Clamping device and dental handpiece including same

Abstract

A clamping device for clamping a member to a housing, includes a sleeve unit and a chuck unit having interengaging threads such that both units are rotatably and axially displaceable relative to each other. A spring normally urges one unit in one rotary direction relative to the other unit such that the sleeve unit contracts the open end of the chuck unit to a clamping position. A manual operator is effective, when operated, to produce a rotary displacement of one unit in the opposite rotary direction relative to the other unit, while restraining a rotary displacement of the other unit, such as to effect an axial displacement between the two units to permit the open end of the chuck unit to expand to a releasing position. Several embodiments are described in which the manual operator is a depressible push-button assembly. In one embodiment, depression of the push-button rotates the sleeve unit while rotation of the chuck unit is restrained, whereas in other described embodiments, depression of the push-button rotates the chuck unit while rotation of the sleeve unit is restrained.

1 . A clamping device for clamping a member to a housing, comprising: 
 a sleeve unit carried by said housing and having an open end formed with a tapered inner surface;    a chuck unit receivable within the open end of the sleeve unit and having an open end which is radially contractible for receiving and clamping said member;    the inner surface of said sleeve unit and the outer surface said chuck unit including interengaging threads such that said sleeve unit and chuck unit are rotatably and axially displaceable relative to each other;    a spring normally urging one unit in one rotary direction relative to the other unit such that the tapered inner surface of the sleeve unit is axially displaced relative to the chuck unit in one direction to engage and contract said open end of the chuck unit to a clamping position with respect to said member;    and a manual operator effective, when operated, to produce a rotary displacement of said one unit in the opposite rotary direction relative to the other unit such as to displace said tapered inner surface of the sleeve unit axially in the opposite direction relative to said open end of the chuck unit and thereby to permit said open end of the chuck unit to expand to a releasing position with respect to said member.    
   
   
       2 . The clamping device according to  claim 1 , wherein said manual operator is a push-button assembly which, in its normal position, permits said spring to urge the two units to the clamping position of said clutch unit, and which is depressible to rotate one of said units in said opposite direction to thereby permit the open end of said chuck unit to expand to a releasing position.  
   
   
       3 . The clamping device according to  claim 2 , wherein said first-button assembly is constructed so as to be effective, when depressed, to rotate said sleeve unit, while rotation of the chuck unit is restrained, to thereby produce an axial displacement of the chuck unit relative to the sleeve unit in the direction permitting the open end of the chuck unit to expand to its releasing position.  
   
   
       4 . The clamping device according to  claim 3 , wherein said push-button assembly includes a first element engageable with said chuck unit upon the initial depression of the push-button assembly to restrain said chuck unit from rotating, and a second element engageable with said sleeve unit, upon the continued depression of said push-button assembly, to rotate said sleeve unit relative to said chuck unit in said opposite direction to thereby permit the open end of said chuck unit to expand to its releasing position.  
   
   
       5 . The clamping device according to  claim 4 , wherein said push-button assembly includes a first group of teeth engageable with said chuck unit upon the initial depression of the push-button assembly to restrain the chuck unit from rotating and a second group of teeth engageable with said sleeve unit, upon the continued depression of said push-button assembly, to rotate said sleeve unit relative to the chuck unit in said opposite direction to thereby move the chuck unit axially to said releasing position.  
   
   
       6 . The clamping device according to  claim 3 , wherein said push-button assembly is coupled to said chuck unit by a cam surface to effect rotation of the chuck unit upon depression of the push-button, and is coupled to said sleeve unit by a pin movable within an elongated slot to restrain rotation of the push-button assembly upon depression of the push-button but to permit axial displacement of the chuck unit relative to the sleeve unit to thereby permit the open end of the chuck unit to expand to its releasing position.  
   
   
       7 . The clamping device according to  claim 6 , wherein said push-button assembly includes a depressible push-button, and a coupling member between said depressible push-button and said chuck unit; 
 and wherein said coupling includes said cam surface engageable with a cam surface on said chuck unit effective to rotate the chuck unit upon depression of said push-button, and said pin moveable within an axial slot in said sleeve unit to restrain rotation of the coupling member upon depression of said push-button.    
   
   
       8 . The clamping device according to  claim 2 , wherein said push-button assembly is constructed so as to be effective, when depressed, to rotate said chuck unit while rotation of the sleeve unit is restrained, to thereby produce an axial displacement of the chuck unit relative to the sleeve unit in the direction permitting the open end of the chuck unit to expand to its releasing position.  
   
   
       9 . The clamping device according to  claim 8 , wherein said push-button assembly includes a depressible push-button and a coupling member between and coupled to said push-button and said chuck unit; said coupling member including a pin movable within an angular slot in said sleeve unit effective to rotate said coupling member, and said chuck unit coupled thereto, upon depression of the push-button.  
   
   
       10 . The clamping device according to  claim 9 , wherein said coupling member is coupled to said chuck unit by interengaging surfaces which permit axial displacement, but not rotary displacement, of the chuck unit relative to the coupling member.  
   
   
       11 . The clamping device according to  claim 10 , wherein said interengaging surfaces include axially-extending fingers formed in the coupling member receivable within, and axially movable with respect to, axially-extending slots formed in said chuck unit.  
   
   
       12 . The clamping device according to  claim 10 , wherein said coupling member of the push-button assembly includes a rounded outer surface engageable by the push-button to reduce friction upon the rotation of the coupling member.  
   
   
       13 . The clamping device according to  claim 1 , wherein said spring has one end coupled to said sleeve unit, and an opposite end coupled to said chuck unit.  
   
   
       14 . The clamping device according to  claim 13 , wherein said spring is a spiral leaf spring normally urging said one unit in said one rotary direction to thereby contract the open end of said chuck unit to its clamping position.  
   
   
       15 . The clamping device according to  claim 13 , wherein said spring is a helical spring normally urging said one unit in said one rotary direction to thereby contract the open end of said chuck unit to its clamping position.  
   
   
       16 . A dental handpiece comprising a housing including a clamping device according to  claim 1 , wherein: 
 said chuck unit is constructed for releasably clamping a dental tool;    said sleeve unit and chuck unit are both mounted on rotary bearings for rotation within said housing with said dental tool clamped therein; and    said sleeve unit includes turbine blades for rotating said sleeve unit together with said chuck unit and the dental tool when clamped therein.    
   
   
       17 . The dental handpiece according to  claim 16 , wherein said manual operator is a depressible push-button coupled to said sleeve unit and chuck unit such that depression of the push-button rotates said chuck unit and restrains rotation of said sleeve unit.  
   
   
       18 . The dental handpiece according to  claim 17 , wherein said first-button assembly is constructed so as to be effective, when depressed, to rotate said sleeve unit, while rotation of the chuck unit is restrained, to thereby produce an axial displacement of the chuck unit relative to the sleeve unit in the direction permitting the open end of the chuck unit to expand to its releasing position.  
   
   
       19 . The dental handpiece according to  claim 17 , wherein said push-button assembly is constructed so as to be effective, when depressed, to rotate said chuck unit while rotation of the sleeve unit is restrained, to thereby produce an axial displacement of the chuck unit relative to the sleeve unit in the direction permitting the open end of the chuck unit to expand to its releasing position.  
   
   
       20 . The dental handpiece according to  claim 19 , wherein said push-button assembly includes a depressible push-button and a coupling member between and coupled to said push-button and said chuck unit; said coupling member including a pin movable within an angular slot in said sleeve unit effective to rotate said coupling member, and said chuck unit coupled thereto, upon depression of the push-button.