Methods of molding fasteners and of forming fastener molds

• US 6,224,807 B1
• Filed: 03/25/1999
• Issued: 05/01/2001
• Est. Priority Date: 03/25/1999
• Status: Expired due to Fees

• Current Assignee: Velcro Industries BV (Chartwell Industries Ltd)
• Original Assignee: Velcro Industries BV (Chartwell Industries Ltd)
• Inventors: Clune, William
• Primary Examiner(s): Vargot, Mathieu D.
• Assistant Examiner(s): McDowell, Suzanne E.
• Application Number:
  US09/276,607
• Time in Patent Office: 768 Days
• Field of Search: 264/219, 264/297.8, 264/297.1, 219/69.17
• US Class Current: 264/219
• CPC Class Codes: B23H 9/006 Cavity sinking B23H9/14 takes precedence
• CPC Class Codes: B29C 33/42 characterised by the shape of the moulding surface, e.g. ribs or grooves
• CPC Class Codes: B29L 2031/729 Hook and loop-type fasteners

Abstract

A method is provided for making a mold cavity for forming a fastener element having a predetermined shape including an undercut portion. The method includes: (a) providing a mold body having a surface; (b) providing a shaped electrode, the shape of the electrode being selected to enable the predetermined shape of the mold cavity to be described by motions of the electrode; (c) moving the shaped electrode into the surface of the mold body to form an initial opening in the mold body; (d) moving the shaped electrode within the initial opening in a set of motions referenced to multiple axes to enlarge the initial opening and form the predetermined shape of the mold cavity; and (e) removing the shaped electrode from the mold body. Methods of molding fastener elements are also provided.

Claims

1. A method of making a mold cavity for forming a fastener element having a predetermined shape including an undercut portion, the method comprising:

providing a mold body having a surface, said mold body consisting of a single, integral mold roll;

providing a shaped electrode, the shape of the electrode being selected to enable the predetermined shape of the mold cavity to be described by motions of said electrode, said predetermined shape including a stem and a head and corresponding to the predetermined shape of the fastener element, said head being shaped for engagement with a loop of a hook and loop fastener;

moving said shaped electrode into said surface of said mold body to form an initial opening in said mold body;

moving said shaped electrode within said initial opening in a set of motions referenced to multiple axes to enlarge said initial opening and form the predetermined shape of the mold cavity; and

removing said shaped electrode from said mold body.

2. The method of claim 1 wherein the step of moving said shaped electrode includes moving said electrode into said surface in a direction substantially perpendicular to said surface.

3. The method of claim 1 or 2 wherein the step of moving said shaped electrode within said initial opening in a set of motions includes moving said shaped electrode substantially parallel to said surface.

4. The method of claim 1 or 2 wherein the step of moving said shaped electrode within said initial opening includes rotating said shaped electrode.

5. The method of claim 1 wherein the step of removing said shaped electrode includes returning said shaped electrode through said set of motions.

6. The method of claim 1 wherein the step of moving said shaped electrode within said initial opening in a set of motions includes the set of motions of:

moving said shaped electrode in a first direction substantially parallel to said surface from a first position in said initial chamber to a second position in said mold body; and

,

moving said shaped electrode in a second direction substantially parallel to said surface from said second position past the first position to a third position in said mold body.

7. The method of claim 1 further comprising the step of providing a shaped electrode wherein said shaped electrode has an elongated shaft and a curved tip.

8. The method of claim 1 wherein said shaped electrode has a length at least as deep as the cavity to be formed.

9. The method of claim 1 wherein said shaped electrode has at least one transverse dimension that is smaller than the corresponding dimension of the cavity to be formed.

10. The method of claim 1 wherein said set of motions includes moving said electrode to form an engagement-tip forming portion in the cavity corresponding to the undercut portion of the fastener element.

12. The method of claim 1 or 11 wherein said predetermined shape comprises a hook.

13. The method of claim 1 or 11 wherein said predetermined shape comprises a loop-engaging fastener shape selected from the group consisting of corkscrews, spirals, mushrooms and double-sided hooks.

11. A method for molding a fastener element having a predetermined shape, the method comprising:

providing a mold body having a surface, said mold body consisting of a single, integral mold roll;

providing a shaped electrode having a length at least as deep as the cavity to be formed and having at least one transverse dimension smaller than the corresponding dimension of the cavity to be formed, the shape of the electrode selected to enable the predetermined shape of said cavity to be described by motions of said electrode, said predetermined shape including a stem portion and a head portion and corresponding to the predetermined shape of the fastener element, said head being shaped for engagement with a loop of a hook and loop fastener;

moving said shaped electrode into said surface of said mold body to form an initial chamber in said mold body;

moving said shaped electrode within said initial chamber in a set of motions to form said stem portion and said head portion and to enlarge said initial chamber to form said cavity;

returning said shaped electrode to remove said shaped electrode from said mold body;

delivering moldable resin to said cavity such that moldable resin is forced into said cavity;

solidifying said resin in said cavity to form a fastener element; and

removing said fastener element from said cavity.

14. A method for molding a fastener element having a predetermined shape including an undercut portion, the method comprising:

providing a mold body having a surface, said mold body consisting of a single, integral mold roll;

providing a shaped electrode having a length at least as deep as the cavity to be formed and having at least one transverse dimension smaller than the corresponding dimension of the cavity to be formed, the shape of the electrode selected to enable the predetermined shape of said cavity to be described by motions of said electrode, said predetermined shape including a stem portion, a head portion and an undercut portion, and corresponding to the predetermined shape of the fastener element, said head being shaped for engagement with a loop of a hook and loop fastener;

moving said shaped electrode into said surface of said mold body to form an initial chamber in said mold body;

moving said shaped electrode within said initial chamber in a set of motions to form said stem portion, said head portion and said undercut portion, and to enlarge said initial chamber to form said cavity, said set of motions including moving said shaped electrode substantially parallel to said surface and rotating said shaped electrode;

returning said shaped electrode to remove said shaped electrode from said mold body;

delivering moldable resin to said cavity such that moldable resin is forced into said cavity;

solidifying said resin in said cavity to form a fastener element; and

removing said fastener element from said cavity.