Method of manufacturing contoured objects by radio frequency welding and tooling assembly for same
10773462 ยท 2020-09-15
Assignee
Inventors
Cpc classification
B29C66/301
PERFORMING OPERATIONS; TRANSPORTING
B29K2067/00
PERFORMING OPERATIONS; TRANSPORTING
B29C66/8322
PERFORMING OPERATIONS; TRANSPORTING
B29C66/3494
PERFORMING OPERATIONS; TRANSPORTING
B29C66/474
PERFORMING OPERATIONS; TRANSPORTING
B29C66/83221
PERFORMING OPERATIONS; TRANSPORTING
B29C65/04
PERFORMING OPERATIONS; TRANSPORTING
Y10T156/1028
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
B29C66/81457
PERFORMING OPERATIONS; TRANSPORTING
B29K2071/00
PERFORMING OPERATIONS; TRANSPORTING
B29C66/1122
PERFORMING OPERATIONS; TRANSPORTING
B29K2075/00
PERFORMING OPERATIONS; TRANSPORTING
B29C65/7841
PERFORMING OPERATIONS; TRANSPORTING
A43B7/144
HUMAN NECESSITIES
B29C66/71
PERFORMING OPERATIONS; TRANSPORTING
B29C66/71
PERFORMING OPERATIONS; TRANSPORTING
B29C66/8242
PERFORMING OPERATIONS; TRANSPORTING
B29C66/433
PERFORMING OPERATIONS; TRANSPORTING
B29K2075/00
PERFORMING OPERATIONS; TRANSPORTING
B29K2067/00
PERFORMING OPERATIONS; TRANSPORTING
B29K2023/086
PERFORMING OPERATIONS; TRANSPORTING
B29K2071/00
PERFORMING OPERATIONS; TRANSPORTING
A43B13/20
HUMAN NECESSITIES
B29C66/532
PERFORMING OPERATIONS; TRANSPORTING
B29C66/8124
PERFORMING OPERATIONS; TRANSPORTING
B29C66/81451
PERFORMING OPERATIONS; TRANSPORTING
International classification
B29D35/12
PERFORMING OPERATIONS; TRANSPORTING
A43B13/20
HUMAN NECESSITIES
B29C65/04
PERFORMING OPERATIONS; TRANSPORTING
B29C65/00
PERFORMING OPERATIONS; TRANSPORTING
B29C65/78
PERFORMING OPERATIONS; TRANSPORTING
Abstract
A method includes compressing a non-dielectric, elastically-deformable component, a wire mesh component, and a dielectric, contoured object between first and second forming tools. Once the components are compressed, radio frequency energy is supplied to the first forming tool, thereby causing a radio frequency electromagnetic field to be generated between the first forming tool and the wire mesh component that results in a contoured weld of the contoured object. A tooling assembly is configured to carry out the method.
Claims
1. An assembly for radio frequency welding of a dielectric, contoured object, the assembly comprising: a first forming tool and a second forming tool at least one of which is configured to be movable toward and away from the other; at least one non-dielectric, elastically-deformable component supported on the second forming tool; a first wire mesh component positioned and supported on the non-dielectric, elastically-deformable component; a second wire mesh component separated from the first wire mesh component and positioned on the non-dielectric, elastically-deformable component independently of the first wire mesh component so that spacing between the first wire mesh component and the second wire mesh component is variable dependent upon the positioning of the second wire mesh component; wherein the first forming tool, the first wire mesh component, and the second wire mesh component are configured to transmit radio frequency energy to a dielectric, contoured object, wherein the dielectric, contoured object is compressed between the first forming tool and the first and second wire mesh components by: movement of said at least one of the forming tools toward the other forming tool; and the at least one non-dielectric, elastically-deformable component elastically deforming to distribute pressure of the first and second forming tools on the first wire mesh component and the second wire mesh component, the pressure flexing the first and second wire mesh components against the dielectric, contoured object to provide a first contoured weld of the dielectric, contoured object via the first wire mesh component and a second contoured weld of the dielectric, contoured object via the second wire mesh component.
2. The assembly of claim 1, wherein the at least one non-dielectric, elastically-deformable component is one of polymeric foam, foamed rubber, and butyl rubber.
3. The assembly of claim 1, wherein the first wire mesh component is one of bronze, brass, copper, and stainless steel, or alloys thereof.
4. The assembly of claim 1, wherein the first wire mesh component has from 120 by 120 wires per inch to 500 by 500 wires per inch.
5. The assembly of claim 1, wherein the at least one non-dielectric, elastically-deformable component has a surface supporting the first wire mesh component; and wherein the surface is substantially flat when not compressed between the first and second forming tools.
6. The assembly of claim 1, wherein the non-dielectric, elastically-deformable component is compliant and the first wire mesh component has a flexibility enabling the first wire mesh component to conform to a contoured surface when compressed under a pressure.
7. The assembly of claim 1, in combination with the dielectric, contoured object; and wherein the dielectric, contoured object is an inflatable bladder element that has at least partially thermoplastic polyurethane (TPU) sheets.
8. The assembly of claim 7 in combination with the dielectric, contoured object, and in further combination with a footwear upper; and wherein the first contoured weld is between the footwear upper and the inflatable bladder element.
9. The assembly of claim 1, wherein: the second forming tool has a contoured surface; and the at least one non-dielectric, elastically-deformable component compresses against the contoured surface of the second forming tool when the at least one of the forming tools moves toward the other forming tool and the at least one non-dielectric, elastically-deformable component elastically deforms.
10. The assembly of claim 1, further comprising: a piston configured to move the first forming tool toward the second forming tool when pneumatic or hydraulic pressure is applied through the piston.
11. The assembly of claim 1, further comprising: a power source configured to supply radio frequency energy; and a switch disposed between the power source and the first forming tool and closable to operatively connect the power source to the first forming tool.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
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DETAILED DESCRIPTION
(11) Referring to the drawings, wherein like reference numbers refer to like components throughout the several views,
(12) A multi-dimensional fabric tensile element 16 is positioned in the internal cavity 17 formed between the upper and lower sheets 12, 14, as shown in
(13) The bladder element 10 is a non-limiting example of an arrangement of the tensile element 16. In other embodiments, the bladder element 10 may have no tensile element. In still other embodiments, the tensile element 16 can have other configurations with only selected portions of the tensile element 16 welded to the upper or lower sheets 12, 14 to enable a desired three-dimensional configuration. A plurality of bladder elements with various tensile element configurations are shown and described in U.S. Pat. No. 5,802,739, issued to Potter et al., which is hereby incorporated by reference in its entirety. Tensile members and/or reinforcing structures can be integrated with the bladder element 10 to provide desired responsiveness, such as disclosed in U.S. Pat. No. 4,906,502 to Rudy et al., and U.S. Pat. No. 8,061,060 to Swigart et al., which are incorporated by reference in their entireties.
(14) The bladder element 10 can be formed from a variety of materials including various polymers that can resiliently retain a fluid such as air or another gas. Examples of polymer materials for the bladder element 10 include thermoplastic urethane, polyurethane, polyester, polyester polyurethane, and polyether polyurethane. Moreover, the bladder element 10 can be formed of layers of different materials. In one embodiment, the bladder element 10 is formed from thin films having one or more thermoplastic polyurethane (TPU) layers with one or more barrier layers of a copolymer of ethylene and vinyl alcohol (EVOH) that is impermeable to the pressurized fluid contained therein as disclosed in U.S. Pat. No. 6,082,025 to Bonk et al., which is incorporated by reference in its entirety. Bladder element 10 may also be formed from a material that includes alternating layers of thermoplastic polyurethane and ethylene-vinyl alcohol copolymer, as disclosed in U.S. Pat. Nos. 5,713,141 and 5,952,065 to Mitchell et al. which are incorporated by reference in their entireties. Alternatively, the layers may include ethylene-vinyl alcohol copolymer, thermoplastic polyurethane, and a regrind material of the ethylene-vinyl alcohol copolymer and thermoplastic polyurethane. The bladder element 10 may also be a flexible microlayer membrane that includes alternating layers of a gas barrier material and an elastomeric material, as disclosed in U.S. Pat. Nos. 6,082,025 and 6,127,026 to Bonk et al. which are incorporated by reference in their entireties. Additional suitable materials for the bladder element 10 are disclosed in U.S. Pat. Nos. 4,183,156 and 4,219,945 to Rudy, which are incorporated by reference in their entireties. Further suitable materials for the bladder element 16 include thermoplastic films containing a crystalline material, as disclosed in U.S. Pat. Nos. 4,936,029 and 5,042,176 to Rudy, and polyurethane including a polyester polyol, as disclosed in U.S. Pat. Nos. 6,013,340, 6,203,868, and 6,321,465 to Bonk et al. which are incorporated by reference in their entireties. In selecting materials for the bladder element 10, engineering properties such as tensile strength, stretch properties, fatigue characteristics, dynamic modulus, and loss tangent can be considered. The thicknesses of sheets of materials used to form the bladder element 10 can be selected to provide these characteristics. The bladder element 10 is resilient and provides cushioning and flexibility that can be tuned such as by selecting a level of pressurization. Tensile members and/or reinforcing structures can be integrated with the bladder element 16 to provide desired responsiveness, such as disclosed in U.S. Pat. No. 4,906,502 to Rudy et al., and U.S. Pat. No. 8,061,060 to Swigart et al., which are incorporated by reference in their entireties.
(15) Welding of the tensile element 16 to the first and second sheets 18, 20 is one example of a contoured weld required for a contoured object (i.e., the bladder element 10). The tooling assembly 30 shown and described in
(16) The tooling assembly 30 is configured to enable radio frequency welding of contoured objects such as the bladder element 10 by utilizing components that easily and reliably conform to the contoured outer surface 34. The tooling assembly 30 includes at least one wire mesh screen 40, shown in
(17) The wire mesh screen 40 can be any of a variety of materials capable of cooperating with the first forming tool 44 in causing an alternating magnetic field within the bladder element 10 when radio frequency energy is supplied to the first forming tool 44, which functions as an electrode. For example, the wire mesh screen 40 can be bronze, brass, copper, stainless steel, or alloys of any of these materials. Additionally, a range of mesh sizes for the wire mesh screen 40 may be suitable. For example, wire mesh screens 40 with 120 by 120 wires per square inch mesh and with 500 by 500 wires per square inch mesh have been determined to be suitable. The wire mesh 40 screen may have mesh sizes smaller or larger than these sizes, however. As shown in
(18) The non-dielectric, elastically-deformable component 42 of
(19) The component 42 can be a generally rectangular shape when not compressed, as shown in
(20) When compressed, the material of the component 42 is such that the component 42 exerts a biasing force acting against the compressing forces as the component 42 is resiliently biased to its original shape and thickness T1. Suitable materials for the component 42 include but are not limited to polymeric foam, rubber, foamed rubber, and silicone butyl rubber. These suitable materials are non-dielectric, enabling the component 42 to insulate the second forming tool 46 from the effect of the radio frequency energy supplied to the first forming tool 44. Accordingly, the component 42 not only serves to force the wire mesh screen 40 to conform to the contoured outer surface 34 of the bladder element 10, but also ensures that the wire mesh component 40 will serve as the component that pairs with the first forming tool 44 to generate the alternating magnetic field within the material of the bladder element 10.
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(22) The first forming tool 44 is operatively connected to a power source 52 that supplies radio frequency energy to the first forming tool 44, such as when a switch 54 is closed. The first forming tool 44 is electrically conductive, such as a ferromagnetic material. The first forming tool 44 contacts the upper surface 56 of the first sheet 12 and the wire mesh tool 40 conforms to and is in contact with the contoured surface 34 of the second sheet 14 as discussed herein.
(23) The radio frequency energy creates an alternating magnetic field between the first forming tool 44 and the wire mesh component 40 and is therefore within the bladder element 10. The alternating magnetic field excites the dielectric material of the sheets 12, 14, fusing them to the first and second inner sheets 18, 20 of the tensile element 16. Because the entire upper surface of the first sheet 12 is in contact with the first forming tool 44, and the contoured lower surface 34 of the second sheet 14 is in contact with the wire mesh component 40, the entire outer surfaces of the inner sheets 18, 20 are welded to the inner surfaces of the sheets 12, 14, including a portion that is a contoured weld W1. The weld W1 is of a first portion of the bladder element 10 (i.e., the tensile element 16) to a second portion of the bladder element 10 (i.e., the sheet 14). Welds such as weld W1 created by radio frequency energy heat the material, causing it to intermingle, fusing the material of the two components welded to one another and as such are as strong as either of the materials.
(24) The flow diagram of
(25) When the radio frequency energy is stopped, the compression of the non-dielectric, elastically-deformable component 42, the wire mesh component 40, and the dielectric, contoured object (bladder element 10) is maintained by the first and second forming tools 44, 46 for at least a predetermined amount of time in step 108. During this time, the bladder element 10 cools, and pressure is released in step 110, allowing the first forming tool 44 to be moved away from the second forming tool 46. The welded contoured object, i.e., bladder element 10, is then removed from between the forming tools 44, 46 in step 112. The bladder element 10 is inflated in step 114. Inflation may occur prior to or after removal in step 112.
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(27) The tooling assembly 230 also includes a first wire mesh screen 240A and a second wire mesh screen 240B, shown in
(28) The wire mesh screens 240A, 240B can be any of a variety of materials capable of cooperating with the first forming tool 244 in causing an alternating magnetic field within the bladder element 210 when radio frequency energy is supplied to the first forming tool 244, which functions as an electrode. For example, the wire mesh screen 240 can be bronze, brass, copper, stainless steel, or alloys of any of these materials. Additionally, a range of mesh sizes for the wire mesh screens 240A, 240B may be suitable. For example, wire mesh screens 240A, 240B with 120 by 120 wires per square inch mesh and with 500 by 500 wires per square inch mesh have been determined to be suitable. The wire mesh screens 240A, 240B may have mesh sizes smaller or larger than these sizes, however. As shown in
(29) The non-dielectric, elastically-deformable component 242 of
(30) The component 242 can be a generally rectangular shape, similar to component 42, with a substantially uniform thickness T4. The thickness T4 is chosen so that the component 242 will be compressed over its entire contact area with the second forming tool 246 and with the wire mesh components 240A, 240B. For example, some portions of the component 242 will be compressed to a thickness T5, and others will be compressed to an even smaller thickness T6, both of which are less than thickness T4.
(31) When compressed, the material of the component 242 is such that the component 242 exerts a biasing force acting against the compressing forces as the component 242 is resiliently biased to its original shape and thickness T4 of
(32) A footwear upper 270 is clamped or otherwise secured to the first forming tool 244, such as with a clamp 272. The first forming tool 244 is shaped to mate to the footwear upper 270, similarly to a last. The outer surface 274 of the footwear upper 270 is a contoured surface to which contoured surfaces 276A, 276B of the upper sheet 212 are to be welded by radio frequency welding. Although the embodiment of
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(34) The first forming tool 244 is operatively connected to the power source 52 that supplies radio frequency energy to the first forming tool 244, such as when the switch 54 is closed. The first forming tool 244 is electrically conductive, such as a ferromagnetic material. When the first forming tool 244 is moved toward the second forming tool 246, the footwear upper 270 contacts the upper surfaces 276A, 276B of the lateral and medial portions 213, 215 of the first sheet 212, and the wire mesh tools 240A, 240B conform to and are in contact with the contoured surfaces 234A, 234B of the second sheet 214 as discussed herein.
(35) The radio frequency energy supplied from the power source 52 creates an alternating magnetic field between the first forming tool 244 and the wire mesh components 240A, 240B and is therefore within the bladder element 210. The alternating magnetic field excites the dielectric material of the sheet 212, fusing the surfaces 276A, 276B to the footwear upper 270. Because the entire surfaces 276A, 276B are in contact with the footwear upper 270, and the contoured lower surfaces 234A, 234B of the second sheet 214 are in contact with the wire mesh components 240A, 240B, contoured welds W2, W3 are formed between a first component, the first sheet 212, and a second component, the footwear upper 270.
(36) The flow diagram of
(37) In step 306, the non-dielectric, elastically-deformable component 242, the wire mesh components 240A, 240B, and the dielectric, contoured object (bladder element 210) are compressed between the first and second forming tools 244, 246. The method 300 then proceeds to step 308, supplying radio frequency energy to the first forming tool 244, thereby causing a radio frequency electromagnetic field between the first forming tool 244 and the wire mesh components 240A, 240B that results in the contoured welds W2, W3 of the bladder element 210 to the footwear upper 270. After a predetermined amount of time, or when some other predetermined parameter has been achieved, the method 300 moves to step 310 and the radio frequency energy is stopped, or, in other words, is no longer supplied to the first forming tool 244, such as by opening switch 54.
(38) When the radio frequency energy is stopped, the compression of the non-dielectric, elastically-deformable component 242, the wire mesh components 240A, 240B, and the dielectric, contoured object (bladder element 210) is maintained by the first and second forming tools 244, 246 for at least a predetermined amount of time in step 312. During this time, the bladder element 210 cools, and pressure is released in step 314, allowing the first forming tool 244 to be moved away from the second forming tool 246. The welded contoured object, i.e., bladder element 210 with footwear upper 270 welded thereto, is then removed from between the forming tools 244, 246 in step 316. This may require unclamping the footwear upper 270 and removing it from the first forming tool 244.
(39) Although the methods 100 and 300 are shown and described with respect to radio frequency welding of bladder elements 10, 210 for articles of footwear, the methods 100, 300 may be used for radio frequency welding of other dielectric objects requiring contoured welds.
(40) While the best modes for carrying out the many aspects of the present teachings have been described in detail, those familiar with the art to which these teachings relate will recognize various alternative aspects for practicing the present teachings that are within the scope of the appended claims.