# US 4,635,808 A · Plastic cap > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 4,635,808 A - Document ID: US4635808A - Status: Granted - Kind: A - Application number: 06/692,908 - Filed: 1985-01-22 - Granted: 1987-01-13 - Earliest claimed: 1982-12-14 - Assignees: Maxcap, Inc. - Inventors: Robert L. Nolan - Web page: https://patentgrep.com/patent/US4635808A ## CPC - B29C 45/44: for undercut articles - B65D 41/3452: {with drive means between closure and tamper element} - B29L 2031/565: {for containers} - B65D 2401/30: Tamper-ring remaining connected to closure after initial removal - B65D 2401/35: Vertical or axial lines of weakness - B65D 2401/40: Bridges having different cross-sections - B29C: SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING (making preforms B29B11/00; making laminated products by combining previously unconnected layers which become one product whose layers will remain together B32B37/00 - B32B41/00) - B65D: CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES - B29L: INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES ## Abstract A plastic bottle cap having a tamper indicating skirt with inwardly extending flaps which move to a position in which they decrease the diameter of the skirt and thus prevent removal of the cap while the skirt is connected to the cap. ## Claims ### Claim 1 A molded plastic cap for use with a bottle having a neck carrying an outwardly extending thread and having an outwardly extending shoulder beneath said thread, said cap comprising a top wall, an annular sidewall extending down from said top wall and having an inwardly extending thread for cooperation with said neck thread, and an integral antitamper skirt below said side wall and connected thereto, said skirt having at least a lower portion which, when the cap is fully screwed onto said neck, is at a level below said shoulder, said skirt having also a plurality of circumferentially spaced integral inwardly projecting flaps which are integrally hinged thereto and which as molded project inwardly, the construction and arrangement being such that (a) when during the operation of screwing said cap onto said neck, said cap moves downward, said flaps are engaged by said shoulder and pushed outward thereby and then, on further downward movement of said cap during said operation, said flaps are moved past said shoulder and (b) when, during the operation of unscrewing said cap from said neck, said cap moves upward, said flaps engage the lower part of said shoulder and are forced by said engagement downward and outward into abutting relationship with said lower portion of said skirt so that the presence of said flaps decreases the effective internal diameter of said lower portion of said skirt so as to prevent said skirt, while intact, from passing up over said shoulder. ### Claim 2 (depends on 1) A cap as in claim 1 in which there are frangible connectors connecting said side wall to said skirt, the construction being such that, on said unscrewing, said connectors break owing to said prevention of upward movement of said skirt, and said skirt is left on said neck. ### Claim 3 (depends on 1) A cap as in claim 1 said flaps being molded as thin flexible inwardly extending elements each having a lower face and an upper face, the construction and arrangement being such that during said screwing-on operation said lower face is engaged by said shoulder and during said unscrewing operation said upper face is pressed against said lower part of said shoulder thereby pressing said lower face against said lower portion of said skirt to decrease the effective internal diameter of said lower portion of said skirt so as to prevent said skirt, while intact, from passing up over said shoulder. ### Claim 4 (depends on 1) A cap as in claim 1, said cap having (a) above the zones where said flaps are integrally attached to said skirt, a first portion having an inner surface toward which said flaps swing during said screwing-on operation and (b) below said zones, a second portion having an inner surface against which said flaps abut during said unscrewing operation, said second portion having a diameter less than that of said first portion. ### Claim 5 (depends on 4) A cap as in claim 4, each of said flaps having an upper face which meets the inner surface of said first portion of said cap along a curve having a radius of at least about 0.015 inch. ### Claim 6 (depends on 5) A cap as in claim 5 in which said radius is about 0.015 to 0.05 inch. ### Claim 7 (depends on 4) A cap as in claim 4 in which said flaps are spaced from each other by intervals and are independently movable. ### Claim 8 (depends on 7) A cap as in claim 7 in which said intervals are each less than about 80.degree.. ### Claim 9 (depends on 7) A cap as in claim 7 in which said intervals are each less than 40.degree.. ### Claim 10 (depends on 7) A cap as in claim 7 in which said flaps cover a total of more than half of the inner circumference of said skirt. ### Claim 11 (depends on 7) A cap as in claim 7 in which the outer diameter of said sidewall and skirt are substantially equal. ### Claim 12 (depends on 11) A cap as in claim 11 in which said flaps cover a total of more than half of the inner circumference of said skirt, said intervals correspondingly covering a total of less than half of said circumference, and in which there are circumferentially spaced frangible connectors extending integrally between said side wall and said skirt. ### Claim 13 (depends on 1) A combination of a cap as in claim 1 with a bottle as described in claim 1. ### Claim 14 (depends on 2) A combination of a cap as in claim 2 with a bottle as described in claim 2. ### Claim 15 (depends on 12) A combination of a cap as in claim 12 with a bottle as described in claim 12. ### Claim 16 (depends on 1) S A cap as in claim 1 in which said skirt is outwardly imperforate. ### Claim 17 (depends on 16) A cap as in claim 16 in which said skirt is outwardly smooth and imperforate. ### Claim 18 (depends on 1) A cap as in claim 1 in which the top wall of the cap is imperforate. ### Claim 19 (depends on 1) A cap as in claim 1 in which the top wall of said cap has a hole through which the contents of a bottle carrying said cap may be dispensed from a spout of said bottle, the construction and arrangement being such that said cap seals said spout when the cap is fully screwed onto the neck of said bottle. ### Claim 20 (depends on 13) A combination as in claim 13; said bootle having a dispensing spout, said cap having in its top wall a hole through which the material dispensed from said spout passes, a the construction and arrangement being such that said cap seals said spout when the cap is fully screwed onto the neck of said bottle.