Patent Application
20110300784
1. Field of the Invention
This invention relates generally to a multi-head disk assembly for a floor grinding and/or polishing machine and, more particularly, to a floor polishing disk assembly which includes multiple abrasive heads, is flexible to better accommodate unevenness in the floor surface, and uses a hook and loop fastener material for attachment to a drive plate of a floor grinding and/or polishing machine.
2. Discussion of the Related Art
Grinding and polishing machines have been used for many years for finishing floors—including floors made of concrete, granite, marble, terrazzo, epoxy, hardwood, vinyl, and other materials. These machines include scrubber machines, swing machines, buffer machines, planetary grinding machines, counter-rotating grinders, burnishing machines, etc. These machines may use multiple abrasive heads to do the work of grinding and polishing the floor surface. The abrasive heads are available in a variety of grit sizes, or levels of coarseness, to facilitate the entire floor finishing process—from the rough grinding of the floor as initially installed, to the fine polishing of the floor surface to a finished condition.
In order for the abrasive heads to be changed from one grit size to another, they are usually detachable from a drive plate of the floor polishing machine. Some machines use a simple hook and loop type fastener material to attach the individual abrasive heads to the drive plate. Other machines use metal plug-type cutting head tools which are inserted into tool holders on the drive plate. While these existing designs allow the abrasive heads to be interchanged, they require each individual abrasive head to be changed separately, and this process can be somewhat time consuming and error prone. This is especially true considering that many floor polishing machines have multiple drive plates, with each drive plate supporting multiple abrasive heads.
Furthermore, in the machines described above, the abrasive heads are directly attached to the drive plate of the floor polishing machine. This results in a rigid planar cutting surface which does not readily conform to the uneven or curved surfaces that are common in many floor applications. A need exists for a abrasive head apparatus which can be used on existing floor polishing machines, which allows some flexibility between the individual abrasive heads, and which can be quickly and easily changed from one grit size to another without handling multiple components.
In accordance with the teachings of the present invention, a grinding and/or polishing disk assembly is disclosed for use with a floor grinding and/or polishing machine. The disk assembly includes a thin flexible polishing disk having multiple abrasive heads and a backing pad to allow deflection of the polishing disk as the abrasive heads pass over uneven or curved floor surfaces. The flexible polishing disk and backing pad can have a hook and loop type fastener material on their surfaces that allows them to be easily attached to and detached from each other and the drive plate of the floor polishing machine.
Additional features of the present invention will become apparent from the following description and appended claims, taken in conjunction with the accompanying drawings.
The following discussion of the embodiments of the invention directed to a flexible and interchangeable multi-head floor polishing disk assembly is merely exemplary in nature, and is in no way intended to limit the invention or its applications or uses.
The present invention proposes a disk assembly for use on a floor grinding and/or polishing machine. The disk assembly includes multiple abrasive heads integrated into a single flexible polishing disk, and a foam backing pad which, in conjunction with the flexibility of the polishing disk, allows the abrasive heads to follow the contour of a curved or uneven floor surface. The disk assembly features easy attachment to and detachment from the floor grinding and polishing machine via hook and loop fastener material, and may include an optional rigid backing plate for flat floor applications.
The diameter of the disk assembly 18 would be selected to accommodate the particular machine that it is being with.
The disk assembly 18 also includes a thin flexible disk 30 being made of a flexible material suitable for the purposes described herein, such as rubber. The disk 30 is thinner that the pad 20, where the pad 30 acts as a support layer for the disk 30. The flexible disk 30 has the same diameter as the pad 20 so that the central opening 28 of the pad 20 aligns with a central opening 32 in the flexible disk 30. The flexible disk 30 includes an attachment layer 34 on one face directed towards the pad 20 which can be the opposite hook and/or loop material as the attachment layer 26 of the pad 20. In this manner, the flexible disk 30 is removably attached to the pad 20. The flexible disk 30 also includes an attachment layer 36, such as a hook and loop layer, on an opposite face of the disk 30. In an alternate embodiment, the openings 28 and 32 are not provided in the pad 20 and the disk 30, respectively, as they are not necessary to attach the disk assembly 18 to the machine 10.
The disk assembly 18 also includes a plurality of round abrasive heads 40 secured to the flexible disk 30 opposite to the pad 20. In an alternate embodiment, the abrasive heads 40 are permanently attached to the flexible disk 30, such as by glue, where the flexible disk 30 would need to be removed from the pad 20 to change the abrasive heads 40. In this non-limiting embodiment, the abrasive heads 40 are removably attached to the flexible disk 30 using an attachment layer 42 that corresponds to the attachment layer 34. In this regard, each abrasive head 40 includes a hook or loop layer that is opposite to the attachment layer 36 on the flexible disk 30. The detachability of the abrasive heads 40 from the flexible disk 30 would allow individual abrasive heads 40 to be replaced in the event that they were damaged or become excessively worn.
Many different types of abrasive heads 40 may be used, with diamond-impregnated materials being among the most common. A feature of many of the abrasive heads 40, especially the diamond-impregnated type used to finish hard stone floor surfaces, is that the abrasive head 40 is made up of many small elements of a cutting material defined by a series of grooves 44 and raised lands 46 that provide the desired grinding, polishing, cleaning or smoothing, such as different grit sizes, in a desired orientation. The grooves 44 allow water and solid debris to flow out from under the abrasive head 40 and be swept out to the side of the grinding and polishing machine 10. The grooves 44 and lands 46 on the abrasive head 40 can be arranged in many different patterns, with circular and spiral patterns on round abrasive heads 40 being among the most common designs.
The abrasive heads 40 can be positioned at any location on the flexible disk 30, can include any suitable number of abrasive heads, which would generally depend on the diameter of the disk assembly 18, and/or have any suitable diameter.
From the discussion above, two advantages of the present invention are readily apparent. The first advantage of the disk assembly 18 is its bending flexibility. Some floor surfaces are intended to be perfectly flat. But in many floor applications, non-planar surfaces, both convex and concave, are present. Other unevenness in the form of lippage, or height variation between sections of the floor, may also be present. Typical floor grinding and/or polishing machines have difficulty treating non-planar or uneven surfaces, because these machines have their cutting heads directly attached to a rigid drive plate. This makes such machines desirable for finishing very flat planar floor surfaces, but less desirable for finishing floors which contain unevenness or curvature. In contrast, the embodiments of the present invention allow the individual abrasive heads 40 to follow the contour of the floor surface even if it is not flat. The flexible disk 30 is of a sufficient thickness, for example, at least 2 mm, to provide enough in-plane stiffness to drive the abrasive heads 40 in their circular motion. However, the flexible disk 30, when attached to the backing pad 20, allows a significant amount of flexibility or compliance in the direction normal to the floor surface. This allows the individual abrasive heads 40 to follow the contour of the floor when there is curvature or unevenness.
The second advantage of the present invention is the ease with which the abrasive heads 40 can be replaced. In a typical floor grinding and polishing process, multiple grits, or levels of coarseness, of the abrasive heads 40 are used in successive steps. For example, a rough concrete or terrazzo floor as poured will require a very coarse grit for the first pass of the grinding machine 10. The coarse grit removes a relatively large amount of floor material, resulting in a significantly smoother surface than as-poured. The coarse grit is followed by a medium-coarse grit, and so on until a very fine grit abrasive head 40 is used to create an extremely smooth surface finish. The inevitable changing of abrasive heads 40 can be time consuming and error prone when each abrasive head 40 must be replaced individually. By combining all abrasive heads 40 of a given grit size into a single polishing disk, with a simple hook and loop type fastening surface, the process of changing abrasive head grit sizes is significantly simplified. In addition, having all of the abrasive heads of a given grit size incorporated into a single polishing disk eliminates the possibility of erroneously installing mismatched abrasive heads on the grinding machine.
The disk assembly 18 as disclosed has been shown to be effective when used on floor grinding and scrubbing machines, which typically operate in the range of 135-300 rpm, and also to work effectively on high-speed floor burnishing machines, which typically operate in the range of 1200-3000 rpm.
The foregoing discussion discloses and describes merely exemplary embodiments of the present invention. One skilled in the art will readily recognize from such discussion and from the accompanying drawings and claims that various changes, modifications and variations can be made therein without departing from the spirit and scope of the invention as defined in the following claims.
