U.S. patent application number 10/818252 was filed with the patent office on 2004-09-30 for ultrasonic swivel insert.
Invention is credited to Chen, Shu, Parker, Patricia H., Rahman, Anisur Mithu.
Application Number | 20040191724 10/818252 |
Document ID | / |
Family ID | 27397234 |
Filed Date | 2004-09-30 |
United States Patent
Application |
20040191724 |
Kind Code |
A1 |
Rahman, Anisur Mithu ; et
al. |
September 30, 2004 |
Ultrasonic swivel insert
Abstract
An ultrasonic insert carries a rotary bearing adjacent to the
transducer. The bearing slidably engages an ultrasonic handpiece.
When seated in the handpiece, the insert is substantially
decoupled, on a rotary axis, from the handpiece. A rotary force
need only be applied to the insert to rotate it in the handpiece.
Alternately, an adaptor can be inserted into the handpiece. The
adaptor slidably receives a conventional ultrasonic insert. The
conventional insert can be easily rotated with a force applied only
thereto, relative to the handpiece.
Inventors: |
Rahman, Anisur Mithu;
(Gurnee, IL) ; Chen, Shu; (Buffalo Grove, IL)
; Parker, Patricia H.; (Midlothian, IL) |
Correspondence
Address: |
WELSH & KATZ, LTD
120 S RIVERSIDE PLAZA
22ND FLOOR
CHICAGO
IL
60606
US
|
Family ID: |
27397234 |
Appl. No.: |
10/818252 |
Filed: |
April 5, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10818252 |
Apr 5, 2004 |
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09917101 |
Jul 27, 2001 |
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6716028 |
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60223447 |
Aug 4, 2000 |
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60270687 |
Feb 22, 2001 |
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Current U.S.
Class: |
433/119 |
Current CPC
Class: |
A61C 1/07 20130101; A61C
17/20 20130101 |
Class at
Publication: |
433/119 |
International
Class: |
A61C 003/08 |
Claims
1-69. (canceled)
70. An ultrasonic insert which is engageable with a hollow
handpiece, the insert comprising: a treatment applying tip; an
ultrasonic transducer coupled to the tip; and a rotary bearing
non-removably carried between the transducer and the tip wherein
the bearing is rotatable relative to the tip.
71. An insert as in claim 70 wherein the bearing comprises a
cylindrical sleeve rotatably carried adjacent to the end of the
transducer.
72. An insert as in claim 70 which includes a generally
cylindrical, manually grippable section between the tip and the
bearing wherein the bearing is rotatable relative to the grippable
section.
73. An insert as in claim 70 wherein the bearing comprises a
cylindrical sleeve rotatably carried adjacent to an end of the
transducer, and wherein the sleeve rotatably abuts an end of a
grippable element.
74. An insert as in claim 73 wherein the sleeve includes an
exterior feature slidably engageable with the handpiece.
75. An insert as in claim 73 wherein the sleeve carries an annular
flange of greater diameter than the sleeve wherein the flange
rotates adjacent to the grippable element.
76. A rotatable ultrasonic dental insert comprising; a treatment
applying tip, a transducer non-rotatably coupled to the tip and a
handpiece engaging element, rotatably coupled to the tip, wherein
the tip is rotatable relative to the engaging element by a force
applied adjacent to the tip.
Description
[0001] This is a Utility Application claiming the benefit of the
earlier filing date of Provisional Application Ser. No. 60/223,447,
filed Aug. 4, 2000 and Ser. No. 60/270,687, filed Feb. 22,
2001.
FIELD OF THE INVENTION
[0002] The invention pertains to ultrasonic inserts of a type used
in medical/dental treatments. More particularly, the invention
pertains to such inserts with enhanced operating efficiency and
user comfort.
BACKGROUND OF THE INVENTION
[0003] Ultrasonic scalers are used in dental offices for
de-plaqueing teeth. Unlike manual scalers, these instruments are
powered i.e., the tip of the instrument vibrates at an ultrasonic
frequency allowing quick and easy debridement. The operator has
less hand fatigue as most of the energy for removing the plaque
comes from the generator that powers the instrument. The dental
practitioner need only lightly touch the tip of the instrument at
an angle to the tooth surface to dislodge the plaque.
[0004] Known ultrasonic scalers, such as scaler 10 illustrated in
FIG. 1A, have a handpiece 12a coupled at one end 12a-1 to a cable
12b which includes a hose, to provide a fluid, and conductors to
provide electrical energy. The other end of the cable 12b
terminates at an electrical generator and fluid source 12c. One
type of fluid is water.
[0005] The other end of the handpiece 12a-2 is hollow and is
intended to receive a replaceable insert 14 with a transducer 14a
(magnetostrictive or piezoelectric) carried on the insert. The
transducer 14a extends from a proximal end of the insert 14 into
the hollow body 12a-2. An ultrasonically vibrated tip 14b extends
from a distal end of the insert. One such insert has been disclosed
and claimed in U.S. Pat. No. 5,775,901, entitled "Insert For
Ultrasonic Scaler", incorporated herein by reference.
[0006] Known magnetostrictive ultrasonic inserts function by
exciting a stack of thin nickel plates at a frequency equal to the
stack's natural frequency. The excitation is induced through an
electrical generator in unit 12c, which supplies a current to a
coil embedded in the handpiece. When the insert 14 is placed in the
handpiece 12a and the frequency generator 12c is powered on, the
operator tunes the generator (manual tuning) until it reaches the
resonance frequency i.e., attains the natural frequency of the
insert. Alternately, auto-tune units automatically lock on the
insert resonance frequency once powered on. At this time, the stack
starts vibrating. This vibration of the stack is amplified and
transmitted to the tip 12b by means of a connecting body or
concentrator. The connecting body is made from material that
provides good sound transmission efficiency.
[0007] While the insert 14 is operational, fluid is pumped through
the cable-generator system 12b, c and through the handpiece 12a to
the tip 14b of the insert 14. The vibrating tip 14b breaks the
fluid stream into a spray. The spray not only keeps the tip cool,
but also keeps the surface of the tooth cool and provides
protection against tissue damage.
[0008] The fluid path through the handpiece 12a needs to be sealed
such that no leakage occurs until the fluid stream exits from the
insert at the very tip through a fluid delivery channel. Typically,
ultrasonic inserts do not have any moving parts other than the
minuscule displacement of the nickel stack, the connecting body or
the tip.
[0009] Known magnetostrictive dental scaling ultrasonic inserts
used in the U.S.A. are designed to vibrate at 25 kHz or 30 kHz
frequencies. Another system, popular in Europe, uses a
piezoelectric transducer.
[0010] In using an ultrasonic scaler during a cleaning, the dental
practitioner will need to repeatedly re-orient the location of the
insert tip 14b with respect to tooth surface depending on which
tooth of the mouth is being cleaned. In making this angular
adjustment, as illustrated in FIG. 1B, the practitioner will
typically take the insert out of the patient's mouth, rotate the
insert 14, and tip 14b, inside the handpiece 12a locating tip 14b
at a desired angular position. Both hands are used for this
rotation as the frictional forces that produce a tight fit of the
insert 14 in handpiece 12a must be overcome. During a typical
treatment, the process of reorienting the tip must be carried out
numerous times. This is not only time consuming but also interrupts
the ease and smooth flow of work.
[0011] In areas of the mouth where the practitioner chooses not to
rotate the insert 14, the practitioner's wrist must be twisted
sufficiently to achieve the same function. This twisting action is
opposed by the resistance of the cable 12b, the fluid supply hose
and power conductors, which is attached to the handpiece 12a.
[0012] There continues to be a need for ultrasonic scalers which
are more comfortable and less fatiguing to use than known
instruments. Preferably, any improvements will be downwardly
compatible with the numerous generators and handpieces that are
already present in dental offices.
SUMMARY OF THE INVENTION
[0013] A rotatable ultrasonic insert has a body section which
carries a bearing for rotatably engaging an ultrasonic handpiece.
The body is rotatable, about an axial centerline.
[0014] Rotation can be effected by applying a force only to the
insert. In response, the insert rotates but the handpiece does not.
Hence, single handed, two finger rotation is possible.
[0015] Preferably, a swivel feature is located at the gripping
region of the insert, i.e., close to the treatment tip, where the
practitioner would typically position his or her fingers. The
swivel allows the insert to rotate 360 degrees without any
limitation. This enables the practitioner to position the insert,
and the tip, at any angular orientation without having to take the
insert out of the patient's mouth. The swivel also allows rotation
of the gripping region and tip without having to rotate the
handpiece and/or the supply cord. This removes the resistance from
the operator's hand and reduces hand fatigue.
[0016] Additionally, a large diameter grip or handle, not only
reduces finger fatigue but also transmits a larger torque to the
swivel feature for the same amount of force.
[0017] An elastomeric handle, carried by the body, comfortably
interfaces with a user's fingers. The user can rotate the
elastomeric handle and the insert with two fingers relative to the
handpiece. Hence, during treatment there will be no need to rotate
the handpiece.
[0018] The elastomeric material allows for a positive grip since it
deforms under finger pressure and becomes locally non-cylindrical
in shape. The preferred material is silicone. Silicone is not only
repeatedly sterilizable under most sterilization processes found in
dental offices but also provides good traction with respect to the
type of gloves which are commonly used in dental offices.
[0019] The elastomeric handle engages the body only at a region of
minimal ultrasonically induced, vibration. The limited connectivity
between the body and the elastomeric handle minimizes build up of
heat between the body and that handle. It also avoids damping
ultrasonic vibrations transmitted along the body.
[0020] A method of assembly includes:
[0021] providing a body which carries an ultrasonic transducer, at
one end, and, a displaced treatment applying tip at the other
end;
[0022] sliding a rotary handle past the treatment applying tip
toward the bearing;
[0023] connecting the handle to the body at a region of minimal
ultrasonic vibration.
[0024] In another aspect of the invention, an adaptor has an
external periphery which can be slidably and releasibly inserted
into the opening in the handpiece. A standard ultrasonic insert is
inserted through the adaptor into the handpiece. The insert can
then be rotated relative to the handpiece with a rotational force
applied only thereto. Alternatively, the adaptor can be snap fitted
onto an exterior periphery of a handpiece.
[0025] Numerous other advantages and features of the present
invention will become readily apparent from the following detailed
description of the invention and the embodiments thereof, from the
claims and from the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] FIG. 1A illustrates a prior art ultrasonic scaler having an
insert and handpiece;
[0027] FIG. 1B illustrates one aspect of usage of the prior art
insert/handpiece combination of FIG. 1A;
[0028] FIG. 2A illustrates an insert in accordance with the present
invention;
[0029] FIG. 2B illustrates the insert of FIG. 2A in a handpiece as
in FIG. 1A and aspects of usage thereof;
[0030] FIGS. 3A, B and C are various views of an ultrasonic insert
body in accordance with the present invention;
[0031] FIGS. 4A, B, C and D are various views of a snap-fit rotary
bearing usable with the body of FIG. 3A;
[0032] FIGS. 5A, B, C and D are various views of a torque lock in
accordance with the present invention;
[0033] FIGS. 6A, B and C are various views of a swivel housing in
accordance with the present invention;
[0034] FIGS. 7A, B are various views of a cone usable in an insert
in accordance with the present invention;
[0035] FIGS. 8A, B and C illustrate steps in assembling an insert
in accordance with the present invention;
[0036] FIG. 9A is a side sectional view of an insert in accordance
with the invention illustrating the relationship of various
elements assembled in the steps of FIGS. 8A, B and C;
[0037] FIG. 9B is an enlarged sectional view illustrating aspects
of a section of FIG. 9A;
[0038] FIG. 10A is a side sectional view of a handpiece carrying a
snap-on adaptor in accordance with the present invention;
[0039] FIG. 10B is an enlarged partial side view of the handpiece
and adaptor of FIG. 10A with a conventional ultrasonic insert
positioned therein;
[0040] FIG. 10C is an over-all view of an insert as in FIG. 1
combined with an adaptor as in FIG. 10A;
[0041] FIG. 11A is an enlarged side view of an alternate embodiment
of an insert in accordance with the present invention;
[0042] FIG. 11B is an enlarged partial side sectional view of the
insert of FIG. 11A inserted into a handpiece of an ultrasonic
scaling unit, generally of a type illustrated in FIG. 1;
[0043] FIG. 11C is a side view of a portion of the handpiece of
FIG. 11B;
[0044] FIG. 11D is a side view of a collar threadable onto the
handpiece of FIG. 11B;
[0045] FIGS. 12A, B are top and side views of a preferred form of
an ultrasonic transducer; and
[0046] FIG. 12C is an end view of the transducer of FIG. 12B.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0047] While this invention is susceptible of embodiment in many
different forms, there are shown in the drawing and will be
described herein in detail specific embodiments thereof with the
understanding that the present disclosure is to be considered as an
exemplification of the principles of the invention and is not
intended to limit the invention to the specific embodiments
illustrated.
[0048] FIG. 2A illustrates an insert 20 in accordance with the
present invention. The insert 20 includes a transducer 20a which is
illustrated as a magnetostrictive transducer. Alternately, it could
be a piezoelectric ultrasonic transducer without departing from the
spirit and scope of the present invention.
[0049] The transducer is rigidly coupled to an elongated body 20b
which is covered in part by a cylindrical, elongated deformable
elastomeric grip 20c. The grip 20c terminates in a cone 20d which
is positioned between the grip 20c and operative treatment applying
tip 20e.
[0050] The insert 20 operates in accordance with the principals of
known ultrasonic dental instruments as discussed above relative to
FIG. 1A. However, insert 20 also carries a rotary bearing 24 which
exhibits a hollow cylindrical stem section 24a which defines a
cylindrical region 24b which receives a sealing O-ring 24c. The
hollow member 24a terminates at a disc 24d of larger diameter. A
planar surface 24d-1 of disk 24 is adjacent to stem 24a
[0051] As discussed subsequently, when installed on the elongated
body 20b, the rotary bearing member 24 is rotatable relative to the
body 20b, gripping member 20c and tip 20e. Hence, if the member 24
is fixed, the body 20b, gripping member 20c and tip 20e are readily
rotatable therein.
[0052] FIG. 2B illustrates the standard ultrasonic handpiece 12a,
cable 12b and generator 12c, discussed above, of a type found in
dental offices. The insert 20 is slidably receivable, in a
direction 16a, in the hollow end 12a-2 of the handpiece 12a.
[0053] The cylindrical stem 24a of the rotary bearing 24 slides
into the hollow handpiece 12a. The O-ring 24c slidably engages the
interior periphery of the handpiece 12a providing a fluid seal and
reliably engaging the insert 20 with the handpiece 12a
[0054] When installed in the handpiece 12a, as illustrated in FIG.
2B, insert 20 can be rotated relative to handpiece 12a with rotary
forces applied to the deformable gripping member 20c for purposes
of orienting the tip 20e relative to a tooth being de-plaqued. As
illustrated in FIG. 2B, the practitioner need not restrain the
handpiece 12a while rotating the insert 20. Additionally, insert 20
is relatively rotatable relative to handpiece 12a using only two of
the practitioner's fingers. Thus, the orientation of the tip 20e
can be continuously altered with only two of the practitioner's
fingers, requiring only one hand, while the scaling operation
proceeds. This will reduce operator fatigue and substantially
shorten the time necessary for the scaling process. The expected
torque needed to rotate insert 20 preferably will be less than 2.0
inch-oz.
[0055] When the practitioner has concluded the de-plaqueing
process, the insert 20 can be removed from the handpiece by pulling
it axially from the handpiece in a direction 16b and sterilized.
The same insert or a different insert can then be subsequently
inserted into handpiece 12a to treat the next patient. It will be
understood that the present invention is applicable to ultrasonic
inserts which utilize either magnetostrictive or piezoelectric
transducers without limitation.
[0056] FIGS. 3A, 3B, 3C illustrate different views of the body 20b
of the insert 20. As illustrated in FIGS. 3A and 3B, body portion
20b is attached to a first end 20a-1 of transducer 20a as would be
understood by those of skill in the art. An elongated cylindrical
extension 20b-1 extends axially from transducer 20a toward tip
20e.
[0057] The elongated cylindrical metal member 20b-1, as would be
known to those of skill in the art, is caused to vibrate axially,
in response to electro-magnetic signals received at transducer 20a
from handpiece 12a. The signals are produced by generator 12c. This
axial ultrasonic vibration is in turn coupled to the tip 20e and
used for effecting de-plaqueing of the subject tooth T, in a spray
of fluid M, illustrated in phantom in FIG. 3C.
[0058] A pair of notches 20b-2, 20b-3 is formed on elongated body
member 20b-1 in a region of substantially zero axial ultrasonic
vibration. While a pair of notches 20b-2, -3 has been illustrated
in FIG. 3B, it will be understood that a single notch, or three
notches could be used without departing from the spirit and scope
of the present invention. Additionally, the exact shape of the
generally rectangular notches 20b-2, -3 is not a limitation of the
present invention.
[0059] An interior or base plane 20b-2', 20b-3' of each notch
20b-2, -3 is parallel to a plane through the central axis of tip
20e. This notch/tip configuration facilitates energy transmission
along insert 20 without increasing the risk of a mechanical
fracture due to potential fatigue stress.
[0060] An elongated fluid flow slot 20b-4 extends axially in the
region where the body 20b-1 interfaces with the tip 20e. As
discussed subsequently, fluid for the spray M flows
therethrough.
[0061] FIGS. 4A, B, C and D illustrate different views and
additional details of rotary bearing 24. As illustrated therein,
the cylindrical stem 24a is hollow and defines an interior
peripheral surface 24e which is adjacent to the elongated body
portion 20b, see FIG. 2A. The bearing member 24 carries a second
O-ring 24c-1 in a cylindrical region 24d-2 which is adjacent to a
plurality of radially disposed spring-loaded fingers indicated
generally at 24g.
[0062] The fingers 24g each terminate at a barbed free end, such as
24g-1, -2, -3 with preferably four such fingers disposed radially
about the annular surface 24d-2. Neither the number nor the exact
shape of the ends 24g-1, -2 . . . -n are limitations of the present
invention. As discussed in more detail subsequently, the fingers
24g-1, -2, -3, -4 are deflectable radially inward during assembly
and are biased radially outwardly to return to their undeflected
condition, illustrated in FIGS. 4A, 4B.
[0063] The second O-ring 24c-1 which is positioned adjacent annular
surface 24d-2 cooperates with O-ring 24c to provide a sealed fluid
flow path between handpiece 12a and cone 20d. Cooling fluid flows
from handpiece 12a through aperture 24-1, FIG. 4c, and past the
fingers 24g-1, -2, -3, -4. It will be understood that the number of
fingers 24g is not a limitation of the present invention.
[0064] FIGS. 5A-5D illustrate various views of a torque lock 30
which couples a torque due to force applied to deformable gripping
member 20c by the user's fingers to the body 20b and treatment tip
20e. The torque lock 30 is preferably molded of a sterilizable
thermoplastic which, as discussed below, permits it to deform
during assembly without fracturing.
[0065] The torque lock 30 has a hollow body section 32a with an
exterior periphery 32b and an internal circumferential periphery
32c. The torque lock is molded with a slot 34a formed in the body
32a which permits outward radial deformation of sections 34b and
34c, adjacent the slot 34a, as the torque lock 30 is slid onto the
elongated body portion 20b-1. Surfaces 36a, 36b slidably engage the
notches 20b-2, -3 of the elongated member 20b-1. When the notches
are so-engaged, the deformable members 34b, c move radially
inwardly to a non-deformed condition. In this state, torque lock 30
is locked to the body 20b at the notches 20b-2, -3.
[0066] The interaction between the surfaces 36a, b, in the slots
20b-2, -3 inhibits both rotation and translation of the torque lock
30 relative to the body member 20b-1. Hence, rotating the torque
lock 30 will also rotate the body 20b of the insert.
[0067] Once the torque lock 30 has been installed on the body
member 20b-1 at the slots 20b-2, -3, it will be fixedly located at
a region of substantially zero axial ultrasonic vibration. This
minimizes a build-up of heat between the vibrating body 20b-1 and
the torque lock 30. As will be understood by those of skill in the
art, in addition to locating the notches 20b-2, -3 at a region of
minimal axial ultrasonic vibration, preferably centered on the
expected nodal point of zero vibration, the cross section of the
connecting body portion 20b-1 through the notches 20b-2, -3 will
have a large enough cross-sectional area to transmit ultrasonic
vibrations without constriction.
[0068] FIGS. 6A, B, C illustrate various views of a housing 40
which is press fit over torque lock 30 and which slidably and
lockingly engages barbed fingers 24g-1, -2, -3, and -4 of the
rotary bearing 24. The housing 40 has an elongated generally
cylindrical body 42a with a smooth exterior periphery 42b. The body
42a terminates at an end 42c adjacent an annular shoulder 42d.
[0069] The shoulder 42d in turn has an end surface 42d-1. When
installed, the end surface 42d-1 is adjacent to and rotates
relative to annular surface 24d-3 of bearing 24.
[0070] The annular member 42d exhibits an internal cylindrical
peripheral surface 42d-2 which traps O-ring 24c-1 in position,
forming a fluid seal with bearing 24 when surface 42d-1 is
positioned adjacent to surface 24d-3. When so-positioned, the
housing 40 can rotate relative to bearing 24 but is not movable
axially relative thereto.
[0071] When the housing 40 is rotated relative to the bearing 24,
the surface 42d-2 slides over O-ring 24c-1 without excessive
friction thereby enabling a practitioner to rotate the tip 20e
relative to the handpiece 12a with the use of force applied to
elastomeric gripping member 20c by only two fingers.
[0072] The housing 40 has an interior, cylindrical peripheral
surface 42b-1 which surface deflects the barbed fingers 24g-1, -2,
-3, -4 radially inwardly when the housing 40 is slid onto the
fingers 24g. The fingers 24g, which have been inwardly radially
deflected by the surface 42b-1 engage a cylindrical slot 42b-2 with
a snap fit. The radially compressed fingers 24g expand outwardly
radially and the barbed ends 24g-1, -2, -3, 4 lock into the slot
42b-2 precluding axial motion of the housing 40 away from surface
24d-3 of bearing 24.
[0073] As the housing 40 is slidably engaging the barbed fingers
24g-1, -2, -3, -4 and internal cylindrical peripheral surface 42b-3
engages exterior cylindrical peripheral surface 32b of torque lock
30 with a press or interference fit. The press fit between torque
lock 30 and housing 40 locks those two parts together precluding
either axial linear movement or rotary movement therebetween. The
end 42b of housing 40 carries a plurality of threads 42b-4.
[0074] The snap fit between the housing 40 and the rotary bearing
24, in combination with the O-ring 24c-1 provide a sealed fluid
flow path from inflow periphery 24e of bearing 24 through outflow
end surface 42b-5 of housing 40. This fluid flow seal, as noted
above, precludes fluid leakage. The exterior cylindrical surface
24g' of each of the fingers 24g rotatably engages the internal
cylindrical surface 42b-1 of the housing 40. This provides a pair
of rotatable bearing surfaces which permit smooth two finger
rotation of the deformable member 20c and the treatment tip 20e. A
medically acceptable, sterilizable, lubricant is preferably
provided between the bearing surfaces to improve rotational
smoothness and further reduce friction and required torque.
[0075] FIGS. 7A and 7B are views of cone 20d which is carried by
rotatable housing 40. Cone 20d has an internal flow path 50a which
is sealed by O-ring 50b. Cone 20d includes a set of threads 52.
Cone 20d is coupled to housing 40 by the rotatable engagement of
threads 42b-4 of housing 40 and 52 of cone 20d.
[0076] The O-ring 50b precludes leakage between an end 50c and a
region of body portion 20b-1 which extends therethrough. Fluid
exits cone 20d via fluid flow channel 20b-4 in the body portion
20b-1. Fluid exits the cone 20d in the channel 20b-4 as a stream.
The stream of fluid impacts the vibrating tip 20e and creates a
smooth spray pattern M suited for cooling and cleaning tissues.
Adhesives, such as epoxy, can be used to permanently attach the
cone 20d to the housing 40.
[0077] FIGS. 8A, 8B and 8C illustrate the steps of assembly of the
insert 20. Groove 20b'-1 in body section 20b' provides a positive
gripping surface usable during assembly by manufacturing fixtures
to block axial movement of the insert 20.
[0078] As illustrated in FIG. 8A, initial steps of assembly of the
insert 20 include sliding rotary bearing member 24 past operative
tip 20e onto body portion 20b-1. The torque lock 30 is then slid
onto the operative element 20e and forced along the elongated body
20b-1, which in turn forces elements 34b, c radially outward until
surfaces 36a, b thereof slidably engage the slots 20b-2, -3. This
slidable engagement with the slots in the body member 20b locks the
torque lock 30 to the body member 20b and traps the bearing member
24 against a portion 20b' of the body 20b precluding axial movement
thereof. The bearing member 24 continues to be rotatable relative
to the elongated body portion 20b.
[0079] As illustrated in FIG. 8B, the housing 40 is then slid onto
and past the operative element 20e and forced onto the rotary
bearing 24, thereby radially inwardly deflecting the barbefingers
24g-1, -2, -3, -4 and also press fit onto external peripheral
surface 32b of torque lock 30 adjacent to disc 24d. When seated on
the bearing member 24, the inwardly deflected fingers 24g expand
into radial slot 42b-2, axially locking the housing 40 to the
bearing 24 while still permitting relative rotary motion
therebetween.
[0080] The circular elastomeric gripping member 20c can be slid
onto housing 40 either before or after the cone 20d is threadably
engaged therewith. The gripping region 20c has an inner diameter
which is slightly smaller than the outer diameter of the housing
40. The member 20c thus elastically attempts to contract around the
housing 40 which minimizes unintended slippage of the grip 20c
relative to the housing 40. Member 20c can also be permanently
attached to housing 40 with adhesive.
[0081] FIG. 9A illustrates a side sectional view of an assembled
insert 20 in accordance with the method of steps of FIGS. 8A, B and
C. FIG. 9B is an enlarged side sectional view of a portion of FIG.
9A further illustrating the relationships of the various elements
therein.
[0082] As will be understood by those of skill in the art,
preferably tip 20c will be formed and heat treated prior to the
start of the assembly process illustrated in FIG. 8A. By forming
housing 40 as a separate element from core 20d, the length of each
is less than the combined length of 20d and 40. Hence, each can be
independently slid over exemplary curved tip 20e though the
assembled combination 20d and 40 will not slide over tip 20e.
[0083] FIG. 10A illustrates a snap-on plastic adaptor 70 which is
intended to be used with a standard handpiece, such as the
handpiece 12a. As illustrated in FIG. 10A, handpiece 12a includes
an annular depression 12c adjacent to open end 12a-2. The adaptor
70 snap-fits onto the handpiece 12a at the groove 12c.
[0084] Adaptor 70 has a body section 72a which carries an annular
locking protrusion 72b which slidably engages the slot 12c locking
the adaptor 70 thereto. The adaptor 70 also includes a bearing 74a
which is carried in an interior region 74b of the body 72a. An
O-ring seal 74c can be positioned adjacent to the bearing 74a to
minimize the likelihood of leakage from fluid flowing through the
handpiece 12a into an insert coupled thereto.
[0085] The insert 70 defines a channel 76a which co-extends with
and abuts channel 12d in handpiece 12a. The channels 76a and 12d
receive a standard insert such as the insert 14, which is to be
rotatably coupled to handpiece 12a and to be energized thereby.
[0086] FIG. 10B illustrates added details of standard insert 14
coupled to adaptor 70 for rotation relative to handpiece 12a. In
the embodiment illustrated in FIG. 10B, the adaptor 70 in
combination with handpiece 12a and insert 14 provide a sealed fluid
flow path between the interior peripheral surface 12b of the
handpiece and tip 14b of the insert. In this configuration, a user
can rotate insert 14 relative to handpiece 12a by applying rotary
forces to the grip 14c in a manner analogous to the way in which
rotary forces are applied to the grip 20c of rotatable insert 20
previously described.
[0087] Using insert 70, a standard handpiece, in combination with
standard inserts, such as the insert 14, can cost effectively
provide improved convenience and comfort for the practitioner. It
will be understood, if desired, that the insert 70 could be color
coded. The insert 70 can be molded of any sterilizable plastic such
a thermoplastic material commercially available and known as
polyphenylsulfone. It will also be understood that a plurality of
snap-fit fingers, such as the fingers 72b, can be molded in housing
72a for purposes of releasibly attaching the adaptor to the
handpiece 12a.
[0088] FIG. 10C is an over-all view of insert 14 coupled to
handpiece 12a via adaptor 70.
[0089] FIGS. 11A and 11B illustrate an alternate form of an adaptor
80 usable with a handpiece 82. The adaptor 80 includes a
cylindrical body section 80a which carries a bearing 80b which
could be implemented as a plastic ring bearing. The bearing 80b is
carried in a cylindrical slot 80c in housing 80a.
[0090] Housing 80a also carries an O-ring seal 80d in a second slot
80e. Finally, the body 80a terminates at a plurality of deflectable
locking fingers 80f. The body 80a is hollow and defines an internal
peripheral cylindrical surface 80g.
[0091] Insert 80 is slidably receivable into handpiece 82 with a
snap-fit. The exterior surfaces of the fingers 80f slidably engage
a locking slot 82a formed in an interior peripheral surface 82b of
the handpiece 82. The interior peripheral surface 82b also includes
a slot 82c for receipt of the O-ring seal 80e, and, a slot 82d
which receives the rotary bearing 80b carried by the insert 80. It
will be understood that the O-ring 80d provides a fluid seal
between handpiece 82 and an insert, such as the insert 14 shown in
part in phantom, which has been slidably inserted into the adaptor
80 in contact with the internal peripheral cylindrical surface 80g.
When so-inserted, the insert 14 can be rotated, along with adaptor
80 relative to the handpiece 82 so as to promote the convenience
and comfort of a practitioner. A collar 86 is threadable onto the
end of the handpiece 82 to trap the adaptor 80 in place and prevent
axial movement thereof.
[0092] FIGS. 12A-C illustrate details of a preferred structure of
stack 20a. By impressing a "W" bend 20a-1 along the length of each
member of the stack, as illustrated, stiffness of the stack can be
increased. This in turn promotes continued alignment of the stack
relative to central axis HP-A, see FIG. 2B, while the insert 20 is
being rotated. The improved alignment minimizes the likelihood of
the stack 20a rubbing against internal peripheral surface 12d
during rotation, hence eliminating a possible source of friction
and noise.
[0093] From the foregoing, it will be observed that numerous
variations and modifications may be effected without departing from
the spirit and scope of the invention. It is to be understood that
no limitation with respect to the specific apparatus illustrated
herein is intended or should be inferred. It is, of course,
intended to cover by the appended claims all such modifications as
fall within the scope of the claims.
* * * * *