Abstract:
Various aspects of an apparatus are disclosed. In a particular aspect, an apparatus comprising a cylindrical filter, a filter cleaning knob, and a filter cleaning flap is disclosed. Within such embodiment, the filter cleaning knob is configured to rotate the cylindrical filter. The filter cleaning flap is coupled to the cylindrical filter and configured to sequentially make contact with a plurality of pleated segments of the cylindrical filter as the filter cleaning knob is rotated.

Description:
PRIORITY CLAIM 
       [0001]    This application is a continuation-in-part of U.S. patent application Ser. No. 14/506,531, filed Oct. 3, 2014, entitled “CHOP SAW WITH DUST COLLECTION SYSTEM,” which claims priority to and the benefit of U.S. patent application Ser. No. 12/497,390, filed Jul. 2, 2009, entitled “CHOP SAW WITH DUST COLLECTION SYSTEM,” which claims priority to and the benefit of provisional U.S. patent application No. 61/078,250, filed on Jul. 3, 2008, entitled “COMBINATION CHOPSAW AND DUST COLLECTION SYSTEM,” and provisional U.S. patent application No. 61/152,574, filed on Feb. 13, 2009, entitled “COMBINATION CHOPSAW AND DUST COLLECTION SYSTEM.” Accordingly, the entire contents of each of the aforementioned patent applications are hereby expressly incorporated by reference. 
     
    
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
       [0002]    The present invention pertains generally to power masonry tools and related devices for cutting and grinding. More specifically, the present invention relates to power saws of the “cutoff” type and systems that further maximize containment of dust contaminant while cutting cinder block, concrete, brick, clay, stone, tile and the like. 
       Description of the Prior Art 
       [0003]    Power saws of the “cut-off” variety have been known for some time that employ a rotating circular blade applied to a stationary workpiece, such as wood, masonry or stone materials. An early version of a radial saw was invented by Raymond De Walt in 1922. These types of saws further include what is known as a “chop saw” which may be used for cutting lengths of pipe, steel, and other masonry objects. The chop saw comprises a motor coupled to a circular blade (or grinding wheel) pivotally supported for manual arcuate movement relative to a supporting surface such as a worktable. 
         [0004]    An example of systems and methods comprising a chop saw are disclosed in U.S. Pat. No. 7,543,522 entitled “Adjustable Fence Assembly for Chop Saw,” to Chen, which is hereby incorporated by reference in its entirety. Some additional features known for chop saws include compounding the blade to change its angle with respect to the horizontal plane; or a sliding compound feature so that the blade can make larger cuts relative to a circular blade diameter. Some chop saws further employ a laser guide such as the configuration disclosed in U.S. Pat. No. 4,257,297 entitled “Circular Saw with Visual Cut Line Indicator,” to Nidbella, which is hereby incorporated by reference in its entirety. 
         [0005]    Also known, is a problem of uncontrolled release of and exposure to airborne dust and particulate matter resulting from cutting a workpiece. Accordingly, government agencies such as the Occupational Safety and Health Administration (OSHA) have promulgated safety and health requirements for wet and dry cutting. The California Occupational Safety and Health Act of 1973 (Cal/OSHA) requires employers to provide a safe and healthful work place and gives Cal/OSHA regulatory jurisdiction over all public and private employers in California. Henceforth, employers must be compliant with all regulations set forth in Title 8 of The California Code of Regulations. In addition to health issues, the dust by-products present a clean-up challenge, even if all individuals in a contained environment have donned respirators. 
         [0006]    Development of wet cutting devices and methods is one solution to dust abatement. In doing so, water is applied at a blade cutting edge where dust is entrained to a fluid and directed to a holding area. While most wet cutting methods work relatively well, they create additional problems of waste water pollution and environmental concerns. Further, the slurry created will adhere to cutting tool materials and components that also require periodic cleaning. 
         [0007]    Many prior art solutions have been proposed that specifically employ dry means to control dust. Examples of such designs include, “Cutting And Dust Collecting Assembly,” by Johansson, U.S. Pat. App. Pub. No. 2008/0163492, “Cutting Apparatus with Dust Discharging,” to Kodani et al., U.S. Pat. No. 7,223,161, “Dust-Free Masonry Cutting Tool,” to Bath, U.S. Pat. No. 6,595,196, “Dust Collector for A Power Tool,” by Miller et al., U.S. Pat. Pub. No. 2007/0017191, to name a few, each of which are hereby incorporated by reference in their entireties. Such solutions generally may be suitable for their general purposes however none of these solutions are applicable for a chop saw. Yet another similar device was proposed by one of the present inventors, Guth entitled “Dust Collection System for A Masonry Saw,” U.S. Pat. No. 7,013,884, and assigned to Masonry Technology Incorporated, which is hereby incorporated by reference in its entirety. This dust abatement design is applicable to a masonry chop saw; however this design is not easily portable and requires a separate hook up to a vacuum system. 
         [0008]    In light of the above, it is an object of the present invention to provide a Chop Saw with Dust Collection that is highly portable and lighter in weight as compared prior art solutions. More specifically, it is an object of the present invention to provide a masonry chop saw that integrates dust collection to a single portable unit. It is still a further object of the present invention to provide a dry dust collection design that is easily cleaned. It is still further an object of the present invention to provide a design that includes a variety of innovative features over prior designs. 
       BRIEF SUMMARY OF THE INVENTION 
       [0009]    The present invention specifically addresses and alleviates the above mentioned deficiencies, more specifically, the present invention, in a first aspect, is directed to a cut off saw comprising: a worktable for supporting a work piece; a rotatable arm fixed to a circular saw blade and pivotably secured to the worktable; a center slot carved out of the worktable axially aligned to the circular saw blade; a vacuum apparatus at an interior of the worktable, the vacuum apparatus providing negative pressure with respect to atmosphere at the center slot and collecting dust from the work piece created as a byproduct from use of the cut off saw. 
         [0010]    The invention embodiment is additionally characterized in that worktable further comprises: a saw motor mechanically coupled to a circular saw blade; an upper housing; and a lower dust bin connected below the upper housing, the upper housing and lower dust bin each including a front panel, a back panel and first and second lateral sides, wherein the upper housing further comprises a lateral partitioning wall extending from first and second later sides, the lateral partitioning wall defining a suction chamber below the center slot, and wherein the upper housing further comprises a transverse partitioning wall defining both a vacuum motor chamber and a tilter chamber. 
         [0011]    The invention embodiment is additionally characterized wherein each of the upper housing front panel and upper housing back panel further comprises a lifting handle, each of the lifting handles comprising an indentation in the upper housing front and back panels. In addition to the center slot, the worktable further comprises a plurality of blade slots angularly aligned to the center slot. 
         [0012]    The cut off saw is further characterized wherein the filter chamber comprises: an access panel covering an area carved out of the first lateral side; a filter cleaning knob connected to a first filter end cap via a connection bolt, the connection bolt penetrating a hole in the access panel; a panel bushing providing translational and rotational support to the connection bolt; a second filter end cap, the first and second filter end caps together securing ends of a cylindrical media tilter; a vacuum suction tube connected to the vacuum apparatus, the vacuum tube penetrating the transverse partitioning wall; and an annular rim protrusion extending from the vacuum suction tube, the annular rim protrusion mating with the second filter end cap via a gasket and a bearing, the second filter end cap further comprising a bearing seat acting as an abutment to the bearing. 
         [0013]    Still further, the invention embodiment is characterized wherein the upper housing comprises a lower rim, the lower rim comprising a groove around a perimeter thereof, and wherein the lower dust bin further comprises an upper rim, the upper rim comprising a groove around a perimeter thereof, and wherein the upper and lower rims comprising grooves are matingly and removably connected to each other. 
         [0014]    Yet further, the invention embodiment is characterized wherein the lower dust bin first and second lateral sides each comprise a lifting handle, the lifting handles each comprising an indentation in the first and second lateral sides, respectively; and wherein the lower dust bin further comprises a latch for securing the lower dust bin to the upper housing. 
         [0015]    In a second aspect, the invention is a cut off saw comprising: a worktable for supporting a work piece; a saw motor mechanically coupled to a circular saw blade; a rotatable arm fixed to the circular saw blade and pivotably secured to the worktable; a filter chamber at an interior to the worktable, the filter chamber comprising: a cylindrical media filter; and a vacuum tube coupled to an interior of the cylindrical media filter providing negative pressure with respect to atmosphere to said interior of the cylindrical media filter. 
         [0016]    The cut off saw in this embodiment may be further characterized in that the worktable further comprises: a center slot carved out of the worktable axially aligned to the circular saw blade; and a plurality of blade slots angularly aligned to the center slot. Further, the filter chamber further comprises a filter cleaning flap secured to a lateral partitioning wall at an interior of the filter chamber, the cylindrical filter media having a plurality pleated segments about a cylindrical surface, wherein the filter cleaning flap contacts the pleated segments when the filter cleaning knob is rotated. Also, the filter chamber further comprises: an access panel covering an area carved out of the first lateral side; and a filter cleaning knob connected to a first filter end cap via a connection bolt, the connection bolt penetrating a hole in the access panel. Still further, the filter chamber further comprises: a panel bushing providing translational and rotational support to the connection bolt; and a second filter end cap, the first and second filter end caps together securing ends of a cylindrical media filter. Yet still further, the filter chamber further comprises: a vacuum suction tube connected to the vacuum apparatus, the vacuum tube penetrating the transverse partitioning wall; and an annular rim protrusion extending from the vacuum suction tube, the annular rim protrusion mating with the second filter end cap via a gasket and a bearing, the second filter end cap further comprising a bearing seat acting as an abutment to the bearing. To facilitate portability of the cut off saw, the invention additionally comprises two or more wheels. 
         [0017]    In a third aspect, the invention may be characterized as a method for cutting masonry objects comprising the steps of: mounting a circular saw blade pivotably with respect to a worktable; carving out a center slot in the worktable aligned to the circular saw blade; aligning a plurality of side slots at an angle to the center slot; imparting a negative pressure with respect to atmosphere to an interior of the worktable; and collecting dust through the center slot and the side slots from the work piece created as a byproduct from use of the circular saw blade. 
         [0018]    The method herein may be additionally characterized as comprising: providing start-lip current to a first motor; providing start-up current to a second motor sequentially to minimize undesirable current surges; providing a cylindrical filter below the worktable; and filtering the dust from air passing through the cylindrical filter. The method additionally comprises pleating the cylindrical filter thereby increasing usable surface area of the cylindrical filter. 
         [0019]    Still further, the method for cutting masonry objects herein may be characterized as comprising: contacting a filter cleaning flap to the cylindrical filter; rotating a filter cleaning knob; clearing dust from the cylindrical filter; and collecting dust in a dust bin located at an area below the worktable. Also the method includes connecting a vacuum tube to a center area of the cylindrical filter; imparting a negative pressure with respect to atmosphere to a center area of the cylindrical filter; and exhausting filtered air to a lateral side of the worktable. Another method step includes providing a plurality of lifting handles at lateral sides of the worktable. 
         [0020]    In yet another aspect of the disclosure, an apparatus comprising a cylindrical filter, a filter cleaning knob, and a filter cleaning flap is disclosed. Within such embodiment, the filter cleaning knob is configured to rotate the cylindrical filter. The filter cleaning flap is coupled to the cylindrical filter and configured to sequentially make contact with a plurality of pleated segments of the cylindrical filter as the filter cleaning knob is rotated. 
         [0021]    While the apparatus and method has or will be described for the sake of grammatical fluidity with functional explanations, it is to be expressly understood that the claims, unless expressly formulated under 35 USC §112, or similar applicable law, are not to be construed as necessarily limited in any way by the construction of “means” or “steps” limitations, but are to be accorded the full scope of the meaning and equivalents of the definition provided by the claims under the judicial doctrine of equivalents, and in the case where the claims are expressly formulated under 35 USC §112 are to be accorded full statutory equivalents under 35 USC §112, or similar applicable law. The invention can be better visualized by turning now to the following drawings wherein like elements are referenced by like numerals. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0022]    The novel features of this invention, as well as the invention itself, both as to its structure and its operation, will be best understood from the accompanying drawings, taken in conjunction with the accompanying description, in which similar reference characters refer to similar parts, and in which: 
           [0023]      FIG. 1  is a perspective view of a preferred chop saw embodiment of the present invention; 
           [0024]      FIG. 2  is a rear perspective view of a the invention embodiment illustrated in  FIG. 1 ; 
           [0025]      FIG. 3  is cross-sectional view of the invention embodiment as taken along line  3 - 3  in  FIG. 1 ; 
           [0026]      FIG. 4  is a cross-sectional view of the invention embodiment as taken along line  4 - 4  in  FIG. 1 ; 
           [0027]      FIG. 5A  is close up cut-away view of the perspective illustration shown in  FIG. 1 ; 
           [0028]      FIG. 5B  is an end view of a filter cleaning knob of the present invention; 
           [0029]      FIG. 6  is a schematical illustration of a cylindrical filter configuration embodiment of the present invention; and 
           [0030]      FIG. 7A  and  FIG. 7B  illustrate how an upper housing and a lower dust bin relate to one another. 
           [0031]      FIG. 8  illustrates a cylindrical filter in accordance with an aspect of the disclosure. 
           [0032]      FIG. 9  illustrates an exploded view of the cylindrical filter illustrated in  FIG. 8 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0033]    Referring initially to  FIG. 1 , a preferred embodiment  100  comprises a cut-off type saw which is configured to cut masonry, and more specifically stones, bricks, pavers, and other masonry items. It should be understood that inventive concepts herein can also apply to woodworking circular saws and additionally saws for cutting plastic and roofing. The dust collection system  100  of the invention works in connection with a specifically configured saw  201 , with a unique cutting table  200  and dust collector arrangement. The saw may be a cut-off saw or a chop saw, which has a circular toothed blade  201  or grinding wheel, and which rotates in a vertical plane of rotation as shown. The cut-off saw is further mounted on a pivotable arm  205  which allows the saw to be raised and lowered from a non-cutting position onto a cutting position so that the blade contacts a masonry work piece  420 , and is lowered through the work piece  420  as the saw blade cuts. 
         [0034]    In the  FIG. 1  embodiment, saw  201  is shown coupled to a saw motor  204 . It should be further appreciated that a similar circular saw could be coupled to a belt or pulley system for driving the saw  201 . Still further, saw  201  is provided with a cutting table  200  which includes a blade center slot  202 . As the cutting blade passes through the work piece, the blade continues until it enters the center slot  202 ; and additionally passes through the surface of the cutting table  200  into the slot  202 . Cutting table  200  should be broadly construed as a substantially flat structure supporting a workpiece. 
         [0035]    As circular blade  201  teeth engage the work piece  420  ( FIG. 4 ), dust and particulate matter  410  are ejected from the work piece in various directions. A negative pressure provided by vacuum apparatus  321  ( FIG. 3 ) causes air to flow in a downward direction thereby curtailing outward dispersion of the dust and particulate matter  410 . In conventional prior art systems, the saw blade  201  would not pass through a blade slot, and thus ejected material would strike the cutting table and be collected after striking the cutting table. In the saw and dust collection system  100  of the present invention, a powerful flow of air is directed past the cutting blade  201 , through center slot  202  and angled side slots  203  and into a filter chamber  310  below the cutting table  200 . Also importantly, a flow of air is provided to remove dust at the instant the workpiece  420  is contacted by the saw blade  20 ] and throughout the cutting thereof. 
         [0036]    With reference to  FIG. 2 , a rear perspective view of the present invention is shown. Exhaust port  211  is provided for discharge of filtered air  330 . Air vents  213  provide for ventilation and heat transfer from vacuum apparatus  321 . Lifting handles  221 ,  223  are further provided on first and second lateral sides to assist portability of the unit  100 . Electrical connections  212  allow for external power to be supplied to the device  100  as shown. 
         [0037]    In a preferred embodiment system  100  additionally comprises two motors  204 ,  321 ; a first  204  that drives the saw blade  201  and a second  321  that provides a prime mover for air flow. The saw and collection system  100  of the present invention may further include a time delay relay associated with power switch  214 . When the saw and collection system is switched on, a first of two loads  204 ,  321  is engaged for a pre-determined period of time as designed into the time delay relay. Subsequently, a second of the two electrical loads  204 ,  321  is engaged. By staggering the two starting current surges, the peak load on the electrical system is reduced. Additionally, this will reduce a likelihood that the system  100  current surge causes a circuit breaker to be tripped. 
         [0038]    Also as shown in  FIG. 1  and in  FIG. 2 , the worktable  200  has two separable units, namely upper housing  210  and lower dust bin  220 . In addition to lifting handles  221 ,  223  on lateral sides, lifting handles  215  are provided on a front and a back of the unit  100  to also serve as hand holds for a user transporting the device. Latch  222  is provided to secure upper housing  210  to lower dust bin  220  also as shown in  FIG. 7A  and  FIG. 7B . 
         [0039]    With reference to  FIG. 3 , a sectional view taken along line  3 - 3  in  FIG. 1  is shown. Particulate matter  410  from workpiece  420  is drawn through center slot  202  and angled side slot  203 . It should also be appreciated that side slot could be aligned parallel to the center slot  202  and at right angles thereto. Air containing dust  410  flows as shown by directional arrows  330  around partitioning wall  340 . Dust  410  is fmlher filtered from the air through cylindrical pleated filter  311 . Some of the dust and particulate matter will fall to dust bin  220  and some will be trapped by the filter. Filter cleaning flap  312  is provided connected to a ledge  313  adjacent to partitioning wall  340 . The cleaning flap  312  will assist in clearing the cylindrical filter  311  when a user rotates knob  217 . Translational wall  350  serves to separate filter chamber  310  from vacuum chamber  320 . Exhaust hose  322  is shown in the vacuum chamber  320  for exhausting air to an exterior of the device  100 . The vacuum apparatus  321  may use various types of motors to generate negative pressure and CFM to include blower motor, centrifugal fan, squirrel cage fan, propeller fan, or any other conventional moving device. 
         [0040]      FIG. 4  similarly shows the flow of air with directional arrows  330  as a sectional view along line  4 - 4  of  FIG. 1 . A cutaway in translational wall  350  reveals filter compartment  310 . It will be appreciated that other configurations for filter chamber  310  and vacuum chamber  320  could be well within the scope of the present invention, such as, for example the filter chamber  310  configured directly below slots  202 ,  203 . 
         [0041]      FIG. 5A  shows a closer view of the embodiment  100  in the  FIG. 1  illustration. The cut-a-way view also reveals a perspective illustration of the pleated cylindrical filter  311 . A carve out in a lateral side of upper housing  210  is provided to accommodate access panel  218 . Filter cleaning knob  217  is connected to the cylindrical filter  311  through the access panel  218  as further illustrated in  FIG. 6 . Access panel  218  can further be removed for maintenance and disassembly of the cylindrical filter  311  for replacement or deep cleaning.  FIG. 5  shows an end view of filter cleaning knob  217 . 
         [0042]      FIG. 6  illustrates more specifically how a cylindrical filter  311  connects to a vacuum apparatus  321  via vacuum tube  630  penetrating transverse wall  350 . Initially, filter  311  is supported on it is sides by filter end caps  610 ,  620 . Knob  217  connects to the first end cap  610  via coupler spacing  611  and connection bolt  612 . Panel bushing  613  provides translational and rotational support to connection bolt  612 . Hexagonal nut  614  secures the first filter end cap  610 . At the other end, vacuum tube  630  has an annular rim  631  protruding therefrom and provides an abutment for bearing  623  also supported by gasket  622 . Recess  621  in the second filter end cap  620  provides the space to connect bearing  623  around rim  631  as shown. 
         [0043]      FIG. 7A  and  FIG. 7B  provide a more detailed view of how upper housing  210  connects to lower dust bin  220 . Rim  710  mates with groove  720  as shown for a secure connection upon closure of latch  222 . An inside of the dust bin  220  shows an area where dust ultimately settles for later removal. 
         [0044]    In another aspect of the disclosure, particular configurations of the aforementioned cylindrical filter  311  are contemplated. To this end, it should be noted that conventional air filters are inherently problematic because during their use they become saturated with dust and debris which at some point significantly reduces airflow. As previously disclosed herein, a filter pleat agitator mechanism (e.g., flap  312 ) may be included to periodically clean the aforementioned cylindrical filters in place by rotating these filters against the filter pleat agitator mechanism which would dislodge dust/debris and thus increase filter efficiency. 
         [0045]    This rotational cleaning method, however, creates the problem of sealing the cylindrical filter to the intake port while still allowing it to rotate. In addition, it would be desirable for this rotating filter/seal to endure in an extreme environment of high temperature, high vibration, and micro fine dust. It would be further desirable that the seal material is chosen such that it does not damage the intake port during the rotation process or from the high vibration environment. 
         [0046]    Referring next to  FIGS. 8-9 , an exemplary cylindrical filter with a seal configured for such extreme environments is provided in accordance with an aspect of the disclosure. As illustrated in  FIG. 8 , cylindrical filter  800  comprises an intake port  820 , wherein intake port  820  may be configured to facilitate the illustrated air flow via a vacuum suction tube (e.g., vacuum suction tube  630 ) coupled to a vacuum device. It is also contemplated that cylindrical filter  800  further includes annular seal  810 , wherein annular seal  810  is firmly embedded within end cap  830  by annular seal retainer  812 . 
         [0047]    Here, it should be appreciated that cylindrical filter  800  illustrated in  FIGS. 8-9  is substantially similar to the aforementioned cylindrical filter  311 , wherein the structure and functionality of cylindrical filter  800  is substantially similar to cylindrical filter  311 . For instance, similar to cylindrical filter  311 , it is contemplated that cylindrical filter  800  is configured to rotate against a filter pleat agitator mechanism (e.g., flap  312 ) for the purpose of cleaning dust and debris from the filter pleats of filter media  840  to increase filter efficiency. It is further contemplated that gasket  622  illustrated in  FIG. 6 , may be substantially similar to annular seal  810 , wherein annular seal  810  is made of material configured to maintain a vacuum tight seal and allow for rotation of cylindrical filter  800  in an extreme environment of high heat, high vibration, and micro fine dust. Moreover, it would be desirable to manufacture annular seal  810  from a substance that most mitigates the damaging effects to the intake port  820  of cylindrical filter  800  during rotation and/or within a high temperature/vibration environment. 
         [0048]    In a particular aspect, it contemplated that annular seal  810  is made of a spongy foam-like material. For instance, annular seal  810  may be made of silicone foam. Indeed, as is well known, silicone foam has a wide operating temperature (e.g., temperature range of −67° F. to 392° F. (−55° C. to 200° C.)), and provides excellent dust sealing capabilities (e.g., it is well known that open cell and closed cell silicone foam products can be used for sealing out dust with low compressive forces). As is also generally known, silicone foam products are typically manufactured from platinum cured, liquid silicone rubber. The raw compound is expanded and dispensed on a continuous casting line, then heat cured. The expansion process is controlled to create a range of products having different densities, softness/firmness and cell structures. Open cell silicone foams are widely used for cushioning, dust sealing or light water sealing. Closed cell silicone foam materials are used for outdoor gaskets, wash-down gaskets and resilient cushioning pads. Expanded silicone foam products have a firmness range from ultra soft to extra firm, allowing engineers to select the best product for their application. 
         [0049]    During use, it is thus contemplated that cylindrical filter  800  yields various desirable aspects. For instance, it is contemplated that cylindrical filter  800  may be configured to rotate via knob  850  such that cylindrical filter  800  rotates against a filter pleat agitator mechanism (e.g., flap  312 ) for the purpose of cleaning the filter pleats filter media  840 , and thus optimizing airflow. The material of annular seal  810  may also be particularly selected (e.g., silicone foam) so as to maintain a vacuum tight seal and allow for rotation in an extreme environment of high heat, high vibration, and micro fine dust, while being soft enough so as to not damage intake port  820 . Namely, it is contemplated that annular seal  810  may be configured to function as a diaphragm between cylindrical filter  800  and intake port  820  to isolate vibration during use, and thus eliminating premature damage to intake port  820 . 
         [0050]    While the particular aspects herein shown and disclosed in detail is fully capable of obtaining the objects and providing the advantages herein before stated, it is to be understood that it is merely illustrative of the presently preferred embodiments of the invention and that no limitations are intended to the details of construction or design herein shown other than as described in the appended claims. 
         [0051]    Insubstantial changes from the claimed subject matter as viewed by a person with ordinary skill in the art, now known or later devised, are expressly contemplated as being equivalently within the scope of the claims. Therefore, obvious substitutions now or later known to one with ordinary skill in the art are defined to be within the scope of the defined elements.