U.S. patent number 3,827,147 [Application Number 05/255,861] was granted by the patent office on 1974-08-06 for dental tool.
Invention is credited to John J. Condon.
United States Patent |
3,827,147 |
Condon |
August 6, 1974 |
DENTAL TOOL
Abstract
A dental tool is described for use in the impression process of
dental prosthesis. The hand-held dental tool includes an impression
material cartridge releasably connected to a cylindrical tool
housing. A controlled amount of air pressure is directed from a
source through a hose and into a bore of the cylindrical housing to
force a freely movable piston against the rear end of an elongated
plunger which has its forward end slidably mounted in the
cartridge. The plunger, in turn, forces a flowable impression
material along the interior of the cartridge to flow from a reduced
opening.
Inventors: |
Condon; John J. (Spokane,
WA) |
Family
ID: |
26833480 |
Appl.
No.: |
05/255,861 |
Filed: |
May 22, 1972 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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135595 |
Apr 30, 1971 |
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Current U.S.
Class: |
433/90 |
Current CPC
Class: |
A61C
9/0026 (20130101); B05C 17/00593 (20130101); B05C
17/00516 (20130101) |
Current International
Class: |
A61C
9/00 (20060101); A61c 009/00 () |
Field of
Search: |
;32/60,17 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Peshock; Robert
Attorney, Agent or Firm: Wells, St. John & Roberts
Parent Case Text
RELATED APPLICATIONS
This application is a continuation-in-part of the application Ser.
No. 135,595 filed April 30, 1971, now abandoned, having the same
title.
Claims
Having thus described my invention, I claim:
1. A dental tool for applying impression material onto a patient's
tooth; comprising
a cylindrical cartridge having an open end and a reduced end with a
reduced opening, in which the cartridge is filled with a flowable
impression material;
an elongated plunger having a forward end slidably mounted in the
cartridge for pushing the impression material out the reduced
opening and a rear end extending outward from the open end;
a cylindrical housing having a bore with an open end for receiving
the rear end of the plunger therein; said housing having a free
piston slidably mounted in the bore for engaging the rear end of
the plunger;
an air line communicating with the bore behind the piston and
connectable to a source of air pressure to force the free piston
toward the open end to push the plunger and thereby dispense the
impression material from the reduced end of the cartridge;
a releasable connection means for operatively connecting the open
end of the cartridge to the cylindrical housing; and
a locking lever pivotally mounted to the cylindrical housing in
which the lever has a projecting section extending forward of the
housing terminating in a nose element for releasably gripping the
reduced end of the cartridge when the cartridge is operatively
connected to the cylindrical housing.
2. The dental tool as defined in claim 1 wherein the free piston
has a diameter greater than the cross-section of the rear end of
the plunger.
3. The dental tool as defined in claim 1 wherein the open end of
the cartridge has a male connector element associated therewith and
wherein the open end of the housing has a female connector element
therewith for receiving a male connector element and for releasably
interlocking with the male connector element to operatively connect
the cartridge to the housing.
4. The dental tool as defined in claim 3 wherein the male connector
element includes shoulder projections extending radially outward
from the open end of cartridge and wherein the female connector
element includes a recess for receiving the open end of the
cartridge therein with corresponding shoulders for engaging the
male connector shoulders when the open end of the cartridge is
inserted into the pocket and rotated relative to the housing.
5. The dental tool as defined in claim 1 wherein the locking means
includes a handle section for extending alongside the exterior of
the housing.
6. The dental tool as defined in claim 1 wherein the housing has an
air passageway communicating with the air line and extending to the
reduced end of the cartridge for directing air into the patient's
mouth to keep the tooth receiving the impression material dry.
7. The dental tool as defined in claim 1 further comprising a
safety valve means for preventing the inadvertent application of
air pressure to the free piston.
Description
BACKGROUND OF THE INVENTION
This invention relates to dental tools and more particularly to
those tools used in taking impressions for dental prosthesis.
Most impressions for dental prosthesis are presently made by
manually applying a quick-drying, flowable impression material
about the area of a patient's mouth to be reshaped. The material is
usually applied through use of a hand-operated impression material
syringe.
The impression material, consisting mainly of a flowable rubber
base and drying agent, is quite viscous requiring a force of
approximately 40 psi to initiate and maintain flow from the present
impression material syringes. It is difficult for the operator to
manually apply a force to the syringe sufficient to create a
pressure in excess of 40 psi and at the same time guide the syringe
to deposit the material accurately in a patients' mouth. At such
force levels it is easy for the operator to loose his grip and jab
the end of the syringe against the mouth and facial tissues of the
patient. Furthermore, the operation is quite fatiguing causing the
arm and hand muscles to tighten up affecting the operator's
dexterity.
With one hand operating the impression material syringe, the other
must gently hold the patient's lip or cheek away from the critical
area. An assistant is also required to operate a suction tube to
remove tooth chips and to keep the tooth and gum area dry while the
impression material is being applied. The result is that the
patient often has at least one finger, the syringe and a suction
tube in his mouth at one time, causing discomfort.
One of the principal objects of this invention is to provide a
powered dental tool for applying the impression material accurately
and with complete safety into the patient's mouth.
An additional object of this invention is to provide a dental tool
for accurately injecting the impression material in readily
controllable quantities.
A further object of this invention is to provide a dental tool that
is powered by a source readily available in dentist's offices which
will not require the modifications of existing equipment.
A further object of this invention is to provide a dental tool that
can be adapted to accommodate prior dental devices used in the
impression process of dental prosthesis.
A further object of my invention is to provide a dental tool having
the capability of keeping the impression area dry and free from
tooth particles while the impression material is being ejected
therefrom.
A further object of my invention is to provide such a dental tool
that is relatively inexpensive to manufacture and easy to
operate.
An additional object of this invention is to provide a dental tool
for applying impression material into the mouth of a patient
utilizing only one person without the need of an assistant.
A further object is to provide an impression ejecting dental tool
that utilizes a disposable cartridge filled with the impression
material with a mechanism for locking the cartridge to the
tool.
These and other objects and advantages of this invention will
become apparent upon the reading of the following detailed
description of a preferred and alternate embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
A preferred and alternate embodiment of this invention is
illustrated in the accompanying drawings, in which:
FIG. 1 is an isometric view of a typical prior art disposable
impression material cartridge;
FIG. 2 is an orthographic side view showing a dental tool
incorporating the principal features of this invention;
FIG. 3 is an orthographic cross-sectional view taken along line
3--3 in FIG. 1 in the direction of the arrows located thereon;
FIG. 4 is an orthographic end view of my invention taken along line
4--4 in FIG. 1 in the direction of the arrows located thereon;
FIG. 5 is a pictorial view illustrating the dental tool being held
by an operator's hand during the application of impression material
to a tooth area;
FIG. 6 is an isometric view of a typical prior art re-usable
impression material syringe.
FIG. 7 is an exploded isometric fragmentary view of an alternate
embodiment of my invention, its parts and their relation to one
another;
FIG. 8 is an orthographic frontal view taken along line 8--8 in
FIG. 7 in the direction of the arrows located thereon;
FIG. 9 is an isometric view of a disposable impression material
cartridge;
FIG. 10 is a fragmentary isometric view of a modified disposable
impression material cartridge;
FIG. 11 is an isometric view of an alternate embodiment of the
dental tool including illustrating a locking means for securing the
cartridge to the tool;
FIG. 12 is a rear end view of the dental tool illustrated in FIG.
11;
FIG. 13 is an orthographic side view of the dental tool illustrated
in FIG. 11 illustrating the alternate positions of the locking
means with the locking means shown in solid line in a locking
position and in dotted line in an unlocking position; and
FIG. 14 is an orthographic longitudinal vertical cross-sectional
view of the dental tool illustrated in FIG. 11.
DETAILED DESCRIPTION OF A PREFERRED AND ALTERNATE EMBODIMENT
A presently available impression material syringe 10 is shown in
detail in FIG. 1. Syringes of this type are generally purchased in
multiples and are inexpensively constructed to facilitate their
disposal after use. The syringe 10 comprises an elongated tube 11
having a reduced end 12 and an open end 15. Reduced end 12 rigidly
supports a curved discharge tube 13 which tapers to a reduced
opening 14. The open end 15 of the tube 11 rigidly supports a
finger grip 16 which is formed by opposed radially extending ears
17 and 18.
The open end 15 and the interior of tube 11 slidably accommodate an
elongated plunger 20. The plunger 20 comprises an elongated body 21
having a forward end 22 and a rear end 24. The forward end 22 of
plunger 20 structurally mounts a rubber piston 23. The rubber
piston 23 is of a diameter slightly larger than that of the
interior of tube 11 to provide an airtight but frictionally
slidable relationship between the piston and the interior of tube
11. The rear end 24 of plunger 20 has a disc-shaped plunger cap
25.
Before operating the syringe 10, the plunger 20 must be removed
from the tube 11 to allow the operator or his assistant to
partially fill the tube 11 with impression material 19. The plunger
20 is then pushed back into the tube 11. To operate the syringe 10,
the operator must grasp the syringe in one hand by simultaneously
engaging the projecting ears 17 and 18 with the index and middle
fingers while the thumb engages the plunger cap 25. The operator
then attempts to reduce the distance between his thumb and fingers
thereby forcing the plunger 20 further into the tube 11. If enough
force has been applied, the plunger will move the piston 23 and
thus, the impression material toward the discharge tube. The
impression material being flowable, is thereby forced to exit
through the reduced opening 14 of the syringe to a patient's tooth
or gum. As previously mentioned, the impression material 19 is
quite viscous, requiring a very strong grip to dispense the
material from the syringe 10.
The syringe 10 as described above may be utilized as a replaceable
or refillable cartridge 10 of a dental tool 26 illustrated in FIG.
2. As a component of the dental tool 26, the finger grip 16 becomes
a male connecting element 16 releasably connectable to a
corresponding female connecting element 31.
As seen in FIG. 2, the dental tool 26 further includes a hollow
elongated cylindrical tool housing 27 with female connecting
elements 31 at an open end 30 and a male threaded air supply
fitting 37 at a partially closed end 36. The tool housing has a
cylindrical cross that is sufficiently small to enable the tool to
be conveniently held in one hand between the thumb and the index
finger in a manner similar to holding a pencil.
The tool housing 27 has an interior bore 28 of a diameter slightly
larger than that of the plunger cap 25 of the impression material
cartridge 10. The bore 28 slidably supports a piston 29 which is
freely slidable along the bore while maintaining an airtight
contact with the inner surface of the bore 28.
The female connecting element 31 located on the periphery of open
end 30, is formed by radially opposed shoulders 32 and 33.
Shoulders 32 and 33 extend radially outward beyond open end 30 then
inward forming opposed radial slots 34 and 35. Slots 34 and 35 are
spaced apart to form a recess 40 at the open end 30 of the cylinder
27. Recess 40 enables the ears 17 and 18 of the male connecting
element 16 to be inserted therein and then rotated to move the ears
17 and 18 into the slots 34 and 35 respectively of the female
engaging elements 31.
The partially closed end 36 rigidly supports a threaded male air
supply fitting 37 which contains a main air supply tube 38 and an
auxillary air supply tube 39. The fitting 37 conforms in
configuration to accommodate a female air supply fitting 41 (FIG.
5) which are common to the dental arts and available in most
dentist offices. The main air supply tube 38 extends longitudinally
through fitting 37 to supply air under pressure of between 5 psig
and 60 psig from a source (not shown in drawings) available in
about all dental facilities. The auxillary tube 39 extends
partially through fitting 37 and then outwardly to extend along the
outside of air cylinder 27 and the attached cartridge 10 to the
reduced opening 14. The auxillary tube 39 is held against air
cylinder by an annular clip 42 and removably attached to cartridge
10 by a spring clip 43 and a slidable clip 44.
To operate the dental tool 26, a filled impression material
cartridge 10 is fitted to the air cylinder 27 by inserting end 24
of the plunger 20 including cap 25 through the open end 30 and into
the bore 28 of the air cylinder 27. The plunger cap 20 comes in
contact with the piston 29 and moves it back to a position near end
36 of cylinder 27. The cartridge is angularly oriented to enable
the end 15 to move into recess 40 of the cylinder 27. The operator
then rotates the cartridge 10 relative to the air cylinder 27 to
move the ears 17 and 18 into the slots 34 and 35 respectively to
interlock the male connecting element 16 within the female
connecting element 31. Spring clip 43 is then attached near the
reduced end 12 of the cartridge 10 and the slidable clip 44 is
moved onto the reduced opening 14.
The operator holds the tool in one hand by engaging the tool
between the thumb and the index finger in a manner similar to
holding a pencil (FIG. 5). The tool 26 may then be operated by
regulating the air pressure through hose 65 simultaneously to
auxillary tube 39 and to the bore 29 of air cylinder 27. The air
pressure forces the free piston 29 against the plunger cap 25 to
move the plunger 20 towards the discharge tube 13 thus forcing the
impression material 19 to exit from the reduced opening 14 of the
cartridge 10. Flow of the impression material 19 from the tool 27
is controlled by the operator through a foot-controlled valve or
other air pressure control means common to the dental art.
By utilizing dental tool 26, the operator can deposit the
impression material 19 in a patient's mouth while keeping the
impression area dry to allow the impression material to adhere.
Since the operator is not required to manually force the impression
material from the cartridge, the material can be effortlessly
deposited with greater care and accuracy. The operator is required
to use only one hand to hold the tool 26, enabling the other hand
to operate a suction tube or hold the patient's cheek or lip away
from the impression area.
After the impression has been made, the disposable cartridge 10 may
then be removed from the housing 27 and thrown away. The spend
cartridge 10 is removed from the housing 27 by disengaging clips 43
and 44 then rotating the tube 11, relative to housing 27, to
disengage the male connecting means 16 of the cartridge 10 from
female connecting means 31 of the air cylinder. The plunger 20 is
then retracted from the bore 28 by axially pulling the cartridge 10
away from the housing 27.
FIG. 6 illustrates a presently available re-usable impression
material syringe 46. The re-usable syringe 46 consists of a tube
47. The tube 47 has external threads at a discharge end 48 and at
an open end 52. The discharge end 48 threadably accepts a retaining
cap 51 which holds a curved discharge tube 49 thereto. Discharge
tube 49 may be removed for cleaning purposes or for replacement.
The open end 52 threadably supports a finger grip 53 which is also
removable for cleaning purposes.
An elongated plunger shaft 54 supports a piston 55 at a forward end
and threadably supports a disc-shaped plunger cap 57 of a diameter
somewhat larger than that of the plunger cap 25 of cartridge
10.
The operation of the re-usable syringe 46 is similar to the
operation of the disposable syringe 10 as described above. However,
the construction of the re-usable syringe 46 is such that it may be
dismantled for cleaning purposes, then re-assembled for repeated
use.
The re-usable syringe 46 may be utilized as a re-usable,
replaceable impression material cartridge 46 of an alternate
embodiment of dental tool 26 as shown in FIG. 7. However, finger
grip 53 is replaced with a male connecting adaptor 58 and the
plunger cap 57 is replaced by a plunger cap 63 of a smaller
diameter.
The male connecting adaptor 58 is comprised of opposed projecting
ears 59 and 60 of dimensions similar to ears 17 and 18 of cartridge
10. An internally threaded cap 61 is rigidly attached to ears 59
and 60 to provide means for attaching adapter 59 to the threaded
end 52 of hollow cylinder 47. Plunger cap 63 is of a diameter
sufficient to allow its passage into the bore 28 of air cylinder
27.
The re-usable cartridge 46 is attached to the housing 27 using the
same procedure as described above for attaching the disposable
cartridge 10.
The operation of the alternate embodiment of my invention is
similar to that of the preferred embodiment. As previously
described however, upon completion of the impression making
process, the re-usable cartridge 46 may be dismantled for cleaning
purposes then re-used at a later time.
An alternate embodiment of the dental tool 26 is illustrated in
FIGS. 9-14. FIG. 9 shows a syringe 70 having an elongated tube body
71 with a reduced end 72 and an open end 74. An annular shoulder 75
is formed at the reduced end 72. Diametrically opposed projecting
ears 77 and 78 are formed at the opened end 74. The syringe 70
includes a plunger 80 having an elongated body 81 with a forward
piston end 82 and a rear end 83. A plunger cap 84 formed at the
rear end 83.
The dental tool 26 includes a cylindrical housing 88 having an
interior bore 90 forming an open end 91 and a closed end 92. A free
piston is slidably mounted in the interior bore for moving between
the ends. A stop pin 94 is positioned adjacent the open end 91 to
prevent the free piston 93 from being ejected from the open end
91.
A main air passage 96 is formed in the closed end 92 communicating
with the interior bore 90 to apply pressurized air to the free
piston to drive the free piston from the closed end 92 toward the
open end 91.
An auxiliary passageway 97 is formed in the cylindrical housing 88
and extends from the closed end 92 through the body of the housing
to a location adjacent the open end 91 terminating in a open
fitting 98.
An important feature of this embodiment is a locking means 100 for
releasably securing the syringe 70 to the cylindrical housing to
prevent the inadvertent ejection of the syringe while air pressure
is being applied against the free piston 93. The locking means
includes a lever 101 that has a front end 102 that extends to the
reduced end 72 of the syringe as illustrated in FIGS. 10, 12 and
13. The lever has a rear end 103 that extends to the closed end 92
of the cylindrical housing. The locking lever 101 has an
intermediate angular section 105 that circumscribes the open end 91
of the housing. The lever 101 is pivotally mounted to the
cylindrical housing by pivot pins 106 that connect with the angular
section 105 to enable the lever 101 to be pivoted intermediate its
ends. The lever 101 includes a forward section 107 that extends
forward of the angular section 105 to the front end 102. The
forward section 107 has a length substantially equal to the length
of the elongated tube 71. The front end 102 has a nose section 108
with forked elements 111 that extend angularly about the angular
shoulder 75 for engaging the shoulder to prevent the ejection of
the syringe 70 when the locking means is in a locking position. A
fine air line 112 extends from the nose section 108 in a curved
manner along the reduced end 72 to direct air into the patient's
mouth adjacent the outlet of the syringe to maintain the tooth area
receiving the impression material dry and to force the impression
material against the tooth and down between the gum and the tooth
to provide a more accurate impression. The lever 101 has a handle
section 114 that extends rearward from the angular section 105 to
the rear end 103. The handle section 114 has a length substantially
equal to the length of the cylindrical housing 88. A heel portion
115 is formed at the rear end 103 for engaging the exterior of the
closed end 92. A flexible line 117 extends from the fitting 98 to
the curved fine air line 112 to direct the air from the auxiliary
passageway 97 to the fine air line 112.
An additional feature of this embodiment is a safety valve means
120 for preventing the buildup of pressure behind the free piston
93 until the locking means 100 is closed and for venting the
pressure behind the free piston 95 when the locking means 100 is
released. The safety valve means 120 includes a bent hole 121
formed in the housing 88 near the closed end 92. A rubber plug 122
is mounted on the locking lever 101 in alignment with the vent hole
121 to fill and close the vent hole 121 when the locking lever 101
is closed and open the hole 121 when the lever is open.
During the operation of the embodiment illustrated in FIGS. 9-14,
the syringe 70 is filled with impression material and then the
syringe is loaded into the cylindrical housing with the plunger 80
extending through the open end 91 into the interior bore 90. The
syringe is rotated to interconnect the ears 77 and 78 with
corresponding interlocking means of the cylindrical housing. During
the loading procedure, the locking lever 101 is in the unlocking
position illustrated in dotted lines in FIG. 13. After the syringe
70 has been loaded into the cylindrical housing 88 the locking
lever 101 ia pivoted to the locking position with the forward
position 107 extending over the elongated tube 81 with the nose
section 108 engaging the angular shoulder 75 as illustrated in
FIGS. 11 and 14. The handle section 114 is pivoted to engage the
exterior of the cylindrical housing 88 with the heel 115 engaging
the rear end and the plug 122 closing the vent hole 121. In this
manner should the ears 77 and 78 be in improper alignment or should
breakage occur, the syringe cannot be removed from the cylindrical
housing.
The dental tool is held by the operator between his thumb and index
finger. The operator projects the reduced end of the syringe and
the fine air line 112 into the patient's mouth. The air through the
fine air line 112 is used to force the impression material against
the tooth and between the tooth and gum and to maintain the tooth
area dry to provide good cohesion between the impression material
and the tooth area. The operator can adjust the amount of air
pressure applied to the free piston 93 through a foot valve or
other means normally found in dental offices. With air applied to
the free piston the free piston is moved forward to engage the
plunger cap 84 and to drive the plunger 80 to eject the impression
material. When the free piston reaches the open end 91, it engages
the stop pin 94 to prevent the free piston from providing
additional force to the syringe. Stop pin 94 also prevents the free
piston from being blown from the cylindrical housing 88 when the
syringe is removed. The stop pin 94 provides a safety feature to
prevent the free piston from becoming a dangerous flying object. At
the conclusion of the operation, the operator opens the lever 101
to release the air pressure behind the free piston 93 and to
release the cartridge for removal.
The syringe 70 as shown in FIG. 10 may have a reduced end 82 that
is removable from the elongated tube body 71. In this manner,
different size reduced ends 72 may be applied to the syringe as
desired.
Modifications can obviously be made in the specific features shown
and therefore the foregoing description is not intended to limit or
restrict the scope of the application, the invention being set out
in the following claims.
* * * * *