Dispensing – With discharge assistant – Plural
Reexamination Certificate
2002-07-02
2004-12-28
Derakshani, Philippe (Department: 3754)
Dispensing
With discharge assistant
Plural
C222S387000, C222S517000, C141S357000
Reexamination Certificate
active
06834780
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to the field of dispensers. More particularly, the invention relates to a paste dispenser, wherein a dispenser head may be actuated and paste may be dispensed in metered fashion with the use of only one hand. A rigid container for the paste is employed within which a unit is displaceable based on a pressure differential between the interior and exterior of a pumping chamber.
BACKGROUND OF THE INVENTION
Toothpaste is a well known dentifrice that effectively prevents tooth decay. Toothpaste is generally contained in a collapsible tube and is applied to a toothbrush to facilitate the cleaning of teeth. Several drawbacks are associated with the usage of a conventional tube for the dispensing of toothpaste therefrom. Since toothpaste is dispensed by squeezing the tube, a significant amount of toothpaste remains in the tube due to the inability of deforming the tube to such an extent so as to allow for the removal of the entire amount of the semi-fluid material. Also, an uncontrollable amount of toothpaste may be applied to a toothbrush, often resulting in unnecessary waste. At times, the cap of the toothpaste tube is misplaced and a significant amount of toothpaste is liable to dry, proximate to the aperture through which the toothpaste is released. Furthermore, the application of toothpaste to a toothbrush is an awkward procedure, in which two hands are generally needed for accurate and speedy dispensing.
Numerous prior art toothpaste dispensers, which overcome some of the aforementioned drawbacks, are known. For example, GB 2150105 discloses a dispenser that incorporates a means for mounting and moving a collapsible container relative to an evacuating means. Upon insertion of a toothbrush into a recess, a closure arm bears against an dispenser head lever, thereby moving the container a predetermined distance by the interengagement of a pinion and rack. DE 19808864 discloses an apparatus that includes a slide which is horizontally displaced upon insertion of a toothbrush, whereby a protrusion carried by the slide engages another member which uncovers the aperture through which toothpaste is dispensed. The slide is also provided with teeth which are engageable with a ratchet-toothed gear, the rotation of which causes rollers to squeeze a toothpaste tube. DE 3417312 is directed to a metering device which comprises a stationary housing part and a movable housing part. By pivoting the movable housing part relative to the stationary housing part, an actuating element is pressurized so that the required quantity of the substance to be metered is dispensed. U.S. Pat. No. 5,975,362 discloses a dispenser which comprises a rotatable power source for rotating a pair of pinch rollers, which move along a toothpaste tube to collapse a portion of the tube to thereby dispense toothpaste. All of these references are characterized by having a relatively large number of moving parts, resulting in a higher cost and a higher chance of malfunction.
U.S. Pat. No. 3,088,636 discloses a dispenser for a fluent mass, which is discharged therefrom as the effective volume of the container forwardly of a piston means is decreased, after which the volume is increased to create a partial vacuum, thereby allowing atmospheric pressure rearwardly of the piston means to act thereon and to move it forwardly in the container, so that the effective volume of the container is again decreased.
U.S. Pat. No. 3,268,123 provides a similar dispenser, without application of pressure to the fluent mass during the initial phase of decreasing the effective volume forward of the piston means. The device comprises means for resisting movement of the piston means in a rearward direction while permitting its movement in a forward direction within the container. Similar arrangements are taught in e.g. U.S. Pat. Nos. 4,978,037, 4,991,744 and 6,047,862.
Dispensers having a flexible membrane, which is flexed by means of a dispenser head following the depressing thereof, so that the membrane is longitudinally displaced in a rearward direction to allow for the decreasing of the effective volume of the container, are taught in e.g. U.S. Pat. No. 4,691,847, GB 2,161,222, U.S. Pat. No. 4,776,496, U.S. Pat. Nos. 4,936,493, 4,962,851. Paste is dispensed from the dispensers of the aforementioned citations with the use of two hands, and is at times an awkward procedure.
FIG. 1
schematically illustrates a toothpaste dispenser described in U.S. Pat. No. 6,047,862. In
FIG. 1
said dispenser is generally designated by
5
and is provided with reservoir
2
, pump head
3
and dispensing orifice
7
. Closure
8
generally covers nozzle
7
, and is separated therefrom during the dispensing of toothpaste. Reservoir
2
is cylindrical and contains toothpaste within pumping chamber
6
, defined by the region between pressurizing means
9
and a follower piston, generally designated by
15
. Distal end
10
of the dispenser which may have a larger outer diameter than container
2
, is adapted to admit air to the distal end of unit
15
. Toothpaste does not come in contact with air, and therefore cannot dry.
An exploded drawing of an exemplary incrementally displaceable unit
15
is shown in FIG.
2
. Unit
15
comprises three elements: piston
18
, clamp module
27
and disc
32
. Piston
18
is described in detail in U.S. Pat. No. 4,978,037, and is provided with a plurality of circumferential fields
19
and
20
, wherein each adjacent field is separated by a radially oriented groove
22
and
23
, respectively. Each field
20
is disposed closer to the outer wall of centrally disposed seat
13
than a corresponding field
19
. The piston is provided with distal lip
25
and proximate lip
26
. Lips
25
and
26
have an outer diameter substantially equal to the inner wall of a tubular paste container and serve as a seal.
By means of clamp module
27
, unit
15
is displaceable in only one direction, i.e. towards dispenser head
3
, after dispenser
5
has been loaded with toothpaste. Clamp module
27
is shaped in the form of a star, with radially oriented prongs
29
interspersed between circumferential spacers
30
, and is made of spring steel. The center of clamp module
27
is formed with aperture
31
having a diameter substantially equal to the outer wall of seat
13
. Aperture
31
allows the clamp module to be pressed fit with diaphragm
18
, such that each spacer
30
contacts distal lip distal lip
25
. The diameter spanned by the ends of prongs
29
is slightly larger than the inner wall of container
2
, and since the prongs are angled in a direction away from distal lip
25
, displacement of unit
15
in a direction away from dispenser head
3
is prevented.
Disc
32
is the means by which unit
15
is displaced, as will be described hereinafter. Disc
32
is planar and circular, and is provided with peg
34
protruding from the proximate side thereof. Peg
34
is insertable within seat
13
, so that disc
32
is carried by piston
18
as the latter is displaced.
All the methods described above have not yet provided satisfactory solutions to the problem of providing an inexpensive toothpaste dispenser with a minimal number of moving parts, which can apply toothpaste to a toothbrush by the use of only one hand and capable of dispensing a metered amount of toothpaste.
It is an object of the present invention to provide a toothpaste dispenser which can apply toothpaste to a toothbrush by the use of only one hand.
It is an additional object of the present invention to provide a toothpaste dispenser which is capable of dispensing a metered amount of toothpaste.
It is an additional object of the present invention to provide a toothpaste dispenser which is inexpensive with a minimal number of moving parts.
It is a further object of the present invention to provide a toothpaste dispenser wherein the toothpaste cannot dry.
Other objects and advantages of the invention will become apparent as the description proceeds.
SUMMARY OF THE INVENTION
The present invention relates to an improved dispenser
Browdy and Neimark , P.L.L.C.
Derakshani Philippe
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