Abstract:
A closure cap for containers of harmful products when rotationally tightened on the threaded container neck becomes freewheeling in the opposite direction of rotation and resistant to opening by a child. Indicator elements on the inner and outer cap components can be aligned to locate a push button of the outer cap component at a depressable position where a driving element thereof can engage an unscrewing abutment of the inner cap component. The two cap components have initial and final tightening abutments which are sequentially engaged during tightening rotation. The inner cap component has a ramp which coacts with the push button to elevate the push button above all abutment surfaces of the inner cap component during freewheeling of the outer cap component in the child-resistant mode.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a continuation-in-part of prior copending application Ser. No. 074,780, filed Sept. 12, 1979, for PUSH BUTTON SAFETY CAP FOR GLASS BOTTLES, now U.S. Pat. No. 4,223,794. 
    
    
     BACKGROUND OF THE INVENTION 
     The objective of the present invention is to improve the operational efficiency and reliability of a child-resistant push button closure cap for containers of the general type disclosed in the referenced prior patent application. More particularly, the present invention seeks to render the closure cap more compatible with plastics molding techniques and to render the closure cap components more dimensionally stable and precise in their manufactured forms. 
     A further objective is to provide a closure cap for medicine containers and containers of other harmful products which will indicate to a viewer of the closure cap whether it is in a child-resistant or non-child-resistant mode. 
     Another objective is to provide a closure cap of the mentioned type having a push button release element which responds to very light finger pressure, thereby rendering the closure cap easy to operate by the elderly. 
     An important object and feature of the invention resides in an arrangement whereby the closure cap is tightened in two stages, and the momentum developed in the first stage of tightening is used to assist in the second or final stage of tightening. 
     A further object is to provide a closure cap of the mentioned type which can be closed or sealed with two degrees of tightness, and in either case will effectively seal a liquid in the container. In the first or lesser degree of tightness, however, the closure cap will not be safe or child-resistant, as it will be in the fully tightened condition. 
     Another object is to provide a push button child-resistant closure cap which can be conveniently operated by the blind. 
     Other objects and advantages of the invention will become apparent during the course of the following description. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side elevation of a container and closure cap according to the present invention. 
     FIG. 2 is a plan view thereof. 
     FIG. 3 is an enlarged central vertical section taken on line 3--3 of FIG. 2. 
     FIG. 4 is a plan view of an inner cap component. 
     FIG. 5 is a bottom plan view of an outer cap component. 
     FIG. 6 is a perspective view of the inner cap component shown in FIG. 4. 
     FIG. 7 is an enlarged fragmentary plan view of the outer cap component showing push button detent means. 
     FIG. 7a is a fragmentary vertical section taken on line 7a--7a of FIG. 7. 
     FIG. 8 is a vertical section similar to FIG. 3, parts in elevation, with the push button depressed in preparation for unscrewing the closure cap. 
     FIG. 9 is horizontal section taken on line 9--9 of FIG. 8. 
     FIG. 9a is a fragmentary developed section taken on line 9a--9a of FIG. 9. 
     FIG. 10 is a view similar to FIG. 9a showing the corresponding part in a further operational stage of cap release. 
     FIG. 11 is a view similar to FIG. 9 illustrating the beginning of cap tightening. 
     FIG. 11a is a view similar to FIG. 9a and showing the beginning of cap tightening as in FIG. 11. 
     FIG. 12 is a further view similar to FIG. 9 showing the elements in the first stage of cap tightening actively engaged. 
     FIG. 12a is a view similar to FIG. 9a depicting the ascent of the push button during the cap tightening cycle. 
     FIG. 12b is an enlarged fragmentary developed section taken on line 12b--12b of FIG. 12. 
     FIG. 13 is a further view similar to FIG. 9 showing the beginning of the final stage of cap tightening. 
     FIG. 13a is a view similar to FIG. 9a showing full engagement of the parts involved in final cap tightening while the push button remains elevated. 
     FIG. 13b is a view similar to FIG. 12b following override and release of the first stage tightening parts on the two cap components. 
    
    
     DETAILED DESCRIPTION 
     Referring to the drawings in detail wherein like numerals designate like parts and referring first to FIGS. 1 through 7a, the numeral 20 designates a container, such as a glass medicine bottle, having a conventionally screw-threaded neck 21 formed thereon. The numeral 22, FIGS. 1 and 3, designates a push button child-resistant closure cap in its entirety adapted to be molded from plastics material. The closure cap 22 comprises an inner cap section or component 23 having internal screw-threads 24 to engage the threads of the container neck and having the usual interior disc seal 25 to compressively engage the mouth of the container neck. The inner cap component 23 carries a preferably pointed radial indicator element 26 near its lower end and projecting somewhat beyond its periphery. 
     On its top, the inner cap component 23 is provided with an upstanding annular ramp 27 of considerably lesser diameter than the body of the cap component 23 and being concentric therewith. The ramp 27 has inclined terminals 28 and 29. A center post 30 is fixed to the top wall 31 of cap component 23 and rises therefrom to a point well above the annular ramp 27. 
     Immediately inwardly of the annular ramp 27, inner cap component 23 carries a fixed radial first stage cap tightening abutment face 32 having a tapered ramp surface 33 leading downwardly therefrom to the plane of top wall 31. The ramp surface 33 extends circumferentially of the cap component 23 for about 70 degrees, FIG. 4. The abutment surface 32 is approximately opposite diametrically from the indicator element 26 although this relationship is not required. 
     Outwardly of the annular ramp 27, a fixed steeply inclined final stage tightening abutment shoulder 34 or surface rises from the top wall 31 and is joined therewith by a gradually inclined ramp surface 35. The surface 34 extends radially of cap component 23, and forms an included angle of approximately 160 degrees with the abutment surface 32. A radial cap unscrewing abutment surface 36 rises from the top wall 31 in spaced relationship to surface 34 and in radial alignment with the end face 37 of ramp 28, FIG. 4. 
     Another inclined ramp surface 38 is formed on the cap component 23 between abutment surfaces 36 and 34 and the degrees of inclination of ramp surfaces 29 and 38 are the same and these surfaces lie in a common plane, as best shown in FIG. 9a. A shallow recess 39 exists between ramp surface 38 and abutment surface 36, FIG. 9a. The two surfaces 34 and 36 are separated circumferentially approximately 30 degrees, FIG. 4. 
     The top edge 40 of final tightening abutment surface 34 is somewhat above the top surface 41 of the lug or projection having the abutment surface 36. 
     The closure cap 22 further comprises an outer cap section 42 or component telescoped over the inner cap section 23, FIG. 3, and having swiveled engagement therewith. The two cap sections are held in assembled relationship by interengaging annular flanges 43 and 44. The outer cap section 42 includes a top wall 45 including a depressed roughly semi-circular wall portion 46 having a radial slot 47. The depressed wall portion 46 has an aperture 48 disposed at the center of the closure cap through which post 30 projects. The top wall 45 may carry thereon molded operational instructional indicia, not shown. 
     The outer cap section 42 carries a pointed indicator element 49 at its lower edge adapted for alignment with the element 26 of the inner cap section when the release of the closure cap is desired, as will be further explained. The element 49 is preferably in the same radial plane as the slot 47, FIG. 5. 
     The outer cap section 42 is equipped with a push button tab 50 having an aperture 51 to receive the top of post 30. Push button tab 50 is preferably, although not necessarily, integrally connected with cap section 42 by a narrow hinge web 52 which is flexible. The push button tab carries depending radial drive lug 53 which is received through the slot 47 so as to project below the wall portion 46 when the push button tab is depressed, FIG. 8. Push button tab 50 and lug 53 are then somewhat inclined, as shown. Within the well 54 formed around depressed wall portion 46 pairs of rear push button detents 55 and a single pair of forward detents 56 are formed for the control of push button tab 50 with a snap action so that once the tab is depressed by the finger, it does not have to be held down during closure cap unscrewing. Likewise, in closure cap tightening, when the push button tab pops up in a manner to be further described, the detent means 55-56 positions the push button tab in a constrained manner in its raised position. The push button tab 50 is shown in phantom lines in FIG. 7a in the depressed and raised positions. 
     On the bottom of depressed wall portion 46, the outer cap section 42 has a first stage radial cap tightening rib 57 near the aperture 48, FIG. 5. A second and final stage cap tightening lug 58 is similarly formed on the bottom of depressed wall portion 46 and is radially disposed immediately inwardly of the peripheral wall 59 of the outer cap section. The two elements 57 and 58 are separated circumferentially by an included angle of roughly 165 degrees, FIG. 5. 
     FIGS. 8 through 9a illustrate the closure cap unscrewing operation and FIGS. 11 through 13b illustrate the two stage closure cap tightening operation. Referring first to FIGS. 8 through 9a and assuming that the closure cap has previously been fully tightened and is in the child-resistant state where the outer cap section 42 is freewheeling in the unscrewing direction shown by the directional arrows in these figures, the following takes place. The outer cap section 42 is turned in the unscrewing direction until the two indicator elements 26 and 49 are in alignment axially of the closure cap. In such relative positions, the user can now depress the push button tap 50 with a finger and the depending lug 53 can move downwardly as shown to a position in the recess 39 with which the lug is now aligned. In this position, the lug is adjacent to the abutment surface 36 on the inner cap section 23. As best shown in FIG. 8, detents 55 and 56 will retain the push button tab 50 and its lug 53 in the depressed position. The user now rotates the outer cap section 42 in the unscrewing direction shown by the arrows in FIGS. 9 and 9a and one side of the lug 53 will contact the unscrewing abutment face 36 of the inner cap section 23 and both cap sections as a unit can be unscrewed and removed from the neck of the container 20. 
     FIG. 10 shows the outer cap section 42 freewheeling in the unscrewing direction as will be the case where the closure cap is fully tightened and the push button tab 50 is not yet depressed by the finger while indicator elements 26 and 49 are aligned. During such freewheeling, push button tab 50 is held elevated by the riding action of the lug 53 on top of the annular ramp 27 and the added control action of detent means 55 and 56. 
     Referring to FIGS. 11 through 13b showing the two stage cap tightening operation, FIG. 11 shows the beginning of the first stage of tightening where the user has re-applied the two cap sections to the container neck and has begun to rotate the outer cap section 42 in the tightening direction shown by the directional arrow. The first stage tightening rib 57 of outer cap section 42 is approaching the first stage tightening abutment face 32 of the inner cap section 23 but has not yet contacted such surface. As shown in FIG. 11a, the push button lug 53 is beginning to climb the inclined ramp 38 as the inner cap section gradually encounters frictional resistance on the neck of the container. Initially, in the tightening process, the two cap sections, due to the friction of the engagable cam surfaces 29,38 and that on the lug 53, and the resistance of the lower detents 55 and 56, rotate as a unit until the inner cap section 23 begins to encounter frictional resistance on the neck of the container. As this frictional resistance builds up, the two cap sections begin to have relative movement because the progress of the inner cap section will be retarded whereas the outer cap section can still turn freely in the tightening direction. 
     In FIGS. 12 and 12b, the first stage tightening rib 57 of the outer cap section has positively engaged the first stage abutment surface 32 of the inner cap section 23. Further tightening rotation of the closure cap by the user will complete the first stage of tightening. At this point, the closure cap is liquid-tight on the container but is not child-resistant, as the push button tab 50 and lug 53 are still depressed. 
     Still further tightening by the user will overcome the resistance of the abutment surface 32 against the rib 57 and the rib will escape and snap over the abutment and move on to a position such as illustrated in FIG. 13b. Substantially simultaneously with this escapement, the pressure of the ramp surface 29 on the push button lug 53 will cause the push button to escape or snap over the lower detents 55 and 56, FIG. 7a, and pop up to the child-resistant position as indicated by the arrow in FIG. 12a. The top detent 55 constrains the push button tab in this upper child-resistant position where the unscrewing lug 53 is above the level of the unscrewing abutment surface 36. 
     Substantially simultaneously with the above escapement of the rib 57 from the abutment surface 32 and the popping up of the push button tab 50, the second and final stage of the cap tightening process commences by the engagement of second stage tightening lug 58 of the outer cap section with the second stage abutment shoulder 34 of the inner cap section, as best shown in FIG. 13a. An important feature of the invention resides in the utilization of the turning inertia developed in the first stage of tightening to complete the second and final stage. When the rib 57 escapes over the abutment surface 32 at the end of the first stage of tightening, further turning effort by the user will cause the lug 58 to slam into the abutment shoulder 34 almost instantly and without any slowing down of the tightening process, thus taking advantage of inertia developed in the process. 
     At the completion of closure cap tightening where the screw-threads 21 offer firm resistance to any further manual rotation of the cap, the container is tightly sealed and child-resistant, in that the outer cap section 23 is freewheeling in the unscrewing direction. This is due to the fact that the push button lug 53 is now riding on top of the annular ramp 27. 
     Only after the user re-aligns the two indicator elements 26 and 49 and depresses the push button tab 50, thus returning the parts to the relative positions shown in FIG. 9a, can the closure cap be removed in the manner described relative to FIGS. 8 through 9a. 
     The described arrangement provides a foolproof, child-resistant closure cap which is very easy to operate by elderly adults because it requires little physical effort to operate the push button and to twist the outer cap section 42 through the two stages of tightening and the subsequent unscrewing operation. The stated objectives of the invention are achieved in a cap structure which is economical and fully practical from a manufacturing standpoint. A user of the container can see at a glance whether the cap is in a child-resistant or unsafe state. 
     It should be pointed out that the engagement of the post 30 in the push button aperture 51, together with the action of detent elements 55, forms a horizontal axis fulcrum for the push button tab 50 in its movement between two positions shown in FIGS. 3 and 8. 
     The terms and expressions which have been employed herein are used as terms of description and not of limitation, and there is no intention, in the use of such terms and expressions, of excluding any equivalents of the features shown and described or portions thereof but it is recognized that various modifications are possible within the scope of the invention claimed.