US3857509A

US3857509A - Bottle

Info

Publication number: US3857509A
Application number: US00298656A
Authority: US
Inventors: M Baldwin; G Miles
Original assignee: Colgate Palmolive Co
Current assignee: Colgate Palmolive Co
Priority date: 1972-10-18
Filing date: 1972-10-18
Publication date: 1974-12-31
Anticipated expiration: 1991-12-31
Also published as: FR2203744B1; FR2203744A1; CA1024938A

Abstract

A container having a protruding, threaded neck portion and a screw on cap is disclosed. The container includes a pair of mating seating surfaces on the base of the cap and neck and sealing surfaces on the top of the neck and on the inside surface of the top of the cap. The sealing surfaces are adapted to engage in response to torque applied to the cap after said seating surfaces have been engaged.

Description

llnited States Patent 1191 Baldwin et al.

[ 11 Dec. 31, 1974 [54] BOTTLE 3,339,773 9/1967 Stull 2l5/43 3, 2, 6 1 1 Marsha" Glenn Baldwm, Weapon, 3331,3251 3113?; 23,131? iii/315 Conn; Gilbert Dwayne Miles, Ossiningy FOREIGN PATENTS OR APPLICATIONS 1 1 11522;? 11/12:? 9122:1111;-------'--------;;;;;; 212/1; York 1,101,388 5/1954 France 215/43 22 Filed: Oct. 1 1972 968,767 3/1958 Germany 215/43 [21] Appl- N05 298,656 Primary ExaminerWilliam I. Price Assistant Examiner-R0 E. Hart 52 11.5. c1. 215/329, 220/4 B Attorney, Agent. or Firm-Herbert Sylvester, q-; 151 1111. c1 B6511 41/04 Murray Grill, 14 Kenneth Koch, q- [58] Field of Search 215/43, 44, 49 R, 11, II R,

215/11 A, 11 C, 329, 218; 220/4 B, 4 E, 39 R [57] ABSTRACT A container having a protruding, threaded neck por- [56] References Clted tion and a screw on cap is disclosed. The container in- UNITED STATES PATENTS cludes a pair of mating seating surfaces on the base of 774,014 11/1904 Wilson 215/44 the cap nd neck and sealing surfaces on the top of 1,682,403 8/1928 Murray 220/4 B the neck and on the inside surface of the top of the ,152 9/1932 Sheaffer 215/43 R cap. The sealing surfaces are adapted to engage in reg ig l sponse to torque applied to the cap after said seating ry en er 1. 4 3,010,596 11/1961 Williams 215/43 Surfaces have been engaged 3,027,034 3/1962 Christian 215/43 8 Claims, 4 Drawing Figures f A 16 //,1// yam c I k I I 11 l l I 13 1O PAIENTEDBEBB 1 IBM 3'. 857. 509

' sum 20F 2 BOTTLE The present invention pertains to containers for the packaging of liquids such as light and heavy duty detergents, shampoos, etc. More specifically, the invention provides a container of the thermoformed type having an improved leak resistant threaded dispensing neck and screw-on cap.

Thermoformed bottles are characterized by a top and bottom portion that are separately made and joined together by suitable means such as a circumferencially welded seam. Bottles of this type have been used to package a variety of products, including powdered cleansers, yogurt, milk and juices. In recent years, their use has substantially increased because of the attractive economics involved in employing such containers.

Thermoformed containers are fabricated from two separate thermoplastic sheets of required thickness; each sheet forming, respectively the upper and lower portions of the container. Each sheet is heated and forced into the mold of a high speed thermoforming machine to produce the bottom and top halves of the container. The thermoformed parts coming out of the two forming machines, still attached to the sheet of thermoplastic material, enter two trim presses that automatically trim the sheets. The top and bottom halves are then dropped onto conveyors and supplied to appropriate means for joining the two halves together.

Thermoformed halves can be joined together by various means including spin-welding, heat-sealing, ultrasonic-sealing, solvent-sealing, adhesive-sealing and any other suitable process. In accordance with the invention, it is preferred to utilize spinwelding. When the spin-welding process is used, the top and bottom halves are supplied to a spin-welding apparatus after they are thermoformed.

The spin-welding is either a or -head rotary inside surface of the cap and the top annular surface of the neck. To insure that an adequate seal is made at this point, a space is left between the base of the neck and the bottom of the cap, i.e., the length of the neck is greater than the inside depth of the cap. Accordingly, when the cap is screwed on there is nothing to prevent the top annular surface of the neck from seating against unit. Machine size is dependent on volume requirements. The top and bottom halves are fed into holding mandrels by starwheels and restricted from rotating within the mandrels either by vacuum or by mechanical means.

Seated within the mandrels, the two halves are held apart from each other, with one half stationary while the other is rotated and brought up to welding speed, typically from 2,000 to 5,000 RPM. The mandrel drive is then disengaged and the two halves are brought to-- The use of the thermoform process to make bottles the upper inside surface of the cap when torque is applied to the cap. Because of the deformable nature of the threaded neck of thermoformed bottles designed to accept a screw-on cap, a leak-proof seal between the bottle and the cap is difficult to obtain. When the cap is screwed on and seated, the applied forces can deform the neck to the point where the seal between the cap and neck is broken and the liquid contents of the bottle can escape during handling.

It is a primary advantage of the invention to provide an improved leak-proof threaded neck/screw-on cap combination for use with deformable, thin walled bottle necks, principally those of the: thermoformed type. A further advantage of the invention is the provision of a plurality of seals between the threaded neck of the bottle and the screw-on cap to insure leak-proof performance.

SUMMARY OF THE INVENTION In accordance with the invention, a threaded nozzle neck is provided having an annular shoulder at its base and a length less than the inside depth of the screw-on cap to be used in combination therewith. The shoulder has an upper seating surface designed to form a seal with the lower annular surface of the screw-on cap. Further, pursuant to the invention, the threaded neck, as measured from the seating surface of the shoulder to the annular surface at its top, is shorter than the inside depth of the screw-on cap as measured from the annular seating surface at its base to the inside surface of the cap top. I

By providing the bottle of the invention with nozzle neck shorter than the depth of the cap, the bottom surface of the cap first seats against the annular surface of the neck shoulder. Further torque on the cap after it contacts the shoulder fully seats the base of the cap on the neck shoulder and creates longitudinal forces along the neck. Because of the thin wall thickness and deformable character of the neck, the applied longitudinal forces result in elongation of the neck and seating of the annular surface of the top of the nozzle neck against the top inside surface of the screw-on cap. Accordingly, the invention provides a dual sealing cap providing improved resistance to leakage for bottles having relatively thin nozzle necks and containing liquid products.

In further accordance with the invention, a thermoformed bottle having a screw-on cap suitable for packaging liquid products such as light and heavy duty liquid detergents, shampoos, etc., is provided. The use of a screw-on cap thermoformed container for packaging liquid products of this type has not been generally accepted because of the leakage problem present when a conventional screw-on cap is used. in conjunction with a thin walled deformable nozzle neck.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a perspective view of a container according to the invention.

DESCRIPTION OF PREFERRED EMBODIMENTS Referring to the drawing, FIGS. 1 and 2 show a thermoformed spin-welded container 1 having an integral protruding threaded neck portion 2 adapted to accept screw-on cap 3. The container 1 is typically generally cylindrical in shap consisting of thermoformed upper and lower portions 4 and 5. Portions 4 and 5 are joined together by a spin-welded girth seam 6 to form a complete container. The bottom portion 5 of the container 1 includes a frusto-conical wall 7 of circular cross section and a bottom wall 8. The upper portion of container 1 includes a side wall 9 of circular cross section, threaded neck 2 and a sloping connecting portion 10 joining side wall 9 and neck 2.

Pursuant to the invention, container 1 is fabricated from thermoplastic sheet material such as polyethylene, polypropylene, polyvinyl chloride, or any other suitable thermoplastic material, by the aforementioned thermoforming spin-welding techniques. Threaded neck 2 is usually somewhat thinner than the side walls 7 and 9 as a result of the thermoforming process and is normally quite deformable, having a wall thickness from about 0.01 to about 0.05 inch, typically from about 0.015 to about 0.025 inch. Because of its deformable character and thin wall, neck 2 is capable of elongating a few hundreths of an inch when subjected to longitudinal forces generated by applying torque to partially seated cap 3 in accordance with the invention. According to a further specific aspect of the invention, the neck 2 is provided with threads having a bellows configuration. The bellows threads function to permit uniform elongation upon the application of torque to the partially seated cap 3 and provide a uniform wall thickness for neck 2.

Referring now to FIG. 3, the portion of a bottle 1 having a hollow nozzle neck 2 and a continuous helical thread 11 disposed around its periphery and adapted to engage corresponding threads 12 disposed around the interior circumference of screw-on cap 3 permitting cap 3 to be screwed onto neck 2 is shown. A shoulder 13, having a seating surface 14, is disposed about the base of neck 2.

Cap 3 includes a closed top end 15 having a seating surface 16 adapted to seat against the annular seating flange 17 at the top of the neck 2 as shown in FIG. 4, and an annular seating surface 18 at its base. Cap 3 can also include an annular plug 19 extending from the top end 15 of the cap into the hollow nozzle neck 2 and contacting the inside periphery of seating flange 17.

In accordance with the invention and as shown in FIG. 3, the normal length L. of the nozzle neck 2 is less, by the distance L than the depth of the screw cap, L

FIG. 3, shows the screw cap 3 screwed onto neck 2 to the point where the

surfaces

14 and 18 make contact. FIG. 4 shows the cap 3 fully seated with the nozzle neck 2 elongated an amount equal the distance L by further torque applied to cap 3 after it contacts surface 14 of shoulder 13, so that seating surfaces 16 and 17 are joined under compressive forces.

Further, the elongation of the neck during seating of the cap, in accordance with the invention results in a resiliant lock between the threads of the neck and cap. The aforementioned resiliant lock, which is similar to a lockwasher effect, results in a removal torque less than the applicative torque for ease of opening the container while providing protection against the cap loosening when jarred during shipping in the usual corrugated cartons. Surprisingly, the removal torque remains constant during shipping and warehousing conditions.

The invention provides a combination threaded container neck and screw-on cap that is particularly advantageous for use with containers having thin, deformable walls. The dimensional relationship between the neck and cap is such that a substantially leak-proof seal is obtained. In its preferred form, the invention provides a seal between the base of the cap and the neck and a secondary seal, formed by elongation of the nozzle neck in response to torque applied to the cap after the base sealing surfaces are in contact, between the top of the cap and neck.

We claim:

1. A container comprising a. a body portion,

b. a hollow open-ended cylindrical neck portion protruding from said body portion,

c. said neck portion having a first sealing surface disposed on its top surface and a threaded exterior surface,

d. an annular shoulder disposed around said neck portion,

e. said shoulder being adjacent said body portion and having a first seating surface lying in a plane transverse to the axis of said neck portion,

f. said neck portion having a predetermined height measured from said first seating surface to said first sealing surface,

g. a cap member having a threaded inner surface adapted to engage the threaded exterior surface of said neck portion,

h. said cap member having an open base end, a closed top end, and a second sealing surface, adapted to engage said first sealing surface, disposed on the inner surface of said closed top end,

. said base end defining an annular second seating surface corresponding to said first seating surface,

j. said cap member having a predetermined depth, measured from said second seating surface to said second sealing surface,

k. said predetermined height of said neck portion being less than the predetermined depth of said cap member.

2. A container according to claim 1 wherein said neck portion is adapted to elongate a distance substantially equal to the difference between said predetermined depth and said predetermined height, in response to torque applied to said cap member after said first seating surface engages said second seating surface. i

3. Container according to claim 1, wherein said body portion comprises a thermoplastic material.

4. Container according to claim 3, wherein said body portion comprises upper and lower portions joined by a girth weld of said thermoplastic material.

5. Container according to claim 3, wherein said nozzle neck is from about 0.01 and 0.05 inches in thickness.

6. In a container having a threaded nozzle dispensing neck, a screw-on cap, an annular shoulder adjacent the base of said neck for engaging the base of said cap, a first sealing surface disposed in the inner top surface of said cap, and a second sealing surface, adapted to engage said first sealing surface, disposed on the top surface of said neck, the improvement wherein the depth of said cap measured from its base to said first sealing inch.

Claims

1. A container comprising a. a body portion, b. a hollow open-ended cylindrical neck portion protruding from said body portion, c. said neck portion having a first sealing surface disposed on its top surface and a threaded exterior surface, d. an annular shoulder disposed around said neck portion, e. said shoulder being adjacent said body portion and having a first seating surface lying in a plane transverse to the axis of said neck portion, f. said neck portion having a predetermined height measured from said first seating surface to said first sealing surface, g. a cap member having a threaded inner surface adapted to engage the threaded exterior surface of said neck portion, h. said cap member having an open base end, a closed top end, and a second sealing surface, adapted to engage said first sealing surface, disposed on the inner surface of said closed top end, i. said base end defining an annular second seating surface corresponding to said first seating surface, j. said cap member having a predetermined depth, measured from said second seating surface to said second sealing surface, k. said predetermined height of said neck portion being less than the predetermined depth of said cap member.

2. A container according to claim 1 wherein said neck portion is adapted to elongate a distance substantially equal to the difference between said predetermined depth and said predetermined height, in response to torque applied to said cap member after said first seating surface engages said second seating surface.

6. In a container having a threaded nozzle dispensing neck, a screw-on cap, an annular shoulder adjacent the base of said neck for engaging the base of said cap, a first sealing surface disposed in the inner top surface of said cap, and a second sealing surface, adapted to engage said first sealing surface, disposed on the top surface of said neck, the improvement wherein the depth of said cap measured from its base to said first sealing surface is greater than the height of said neck measured from said annular shoulder to said second sealing surface, said neck being adapted to elongate a sufficient amount to engage said first sealing surface with said second sealing surface when torque is applied to said cap after engaging said annular shoulder.

7. The improved container of claim 6, wherein the base of said cap forms a substantially liquid-tight seal against said annular shoulder.

8. The improved container of claim 6, wherein said dispensing neck comprises a thermoplastic material having a wall thickness from about 0.01 to about 0.05 inch.