Push and twist locking child-resistant and container

Information

  • Patent Grant
  • 6202876
  • Patent Number
    6,202,876
  • Date Filed
    Wednesday, December 30, 1998
    26 years ago
  • Date Issued
    Tuesday, March 20, 2001
    23 years ago
Abstract
The present invention is a push and twist locking child-resistant cap and container. It includes a squeeze tube container having a neck and a dispensing orifice at an outer end of the neck, and the neck has one of a locking track and a locking lug. There is also a cap having at least three components and being assembled to move together as a single unit. This cap includes an outer shell having a sidewall and a top, the outer shell being adapted to receive and contain an inner top and an inner collar member; an inner top inserted into the outer shell, and; an inner collar member fixedly inserted into the outer shell below the inner top and having the other of the locking track and said locking lug. The locking track is generally “U”-shaped with one side of the “U”-shape being an open side for entry and removal of the locking lug, the base of the “U”-shape being at right angles to a central axis of the neck and the other side of the “U”-shape being a truncated, closed side with a locking position for the locking lug.
Description




BACKGROUND OF THE INVENTION




1. Field of the Invention




The present invention relates to a child resistant safety cap which has a push and twist feature, thus requiring a complex motion for effective opening. This invention is particularly useful for dangerous materials, such as drugs, and particularly adaptable to squeezable tubes.




2. Information Disclosure Statement




The following patents are representative of child resistant caps and closures, including compound motion-based child resistant caps.




U.S. Pat. No. 3,072,276 to Anthony Nichols describes a self locking tamper proof vial which comprises the combination of a closure member a container with a cylindrical open neck portion and a spring member, said closure member having a top wall and a cylindrical skirt portion, the cylindrical skirt portion have a plurality of projections spaced around the interior surface thereof and positioned in spaced relationship to the top portion of the closure member, said spring member having a resilient disc portion with a post positioned on one side thereof, said spring member being positioned in the closure in the space between the projections and top portion of the closure member and disc member, said spring member being supported by the plurality of projections in the space between said projections and the interior surface of the top portion of said closure member said container having a number of grooves around the cylindrical open neck portion each with one closed upright end terminated below the rim of said neck and an opposite end open at the rim of said neck, said grooves being spaced around the neck at intervals similar to the spacing of the projections of said closure member so then when closure is properly positioned over the rim of the neck and pressed to the neck the projections enter the open end of said grooves and the post of said spring member is pushed upwardly against the top wall of said closure by the force of the rim of the neck portion against the disc portion of the spring member, said top wall being strong enough to withstand the force of the post without being permanently distorted or broken, whereby if the closure is pressed to the neck of the container and then rotated so the projections enter the closed upright end the force of the disc portion of the spring member on the rim of the neck will keep the projections in the closed upright ends of the slots so the open neck of the container is sealed to form a tamper proof vial.




U.S. Pat. No. 3,339,770 to Bruno Weigand describes in combination with a container provided with a mouth portion: a cap having a cylindrical side wall applicable to the mouth portion container, circumferentially-spaced side lugs carried by the cap on the inside thereof, climbing cams carried by the mouth of the container and peripherally disposed thereon for engagement by said lugs when the cap is turned in the closing direction to draw the cap down, recess means for engagement by the lugs to preclude the cap from turning in the opening direction, and tensionable means depending from said side wall for securing the lugs in the recess means, said tensionable means including an annular extension member in the vicinity of said mouth portion in the applied position of the container, said extension member having a resilient wall portion disposed to extend alongside of said mouth with a free edge curved outwardly therefrom for spreading under tension by contact with a relatively fixed surface when the cap is turned in its closing direction.




U.S. Pat. No. 3,595,417 to Arthur Albert Musher describes a closure and plug for a container is provided with elements interengaging with other elements on the mouth of the container, to secure it against opening by young children. In one modification, the closure is provided with a combination safety plug and measuring device; the measuring device is provided with a more versatile structure, and a means of accurately varying the measured quantity, the closure is also improved.




U.S. Pat. No. 3,749,270 to Lyle Claud Affleck describes an arrangement, for closing a container such as a bottle or like container, including a cap within the skirt of which is mounted one or more projections, for example, pins. Each pin fits into a groove formed in or on the neck or similar formation on the container. Each groove has at least one indent within which the inserted pin can be located to hold the cap in a position to seal the container. The cap is provided with means to bias it away from the container when the latter is sealed, and an enlarged indented section within a groove is used so that the biassing action in combination with the enlarged indented section provide a closure for the container which cannot be easily undone by young children. In another arrangement, the pins are located on the container and the grooves within the cap.




U.S. Pat. No. 3,880,314 to Edward G. Akers describes a container has a neck defined by a cylindrical wall having a planar lip and a frusto-conical interior surface, with the neck opening reducing in diameter toward the interior of the container. The safety cap is cup-shaped having a planar top wall and cylindrical side wall, and having an inner dependent cylindrical skirt concentric with the side wall, the skirt being resilient and disposed to engage the container conical wall in assembled relation. Coacting ratchet lugs extend from the external surface of the container wall and the internal surface of the cap side wall, and are normally urged into engagement to prevent relative rotation of the container and cap by the spring action of the cap skirt and container conical wall. The ratchet lugs have coacting inclined cam surfaces which, in response to rotation of the cap in one direction, force axial inward movement of the cpa to move its top wall contiguous to the container lip; and the container wall and cap have interfering latch means which inhibit reverse rotation from this contiguous position.




U.S. Pat. No. 3,927,783 to Clayton Bogert describes an invention for a leak-proof protective safety closure for containers which is used to prevent inadvertent opening of the container by children or the like. The invention provides a cap having a top and sidewalls which has a wedge-shaped protrusion on the interior of the cap near the base of the sidewalls. A recessed relatively elongated and sloping track is provided on the neck of the container and the wedge rides in the track. Near the base of the track is a notch or groove which accommodates the wedge to lock the cap into position against inadvertent openings. There are pressure means in the form of a rigid ring below the underside of the top of the cap and a flexible plate which flexes while the wedge on the cap rides in the groove and remains under pressure when the wedge snaps into the notch to provide a leak-proof fit. To open the cap it is depressed against the action of the flexible plate to a point where the wedge comes out of the notch or groove and the cap is turned until it is free of the track.




U.S. Pat. No. 4,444,327 to Peter Hedgewick describes a safety container and closure assembly including an integrally-molded, one piece plastic cap having a sealing portion which provides an “oil-can” effect during axial and rotative motion of the cap/relative to the container. The sealing portion comprises a relatively thin, radially outwardly curved wall which is integrally joined to a relatively stiff annular base portion from which a peripheral skirt portion axially projects for receiving the mouth of the container. Integrally formed with the sealing portion is a relatively thin, annular biasing portion which, in turn, is integrally formed with a relatively stiff, inner, disc-like base portion. The biasing portion biases the sealing portion to axially spaced portions such that when the cap is placed on the container, the biasing portion biases the cap in a fixed axial sealing position relative to the container and simultaneously applies pressure to the sealing portion. Preferably, a rib comprising an O-ring seal projects inwardly on the inner surface of the mouth portion of a container and simultaneously engages the sealing portion during the axial and rotative motion of the cap relative to the container.




U.S. Pat. No. 4,567,992 to Eugene E. Davis describes an invention providing a tubular container body and closure assembly with a smooth or flush outside surface. The assembly is provided with bayonet type child resistant closure and tear away tamper resistant band. The container body has a recess to receive a teartap on the tear away band so that the flush outside surface is maintained, the recess in the body being so positioned that when the tear tab is aligned with the recess an internal bead on the closure forming part of the bayonet type locking arrangement is aligned with an external locking slot on the body so that the closure can be applied to the body by a longitudinal downward movement.




U.S. Pat. No. 4,579,238 to James E. Herr describes a child-resistent, moisture-tight safety closure having an end wall with an annular depending skirt, the skirt having a plurality of locking lugs disposed on the inside thereof. The locking lugs cooperate with retaining notches adjacent to the open mouth of an associated container to releasably retain the closure on the container. A sealing plug integral with the end wall of the closure and concentric with the annular skirt effects a moisture-tight seal with the inner wall of the container. A plurality of resilient members are integral with the interior of the closure at the junction of the top wall and the skirt, the resilient members extending downwardly and inwardly so as to engage the end surface of the container opening. The compression of the resilient members serves to bias the locking lugs on the closure into locking relationship with the retaining notches on the container with a force sufficient to ensure the child-resistant characteristics of the closure.




U.S. Pat. No. 4,875,603 to Jack Weinstein describes the present invention is directed to a metered dispensing cap system for containers such as tubes and the like. The system has a base element which is attachable to the neck of a squeezable container and which has a sidewall portion and a top. The base element has an opening in the top for outflow of a material from a squeezable container into a meter element. This base element may be removably attachable, e.g. by being screwed on, or may be permanently attached, e.g. by being integrally molded with the container. A one way valve is located in the opening of the base element to permit the flow of material from a container through the opening while preventing backflow. The system also includes a meter element which acts like an inverted trap and which has a sidewall portion and a top with an opening in the top for dispensing of the material therefrom. The sidewall portion of the meter element is slightly larger than and has the same across section shape as the sidewall portion of the base element and this sidewall portion of the meter element is higher than and located about and encompasses the sidewall portion of the base element. Further, the meter element is vertically slidable along the sidewall portion of the base element with an upward position for receiving a volume of material in a pre-determined amount when the squeezable container is squeezed and downward position whereby the opening in the top of the meter element allows for dispensing of the desired amount of fluid when the meter is pushed down.




U.S. Pat. No. 5,127,553 to Jack Weinstein describes the present invention is a liquid metered dispensing container of the squeezable type. The squeezable container has an opening for dispensing liquid therefrom at one end and a bottom at the other end. A non-flexible trap chamber is connected to the opening and extends outwardly therefrom. The trap chamber has a lower end inserted into the container opening and has an inlet orifice extending from the lower end into the container. The inlet orifice is adapted to receive a dip tube which is attached thereto and extends close to or at the bottom of the container. The trap chamber has an upper end with a dispensing orifice. This is small enough to prevent dripping of liquid therefrom by gravity when the bottle is inverted but is large enough to dispense liquid therefrom when the bottle itself is squeezed. A one way valve is connected to the lower end of the trap chamber which permits liquid to flow from the container to the trap chamber but not vice versa. The trap chamber may have indicia so that exact dosage levels of different amounts may be squeezed into the chamber, or the chamber itself may have a single, predetermined volume.




U.S. Pat. No. 5,161,706 to Jack Weinstein describes a twist and push snap-on, child resistant cap and container has an inner cap seal which is easily snapped onto a neck of a container and an outer cap. The outer cap has a top and sidewalls and has a greater cross-sectional area than the inner cap, and receives and physically restrains the inner cap within the outer cap such that the inner cap may be moved upwardly and downwardly within it over specified distance. The outer cap includes a locking lug located on its inside wall adapted to snap over a circumferential bead located on the neck of the container. There is a stop located on the inside wall of the outer cap and is freely rotatable about the neck of the container except when in contact with stop(s) on the neck of the container at its level of rotation when the outer cap is on the container. A spring mechanism located between the inner and outer cap so as to bias downwardly the inner cap. There is a bead located circumferentially about its neck with a break to allow the lug and stop of the outer cap to pass therethrough. A first stop is located on the neck near but not above or below the opening in the bead and a second stop, larger than the first, is capable of preventing movement of the outer cap when rotated with its stop against its second stop.




U.S. Pat. No. 5,184,760 to Jack Weinstein describes the present invention is directed to a metered side dispensing cap system for containers such as tubes and the like. It includes a chamber unit having an inlet opening in the bottom for flow of a material from a squeezable container into the chamber. The chamber unit has an outlet opening on a sidewall located near the bottom for dispensing material from the chamber in a metered amount. A one-way valve located in the inlet opening on the bottom of the chamber unit permits flow of material through that opening and prevents backflow of material. A piston mechanism moves upwardly and downwardly within the chamber. The piston mechanism is capable of upward movement by material entering the chamber unit when a squeezable container is squeezed and material enters the chamber unit through its inlet opening. The piston is capable of downward movement when its wide top is pushed downward, so as to dispense material through the sidewall outlet opening of the chamber unit. The system is attachable to an open neck of a squeezable container.




Notwithstanding the prior art, the present invention is neither taught nor rendered obvious thereby.




SUMMARY OF THE INVENTION




The present invention is a push and twist locking child-resistant cap and container. It includes a squeeze tube container having a neck and a dispensing orifice at an outer end of the neck, and the neck has one of a locking track and a locking lug. There is also a cap having at least three components and being assembled to move together as a single unit. This cap includes an outer shell having a sidewall and a top, the outer shell being adapted to receive and contain an inner top and an inner collar member; an inner top fixedly inserted into the outer shell, and; an inner collar member fixedly inserted into the outer shell below the inner top and having the other of the locking track and said locking lug. The locking track is generally “U”-shaped with one side of the “U”-shape being an open side for entry and removal of the locking lug, the base of the “U”-shape being at right angles to a central axis of the neck and the other side of the “U”-shape being a truncated, closed side with a locking position for the locking lug. In another embodiment, in place of the container neck is a hollow tube with the same adaptations for attachment to a container. In preferred embodiments, there is a spring mechanism on at least one of the container neck and the inner top so as to permit the cap to be pushed and twisted into the closed side of the “U”-shaped track wherein the spring mechanism biases the cap away from the container to maintain the locking lug in the closed side of the “U”-shaped track.











BRIEF DESCRIPTION OF THE DRAWINGS




The present invention should be more fully understood when the specification herein is taken in conjunction with the drawings appended hereto wherein:





FIG. 1

shows a side view of a container,





FIG. 2

shows a side view of a container with a hollow tube component for a present invention child resistant safety cap and





FIG. 3

shows a side cut view thereof;





FIG. 4

shows a side cut view of a cap component of the present invention,





FIG. 5

shows a bottom view thereof and





FIG. 6

shows a side view of that component attached to the container and collar shown in

FIGS. 2 and 3

above; and,





FIGS. 7 and 8

show a side cut view alternative embodiments of the present invention child resistant safety cap.











DETAILED DESCRIPTION OF THE PRESENT INVENTION




The present invention is adapted for containers requiring child resistant features, and especially, but not limited to squeeze containers and squeeze tubes. For example, some medications may create a safety hazard to children and come in cream or gel form in squeeze tubes and the present invention child resistant safety cap system would be ideal.




Referring to

FIGS. 1 through 6

, identical parts are identically numbered and may not be affirmatively discussed with every Figure and so the Figures should be viewed collectively. Thus,

FIG. 1

shows a side view of a container


1


which has a main body


3


, a neck


5


and a dispensing opening


9


. There is also an annular groove


11


and pinch wedges


7


to allow for permanent, anti-rotation attachment of outer shell


15


in

FIGS. 2 and 3

. In one embodiment of the present invention, the outer shell


15


is a retro fit and in another embodiment of the present invention it may be molded in place with the container. When it is molded in place with the container, it is referred to as the container neck and when it is a separate retro fit piece, it is referred to as a hollow tube. In

FIG. 2

, hollow tube


15


includes a locking track


19


which is generally “U-shaped”. It includes a first ledge


23


of the U, a bottom U portion


28


and a second leg


21


. This track receives a locking lug which will be described below in conjunction with

FIGS. 4

,


5


and


6


. As an alternative, in place of locking track


19


and locking track


29


located on outer shell


15


, locking lugs could be located thereon and the locking track could be located on the inside of a correspondingly cap. In other words, the hollow tube


15


could have either the tracks or the lugs and the cap would have the other of the tracks or lugs.





FIG. 4

shows a side cut view and

FIG. 5

shows a bottom view of a cap


31


which includes an outer shell


33


and inner top


35


and an inner collar


47


. Outer shell


33


is adapted for bonding fit receiving inner top


35


and inner collar


47


so that they cannot be easily separated from one another once they have been assembled. This attachment may be achieved by force fit, gluing, sonic welding or other attachment means available in the art or combinations thereof. Inner top


35


includes a pintle


37


for sealing dispensing opening


9


when closed. Additionally, inner top


35


has plastic spring extensions


39


and


41


. These are to maintain cap


31


relative to hollow tube


15


in their rest position, i.e. with inner top


35


biased upwardly from the top of hollow tube


15


with pintle


37


still in a sealing position. Other alternatives for spring arrangements are available without exceeding the scope of the present invention. For example, springs may be attached to the top of hollow tube instead of the underside of inner top


35


, or separate springs may be attached to both, or springs may be molded or formed separately and attached to either or both, of the cap and the hollow tube. Note that inner collar


47


includes locking logs


43


and


45


. These will ride down first leg


23


of locking track


19


, pass through bottom U portion


28


and rest in a locked position in second leg


21


. Due to the spring force such as is illustrated in

FIG. 6

, inner collar


47


will not drop out of second leg


21


and cannot be opened by mere turning. A user must press down on cap


31


and then rotate while pressing down to get out of second leg


21


, pass through bottom U portion


28


and up first leg


23


to remove cap


31


therefrom. Correspondingly protrusion


45


operates in a similar fashion with respect to locking track


29


. Note in

FIG. 2

that first leg


23


has averted side


25


and a sloped side


27


. Alternative arrangements are illustrated in

FIGS. 7 and 8

below.





FIGS. 7 and 8

show cut views of alternative embodiment cap systems of the present invention. In both Figures, the containers and the caps are identical but

FIG. 7

shows alternative hollow tube


51


and

FIG. 8

shows alternative hollow tube


61


. In

FIG. 7

, the U-shaped track has parallel vertical sides on its open leg and in

FIG. 8

hollow tube


61


has parallel sloped sides to its track open leg.




Obviously, numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein.



Claims
  • 1. A push and twist locking child-resistant cap and container, which comprises:(a) a container having a neck and a dispensing orifice at an outer end of said neck, said neck having one of a locking track and a locking lug; and, (b) a cap having at least three components and being assembled to move together as a single unit, said cap including: (i) an outer shell having a sidewall and a top, said outer shell being adapted to receive and contain an inner top member and an inner collar member; (ii) an inner top member inserted into said outer shell, having a top, and having a sealing protrusion located at its center and extending downwardly therefrom for sealing said dispensing orifice of said container, and having a sidewall extending downwardly therefrom to abut an inner collar, wherein said inner top is in contact with said top of said outer shell and said sidewall abuts an inner collar; and, (iii) an inner collar member fixedly inserted into said outer shell below said inner top member and abutting said inner top member sidewall, and having the other of said locking track and said locking lug; wherein said locking track is generally “U”-shaped with one side of the “U”-shape being an open side for entry and removal of said locking lug, the base of said “U”-shape being at right angles to a central axis of said neck and the other side of said “U”-shape being a truncated, closed side with a locking position for said locking lug.
  • 2. The push and twist locking child-resistant cap and container of claim 1 wherein said locking track includes a ramp at its closed side angled toward a locking position.
  • 3. The push and twist locking child-resistant cap and container of claim 1 wherein said locking track is located on an outside wall of said container neck and said locking lug is located on an inside wall of said inner collar member.
  • 4. The push and twist locking child-resistant cap and container of claim 3 which further includes a spring mechanism on at least one of said container neck and said inner top so as to permit said cap to be pushed and twisted into said closed side of said “U”-shaped track wherein said spring mechanism biases said cap away from said container to maintain said locking lug in said closed side of said “U”-shaped track.
  • 5. The push and twist locking child-resistant cap and container of claim 4 wherein at least two locking tracks and at least two locking lugs are included.
  • 6. The push and twist locking child-resistant cap and container of claim 5 wherein said sealing protrusion is a pintle.
  • 7. The push and twist locking child-resistant cap and container of claim 1 which further includes a spring mechanism on at least one of said container neck and said inner top so as to permit said cap to be pushed and twisted into said closed side of said “U”-shaped track wherein said spring mechanism biases said cap away from said container to maintain said locking lug in said closed side of said “U”-shaped track.
  • 8. The push and twist locking child-resistant cap and container of claim 1 wherein said sealing protrusion is a pintle.
  • 9. A push and twist locking child-resistant cap and container, which comprises:(a) a squeeze tube container having a neck and a dispensing orifice at an outer end of said neck, said neck having one of a locking track and a locking lug; and, (b) a cap having at least three components and being assembled to move together as a single unit, said cap including: (i) an outer shell having a sidewall and a top, said outer shell being adapted to receive and contain an inner top member and an inner collar member; and, (ii) an inner top member inserted into said outer shell, having a top, and having a sealing protrusion extending downwardly therefrom for sealing said dispensing orifice of said container, having a top, and wherein said inner top is in contact with said top of said outer shell, and having a sidewall extending downwardly therefrom to abut an inner collar; and, (iii) an inner collar member fixedly inserted into said outer shell below said inner top member and abutting said inner top member sidewall, and having the other of said locking track and said locking lug; wherein said locking track is generally “U”-shaped with one side of the “U”-shape being an open side for entry and removal of said locking lug, the base of said “U”-shape being at right angles to a central axis of said neck and the other side of said “U”-shape being a truncated, closed side with a locking position for said locking lug.
  • 10. The push and twist locking child-resistant cap and container of claim 9 wherein said locking track includes a ramp at its closed side angled toward a locking position.
  • 11. The push and twist locking child-resistant cap and container of claim 10 wherein said locking track is located on an outside wall of said container neck and said locking lug is located on an inside wall of said inner collar member.
  • 12. The push and twist locking child-resistant cap and container of claim 11 which further includes a spring mechanism on at least one of said container neck and said inner top so as to permit said cap to be pushed and twisted into said closed side of said “U”-shaped track wherein said spring mechanism biases said cap away from said container to maintain said locking lug in said closed side of said “U”-shaped track.
  • 13. The push and twist locking child-resistant cap and container of claim 12 wherein said sealing protrusion is a pintle.
  • 14. The push and twist locking child-resistant cap and container of claim 13 wherein at least two locking tracks and at least two locking lugs are included.
  • 15. The push and twist locking child-resistant cap and container of claim 9 which further includes a spring mechanism on at least one of said container neck and said inner top so as to permit said cap to be pushed and twisted into said closed side of said “U”-shaped track wherein said spring mechanism biases said cap away from said container to maintain said locking lug in said closed side of said “U”-shaped track.
  • 16. A push and twist locking child-resistant cap, which comprises:(a) a hollow tube having a dispensing orifice at an outer end thereof, said hollow tube having adapted for attachment to a neck of a container, said hollow tube having one of a locking track and a locking lug; and, (b) a cap having at least three components and being assembled to move together as a single unit, said cap including: (i) an outer shell having a sidewall and a top, said outer shell being adapted to receive and contain an inner top member and an inner collar member; (ii) an inner top member inserted into said outer shell, having a top, and having a sealing protrusion located at its center and extending downwardly therefrom for sealing said dispensing orifice of said container, having a top, and wherein said inner top is in contact with said top of said outer shell, and having a sidewall extending downwardly therefrom to abut an inner collar; and, (iii) an inner collar member fixedly inserted into said outer shell below said inner top member and abutting said inner top member sidewall, and having the other of said locking track and said locking lug; wherein said locking track is generally “U”-shaped with one side of the “U”-shape being an open side for entry and removal of said locking lug, the base of said “U”-shape being at right angles to a central axis of said hollow tube and the other side of said “U”-shape being a truncated, closed side with a locking position for said locking lug.
  • 17. The push and twist locking child-resistant cap of claim 16 wherein said locking track includes a ramp at its closed side angled toward a locking position.
  • 18. The push and twist locking child-resistant cap and container of claim 17 wherein said locking track is located on an outside wall of said container neck and said locking lug is located on an inside wall of said inner collar member.
  • 19. The push and twist locking child-resistant cap and container of claim 18 which further includes a spring mechanism on at least one of said container neck and said inner top so as to permit said cap to be pushed and twisted into said closed side of said “U”-shaped track wherein said spring mechanism biases said cap away from said container to maintain said locking lug in said closed side of said “U”-shaped track.
  • 20. The push and twist locking child-resistant cap and container of claim 19 wherein said sealing protrusion is a pintle.
US Referenced Citations (21)
Number Name Date Kind
2041403 Fergusson May 1936
3072276 Nichols Jan 1963
3199704 Davidson Aug 1965
3339770 Weigand Sep 1967
3595417 Musher Jul 1971
3733001 Gach May 1973
3749270 Affleck Jul 1973
3880314 Akers Apr 1975
3927783 Bogert Dec 1975
4004704 Hilaire Jan 1977
4244480 Puig Planas Jan 1981
4444327 Hedgewick Apr 1984
4567992 Davis Feb 1986
4579238 Herr Apr 1986
4875603 Weinstein Oct 1989
5114029 Gibilisco May 1992
5127553 Weinstein Jul 1992
5161706 Weinstein Nov 1992
5181624 Petit Jan 1993
5184760 Weinstein et al. Feb 1993
5213223 Minnette May 1993