Housing of an electronic device formed by doubleshot injection molding

Abstract

A two shot injection process for forming an enclosure for an electronic device is disclosed. The two shot injection process allows for a thinner walled enclosure that uses less materials and allows for added structural features that would not be possible using traditional molding techniques. The two shot injection process generally includes forming one or more walls of an enclosure with a first shot and thereafter forming the remaining walls of the enclosure with a second shot. During the second shot, the walls fuse together thereby forming an integrally molded enclosure that is one piece.

1 . A method of forming a multiwall enclosure that defines an open space for placement of internal components via a double shot injection molding process.  
     
     
         2 . The method as recited in  claim 1  wherein the multiwall enclosure is a five wall enclosure with an open end.  
     
     
         3 . The method as recited in  claim 1  wherein the multiwall enclosure extends longitudinally from a top to a bottom end of the multiwall enclosure.  
     
     
         4 . The method as recited in  claim 1  wherein the double shot injection molding process comprises: 
 forming one or more walls of the multiwall enclosure with a first shot; and    thereafter, forming the remaining walls of the multiwall enclosure with a second shot, the walls of the first shot fusing with the walls of the second shot during the second shot so as to provide an integrally molded multiwall enclosure that is one piece.    
     
     
         5 . The method as recited in  claim 4  wherein a first side of the multiwall enclosure is formed during the first shot, and the second half of the multiwall enclosure is formed during the second shot.  
     
     
         6 . The method as recited in  claim 5  wherein the first side of the multiwall enclosure includes a front wall, right side wall, left side wall and top wall, and the second side of the multiwall enclosure includes a back wall.  
     
     
         7 . The method as recited in  claim 1  wherein the inside surfaces of the multiwall enclosure have limited or no taper, and wherein the thickness of the walls of multiwall enclosure is substantially uniform from a top to a bottom end of the multiwall enclosure.  
     
     
         8 . An enclosure having multiple walls for enclosing internal electronic components of an electronic device, the enclosure being formed by the process comprising: 
 performing a first injection molding process, the first injection molding process forming at least a first wall of the enclosure;    allowing the at least a first wall of the enclosure to solidify;    thereafter performing a second injection molding process, the second injection molding process forming at least a second wall of the enclosure, the at least a second wall of the enclosure fusing with the at least a first wall of the enclosure during the second injection molding process, the at least second wall of the enclosure forming a different side of the enclosure than the at least first wall of the enclosure; and    allowing the at least a second wall of the enclosure to solidify, the at least a second wall of the enclosure being integrally formed with the at least a first wall of the enclosure.    
     
     
         9 . The enclosure as recited in  claim 8  wherein the first and second injection molding processes are performed on the same injection molding machine.  
     
     
         10 . The enclosure as recited in  claim 8  wherein the first and second injection molding processes are performed on the same injection molding machine.  
     
     
         11 . The enclosure as recited in  claim 8  wherein the enclosure extends longitudinally from a top to a bottom end of the enclosure, and wherein the enclosure defines an open space for placement of internal components.  
     
     
         12 . The enclosure as recited in  claim 11  wherein the enclosure includes 5 walls, a front wall, a back wall, a right side wall, a left side wall and a top wall.  
     
     
         13 . The enclosure as recited in  claim 12  wherein the first injection molding process includes forming at least the front wall, and the second injection molding process includes forming at least the back wall.  
     
     
         14 . The enclosure as recited in  claim 13  wherein the first injection molding process further includes forming the right side wall, left side wall and top wall.  
     
     
         15 . The enclosure as recited in  claim 11  wherein the length of the enclosure is about 8 times the depth of the enclosure.  
     
     
         16 . The enclosure as recited in  claim 8  wherein the thickness of each of the multiple walls is substantially uniform, and wherein the thickness of each of the walls is between about 1 mm to about 1.5 mm.  
     
     
         17 . The enclosure as recited in  claim 8  wherein at least a portion of the walls include internal features that are formed during the first or second injection molding process and without using mechanical actions.  
     
     
         18 . The enclosure as recited in  claim 8  wherein the inside surfaces of the enclosure are formed with no or a minimal amount of taper during the first and second injection molding processes.  
     
     
         19 . The enclosure as recited in  8  wherein the first and second walls of the enclosure are formed with the same material.  
     
     
         20 . The enclosure as recited in  8  wherein the first and second walls of the enclosure are formed with a different material.  
     
     
         21 . The enclosure as recited in  8  wherein the first and second walls of the enclosure are formed from a plastic material selected from polycarbonate (PC), ABS or PC-ABS.  
     
     
         22 . The enclosure as recited in  claim 8  wherein the enclosure is configured for a miniature electronic device that includes a connector that extends out of the open end of the enclosure.  
     
     
         23 . The enclosure as recited in  claim 8  wherein internal features are formed on the inside surface of the first wall during the first injection molding process.  
     
     
         24 . A method of forming a single opening enclosure, comprising: 
 performing a first injection mold process, the first injection mold process forming a front wall, right and left side walls, and a top wall of the single opening enclosure; and    performing a second injection mold process, the second injection mold process forming a back wall of the single opening enclosure, the back wall being integral with the front, right, left and top walls so as to form a single integral part.    
     
     
         25 . The method as recited in  claim 24  wherein the front wall, back wall, right side wall and left side wall extend longitudinally from a top to an open end of the enclosure.  
     
     
         26 . The method as recited in  claim 24  wherein the length of the enclosure is between about 40 to about 70 times the thickness of the walls.  
     
     
         27 . The method as recited in  claim 24  wherein at least a portion of the walls include internal features that are formed during the first or second injection molding process and without using mechanical actions.  
     
     
         28 . The method as recited in  claim 24  wherein the inside surfaces of the enclosure are formed with no or a minimal amount of taper during the first and second injection molding processes.  
     
     
         29 . The method as recited in  claim 24  wherein the inside surfaces of the front wall, right side wall and left side wall are formed with zero taper along the longitudinal axis of the enclosure between the top and bottom ends of the enclosure.  
     
     
         30 . The method as recited in  claim 24  further comprising: 
 forming internal features on the inside surfaces of one or more walls during the first injection molding process.    
     
     
         31 . The method as recited in  claim 24  further comprising: 
 forming internal features on the inside surfaces of one or more walls during the second injection molding process.    
     
     
         32 . A double shot injection molding method for producing an enclosure of an electronic device having five walls and an open end, the double shot injection molding comprising: 
 providing mold A and mold B, mold A including a first injecting area and second injecting area, the first injecting area including a core, the second injecting area including a cavity and a movable insert for forming a wall of the enclosure, mold B including a cavity that cooperates with the core to form multiple walls of the enclosure;    engaging mold A with mold B so that the core of mold A is partially inserted into the cavity of mold B, the mold cooperating to form a void associated with a first half of the enclosure;    injecting plastic into the void so as to form a first half of the enclosure;    allowing the first half of the enclosure to cool and solidify;    disengaging mold A and mold B, the first half of the enclosure remaining in the mold B after disengagement;    rotating mold B so that the first half of the enclosure is aligned with the second injection area of mold A;    engaging mold A with mold B, the movable insert being inserted into the first half of the enclosure so that only the edges of the first half of the enclosure are exposed to the cavity of mold A;    injecting plastic into the cavity of mold A so as to form a second half of the enclosure, the second half of the enclosure fusing with the first half of the enclosure during the injection;    allowing the second half of the enclosure to cool and solidify, the second half of the enclosure being integrally formed with the first half of the enclosure thereby producing the entire enclosure;    removing the insert from the entire enclosure;    disengaging mold A and mold B, the entire enclosure remaining in mold B after disengagement; and    ejecting the entire enclosure from mold B.    
     
     
         33 . The method as recited in  claim 32  further comprising: 
 retaining the first half of the enclosure inside the cavity when plastic is injected into the cavity to form the second half of the enclosure.    
     
     
         34 . The method as recited in  claim 33  wherein the first half of the enclosure is retained via retention features located inside the cavity.  
     
     
         35 . The method as recited in  claim 32  further comprising: 
 cooling the insert in order to prevent the softening of the first half of the enclosure when plastic is injected into the cavity to form the second half of the enclosure.    
     
     
         36 . The method as recited in  claim 32  wherein the surfaces of the insert are polished in the pull direction so that the polishing lines run parallel to the pull direction.  
     
     
         37 . The method as recited in  claim 32  further comprising: 
 machining the enclosure to its final form factor.    
     
     
         38 . The method as recited in  claim 37  wherein the machining step includes: 
 forming a circle in the front wall to accommodate a button or wheel;    forming a rectangle in the back wall to accommodate a switch; and    removing excess material generated during the second shot from the bottom edge of the enclosure.    
     
     
         39 . A method of forming an enclosure, comprising: 
 forming first void, the first void forming a first set of walls of the enclosure;    injecting plastic into first void to form first part;    allowing first part to solidify;    inserting wedge into first part;    forming second void, the second void forming the remaining walls of the enclosure;    injecting plastic into the second void to form a second part, the second part fusing with the first part during the injection thereby forming a final enclosure with integral first and second parts;    allowing the second part to solidify; and    removing the wedge from the final part, the final part having five walls and an open end.