Patent ID: 12242297

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Looking first atFIGS.1-4, there is shown novel endoscopic cutting forceps5which comprise one preferred embodiment of the present invention.

The Novel Endoscopic Cutting Forceps in General

Endoscopic cutting forceps5generally comprise a pair of jaws10disposed at the distal end of a shaft15, a blade cutter20configured to reciprocate in the space between jaws10(and hence cut tissue disposed between the pair of jaws), and a handle25disposed at the proximal end of shaft15for carrying a lever30for actuating the pair of jaws10and a trigger35for actuating blade cutter20. Endoscopic cutting forceps preferably allow the pair of jaws10and blade cutter20to be rotated as a unit about the axis of shaft15via a knob40, and endoscopic cutting forceps preferably allow the pair of jaws10to be electrically energized via a button45so as to provide electrocautery function to endoscopic cutting forceps5.

More particularly, and looking now atFIGS.1-9, jaws10are each secured to the distal end50of a support rod55, with support rods55and the proximal ends of jaws10being disposed within shaft15. The proximal ends60of support rods55are secured to a hub65, which is itself secured to a wall70of handle25. As a result of this construction, jaws10are effectively fixed to handle25. As seen in the figures, jaws10are outwardly biased relative to support rods55, so that the distal ends of jaws10naturally diverge from one another. Jaws10comprise slots75(FIG.4) which receive blade cutter20.

Shaft15is movable relative to handle25so as to selectively close down jaws10. More particularly, shaft15is hollow and is disposed coaxially over the proximal ends of jaws10and coaxially over support rods55. The proximal end of shaft15is connected to a mount80(FIG.6) which is engaged by lever30as will hereinafter be discussed. Shaft15has a flange85intermediate its length. A compression spring90is disposed about shaft15between a wall95of handle and flange85of shaft15so as to spring-bias shaft15in the proximal direction. Another compression spring100may be disposed about shaft15between flange85of shaft15and a surface of mount80so as to bias mount80proximally.

As noted above, lever30may be used to actuate jaws10. More particularly, lever30is rotatably pinned at105to handle25so that when the finger grip110of lever30is pulled proximally toward palm grip115of handle25, the opposing end120of lever is moved distally, whereby to move mount80distally and thereby move shaft15distally. Such distal movement of shaft15forces jaws10to close. When finger grip110of lever30is released, compression spring90returns shaft15proximally, whereby to cause jaws10to open. Note that blade cutter20is received in slots75of jaws10when jaws are in their open position and blade cutter20is also received in slots75of jaws10when jaws10are in their closed position.

Looking now atFIGS.1-8,10and11, blade cutter is disposed at the distal end125of a drive rod130, with the proximal end of blade cutter20and drive rod130being disposed within shaft15. The proximal end of drive rod130is secured to a hub135.

Trigger35actuates blade cutter20. More particularly, trigger35is rotatably pinned at140to handle25so that when trigger35is pulled proximally toward palm grip115of handle25, the opposing end145of trigger35is moved distally, whereby to move hub135distally and thereby move drive rod130and blade cutter20distally. Note that when jaws10are in their closed position and blade cutter20is moved distally, blade cutter20will ride distally within slots75formed in jaws10.

As noted above, endoscopic cutting forceps5preferably allow the pair of jaws10and blade cutter to be rotated as a unit about the axis of shaft15via a knob40. To this end, knob40drivingly engages mount80such that when knob40is rotated, mount80is also rotated, whereby to rotate hub65and thereby rotate support rods55and hence jaws10. Note that inasmuch as blade cutter20is received within slots75in jaws10when jaws10are in both their open and closed positions, rotation of jaws10will cause blade cutter20to rotate in unison with jaws10.

As also noted above, endoscopic cutting forceps5allow the pair of jaws10to be electrically energized via a button45so as to provide electrocautery function to endoscopic cutting forceps5. More particularly, and looking now atFIGS.1-3,5-9and12-16, in the preferred form of the invention, jaws10and support rods55are formed out of an electrically conductive material, and button45is used to activate a switch which connects a power line150to jaws10. As a result, pressing button45electrically energizes jaws10so as to provide electrocautery function to endoscopic cutting forceps5. In this respect it should be appreciated that, where shaft15is made out of an electrically conductive material, and/or where drive rod130is made out of an electrically conductive material, an insulating member155is disposed between shaft15and support rods55and jaws10, and between drive rod130and support rods55and jaws10, so as to avoid inadvertent short-circuiting of the electrical components of endoscopic cutting forceps5.

Thus it will be seen that endoscopic cutting forceps5generally comprise a pair of jaws10disposed at the distal end of a shaft15, a blade cutter20configured to reciprocate in the space between jaws10(and hence cut tissue disposed between the pair of jaws10), and a handle25disposed at the proximal end of shaft15for carrying a lever30for actuating the pair of jaws10and a trigger35for actuating blade cutter20. Endoscopic cutting forceps preferably allow the pair of jaws10and blade cutter20to be rotated as a unit about the axis of shaft15via a knob40, and endoscopic cutting forceps preferably allow the pair of jaws10to be electrically energized via a button45so as to provide electrocautery function to endoscopic cutting forceps5.

Novel Latching Mechanism

In accordance with the present invention, there is also provided a novel latching mechanism for the lever which actuates the jaws, whereby to allow the jaws to be temporarily locked (or clamped) in a closed position about tissue while the blade cutter is actuated to cut the tissue disposed between the clamped jaws.

Significantly, the latching mechanism of the present invention is mechanically simple and hence easy and inexpensive to manufacture.

In addition, the latching mechanism of the present invention may also be used for the actuating levers of other surgical instruments and/or other lever-actuated devices wherein the latching mechanism is mechanically simple and hence easy and inexpensive to manufacture.

Looking next atFIGS.1-3,5-7,9-11and17-26, there is shown a latching mechanism200which comprises one preferred form of the present invention. Latching mechanism200generally comprises a selector plate205and a latch plate210.

Selector plate205serves to selectively position latch plate210within handle25. Selector plate205is movably mounted to handle25, and latch plate210is mounted to selector plate205, such that, by adjusting the position of support plate205within handle25, the position of latch plate210may also be adjusted within handle25. In this way selector plate205can be used to selectively position latch plate210in a “latch operative position” or in a “latch inoperative position” within handle25, as will hereinafter be discussed.

More particularly, selector plate205is slidably mounted to handle25of endoscopic cutting forceps5. A thumb button215protrudes through a window220formed in handle25so that the user can adjustably position selector plate205(and hence adjustably position latch plate210) within handle25. Detents225are formed in selector plate205and cooperate with a protrusion230formed on handle25whereby to allow selector plate225to be maintained in a “latch operative position” or in a “latch inoperative position” within handle25until urged otherwise by the user.

Latch plate210is slidably mounted to selector plate205. More particularly, latch plate210comprises a body235having a loop spring240extending therefrom (FIG.24). In one preferred form of the invention, loop spring240is formed integral with body235. Loop spring240comprises a bore245which is mounted on a pin250of selector plate205. Loop spring240biases body235of latch plate210into a given position on selector plate205, but permits body235of latch plate210to be slidably moved on selector plate205(both towards and away from pin250on selector plate205) against the power of loop spring240. In one preferred form of the invention, latch plate210moves linearly with respect to handle25as latch plate210moves on selector plate205. Body235of latch plate210includes a flange257which is slidably mounted on selector plate205, whereby to stabilize latch plate210as it moves on selector plate205. As a result of this construction, body235of latch plate210can be urged away from pin250of selector plate205against the power of loop spring240, or body235of latch plate210can be urged toward pin250of selector plate205against the power of loop spring240.

A latch element255is mounted to body235of latch plate210. In one preferred form of the invention, latch element255is formed integral with body235of latch plate210. Latch element255comprises a first surface260, a second surface265, and a third surface270(FIG.26). In one preferred form of the invention, first surface260comprises a substantially linear configuration, second surface265comprises a concave configuration, and third surface270comprises a slightly convex or substantially linear configuration.

First surface260, second surface265and third surface270together define a labyrinth (i.e., a non-linear track comprising a leading first surface260, a concave second surface265, and a trailing third surface270, whereby to form a tortuous path with a concavity intermediate its length), and interact with a latch pin275(FIG.26) formed on lever30, so as to provide the desired latching function.

More particularly, when selector plate205is appropriately positioned within handle25so that the apparatus is configured in the “latch operative position”, and when lever30is thereafter pulled toward palm grip115of handle25(i.e., so as to close jaws10), latch pin275engages first surface260of latch element255and forces latch plate210away from pin250, against the power of loop spring240. Latch pin275rides along first surface260of latch element255until latch pin275reaches the end of first surface260, whereupon latch pin275moves onto second surface265of latch element255. As soon as latch pin275moves onto the concave second surface265, loop spring240pulls body235of latch plate210back toward pin250, until latch pin275seats at the base of concave second surface265. At this point, lever30will be maintained in this position (i.e., the “latched” position, with jaws10clamped) until lever30is thereafter pulled again. More particularly, when it is thereafter desired to unclamp jaws10, lever30is pulled again, against the power of loop spring240, so as to cause latch pin275to move out of the base of concave second surface265of latch element255and further along concave second surface265. As soon as latch pin275clears the end of concave second surface265and moves onto third surface270of latch element255, loop spring240pulls latch plate210back toward pin250, until latch pin275is returned to its original starting position clear of third surface270. At this point, lever30will have been returned to its original starting position, pending a further cycling of endoscopic cutting forceps5.

It will be appreciated that the latching function just described relies upon the interaction of latch pin275with latch element255. It will also be appreciated that selector plate205allows the position of latch plate210to be adjusted within handle25. Thus selector plate205provides the ability to render the latching function operative or inoperative by adjusting the position of latch plate210(and hence the position of latch element255) vis-à-vis the position of lever30(and hence the orbit of latch pin275). More particularly, by positioning selector plate205so that the position of latch element255is outside the orbit of latch pin275, the selector plate can be used to put the apparatus in a “latch inoperative position”. Conversely, by positioning selector plate205so that the position of latch element255is within the orbit of latch pin275, the selector plate can be used to put the apparatus in a “latch operative position”. The user adjusts the position of selector plate205using thumb button215.

Exemplary Operation of the Novel Latching Mechanism of the Endoscopic Cutting Forceps

FIGS.27-38illustrate operation of the endoscopic cutting forceps5(note that the specific constructions shown inFIGS.27-38may differ slightly from the specific constructions shown inFIGS.1-26, however,FIGS.27-38depict a common operation of the latching function of the present invention). More particularly,FIGS.27-35show endoscopic cutting forceps5with selector plate205set in the “latch operative position” and with the apparatus cycling through a complete latching/unlatching operation.FIGS.36-38show endoscopic cutting forceps5with selector plate205set in the “latch inoperative position” and with lever30cycling through a complete “pull and release” operation.

Alternative Preferred Embodiments

In the preceding description, lever30is described as being rotatably pinned to handle25at105. However, it should be appreciated that other connections may also be employed. By way of example but not limitation, lever30may be movably mounted to handle25by the legs of a so-called “4-bar” mechanism.

It should be appreciated that, if desired, selector plate205may move in a direction which is different than the direction of movement of latch plate210, provided, however, that movement of selector plate205moves latch plate210into, and out of, the orbit of latch pin275. By way of example but not limitation, selector plate205could move in a direction perpendicular to the direction of movement of latch plate210, whereby to move latch plate210into, and out of, the orbit of latch pin275.

If desired, latch plate210may be movably mounted to selector plate205by a variety of means, so as to provide a variety of different movements, e.g., linear movement, pivoting movement, prescribed motion such as by a so-called “4-bar” mechanism, traversing in an arcuate track, etc.

Thus it will be seen that the present invention provides a new and improved latching mechanism for an endoscopic cutting forceps wherein the latching mechanism is mechanically simple and hence easy and inexpensive to manufacture.

It will also be appreciated that the new and improved latching mechanism of the present invention may be used in conjunction with the actuating levers of other surgical instruments and/or other lever-actuated devices, whereby to provide a latching mechanism which is mechanically simple and hence easy and inexpensive to manufacture.

Modifications of the Preferred Embodiments

It will be appreciated that various modifications may be made to the preferred embodiments discussed above without departing from the scope of the present invention.

Thus, for example, the locations of selector plate205/latch plate210and latch pin275may be reversed, i.e., selector plate205and latch plate210may be mounted on lever30and latch pin275may be mounted on handle25.

By way of further example but not limitation, selector plate205may be omitted, in which case latch plate210is slidably mounted directly to handle25(or, if the location of latch plate210and latch pin275are reversed, slidably mounted directly to lever30). Of course, in this form of the invention, the apparatus is always set in the “latch operative position” and is incapable of being set in the “latch inoperative position”.

It should be understood that many additional changes in the details, materials, steps and arrangements of parts, which have been herein described and illustrated in order to explain the nature of the present invention, may be made by those skilled in the art while still remaining within the principles and scope of the invention.