U.S. patent number RE28,932 [Application Number 05/575,580] was granted by the patent office on 1976-08-17 for surgical stapling instrument.
This patent grant is currently assigned to United States Surgical Corporation. Invention is credited to Graham W. Bryan, Douglas G. Noiles.
United States Patent |
RE28,932 |
Noiles , et al. |
August 17, 1976 |
Surgical stapling instrument
Abstract
A surgical stapling instrument for applying sterilized staples
to the disunited skin or fascia of a patient in order to effect a
joining of the skin or fascia. The instrument is adapted to
associate with a staple-carrying cartridge having a plurality of
staples therein. The instrument is manually powered and includes a
nose portion rotatably mounted in a hand-held main body portion and
adapted to mount the staple-carrying cartridge so that the stapling
angle can be varied without rotating the hand-held portion of the
stapler. A clutch means is provided for ensuring that the
staple-advancing drive means of the instrument is only activated
once per stapling operation. The instrument is further provided
with means for preventing the insertion of a fresh staple-carrying
cartridge until the instrument is in the readiness position for a
driving stroke, and means for maintaining the unloaded instrument
in its readiness position until equipped with a cartridge.
Inventors: |
Noiles; Douglas G. (New Canaan,
CT), Bryan; Graham W. (Ridgefield, CT) |
Assignee: |
United States Surgical
Corporation (Baltimore, MD)
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Family
ID: |
26967974 |
Appl.
No.: |
05/575,580 |
Filed: |
May 8, 1975 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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Reissue of: |
293470 |
Sep 29, 1972 |
03819100 |
Jun 25, 1974 |
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Current U.S.
Class: |
227/19; 227/121;
227/110; 227/129 |
Current CPC
Class: |
A61B
17/0684 (20130101) |
Current International
Class: |
A61B
17/068 (20060101); B25C 005/02 () |
Field of
Search: |
;227/19,121,129 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Custer, Jr; Granville Y.
Attorney, Agent or Firm: Fleit & Jacobson
Claims
What is claimed is:
1. A surgical stapling instrument for applying sterilized staples
to the disunited skin or fascia of a patient for effecting a
joining of the skin or fascia, the instrument adapted to associate
with a staple-carrying cartridge having anvil means at one end
thereof and adapted to house a plurality of staples therein, a
pusher element slidably mounted therein for ejecting staples from
said cartridge and for forming said staples around said anvil
means, and means for advancing said staples in said cartridge, said
surgical stapling instrument comprising: a main body portion; means
for mounting said staple-carrying cartridge on said main body
portion; drive means to activate said staple-advancing means for
driving the staples toward said anvil means.[.;.]. and
.[.pusher-activating means.]. for driving the pusher element
forward to eject a staple from the staple-carrying cartridge and to
form said staple around said anvil means; said instrument being
manually powered, and further comprising trigger means for
transmitting a manually applied force to said drive means .[.and
said pusher-activating means.]. to power said drive means .[.and
said pusher-activating means.]..
2. The instrument defined in claim 1, wherein said
.[.pusher-activating.]. .Iadd.drive .Iaddend.means comprises a
thrust bar slidably mounted in said main body portion and said
trigger means comprises a handle pivotally mounted to said main
body portion and having a lower hand-engaging portion and an upper
force-transmitting portion associated with said thrust bar.
3. The instrument defined in claim 2, wherein means are associated
with said thrust bar for initiating the advancement of staples,
said initiating means comprising an index pawl pivotally mounted to
said thrust bar and adapted for sliding movement therewith.
4. The instrument defined in claim 3, wherein said thrust bar has a
notch formed therein and wherein said index pawl has an upstanding
leg formed thereon and cooperating with said notch to permit the
pivotal movement of said index pawl, and wherein said index pawl is
pivotally mounted to said thrust bar by means of a resilient
member.
5. The instrument defined in claim 1, wherein said drive means
comprises a ratchet and main gear mounted in said main body portion
for rotation in unison, at least one pinion gear rotatably driven
by said main gear, and a pinion shaft rotatably driven by each said
pinion gear.
6. The instrument defined in claim 5, wherein said drive means is
adapted to be over-driven and thereby advance each staple but the
first in said staple-carrying cartridge more than one staple unit
for each thrust of said thrust bar; and further including means to
reverse the direction of rotation of said drive means so that said
drive means ultimately advances each staple one staple unit, said
reversing means comprising a spring pawl biasing said drive means
in said reverse directon when said drive means is in the
over-driven state.
7. The instrument defined in claim 1, and further comprising means
for alerting the surgeon that a staple has reached a readiness
position for ejection and formation.
8. The instrument defined in claim 7, wherein said alerting means
comprises a notch associated with said pusher-activating means and
a spring-biased wedge housed in said main body portion and adapted
to cooperate with said notch to provide said alerting function.
9. A surgical stapling instrument for applying sterilized staples
to the disunited skin or fascia of a patient for effecting a
joining of the skin or fascia, the instrument adapted to associate
with a staple-carrying cartridge having anvil means at one end
thereof and adapted to house a plurality of staples therein, a
pusher element slidably mounted therein for ejecting staples from
said cartridge and for forming said staples around said anvil
means, and means for advancing said staples in said cartridge, said
surgical stapling instrument comprising: a main body portion; a
nose portion; means for mounting said staple-carrying cartridge on
said nose portion so that said cartridge is rotatable therewith;
drive means housed in said nose portion and rotatable therewith for
activating said staple-advancing means for driving the staples
toward said anvil means .[.;.]. and .[.pusher-activating means
housed in said nose portion and rotatable therewith.]. for driving
the pusher element forward to eject a staple from the
staple-carrying cartridge and to form said staple around said anvil
means, wherein said instrument is manually powered, and further
comprising trigger means for transmitting a manually applied force
to said drive means .[.and said pusher-activating means.]. to power
said drive means .[.and said pusher-activating means.]..
10. The instrument defined in claim 9, wherein said
.[.pusher-activating.]. .Iadd.drive .Iaddend.means comprises a
thrust bar slidably mount in said nose portion and said trigger
means comprises a handle pivotally mounted to said main body
portion and having a lower hand-engaging portion and an upper
force-transmitting portion, and wherein said instrument further
comprises collar means housed in said main body portion and
slidably mounted on and rotatable with said nose portion for
transmitting force from said trigger means to said
.[.pusher-activated.]. .Iadd.drive .Iaddend.means.
11. The instrument defined in claim 10, wherein said collar means
comprises a cylindrically-shaped body member having outwardly and
radially extending flange portions at each end thereof, and wherein
said upper force-transmitting portion of said trigger means is
formed in the shape of a yoke and is positioned around said
cylindrically-shaped body member and between said flange portions
of said collar means so that said collar means can rotate relative
to said trigger means.
12. A surgical stapling instrument for applying sterilized staples
to the disunited skin or fascia of a patient for effecting a
joining of the skin or fascia, the instrument adapted to associate
with a staple-carrying cartridge having anvil means at one end
thereof and adapted to house a plurality of staples therein, a
pusher element slidably mounted therein for ejecting staples from
said cartridge and for forming said staples around said anvil
means, and means for advancing said staples in said cartridge, said
surgical staple instrument comprising: a main body portion; means
for mounting said staple-carrying cartridge on said main body
portion; drive means to activate said staple-advancing means for
driving the staples toward said anvil means .[.; pusher-activating
means.]. .Iadd.and .Iaddend.for driving the pusher element forward
to eject a staple from the staple-carrying cartridge and to form
said staple around said anvil means; and clutch means for
preventing said drive means from activating said staple-advancing
means more than once in each stapling operation, said clutch means
comprising two surfaces movable relative to one another with one of
said two surfaces being sloped relative to the other, a roller
positioned between said two surfaces, and a wedge member in one of
said two surfaces, said wedge member adapted to permit said roller
means to move therepast only at the respective ends of the drive
means stroke. 13. The instrument defined in claim 12, wherein said
.[.pusher-activating.]. .Iadd.drive .Iaddend.means comprises a
thrust bar slidingly mounted for reciprocative movement in said
main body portion and wherein said clutch means prevents said
thrust bar from returning to its initial rest position until said
thrust bar has completed its forward
thrust movement. 14. The instrument defined in claim 13, wherein
the sloped surface is inclined relative to said thrust bar and
defines an opening therewith which increases in size in the
direction of the forward thrust movement of said thrust bar, and
wherein said roller is positioned
between and cooperating with said sloped surface and said thrust
bar. 15. The instrument defined in claim 14, wherein said wedge
member
cooperating with said roller is spring-biased. 16. A surgical
stapling instrument for applying sterilized staples to the
disunited skin or fascia of a patient for effecting a joining of
the skin or fascia, the instrument adapted to associate with a
staple-carrying cartridge having anvil means at one end thereof and
adapted to house a plurality of staples therein, a pusher element
slidably mounted therein for ejecting staples from said cartridge
and for forming said staples around said anvil means, and means for
advancing said staples in said cartridge, said surgical stapling
instrument comprising: a main body portion; means for mounting said
staple-carrying cartridge on said main body portion: drive means to
activate said staple-advancing means for driving the staples toward
said anvil means .[.; pusher-activating means.]. .Iadd.and
.Iaddend.for driving the pusher element forward to eject a staple
from the staple-carrying cartridge and to form said staple around
said anvil means; and locking means associated with said
.[.pusher-activating.]. .Iadd.drive .Iaddend.means and adapted to
cooperate with said staple-carrying cartridge for ensuring that
said .[.pusher-activating.]. .Iadd.drive .Iaddend.means is in its
initial rest position when said staple-carrying
cartridge is mounted on said main body portion. 17. The instrument
defined in claim 16, wherein said locking means is adapted to lock
said .[.pusher-activating.]. .Iadd.drive .Iaddend.means in its
initial rest position until said staple-carrying cartridge is
mounted on said main body
portion. 18. The instrument defined in claim 17, wherein said
.[.pusher-activating.]. .Iadd.drive .Iaddend.means comprises a
thrust bar mounted for reciprocative movement in said main body
portion, and wherein said locking means comprises a movable
cartridge interlock member adapted to lie in blocking and abutting
relationship with the forwardmost end of said thrust bar when said
thrust bar is in its initial rest position and adapted to move out
of said blocking relationship with said thrust bar when said
staple-carrying cartridge is mounted on said main body portion.
9. The instrument defined in claim 18, wherein said cartridge
interlock member comprises a body portion spring-biased toward a
blocking relationship with said thrust bar and having an opening
therein through which said thrust bar can pass when moved out of
said blocking relationship, said cartridge inter-lock member
further having a leg porton adapted to contact said staple-carrying
cartridge when said staple-carrying cartridge is mounted on said
main body portion such that said cartridge inter-lock member is
moved out of said blocking
relationship. 20. The instrument defined in claim 16, wherein said
locking means comprises a movable cartridge stop lock member
adapted to prevent the mounting of said staple-carrying cartridge
in said main body portion unless said .[.pusher-activating.].
.Iadd.drive .Iaddend.means is in said
initial rest position. 21. The instrument defined in claim 20,
wherein said .[.pusher-activating.]. .Iadd.drive .Iaddend.means
comprises a thrust bar mounted for reciprocative movement in said
main body portion and wherein said cartrige stop lock member is
adapted to block the mounting of said staple-carrying cartridge
when said thrust bar is not in said initial rest position, and is
adapted to be moved into a non-blocking position by said thrust bar
when said thrust bar is in said initial rest position.
The instrument defined in claim 20, wherein said cartridge stop
lock member comprises a body portion and a leg portion, said leg
portion being spring-biased into a position adapted to block the
mounting of said staple-carrying cartridge when said thrust bar is
not in said initial rest position, and wherein each of said
cartridge stop lock member and said thrust bar have correspondingly
inclined surfaces such that said cartridge stop lock member is
moved into a non-blocking position by said thrust bar when said
thrust bar is in said initial rest position.
Description
BACKGROUND OF THE INVENTION
In U.S. Pat. No. 3,643,851, assigned to the present assignee and
entitled SKIN STAPLER, there is disclosed a surgical stapler for
joining the disunited skin of a patient. The surgical stapler
disclosed in this commonly assigned patent employs a
staple-carrying cartridge comprising an anvil adapted to lie flush
with the skin, a plurality of staples which are to be folded around
the anvil, and a pusher for ejecting and bending the staples around
the anvil. The surgical stapling instrument adapted to accept the
staple-carrying cartridge in this commonly assigned patent is
powered by a pressurized gas. Later developments of the gas-powered
stapler and cartridges for applying surgical staples to external
skin and internal fascia are disclosed in U.S. Pat. No. 3,662,939,
assigned to the present assignee and entitled "SURGICAL STAPLER FOR
SKIN AND FASCIA."
Although these gas-powered instruments represent a marked advance
over the state-of-the-art, there are certain disadvantages
associated with the use of gas-powered units of this type. One of
the obvious disadvantages is the necessity for replacing the gas
cartridges after their contents have been exhausted, and a second
is the inconvenience associated with storing and maintaining a
supply of these cartridges. Also, the powering mechanism is
complex, is hence somewhat costly, and comprises numerous
close-tolerance elements which tend to be susceptible to
malfunction. For these and other obvious reasons, it would be
advantageous to have a simple surgical stapling instrument adapted
to accept staple-carrying cartridges of the type disclosed in the
above commonly assigned patents, but which is powered manually and
without the intervention of a gaseous medium and the disadvantages
associated therewith.
Accordingly, it is a broad object of the present invention to
provide a surgical stapling instrument for stapling the disunited
skin or fascia of a patient which is manually powered and wholly
operated by mechanical means.
It is another object of the present invention to provide a surgical
stapler in which the staple-carrying cartridge is mounted so that
it is rotatable relative to the hand-held main body portion of the
instrument so that the staples can be applied at any angle without
the necessity for rotating the hand-held portion of the
instrument.
It is yet another object of the present invention to provide a
surgical stapler with means for ensuring that the staple-advancing
drive means of the instrument is activated only once in each
stapling operation.
Another object of the invention is to provide means for preventing
a driving stroke of a surgical stapler absent the association with
a staple-carrying cartridge.
It is yet a further object of the present invention to provide
means for preventing the insertion of a staple-carrying cartridge
into the surgical stapler until the driving mechanism of the
stapler has been returned to its initial position.
It is still a further object of the present invention to provide a
surgical stapler with means to alert the surgeon when a staple has
been advanced into the ready position and is about to be ejected
and formed.
These and other objects of the invention, as well as many of the
attendant advantages thereof, will become more readily apparent
when reference is made to the following description taken in
conjunction with the accompanying drawings.
SUMMARY OF THE INVENTION
The present invention relates to a surgical instrument for stapling
together disunited segments of the external skin or internal fascia
of a patient.
The surgical stapling instrument generally comprises a main body
portion having a nose portion rotatably mounted therein and adapted
to receive and mount a staple-carrying cartridge. The nose portion
of the stapler houses the drive means for advancing and forming the
staples. A pusher-activating means for driving the pusher element
of the staple-carrying cartridge to eject and form the staples
around the anvil means of the cartridge comprises a thrust bar
slidably mounted for reciprocative movement in the nose portion of
the stapler. The thrust bar is attached to and adapted to move with
a collar element slidably mounted on the nose portion of the
stapler. A trigger means comprises a handle which is pivotally
mounted on the main body portion of the stapler and has means for
engaging the collar element so that the thrust bar is moved
forwardly by squeezing the trigger. A return spring attached to the
trigger and to the main body portion of the stapler functions to
return the thrust bar to its initial position after the thrust
stroke of the bar has been completed.
The drive means to activate the staple-advancing means in the
staple-carrying cartridge for driving the staples toward the anvil
comprises pinion gears and pinion shafts also housed within the
nose portion of the stapler. The teeth of the pinion gears mesh
with the teeth of a main gear which is adapted to rotate in unison
with a ratchet. The main gear and ratchet are rotatably mounted in
the rear nose portion of the stapler. An index pawl pivotally
attached to the thrust bar and operatively associated with the
ratchet causes the ratchet, main gears and pinions to rotate when
the thrust bar is initially moved forward and thus activates the
staple-advancing means in the cartridge.
As was the case in the above-referenced commonly assigned patents,
it is desirable to rotate the particular drive screws of the
staple-carrying cartridge 360.degree. each time a staple is being
ejected by first over-driving and then return-driving the screws.
Accordingly, and similar to the gear boxes disclosed in the
commonly assigned patents, the drive means for advancing staples of
the present invention is adapted to be over-driven and then
returned to a position wherein the drive screws of the cartridge
are rotated exactly 360.degree.. The return movement of the
staple-advancing drive means is accomplished by a spring pawl which
cooperates with the above-mentioned ratchet. This spring pawl also
functions as a stop preventing excessive return rotation of the
ratchet.
Means are also provided for preventing more than one staple from
being placed in the ready position of the staple-carrying cartridge
during the stapling operation. This means comprises a clutch means
which prevents the return of the thrust bar to its initial position
until it has completed a full stroke, thereby ejecting a staple
from the staple-carrying cartridge. The clutch means includes a cam
block mounted in the forward end of the nose portion of the stapler
and having an inclined surface facing the thrust bar. The forward
end of the thrust bar passes through the cam block and operatively
engages a cylindrical roller positioned between the thrust bar and
the inclined surface of the cam block. The cam block houses a
spring-biased wedge which cooperates with the cylindrical roller.
The cooperation between these elements is such that the cylindrical
roller prevents the thrust bar from being returned to its initial
position until it has completed a full driving thrust movement.
Means are further provided for preventing the forward movement of
thrust bar until a staple-carrying cartridge has been mounted on
the stapler. This means comprises a cartridge interlock housed in
the forward end of the nose portion of the stapler and
spring-biased into a position such that it blocks the forward
movement of the thrust bar until a cartridge is properly mounted.
In its initial position, the forward end of the thrust bar abuts
the rear face of the cartridge interlock. When the staple-carrying
cartridge is mounted, the cartridge interlock is forced upward by
the staple-carrying cartridge thereby registering an opening in the
cartridge interlock with the forward end of the thrust bar such
that the thrust bar is capable of being moved forward and driving
the pusher element of the staple-carrying cartridge to eject and
form the staples.
The forwardmost staple in the staple-carrying cartridge is advanced
into the ready position during the initial stage of the forward
thrust stroke of the thrust bar. At this point and with the thrust
bar partially advanced, it is possible to remove the
staple-carrying cartridge from the stapler. Under these
circumstances, the clutch means prevents the thrust bar from
returning to its initial position. Accordingly, the thrust bar must
be fully advanced before it will be automatically returned to its
initial position. The surgeon or his attendant may not remember to
follow this procedure, however, and may attempt to mount a
staple-carrying cartridge in the stapler while the thrust bar is in
this partially advanced position. This procedure could result in
jamming the drive mechanisms of the staple-carrying cartridge or
other undesirable mechanical difficulty.
To prevent such jamming, means are provided for preventing a
cartridge from being mounted unless the thrust bar has returned to
its initial position. This means comprises a cartridge stop lock
mounted in the forward end of the nose portion of the stapler. When
the thrust bar is in its initial position, the cartridge stop lock
is oriented so that a staple-carrying cartridge can be easily
locked in the stapler. If the thrust bar is not in its initial
position, however, but rather is in a partially advanced position,
the cartridge stop lock is spring-biased into a blocking position
so that a staple-carrying cartridge cannot be fully mounted in the
stapler.
While the initial movement of the trigger advances the staples and
the intermediate movement readies the cartridge for the stapling
operation, only the final stages of trigger movement effect the
ejection and formation of a staple. Accordingly, it is desirable to
alert the surgeon to the fact that a staple is about to be ejected
so that the surgeon can be sure that the instrument is properly
positioned. In fact, the inventive instrument could be operated
remote from the patient until the last stage of trigger movement,
and only then oriented in readiness for a stapling operation. As
part of the present invention, the stapler is provided with a
spring-biased wedge housed in the nose portion of the stapler which
snaps into a notch on the top surface of the thrust bar with an
audible "click" just before a staple is to be ejected. At the same
time, the surgeon will also feel a slight but noticeable change in
the force required to squeeze the trigger, thus further alerting
him to the fact that a staple is about to be ejected.
As just described, the drive means for advancing staples in the
staple-carrying cartridge and for ejecting staples therefrom are
housed in the nose portion of the stapler which is rotatably
mounted in the main body portion. Since the staple-carrying
cartridge is mounted in the nose portion and rotatable therewith,
it is possible to change the stapling angle of the stapler by
merely rotating the nose portion while maintaining the handheld
main body portion in a fixed position.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a vertical cross-section of the surgical stapling
instrument of the present invention;
FIG. 2 is a horizontal cross-section taken along line 2--2 of FIG.
1;
FIG. 3 is similar to FIG. 2 but shows a portion of the stapler
during the stapling operation;
FIG. 4 is a horizontal, fragmentary view of a portion of the
staple-advancing drive mechanism of the stapler during the stapling
operation;
FIG. 5 is a vertical cross-section of the stapler looking
rearwardly;
FIG. 6 is a side view, partially in section, of the staple-carrying
cartridge mounting portion of the stapler after the cartridge is
mounted and ready for use;
FIG. 7 is a front view of the stapler with the staple-carrying
cartridge mounted and ready for use;
FIG. 8 is a vertical cross-section taken along line 8--8 of FIG. 2
and showing the clutch means;
FIGS. 9-12 are sequential views showing the operation of the clutch
means during a stapling operation;
FIG. 13 is a vertical cross-section taken along line 13--13 of FIG.
2 and showing the position of the cartridge interlock before the
staple-carrying cartridge is inserted;
FIG. 14 is similar to FIG. 13 but shows the cartridge interlock
after the insertion of the staple-carrying cartridge which is shown
in phantom lines;
FIG. 15 is a vertical cross-section taken along line 15--15 of FIG.
2 and showing the position of the cartridge stop lock before the
thrust bar has been advanced;
FIG. 16 is similar to FIG. 15 but shows the cartridge stop lock
after the thrust bar has been partially advanced;
FIG. 17 shows the cooperation between the inclined surfaces of the
thrust bar and cartridge stop lock;
FIG. 18 is a horizontal cross-section taken along line 18--18 of
FIG. 1 and showing the location plate for locating the cartridge
interlock, cartridge stop lock and pusher-engaging portion of the
thrust bar;
FIG. 19 is an enlarged view of the rear portion of a
staple-carrying cartridge with its cover removed;
FIG. 20 is a cross-section taken along line 20--20 of FIG. 19;
FIG. 21 is a vertical cross-section of the front portion of a
staple-carrying cartridge; and
FIG. 22 is a view of the front portion of the cartridge during the
stapling operation, with the cover removed.
DETAILED DESCRIPTION OF THE INVENTION
With reference first to FIGS. 1-6, the surgical stapler of the
present invention will be described in general terms. The stapler
shown generally at 10 comprises housing 12 having main body portion
14 and handle portion 16. Nose portion 20 of stapler 10 is
rotatably mounted in main body portion 14 of housing 12. Nose
portion 20 includes a front section 22 extending out of housing 12
and adapted to mount staple-carrying cartridge 26. Nose portion 20
further includes a rear section 24 located inside housing 12 and
acting to house the driving means for advancing, ejecting and
forming staples from the staple-carrying cartridge. Nose portion 20
is conveniently formed in two parts, upper and lower, held together
by a pair of screws 21 and held in relative alignment by dowel pins
23 and 25. Staple-carrying cartridge 26 is shown fitted into nose
portion 20 of stapler 10 in FIG. 6.
The staples in staple-carrying cartridge 26 are advanced, ejected
and formed by mechanical means only and without the intervention of
a gaseous medium. Accordingly, the power for advancing, ejecting
and forming the staples in cartridge 26 comes from the manipulative
force supplied to stapler 10 by the surgeon. This force is
transmitted to the drive means of stapler 10 by means of trigger 28
which generally comprises a handle pivotally attached to housing
12. Pivoting of trigger 28 causes a thrust bar 30, the
pusher-activating means, to drive the pusher element of staple
carrying cartridge 26 forward to eject and form a staple around the
anvil means. At the same time, a .[.pusher-engaging.].
.Iadd.ratchet .Iaddend.32 and a main gear 34 housed in the rear
portion 24 of nose 20 are caused to rotate. Main gear 34 in turn
rotates a pair of pinion gears 36 and pinion shafts 38 which
associate with the cartridge 26 to advance the staples.
With reference now to FIGS. 1 and 5, trigger 28 will be described.
Trigger 28 is pivotally mounted to housing 12 by means of stud 40
and drive pin 42. Trigger 28 is of appropriate size and shape to be
conveniently gripped by the operating hand of a surgeon. The
trigger includes a rearward extending portion 44 to which is
attached one end of a return spring 46. The other end of return
spring 46 is attached to housing 12 and functions to return trigger
28 and thrust bar 30 to their initial positions after staple
forming has occurred. Trigger 28 is of Y-shape and includes a lower
hand-engaging portion 48 and an upper force-transmitting yoke
portion 50. Yoke 50 embraces a collar 52 slidingly mounted around
the mid-section of nose portion 20 and adapted to rotate therewith.
Collar 52 includes a cylindrically-shaped body member 54 having
outwardly and radially extending flange portions 56 at each end.
Yoke 50 is positioned around cylindrically-shaped body member 54
and between the flange portions 56. Shoulder portions 55 and 57 of
nose portion 20 limit the forward and rearward movement,
respectively, of collar 52. Pivoting of trigger 28 results in
longitudinally directed force being exerted on collar 52 by yoke
portion 50 of trigger 28. Accordingly, when the trigger is
activated, collar 52 simultaneously slides along the mid-section of
nose 20. Also, by this arrangement, collar 52 is free to rotate
relative to trigger 28.
As best seen in FIGS. 1, 3 and 17, the means for driving the pusher
element of the staple-carrying cartridge to eject and form staples
comprises thrust bar 30 which includes an elongated central section
58 having a wing portion 60 near the rear end thereof. A
pusher-engaging extension 62 and an inclined surface 64 are
positioned at the forwardmost end of thrust bar 30. Inclined
surface 64 is adapted to engage a stop lock mechanism which will be
discussed subsequently. Also located near the front end of thrust
bar 30 is an elongated notch 66 which forms a part of the clutch
means of the present invention. Located near the rear end of thrust
bar 30 is a second notch 68 which engages the forward end of index
pawl 70. Thrust bar 30 is slidingly mounted in nose portion 20 and
is adapted to rotate therewith. As illustrated in FIG. 2, wing
portion 60 of thrust bar 30 lies near the mid-section of collar 52,
conveniently formed as two semi-circular parts, and is rigidly
attached to collar 52 by means of bolts 53. Accordingly, thrust bar
30 reciprocates back and forth with collar 52 when trigger 28 is
pivoted, and collar 52 rotates with thrust bar 30 when nose portion
20 is rotated.
The staple-advancing drive means of the stapler 10 is arranged so
that when thrust bar 30 is moved forward, the elements forming a
part of this arrangement are activated. That is, the forward motion
of the pusher-activating element causes the rotation of the screws
of staple-carrying cartridge 26 thereby advancing the staples. And
as will be more fully described below, the staples are slightly
over-driven during the forward stroke of thrust bar 30 and are then
returned to their proper positions as will be discussed
subsequently.
With reference now to FIGS. 1-4, the staple-drive mechanism will be
explained. The index pawl 70 is pivotally attached to the rear end
of thrust bar 30. The transverse base portion 74 of spring 72
passes through aperture 76 in thrust bar 30 and the inturned end of
upstanding leg 78 of spring 72 fits into one end of an aperture 80
in the rear end of thrust bar 30 and the inturned end of upstanding
leg 82 fits through an aperture 84 in index pawl 70 and then into
the other end of aperture 80 in thrust bar 30. An upstanding leg 86
on the forward end of index pawl 70 fits into notch 68 in thrust
bar 30. Notch 68 is trapezoidal in shape and has inclined surface
88. The combination of spring 72 and inclined surface 88 of notch
68 allows index pawl 70 to pivot outwardly.
Index pawl 70 rides along on wall of a six-tooth ratchet 32 and
engages one of the teeth thereof. The index pawl, pivotally mounted
on thrust bar 30, is biased toward ratchet 32 by spring 72. Ratchet
32 is attached to, and rotates with, a main gear 34. Ratchet 32 and
main gear 34 are of unitary construction, as illustrated, and are
rotatably mounted in the rear end 24 of nose portion 20 by means of
shaft 90. The teeth of main gear 34 mesh with the teeth of two
pinion gears 36, both of which are seen in the drawings. Pinion
gears 36 are in turn attached to pinion shafts 38 which are housed
in, and extend longitudinally through, the nose portion 20 of
stapler 10. A tapered cylindrical body portion 92 on the ratchet 32
and main gear 34 assembly provides a stop for pinion gears 36 which
have a rear portion 94 which abuts body portion 92 of the ratchet
32 and main gear 34 assembly. (See FIG. 1). This arrangement
prevents the pinion shafts from inadvertently being moved out of
their proper longitudinal position.
Thrust bar 30, index pawl 70 and ratchet 32 are arranged in such a
manner that the forward stroke of thrust bar 30 causes ratchet 32
and accordingly main gear 34 to move slightly more than 60.degree..
As noted previously, it is desired to ultimately rotate the screws
associated with staple-carrying cartridge 26 precisely 360.degree.
for each staple driving operation. The staple-advancing drive means
in stapler 10 is arranged so that for each 60.degree. turn of
ratchet 32 and main gear 34, pinion shafts 38 and the screws in
cartridge 26 are rotated 360.degree.. However, to ensure that the
staples are advanced a proper amount, it has been found desirable
to over-drive the screws in cartridge 26 and thus the staples, and
then to reverse the rotation of the screws so that ultimately they
experience a net 360.degree. rotation. It is for this reason that
six-tooth ratchet 32 is rotated slightly more than 60.degree.. It
becomes necessary therefore to provide means for returning ratchet
32 to its 60.degree. position. The ratchet return is brought about
by means of spring pawl 96 as will be discussed subsequently.
With particular reference now to FIGS. 2-4, the operation of the
drive means for activating the staple-advancing mechanism of the
staple-carrying cartridge and for driving the staples toward the
anvil will be described. As shown in FIG. 2, thrust bar 30 is in
its initial at rest position. In this position, index pawl 70 is in
engagement with ratchet 32. Tooth portion 102 of index pawl 70,
which is the driving region thereof, is removed from the nearest
tooth on ratchet 32 to allow for slight "play" before the ratchet
32 is rotated.
When thrust bar 30 moves forward, during a stapling operation,
index pawl 70 rotates ratchet 32. Ratchet 32 is rotated in a
clockwise direction as index pawl 70 is moved forward with thrust
bar 30. When ratchet 32 has been rotated through approximately its
desired maximum angle of slightly greater than 60.degree., the back
surface of an advancing tooth of ratchet 32 engages planar portion
104 near the end of index pawl 70 and forces tooth portion 102 of
index pawl 70 out of engagement with ratchet 32 (See FIG. 4). The
maximum angle through which ratchet 32 is rotated is greater than
that needed to advance each staple one "staple unit." Thus, the
staple-advancing drive means is momentarily over-driven; however,
this condition is automatically corrected by spring pawl 96.
Referring now to FIGS. 2 and 4, it can be seen that spring pawl 96
is attached to the rear end 24 of nose portion 20 by means of a pin
97 and comprises an arcuate section terminating at end 106. Spring
pawl 96 contacts ratchet 32 at two points in its initial position.
First, end 106 of spring pawl 96 contacts one of the teeth of
ratchet 32. Second, a point on spring pawl 96 partially between end
106 and the arcuate section contacts the back surface of the
adjacent tooth. Accordingly, when ratchet 32 is momentarily
over-driven, spring pawl 96 is cammed outward as shown in FIG. 4;
however, ratchet 32 is then immediately returned to an exactly
60.degree. rotation by the biasing action of spring pawl 96. It
will be noted that the counterclockwise rotation of ratchet 32
terminates when end 106 of spring pawl 96 contacts a tooth on
ratchet 32. Accordingly, when thrust bar 30 and index pawl 70 are
in the fully advanced position, shown in solid lines in FIG. 3,
spring pawl 96 has the same relationship to ratchet 32 as it did
when thrust bar 30 and index pawl 70 were in their initial
positions illustrated in FIG. 2.
After the forward thrust of thrust bar 30 has been completed and a
staple ejected from the cartridge and formed in the patient, return
spring 46 returns thrust bar 30 to its initial position. During
this phase of operation, the end portion 106 of spring pawl 96
prevents counterclockwise rotation of ratchet 32. At the stage of
the thrust bar return stroke when sloped surface 107 on index pawl
70 contacts a tooth on ratchet 32, the index pawl begins to be
cammed against the force of spring 72. Further camming action then
occurs when the tooth portion 102 of index pawl 70 contacts the
backside of a tooth of ratchet 32. At this stage, index pawl 70 is
pivoted outwardly into the position shown in phantom lines in FIG.
3. This outward pivotal movement is permitted by spring 72 and the
inclined surface 88 of notch 68 of thrust bar 30. Finally, index
pawl 70 reassumes the position shown in FIG. 2. At this point,
stapler 10 is ready for another firing.
As previously stated, it is desirable to alert the surgeon to the
fact that a staple is about to be ejected and formed so that the
surgeon can be sure that cartridge 26 is properly positioned to
effect a neat suture. This is accomplished by means of
spring-biased means 115 housed in nose portion 20 of stapler 10.
Spring-biased means 115 comprises an upper U-shaped member 116
which bears against housing 12 and a lower member 117 terminating
in a V-shaped point which rides along the top of thrust bar 30.
Members 116 and 117 are spring-biased apart by a coil spring 118. A
notch 119 is provided on the top surface of thrust bar 30, in
alignment with member 117, and is adapted to receive the V-shaped
pointed end of member 117 at a stage of the stapling operation just
before a staple leaves the cartridge. At this stage, member 117 is
snapped into notch 119 on the top surface of thrust bar 30 by
spring 118 with an audible "click." Further movement of thrust bar
30 in the forward direction forces member 117 upward against the
force of spring 118 so that thrust bar 30 can continue its forward
movement. This sequence of events will also cause the surgeon to
feel a slight but noticeable change in the force required to
squeeze the trigger, thus further alerting him to the fact that a
staple is about to be ejected. Member 116 also functions to provide
additional frictional resistance between housing 12 and nose
portion 2 to avoid uncontrolled rotation between nose portion 20
and housing 12 during normal handling and use.
Turning now to FIG. 8, there is illustrated an end view of a clutch
means 120. Clutch means 120 includes a cam block 122 mounted in an
opening 124 in forward end 22 of nose portion 20. Cam block 122 has
an inclined surface 126 facing thrust bar 30 which passes through
an opening 128 in cam block 122. Inclined surface 126 is positioned
relative to thrust bar 30 such that the spacing 130 between
inclined surface 126 and thrust bar 30 increases in the forward
thrust direction of the thrust bar. A cylindrical cam roller 132 is
positioned between inclined surface 126 of cam block 122 and thrust
bar 30. An elongated wedge pin 134 is housed in an aperture 136 in
cam block 122. The forward end of wedge 134 is V-shaped and extends
into opening 130 between inclined surface 126 and thrust bar 30.
The wedge pin 134 is spring-biased toward thrust bar 30 by means of
a spring 138 housed in a recess 140 in cam block 122. Recess 140
lies perpendicular to aperture 136 and the end of spring 138, which
is hook-shaped, is seated in a bore 142 through wedge 134. Cam
roller 132 lies adjacent elongated notch 66 in thrust bar 30 and
its movement is confined by notch 66 as will be discussed
subsequently. The cooperation between these elements is such that
cylindrical roller 132 prevents thrust bar 30 from being returned
to its initial position until completion of a full thrust
stroke.
FIGS. 9-12 are sequential views showing the operation of clutch
means 120 during a stapling operation. Turning first to FIG. 9,
thrust bar 30 is shown in its initial position. In this position,
cam roller 132 lies in a shallow cut-out 144 positioned at the
forwardmost end of notch 66. Cam roller 132 is positioned in the
narrowest part of opening 130 and at the rear of clutch means 120.
Spring-biased wedge pin 134 maintains the cam roller 132 toward the
rear end of clutch means 120.
Turning now to FIG. 10, the clutch means 120 is illustrated during
the forward stroke of thrust bar 30. Cam roller 132 is shown
rotating in a counterclockwise direction. During this stage of
thrust, the surface of cam roller 132 contacts base 146 of notch 66
and inclined surface 126, and is rotated by the movement of thrust
bar 30. This rotational movement is permitted since cam roller 132
is in effect rotating "downhill" toward the widest part of opening
130. At the same time, cam roller 132 bears against spring-biased
wedge 134 which restrains the longitudinal forward movement of cam
roller 132 so that the cam roller is kept in the narrowest part of
opening 130.
Still referring to FIG. 10, it can be seen that an attempted return
movement of thrust bar 30 to its initial position from its
partially advanced position would cause cam roller to rotate in a
clockwise direction. This movement is not permitted by clutch means
120, however, since clockwise rotation of cam roller 132 causes cam
roller 132 to "lock" itself between thrust bar 30 and inclined
surface 126 of cam block 122 thereby preventing all but the
slightest movement of thrust bar 30 toward its initial position.
This occurs because cam roller 132 is in effect rotating "uphill"
toward the narrowest part of opening 130. Furthermore, cam roller
132 would no longer be bearing against spring-biased wedge 134.
Turning now to FIG. 11, clutch means 120 is seen at the forward end
of the stroke of thrust bar 30. In this position, cam roller 132
has been forced to the other side of wedge pin 134 by shoulder
porton 148 of notch 66 and lies in the widest region of opening
130. Once cam roller 132 has so passed wedge 134, it is housed in
an area wider than its diameter and hence is free to rotate in any
direction. Accordingly, cam roller 132 permits thrust bar 30 to
move rearward toward its initial position. A portion of this
operational sequence is shown in FIG. 12 illustrating thrust bar 30
during its return stroke. Here, base portion 146 of notch 66 of
thrust bar 30 may still lightly contact cam roller 132. However,
cam roller 132 can freely rotate since opening 132 is sufficiently
wide at this location. Near the end of the return movement of
thrust bar 30 to its initial position, cam roller 132 is moved into
cut-out 144 in notch 66 and is then forced past wedge 134 by
shoulder portion 150 of notch 66. Cut-out portion 144 allows cam
roller 132 to be moved past wedge 134 and back to its initial
position shown in FIG. 9, without "locking" before the completion
of the return stroke.
Turning now to FIG. 13, there is shown an end view of a cartridge
interlock 152 in its initial blocking position which prevents the
initiation of a thrust stroke until a cartridge is properly
installed on the stapler. Cartridge interlock 152 lies in blocking
and abutting relationship with the forwardmost end of thrust bar 30
when thrust bar 30 is in its initial position. Cartridge interlock
152 is positioned in an opening 154 in the forward end 22 of nose
portion 20 and comprises a body portion 156 and leg portions 158.
As shown in FIG. 13, cartridge interlock 152 is spring-biased into
its initial blocking position by a pair of coil springs 160. In
this position, leg portions 158 of cartridge interlock means 152
extend through openings 165 in a location plate 164. When a
cartridge 26 is mounted on the stapler 10 as shown in FIG. 6,
cartridge interlock 152 is forced upward against the action of
springs 160 and into the position illustrated in FIG. 14. In this
position, opening 166 in cartridge interlock 152 registers with
thrust bar 30 and allows thrust bar 30 to pass therethrough.
Accordingly, cartridge interlock 152 is in the position shown in
FIG. 13 when a cartridge is absent and thrust bar 30 is in its
initial position, and is in the position shown in FIG. 14 the
remainder of the time.
Referring now to FIG. 15, there is shown an end view of a cartridge
stop lock 170 in its initial position. Cartridge stop lock 170 is
adapted to prevent the mounting of a staple-carrying cartridge 26
in stapler 10 unless thrust bar 30 is in its fully retracted
initial position. Cartridge stop lock 170 is mounted in an opening
172 in forward end 22 of nose portion 20. The cartridge stop lock
170 comprises a body portion 174 and leg portions 176. Opening 178
in cartridge stop lock 170 registers with thrust bar 30 when thrust
bar 30 is in its initial position. In the position shown in FIG.
15, leg portions 176 are retracted above the bottom of location
plate 164. Accordingly, staple-carrying cartridge 26 can be easily
mounted on stapler 10.
As best seen in FIG. 17, the cartridge stop lock 170 is held in its
initial position by the inclined surface 64 of thrust bar 30 which
engages a correspondingly inclined surface 180 of cartridge stop
lock 170 when thrust bar 30 is in its initial position. After
thrust bar 30 has left its initial position and is in the thrust or
return portion of its stroke, cartridge stop lock 170 is
spring-biased downward by a pair of coil springs 182 and into the
position shown in FIG. 16. In this position, leg portions 176
extend through openings 184 in location plate 164 and below the
bottom thereof to prevent the mounting of staple-carrying cartridge
26 until thrust bar 30 has been returned to its initial position.
The return of thrust bar 30 to its initial position. The return of
thrust bar 30 to its initial position causes cartridge stop lock
170 to be forced upward against the action of springs 182 as best
shown in FIG. 17, wherein the initial position of thrust bar 30 and
stop lock cartridge 170 are shown in phantom lines.
FIG. 18 shows a top view of the location plate 164, with thrust bar
30 in its initial position. Location plate 164 is housed in an
opening 185 in the forward end 22 of nose portion 20. As previously
described, location plate 164 has openings 164 and 184 therein for
receiving leg portions 158 and 176 of cartridge interlock 152 and
cartridge stop lock 170, respectively. Location plate 164 also has
a longitudinally extending opening 186 which receives
pusherengaging extension 62 and thereby allows thrust bar 30 to
reciprocate.
With reference now to FIGS. 6, 7, 19 and 20, the association of the
staple-carrying cartridge 26 with the stapler 10 will be explained.
Staple-carrying cartridge 26, as can be seen in the figures, is
detachably mounted on nose portion 20. Staple-carrying cartridge 26
is elongated and has a pair of upwardly extending spaced tabs 202
at its rear end. The spacing between tabs 202 is sufficient to
allow pusher-engaging extension 62 to freely slide therebetween and
tabs 202 are dimensioned and positioned so as to engage surface 203
at rearmost end of location plate 164. Therefore, when tabs 202
engage surface 203, staple-carrying cartridge 26 cannot be
inadvertently pulled out of the nose, and cartridge 26 is fixed
against forward movement during the stapling operation.
Staple-carrying cartridge 26 is mounted in stapler 10 by inserting
the end of cartridge 26 into opening 110 in nose portion 20. The
rearward end of staple-carrying cartridge 26 engages a leaf spring
108 which urges the cartridge 26 upwardly until tabs 202 are
positively locked into their associated indentations in the body of
nose portion 20. With cartridge 26 in this position, the rearward
ends 228 of the drive screws 218 forming a part of staple-carrying
cartridge 26 are engaged by slots 39 of pinion shafts 38. The
cartridge 26 is removed from the stapler 10, when exhausted of
staples, by reversing the insertion steps.
With specific reference now to FIGS. 19-22, the construction and
operation of the staple-carrying cartridge 26 will be explained.
The cartridge 26 is defined by a main body 200 and has an anvil 204
at its forwardmost region projecting out as an extension of the top
of cover plate 206. Staple-carrying cartridge 26 houses a plurality
of staples 208 whose cross bars 210 lie transverse to the length of
cartridge 26 and whose points 212 face anvil 204. A pusher element
214 covers staples 208 and is slidingly mounted within indentations
216 in cover plate 206. Pusher element 214 is adapted to be engaged
by pusher-engaging extension 62 of thrust bar 30 and serves both to
eject staples 208 from the cartridge 26 and to form the ejected
staples around anvil 204.
The means for advancing staples 208 along the length of cartridge
26 comprises a pair of drive screws 218. Screws 218 are provided
with threads 220 for guiding and propelling staples 208 along main
body ledges 222 between the lateral walls 221. The pusher element
214 is guided between the tops of screws 218 and the bottom of
cover plate 206, and serves to hold each of the staples 208 against
ledges 222, except during the driving operation. Then, the
forwardmost staple 208 is advanced out of the screw guiding threads
220 by means of inclined surfaces 224, at the forward ends of
ledges 222, into the plane of pusher element 214, and is propelled
forward, out of the main body portion and against anvil 204.
Each screws 218 is provided at its rearwardmost end with an
extension 226 fitted at its extremity with a flat projection 228.
Screws 218 are threaded so that when they, by means of projections
226 associating with pinion shafts 38 are rotated through
360.degree., each staple 208 moves one staple unit. A "staple unit"
is defined as that distance which is required to move the second
staple from its readiness position into a position ready to be
fired. Thus, in FIG. 21, one staple unit is shown at a.
In operation, while pusher element 214 is moving forward by thrust
bar 30, and after the forwardmost staple has been raised into the
plane of the pusher, pusher element 214 makes contact with the
staple as illustrated in FIG. 22. Then, the staple is ejected and
formed in the disunited skin or fascia of the patient as is more
fully described in the above-referenced commonly assigned patents,
the pertinent disclosures of which are expressly incorporated
herein by reference.
Above there have been described specific embodiments of the present
invention. It should be noted, however, that the above description
was given for illustrative purposes only and that many alterations
and modifications may be practiced by those skilled in the art
without departing from the spirit or the scope of the present
invention. It is the intent therefore that the present invention
not be limited to the above but be limited only as defined in the
appended claims.
* * * * *