Abstract:
A dust shroud for an angle grinder includes an access hatch which slides along the shroud body to selectively expose an edge of a grinding disc to allow grinding into a corner. The hatch remains attached to the shroud body in both the open and closed position, making the hatch easier to use and less likely to become lost, resulting in increased worker compliance in properly using the hatch.

Description:
PRIORITY 
       [0001]    The present application claims the benefit of U.S. Provisional Application Ser. No. 61/227,178, filed Jul. 21, 2009, which is herein incorporated by reference in its entirety. 
     
    
     THE FIELD OF THE INVENTION 
       [0002]    The present invention relates to dust shrouds. More specifically, the present invention relates to a dust shroud for an angle grinder with contains a slideable access hatch to allow for grinding with the edge of the grinding disc. 
       BACKGROUND 
       [0003]    Angle grinders are commonly used for grinding cement or other similar tasks. Without a dust shroud, debris is scattered over a wide area. It is desirable to contain the dust which is created for several reasons. It is desirable to contain the dust and debris to keep the workplace cleaner and to minimize the time necessary to clean up afterwards. While grinding cement, for example, fine dust is often created which spreads a large distance and can be quite difficult to clean up afterwards. It is also desirable to contain the dust and debris to keep the same from getting into the tool itself, causing premature failure of the bearings, motor, etc. Additionally, debris such as concrete dust poses a health risk to the machine operator and others who may breathe it. It is thus desirable to collect the dust to minimize any exposure to the dust. 
         [0004]    Dust shrouds are often used to both contain grinding dust and prevent a mess as well as to protect an operator from debris and dust. Additionally, the dust shroud should protect the operator from contact with the grinding disc. These shrouds generally attach to an angle grinder between the grinder body and the grinding disc, typically to a cylindrical collar formed around the grinder output shaft. The shroud then forms a barrier between the operator and the grinding disc. The shroud often extends around the edges of the grinding disc, leaving the bottom grinding portion open for use. Thus, the dust shroud provides a dust and debris barrier and a safety barrier. 
         [0005]    Many dust shrouds provide a vacuum port so that a vacuum may be used to suction dust and debris out of the shroud. This avoids airborne dust and debris that can lead to such health problems as silicosis. The use of a vacuum also keeps the workplace clean of debris, dramatically reducing the time necessary to clean up after a grinding job. Vacuum dust shrouds are commonly used while grinding concrete. It can be appreciated how, without a shroud, a significant amount of concrete dust is spread across a wide area. With a vacuum shroud, very little dust goes uncollected. The use of a vacuum shroud can also protect the tool by preventing dust and debris from entering the motor and gears, thus extending tool life. 
         [0006]    Effective vacuum shrouds typically cover the top and entire perimeter of the grinding disc so that most of the dust and debris is captured by the vacuum and the disc is not exposed to the operator. Complete enclosure of the perimeter of the grinding disc, however, prevents the tool operator from grinding into a corner, such as when grinding the edge of a floor adjacent a wall. A dust shroud with an opening on a side of the shroud, while allowing grinding into such a corner, captures dust less effectively than a completely enclosed shroud. It is thus desirable to have a shroud with an opening while grinding into a corner and a completely enclosed shroud while during other times. 
         [0007]    Vacuum shrouds for grinders have been made which allow a user to remove a hatch portion of the shroud from the rest of the shroud body to expose a side of the grinding disc and allow grinding into a corner. It has been found, however, that workers tend to remove the hatch to grind into a corner and often either lose the hatch or simply neglect to replace the hatch after finishing the corner. Workers will often leave the hatch off of the shroud to save the time required to remove and replace the hatch. A worker needs both hands for operating the grinder, and thus can not hold the hatch while grinding. It is thus not uncommon for workers to simply place the hatch in a toolbox or on the floor, and lose the hatch or simply not replace the hatch as is desired. 
         [0008]    Some shrouds have been made with a hatch that is attached to the shroud with a hinge. The hatch folds open when desired. These hatches, however, do not stay open well. The hatches often close during use when the hatch catches on something in the workplace or simply closes due to the vibration of the grinder. These hatches thus become an inconvenience to the operator and may even pose a safety hazard if the hatch interferes with the use of the grinder. 
         [0009]    The failure to replace the hatch when not grinding a corner is more detrimental than one might think. In addition to the danger of having an exposed grinding disc, having an opening in the perimeter of the dust shroud allows a significant portion of the grinding dust to escape and not be collected by the vacuum. The dust from grinding concrete is very fine, and will float in the air for a long period of time, allowing uncollected dust to settle over a large area. Additionally, the dust contains compounds from the concrete which are harmful to the lungs, and uncollected dust poses more of a health risk to the worker and to others. 
         [0010]    Thus there is a need for a grinder dust shroud with a corner grinding hatch which better encourages workers to use the hatch. There is a need for a grinder dust shroud with an access hatch which is attached to the shroud itself so that the hatch can not be removed from the shroud and lost. There is a need for a hatch design which is easily opened and closed while still remaining effective in capturing dust and while still protecting a worker from the grinding disc and the grinding debris. 
       SUMMARY OF THE INVENTION 
       [0011]    It is an object of the present invention to provide an improved dust shroud for an angle grinder. 
         [0012]    According to one aspect of the invention, a dust shroud is provided which includes a slideable access hatch. The access hatch slides around the perimeter of the shroud to expose a portion of the grinding disc and allow grinding into a corner. Because the hatch is not removable from the shroud, it is unlikely that the hatch is lost. The shroud increases worker compliance in properly using the hatch (i.e. closing the hatch when not grinding into a corner) because the hatch is easy to use and does not require the worker to put down the grinder and find/use a separate hatch. 
         [0013]    These and other aspects of the present invention are realized in a dust shroud as shown and described in the following figures and related description. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]    Various embodiments of the present invention are shown and described in reference to the numbered drawings wherein: 
           [0015]      FIG. 1  shows a top perspective view of a shroud of the present invention; 
           [0016]      FIG. 2  shows a bottom perspective view of the shroud of  FIG. 1 ; 
           [0017]      FIG. 3  shows another top perspective view of the shroud of  FIG. 1 ; 
           [0018]      FIG. 4  shows another bottom perspective view of the shroud of  FIG. 1 ; 
           [0019]      FIG. 5  shows a side perspective view of the shroud of  FIG. 1 ; and 
           [0020]      FIG. 6  shows another side perspective view of the shroud of  FIG. 1 . 
       
    
    
       [0021]    It will be appreciated that the drawings are illustrative and not limiting of the scope of the invention which is defined by the appended claims. The embodiments shown accomplish various aspects and objects of the invention. It is appreciated that it is not possible to clearly show each element and aspect of the invention in a single figure, and as such, multiple figures are presented to separately illustrate the various details of the invention in greater clarity. Similarly, not every embodiment need accomplish all advantages of the present invention. For clarity, not all figures show all reference numerals. 
       DETAILED DESCRIPTION 
       [0022]    The invention and accompanying drawings will now be discussed in reference to the numerals provided therein so as to enable one skilled in the art to practice the present invention. The drawings and descriptions are exemplary of various aspects of the invention and are not intended to narrow the scope of the appended claims. 
         [0023]    Turning now to  FIG. 1 , a dust shroud  10  for an angle grinder is shown. The dust shroud  10  includes a generally flat upper surface  14  and a skirt  18  that enclose a grinding disc. A vacuum port  22  is attached to the shroud  10  and is open to the interior of the shroud. The vacuum port  22  preferably connects to a standard vacuum hose. The dust shroud  10  includes a mounting collar  26  which surrounds an opening  30  and which is designed to attach to the collar surrounding the output shaft of an angle grinder. The collar  26  may be a universal fit collar or may be designed to work specifically with a single angle grinder. The output shaft of an angle grinder is passed through the opening  30 , allowing the collar  26  to be attached to the angle grinder. A grinding disc is then attached to the angle grinder and the grinding disc is generally enclosed within the shroud  10 . 
         [0024]    The dust shroud  10  includes an access hatch  34 . The access hatch  34  slides around the circumference of the shroud  10  to selectively expose or cover an opening  38  in a side of the skirt  18 . The opening  38  exposes an edge portion of a grinding disc and allows a worker to grind into a corner, such as when grinding the surface of a floor against a wall. To accommodate the hatch  34 , the shroud  10  includes an upper guide channel  42  and a lower guide  46 . The upper guide channel  42  is circular in shape and extends across the top surface  14  of the shroud  10 . The upper guide channel  42  has an opening  42   a  on the outward edge thereof, and has an L shaped internal cross section so as to capture a ridge on the inner edge  50  of the hatch  34 . The lower guide  46  may be formed as a channel in the bottom of the skirt  18 , or may be formed with the edge of the skirt. 
         [0025]    The hatch  34  follows the shape of the upper surface  14  and skirt  18  of the shroud so that the shroud  10  maintains an enclosed interior when the hatch is closed. The hatch  34  includes a finger ridge  54  or tab which allows a worker to easily slide the hatch between an open position (as shown) and a closed position (as shown in  FIG. 3 ) without putting their hands near the grinding or cutting blade. The hatch  34  protects the worker&#39;s fingers while using the finger tab  54  since the tab is placed near the center of the hatch. Hatches which are attached to the body with a hinge may pose a greater safety risk to the operator as they may be more likely to contact the blade with their fingers while operating the hatch. Additionally, hatches attached with a hinge may move or fall closed during use, interfering with the use of the angle grinder. The upper surface  14  of the shroud has ridges  58  formed thereon which interact with the hatch  34  to hold the hatch in an open or closed position. 
         [0026]      FIG. 2  shows the bottom of the shroud  10 . It can be better seen how the outer edge  18   a  of the skirt forms a guide for the outer portion of the hatch  34 . The hatch  34  includes tabs  62  which extend around the skirt edge  18   a  and secure the hatch  34 . A slot  20  is formed in the bottom of the outer edge  18   a  of the shroud  10 , and a skirt of bristles ( 28 , shown only in  FIG. 1  for clarity) may be located in the slot to help capture grinding dust. The outer edge of the hatch  34  as well as the hatch tabs  62  form a C shape which extends around the edge  18   a  of the shroud  10  and secures the hatch without interfering with a bristle skirt if such is used. Similarly, the hatch  34  may have a slot  36  formed in the bottom of the hatch edge to receive a section of bristle skirt  28 . The shroud  10  thus allows a bristle skirt to be used without the skirt and the hatch interfering with each other. 
         [0027]      FIGS. 3 and 4  show the shroud  10  with the hatch  34  in a closed position. It can be seen how the hatch  34  maintains the circular shape of the shroud  10  and does not interfere with the normal use of the shroud. The upper guide  42  has closed ends which, in addition to the ridges  58 , keep the hatch  34  in the proper open or closed position and prevent the hatch from moving past the intended open and closed positions. 
         [0028]      FIGS. 5 and 6  show side perspective views of the shroud  10 , and better illustrate some of the details of the shroud. The shape of the tabs  62  is better seen, allowing a better understanding of how the hatch  34  engages the edge  18   a  of the skirt  18 . The shape and design of the upper guide  42  is also better seen. The upper guide  42  may form a guide channel that extends inwardly towards the center of the shroud  10  and then down through the upper surface of the shroud body in an L shape. This L shaped channel retains the top of the shroud  34 . The guide channel also forms an air inlet into the top of the shroud, aiding in the collection of debris and in cooling the grinder motor and bearings. 
         [0029]    The shroud  10  provides several benefits. By providing a slideable hatch  34 , the shroud  10  allows a worker to more easily open and close the hatch to expose a portion of the grinding disc for grinding into a corner. The finger tab  54 , placed near the center of the hatch  34 , allows a user to open and close the hatch more safely. Because the hatch  34  is integrally connected to the shroud body, the hatch is not easily lost or set aside like prior art hatches. As the shroud  10  provides a hatch  34  which is always connected to the shroud and easily and quickly used, worker compliance is improved. Workers are more likely to close the hatch  34  after grinding into a corner because there is not any inconvenience or time loss to do so. Increased worker compliance results in a cleaner working environment, reduced health risks, and prolonged tool life. 
         [0030]    There is thus disclosed an improved dust shroud for angle grinders. It will be appreciated that numerous changes may be made to the present invention without departing from the scope of the claims.