One-piece cap and brush and method of forming it

• US 4,712,936 A
• Filed: 03/23/1983
• Issued: 12/15/1987
• Est. Priority Date: 06/26/1981
• Status: Expired due to Fees

• Current Assignee: Milton Kessler
• Original Assignee: Milton Kessler
• Inventors: Kessler, Milton
• Primary Examiner(s): Bratlie, Steven A.
• Application Number:
  US06/478,051
• Time in Patent Office: 1,728 Days
• Field of Search: 401/126, 401/129, 300/21, 425/805
• US Class Current: 401/129
• CPC Class Codes: A45D 40/265 connected to the cap of the container
• CPC Class Codes: A46B 1/00 Brush bodies and bristles moulded as a unit
• CPC Class Codes: B29C 33/0027 with deep narrow cavities, e.g. for making piles non-woven pile fabrics D04H11/00
• CPC Class Codes: B29C 45/2618 having screw-threaded mould walls
• CPC Class Codes: B29C 45/2626 provided with a multiplicity of narrow cavities connected to a common cavity, e.g. for brushes, combs
• CPC Class Codes: B29C 55/00 Shaping by stretching, e.g. drawing through a die; Apparatus therefor B29C61/08 takes precedence
• CPC Class Codes: B29L 2031/7654 Brushes; Brooms
• CPC Class Codes: B65D 51/32 with brushes or rods for applying or stirring contents droppers B65D47/18; eating utensils or spatulas B65D51/246
• CPC Class Codes: Y10S 425/805 Comb or brush

Abstract

A container closure includes a cap for sealing a container against leakage, and a brush-like pliable member for spreading contents of the container. The cap includes a top wall, an internally threaded skirt depending from perimetrical portions of the top wall, and a stem depending from a central portion of the top wall. The brush includes a paddle-shaped member or a plurality of bristles which depend below the stem for brushing the contents of the container onto a surface. The cap and the brush are formed as a one-piece structure. A method of forming the one-piece cap and brush includes the step of molding the cap using a specially configured mold which has at least three relatively movable parts for defining a mold cavity and for effecting a pop-off type of ejection of the threaded skirt from the mold once the integral cap and brush have been molded. The brush bristles can have relatively large diameters as molded, and can be elongated after molding as by stretching to reduce their diameters and to give bristles of proper pliability.

Claims

1. A method of forming a one-piece internally threaded cap and brush structure for closing a container and for spreading liquid content of the container, comprising the steps of:

(a) providing a mold having at least three relatively movable mold parts which cooperate to define a cavity configured to form a one-piece cap, stem and brush structure which includes;

(i) a top wall;

(ii) a skirt depending from the top wall and formed integrally therewith, the skirt having threads formed on its inner surface;

(iii) an elongated stem depending from central portions of the top wall along a central axis of the mold cavity and formed integrally with the top wall;

(iv) a brush formed of discrete bristles depending from the stem and formed integrally therewith; and

wherein said mold includes a cavity for forming said elongate stem with a plurality of discrete bristle projections integrally extending axially therefrom;

(b) injecting molten plastics material into the mold cavity to form the cap and brush structure;

(c) removing the cap and brush structure from the mold cavity by effecting relative movement of the three mold parts, with two of the mold parts separating to open the mold cavity to permit removal of the cap and brush structure from the mold cavity, and with a third of the mold parts moving in a direction paralleling the central axis to engage the cap and brush structure and to pop the threaded shirt off such one of the other two mold parts as formed the threaded inner surface of the skirt; and

(d) elongating the plurality of discrete bristle projections to diminish their cross-sections, the elongation being effected after the cap and brush structure is removed from the mold cavity.

2. A one-piece cap and brush structure formed by the method of claim 1.

3. The method of claim 1 wherein the step of providing a mold includes the steps of:

(a) providing a pin-shaped member to form at least portions of the bristles; and

,

(b) providing a vent extending along at least a part of the pin-shaped member for permitting gases to escape from the mold cavity as molten plastic material enters the portion of the cavity wherein the stem and brush are formed.

4. A one-piece cap and brush structure formed by the method of claim 3.

5. The method of claim 1 wherein the step of elongating the bristles includes the steps of heating the plurality of discrete bristle projections to bring the material from which they are formed to a workable temperature which will permit the bristles to be stretched, and then stretching the bristles.

6. A one-piece cap and brush structure formed by the method of claim 5.

7. The method of claim 1 wherein the step of providing a mold includes the step of providing one of the mold parts with a first elongate passage extending along the central axis for molding the stem, and providing said one mold part with a first generally cylindrical pin-shaped member extending into the elongate passage, said first pin-shaped member defining a peripheral ring of bristle projection-forming cavities for molding at least some of said plurality of discrete bristle projections.

8. A one-piece cap and brush structure formed by the method of claim 7.

9. The method of claim 7 wherein the step of providing said one mold part with a first pin-shaped member includes the step of forming a central passageway through the first pin-shaped member and providing a second pin-shaped member extending into the second passage and having a plurality of bristle projection-forming cavities for molding other of said plurality of discrete bristle projections.

10. A one-piece cap and brush structure formed by the method of claim 9.

11. The method of claim 9 wherein the step of providing said one mold part with first and second pin-shaped members includes the steps of providing said bristle projection-forming cavities on outer surfaces of the fist and second pin-shaped members to mold generally concentric rings of said bristle projections.

12. A one-piece cap and brush structure formed by the method of claim 11.