Surgery – Means for introducing or removing material from body for... – Treating material introduced into or removed from body...
Reexamination Certificate
1999-12-06
2001-09-04
Kennedy, Sharon (Department: 3763)
Surgery
Means for introducing or removing material from body for...
Treating material introduced into or removed from body...
C604S235000
Reexamination Certificate
active
06283946
ABSTRACT:
BACKGROUND OF THE INVENTION
1. The Field of the Invention
The present invention relates to a syringe apparatus for dispensing compositions such as dental cements. More particularly, the present invention is directed to syringes which enable compositions to be delivered without requiring significant exertion and preferably in relatively small quantities.
2. The Relevant Technology
An example of a widely used conventional syringe is shown in
FIGS. 1A-1D
at
10
. Syringe
10
is shown having a barrel
20
with a plunger
50
slidably engaged therein. In order to appreciate certain limitations of syringes such as syringe
10
, it is necessary to understand the details of the elements of such a syringe. These elements are briefly described hereinbelow.
Barrel
20
has a top grasping end
21
opposite a bottom end
29
with a substantially cylindrical sidewall
22
extending therebetween. Sidewall
22
has an exterior surface
23
and an interior surface
24
. Interior surface
24
defines a substantially cylindrical chamber
25
for holding a composition. Chambers such as chamber
25
of barrel
20
are typically configured to hold about 1.2 cc of liquid.
Barrel
20
has a grasping handle
26
which is an annular flange extending radially outward from sidewall
22
at top grasping end
21
of barrel
20
. Grasping handle
26
is centrally located around opening
27
which has the same diameter as the interior surface
24
of chamber
25
.
A radial extension
28
extends integrally from sidewall
22
at bottom end
29
inward to define an exit port
32
. Radial extension
28
acts as a stop for plunger
50
as plunger
50
is depressed.
Exit port
32
is the opening into channel
33
which enables channel
33
to communicate with chamber
25
. Note that channel
33
is the interior surface of tapered exit tube
30
. Channel
33
extends through tapered exit tube
30
and terminates at outlet
34
.
Surrounding exit tube
30
is an attachment sleeve
36
. Attachment sleeve
36
has an interior surface
37
with engagement threads
38
positioned thereon. A nozzle or tip
40
, shown in
FIGS. 1C and 1D
, may be selectively attached to barrel
20
by coupling with threads
38
. A variety of tips are available which may be attached such that channel
33
of exit tube
30
is in fluid communication with the tip for guided delivery of the composition to a desired location.
Tip
40
is configured to selectively attach in fluid communication with exit tube
30
. To accomplish this end, tip
40
has a threaded end
42
for engagement with threads
38
of attachment sleeve
36
. Opposite threaded end
42
is a flexible and angled spout
44
for guiding delivery of the composition to a desired location. It is of course envisioned that different sizes and shapes of spouts
44
can be used depending on the type and intended use of the composition. Furthermore, in alternative embodiments, tip
40
may be permanently attached to bottom end
29
or means other than threads may be used to attach different sizes and/or shapes of tips.
Plunger
50
has a distal lead end
51
opposite from a proximal pushing end
53
with a stem
52
extending therebetween. Radially extending outward at pushing end
53
is an annular pushing handle
58
used in advancing plunger
50
. Plunger
50
is sized to be slidably received within chamber
25
through opening
27
at top grasping end
21
. Plunger
50
has a length that permits it to be advanced to bottom end
29
such that a small portion of plunger
50
remains extending beyond opening
27
.
Positioned at lead end
51
of plunger
50
is a cylindrically shaped sealing gasket
60
. More particularly, gasket
60
is coupled to stem
52
via a gasket holder as shown in
FIG. 1B
at
64
. Gasket
60
is made of a soft, compressible, sealing material, such as rubber, which allows the exterior surface of gasket
60
to seal against interior surface
24
of chamber
25
as plunger
50
is advanced within chamber
25
or selectively slid down to bottom end
29
. Gasket holder
64
has a post
66
with a head element
65
integrally extending at one end and a base
67
integrally extending from the other end. Head element
65
and post
66
are inserted into an opening
62
of gasket
60
which expands such that head element
65
can be inserted therein and then elastically return to its original size such that head element
65
is removably held in gasket
60
. Base
67
is connected to stem
52
to hold gasket holder
64
in position.
As discussed above, a small portion of plunger
50
remains extending beyond opening
27
, as shown in
FIG. 1D
, when plunger
50
has been fully depressed such that gasket
60
contacts radial extension
28
. The length of the portion of plunger
50
extending beyond opening
27
of syringe
10
when plunger
50
is fully depressed is about 1 cm. This configuration is typical for a conventional 1.2 cc syringe. Note that the length of the barrel is about 5 cm while the length of the plunger which includes gasket
60
is about 6 cm such that the ratio of the length of the plunger to the length of the chamber is 1.2:1.
While syringes such as syringe
10
are ideal for many uses, these syringes also have certain limitations. For example, in some instances it can be difficult to apply an adequate amount or the appropriate amount of force required to push the composition from chamber
25
into channel
33
and ultimately out of tip
40
attached to barrel
20
.
FIG. 1C
depicts a loaded syringe with only gasket
60
and a portion of stem
52
in chamber
25
of barrel
20
. As shown in
FIG. 1C
, a user typically grasps syringe
10
such that barrel
20
is held by the user's middle and index fingers as well as the user's thumb. As the plunger is depressed further and further into chamber
25
until gasket
60
contacts radial extension
28
to stop the depression of plunger
50
as shown in
FIG. 1D
, the user may have to exert increasing effort to dispense the composition. Accordingly, it becomes difficult to dispense the composition at a uniform rate and in a controlled manner. When a composition is relatively viscous, the difficulty experienced in applying either an adequate amount or the appropriate amount of force may further increase.
When an inappropriate amount of force is applied to pushing handle
58
, gasket
60
may press against sidewall
22
of chamber
25
in a manner such that plunger
50
is not smoothly pushed into chamber
25
in a controlled manner. Plunger
50
may stop and then suddenly move downward in what is known as a stuttering effect. This can potentially result in delivery of excessive amounts of a composition which the practioner is attempting to deliver in a discrete amount.
Syringes such as syringe
10
are used for delivering many different types of compositions. Such syringes may be sold with preloaded compositions ready for immediate use. However, when it is necessary to deliver a two part composition having an A component and a B component which are mixed just before use, other syringes are typically utilized.
Upon mixing a formulation packaged in two parts, including A and B components, the A and B components typically undergo a chemical reaction which causes the resultant composition to “set up” in some desired manner. Such two part compositions are widely used in the dental field. For example, glass ionomer cements and resinous luting cements are frequently used for applications such as securing dental crowns in place. Temporary cements are also provided as two separate components which are mixed shortly before delivery. Also, some dental impressions are made using compositions of A and B components.
In order to work properly, it is important that the A and B components of these multi-component compositions be mixed together rapidly and thoroughly and in the right proportions. Failure to rapidly mix the components can result in loss of valuable working time due to the quick setting nature of the compositions. Furthermore, failure to rapidly mix the components can result in a non-homogenous
Kennedy Sharon
Ultradent Products Inc.
Workman & Nydegger & Seeley
LandOfFree
Long stem syringe apparatus for dispensing compositions and... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Long stem syringe apparatus for dispensing compositions and..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Long stem syringe apparatus for dispensing compositions and... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2528571