Twist Release Safety Cap

Abstract

A safety cap for hand-held dispensers, comprising a tubular cap body having a top discharge opening, a captive closure cap adapted to fit over the opening of the cap body so as to seal the same, cooperable yieldable detent means on the cap body and cap tending to hold the latter firmly on the body, in sealing position, a flexible hinge web structure connecting the cap body and cap for holding the latter captive while enabling it to be swung from the sealing position closing off the body to a discharge position removed from the opening of the body, and an interference lug and a lifting tab disposed respectively on the cap body and cap. The lug and tab overlie and register with each other when the cap has been swung about the web structure and forced down to its sealing position on the body. In the sealing position, the cap can be turnably shifted on the body within limits determined by the web structure, which is sufficiently long to enable the user to bring the lifting tab of the cap out of registration with the interference lug on the cap body, whereby the user's finger can then be applied to the underside of the lifting tab for the purpose of removing the cap.

Description

BACKGROUND

This invention relates generally to safety closures for small dispensers, and more particularly to devices of this type which require rotation of the cap to a predetermined position to enable its removal from the cap body. In the past, a number of safety closures have been proposed and constructed. In many cases, the closure cap was provided with an internal tab which was cooperable with a discontinuous bead disposed on a bottle neck or cap body. To effect its removal the cap had to be rotated to a particular position with respect to the body, wherein the tab was aligned with and could pass by a notch or discontinuous area of the bead. Other prior closures involved a cap having an external tab which in the sealing or closed position, was in close abutment with an external annular bead on the cap body. The bead had a flat or notch, and there were no accessible protrusions on the cap for lifting the same until it was rotated with respect to the cap body so as to bring a lifter tab into registration with the flat or notch of the annular body bead. After this was done, the tab could be readily engaged by the user's finger, to thereby forcibly lift the cap off the body. Frequently there were marker arrows disposed on the cap and cap body which provided to the user an indication of the proper rotary position to which the cap had to be turned if it was desired to remove the same. While many of these prior constructions functioned acceptably, there were a number of distinct drawbacks. In several cases, the reassembly of the cap to the container was complicated by the fact that the cap had to be oriented to a particular position in order to enable it to be snapped on. After such assembly, the cap then had to be rotated in order to bring it to the "lock" position or condition. In the absence of this last step, the cap would undesirably remain in an unlocked position. In such cases, a child who inadvertently found or handled the container could readily snap off the cap without any initial unlocking movement to effect registration of marker arrows, or other safety activity involving rotation of the cap. Thus, some of the safety features would be lost, merely by careless reassembly of the cap. Also, many closure caps which were not of the captive type inevitably become lost or misplaced, which had the effect of completely defeating the safety closure concept, as can be readily understood.

SUMMARY

The above disadvantages and drawbacks of prior safety closure devices are obviated by the present invention which has for its main object the provision of a novel and improved safety cap which is extremely simple in construction, reliable in operation and which can be molded inexpensively as a single plastic piece. A related object is the provision of a safety cap as above characterized, in which the closure cap is reliably guided during reassembly to a fully sealing, locked position wherein the closure cannot be reopened until the cap is first twisted or turned to expose a lift tab which can then be engaged by the user's finger to effect the lifting.

These objects are accomplished by a novel safety closure comprising a cap body and closure cap held in sealing position thereon by yieldable detent means, there being a flexible hinge web structure connecting the body and closure cap. The hinge web enables the cap to be swung from a sealing position on the body to a discharge position removed from the body. An interference lug and a lifting tab are disposed respectively on the cap body and cap; the lug and tab overly one another after the cap has been swung about the web structure to its sealing position on the body. The hinge web structure is sufficiently long so as to enable the assembled cap to be turned a limited amount with respect to the cap body, to thereby shift the lifting tab out of registration with the interference lug, wherein the lifting tab can be readily engaged by the fingers of the user for the purpose of removing the cap. The hinge web structure tends to automatically align the lift tab and interference lug with each other when the cap is swung from an open position to its sealed position, such that the cap, once sealed, cannot be removed directly without first being twisted to expose the lifting tab.

Other features and advantages will hereinafter appear.

In the drawings, illustrating several embodiments of the invention:

FIG. 1 is a vertical sectional view of a safety cap construction comprising a cap body and captive closure cap, constituting one embodiment of the invention.

FIG. 2 is a top plan view of the safety cap of FIG. 1.

FIG. 3 is a bottom plan view of the safety cap.

FIG. 4 is a vertical section of the safety cap of FIG. 1, this view showing the closure cap assembled to the cap body and occupying a sealed position.

FIG. 5 is a top plan view of the safety cap of FIG. 1, with the closure cap assembled to the cap body and occupying a sealed position.

FIG. 6 is a view like that of FIG. 5 but showing the closure cap as having been partially rotated so as to expose the lifting tab, thereof, such that the cap can be lifted by engagement of the tab by a user's finger.

FIG. 7 is a top plan view of a modified safety cap, constituting another embodiment of the invention.

FIG. 8 is a top plan view of a further modified safety cap, constituting yet another embodiment of the invention.

FIG. 9 is a top plan view of a still further modified safety cap, constituting still another embodiment of the invention.

FIG. 10 is a top plan view of still another form of safety cap, wherein the interference lug and lifting tab have incomplete annular configurations and extend through arcs substantially greater then 180.degree..

FIG. 11 is a top plan view of the cap of FIG. 10, showing the closure cap assembled to the cap body and occupying a sealed position.

FIG. 12 is a view like that of FIG. 11 but showing the closure cap as having been rotated so as to expose a portion of the enlarged lifting tab, thus enabling the cap to be lifted by engagement of the tab by a user's finger.

Referring first to FIGS. 1-4 there is illustrated a safety cap 10 for small dispensers and the like, comprising a tubular body 12 having a top discharge opening 14 and a captive closure cap 16 adapted to fit over and close the opening. The safety cap 10 has a conical undercut retainer bead 17 by which it can be permanently assembled to a container 19 by means of a force fit. The body 12 comprises an annular sealing lip 18 which closely abuts and forms a tight seal with an annular sealing skirt 20 disposed in the cap 16. The body of the safety cap further includes an external annular detent bead 22 which is cooperable with an annular detent groove 24 on the cap 16 such that the latter is normally held captive on the cap body 12 when occupying the sealing position as illustrated in FIG. 2. The detent groove 24 and detent bead 22 are circular with no interruptions. In addition, the bead 22 and detent groove 24 constitute bearing means disposed on the cap body and cap, enabling the latter to be turnably shifted on the body. As illustrated in FIG. 6, the web 26 has sufficient length to enable the cap 16 to undergo limited turning movement with respect to the cap body 12.

In accordance with the present invention, there is provided a novel combination of flexible hinge web structure 26 connecting the cap body 12 and cap 16 and interference lug 28 on the cap body cooperating with a lifting tab 30 disposed on the cap. The lug and tab are so arranged as to overlie one another when the safety cap is in the sealing position illustrated in FIGS. 4 and 5. Referring to FIGS. 1 and 5, by the construction of the present invention, it will be readily understood that, as the cap 16 is swung from an open position (FIG. 1) to a closed position, (FIGS. 4 and 5) the web structure 26 will automatically tend to align the lift tab 30 with the interference lug 28, thus placing the closure in a locked position from which it cannot be directly opened, as will be explained below.

Also as provided by the invention, the cap body 12 and cap 16 preferably have smooth external annular surfaces 32, 34 respectively which closely abut one another along a common edge and which are substantially flush with one another, as shown in FIG. 4. The cap and body also have planar surfaces 33, 35, respectively facing and closely juxtaposed to one another to prevent insertion of a tool therebetween for lifting the cap off the body. It will be understood that, once the cap is assembled to the cap body as in FIG. 5, the cap is firmly held thereon by the cooperable detent bead 22 and detent groove 24. Due to the fact that the fit therebetween is moderately snug, and the fact that there are no protrusions exposed on the cap, it is virtually impossible to remove the cap when it occupies the position of FIG. 5.

The cap is also provided with oppositely disposed shoulders 37, 39 (FIG. 5) constituting a finger grip to facilitate turning of the cap by the fingers. As illustrated in FIG. 6, to remove the cap 16, it is only necessary for the user to grasp the body 12 with one hand, and the shoulders 37, 39 of the cap with the other so as to rotate the latter to the position of FIG. 6, wherein the lifting tab 30 is brought out of registration with the interference lug 28. Now, with his finger the user simply engages the exposed lifting tab, and exerts a relatively strong upward force thereon so as to lift the tab and cap from the cap body, during which the detent groove 24 is forced past and out of engagement with the detent bead 22. The groove and bead both undergo limited deformation to enable this removal to occur.

The above construction has a number of distinct advantages. First, the closure cap is inherently a reliable safety cap, since the hinge automatically operates to align the lifting tab and interference lug each time the cap is reassembled to the cap body. Thus, no additional steps are required by the user, such as rotating the cap to a "lock position" following reassembly. The lifting tab is preferably of smaller size than the interference lug so that precise alignment of the two is not required. By this arrangement, even if the hinge has taken a temporary step, the lift tab will still be in alignment with a substantial portion of the interference lug, such that there will not exist any protruding portion of the tab by which unauthorized personnel such as small children could inadvertently open the cap. Finally, by virtue of the fact that the cap is always held captive, there is no possibility that it can inadvertently become lost. Since such a loss would completely defeat the safety closure concept, this feature of a captive cap is a most important one.

In FIGS. 7-9, there are illustrated modified forms of the safety closure cap. FIG. 7 shows a cap body 12a and cap 16a connected by a single web 36 having a serpentine configuration, the web being characterized by a pair of reversely curved portions 38 and 40. FIG. 8 shows a single web 42 having a zig-zag configuration, connecting the cap 16b to the cap body 12b. FIG. 9 illustrates a pair of flexible hinge webs 44, 46, each web having a tenuous configuration, and each supplementing the other to thereby guide the cap 16c when the latter is assembled onto the cap body 12c.

Yet another embodiment of the invention is illustrated in FIGS. 10-12, showing a cap 48, cap body 50 and connecting hinge web structure 52. In accordance with the present invention, the cap 48 is provided with a lifting tab 54 having an incomplete annular configuration extending through an arc substantially greater than 180.degree.. The cap body 50 comprises an interference lug 56, also having an incomplete annular configuration and extending through an arc greater than 180.degree.. As best illustrated in FIG. 10, the interference lug 56 and lifting tab 54 have center portions 58 and 60, respectively located adjacent the web structure 52.

The operation of this embodiment of the invention can readily understood. Following use of the container, the cap 48 can be reseated on the cap body 50 in a manner analogous to that explained above in connection with the safety cap of FIGS. 1-6. During the seating, the hinge 52 operates in such a way as to maintain the alignment of the lifting tab 54 and interference lug 56. When seated, the cap 48 will thus have the position illustrated in FIG. 11. Due to the smooth external surface 59 of the cap 48, direct removal of the latter when it occupies this position is virtually impossible, since there is little or no gripping surface exposed thereon. There is a sufficiently tight fit between the cap body detent bead (22 in FIG. 1) and the cap detent groove (24 in FIG. 1) so as to maintain the cap in the seated position even in the presence of a moderate lifting force applied thereto. Removal of the cap can be readily accomplished however, by gripping the cap body 50 with the fingers on one hand, and gently rotating the cap 48 to the position of FIG. 12 so as to bring the lifting tab 54 out of registration with the interference lug 56, and then gently prying the tab (and cap) upwards with the finger as illustrated. In this position, sufficient force can be applied to the cap (through the lifting tab) so as to force the detent groove of the cap over and out of engagement with the detent bead of the cap body.

The embodiment of FIGS. 10-12 include fillet portions 64 are the respective ends of the hinge web 52. These fillet portions 64 serve two important purposes. First, they reduce the likelihood of the web breaking, particularly where it joins the cap 48 and the body 50. Also, it provides more stiffness in an edge wise direction to the web, not for bending as in FIG. 11 but with respect to the twisting force in FIG. 12. This added stiffness is so arranged so as to be sufficient to return the cap from the twisted portion of FIG. 12, virtually to the non-twisted, registration position of FIG. 11, thereby making it still more difficult for a child or unauthorized person to remove the cap. The biasing force of the web 52 requires the user to not only turn the cap to the FIG. 12 position but also to hold it therein against return movement, while the lifting force is being applied. The webs 64 can, as well, be used with the embodiment of the invention illustrated in FIGS. 1-6 to increase the difficulty of unauthorized removal.

From the above it can be seen that I have provided a novel safety closure cap which is extremely simple in construction, being essentially a one-piece molded plastic part, which is foolproof in its operation, and which provides an excellent degree of safety against inadvertent removal by small children. The cap construction is thus seen to be a distinct advance and improvement in the field of safety closures.

Variations and modifications are possible without departing from the spirit of the invention.

Claims

I claim:

1. A safety cap for small dispensers of the hand-held type and the like, comprising in combination:

a. a tubular cap body having a top discharge opening,

b. a captive closure cap adapted to fit the opening of the cap body so as to seal the same,

c. cooperable yieldable detent means on the cap body and cap, tending to hold the latter firmly on said body so as to seal the same,

d. a flexible hinge web structure connecting said cap body and closure cap for holding the latter captive while enabling it to be swung from a sealing position closing off the body to a discharge position removed from the opening of the body,

e. said cap and body having cooperable bearing means enabling the cap to be turnably shifted on the body within limits as determined by the said web structure, and

f. said cap body having a radially outwardly projecting interference lug,

g. said cap having a projecting lifting tab adapted to overlie and register with said interference lug when the cap has been swung about the web structure to its sealing position on the cap body, so as to prevent access to said lifting tab and thus prevent removal of the cap,

h. said hinge web structure being sufficiently long to enable the cap, when in its sealing position, to be turned on said bearing means within said limits so as to shift the lifting tab thereof out of registration with the interference lug on the cap body whereby a user's finger can be applied to the underside of the lifting tab for the purpose of removing the cap.

2. The invention as set forth in claim 1, wherein:

a. said closure cap and cap body have external annular surfaces which are substantially flush with each other, whereby no protrusions are accessible on the cap for lifting the same from the body by means of finger pressure.

3. The invention as set forth in claim 1, wherein:

a. said web structure comprises two flexible hinge webs connected with the cap and cap body, each to supplement the other for guiding the cap in its hinging movements.

4. The invention as set forth in claim 1, wherein:

a. said web structure comprises a single web having a zig-zag configuration.

5. The invention as set forth in claim 1, wherein:

a. said web structure comprises a pair of webs each having a tenuous configuration.

6. The invention as set forth in claim 4, wherein:

a. said single web is characterized by a pair of reversely curved portions.

7. The invention as set forth in claim 1, wherein:

a. said web structure has a serpentine configuration capable of being straightened, whereby it can have a greater effective length.

8. The invention as set forth in claim 1, wherein:

a. the cap has oppositely disposed shoulders constituting a finger grip to facilitate turning of the cap by the fingers.

9. The invention as set forth in claim 1, wherein:

a. the tab and lug on said cap and cap body have planar surfaces facing and closely juxtaposed to one another to prevent insertion of a tool therebetween for lifting the cap off the body.

10. The invention as set forth in claim 1, wherein:

a. said cap has a smooth external surface for reducing grip capability thereof by the fingers.

11. The invention as set forth in claim 1, wherein:

a. said interference lug has an incomplete annular configuration and extends through an arc substantially greater than 180.degree.,

b. said lifting tab also having an incomplete annular configuration and extending through an arc substantially greater than 180.degree..

12. The invention as set forth in claim 11, wherein:

a. said interference lug and said lifting tab have center portions located adjacent the hinge web structure.

13. The invention as set forth in claim 1, and further including:

a. fillet portions integral with said web structure at the juncture of the latter with the cap body and closure cap, for increasing the stiffness of the web structure and minimizing the likelihood of breakage thereof,

b. said web imparting a bias force to the cap, to partially return the latter toward the registration position thereof when the twisting force is removed.

14. The invention as set forth in claim 1, wherein:

a. said web structure has a stiffness in an edge wise direction sufficient to partially return the cap toward the registration position thereof when twisting force is removed.