| Housing of an electronic device formed by doubleshot injection molding -> Monitor Keywords |
|
|
 
Housing of an electronic device formed by doubleshot injection moldingRelated Patent Categories: Stock Material Or Miscellaneous Articles, Hollow Or Container Type Article (e.g., Tube, Vase, Etc.), Polymer Or Resin Containing (i.e., Natural Or Synthetic)Housing of an electronic device formed by doubleshot injection molding description/claimsThe Patent Description & Claims data below is from USPTO Patent Application 20070048470, Housing of an electronic device formed by doubleshot injection molding. Brief Patent Description - Full Patent Description - Patent Application Claims
BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates generally to methods of injection molding and housings formed therefrom. More particularly, the present invention relates to a housing of an electronic device formed by double shot injection molding. [0003] 2. Description of the Related Art [0004] Injection molding is one of the most popular processes for manufacturing plastic products. The injection molding process generally includes (1) injecting molten plastic material into a closed mold, (2) allowing the plastic to cool down and solidify, and (3) ejecting the finished product from the mold. This process may for example be used to form enclosures or housings for various electronic products. [0005] Referring to FIG. 1, in order to mold a single opening enclosure for electronic devices using standard injection molding processes, the mold 10 typically consists of two parts, a first mold half 12 that includes a cavity 14, and a second mold half 16 that includes a core 18. When the two mold halves 12 and 16 close, the core 18 is placed inside the cavity 14, and plastic is injected through a gate into the open space 22 found between the cavity 14 and the core 18 thereby forming a box like part with an open end. The part is typically formed vertically along its longitudinal axis 24. After allowing the part to cool, the two mold halves 12 and 16 open and the solidified part is ejected out of the mold, and more particularly the cavity 14 of the first mold half 12. [0006] In order to allow proper removal of the core 18 when the mold halves 12 and 16 are opened, the core 18 typically includes a draft angle 28 on each of its sides (e.g., four sides). The draft angle 28 is the amount of taper required to allow the proper removal of the core 18 from the molded part along the axis 24. That is, the draft angle 28 allows the core 18 to slide out of the molded part when the molds are opened. The larger the draft angle 28, the easier it is to get the core 18 out of the part. If there is no draft angle 28 the core 18 may be difficult to remove from the molded part (the part shrinks around the core). Although the draft angle depends on the part design, in most cases a 2 degree draft angle per side is used. However, the minimum requirement is typically 1 degree and in some cases the draft angle may be as small as 1/2 degree. However, in elongated parts that extend longitudinally as shown, the draft angle 28 tends to be on the high side as for example at least one degree and more likely 2 degrees. If a large draft angle is not used, the sticktion force between the part and the core 18 is difficult to overcome. And even if the sticktion force is overcome, stresses may be induced in the molded part and/or the part may be damaged during ejection. A large sticktion force is typically caused by the large surface area between the part and the core in the direction of the release (e.g., along the longitudinal axis 24). [0007] Unfortunately, because of the draft angle 28, the inside walls of the molded part are also tapered and as a result the thickness of the molded part is non-uniform. The thickness varies longitudinally from thin at the open end 30 to thick at the closed end 32. While this may not be too problematic in low depth parts, it can be especially problematic in elongated parts, as the thickness can become very large at the closed end. In enclosures for electronic devices, especially small handheld electronic devices, either the outer dimensions of the part have to grow to provide the internal space necessary for the internal electronics or the device is left with less room for these components. That is, the draft either reduces the amount usable space inside the enclosure or drives the outside of the enclosure larger to create the same space for the electronic components inside. Neither of these results is desirable in small handheld devices where the outer dimensions are highly controlled and the internal space is at a premium. Furthermore, the thick wall sections may yield cosmetic issues such as sinks, cooling/flatness issues, etc. and require additional plastic material that is not needed thereby driving up the cost of the product. [0008] In some cases, it may be desirable to place internal features such as protrusions, recesses, undercuts, on the inside surfaces of the molded part. In cases such as these, the core may include a mechanical action. The mechanical action forces the part off of the core and at the same time causes the part to be lifted away from the internal feature thereby allowing the core to be released from the molded part. If the core was not lifted away, the part would get stuck on the core as its removed along the longitudinal axis. By way of example, the core may include a lifter that forms the internal feature on the inside surface and then moves away from the internal feature in order to provide enough clearance during removal. [0009] Unfortunately, mechanical actions require large cores so they are not possible with smaller parts, especially small parts that are thin and long (as shown). With parts such as these, there is simply not enough room inside the part for mechanical actions such as those created by lifters. This is especially true at the closed end of the part. Even if a lifter was somehow placed on the core, it probably wouldn't make too many cycles before it failed. Because of the small size, the lifter would overheat and self destruct. [0010] Injection molding is not limited to forming parts as described above. In some cases, injection molding may be used to put decorative features on the outer surfaces of a part. This may be accomplished using a technique called double shot injection molding. In double shot injection molding, the molding process utilizes two injections. One of the injections is used to form the part (as described above for example), and the second injection is used to create an outer layer around some or all of the part (or vice versa). By way of example, double shot injection molding may be used to place a soft layer on top of a hard layer, a transparent layer on top of an opaque layer, or create multicolored layers. In the case of an enclosure as discussed above, double shot injection molding typically only serves to enhance the look and feel of the enclosure. It does not help form the enclosure itself, as for example each of the various walls [0011] Thus, there is a need for improved approaches for molding thin elongated enclosures, especially those for small handheld electronic devices. SUMMARY OF THE INVENTION [0012] The invention relates, in one embodiment, to a method of forming a multiwall enclosure that defines an open space for placement of internal components via a double shot injection molding process. [0013] The invention relates, in another embodiment, to an enclosure having multiple walls for enclosing internal electronic components of an electronic device. The enclosure is formed by a process that includes performing a first injection molding process. The first injection molding process forms at least a first wall of the enclosure. The process also includes allowing the at least a first wall of the enclosure to solidify. The process further includes performing a second injection molding process. The second injection molding process forms at least a second wall of the enclosure. The at least a second wall of the enclosure fuses with the solidified at least a first wall of the enclosure during the second injection molding process. The at least second wall of the enclosure forms a different side of the enclosure than the at least first wall of the enclosure. The process additionally includes allowing the at least second wall of the enclosure to solidify. The at least a second wall of the enclosure is therefore integrally formed with the at least a first wall of the enclosure. [0014] The invention relates, in another embodiment, to a method of forming a single opening enclosure. The method includes performing a first injection mold process. The first injection mold process forms a front wall, right and left side walls, and a top wall of the single opening enclosure. The method also includes performing a second injection mold process. The second injection mold process forms a back wall of the single opening enclosure. The back wall is made integral with the front, right, left and top walls so as to form a single integral part. [0015] The invention relates, in another embodiment, to 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 method includes providing a mold A and a mold B. Mold A includes 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 includes a cavity that cooperates with the core to form multiple walls of the enclosure. The method also includes 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. The method further includes injecting plastic into the void so as to form a first half of the enclosure. The method additionally includes allowing the first half of the enclosure to cool and solidify. [0016] Once solidified, the method continues by disengaging mold A and mold B. The first half of the enclosure remains in the mold B after disengagement. The method also includes rotating mold B so that the first half of the enclosure is aligned with the second injection area of mold A. The method further includes engaging mold A with mold B. The movable insert is 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. The method further includes injecting plastic into the cavity of mold A so as to form a second half of the enclosure. The second half of the enclosure fuses with the first half of the enclosure during the injection. The method additionally includes allowing the second half of the enclosure to cool and solidify. The second half of the enclosure is integrally formed with the first half of the enclosure thereby producing the entire enclosure. [0017] Once formed, the method continues by removing the insert from the entire enclosure. The method also includes disengaging mold A and mold B. The entire enclosure remains in mold B after disengagement. The method further includes ejecting the entire enclosure from mold B. [0018] The invention relates, in another embodiment, to a method of forming an enclosure. The method includes forming first void. The first void forms a first set of walls of the enclosure. The method also includes injecting plastic into first void to form a first part. The method further includes allowing first part to solidify. The method additionally includes inserting wedge into first part. [0019] Moreover, the method includes forming second void. The second void forms the remaining walls of the enclosure. The method also includes injecting plastic into the second void to form a second part. The second part fuses with the first part during the injection thereby forming a final enclosure with integral first and second parts. The method further includes allowing the second part to solidify. The method additionally includes removing the wedge from the final part. The final part having five walls and an open end. BRIEF DESCRIPTION OF THE DRAWINGS [0020] The invention may best be understood by reference to the following description taken in conjunction with the accompanying drawings in which: [0021] FIG. 1 illustrates a standard injection molding process. Continue reading about Housing of an electronic device formed by doubleshot injection molding... Full patent description for Housing of an electronic device formed by doubleshot injection molding Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Housing of an electronic device formed by doubleshot injection molding patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like Housing of an electronic device formed by doubleshot injection molding or other areas of interest. ### Previous Patent Application: Decorative glazing panels and methods of manufacturing the same Next Patent Application: Injection stretch blow-molded container Industry Class: Stock material or miscellaneous articles ### FreshPatents.com Support Thank you for viewing the Housing of an electronic device formed by doubleshot injection molding patent info. IP-related news and info Results in 1.22778 seconds Other interesting Feshpatents.com categories: Software: Finance , AI , Databases , Development , Document , Navigation , Error 174 |
 * Protect your Inventions * US Patent Office filing 
PATENT INFO |
|
