Blade clamp for reciprocating saw

Abstract

A jigsaw drive shaft is connected to a blade by the blade clamp of the present invention. The blade clamp comprises a clamp body mounted securely to the drive shaft by a bracket. The clamp body has a hollow portion formed to receive an upper portion the jigsaw blade. The clamp body also includes a hollow tubular extension. A cam body is pivotable about an axis through a cylindrical bore such that cam surfaces move in and out of contact with an interior surface of the clamp body to engage or release the blade. A spring biases the cam body into engagement with the clamp body surface. The user must press on a protrusion of the cam body to pivot the cam surfaces way from the clamp surface and against the force of the spring.

1 . A clamp assembly for removably mounting a working member of a reciprocating tool to a reciprocating output shaft, the assembly comprising:—
 a body member adapted to be mounted to said output shaft;    at least one engaging member having at least one first engaging portion adapted to be located at least partially in front of a respective second engaging portion on said working member in the direction of reciprocation of the working member, wherein said engaging member is pivotable in use relative to said body member between a first position, in which said first engaging portion engages said second engaging portion to retain the working member in position on the output shaft, and a second position in which the working member is removable from the output shaft; and    first biasing means for urging said engaging member towards said first position;    wherein application of a force to said working member tending to remove the working member from the body member when at least one said engaging member is in a first position thereof causes movement of at least one said second engaging portion to be prevented by the corresponding said first engaging portion.    
   
   
       2 . An assembly according to  claim 1 , comprising a plurality of said first engaging portions, wherein at least one said first engaging portion is capable of limited pivotal movement relative to at least one other said first engaging portion.  
   
   
       3 . An assembly according to  claim 2 , comprising a plurality of said engaging members, wherein at least one said engaging member is capable of limited pivotal movement relative to at least one other said engaging member about a common axis.  
   
   
       4 . An assembly according to  claim 3 , comprising at least one first said engaging member having a respective protrusion, and at least one corresponding second said engaging member having a respective recess for receiving at least one respective said protrusion, wherein at least one said recess permits limited pivotal movement of the corresponding said protrusion therein such that the corresponding said first engaging member is pivotable about said common axis.  
   
   
       5 . An assembly according to  claim 1 , wherein at least one said engaging member further comprises at least one elongate protrusion adapted to enable the user to pivot said engaging means towards said second position.  
   
   
       6 . An assembly according to  claim 5 , wherein at least one said elongate protrusion is formed on a corresponding said first engaging member.  
   
   
       7 . An assembly according to  claim 5 , wherein said first biasing means comprises at least one torsional spring adapted to engage at least one said elongate protrusion and said body member.  
   
   
       8 . An assembly according to clam  1 , wherein at least one said first engaging portion comprises at least one respective cam surface for engaging the working member and wherein application of a force to said working member so as to remove the working member from the output shaft urges at least one said cam surface further into engagement with said working member.  
   
   
       9 . An assembly according to  claim 1 , wherein the or each said engaging member is adapted to be displaced from the first position thereof by movement of the working member towards the output shaft to enable mounting of the working member to the assembly by such movement thereof.  
   
   
       10 . A reciprocating tool using a replaceable working member, said tool comprising:—
 a body;    a motor having a rotary shaft;    drive means for converting rotary movement of said rotary shaft to reciprocating movement of an output shaft; and 
 a clamp assembly for removably mounting the working member to the output shaft, the assembly comprising  
 a body member adapted to be mounted to said output shaft;  
 at least one engaging member having at least one first engaging portion adapted to be located at least partially in front of a respective second engaging portion on said working member in the direction of reciprocation of the working member, wherein said engaging member is pivotable in use relative to said body member between a first position, in which said first engaging portion engages said second engaging portion to retain the working member in position on the output shaft, and a second position in which the working member is removable from the output shaft; and  
 first biasing means for urging said engaging member towards said first position;  
 wherein application of a force to said working member tending to remove the working member from the body member when at least one said engaging member is in a first position thereof causes movement of at least one said second engaging portion to be prevented by the corresponding said first engaging portion.  
   
   
   
       11 . A tool according to  claim 10 , wherein the tool comprises a jigsaw.  
   
   
       12 . A tool according to  claim 10 , wherein at least one said second engaging portion comprises at least one respective slot.  
   
   
       13 . A tool according to  claim 10 , wherein said working member is a saw blade and at least one said second engaging portion is provided in an edge of the blade.  
   
   
       14 . A tool according to  claim 10 , further comprising a second biasing means for urging said working member out of engagement with said output shaft.  
   
   
       15 . A jig saw comprising a: 
 a housing;    a motor having a rotary output shaft    a reciprocating drive shaft    a transmission connected between the rotary output shaft and the reciprocating drive shaft and converting the rotation of the motor output shaft into reciprocating movement of the drive shaft;    a removable saw blade including a cutting portion and a shank, the shank including an engaging portion and defining a slot between the engaging portion and the cutting portion; and    a blade clamping assembly, the blade clamping assembly including: 
 a body member connected to the drive shaft;  
 a cam body pivotably connected to the body member and including an engaging surface, the cam body pivotable between a first position and a second position.  
 a first spring for biasing the cam body into the first position; and  
 wherein when the cam body is in the first position then the cam body engaging surface extends into the saw blade shank slot to retain the saw blade in the blade clamp assembly, and when in the second position then the cam body engaging surface is retracted from the saw blade shank slot so that the saw blade is removable from the blade clamp assembly.  
   
   
   
       16 . A jig saw according to  claim 15 , wherein the cam body engaging surface is a cam shaped surface.  
   
   
       17 . A jig saw according to  claim 15 , wherein the saw blade shank slot is a first slot and the saw blade shank defines a second slot, and wherein the cam body is a first cam body and the engaging surface is a first engaging surface, and the blade clamping assembly further includes: 
 a second cam body pivotably connected to the body member and coaxial with the first cam body, the second cam body including a second engaging surface, and pivotable between a first position and a second position.    a second spring for biasing the second cam body into the first position; and    wherein when the first cam body and the second cam body are in the first position then the first engaging surface extends into the saw blade shank's firsts slot and the second engaging surfaces extends into the saw blade shank's second slot to retain the saw blade in the blade clamp assembly, and when in the second position then the first engaging surface is retracted from the first slot and the second engaging surface is retracted from the second slot so that the saw blade is removable from the blade clamp assembly.    
   
   
       18 . A jig saw according to  claim 17  wherein the first cam body and second cam body are loosely interconnected so as to permit limited rotational movement between the first cam body and the second cam body as they pivot from the second position to the first position.  
   
   
       19 . A jig saw according to  claim 17  wherein the first cam body includes a protruding lever for pivoting the first cam body and the second cam body from the first position to the second position against the biasing forces of the first spring and the second spring, for the purpose of removing the saw blade from the blade clamp assembly.  
   
   
       20 . A jig saw according to  claim 15  and further comprising a biasing means for urging the saw blade out of the blade clamp assembly.