Wheel coupler and scraper for floor stripper

A drive wheel assembly for a floor stripping machine permits a drive wheel to be selectively locked to and unlocked from a drive axle and reduces the quantity of debris that is able to accumulate on the tire of a wheel during a floor stripping operation.

CROSS-REFERENCED TO RELATED APPLICATIONS

Not applicable.

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BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates generally to machines for stripping materials, such as adhesively bonded floor coverings from floor surfaces, and more particularly to an improved machine of this type incorporating at least one driven axle, at least one wheel and a novel coupler adapted to selectively couple the wheel to the axle so that the wheel may be driven by the axle and decouple the wheel from the axle so that the wheel may rotate freely about the axle. A novel wheel scraper is also disclosed that is adapted to remove debris from the surface of the wheel irrespective of the direction of rotation of the wheel.

2. Discussion of the Prior Art

In 1979, Lloyd E Anderson was awarded U.S. Pat. No. 4,162,809 on a motorized carpet and tile stripping machine that comprised a box-like housing mounted on a pair of wheels disposed near the rear of the housing and a cutting blade projecting outwardly from the front of the housing and adapted to engage the ground beneath a floor covering that had been adhesively bonded to the floor. Supported on an upper deck of the housing was an electric motor whose output shaft was coupled to the machine's cutting head by means of an eccentric drive shaft such that the cutting head was made to move in an orbital or elliptical pattern. An elongated handle was also affixed to the upper deck of the housing and sloped rearward and upward terminating in handle grips.

When this machine was used to strip a floor covering, such as adhesively bonded carpeting from a concrete floor, the operator would first use a knife to cut the carpeting into strips. Next, the stripping machine would be placed at one end of the cut strip with its cutting head disposed in the interface between the carpeting and floor. The operator would then activate the motor to cause the cutting blade to orbitally rotate while he manually urged the machine forward by pushing against the handle.

While the machine made in accordance with U.S. Pat. No. 4,162,809 was somewhat effective in its operation, it required a high degree of manual effort and vibrated excessively making it somewhat difficult to control.

In 1986, Lloyd Anderson's son, Martin, was awarded U.S. Pat. No. 4,626,033. In this patent, Martin described an improvement made to his father's design to make the machine easier for an operator to control. Specifically, Martin added a motion retainer bar assembly between the machine's frame and the cutting head's drive bar to modify the degree of eccentricity between the drive bar and the shaft of the electric drive motor. While this improvement did make the machine somewhat easier to control, vibration remains somewhat excessive and the cutting blade actuation, while separating the carpeting from the floor, left considerable adhesive residue on the floor.

In U.S. Pat. No. 4,963,224, Martin Anderson described yet another improvement that he made to the floor stripping machine to reduce vibration. He designed in a pair of OILITE® sleeve bearings and affixed a pair of guide rods to the cutting head and which fit into the sleeve bearings to thereby constrain motion of the cutting head to reciprocating, back-and-forth movement parallel to the path of travel of the machine. While this improvement did, in fact, reduce machine vibration and prolong its useful life, minimizing its mean time to repair, no improvement was seen in the ability of the machine to remove adhesive residue from the floor following the stripping of the carpet therefrom.

In 2000, Martin Anderson was awarded U.S. Pat. No. 6,135,566 based on still other improvements to walk-behind floor stripping machines of the type described above. In this patent, he disclosed a machine that significantly increased the downward force of the machine's cutting blade against the floor by drastically increasing the overall weight of the machine. The scraping action of the cutting blade, when being pressed down on the floor by the weight of the machine, markedly improved its ability to remove adhesive residues. Increasing the weight of the machine, however, made it that much more difficult for an operator to push. Thus, he also disclosed a drive system for the machine in which the same motor used to drive the cutting blade also drives the machine's wheels, making it self-propelled and reducing the work effort required by the human operator.

The drive system drove an axle journaled in bearings. Wheels were keyed to the axle by key members such that they rotated with the axle. There was, however, no convenient way to disengage the key members to permit the wheels to freely rotate about the axle when the axle was not being rotated by the drive. This increased the steps required to load the machine into another vehicle for transport between job sites. It also made it difficult to move the machine within a job site between different areas where a floor scrapping operation was to be performed.

U.S. Pat. No. 6,609,762 was granted to Martin Anderson on Aug. 26, 2003. This patent describes a hydraulically powered self-propelled stripping machine having an electric motor driving a pump for pumping hydraulic fluid to hydraulic motors that turned axles coupled to the wheels. The hydraulic circuit included valves that could be actuated to control the speed and direction of the machine. There was, again, no mechanism for disengaging the wheels from the drive to permit the wheels to freely rotate about the axle.

U.S. Pat. No. 6,578,931, granted to Martin Anderson on Jun. 17, 2003, shows a mechanism for disengaging a drive wheel from a drive axle to allow the drive wheel to spin freely about the drive axle. However, that design mechanism included cross holes that needed to be aligned so that a pin could be inserted through the cross holes to re-engage the drive wheel with the drive axle. Aligning the cross holes proved to be difficult and often required lifting the machine to turn the wheel to achieve such alignment so the pin would be inserted. Also, the mechanism had loose parts that would become lost.

Another problem with the prior art machines described above is that material scrapped from a floor and stick to the wheels of the machine. If this material collects on the wheels and resides between the wheels and the floor, the machine will not ride smoothly over the floor and traction can be reduced.

Accordingly, the present invention provides a novel coupler adapted to selectively couple the wheels to the axle so that the wheels may be driven by the axle and decouple the wheel from the axle so that the wheel may rotate freely about the axle. The present invention also provides a novel wheel scraper adapted to remove debris from the surface of the wheel irrespective of the direction of rotation of the wheel.

SUMMARY OF THE INVENTION

The present invention relates to self-propelled machines for stripping adhesive-backed floor coverings from floor surfaces. The machine includes drive wheels comprising an outer surface, a round center opening of a first inner diameter, and a plurality of locking bores positioned about the round center opening. The machine also includes an axle extending about a longitudinal axis, adapted to be driven by a motor, and comprising a first, round section of a first outer diameter smaller than the first inner diameter and adapted to reside within the round center opening of the wheel and permit the wheel to rotate about the first, round section and longitudinal axis of the axle, a second, round section terminating in an end, a polygonal engagement section comprising a plurality of first longitudinal engagement surfaces and a polygonal radial engagement surface, and a threaded bore extending into the axle from the end. To permit effective, quick, and convenient coupling of the wheel to the axle so that the wheel may be driven by the axle and decouple the wheel from the axle so that the wheel may rotate freely about the axle, a novel lock is also provided.

The lock comprises a locking flange having a first side and a second side, a center opening surrounded and defined by a plurality of second engagement surfaces, collar extending from the first side and surrounding the center opening, and a plurality of locking pins extending from the second side. The lock further comprises a washer, a coil spring adapted to reside within the collar around the second, round section of the axle between the washer and the first side of the flange, and a threaded screw adapted to mate with the threaded bore of the axle to couple the washer to the end of the axle.

The locking flange is adapted to be moved between a locked position, an unlocked position, and an intermediate staging position. In the locked position, the spring holds the flange so that the flange surrounds the engagement section of the axle, the first longitudinal engagement surfaces of the axle are in face-to-face registration with the second engagement surfaces of the flange, and each of the plurality of locking pins of the flange resides in locking bores of the wheel. In the unlocked position, the first engagement surfaces are out of face-to-face registration with the second engagement surfaces, the second side of the flange is in engagement with the polygonal radial engagement surface of the axle, and the locking pins out of the locking bores. In the intermediate staging position, the spring and locking pins cooperate with the outer surface of the wheel to hold the flange away from the engagement section of the axle with the first engagement surfaces are out of face-to-face registration with the second engagement surfaces. More specifically, the locking pins are held out of the locking bores with their free ends bearing against the outer surface of the wheel.

The locking flange is easily moved from the locked position to the unlocked position. The locking flange is so moved by gripping the collar, pulling with sufficient force to overcome the force of the spring, and moving the flange so that locking pins are retracted from the locking bores and the center opening of the flange surrounds the second, round section of the axle rather than the engagement section of the axle. The flange is then rotated until the locking pins of the flange are no longer in alignment with the locking bores of the wheel. The collar is then released, and the spring holds the flange so that the second side of the flange resides against polygonal radial engagement surface of the axle with the locking pins out of engagement with the wheel, i.e., outside of the locking bores and not in engagement with the outer surface of the wheel, and the center opening of the flange surrounds the second, round section of the axle rather than the engagement section of the axle. This permits free rotation of the wheel about the axle. The flange is moved from the unlocked position to the intermediate staging position by rotating the flange to disengage its second surface of the flange from the polygonal radial engagement surface of the axle. When the flange is so rotated and then released, the spring will force the ends of the pins into contact with the outer surface of the wheel. Further rotation of the flange relative to the wheel (or the wheel relative to the flange) will bring the pins into alignment with the bores permitting the spring to force the pins into the bores thus returning the flange to the locked position. One skilled in the art will recognize that it is possible to return the flange directly to the locked position without first placing the flange in the intermediate staging position. This is achieved by carefully aligning the pins with the bores before releasing the flange. When the pins and bores are so aligned, releasing the collar allows the spring to force the flange away from the washer so that the locking pins reside in the locking bore and the engagement section of the axle resides within the center opening of the flange with the first engagement surfaces of the axle in face-to-face registration and engagement with the engagement surfaces of the flange.

When the locking flange is in the locked position, rotational forces applied by the drive to the axle are transmitted to the wheels. The drive can be operated to drive the wheels through the axle in either a clockwise or counterclockwise direction. A novel wheel scraper may be provided to remove debris from wheel as it rotates in either direction the clockwise or counterclockwise direction. The wheel scraper includes a stem, a shoulder, and a pair of diverging blades, e.g., an upper blade and a lower blade, extending from opposite ends of the shoulder. The stem includes at least one elongate slot adapted to receive a pair of mounting bolts. The mounting bolts extend from the machine through the elongate slot(s) and nuts are used to couple the wheel scraper to the machine. The slot(s) and bolts are arranged so the stem extends along an axis perpendicular to the longitudinal axis of the axle. As the wheel turns in the counterclockwise direction, the machine moves forward, and the wheel is scraped clean by the lower blade. As the wheel turns in a clockwise direction, the machine moves backward, and the upper blade scrapes the wheel clean. The slots permit adjustment of the position of the blades relative to the outer surface of the wheel.

DETAILED DESCRIPTION

This description of the preferred embodiment is intended to be read in connection with the accompanying drawings, which are to be considered part of the entire written description of this invention. In the description, relative terms such as “lower”, “upper”, “horizontal”, “vertical”, “above”, “below”, “up”, “down”, “top” and “bottom”, “under”, as well as derivatives thereof (e.g., “horizontally”, “downwardly”, “upwardly”, “underside”, etc.) should be construed to refer to the orientation as then described or as shown in the drawings under discussion. These relative terms are for convenience of description and do not require that the apparatus be constructed or operated in a particular orientation. Terms such as “connected”, “connecting”, “attached”, “attaching”, “joined”, and “joining” are used interchangeably and refer to one structure or surface being secured to another structure or surface or integrally fabricated in one piece unless expressly described otherwise.

A self-propelled machine1for stripping adhesive-backed floor coverings from floor surfaces is partially shown inFIG.1. The machine includes a plurality of drive wheels10. Each drive wheel is adapted to be coupled to and decoupled from a drive axle by a lock50. Further, the tread surface20of the tire18surrounding each wheel10is cleaned by a wheel scraper80as the machine1travels in either the forward or reverse direction.

As shown inFIGS.2,3, and6each drive wheel10includes an outer surface12, a round center opening14of a first inner diameter, and a plurality of locking bores16positioned about the round center opening14. A tire18having a tread surface20is mounted to the wheel10.

The drive wheels10are each mounted to an axle30driven by a motor31. The axle30has first, round section34of a first outer diameter smaller than the first inner diameter of the round center opening14of the wheel10. This first, round section34is adapted to reside within the round center opening14of wheel10and permit the wheel10to rotate about the first, round section34and longitudinal axis of the axle30. The axle30has a second, round section36terminating in an end38. A threaded bore40extends into the axle30from the end38. Each axle30also has a polygonal engagement section42comprising a plurality of longitudinal engagement surfaces44(four of which are present in the embodiment shown) residing between the first, round section34and the second, round section36. The polygonal engagement section also has an engagement surface45from which the second, round section36extends. The second, round section36has a circumferential engagement surface37. Having the circumferential engagement surface37tangentially meet the longitudinal engagement surfaces44as shown inFIG.6offers advantages with respect to alignment.

A lock50is provided to selectively couple the wheel10to the axle30so that the wheel10rotates with the axle30and decouple the wheel10from the axle30so that the wheel10can freely rotate about the axle30. A snap ring53is provided to prevent the wheel from moving axially. The lock50includes a locking flange52. The locking flange52has a first side54and a second side56, and a center opening57defined by a plurality of second engagement surfaces58. As shown, the center opening57is both rectangular and square matching the shape of the engagement section42of the axle. A different shape for both the engagement section42and the center opening57may be employed without deviating from the invention. The number of second engagement surfaces58will typically match the number of first engagement surfaces44.

A collar60extends from the first side54of the locking flange52. The collar60surrounds the center opening57. A plurality of locking pins62extend from the second side56of the locking flange52. These pins62are adapted to be simultaneously aligned and mate with the locking bores16of the wheel10. The lock50also includes a stop washer64, a coil spring66adapted to reside within the collar60around the second, round section36of the axle30between the stop washer64and a portion of the first side54of the flange52within the collar60. The lock further includes a threaded screw68adapted to mate with the threaded bore40to couple the stop washer64to the end38of the axle30.

The lock50, and more specifically the flange52, is adapted to be moved between a locked position, and intermediate staging position, and an unlocked position. When the flange52is in the locked position, the spring66holds the flange52so that the flange52surrounds the polygonal engagement section42of the axle30, the first longitudinal engagement surfaces44of the axle30are in face-to-face registration with the second engagement surfaces58of the flange52, and the plurality of locking pins62reside in the locking bores16of the wheel10. When the lock is in the unlocked condition, the spring66and a portion of the second side56of the flange52cooperate with the radial polygonal engagement surface45to hold the locking pins62both out of the locking bores16and away from the outer surface12of the wheel10, and the first longitudinal engagement surfaces44of the axle30out of face-to-face registration with the second engagement surfaces58of the flange52.

In the intermediate staging position, the second side56of the flange52is out of contact with the radial polygonal engagement surface45of the axle and the spring66cooperates with the washer and the flange to hold the free ends of the pins62against the outer surface12of the wheel10.

Moving the locking flange52from the locked position to the unlocked position is achieved by gripping the collar60and pulling with enough force to overcome the force of spring66and retract the locking pins62from the locking bores16. While still gripping the collar60, the flange52is rotated relative to the axle so that when the collar is released60the spring forces the second side56of the flange52into contact with the radial polygonal engagement surface45of the axle's polygonal engagement section42thus holding the locking pins62both out of the locking bores16and away from the outer surface12of the wheel10, and the first longitudinal engagement surfaces44of the axle30out of face-to-face registration with the second engagement surfaces58of the flange52. When the lock50is in the unlocked configuration, the wheel10freely rotates about the axle30even when the axle30is not rotating.

One can move the locking flange52from the locked position to an intermediate staging position by gripping the collar60and pulling with enough force to overcome the force of spring66and then twisting the locking flange52so that the radial polygonal engagement surface45of the axle can pass through the center opening57of the flange52and the locking pins62are out of alignment with the locking bores16of the wheel. Releasing the collar60will cause the free ends of locking pins62to firmly engage the outer surface12of the wheel10.

Moving the locking flange52from the intermediate staging position to the locked position is easily achieved by rotating the wheel10and the locking flange52relative to each other bringing the locking pins62into alignment with the locking bores16. As soon as such alignment is achieved, the spring and the washer cooperate to push the flange52toward the outer surface12of the wheel10such that the locking pins62reside within the locking bores16and the longitudinal engagement surfaces44of the polygonal engagement section of the axle30engage the second engagement surfaces58of the flange52.

Moving the locking flange52from the unlocked position to the intermediate position, and then to the locked position as described above is the most efficient approach to locking when performed in separate steps and is the preferred approach. Moving directly from the unlocked position to the locked position will not be the most efficient approach to locking as it requires simultaneous alignment of the wheel bore with lock pins, and polygonal shapes on the axle and lock. However, moving the locking flange52directly from the unlocked position to the locked position can be achieved in two different ways. One way is by gripping and twisting the collar60, while holding the wheel10steady, until the locking pins62are aligned with the locking bores16and the center opening57of flange52is aligned with the polygonal engagement section42of the axle so that the radial polygonal engagement surface45of the polygonal engagement section42can pass through the center opening57of the flange52. Another way is to grip and pull on the collar60, while rotating the wheel10until the locking pins62are aligned with the locking bores16and the center opening57of flange52is aligned with the polygonal engagement section42of the axle so that the radial polygonal engagement surface45of the polygonal engagement section42can pass through the center opening57of the flange52. In either case, releasing the collar60with the locking pins62and locking bores16, and the center opening57and the polygonal engagement section42, so aligned will result in the spring66pushing the flange52so that the locking pins62reside within the locking bores16and the first longitudinal engagement surfaces44of the axle30are in face-to-face registration and engagement with the second engagement surfaces58of the flange52. In this configuration, the wheel10is unable to rotate independent of the axle30and will rotate in the same direction (either clockwise or counterclockwise) as the axle30.

More specifically, when the locking flange52is in the locked position, rotational forces applied by the drive to the axle30are transmitted to the wheels10and the tires18mounted thereon. The drive motor31thus can be operated to drive the wheels10through the axle30in either a clockwise or counterclockwise direction.

Much debris is generated on the surface of the floor being stripped during any stripping operation. Typically, such debris includes adhesive materials stripped from the floor. Such debris often accumulates on the tires18hindering efficient and effective operation of the machine1.

To address this problem, a wheel scraper80may be provided to remove debris from tread surface20of the tire18as the tire18and wheel10rotate in either the clockwise or counterclockwise direction. The wheel scraper80includes a stem82, a shoulder84, and a pair of diverging blades86and88, e.g., an upper blade and a lower blade, extending from opposite ends of the shoulder84. The stem82includes at least one elongate slot83adapted to receive a pair of mounting bolts90and92. The mounting bolts90/92extend through the elongate slot(s)83and are used to couple the wheel scraper80to the machine using a pair of nuts91/93, with the stem82extending along an axis perpendicular to the longitudinal axis of the axle. As the wheel10turns in the counterclockwise direction, the machine moves forward, and the tread surface20of the tire18is scraped clean by the lower blade88. As the wheel10turns in a clockwise direction, the machine moves backward, and the upper blade86scrapes the tread surface20of tire18clean. The slot(s)83permit adjustment of the position of the blades86and88relative to the tread surface20.

Within the scope of the following claims, the invention may be practiced otherwise than as specifically shown in the drawings and described above. The foregoing description is intended to explain the various features and advantages, but is not intended to be limiting. The scope of the invention is defined by the following claims which are also intended to cover a reasonable range of equivalents.