Note: Descriptions are shown in the official language in which they were submitted.
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APPARATUS AND METHOD FOR ASSEMBLY AND DISASSEMBLY
OF INTERCHANGEABLE SURGICAL ACOUSTIC MEMBERS
BACKGROUND OF THE INVENTION
,~
This invention relates to an apparatus and method
for an assembly and a disassembly of interchangeable
surgical acoustic members. More particularly, this
invention relates to a fixture for securing a suxgical
handpiece for cooperating with a torquing wrench having a
tightening head with predetermined torquing lLmits and a
10 loosening head mounted on the same body. Still more
particularly, this invention relates to a method of
assembling and disassembling such interchangeable surgical
acoustical members.
Ultrasonic surgical devices are known for
15 performing a number of surgical procedures.
representativP device is shown in United States Patent No~
3,589,363 describing a hand-held instrument having an
operative tip vibrating at a frequency in the ultrasonic
range, and in which a handpiece includes a transducer.
20 Connections are provided on the handpiece to a source of
treatment fluid and a pump to withdraw suspended tissue
particles in a fluid from an operative site. The tip is
elongated and provided with a thickened shank portion
formed with a pair of flats, originally intended to
25 accommodate a wrench for tightening.
In practice, the design of such ultrasonic
surgical devices depends not only on the technical and
functional requirements of a resonant body, but also upon
their surgical application. Thus, the length of the tip
30 and its diameter to be acceptable for a useful surgical
device in various operative site areas has developed over
the years, based upon experience with such devices. In
particular, it has been determined in the art that an
especially useful arrangement incorporating proportioned
35 surgical acoustic members, both from the standpoint of its
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surgical application and with respect to its
manufacturability and costs, is based upon a combination of
parts that are threaded together for easy interchange. The
joint between the tip and the device is generally made at a
point between a half- and quarter-wave length of the
acoustic member in question.
However, as the length of the interchangeable
part approaches a quarter wavelength, the stress at the
threaded joint increases, thus requiring a greater force to
maintain the coupling surfaces in appropriate contact
during ultrasonic vibrations. In practice, it is important
for intimate contact to be maintained between the coupling
surfaces to maximize energy transfer, minimize mechanical
losses, obtain consistent performance during surgical use
of the device, and to minimize parasitic vibrations during
operation. In particular, the latter may cause premature
failure of either or both o~ the coupled acoustic members.
Experience with such devices has also determined
an appropriate coupling force or torque for such systemsO
The coupling torque is sufficiently great that the acoustic
members cannot be adequately fastened with normal finger
force, requiring a wrench with an appropriate mechanical
advantage. Thus, a techni~ue for fastening and unfastening
such surgical tips to such devices has been available to
the art, as will be described in greater detail.
The techni~ues of fastening and unfastening the
surgical tip to the device are based upon a number of
constraints in the art. On the one hand, the design and
size of the threaded joint between the tip and the
acoustical member is made as small as possible to minimize
the weight for the surgeon ~nd to minimize visual
interference with the surgical procedure. Partly because
of such size, o~ertightening of the threaded joint is
notdesirable since overtightening may overstress the
threaded joint resulting in its fracture. On the
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contrary, insufficient tightening can result in incomplete
acoustical coupling, heating of the ~hreaded joint,
degraded surgical performance, and a potential for
eventual catastrophic failure of the acoustic parts.
A system available to the art, which will be
described in connection with Figs. 1 and 2, has provided
two toxque wrenches, a tip socket, a stack socket and a
holding fixture to provide operating room personnel with
an ability to secure the handpiece of the surgical device,
tighten the tip to the handpiece to a preset level, and
then later untighten the interchangeable acoustic members
used for each surgical case. Such an apparatus used a
conventional tightening wrench, but some difficulty was
experienced in providing enough force to loosen the
ultrasonic tip a~ter a surgical usage. Accordingly, a
second wrench, for untightening, was provided as an
adapted commercial devi~e allowing disassembly of the
acoustic members without allowing uncontrolled tightening
by the use of a single direction clutch. Such an
~0 apparatus was intended Eor use in a non-sterile field and
somewhat cumbersome as surgical devices developed to
include curved and straight extenders. The availability
of alternative tip structures for use by the surgeon
resulted in a more elaborate and more complex device which
is difficult and confusing to utilize, was nôt easily
portable, and tended to be expensive to manufacture. In
addition, such device was not readily sterilizable for use
in an operative field for the convenience of changing tips
during surgery.
Accordinglyi it was a problem in the use of such
a device to develop a simplified tor~ue wrench to combine
the tightening and loosening features in a single wrench,
capable in this environment of cooperating with an
existing handpiece holding fixture. One particular
problem was that socket wrenches which were commercially
available were not readily useable on elongated members
because the available sockets are solid and not suited for
use at a position intermediate an elongated member.
Accordingly, it is an overall object of this
invention to provide a modified fixture for securing the
handpiece of the surgical device for tightening and
loosening a surgical tip secured to the handpiece.
It is another overall object of the invention to
provide such a handpiece fixture which can be h~nd-held or
readily mounted on a stand on a table to support the
handpiece and handpiece fixture during assembly or
disassembly.
It is still another object of the invention to
provide such a handpiece fixture which is capable of
accepting in a rotatably secure position various handpiece
and tip combinations, such as are comprised by a standard
straight handpiece or an angled handpiece, on the one
hand, connected directly to straight, curved or flexible
tips, or to straight or curved extenders which the tip is
attached.
It is still another object of the invention to
provide such a fixture for a handpiece of the type
described, wherein the relative rotation between the
fixture, a handpiece, and the acoustic vibrator can be
secured to a key as in the currently commercial embodiment
so that the fixture and wrench according to this invention
can be utilized with existing surgical devices and
handpieces currently available to ~perating personnel.
It is another overall object of this invention
to provide a convenient method and apparatus to facilitate
a change in the fragmenting and related elements during a
surgical procedure in a way which eliminates a need for
removing the acoustic vibrator from the handpiece as in
the prior art.
It is still another overall object of this
invention to provide a torque wrench which is capable of
sliding over an assembled and hand-tightened combination
of a handpiece~ tip, and/or extender and to provide a
socket which is structurally accommodated to such an
elongated subassembly.
It is still another object of this invention to
provide a tor~ue wrench with a socket assembly of the type
described having both a tightening head preset to a
10 predetermined torquing limit and a loosen~ng head,
arranged in such a way to preclude an operator from
applying the wrench in an erroneous direction.
It is still another object of this invention to
provide a fixture for use with such a wrench that can be
15 used in hand to cooperate with the wrench in a scissor
fashion, or be supported on a table support plate at the
choice of the user.
It is a further overall object of this invention
to provide such a handpiece torquing set in kit form for
the convenience of medical personnel and arranged for easy
sterilization within the sterile ield so that the tips
can be quickly and easily exchanged either prior to,
during or after surgery with a minimum disassembly of the
handpiece, while avoiding inadvertent damage to the
25 exposed acoustic vibrator stack and human engineered to
minimize operator error and confusion.
BRIEF SUMMARY OF THE INVENTION
Directed to achieving the foregoing objects of
the invention and overcoming problems in connection with
the tightening and loosening of an acoustic vibratory
assembly having a transducer and a tip to a handpiece in a
surgical device, the invention comprises a handpiece
fixture for use in combination with a torquing wrench
having a tightening head and a loosening head disposed in
a common body for receiving a socket therein for engaging
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mating tool pads on a surgical tip to tighten the tip to
form an ac~ustic vibrator tightened to a prede-termined
tightening tolerance.
The fixture includes a body, having a base
surface and a thickness capable of being held in the hand
of a user. A top surface includes an inclined portion
merging into a top end surface defining an elongated
keyway for receiving a key therein to secure a hand
tightened preassembly of a handpiece acoustic vibrator in
an elongated transverse opening passing through the body
from the opposed side surfaces of the fixture. The opening
is significantly defined in cross section by a circle
havi~g its radius at the center of an opening, portions of
which merge with the segments of a circle having a second
radius centered on an axis horizontally remote from the
main axis of the opening and a second circle centered on
an axis oblique to the main axis. Thus, the opening is
defined by four connected arcuate surfaces to accommodate
and secure various types of handpieces (straight or
angled) in combination with various tips ~straight or
angled) in com~ination, when used, with various extenders
~straight or angled). Preferably, the body i9 made of a
suitable rigid plastic material and the transverse opening
is defined in a block made from metal or other mat~rial
~5 o sufficient mechanical strength, and secured in an upper
foremost location of the body by threaded fasteners. The
lower surface of the fixture defines a plurality of
openings for mating with extending pins on the upper
surface of a table support device. The table support
device includes a base plate which comprises a rectangular
body to which are secured a plurality of table-engaging
foot pads. Mediately disposed on the upper surface of the
body is an upwardly-extending elongated support plate from
which the fixture engaging pins extend9 and further
defining a transverse channel in the upper surface
thereof.
The handpiece fixture is thus held by hand or
mounted to a table support device positioned on a table to
support the handpiece and the fixture during assembly or
disassembly. When used by hand, the torquing wrench is
positioned so that the handpiece fixture and wrench are
used in a scissor-like fashion. When the operator uses
the table support device, the wrench is positioned so that
it may be pushed downwardly while holding the handpiece
fixture against the table with the opposite hand of the
operator. The transverse channel in thej upwardly
extending elongated support plate of the table support
device is used during the disassembly of the tip from the
extender.
The method of using the fixture and the wrench
according to the invention includes the step of providing
a handpiece fixture of the type described, hand-tightening
a selected tip and/or extender to a transducer, selecting
a socket having a bore therethrough for mating ~7ith the
tip or extender, placing the socket on the tip or
extender, sliding the torque wrench ov~r the socket to
engage the socket, rotating the wrench in a ~irst
tightening direction about the socket to tighten the tip
or extender to a set predetermined torque. It is a
feature of the socket and wrench that they may be axially
slid over the axially elongated hand tightened subassembly
of the transducer tip and/or extender.
In an alternative method of use, the handpiece
fixture is positioned on the table support device so that
the openings in the base portion thereof engage the pins
extending from the table support plate, and the
hand-tightened subassembly is secured by a key in the
transversely extending opening in the handpiece fixture.
A socket is slid over the subassembly, the wrench engages
the socket, and the tip and/or extender is tightened with
the torquing wrench.
- 8 - 70557-~0
After use, or to change a tip and/or extender, the
untig~tening head of the torque wrench is used in conjunction wi-th
the handpiece fixture and/or the transverse slot in the table
support device.
As described, the apparatus and method provides the user
with a significantly simplified and enhanced capability to quickly
and easily exchange a variety of tips either prior -to, during, or
after surgery, while requiring a minimum disassembly of the hand-
piece to facilitate quick attachment and removal.
1~ In acco.rdance with a broad aspect of the invention there
is provided an apparatus for assembling and disassembling an
interchangeable acoustic member relative to a surgical handpiece,
the surgical handpiece defining a generally axially elongated
structure, comprising: a fixture comprising a body structurally
adapted to be he.ld in a hand of a user, said body deining an
opening transversely through said body which is structurally
adapted for receiving the surgical handpiece therein in a position
so that an acoustic member can be tightened, changed, or loosened
relative to the surgical handpiece by a torquing tool at a loca-
~0 tion adjacent to said fixture; said fixture further defining a key
slot in communication with said surgical handpiece-receiving open-
ing for securing the handpiece an.d said fixture against relative
rotation during tightening and untightening of the acoustic member
relative to the handpiece by use of a key; means for securing said
handpiece in a secure non-rotatable position adjacen-t to the
surgical handpiece, a socket defining a bore therein which is
structurally adapted for being slid over the acoustic member to
- 8a -
engage tool-pads on the surgical handpiece at one end thereof and
structurally adapted for being secured in socket receiving open-
ings in a torquing wrench; and said torquing wrench comprising a
body connected to a handle, said body defininy a first socket-
receiving opening for tightening said socket to a predetermined
torque and an adjacent second socket-receiving opening for loosen-
ing ~he surgical handpeice by said socket, said wrench and said
socket combination being capable of sliding over the elongated
acoustic member to perform said tightening and loosening
l~ operation.
In accordance with another broad aspect of the invention
there is provided a method for asse~bling and disassembling inter-
changeable acoustic members to a surgical handpiece, said method
comprising the steps of providing a fixture having a body defining
a handpiece-receiving opening therethrough for rotatably securing
said handpiece against rotation during torquing; hand tightening a
selected acoustic member to a transducer on said handpiece;
selecting a socket having a bore therethrough for mating with said
acoustic member; placing said selected socket on said acoustical
~0 member by sliding said socket over said acous-tic member through
said bore; sliding a torque wrench over said acoustic member to
engage said socket; rotating said wrench in a first tightening
~irection about said socket to tighten the acoustic member to a
predetermined torque; and removing said wrench and said socket
~rom said acoustic member.
In accordance with another broad aspect oE the invention
there is provided a torquing wrench having unlimited rotational
- 8b - 70557_40
travel for use with an assembly and a disassembly of surgical
acoustic members comprising: a body, including a handle, de~ining
a first socket-receiving opening for tightening a socket having a
bore therein to a predetermined torque, said socket-receiving
opening and said socket therein being structurally adapted to
receive -therethrough an elonga-ted surgical acoustic member; torqu-
ing means in said body cooperating with said Eirst socket-receiv-
ing opening for adjustab~.y setting the tightening torque to a
predetermined tightening value, said torquing means structurally
adapted and being operative to tighten said acoustic member on a
mating member upon rotation of said wrench to permit ~ree rotation
of said body about said acoustic member for tightening upon con-
tinued rotation of said wrench, thus permitting unlimited angular
rotation without overtightening beyond said predetermined tighten-
ing value.
In accordance with another broad aspect of the invention
there is provided, in combination, a torquing wrench and a body
including a handle having a socket for tightening and untightening
elongated surgical members, said combination comprising: a torqu-
ing wrench which includes a socket receiving opening therein and
~eans in said body for adjustably setting a predetermined -torquing
value applied to a socket, said torquing wrench being structurally
adapted to receive through said opening said elongated surgical
member so that said surgical member can be tightened to said pre-
determined torquing value upon rotati.on of said torquing wrench;
and a socket having a bore therein and structurally adapted to be
securely receiving in said socket receiving opening in said
- 8c -
torquing wrench, said elongated surgical member passing through
the bore of said socket member during tig~l-tening and untightening.
BRIEF DESC~IPTION OF THE DRAWINGS
In the drawings:
Fig. 1 provides a basis for understanding a prior art
method and apparatus for interchanging surgical acoustic members,
wherein:
Fig. l(a) depicts the attachment of a tip to a trans-
ducer, with or without an extender;
1~) Fig. l(b) shows the use of a stack socket to prepare the
subassembly ~or tightening;
Fig. l(c) shows the manner of securing the stack socke-t-
tip-transducer subassembly for tightening;
Fig. l(d) shows the tightening operation with the use of
a tip socket,
Figs. l(e) and l(f) show the attachment of the nose cone
assembly;
Figs. l(g) and l(h) show the attachment of the flue
assembly;
Figs. l(i) and l(j) show the attachment of the handpiece
assembly to the acoustic vibrator and nose cone with the flue
and
Figs. l(k) and 1(1) show the completion of the assembly
by connecting the manifold assembly;
Fig. 2 is a depiction of a prior art kit containing both
an assembly wrench and disassembly wrench with a stack socket and
a tip socket for performing the operations of Fig. l;
~2~
Fig. 3 is a perspective view, partly in section,
of the handpiece fixture according to the invention;
Figs. 4(a) and 4tb) together ~how a top view and
side view, partially in section, of a tor~uing wrench
according to the invention;
Fig. 5 shows a tip socket wherein Fig. 5(a) i5
an end view; and Fig. 5~b) shows a side view of the tip
socket;
Fig. 6 illustrates an extender socket where Fig.
61a) is an end view and Fig. 6(b) is a side view of the
extender socket;
Fig. 7 is a diagrammatic view of the coopera~ion
of the fixture and torquing wrench acting as a scissor,
when the operator prefers to hand hold the fixture;
Fig. 8 is a top diagrammatic view of a handpiece
assembly secured in the handpiece fixture with the torque
wrench engaging an exchangeable socket for exchanging the
tip or other acoustical member;
Fig. 9 is a view of the table support device
~ wherein Fig. 9(a) is a top view thereof and Fig. 9(b) is a
side elevational view partially in section,
Fig. lO is a side elevational view of the table
support member of Fig. 3, securing the Eixture of Fig. 3,
for use with the wrench of Fig. 4; and
Fig. ll(a) and ll(b) together show a top view
and side view, partially in section, of an alternative
embodiment of the torquing wrench of Figs. 4(a) and 4(b).
The drawings are illustrative of the concept of
the wrench to teach the selected art and should not unduly
limit the invention which obviously could include other
embodiments obvious to a person of ordinary skill in the
art within the spirit of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In order to facilitate an understanding of the
features and advantages of the fixture and wrench assembly
-- 10 --
is axially aligned, whereas if a curved extender is used,
the relationship between the grooves beneath the hold down
plate 33 and associated grooves in the set is such to
accommodate the angle subtended by the extender-transducer
S subassemblyO In either event/ the hold down plate 33 is
rotated to an open position and the acoustic vibrator is
positioned in the torquing kit in an appropriate groove.
When only a tip is used, a single key will mate with the
opening 24 in the transducer, whereas if an extender is
used, a pair of keys are used in vertically spaced slots
to secure the acoustic vibrator therein.
As shown in Fig. l(d~, the hold down plate 33 is
pivoted to its closed position, and the tip socket 30 is
slid over the tip 20. An assembly wrench 31 is attached
to the tip socket and rotated until a predetermined,
preset torque is achieved according to the construction of
the assembly wrench, and the wrench 31 is removed. The
tightening wrench 31 is then attached to the stack socket
30 and rotated until a predetermined torque is achieved so
that both the extender and the tip have been tightened to
the predetermined torque.
After the acoustic vibrator is assembled as
shown in Figs~ l(a)-l(d) r a nose cone is assembled as
shown in Figs. l(e) and l(f). A pair of O-rings 36 and
37 are provided adjacent a flange on the transducer remote
from the tip 20 and seated therein. A third O ring 38 is
provided in a groove on the transducer 23 proximate to the
tip 20 and a nose cone 39 i5 axially slid and rotated to
seat the nose cone 39 to the acoustic vibrator by threaded
engagement.
Thereafter, as shown in Figs. l(g) and l(h), a
flue 40 secured to a body 41 having a nose cone adap~er 42
at one end thereof is slid over the tip-extender
combination. Where only the tip 20 is used, only the flue
40 and nose cone adapter 42 are needed. The flue 40 is
then aligned relative to the tip 20 to centralize the tip
20 within the lue 4Q.
Thereafter~ the subassembly comprisiny the
acoustic vibrator, the nose cone, and the flue are
inserted into a handpiece housing 42 and rotated until
snug, as shown in Figs. l(i) and l(j)~ Thereafter, an
aspiration tube 44 with a flexible applicator cable 45 is
inserted through a slot in the nose cone 38 and fed
through an aspiration port 46 within the nose cone~ By
pulling the cable 45 through the tip 20, the aspiration
tube 44 will attach to the aspiration port ~6. As shown
in Fig. 1(1), the irrigation tube is secured to an
irrigation port 48, and clips 47 secure the tubing to the
body of the ins~rument. The irrigation and aspiration
tubing is then connected to the instrument.
To disassemble the acoustic vibrator after
surgical procedure, the above-described assembly
instructions are reversed, using a disasse~bly wrench 32.
An improved ixture acrording for use to the
invention i~ shown in Fig. 3 for securing the assembled
handpiece acoustic members therein to complete tightening.
The fixture includes a body 50 defining a lower surface 51
having a pair of openings 52 therein. The body 50 defines
a sloped upper surface 53 merging into a left end surface
54 and a generally horizontal upper surface 55 merging
into a right end surface 56 having a height greater than
the height of the surface 54. Such a structure, which
resembles a staple gun, is designed to be held
conveniently in the hand of the user. The upper surface
55 defines a key slot 57 merging into a transversel~
extending opening 58 for receiving and securing the
handpiece. The structure of the transverse opening 58 is
designed to receive a straight handpiece, an angled
handpiece, which is angled at any angle up to 90 degrees,
a straight extender, a curved extender, or othax handpiece
- 12 -
assembles. Thus, the opening 58 is defined by a pair of
arcs 59 and 60 about a center ~1, a third arc 62a defined
about a center 62 located horizontally remote from the
center a~is 61 and an arc 64 located about a center 65 at
an upwardly oblique angle from the center axis 61~ The
handpiece which is axially elongated and its tip (or
tip~extender combination) are fixedly secured by a key
inserted into the key slot 57 to couple the fixture with
the handpiece to prevent relative rotation between the
fi~ture, handpiece and acoustic vibrator. The fixture
according to Fig. 3, in conjunction with the tip wrench of
Fig. 4, significantly enhances the ability of operating
room personnel to change fragmenting and related elements
during the operating procedure, thus eliminating the
necessity of removing the acoustic vibrator from the
handpiece proper as had been required in connection with
the procedure described in connection with prior art Fig.
1. The new fixture is intended to accept the assembled
handpiece.
Fig. 4 is a diagra~natical illustration of the
torque wrench 70 constructed for use with the invention.
The wrench 70 comprises a body 71 connected to a handle
72. The body defines a first socket receiving opening 73
~or tightening to a predetermined torque and an adjacent
socket receiving opening 74 for loosening a tip or
extender from the transducer. Preferably, the tightening
head of the wrench only tightens when the wrench is
rotated in a clockwise direction and incorporates a
one-way clutch to prevent a reverse (or loosening)
operation. Conversely, the loosening head of the wrench
preferably only loosens when rotated in a counterclockwise
direction and likewise incorporates a one way clutch
operated in reverse to that associated with the tightening
action in order to prevent tightening and to minimize a
possibility of human error~ The tightening head 73
- 13 -
includes a sleeve insert receiver 76, a bearing plate 77
for retaining a clutch bearing 78, and a retaining ring 79
to form an operative assembly, as is well known in the
art. The clutch bearing 78 is pressed into a cam member
80 and the bearing plate 77 is positioned in the housing
71. The cam assembly is inserted into the housing to mesh
with the bearing plate 77 and the handle 72 is added as a
subassembly.
The handle 72 includes a lubricated ~ember 82,
(either a ball or roller) a ball or slider 83f bjiased by a
spring 84, and a spring retaining member 85 to provide a
preselected amount of torquing according to positioning of
the screw 86. Labels 87 and 87a bearing suitable indicia
are respectively secured on the tightening and loosening
lS heads 73 and ~4 to indicate the direction of operation of
the wrench.
The loosening head 74 includes a sleeve insert
member 88, a roller clutch 90, and a bearing plate 92 to
define the socket receiving opening for tightening. It is
~ feature of this torquin~ wrench to be able to mate with a
socket which is axially slidable along the elongated
member, such as the transducer, tip, and extender, if
used.
While the individual elemants of the wrench are
known, for the first time they are being used together in
a novel combination for applications in a surgical
environment. The surgical and especially the sterile
surgical field present a set of unique technical
requirements in that~
(a) the device must be reasonably light and
easy to use by a non-technical person, such as a nurse;
(b) the wrench must be reasonably inexpensive
so that, as an accessory, its cost benefit ratio will be
considered advantageous to the customer and the producer,
and
- 14 -
(c) the wrench must remain in calibration for
long periods of time or the proper function of the
ultrasonic surgical device it services will be impaired.
Hospital personnel traditionally have no way of checking
the calibration of the device.
As shown in Figs. 4ta) and 4(b), the design of
the torque wrench addresses requirement (a) in a number of
ways to provide a number of advantages.
First, the shape of the head is stepped and is
thus human engineered to require its applica~on in the
proper direction only.
Second, the sleeves which accept the hex sockets
are stepped to prevent an improper insertion of the
sockets.
Thirdt the head material is aluminum for light
weight.
Fourth, the handle length is proportioned for
proper balance and yet easy mechanical advantage.
The design of the torque wrench in FigsO 4(a)
and 4(b) also addresses the cost requirement.
An application of one way roller ~clutch)
bearings to a torgue wrench is a low cost, functionally
effective application of a well known art to a new field.
one way ratchet devices which are usually seen in this
~5 type of device are complex~ expensive or unreliable. The
one way roller clutch is a simple, elegant solution to an
old problem and is especially suitable to the surgical
environment in question.
The design of the torque wrench in Figs. 4(a)
~nd 4(b) addresses the requirement of calibration as
follows:
The two element mechanism in the handle
comprising elements 82 and 83 of Fig. 4(a), provides a way
to apply the spring force in an appropriately constrained
fashion so that the torque applied is consistent and
~'~8i~
-- 15 --
repeatahle without recalibration for long periods of time.
Normal torque wrenches lose their calibra~ion after
hundreds of cycles. This device is designed to operate
for thousands of cycles without recalibration.
Thus, the wrench of Figs. 4(a) and 4(b) provides
for an unlimi~ed angular rotation of the torquing device
without fear of overtightening. Moreover, it provides a
device with a resettable torque which allows a tightening
of unlimited length members. These features are in
contrast to devices which do not feature open pr through
sockets, ratchet wrenches which have a limited rotation,
or open end torque limiting wrenches in which, if the
present angular rotation were exceeded, the torque
limitation would no longer be available.
Figs. 5 and 6 respectively show a tip socket 92
and an extender socket 93 to be received in the
tightening and loosening socket receiving openings as
described. Pre~erably, the sockets define a bore 92a, 93a
therethrough so that the sockets may also be slid axially
along any elongated member, such as the tip and extender
of this invention. Preferably, the bore 93a in the
extender socket is laterally extended to define a slot as
shown in Fig. 6 so that the curved surface of a curved
extender can be readily accommodated. The mating portion
of the socket is for the wrench preferably hexagonal. In
use, the handpiece is secured to the handpiece fixture as
discussed above and the tip and/or extender is screwed
thereto in a finger tight fashion. An appropriate socket,
such as a tip socket 92 for a tip 20 or an extender socket
93 for an extender 26 is selected and axially slid over
the tip 20 or transversely placed over the extender 26
respectively to engage the tool pads on the tip or
extender. The torque wrench 70 is then slid over the
elongated tip/extender structure and engages the selected
socket.
.
- 16 -
Fig. 7 shows the use of the fixture 50 and the
wrench 70 to perform the operation as discussed above when
the operator holds the Eixture 50 in hand. Thus, the
cooperation between the fixture and the wrench act as a
scissor to perform the assembly or disassembly operation
as described.
Fig. 8 shows a view in diagrammatic fashion of
an angled handpiece secured by a key assembly to the
handpiece fixture 50 wherein the tip or other acoustic
member is engaged by an exchangable socket 92 qr rotation
by the torque wrench 70, in summary of the discussion
above.
Figs. 9A and 9B show a table support device for
mounting the fixture of Fig. 3 thereon when an operator
wishes to utilize the method and apparatus according to
this invention in connection with the table. The table
support comprises a base plate 102 having a plurality of
table-engaging foot-pads 103 to which is secured an
upwardly-extending rectangular member 104 having a
plurality of upwardly extending pins 105 from the upper
surface thereof. The pins 105 engage the mating recesses
52 in the lower surface 51 of the fixture shown in Fig. 3.
Fig. 10 is a diagrammatic illustration of the
support member of Fig. 9 and the fix~ure of Fig. 3 during
use. The wrench is positioned so it is pushed down while
the operator holds the fixture against the table with the
other hand.
A significant advantage of the invention is that
all parts of the handpiece torquing set are capable of
sterilization, such as by ethylene oxide yas, so that the
tips and other parts may be interchanged during surgery in
the sterile field. As in the case of the prior art
embodiment, the components of the system are preferably
provided in the form of a set which includes a handpiece
fixture, a table support plate, a torquing wrench, a
- 17 -
plurality of sockets, a key, and instructions in a
convenient pack.
Figs. ll(a) and ll(b) shows an alternative
embodiment of the torquing wrench which is quite similar
to the embodiment of Figs. 4(a) and 4(b). In this
alternative embodiment, the ball members 82 and 83 are
replaced by a roller member 101 having its outermost
sur~ace in line contact with the cam memher 80. The
roller member 101 is restrained against rotational
movement by a pin 102 slidably located in ~ pair of
openings in an elongated tappet member 103. Thus, the
roller member is free to slide to the left and right as
shown in Fig. ll(a). The roller member 101 is in line
contact with the cam, rather than in point contact, as in
the case of the ball 82 in Fig. 4(a). As in Fig. 4(a),
the tappet member 102 is biased by a spring 84. The
advantages and operational features of the wrench
embodiment in Fig. ll(a) are thus the same as in the
embodiment of Fig. ~(a~.
This invention may be embodied in other specific
forms without departing from its spirit or essential
characteristics. The present embodiments are, therefore,
to be considered in all respects as illustrative and not
restrictivel the scope of the invention being indicated by
the claims rather than by the foregoing description, and
all changes which come within the meaning and range of the
equivalents of the claims are thereore intended to be
embraced therein.
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