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, and cooperable yieldable retainer means on the cap body and cap tending to hold the latter firmly in a closed, sealing position on the cap body. The cap is held captive on the body by means of a flexible hinge web structure which enables the cap to be swung from a sealing position closing off the body to a discharge position removed from the opening thereof. An interference lug and a lifting tab are disposed respectively on the cap body and cap. The lug and tab normally 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 such a position, the cap can be turnably shifted on the body within limits determined by the web structure. The cap body and cap have cooperable detent lugs which can by-pass one another when the cap is turned, to yieldably retain the cap in a position wherein its lifting tab is out of registration with the interference lug on the cap body, such that the user's finger can then be easily 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 became lost or misplaced, which had the effect of completely defeating the safety closure concept, as can be readily understood.

In applicant's U.S. Pat. No. 3,765,578, there is shown a safety cap having a cap body with an interference lug and a captive cap with a lifting tab normally overlying the lug, the latter preventing direct access to the lifting tab by the fingers of the user. Removal of the cap is effected by first rotating it with respect to the body to a position wherein the tab is brought out of registration with the interference lug, thus enabling the user to pry the tab (and cap) off the body. While this arrangement operated very satisfactorily, it was found that during removal, in some cases the resilience of the hinge web connecting the cap body and cap tended to restore the overlying relation of the interference lug and lifting tab before the user could engage the latter. As a result, it was often necessary to simultaneously hold the cap in its "turned" position while applying a prying force to the lifting tab. The user who was new or unaccustomed to the operation of the safety cap sometimes found the above procedure somewhat awkward, althought the safety features inherent in such a construction have been found to be excellent.

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 re-assembly 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. A further object is to provide a safety closure as above characterized wherein the cap can be yieldably held in a turned or twisted position with respect to the cap body in order to facilitate easier opening of the closure.

These objects are accomplished by a novel safety closure comprising a cap body and closure cap held in sealing position thereon by yieldable retainer means, as well as a flexible hinge web structure connecting the body and closure cap. The 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 cap body and cap have cooperable lugs which can by-pass one another during the turning of the cap and thus yieldably retain the latter in such a "turned" position to facilitate prying the lifting tab (and cap) upward, thus removing the cap from the body. 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 a sealed position, such that the cap, once closed, cannot be removed directly without first being twisted to expose the lifting tab.

Other features and advantages will hereinafter appear.

In the drawings, illustrating a preferred embodiment of the invention:

FIG. 1 is a vertical sectional view of the safety cap of the present invention, shown in the open or discharging position.

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 thereon.

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 thereon.

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 section taken on line 7--7 of FIG. 2.

FIGS. 1-6 show a safety or childproof cap 10 for small handheld dispensers comprising a tubular body 12 having a top discharge opening 14 and a captive closure cap 16 adapted to fit over and close off the opening. A depending skirt 20 of annular configuration seals against the opening 14 of the body when the cap is in the closed position of FIG. 4. The safety cap 10 has a conical undercut retainer bead 18 by which it can be permanently assembled to a container 19 by means of a force fit. The body 12 has an external annular retainer bead 22 which is cooperable with an annular recess 23 formed by an internal bead 24 on the cap 16 such that the latter is normally held captive on the body 12 as in FIG. 4. In addition, the cap can be turnably shifted with respect to the body as shown in FIG. 6, the web 26 having sufficient length to enable such limited turning movement to occur.

The cap body 12 has an interference lug 28 which normally underlies a lifting tab 30 on the cap when the latter is in the sealing position illustrated in FIGS. 4 and 5. It is seen 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.

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 and direct lifting of the cap off the body. It will be understood that once the cap is assembled to the body as in FIG. 5, it is firmly held thereon by the cooperable retainer beads 22 and 24. Due to the fact that the fit therebetween is moderately snug and since there are no protrusions exposed on the cap, it is virtually impossible to directly remove the latter when it occupies this position. 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 in either of opposite directions.

In accordance with the present invention, there is provided a novel detent means on the cap body and cap for momentarily holding the latter in a turned position (FIG. 6) with respect to the body. Referring to FIGS. 1 and 2, the detent means comprises an upstanding lug 40 disposed on the exterior of the cap body, and wall portions defining a pair of notches or recesses 42, 44 in the cap bead 24. The walls of the notches 42, 44 are indicated by the numerals 46, 48, respectively. It can be seen that the bead itself extends through an arc of substantially less than 360.degree., being discontinuous in the vicinity of the lifting tab 30. A pair of camming surfaces 50, 52 operate to enable smooth by-pass of the lug 40 and either wall 46, 48 as the cap is turned in one direction or the other.

As illustrated in FIG. 6, to remove the cap 16, it is only necessary for the user to grasp the body 12 (or the dispenser 19) with one hand and the shoulders 37, 39 of the cap with the other, and then rotate the latter to the position of FIG. 6, wherein the lifting tab 30 is brought out of registration with the interference lug 28. As this is done, the camming surface 50 will be forced past the lug 40 and the latter will eventually be seated in the notch or recess 42. If the cap is then momentarily released, so as to enable the user to alter his grip and place his finger in position to pry up the lifting tab, the cap will remain in this same "turned" position against the resilient action of the web 26 which would normally tend to return the cap to the locked position of FIG. 5. The cap thus remains in this position due to the engagement of the lug 40 and the wall 46 of the recess 42. As will be understood, if the cap is initially turned in the opposite direction, the cam surface 52 will by-pass the lug 40, and the latter will eventually be seated in the notch 44. To remove the cap from the position of FIG. 6, the user simply engages the exposed lifting tab with his finger, and exerts a relatively strong upward force thereon so as to lift the tab and cap from the cap body during which the retainer bead 22 is forced out of the groove 23.

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 rotation 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 set, 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 addition, the provision of the detent means (the lug 40 and the bead having notches 42, 44) makes the operation and use of the cap considerably easier for the typical consumer, since the detent means overcomes the effect of the resilient hinge tending to restore the cap to its locked position while the user is trying to pry off the cap. I have found that this improvement has not altered the safety features of the cap in the least, but has represented significantly improved operability of the product.

The improved safety cap also includes fillet portions 54 at the respective ends of the hinge web 26. These fillet portions 54 serve two important purposes. First, they reduce the likelihood of the web breaking, particularly where it joins the cap 16 and body 12. Also, it provides more stiffness in an edge wise direction to the web, not for bending as in FIG. 4 but with respect to the twisting force in FIG. 6. This added stiffness assures that the cap will be re-seated in the locked position of FIG. 5, following use.

In accordance with the present invention, the cap 16 is cup-shaped, having a top wall center portion 51, an annular side wall portion 53 and a plurality of radial stiffening ribs 56 extending therebetween. These tend to maintain the cap rigid and to minimize flexing movement of the top and also the annular wall portion thereof. The addition of these ribs greatly reduces the tendency for the cap to assume an undesirable egg-shaped or oval configuration when the opposite portions (such as shoulders 37, 39) of the annular wall are grasped (in the position of FIG. 5) to effect initial turning of the cap. I have found that without the ribs 56, the bead 24 tends to bind with the bead 22 when the cap is first grasped and squeezed. Such binding opposes the twisting force necessary to bring the cap to the position of FIG. 6, and has been found to be undesirable. By reducing the deformation of the cap when the latter is squeezed, the ribs 56 substantially reduce such binding and enable smoother twisting or turning movement of the cap 16 during removal. In addition, FIGS. 1 and 4 show a deep annular groove 58 on the body between the bead 22 and a thin, feathered edge 60 which constitutes a dripless spout for facilitating pouring of liquids. The bead 22 is yieldable and can undergo moderate flexing so as to occupy part of this groove. Thus, localized portions of the bead 22 can yield in response to pressure applied by adjacent parts of the bead 24 when the cap is initially grasped and turned from the position of FIG. 5 to that of FIG. 6. Also, a more generalized yielding of the bead 22 occurs as it by-passes the cap bead 24 during both removal of the cap and the replacement thereof.

Further, in accordance with the present invention, there is provided a raised ledge or shield portion 62 on the interference lug 28. This ledge is particularly illustrated in FIGS. 1 and 4, and by blocking direct access to the crack between the lug 28 and lifting tab 30 and insertion of a tool or the user's fingernail in the crack, the ledge effectively prevents direct removal of the cap from the position of FIGS. 4 and 5. As shown, the ledge extends in a circumferential direction only and thus does not interfere with the movement of the lifting tab 30 or the twisting of the cap 16.

It is to be noted that the present cap construction is also self-centering when being re-closed due to the bevelling or camming action of the bead 24. In this connection, the radius of curvature of the bead is sufficiently large to effect the self-centering feature and as a result, the re-closing or replacement of the cap is greatly facilitated.

From the above it can be seen that I have provided a novel childproof or safety closure cap which is extremely simple in construction, being essentially a one-piece molded plastic part, and which is foolproof in its operation. It has been found to provide an excellent degree of safety against inadvertent removal by small children. By the present construction, a considerably simplified removal procedure by an authorized person is realized without any sacrifice in its safety features. The closure device is thus seen to represent a distinct advance and improvement in the field of safety caps.

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 retainer means on the cap body and cap, tending to hold the latter firmly on said body in sealing position,

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 the 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 web structure,

f. an interference lug and a lifting tab disposed respectively on the cap body and cap so as to overlie and be in registration with one another when the cap has been swung about the web structure to its sealing position on the body,

g. said hinge web structure being sufficiently long to enable the cap, when in its sealing position, to be turned within said limits so as to shift the lifting tab thereof out of registration with the interference lug on the cap body, and

h. detent means for yieldably holding the cap in a turned position on the cap body wherein the lifting tab is out of registration with the interference lug so that a user's finger can be applied to the underside of the lifting tab for the purpose of removing the cap, thereby enabling the user to readily remove the cap without tending to return to the registration position under the action of the web structure.

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 it directly off the body by means of finger pressure.

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

a. said cooperable retainer means comprises an internal bead disposed on the underside of the cap, and

b. a second bead disposed on the cap body adapted to be engaged by said cap bead.

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

a. said internal cap bead is discontinuous,

b. said detent means comprising an upstanding lug on the cap body,

c. said internal cap bead having a notch for receiving said upstanding lug when the cap is turned in one direction to a predetermined position on the cap body.

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

a. said internal cap bead has a camming portion adjacent the notch, adapted to facilitate the by-pass of the upstanding lug and the seating thereof into the notch.

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

a. said internal cap bead has an additional notch circumferentially spaced with respect to said first notch and adapted to receive said upstanding lug when the cap is turned in the opposite direction to another predetermined position on the cap body.

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

a. said internal cap bead has an additional camming portion adjacent said additional notch to facilitate by-pass of the upstanding lug and the seating thereof into said additional notch.

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, 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.

12. The invention as defined in claim 1, and further including:

a. a raised shield portion of the interference lug, covering the edge of the lifting tab to prevent insertion of a fingernail thereunder.

13. The invention as defined in claim 1, wherein:

a. said cap has a cup-shaped configuration comprising a top wall outer portion and an annular side wall portion, and

b. radial stiffening ribs extending between said top wall center and annular side wall portions of the cap to provide added rigidity thereto, and minimize deformation of the cap during its removal.