Power Tools With Titanium Hammer Cases And Associated Flange Interfaces

Abstract

Power tools with housings or hammer cases include a thin wall titanium shell tapering from a smaller forward section to a larger rearward section; with at least the rearward section having a wall with a substantially constant wall thickness and an interface flange that includes an outer perimeter profile that is curvilinear and defines a plurality of outwardly extending detents that provide an interference fit with the wall of the hammer case.

That which is claimed is: 
     
         1 . A power tool, comprising:
 an external titanium housing having a forward portion and an opposing rearward portion and a cavity extending therebetween, wherein the titanium housing has a body of titanium with at least a major portion thereof, including a rear section thereof, having a thin wall with a substantially constant thickness;   an interface flange residing inthe titanium housing cavity; and an external motor housing extending rearward of the external titanium housing and attached to the interface flange;   wherein the interface flange has a plurality of corner detents extending outwardly thereby defining at least a portion of an outermost curvilinear perimeter thereof, the corner detents provide an interference fit with corners of an inner surface of the titanium housing; and   wherein an air gap between a perimeter of the interface flange and the inner surface of the titanium housing and adjacent at least one of the corner detents.   
     
     
         2 . The power tool of  claim 1 , wherein the power tool is an impact wrench and the titanium housing is a hammer case. 
     
     
         3 . The power tool of  claim 1 , whereinthe titanium housing body is a deep drawn titanium body, whereinthe forward portion has a cylindrical shape, and whereinthe rearward portion has a curvilinear shape. 
     
     
         4 . The power tool of  claim 1 , whereinthe interface flange has a plurality of detents extending outwardly from an outer perimeter thereof that are sized and configured to provide an interference fit with an inner surface of the titanium housing, and whereinthe interface flange can withstand a pull out force of 1000 lbs. for two seconds. 
     
     
         5 . The power tool of  claim 1 , whereinthe titanium housing body is a monolithic unitary body of deep drawn titanium that has a thin wall of substantially constant thickness. 
     
     
         6 . The power tool of  claim 1 , wherein, in use, the small gap spaces are closed with adhesive or epoxy. 
     
     
         7 . The power tool of  claim 1 , wherein the interface flange has opposing front and rear ends and an outerwall extending therebetween with at least a first and a second outerwall attachment feature on the outerwall residing between the front and rear ends, wherein the titanium housing body has a plurality of first cooperating attachment features residing on an internal surface thereof mating with the first outerwall attachment feature and a second cooperating attachment feature residing on an internal surface thereof mating with the second outerwall attachment feature, and whereinthe interface flange and titanium housing body attachment features tightly abut to define a mechanical joint. 
     
     
         8 . The power tool of  claim 7 , whereinthe interface flange attachment feature comprises at least one transversely extending recess, and whereinthe titanium housing body attachment feature comprises at least one inwardly extending projection. 
     
     
         9 . A hammer case for a power tool impact wrench, comprising:
 a thin wall titanium shell tapering from a smaller forward section to a larger rearward section, with at least the rearward section having a wall with a substantially constant wall thickness and the rearward section having an inner surface being configured to provide an interference fit with and to be bonded with an interface flange.   
     
     
         10 . The hammer case of  claim 9 , in combination with an interface flange, wherein the interface flange comprises an outer perimeter profile that is curvilinear and defines a plurality of outwardly extending detents that provide an interference fit with the wall of the hammer case. 
     
     
         11 . The hammer case of  claim 9 , whereinthe interface flange detents include a plurality of corner detents with small gap air spaces residing on opposing sides of each detent prior to bonding. 
     
     
         12 . The hammer case of  claim 9 , whereinthere are six substantially equally spaced apart interface flange detents providing interference fit interleaved with adjacent gap spaces. 
     
     
         13 . The hammer case of  claim 11 , wherein the interface flange is bonded to the hammer case so that a rear surface of the flange is flush with a rear of the hammer case, and wherein the interface flange can withstand a pull out force of 1000 lbs. for two seconds. 
     
     
         14 . The hammer case of  claim 9 , whereinthe titanium housing is a monolithic unitary body that is formed from deep drawn titanium. 
     
     
         15 . The hammer case and interface flange combination of  claim 10 , whereinthe interface flange has opposing front and rear ends and an outerwall extending therebetween with at least one attachment feature on the outerwall residing between the front and rear ends, whereinthe titanium shell has at least one cooperating attachment feature residing on an internal surface thereof residing proximate an end of the rearward section, and whereinthe interface flange and shell attachment features tightly abut to define a mechanical joint. 
     
     
         16 . The hammer case and interface flange of  claim 15 , whereinthe interface flange attachment feature comprises at least one transversely extending recess, and whereinthe titanium shell attachment feature comprises at least one inwardly extending projection. 
     
     
         17 . A method of assembling a power tool, comprising:
 providing a hammer case having a titanium shell body opposing first and second end portions, with at least one of the first or second end portions having a thin wall; and press fitting an interface flange into a portion of the shell body of the hammer   
     
     
         18 . The method of  claim 17 , whereinthe titanium housing shell body is a monolithic unitary body of deep drawn titanium and the thinwall extends about at least a major portion of the shell body with a substantially constant wall thickness, the method further comprising, after the press fitting, welding, brazing, bonding, or otherwise permanently attaching the interface flange to the hammer case shell body so that the interface flange can withstand a pull out force of about 1000 pounds for two seconds. 
     
     
         19 . The method of  claim 17 , wherein the titanium shell body is a deep drawn titanium shell body that has at least one cooperating flange attachment feature residing on an internal surface thereof residing proximate a rear end portion of the titanium shell body, and whereinthe interface flange has opposing front and rear ends and an outerwall extending therebetween with at least one attachment feature on the outerwall residing between the front and rear ends that engages the at least one attachment feature of the shell body and also includes outwardly extending spaced apart corner detents that form an interference fit against an inner surface of the thinwall of the shell body leaving small air gap spaces about a perimeter of a junction of the shell body and the flange, the method further comprising, after the press fitting, inserting an epoxy into the gap spaces and curing to secure the interface flange to the hammer case. 
     
     
         20 . The method of  claim 17 , whereinthe interface flange comprises an outer perimeter profile that is curvilinear and an inner perimeter profile that is circular, wherein there are six substantially equally spaced apart interface flange detents, whereinthe flange interface comprises at least one transversely extending recess, and whereinthe titanium shell body comprises at least one inwardly extending projection, and whereinthe press fitting includes pushing the interface flange into the shell body of the hammer case so that a rear surface of the flange is flush with a rear of the hammer case.