The invention disclosed and claimed herein is the work product of a continuing development effort that resulted in the inventions which constitute the subjects matter of the First, Second and Third Parent Cases (referred to collectively hereinafter as the Parent Cases), and provides a number of improvement features that can be used separately from or in conjunction with features of the inventions of one or more of the Parent Cases, as will be apparent from the description and claims that follow, taken together with the accompanying drawings.
Background of the Invention
1. Field of the Invention
The present invention relates to the application of coating constituents to form desired types of coatings on relatively large surface areas that characteristically are referred to as "traffic surfaces," typically roadway surfaces such as highways, streets, driveways, parking lots, runways, taxiways, and tarmacs that are of sufficient size to warrant the use of relatively large power operated machinery to dispense and mix coating constituents to form desired types of coatings, and to spread and apply the mixed constituents to form coatings of desired character that are intended to protect, restore and enhance traffic surface integrity.
More particularly, the present invention relates to a center-fed system for dispensing coating constituents onto a traffic surface, for mixing the dispensed constituents in situ on the traffic surface (to such extent may be needed), for spreading the mixed constituents, and for effecting a controlled application of the resulting coating by utilizing at least one set of rotary tools that extends beneath a wheeled support carriage, with the tools of each such set being connected to a separate, hollow, tubular stub shaft that is journaled for rotation relative to the carriage about the stub shaft's vertically extending center axis. In accordance with a feature of the present invention, at least a portion of the coating constituents that are to be applied to a traffic surface are dispensed onto the traffic surface as by being ducted through the hollow stub shaft(s) for discharge substantially centrally relative to the associated set(s) of rotating tools, whereby the tools are brought into engagement with the deposited constituents to effect desirable types of in situ mixing, spreading and application of the deposited constituents to the traffic surface.
2. Prior Art
In the present document, the term "traffic surface" is used in a generic sense to refer to a wide class of substantially horizontal surfaces such as highways, streets, driveways, parking lots, runways, taxiways, tarmacs, floors of large garages and industrial buildings, loading dock decks, and the like that need to be coated from time to time to protect, restore and enhance surface integrity.
Because traffic surfaces are exposed to wear and often to the effects of the elements, they are subject to deterioration and periodically require the application of coatings to protect, restore and enhance their integrity, and to thereby extend their useful lives. Some traffic surfaces should be coated when constructed, as by the application of a coating that seals exposed surfaces and thereby protects against water penetration that, in winter, can cause spalding or cracking. Many traffic surfaces require protective and reconditioning coatings periodically and/or after the surfaces have been subjected to a certain amount of use.
Due to the wide variety of materials that are used to form traffic surfaces, the wide range of uses to which traffic surfaces are subjected, and the many types of coating constituents that are available to protect against specific kinds of wear and deterioration, there has been a longstanding need for a highly versatile system for dispensing, mixing, spreading and applying coatings to traffic surfaces. The need has been particularly pressing with respect to the protective coating of traffic surfaces of large area such as highways, airport runways, bridge roadways, and the like where manual dispensing, mixing, spreading and application of coating constituents is impractical.
While a variety of proposals have been made for apparatus to dispense, mix, spread and coat large traffic surfaces, most prior proposals have been characterized by drawbacks such as a lack of versatility of the apparatus to dispense, mix, spread and apply coating constituents of a wide range of kinds and types, and/or a lack of adjustability to enable coating applications to be made that differ in desired ways such as thickness and the degree to which the resulting coating conforms to the shape of the surface being coated (e.g., whether the coating tends to smooth or diminish surface irregularities). Indeed, the problems that are associated with efforts to provide a highly versatile traffic surface coating system have been deemed to be so extensive in character that it has become standard practice to design and build traffic surface coating apparatus such that it is intended to apply only a limited selection of coating constituents, with the apparatus being designed for use on only selected types of traffic surfaces.
Further and significant limitations of many prior applicator proposals reside in such drawbacks as 1) their inability to effectively dispense and admix in situ materials such as epoxy substances, fibrous, beaded, or heavy particulates, 2) their inability to effectively dispense and admix in situ quick-setting soluble substances to form uniform slurry compositions, and/or 3) their inability to properly spread and apply resulting coatings.
3. The Referenced Parent Cases
While the referenced Parent Cases address certain of the foregoing and other drawbacks of prior proposals as by providing novel and improved systems that are well suited for use in a wide variety of coating application situations, the approach that has tended to be employed in carrying out the preferred practice of the inventions of the referenced Parent Cases is one of applying coating constituents to traffic surfaces at locations that are spaced from where sets of rotary tools are operating. Typically, prior proposals call for one or more sets of rotary tools to be moved forwardly along paths of travel in order to bring the rotary tools into engagement with deposited coating constituents to effect such functions as the mixing of constituents, and the spreading and application of the resulting coating.
Not specifically addressed by the inventions of the referenced Parent Cases are certain advantages that have been found to result from taking a somewhat different approach than is described above, namely the approach of dispensing selected coating constituents at a central location or at central locations about which one or more sets of rotary tools are moving. The system of the present invention provides such advantages, as will become apparent from the discussion that follows. Thus, while the system of the present invention may, in some modes of practice, make use of a number of features that are disclosed in the referenced Parent Cases, the system of the present invention provides improved method and apparatus features that extend beyond the scope of the referenced Parent Cases.
Summary of the Invention
The present invention addresses the foregoing and other drawbacks of the prior art by providing a system that is capable of dispensing, mixing, spreading and applying coating constituents on smooth and/or irregular traffic surfaces ranging in size from relatively small to relatively large, wherein a power driven apparatus is utilized that carries at least one set of rotary tools, with the tools of each such set being rotated about a separate, substantially vertically extending center axis, and with coating constituents being center-fed as by being ducted along a center axis for discharge onto the traffic surface at a location or locations that are relatively central with respect to one or more associated sets of rotating tools that serve to mix, spread and apply the deposited constituents as the apparatus moves forwardly along a path of travel.
The present invention represents the work product of a continuing development program that also generated the subjects matter of the referenced Parent Cases. An advantage of the present invention resides in the fact that its features do not necessarily exclude the use of or supplant concurrent use of many of the features of the inventions of the referenced Parent Cases. Thus, the present invention can be utilized together with selected features of the inventions of the Parent Cases while, at the same time, providing advantages that result from also utilizing a center-fed system for dispensing selected coating constituents, thereby providing versatility, controllability, ease of use, and many other advantages.
Likewise, features of the present invention also can be employed quite usefully "on their own" so as to provide advantages of a center-fed dispensing system used with at least one array of rotary tools to effect mixing, spreading and application of dispensed coating constituents. Thus, features of the present invention can be utilized in a variety of manners and modes to provide a highly versatile system for dispensing, mixing, spreading and applying coating constituents of a wide variety of types on traffic surfaces of widely differing characteristics and sizes.
In accordance with the preferred practice of the present invention, a system for applying a coating to a traffic surface utilizes a power driven unit that dispenses coating constituents onto the traffic surface as the unit moves forwardly across the traffic surface along a path of travel. The unit preferably includes a wheel supported transport carriage beneath which is provided at least one set of applicator tools that rotates relative to the carriage about a substantially vertically extending center axis. A hollow, tubular stub shaft and bearings preferably are provided to connect the set of tools to the carriage for rotation about the center axis. As the unit moves forwardly, at least a portion of the coating constituents that are being dispensed onto the traffic surface are ducted along the center axis through the hollow stub shaft for discharge substantially centrally relative to the associated set of rotating tools, whereby the set of rotating tools is brought into engagement with deposited constituents, thereby causing the tools mix the constituents in situ, and to spread and apply the resulting mixture of constituents to coat the traffic surface.
In preferred practice, a plurality of storage compartments are defined atop the transport carriage for containing bulk quantities of coating constituents, and an adjustable valving system is provided to separately regulate the dispensing of the coating constituents from each of the storage compartments. While at least one of the storage compartments is utilized to supply center-fed constituents for dispensing at one or more central locations relative to one or more sets of rotating tools, others of the compartments may be used to supply non-center-fed dispensing apparatus (e.g., such dispensing apparatus as is disclosed in the referenced Parent Cases).
In preferred practice, tubular arms pivotally connect with a rotary member that is bearing-mounted on the stub shaft for rotation about the center axis. The tubular arms also pivotally connect with the rotary tools. These pivotal connections permit movement of the tools relative to the rotary member so that the tools can move toward and away from the traffic surface in a manner that assists in maintaining engagement between the tools and the traffic surface as the tools are rotated about the center axis. The weight of the tools and their associated arms preferably serves to bias the tools toward engagement with the traffic surface. Selected ones of the pivot axes about which the tools are movable relative to the arms may be inclined slightly relative to the horizontal (e.g., by about five degrees relative to a horizontal plane) so as to rearwardly incline the blades as they depend from the arms. This slight inclination often is useful in helping to minimize or prevent tool "chatter," and tends to assure that a smooth coating application can be provided by the apparatus.
In preferred practice, a trailing finishing blade depends from rearward portions of the carriage to effect final smoothing of the applied coating, and to minimize wheel marks in the resulting coating. The finishing blade is adjustably connected to the carriage so that it can be adjusted vertically as may be needed to accommodate wear and to assure that the blade is positioned properly with respect to the traffic surface during operation of the apparatus.
While the preferred embodiment of the invention that is depicted in the drawings and that is described later herein includes only one set of rotary tools and defines only one center axis about which a set of rotary tools rotates to effect mixing, spreading and application of coating constituents, it will be understood by those who are skilled in the art that a plurality of rotary tool units, each rotating about a separate, substantially vertically extending center axis, can be utilized to advantage, for example in such "tandem" arrangements as are described and illustrated in the referenced Third Parent Case In one form of practice, the "tandem" rotary tool units are arranged side-by-side so that, as the apparatus is moved forwardly along a path of travel, each of the side-by-side rotary tool units treats a separate portion of the width of a "treatment zone" or "travel path" that is traversed by the apparatus. In another form of practice, at least some of the rotary tool units are arranged relatively forwardly and rearwardly with respect to each other so that as the apparatus is moved forwardly along its travel path, the forward and rearward rotary tool units are brought sequentially into contact with portions of the treatment zone. In this latter form of practice, it is possible (and, indeed preferable in many instances) to utilize the forward and rearward rotary tool units to serve somewhat different but complementary functions. For example, the forward rotary tool units can have their rotary blades urged into contact with the traffic surface area being treated, whereby the forward finishing assemblies serve to mix and spread coating constituents and to work the constituents into the pores of the surface that is being treated--whereas the rearward finishing assemblies can have their rotary blades held in spaced relationship above the surface being treated so that they serve to effect a smooth application of the resulting coating so that it has a predetermined average coating thickness.
In still another form of practice, the forward rotary tool units can (through the use of their hollow stub shafts to duct coating constituents onto the traffic surface being coated) serve to effect a first center-fed dispensing and mixing in situ of selected coating constituents; and, the rearward tool units can (through the use of their hollow stub shafts to duct coating constituents onto the traffic surface being coated) serve to effect a second dispensing and mixing in situ of other selected coating constituents--whereby selected coating constituents can be deposited onto and at least partially mixed, spread and/or applied to a traffic surface before other selected coating constituents are deposited, mixed, spread and applied. Inasmuch as staged or separate deposits of coating ingredients often represent desirable approaches to use in effecting desired types of coating applications (e.g., in conjunction with applications of liquids that are to be mixed with particulates, or in conjunction with applications of constituents that harden or cure when mixed to form epoxy coatings, etc.), the use of staged center-fed sets of rotary tools represents a good example of how features that are disclosed in the referenced Parent Cases can be combined with features of the present invention to provide desired types of system performance.
Other features of the referenced Parent Cases likewise can be used with the system of the present invention, as will be readily apparent from the description and claims that follow, taken in conjunction with the accompanying drawings. For example, center-fed dispensing of certain constituents often is desirable so as to bring the deposited constituents first into contact with the relatively slow moving inner end regions of the rotary tools to effect a relatively gentle mixing, followed by a radially outward distribution and spreading of the mixed constituents (which subjects the mixed constituents to the more vigorous and faster moving action that is provided by radially-outwardly-located portions of the blades) as the application of the coating is effected. However, non-center-fed dispensing (i.e., dispensing at one or more locations forward of the location of rotary tools) often is desirable where the limited mobility of the constituent being dispensed (e.g., sand--which may require a considerable amount of energy to spread across the width of the travel path) can be advantageously spread relatively uniformly onto the traffic surface at a location ahead of the center-fed dispensing of more mobile constituents (e.g., water-like slurries and other non-viscous liquids) which tend to be relatively easy to spread across the width of the travel path as by the action of rotary tools engaging center-fed deposits.
Other advantages that can obtain through the use of features of the inventions of the referenced Parent Cases reside in the provision of finishing apparatus that is capable of effecting uniform, in situ mixing of coating ingredients that range in consistency from very thin, slurry-like liquids to very viscous tar-like gels and/or particulates. Where very viscous ingredients are being used, often it is desirable to utilize arrays of alternating mixing and spreading tools. By way of example (and as is described in detail in the referenced Parent Cases), rake-like mixing tools may be used to break up and mix particulate coating ingredients with viscous slurry coatings so that blade-like spreading tools can effect application of coating materials with a desired degree of uniformity.
Brief Description of the Drawings
The foregoing and other features of the invention will be better understood by referring to the description of the preferred embodiment and the claims which follow, taken together with the accompanying drawings, wherein:
FIG. 1 is a perspective view of a surface finishing apparatus that embodies the preferred practice of the present invention, with the apparatus employing a set of rotary tools to mix, spread and apply coating constituents to traffic surface portions that underlie a wheel-supported carriage portion of the apparatus, with the view showing principally top, front and right side portions thereof;
FIG. 2 is a left side elevational view thereof with portions broken away to permit certain otherwise hidden features to be seen, and with a few hidden features depicted by broken lines;
FIG. 3 is a top plan view thereof with portions broken away to permit certain otherwise hidden features to be seen, and with a few hidden features depicted by broken lines;
FIG. 4 is a rear elevational view thereof with portions broken away to permit certain otherwise hidden features to be seen, and with a few hidden features depicted by broken lines;
FIG. 5 is a left side elevational view, on an enlarged scale, showing components of a finishing blade assembly that is supported by rear portions of the carriage of the apparatus;
FIG. 6 is a right side elevational view, on an enlarged scale, showing components of the carriage, its right rear drive wheel, and selected other apparatus components; and,
FIG. 7 is a left side elevational view, on an enlarged scale, showing components of the carriage, its left rear drive wheel, and selected other apparatus components.
Description of the Preferred Embodiment
Referring to FIGS. 1-4, a preferred form of apparatus or machine for dispensing, mixing, spreading and applying coating constituents to traffic surfaces is indicated generally by the numeral 10. In FIGS. 1, 2 and 4, the machine 10 is shown positioned atop a traffic surface 12.
An imaginary "center axis" of the machine 10 is depicted in FIGS. 1, 2 and 4 by a centerline, indicated by an arrow 40. In FIG. 3, the machine's center axis is depicted by a dot, indicated by an arrow 40. The center axis 40 extends substantially normal to (i.e., substantially perpendicular to) the plane of the traffic surface 12. When the plane of the traffic surface 12 is horizontal (i.e., as it is depicted in FIGS. 1, 2, 4, 6 and 7), the center axis 40 extends substantially vertically. However, if the plane of the traffic surface that is supporting the machine 10 does not extend horizontally, it will be understood by those who are skilled in the art that the center axis 40 will be correspondingly inclined from the vertical. Thus, while for purposes of simplification in many portions of this document, the center axis 40 is referred to by such terms as "extending vertically," it will be understood that such references technically are true only if the traffic surface 12 atop which the machine 10 is positioned extends horizontally, as is depicted in the accompanying drawings. Clearly, the use of such terms as "extending vertically" or "being substantially vertical" in referring to the center axis 40 is not intended to limit the coverage that is afforded herewith.
Referring to FIGS. 1, 2 and 4, the apparatus or machine 10 includes forward and rearward wheels 16, 18 that support a carriage structure 20 for movement across the traffic surface 12. The wheels 16, 18 support the carriage structure 20 so that it is positioned to extend substantially parallel to the plane of such portions of the traffic surface 12 as underlie and are engaged by the wheels 16, 18. When the traffic surface portions that underlie and support the wheels 16, 18 extend in a substantially horizontal plane, the carriage structure 20 likewise extends substantially horizontally.
The carriage structure 20 preferably is formed as a welded assembly of a plurality of lengths of channel-shaped steel members that include such components as a pair of side bars 22 that extend along lower portions of the left and right sides of an upstanding, generally rectangular tank assembly that is indicated generally by the numeral 50; a pair of front and rear cross bars 24 that extend along lower portions of the front and rear sides of the tank assembly 50 (with the bars 22, 24 cooperating to perimetrically surround bottom portions of the tank assembly 50); a trailer bar 26 that extends between and rigidly connects rear end regions of the left and right side bars 22, and that extends in parallel spaced relationship to the rear one of the cross bars 24; and a bottom beam 28 that extends between and rigidly connects with opposed central portions of the left and right side bars 22 (with the bottom beam 28 extending parallel to the front and rear cross bars 24 at a location that intercepts the center axis 40). The components 22, 24, 26 and 28 define a rigid, welded, lower framework (indicated generally by the numeral 21) that receives and supports lower portions of the tank assembly 50.
Similarly, a rigid, welded, upper framework (indicated generally by the numeral 31) is formed principally from channel-shaped steel members and serves to receive and support upper portions of the tank assembly 50. The upper framework 31 includes such components as a pair of side bars 32 that extend along upper portions of the left and right sides of the tank assembly 50; a pair of front and rear cross bars 34 that extend along upper portions of the front and rear sides of the tank assembly 50 (with the bars 32, 34 cooperating to perimetrically surround top portions of the tank assembly 50); and, a top beam 38 that extends between and rigidly connects with opposed central portions of the front and rear cross bars 34 (with the top beam 38 extending parallel to the left and right side bars 32 at a location that intercepts the center axis 40).
A plurality of upright members 42 are welded to and rigidly interconnect various components of the lower framework 21 with corresponding components of the upper framework 31. As will be noted from a review of the drawings, the upright members 42 parallel the center axis 40 but are located principally near corner regions of the tank assembly 50 and near junctures between individual tank-like containers that are carried within the frame structures 21, 31 to comprise the tank assembly 50 (i.e., the uprights 42 preferably are positioned near junctures of front and rear walls with side walls of such tank-like containers 52, 54 as comprise the tank assembly 50, as will be explained in greater detail).
The tank assembly 50 can define a single compartment for receiving coating constituents that are to be dispensed onto the traffic surface 12, or can define a plurality of compartments for receiving segregated quantities of coating constituents. Moreover, the lower and upper frame structures 21, 31 that are described above, may, if desired, be constructed so that the top beam 38 can be removed temporarily from the upper framework 31 to permit substitution of one or more alternate tank-like containers (not shown) in place of one or both of the containers 52, 54 that are depicted as comprising the tank assembly 50, whereby the versatility of the apparatus or machine 10 can be enhanced.
What specifically comprises the tank-like containers that form the tank assembly 50 of the machine 10 are a pair of generally rectangular welded steel tanks that are indicated by the numerals 52, 54. The tank 52 is the larger of the two, and it occupies a central position extending along the center axis 40 and overlying a set of rotary tools 100 that is rotatably supported beneath the carriage structure 20, as will be explained. The large tank 52 extends from side to side within the confines of the lower and upper frameworks 21, 31 so as to define rearward portions of the tank assembly 50. The tank 54 is a smaller tank that is located forwardly with respect to the tank 52 and extends from side to side within the confines of the lower and upper frameworks 21, 31 so as to define frontal portions of the tank assembly 50.
Referring variously to FIGS. 1-4, the large tank 52 has opposed side walls 62 (FIGS. 1, 2) that are engaged near their lower and upper end regions by the side bars 22, 32; has a front wall 63 (FIG. 2) that extends in juxtaposition with a rear wall 73 (FIG. 2) of the small tank 54; has a rear wall 64 (FIGS. 3, 4) that is engaged near its lower and upper end regions by the rear ones of the cross bars 24, 34; has a complexly inclined bottom wall 67 (FIG. 2) with a center portion 68 that is engaged by the bottom beam 28; and has a fixed upper wall portion 69 (FIG. 1) that extends between the side walls 62 and is engaged by the top bar 38. Likewise, the small tank 54 also has opposed side walls 72 (FIGS. 1, 2); has a rear wall 73 (FIG. 2) that extends in juxtaposition with the front wall 63 of the large tank 52; has a front wall 74 (FIG. 1) that is engaged near its lower and upper end regions by the front ones of the cross bars 24, 34; and has bottom wall 77 (FIG. 2) that is inclined forwardly and downwardly, and that carries a transversely extending hinge 78 that pivotally mounts a discharge door 90 that extends across a majority of the width of the front of the machine 10 at a location beneath the front tank 54 for selectively permitting and preventing discharge of contents of the tank 54 onto the path of travel that is being followed as the machine 10 moves forwardly in the direction of the arrow 14.
Dispensing of contents from the forward tank 54 (typically particulate material such as sand) is controlled by a pair of rod-like links 91 that have their lower end regions pivotally connected to opposite end regions of the pivotally mounted door 90. The links 91 have upper end regions that pivotally connect with a pair of levers 92 that are located near forward end regions of the side bars 32. A shaft 93 extends across the front side of the tank 54 to rigidly interconnect the levers 92 for concurrent pivotal movement. An adjustable crank handle 94 is provided to position the levers 92, and to thereby operate the links 91 to selectively open and close the discharge door 90. Contents that discharge through the opening that is controlled by the door 90 are prevented from dropping onto rotating tools 250 (that are located beneath the carriage structure 20) by the forwardly extending skirt 120 which deflects portions of the discharging contents slightly forwardly for deposit along the travel path of the machine 10.
Referring to FIG. 1, a pair of pivoted doors 61 provide access to the interior of the tank 52 or selectively close open top portions of the tank 52. Handles 61a are provided on the doors 61 for pivoting the doors about hinged mounts that are indicated by the numeral 61b. A pair of pivoted doors 71 provide access to the interior of the tank 54 or selectively close open top portions of the tank 54. Handles 71a are provided on the doors 71 for pivoting the doors about hinged mounts that are indicated by the numeral 71b.
Referring to FIG. 2, a central outlet opening 80 is provided in the bottom wall 67 of the large tank 52. The outlet opening 80 extends in coaxial relationship with the center axis 40. Communicating with the outlet opening 80 is an aligned opening 81 that is formed through the bottom beam 28. Welded to the bottom beam 28 is a hollow, tubular stub shaft 120 that communicates with the aligned openings 80, 81, and that depends from the bottom beam 28 so as to extend coaxially along the center axis 40. A discharge opening 122 is defined by the lower end region of the tubular stub shaft 120.
Referring still to FIG. 2, a tapered, stopper-like valve member 84 is provided for controlling the flow of coating constituents from the large tank 52 through the outlet opening 80 and through the tubular stub shaft 120 for downward discharge onto the traffic surface 12 through the discharge opening 122. A control rod 85 carries the valve member 84 and extends upwardly through the tank 52 along the center axis 40 to define a coarsely threaded upper end region 86 that is threaded through a coarsely threaded nut 87. The nut 87 is welded to the top beam 38. An operator control in the form of a handle 88 is provided for threading the control rod 85 through the nut 87 to vertically position the valve member 84 relative to the outlet opening 80. By this arrangement, an operator can move the valve member 84 between positions of seating engagement with such structure as defines the outlet opening 80 to positions that selectively permit and regulate the flow of contents from the tank 52 through the outlet opening 80. The coarse threads provided on the upper end region 86 and within the nut 87 permit the valve member 84 to be moved vertically as by rotating the control rod 85 about the axis 40 through relatively few revolutions so that an operator can effect the desired positioning of the valve member 84 quickly and easily. A guide and support structure 89 is provided within lower regions of the tank 52 to assist in maintaining alignment of the control rod 85 with the center axis 40, and to assure smooth movements of the valve member 84 into and out of seating engagement with such structure as defines the outlet opening 80.
Disposed beneath the carriage assembly 20 and extending in a radially arranged array relative to the center axis 40 is a set of rotary finishing tools 200 that is power driven to rotate about the center axis 40 (as will be described), and that functions to effect mixing, spreading and application to the traffic surface 12 of such coating constituents as are dispensed onto the traffic surface 12 from carriage supported containers such as the tanks 52, 54 of the tank assembly 50 (which also will be described). However, before turning to a description of the rotary finishing tools 200, and before discussing the various modes of operation of the apparatus 10, the discussion that was begun above of various carriage supported components and features thereof will be completed.
Referring to FIGS. 3 and 4, the side bars 22 of the carriage structure 20 extend rearwardly beyond the rear wall 64 of the large tank 52. Rearwardly extending portions of the side bars 22 are bridged by a plate 108. The plate 108 is secured atop the rearwardly-extending portions of the side bars 22, atop the rear cross bar 24, and atop the trailer bar 26, and thereby define a support platform 110 that extends across the back of the machine 10.
Referring to FIGS. 2 and 4, a gasoline engine 150 is rigidly connected to the support platform 110 to provide power for driving the rotary finishing tools 200, and to provide power for driving the rear wheels 18 to move the machine 10 forwardly along a desired travel path. A drive shaft 152 depends from the engine 150 and carries a centrifugal clutch 160. The engine 150 and the centrifugal clutch 160 are conventional, commercially available items that are available from a variety of sources. In preferred practice, the engine 150 is selected to be of the type that will idle smoothly at a speed of about 1,000 revolutions per minute (rpm) and at lesser speeds; and that is of the type that is intended to supply rotary power at speeds within the range of about 1,500 to 3,000 rpm. In preferred practice, the centrifugal clutch 160 is selected to be of the type that must be driven at a speed of at least about 1,500 rpm (or at higher speeds) in order for the clutch 160 to transmit rotary motion from the engine's drive shaft 152 (on which inner diameter portions of the clutch 160 are mounted) to a double V-belt pulley 162 that is defined by outer diameter portions of the clutch 160. By this arrangement, when the engine 150 is shut off or is idling at an engine speed of less than about 1,500 rpm, no rotary motion is transferred from the engine's drive shaft 152 to the double V-belt pulley 162; however, when engine speed is within the range of about 1,500 to about 3,000 rpm, the centrifugal clutch 160 serves to directly drivingly connect the engine's drive shaft 152 to the double V-belt pulley 162 for concurrent rotation.
Referring to FIGS. 1 and 3, a throttle knob 149 is provided near the handle 118 that an operator utilizes to steer the machine 10. By adjusting the knob 149, the operator is able to control the operating speed of the engine 150. A conventional Bowden cable 147 connects with the throttle knob 149 and with the engine 150 in the usual manner to control the supply of gasoline to the engine, and to thereby control engine operating speed.
Referring to FIG. 3 and 4, two V-belts 164, 166 are reeved around and drivingly connect with the pulley 162. The V-belt 164 is relatively short, is reeved around the lower half of the double pulley 162, and extends toward the right side of the machine (i.e., rightwardly with respect to the forward direction of movement of the machine 10, as is indicated by the arrow 14 in FIG. 3) for establishing a driving connection between the pulley 162 and a pulley 172 that is connected to an input shaft 171 of a right angle speed reducer unit 170. An output shaft 173 of the unit 170 carries a sprocket 174. A roller chain 176 is reeved around the sprocket 174 and extends downwardly and forwardly (as is best seen in FIG. 6) to establish a driving connection between the sprocket 174 and a sprocket 175. The sprocket 175 is drivingly connected to a rear axle 125 that drives the rear wheels 18 of the machine 10, as will be explained.
In preferred practice, the reduction in speed that is provided by the speed reducer unit 170 is selected such that, when the engine 150 is operated within a normal range of from about 1,500 to about 3,000 rpm, the rear wheels 18 are caused to rotate so as to drive the machine 10 across the traffic surface 12 in a forward direction 14 at a rate of speed that falls within a normal range of from about 11/2 to about 3 miles per hour.
The other V-belt 166 is reeved around the upper half of the double pulley 162, and extends toward the left side of the machine 10 (i.e., leftwardly with respect to the forward direction of movement of the machine 10, as is indicated by the arrow 14 in FIG. 3) for establishing a driving connection between the pulley 162 and a pulley 182 that is connected to an stub shaft 180. A bearing block, indicated generally by the numeral 181 in FIG. 3, rotatably mounts the stub shaft 180 for rotation relative to the carriage structure 20 about a substantially vertical axis.
The pulley 182 is of relatively large diameter and cooperates with the much smaller diameter pulley 162 to cause the stub shaft 180 to rotate at a relatively slow speed in response to rotation of the clutch pulley 162. Also carried on the stub shaft 180 for concurrent rotation therewith is a relatively small diameter pulley 184. A third V-belt 186 is reeved around the pulley 184 and extends toward the center axis 40 of the machine 10 where it is reeved around a relatively large diameter pulley 188 for driving the pulley 188 at a further reduced speed of rotation with respect to the speed of rotation of the clutch pulley 162. As will be explained in conjunction with the description that follows later herein of the rotary tool unit or assembly 200, the pulley 188 is drivingly connected to the rotary tool unit 200 and serves to rotate the unit 200 about the center axis 200 in a direction of rotation that is indicated in FIG. 3 by an arrow 190.
Referring to FIG. 1, the front wheels 16 are conventional, commercially available swivel caster assemblies that are connected by short post-like spacers 116 to front corner regions of the carriage structure 20. The provision of swivel caster assemblies to comprise the front wheels 16 is desirably in that, as the machine 10 is moved forwardly, the desired path of travel often is of a curved nature, whereby it is necessary for the machine 10 to be guided by an operator who walks ahead of the machine 10 and controls its direction of movement as by exerting force on a handle 118 that extends forwardly from the front cross bar 34 of the upper welded framework 31. To protect the operator from being inadvertently splattered with coating constituents as the rotary tools 200 operate beneath the carriage structure 20, a curved guard member 120 preferably is attached to and depends from the carriage structure 20 at a location extending between the front wheels 16.
Referring to FIGS. 6 and 7 in conjunction with FIG. 1, the rear wheels 18 are conventional, commercially available drive wheels of a type that have center holes for receiving opposed end regions of the rear axle 125. As is best seen in FIGS. 3 and 4, the rear axle 125 extends between the left and right rear wheels 18, and beneath rear portions of the tank assembly 50.
In preferred practice, the wheels 18 are commercially purchased drive wheel assemblies that are available from a variety of manufacturers and distributors, and that are selected to be of the type that each incorporate (as an integral component of its assembly) a one-way clutch (not shown) that 1) provides for transmission of rotary motion from the axle 125 to the wheels 18 in one direction of rotation only, and 2) permits what is referred to in the art as "overdrive" of either of the wheels 18 relative to the axle 125 in said one direction of rotation. By this arrangement, when the axle 125 is driven in a proper direction to rotate the wheels 18 for moving the machine 10 forwardly, a driving force that is imparted to the wheels 18 by the axle 125, and this driving force normally will cause the wheels 18 to rotate in unison, as though they were rigidly interconnected. However, if an operator who is guiding the machine 10 as by applying force to the handle 118 wants to turn the machine 10 (so as to deviate from a straight line path of travel), he or she can apply added forwardly directed force to advance either the left or right sides of the machine 10 at a faster pace than is being provided by the power-driven wheels 18, and the one-way clutches that are incorporated in the wheel assemblies 18 will permit the needed "overdrive" of the left or right rear wheel 18 to take place as may be needed to selectively advance either the left or right side of the machine 10 to thereby effect the desired steering or turning action.
As a more commonly employed and somewhat more conventional alternative, a "differential" unit (not shown) of the general type that is used to transmit rotary drive motion to the left and right rear wheels of vehicles such as automobiles and the like, or other types of drive axle mechanisms that permit rotary drive energy to be transmitted to a pair of axles while permitting some relative movement between the driven axles, may be employed in an appropriate manner, as will be well understood by those who are skilled in the art, in place of wheel assemblies that are provided with one-way clutches. A disadvantage of the use of wheel assemblies that incorporate one-way clutches is that the presence of the clutches often makes it difficult for an operator to reverse the forward movement of a power-driven machine--which, in some instances, may not provide an acceptable solution, especially if the machine 10 is to be used in tight quarters wherein a capability for ease of maneuvering is of importance. An advantage, on the other hand, of the use of wheel assemblies that incorporate one-way clutches is that, if the power-driven machine is being operated principally in an uphill-driven mode, the presence of the one-way clutches often is an asset in preventing unwanted downhill movement of the machine both while the machine is being driven and when the machine is at rest.
Referring to FIGS. 1-3, a finishing blade assembly 130 is supported by rearward portions of the carriage structure 20 and provides a resilient blade-like member 132 that depends from a mounting assembly 134 toward a position of engagement with the traffic surface 12. The mounting assembly 134 includes a pair of brackets 135 that are connected to the carriage structure 20 near opposite sides thereof for mounting the resilient member 132 to extend across substantially the full width of the travel path that is traversed by the machine 10, with the resilient member 132 depending into engagement with the traffic surface at a location behind the rear wheels 18.
Referring to FIG. 5, the brackets 135 define internally threaded, substantially vertically extending holes 137. Externally threaded tubular adjustment sleeves 138 are threaded into the holes 137 and have hex formations 139 near their upper end regions for permitting a wrench to be utilized to thread the sleeves upwardly or downwardly through the holes 137 as may be needed to selectively adjust the position of the resilient member 132 relative to the traffic surface 12. A pair of support rods 140 extend through the sleeves 138. Lower end regions of the support rods 140 define yoke formations 142 that receive upper edge portions of the resilient member 132, and that are connected to the received upper edge portions as by fasteners 144 that extend through aligned holes that are formed through the yoke formations 142 and through the upper edge portions of the resilient member 132. Upper end regions of the support rods 140 are threaded and carry, and carry at least one lock nut 146. Compression coil springs are 148 are interposed between lower end regions of the tubular adjustment sleeves 138 and between the yoke formations 142 to bias the resilient member 132 downwardly toward engagement with the traffic surface 12. By treading the sleeves 138 upwardly or downwardly relative to the support brackets 135, and by selectively positioning the lock nuts 146 on the support rods 140, the resilient member 132 can be positioned such that its lower end region gently engages the traffic surface 12, the permissible range of vertical movement of the resilient member can be defined, and the extent to which the compression coil springs 148 exert a downwardly biasing action on the resilient member 132 can be adjusted.
Referring principally to FIG. 2, but also with occasional reference to FIGS. 3 and 4, the rotary tool unit 200 includes a rotary member 210 that is rotatably connected by bearings 212 to the hollow, depending stub shaft 120 through which coating constituents from the tank 52 are dispensed for deposit onto the traffic surface 12. The rotary member 210 is a four-sided block of steel (see FIG. 3), through which a centrally-extending passage 216 has been formed that is enlarged near its upper and lower end regions to receive the bearings 212. A snap ring 218 (FIG. 2) engages a circumferentially extending groove that is formed toward the bottom end region of the stub shaft 120 to hold a washer 222 in place above the snap ring 218. The washer 222 engages the bottom bearing 212 and assists in retaining the rotary member 210 in place on the stub shaft 120. A sleeve-like spacer 224 is provided atop the upper bearing 212 and extends into engagement with portions 226 of the carriage structure 20 to which the stub shaft 120 is connected.
The pulley 188 is bolted to the upper end region of the rotary member 210 and serves to rotate the rotary member 210 about the center axis 40 preferably within the range of about 40-60 rpm in response to operation of the engine 150 at speeds within the range of about 1,500-3,000 rpm.
Referring to FIG. 3, the four-sided block of steel that forms the rotary member 210 carries four yoke-like formations 230 that extend radially outwardly from the center axis 40, with each of the formations 230 extending substantially perpendicular to its two nearest neighbor formations 230. Inner end regions 242 of four tubular arms 240 are received within the yoke-like formations 230, and are pivotally connected thereto by pivot pins 244 that extend substantially horizontally through aligned holes formed in the yoke formations 230 and in the inner end regions 242 of the tubular arms 240.
Four blade-like applicator tools 250 are positioned beneath outer end regions 248 of the tubular arms 240. The applicator tools 250 can take any of a variety of forms, but preferably take the forms that are described in detail in the referenced Parent Patents, whereby each of the tools 250 has a resilient, blade-like bottom portion 252 that extends upwardly and connects with a rigid support 254 that is pivotally connected to a separate one of outer end regions 248 of the arms 240. In preferred practice, yoke-like structures 256 are defined by the supports 254 to extend along opposed sides of the outer end regions 248, and pivot pins 260 extend through aligned holes that are formed through the outer end regions 248 and through the yoke-like structures 256 to pivotally connect the applicator tools 250 to the radially extending arms 240.
While the arms 240 extend substantially radially with respect to the center axis 40, as is best seen in FIG. 3, the blade-like applicator tools 250 are inclined relative to the arms 240 so that outer end regions of the blades 250 tend to lead inner end regions when the rotary tool unit 200 is rotated about the axis 40 in a forward direction of rotation indicated in FIG. 3 by the arrow 190. Moreover, the pivot pins 260 that pivotally connect the blade-like applicator tools 250 to the tubular arms 240 preferably are inclined relative to the horizontal by a small amount, typically about five degrees, so that upper portions of the blade-like applicator tools 250 tend to slightly lead lower portions of the tools 250 when the rotary tool unit 200 is rotated in the direction of the arrow 190. This slight inclination of the applicator tools to cause the traffic-surface-engaging portions of the blades to trail or "drag" has been found to help prevent tool "chatter," and to help assure that the machine 10 has the capability to apply a smooth coating to the traffic surface 12.
A number of advantages obtain with the use of the above-described type of center-fed dispensing system in combination with a rotary tool unit of the type that has been described, and wherein the dispensing is being carried out as the first step in a process of mixing, spreading and applying coating constituents to a traffic surface. Especially when a quantity of coating constituents that is to be dispensed comprises a runny, non-viscous liquid that is relatively easy to mix, spread and apply, an improved result often obtains if the dispensing takes place centrally relative to a set of rotating tools so that, as the machine that carries the rotating tools moves across a surface that is to be coated, the relatively slowly moving inner end regions of the blade-like applicator tools are first brought into engagement with the newly deposited coating constituents so that a relatively gentle mixing action can be initiated before faster moving blade portions are brought into engagement therewith to effect spreading and application of the resulting coating.
Furthermore, when a relatively non-viscous, easily spread liquid is to be mixed, spread and applied in combination with a relatively heavy dry particulate material such as sand, advantages have been found to exist in using a non-center-fed type of dispensing system for spreading the sand relatively widely across the path of travel, and then by utilizing a center-fed dispensing system with rotating blade-like applicator tools to mix, spread and apply the resulting mixture of coating ingredients.
Still further, the use of a finishing blade to extend substantially the full width across a travel path so as to effect a final smoothing of a center-fed coating mix, spread and apply operation that has been carried out utilizing one or more sets of rotary tools has proved to further enhance the quality of the resulting coating in many instances.
Although the invention has been described in its preferred form with a certain degree of particularity, it is understood that the present disclosure of the preferred form has been made only by way of example and that numerous changes in the details of construction may be resorted to without departing from the spirit and scope of the invention as hereinafter claimed. It is intended that the patent shall cover, by suitable expression in the appended claims, whatever features of patentable novelty exist in the invention disclosed.