Abstract:
A miter saw including a bevel lock assembly and bevel actuation lever assembly. The bevel lock assembly locks and unlocks a bevel post at a selected position in response to movement of an actuation handle located at a front of the miter saw easily accessible by a user. The bevel lock assembly locks the bevel post in place when the actuation handle is at a rest position. Rotation of the handle to a tensioned position unlocks the bevel lock assembly to enable repositioning of the bevel post to thereby adjust a cutting angle of a saw blade of the miter saw.

Description:
[0001]    This application claims priority to U.S. provisional patent application number 61/916,354, filed on Dec. 16, 2013 and entitled “Miter Saw including Front Accessible Bevel Lock System,” the disclosure of which is incorporated herein by reference in its entirety. 
     
    
     FIELD 
       [0002]    This disclosure relates generally to the field of powered saws, and more particularly to a powered miter saw having an adjustable saw blade. 
       BACKGROUND 
       [0003]    Miter saws are used for cutting many different types of material, including lumber of different types and synthetic materials. The typical miter saw includes a base or a platform on which a turntable is positioned. The turntable includes a workpiece support surface to support a workpiece to be cut by the miter saw. A support assembly is coupled to the turntable and functions to support a cutting assembly that is operable to perform a cutting operation on the work piece. The support assembly includes adjustable components which enable the cutting assembly to move away from or toward the support surface in order to cut the workpiece. The support assembly also typically includes other adjustable components configured to pivot the cutting assembly about an angle inclined with respect to a plane of the support surface along the direction of a saw blade slot in order to produce beveled or angled cuts on the work piece. 
         [0004]    In many, if not all powered miter saws, the miter saw includes a lock system to lock or to hold the saw blade at a desired inclined cutting angle established by a user. Since the inclined cutting angle often displaces at least some of the components from a location of balance, the lock system must provide reliable and repeatable fixed locations, each of which remains stationary during a cutting operation. 
         [0005]    Different types of bevel lock systems are known and used on miter saws and are typically characterized by complex, heavy, and expensive components. Such designs are described in the following patents and patent application: U.S. Pat. No. 7,311,028B2; U.S. Pat. No. 7,703,366B2; U.S. Pat. No. 7,127,977B2; US2009/0249933A1; US2012/0160073, U.S. Pat. No. 6,758,123B2; U.S. Pat. No. 7,631,587B2; and U.S. Pat. No. 8,176,823B2. In particular, a front accessible bevel lock system including steel cams and connecting arms is illustrated in U.S. Pat. No. 7,631,587B2. In another of the above referenced patents, U.S. Pat. No. 8,176,823B2, a bevel lock system includes two brake pads clamping on a sheet metal plate. In addition, commercially available miter saws having locking systems are available from Robert Bosch LLC of Farmington Hills, Mich. USA. Such miter saws include the Bosch CM12 miter saw equipped with a brake pad style bevel lock and the Bosch GCM12SD miter saw equipped with a front accessible bevel lock system. 
         [0006]    As can be seen in the above references, the locking sytems include a large number of components which are arranged in complex fashion. Not only do the locking systems require accurately formed components to achieve a locking function, the number and complexity of components increases the amount of time necessary to assemble a locking system for a miter saw. Therefore, there is a need for a powered miter saw having an adjustable saw blade which can be fixed in position using a locking system having a reduced footprint, reduced complexity, and reduced assembly time. 
       SUMMARY 
       [0007]    In one embodiment, there is provided a miter saw having a front accessible bevel lock which is relatively uncomplicated to assemble, which provides a cost-effective design, and is relatively simple to repair if the bevel lock mechanism becomes defective. The bevel lock mechanism includes a user accessible control for activating the lock at the front of a miter saw. 
         [0008]    The bevel lock activation mechanism includes a wire, rope or cable. The need for complex cams and steel connecting arms found in other designs is eliminated. In one or more embodiments, the bevel locking system and the miter saw incorporating the bevel locking system provide a reduced cost and assembly time when compared to existing systems. Other advantages include providing for easier user activation when compared to over-center cam mechanisms having spring-loaded levers. Overall miter saw and locking system weight is reduced by replacing steel components with a wire cable in one embodiment. In addition, the number and complexity of individual components and sub-assemblies is reduced. 
         [0009]    In accordance with one embodiment of the disclosure, there is provided a miter saw including a front accessible bevel locking system that includes a steel cable, cam and lever arms to momentarily disengage the bevel lock in order to adjust the saw&#39;s bevel angle. 
         [0010]    In accordance with another embodiment of the disclosure, there is provided a miter saw and bevel lock system including two primary assemblies, a bevel locking assembly and a bevel actuation lever assembly. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]      FIG. 1  is a schematic perspective view of a miter saw with a front accessible bevel lock system. 
           [0012]      FIG. 2  is a schematic perspective view a portion of a bevel lock assembly for a miter saw including a rotor and a table. 
           [0013]      FIG. 3  is a schematic cross-sectional side view of a portion of a bevel lock assembly for a miter saw. 
           [0014]      FIG. 4  is a schematic perspective view of a portion of a bevel lock assembly for a miter saw including an actuation lever assembly. 
           [0015]      FIG. 5  is a schematic perspective view of a portion of a bevel lock assembly for a miter saw including an activation handle and a mounting bracket. 
           [0016]      FIG. 6  is a schematic perspective bottom view of an accessible bevel lock system including cam arm components. 
           [0017]      FIG. 7  is a schematic elevational side view of a miter saw including a bevel lock system in a rest, closed, or locked position. 
           [0018]      FIG. 8  is a schematic elevation side view of the bevel lock system of  FIG. 7 . 
           [0019]      FIG. 9  is a schematic elevational side view of a miter saw including a bevel lock system in an activated, open, or unlocked position. 
           [0020]      FIG. 10  is a schematic elevation side view of the bevel lock system of  FIG. 9 . 
       
    
    
     DESCRIPTION 
       [0021]    For the purposes of promoting an understanding of the principles of the embodiments disclosed herein, reference is now made to the drawings and descriptions in the following written specification. No limitation to the scope of the subject matter is intended by the references. The present disclosure also includes any alterations and modifications to the illustrated embodiments and includes further applications of the principles of the disclosed embodiments as would normally occur to one skilled in the art to which this disclosure pertains. 
         [0022]      FIG. 1  is a schematic elevational side view of a saw device such as a miter saw  100  including a turntable  102  supported by a base  104 . Other saw devices include a table saw, a planar, a compound saw, a floor saw, a bevel saw, or a device having a saw blade and base supporting the blade. The turntable  102  is rotatably adjustable on the base  104  about a pivot axis extending generally perpendicular to a plane defined by a support surface  108  of the turntable  102 , and includes a support arm  140 . 
         [0023]    The miter saw  100  includes a support assembly  110 . The support assembly  110  is configured to support a saw blade (not shown) located within a blade guard  112 , and includes a bevel post  120 , and one or more support bars  130 . A guide fence  116  is mounted on the turntable  102 . The saw blade is configured to cut a workpiece supported on one side by the support surface  108  and on another side by the guide fence  116 . A pivot mechanism  134  is rotatably coupled to the saw blade 
         [0024]    The guide fence  116  includes a workpiece guide surface  118  upon which the workpiece is positioned for a cutting operation. The guide fence  116 , as illustrated, is generally perpendicularly aligned with the turntable surface  108 . In other embodiments, the guide fence  116  is adjustable such that the workpiece guide surface  118  is inclined with respect to the turntable surface  108 . 
         [0025]    The bevel post  120  is rotatably supported on the turntable  102  about an axis  122  (See  FIGS. 2 and 3 ) that may be generally parallel to the turntable surface and aligned with a cutting plane of the blade. The bevel post  120  rotates about the axis  122  to provide angle cuts to the workpiece. The one or more support bars  130  are configured to support a portion  132  of the bevel arm  120  for sliding movement. One end of the bar(s)  130  extend(s) toward the saw blade and terminates where. The saw blade is rotatably positionable around a pivot of the pivot mechanism  134 , the position of which is fixed and released by a handle  135 . Since the support bars  130  slide within the portion  132 , the saw blade is positionable in a direction of and along a cutting slot  136  of the turntable  102 . In addition, the saw blade  122  is adjustable about an arc defined by the pivot mechanism  134 . 
         [0026]    The support arm  140  extends from the turntable  102  and provides an additional support surface for supporting a workpiece if necessary. A turntable lock  142  located at a terminating end of the support arm  140  locks and unlocks the turntable  102  at a location determined by a user. 
         [0027]    A bevel lock handle  150  is located on one side of the support arm  140 . In other embodiments, the bevel lock handle  150  may be located on other sides or portions of the support arm  140 . In addition, the bevel lock handle  150  in other embodiments may include a pushbutton or other levers to lock and unlock the bevel lock post  120 . The bevel lock handle  150  is one component of a bevel lock assembly described herein and includes a locked position, as illustrated in  FIGS. 1, 7 and 8 , and an unlocked position illustrated in  FIGS. 9 and 10 . The bevel lock handle  150  is positionable to lock the bevel post  120  at a selected location and to unlock the bevel post  120  for movement and locking at a new location selected by a user. Other examples of bevel lock handle  150  such as an electronic button other than a mechanical button are possible. 
         [0028]    Alternatively, the bevel lock handle  150  can be replaced by a touch sensor lock, a GMR sensor lock, a motion sensor lock, a pressure sensor lock, a bolometer lock, a transducer lock, or the like to lock and unlock the bevel post  120  for the same purpose. The lock handle  150  can be controlled via a user by directly locking or unlocking the lock handle, or indirectly via an electronic control connected to the saw device  100 , or another electronic device such as cellular phone, smart phone, tablet, Ptablet, console, remote control, or the like through wired or wireless communication protocol (WiFi, NFC, Bluetooth, UWB, Internet, or the like). 
         [0029]      FIGS. 2 and 3  illustrate one of two primary assemblies comprising the bevel lock assembly. A first bevel lock assembly  160  includes a clamp arm  162  having a first end which is pivotably connected to the bevel post  120  at a pivot connection  164  by way of a pivot pin  166  about which the clamp arm  162  pivots at a first pivot. The pivot pin  166  may extend through a boss, formed in the bevel post  120 , and a hole, formed at a first end of the clamp arm  162 . 
         [0030]    In addition to being pivotably located at the bevel post  120 , the clamp arm  162  rotates about a second pivot  168  defined by a rod or post  170  fixedly attached to the bevel post  120  as further illustrated in  FIG. 3 . The second pivot  168  may be substantially perpendicular to the pivot axis of the pivot pin  166 . The post  170  extends through an aperture of the clamp arm  162  such that the clamp arm  162  rotates about the second pivot  168 . An extended lug or projection  171  is located at a second end of the clamp arm  162  and is configured in the shape of an arc. The arc generally follows a radius of curvature defined by the rotation of a second end of the arm  162  about the second pivot  168 . 
         [0031]    The clamp arm  162  further includes a pad pivot  172  to which a pad support  174  is pivotably coupled. The pad pivot  172  defines a pivot axis that may be generally parallel to the pivot axis defined by the pivot pin  166 . The pad support  174  includes an outer brake pad  176  (see  FIG. 3 ) which is configured to contact a rotor  178  fixedly attached to the turntable  102 . In one embodiment, the rotor is made of a sheet metal. An inner brake pad  180  is fixedly attached to the bevel post  120  such that forced contact of the pad support  174  to the rotor  178  engages the rotor  178  with the inner brake pad  180  to lock the bevel post  120  in position. The pad pivot  172  allows the brake pad  176  to pivot to insure flush contact with the rotor  178 . 
         [0032]    As illustrated in  FIG. 3 , the post  170  extends through an aperture of the clamp arm  166  and extends through a resilient member such as a spring  182 . While a helical spring  182  is illustrated, in other embodiments other types of springs including a leaf spring and a flat spring may be included. The spring  182  may be retained on the post  170  by a washer  184  and a nut  186 , although other mechanisms for retaining the spring  182  on the post  170  are contemplated. The spring  182  located on the rod  170  is in a loaded condition such that the locations of the washer  184  and nut  186  prestress the spring  182 . In the prestressed condition, the clamp arm  162  is forced toward the bevel post  120  about the pivot  166  such that the outer brake pad  176  is forced into contact with the rotor  178  as long as a force is not applied at the extended lug  171  in a direction away from the turntable  102 . Consequently, as long as no force or a minimal force is applied at the second end of the arm  162 , the bevel post  120  remains in a locked position. 
         [0033]    To unlock the first bevel lock assembly  160 , a force is applied in a direction  190  with a cam arm  192  which contacts an interior surface of the extended lug  171  to move the second end of the clamp arm  162  away from the turntable  102 . The cam arm  192  is a component of a second bevel lock assembly described later herein. In response to the force, the clamp arm  162  rotates about the pivot  166  and the outer brake pad  176  moves away from the rotor  178  to unlock the first bevel lock assembly  160 . Once the outer brake pad  176  is sufficiently distanced from the rotor  178 , the bevel post  120  is free to move about the pivot  122  to another location which alters the inclined angle of the cutting plane of the saw blade with the plane of the support surface  108  of the turntable  102 . Movement of the cam arm  192  in the direction  190  compresses the spring  182  an additional amount. Once the cam arm is released, the spring returns the arm and the brake pad to the locked position. 
         [0034]    As further illustrated in  FIGS. 4 and 5 , a second bevel lock assembly, also called a bevel actuation lever assembly, includes the bevel lock handle or activation handle  150  which locks or unlocks the first bevel lock assembly  160 . The activation handle  150  is coupled to a wire, cable, rope or string  194  which is coupled to the cam arm  192  as seen in  FIG. 2 . In different embodiments, the cable  194  is a solid material, a threaded material or a braided material formed of a metal or other material, such as a polymer. The bevel actuation assembly includes a rod  196 , which is fixed to the support arm  140 . The rod  196  acts as a pivot shaft for the activation handle  150 , both of which are supported by a mounting bracket  198  through which the rod  196  is inserted. In one embodiment, the bracket  198  is formed of a sheet metal bent in the shape of a “U” and located within the support arm  140 . A collar  200  is fixedly located on the rod  196  and includes an extended lug  201  which captures one end of the cable  194 . Movement of the handle  150  and the rod  196  (which form a pivot arm  199 ), thereby pulls the cable  194  toward the terminating end of the support arm  140  or moves the terminating end of cable  194  of  FIG. 4  away from the terminating end of the support arm  140 . 
         [0035]      FIG. 6  illustrates a bottom plan view of the cam arm  192  which is also seen in  FIGS. 2 and 3 . The cam arm  192  is pivotally connected to the turntable  102  at a pivot connection  202 . A second end of the cable  194  is fixed to a first end  204  of the cam arm  192  which thereby responds to movement of the activation handle  150 . The cam arm  192  includes a second end  206  which includes a contact portion  208  configured to contact the extending lug  171  of the clamp arm  162 . When the cable  194  is placed under tension by the activation handle  150 , the contact portion  208  engages the extending lug  171  which is forced in direction  190  and which compresses the spring  182 . Compression of the spring  182  unlocks the locking mechanism and the bevel post  120  is free to move. 
         [0036]    As previously described in  FIG. 2 , the extending lug  171 , in one embodiment, may be formed along the line of an arc. Since the clamp arm  162  is fixed to the bevel post  120  at the pivot pin  166 , the arc shaped portion of the extending portion  171  moves along a path which is accessible for contact by the cam arm  192 . In other embodiments, the extending portion  171  is rectangular, but includes a sufficient contact area such that cam arm  192  contacts the extending portion  171  in all positions of the bevel post  120 . 
         [0037]      FIG. 7  is a schematic elevational side view of a portion of the miter saw including a bevel lock system in a rest, closed, or locked position. In  FIGS. 7 and 8 , the activation handle  150  is positioned to be substantially parallel with the support surface of the table. In this position, the cable is in a released position having a tension insufficient to move the cam arm  192  into contact with the clamp arm  162 . In this position, the outer brake pad  176  contacts the rotor  178  to lock the bevel post  120  in position. 
         [0038]    As further illustrated in  FIGS. 9 and 10 , the activation handle  150  is depressed or moved by a user to a position where the activation handle  150  is inclined with respect to the support surface of the table. In this position, the user disengages the bevel lock by applying a tension to the cable  194  which causes the cam arm  192  to move into contact with the clamp arm  162  such that the brake pad  176  moves away from the rotor  180  to thereby unlock the bevel post for free rotation. In one embodiment, the bevel lock assembly includes a ratchet assembly such that the handle  150  includes a continuous or fine adjustment such that a sufficient amount of tension is applied by the cable  194  to vary the force applied by the brake pad  176  to the rotor  180 . 
         [0039]    With the described embodiments, the bevel lock system is locked when in the rest position, i.e. no tension is applied by the handle  150  to the cable  194 . By rotating the activation handle  150 , the user momentarily disengages the bevel lock thereby permitting movement of the bevel post  120 . Once the activation handle is released, i.e. returned to the illustrated horizontal position of  FIG. 7 , the locking system is automatically returned to the locked position due to the compression spring in the bevel lock assembly. In other embodiments, other positions of the activation handle  150  for locking and unlocking the bevel lock system are possible. 
         [0040]    It will be appreciated that variants of the above-disclosed and other features and functions, or alternatives thereof, may be desirably combined into many other different systems, applications or methods. Various presently unforeseen or unanticipated alternatives, modifications, variations or improvements may be subsequently made by those skilled in the art that are also intended to be encompassed by the following embodiments. The following embodiments are provided as examples and are not intended to be limiting.