Note: Descriptions are shown in the official language in which they were submitted.
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ANTI-BACKUP MECHANISM
BACKGROUND OF THE INVENTION
The present invention relates to surgical clip appliers embodied as an
instrument having a supply of clips for rapidly deploying several clips in
closing
severed blood vessels and other small fluid carrying ducts in surgical
procedures.
There are many different designs for surgical clip applicators for a variety
of surgical
procedures including both open surgery and laparoscopy in which a clipping
appliance fits through a trocar tube into a body cavity where the clips are
applied.
A surgical clip applicator comprises an operating handle and clip applying
1o mechanism having an operating cycle in which operating levers are squeezed
together and released. In this operating cycle, a clip is applied in surgery
and the clip
applicator jaws are reloaded with a single clip from a clip supply channel for
clip
application in the next cycle. The applicator provides a moveable clip supply
channel
containing a line of clips that are released seriatim. The supply channel
integrates a
clip pusher and an escapement or clip stop spring in a single unit.
A well-known hazard with clip appliers is a condition of releasing a partially
closed clip in a surgical site. This condition results when operating handles
are given
a partial pull or closing and then released. The partial pull crimps.but does
not close
a clip located in the instrument jaws. When partially pulled handles. of some
older
instruments are released, the instrument jaws re-open and the partially closed
clip
falls from the jaws into the surgical site.
This invention provides an anti-backup mechanism for a repeating multi-clip
applier to prevent this operating hazard.
The present invention also relates generally to mechanical devices used in
applications other than clip appliers, where such devices have reciprocal
motion in
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one or more components, and where it is desirable for proper operation of the
devices to ensure that full reciprocal motion of components occurs in
operating or
using the devices. The invention ensures that reciprocal translators (i.e.,
that
component of the device which undergoes reciprocal motion) forming part of a
mechanical device move through the full reciprocal excursion assigned to the
translator as a component of a mechanical device. Specifically, the invention
prevents reversal of movement of a reciprocal translator at a point
intermediate the
full excursion assigned to the translator. If a translator comes to rest at a
point
intermediate full excursion, the anti-backup device of the invention ensures
that the
io translator is restricted to resuming movement only in the same direction as
before it
came to rest.
SUMMARY OF THE INVENTION
A preferred embodiment of repeating multi-clip applier according to the
present invention comprises an instrument having an operating handle housing
and
a removable, fully rotatable and disposable clip applying cartridge. A full
squeeze
and release of operating handles applies a clip to a surgical site and reloads
another
clip into clip applying jaws of the instrument.
The operating handle housing accommodates an anti-backup mechanism to
prevent a partial pull and release of the operating handles to prevent the
hazard of a
partially closed clip falling into the surgical site. The present invention
prevents
occurrence of this condition by means of an anti-backup mechanism to ensure
that
when the appliance handles are pulled, the handles must be given a full pull
to
execute a complete cycle of the clip applier mechanism. If a partial pull of
the
appliance handles occurs, the anti-backup mechanism retains or holds the clip
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applier mechanism in fixed position without possibility of backup or reverse.
The anti-
backup "hold" is released simply by giving the handles a complete pull. When a
partial pull occurs and the anti-backup mechanism holds the clip applying
mechanism in place, the instrument jaws remain partially closed holding a
partially
closed clip thereby preventing the clip from falling into a surgical site. The
anti-
backup mechanism also functions in the. opposite, or release, motion of
operating
handles. That is, the operating handles when being released are constrained by
the
anti-backup mechanism to undergo a full release . motion. The anti-backup
mechanism prevents partial release and re-pull of the trigger thereby to
prevent
1o double loading of a clip into the crimping jaws, a condition that would jam
the
instrument.
Another embodiment of anti-backup mechanism has general application in
devices having one or more components undergoing reciprocal motion during
operation of the device, where it is desirable to ensure full reciprocal
excursion occur
in each operating use of the device. For this purpose, an anti-backup spring
is held
stationary along spaced edges within the device housing, with the spring
itself having
spring blades positioned in confronting relation. across an opening in the
spring. A
reciprocal translator, passes through the spring opening in, sliding
engagement with
operative edges of the spring blades.. In this sliding engagement the spring
blades
deflect slightly in that direction of motion of the translator. An attempt to
reverse
motion of the translator to travel in the opposite direction is blocked by the
spring
blades which cooperate by engaging translator surfaces to prevent reverse
motion.
So, the only motion available to the translator is full excursion in the
original direction
to a point where the spring blades disengage the translator. Motion may be
reversed
only after such disengagement of the spring blades. In like manner, the spring
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blades engage the translator on the return excursion preventing backup motion
until
full return excursion occurs.
Full excursion of the translator is selected according to the task it performs
as
part of an operating mechanism and the translator is confined to that full
excursion
by locating transition points a specified distance apart on the translator
body. At each
transition point, the spring blades disengage the translator and motion can be
reversed.
Specific examples are included in the following description for purposes of
clarity, but various details can be changed within the scope of the present
invention.
OBJECTS OF THE INVENTION
An object of the invention is to provide a clip applicator having an operating
handle that provides anti-backup linear reciprocating motion of a clip
applying
cartridge.
Another object of the invention is to provide a clip applicator having an
operating handle with an anti-backup mechanism that. permits full forward and
reverse strokes of a clip applying cartridge to avoid the hazard of releasing
a partially
crimped clip at a surgical site.
Another object of the invention is to provide a clip applicator having an
operating handle with an anti-backup mechanism that permits full forward and
reverse strokes of a clip applying cartridge to prevent double loading of a
clip into the
crimping jaws, a condition that would jam the instrument.
Another object of the invention is to provide an anti-backup mechanism
having general application in devices with components undergoing reciprocal
motion
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where it is desirable or necessary for the component always to complete full
motion
in one direction before reversal of motion is possible.
Other and further objects of the invention will become apparent with an
understanding of the following detailed description of the invention or upon
employment of the invention in practice.
BRIEF DESCRIPTION OF THE DRAWING
A preferred embodiment of the invention has been chosen for detailed
description to enable those having ordinary skill in the art to which the
invention
appertains to readily understand how to construct and use the invention and is
shown in the accompanying drawing in which:
Figure 1 is a side elevation view of the applicator of Figure 1 with the
operating handle housing partially in section and with handles in release
position.
Figure 2 is a side elevation view of the applicator of Figure 1 with the
operating handle housing partially in.section and with handles in pull
position.
Figure 3 is a side elevation of a rotary translator.
Figure 4a is a side elevation view of the rotary drum.
Figure 4b is a longitudinal section view of the rotary drum of Figure 4a.
Figure 5 is a front elevation of anti-backup disc.
Figures 6 a-g are sequential views of anti-backup mechanism with disc in (a)
rear groove, (b)&(c) between grooves, (d) in front groove, (e)&(f) between
grooves,
and (g) again in rear groove, and with arrows indicating directions of
permitted and
prevented movement of operating handle and cartridge mechanism.
Figure 7 is an exploded view of components of a modified embodiment of
anti-backup mechanism according to the invention.
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Figure 8 is a front elevation view of anti-backup spring of the embodiment of
Figure 7.
Figure 9 is a front elevation view of anti-backup spring of the embodiment of
Figure 7 showing the position of a reciprocal translator.
Figures 10a-e are sequential views of the anti-backup mechanism of Figures
undergoing full reciprocal motion in relation to the anti-backup spring.
Figures 11 and 12 are perspective views of the mechanism of Figure 7
showing positions of spring and spring blades and reciprocal translator in
travel in
opposite directions.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawing, a preferred embodiment of the repeating multi-clip
applier 10 comprises operating handle housing 12 and clip applicator cartridge
14.
The operating handle housing 12 shown in Figures 1-2 comprises handle
members including a depending grip 12c, a center section. defining a central
chamber 12e, and a forward cylindrical portion 12f defining a forward chamber
12g.
A trigger 18 for actuating applier mechanisms is mounted on the housing for
pivotal movement about axis A-A', normal to Figure 1. The trigger includes a
depending grip portion 18.
The trigger when pulled transmits motion to the clip cartridge mechanism (not
shown) through the intermediation of fixed translator slide 20 and a rotary
translator
22. The trigger acts against the forward bias of bar spring 16 with its end
16a held by
translator slide recess 20a.
The rotary translator 22 (Figs 1, 2, and 3) forms a subassembly with an anti-
backup mechanism 24, a rotatable drum 26, and a thumb wheel hub 28 which
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subassembly interconnects the fixed translator 20 and the clip cartridge 14
for
performing the functions of transmitting reciprocating rectilinear motion with
a fixed
excursion, accommodating rotary motion of the clip cartridge, enabling
mounting and
disconnecting of the clip cartridge from the operating handle, and providing
an anti-
backup capability for the operating handle and cartridge mechanism.
The rotary drum subassembly 22, 24, 26 comprises the rotary translator 22
positioned axially within the drum 26. An anti-backup disc 24 (Figs 2, 3 and
5),
defined by an open center 24a and extending radially from the center to define
a
plurality of inwardly directed spring fingers 24c, fits onto the rotary
translator 22 and
is assembled to the enlarged rear end flange 26h of the rotary drum by means
of a
drum cap 26i (Figs. 1 and 2). In normal position of the clip applicator with
the trigger
released, the anti-backup spring, fingers 24c are located in the rear anti-
backup
groove as shown in Fig. 1.
The rotary drum subassembly is assembled into the forward chamber 12g of
the operating handle housing. The center section. 22c (Fig 3) of the rotary
translator shaft has spaced anti-backup grooves 22d, 22e with the distance
between
the grooves being approximately equal to the distance of reciprocating
rectilinear
motion of the fixed translator and equal to the rectilinear excursion of the
clip
applicator mechanism.
The operation of the anti-backup. mechanism is illustrated in Figures 6a-g.
In the mechanism position of Figs 1 and 6a, the handle trigger 18 is in
released position with the anti-backup disc 24 in registry with the rear anti-
backup
groove 22d of the rotary translator 22. When the trigger is pulled (Fig 2)
(for crimping
and applying a clip at a surgical site), the rotary translator moves in the
direction of
arrow 6a. As the rotary translator continues movement, the spring- fingers 24c
of the
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disc engage the outer surface 22c of the rotary translator in the manner shown
in
Figures 6b-c. The anti-backup mechanism applied by the canted spring fingers
24c
(Figs 6b-c) to the outer surface 22c of the rotary translator permits
continued
movement in the direction of arrow 6a and prevents movement in the opposite
direction of arrow 6b. If a surgeon releases the trigger with less than a full
pull stroke
leaving anti-backup components in the position of Fig 6c, for example, the
anti-
backup mechanism holds the rotary translator in position against the bias of
bar
spring 16 which tends to return the trigger to release position. In this Fig
6c hold
position, the applicator jaws retain the partially crimped clip preventing it
from falling
into a surgical site. A continuing pull of the trigger (in. direction of arrow
6a) moves
the rotary translator through the position of Figure 6c to the position of
Figure 6d in
which the spring fingers 24c enter the forward groove 22e.
In this position (Fig 6d), the rotary translator may now be moved
forward (by releasing the trigger and by force of return spring 16) in the
direction of
arrow 6c. In this forward movement, the spring fingers 24c are effective to
allow
continued forward movement while preventing movement in. the direction of
arrow
6e. If the handle trigger is held by a surgeon with components as in Fig 6f,
the anti-
backup mechanism will prevent the surgeon from pulling the trigger in the
direction of
arrow 6e. The surgeon must allow full release of the trigger to component
position of
Figure 6g. Direction of movement can be changed again when the-spring fingers
24c
enter the rear groove 22e as in Figure 6g.
A pull on the trigger against the force of bar spring produces unitary
rearward
rectilinear movement of the fixed translator, the rotary translator passing
through the
stationary spring fingers of the anti-backup disc, and the puller bar emerging
from
within the cartridge casing until the trigger and fixed translator reach the
end of travel
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and with the anti-backup disc spring fingers positioned at the front groove.
The
rearward excursion is now complete, and when the trigger is released, the bar
spring
urges the fixed translator forward until all components reach normal position.
In the event a pull on the trigger, is released without reaching the full
extent of
rectilinear motion, the anti-back up spring fingers will not have reached
their front
groove remaining instead in contact with the outer surface of the rotary
translator.
The spring fingers in contact with outer surface function as a brake against
the action
of the bar spring tending to force the released components to return to normal
position. In this partial pull condition of the trigger a clip has been
crimped in the
instrument jaws which clip will fall. out of the jaws into a surgical site if
the jaws
reopen by return of the mechanism to normal position. So the anti-backup
mechanism retains the instrument in "partial pull position" against the
normalizing
force of the bar spring and most importantly prevents fallout from the jaws of
a
partially crimped clip. The anti-backup, device retaining action is removed
simply by
means of a full pull on the trigger causing the spring fingers to enter the
forward
groove where they can go "over center" thereafter permitting the rotary
translator to
pass through the spring fingers. It is to be noted that the anti-backup
mechanism is
effective in both directions. The anti-backup mechanism has effect when the
trigger
is released after a full pull so that if there is a "partial release" of the
trigger, the
trigger must nonetheless return to normal position with full release of the
trigger
before allowing the trigger to be pulled. The design requirement for full
release
achieved by the anti-backup mechanism prevents double loading of ' clips into
cartridge jaws.
It is a further aspect of the anti-backup mechanism that the cartridge may be
rotated on the B-B' axis as the anti-backup mechanism holds the instrument in
partial
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pull position enabling a surgeon to adjust cartridge or jaw position even
after a partial
pull has occurred.
A modified embodiment of the invention is shown in Figures 7-12 wherein the
anti-backup mechanism 30 assembly comprises a reciprocal translator 32, an
anti-
backup spring 34 and a stationary mounting pocket 36.
The reciprocal translator 32 is an active component. of an operating
mechanism (not shown) and is assigned a task in the mechanism which is
accomplished by back and forth movement or excursion over a fixed distance.
Motion is imparted to the reciprocal translator either directly or indirectly
by means
forming part of the operating mechanism, usually a manually operated component
whose action may be stopped in mid-stroke by its operator. A typical operating
mechanism of this sort is a surgical instrument in the hands of a surgeon
performing
a medical procedure.
The translator has a block- body with rectangular cross-section and generally
planar parallel opposite sides 32a-b, and 32c-d (Figs 11-12). Opposite sides
(e.g.,
32c and 32d) have transition points 32e defined by first and second sets of
recesses
32f in their surfaces. A recess may be aligned grooves 32h (one set) or
shoulders
32i (another set) on opposites sides of the translator. The transition points
on the
translator are spaced apart a distance equal to the excursion assigned to the
translator as a component of the operating mechanism. As will be fully
understood
with description of the anti-backup spring next below, the transition points
allow for
spring action on the translator to .be' neutralized as the spring registers
with the
transition points.
The anti-backup spring 34 preferably comprises.a rectangular sheet of spring
steel with its interior portion removed as by metal stamping to define an
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opening 34f leaving a unitary body with side struts 34a-b and end struts 34c-
d.
Spring blades 34e integral with the end struts project inwardly of the spring
interior
opening 34f with spring blade edges 34g in generally parallel, confronting
relation.
As shown in Fig 9, the spring interior 34f accommodates a cross-section of the
body
of the reciprocal translator for both reciprocal movement as well reversal of
movement. In Fig 9 the spring blades are shown in position at translator
transition
points 32e. The spring may be fabricated of any suitable material that can be
formed
into the spring shape shown in Figures 8, 11 and 12 and perform the spring
action
required of blades 34e.
The translator and spring are assembled with a support housing preferably in
the form of stationary mounting pocket 36 situated within a host operating
mechanism. The mounting pocket is a U-shape housing 36a defining a pocket or
chamber 36b between confronting arms 36c for receiving the reciprocal
translator
body. Each arm has a recess in the form of a V-shape channel 36d with opposed
channels being aligned for receiving and holding anti-backup spring 34 by
their side
struts 34a-b as shown in Figure 10. Referring to Fig 7, the mechanism is
assembled
by inserting spring 34 into channels 36d and by passing the translator through
the
spring interior 34f until spring blades 34e register with transition grooves
32h.
Figures 10a-e illustrate operation of the anti-backup spring mechanism from:
stop (Fig 10) with spring blades 34e in registry with transition shoulder
32i;
motion to the right (Figs 10b and 12) where blade edges 34e engage
the sides 32c-d of the translator and deflect in the direction of motion
allowing
the translator to continue moving right and preventing by digging-in
engagement with sides 32c-d any reverse movement of the translator;
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registry (Fig 10c) of spring blade edges 34e with transition groove 32h
where the restraining effect of the blade edges is neutralized and rightward
movement of the translator stops;
reversal of movement (Figs 1 Od and 11) where the spring blades now
bow in the direction of travel of the translator; and
stop (Fig 1 Oe) where the blades again register with transition shoulders
32i.
Various changes may be made to the structure embodying the principles of the
invention. The foregoing embodiments are set forth in an illustrative and not
in a
limiting sense. The scope of the invention is defined by the claims appended
hereto.
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