Latch mechanism for surgical instruments

A surgical instrument includes a pair of jaw members moveable between a spaced-apart and an approximated position. A drive bar is translatable between a distal and a proximal position for moving the jaw members between the spaced-apart and approximated positions. A lever is moveable between an initial position and an actuated position for translating the drive bar between the distal and proximal positions. A sleeve disposed about the drive bar includes an annular track having a substantially radial segment(s) and a substantially longitudinal segment(s). A collar interdisposed between the sleeve and the drive bar includes a stop member(s) extending radially outwardly therefrom. The stop member(s) is engaged within the track and is translatable from a first position, wherein the stop member is positioned within the longitudinal segment, to a second position, wherein the stop member is engaged within the radial segment, to lock the lever in the actuated position.

BACKGROUND

The present disclosure relates to surgical instruments. More particularly, the present disclosure relates to releasable latch mechanisms for use with surgical instruments.

TECHNICAL FIELD

Electrosurgical instruments, e.g., forceps, utilize both mechanical clamping action and electrical energy to effect hemostasis by heating tissue and blood vessels to coagulate, cauterize and/or seal tissue. As an alternative to open forceps for use with open surgical procedures, many modern surgeons use endoscopic or laparoscopic instruments for remotely accessing organs through smaller, puncture-like incisions or natural orifices. As a direct result thereof, patients tend to benefit from less scarring and reduced healing time.

Many endoscopic surgical procedures require cutting or ligating blood vessels or vascular tissue. Due to the inherent spatial considerations of the surgical cavity, surgeons often have difficulty suturing vessels or performing other traditional methods of controlling bleeding, e.g., clamping and/or tying-off transected blood vessels. By utilizing an endoscopic electrosurgical forceps, a surgeon can either cauterize, coagulate/desiccate and/or simply reduce or slow bleeding simply by controlling the intensity, frequency and duration of the electrosurgical energy applied through the jaw members to the tissue. Most small blood vessels, i.e., in the range below two millimeters in diameter, can often be closed using standard electrosurgical instruments and techniques. However, if a larger vessel is ligated, it may be necessary for the surgeon to convert the endoscopic procedure into an open-surgical procedure and thereby abandon the benefits of endoscopic surgery. Alternatively, the surgeon can seal the larger vessel or tissue. Typically, after a vessel or tissue is sealed, the surgeon advances a knife to sever the sealed tissue disposed between the opposing jaw members.

SUMMARY

The present disclosure relates to a surgical instrument including an end effector assembly having a pair of jaw members pivotably coupled to one another. One or both of the jaw members is moveable relative to the other between a spaced-apart position and an approximated position for grasping tissue therebetween. A drive bar defining a longitudinal axis is longitudinally translatable between a distal position and a proximal position for moving the jaw members between the spaced-apart position and the approximated position. A latch mechanism is also provided. The latch mechanism includes a lever that is moveable between an initial position and an actuated position for translating the drive bar between the distal position and the proximal position and, thus, for moving the jaw members between the spaced-apart position and the approximated position. A sleeve is co-axially disposed about the drive bar. The sleeve includes a track extending annularly therearound. More specifically, the track includes one or more substantially radial segments and one or more substantially longitudinal segments. A rotatable collar is interdisposed between the sleeve and the drive bar. The rotatable collar includes one or more stop members extending radially outwardly from an outer periphery thereof. The stop member(s) is engaged within the track and is configured to translate along the track from a first position, corresponding to the initial position of the lever, wherein the stop member(s) is positioned within one of the substantially longitudinal segments, to a second position, corresponding to the actuated position of the lever, wherein the stop member(s) is engaged within one of the substantially radial segments to lock the lever in the actuated position.

In one embodiment, the stop member(s) are configured to translate from the first position to a third position, corresponding to an over-actuated position, and back to the second position such that the stop member(s) is translated along the track from one of the substantially longitudinal segments to one of the substantially radial segments to lock the lever in the actuated position. Similarly, upon movement of the lever from the actuated position to the over-actuated position, e.g., upon movement of the stop member(s) from the second position to the third position, the stop member(s) is translated along the track from the substantially radial segment to one of the substantially longitudinal segments to unlock the lever from the actuated position.

In another embodiment, the track includes a plurality of alternating substantially longitudinal segments and substantially radial segments disposed annularly about the sleeve. The substantially longitudinal segments may be configured to extend distally along the sleeve relative to the substantially radial segments.

In yet another embodiment, a biasing member is annularly disposed between the drive bar and the sleeve. The biasing member is configured to bias the rotatable collar distally relative to the sleeve.

Another embodiment of a surgical instrument in accordance with the present disclosure includes an end effector assembly, a drive bar and a latch mechanism. The end effector assembly includes a pair of jaw members pivotably coupled to one another. One or both of the jaw members are moveable relative to the other between a spaced-apart position and an approximated position for grasping tissue therebetween. The drive bar defines a longitudinal axis and is longitudinally translatable between a distal position and a proximal position for moving the jaw members between the spaced-apart position and the approximated position. The latch mechanism includes a lever that is moveable between an initial position and an actuated position for translating the drive bar between the distal position and the proximal position and, thus, for moving the jaw members between the spaced-apart and approximated positions. The latch mechanism further includes a cartridge including first and second lumens defined therein and extending longitudinally therethrough in substantially parallel orientation relative to one another. The first lumen is configured to slidably receive a portion of the drive bar therethrough. A rotatable post including a fixed end and a free end is slidably disposed within the second lumen of the cartridge and includes a track extending annularly therearound toward the free end thereof. The track includes one or more substantially radial segments and one or more substantially longitudinal segments. One or more stop members are fixedly coupled to the cartridge. More specifically, the stop member(s) extends radially inwardly into the second lumen of the cartridge to engage the track. The stop member(s) is configured to translate along the track from a first position, corresponding to the initial position of the lever, wherein the stop member(s) is positioned within one of the substantially longitudinal segments, to a second position, corresponding to the actuated position of the lever, wherein the stop member(s) is engaged within one of the substantially radial segments to lock the lever in the actuated position.

In one embodiment, the stop member(s) are configured to translate from the first position to a third position, corresponding to an over-actuated position, and back to the second position such that the stop member(s) is translated along the track from one of the substantially longitudinal segments to one of the substantially radial segments to lock the lever in the actuated position. Similarly, upon movement of the lever from the actuated position to the over-actuated position, e.g., upon movement of the stop member(s) from the second position to the third position, the stop member(s) is translated along the track from the substantially radial segment to one of the substantially longitudinal segments to unlock the lever from the actuated position.

In another embodiment, a biasing member is annularly disposed between the drive bar and the cartridge. The biasing member is configured to bias the cartridge distally relative to the rotatable post.

Still another embodiment of a surgical instrument in accordance with the present disclosure includes an end effector assembly, a drive bar, and a latch mechanism. The end effector assembly includes a pair of jaw members pivotably coupled to one another. One (or both) of the jaw members is moveable relative to the other between a spaced-apart position and an approximated position for grasping tissue therebetween. The drive bar, as in the previous embodiments, is longitudinally translatable between a distal position and a proximal position for moving the jaw members between the spaced-apart position and the approximated position and a lever of the latch mechanism, in turn, is moveable between an initial position and an actuated position for translating the drive bar from the distal position to the proximal position. The latch mechanism further includes a post having a fixed end and a free end. The post is pivotable about the fixed end thereof. A sleeve is rotatably and slidably disposed about the post and includes a track defined therein and extending annularly therearound. The track includes one or more substantially radial segments and one or more substantially longitudinal segments. One or more stop members is engaged within the track, the stop member(s) configured to translate along the track from a first position, corresponding to the initial position of the lever, wherein the stop member(s) is positioned within one of the substantially longitudinal segments, to a second position, corresponding to the actuated position of the lever, wherein the stop member(s) is engaged within one of the substantially radial segments to lock the lever in the actuated position.

As in the previous embodiment, the stop member(s) may be configured to translate from the first position to a third position, corresponding to an over-actuated position, and back to the second position such that the stop member(s) is translated along the track from one of the substantially longitudinal segments to one of the substantially radial segments to lock the lever in the actuated position. Similarly, upon movement of the lever from the actuated position to the over-actuated position, e.g., upon movement of the stop member(s) from the second position to the third position, the stop member(s) is translated along the track from the substantially radial segment to one of the substantially longitudinal segments to unlock the lever from the actuated position.

In one embodiment, the lever includes a pair of flanges disposed on either side of the sleeve. Each flange includes a stop members extending inwardly therefrom, e.g., toward the sleeve, such that movement of the lever effects corresponding movement of the stop members along the track.

In another embodiment, a biasing member is disposed between the sleeve and the free end of the post. The biasing member is configured to bias the sleeve distally relative to the post.

In yet another embodiment, an interference member is disposed at the free end of the post. The interference member is configured such that, upon movement of the lever to the actuated position, the interference member is pivoted into engagement with the drive bar to inhibit the drive bar from returning distally, i.e., to retain the drive bar in the proximal position.

In still another embodiment, the latch mechanism further includes an “L”-spring. The “L”-spring includes a first end that is rotatably coupled to the post toward the fixed end of the post, and a second end that has the stop member extending therefrom.

In still yet another embodiment, the lever includes a pair of flanges disposed on either side of the post and coupled between the sleeve and the free end of the post such that movement of the lever effects corresponding movement of the sleeve relative to the stop member, e.g., the “L”-spring, thereby moving the stop member along the track.

Similar to previous embodiments, the track may include a plurality of alternating substantially longitudinal segments and substantially radial segments disposed about the sleeve.

In another embodiment, the track includes a contoured floor to define a three-dimensional track. More specifically, the contoured floor is configured such that the stop member(s) is moved three-dimensionally relative to the track as the stop member(s) is moved along the track between the substantially longitudinal segments and the substantially radial segments thereof.

DETAILED DESCRIPTION

Embodiments of the present disclosure are described in detail with reference to the drawing figures wherein like reference numerals identify similar or identical elements. As used herein, the term “distal” refers to the portion that is being described which is further from a user, while the term “proximal” refers to the portion that is being described which is closer to a user.

Turning now toFIGS. 1A and 1B, forceps10is one example of an instrument for use in accordance with the present disclosure. Forceps10including a housing20, a handle assembly30, a lever latch assembly40, a trigger assembly80, a rotating assembly85, and an end effector assembly100. Forceps10further includes a shaft12having a distal end14configured to mechanically engage end effector assembly100and a proximal end16that mechanically engages housing20. Alternatively, any surgical instrument having a lever operable to control one or more functions of the end effector assembly may be used in accordance with the present disclosure.

With continued reference toFIGS. 1A and 1B, end effector assembly100includes a pair of opposing jaw members110and120. End effector assembly100is designed as a unilateral assembly, i.e., jaw member120is fixed relative to the shaft12and jaw member110is moveable about a pivot103relative to jaw member120. However, either, or both of jaw members110,120may be moveable with respect to the other. In either embodiment, jaw members110,120are moveable from a spaced-apart position, as shown inFIG. 1A, to an approximated position, as shown inFIG. 1B, to grasp tissue therebetween. Further, one or both of jaw members110,120may include an electrically conductive tissue sealing surface112,122, respectively. Sealing surfaces112,122are disposed in opposed relation relative to one another such that, with jaw members110,120in the approximated position grasping tissue therebetween, electrosurgical energy may be supplied to one or both of sealing surfaces112,122of jaw members110,120, respectively, to seal tissue grasped therebetween.

One or both of jaw members110,120may also include a longitudinally extending blade channel130to permit reciprocation of a blade (not shown) therethrough for dividing tissue grasped therebetween. Trigger assembly80is operably coupled to the blade (not shown) such that, upon actuation of trigger82, the blade (not shown) is translated from a retracted position to an extended position wherein the blade (not shown) is advanced between jaw members110,120to cut tissue grasped therebetween. Further, trigger82may be biased toward an un-actuated position such that, upon release of trigger82, the blade (not shown) is returned to the retracted position. A blade-lock feature may also be provided to inhibit translation of the blade to the extended position when jaw members110,120are in the spaced-apart position.

Rotating assembly85is integrally associated with housing20and is rotatable in either direction about a longitudinal axis “X-X” to rotate jaw members110,120with respect to housing20about longitudinal axis “X-X,” allowing jaw members110,120to be repositioned relative to tissue to be grasped, sealed and/or divided.

Handle assembly30extends downwardly from housing20and is releasably engageable with housing20. Handle assembly30is ergonomically configured such that, when engaged with housing20, a surgeon may grasp handle assembly30and operate lever latch assembly40, trigger assembly80and/or rotating assembly85with a single hand. Handle assembly30may further includes a battery pack (not shown) disposed within a battery housing32. The battery pack (not shown) of handle assembly30provides power to forceps10, e.g., for energizing sealing surfaces112,122of jaw members110,120, respectively. More particularly, the battery pack (not shown) may be configured to electrically couple to a generator (not shown) disposed within housing20for powering the generator (not shown). The generator (not shown), in turn, supplies the desired energy to sealing surfaces112,122of jaw members110,120, respectively, of end effector assembly100. Alternatively, forceps10may be configured to connect to an external energy source (not shown), e.g., via an electrosurgical cable (not shown), obviating the need for the battery pack (not shown) and generator (not shown) to be disposed within handle assembly30and housing20, respectively.

With continued reference toFIGS. 1A and 1B, battery housing32of handle assembly30may include mechanical keying features (not shown) configured complementarily to mechanical keying features associated with housing20such that handle assembly30may be securely locked in mechanical engagement with housing20. Upon such engagement, the battery pack (not shown) is electrically coupled to the generator (not shown). The battery housing32may also be released from housing20, e.g., to replace or recharge the battery pack (not shown).

Continuing with reference toFIGS. 1A and 1B, lever latch assembly40includes a lever41pivotably coupled to housing20and extending downwardly therefrom. Lever41is ultimately connected to a drive assembly that, as will be described in greater detail below, together mechanically cooperate to impart movement of jaw members110and120between the spaced-apart position (FIG. 1A) and the approximated position (FIG. 1B). More particularly, lever41is selectively moveable from an initial position (FIG. 1A), wherein lever41is spaced-apart from handle assembly30, to an actuated position (FIG. 1B), wherein lever41is positioned adjacent handle assembly30, to move jaw members110,120from the spaced-apart position (FIG. 1A) to the approximated position (FIG. 1B). Lever latch assembly40is configured to permit movement of lever41between the initial position and the actuated position and for releasably locking lever41in the actuated position. In other words, lever latch assembly40is configured to selectively move jaw members110,120between the spaced-apart position and the approximated position and to releasably lock jaw members110,120in the approximated position. Further, lever41may be biased toward the initial position, such that jaw members110,120are biased toward the spaced-apart position. Various embodiments of lever latching assemblies configured for use with forceps10(or other suitable surgical instruments (not shown)) will be described below with reference toFIGS. 2A-20B.

With reference now toFIGS. 2A-7, and initially toFIG. 2A, one embodiment of a lever latch assembly in accordance with the present disclosure, lever latch assembly140, is shown. Lever latch assembly140includes a lever141that is pivotably coupled to housing20and extends downwardly therefrom. More specifically, lever141includes a grasping portion142that extends downwardly from housing20, and first and second flanges143that extend upwardly from grasping portion142into housing20. Flanges143extend upwardly on either side of drive bar191, ultimately engaging pivot pin145on either end thereof, thus allowing lever141to pivot about pivot pin145relative to housing20.

Continuing with reference toFIG. 2A, drive bar191is disposed about longitudinal axis “X-X” and extend distally through housing20and shaft12, ultimately coupling to jaw member110(and/or jaw member120) of end effector assembly100. More specifically, drive bar191is pivotably engaged to jaw member110at a position offset relative to pivot pin103such that proximal translation of drive bar191pulls jaw member110to rotate in a first direction about pivot pin103relative to jaw member120, e.g., from the spaced-apart position (FIG. 1A) to the approximated position (FIG. 1B) and such that distal translation of drive bar191pushes jaw member110to rotate about pivot pin103in the opposite direction, e.g., from the approximated position to the spaced-apart position. The reverse configuration, e.g., wherein distal translation of drive bar191effects closure of jaw members110,120and where proximal translation of drive bar191opens jaw members110,120and other suitable drive mechanisms (not shown) are also contemplated.

As shown inFIG. 2A, a mandrel192is disposed about drive bar191toward a proximal end thereof and includes proximal and distal rims193,194, respectively, Mandrel192is fixedly engaged to drive bar191and is annularly disposed between drive bar191and flanges143of lever141. Proximal and distal rims193,194, respectively, of mandrel192extend radially outwardly therefrom to retain flanges143of lever141therebetween. Accordingly, as lever141is moved proximally, e.g., as lever141is pivoted about pivot pin145from the initial position to the actuated position, flanges143contact proximal rim193of mandrel192and urge drive bar191proximally. On the other hand, as lever141is moved distally, e.g., as lever141is returned to the initial position, flanges143contact distal rim194of mandrel192and urge drive bar191distally. Put more generally, mandrel192couples flanges143of lever141to drive bar191such that jaw members110,120are moved from the spaced-apart position (FIG. 1A) to the approximated position (FIG. 1B) as lever141is moved from the initial position to the actuated position and such that jaw members110,120are moved from the approximated position (FIG. 1B) back to the spaced-apart position (FIG. 1A) as lever141is returned from the actuated position back to the initial position.

With reference now toFIGS. 2A-3, housing20of forceps10includes an outer sleeve150disposed therein and fixedly engaged thereto and an inner sleeve151disposed within outer sleeve150and engaged to drive bar191. Outer and inner sleeves150,151, respectively, are centered about longitudinal axis “X-X.” inner sleeve151, drive bar191, and mandrel192are slidably disposed within outer sleeve150such that proximal and distal rims193,194, respectively, of mandrel192protrude radially outwardly from the open lateral sides of inner sleeve151, allowing flanges143of lever141to engage mandrel192and, thus, drive bar191, externally of outer sleeve150. Further, a biasing member, e.g., spring154, is disposed between proximal wall152of inner sleeve151and proximal flange193of mandrel192to bias drive bar191toward a distal position, e.g., to bias jaw members110,120toward a spaced-apart position. As can be appreciated, as lever141is moved from the initial position to the actuated position, mandrel192and drive bar191are translated proximally relative to outer and inner sleeves150,151, respectively, against the bias of spring154to move jaw members110,120from the spaced-apart position to the approximated position. Likewise, when lever141is released, mandrel192and drive bar191are translated distally relative to outer and inner sleeves150,151, respectively, under the bias of spring154, to return jaw members110,120to the spaced-apart position.

Continuing with reference toFIGS. 2A-3, mandrel192further includes a distal extension155extending distally therefrom. Distal extension155of mandrel192is configured to retain a rotatable collar156therein. Rotatable collar156is longitudinally fixed relative to mandrel192and drive bar191but is permitted to rotate about longitudinal axis “X-X” relative to mandrel192and drive bar191. As best shown inFIG. 3, rotatable collar156includes a pair of diametrically-opposed stop members158extending radially outwardly from an outer periphery thereof. Although two stop members158are shown, greater or fewer than two stop members158may also be provided.

Stop members158, as mentioned above, extend radially outwardly from rotatable collar156to engage track160defined within outer sleeve150. More specifically, proximal portion159of outer sleeve150includes a track160extending annularly therearound and configured to retain stop members158therein. As will be described in greater detail below, once lever141is moved from the initial position past the actuated position, e.g., to the over-actuated position, stop members158of rotatable collar156are translated along and rotated relative to track160of proximal portion159of outer sleeve150. Thereafter, lever141may be released such that stop members158are engaged within track160to latch lever141in the actuated position, releasably latching jaw members110,120in the approximated position. Upon further actuation of lever141, followed by release of lever141, stop members158of rotatable collar156are further translated along and rotated relative to track160of distal portion159of outer sleeve150to unlatch lever latch assembly140, allowing lever141to return to the initial position and allowing jaw members110,120to return to the spaced-apart position.

Referring once again toFIGS. 2A-7, the use and operation of lever latch assembly140will be described. Initially, as shown inFIG. 2A, lever141is disposed in the initial position, jaw members110,120are disposed in the spaced-apart position, and stop members158of rotatable collar156are disposed at distal ends163of longitudinal segments162of track160of outer sleeve150(FIGS. 2B and 7). In this position, forceps10may be manipulated and/or end effector assembly100may be rotated to position jaw members110,120such that tissue to be grasped, sealed and/or divided is disposed therebetween.

Once end effector assembly100is positioned as desired, e.g., with tissue disposed between jaw members110,120, jaw members110,120may be moved to the approximated position to grasp tissue. To move jaw members110,120to the approximated position, lever141is pulled proximally from the initial position toward the actuated position, as shown inFIG. 4A. As lever141is pulled toward the actuated position, mandrel192, drive bar191, and collar156are translated proximally against the bias of spring154, pulling jaw member110to rotate about pivot pin103relative to jaw member120toward the approximated position. At the same time, stop members158of rotatable collar156are translated proximally along longitudinal segment162of track160of outer sleeve150.

Lever141is moved further proximally past the actuated position such that mandrel192, drive bar191, and rotatable collar156are likewise translated further proximally to move jaw members110,120into further approximation with one another. More specifically, lever141is moved proximally past the actuated position until stop members158have been translated proximally completely through longitudinal segments162of track160and into abutment with proximal surface165of annular segment164of track160, as best shown inFIG. 4BandFIG. 7(position2). This position corresponds to the over-actuated position, e.g., where lever141has been moved proximally beyond the actuated position and is inhibited from being depressed further due to the engagement of stop members158within proximal surface165of track160. Proximal surface165of annular segment164of track160defines a triangle-wave-shaped configuration including a plurality of alternative peaks166and valleys167. Accordingly, when stop members158contact proximal surface165of track160, due to the triangle-wave-shaped configuration of proximal surface165of track160, stop members158are urged along the angled proximal surface165from the peaks166of proximal surface165to the valleys167thereof. In other words, upon movement of lever141to the over-actuated position, stop members158are urged into contact with proximal surface165track160and are translated annularly along track160such that rotatable collar156is rotated about longitudinal axis “X-X” relative to outer sleeve150. As can be appreciated, with rotatable collar156having been rotated about longitudinal axis “X-X” relative to outer sleeve150, stop members158are no longer longitudinally aligned with longitudinal segments162of track160.

As shown inFIG. 5B, upon release of lever141from the over-actuated position, e.g., allowing spring154to urge lever141distally back to the actuated position, stop members158are translated distally relative to track160. However, with stop members158no longer aligned with longitudinal segments162of track160, lever141is only permitted to return distally to the actuated position, wherein stop members158contact distal surface168of track160inhibiting further distal movement. More specifically, similar to proximal surface165of track160, distal surface168of track160defines a triangle-wave-shaped configuration. As a result, as stop members158are urged into contact with distal surface168of track160, rotatable collar156is rotated about longitudinal axis “X-X” such that stop members158are translated from the peaks169of distal surface168of track160to the valleys171thereof. Once rotated into position, stop members158are retained in the valleys171of distal surface168of track160under the bias of spring154. The engagement of stop members158within valleys171of distal surface of track160(FIG. 7) inhibits stop members158, lever141, and drive bar191from returning distally. This position corresponds to the actuated position of lever141and the approximated position of jaw members110,120. In other words, the engagement of stop members158within distal surface168of track160latches jaw members110,120in the approximated position.

With jaw members110,120latched in the approximated position grasping tissue therebetween, electrosurgical energy may be supplied to one or both of sealing surfaces112,122of jaw members110,120, respectively, of end effector assembly100to effect a tissue seal (seeFIGS. 1A-1B). Thereafter, as mentioned above, a knife (not shown) may be advanced between jaw members110,120to divide the previously sealed tissue.

With lever latch assembly140in the latched condition, as described above, the surgeon need not retain lever141in the actuated position during sealing and/or dividing of tissue. Such a feature helps reduces surgeon fatigue and helps ensure that a consistent and accurate closure force between jaw members110,120is applied. As can be appreciated, the length of longitudinal segments162of track160may be selected to achieve a specific closure force between jaw members110,120when moved to the approximated position. As such, outer sleeve150may be configured as an interchangeable component that is releasably engageable to housing20, allowing the user to select the desired outer sleeve150in accordance with the desired closure force between jaw members110,120when in the approximated position.

The above-described lever latch assembly140may be selectively used by the surgeon. For example, where it is desirable to retain jaw members110,120in the approximated position upon each stroke of lever141, the surgeon may simply translate lever141from the initial position to the over-actuated position, e.g., the proximal-most position, and may thereafter release lever141such that lever141is latched in the actuated position and such that jaw members110,120are latched in the approximated position. On the other hand, where repeated and/or rapid tissue sealing is desired, the surgeon may depress lever141to the actuated position (but not the over-actuated position) to move jaw members110,120to the approximated position. In this configuration, upon release of lever141, since lever141and jaw members110,120are not latched, lever141and jaw members110,120are returned to the initial position and the spaced-apart position, respectively. This operation may then be repeated to grasp, seal and/or divide numerous portions of tissue, without requiring lever latch assembly140to be unlatched after each successive operation. Further, audible and/or tactile feedback may be provided to alert the surgeon as to the position of stop members158relative to track160, e.g., to notify the surgeon as to when lever141has reached the actuated position and/or the over-actuated position.

Turning now toFIGS. 6A-6B, in order to unlatch lever latch assembly140, lever141is pulled proximally from the actuated position to the over-actuated position such that mandrel192, drive bar191and rotatable collar156are moved proximally. Likewise, stop members158are translated proximally from valleys171of distal surface168of track160until stop members158contact proximal surface165of track160. Once again, the triangle-wave-shaped configuration of proximal surface165of track160urges rotatable collar156to rotate about longitudinal axis “X-X” as stop members158are translated from the peaks166of proximal surface165of track160to the valleys167thereof. Once lever141has been moved proximally back to the over-actuated position, lever141may be released, allowing mandrel192, drive bar191, and rotatable collar156to return distally under the bias of spring154. As mandrel192and drive bar191are returned distally, jaw members110,120are moved back toward the spaced-apart position. Eventually, upon further distal translation, stop members158contact triangle-wave-shaped distal surface168of track160. The triangle-wave-shaped configuration of distal surface168of track160urges stop members158and, thus, collar156to once again rotate relative to track160. More specifically, triangle-wave-shaped distal surface168urges stop members158to rotate back into alignment with longitudinal segments162of track160. Accordingly, with stop members158aligned with longitudinal segments162of track160, lever141, mandrel192, drive bar191and rotatable collar156are permitted to translate further distally under the bias of spring154as stop members158are translated distally through longitudinal segments162of track160until lever141returns to the initial position. At the same time, jaw members110,120are moved apart from one another, eventually returning to the spaced-apart position.

With reference now toFIG. 7, a schematic illustration of track160is shown. Although track160extends annularly about outer sleeve150, it is shown in a linear orientation for illustration purposes. As shown inFIG. 7, the triangle-wave-shaped configurations of proximal and distal surfaces165,168, respectively, of track160are offset relative to one another such that, as stop members158are longitudinally translated into contact with proximal and distal surfaces165,168, respectively, of track160, rotatable collar156is urged to rotate about longitudinal axis “X-X,” e.g., such that stop members158are moved from longitudinal segments162of track160to the annular segments164of track160. Further, the number of longitudinal and annular segments162,164, respectively, may be varied. More specifically, track160may include a pair of alternating longitudinal segments162and annular segments164such that rotatable collar156is rotated through one complete revolution about longitudinal axis “X-X” upon movement of lever141through one cycle, e.g., from the initial position to the over-actuated position back the actuated position and from the actuated position to the over-actuation position back to the initial position. However, track160may alternatively be configured to include four alternating longitudinal segments162and annular segments164such that rotatable collar156is rotated one-half a revolution per cycle of lever141, or track160may define various other configurations.

Referring now toFIGS. 8-11, another embodiment of a lever latch assembly configured for use with forceps10is shown generally identified by reference numeral240. Lever latch assembly240, similar to lever latch assembly140(FIGS. 2A-7) includes a lever241that is pivotably coupled to housing20of forceps10via pivot pin245and is configured to move between an initial position and an actuated position for translating drive bar291between a distal position and a proximal position to move jaw members110,120(FIGS. 1A-1B) between the spaced-apart position (FIG. 1A) and the approximated position (FIG. 1B).

Similar to the previous embodiment, lever241includes a pair of flanges243extending upwardly on either side of drive bar291. Lever latch assembly240further includes a cartridge250having first and second sleeves252,260, respectively, extending longitudinally therethrough in generally parallel orientation relative to one another. First sleeve252is centered about longitudinal axis “X-X” (seeFIGS. 1A and 1B) and is configured for fixedly receiving drive bar291therethrough. More specifically, cartridge250is interdisposed between drive bar291and flanges243of lever241and includes proximal and distal shoulders253,255, respectively, configured to retain flanges243of lever241therebetween. Accordingly, when lever241is moved from the initial position to the actuated position, flanges243contact proximal shoulder253of cartridge250and urge drive bar291proximally to move jaw members110,120toward the approximated position (FIG. 1B). On the other hand, when lever241is returned from the actuated position back to the initial position, flanges243contact distal shoulder255of cartridge250and urge drive bar291distally to move jaw members110,120back toward the spaced-apart position (FIG. 1A). Further, a spring254(or other biasing member) may be disposed within cartridge250to bias cartridge250and drive bar291distally. As such, with flanges243of lever241engaged between shoulders253,255of cartridge250, spring254also biases lever241toward the initial position and jaw members110,120toward the spaced-apart position (FIG. 1A).

With continued reference toFIGS. 8-11, second sleeve260of cartridge250is configured to slidably receive free end263of post262therethrough. Post262is rotatably coupled to housing20of forceps10at a fixed end264thereof and extends proximally therefrom to free end263. Further, post262includes a track270defined therein, extending annularly therearound, and disposed toward free end263thereof. A pair of opposed stop members278disposed on cartridge250and extending radially inwardly into second sleeve260are engaged within track270of post262. More specifically, as described above with respect to lever latch assembly140, stop members278of cartridge250are configured to translate along track270upon translation of cartridge250relative to post262, e.g., upon movement of lever241from the initial position to the actuated position. Track270is configured substantially similarly to track160(FIG. 7) and stop members278are configured to translate and rotate relative to track270to latch and unlatch lever latch assembly240in a similar fashion as described above with respect to lever latch assembly140(seeFIGS. 2A-7). In particular, as will be described in greater detail below, as stop members278of cartridge250are translated along track270, post262is urged to rotate relative to cartridge250and, thus, stop members278such that lever241may be latched in the actuated position, thereby latching jaw members110,120in the approximated position (FIG. 1B). Thus, different from lever latch assembly140(FIGS. 2A-7), stop members278are fixed relative to housing20of forceps10, while track270is translatable and rotatable relative to stop members278upon latching and unlatching of lever latch assembly240. Lever latch assembly240may otherwise include any of the features of lever latch assembly140, discussed above, and vice versa.

Continuing with reference toFIGS. 8-11, the use and operation of lever latch assembly240will be described. Initially, as shown inFIG. 8, lever241is disposed in the initial position, cartridge250and drive bar291are disposed in the distal position and jaw members110,120are disposed in the spaced-apart position (FIG. 1A). Further, in this position, stop members278are disposed at the distal ends273of longitudinal segments272of track270of post262.

Turning now toFIG. 9, when it is desired to move jaw members110,120to the approximated position, e.g., to grasp tissue between sealing surfaces112,122of jaw members110,120, respectively, (seeFIGS. 1A-1B) lever241is moved proximally from the initial position toward the actuated position. As mentioned above, moving lever241from the initial position toward the actuated position translates cartridge250and, thus, drive bar291proximally to pivot jaw member110about pivot pin103toward jaw member120(seeFIG. 1B). At the same time, cartridge250is translated proximally relative to post262such that stop members278are translated proximally along longitudinal segments272of track270. Lever241is moved further proximally past the actuated position until stop members278have translated proximally completely through longitudinal segments272of track270and into abutment with proximal surface275of track270(the over-actuated position). As stop members278contact the triangle-wave-shaped proximal surface275of track270, post262is urged to rotate relative to stop members278such that stop members278are translated along track270of post262from the peaks276of proximal surface275of track270to the valleys277thereof. In this position, due to the rotation of post262relative to stop members278, stop members278are no longer aligned with longitudinal segments272of track270.

Once this over-actuated position has been achieved, lever241may be released, allowing lever241to return distally toward the actuated position under the bias of spring254. As lever241is translated distally, stop members278are likewise translated distally relative to track270of post262, eventually contacting distal surface281of track270, which inhibits further distal translation of lever241. Once again, due to the triangle-wave-shaped configuration of distal surface281of track270, stop members278are urged from the peaks283of distal surface281of track270to the valleys285thereof, urging post262to rotate relative to stop members278. Stop members278are retained in the valleys285of distal surface281of track270under the bias of spring254such that lever241is latched in the actuated position and such that cartridge250and drive bar291are inhibited from returning distally. Accordingly, with stop members278retained within valleys285of distal surface281of track270, jaw members110,120are latched in the approximated position (seeFIG. 18). As discussed above, with jaw members110,120latched in the approximated position grasping tissue therebetween, forceps10may be used to seal and/or divide tissue grasped between jaw members110,120(seeFIG. 1B).

Turning now toFIG. 11, in order to unlatch lever latch assembly240, lever241is pulled proximally from the actuated position to the over-actuated position such that stop members278are translated proximally from valleys285of distal surface281of track270into contact with proximal surface275of track270. Upon contacting proximal surface275of track270, the triangle-wave-shaped proximal surface275of track270urges post262to rotate relative to stop members278such that stop members278are moved along track270from the peaks276of proximal surface275of track270to the valleys277thereof. This rotation of post262relative to stop members278aligns stop members278with distally-sloping portions of the triangle-wave-shaped distal surface281of track270. The distally-sloping portions of distal surface281of track270feed into longitudinal segments272of track270. As such, upon release of lever241from the over-actuated position, stop members278are translated proximally into contact with distal surface281of track270, rotating post262relative to stop members278. Eventually, post262is rotated sufficiently such that stop members278are once again aligned with longitudinal segments272of track270. Once this alignment is achieved, cartridge250and drive bar291are permitted to translate distally under the bias of spring254as stop members278are translated distally through longitudinal segments272of track270. At the same time, lever241is returned to the initial position and jaw members110,120are returned to the spaced-apart position.

Turning now toFIGS. 12-15, yet another embodiment of a lever latch assembly configured for use with forceps10is shown. Similar to lever latch assembly140, lever latch assembly340includes a lever341that is pivotably coupled to housing20and extends downwardly therefrom. Lever341includes a pair of flanges343that extend upwardly on either side of drive bar391, ultimately engaging pivot pin345on either end thereof. Lever341is pivotable about pivot pin345relative to housing20between an initial position and an actuated position. Similarly as discussed above, flanges343of lever341are coupled to drive bar391via a mandrel392such that moving lever341from the initial position to the actuated position translates drive bar391proximally to move jaw members110,120toward the approximated position. On the other hand, moving lever341from the actuated position back to the initial position translates drive bar391distally to move jaw members110,120back toward the spaced-apart position.

Housing20further includes a cartridge350disposed therein and configured for longitudinal translation along longitudinal axis “X-X.” Cartridge350is configured to retain drive bar391and mandrel392therein. Further, a biasing member, e.g., spring354, may be disposed between proximal wall352of cartridge350and mandrel392to bias drive bar391toward a distal position, e.g., to bias jaw members110,120toward a spaced-apart position. Thus, when lever341is released, cartridge350, mandrel392and drive bar391are translated distally along longitudinal axis “X-X,” under the bias of spring354, to return jaw members110,120to the spaced-apart position.

With continued reference toFIGS. 12-15, lever latch mechanism340further includes a post360pivotably coupled to housing20at proximal end362thereof. Post360includes a proximal shoulder364disposed at proximal end362thereof and a distal snap feature366disposed at a distal end365thereof. As best shown inFIG. 15, a biasing member, e.g., a spring367, is positionable about post360adjacent proximal shoulder364. A sleeve370having a track372defined therein on an outer periphery thereof is slidably and rotatably positionable about post360. More particularly, sleeve370is configured to slide over distal end365of post360such that sleeve370is snap-fittingly retained thereon. In other words, once sleeve is slid over post360, snap-fit feature366inhibits sleeve370from being removed from post360. Other mechanisms (not shown) that are configured to retain sleeve370on post360while allowing sleeve370to translate and rotate relative to post360may also be provided. As assembled, as shown inFIGS. 12 and 13, spring367is interdisposed between proximal shoulder364of post360and sleeve370, biasing sleeve370toward distal end365of post360.

As mentioned above, sleeve370includes a track372defined therein. Track372is similar to track160defined within sleeve150of lever latch assembly140(seeFIGS. 2A-7) and extends annularly about sleeve370. More specifically, track372includes one or more longitudinal segments373and one or more annular segments375. The proximal and distal surfaces377,379, respectively, of annular segments375of track372define triangle-wave-shaped configurations that are offset relative to one another.

As best shown inFIG. 15, lever341includes a pair of opposed stop members378extending inwardly from flanges343. Stop members378are configured to engage track372of sleeve370and to translate along track372of sleeve370. Due to the triangle-wave-shaped configuration of track372, stop members378also urge sleeve370to rotate about post360upon translation of stop members378along track372, as will be described in greater detail below.

Turning now toFIGS. 12-13, in conjunction withFIG. 14, the use and operation of lever latch assembly340will be described. Initially, as shown inFIG. 12, lever341is disposed in the initial position, jaw members110,120are disposed in the spaced-apart position, and stop members378of lever341are disposed at distal ends374of longitudinal segments373of track372of sleeve370. In this initial position, post360is angled upwardly off of post axis “P-P” toward drive bar391and sleeve370is biased toward distal end365of post360by spring367.

In order to move jaw members110,120to the approximated position, e.g., to grasp tissue therebetween, lever341is pulled proximally from the initial position toward the actuated position. As lever341is pulled proximally, cartridge350and drive bar391are likewise translated proximally against the bias of spring354to pivot jaw members110,120relative to one another from the spaced-apart position toward the approximated position. At the same time, stop members378of lever341are translated proximally along longitudinal segments373of track372of sleeve370. Further, as stop members378are translated along track372of sleeve370, i.e., as lever373is translated proximally, post360is pivoted downwardly about proximal end362thereof toward post axis “P-P.”

As in the previous embodiments, lever341is moved further proximally until stop members378have translated proximally completely through longitudinal segments373of track372and into abutment with proximal surface377of track372. This position corresponds to the over-actuated position of lever341. Upon contact of stop members378with the proximal surface377of track372, stop members378are urged against the triangle-wave-shaped proximal surface377of track372, causing sleeve370to rotate about post360, moving stop members378along track372from the peaks381of proximal surface377of track372to the valleys383thereof (seeFIG. 14).

Once lever341has been moved to the over-actuated position, lever341may be released such that lever341and stop members378are translated distally relative to track372under the bias of spring367. Eventually, stop members378are translated distally into engagement with distal surface379of track372under the bias of spring367, while cartridge350and drive bar391are returned distally under the bias of spring354. However, upon engagement between stop members378and distal surface379of track372, further distal translation of stop members378, lever341, cartridge350and drive bar391is inhibited. More specifically, as stop members378are translated distally into engagement with distal surface379of track372, stop members378urge sleeve370to rotate about post360such that stop members378are translated from the peaks385of distal surface379to the valleys387thereof (seeFIG. 14). Spring367biases stop members378into valleys387of distal surface379of track372, inhibiting further distal translation of lever341, mandrel392and drive bar391. This position, as shown inFIG. 13, corresponds to the latched condition of lever latch assembly340, wherein lever341is latched in the actuated position and wherein jaw members110,120are latched in the approximated position.

Similarly as described above with reference to lever latch assemblies140and240(seeFIGS. 2A-7and8-11, respectively), to unlatch lever latch assembly340, lever341is pulled proximally from the actuated position to the over-actuated position to translate stop members378proximally into engagement with proximal surface377of track372. Upon contact with the triangle-wave-shaped proximal surface377of track372, stop members378urge sleeve370to rotate about post360such that stop members378are moved to the valleys383of proximal surface377of track372.

Thereafter, lever341may be released, allowing lever341, cartridge350and drive bar391to return distally, thus allowing jaw members110,120to move back toward the spaced-apart position. At the same time, stop members378are translated distally along track372, eventually contacting distal surface379of track372and urging sleeve370to rotate about post360until stop members378are once again aligned with longitudinal segments373of track372. Once this position is achieved, lever341is permitted to translate distally back to the initial position as stop members378are translated distally through longitudinal segments373of track372to distal ends374thereof. Likewise, cartridge350and drive bar391are return distally under the bias of spring354, urging jaw members110,120to pivot relative to one another back to the spaced-apart position.

With reference now toFIGS. 16-17, yet another embodiment of a lever latch assembly is shown. Lever latch assembly440is substantially similar to lever latch assembly340(FIGS. 12-15) and includes a post460pivotably coupled to housing20at proximal end462thereof. Post460further includes a proximal shoulder464disposed at proximal end462thereof and an interference member466disposed at a distal end468thereof. A spring472is positionable about post460adjacent proximal shoulder464. A sleeve470including a track474defined therein on an outer periphery thereof is slidably and rotatably positionable about post460such that spring472is interdisposed between proximal shoulder464of post460and sleeve470. Sleeve470is substantially similar to sleeve370of lever latch assembly340(seeFIGS. 12-15) and includes a track474having one or more longitudinal segments475and one or more annular segments477extending annularly about sleeve470in alternating relation relative to one another. As described above in previous embodiments, stop members478of lever441are engaged within track474of sleeve470and are translatable therealong. Track474of sleeve470is substantially similar to the tracks of lever latch assemblies140,240,340, described above.

Initially, as shown inFIG. 16, lever441is disposed in the initial position, jaw members110,120are disposed in the spaced-apart position, and stop members478of lever441are disposed at distal ends479of longitudinal segments475of track474of sleeve470. Further, in this initial position, post460is angled downwardly relative to post axis “P-P.”

In order to move jaw members110,120to the approximated position, lever441is pulled proximally from the initial position toward the actuated position, translating cartridge450and drive bar491proximally against the bias of spring452and pivoting jaw members110,120toward the approximated position. At the same time, stop members478of lever441are translated proximally along longitudinal segments475of track474of sleeve470. As stop members478are translated along longitudinal segments475of track472of sleeve470, post460is pivoted upwardly into alignment with post axis “P-P.” In this position, interference member466, which is disposed at distal end468of post460, is moved into position adjacent a distal end454of cartridge450. More particularly, in this position, interference member466is disposed between housing20and cartridge450to inhibit distal translation of cartridge450along longitudinal axis “X-X.”

As in the previous embodiments, lever441is moved proximally until stop members478have been translated proximally completely through longitudinal segments475of track474and into abutment with triangle-wave-shaped proximal surface483of track474to rotate sleeve470about post460, as discussed above. Thereafter, upon release of lever441, stop members478are translated distally relative to track474into engagement with distal surface481of track474. With stop members478engaged within distal surface481of track474of sleeve470, post460is retained in position relative to post axis “P-P,” e.g., in alignment with post axis “P-P.” As mentioned above, in this position, interference member466is disposed between housing20and cartridge450, inhibiting cartridge450and, thus, drive bar491from returning distally, thereby latching jaw members110,120in the approximated position. As can be appreciated, when jaw members110,120are latched in the approximated position, lever441is latched in the actuated position.

In order to unlatch lever latch assembly440, lever441is pulled proximally from the actuated position to the over-actuated position such that stop members478are translated proximally from distal surface481of track474, into engagement with proximal surface483of track474. The triangle-wave-shaped configuration of proximal surface483of track474urges sleeve470to rotate about post460upon contact with stop members478such that stop members478are moved into alignment with longitudinal segments475of track474. With stop members478aligned with longitudinal segments475of track474, lever441is permitted, upon release thereof, to translate from the actuated position back to the initial position as stop members478are translated distally through longitudinal segments475of track474. At the same time, post460is pivoted about proximal end462thereof downwardly relative to post axis “P-P,” disengaging interference member466from between cartridge450and housing20. With interference member466no longer inhibiting cartridge450and drive bar491from returning distally, spring452urges cartridge450and drive bar491distally such that jaw members110,120are returned to the spaced-apart position.

With reference now toFIGS. 18-20B, still another embodiment of a lever latch assembly is shown configured for use with forceps10. Lever latch assembly540includes a lever541having a pair of flanges543disposed on either side of drive bar591and between proximal and distal rims593,594, respectively, of mandrel592, such that moving lever541between the initial position and the actuated position translates drive bar591longitudinally along longitudinal axis “X-X” to move jaw members110,120between the spaced-apart position and the approximated position. Further, mandrel592and drive bar591are disposed within a cartridge550. Cartridge550is disposed within housing20and is positioned about longitudinal axis “X-X.” Cartridge550is configured to retain drive bar591and mandrel592therein and includes a spring552disposed between proximal wall554of cartridge550and proximal rim593of mandrel592to bias drive bar591distally, e.g., to bias jaw members110,120toward the spaced-apart position.

Continuing with reference toFIGS. 18-20A, lever latch mechanism540further includes a post560pivotably coupled to housing20at proximal end563thereof. Post560includes a proximal shoulder562disposed at proximal end563thereof and a distal snap feature566disposed at a distal end565thereof. A sleeve570including a track572defined on an outer periphery thereof and an annular recess580defined therein is slidably and rotatably positionable about post560. An “L”-shaped spring576is disposed about and engaged to post560at proximal end563thereof and extends distally therefrom. “L”-shaped spring576includes a stop member578disposed at the free end thereof that extends downwardly into engagement with track572of sleeve570.

Track572of sleeve570is similar to track572defined within sleeve570of lever latch assembly140(seeFIGS. 2A-7), except that longitudinal segments573of track572extend proximally along sleeve570from annular segments574of track572. As mentioned above, stop member578of “L”-shaped spring576is engaged within track572and is translatable along track572. Lever541, on the other hand, includes a pair of protrusions542extending inwardly from flanges543. Protrusions542of lever541are engaged within annular recess580of sleeve570such that, as lever541is moved between the initial position and the actuated position, sleeve570is translated along post560. At the same time, post560is pivoted relative to post axis “P-P” about proximal end563of post560as lever541is moved between the initial position and the actuated position. As will be described in greater detail below, as lever451is moved between the initial position and the actuated position to pivot post560and translate sleeve570along post560, stop member578of “L”-shaped spring576is translated along track572defined within sleeve570to latch and unlatch lever latch assembly540.

With continued reference toFIGS. 18-20A, the use and operation of lever latch assembly540will be described. Initially, as shown inFIG. 18, lever541is disposed in the initial position, jaw members110,120are disposed in the spaced-apart position, stop member578of “L”-shaped spring576is disposed at proximal end575of longitudinal segment573of track572, and protrusions542of lever541retain sleeve570toward a distal end565of post560. Further, in this initial position, post560is angled upwardly relative to post axis “P-P” toward drive bar591, as shown inFIG. 18.

In order to move jaw members110,120to the approximated position, as in the previous embodiments, lever541is pulled proximally from the initial position toward the actuated position, translating cartridge550and drive bar591proximally against the bias of spring552to pivot jaw members110,120toward the approximated position. At the same time, protrusions542of lever541urge sleeve570proximally along post560and effect pivoting of post560downwardly toward post axis “P-P.” Further, upon movement of lever541toward the actuated position, stop member578of “L”-shaped spring576is moved distally relative to sleeve570along longitudinal segment573of track572.

Lever541is moved further proximally to the over-actuated position to translate sleeve570further distally relative to post560such that stop member578of “L”-shaped spring576is translated completely through longitudinal segment573of track572and into engagement with distal surface583of track572. As stop member578is urged against the triangle-wave-shaped distal surface583of track572, sleeve570is rotated above post560and relative to “L”-shaped spring576to engage stop member578within distal surface583of track572.

Thereafter, upon release of lever541, stop member578is translated proximally relative to track572, under the bias of “L”-shaped spring576, into engagement with proximal surface581of track572. Stop member578is retained in engagement with the triangle-wave-shaped proximal surface581of track572under the bias of “L”-shaped spring576, inhibiting lever541, sleeve570, cartridge550and drive bar591from returning distally. This latched condition, as shown inFIG. 19, corresponds to the actuated position of lever541and, thus, the approximated position of jaw members110,120. In the actuated position, as shown inFIG. 19, post560is substantially aligned with post axis “P-P.”

Lever latch assembly540is unlatched similarly to lever latch assemblies140,240,340, and440, discussed above. More specifically, to unlatch lever latch assembly540, lever541is pulled proximally from the actuated position to the over-actuated position such that protrusions542of lever541urge sleeve570proximally along post560. As a result, sleeve570is moved distally relative to stop member578such that stop member578is translated from proximal surface581of track572into engagement with distal surface583of track572. The triangle-wave-shaped configuration of distal surface583of track572urges sleeve570to rotate about post560upon contact with stop member578.

Thereafter, upon release of lever541, cartridge550and drive bar591are returned distally under the bias of spring552such that jaw members110,120are moved back toward the spaced-apart position. At the same time, lever541is returned distally, thereby translating sleeve570distally along post560, causing post560to pivot upwardly relative to post axis “P-P” toward drive bar591. Further, due to the distal translation of sleeve570relative to “L”-shaped spring576, stop member578is translated along track572into engagement with triangle-wave-shaped distal surface583of track572. More particularly, stop member578is urged into engagement with distal surface583of sleeve570such that sleeve570is rotated about post560until stop member578is moved into alignment with longitudinal segment573of track572. With stop member578aligned with longitudinal segment573of track572, lever541is permitted to translate distally back to the initial position as stop member578is translated proximally through longitudinal segment573of track572. At the same time, sleeve570, cartridge550and drive bar591are returned distally and jaw members110,120are returned to the spaced-apart position.

Turning now toFIGS. 20A and 2013, post560is shown including sleeve570disposed thereabout. As discussed in detail above, track572defined within sleeve570includes one or more annular triangle-wave-shaped segments574and one or more longitudinal segments573extending proximally from annular segment(s)574. Track572may further include a contoured floor585correspondingly configured relative to the annular and longitudinal segments574,573, respectively, of track572. More specifically stop member578of “L”-shaped spring576(FIGS. 18-19) may be configured to not only translate longitudinally and rotationally relative to track572, but may further be configured to translate radially, e.g., inwardly and outwardly, with respect to track572, as a function of the contoured floor585of track572. Such a feature provides for three-dimensional translation of stop member578(FIGS. 18-19) along track572to increase the engagement and positioning of stop member578(FIGS. 18-19) relative to sleeve570. For example, as stop member578(FIGS. 18-19) is translated distally along longitudinal segment573of track572, stop member578(FIGS. 18-19) may likewise be translated along an upwardly-angled portion586of contoured floor585of track572. Stop member578(FIGS. 18-19) may then drop-off into a lower-disposed portion588of floor585upon positioning within annular segment574of track572. As can be appreciated, and as shown inFIG. 206, floor585of track572may define a plurality of other varying depth and/or angled portions such that stop member578(FIGS. 18-19) may be translated through these various portions of floor585as stop member578(FIGS. 18-19) is translated from longitudinal segment573, proximal and distal surfaces581,583, respectively, of annular segment574, and back to longitudinal segment573of track572. Other configurations of track572may also be provided. Additionally, any of the tracks of lever latch assemblies140,240,340,440discussed above may include similarly-configured contoured floors to define a three-dimensional configuration.