U.S. patent application number 11/410861 was filed with the patent office on 2006-08-24 for surgical stapling apparatus with locking mechanism.
This patent application is currently assigned to Tyco Healthcare Group LP. Invention is credited to Stanislaw Marczyk.
Application Number | 20060185682 11/410861 |
Document ID | / |
Family ID | 34700231 |
Filed Date | 2006-08-24 |
United States Patent
Application |
20060185682 |
Kind Code |
A1 |
Marczyk; Stanislaw |
August 24, 2006 |
Surgical stapling apparatus with locking mechanism
Abstract
The present disclosure provides for a loading unit for use with
and/or supportable on a distal end of a surgical stapling
apparatus. The loading unit includes a housing portion including a
distal end and a proximal end, a drive assembly slidably supported
within the housing portion of the loading unit, and a locking
mechanism supported on the housing portion of the loading unit. The
locking mechanism has a first position wherein the locking
mechanism engages the drive assembly and maintains the position of
the drive assembly in a ready-to-load position relative to the
housing portion of the loading unit. The locking mechanism is
pivotable to a second position wherein the locking mechanism
disengages the drive assembly and enables the drive assembly to
move relative to the housing portion.
Inventors: |
Marczyk; Stanislaw;
(Stratford, CT) |
Correspondence
Address: |
UNITED STATES SURGICAL,;A DIVISION OF TYCO HEALTHCARE GROUP LP
195 MCDERMOTT ROAD
NORTH HAVEN
CT
06473
US
|
Assignee: |
Tyco Healthcare Group LP
|
Family ID: |
34700231 |
Appl. No.: |
11/410861 |
Filed: |
April 24, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11059975 |
Feb 17, 2005 |
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11410861 |
Apr 24, 2006 |
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60545621 |
Feb 17, 2004 |
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Current U.S.
Class: |
128/898 |
Current CPC
Class: |
A61B 2017/00477
20130101; A61B 2017/00473 20130101; A61B 17/07207 20130101; A61B
2017/07214 20130101; A61B 2017/320052 20130101 |
Class at
Publication: |
128/898 |
International
Class: |
A61B 19/00 20060101
A61B019/00 |
Claims
1. A surgical apparatus comprising: a body; a handle supported by
the body; and a loading unit supportable on a distal end of the
body, the loading unit including: a housing portion including a
distal end and a proximal end; a drive assembly supported for axial
movement within the housing portion of the loading unit, the drive
assembly having a proximal-most position relative to the housing
portion of the loading unit; and a locking mechanism supported on
the housing portion of the loading unit, the locking mechanism
having a first position wherein the locking mechanism engages the
drive assembly and maintains the drive assembly in the
proximal-most position, the locking mechanism being movable to a
second position wherein the locking mechanism disengages the drive
assembly and allows the drive assembly to move relative to the
housing portion.
2. The surgical apparatus of claim 1, wherein the locking mechanism
includes: a lever having a first end pivotably connected to the
housing portion and a second free end; and a projection extending
radially inward from the lever, wherein the projection selectively
engages an engagement surface formed on the drive assembly such
that when the locking mechanism is in the first position the
projection engages the engagement surface of the drive assembly and
when the locking mechanism is in the second position the projection
is disengaged from the engagement surface of the drive
assembly.
3. The surgical apparatus of claim 2, wherein the body comprises an
elongate body and has a control rod disposed therein for axial
movement, the control rod being operatively connected to the
handle.
4. The surgical apparatus of claim 3, wherein the drive assembly is
in a position to connect to a distal end of the control rod when
the drive assembly is in the proximal-most position.
5. The surgical apparatus of claim 3, wherein when the locking
mechanism is moved from the first position to the second position,
the lever is pivoted about the distal end thereof such that a
longitudinal axis of the lever is angled with respect to a
longitudinal axis of the housing portion.
6. The surgical apparatus of claim 5, wherein the elongate body has
a channel for receiving a proximal end of the loading unit.
7. The surgical apparatus of claim 6, wherein the locking mechanism
is moved from the first position to the second position by a wall
defined in the channel of the elongate body, the wall acting on a
side surface of the lever as the loading unit is rotated into
loaded engagement in the elongate body.
8. The surgical apparatus of claim 2, wherein when the locking
mechanism is in the first position the lever is substantially
axially aligned with a nub extending radially outward from the
proximal end of the housing portion and when the locking mechanism
is in the second position the lever is out of axial alignment with
the nub of the housing portion.
9. The surgical apparatus of claim 2, wherein the proximal end of
the lever includes a detent extending toward the proximal end of
the housing portion, and wherein the proximal end of the housing
portion includes a recess formed in the surface thereof for receipt
of the detent of the lever when the lever is in the first
position.
10. The surgical apparatus of claim 9, wherein the locking
mechanism further includes a biasing member operatively associated
therewith, wherein the biasing member tends to maintain the lever
in the first position.
11. The surgical apparatus of claim 4, wherein the surgical
apparatus is a stapler.
12. A method of loading a loading unit for a surgical apparatus:
providing a loading unit having a locking mechanism in a first
position, the loading unit having a drive assembly supported for
axial movement within a housing portion of the loading unit, the
drive assembly being engaged by the locking mechanism when the
locking mechanism is in the first position; providing an elongate
body and a handle supported by the elongate body, the elongate body
having a distal end configured to be assembled with a proximal end
of the loading unit, the distal end of the elongate body being
configured to move the locking mechanism; assembling the proximal
end of the loading unit with the distal end of the elongate body so
that the locking mechanism moves to a second position wherein the
locking mechanism disengages the drive assembly.
13. The method of claim 12, wherein the locking mechanism is moved
to the second position upon rotation of the loading unit.
14. The method of claim 13, wherein the elongate body has a channel
for receiving the proximal end of the loading unit.
15. The method of claim 14, wherein the channel defines a wall for
moving the locking mechanism upon rotation of the loading unit.
16. The method of claim 12, wherein the locking mechanism includes
a lever with a projection that engages the drive assembly when the
locking mechanism is in the first position.
17. The method of claim 16, wherein the lever pivots to the second
position so that the projection disengages the drive assembly.
18. The method of claim 14, wherein the proximal end of the loading
unit defines at least one nub, and wherein assembling the loading
unit includes rotating the loading unit so that the at least one
nub enters a slot defined in the channel of the loading unit.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present application claims the benefit of and priority
to U.S. Provisional Application Ser. No. 60/545,621, filed Feb. 17,
2004, the entire content of which being incorporated herein by
reference.
BACKGROUND
[0002] 1. Technical Field
[0003] The present disclosure relates to a surgical apparatus,
e.g., a surgical stapling apparatus. More particularly, the present
disclosure relates to an endoscopic surgical stapling apparatus
that includes a locking mechanism for retaining the drive assembly
of a loading unit, e.g., a single use loading unit ("SULU") or
disposable loading unit ("DLU"), at a substantially fixed axial
position until the SULU or DLU has been loaded with or secured to a
surgical stapling apparatus, to ensure proper or complete
engagement of the SULU or DLU, especially its drive assembly, to
the surgical stapling apparatus. For simplicity, hereinafter, SULU
or DLU will be referred to as "DLU", but it should be understood to
include either or both a DLU or SULU.
[0004] 2. Background of Related Art
[0005] Surgical devices wherein tissue is first grasped or clamped
between opposing jaw structure and then joined by surgical
fasteners are well known in the art. In some instruments a knife is
provided to cut the tissue which has been joined by the fasteners.
The fasteners are typically in the form of surgical staples but two
part polymeric fasteners can also be utilized.
[0006] Instruments for this purpose can include two elongated jaw
members which are respectively used to capture or clamp tissue.
Typically, one of the jaw members carries a staple cartridge which
houses a plurality of staples arranged in at least two lateral rows
while the other jaw member has an anvil that defines a surface for
forming the staple legs as the staples are driven from the staple
cartridge. Generally, the stapling operation is effected by cam
members that travel longitudinally through the staple cartridge,
with the cam members acting upon staple pushers to sequentially
eject the staples from the staple cartridge. A knife can travel
between the staple rows to longitudinally cut and/or open the
stapled tissue between the rows of staples. Such instruments are
disclosed, for example, in U.S. Pat. No. 3,079,606 and U.S. Pat.
No. 3,490,675.
[0007] A later stapler disclosed in U.S. Pat. No. 3,499,591 also
applies a double row of staples on each side of the incision. This
patent discloses a surgical stapler that has a disposable loading
unit in which a cam member moves through an elongate guide path
between two sets of staggered staple carrying grooves. Staple drive
members are located within the grooves and are positioned in such a
manner so as to be contacted by the longitudinally moving cam
member to effect ejection of the staples from the staple cartridge
of the disposable loading unit. Other examples of such staplers are
disclosed in U.S. Pat. Nos. 4,429,695 and 5,065,929.
[0008] Each of the instruments described above is designed for use
in conventional surgical procedures wherein surgeons have direct
manual access to the operative site. However, in endoscopic or
laparoscopic procedures, surgery is performed through a small
incision or through a narrow cannula inserted through small
entrance wounds in the skin. In order to address the specific needs
of endoscopic and/or laparoscopic surgical procedures, endoscopic
surgical stapling devices have been developed and are disclosed in,
for example, U.S. Pat. No. 5,040,715 (Green, et al.); U.S. Pat. No.
5,307,976 (Olson, et al.); U.S. Pat. No. 5,312,023 (Green, et al.);
U.S. Pat. No. 5,318,221 (Green, et al.); U.S. Pat. No. 5,326,013
(Green, et al.); U.S. Pat. No. 5,332,142 (Robinson, et al.); and
U.S. Pat. No. 6,241,139 (Milliman et al.), the entire contents of
each of which are incorporated herein by reference.
[0009] Tyco Healthcare Group, LP, the assignee of the present
application, has manufactured and marketed endoscopic stapling
instruments, such as the Multifire ENDO GIA.TM. 30 and Multifire
ENDO GIA.TM. 60 instruments, for a number of years. These
instruments include a surgical stapling apparatus and a DLU.
Typically, the DLU is attached to the apparatus immediately prior
to surgery. After use, the DLU can be removed from the apparatus
and a new DLU can be fastened to the apparatus to perform
additional stapling and/or cutting operations. These instruments
have provided significant clinical benefits. Nonetheless,
improvements to these instruments are still possible.
[0010] It would be desirable to provide an improved DLU for a
surgical stapling apparatus and an improved surgical stapling
apparatus having the DLU loaded thereon.
[0011] It would also be desirable to provide a locking member for a
DLU to assure proper loading of the DLU to the shaft of a surgical
stapling apparatus.
[0012] Accordingly, it is an object of this disclosure to provide
an improved DLU which locks or retains its drive assembly in proper
position to be loaded onto the shaft of a surgical stapling
apparatus (hereinafter referred to as the or a "ready-to-load
position") until the DLU is loaded onto a surgical stapling
apparatus to assure that when the DLU is loaded thereto, the drive
assembly is properly engaged by, coupled to or connected to a drive
member of the shaft, thereby helping to ensure proper operation of
the DLU and the surgical stapling apparatus. For example, with the
DLU loaded onto the surgical stapling apparatus, after firing of
the surgical stapling apparatus, retraction of the control rod will
unapproximate or open and/or unclamp the anvil and cartridge
assemblies.
[0013] An object of the disclosure is to provide an improved DLU
that includes a locking mechanism that retains the drive assembly
in such a ready-to-load position until the DLU is loaded onto the
surgical stapling apparatus.
[0014] Another object of the disclosure is to provide such a
locking mechanism for a DLU.
[0015] Another object of the present disclosure is to provide a
locking mechanism for a DLU and a DLU having a locking mechanism,
such that firing of the surgical stapling apparatus is prevented
unless and until the DLU is loaded onto the shaft of the surgical
stapling apparatus.
[0016] Yet another object of the disclosure is to provide a DLU
that, after firing, can be disconnected from the surgical stapling
apparatus.
[0017] Yet another object of the disclosure is to provide a DLU
that has only two conditions, one in which it is not loaded and its
drive assembly is locked or retained in the ready-to-load position,
and another in which the DLU is loaded onto the shaft of a surgical
stapling apparatus and in which the drive assembly is unlocked and
free to be actuated.
[0018] Still another object of the present disclosure is to provide
the above objects in a roticulating, i.e., roticulable, DLU.
SUMMARY
[0019] In accordance with the present disclosure, a surgical
apparatus, e.g., a surgical stapling apparatus, including a locking
mechanism for ensuring proper engagement of a disposable loading
unit to an end of the surgical apparatus is provided. According to
one aspect of the present disclosure the surgical apparatus
includes a housing, a handle supported by the housing, and a
loading unit supportable on a distal end of the housing. The
loading unit includes a housing portion including a distal end and
a proximal end, a drive assembly slidably supported within the
housing portion of the loading unit, and a locking mechanism
supported on the housing portion of the loading unit. The locking
mechanism has a first position in which the locking mechanism
engages the drive assembly and maintains the position of the drive
assembly in a ready-to-load position relative to the housing
portion of the loading unit. The locking mechanism is movable,
preferably pivotable in a plane substantially tangential to an
outer surface of the housing portion, to a second position in which
the locking mechanism disengages the drive assembly and enables the
drive assembly to move relative to the housing portion.
[0020] Preferably, the locking mechanism includes a lever having a
distal end pivotably connected to the housing portion and a free
proximal end, and a tooth extending radially inward from the lever.
Desirably, the tooth selectively engages an engagement surface,
e.g., a notch, formed in, on or of the drive assembly such that
when the locking mechanism is in the first position the tooth
engages the engagement surface of the drive assembly, and when the
locking mechanism is in the second position the tooth is disengaged
from the engagement surface of the drive assembly.
[0021] It is envisioned that when the locking mechanism is urged
from the first position to the second position, the lever is
pivoted about the distal end thereof such that a longitudinal axis
of the lever is angled with respect to a longitudinal axis of the
housing portion. The locking mechanism is preferably urged from the
first position to the second position by a projection extending
radially inward of the elongate body. Desirably, the projection
acts on a side surface of the lever as the loading unit is twisted
into loaded engagement in the elongate body.
[0022] Preferably, when the locking mechanism is in the first
position the lever is substantially axially aligned with a nub
extending radially outward from the proximal end of the housing and
when the locking mechanism is in the second position the lever is
out of axial alignment with the nub of the proximal end of the
housing.
[0023] The proximal end of the lever can include a nub extending
preferably radially toward, the proximal end of the housing. The
proximal end of the housing preferably includes a recess formed in
the surface thereof for receipt of the lever nub of the lever when
the lever is in the first position.
[0024] The locking mechanism can further include a biasing member
operatively associated therewith, wherein the biasing member tends
to maintain the lever in the first position.
[0025] Preferably, the surgical apparatus is a fastener applier or
stapler, preferably a laparoscopic or endoscopic stapler.
[0026] This disclosure also is of a DLU, preferably a roticulator
DLU for a surgical fastener applier or stapler.
[0027] The surgical apparatus may further include an elongate body
extending from the housing.
[0028] It is further envisioned that the proximal end of the
housing portion of the loading unit may define an insertion
tip.
[0029] The present disclosure further provides for a loading unit
for use with and/or supportable on a distal end of a surgical
stapling apparatus. The loading unit includes a housing portion
including a distal end and a proximal end, a drive assembly
slidably supported within the housing portion of the loading unit,
and a locking mechanism supported on the housing portion of the
loading unit. The locking mechanism has a first position wherein
the locking mechanism engages the drive assembly and maintains the
position of the drive assembly in a ready-to-load position relative
to the housing portion of the loading unit. The locking mechanism
is pivotable, in a plane substantially tangential to an outer
surface of the housing portion, to a second position wherein the
locking mechanism disengages the drive assembly and enables the
drive assembly to move relative to the housing portion.
[0030] Additional advantages will become apparent from the
description which follows, taken in conjunction with the
accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] The present disclosure will be further described with
reference to the accompanying drawings, wherein like reference
numerals refer to like parts in the several views, and wherein:
[0032] FIG. 1 is a top perspective view of a preferred embodiment
of the presently disclosed surgical stapling apparatus;
[0033] FIG. 2 is a top view of the surgical stapling apparatus
shown in FIG. 1;
[0034] FIG. 3 is a side view of the surgical stapling apparatus
shown in FIGS. 1 and 2;
[0035] FIG. 4 is a top perspective view of the surgical stapling
apparatus of FIGS. 1-3 with the DLU disengaged from the elongate
body of the surgical stapling apparatus;
[0036] FIG. 5 is a bottom perspective view of a non-articulating
DLU for use with the surgical stapling apparatus of FIGS. 1-4;
[0037] FIG. 6 is a bottom perspective view of the preferred
articulating DLU of the surgical stapling apparatus of FIGS.
1-4;
[0038] FIG. 7 is a top perspective view of the DLU of FIG. 6;
[0039] FIG. 8 is a top perspective view of the DLU of FIGS. 6 and
7;
[0040] FIG. 9 is a top perspective view, with parts separated, of
the proximal housing portion and mounting assembly of the DLU of
FIGS. 6-8;
[0041] FIG. 10 is an enlarged top perspective view, with parts
separated, of a proximal portion of the upper housing half of the
DLU of FIGS. 6-9;
[0042] FIG. 11 is a top perspective view of the proximal housing
portion and mounting assembly of the DLU of FIGS. 6-9 with the
upper half of housing portion removed;
[0043] FIG. 12 is a top perspective view, with parts separated, of
a portion of the axial drive assembly of the DLU of FIGS. 6-9;
[0044] FIG. 13 is a top perspective view of the portion of the
axial drive assembly of FIG. 11 of the DLU of FIGS. 6-9;
[0045] FIG. 14 is an enlarged top perspective view of a lower
housing half of the housing portion of the DLU of FIGS. 6-9;
[0046] FIG. 15 is an enlarged perspective view of the distal end of
the elongated body of the stapling apparatus shown in FIGS. 1-4,
shown with the control rod extending therethrough;
[0047] FIG. 15a is an enlarged perspective view of the distal end
of the elongate body of FIG. 15, shown without the control rod
extending therethrough;
[0048] FIG. 16 is an enlarged perspective view of the proximal end
of the DLU of FIGS. 6-9 illustrating a locking mechanism according
to the present disclosure;
[0049] FIG. 17 is an enlarged top plan view with portions broken
away illustrating a stage in the attachment of the DLU of FIGS. 6-9
to the elongate body of the surgical stapling apparatus shown in
FIGS. 1-3;
[0050] FIG. 18 is an enlarged top plan view with portions broken
away illustrating another stage in the attachment of the DLU of
FIGS. 6-9 to the elongate body of the surgical stapling apparatus
shown in FIGS. 1-3;
[0051] FIG. 19 is an enlarged top plan view with portions broken
away illustrating yet another stage in the attachment of the DLU of
FIGS. 6-9 to the elongate body of the surgical stapling apparatus
shown in FIGS. 1-3;
[0052] FIG. 20 is a longitudinal cross-sectional view of the
proximal end of the DLU of FIGS. 6-9 as taken along line 20-20 of
FIG. 16;
[0053] FIG. 21 is an enlarged transverse cross-sectional view of
the proximal end of the DLU of FIGS. 6-9 with the distal end of the
elongate body on the proximal end of the DLU as would be taken
along 21-21 of FIG. 16, illustrating the locking mechanism in the
first position; and
[0054] FIG. 22 is an enlarged transverse cross-sectional view of
the proximal end of the DLU of FIGS. 6-9 with the distal end of the
elongate body on the proximal end of the DLU as would be taken
along 21-21 of FIG. 16, illustrating the locking mechanism in the
second position.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0055] Preferred embodiments of the presently disclosed surgical
apparatus, DLU and locking mechanism or member will now be
described in detail with reference to the drawings, in which like
reference numerals designate identical or corresponding elements in
each of the several views.
[0056] In the drawings and in the description that follows, the
term "proximal", as is traditional, will refer to the end of the
stapling apparatus which is closest to the operator, while the term
"distal" will refer to the end of the apparatus which is furthest
from the operator.
[0057] FIGS. 1-4 show a surgical apparatus, e.g., surgical stapling
apparatus, generally referred to as 10. In the interest of brevity,
this disclosure will focus primarily on systems, methods and
structures for loading, engaging, coupling or connecting a
disposable loading unit ("DLU") 16 to surgical stapling apparatus
10. A detailed discussion of the remaining components and method of
use of surgical stapling apparatus 10, is disclosed in U.S. Pat.
No. 6,241,139.
[0058] Surgical stapling apparatus 10 is an endoscopic apparatus
and includes a handle assembly 12 and an elongated body 14
extending from handle assembly 12. A DLU 16 is releasably secured
to the distal end of elongated body 14. While this disclosure
relates to the use of a DLU with surgical stapling apparatus 10, it
is understood and within the scope of the present disclosure that a
single use loading unit (SULU) or other end effector and/or tool
assembly can equally be used in cooperation with surgical stapling
apparatus 10.
[0059] DLU 16 includes a tool assembly 17 having a cartridge
assembly 18 housing a plurality of surgical staples (not shown) and
an anvil assembly 20 movably secured in relation to cartridge
assembly 18. As shown herein, DLU 16 is configured to apply six (6)
linear rows of staples, each row in the DLU's measuring from about
30 mm to about 60 mm in length. DLUs for applying any number of
rows of staples, having staple pockets arranged in various patterns
and/or DLUs and end effectors having any other lengths, e.g., 45
mm, are also envisioned. Handle assembly 12 includes a stationary
handle member 22, a movable handle member 24, and a barrel portion
26.
[0060] A rotatable member 28 preferably is mounted on the forward
end of barrel portion 26 to facilitate rotation of elongated body
14 and attached DLU 16 with respect to handle assembly 12. An
articulation lever 30 preferably is also mounted on the forward end
of barrel portion 26 adjacent rotatable member 28 to facilitate
articulation of tool assembly 17. Preferably, a pair of knobs 32
are movably positioned along barrel portion 26. Knobs 32 are
advanced distally to approximate or close cartridge and/or anvil
assembly 18, 20, and retracted proximally to unapproximate or open
cartridge and/or anvil assembly 18, 20.
[0061] As seen in FIG. 4, DLU 16 is desirably selectively removably
couplable to elongated body 14. DLU 16 includes a housing portion
200 having a proximal end adapted to releasably engage the distal
end of elongated body 14. A mounting assembly 202 is pivotally
secured at 203 to the distal end of housing portion 200, and is
configured to receive the proximal end of tool assembly 17 such
that pivotal movement of mounting assembly 202 about an axis at 203
perpendicular to the longitudinal axis of housing portion 200
effects articulation of tool assembly 17.
[0062] FIGS. 5-8 show various perspective views of DLU 16. Surgical
stapling apparatus 10 is capable of receiving a non-articulating
DLU 16a, as seen in FIG. 5, or an articulating DLU 16, as seen in
FIGS. 6-8. U.S. Pat. No. 6,241,139 includes a detailed discussion
of articulating and non-articulating DLU.
[0063] With reference to FIGS. 9-14, DLU 16 includes a mounting
assembly 235. Mounting assembly 235 includes an upper and a lower
mounting portion 236, 238, respectively. A centrally located pivot
member 284 extends from each of upper and lower mounting portions
236, 238 through respective openings 246a formed in coupling
members 246. Coupling members 246 each include an interlocking
proximal portion 246b configured to be received in grooves 290
formed in the distal end of upper and lower housing halves 250, 252
to retain mounting assembly 235 and upper and lower housing halves
250, 252 in a longitudinally fixed position in relation to each
other.
[0064] Upper housing half 250 and lower housing half 252 are
contained within an outer sleeve, shell or casing 251. The proximal
end of upper housing half 250 includes an insertion tip 193
extending proximally therefrom. Insertion tip 193 includes
engagement nubs 254, preferably a pair of diametrically opposed
engagement nubs 254, extending radially outwardly therefrom, for
releasably engaging the distal end of body 14. Nubs 254 form a
bayonet-type coupling with the distal end of body 14. Housing
halves 252 and 254 define a channel 400 for slidably receiving
axial drive assembly 212 therein. An articulation link 256 is
dimensioned to be slidably positioned within a slot 402 formed in
upper and lower housing halves 250, 252. A pair of blow out plate
assemblies 255 are positioned adjacent the distal end of housing
portion 200 adjacent the distal end of axial drive assembly 212 to
prevent outward buckling and bulging of drive assembly 212 during
articulation and firing of surgical stapling apparatus 10. For a
detailed discussion of the structure and operation of blow out
plate assemblies 255, reference is made to International
Application Serial No. PCT/US02/32031, filed on Oct. 4, 2002,
entitled "Surgical Stapling Device", the entire content of which is
herein incorporated by reference.
[0065] Referring to FIG. 9, optionally, a locking member 288 may be
supported on engagement section 270 of axial drive assembly 212. In
operation, when axial drive assembly 212 is actuated, by applying a
predetermined force to movable handle member 24 to advance axial
drive assembly 212 distally, locking member 288 provides an audible
and tactile indication that surgical stapling apparatus 10 has been
actuated. For a detailed discussion of the structure and operation
of locking member 288, reference is made to the aforementioned
International Application Serial No. PCT/US02/32031. Locking member
288 may also prevent inadvertent partial actuation of DLU 16, such
as during shipping, by locking axial drive assembly 212 at a fixed
position within DLU 16 until a predetermined axial force has been
applied to axial drive assembly 212.
[0066] With reference to FIGS. 9-12, axial drive assembly 212
includes an elongated drive beam 266 (FIGS. 11 and 12) including a
distal working head 268 (FIGS. 11 and 12) and a proximal engagement
section 270. Drive beam 266 may be constructed from a single sheet
of material or, preferably, multiple stacked sheets, as shown in
FIG. 11. Engagement section 270 includes a pair of resilient
engagement fingers 270a and 270b which are dimensioned and
configured to mountingly engage a pair of corresponding retention
slots 272a and 272b formed in drive member 272 (FIGS. 11 and 13).
Drive member 272 includes a proximal porthole 274 configured to
receive distal end 276 of a drive member, e.g., drive rod or
control rod 52 (FIGS. 15 and 20-22) when the proximal end of DLU 16
is being engaged with elongated body 14 of surgical stapling
apparatus 10. Control rod 52 functions to impart axial movement of
drive assembly 212 from handle assembly 12.
[0067] As seen in FIGS. 9, 10 and 16-22, DLU 16 further includes a
locking mechanism 300, preferably, pivotably supported on upper
housing half 250. Locking mechanism 300 is manipulatable from a
first position, in which drive assembly 212 is maintained in a
ready-to-load position, to a second position, in which drive
assembly 212 is free to move. DLU 16 is considered to be loaded to
elongate body 14 when locking mechanism 300 is in the second
position, i.e., when drive assembly 212 is connected to control rod
52 of elongate body 14. Locking mechanism 300 includes a lever 302
including a distal end 304 pivotally connected to upper housing
half 250 and a free proximal end 306 in operative association with
an outer surface of insertion tip 193. Desirably, distal end 304 is
pivotably connected to upper housing half 250, via a pin 308 or
preferably a ball-type pivot member. Alternatively, other known
pivot structures formed integrally with or separate from upper
housing half 250 may be used. Lever 302 further includes a
projection, here shown as a tooth 310, extending radially inwardly
from the inner surface of lever 302, preferably at a location
between distal end 304 and proximal end 306.
[0068] In use, as best seen in FIGS. 16-22, when locking mechanism
300 is in the first position (i.e., in a ready-to-load, locked, or
coupled position) (FIGS. 16, 17, 18, 20 and 21), lever 302 is
substantially axially aligned with a longitudinal axis of housing
portion 200 such that tooth 310 passes through an aperture 250a
formed in upper housing half 250 and is engaged with an engagement
surface, e.g., a notch, shoulder or recess 270c formed in the edge
of engagement section 270 of drive assembly 212 to thereby
effectively lock and maintain drive assembly 212 in the
ready-to-load position wherein drive assembly 212 is in a retracted
or proximal-most position relative to upper housing half 250. When
DLU 16 is being coupled to the distal end of body 14, locking
mechanism 300 ensures that engagement section 270 of drive assembly
212 is in a position to and properly engages, coupled with or
connects to distal end 276 of control rod 52 (see FIGS. 20-22) of
surgical stapling apparatus 10. Distal end 276 of control rod 52
has one or more engagement surfaces, preferably, and here shown as,
including a head 276a and a smaller diameter annular recess 276b
just proximal of head 276a and partially defined by head 276a.
Thereafter, less preferably concomitantly therewith, locking
mechanism 300 is manipulated (here rotated) to the second position
wherein drive assembly 212 is in an unlocked, operative position in
which lever 302 is angled with respect to the longitudinal axis of
housing portion 200 such that tooth 310 is released from and/or
otherwise disengaged from engagement surface 270c of engagement
section 270 of drive assembly 212 to free drive assembly 212 to
move relative to housing portion 212, here, upper and lower housing
portion 250, 252 of DLU 16.
[0069] When locking mechanism 300 is in the second position, DLU is
considered loaded onto ad/or into elongate body 14 of surgical
stapling apparatus 10. Thus, drive assembly 212 is free to be
actuated and reciprocated axially by drive rod 52 to perform its
operative functions of approximating and closing anvil and
cartridge assemblies 18, 20, driving knife 280 and firing staples,
as well as of un-approximating, un-clamping, and retracting drive
assembly 212. DLU 16 is considered to be loaded to elongate body 14
when locking mechanism 300 is in the second position, i.e., when
drive assembly 212 is connected to control rod 52 of elongate body
14.
[0070] With continued reference to FIGS. 15-20, preferably lever
302 of locking mechanism 300 further includes a nub or detent 314
extending radially inward from an inner surface 302a of distal end
306 of lever 302. In use, nub 314 selectively engages and
disengages a recess or dimple 193a formed in the outer surface of
insertion tip 193. Preferably, dimple 193a is substantially in
axial alignment with nubs 254 extending radially outward from
insertion tip 193. Nub 314 and dimple 193a create a snap-fit type
engagement wherein nub 314 and dimple 193a cooperate with one
another to prevent and/or otherwise inhibit locking mechanism 300
from inadvertently or prematurely pivoting from the first position
to the second position and thereby disengaging drive assembly 212.
Locking mechanism 300 thus can include nub 314 and dimple 193a.
[0071] Preferably, insertion tip 193 includes a recessed area 193b
(FIGS. 10 and 16) formed therein such that locking mechanism 300
does not extend radially outward beyond the outer surface of upper
housing half 250. Lever 302 is able to pivot an amount sufficient
to allow tooth 310 to disengage engagement surface or shoulder 270c
of engagement section 270 of drive assembly 212 when locking
mechanism 300 is in the second position. Locking mechanism 306
preferably includes a spring or other biasing means 312 in
operative association with lever 302 and housing portion 200
mounted and/or positioned in such a manner so as to bias lever 302
to the first position. As seen in FIG. 16, spring 312 includes an
arm 312a in contact with a side surface 302a of lever 302 thereby
tending to maintain lever 302 in the first position. The twisting
force applied with respect to DLU 16 and/or elongate body 14 of
surgical stapling apparatus 10 is sufficient to overcome the bias
of spring 312 to allow lever 302 to move to the second
position.
[0072] With continued reference to FIGS. 15-20, a method of use
and/or operation of locking mechanism 300, in securing DLU 16 to
the distal end of elongate body 14, will be discussed. Initially,
with locking mechanism 300 in the first position such that tooth
310 is in locking engagement with shoulder 270c of engagement
section 270, to ensure that drive assembly 212 is in the proper
position (e.g., in the proximal-most position) for coupling with
head 276a of distal end 276 of control rod 52, insertion tip 193 of
DLU 16 is introduced longitudinally into the distal end of elongate
body 14, in the direction of arrow "A", such that nubs 254 slide
into channels 276d, through and past projections 276c (see FIGS. 15
and 15a) extending radially inward from elongate body 14 of
surgical stapling apparatus 10 near the distal end thereof.
[0073] When nubs 254 have reached slots 276e, and when insertion
tip 193 has been fully inserted into the distal end of elongate
body 14, DLU 16 is rotated, in the direction of arrow "B" (see FIG.
21). At this point in the coupling, rotation of DLU 16 results in
three separate actions, namely, nubs 254 enter slots 276e, thus
connecting DLU 16 to distal end 14 of stapling apparatus 10;
projections 276b of firing rod 52 engage sections 270a and 270b of
drive assembly 212, thus connecting firing rod 52 and drive
assembly 212; and side wall of channel 276d urges lever 302 (such
that side wall of channel 276d abuts against and engages proximal
end of lever 306, preferably against a side surface 302b of lever
302) of locking mechanism 300 to pivot from the first position to
the second position about pivot pin "P" to thereby disengage tooth
310 from shoulder 270c of engagement section 270 and thereby free
drive assembly 212 to allow movement of drive assembly 212 and
permit operation or continued operation of surgical stapling
apparatus 10.
[0074] As can be appreciated, if lever 302 has been inadvertently
moved to the second position, prior to coupling of DLU 16 to
elongate body 14, and drive assembly 212 has prematurely moved from
its proximal-most or ready-to-load position, lever 302 can not move
to the first position since tooth 310 is not aligned with drive
assembly 212 and can not pass in front of shoulder 270c. In such a
situation, tooth 310 will abut against a portion of engagement
section 270 to prevent lever 302 from returning to the first
position. Thus, upon insertion of DLU 16 into elongate body 14,
proximal end 306 of lever 302 will abut against and/or otherwise
contact projection 276c of elongate body 14 and thus prevent
loading of DLU 16 to elongate body 14.
[0075] Accordingly, the attachment of a DLU having a drive assembly
which is not in its proximal-most or ready-to-load position is
prevented.
[0076] It will be understood that various modifications may be made
to the embodiments disclosed herein. Therefore, the above
description should not be construed as limiting, but merely as
exemplifications of preferred embodiments. Those skilled in the art
will envision other modifications within the scope and spirit of
the claims appended hereto.
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