Dosage control for dispenser with child-resistant feature

Information

  • Patent Grant
  • 6186364
  • Patent Number
    6,186,364
  • Date Filed
    Monday, November 22, 1999
    25 years ago
  • Date Issued
    Tuesday, February 13, 2001
    23 years ago
Abstract
A manually actuated pump dispenser has a control ring mounted on the pump body for rotation about its central axis and engaging the pump plunger for controlling the number of plunger strokes and thereby the dosage of the dispenser for each cycle of revolution of the control ring, the plunger being releasably locked with the control ring against plunger reciprocation at the commencement and at the end of each cycle of revolution of the control ring to thereby render the same child-resistant.
Description




BACKGROUND OF THE INVENTION




This invention relates to a manually actuated pump dispenser which provides for a predetermined number of pump strokes for dosage control prior to automatically resetting after the final stroke. The pump plunger of the dispenser is locked against actuation in a condition prior to the first stroke and following the final stroke.




More particularly the dispenser according to the invention has a freely rotatable control ring engaging the plunger for controlling the number of plunger strokes and thereby the dosage during an unlocked condition of the pump for each revolution of the control ring. The control ring is coupled to the plunger in a manner for releaseably locking the plunger against reciprocation. The control ring and the plunger must be relatively rotated to unlock the ring thereby rendering the dispenser child-resistant.




U.S. Pat. No. 5,335,823 discloses a discharge apparatus for media of a random type in which a discharge process is performed with one or more discharge actuating means. The dispenser is so constructed that it can be moved backwards and forwards in one or more motion cycles in manual manner between one or more starting positions and one or more end positions. In one or more of such positions the discharge actuating means can be fixed by one or more catch systems at least within certain movement limits against movements in the actuating direction, and/or return direction in the catch system can be released again by one or more manual actuations.




U.S. Pat. No. 4,565,302 discloses an actuatable dosing mechanism with an actuating pusher for dispensing a measured quantity of a flowable substance from a container. A counter is provided for automatically counting the actuated strokes, the counter being started up by the actuation of the actuating pusher. A locking device is provided for the actuating stroke which can be actuated as a function of the counter. The locking means is activated after a daily maximum dose of a certain number of strokes and can then be released again.




These prior art dosing mechanisms, however, generally lack the ability providing for a specified number of strokes for dosage control prior to being automatically reset after the final stroke. For example, the user may require three strokes of nasal medicant per nostril such that after the end of the third stroke the dispenser is rendered child proof until the operator restarts the device. The known prior art dispensers having a dosage or metering control are incapable of achieving a specified control of designated strokes.




SUMMARY OF THE INVENTION




It is therefore an object of the present invention to provide a dispenser having a dosage control mechanism which provides for a specified number of strokes ending in automatic resetting and locking of the pumping actuator after the end of the last stroke. The dispenser with such a control according to the invention is developed as having relatively few moving parts, is easy to operate and assemble yet is highly economical.




The control ring is mounted on the dispenser body and is coupled to the plunger for rotation in only one direction from a locked position and through a plurality of predetermined cam cycles whereupon the plunger is automatically reset at a relocked position. The coupling between the control ring and the plunger converts translatory motion to rotatory motion such that the plunger is capable of only a specified number of strokes in each revolution of the control ring.




A cam on the plunger engages an abutment shelf on the control ring for locking the plunger against reciprocation before the beginning of the first stroke and after the end of the last stroke. The control ring and plunger are both freely rotatable and are rotatable relative to one another. And limit stops are provided on the shelf, one of which is overridden upon relative rotation of the ring and plunger to place the same in readiness for actuation. After the end of the last stroke the plunger is automatically locked as the cam returns to the shelf.




The coupling between the control ring and the plunger further includes a zigzag track in which the cam engages the rearward faces of track walls forming index ramps at acute and obtuse angles. The track walls have free ends which deflect and permit the cam to pass from one angular ramp to the other, thereby acting as a one-way gate for each individual cam cycle.




The need to relatively rotate the control ring to that of the plunger renders the dispenser child resistant as the relative rotation between the two parts is generally incapable of being carried out by a young child.




Other objects, advantages and novel features of the invention will become more apparent from the following detailed description of the invention when taken in conjunction with the accompanying drawings.











DETAILED DESCRIPTION OF THE DRAWINGS





FIG. 1

is a vertical sectional view of a manually actuated pump dispenser incorporating the invention;





FIG. 2

is an enlarged side elevational view of the control ring of

FIG. 1

;





FIG. 3

is a view taken substantially along the line


3





3


of

FIG. 2

;





FIG. 4

is a perspective view of a portion of the control ring, at an enlarged scale, showing the sequential path of the plunger cam with which the ring is coupled; and





FIG. 5

is a perspective view of the

FIG. 1

dispenser, partly broken away to illustrate the plunger head cam.











DETAILED DESCRIPTION OF THE INVENTION




Turning now to the drawings wherein like reference characters refer to like and corresponding parts throughout the several views, the dispenser incorporating the invention is generally designated


10


in

FIG. 1

of generally known construction as disclosed in U.S. Pat. No. 4,051,983, commonly owned herewith. The entirety of the disclosure of that patent is therefore specifically incorporated herein by reference. Thus the dispenser has a pump body


11


coupled to an internally threaded closure cap


12


for mounting the dispenser to the externally threaded neck of a container C of product to be dispensed. The pump body includes a pump housing


13


having a pump cylinder portion


14


for the reception of a reciprocable pump piston


15


which therewith defines a variable volume pump chamber


16


. The pump piston has a hollow stem


17


to which is fixedly mounted to a pump head


18


having a cylindrical skirt


19


. The hollow stem defines a discharge passage


21


which communicates with a discharge opening


22


at the end of a discharge spout


23


or the like, through which liquid product is discharged in any normal manner as known in this art.




A three-piece poppet valve, generally designated


24


, has a poppet valve part


25


seated against a valve seat formed in the pump piston, part


25


being coupled to a small diameter piston


26


which reciprocates within a small diameter cylinder


27


as an integral portion of pump housing


13


. An inlet ball check valve


28


is captured between parts


25


and


26


for the inletting of product into the pump chamber during each piston suction stroke as in the known manner and as specifically described in the '


983


patent. A piston return spring


20


is located in cylinder


27


and bears against the three-piece poppet for returning the piston to its

FIG. 1

position.




In accordance with the invention a control ring


29


is coupled to closure cap


12


in telescoping relation to plunger skirt


19


. The control ring has an external annular bead


31


(

FIG. 2

) engageable with an annular groove


32


(

FIG. 1

) in upstanding flange


33


of the closure cap permitting the control ring to freely rotate relative to the plunger and relative to the closure cap. A retainer collar


34


mounted to the upper end of the control ring may be provided for snugly embracing the plunger skirt. Otherwise, the control ring may have an integral annular collar or flange for this purpose.




According to the invention control ring


29


is coupled to cylindrical skirt


19


of the pump plunger so that the translatory movement of the plunger is converted to rotary movement of the control ring during each individual cam cycle


30


(FIG.


3


). For this purpose plunger skirt


19


has a radially extending projection


35


in the form of a cam which may be of circular cross-section. The inner surface of the control ring has a horizontal shelf defined by a flat rib


36


or the like on which cam


35


rests in a given rotative orientation of the control ring. When cam


35


abuts against rib


36


, the pump plunger is inactivated and cannot be depressed. In the embodiment disclosed the plunger is thus locked in its up position at the end of the piston suction stroke when cam


35


is in its “a” position of FIG.


4


.




In this position manual rotation of the plunger or manual rotation of the control ring about the central axis of the dispenser will cause both parts


18


and


29


to rotate together as they are both freely rotatable about that axis. Provided at opposite ends of shelf


36


are detents forming stop elements


37


and


38


which normally confine cam


35


to shelf


36


during rotation of either the plunger head or the control ring about the central axis. The stop element


37


is deflectable such that upon relative rotation of the plunger head and the control ring (as by manually turning the plunger head and control ring in relatively opposite directions), the cam overrides stop element


37


to its “b” position of

FIG. 4

, thereby permitting plunger reciprocation. The dispenser is thus rendered child-resistant as a young child is unlikely able to carry out a two-handed operation by manipulating the plunger head and the control ring so as to rotate them relative to one another to thereby unlock the plunger. It should be pointed out that relative rotation causing cam


35


to shift in an opposite direction toward stop


38


, does not unlock the plunger as prevented by end


48


of rib


44


.




The inner wall of the control ring likewise has a zigzag track along the circumference commencing at stop element


37


, extending about the entire circumference along the inner surface of the control ring, and terminating at stop element


38


. The track may be comprised of a plurality of index ramps defined by ribs


39


,


41


,


42


,


43


, etc., and terminating in rib


44


, alternatively at obtuse and acute angles. The control ring is rotatable about its axis only in the direction of the curved arrows of FIG.


4


. Thus relative to that direction it can be seen that rib


39


slopes downwardly and rearwardly, terminating in a deflectable end


45


slightly spaced apart from the confronting end of rib


41


a distance slightly less than the diameter of cam


35


. End


45


is elongated as shown in

FIG. 3

to permit cam


35


on the plunger to shift as necessary through its full downstroke upon manual reciprocation.




Rib


41


slopes upwardly and rearwardly and terminates in a deflectable end


46


which is spaced a slight distance from the confronting end of rib


42


a distance slightly less than the diameter of cam


35


. Rib


42


slopes downwardly and rearwardly, parallel to rib


39


, terminates in a deflectable end


47


which is spaced from the confronting end of rib


43


a distance slightly less than the diameter of cam


35


. Rib


43


slopes upwardly and rearwardly, parallel to rib


41


, and has its upper end (not shown) terminating in a deflectable end (not shown) similar to that of end


46


. Ribs such as


41


and


42


with their deflectable ends as aforedescribed continue throughout the entire circumference along the entire inner surface of the control ring and terminate in rib


44


having a deflectable end


48


which is spaced from confronting end


38


a distance slightly less than the diameter of cam


35


.




In operation, the dispenser is shipped and stored and is maintained during non-use with its plunger in its up locked position in

FIG. 4

immobilized against actuation as its cam


35


rests against lock shelf


36


located in its path. Any attempt by a child in this position to rotate the plunger head or the control ring about the central axis of the dispenser will effect rotation of both of these parts together as cam


35


shifts into position against either stop element


37


or against stop element


38


. To place the dispenser in readiness for pumping by the user, the plunger and the control ring must be relatively rotated in opposition directions (as by holding one part and rotating the other) causing cam


35


to override end element


37


by deflecting the same whereupon the cam is shifted from its position “a” to its position “b” as illustrated in FIG.


4


. Upon manual application of finger force to the top surface of the plunger head, cam


35


is guided along the rear surface of rib


39


(relative to the direction of the curved arrows of

FIG. 4

) until the cam reaches position “c” shown in FIG.


4


. At this position the cam is forced through the space between deflectable end


45


and the confronting end of rib


41


such that the cam is guided along the rear surface throughout the length of end


45


to position “C′” (

FIG. 3

) during the extent of the plunger downstroke. During the return movement of the plunger the cam is guided from its “C′” position back to its “c” position at which it is now disposed at the underside of rib


41


. As known in this art, piston return is effected by the resilient expansion of return spring


20


to return the piston


15


and the plunger to its initial position of

FIG. 1

, upon release of the finger pressure applied to the plunger. In this process cam


35


is guided along the rear surface of rib


41


and out through the spacing between end


46


and the confronting end of rib


42


. The cam deflects end


46


as it moves through this space to its position shown at “d” in FIG.


4


. Repeated application of finger force against the top of the head again lowers the head and the pump piston such that cam


35


is now guided along the rear surface of rib


42


and when it reaches the lower end of the rib it deflects end


47


away from the confronting end of rib


43


and is guided along the extension of end


47


through the extent of the plunger downstroke so as to be placed in a position during the return stroke in readiness to be guided along the rear surface of rib


43


as in the same manner as described above relative to rib


41


. During each pressure and return stroke the plunger reciprocates and is guided along the ribs forming index ramps which thereby act as a one-way gate for each complete pressure and return stroke. As the plunger head is shifted through one reciprocation cycle, the control ring rotates about the head through a single cam cycle


30


(

FIG. 3

) via the fixed cam


35


on the head skirt. During continued plunger reciprocation the control ring rotates progressively through like cam cycles as the cam traverses the sets of one-way gate ramps until the cam finally ends up being guided along the underside of rib


44


during the final plunger return stroke of the series. The cam thereupon moves through the space between end


48


and stop element


38


deflecting element


48


so as to finally end up back on top of lock shelf


36


from which it started.




Thus each adjoining pair of ramps such as


39


and


41


rotates the control ring a single cam cycle


30


during a single piston pressure and return stroke. The circumferential distance


30


depends on the number of adjoining rib pairs and the slope thereof. The number of pairs of ribs such as


39


and


41


and


42


,


43


around the inner circumference of the control ring determines the number of pressure strokes the designed for the dispenser before the plunger automatically resets itself after the final stroke such as by ending back up on the shelf at position “a”. The dosage through a predetermined number of cam cycles of the control ring is therefore limited with the plunger being automatically reset back to its locked and child resistant position after the final stroke. Thus if four pressure strokes, for example, are determined for a throat spray, the control ring


29


will be designed with four pairs of ramps such as


39


,


41


. The number of pressure strokes intended for dosage control in accordance with the invention of course depends on the number of ramp pairs which, in order to extend the ramp pairs from one end


37


of shelf


36


throughout the circumference of the control ring and ending back at the opposite end


38


, requires the slope of the ramp pairs to be adjusted accordingly.




Another child-resistant feature which may be provided for the dispenser comprises an overcap


49


surrounding closure cap


12


. The overcap is freely rotatable about the closure cap axis. Cooperating snap beads


51


and


52


on the overcap and on the closure cap permit a snap-fit mounting of the overcap in place. One-way internal ratchet teeth


53


at the upper end of the overcap may be provided as in any known manner for engagement with like ratchet teeth


54


on the closure cap permitting engagement between the two sets of ratchet teeth in the loosening direction of the closure cap. Thus the dispenser is removable from its container upon the application of a slight downward force applied to the overcap causing the ratchet teeth sets


53


,


54


to interengage, while rotating the overcap in a loosening direction. It is apparent that a young child is incapable of such a two-step operation, thereby further rendering the dispenser child-resistant.




As shown in

FIG. 5

, discharge spout


23


is generally aligned with cam


35


, and an indicating arrow


55


is provided on the outer surface of control ring


29


indicating that the plunger head is in a locked position with cam


35


in its position “a” of FIG.


4


.




Although the guide track for the cam has been aforedescribed as extending about the inner circumference of the control ring, it should be pointed out that two complete guide tracks may be provided, each extending along a portion of the inner circumference of the control ring and each being identical. Each track would function in the identical manner as aforedescribed as each having a lock shelf


36


, and ribs


39


,


41


, etc. The other plunger locked position may therefore be indicated by a indicating arrow


56


(

FIG. 2

) applied to the outer surface of the control ring.




Obviously, many modifications and variations of the present invention are made possible in the light of the above teachings. For example the track from the inner circumference of the control ring can be formed by grooves in the surface of the control ring rather than by the provision of ribs such as


39


,


41


, without departing from the invention. Also cam


35


can be freely rotatable or can be of any other shape or form so long as it functions to convert the translatory motion of the plunger to the rotational movement of the control ring as it is guided about the track or tracks as in the manner aforedescribed for controlling the dosage of the dispenser. Moreover, the pump sprayer as aforedescribed is not required for carrying out the invention. Any other known pump sprayer can be adopted without departing from the scope of the invention. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.



Claims
  • 1. A dispenser having a plunger manually reciprocable through a central opening in a closure cap of a container of product to be dispensed, a control ring rotatably mounted on said closure cap in only one direction, cam means on said plunger engageable with abutment means on said control ring for selectively locking said plunger in an initial set position, and means on said control ring engageable with said cam means during plunger reciprocation in a plunger unlocked position for converting translatory motion of said plunger to rotary motion of said control ring in said one direction, said converting means comprising one way gate means establishing individual cam cycles for each reciprocating movement of the plunger causing said control ring to sequentially rotate from said unlocked position through a cycle of rotary motion and to be automatically reset to said locked position.
  • 2. The pump sprayer according to claim 1, wherein a detent at said abutment means defines a limit stop for said cam means, relative manual rotation between said plunger and said ring acting to override said limit stop into said plunger unlocked position.
  • 3. The pump sprayer according to claim 1, wherein said converting means comprise zigzag links for guiding said cam means only along rear faces of said links.
  • 4. The pump sprayer according to claim 3, wherein pairs of said links are angularly related and are spaced apart to facilitate the guiding of said cam means only along said rear faces through said individual cam cycles.
  • 5. The pump sprayer according to claim 1, wherein said cam means comprises a lateral projection on said plunger.
  • 6. The pump sprayer according to claim 5, wherein said abutment means comprises an abutment wall in alignment with said lateral projection in said locked position.
  • 7. A pump dispenser, comprising a pump body having means for mounting the body to a container of liquid product to be dispensed, the dispenser being manually reciprocable between pressure and return strokes, a control ring mounted on said body for rotation about a central axis of said plunger, said ring being coupled to said plunger by a plurality of index ramps for controlling the number of pressure strokes and thereby the dosage of the dispenser for a cycle of revolution of the control ring, and means acting between said ring and said plunger for locking said plunger against reciprocation at the commencement and at the end of each said cycle of revolution of the control ring.
  • 8. The pump dispenser according to claim 7, wherein said locking means comprise a cam on said plunger and an abutment wall on said ring.
  • 9. The pump dispenser according to claim 8, wherein said index ramps comprise a plurality of contiguous angularly related rib pairs having deflectable ends permitting said cam to pass therethrough, said rib pairs acting as one-way gates for each complete pressure and return stroke.
  • 10. The pump dispenser according to claim 9, wherein said abutment wall has a detent at said one end for confining said cam to said wall, said ring being manually rotatable in a forward direction relative to said plunger for overriding said detent.
  • 11. The pump dispenser according to claim 8, wherein said control ring has indicia on an outer surface thereof in alignment with said cam for indicating a locked position of said plunger.
US Referenced Citations (9)
Number Name Date Kind
3678884 Robbins Jul 1972
4051983 Anderson Oct 1977
4565302 Pfeiffer et al. Jan 1986
4566611 Sukopp Jan 1986
5277334 Malinconico Jan 1994
5335823 Fuchs et al. Aug 1994
5405057 Moore Apr 1995
5725128 Foster Mar 1998
5791518 Amann et al. Aug 1998