Safety closure device

Abstract

The invention contemplates a safety closure cap having threaded engagement to a bottle or the like neck, with the feature of ratchet-lock engagement between (a) parts of a compliant integral tab on the cap and (b) a circumferential succession of ratchet-tooth serrations at the base end of the neck. Plural ratcheting elements on the tab span an arcuate succession of the neck serrations, so that plural ratchet-engagement relations are offered at any one time, and yet a single compliant displacement of the tab simultaneously disengages all ratchet locking, to permit unthreading of the cap from the bottle. By having the tooth formations on the respective ratchet elements at other than integer multiples of the basic tooth spacing of neck serrations, it is further possible to offer more ratchet-lockable angular positions, per revolution of the cap, than there are serrations on the neck.

Description

This invention relates to bottles or the like containers adapted to contain hazardous substances, and more particularly relates to safety closures for such containers which render them child-resistant, i.e., resistant to tampering by children.

It is an object of the invention to provide a new and improved safety cap for such a container, particularly of the variety having rotary engagement, as by threads.

Another object of the invention is to provide a new and improved safety cap for a bottle which is economical to manufacture and readily lends itself to automatic production-line facilities for filling and capping a bottle.

A further object of the invention is to provide a new and improved safety cap and bottle combination in which the cap is readily locked onto the bottle but may be unlocked therefrom by a very simple manipulation of the cap itself.

A still further object is to meet the above objects with a construction of inherent low cost, involving minimum alteration of present constructions.

It is also an object to provide the above-noted features in application to molded glass or plastic containers, and involving minimal change in container molds.

A specific object is to meet the above objects with structure requiring no additional parts but rather involving simple modification of existing bottle and cap parts.

Other objects and various further features of novelty and invention will be pointed out or will occur to those skilled in the art from a reading of the following specification in conjunction with the accompanying drawings. In said drawings, which show, for illustrative purposes only, a preferred form of the invention:

FIG. 1 is a perspective view of assembled and safety-locked cap and bottle parts of the invention;

FIG. 2 is an enlarged view in side elevation of neck formations of the bottle of FIG. 1;

FIG. 3 is a plan view of neck formations of FIG. 2;

FIG. 4 is a bottom view of the cap of FIG. 1;

FIG. 5 is a view in side elevation, partly broken-away and in section, for the cap of FIGS. 1 and 4, the section being taken on the line 5--5 of FIG. 4; and

FIG. 6 is a view of the cap in side elevation, viewing the left aspect of FIG. 4.

Referring to the drawings, the invention is shown in application to a container or bottle 10 having an integral threaded neck 11 and selectively opened and closed by a cap having a threaded bore 13. The bottle may be of any suitable material such as glass, metal or plastic but is shown in the style of a blow-molded plastic bottle, made from a two-part mold such that each half of the mold defines a generally semi-cylindrical half of the bottle, with symmetry about a parting line which includes the neck axis, as suggested by legend in FIG. 3. Cap 12 may be of any suitable construction, being typically an injection-molding part, for the case of a plastic bottle 10.

In accordance with the invention, the neck region of the bottle, at the base end of the threads, is integrally formed with a circumferential succession of ratchet serrations 14, shown in FIG. 2 as radially outwardly facing formation in a base enlargement 15 of the neck. A tab projection 16 has integral axially compliant connection to the body of cap 12 and unites the common suspension of an arcuate array of ratchet elements or fingers 17-18-19-20. Ratchet-tooth formations on the inner surfaces of these fingers interfere with and independently ratchet-engage the serration 14 in the course of cap-threaded approach to and attainment of the cap-secured or bottle-closed position.

More specifically, and with particular reference to FIGS. 4, 5, and 6. the outwardly projecting finger-engageable end of tab 16 is seen to include a short radial bridge 21 of lesser thickness adjacent its compliant integral connection to the cylindrical body of cap 12. Provision of such reduced thickness will be understood to localize compliant bending of the tab 16 essentially to the region 21, such bending being primarily about a hroizontal "hinge" axis 23 that is essentially tangent to the outer wall of the cap body, as tab 16 is actuated in the axial direction. An arcuate yoke is defined by arcuate projections 22-22' formed integrally with the actuable part of tab 16, and the ratchet fingers 17-18-19-20 are formed as an angularly spaced arcuate array, integrally cantilevered in their suspension from this yoke. As shown, the lower end of each of these fingers has at least two ratchet-tooth formations, for example the teeth 20'-20" of finger 20; and these teeth 20'-20" are sized to match the tooth-to-tooth spacing .delta. of the neck serrations 14, being preferably with holding faces at a slight undercut or rake angle .beta., as labeled for the tooth 20', the same being in the order of up to 5.degree. for more highly effective ratchet-locking action. The teeth 20'-20" may also be so spaced in relation to teeth 19'-19" of the next adjacent ratchet finger 19 that all ratchet-finger teeth are disposed at integer multiples of the same basic serration-tooth space .delta.; however, in the drawings, I show my preference of such spacing .delta.' between ratchet fingers to be at other than an integer multiple of space .delta.. For example, by selecting the space .delta.' between ratchet fingers so as to be approximately .delta./2, the teeth of finger 19 will be caused to ratchet-engage the serrations 14, in alternation with those of finger 20, in the course of a threaded bottle-closing advance of cap 12. Such alternate ratcheting will also characterize the coaction between the teeth of fingers 17 and 18, in that the same spacing .delta.' applies between finger 17-18, and between fingers 18-19; and for the illustrative case of .delta.' = .delta./2, any given closure setting will be held by two engaged and spaced ratchet fingers. In any case, whatever the engaged relation upon cap closure, a single finger-actuated axial lift of tab 16 will cause radially outward displacement of all fingers, to clear the way for unthreaded removal of the cap.

In accordance with a further feature of the invention, the serrations 14 on the neck base 15 are so formed with such symmetry about the parting line that no tooth interference exists to impair free removal of the mold halves from the newly molded bottle. In FIG. 3, I shall describe such symmetry in connection "Right-Half Formations" with respect to "left-Half Formations", the same being on opposite sides of the central axial plane of the parting line; I have identified at 25 to 40 the regular spacing of all tooth projections of the Right-Half-Formation, Formation, and I shall refer to each particular tooth in terms of its holding face and its camming face. In the case of the Right-Half Formations, the mold half is separable from the molded product upon relative displacment generally normal to the parting line, and therefore no serration-tooth faces represent undercuts to interfere with such removal. Thus, the camming faces 25'-26' of the first two teeth 25-26 are normal to the parting line, and all succeeding camming faces of the right-half serrations 14 are at acute, i.e., lesser, angles to the parting line. In similar fashion, the holding faces of all teeth are provided within the acute-angle range. In the upper-right quadrant of FIG. 3, this means that an effective undercut .beta. can be designed into the holding faces of teeth 25-26 and up to tooth 31, but that the holding faces 32"-33" of teeth 32-33 are substantially normal to the parting line, since these faces occur in the lower-right quadrant. It will later be clear that no reliance need be placed upon serration-tooth locations 34 to 40, and therefore the "holding" faces thereof may be at convenient acute angles having no other purpose than to present the appearance of circumferential continuity.

The same description will be understood to apply for serration teeth of the Left-Half Formations, for which product removal is via leftward mold-half displacement normal to the parting line. What has been said for teeth 25 to 40 of the Right-Half Formations holds for the teeth of the left half which sequence circumferentially clockwise beyond the parting-line tooth location 40.

Even though a certain number of the described tooth locations are ineffective as ratchet-holding locations, it will be observed (1) that they characterize locations 34 to 40 of the Right-Half Formations (and corresponding diametrically opposite locations of the Left-Half Formations), (2) that they represent less than quadrant-size groupings, and (3) that the net effective angular ratchetable span .alpha. of ratchet fingers 17-18-19-20 exceeds quadrant proportions, being preferably in the order of 110.degree. to 120.degree., as shown in FIG. 4. This being the case, in spite of the ratchet disability at locations 34 to 40 (and their diametrically imaged locations), the ratchet-finger teeth will always span ratchet-engageable positions, whatever the angular relation of cap and neck at the secured position. Furthermore, for the described .delta.' = .delta./2 relationship, the alternating ratchet action will assure ratchet retention within an angular resolution which could only otherwise be achieved by doubling the number of serrations 14.

It will be seen that I have described an improved closure meeting all stated objects, with inherent simplicity, low cost and effectiveness. The cap 12 with its tab 16 and dependent locking fingers is the product of a single injection-molding operation, providing plural ratchet fingers with the necessary degree of independent ratcheting deflection and unitary removal from ratchetable positions. The serrations 14 may be pitched for ruggedness and durability (e.g., 32 tooth locations circumferentially distributed about a 1.5-inch diameter neck base 15), and yet ratchet-divided resolution of the cap-closed position is as if twice the number of serrations existed (e.g., effectively 64 tooth locations, or one for every 6.degree. increment of cap rotation). At the same time, standard blow-molding techniques may be employed with a two-part bottle mold.

While the invention has been described in detail for the preferred form shown, it will be understood that modifications may be made without departure from the claimed scope of the invention.

Claims

What is claimed is:

1. In combination, a bottle or the like having a body with an externally threaded neck, and a safety cap with a body having a threaded bore to removably engage said neck, said neck having beneath said threads a circumferentially extending plurality of spaced ratchet serrations, and said cap including a radially outwardly extending tab having compliant integral connection to said body; the underside of said tab including a plurality of angularly spaced finger elements having independent compliant integral connection to said tab at locations radially offset from said cap body, and an arcuate succession of ratchet-tooth formations on said finger elements and positioned for compliant ratcheting interference with said neck serrations in approach to and at the location of fully threaded cap-to-neck engagement, whereby plural independent ratchet-lock relationships are obtained for the fully engaged position and yet a single deflection of said tab against the compliance of its connection to the cap body will disengage all ratchet-lock relationships, to permit cap-unthreading from said neck.

2. The combination of claim 1, in which the spacing of ratchet-tooth formations of adjacent fingers is other than in conformance with the ratchet-tooth spacing of said serrations, whereby the number of ratchet-locked positions attainable per turn of threaded cap-to-neck engagement is greater than the number of neck serrations.

3. The combination of claim 1, in which at least two ratchet teeth are provided on each finger element, the spacing between the two ratchet teeth of each finger element being substantially equal to the spacing of adjacent teeth of said neck serrations.

4. The combination of claim 1, in which said bottle or the like is of molded construction with semi-cylindrical symmetry about a parting-line plane which includes the axis. of said neck, the neck serration on each side of the parting line being characterized by equal angular separation of all outer corners and by tooth-face slopes which form no greater than a 90-degree angle to the parting-line plane; and in which the maximum overall effective angular spread of tab-mounted ratchet-tooth formations is in excess of 90.degree..

5. The combination of claim 4, in which said maximum effective angular spread is approximately 120.degree..

6. The combination of claim 1, in which the number of finger elements is four.

7. The combination of claim 3, in which the two teeth of one finger element are spaced in conformance with a first uniformly spaced succession of serrated-tooth locations and in which the two teeth of another finger element are spaced in conformance with a second and like succession, said successions being angularly offset with respect to each other to the extent of a fraction of the space between adjacent teeth of said neck serrations.

8. The combination of claim 7, in which said angular offset is substantially one half the space between adjacent teeth of said neck.

9. As an article of manufacture, a safety cap with a body having a threaded bore for removable closure of a threaded bottle or the like neck, said cap including a radially outwardly extending locking tab having compliant integral connection to said body, the underside of said tab including a plurality of angular spaced finger elements having independent compliant integral connections to said tab in an array that is generally arcuate about the axis of the cap body, and an arcuate succession of radially inwardly facing ratchet-tooth formation on said finger elements.