Power tool with spindle lock

Abstract

A spindle lock equipped hand-held power tool, such as a grinder or circular saw, includes a housing assembly, a motor including a rotating armature shaft, a spindle carried externally of the housing adapted for selectively affixing and releasing a rotating cutting tool and a drive train which drivingly interconnects the motor armature shaft and spindle for the application of torque to the tool upon electrical energization of the motor. A lock member carried in the housing is selectively displaceable along a fixed axis between a locked position wherein it engages a rotating element of the drive train to prevent rotation of the spindle, and a released position. A spring continuously urges the lock member toward the released position. A manually operable lever selectively displaces the lock member between the released and locked positions.

1 . A power tool comprising:
 a housing assembly;   a motor including a rotating armature shaft disposed within said housing assembly;   a spindle carried externally with said housing assembly for relative rotation about a drive axis;   a drivetrain interconnecting said motor armature shaft and spindle for the application of torque therebetween upon the electrical energization of said motor;   a lock member carried with said housing assembly, said lock member selectively displaceable along a fixed axis between a locked position in which a first end portion of said lock member engages a rotating element of said drivetrain to prevent rotation of said spindle and a released position in which said first end portion of said lock member is spaced from said rotating element to permit rotation of said spindle;   means operative to continuously resiliently urge said lock member toward said released position; and   a lever carried externally of said housing assembly and engaging said lock member, said lever manually operable to displace said lock member from said released position to said locked position.   
   
   
       2 . The power tool of  claim 1 ,
 wherein said lock member has an elongated cylindrical form with a second end portion opposite said first end portion, said second end portion extending externally of said housing assembly,   wherein said lever is operatively carried with and extends radially outwardly from said second end portion, and   wherein said lock member extends inwardly through a through-bore formed in said housing assembly, said lock member and through-bore defining cooperating helical thread-forms.   
   
   
       3 . The power tool of  claim 1 ,
 wherein said lock member has an elongated form with a second end portion opposite said first end portion, said second end portion defining a cam-follower surface exposed externally of said housing assembly,   wherein said lock member extends inwardly through a through-bore formed in said housing assembly, and   wherein said lever has a handle portion and a cam portion mounted for limited rotation adjacent an outer surface of said housing assembly whereby said cam portion remains in sliding engagement with said second end portion of said lock member.   
   
   
       4 . The power tool of  claim 3 , wherein said handle and cam portions of said lever are integrally formed in a unified structure. 
   
   
       5 . The power tool of  claim 4 , wherein said lever is mounted for rotation about a hinge pin carried on the external surface of said housing assembly. 
   
   
       6 . The power tool of  claim 5 , further comprising at least one flange member rigidly carried by and extending outwardly from said housing assembly, said flange supporting said hinge pin in a fixed spaced relationship with the housing assembly adjacent to said lock member. 
   
   
       7 . The power tool of  claim 6 , wherein said at least one flange member comprises a pair of spaced flange members, respectively supporting opposed ends of said hinge pin with the cam portion of said lever positionally juxtaposed therebetween. 
   
   
       8 . The power tool of  claim 7 , wherein said pair of spaced flange members are integrally formed with said housing assembly. 
   
   
       9 . The power tool of  claim 7 , wherein said pair of spaced flange members are carried by a support band extending circumferentially about the outer surface of said housing assembly. 
   
   
       10 . The power tool of  claim 3 , wherein said second end portion of said lock member defines a roller-follower. 
   
   
       11 . The power tool of  claim 3 , wherein said lever is elongated and is rotatably displaceable about the cam portion thereof between a stowed orientation substantially parallel to an adjacent outer surface of said housing assembly wherein said lock member is in a released position and a deployed orientation generally normal to the adjacent outer surface of the housing assembly wherein said lock member is in a locked position. 
   
   
       12 . The power tool of  claim 1 , further comprising an operator sensible flag carried on said lever and masking means carried with said housing assembly, said flag and masking means configured and juxtaposed whereby the flag is hidden from view by the masking means when the lever is in said stowed orientation and whereby the flag is visible to the power tool operator when the lever is in said deployed orientation. 
   
   
       13 . The power tool of  claim 11 , further comprising means operative to releasable affix said lever in said released position. 
   
   
       14 . The power tool of  claim 1 , wherein said lever and said housing assembly define cooperating features operative to form a first detent operative to retain said lever in a first end-of-travel position corresponding with the locked position of the lock member, and a second detent operative to retain said lever in a second end-of-travel position corresponding with the released position of the lock member. 
   
   
       15 . The power tool of  claim 1 , wherein said spindle comprises a base portion carried for rotation with said rotating element, and attachment means for alternatively affixing and releasing a rotating tool by the application of torque about said drive axis. 
   
   
       16 . The power tool of  claim 1 , further comprising a control circuit operative to sense the position of the lock member and/or lever and to electrically disable operation of said motor whenever said lock member is in said locked position. 
   
   
       17 . The power tool of  claim 1 , further comprising an outwardly opening recess in said housing assembly to nestingly receive said lever when said lock member is in said released position.