Miter saw

Abstract

A miter saw includes a miter saw for placing a work thereon, a miter saw unit having a saw blade mounted thereon, and a support mechanism for supporting the miter saw unit for rightward and leftward pivotal movement relative to the base. The support mechanism includes a first member on one side of the base and the miter saw unit and a second member on the other side of the base and the miter saw unit. The first member and the second member are pivotable relative to each other about a pivotal axis. A stopper mechanism is disposed between the first member and the second member for holding the miter saw unit in a vertical position. The stopper mechanism includes a first pressing member mounted on the first member, a first biasing member for biasing the first pressing member, and an abutting surface provided on the second member for abutment of the first pressing member. The abutting surface has a first recess formed therein. The pressing member is brought to automatically engage the first recess by the biasing force of the first biasing member when the miter saw unit is pivoted from a laterally pivoted position to the vertical position.

What is claimed is:  
     
       1. In a miter saw comprising a miter saw base for placing a work thereon, a miter saw unit having a saw blade mounted thereon, and a support mechanism for supporting the miter saw unit for both rightward and leftward pivotal movement in pivotal directions from and to a vertical position relative to the base, the support mechanism including a first side member on one of the base and the miter saw unit and a second side member on the other of the base and the miter saw unit, the first side member and the second side member being pivotable relative to each other about a pivotal axis, said first side member being fixed to said one of the base and the miter saw unit for precluding movement therebetween about said pivotal axis, said second side member being fixed to said other of the base and the miter saw unit for precluding movement therebetween about said pivotal axis, the improvement comprising: 
       a stopper mechanism disposed between the first side member and the second side member for releasably holding the miter saw unit in a vertical position;  
       said stopper mechanism including:  
       a first pressing member mounted on and extendible relative to the first side member toward said second side member, the first pressing member comprising a semispherical surface;  
       first biasing means for resiliently biasing said first pressing member toward said second side member; and  
       ana plate defining a substantially vertically oriented abutting surface providedadjustably disposed on said second side member with, wherein said semispherical surface of the first pressing member is resiliently biased thereagainst , against the plate, the position of said plate is adjustable in the circumferential direction about the pivotal axis and a first recess is formed within said abutting surface having a first recess formed therein ;  
       said semispherical surface of the first pressing member automatically engaging in and being retained in said first recess by a biasing force of said first biasing means upon positioning of said miter saw unit in the vertical position relative to said base, wherein the engagement of said first pressing member in said first recess indicates the vertical positioning of said miter saw unit and said semispherical surface of the first pressing member automatically disengages from said first recess upon application of a lateral force to the miter saw unit or the support mechanism and wherein each of the first and second side members has a substantially cylindrical configuration.  
     
     
       2. The miter saw as defined in  claim 1  wherein said first pressing member is biased by said first biasing means in a direction parallel to the pivotal axis of the miter saw unit. 
     
     
       3. The miter saw as defined in  claim 2  wherein said first pressing member comprises a first ball, and wherein said first recess has a substantially circular configuration with a peripheral edge, so that said first ball is in engagement with said first recess with said first ball being pressed onto the peripheral edge of said first recess when the miter saw unit is in the vertical position. 
     
     
       4. The miter saw as defined in  claim 1  wherein said abutting surface having said first recess is formed on a plate mounted on the second side member, and wherein the position of said plate relative to the second side member is adjustable. 
     
     
       5. The miter saw as defined in claim  4   1 wherein each of the first and second side members has a substantially cylindrical configuration, and wherein the position of said plate is adjustable in a the circumferential direction about the pivotal axis of the miter saw unit . 
     
     
       6. The miter saw as defined in claim  5   1 wherein said second side member has an inner periphery with a circumferential length, said plate being slidably movable along the inner periphery of the second side member, and wherein said plate has a circumferential length greater than half the circumferential length of the inner periphery of the second side member. 
     
     
       7. The miter saw as defined in claim  5   1 further including adjusting means operable from outside of the miter saw for adjusting the position of said plate. 
     
     
       8. The miter saw as defined in  claim 7  wherein said adjusting means includes a stopper portion formed on said plate and a pair of bolts threadably engaged with the second side member and disposed on both sides of said stopper portion, each of said bolts having a head positioned outside of the second side member and a shank end positioned within the second side member, so that said stopper portion of said plate is fixed between said shank ends of said bolts. 
     
     
       9. The miter saw as defined in claim  5   1 wherein said plate has an annular configuration and is disposed between confronting ends of the first side member and the second side member, wherein said plate has an outer peripheral part extending outwardly from the first side member, and wherein said outer peripheral part is secured to the second side member by means of a screw which is inserted into said outer peripheral part through a slot formed in said outer peripheral part and elongated in the circumferential direction, so that the position of said plate is adjustable within the length of said slot. 
     
     
       10. The miter saw as defined in  claim 2  and further including a stopper assist means for pressing the first side member and the second side member relative to each other in the pivotal direction of the miter saw unit when the miter saw unit is in the vertical position with said first pressing member being in engagement with said first recess by the biasing force of said first biasing means. 
     
     
       11. The miter saw as defined in  claim 10  wherein said miter saw unit includes a motor positioned on one lateral side in the pivotal directions of the miter saw unit when the miter saw unit is in the vertical position, wherein the first side member is fixed on the base, and the second side member is fixed on the miter saw unit, and wherein said stopper assist mechanism is operable to force the second side member in a direction toward the pivotal direction on the same lateral side as said motor. 
     
     
       12. The miter saw as defined in  claim 10  wherein said stopper assist means includes a second pressing member and second resilient biasing means mounted on the first side member, and includes a second recess formed in said abutting surface provided  defined on the second side member  plate, said second pressing member being engageable with said second recess, and said second pressing member riding onto a peripheral edge part of said second recess on one side in the pivotal directions when the miter saw unit is in the vertical position, so that said second pressing member biased by said second resilient biasing means applies a pressing force to the first side member in one of the pivotal directions of the miter saw unit. 
     
     
       13. The miter saw as defined in  claim 12  wherein said first recess and said second recess are formed in said abutting surface at different positions from each other in a radial direction about the pivotal axis, and wherein said first pressing member and said second pressing member are mounted on the second side member at different positions from each other in the radial direction. 
     
     
       14. In a miter saw comprising a miter saw base for placing a work thereon, a miter saw unit having a saw blade mounted thereon, and a support mechanism for supporting the miter saw unit for both rightward and leftward pivotal movement in pivotal directions from and to a vertical position relative to the base, the support mechanism including a first member on one side of the base and the miter saw unit and a second member on the other side of the base and the miter saw unit, and the first member and the second member being pivotable relative to each other about a pivotal axis, the improvement comprising: 
       a stopper mechanism disposed between the first member and the second member for holding the miter saw unit in a vertical position;  
       said stopper mechanism including:  
       a first pressing member mounted on the first member;  
       first biasing means for biasing said first pressing member; and  
       an abutting surface provided on said second member for abutment of said first pressing member, said abutting surface having a first recess formed therein;  
       said first pressing member being brought to automatically engage said first recess by a biasing force of said first biasing means when the miter saw unit is pivoted from a laterally pivoted position to the vertical position, said first pressing member being biased by said first biasing means toward the second member in a direction parallel to the pivotal axis of the miter saw unit, a stopper assist means for pressing the first member and the second member relative to each other in the pivotal direction of the miter saw unit when the miter saw unit is in the vertical position with said first pressing member being in engagement with said first recess by the biasing force of said first biasing means, said stopper assist means including a second pressing member and second biasing means mounted on the first member, and including a second recess formed in said abutting surface provided on the second member, said second pressing member being engageable with said second recess, and said second pressing member riding onto a peripheral edge part of said second recess on one side in the pivotal directions when the miter saw unit is in the vertical position, so that said second pressing member biased by said second biasing means applies a pressing force to the first member in one of the pivotal directions of the miter saw unit,  
       said first pressing member comprising a first ball;  
       said second pressing member comprises a second ball;  
       each of said first and second recesses has a substantially circular configuration, so that said first and second balls are partly received by said first and second recesses, respectively; and  
       when the miter saw unit in the vertical position, said first ball engages said first recess with said first ball abutting on opposed peripheral edge parts in the pivotal directions of the miter saw unit, and said second ball is engaged with and partially on said peripheral edge part of said second recess.  
     
     
       15. The miter saw as defined in  claim 14  wherein the center of said first ball and the center of said second ball are angularly displaced by an angle X about the pivotal axis of the miter saw unit, and the center of said first recess and the center of said second recess are angularly displaced by an angle Y which is different from said angle X. 
     
     
       16. The miter saw as defined in  claim 14  wherein said second recess has a bottom on which said second ball abuts when said second ball is in engagement with said second recess. 
     
     
       17. The miter saw as defined in  claim 14  wherein said first ball and said second ball have the same diameter, wherein said first recess and said second recesses are through holes, wherein the diameter of said second recess is smaller than the diameter of said first recess, and wherein the biasing force of said second biasing means is smaller than the biasing force of said first biasing means. 
     
     
       18. A miter saw comprising: 
       
         a base adapted to support a workpiece,  
       
       
         a saw unit comprising a saw blade,  
       
       
         a base side member connected to the base,  
       
       
         a saw unit side member connected to the saw unit, wherein the saw unit side member is arranged and constructed to pivot relative to the base side member about a pivotal axis,  
       
       
         a first one of the base side member and the saw unit side member comprising a first substantially horizontally oriented retainer hole, a second horizontally oriented retainer hole, a first compression spring disposed within the first retainer hole and a second compression spring disposed within the second retainer hole, the first retainer hole being spaced from the second retainer hole by an angle X about the pivotal axis, and  
       
       
         a second one of the base side member and the saw unit side member comprising a first recess having a first diameter and a second recess spaced from the first recess by angle Y about the pivotal axis, wherein X is different from Y, and alignment of the first recess and the first retainer hole represents a vertical position, or a substantially vertical position, of the saw unit relative to the base,  
       
       
         a first pressing member selected from the group consisting of a ball and a hemispherical pin and being at least partially disposed within the first retainer hole and biased in the horizontal direction by the first compression spring toward the first recess, the first pressing member having a second diameter, wherein the second diameter is greater than the first diameter so that the first pressing member only partially engages the recess when the saw unit is positioned vertically, or substantially vertically, relative to the base and  
       
       
         a second pressing member selected from the group consisting of a ball and a hemispherical pin and being at least partially disposed within the second retainer hole, the second compression spring biasing the second pressing member toward the second recess, wherein the second pressing member at least partially engages the second recess when the saw unit is vertically positioned, or substantially vertically positioned, relative to the base. 
       
     
     
       19. A miter saw as in  claim 18 , further comprising a support shaft rotatably supporting the base side member and the saw unit side member. 
     
     
       20. A miter saw as in  claim 18 , further comprising a lock screw adapted to releasably lock the saw unit side member relative to the base side member. 
     
     
       21. A miter saw as in  claim 18 , wherein the second recess has a closed bottom. 
     
     
       22. A miter saw as in  claim 18 , wherein the angle Y is slightly greater than angle X. 
     
     
       23. A miter saw as in  claim 22 , wherein one of the first recess and the second recess is disposed slightly radially inward from the other of the first recess and the second recess. 
     
     
       24. A miter saw as in  claim 18 , wherein the second recess is a through hole having a diameter smaller than the first diameter of the first recess. 
     
     
       25. A miter saw as in  claim 24 , wherein the second compression spring has a greater biasing force than the first compression spring. 
     
     
       26. A miter saw, comprising: 
       
         a base adapted to support a workpiece,  
       
       
         a support shaft secured to the base,  
       
       
         a saw unit pivotable about the support shaft from a left bevel angle position through a vertical position to a right bevel angle position and vice versa,  
       
       
         a first pressing member selected from the group consisting of a ball and a hemispherical pin,  
       
       
         a second pressing member selected from the group consisting of a ball and a hemispherical pin,  
       
       
         a first compression spring substantially horizontally disposed between the first pressing member and one of the base and the saw unit, wherein the first pressing member is biased towards the other of the base and the saw unit,  
       
       
         a second compression spring disposed between the second pressing member and one of the base and the saw unit, wherein the second pressing member is biased towards the other of the base and the saw unit, and  
       
         a substantially vertically oriented abutting surface defined by the other of the base and the saw unit, wherein the first pressing member  (   1   )  engages a first recess in the abutting surface in order to releasably secure the saw unit in the vertical position and  (   2   )  disengages from the first recess upon application of a lateral force to the saw unit, and the second pressing member engages a second recess defined in the abutting surface when the saw unit is in the vertical position, and wherein the first pressing member and second pressing member are disposed slightly farther apart than the first recess and the second recess.   
     
     
       27. A miter saw as in  claim 26 , wherein the second recess has a closed bottom. 
     
     
       28. A miter saw as in  claim 26 , wherein one of the first recess and the second recess is disposed slightly radially inward from the other of the first recess and the second recess. 
     
     
       29. A miter saw as in  claim 26 , wherein the center of the first pressing member and the center of the second pressing member are angularly displaced by an angle X about a pivotal axis of the support shaft, and the center of the first recess and the center of the second recess are angularly displaced by an angle Y, which is different from said angle X. 
     
     
       30. A miter saw as in  claim 26 , wherein the second recess has a bottom on which the second pressing member abuts when the second pressing member at least partially engages the second recess. 
     
     
       31. A miter saw as in  claim 26 , wherein the first pressing member and the second pressing member have the same diameter, the first recess and the second recess are through holes, the diameter of the second recess is less than the diameter of the first recess, and the biasing force of the second compression spring is less than the biasing force of the first compression spring. 
     
     
       32. A compound miter saw comprising: 
       
         a base,  
       
       
         a turntable rotatably supported on the base and adapted to support a workpiece,  
       
       
         a support arm pivotally secured to the base,  
       
       
         a saw unit coupled to the support arm and capable of pivoting with respect to the turntable from a left bevel angle position through a vertical position to a right bevel angle position and vice versa,  
       
       
         a first ball,  
       
       
         a first compression spring substantially horizontally disposed between the first ball and one of the base and the saw unit, wherein the first ball is biased towards the other of the base and the saw unit,  
       
         a substantially vertically oriented abutting surface defined by the other of the base and the saw unit, wherein a first recess is defined within the abutting surface, the diameter of the first ball being greater than the diameter of the first recess, and wherein the first ball  (   1   )  only partially engages the first recess in the vertical position in order to releasably retain the saw unit in the vertical position and  (   2   )  disengages from the first recess upon application of a lateral force to the saw unit,    
       
         a second ball and  
       
       
         a second compression spring substantially horizontally disposed between the second ball and one of the base and the saw unit, wherein the second compression spring biases the second ball towards the other of the base and the saw unit, wherein a second recess is defined in the abutting surface, the diameter of the second ball is greater than the diameter of the second recess and the first ball and second ball are disposed slightly farther apart than the first recess and the second recess. 
       
     
     
       33. A compound miter saw as in  claim 32 , wherein the second ball (   1   )  only partially engages the second recess in order to releasably retain the saw unit in the vertical position and  (   2   )  disengages from the second recess upon application of a lateral force to the saw unit.   
     
     
       34. A compound miter saw as in  claim 32 , wherein one of the first recess and the second recess is disposed slightly radially inward from the other of the first recess and the second recess. 
     
     
       35. A miter saw as in  claim 32 , wherein the center of the first ball and the center of the second ball are angularly displaced by an angle X with respect to a pivotal axis of the support arm, and the center of the first recess and the center of the second recess are angularly displaced by an angle Y, which angle Y is different from said angle X. 
     
     
       36. A miter saw as in  claim 32 , wherein the first ball and the second ball have the same diameter, the first recess and the second recess are through holes, the diameter of the second recess is smaller than the diameter of the first recess, and the biasing force of the second compression spring is less than the biasing force of the first compression spring. 
     
     
       37. A compound miter saw as in  claim 36 , wherein one of the first recess and the second recess is disposed slightly radially inward from the other of the first recess and the second recess, the center of the first ball and the center of the second ball are angularly displaced by an angle X with respect to a pivotal axis of the support arm, and the center of the first recess and the center of the second recess are angularly displaced by an angle Y, which angle Y is different from said angle X.