Cartridge for containing and dispensing viscous material

A cartridge for containing and dispensing caulking compound comprises an elongated tubular member, generally cylindrical in configuration, one end of which has a fixed end wall including a dispensing opening therethrough and a spout attached to the end wall, while the other end of the tubular member is closed by a resilient, annular, floating member slidably mounted within the tubular member. The floating member is impervious and is made of a flexible material. When employed in conjunction with a standard caulking gun of the plunger type, the force of the plunger bears directly on the floating member which thereby expands in diameter and decreases in width and transmits pressure to the caulking for dispensing. When the plunger is suddenly withdrawn, the expansion of the floating member effectively absorbs the pressure forces within the cartridge thereby minimizing the amount of undesirable leakage of the caulking from the cartridge.

BACKGROUND OF THE INVENTION 
This invention relates to an improved cartridge for containing and 
dispensing viscous material such as caulking compound. These cartridges 
are in widespread use and quite familiar to the average homeowner, who at 
one time or another must seal or weather-proof a surface in his home. 
Generally, the cartridges are comprised of a cylindrical tube having at one 
end a fixed circular wall. This fixed wall has a discharge opening which 
is covered by a frangible seal to prevent leakage of the material 
contained in the tube, and also to prevent the material from being exposed 
to air before the cartridge is used. A spout or nozzle is attached to the 
fixed end wall for easy application of the caulking. The other end of the 
tube is usually closed by a flat circular piston slidably mounted in the 
tube. 
Cartridges are usually used in combination with a dispensing gun having a 
plunger by which pressure is applied to the material in the tube. The 
plunger presses against the slidable piston of the tube pushing it through 
the tube thereby causing the material to discharge. 
One shortcoming that has been associated with known dispensing cartridges 
is the undesirable discharge of material that continues even after the 
plunger has been withdrawn. This excess discharge is generally caused by 
pressures built up in the viscous material when the plunger applies a 
force to it. 
Several methods have been devised to cope with this shortcoming. One method 
employs a cartridge having a shut off nozzle. This cartridge has a fixed 
end wall and a closure disc carried by the nozzle. Each have a discharge 
opening formed therein. By rotating the nozzle relative to the fixed end 
wall the openings are brought into alignment to allow discharge of 
material. To stop the flow of material the nozzle is rotated so that the 
discharge openings are not aligned. 
Another known cartridge employs valves to control the discharge of 
material. Depending on whether the valves are open or closed the material 
in the cartridge may or may not be discharged. 
With the above two devices manipulation by means of rotating a nozzle or 
closing valves is required to stop the flow of material. Though this extra 
manipulation is only a minor inconvenience it would be preferable for a 
cartridge to be able to stop the flow of material by merely pulling back 
the plunger. In addition, it would be preferable to keep the cartridge, as 
well as the dispensing gun, as simple in construction as possible, having 
fewer parts that may malfunction or increase the cost of the cartridge. 
One device that attempts to accomplish this is a cartridge that uses a 
flexible member of semi-spherical configuration instead of a flat piston. 
In operation the plunger of the gun presses against the semi-spherical 
member thereby flattening the member. Application of additional pressure 
forces the member through the tube causing the material therein to be 
discharged. Theoretically when the plunger is released the forces in the 
tube act in the direction of the spherical member to restore it to its 
original configuration, rather than in the opposite direction to force 
material out of the tube. In practice, however, this device has been found 
not to be a fool-proof method of preventing unwanted discharge because 
only a small area of the semi-spherical member is displaced by the 
pressure of the plunger. Accordingly, only a portion of the energy 
accumulated in the material is dissipated in restoring the semi-spherical 
member to its original configuration. In addition, because the 
semi-spherical member is in tight contact with the inner surface of the 
cartridge at all times, it is easier for the forces in the viscous 
material to act to discharge the material than it is to move the 
semi-spherical member back. As a result the remaining energy causes 
leakage of the material from the cartridge. 
It is an object of the invention to overcome the shortcomings of the prior 
art and to provide a cartridge for containing and dispensing viscous 
material which is simple in construction and in which the viscous material 
will substantially stop flowing when the plunger is pulled, and which does 
not require rotation or manipulation of additional parts. 
It is a further object of this invention to provide a cartridge for 
containing and dispensing viscous material which is inexpensive to 
manufacture and simple to operate. 
SUMMARY OF THE INVENTION 
The subject invention relates to a new and improved cartridge for 
containing and dispensing a viscous material such as caulking compound. 
The cartridge is comprised of an elongated tubular member, generally 
cylindrical in configuration. One end of the tubular member has a fixed 
end wall, having a dispensing opening therethrough, and a spout attached 
to the end wall. The other end of the tubular member is closed by a 
resilient, annular, floating member which is slidably mounted within the 
tubular member. The floating member is preferably made of sponge rubber, 
sponge plastic, silastic or other suitable material. 
In the preferred embodiment, the floating member has a plurality of annular 
wipers or scrapers on its outside diameter. When pressure is applied to 
the floating member, its width decreases and its diameter increases, 
forcing the annular wipers into tight contact with the inner surface of 
the tubular member. Further pressure advances the floating member through 
the tubular member causing the material contained therein to discharge 
through the spout. When the pressure is removed, the floating member 
reverts to its original width and diameter thus removing the wipers from 
tight contact with the inner surface of the tubular member. As a result 
the pressure accummulated in the material contained in the tubular member 
acts to push the floating member back. Because it takes less energy to act 
on the floating member than it does to force the material through the 
dispensing opening, little or no further discharge of material occurs once 
the pressure has been removed from the floating member.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
FIG. 1 is an exploded perspective view of the cartridge 1, floating member 
2, and dispensing gun 3 of the subject invention. The dispensing gun 3 is 
one that is in common use today. It includes a handle 4, an elongated 
semi-cylindrical chamber member 5 extending forwardly from the handle 4, a 
front wall 6 fixed to the outer end of the chamber member 5, a plunger 7, 
and a trigger assembly 8 engageable with the plunger 7 for advancing the 
plunger 7 in the chamber 5. 
The cartridge 1 includes an elongated tubular member 9, generally 
cylindrical in configuration. This member 9 is standard in existing 
cartridges and may be made of paperboard, plastic or other suitable 
material. At one end of the tubular member 9 is a fixed end wall 10 having 
a dispensing opening 11, covered by a frangible seal. This seal prevents 
leakage of the viscous material from within the cartridge 1, and also 
prevents the material from being exposed to air before the cartridge 1 is 
used. Attached to the fixed end wall 10 is a spout 12 through which the 
material contained in the cartridge 1 may be discharged. The front end 
wall 10 and the spout 12 may be made from plastic or any other suitable 
material. 
The back end of the tubular member 9 is closed by a resilient floating 
member 2 which is annular in configuration. In one preferred embodiment 
the floating member 2 is hollow and may be made from plastic, rubber or 
other suitable material. In another preferred embodiment the floating 
member 2 may be a collapsible resilient body of sponge plastic, sponge 
rubber or other similar material. Referring to FIG. 2 the upper and lower 
surfaces of the floating member 2 may preferably be sloped 4.degree. from 
the horizontal. This will facilitate entry of the floating member 2 into 
the cylinder 9. 
Further referring to FIG. 2 the floating member 2 has a plurality of 
annular wipers or seals 13 on its exterior diameter. The function of these 
wipers will later become apparent. 
In operation, when it is desired to use the caulking cartridge 1, the 
frangible seal of the fixed end wall 10 of the cartridge 1 is punctured, 
and the cartridge 1 is mounted in the semi-cylindrical chamber member 5 of 
the dispensing gun 3, with the plunger 7 of the gun 3 bearing against the 
floating member of the cartridge 2. As depicted in FIG. 3 the floating 
member 2 has a width W.sub.1 before the plunger 7 is actuated. To 
discharge the material in the cartridge 1, the trigger assembly 8 of the 
caulking gun 3 is actuated thereby causing the plunger 7 to press against 
the floating member 2. As a result of its configuration and resilience, 
the width of the floating member 2 is reduced to W.sub.2. Simultaneously, 
the diameter of the floating member 2 expands, pressing the wipers 13 
tightly against the inner surface of the tube 9. Continued force by the 
plunger 7 advances the floating member 2 through the tube 9, thereby 
forcing the material in the cartridge 1 to discharge. As the floating 
member 2 advances through the tube 9 the annular wipers 13 scrape the 
inner surface of the tube 9 so that all of the material contained therein 
is advanced as well. 
When it is desired to stop the flow of the caulking from the cartridge 1 
the plunger 7 of the caulking gun 3 is quickly withdrawn. As a result of 
the elimination of pressure by the plunger 7, the floating member 2, 
because of its resilience, reverts to its original configuration having a 
width W.sub.1. Simultaneous to this action, the diameter of the floating 
member decreases to its original size, thus removing the wipers 13 from 
tight contact with the inner surface of the tube 9. As a result, the 
forces accumulated within the material contained in the cartridge 1 can 
act to move the floating member 2 back. Because it takes less energy to 
act on the floating member 2 than it does to continue to force the 
material out the discharge opening 11 and spout 12, little or no further 
discharge of material occurs. All the energy within the material in the 
cartridge 1 is dissipated in acting upon the floating member 2. 
Although the cartridge 1 of the subject invention is described as having 
the floating member 2 as an integral part thereof, it is conceivable that 
the floating member 2 is distinct from the cartridge 1, with the cartridge 
1 having merely a frangible seal closing its back end. 
In summary, the subject invention provides a new and improved device for 
containing and dispensing viscous material. It is simple in construction 
and may be economically manufactured. Because of its construction it 
effectively eliminates any unwanted discharge of material once the plunger 
has been withdrawn. Unlike some existing devices no additional parts such 
as a shut-off nozzle or valves, and consequently no rotation or 
manipulation thereof is required to effectively control the flow of 
material. In addition, the subject invention is a more effective means of 
stopping unwanted discharge than the cartridge employing a semi-spherical 
piston member. It employs a floating member of such configuration that it 
is in tight contact with the inner surface of the cartridge only when 
pressure is being applied to ti by a plunger. When the plunger is 
withdrawn, the floating member decreases in diameter removing it from 
tight contact with the cartridge. As a result, it is easier for the forces 
in the viscous material to move the floating member back than it is to 
discharge material through the spout. There is virtually complete 
dissipation of the energy in the viscous material and little or no 
unwanted discharge through the spout. Further, there is a much greater 
area of displacement in the floating member of the subject invention than 
there is in the semi-spherical piston member, and hence greater ability to 
dissipate the energy in the viscous material. 
While there have been described herein what are at present considered 
preferred embodiments of the invention, it will be obvious to those 
skilled in the art that many modifications and changes may be made therein 
without departing from the essence of the invention. It is therefore to be 
understood that the exemplary embodiments are illustrative and not 
restrictive of the invention, the scope of which is defined in the 
appended claims, and that all modifications that come within the meaning 
and range of equivalency of the claims are intended to be included therein 
.