Note: Descriptions are shown in the official language in which they were submitted.
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BACKGROUND OF THE -[NVENTION
It is conventional dental practice to employ an
evacuating device, commonly calLed a saliva ejector, for
removing saliva and debris from the mouth of the patient
during the performance of such dental work as cleaning
and filling teeth. The usual dental saliva ejector
comprises an ejector tube having the general form of
a J, the tip of the shorter arm of the J constituting
an inlet end to receive the saliva and any debris
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entrained therein, the tip of the stem of the J being
~ connected to a hose which communicates with a source of
- reduced pressure. In many saliva ejectors, connection
of the ejector tube to the hose is accomplished by a
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one-piece tubular connector, the outlet end of the
ejector tube being forced into one end of the connector, ~
the other end of the connector being internally threaded ~ --
for attachment to an externally threaded connector
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member on the end of the hoseO In such ejectors, the -
ejector tube can be rotated, relative to the connector
; 20 and the hose, by holding the connector with one hand
'~ and using the other hand to apply enough force to the
;~` ejector tube to overcome the frictional engagement of
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the ejector tube in the connector. In other saliva
ejectors, the ejector tube is connec~ed to the hose by
a swivel joint, so that rotation of the ejector tube is
more easily accomplished, The general state of the art
¢ is illustrated by the following UOS. patents:
2,130~406 Angell
2,519,595 Older
3,460,253 Hutson
` 3,S41,583 Deuschle
;~ 3,645,497 Nyboer
'-~ 3,758,950 Krouzian
3,864,831 Drake
- 3,890,712 Lopez
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~` While prior-art saliva ejectors have been widely adopted, there
ci has been a continuing need for improvements which would allow
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, such free swivelling of the ejector tube that adjustment of
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, the tube in the patient's mouth could be accomplished by manipu-
lating the tube between the thumb and forefinger of one hand,
!-, yet would not involve an unduly expensive swivel connector
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` and which would allow complete and easy disassembly for
cleaning.
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OBJECTS OF THE INVENTION
A general object of the invention is to devise a
~ swivelled saliva ejector which is of inexpensive construction
`-; yet allows the ejector tube to be adjusted with tha thumb and
- forefinger of one hand.
.' Another object is to provide such a device which can
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,`~ be completely disassembled, cleaned and reassembled without
exarcise of mechanical skill or the use of tools.
-~1 A further object is to provide such a device wherein
all parts of the connector can be fabricated from a rigid poly-
'~ metric material of such nature that all surfaces will be
easily cleanable and will have a minimum tendancy to accept
and retain foreign materials.
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Yet another object is to devise a saliva ejector which
is leak-free, yet s~ivels freely and does not require complex
or expensive sealing features.
A still further object is to provide such a device
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in which debris entrained in the saliva doas not enter the
working area of the swivel connector.
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: ~ SUMMP.RY OF THE INVENTION
- Saliva ejectors according to the invention comprise
an ejector tube and a swivel connector. The outlet end
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portion of the tube is of a resiliently deformable polymeric
material and is forced through an axial bore in the body of
a female connector member. The connector includes a male
connector member having a first portion adapted to be con-
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nected to the evacuating hose, as by screw threads, the
-; male member also having a shank provided with an outer trans-
verse annular groove and an outer surface portion which tapers
: inwardly from the groove toward the tip of the shank. The
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, female connector member has an axially projecting thin-walled
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sleeve equipped with an inwardly projecting transverse
annular flange dimensioned to engage with a snap fit in the ~ -
groove presented by the shank of the male connector member. -
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The shank of the male connector member has a through bore
i which advantageously is of larger transverse dimension
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than and receives the end of the ejector tube. With the
device fully assembled, and the hose connected to a source
; of reduced pressure, fluid flow adequate for evacuation via
.; .~. . . the ejector tube and the bore of the male connector member
is established, and a small air flow is induced via the space
between the connector members to prevent leakage.
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In order that the manner in which the foregoing and
other objects are achieved according to the invention can be
understood in detail, particularly advantageous embodiments
thereof will be described with reference to the accompanying
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drawings, which form a part of the original disclosure hereof,
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and wherein:
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.~ Fig. 1 is a side elevational view of a saliva ejector
s in accordance with one embodimen1: of the invention;
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Fig. 2 is a longitudinal sectional view of a swivel
connector forming part of the device of Fig. l;
~ Fig. 3 is a transverse sectional view taken generally
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; on line 3-3, Fig. 2;
; Fig. 4 is a side elevational view of the connector
~ of Figs. 2 and 3 with a portion of the female connector member
S`,~;broken away for clarity of illustrationj showing the manner
i~in which the connector is assembled and disassembled, and
~:~ Fig. 5 is a view similar to Fig. 2 of a swivel
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~connector according to another embodiment of the invention.
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DETAILED DESCRIPTION OF THE EMBODIMENT OF FIGS. 1-4
In this embodiment, the saliva ejector comprises an
ejector tube 1 and a swivel connector 2 via which the ejector
tube is connected to a hose 3, Fig. 1, which according to
usual practice extends to a dental unit (not shown) and communi-
cates with a source of reduced pressure. Ejector tube 1 can -
be of oonventional type, comprising a length of resiliently
deformable tubing 4 having a metal wire 5 incorporated therein
as a stiffener, the tube being bent into the general form of
a J and retaining that shape because of the stiffening wire.
The tip of the shorter arm of the J is equipped with a slotted
inlet cap 6 and consitutes the inlet for saliva and entrained
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~ debris. The longer arm of the J terminates in outlet end
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portion 7, Fig. 2, which has a flat annular end surface 8
lying in a plane at right angles to the longitudinal axis
of portion 7.
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:~ Connector 2 comprises a male connector member 9 and
;~- a female connector member 10 both formed, as by injection
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;, molding, from a rigid polymeric material having low moisture
!`; absorption, high impact strength, stiffness and yield stress.
Advantageously, members 9 and 10 are of acetal resin, i.e.,
a polyoxymethylene polymer, such as the resin marketed by E.I.
duPont de Nemours & Co., Inc., Wilmington, Delaware, 19898,
under the trademark DELRIN. Such resins are available in non-
yellowing white formulations and, when molded, present slick
surfaces which are easily cleaned and have little tendancy
` to accept and retain foreign materials.
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Member 9 includes a first tubular portion 11 having
~ a right cylindrical outer surface of larger diameter, portion
;; 11 being internally threaded for connection to a threaded fitting -
12, Fig. 1, on hose 3. Member 9 also includes a shank which is
integral with and projects axially from portion 11 and is
~- provided with an outwardly opening transverse annular groove
13, Fig. 4, defined by a first shoulder 14, at the end of
'` portion 11, a right cylindrical bottom surface 15, and a second
;, shoulder 16, the outer diameter of shoulder 16 being smaller
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~ than that of shoulder 14. The main outer surface 17 of
:~ the shank is frustoconical, tapering inwardly from shoulder
;~ 16 toward the tip of the shank. At its tip, the shank has a
,;~ flat transverseend face 18. An axial through bore l9 extends
through the shank and is of a diameter slightly larger than
that of outlet end 8 of the ejector tube. The inner diameter
~;~ of the threaded portion of member 9 is large compared to
~ !; '; ,~`t bore 19 so that there is a transverse annular shoulder 20,
;~` Fig. 2, against which a suitable screen or filter element
can be held by fit~ing 12.
" Female connector member 10 includes a body portion 21. ~,. . .
having an axial through bore 22 of a diameter slightly smaller
than the outer diameter of tubing 4 when the tubing is in relaxed
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undeformed condition. Projecting from one end of body portion
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21 is a thin-walled sleeve 23 which terminates at its free
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- end in a transverse annular inwardly directed flange 24
` dimensioned to engage in and substantially fill groove 13 of
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member 9. Body portion 21, sleeve 23 and flange 24 are integral.
The outer diameter of sleeve 23 is equal to the outer diameter
of body potion 21 at the juncture of the sleeve and body
portion. The inner diameter of sleeve 23 is large as
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compared to the diameter of bore 22, and there is a flat trans-
verse annular shoulder 25, Fig. 2, at the end of body portion
21 to which sleeve 23 is joined. Near the opposite end of
body portion 21, bore 22 is interrupted by a transverse
annular groove which accomodates an O-ring 26 of elastomeric
material. The outer surfaces of sleeve 23 and the part of
body portion 21 adjacent the sleeve are right cylindrical when
the sleeve is relaxed and undeformed. Over most of its length,
however, the outer surface of body portion 21 is annularly con-
cave, as seen in Fig. 4, to provide for positive engagement of
the body portion between the thumb and orefinger.
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For assembly of the device, the outlet end portion
7 of ejector tube 1 is pushed into and through bore 22 of
connector member 10 until the tip of portion 7 projects beyond
shoulder 25, Fig. 2. As a result, portion 7 is deformed
radially inwardly, engaging the wall of bore 7 in a compressive
force fit and being engaged by O-ring 26 in good fluid-tight
sealing relation. To assemble the swivel connector ~, female
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connector member 10 is forced toward member 9, with flange
27 embracing the tapered surface 17 of the shank, in the
manner seen in Fig. 4, this operation being continued until
flange 24 reaches and snaps into groove 13.
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~ Though rigid in the sense of meeting the required
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~ minimum elasticity when tested in accordance with ASTM D747,
; D790, D639 or D882 ~ASTM D883-65T)~ the polymeric materials
suitable for female connector member 10 have substantial
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, resilience, allowing outward deformation of sleeve 23 in the
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manner shown in Fig. 4, followed by return of the sleeve to its
- - original relaxed configuration when flange 23 reaches groove
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~; 13. The return to relaxed configuration is immediate and
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essentially complete, so that flange 24 is positively retained
in groove 13 and there is low-friction rubbing engagement between
the mating annular surfaces of the flange and groove. ThusJ
while members 9 and 10 are locked securely together against
significant axial relative movement, the interengagad flange
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. and groove act as a low-friction bearing with respect to
rotation of member 10, about the axis of the connector,
p relative to member 9, and adjustment of the position of
tip 6 of the ejector in the patient's mouth can be accomplished
easily by use of only the thumb and forefinger of one hand.
Fro~ Fig. 2, it will be seen that, in the assembled
device, shoulder 25 is spaced a signigicant distance from
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end face 18 of the shank of the male connector member, and
that there is significant annular space between frusto-conical
surface 17 and the inner surface of sleeve 23. As a final
step of assembly, outlet po~tion 7 of the ejector tube is
pushed further through member 10 to insert ena 8 thereof into
through bore 19 of male member 9. While flange 24 substantially
fills groove 13, the mating surfaces of the flange and groove
are in only rubbing engagement. Nith hose 3, Fig. 1,
connected to the usual reduced pressure source, the interior
space defined by surfaces 17, 18, 25 and the inner surface of
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~ sleeve 23 is evacuated and a very small air flow is established
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~ from outside of the connector via groove 13. The end 8 of the
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~ ejector tube is disposed within the adjacent end of bore 19
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so that a significant portion of the tube is surrounded by the
wall of the bore, and there is only a small space between
tube end 8 and the surrounding wall of bore 19. Accordingly,
while there is substantial flow of saliva and entrained
debris via ejector tube 1 and bore 19 in series, there is
little or no opportunity for saliva and debris to escape
from the outlet end portion 7 of the ejector tube into the space
between surfaces 18 and 25. `
Ejector tube 1 is fabricated conventionally, and the
material of tubing 4 can be any of the flexible, resiliently -
deformable polymeric materials. Advantageously, tubing 4 is
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of a highly plasticized polyvinyl chloride formulation chosen
both for flexibility and resilient deformability. Tubing
extruded from such materials has adequate strength to maintain
its tubular form, yet is sufficiently deformable to allow
the radial compression necessary to allow outlet portion 7
to be pushed through bore 22. In the assembled device, com~
pression of outlet portion 7 causes the outer surface of
that portion to be firmly and uniformly engaged with the
wall of bore 22, tending to establish a good seal between
member 10 and the ejector tube. That seal is further aided
by inclusion of the O-ring 26. Accordingly, essentially
all of the pressure differential applied via the engaged
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~; surfaces 8 and 18 is effective to evacuate the space
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defined by surfaces 17, 18, 25 and the inner surface of
sleeve 23.
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: ~ EMBODIMENT OF_IG . 5
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Fig. S illustrates a second embodiment of the invention
wherein female connector member 10 is as hereinbefore described,
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` but male member 9a is modified so that the diameter of bore
: l9a is slightly smaller than the outer diameter of end 8 of
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the ejector tube. In this embodiment, outlet end portion 7
of the ejector tube is forced through bore 22 until end 8
is in flush rubbing engagement with the flat end face 18a
of the male member. Through bore l9a thus serves as an exten-
sion of the bore of the outlet end portion 7 of the ejector
tube, and the suction effect provided by hose 3 evacuates
the interior of the swivel connector because of air flow
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~ between end face 18a and the end face of tuhe end 8. Again,
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- there is little or no opportunity for debris to escape into
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~ the interior of the swivel.
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While particularly advantageous embodiments have
been chosen to illus-trate the invention, it will be apparent
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~~ that various changes and modifications can be made without
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departing from the scope of the invention as defined in the
appended claims~ Thus, for example, the tip of the shank
;: can be fo~med with a socket to receive the tip of outlet
' portion 7 of the ejector tube.
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