PATENT DOCUMENT

Publication Number: US-8690638-B2
Application Number: US-201113107325-A
Country: US
Kind Code: B2

Title: Curved plastic object and systems and methods for deburring the same

Abstract:
Curved plastic objects and systems and methods for deburring the same are disclosed. The curved plastic object can be the cap or grill of a headphone or earbud.

Claims:
What is claimed is: 
     
       1. A method of deburring a curved plastic object, the method comprising:
 providing a curved plastic object having a plurality of holes, the curved plastic object having a curved surface; 
 applying a deburring tool having a contoured surface that substantially matches the curved surface of the plastic object to the curved surface of the plastic object; and 
 vibrating the deburring tool according to a vibration profile to deburr and polish the curved surface. 
 
     
     
       2. The method of  claim 1 , further comprising:
 removing the deburring tool and cleaning the deburring tool. 
 
     
     
       3. The method of  claim 1 , wherein the vibrating of the deburring tool comprises removing remnants disposed in or around the plurality of holes. 
     
     
       4. The method of  claim 1 , wherein the curved plastic object is a headphone cap, and the curved surface is an inner surface of the headphone cap. 
     
     
       5. The method of  claim 1 , wherein the curved plastic object is a headphone cap, and the curved surface is an outer surface of the headphone cap. 
     
     
       6. The method of  claim 1 , wherein the plurality of holes each have a diameter of about 0.2 mm. 
     
     
       7. The method of  claim 1 , wherein the plurality of holes are disposed in a predetermined pattern. 
     
     
       8. A method for deburring a curved surface of a plastic object, the curved object having a plurality of holes that terminate at the curved surface, the method comprising:
 contacting an abrasive surface of a deburring tool to the curved surface of the plastic object, the deburring tool having a contoured surface that substantially corresponds to the curved surface; and 
 vibrating the deburring tool according to a vibration profile to remove remnants disposed within and around the plurality of holes from the plastic object, wherein during the vibrating the deburring tool vibrates out the remnants disposed within the holes and the abrasive surface of the deburring tool removes the remnants around the holes, wherein the deburring tool is vibrated for a predetermined period of time. 
 
     
     
       9. The method of  claim 8 , wherein vibrating the deburring tool further polishes the curved surface, wherein during the polishing the abrasive strips smoothes out bumps on the curved surface. 
     
     
       10. The method of  claim 8 , wherein vibrating the deburring tool comprises ultrasonically vibrating the deburring tool. 
     
     
       11. The method of  claim 8 , wherein the vibration profile comprises vibrating the deburring tool at a fixed frequency during the predetermined period of time. 
     
     
       12. The method of  claim 8 , wherein the vibration profile comprises modulating the vibration of the deburring tool during the predetermined period of time. 
     
     
       13. The method of  claim 8 , wherein the plurality of holes range in number from about 200-1000, 300-900, 400-750, 500-600, 650-750, or 700-725. 
     
     
       14. The method of  claim 8 , wherein the curved surface is convex. 
     
     
       15. The method of  claim 8 , Wherein the curved surface is concave. 
     
     
       16. A method for finishing a curved surface of a portion of a headphone cap, the headphone cap having a plurality of holes disposed therethrough, wherein remnants from a prior operation remain around and within the plurality of holes, the method comprising:
 contacting an abrasive surface of a deburring tool to the curved surface, the abrasive surface having a shape in accordance with the curved surface; and 
 ultrasonically vibrating the deburring tool while the abrasive tool is contacting the curved surface such that a resultant ultrasonic vibration vibrates out remnants disposed within the hole and the abrasive surface removes remnants around the holes, wherein after the contacting and ultrasonic vibrating the curves surface around the holes is substantially smooth. 
 
     
     
       17. The method of  claim 16 , wherein the remnants are a byproduct of formation of the plurality of holes. 
     
     
       18. The method of  claim 16 , wherein the abrasive surface comprises diamond.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of previously filed U.S. Provisional Patent Application No. 61/390,936, filed on Oct. 7, 2010, entitled “CURVED PLASTIC OBJECT AND SYSTEMS AND METHODS FOR DEBURRING THE SAME,” which is incorporated by reference herein in its entirety. 
    
    
     BACKGROUND 
     Wired headsets are commonly used with many portable electronic devices such as portable music players and mobile phones. Headsets can include non-cable components such as a jack, headphones, and/or a microphone and one or more cables that interconnect the non-cable components. Plastic headphones typically include holes that permit the passage of soundwaves from from the inside of the headphones to the outside of the headphones. The creation of these holes can result in remnants left in or around the holes that degrade the aesthetic and acoustic properties of the headphones. Therefore, what are needed are systems and methods for deburring curved plastic objects. 
     SUMMARY 
     Curved plastic objects and systems and methods for deburring the same are disclosed. The curved plastic object can be the cap or grill of a headphone or earbud. 
     According to some embodiments, a headphone can include a headphone cap with a number of holes extending from the inner surface to the outer surface. The inner and outer surfaces can be deburred and polished to ensure that no remnants remain in the holes or on any surface of the headphone. 
     In some embodiments, a tool for deburring a curved plastic object is disclosed. The tool can be coated in an abrasive material and substantially conform to the shape of the curved plastic object. The curved plastic surface can be deburred and polished by vibrating the tool while it is in contact with the curved plastic surface. Separate tools may be provided for deburring each side of the curved plastic object. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other aspects and advantages of the invention will become more apparent upon consideration of the following detailed description, taken in conjunction with accompanying drawings, in which like reference characters refer to like parts throughout, and in which: 
         FIGS. 1A and 1B  illustrate different headsets having a cable structure that seamlessly integrates with non-cable components in accordance with some embodiments of the invention; 
         FIG. 2  shows an illustrative top and side views of a cap constructed in accordance with an embodiment of the invention; 
         FIG. 3  shows an illustrative cross-sectional view of a cap and a deburring tool in accordance with an embodiment of the invention; 
         FIG. 4  shows illustrative cross-sectional views of a cap and a deburring tool in accordance with an embodiment of the invention; and 
         FIG. 5  shows illustrative steps for deburring and polishing a surface of a curved plastic object in accordance with an embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE DISCLOSURE 
     Curved plastic objects and systems and methods for deburring the same are disclosed. The curved plastic object can be the cap or grill of a headphone or earbud. A number of holes extending from the inner surface to the outer surface of a headphone cap can be drilled or otherwise provided as described more fully below with respect to  FIG. 2 . 
     After the holes are created, tools with substantially the same shape as the inner and outer surface of the headphone cap can be used to deburr and polish each surface. The tool can be coated in an abrasive material suitable to remove remnants left over from the process that created the holes. The headphone cap can then be joined with a second headphone component to form a headphone. In some embodiments, the headphone can appear to be a one-piece unibody headphone, seamlessly joined from two headphone component pieces. The headphone can then be connected to a cable structure and other non-cable components as part of a headset. 
       FIG. 1A  shows an illustrative headset  10  having cable structure  20  that seamlessly integrates with non-cable components  40 ,  42 ,  44 . For example, non-cable components  40 ,  42 , and  44  can be a male plug, a left headphone, and a right headphone, respectively. Cable structure  20  has three legs  22 ,  24 , and  26  joined together at bifurcation region  30 . Leg  22  may be referred to herein as main leg  22 , and includes the portion of cable structure  20  existing between non-cable component  40  and bifurcation region  30 . In particular, main leg  22  includes interface region  31 , bump region  32 , and non-interface region  33 . Leg  24  may be referred to herein as left leg  24 , and includes the portion of cable structure  20  existing between non-cable component  42  and bifurcation region  30 . Leg  26  may be referred to herein as right leg  26 , and includes the portion of cable structure  20  existing between non-cable component  44  and bifurcation region  30 . Both left and right legs  24  and  26  include respective interface regions  34  and  37 , bump regions  35  and  38 , and non-interface regions  36  and  39 . 
     Legs  22 ,  24 , and  26  generally exhibit a smooth surface throughout the entirety of their respective lengths. Each of legs  22 ,  24 , and  26  can vary in diameter, yet still retain the smooth surface. 
     Non-interface regions  33 ,  36 , and  39  can each have a predetermined diameter and length. The diameter of non-interface region  33  (of main leg  22 ) may be larger than or the same as the diameters of non-interface regions  36  and  39  (of left leg  24  and right leg  26 , respectively). For example, leg  22  may contain a conductor bundle for both left and right legs  24  and  26  and may therefore require a greater diameter to accommodate all conductors. In some embodiments, it is desirable to manufacture non-interface regions  33 ,  36 , and  39  to have the smallest diameter possible, for aesthetic reasons. As a result, the diameter of non-interface regions  33 ,  36 , and  39  can be smaller than the diameter of any non-cable component (e.g., non-cable components  40 ,  42 , and  44 ) physically connected to the interfacing region. Since it is desirable for cable structure  20  to seamlessly integrate with the non-cable components, the legs may vary in diameter from the non-interfacing region to the interfacing region. 
     Bump regions  32 ,  35 , and  38  provide a diameter changing transition between interfacing regions  31 ,  34 , and  37  and respective non-interfacing regions  33 ,  36 , and  39 . The diameter changing transition can take any suitable shape that exhibits a fluid or smooth transition from any interface region to its respective non-interface region. For example, the shape of the bump region can be similar to that of a cone or a neck of a wine bottle. As another example, the shape of the taper region can be stepless (i.e., there is no abrupt or dramatic step change in diameter, nor a sharp angle at an end of the bump region). Bump regions  32 ,  35 , and  38  may be mathematically represented by a bump function, which requires the entire diameter changing transition to be stepless and smooth (e.g., the bump function is continuously differentiable). 
     Interface regions  31 ,  34 , and  37  can each have a predetermined diameter and length. The diameter of any interface region can be substantially the same as the diameter of the non-cable component it is physically connected to, to provide an aesthetically pleasing seamless integration. For example, the diameter of interface region  31  can be substantially the same as the diameter of non-cable component  40 . In some embodiments, the diameter of a non-cable component (e.g., component  40 ) and its associated interfacing region (e.g., region  31 ) are greater than the diameter of the non-interface region (e.g., region  33 ) they are connected to via the bump region (e.g., region  32 ). Consequently, in this embodiment, the bump region decreases in diameter from the interface region to the non-interface region. 
     In another embodiment, the diameter of a non-cable component (e.g., component  40 ) and its associated interfacing region (e.g., region  31 ) are less than the diameter of the non-interface region (e.g., region  33 ) they are connected to via the bump region (e.g., region  32 ). Consequently, in this embodiment, the bump region increases in diameter from the interface region to the non-interface region. 
     The combination of the interface and bump regions can provide strain relief for those regions of headset  10 . In one embodiment, strain relief may be realized because the interface and bump regions have larger dimensions than the non-interface region and thus are more robust. These larger dimensions may also ensure that non-cable portions are securely connected to cable structure  20 . Moreover, the extra girth better enables the interface and bump regions to withstand bend stresses. 
     The interconnection of legs  22 ,  24 , and  26  at bifurcation region  30  can vary depending on how cable structure  20  is manufactured. In one approach, cable structure  20  can be a single-segment unibody cable structure. In this approach all three legs are manufactured jointly as one continuous structure and no additional processing is required to electrically couple the conductors contained therein. That is, none of the legs are spliced to interconnect conductors at bifurcation region  30 , nor are the legs manufactured separately and then later joined together. Some single-segment unibody cable structures may have a top half and a bottom half, which are molded together and extend throughout the entire unibody cable structure. For example, such single-segment unibody cable structures can be manufactured using injection molding and compression molding manufacturing processes (discussed below in more detail). Thus, although a mold-derived single-segment unibody cable structure has two components (i.e., the top and bottom halves), it is considered a single-segment unibody cable structure for the purposes of this disclosure. Other single-segment unibody cable structures may exhibit a contiguous ring of material that extends throughout the entire unibody cable structure. For example, such a single-segment cable structure can be manufactured using an extrusion process. 
     In another approach, cable structure  20  can be a multi-segment unibody cable structure. A multi-segment unibody cable structure may have the same appearance of the single-segment unibody cable structure, but the legs are manufactured as discrete components. The legs and any conductors contained therein are interconnected at bifurcation region  30 . The legs can be manufactured, for example, using any of the processes used to manufacture the single-segment unibody cable structure. 
     The cosmetics of bifurcation region  30  can be any suitable shape. In one embodiment, bifurcation region  30  can be an overmold structure that encapsulates a portion of each leg  22 ,  24 , and  26 . The overmold structure can be visually and tactically distinct from legs  22 ,  24 , and  26 . The overmold structure can be applied to the single or multi-segment unibody cable structure. In another embodiment, bifurcation region  30  can be a two-shot injection molded splitter having the same dimensions as the portion of the legs being joined together. Thus, when the legs are joined together with the splitter mold, cable structure  20  maintains its unibody aesthetics. That is, a multi-segment cable structure has the look and feel of single-segment cable structure even though it has three discretely manufactured legs joined together at bifurcation region  30 . Many different splitter configurations can be used, and the use of some splitters may be based on the manufacturing process used to create the segment. 
     Cable structure  20  can include a conductor bundle that extends through some or all of legs  22 ,  24 , and  26 . Cable structure  20  can include conductors for carrying signals from non-cable component  40  to non-cable components  42  and  44 , which can be seamless, unibody headphones. A unibody headphone may be composed of two separate headphone components. According to some embodiments, one component can contain headphone components (e.g., speaker(s) and a circuit board that can connect to cable structure  20 ), while the other component can have ports to allow sound to be readily transmitted from the headphone. The two components can be welded together such that no air bubbles remain and gaps between the two components are completely filled in. The weld ring created at the interface of the two components can then be cut, sanded, polished, and cleaned, resulting in a headphone that appears to be of one-piece or unibody construction. 
     Cable structure  20  can include one or more rods constructed from a superelastic material. The rods can resist deformation to reduce or prevent tangling of the legs. The rods are different than the conductors used to convey signals from non-cable component  40  to non-cable components  42  and  44 , but share the same space within cable structure  20 . Several different rod arrangements may be included in cable structure  20 . 
     In yet another embodiment, one or more of legs  22 ,  24 , and  26  can vary in diameter in two or more bump regions. For example, the leg  22  can include bump region  32  and another bump region (not shown) that exists at leg/bifurcation region  30 . This other bump region may vary the diameter of leg  22  so that it changes in size to match the diameter of cable structure at bifurcation region  30 . This other bump region can provide additional strain relief. 
     In some embodiments, another non-cable component can be incorporated into either left leg  24  or right leg  26 . As shown in  FIG. 1B , headset  60  shows that non-cable component  46  is integrated within leg  26 , and not at an end of a leg like non-cable components  40 ,  42  and  44 . For example, non-cable component  46  can be a communications box that includes a microphone and a user interface (e.g., one or more mechanical or capacitive buttons). Non-cable component  46  can be electrically coupled to non-cable component  40 , for example, to transfer signals between communications box  46  and one or more of non-cable components  40 ,  42  and  44 . 
     Non-cable component  46  can be incorporated in non-interface region  39  of leg  26 . In some cases, non-cable component  46  can have a larger size or girth than the non-interface regions of leg  26 , which can cause a discontinuity at an interface between non-interface region  39  and communications box  46 . To ensure that the cable maintains a seamless unibody appearance, non-interface region  39  can be replaced by first non-interface region  50 , first bump region  51 , first interface region  52 , communications box  46 , second interface region  53 , second bump region  54 , and second non-interface region  55 . 
     Similar to the bump regions described above in connection with the cable structure of  FIG. 1A , bump regions  51  and  54  can handle the transition from non-cable component  46  to non-interface regions  50  and  55 . The transition in the bump region can take any suitable shape that exhibits a fluid or smooth transition from the interface region to the non-interface regions. For example, the shape of the taper region can be similar to that of a cone or a neck of a wine bottle. 
     Similar to the interface regions described above in connection with the cable structure of  FIG. 1A , interface regions  52  and  53  can have a predetermined diameter and length. The diameter of the interface region is substantially the same as the diameter of non-cable component  46  to provide an aesthetically pleasing seamless integration. In addition, and as described above, the combination of the interface and bump regions can provide strain relief for those regions of headset  10 . 
     In some embodiments, non-cable component  46  may be incorporated into a leg such as leg  26  without having bump regions  51  and  54  or interface regions  52  and  53 . Thus, in this embodiment, non-interfacing regions  50  and  55  may be directly connected to non-cable component  46 . 
     Cable structures  20  can be constructed using many different manufacturing processes. The processes discussed herein include those that can be used to manufacture the single-segment unibody cable structure or legs for the multi-segment unibody cable structure. In particular, these processes include injection molding, compression molding, and extrusion. Embodiments of this invention use compression molding processes to manufacture a single-segment unibody cable structure or multi-segment unibody cable structures. 
     In one embodiment, a cable structure can be manufactured by compression molding two urethane sheets together to form the sheath of the cable structure. Using this manufacturing method, the finished cable structure has a bi-component sheath that encompasses a resin and a conductor bundle. The resin further encompasses the conductor bundle and occupies any void that exists between the conductor bundle and the inner wall of the bi-component cable. In addition, the resin secures the conductor bundle in place within the bi-component sheath. 
     Headphones  42  and  44  can be constructed to have any suitable shape and seamless unibody aesthetics even if the headphones are formed from at least two components that are welded together. The shape of the headphones can resemble those of non-occluding earbuds that fit in the ear, but do not form an airtight seal between the earbud and ear canal. This type of headphone typically has a cap portion and a body portion. The cap portion has one or more holes to permit passage of soundwaves from inside the headphones to the outside of the headphones. The cap portion and holes are also substantially free of any remnants. 
     In embodiments of this invention, the cap portion is constructed to have a relatively large number of ports or holes. For example, the number of holes may be in the hundreds. The number of holes may range from 200-1000, 300-900, 400-750, 500-600, 650-750, or 700-725. The number of holes can depend on the size of the holes, the available surface area in the cap suitable for hole placement, and a pattern in which holes reside in the available surface area. The holes may be sized to mitigate passage of particulate matter such as dust and water. Moreover, the use of such holes eliminates the need to use a wire mesh. 
       FIG. 2  shows an illustrative top and side views of a cap  200  constructed according to an embodiment of the invention. Cap  200  includes several holes  202  disposed throughout. In one embodiment, cap  200  can have 721 holes, each having a diameter of about 0.2 mm, with about 0.14 mm of spacing between the holes. In another embodiment, cap  200  can have holes ranging in diameter between 0.2 mm and 0.45 mm. The side view shows that cap  200  can have a curved surface. 
     Cap  200  is constructed from a plastic material and the holes can be provided in one of two approaches. In the first approach, each of holes  202  is individually drilled in a cap that initially has no holes. The holes may be drilled one at time or simultaneously. After the holes are drilled, remnants of drilled plastic may remain in or around the holes, and in some cases, some plastic remnants may be partially attached to their respective holes. These remnants detract from a desired aesthetic look and feel of a finished cap and thus need to be deburred and removed using methods according to embodiments of the invention. 
     In the second approach, cap  200  can be molded with holes  202 . When cap  200  is molded, pins corresponding to each desired hole  202  are positioned within a molding apparatus and held in place while the mold is formed. However, when the pins are pulled out of the mold, this may result in formation of plastic remnants that need to be removed using a method according to an embodiment of the invention. 
     The plastic remnants can be removed using a tool shaped to match the contours of a surface of the cap and that is coated with an abrasive. Referring to  FIG. 3 , an illustrative cross-sectional view of cap  300  and tool  310  are shown. Cap  300  has contoured inner surface  304  and contoured outer surface  306 . The holes and plastic remnants are not shown. Tool  310  has contoured surface  314  that matches the contours of inner surface  304 . The contoured surface of tool  310  enables it to fit flush against all or substantially all of inner surface  304 . Contoured surface  314  may be convex in shape. 
     Abrasive  318  is mounted to tool  310  and may mimic the contours of surface  314 . Abrasive  318  may be any substance suitable for deburring plastic remnants such as, for example, a diamond coated abrasive. 
       FIG. 4  shows illustrative cross-sectional views of cap  400  and tool  410 . Cap has inner surface  404  and outer surface  406 . Tool  410  has contoured surface  416  that matches the contours of outer surface  406  and also has abrasive  418  mounted to surface  416 . Tool  410  is designed to remove remnants from and polish outer surface  406  of cap  400 . Contoured surface  416  may be convex in shape. 
     When the tool is applied to a surface of a cap, it can be ultrasonically vibrated to deburr remnants from the surface and to polish the surface. The combination of the contoured surface, abrasive, and vibration provides a cap that is both visually and tactilely aesthetically pleasing. Separate tools may be applied to both the inner and outer surfaces of the cap to deburr and polish both surfaces. 
     The tool can be vibrated according to any number of vibration profiles. The vibration may be an ultrasonic vibration. For example, the vibration profile can vibrate the tool at a fixed frequency for a predetermined period of time. As another example, the vibration profile can modulate the vibration of the tool so that the vibration can be selectively turned ON or OFF at any suitable frequency. 
       FIG. 5  shows illustrative steps for deburring and polishing a surface of a curved plastic object in accordance with an embodiment of the invention. Starting at step  502 , a curved plastic object having several holes is provided. The curved plastic object can have a curved surface. For example, if the curved plastic object is a headphone cap, it has a curved inner surface and a curved outer surface. The creation of the holes can leave remnants disposed in and about the holes and surface of the object. In addition, the creation of the holes can also result in bumps in the inner and/or outer surfaces. 
     At step  504 , a deburring tool having a contoured surface that substantially matches the curved surface of the plastic object is applied to the curved surface. The contoured surface of the deburring tool provides for a flush fit to the curved surface of the plastic object. In one embodiment, the tool may be constructed to fit flush against an inner surface of a headphone cap, and in another embodiment, the tool may be constructed to fit flush against an outer surface of the headphone cap. In addition, an abrasive, which is mounted to the contoured surface of the tool, can nestle into the holes when the tool is applied. 
     If desired, both the inner and outer surfaces of the plastic object may be deburred and polished by a deburring tool. For example, the deburring tool of  FIG. 3  may be applied to the inner surface and the deburring tool of  FIG. 4  may be applied to the outer surface. 
     At step  506 , the deburring tool is vibrated according to a vibration profile to deburr and polish the curved surface. As the tool is vibrated, the abrasive strips away remnants attached to the holes and smoothes out the surface by eliminating the bumps. After the object has been deburred and polished, the deburring tool is removed and cleaned, as indicated at step  508 . The deburring tool may be cleaned by agitating it against a piece of rubber. This shakes any collected remnants off the abrasive so that a relatively debris free abrasive can be applied to the next plastic object. 
     It should be understood that steps in  FIG. 5  are merely illustrative. Any of the steps may be removed, modified, or combined, and any additional steps may be added, without departing from the scope of the invention. 
     The described embodiments of the invention are presented for the purpose of illustration and not of limitation.

Metadata:
Filing Date: 20110513
Publication Date: 20140408
Grant Date: 20140408
Priority Date: 20101007
Inventors: HAYASHIDA JEFF
AASE JONATHAN
Assignee: APPLE INC
CPC Classifications: [{"code": "H04R1/1033", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04R1/1016", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04R1/1016", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04R2460/17", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04R1/023", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04R1/023", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04R2460/17", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04R1/1033", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 45925362