Resilient squeeze bottle package for dispensing viscous products without belching

A resilient squeeze bottle dispensing package capable of dispensing viscous products without excessive air entrainment and belching on successive dispensing cycles. In a preferred embodiment, the viscous product is preferably suspended inside a resilient squeeze bottle in a thin flexible bag. The flexible bag is secured about its perimeter to the interior of the squeeze bottle at its top and approximately at its midpoint to facilitate both complete emptying of product and desirable suckback characteristics when the opposed squeezing forces ae removed from the resilient outer wall of the bottle. A suckback valve is located between the dispensing orifice in the shroud of the package and the flexible bag to limit the amount of air which can enter the package through the dispensing orifice at the conclusion of each dispensing cycle and to prevent slumping of viscous product remaining in the shroud into the bottom of the flexible bag between dispensing cycles. An air check valve is preferably provided in the bottom of the resilient squeeze bottle to facilitate a pressure buildup within the bottle when opposed squeezing forces are applied thereto.

TECHNICAL FIELD 
The present invention has relation to a resilient squeeze bottle dispensing 
package which is suitable for dispensing viscous products such as 
toothpaste. 
The present invention has further relation to such a dispensing package 
which is easy to use, which is able to dispense the desired amount of 
toothpaste on a toothbrush, which reduces the accumulation of product 
around the dispensing orifice and which regains its original shape after 
each use. 
The present invention has further relation to such a package which 
substantially prevents belching due to air entrainment on successive 
dispensing cycles. 
The present invention has further relation to such a package which is 
capable of upright storage and which exhibits a relatively small 
footprint, thereby minimizing the amount of counter space required. 
Finally, the present invention has relation to such a package which is 
economical to manufacture. 
BACKGROUND OF THE INVENTION 
Viscous materials, such as toothpaste, are commonly packaged in collapsible 
tubes which offer the advantages of low cost and ease of use. However, 
consumer satisfaction with tubes has been limited by their messiness and 
their poor appearance during storage and use. In addition, they can be 
inconvenient to store because they occupy a large area when laid flat. 
More recently, mechanical pumps have been introduced with some success 
because they overcome the negative of poor appearance during use and 
provide ease of storage. However, their acceptance has been somewhat 
limited by poor economy and the difficulties they present in dispensing 
product. 
Conventional squeeze bottles have not been a practical alternative because 
viscous products, such as toothpaste, will not readily flow or drain to 
the dispensing orifice. In addition, the dispensing operation becomes 
increasingly difficult as more and more of the package contents are 
dispensed. This is due to the fact that more and more air is drawn into 
the package as the contents are dispensed. 
Some liquid dentifrice formulations which will flow and which can be 
dispensed from a squeeze bottle without extreme difficulty have been 
introduced in conventional squeeze bottle packages. However, for the most 
part, these products have not been as well received by consumers as the 
more conventional viscous paste formulations which are not easily 
dispensed from a conventional squeeze bottle. 
OBJECTS OF THE INVENTION 
A primary object of the present invention is to provide a resilient squeeze 
bottle package which can easily and reliably dispense viscous products 
such as toothpaste. 
Another object of the present invention is to provide such a resilient 
squeeze bottle package which preserves the advantages of collapsible tubes 
and pumps, while avoiding the major negatives associated with each of 
these prior art package forms. 
It is still another object of the present invention to provide a resilient 
squeeze bottle package exhibiting the following attributes: 
1. Ease of use--easy to hold and physically manipulate the package to 
dispense product; 
2. Control of dispensing--able to dispense the desired amount of viscous 
product on an object such as a toothbrush; 
3. Less mess--reduce the accumulation of product around the dispensing 
orifice; 
4. Neater package appearance throughout use--the package is resilient and 
regains its original shape after each use; 
5. Economy--less costly than the majority of prior art pump dispensers; and 
6. Convenient storage--the package stands upright and has a relatively 
small footprint. 
SUMMARY OF THE INVENTION 
A package in accordance with the present invention contains a viscous 
product, such as toothpaste, in a thin flexible bag which is suspended 
inside a resilient squeeze bottle. The bag is secured about its periphery 
to the interior of the squeeze bottle at its top and approximately at its 
midpoint to facilitate both complete emptying of product from the bag as 
well as desirable suckback characteristics when the squeezing force is 
removed from the bottle. A suckback valve is located between the 
dispensing orifice and the bag to limit the amount of air which can enter 
through the dispensing orifice at the conclusion of each dispensing cycle. 
An air check valve is preferably provided in the resilient squeeze bottle 
to facilitate a pressure build-up between the flexible bag and the 
interior of the bottle when external squeezing forces are applied to the 
bottle. 
When the bottle is squeezed, the air check valve closes. Air pressure 
builds inside the bottle and exerts pressure on the flexible bag and its 
contents, causing the suckback valve to open and viscous product in the 
bag to pass through the suckback valve and be dispensed through the 
dispensing orifice. When the squeezing force on the bottle is released, 
the resilient outer side walls of the squeeze bottle spring back toward 
their undeformed position, carrying the flexible bag secured thereto at 
its midpoint along with them. This action sharply cuts off the flow of 
viscous product from the dispensing orifice and causes air to enter the 
dispensing orifice. It also causes the suckback valve to close, thereby 
limiting the amount of air allowed to enter the package through the 
dispensing orifice. In addition, air is drawn through the air check valve 
which is preferably located in the bottom of the outer container, into the 
space between the bag and the interior of the squeeze bottle. This 
collapses the bottom portion of the bag by an amount substantially 
corresponding to the volume of viscous product dispensed. Limiting the 
amount of air drawn into the dispensing orifice with the suckback valve 
permits subsequent dispensing of product, without belching or spurting due 
to entrained air, on the first squeeze of the bottle.

DESCRIPTION OF THE KAGE 
FIG. 1 is a simplified exploded view of a preferred resilient squeeze 
bottle dispensing package 50 of the present invention. The basic elements 
comprising the package 50 illustrated in their assembled condition in the 
cross-section of FIGS. 2-8 are: 
1. Resilient outer wall 12; 
2. Base 2 to which the lowermost end of resilient outer wall 12 is 
sealingly secured; 
3. Full length flexible inner bag 10 containing viscous product 60 secured 
about its periphery to resilient outer wall 12 at its top edge 14 and at a 
point 11 approximately intermediate the two ends of the resilient outer 
wall; 
4. Suckback valve 30 comprising an orifice plate 32 containing orifices 33 
and 34 and a flex plate 35 containing resilient flaps 36 and 38 which, in 
their closed position, block orifices 33 and 34, respectively; 
5. Means, such as air check valve 1, to regulate the flow of air to and 
from the space 13 existing below the flexible bag 10 and the interior of 
the package 50; 
6. Shroud 22, containing a viscous product dispensing orifice 20; and 
7. Closure member 21 hingedly secured to shroud 22. 
The Resilient Outer Wall of the Package 
The resilient outer wall 12 of package 50 may have any cross-section that 
accommodates the hand of the user. It has been found that an oval 
cross-section, as generally shown in FIG. 3, having a minor axis of about 
3-4 centimeters and a major axis of about 5-6 centimeters is particularly 
well suited for both children and adults to use. The force required to 
deflect the resilient outer wall 12 depends upon several factors 
including: flexural modulus of the materials comprising the outer wall; 
the wall thickness; the cross-section geometry of the wall; the stiffness 
of the flexible bag 10; the viscosity of the product 60 contained in the 
flexible bag 10; the size of the orifices 33 and 34 in orifice plate 32; 
the stiffness of resilient flaps 36 and 38 in flex plate 35; and the size 
of the dispensing orifice 20 in shroud 22. The resilient outer wall 12 is 
preferably made from a resilient plastic, e.g., low density polyethylene, 
and may be formed by any of several common methods of plastic molding. For 
example, it may be blow molded, injection molded or extruded. In a 
particularly preferred embodiment it is comprised of a material capable of 
being heat sealed to the various other components of the package. 
The Base 
The base 2 is preferably sealingly secured to the lowermost end of the 
resilient outer wall 12 by any of several means well known in the art, 
e.g., adhesive, heat sealing, mechanical interlocking or the like. The 
lowermost portion of the base 2 preferably comprises a pedestal which 
provides a flat surface for standing the package 50 erect in a medicine 
chest or on a countertop. In the illustrated embodiment, the base 2 
includes a recesed groove 4 having an exterior dimension substantially 
coinciding with the interior dimension of the lowermost end of resilient 
outer wall 12 to permit easy joinder of the base to the lowermost end of 
the outer wall. Located near the center of the base 2 is a vent hole 3 for 
admitting air into the package after a dispening cycle has been completed. 
Immediately adjacent vent hole 3 is a second hole 6 into which the base 8 
of a resilient check valve 1 is inserted to secure the check valve in 
position on the base of the container. A raised ring 5 slightly larger in 
diameter and taller in height than the uppermost portion of check valve 1 
is preferably molded about apertures 3 and 6 to prevent the lowermost 
surface of the flexible bag 10 from interfering with the operation of the 
check valve 1 during dispensing, particularly while the bag is full or 
nearly full. 
The Flexible Inner Bag 
The flexible inner bag 10 containing the viscous product 60 to be dispensed 
can be formed by rolling a sheet of flat flexible stock over on itself and 
forming a lap seal along its length. The outside cross-sectional 
dimensions of the fully expanded bag are preferably substantially equal to 
the inside cross-sectional dimensions of the undeformed resilient outer 
wall 12 of the package. The lower end of the flexible bag 10 is preferably 
sealed with a gusset so that the width of the seal is no greater than the 
internal cross-section of the resilient outer wall 12 of the package when 
the outer wall is in its undeformed condition. 
Alternatively, if increased drop strength is desired in the package, the 
flat stock can be folded upon itself to form the bottom of the flexible 
bag 10 and a pair of substantially parallel side seals can be made. The 
flexible bag 10 thus formed exhibits an integral bottom and a pair of 
face-to-face side seals. 
The full length flexible bag 10 shown in Drawing FIGS. 1-8 is preferably 
placed inside the resilient outer wall 12 of the package and secured at 
its top edge 14 to the uppermost end of the resilient outer sidewall 12. 
In addition the flexible bag 10 is secured to the interior of the 
resilient outer wall 12 approximately at its midpoint 11. The top seal is 
continuous about the periphery of the bag to prevent loss of viscous 
product, while the midpoint seal can be continuous or discontinuous, i.e., 
no leakage will occur from the bag at this point even if the bag is not 
joined to outer wall 12 about its entire periphery. Midpoint securement of 
the flexible bag 10 to the resilient outer wall 12 not only insures 
substantially complete emptying of the viscous product 60 from the 
package, but in addition, aids the suckback action at the conclusion of 
each dispensing cycle. This in turn provides sharp cut-off of viscous 
product at the dispensing orifice 20 as well as a drawing back of air into 
the dispensing orifice of the package at the end of each dispensing cycle, 
i.e., the resilience of the outer wall 12 is effectively imparted to the 
flexible bag 10 due to the area of securement 11 at the approximate 
midpoint of the bag. Accordingly, the package attempts to create a void 
corresponding to the dispensed product within the flexible bag 10 almost 
instantaneously upon removal of the opposing squeezing forces "F" shown in 
FIG. 4. 
In still another resilient squeeze bottle package embodiment 150 of the 
present invention illustrated in the partial cross-sectional view of FIG. 
9, the flexible bag 110 can be approximately half the overall length of 
resilient outer wall 12, and its top 114 sealingly secured to the interior 
of the outer wall at the approximate midpoint of the outer wall. This seal 
must be continuous to prevent leakage of product at the point of joinder 
between the top 114 of the bag 110 and the outer wall 12. While the half 
bag package embodiment 150 shown in FIG. 9 will dispense viscous product 
60 in substantially the same manner as the full length bag package 
embodiment 50 shown in FIGS. 1-8, the full length bag embodiments are 
generally preferred when handling viscous products requiring barrier 
protection during storage. Use of the half bag embodiment in such 
situations would require imparting barrier properties to both the bag and 
the product contacting surfaces of resilient outer wall 12. 
Filling of the full length flexible bag 10 of package embodiment 50 or the 
half length bag 110 and the upper portion of the resilient outer side wall 
12 of package embodiment 150 with viscous product 60 can be performed 
after the bag has been secured to the innermost surface of the resilient 
outer wall 12 and before the addition of suckback valve 30 and shroud 22 
to the package. The base 2, including the air check valve 1, is preferably 
sealingly secured to the lowermost end of the resilient outer wall 12 
before filling to permit standing the open topped outer wall and the 
flexible bag sealingly secured thereto erect during the filling and final 
assembly operations. 
The material for the flexible bag 10 preferably exhibits a low flexural 
modulus so that the bag can be readily flexed as viscous product 60 is 
dispensed. This minimizes any contribution to the force required to 
squeeze the package and dispense product. In addition, because the bag is 
preferably sealed to itself as well as to the resilient outer wall 12 at 
its top and midpoint, the bag material is preferably readily heat sealable 
for ease of assembly. 
For products that require a barrier to prevent losses from the product, 
e.g., flavor or perfume or other active ingredients, the barrier may be 
incorporated as a layer in the flexible bag 10. Because the bag material 
may need to possess several different characteristics, the use of a 
multi-layered laminate film may be particularly suitable. One particularly 
preferred laminate structure for a multi-layered flexible bag material 
which has been found satisfactory for housing dentifrice paste comprises 
the following layers, listed in the order of outer surface to inner 
surface: 
1. Polyethylene layer--0.0010 inches; 
2. Metalized aluminum coating--thickness incapable of measurement by 
conventional means; 
3. Polyethylene terephthalate--0.0005 inches; and 
4. Polyethylene--0.0010 inches. 
The particular material selected for flexible bag 10 will, of course, be 
dependent upon the particular character and needs of the viscous product 
60 to be dispensed, the expected shelf life for the viscous product 60 
prior to and during consumption, the anticipated strength needs of the 
package and the type of sealing operations to be employed. 
The Suckback Valve 
The suckback valve 30 serves several functions. In a highly preferred 
embodiment it contributes to creating suckback at the dispensing orifice 
20 in the shroud 22 as soon as the opposed squeezing forces "F" are 
removed from the package, it substantially controls the volume of air 
allowed to enter the dispensing orifice 20 during the recovery cycle of 
the resilient outer wall 12 to its substantially undeformed condition, and 
it substantially prevents the entry of air into the product contained 
within the flexible bag 10 over extended periods of time between 
dispensing cycles even if the closure 21 is not reapplied to seal the 
dispensing orifice 20. This not only prevents dryout of the viscous 
product 60 contained within the flexible bag 10, but in addition, 
minimizes the slumping of product from the shroud 22 into the bottom of 
the bag between dispensing cycles. 
By permitting only a limited volume of air to be drawn into the dispensing 
orifice 20 at the end of each dispensing cycle and by preventing slumping 
of product from the shroud 22 into the bottom of the flexible bag between 
dispensing cycles, the succeeding dispensing cycle can normally be 
initiated with only a single squeeze on the resilient outer wall 12 of the 
package 50 without any appreciable belching due to entrained air within 
the viscous product being dispensed. 
In the illustrated embodiment, the suckback valve 30 comprises an orifice 
plate 32 containing orifices 33 and 34. A flex plate 35 is secured over 
the top of orifice plate 32. Flex plate 35 contains a pair of oppositely 
oriented resilient flaps 36 and 38 which, in their fully closed position, 
block orifices 33 and 34, respectively, in orifice plate 32. The suckback 
valve 30 illustrated in the accompanying Drawing Figures provides a large 
flow area when resilient flaps 36 and 38 are in their open position. This 
minimizes the pressure drop across the valve as the viscous product 60 is 
being dispensed. In addition, suckback valve 30 helps to transport a 
substantially constant volume of viscous product 60 from the shroud 22 
back to flexible bag 10 each time it moves from its fully open position, 
as shown in FIG. 4, to its fully closed position, as shown in FIG. 5. This 
volume of product is essentially equivalent to the volume swept by the 
flexible flaps 36 and 38 as they move from their fully open to their fully 
closed position. This constant volume closing characteristic of preferred 
suckback valve 30 helps to ensure that a substantially constant volume of 
air is drawn back into dispensing orifice 20 at the conclusion of each 
dispensing cycle, regardless of how much viscous product 60 is dispensed 
during the cycle or how much viscous product 60 is remaining within the 
flexible bag 10. As mentioned earlier herein, suckback valve 30 thereby 
helps to provide substantially constant dispensing characteristics with a 
single squeeze of the resilient outer wall 12. 
As will be appreciated by those skilled in the art, the exact physical 
configuration of the suckback valve is not critical. However, the same 
basic operational characteristics described in relation to the illustrated 
suckback valve 30 are preferably provided by whatever valve configuration 
is ultimately selected. 
The Air Check Valve 
In order to ensure that pressure is exerted on viscous product 60 contained 
within flexible bag 10 whenever opposed squeezing forces "F" are applied 
to the resilient outer wall 12 of the package 50, there needs to be some 
means of stopping or at least limiting the flow of air from the area 13 
between the bottom of the flexible bag 10 and the interior of the package 
50. While a resilient air check valve 1 has been shown in the illustrated 
embodiment, the use of a check valve is not absolutely essential. If 
desired for reasons of economy, a small diameter hole which throttles the 
flow of air to and from the area in question will serve substantially the 
same function. As the package is squeezed, the escape of air needs to be 
slow enough that pressure builds within flexible bag 10 and viscous 
product 60 is dispensed from the bag before an appreciable amount of air 
is lost from area 13 of the package. If desired, the hole could even be 
positioned so that it is blocked by the user's hand or finger during the 
dispensing operation. 
Resilient air check valve 1 is particularly preferred, because the 
application of pressure in area 13 of the package will cause the uppermost 
portion of resilient air check valve 1 to seat tightly over the area of 
the base 2 containing vent hole 3, thereby substantially preventing the 
escape of air from the package while the opposed squeezing forces "F" are 
being applied. Once the opposed squeezing forces "F" are removed from 
resilient outer wall 12, the negative pressure created within area 13 as 
the resilient outer wall 12 attempts to return to its substantially 
undeformed condition will lift the uppermost portion of resilient air 
check valve 1 away from the base 2 of the package, thereby allowing air to 
readily enter area 13 through vent hole 3. Thus, vent hole 3 can be sized 
large enough to allow reasonably quick recovery of the resilient outer 
wall 12 upon removal of the opposed squeezing forces "F" from the package. 
If a small hole is utilized to restrict the flow of air in both directions 
in lieu of the check valve 1, return of the resilient outer wall 12 to its 
fully undeformed condition may be slowed, thereby requiring the user to 
wait for a few seconds before applying another squeezing force to dispense 
additional viscous material 60 from the package. 
The Shroud and Dispensing Orifice 
The shroud 22 is preferably secured to the uppermost end of the resilient 
outer wall 12 in such a manner that it retains suckback valve 30 secured 
in position between the uppermost end 14 of flexible bag 10 and the 
dispensing orifice 20 located at the uppermost tip of the shroud. The 
particular means employed to secure shroud 22 in position is not critical, 
and can comprise conventional adhesives, interlocking flanges, heat 
sealing or the like. As can be seen in FIGS. 2-8 the shroud 22 secures 
flex plate 35 immediately adjacent the uppermost surface of orifice plate 
32, such that resilient flaps 36 and 38 in the flex plate will 
substantially block orifices 33 and 34, respectively, in the orifice plate 
32 when the package is in an undistored, equilibrium condition. 
In a particularly preferred embodiment, the interior surface of shroud 22 
also includes a pair of stop members 41 and 42 which limit the amount of 
travel of resilient flaps 36 and 38 can undergo, thereby defining their 
fully open position. This helps to ensure that the volume of product swept 
by the resilient flaps when they move from their fully open to their fully 
closed position remains substantially constant throughout the useful life 
of the package 50. 
A dispensing orifice 20 is provided at the uppermost tip of the shroud 22. 
The size and cross-sectional shape of the dispensing orifice 20 will, of 
course, depend upon such factors as the intended end use for the viscous 
material 60 to be dispensed and the surface onto which the material is to 
be dispensed. For a material such as dentifrice, a cylindrical dispensing 
orifice 20 having an inner diameter of approximately one quarter inch has 
been found to work well for dispensing an appropriate size ribbon of 
dentifrice paste onto the surface of a conventional toothbrush. 
The Closure Member 
In the resilient squeeze bottle dispensing package 50 illustrated in the 
accompanying Drawing FIGS. 1-8, a hingedly connected closure member 21 has 
been illustrated. The hingedly connected closure member 21 preferably 
includes means for establishing a airtight seal with the dispensing 
orifice in its closed position as well as an access lip, such as 23, to 
permit easy opening to initiate dispensing. While it is not a requirement 
that the closure member 21 be secured to the shroud 22 by means of a hinge 
24, as shown in Drawing FIGS. 1-8, this form of attachment prevents loss 
of the closure member 21 between dispensing cycles, thereby providing 
greater convenience for the end user. In addition, it makes it more likely 
that the closure member will indeed be closed at the end of each 
dispensing cycle, thereby minimizing the chance of air being allowed to 
dry out the viscous product 60 contained within shroud 22 above the 
suckback valve 30. 
As will be appreciated by those skilled in the art, the particular closure 
member selected is non-critical. Conventional screw thread closures, 
snap-on closures, plug-type closures or the like could be utilized with 
equal facility without affecting the dispensing characteristics of the 
present resilient squeeze bottle dispensing package. In still another 
embodiment of the present invention a secondary valve could be provided at 
the dispensing orifice to minimize the possibility of viscous product 
dry-out in the uppermost portions of the package between dispensing 
cycles. While the particular type of valve employed is non-critical, it 
should permit viscous product 60 to be discharged without creating 
significant pressure build up. In addition, it should permit air to enter 
the dispensing orifice 20 until the suckback valve 30 has closed. Such a 
valve 121 is schematically illustrated in cross-section secured across the 
dispensing orifice 20 of shroud 22 in the package embodiment 150 shown in 
FIG. 9. 
The Dispensing Cycle 
FIGS. 4, 5 and 6 show an initial dispensing cycle for a resilient squeeze 
bottle dispensing package 50 of the present invention. FIG. 7 shows the 
condition which exists within the package intermediate the initial 
dispensing cycle shown in FIGS. 4-6 and the next dispensing cycle shown in 
FIG. 8. 
FIG. 4 illustrates the condition existing when a resilient squeeze bottle 
dispensing package 50 is initially placed in service by the consumer. In 
particular, opposed squeezing forces "F" are applied in a direction 
substantially parallel to the minor axis of the resilient outer wall 12 of 
the package. This increases the air pressure inside the package within 
area 13 below the flexible bag 10, thereby causing resilient air check 
valve 1 to seal against the base 2. This blocks the escape of air through 
vent hole 3 in the base of the package. The opposed squeezing forces "F" 
therefore increase the pressure on viscous product 60 contained within 
flexible bag 10. The increased pressure of the viscous product 60 causes 
the resilient flaps 36 and 38 of suckback valve 30 to move from their 
fully closed to their fully open position, as generally shown in the 
cross-section of FIG. 4. Viscous product 60 flows through the orifices 33 
and 34 in orifice plate 32 and enters the interior of the shroud 22. From 
there, the viscous material 60 passes through dispensing orifice 20 in the 
form of a ribbon which, in the case of a dentifrice paste, is normally 
deposited onto the uppermost surface of a toothbrush 90, as shown in FIG. 
4. 
Once the desired amount of viscous product 60 has been applied to the 
surface of the toothbrush 90, the opposed squeezing forces "F" are removed 
from the resilient outer wall 12 of the package. Because the flexible bag 
10 is secured about its periphery to the innermost surface of the 
resilient outer wall 12 at area 11, the resilience of the outer wall 12 is 
effectively imparted to the flexible bag 10. 
The action of the resilient outer wall 12 in attempting to return to its 
undeformed condition causes an immediate cessation of product discharge 
through the dispensing orifice 20 as well as an opening of the air check 
valve 1 in the base 2 of the package 50. The suckback action created 
within the flexible bag 10 causes a portion of the paste contained within 
the shroud 22 to be drawn back inside the flexible bag 10. This, in turn, 
causes air to be drawn into the dispensing orifice 20 as generally shown 
in the cross-section of FIG. 5. However, the amount of air which can be 
drawn back into dispensing orifice 20 is controlled by the suckback valve 
30, i.e., when the resilient flaps 36 and 38 sweep from their fully open 
to their fully closed position, a predetermined volume of viscous product 
is reintroduced into the flexible bag 10. As soon as the flaps 36 and 38 
block orifices 33 and 34, respectively, in orifice plate 32, there is no 
further tendency to draw in additional air through the dispensing orifice 
20. Accordingly, only a limited and substantially constant volume of air 
is drawn into the dispensing orifice 20 at the conclusion of any given 
dispensing cycle. In addition, closure of suckback valve 30 substantially 
prevents slumping of the viscous product contained within shroud 22 into 
the bottom of the flexible bag 10. Both of these actions minimize the 
tendency toward belching due to entrained air on subsequent dispensing 
cycles. In addition, packages of the present invention permit almost 
immediate dispensing in response to a single subsequently applied 
squeezing force, since viscous product 60 substantially fills the interior 
of shroud 22. 
As mentioned earlier herein, the resilience of outer wall 12 also causes 
the uppermost portion of check valve 1 to move inwardly, thereby breaking 
its seal against the base 2 of the package. This allows atmospheric air to 
enter the interior of the package in area 13 through vent hole 3, thereby 
causing the flexible bag 10 to move upwardly within the package, as 
generally shown in FIG. 6. 
After the intial dispensing cycle, the hingedly connected closure member 21 
is normally closed over the dispensing orifice 20, as generally shown in 
FIG. 7, and the package is stored in a substantially upright position on 
its base 2 until it is desired to dispense more viscous product 60 from 
the package. Because the suckback valve 30 prevents slumping of the paste 
contained within shroud 22 into the flexible bag 10, the void space 
existing at the dispensing orifice 20 does not increase appreciably 
intermediate dispensing cycles. This ensures that the subsequent 
dispensing cycle shown generally in FIG. 8 will again produce a 
substantially instantaneous discharge of viscous product 60 as soon as 
opposed squeezing forces "F" are again applied to the resilient outer wall 
12 of the package. 
Because of the sharp product cut-off and suckback characteristics provided 
at the dispensing orifice 20, resilient squeeze bottle package 50 remains 
substantially clean throughout successive dispensing operations from the 
time the package is initially placed in service until substantially all of 
the contents have been dispensed therefrom. By securing the flexible bag 
10 to the resilient outer wall 12 substantially at the midpoint 11 of the 
bag, successive dispensing cycles cause the bag to gradually invert upon 
itself, thereby discharging substantially all of the viscous product 60 
initially contained therein. 
To ensure that the consumer is able to utilize substantially all of the 
viscous product 60 contained in the resilient squeeze bottle package 50, 
the interior volume of shroud 22 is normally limited to: (1) that which is 
required to ensure proper operation of resilient flaps 36 and 38 of 
suckback valve 30; and (2) that which is required to substantially prevent 
entry of air into the flexible bag 10 as the resilient flaps 36 and 38 are 
moving from their fully open to their fully closed position. 
As a further aid to utilizing all of the available viscous product 60 
within resilient squeeze bottle package 50, the shroud 22 can be formed of 
a manually deformable material which can be squeezed to empty the contents 
of the shroud 22 after the flexible bag 10 has been emptied. 
While the present invention has been described in the context of a 
resilient squeeze bottle dispensing package particularly well suited for 
dispensing dentifrice paste, it is recognized that the present invention 
may be practiced to advantage in many other environments where controlled 
dispensing of a viscous product is desired. It is further recognized that 
the specific design of many of the structural elements employed may vary 
from one application to another. It will be obvious to those skilled in 
the art that various changes and modifications can be made to the present 
resilient squeeze bottle dispensing package without departing from the 
spirit and scope of the invention, and it is intended to cover in the 
appended claims all such modifications that are within the scope of this 
invention.