Patent Application
20190240803
The present invention relates generally to surface treatment wherein said surface is a floor or pavement constructed of concrete, stone, terrazzo, and/or similar materials and the said treatment is grinding, polishing, coating removal, or the like.
Floor and pavement surfaces are commonly constructed of durable materials such as concrete, stone, and terrazzo. This has been the case for thousands of years and is common globally. In recent years, beginning in the 1990s, treating such surfaces with modern grinding and polishing equipment is a practice that has seen increasing popularity and widespread common use. This practice is for the purpose of achieving surface qualities that are recognized as valuable to the application for which the surface is used. Such qualities include, but are not limited to: roughness, waviness, hardness, flatness, levelness, profile, and reflectivity. These surface qualities are modified to achieve: improved aesthetics, increased service life, easy low-cost maintenance, better vehicle ride quality, increased traction, improved bonding with toppings and coverings, and more. These improvements are so valued by surface owners, and end users of the surface, that there exists a global market for thousands of contractors to compete in providing surface treatment services. As a result, these contractors are willing to invest in acquiring equipment which will better enable them in meeting the surface treatment needs of their clients. This has therefore resulted in a market for such equipment where developers, manufacturers, and marketing companies compete to produce and sell surface treatment equipment favored by the contractors.
The modern grinding and polishing equipment which has been key to the growth in the surface treatment industry is the abrasive diamond-impregnated tooling and the floor grinder or planetary grinder, hereafter referred to as “grinder”, to which this tooling is attached. The most common embodiment of the grinder used for floor and pavement surface treatment incorporates a grinding head. This grinding head has the diamond tooling affixed to multiple rotatable discs; these discs are mounted to a rotatable drum; there is an input shaft which, when rotated, drives a mechanism which causes the drum to rotate and the discs to rotate and move the diamonds across and against the surface which is being treated. The grinding head is most commonly driven by an electric motor which is mounted upon it. This grinding head assembly and motor is pivotally mounted to a wheeled chassis which has handle bars; the operator stands behind the machine holding the handle bars and pushes it across the surface while the diamond tooling rotates across and against the surface to treat the surface as per desired. This equipment is commonly referred to herein as the walk-behind grinder.
There are a variety of types of diamond tooling which are designed to achieve a specific quality when treating the surface. The diamond tooling often incorporates specific sizes of impregnated diamond particles in a bonding material. This bonding material also can be varied with the type of surface treatment needed. Often, multiple subsequent stages of surface treatment are required. These stages are performed as follows: the operator will treat an area of the surface with one type of diamond tooling and when that is complete they will replace the diamond tooling on the grinder with a different type of diamond tooling and proceed to treat the same area again with the grinder; this process will be repeated with as many types of diamond tooling and stages necessary to achieve the desired results. The diamond tooling wears out as it is abraded against the surface. The operator will service or replace the diamond tooling numerous times during the course of the surface treatment job, therefore, it is important that they can safely and conveniently access the underside of the discs to which the diamond tooling is mounted.
Consistency in the quality of finished surface is important when treating a surface and the surface treatment contractor is expected to deliver similar quality of results across the entire surface being treated. Three factors that affect the quality of results are: the speed of the diamond tooling across the surface, the pressure of the diamond tooling against the surface, and the ability for the diamond tooling to freely follow the contours of the surface. Variations in the speed of the diamond tooling across the surface will effect varying surface treatment results and affect the longevity of the diamond tooling. To maximize productivity the speed of the diamond tooling is maximized, however, there is a limit to the speed. If the speed of the diamond tooling is excessive the longevity of the diamond tooling and the quality of surface treatment results are adversely affected. Therefore, the rate of productivity is limited because the ramifications, such as higher cost of replacing diamond tooling and more time spent repeating surface treatments to achieve desired consistency of results, outweigh the benefit of any additional increase in productivity. Variations in the pressure of the diamond tooling against the surface will achieve varying surface treatment results and affect the longevity of the diamond tooling.
It is also to be noted, every surface has imperfections in flatness and levelness, if the design of the grinding equipment does not allow the diamond tooling to adjust to these imperfections, and maintain contact with the contour of the surface, then areas of the surface will be skipped and remain untreated and/or areas will be treated excessively with excessive pressure. This will result in inconstancies in the finished surface as well as higher costs in replacing diamond tooling. Therefore, it is important for the grinding equipment to allow reasonable control of the speed and down pressure of the diamond tooling and to allow the diamond to freely ride along the contours of the surface.
The process of surface treatment is time consuming; to achieve the specified surface qualities contractors work many hours and surface treatment jobs usually span many days and weeks and, for larger surface areas, the process may span months. The surface is not available for use during the surface treatment process, therefore, it is in the surface owner's interest to complete the process as quickly as possible so that the surface can be again put to use for the intended purpose. To expedite the surface treatment process a contractor requires numerous personnel operating many grinders. The cost of employing skilled laborers is the often the greatest expense relating to the surface treatment process.
Treating a surface usually requires multiple parallel passes to treat the entire surface area. It is important that the entire surface area gets treated and no areas are missed. In common practice, when performing parallel passes, the operator will overlap the current area of treatment pass with the previous treatment pass. To maximize productivity the operator will strive to keep the overlap to a minimum since the treatment in the area of overlap is redundant. If any gap exists between the two passes then the area in the gap will be left untreated and the quality of results will be unsatisfactory. To ensure there is complete coverage of the surface area the common industry practice is for the operator to blend each pass by moving the surface treatment apparatus side-to-side while traveling forwards, resulting in a sinusoidal-like path of motion across the surface. This practice has been found to be a reliable way to achieve a consistent quality of treatment results across an entire surface without sacrificing productivity.
There has been an ever-growing demand for surface treatment services. This increasing popularity stems from industries becoming more aware of the advantages of various surface treatment practices while the cost for such services lowers with improved surface treatment technology and methods that increase productivity and reduce material costs. Existing facilities and infrastructure have surfaces that are constantly deteriorating from environmental conditions and use and therefore regularly require surface treatment to enable continued use of the surface. Newly constructed surfaces also receive surface treatment to achieve the surface qualities specified by the surface owner. Also, with the lower cost of surface treatment services, more surface owners can afford these services for even larger surface areas. As the demand has grown for even larger surface areas to be treated there has been a corresponding growing impetus to increase the productivity of the surface treatment equipment.
To achieve productivity gains and treat larger surfaces in shorter amounts of time, without increasing labor cost by employing additional personnel for the task, extensive efforts have been made to improve the design of the traditional walk-behind grinder. The productivity gains possible with a walk behind grinder using current diamond tooling technology have plateaued. This is because the diamond tooling has operational speed limitations, therefore, to increase the rate of productivity the design must have an increased surface area of diamond tooling, however, to maintain the required pressure of the diamond tooling against the surface there must be an increase in the weight of the machine to correspond with the increased diamond tooling surface area. Since the walk-behind grinder is manually operated by a person pushing and maneuvering it across the surface there is a limit how heavy the machine can be before the physical bodily strength and endurance required to operate the machine exceeds what the average human body can sustain. Any increase in weight of the walk-behind polisher results in a higher rate of fatigue and risk of injury to the operator. This has led to the development of larger, mechanically assisted ride-on machines.
Realizing the limitations of the walk-behind grinder, developers have designed specialized ride-on grinders to achieve additional productivity gains. These are wheeled drivable machines which are equipped with mechanical lifting devices attached to one or more grinding heads; the operator rides on the machine and control the mechanical lifting device to lower the grinding heads to engage the diamond tooling with the surface or to raise the grinding heads for transport across the floor and/or service the diamond tooling. One example of a ride-on grinder that has been made commercially available, by the company HTC Sweden AB, is the “HTC 2500 iX”. These types of specialized ride-on machines tend to be too expensive for most surface treatment contractors to afford, and there is not yet a large enough market demand for these machines to manufacture in volumes that would achieve economies of scale which would lower costs of these machines to a more affordable amount. Since these machines are highly specialized and expensive a contractor must commit to investing a high capital expense with the risk of not securing enough contracts, for floor treatment jobs using the machine, to get a positive return on investment. Some companies have taken an alternative approach by innovating a less costly, and more versatile, high-productivity grinding machine by utilizing currently existing mobile hydraulic equipment.
This different approach to a less costly, and more versatile, high-productivity grinding machine involves utilizing commonly available mobile hydraulic equipment to hydraulically power the grinding equipment which is mounted on a separate attachment to the machine. Mobile hydraulic equipment is in common use in many forms on most construction jobs around the world, and many forms have been developed to accommodate various implement attachments which can be powered by an auxiliary hydraulic system integrated on the machine. Some examples of these forms of mobile hydraulic equipment are skid-steer loaders, compact track loaders, compact loaders, and telehandlers. These machines can lift, carry, manipulate, and power attachments mounted to an interface design which is universally common and standard to construction industries. By designing a surface treatment apparatus as an attachment for mobile hydraulic equipment, the overall investment cost can be kept significantly lower than a specialized ride-on grinder. This is because the mobile hydraulic equipment is produced in much greater volumes and can be produced at economies of scale to be more affordable; thereby accomplishing the mobility and power required at lower cost while the only specialized portion is on the attachment. One example of a machine attachment designed for use as a surface treatment apparatus is the “Stone Extreme” made commercially available by the company Stonekor, LLC. The specialized grinding equipment attachment will be known hereafter as an apparatus.
The idea of a surface treatment apparatus as an attachment for use with mobile hydraulic equipment is not a novel concept, however, there exists several problems with the prior art that limit the productivity and quality that is achievable and also presents a potential safety hazard. As aforementioned, it is important for the surface treatment apparatus to achieve a consistent quality of results but unequal distributions of downward force are detrimental to such. With the prior art, the apparatus is restricted from floating on a bumpy or uneven surface or moving with a sufficient range of motion independent from the mobile hydraulic equipment. Irregularities in the flatness of the surface being treated cause the surface contact points of the surface treatment apparatus to be on a different plane than the surface contact points of the wheels on the surface treatment apparatus. When this occurs, if the apparatus does not have sufficient range of motion independent from the mobile hydraulic equipment the rigidity of the system will cause unequal distributions of downward force on the diamond tooling, causing an undesirable quality of results. One example of these undesirable results is that the apparatus will cut off the high spots of the floor and bridge over the low spots leaving noticeable variation in the look and finish of the floor which is undesirable.
Additionally, with the prior art the grinding heads are restricted from moving with a sufficient range of motion independent from the frame to which they are attached. When irregularities in the flatness of the surface being treated cause the surface contact points of one grinding head to be on a different plane than another grinding head the rigidity of the system will cause unequal distributions of downward force on the diamond tooling, causing an undesirable quality of results. When the quality inconsistencies occur, the operator often attempts to improve the quality by making multiple staggered passes with the machine and/or passes with different directions of travel. These additional efforts increase the time required, consume additional diamond tooling, and reduces the overall productivity.
Another problem experienced with prior art results from the tendency for hydraulic cylinders on mobile hydraulic equipment to drift. When the operator parks and exits the mobile hydraulic equipment they will often leave the apparatus attached to the machine in a raised and tilted position. In raising and tilting the apparatus a significant amount of gravitational potential energy is stored and is held aloft only by hydraulic jacks on the mobile hydraulic equipment. Inherent to the design of the hydraulic system on the mobile hydraulic equipment these cylinders will slowly drift under the load. When left unattended for a sufficient amount of time, such as overnight, the apparatus will have drifted until it contacts the surface or any obstacle, such as a wall, structure, or other equipment. This can result in costly damages. The alternative is to detach the apparatus from the machine which is time consuming and unproductive since the apparatus will need to be reattached again when the operator proceeds to resume use of the apparatus.
Finally, use of the prior art can present a potential safety hazard to personnel attempting to service the diamond tooling. When servicing the diamond tooling the attachment is raised and tilted to expose the underside of the apparatus to make the diamond tooling accessible to personnel servicing the diamond tooling. In raising and tilting the apparatus a significant amount of gravitational potential energy is stored and is held aloft only by hydraulic jacks on the mobile hydraulic equipment. If the hydraulic system were to fail, or be inadvertently actuated, the personnel servicing the diamond tooling would be in grave danger of being crushed since they would likely be standing in the path of motion of the falling apparatus. Standard Title 29 CFR 1926.600(a)(3)(i) issued by United States Department of Labor Occupational Safety and Health Administration (OSHA) states that “Heavy Machinery, equipment, or parts thereof, which are suspended or held aloft by use of slings, hoists, or jacks shall be substantially blocked or cribbed to prevent falling or shifting before employees are permitted to work under or between them. Bulldozer and scraper blades, end-loader buckets, dump bodies, and similar equipment, shall be either fully lowered or blocked when being repaired or when not in use. All controls shall be in neutral position, with the motors stopped and brakes set, unless work being performed requires otherwise.” To safely service the diamond tooling on the prior art personnel must take additional measures to block up the apparatus. This can easily be overlooked without proper training or forgotten by personnel and also adds to the time it takes to service the diamond tooling, negatively impacting productivity.
During a surface treatment process the operator of a surface treatment apparatus seeks to achieve the desired surface qualities at the highest rate of productivity possible without risking the safety of any personnel and minimizing the diamond tooling consumption. The current invention is an apparatus, in the form of a machine attachment, for surface treatment which achieves greater productivity than traditional methods and improves upon the prior art to solve a plurality of problems inherent with the function of said prior art. One advantage of said apparatus over prior art is that it achieves a consistent quality of surface treatment because the configuration of the machine attachment results in a consistent and evenly distributed downward force of the abrasive tooling onto the surface being treated By designing the apparatus to be freely floating, or moving up and down, independently from the machine to which it is attached. Another advantage of the said apparatus over prior art is that it achieves a greater consistency in the quality of surface treatment because it allows each rotating drum assembly within a plurality of rotating drum assemblies to move independently, pivoting about multiple independent axis and thereby conforming to the unevenness of the surface. Another way the said apparatus achieves a greater consistency in the quality of surface treatment results is through a design which allows the apparatus to move freely within a limited distance side-to-side while treating a surface, effectively blending passes with a natural sinusoidal motion. Additionally, the said apparatus incorporates features which prevent the apparatus from unexpectedly moving due to drifting hydraulic cylinders on the mobile hydraulic equipment. The said apparatus also allows personnel to safely and conveniently service the diamond tooling without being endangered by working under a suspended load.
The present disclosure provides an apparatus, in the form of a machine attachment, for surface treatment; wherein said surface is a floor or pavement constructed of concrete, stone, terrazzo, and/or similar materials and the said treatment is grinding, polishing, coating removal, or the like.
In one embodiment, illustrated in
In one implementation, illustrated in
In one embodiment, shown in
It is to be understood that, although the invention herein has been described and depicted with reference to particular embodiments and implementations, these embodiments are merely illustrative of the principles and applications of the present invention. Various changes may be made to the illustrative embodiments and other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims.
