Patent Application
20190210192
The disclosure relates generally to a pad assembly and more particularly to a floor polishing or grinding pad with a multilayer reinforcement.
It is known to use fibrous pads for polishing and grinding floors within industrial or commercial buildings. Such polishing or grinding pads are ideally suited for use on concrete, terrazzo, and natural (e.g., marble), engineered and composite stone floors. Examples of such pads and the powered machines used to rotate such can be found in the following U.S. patent publication numbers: 2011/0300784 entitled “Flexible and Interchangeable Multi-Head Floor Polishing Disk Assemby” which was invented by Tchakarov et al. and published on Dec. 8, 2011; 2017/0361423 entitled “Polishing or Grinding Pad Assembly” which was invented by Tchakarov and published on Dec. 21, 2017; and 2017/0361414 entitled “Polishing or Grinding Pad Assembly” which was invented by Tchakarov and published on Dec. 21, 2017. All of these patent publications are incorporated by reference herein. While these prior constructions are significant improvements in the industry, improved floor polishing and grinding performance, and improved durability of the pad assembly are still desired.
In accordance with the present invention, a polishing or grinding pad with a multilayer reinforcement is provided. In one aspect, a floor polishing or grinding pad assembly employs a flexible pad, at least two reinforcement layers or rings with different characteristics, and multiple floor-contacting tools such as abrasive disks. In another aspect, a workpiece polishing or grinding pad assembly includes a flexible and rotatable pad, a polymeric reinforcement layer coupled to the pad and a metallic reinforcement layer to which are coupled abrasive tools. In yet another aspect, a floor-facing reinforcement is more flexible than a pad-facing reinforcement which is more rigid. A further aspect employs scallops or recesses on an outer periphery of a reinforcement ring. A method of making and using a flexible pad, employing a multilayer reinforcement with multiple polishing or grinding tools attached thereto, is also presented.
The present pad assembly is advantageous over traditional devices. For example, the scallops or recesses of the metallic or floor-facing reinforcement used in the present pad assembly advantageously creates a clearance to the floor during pad and reinforcement flexure, thereby reducing contact, and thus wear, of the floor-facing reinforcement when polishing or grinding; this angular clearance increases the assembly's useful life and deters floor-scraping while providing consistency of polishing or grinding. Furthermore, the present pad assembly advantageously allows greater floor contact with the multiple abrasive tools due to the metallic reinforcement flexing due to floor imperfections, yet reduces premature reinforcement wear by providing additional rigidity due to the addition of the less expensive polymeric reinforcement, which is expected to reduce downward flexure of the metal reinforcement between the tools. Additional advantages and features of the present invention will be readily understood from the following description, claims and appended drawings.
A first embodiment of a pad assembly 21 is shown in
Referring to
A multilayer reinforcement ring or layer includes a floor-facing and lower ring or layer 41, and a pad-facing or intermediate ring or layer 43. Pad-facing ring 43 is secured to a bottom face of base pad 31, such as by adhesive. The pad-facing reinforcement ring 43 is generally annular having a central opening 45 with a diameter, for example, of approximately 6.3 inches (160 mm), which surrounds a centerline or rotational axis of pad 31. Furthermore, pad-facing ring 43 is preferably cut from a sheet of ABS polymer with an exemplary thickness of about 0.197 inch (5 mm).
Floor-facing reinforcement ring 41 has an internal hole 47 surrounding the rotational axis of the pad and exposing a center of pad to the floor workpiece. Floor-facing ring 41 has equally spaced apart recesses or arcuate scallops 49 in a peripheral edge thereof. This exposes bottom surface portions 51 of pad-facing ring 43 such that it is unlikely that floor-facing ring 41 will directly contact against the floor even when the floor-facing ring is flexed and tilted. Floor-facing ring 41 is preferably metallic spring steel, having a thickness greater than zero and up to 0.125 inch (preferably 0.25-0.5 mm). Metallic ring 41 is thinner and more flexible than the more rigid yet still flexible polymeric ring 43. Pad-facing reinforcement ring 43 reinforces and adds some stiffness to the floor-facing ring 41, especially where it spans between the abrasive tools, however, the multilayer ring allows some flexibility to pad assembly 21 so it can flex with and follow any floor imperfections thereby producing uniform floor contact for polishing or grinding. Adhesive bonds together at least a majority of the rings at their interfacing surfaces. From a manufacturing and materials cost standpoint, it is less expensive to employ the composite polymer-metal multilayer reinforcement than it is to use only a single thicker metallic ring.
A plurality of abrasive tools, preferably floor-contacting disks 71, are secured to the bottom surface of floor-facing reinforcement ring 41. In the example shown, abrasive tools 71 are approximately 2 inch (54 mm) disks of diamond particles in a polymeric resin matrix. In the example shown, more than two and, more preferably four, of the abrasive tools are generally equally spaced apart and secured to the multilayer reinforcement ring. The disks are fastened to floor-facing ring 41 by crimping central posts 73 extending from a backside of heads of the disks, into holes 75 in the ring. A slightly larger diameter hole 77 of pad-facing ring 43 is coaxially aligned with each hole 75 to provide clearance for the mushroomed post.
As one example, the abrasive pattern of the bottom head of each disk 71 employs at least three, and more preferably five, of linearly elongated channels or spokes 81 which outwardly radiate from a solid center 83 with an innermost end of each spoke being offset from a centerline. Alternately, concentric circles or other channel configurations can be used.
It is noteworthy that inner edges defining holes 45 and 47 of the multilayer ring have a diameter or linear dimension which is larger than a linear dimension of a solid section of the ring layers 41 and 43 which are adjacent to one side of the holes. More preferably, the hole dimensions are at least twice as large as the ring dimensions. The hole relationship is expected to improve floor contact by the fibrous central portion of pad 31 within the inner holes.
Another embodiment of a workpiece polishing or grinding pad assembly 221 is shown in
In one example, a floor-contacting face 295 is at least 0.25 inch (6.35 mm) and more preferably 0.39 inch (10 mm) below surface 283 of tool head 285. Furthermore, an elongated linear dimension of side walls 287 is greater than a width dimension between sidewalls 287 of each wedge. A post 273 centrally projects from the backside of head 285 for crimped attachment to the multilayer reinforcement. A periphery of head 285 is somewhat circular and disk-like although other somewhat polygonal or arcuate shapes may be employed, although some of the advantages may not be realized. Moreover, at least three, and more preferably four tools 271 are provided for an 11 inch (279 mm) outside diameter pad while six tools 271 are provided for a 14 inch (355.6 mm) outside diameter pad. These wedge tool configurations may be employed with a single reinforcement, multilayer reinforcement, inner or outer edge recessed reinforcement or even directly adhered to the pad, although many of the aforementioned multilayer reinforcement ring benefits may not be achieved.
The wedge tools are ideally suited for removing an epoxy coating, paint or other materials from a workpiece, especially a cement floor, through rotation by a powered machine. While angled or tapered leading walls 293 are functionally advantageous, the overall shapes and spacing of wedges 281 on the tools or disks 271 have ornamental and aesthetic benefits. Furthermore, the exact scalloped shapes of the recesses for floor-facing reinforcement ring 241 also has ornamental features.
While various embodiments have been disclosed, it should be appreciated that additional variations of the pad assembly are also envisioned. For example, while preferred dimensions have been disclosed hereinabove, it should alternately be appreciated that other dimensions may be employed; for example a peripheral pad diameter of at least 10 inches (254 mm) may be employed and disk diameters of 0.5-2.5 inches (12.7-63.5 mm) may also be employed. Moreover, circular peripheral shapes for the pad, reinforcement ring and disks are preferred, however, other arcuate or even generally polygonal peripheral shapes may be used although certain of the present advantages may not be fully realized. Alternate recess shapes are possible. It is also envisioned that different abrading patterns may be employed on the abrasive tools (such as disks) which may be attached to the multilayer reinforcement ring with a rivet, adhesive or other fasteners.
Furthermore, it is also possible to employ three or more reinforcement layers with differing characteristics, although some of the present cost advantages may not be achieved. Alternately, other fastening of the rings can be used but adhesive is more beneficial. While certain materials have been disclosed it should be appreciated that alternate materials may be used although all of the present advantages may not be fully achieved. It is also noteworthy that any of the preceding features may be interchanged and intermixed with any of the others. Accordingly, any and/or all of the dependent claims may depend from all of their preceding claims and may be combined together in any combination. Variations are not to be regarded as a departure from the present disclosure, and all such modifications are entitled to be included within the scope and sprit of the present invention.
