Screw closure

Sept 5, 1967 _M. _B. stull 3,339,773

SCREW CLOSURE

Filed May 11, 1966

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INVENTOR.

Morton E>. I

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3,339,773

Patented Sept. 5, 1967

United States Patent Office

3,339,773 SCREW CLOSURE

Morton B. Stull, Boonton, N.J. (% Stull Engraving Company, 221-23 Banta Ave., Garfield, N.J. 07026)

Filed May 11, 1966, Ser. No. 549,323 9 Claims. (Cl. 215—40)

This invention relates to closures for small containers, collapsible tubes and the like, and more particularly to screw-type closures in this category.

Objects of the invention are to provide: (1) a novel and improved screw closure which effects a tactual indication or signal that is readily felt by the user just prior to the closure attaining its final, stopped position; (2) a closure as in (1) and which has a fast lead, i.e. is especially fast-acting in reaching the stopped condition; (3) a threaded fast-lead closure which is especially resistant to opening under adverse conditions such as vibration, etc.; (4) a closure as above set forth, which has a positive and especially effective back-off or removal action; (5) a closure as characterized, which provides an effective seal even prior to attaining the fully-closed condition; (6) a closure as above indicated, wherein the movable part is effectively and positively halted upon the fully-closed condition being attained; (7) a closure which is especially easily and quickly removed and reapplied by the user, providing at virtually all times an effective seal.

Further and important objects of the invention are: (a) to provide an improved threaded neck and closure combination which is free of these stresses and strains that are normally inherent in closures where sealing pressures are axially directed and dependent for maintenance on the engagement of the threads of the closure; (b) to provide an improved closure of the type above set forth, wherein the likelihood of cross threading, stripping or deforming the threads is eliminated; and (c) to provide an improved closure combination wherein the closure member can be readily started to turn towards the open position without it being necessary to overcome the resistance of the mechanical means that is normally utilized to maintain the conventional axial abutment seal in axial-pressure seal arrangements.

Other features and advantages will hereinafter appear.

In the drawings:

FIG. 1 is a view partly in axial section and partly in side elevation, of the present improved closure mounted on a collapsible tube (shown >ⁿ P^art only).

FIG. 2 is a view partly in axial section and partly in side elevation, of the tubular body member of the closure.

FIG. 3 is a view partly in axial section and partly in side elevation, of the screw cap member of the closure.

As shown, the improved closure comprises essentially a tubular body member indicated generally by the numeral 10 (see FIG. 2) and a cup-shaped screw cap member designated generally by the numeral 12 (see FIG. 3). The body member 10 is shown as being in the form of an adaptor or fitment intended to be attached to the neck of a container, such as the collapsible tube 14 shown in FIG. 1. However, the body member 10 may as well constitute an integral or a permanent part of the container, whether this latter is a collapsible tube, a squeeze bottle, a small vial, or other dispensing container. In any case, the body member 10 constitutes one basic part of the closure, whereas the screw cap member 12 constitutes the other part of the closure.

As seen in FIG. 1, the body member 10 is press-fitted on the neck (not shown) of the collapsible tube 14, said member and neck having cooperable detent means, such as the annular bead 20 and the annular groove 22 of the body member. Such cooperable detent means between the body member 10 and the corresponding portion of the container form no part of the present invention, and accordingly further details thereof are not given herein.

The body member 10 comprises a tubular body portion 16 having at its bottom end an annular collar 18 which fits against the conical end of the tube 14 in the manner shown in FIG. 1.

On the tubular body portion 16 there are disposed external screw therads 24, 26 which constitute a double thread and, by virtue of this, can have a fast lead. The external screw threads 24, 26 are shown as being of rounded section, and as being of relatively small height whereby they may be easily wiped clean if this becomes necessary or desirable. Beyond the screw threads 24, 26, the body portion 16 includes an orifice portion 28 of tapered or frusto-conical configuration, there being a discharge passage 30 through the portions 16 and 28.

For cooperation with the external screw threads 24, 26 the screw cap member 12 has internal screw threads 32, 34 also characterized by a fast lead. The internal screw threads 32, 34 are also rounded in section and of small height, and either one or both of the members 10, 12 may be constituted of yieldable molded plastic substance such as polyethylene or the like. With such construction, there is a certain degree of resilience inherent in the members 10, 12 and by virtue of this and also the specific illustrated configuration of the screw threads 24, 26 and 32, 34 these threads constitute a somewhat impositive cap shifting means inasmuch as it is possible to force the cap member 12 axially onto the body member 10 with the screw threads becoming slightly distorted and forced laterally past each other. However, during the normal functioning of the closure the screw threads are not forced past each other in this manner but instead function to axially advance the screw cap 12 onto the body member 10 as the cap is screwed or turned in the usual manner.

In accordance with the present invention, novel detent means are provided in conjunction with the above structure, whereby the user is provided with a tactual indication or signal to- the effect that the closure is fully assembled, this occurring just prior to the termination of the screwing-on movement of the cap member 12. The said detent means, in addition to providing this tactual indication or signal, also helps to effectively retain the screw cap member 12 in its fully closed position under adverse conditions of use, such as vibration and the like, in spite of the fast lead and rounded configuration of the cooperable screw threads 24, 26 and 32, 34.

The said cooperable detent means comprises a yieldable part on one of the members 10, 12 this being shown as in the form of a bead formation constituted as internal ridges 38 (see FIG. 3) disposed circumferentially in the member 12 and cooperable with an annular shoulder 40 and annular groove 42 provided on the orifice portion 28 of the body member 10.

During the assemblage of the cap member 12 to the body member 10, the ridges 38 will ride up on the conical outer surface 44 of the orifice portion 28, thereby tending to initially constrain the said screwing-on movement of the cap. However, as the screwing movement of the cap is continued, the action of the screw threads 24, 26 and 32, 34 will cause the ridges 38 to continue their travel and to be deformed, ultimately forcing the ridges to ride over the annular shoulder 40 of the body member 10, and to occupy the groove 42. As soon as the ridges 38 bypass the annular shoulder 40, the constraining action ceases, and the turning of the cap member 12 becomes very easy for the final fraction of a revolution until the members 10,12 attain the fully assembled condition. This cessation of the constraining action is imparted to the user in the form of a tactual indication or signal, indicating that the cap member 12 has now attained the proper sealing or closing position.

3,339,773 ³

The invention also provides, in conjunction with the above detent means and screw threads, additional cooperable screw elements on the members 10, 12 which operate shortly after initial unscrewing movement of the cap member from the said fully assembled condition, and which forcibly axially shift the cap member a distance which is sufficient to positively disengage the cooperable detent means, that is, a distance sufficient to force the ridges 38 over and past the annular shoulder 40 of the orifice portion 28. Moreover, the said additional cooperable screw elements also are arranged to constitute a positive stop means, by which screwing on of the cap member 12 is forcibly and positively halted when the member attains the fully assembled position on the body member 10.

In affecting this, the body member 10 is provided with a pair of diametrically opposite wedge or screw elements 48 having sloping upper surfaces 50 and squared ends or abutting end surfaces 52. For cooperation with the screw elements 48, the cap member 12 is provided with a pair of internal, diametrically disposed lugs 54 having abutting side surfaces 56 as seen in FIG. 3. With such organization, the abutting end and side surfaces 52, 56 will be brought into engagement with each other as the cap member 12 attains the fully assembled position on the body member 10, thereby effectively preventing further turning movement of the cap member.

Also, upon unscrewing movement of the cap member 12, the lugs 54 will, after a slight initial interval of turning of the closure member 12, ride up on the sloped surfaces or faces 50 of the screw elements 48, causing a positive backing-off movement of the cap member 12 and forcibly shifting the ridges 38 over and past the annular shoulder 40. In consequence, dependence is not had only on the screw threads 24, 26 and 32, 34 to effect removal of the cap member 12 and to force the ridges 38 over the annular shoulder 40. Instead, the additional screw elements 48 will be effective at least until the ridges 38 have been shifted past the annular shoulder 40, whereupon there no longer exists any restraint tending to prevent unscrewing of the cap member 12. The screw threads 24, 26 and 32, 34 will thereafter effectively complete the unscrewing of the cap member, and the fast lead which characterizes the screw threads may be such that the attachment and removal of the cap member 12 is effected by turning the latter through not more than substantially one-half of a complete revolution.

The said initial movement of the member 12 facilitates the breaking of glue bonds, crusts and the like which sometimes form between the closure parts, and this is an important feature.

During the screwing on of the cap member 12, and after the ridges 38 have been forced over and past the annular shoulder 40 of the body member 10, the said annular shoulder engages an internal annular sealing surface 60 of the cap member 12, thereby to effect a seal between the members 10 and 12. Thus, immediately upon the constraint being removed near the termination of the screwing on of the cap member 12, a seal is effected between the shoulder 40 and the sealing surface 60 of the members.

Also, in accordance with the invention, a second seal is effected between the members 10, 12 prior to the attainment of the fully assembled condition of the said members. This second seal comprises cooperable annular sealing elements on the members, in the form of a yieldable annular internal flange 62 in the cap member 12, which cooperates with the top end 64 of the orifice portion 28. This is clearly illustrated in FIG. 1, which shows the fully assembled condition of the members 10, 12. It will be seen that for such condition, the annular shoulder 40 seals against the surface 60, and the flange 62 seals against the top end 64 of the body member. The engagement between the flange 62 and the top end 64 occurs prior to the ultimate attainment of the fully assembled condition, whereby a slight interference exists. The yieldability of the flange 62, however, enables the slight additional amount of movement of the cap member 12 to be effected, until the stop surfaces 52, 56 are brought into engagement with each other.

I have found that with the above construction it is especially easy for a user to quickly remove the screw cap member 12 when dispensing of the contents of the container is to be had, and just as easy for the user to replace the screw cap and effectively restore the desired seal. Not more than a half turn of the screw cap is required, and the user is apprised of the fact that the seal is effected, by virtue of the tactual indication or signal being given when the screw cap approaches the final fully assembled position. The seals which are effected involve mostly radial forces, whereby dependence is not had on the screw threads to maintain the seals. The detent ridges 38 effectively yieldably hold the screw cap in the sealing condition regardless of vibration and other adverse conditions of shipment, storage, etc.

The closure construction is extremely simple, and the components may be readily economically molded by conventional molding techniques, in simple mold equipment. The cost of the components is thus held to a desirably low figure. Also, the likelihood of contamination of the screw threads 24, 26 and 32, 34 by the product being dispensed is diminished by locating the discharge orifice of the portion 28 at a distance from the body portion 16.

Variations and modifications may be made within the scope of the claims, and portions of the improvement may be used without others.