Shaft lock for power tool

Abstract

A power tool includes a tool shaft and a mechanism for restricting movement of the tool shaft. The mechanism includes a pin configured to engage the tool shaft to restrict movement of the tool shaft and a member provided adjacent the tool shaft and fastened to a housing of the power tool The member includes an aperture through which the pin extends when the pin engages the tool shaft.

1 . A power tool having a tool shaft and a mechanism for restricting movement of the tool shaft, the mechanism comprising: 
 a pin configured to engage the tool shaft to restrict movement of the tool shaft; and    a member provided adjacent the tool shaft and fastened to a housing of the power tool to prevent movement of the member, the member comprising an aperture through which the pin extends when the pin engages the tool shaft.    
   
   
       2 . The power tool of  claim 1 , wherein the tool shaft comprises an aperture and the pin is configured for selective insertion into the aperture to restrict movement of the shaft.  
   
   
       3 . The power tool of  claim 1 , wherein the member is configured to transmit a load from the pin to an area of the housing.  
   
   
       4 . The power tool of  claim 1 , further comprising a button coupled to the pin for allowing a user of the power tool to activate the mechanism.  
   
   
       5 . The power tool of  claim 4 , further comprising a spring for biasing the pin and the button away from the tool shaft.  
   
   
       6 . The power tool of  claim 1 , wherein the member comprises an aperture for receiving a feature of the housing to assist in the proper positioning of the member in the housing during assembly of the power tool.  
   
   
       7 . The power tool of  claim 1 , wherein the housing comprises at least two portions coupled together and the mechanism is provided substantially entirely within one of the at least two portions.  
   
   
       8 . The power tool of  claim 1 , wherein the housing comprises at least two portions and the fastener both couples the member to the housing and couples the two portions of the housing together.  
   
   
       9 . The power tool of  claim 1 , further comprising at least one rib provided in the housing to restrain movement of the member when a force is applied to the member by the pin.  
   
   
       10 . The power tool of  claim 1 , wherein the member is a plate having at least one tapered end.  
   
   
       11 . The power tool of  claim 1 , wherein the pin restricts rotation of the tool shaft.  
   
   
       12 . The power tool of  claim 1 , wherein the member is fastened to the housing with a fastener that is selected from the group consisting of a screw and a bolt.  
   
   
       13 . The power tool of  claim 1 , wherein the member is fastened to the housing by hot staking the member to the housing.  
   
   
       14 . The power tool of  claim 1 , wherein the member is provided approximately 10.5 millimeters from a rotational axis of the tool shaft.  
   
   
       15 . The power tool of  claim 1 , wherein the member is formed of a metal.  
   
   
       16 . A power tool comprising: 
 a rotatable shaft having an opening provided therein;    a device for preventing rotation of the shaft during attachment of an accessory to the shaft, the device comprising a rod configured for selective insertion into the opening to prevent rotation of the shaft and a plate having an aperture provided therein through which the rod extends during insertion of the rod into the opening;    wherein the plate is fastened to the power tool with a fastener configured to prevent movement of the plate and is configured to transmit a load from the rod when a user attaches an accessory to the shaft.    
   
   
       17 . The power tool of  claim 16 , further comprising a spring for biasing the rod away from the opening.  
   
   
       18 . The power tool of  claim 16 , wherein the accessory comprises a tool bit.  
   
   
       19 . The power tool of  claim 16 , further comprising means for moving the rod into the opening.  
   
   
       20 . The power tool of  claim 16 , wherein the plate includes at least two apertures for attaching the plate to a housing of the power tool.  
   
   
       21 . The power tool of  claim 16 , wherein the plate is formed of a metal.  
   
   
       22 . The power tool of  claim 21 , wherein the metal is a steel.  
   
   
       23 . The power tool of  claim 16 , wherein the power tool is a rotary cutting tool.  
   
   
       24 . The power tool of  claim 23 , wherein the power tool is a battery-powered tool.  
   
   
       25 . The power tool of  claim 16 , wherein the plate is provided such that it is approximately 10.5 millimeters from a central longitudinal axis of the rotatable shaft.  
   
   
       26 . A power tool having a mechanism for preventing free rotation of a tool shaft during attachment of an accessory to the tool shaft comprising: 
 a tool shaft having an aperture extending at least partially through the tool shaft in a direction transverse to a central longitudinal axis of the tool shaft;    a pin configured for selective movement between a first position in which a portion of the pin is in the aperture and a second position in which the portion of the pin is not in the aperture; and    a metal member provided adjacent the tool shaft and having an aperture through which the pin extends in the first position, the metal member secured to the power tool with at least one fastener to prevent movement of the metal member;    wherein the tool shaft is prevented from freely rotating when the pin is in the first position and is not prevented from freely rotating when the pin is in the second position.    
   
   
       27 . The power tool of  claim 26 , wherein the accessory is a tool bit.  
   
   
       28 . The power tool of  claim 26 , wherein the aperture extends completely through the tool shaft.  
   
   
       29 . The power tool of  claim 26 , wherein the pin is generally cylindrical.  
   
   
       30 . The power tool of  claim 26 , wherein the pin has a tapered end.  
   
   
       31 . The power tool of  claim 26 , wherein the metal member comprises a generally planar plate.  
   
   
       32 . The power tool of  claim 26 , wherein the metal member comprises a generally planar plate having at least one extension with an aperture provided therein for securing the metal member to the power tool.  
   
   
       33 . The power tool of  claim 26 , wherein the power tool comprises a housing having two pieces and the metal member is secured to one of the two pieces with the at least one fastener.  
   
   
       34 . The power tool of  claim 26 , wherein the power tool is a battery-powered tool.