is an enlarged, fragmentary, isometric view similar to FIG. 3, but with shrouds and other parts removed to expose the rotating disk assemblies and various pucks;

FIG. 5 is an enlarged, fragmentary isometric view of the rotating disk assemblies;

FIG. 6 is an exploded, isometric assembly view of the disk assemblies;

FIG. 7 is an enlarged, plan view of the drive plate, taken generally along line 7-7 of FIG. 6, with portions thereof broken away or shown in section for clarity;

FIG. 8 is an isometric view of the preferred drive plate; and,

FIG. 9 is an exploded isometric view of the drive plate, showing the reinforcing collar in better detail.

DETAILED DESCRIPTION OF THE VARIOUS VIEWS OF THE DRAWINGS

In the accompanying drawings, the reference numeral 20 generally denotes a high-power, twin-engine, hydraulic riding polisher that is designed specifically for concrete surface abrading and polishing. The Allen Engineering Corporation patents discussed previously above, including specifically U.S. Pat. No. 7,690,864 issued Apr. 6, 2010 entitled “Hydraulic Riding Trowel With Automatic Load Sensing System,” are hereby jointly incorporated by reference, as if fully set forth herein, for purposes of disclosure.

Troweling ideally begins over exposed concrete surfaces, such as floor surface 21 (FIG. 1) with panning as known in the art when the concrete is plastic. Pan troweling graduates to blading as concrete cures during the subsequent hardening stages. However, as this technology has evolved over the years, it has become increasingly desirable to further treat the concrete surface beyond mere “blading,” by polishing it to a very fine, smooth surface. It is therefore desirable, particularly with large, demanding jobs, to employ a machine specifically designed for polishing and fine finishing, without using retrofitted gadgets and the like.

Referencing FIG. 1-4, the polisher 20 utilizes a chassis and frame similar to those described in the aforementioned Allen Engineering Corporation riding trowel patents. A polisher operator (not shown) comfortably seated within seat assembly 23 (FIG. 1) can operate polisher 20 with a pair of easy-to-use joysticks 26, 27 respectively disposed at the operator's left and right side. Details for the joystick controls are illustrated profusely in one or more of the above-referenced Allen patents. Throttle control is provided by a mechanical, foot-operated pedal 30 that is accessible from seat assembly 23 located atop the frame assembly 34. Pedal 30 controls rotor speed. A pair of spaced-apart rotor assemblies, that are hidden behind ventilation panels 25 and other shroud-like structure are dynamically coupled to the frame assembly 34, and extend downwardly into the proximity of concrete surface 21 (FIG. 1) as is well known in the riding trowel art. Each rotor assembly is independently, pivotally suspended from the polisher 20 with tilting structure detailed in several of the above-mentioned Allen Engineering Corporation patents that is enabled by cross-head 39 (FIG. 6.). Preferably, the twin rotors are each driven by a hydraulic motor 47 (FIG. 6) known in the art, that may be cooled with a conventional heat exchanger disposed to the right (as viewed in FIG. 1) of a seated driver within a compartment 37. The hydraulic drive pump is driven by a gas (i.e., propane) motor 32 (FIG. 2).

Propane gas is stored within tank 36. An air cleaner 38 admits air into the propane motor 32, and engine cooling is provided by radiator 50 (FIG. 2). A substantially rigid front deck 24 is disposed below the polisher operators position. As operation progresses, dust and slurry generated by concrete dust and particles and water is substantially confined below the polisher 20 by a lower, circumferential shroud 43, that minimizes dust and confines the resultant slurry to prevent it from splashing adjacent walls and workmen.

Preferably, each end of the polisher 20 is provided with a removable dolly attachment 40 comprising a bracket 42 for removably pinning it to the main frame. With handles 45 suitably rotated, dolly wheels 46 can be deployed, extending downwardly into contact with surface 21 for elevating the polisher 20 so it can thereafter be conveniently moved to desired locations without running the motor(s), and without scratching or marring traversed surfaces. Preferably the polisher 20 is provided with a water spray system of the type used previously with Allen Engineering Corporation trowel designs. Water for spraying is stored withing a water tank 54 (FIG. 3) which may be conventionally plumbed as in previously cited Allen Engineering Corporation patents.

Unlike conventional riding trowels, that use multiple rotating blades for finishing, there is no blade system used with polisher 20. Therefore there is no need for a blade pitch control system, with all of the attendant accessories and components and wiring that such systems utilize.

The self propelled riding polisher 20 is thus able to quickly and reliably traverse and finish extremely large areas of concrete surface 21, with the suitable abrading devices explained below.

Referring now to FIGS. 5-6, an abrasion assembly has been generally designated by the reference numeral 60. Assembly 60 is suspended from the lower polisher chassis 62 (FIG. 4) by a cross-head 39 that enables rotor tilting for steering and control, as explained in detail in the previously cited Allen riding trowel patents mentioned above. Cross-head 39 is mechanically secured to a generally cubicle hydraulic motor casing 63 that protectively shrouds a hydraulic motor 47 that turns the abrasion assembly. Motor 47 comprises a rigid flange 65 that is attached with suitable fasteners 66 (FIG. 6) to a generally circular, intermediate drive plate 67 that supports a plurality of rotatable, radially spaced apart planetary abrasion rotors 70. Each of the planetary abrasion rotors 70 may be constructed in accordance with the abrasion rotors of my prior U.S. Pat. No. 11,326,359, issued May 10, 2022 that is assigned to Allen Engineering Corporation and herein incorporated by reference. The latter reference discloses an adaptor for retrofitting to a conventional riding trowel, enabling the conversion of prior art riding or walk-behind trowels to function as a polisher.

Each circular abrasion rotor 70 supports a plurality of smaller, radially spaced-apart, rotary abrasion tools 74 (i.e., “pucks”) comprising abrasive diamond material that directly contacts the concrete surface. Each abrasion tool 74 may take the form of a puck constructed as disclosed in U.S. Pat. No. 11,326,359, but a variety of commercially available grinding and polishing pucks known in the art may be employed. For example, a variety of abrasion and surface treatment tools, including pads and pucks, are available from the Runyon Surface Prep Company, www.runyonsurfaceprep.com, and these are adapted for surface removal, grinding, honing, polishing and burnishing. As used herein the term “puck” means any of the latter surface-contacting abrasive elements, or any other polishing disk either in the general form of a truncated cylinder, or having a flat surface to which abrasive components or elements such as diamonds or other hard substances or minerals may be affixed.

Each abrasion rotor 70 (FIG. 6) comprises a circular disk portion 77 supporting an upper flange 78 concentrically disposed beneath a bearing 79. Each flange 78 is compressively sandwiched between disk portion 77 and bearing 79 by a plurality of fasteners. Each of the bearings 79, and thus each of the abrasion rotors 70, are fastened to the intermediate drive plate 67 at radially spaced apart locations about the periphery.

The intermediate drive plate 67 (i.e., FIGS. 7-9) is generally circular, and its configuration enables enough mechanical compensation during rigorous operation to ultimately maintain the grinding pucks and the abrasion rotors generally substantially flat against concrete surface 21. The intermediate drive plate 67 comprises two major components, namely a ringed base plate 80 and a companion reinforcing collar 81 that are coaxially secured and flushly pancaked together with suitable fasteners. The outermost, circular ring portion 82 of ringed base plate 80 is concentric with an inner, circular orifice 84. There are a plurality of integral, radially, spaced-apart connecting segments 83 forming the ring portion 82. Segments 83 extend generally peripherally between integral spokes 85. Voids 87 are bordered by spokes 85, peripheral segments 83, and center orifice 84. Voids 87, which facilitate flexing and reduce weight, are generally in the shape of ovals. Each abrasion rotor 70 is secured to the intermediate drive plate 67 by elongated fasteners 90 (FIG. 6) that penetrate an abrasion rotor 70 and a bearing 79, being seated within and threadably secured to a suitable bung 93 (FIGS. 8, 9) formed in the radial periphery of drive plate 67.

The rigid collar 81 reinforces the intermediate drive plate 67, and it provides a mechanical connection point for the hydraulic motor 47 (FIG. 6). The reinforcing collar 81 has a central circular base portion 91 concentric with internal orifice 92. Base portion 91 is penetrated and secured by suitable fasteners (i.e., bolts) that secure hydraulic motor 47. A plurality of integral, radially spaced apart arms 95 extend from the central orifice 92 and, in assembly, overlie the spokes 85 of ringed base plate 80, facilitating limited flexure without drive plate deformation.

From the foregoing, it will be seen that this invention is one well adapted to obtain all the ends and objects herein set forth, together with other advantages which are inherent to the structure.

It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations.

As many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

Claims

1. A self-propelled polisher for treating concrete surfaces, the polisher comprising: a chassis adapted to be propelled over a concrete surface;at least one downwardly projecting, rotatable rotor;a motor for actuating the rotor;the rotor comprising an intermediate drive plate;the intermediate drive plate comprising a ringed base plate and a winged drive collar for reinforcing the winged base plate;a plurality of planetary abrasion rotors supported by said intermediate drive plate that contact and finish the concrete surface.

2. The polisher as defined in claim 1 wherein the ringed base plate comprises an inner, circular orifice, a ring portion concentric with said inner, circular orifice, and a plurality of integral, radially, spaced-apart spokes facilitating flexure.

3. The polisher as defined in claim 2 further comprising a plurality of voids bordered by said spokes and said ring portion.

4. The polisher as defined in claim 3 wherein said drive collar is flushly secured to said drive plate.

5. A self-propelled dedicated polisher for treating concrete surfaces, the polisher comprising: a chassis adapted to be propelled over a concrete surface;at least one downwardly projecting, rotatable rotor;a motor for actuating the rotor;the rotor comprising a generally circular intermediate drive plate;the intermediate drive plate comprising a circular base plate with a peripheral ring and a flushly mounted winged drive collar for reinforcing the base plate;the base plate plate comprising a peripheral ring and a plurality of spokes;the drive collar comprising a plurality of arms overlying the spokes in assembly;a plurality of planetary abrasion rotors supported by said intermediate drive plate that contact and finish the concrete surface, said abrasion rotors supporting puck rotors for contacting and finishing concrete.