Method of manufacturing an EAS marker

• US 6,182,352 B1
• Filed: 10/28/1999
• Issued: 02/06/2001
• Est. Priority Date: 06/02/1997
• Status: Expired due to Term

• Current Assignee: Avery Dennison Corporation
• Original Assignee: Avery Dennison Corporation
• Inventors: Herrmann, Charles K., Deschenes, Charles L.
• Primary Examiner(s): Hall, Carl E.
• Application Number:
  US09/428,748
• Time in Patent Office: 467 Days
• Field of Search: 296/021, 29/253.5, 340/572.1, 340/572.8, 340/572.5, 340/572.6
• US Class Current: 29/602.1
• CPC Class Codes: B29C 48/07 Flat, e.g. panels
• CPC Class Codes: B29C 48/08 flexible, e.g. films
• CPC Class Codes: B29C 48/35 with rollers
• CPC Class Codes: G08B 13/2408 using ferromagnetic tags
• CPC Class Codes: G08B 13/2434 Tag housing and attachment details
• CPC Class Codes: G08B 13/2437 Tag layered structure, processes for making layered tags
• CPC Class Codes: G08B 13/244 Tag manufacturing, e.g. continuous manufacturing processes
• CPC Class Codes: G08B 13/2445 Tag integrated into item to be protected, e.g. source tagging
• CPC Class Codes: G09F 3/0305 characterised by the type of seal used
• CPC Class Codes: H04R 17/00 Piezoelectric transducers; Electrostrictive transducers piezoelectric or electrostrictive elements in general H10N30/00; details of piezoelectric or electrostrictive motors, generators or positioners H10N30/00
• CPC Class Codes: Y10T 29/4902 Electromagnet, transformer or inductor

Abstract

An EAS marker and method of manufacturing same. In a preferred embodiment, the EAS marker comprises a rigid bottom piece of molded plastic having the shape of an open rectangular box. An elongated resonator is disposed in the bottom piece, the resonator being bowed downwardly about its longitudinal axis. A rigid separator of molded plastic is positioned over the open top of the bottom piece, thereby loosely encasing the resonator in the bottom piece. The foregoing bottom piece, resonator and separator are all positioned within the cavity of a rigid top piece of molded plastic having the shape of an inverted open rectangular box, the separator being press-fit against the interior surface of the top wall of the top piece, the bottom piece being press-fit against the interior surfaces of the side walls and end walls of the top piece. The top wall of the top piece is provided with a recessed area in which a biasing element is disposed, the biasing element being retained in the recessed area by the separator. The separator is shaped to include a projection that extends downwardly beyond the remainder of the bottom surface of the separator, the projection being sized and shaped to contact the top of the resonator only within a circular area approximately 0.1 inch in diameter located in approximately the middle of the resonator. The present invention is also directed to an automated method and apparatus for manufacturing the above EAS marker. In a preferred embodiment, each of the top piece, the bottom piece and the separator is manufactured, by rotary extrusion molding, as part of a continuous web, and the various continuous webs are automatically laminated to one another at nips between pairs of rollers.

Claims

1. A method of manufacturing a magnetostrictive EAS marker, said method comprising the steps of:

(a) providing a resonator container, said resonator container having a resonator cavity and an open top;

(b) inserting a resonator into said resonator cavity through said open top;

(c) providing a biasing element container, said biasing element container having a biasing element cavity and an open bottom;

(d) inverting said biasing element container;

(e) inserting a biasing element into said biasing element cavity of said inverted biasing element container;

(f) encasing said biasing element within said biasing element container with a separator;

(g) inverting said biasing element container to its original orientation; and

(h) joining said resonator container and said biasing element container to form a magnetostrictive EAS marker comprising a resonator and a biasing element wherein said resonator and said biasing element are separated by said separator.

2. The method as claimed in claim 1 wherein at least one of said resonator container, said biasing element container and said separator is formed by continuous molding on one or more webs.

3. A method of manufacturing a magnetostrictive EAS marker, said method comprising the steps of:

(a) continuously molding a first web, said first web comprising a plurality of resonator containers, each of said resonator containers having a resonator cavity and an open top;

(b) inserting a resonator into through the open top and into the resonator cavity of a first resonator container on said first web, whereby a first marker subassembly is formed;

(c) continuously molding a second web, said second web comprising a plurality of biasing element containers, each of said biasing element containers having a biasing element cavity and an open bottom;

(d) inverting said second web;

(e) inserting a biasing element into the biasing element cavity of a first biasing element container on said inverted second web;

(f) continuously molding a third web, said third web comprising a plurality of separator elements;

(g) joining a separator element on said third web to a biasing element container on said second web in such a way as to encase said biasing element within said biasing element container, whereby a second marker subassembly is formed; and

(h) joining said first marker subassembly to said second marker subassembly to form a magnetostrictive EAS marker comprising a resonator and a biasing element wherein said resonator and said biasing element are separated by said separator element.

4. The method as claimed in claim 3 further comprising the step of separating said magnetostrictive EAS marker from the remainders of said first, second and third webs.

5. The method as claimed in claim 3 wherein said step of joining said separator element to said biasing element container comprises laminating said separator element on said third web to said biasing element container on said second web at a first lamination nip.

6. The method as claimed in claim 5 wherein said first lamination nip is formed by a pair of rollers.