Abstract:
A dust shield and adapter, in combination or as separate components, for universal attachment to the bearing housings having different diameter sizes. As separate components, the shield has a skirt for covering a grinding disk and upward extending collar to which a separate component adapter attaches. The adapter has adjustable attachment members which adjustably secure to a bearing housing of numerous varying diameter sizes. The collar has cut-outs to accept the adapter and permit its upward and downward adjustability to ensure an effective distance adjustment and disk contact with a target surface. As a combination single component, the adapter is permanently attached to a collar having no cut-outs. The adapter has adjustable attachment members which adjustably secure to a bearing housing of numerous varying diameter sizes.

Description:
CROSS REFERENCES TO RELATED APPLICATIONS  
       [0001]     None.  
       STATEMENT REGARDING FEDERALLY-SPONSORED RESEARCH OR DEVELOPMENT  
       [0002]     None  
       BACKGROUND  
       [0003]     This device relates to an improvement in the field of power hand tools, and more particularly to rotary tools which generate large amounts of dust and particulate debris.  
         [0004]     Rotary grinders and similar rotary power tools are used extensively in industry. More specifically angle type grinders/sanders having grinding discs or pads, are used for grinding concrete, fiberglass, wood, steel, removing asbestos, and body filler in automobile shops. Such grinders/sanders are also used for making boats and similar products. In use these grinders create large quantities of dust that are both a fire hazard and a health hazard. Wood dust, for example, can be very explosive over a wide range of concentrations and is a known fire hazard. Hot metal grindings are particularly dangerous as fire starters. Both wood dust and metal filings as well as asbestos particles, fiberglass and body filler particles create known health hazards to users of the grinders and to others in the immediate environment. It is known that concrete dust, as typically generated in great quantities from grinding concrete, is a principal cause of pulmonary silicosis.  
         [0005]     Grinder discs and pads often rotate in excess of 7,000 revolutions per minute (RPM). Grinding pads that use a sponge type backing material create a hazard where parts or particles from the backing material break off and are shot from the rotating disc tangently at a high rate of speed. It is often necessary to use a rotary grinder to grind into corners or against surfaces that have side edges, that can cause particles of the foam backing material to break off from the high speed rotating disc and hit the operator or other persons or equipment in the immediate area.  
         [0006]     A dust shield described in U.S. Pat. No. 5,125,190 approached this problem and solved it. It has an upstanding attachment collar [reference character 16 of U.S. Pat. No. 5,125,190] which was diametered to fit onto the bearing housing [reference character 38 of U.S. Pat. No. 5,125,190] of a variety of different grinders. Different make grinders have different diameters for their respective bearing housing. Typical diameters of bearing housing range from one and one-half inch to three inches. A one-size attachment collar on the dust shield would not accommodate the different bearing housings. Consequently, several different models of the dust shield, each having different collar diameters, had to be manufactured for the various make grinders. This, of course, increases manufacturing costs and adds to inventory of a supplier and end-user since most end-users have more than one grinder and more than one make.  
         [0007]     Without the adapter, the retailer generally must carry up to 40 SKUs (stock keeping units) to cover all the grinders made. With the adapter, the retailer will need only 6 stocking units, one for each of the major disc diameters of 2, 3, 5, 6, 7 and 8 inches. Space in a retail store is very valuable. This adds value to the adapter because it can reduce the amount of space needed to provide a line of dust shields that can fit all grinders.  
         [0008]     Additionally, the grinding surface of different brands of grinders with different grinding disks varies in distance from the bearing housing of the grinder where the dust shield is attached. The dust shield of U.S. Pat. No. 5,125,190 was not readily capable of a distance adjustment to bring the grinding surface down to where it can be of effective use or, in some cases, any use at all. The collar (reference character  16  of U.S. Pat. No. 5,125,190) had to be individually and carefully sanded down such that its lower edge (reference character 35 of U.S. Pat. No. 5,125,190) was accordingly raised thereby bringing the grinding surface out to point of use. Cutting the skirt, improper sanding, or improper measurements would in essence ruin the dust shield and be a waste of time and money.  
         [0009]     The presently disclosed device solves the problems associated with various make of grinders as to different bearing housing diameters and different distance adjustments. In particular, the adapter and a modified dust shield will solve the two major problems of U.S. Pat. No. 5,125,190; namely, [1] the onerous need to produce and inventory up to 40 dust shields to cover all the grinders commercially available and [2] the need for the operator to modify the structure of the dust shield to accommodate different thicknesses of grinding disks and different bearing housing to disk surface dimensions.  
         [0010]     Additionally, the formulation for the manufacture of the dust shield is such that, if cutting the dust shield is necessary, it can easily be cut with ordinary household scissors without ruining the dust shield in its entirety. The formulation for the manufacture provides for greater flexibility, particularly where most critical, thereby eliminating much of the need to make distance adjustments of the collar into and away from the bearing housing.  
         [0011]     The formulation also is such that renders the dust shield of this present device more durable and virtually incapable of being damaged in extremely cold climates, even in temperatures as low as −20° Fahrenheit. Lastly, the adapter of this improved dust shield has a diameter adjustment mechanism and distance adjustment mechanism which can be easily sized to fit any diameter bearing housing from one and one-half inches to over three inches while remaining centrally aligned with the axis of rotation of the grinder and can be easily distance adjusted to bring the grinding surface of different grinder out to the proper point of contact.  
         [0012]     The foregoing has outlined some of the more pertinent objects of the device. These objects should be construed to be merely illustrative of some of the more prominent features and applications of the device. Many other beneficial results can be attained by applying the disclosed device in a different manner or by modifying the device within the scope of the disclosure. Accordingly, other objects and a fuller understanding of the device may be had by referring to the summary of the device and the detailed description of the preferred embodiment in addition to the scope of the device defined by the claims taken in conjunction with the accompanying drawings.  
       SUMMARY  
       [0013]     The above-noted problems, among others, are overcome by the device. Briefly stated, the device contemplates a dust shield and adapter for rotary grinders. The dust shield has a cover with an upper surface and a circular skirt for enclosing a rotatable grinding disc; an exhaust opening through the skirt for passage of particles and air out to a connected exhaust; a circular collar upward of the upper section; and one or more cut-outs in the circular collar which are adapted to receive and permit downward movement of an external dust shield adapter. The adapter has an upper surface; a downward projecting wall around the upper surface adapted to fit into the opening of the collar of the aforementioned dust shield; and at least three registration components on the upper surface each having an axially translatable bracket member therein adapted to abut and secure to the bearing housing of an external grinder.  
         [0014]     Another embodiment of the dust shield has an upper surface and a circular skirt for enclosing a rotatable grinding disk; an exhaust opening through the skirt for passage of collected particles and air out to a connected exhaust; a circular collar upward of the upper section; an adapter attached to the collar; and adjustable brackets on the adapter for adjusting and removably attaching to different diameters of bearing housing of rotary grinders.  
         [0015]     The foregoing has outlined the more pertinent and important features of the device in order that the detailed description that follows may be better understood so the present contributions to the art may be more fully appreciated. Additional features of the device will be described hereinafter which form the subject of the claims. It should be appreciated by those skilled in the art that the conception and the disclosed specific embodiment may be readily utilized as a basis for modifying or designing other structures and methods for carrying out the same purposes of the device. It also should be realized by those skilled in the art that such equivalent constructions and methods do not depart from the spirit and scope of the device as set forth in the appended claims. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0016]     For a fuller understanding of the nature and objects of the device, reference should be had to the following detailed description taken in conjunction with the accompanying drawings in which:  
         [0017]      FIG. 1  is an exploded view of the dust shield, adapter, and grinder combination.  
         [0018]      FIG. 2 , as taken on line  2 - 2  of  FIG. 3 , is a cut-away view of the adapter without brackets.  
         [0019]      FIG. 3  is a top plan view of the adapter without brackets.  
         [0020]      FIG. 4 , as taken on line  4 - 4  of  FIG. 5 , is a side elevation cut-away view of a bracket.  
         [0021]      FIG. 5  is a top plan view of a bracket.  
         [0022]      FIG. 6  is a bottom plan view of a bracket.  
     
    
     DETAILED DESCRIPTION  
       [0023]     Referring now to the drawings in detail and in particular to  FIG. 1 , reference character  10  and  70  generally designates an adapter and dust shield constructed in accordance with a preferred embodiment of the present invention.  
         [0024]     The vastly improved dust shield  70  has an upper surface  72  with an integral downward projecting skirt  79 . Projecting upward of the upper surface is a collar  78  with cut-outs  74 . The dust shield  70  can be made of a translucent or transparent molded plastic, fiberglass, metal, or of any other suitable material though best results can be attained by manufacturing the dust shield  70  with the unique formulation described below. The collar  78  should be flexible and the unique formulation described below provides for greater flexibility and, if necessary, trimming of the collar  78  if necessary.  
         [0025]     A unique feature of this improved dust shield  70  is the cut-outs  74  in the collar  78 . The cut-outs  74  are aligned with the respective bracket base  32 . The function of the cut-outs  74  is to accommodate that portion of the bracket base  32  which extends outward of the downward projecting wall  18  of the adapter  10  after the adapter  10  has been attached to the bearing housing  68 . If the bracket base  32  does extend outward after attachment, each portion so extending will slip into the respective cut-out  74  and may be moved down into the cut-out  74  as needed for distance adjustment. Once the proper distance adjustment is attained for the brand grinder being used, the adapter  10  may be secured to the collar  78 .  
         [0026]     The preferred embodiment of the improved dust shield  70  comprises a unique formulation of a copolymer polypropylene, a no-break copolymer polypropylene, produced by Huntsman and bearing trade number 18S2A and a thermoplastic elastomer produced by DSM TPE, Inc., bearing the trademark Sarlink. The preferred ratios of these products is approximately 75% of the copolymer polypropylene and approximately 25% of the thermoplastic elastomer.  
         [0027]     The skirt  79  of the improved dust shield  70  also has an exhaust opening  86  connected to an exhaust port  80  that is aligned tangently with the skirt  79 . An external hose  82  attaches to the exhaust port  80 . The external hose  82  typically is part of a vacuum or vacuum system [not shown] to draw out ground or sanded particles.  
         [0028]     As described above, the upper surface  72  has an attachment collar  78  which houses or receives the adapter  10 . The collar  78  encircles a hole or opening  76  in the upper surface  72 . In one embodiment, the adapter  10  is an integral part of the dust shield  70  permanently affixed to it at or adjacent to the collar  78 . In this embodiment, the collar  78  need not have cut-outs  74  in that the adapter  10  in integral to the dust shield  70  and thereby incapable of distance adjustment.  
         [0029]     In another embodiment, the adapter  10  is a separate unit which is placed into the collar  78  of existing dust shield and secured thereat with a suitable fastener such as, but not limited to, a hose-type clamp  88  with setting screw placed and used around the collar  78 . A typical grinder  60  has bearing housing  68  and arbor or drive shaft  64 . Whether a separate unit or part of the dust shield, the adapter  10  is fitted onto and secured to the bearing housing  68  with a set of at least three adjustable brackets  30  and a hose-type clamp  88 . When the adapter  10  and dust shield  70  are fitted to the grinder, the arbor  64  of the grinder  60  projects through the opening  26  in the adapter  10  and through the opening  76  in the dust shield  70 . In this position, a hose type clamp  88  and setting screw tightens the brackets  30  and onto the bearing housing  68  to hold the dust shield  70  to the grinder  70 .  
         [0030]     Where the adapter  10  is a separate and removable unit from the dust shield, the attachment collar  78  may have any desired diameter or may be of a flexible material attached to the upper surface  72  of the dust shield  70 . Its flexibility will accommodate the insertion of the wall  18  of the adapter  10  inside the collar  78  and further accommodate a suitable securing member, such as a hose clamp  88 , to secure the adapter  10  to the dust shield  70 . It should be understood that in this separate component embodiment, the adapter walls  18  may vary in diameter to accommodate varying diameter collars  78  as, and if, necessary. In addition, the collar  78  in this separate component embodiment also has the cut-outs  74  as described above.  
         [0031]     Since the adapter  10  has adjustable brackets  30 , the adapter  10  is capable of being secured to any diameter bearing housing which ranges in diameter from one and one-half inches to over three inches. Additionally, because of this adjustability, in a dual component embodiments [i.e., separate unit dust shield and separate unit adapter] only a single size diameter for the collar  78  on the dust shield  70  and similar size diameter for the wall  18  of the adapter  10  is necessary thereby eliminating the need to manufacture various sizes of dust shields and adapters. A one-size collar  78  will fit all grinders by use of this combination dust shield  70  and adapter  10 .  
         [0032]      FIG. 1  illustrates the dust shield  70  in combination with the adapter  10  and the grinder  60 . This is illustrated in exploded to show a dual-component device having a separate detachable adapter  10  and a separate detachable dust shield  70  and to also illustrate a single-component device where the adapter  10  is an integral part of the dust shield  70  [in such case the hose clamp  88  around the collar  78  is not necessary].  
         [0033]     The adapter  10  is illustrated in greater detail in  FIGS. 2 through 6 . The top surface  12  of the adapter  10  has an opening  26  through which the arbor  64  of the grinder  60  passes. This top surface  12  also has three axial slots  16  approximately 120° from each other. A guide such as a ridge or berm  14  is fashioned on each side of each slot  16 . A wall  18  projects downwardly from the top surface  12 . In embodiments where the dust shield  70  and adapter  10  are separate detachable components, the wall  18  of the adapter  10  is sized to fit into the collar  78  of the dust shield  70  and is secured thereat by a suitable fastener, such as, but not limited to a hose-type clamp  80  with set screw.  
         [0034]     Sliding adjustable brackets  30  complete the adapter  10 . Each bracket  30  has a base  32  and a gripper  38  upstanding from the front of the base  32 . Each bracket  30  further has two or more apertures  46  in the base  32 . The width of each base  32  is such that the bracket  30  will slidingly fit over the slot  16  and slidingly in between the pair of berms  14  adjacent to its respective slot  16 . The edges of the base  32  should abut the berms  14  thereby permitting accurate axial movement to and from the center of the opening  26  on the top surface  12  of the adapter  10 .  
         [0035]     The apertures  46  on the bracket  30  are aligned with the slot  16 . Suitable fasteners  90 , such as but not limited to a nut and bolt or similar combination, are fitted through the apertures  46  and tightened to the point of retention of the bracket in the berm  14  and slot  16  combination while permitting the bracket  30  to be slid thereon back and forth as necessary to abut the bearing housing  68  of the grinder  60  to which the adapter  10  is being attached. A hose clamp  88  is placed over the adapter  10  on the backs of the gripper  38  and tightened around the bearing housing  68 . Once the gripper  38  of the bracket  30  abuts the bearing housing  68  the adapter  10  is centered to the axis of rotation of the arbor  64 , the hose clamp  88  is secured, and the fasteners  90  in the apertures  46  may be more securely tightened.  
         [0036]     A distance adjustment of any distance from about one-fourth of an inch to about one and one-fourth inches may be made as necessary to bring the grinding surface down or out [in the directions of Arrows A and B] to the required point of contact. As described above, this is facilitated by the cut-outs  74  in the collar  78  which permit insertion of the bracket base  32  if the bracket base  32  extends outward beyond the downward projecting wall  18  and further permits downward movement for distance adjustment as necessary.  
         [0037]     The leading edge of the gripper  38  may be slightly curved as illustrated in  FIGS. 5 and 6 . A curved surface has proven to be more effective in securing the adapter  10  to the bearing housing  68  of the grinder  60 .  
         [0038]     The present disclosure includes that contained in the present claims as well as that of the foregoing description. Although this device has been described in its preferred forms with a certain degree of particularity, it is understood that the present disclosure of the preferred forms has been made only by way of example and numerous changes in the details of construction and combination and arrangement of parts may be resorted to without departing from the spirit and scope of the device. Accordingly, the scope of the device should be determined not by the embodiment[s] illustrated, but by the appended claims and their legal equivalents.  
         [0039]     Applicant[s] have attempted to disclose all the embodiment[s] of the device that could be reasonably foreseen. It must be understood, however, that there may be unforeseeable insubstantial modifications to device that remain as equivalents and thereby falling within the scope of the device.