U.S. patent number 3,874,083 [Application Number 05/378,319] was granted by the patent office on 1975-04-01 for adjustable nozzle dental syringe with pull-back valve.
Invention is credited to George F. Buckley.
United States Patent |
3,874,083 |
Buckley |
April 1, 1975 |
Adjustable nozzle dental syringe with pull-back valve
Abstract
A dental syringe connectable to sources of air and water under
pressure for selectively providing a solid stream of water, a spray
of water and air or a jet of air is described. An adjustable nozzle
capable of varying the diameter of the stream of water without
change in the water pressure at the orifice of the nozzle is
disclosed. The syringe includes a valve for controlling the stream
of water, which valve provides a "pull-back" action with respect to
the water at the orifice of the syringe when the water flow is
interrupted.
Inventors: |
Buckley; George F. (Burlingame,
CA) |
Family
ID: |
23492649 |
Appl.
No.: |
05/378,319 |
Filed: |
July 11, 1973 |
Current U.S.
Class: |
433/80 |
Current CPC
Class: |
A61C
17/0217 (20130101) |
Current International
Class: |
A61C
17/00 (20060101); A61C 17/02 (20060101); A61c
019/02 () |
Field of
Search: |
;138/45
;128/224,257,401,173.1 ;32/22 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Peshock; Robert
Attorney, Agent or Firm: Phillips, Moore, Weissenberger
Lempio & Strabala
Claims
What is claimed is:
1. A dental syringe including a handle portion and a tip portion
interconnected by a valve body portion and comprising:
a. liquid conduit means extending through said syringe from an
inlet in said handle portion to an outlet at the free end of said
tip portion;
b. liquid control means in said valve body portion interposed in
said liquid conduit between said inlet and outlet thereof;
c. gas conduit means extending through said syringe independently
of said liquid conduit means from an inlet in said handle portion
to an outlet at the free end of said tip portion;
d. gas control means in said valve body portion interposed in said
gas conduit between said inlet and outlet thereof;
e. nozzle means at the free end of said tip portion communicating
with said outlets of both said liquid conduit and said gas conduit;
said nozzle means including means providing an orifice of
adjustable diameter at said outlet of said liquid conduit, means
providing a fixed orifice at said outlet of said gas conduit, and
means for adjusting the diameter of said orifice at said outlet of
said liquid conduit without change in said fixed orifice at said
outlet of said gas conduit and without substantial change in the
relationship of said fixed orifice to said adjustable orifice.
2. A dental syringe as claimed in claim 1 wherein the said liquid
control means and said gas control means are arranged with respect
to each other to enable both to be actuated simultaneously by a
single digit of the hand of an operator thereof.
3. A dental syringe as claimed in claim 1 wherein said nozzle means
comprises:
a. a tubular member of elastic material coaxial with the terminal
portion of said liquid conduit at said free end of said tip and
surrounding said outlet of said liquid conduit with one end of said
tubular member in abutment with the end of said liquid conduit to
provide said orifice of adjustable diameter at said outlet of said
liquid conduit; and
b. a tubular member of rigid material having an annular passageway
extending coaxially within the wall thereof from one end toward the
other end thereof and aperture means at said other end thereof for
communication with said outlet of said gas conduit to provide said
fixed orifice of said gas conduit in annular form at said one end
of said tubular member of rigid material; and
c. said tubular member of rigid material coaxially surrounding the
outlet portion of said liquid conduit including said tubular member
of elastic material, said tubular member of rigid material being
provided with annular compression means internally at said one end
thereof for abutment with the other end of said tubular member of
elastic material and said other end of said tubular member of rigid
material being mounted on said liquid conduit for selective axial
movement with respect to said liquid conduit to provide said means
for adjusting the diameter of said orifice at said outlet of said
liquid conduit by axial compression of said tubular member of
elastic material.
4. A dental syringe as claimed in claim 1 wherein said liquid
control means comprises an elongated cavity, first aperture means
at one end of said elongated cavity communicating with said inlet
of said liquid conduit, second aperture means spaced along said
cavity from both said first aperture means and the other end of
said elongated cavity communicating with said outlet of said liquid
conduit, and valve means extending across said cavity intermediate
said first aperture means and said second aperture means adapted to
selectively interrupt fluid communication between said first
aperture means and said second aperture means, said valve means
including a plunger having transverse dimensions which slidably fit
the transverse dimensions of said elongated cavity, said plunger
being located adjacent said second aperture means when said valve
means is actuated and being biased to return to a location adjacent
said first aperture means when said valve means is not actuated,
whereby a reduced pressure is provided in said other end of said
elongated cavity to withdraw fluid from said outlet of said liquid
conduit.
5. In a dental syringe comprising a handle portion and a tip
portion interconnected by a valve body portion;
a. liquid conduit means extending through said syringe from an
inlet in said handle portion to an outlet at the free end of said
tip portion;
b. liquid control means in said valve body interposed in said
liquid conduit between the inlet and outlet thereof; said control
means comprising an elongated cavity in said valve body, said inlet
of said conduit communicating with said cavity through a first
aperture at one end thereof, said outlet of said conduit
communicating with said cavity through a second aperture spaced
along said cavity from both said first aperture and the other end
of said elongated cavity and a valve means extending across said
elongated cavity intermediate said first and second apertures
adapted to selectively interrupt liquid communication between said
inlet and said outlet of said conduit, said valve means including a
plunger having transverse dimensions which slidably fit the
transverse dimensions of said elongated cavity, said plunger being
located adjacent said second aperture when said valve is actuated
and being spring biased to return to a location adjacent said first
aperture when said valve means is not actuated, whereby a reduced
pressure is provided in said other end of said elongated cavity to
withdraw liquid from said outlet of said conduit;
c. gas conduit means extending through said syringe independently
of said liquid conduit means from an inlet in said handle to an
outlet at the free end of said tip portion, at least a portion of
said gas conduit at the outlet thereof coaxially surrounding a
portion of said liquid conduit at said outlet of said liquid
conduit; and
d. gas control means in said valve body portion interposed in said
gas conduit between said inlet and outlet thereof.
Description
BACKGROUND OF THE INVENTION
This invention relates to means for forming and controlling streams
or jets of fluids or mixtures of fluids in space and more
particularly to a syringe capable of selectively providing a solid
stream of water, a spray of water and air or a jet of dry air.
One of the instruments used by a dentist in the practice of his
profession is a so called "three-way dental syringe." Such a
syringe is a hand held instrument connected to sources of air and
water under pressure by appropriate tubing. The syringe includes
air and water valves designed and positioned to enable them to be
operated either independently or simultaneously by a digit or
digits of the hand in which the syringe is held. The air and water
orifices of the syringe are so located with respect to each other
that the simultaneous operation of the air and water valves will
produce a spray of water droplets.
In the practice of his profession, a dentist must often flush out
the oral cavity or specific portions thereof with water. The
dentist must also thoroughly dry specific portions of the oral
cavity or of specific teeth in the performance of certain dental
procedures. Thus, the three-way dental syringe provides a
convenient instrument capable of providing a spray of water or a
solid stream of water for flushing purposes or a jet of dry air for
drying purposes.
However, three-way dental syringes of the prior art have not
provided adequate control over the rate at which water is delivered
when the water valve of the instrument is actuated. Such valves, by
their nature, tend to be "on/off" devices and it would be difficult
and expensive to design such a valve capable of varying degrees of
actuation in use in order to provide control over the rate at which
water is delivered by the syringe. Thus, in the prior art, such
control has been provided by adjusting, at the source, the pressure
of water supplied to the syringe. It will be understood that,
whether the rate at which water is delivered is controlled by
partial actuation of the valve or by adjustment of the water
pressure at the source, the net result will be to change the water
pressure at the orifice of the syringe and thus the characteristics
of the stream of water issuing from the syringe. In other words,
the stream of water issuing from the syringe will tend to be weak
and ineffective at low rates of delivery.
It is an object of this invention to provide an adjustable nozzle
for a dental syringe or the like which will enable the rate of
delivery of water thereby to be reduced without reducing the
effectiveness of the stream of water issuing therefrom.
It is a further object of this invention to provide an adjustable
nozzle for a dental syringe or the like capable of providing a
solid stream of water of varying diameter without change in the
water pressure at the orifice of the nozzle.
It is another object of this invention to provide an adjustable
nozzle for a dental syringe or the like which is inexpensive to
fabricate and convenient to use.
When the dentist wishes to use the three-way syringe to dry a
portion of the oral cavity in the performance of certain dental
procedures, it is necessary that there be no water present adjacent
the air orifice of the syringe since such water would tend to be
picked up in the jet of air issuing therefrom thus reducing the
drying action of the jet of air. Since the water orifice of the
syringe must be located adjacent the air orifice in order to
provide the spray function of the syringe, it is necessary to
provide means for withdrawing water from the water orifice when the
flow of water is interrupted.
In the prior art, various methods and means have been used to
withdraw or pull-back the water which would otherwise remain
present at the water orifice of the syringe when activation of the
water valve is discontinued. However, such methods and means have
been complicated, expensive or relatively ineffective.
It is a still further object of this invention to provide a water
valve for a dental syringe or the like which is designed to perform
the pull-back function of withdrawing water from the downstream
side of the conduit in which it is interposed.
It is yet another object of this invention to provide a water valve
for a dental syringe or the like which is inexpensive to fabricate
and convenient to operate and which provides the pull-back function
automatically upon deactivation thereof.
SUMMARY OF THE INVENTION
According to the teaching of this invention the adjustable nozzle
comprises a conduit having one end adapted to be connected to a
source of fluid under pressure and the other end provided with a
surface extending transversely with respect to the axis of said
conduit at said other end thereof. A tubular member of elastic
material surrounds at least a portion of the orifice of such other
end of the conduit coaxially therewith and a tubular compression
member surrounds the tubular member of elastic material. One end of
the tubular compression member is mounted on the conduit for axial
movement with respect thereto and the tubular compression member
terminates in an inwardly extending flange at its other end adapted
to compressively contact the other end of the tubular member of
elastic material. Thus, axial movement of the tubular compression
member with respect to the conduit will subject the tubular member
of elastic material to varying amounts of compression thereby
changing the inner diameter thereof and the diameter of the fluid
stream that will issue therefrom upon actuation of the fluid
control valve interposed in such conduit between its ends.
According to this invention such valve comprises a body having an
elongated cavity therein with inlet means at one end of the cavity
communicating with one end of the conduit and outlet means spaced
along the cavity from the inlet means and from the other end of the
cavity communicating with the other end of the conduit. A valve
means extends across the cavity between the inlet means and the
outlet means and is adapted to interrupt fluid communication
therebetween The valve means includes a plunger having dimensions
to slidably fit the cavity, the plunger being located adjacent the
outlet means when the valve is actuated and adjacent the inlet
means when the valve is not actuated.
BRIEF DESCRIPTION OF THE DRAWING
This invention together with its objects and advantageous features
will be more fully understood from a reading of the following
description of a preferred embodiment thereof in conjunction with
the attached drawing wherein:
FIG. 1 is a side view partially in elevation and partially in
section of a dental syringe embodying this invention;
FIG. 2 is a fragmentary view in elevation taken along line 2--2 of
FIG. 1 showing the valves thereof;
FIG. 3 is an enlarged fragmentary view in cross-section of the
nozzle of the dental syringe of FIG. 1;
FIG. 4 is an enlarged fragmentary view in cross-section of the
water valve structure of the dental syringe of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1 a three-way dental syringe 10 including a
nozzle and valve according to the teaching of this invention is
shown. The syringe comprises a handle portion 11 and a tip portion
12 interconnected by a valve body portion 13.
In the embodiment shown the handle portion 11 of the syringe 10
comprises a hollow tubular member dimensioned to provide a
convenient grip for the human hand and may be made of any suitable
material such as plastic or metal, for example. A pair of suitable
tubes or hoses 14 and 15 extend through the hollow handle 11 and
are connected to nipples 16 and 17 on the valve body portion 13.
According to this embodiment of the invention one of the tubes 15
is connected to a source of water under pressure (not shown) and
the other of the tubes 14 is connected to a source of air under
pressure (not shown).
The tip 11 of the syringe comprises a pair of rigid coaxial tubes
mounted at one end on the valve body 13 and extending transversely
of the axis of the handle 12. The outer one 18 of the coaxial tubes
of the tip 11 provides a conduit for air under pressure and the
inner one 19 of the coaxial tubes provides a separate conduit for
water under pressure.
As shown in FIG. 1 a valve mechanism 21 is installed in a cavity 23
in the valve body 13 with the control button 25 thereof projecting
from the valve body 13. Passageways 27 and 29 formed in the valve
body 13 communicate with the cavity 23 at spaced points and
interconnect the inner tube 19 of the tip 11 with the nipple 17
through the cavity 23 to form a continuous conduit with the valve
mechanism interposed between the ends thereof.
Referring to FIG. 2, it will be understood that a second valve
mechanism (not shown) is installed in a second cavity in the valve
body 13 with the control button 26 thereof projecting from the
valve body 13 adjacent the control button 25. Appropriate
passageways (not shown) formed in valve body 13 and communicating
with the second cavity interconnect the outer tube 18 of the tip 11
with the nipple 16 through the second cavity to form a second
continuous conduit with the second valve mechanism interposed
between the ends thereof.
Thus, referring to FIGS. 1 and 2, it will be seen that the handle
portion 12 of the syringe 10 may be held in the palm of the hand of
the operator by his fingers with the tip portion 11 of the syringe
pointing away from the operator in the manner of a pistol. The
thumb of the hand of the operator will thus be in an appropriate
position to operate the control buttons 25 and 26 projecting from
the valve body portion 13 of the syringe.
When control button 25 is pressed down by the thumb of the operator
a solid stream of water will be projected from the nozzle 30 at the
free end of the tip 11 and when the control button 26 is pressed
down by the thumb of the operator a jet of air will be projected
from the nozzle 30 at the free end of the tip 11. Since the control
buttons 25 and 26 are located adjacent each other, it is also
convenient for the operator to press both of such buttons down
simultaneously with his thumb, in which case both water and air are
projected from the nozzle 30 at the free end of the tip 11 in the
form of a spray.
Referring to FIG. 3 a nozzle 30 according to the teaching of this
invention is shown in enlarged cross section mounted on the free
end of the tip 11 and in fluid flow communication with the tubes 18
and 19. According to this embodiment of the invention the nozzle 30
comprises a tubular inner member 31 rigidly fixed to the free ends
of the tubular 18 and 19 and forming an extension of the inner tube
19. The free end of the member 31 is provided with a surface 32
extending transversely of the axis of the conduit formed thereby
and provides the orifice from which the stream of water is
projected. A tubular member 33 of elastic material is compressively
held against the surface 32 on the free end of the member 31 in
coaxial alignment therewith by a flange 34 on the free end of an
outer tubular compression member 35. The other end 36 of the outer
tubular compression member 35 is provided with internal screw
threads adapted to engage cooperating exterior screw threads on the
free end of the tube 18. Thus, upon rotation of the outer tubular
compression member 35, the engagement of the screw threads will
cause it to move axially of the inner tubular member 31 to vary the
compression force exerted on the tubular elastic member 33 between
the flange 34 and surface 32.
It will be seen that when the compressive force exerted axially on
the tubular elastic member 33 is increased by proper rotation of
the compression member 35 to cause the flange 34 to approach the
surface 32, the opening through the tubular elastic member 33 will
be reduced by the inward expansion of the walls thereof. Such
reduction in the opening through the tubular elastic member 33 will
reduce the diameter of the orifice from which the stream of water
is projected and will thus reduce the diameter of such stream and
the rate of water flow in such stream without change in the
pressure of the water in such stream.
It has been found that the nozzle 30 according to the teaching of
this invention is most useful in dental procedures since it enables
the quantity of water projected into the oral cavity to be reduced
without reducing the effectiveness of the stream of water. Thus,
for example, an extremely fine stream of water under good pressure
may be directed into a small drilling to flush it out without using
a sufficient quantity of water to require that the patient empty
his mouth. This eliminates the delay involved in waiting for the
patient to reposition himself in the chair before the drilling
operation is continued. At the same time, the nozzle 30 may be
quickly and conveniently readjusted to provide a greater quantity
of water flow as required.
As indicated by dotted lines in FIG. 3 the inner tubular member 31
is provided with passageways 37 in the wall thereof communicating
with the interior of tubular member 18 and with passageways 38
through the wall of the outer tubular compression member 35. The
passageways 38, in turn, communicate with the interior of a tubular
jacket member 39 which is mounted on the free end of the
compression member 35 to provide an annular space thereabout
terminating in an annular orifice coaxially surrounding the orifice
of the water conduit. Thus, such passageways 37 and 38 and the
annular space formed by the jacket member 39 about the free end of
the compression member form an extension of the air conduit and the
orifice of the air conduit is fixed in its relationship to the
orifice of water conduit regardless of axial movement of the
compression member 35.
It will be understood that it is necessary that there be no
internal communication between the air and water conduits in order
to enable a jet of dry air to be provided by the syringe 10 when
desired for the purpose of drying a portion of the oral cavity.
Thus, an O-ring type sealing member 40 is provided between the
inner tubular member 31 and the compression member 35. A set screw
41 passing through the wall of the compression member 35 and
received in an annular groove or channel 42 in the exterior surface
of the inner tubular member 31 limits the amount of relative axial
movement of the compression member 35 with respect to the inner
tubular member 31 and can be used to fix the adjustment of the
nozzle at some particular setting between the established
limits.
Thus, operation of the water valve 21 by pressing down on the
button 25 will allow pressurized water from the source to flow
through the tube 15 and the conduit formed by the nipple 17,
passageways 27 and 29, cavity 23 and inner tube 19 of tip 11, which
water will be projected from the free end of the tip in a stream.
The diameter of the projected stream will be established by the
setting of the nozzle 30 as described above. When the button 25 is
released the valve 21 will cut off the flow of water. However, the
inner tube 19 of the tip 11 would tend to remain full of water and
a large drop of water will tend to form at the orifice of the inner
tube 19 if it were not for the novel features of the valve 21
according to the teaching of this invention.
It will be understood that if the inner tube 19 remain completely
full of water, and more particularly if a drop of water should form
at the end of the tube 19, then such water will tend to be picked
up in the air jet projected from the tip 11 by subsequently
pressing down on the button 26 to actuate the air valve. This is
highly undesirable since it will tend to spray water directly on
the area which it is desired to dry by means of the air jet.
Thus, according to this invention the valve 21 functions to
withdraw or pull-back the water that would otherwise remain in the
tube 19 when the button 25 is released. Referring to FIG. 4 it will
be seen that the passageways 27 and 29 communicate with the cavity
23 at points spaced from each other along the axis of the cavity 23
and that the actual valve means of valve 21 is interposed across
the cavity 23 between such points. The valve means includes a
plunger 43 and an O-ring 44. The O-ring 44 is held tightly against
the outer wall of the cavity 23 and the plunger 43 is provided with
a conical surface dimensioned to compressively contact the inner
periphery of the O-ring 44 when the valve 21 is in its off position
as shown in FIG. 4. The plunger 43 is also dimensioned to fit
within the cavity 23 with fairly close tolerance and is connected
to the button 25 by a shaft 45 received through a bushing 46, which
bushing is fixed in the cavity 23 with its inner end in compressive
contact with the O-ring 44 by means of a wedging screw 47. A spring
means 48 is mounted between the other end of the bushing 46 and the
button 25 to bias the valve 21 to its off position. Further O-rings
49 and 50 are interposed between the bushing 46 and the cavity wall
and between the bushing 46 and the shaft 45, respectively, in order
to make the valve structure fully water right. An appropriate
passageway 51 through the bushing 46 provides direct communication
between the passageway 27 and the interior of O-ring 44.
Thus, when the button 25 is pressed down the spring means 48 will
be compressed and the shaft 45 will slide axially in the bushing 46
causing the plunger 43 to be moved axially away from compresson
contact with the O-ring 44. Water will then flow from nipple 17
through passageway 27 into cavity 23 where it will pass through the
passageway 51 and thus through the O-ring 44 and along the conical
surface of the plunger 43 into the passageway 29 and from there
into the tube 19 of the tip 11.
The axial movement of the plunger 43 is sufficient to cause the
body thereof to be located at a point in the cavity 23 adjacent the
passageway 29 thereby enabling direct communication between
passageways 27 and 29 through the valve means when the button 25 is
fully depressed. When the button 25 is released, the axial movement
of the plunger 43 by the spring means 48 back past the passageway
29 and into compressive contact with the O-ring 44 will tend to
withdraw or pull-back water from the passageway 29 and tube 19 of
tip 11. The clearance between the plunger 43 and walls of cavity 23
in relation to the volume of the cavity 23 through which the body
of the plunger 43 is moved will determine the amount of water
withdrawn or pulled back from the tip 11 and is preferably adjusted
to withdraw only that amount of water necessary to insure that,
when the valve is in its off position, no water is present at the
orifice of the tip 11 that can be picked up in the jet of dry air
issuing from the tip 11 when the air system is actuated.
Although this invention has been described as applied to a syringe
for projecting and controlling a stream of water and a jet of air
in space, it will be understood that other fluids could be
substituted for the water and air. It is believed that those
skilled in the art will find other applications for this invention
and that they will make obvious changes in the specific embodiment
described herein without departing from the teaching of this
invention.
* * * * *