Electrode configurations for surgical instruments

An end effector includes a first electrically conductive layer and a second electrically conductive layer comprising an electrically conductive projection extending from the second electrically conductive layer, wherein at least one of the first electrically conductive layer and the electrically conductive projection is movable relative to the other one of the first electrically conductive layer and the electrically conductive projection to capture tissue therebetween.

BACKGROUND

The present disclosure relates to surgical instruments and, in various circumstances, to surgical sealing and transecting instruments.

SUMMARY

In one embodiment, a surgical instrument is provided. The surgical instrument comprises an end effector. The end effector comprises a first jaw comprising a first electrically conductive layer and a second jaw, wherein at least one of the first jaw and the second jaw is movable relative to the other one of the first jaw and the second jaw to transition the end effector between a first configuration and a second configuration. In at least one embodiment, the second jaw comprises a second electrically conductive layer defining at least one opening and an electrically non-conductive layer, wherein the first electrically conductive layer and the electrically non-conductive layer are configured to be on opposite sides of the second electrically conductive layer. In at least one embodiment, the second jaw further comprises at least one electrically conductive member extending from the electrically non-conductive layer and projecting through the at least one opening to maintain a predetermined gap between the first electrically conductive layer and the second electrically conductive layer, wherein the second electrically conductive layer is configured to conduct electrical energy to the first electrically conductive layer and the at least one electrically conductive member through tissue disposed between the first jaw and the second jaw in the second configuration to treat the tissue.

In another embodiment, an end effector for a surgical instrument is provided. The end effector comprises a first electrically conductive layer and a second electrically conductive layer comprising an electrically conductive projection extending from the second electrically conductive layer, wherein at least one of the first electrically conductive layer and the electrically conductive projection is moveable relative to the other one of the first electrically conductive layer and the electrically conductive projection to capture tissue therebetween. The end effector further comprises a first electrically non-conductive support comprising a first aperture, wherein the electrically conductive projection extends through the first aperture. In at least one embodiment, the end effector further comprises a third electrically conductive layer comprising a second aperture, wherein the electrically conductive projection extends through the second aperture, and wherein the first electrically non-conductive support is positioned between the second electrically conductive layer and the third electrically conductive layer.

Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate various embodiments of the disclosure, in one form, and such exemplifications are not to be construed as limiting the scope of the disclosure in any manner.

DETAILED DESCRIPTION

FIG. 1illustrates a perspective view of a surgical instrument2comprising a handle assembly4and an end effector10according to one embodiment.FIG. 2illustrates a perspective view of the surgical instrument2ofFIG. 1according to one embodiment andFIG. 3illustrates a side elevational view of the handle assembly4of the surgical instrument ofFIG. 1according to one embodiment. Turning toFIGS. 1-3, one form of an electrosurgical instrument2is depicted. The electrosurgical instrument2comprises a handle assembly4, a shaft assembly12coupled to a distal end of the handle assembly4, and an end effector10coupled to the distal end of the shaft assembly12. The handle assembly4is configured as a pistol grip and comprises left and right handle housing shrouds6a,6b, a closure trigger8, a pistol-grip handle14, a firing trigger16, an energy button18, and a rotatable shaft knob20. An electrical cable may enter the handle assembly4at a proximal end15.

In some circumstances, the end effector10can be coupled to the distal end of the shaft assembly12. The end effector10may include a first jaw22aand a second jaw22b. The first jaw22acan be pivotably coupled to the second jaw22b. The first jaw22ais moveable with respect to the second jaw22bto grasp tissue therebetween. In some circumstances, the second jaw22bis fixed. In other circumstances, the first jaw22aand the second jaw22bare pivotably movable with respect to each other. The end effector10may include one or more electrodes such as, for example, electrodes92,94. The electrodes92,94can be configured to pass energy through tissue positioned between the electrodes92,94. Energy delivered by the electrodes92,94may comprise, for example, radiofrequency (RF) energy, sub-therapeutic RF energy, therapeutic RF energy, ultrasonic energy, and/or other suitable forms of energy. In some circumstances, a cutting member (not shown) is receivable within a longitudinal slot40(FIG. 4) defined by the first jaw22aand/or the second jaw22b. The cutting member can be configured to cut tissue grasped between the first jaw22aand the second jaw22b. In some circumstances, the cutting member may include an electrode for delivering energy, such as, for example, RF and/or ultrasonic energy.

In certain instances, an energy button18is configured to deliver energy to the at least one electrode92from a power source. In certain instances, when the energy button18is depressed, a circuit is completed allowing delivery of energy to the electrode92. In some embodiments, the power source is a generator. In certain instances, the generator is external to the surgical instrument2which is separably coupled to the generator. In other instances, the generator is integrated with the surgical instrument2. In certain instances, the power source may be suitable for therapeutic tissue treatment, tissue cauterization/sealing, as well as sub-therapeutic treatment and measurement.

In certain instances, the surgical instrument2may include a closure drive assembly which may comprise an outer sheath23, for example. In certain instances, the closure trigger8can be operatively coupled to at least one of the first and second jaws22a,22bthrough the closure drive assembly such that actuation of the closure trigger8in a closure stroke may transition the first and second jaws22a,22bbetween a plurality of configurations including an open configuration and an approximated configuration, for example. In certain instances, the surgical instrument2may include a firing drive assembly. In certain instances, the firing trigger16may be operatively coupled to the cutting member of the end effector10through the firing drive assembly such that actuation of the firing trigger16in a firing stroke may cause the cutting member to be advanced relative to the end effector10to cut tissue captured between the first and second jaws22a,22b, for example.

When electrical current is supplied to an electrode such as, for example, the electrodes92,94, the electrical current can pass through the tissue positioned against and/or surrounding the electrode, for example. In various circumstances, the current flowing through the electrode can generate heat within the electrode and the surrounding tissue. In certain circumstances, the heat can denature proteins within the tissue and, in co-operation with clamping pressure provided by the first and second jaws22a,22bof the end effector10, the denatured proteins can form a seal within the tissue, for example.

FIG. 2illustrates a side perspective view of the electrosurgical instrument2illustrated inFIG. 1.FIG. 2illustrates the right handle housing6b. The energy button18extends through the handle assembly4and is accessible on both sides of the handle assembly4. The closure trigger8, the firing trigger16, and the energy button18may comprise an ergonomic design. In some circumstances, the handle assembly4is thinner near the energy button18to allow ease of access to the energy button18by a clinician. In some circumstances, the energy button18is disposed on either the left handle housing shroud6aor the right handle housing shroud6b.FIG. 3illustrates a side view of the electrosurgical instrument2and the right handle housing shroud6b. Various electrosurgical instruments suitable for use with the present disclosure are described in U.S. patent application Ser. Nos. 14/075,839 and 14/075,863.

FIG. 4illustrates a perspective view of the end effector10of the surgical instrument2ofFIG. 1, according to one embodiment.FIG. 4Aillustrates a partial cross-sectional view of the end effector10ofFIG. 4, wherein tissue is captured between the first jaw22aand the second jaw22bof the end effector10, according to one embodiment.FIG. 4Billustrates a partial cross-sectional view of the end effector10ofFIG. 4, wherein tissue is captured between the first jaw22aand the second jaw22bof the end effector10, according to one embodiment.FIG. 6illustrates an exploded view of the second jaw22bof the end effector10ofFIG. 4, according to one embodiment. Referring now toFIGS. 4-4C and 6, the second jaw22bmay include an electrically conductive layer42and an electrically non-conductive layer or support46. One or more protrusions or projections50may extend from the non-conductive layer46through the electrically conductive layer42. In certain instances, as illustrated inFIG. 6, the electrically conductive layer42may include one or more openings or apertures44. In certain instances, one or more of the protrusions50may extend from the non-conductive layer46and pass through an opening or aperture44of the electrically conductive layer42.

In certain instances, one or more of the protrusions50may be comprised, or at least partially comprised, of an electrically conductive material. As illustrated inFIG. 4B, a protrusion or projection50may include an electrically non-conductive portion45and an electrically conductive portion50athat extends from the non-conductive portion45. The non-conductive portion45may extend from the non-conductive layer46. The electrically conductive portion50amay extend from the non-conductive portion45in a direction away from the non-conductive layer46, as illustrated inFIG. 4B. The non-conductive layer46and/or the non-conductive portion45may be comprised of an electrically non-conductive, or insulative, material, such as plastic and/or ceramic, for example.

In certain instances, as illustrated inFIG. 4B, the electrically conductive portion50aextends through an opening or aperture44of the electrically conductive layer42. In such instances, the electrically conductive portion50amay be employed to grip tissue in contact therewith. In at least one example, the electrically conductive portion50amay comprise a textured or patterned outer surface to improve its ability to grip the tissue.

In certain instances, one or more of the protrusions50can be comprised of an electrically non-conductive material coated, or at least partially coated, with an electrically conductive material, for example. In certain instances, the electrically conductive portion50ais comprised of an electrically conductive surface or coating disposed at a terminal end of the non-conductive portion45. The electrically conductive surface may be configured to contact tissue captured between the first and second jaws22a,22b. In at least one example, an electrically conductive surface can be textured or patterned to improve its ability to grip tissue in contact therewith.

In certain instances, as illustrated inFIG. 4C, the non-conductive layer46may comprise an electrically non-conductive barrier49. The non-conductive barrier49may partially enclose or insulate the conductive portion50a. In at least one example, the barrier49isolates the conductive portion50afrom the conductive layer42. An outer surface51may remain exposed, as illustrated inFIG. 4C. The surface51may be configured to contact tissue captured between the jaws22a,22b, for example. In certain instances, as illustrated inFIG. 4C, a barrier49may extend through an opening or aperture44of the conductive layer42to surround, or at least partially surround, a protrusion or projection50extending through the opening44. The barrier49may prevent, or at least reduce, arcing between the protrusion50and the conductive layer42.

In certain instances, referring again toFIGS. 4-4C and 6, the electrode92includes the conductive layer42. The conductive layer42may extend between, or at least partially between, the non-conductive layer46and tissue captured between the first and second jaws22a,22b, for example. In certain instances, electrical current can pass between an electrically conductive layer95of the first jaw22aand the conductive layer42through the tissue captured between the first and second jaws22a,22b, for example. The conductive layer95can be positioned between an electrically non-conductive layer97of the first jaw22aand tissue captured between the first and second jaws22a,22b, as illustrated inFIGS. 4A-4C. The non-conductive layer97can be positioned, or at least partially positioned, between the conductive layer95and an outer electrically conductive layer99, as illustrated inFIG. 4A-4C. In certain instances, electrical current can pass between the conductive layer42and the outer conductive layer99through tissue, for example. The conducted current can be employed to treat, seal, and/or cut the tissue.

Further to the above, the electrical current may pass between an electrically conductive layer95of the electrode94and an electrically conductive portion50aof a protrusion or projection50through tissue gripped by the electrically conductive portion50a. In certain instances, the conducted current may also pass between the electrically conductive portion50aand the conductive layer42through the tissue gripped, or at least partially gripped, by the electrically conductive portion50a. The reader will appreciate that the conductive nature of the electrically conductive portion50afacilitates the passing of the current through the tissue gripped, or at least partially gripped, by the electrically conductive portion50a. In certain instances, the conducted current can be employed to treat, seal, and/or cut the tissue gripped by the electrically conductive portion50a.

Referring primarily toFIG. 6, the conductive layer42can be disposed, or at least partially disposed, over an electrically non-conductive layer46. In certain instances, the non-conductive layer46may comprise a receiving shell47. In such instances, the conductive layer42can be embedded, or at least partially embedded, in the receiving shell47, as illustrated inFIG. 4, for example. The receiving shell47may include a plurality of receiving portions or sockets46a. In at least one instance, a protrusion or projection50can be fastened (e.g., glued) to the non-conductive layer46. In certain instances, as illustrated inFIG. 4A, a protrusion or projection50can be partially embedded in a receiving portion46a.

The electrically conductive layer42may include an outer surface43facing away from the non-conductive layer46. The outer surface43may contact tissue captured between the first and second jaws22a,22b, for example. In certain instances, as illustrated inFIG. 6, the non-conductive layer46may extend between the conductive layer42and a base48. In certain instances, as illustrated inFIG. 4, the base48may include an electrically conductive layer101. In such instances, the non-conductive layer46can be positioned, or at least partially positioned, between the conductive layer42and the conductive layer101, as illustrated inFIGS. 4A-4C, for example. In certain instances, electrical current can pass between the conductive layer42and the conductive layer101through tissue, for example. The conducted can be employed to treat, seal, and/or cut the tissue.

In certain instances, referring toFIGS. 4-4B and 6, the electrically conductive layer42may be comprised of a first lateral portion42aand a second lateral portion42b. The lateral portions42a,42bmay extend, or at least partially extend, on opposite lateral sides of the elongate slot40, for example. In certain instances, as illustrated inFIG. 6, the conductive layer42may include a plurality of openings or apertures44. In various instances, the openings44can be arranged in rows that extend in parallel, or at least substantially in parallel, with the elongate slot40. For example, as illustrated inFIG. 4, a first row of the openings44and a second row of the openings44may be disposed on opposite lateral sides of the slot40. Furthermore, the protrusions50can be arranged in rows that extend in parallel, or at least substantially in parallel, with the elongate slot40. For example, as illustrated inFIG. 4, a first row of the protrusions50and a second row of the protrusions50may be disposed on opposite lateral sides of the slot40. In certain instances, the protrusions50can be in any array, offset, laterally across from one another, or staggered along a length of one or both of the jaws22a,22b.

In certain instances, an opening or aperture44may define a through-hole that extends through the conductive layer42along an axis that intersects the conductive layer42. In certain instances, the through-hole can be reamed, drilled, or milled through the conductive layer42along, or at least substantially along, an axis L that intersects the outer surface43of the conductive layer42, as illustrated inFIG. 4A. In certain instances, the axis L can be perpendicular, or at least substantially perpendicular, to a plane extending along, or at least substantially along, the outer surface43of the conductive layer42. In certain instances, the opening44may define a perimeter wall44a. In certain instances, as illustrated inFIG. 6, the perimeter wall44amay comprise cylindrical, or at least substantially cylindrical, shape.

In certain instances, as illustrated inFIG. 4C, a barrier49may extend, or at least partially extend, between a perimeter wall44aof the conductive layer42and a corresponding conductive portion50a, for example. The barrier49may insulate the perimeter wall44afrom the conductive portion50a. An outer conductive surface51may remain exposed. The surface51may be configured to contact tissue captured between the jaws22a,22b, for example. In certain instances, the tissue connecting the electrically conductive surface51and the electrically conductive layer42may create a passage for current to flow between the protrusion50and the electrically conductive layer42. In at least one example, the conducted current can be employed to treat, seal, and/or cut the tissue disposed, or at least partially disposed, between the electrically conductive surface51and the electrically conductive layer42.

FIG. 5illustrates a perspective view of a second jaw23of the end effector10of the surgical instrument2ofFIG. 1, according to one embodiment.FIG. 5Aillustrates a partial cross-sectional view of the second jaw23ofFIG. 5, according to one embodiment. As illustrated inFIG. 5, the second jaw23is similar in many respects to the second jaw22b(FIG. 4). For example, like the second jaw22b, the second jaw23includes the conductive layer42, and the protrusions50. Also, like the jaws22a,22b, tissue is captured between the jaws22a,23, as illustrated inFIG. 5A. However, unlike the jaw22b, the protrusions50of the jaw23extend from an electrically conductive layer48a. In certain instances, as illustrated inFIG. 5A, the base48may comprise the conductive layer48a. In one example, the protrusions50and the conductive layer48amay be formed as a single unit. In another example, the protrusions50and the conductive layer48amay be formed separately and assembled by attaching the protrusions50to the conductive layer48. In certain instances, the protrusions50and the conductive layer48amay be comprised of the same, or similar, conductive materials.

The second jaw23comprises an electrically non-conductive support or layer46′, which is similar in many respects to the non-conductive layer46. For example, like the non-conductive layer46, the non-conductive layer46′ may be comprised of an electrically non-conductive, or insulative, material, such as plastic and/or ceramic. As illustrated inFIG. 5A, the non-conductive layer46′ may extend, or at least partially extend, between the conductive layer48aand the conductive layer42. The conductive layer48aand the conductive layer42can be attached to opposite sides of the non-conductive layer46′. The non-conductive layer46′ may electrically insulate the conductive layer42from the conductive layer48a.

In certain instances, as illustrated inFIG. 5A, the non-conductive layer46′ may comprise a plurality of apertures or openings57. The openings57can be configured to receive the protrusions50. As illustrated inFIG. 5A, an opening57can be aligned, or at least partially aligned, with an opening44of the conductive layer42to permit a protrusion or projection50to extend through the opening57and the opening44away from the conductive layer48a. In certain instances, unlike the openings44, the openings57can be tightly fitted around the protrusions50. An opening57may define a smaller perimeter wall57aaround a protrusion or projection50than the perimeter44adefined by the opening44around the protrusion50. In at least one example, an opening57and an opening44can be concentrically aligned about a longitudinal axis L defined by a protrusion or projection50, as illustrated inFIG. 5A. In at least one example, a protrusion50may be in contact (not shown) with a perimeter wall57aof an opening57surrounding the protrusion50.

Referring again toFIG. 5A, in certain instances, electrical energy can be passed from the conductive layer42to the conductive portions50, the conductive layer95, and/or the conductive layer99, for example. The tissue gripped, or at least partially gripped, by the conductive portions50can act as a conduit for the electrical current passed between the conductive layer42and the conductive portions50. Tissue can also act as a conduit for the electrical current passed between the conductive layer42and the conductive layers95and/or99, for example. In any event, the conducted current can be employed to treat, seal, and/or cut the tissue.

Referring again toFIG. 5A, in certain instances, electrical energy can be passed from the conductive layer95to the conductive portions50, the conductive layer42, and/or the conductive layer99, for example. The tissue gripped, or at least partially gripped, by the conductive portions50can act as a conduit for the electrical current passed between the conductive layer95and the conductive portions50. Tissue can also act as a conduit for the electrical current passed between the conductive layer95and the conductive layers42and/or99, for example. In any event, the conducted current can be employed to treat, seal, and/or cut the tissue.

FIG. 7illustrates a side elevational view of a second jaw25of the surgical instrument2ofFIG. 1, according to one embodiment, andFIG. 7Aillustrates a partial cross-sectional view of the second jaw25ofFIG. 7, according to one embodiment. As illustrated inFIG. 7, the second jaw25is similar in many respects to the second jaw22b(FIG. 4) and/or the second jaw23(FIG. 5). For example, like the second jaws22b,23, the second jaw25includes the conductive layer42, and the protrusions50. Also, like the jaws22a,22band the jaws22a,23, tissue is captured between the jaws22a,25.

Referring now toFIGS. 4-7A, one or more of the protrusions50may extend from the non-conductive layer46, as illustrated inFIG. 4A, or through the non-conductive layer46′, as illustrated inFIG. 5A, toward the electrically conductive layer42. In certain instances, a protrusion or projection50may extend through an opening44of the electrically conductive layer42. In certain instances, the protrusion50may protrude through the outer surface43of the electrically conductive layer42, as illustrated inFIG. 7. In certain instances, one or more electrically conductive portions50amay protrude through the outer surface43of the electrically conductive layer42, as illustrated inFIG. 7A.

Referring toFIG. 7A, an electrically conductive portion50amay protrude or extend a predetermined distance (d1) beyond the outer surface43of the outer layer42. The electrically conductive portion50amay prevent direct contact between the electrode94and the electrically conductive layer42of the electrode92. In certain instances, the electrically conductive portion50amay maintain a minimum gap between the electrode94and the electrically conductive layer42of the electrode92. In certain instances, the minimum gap can be defined by the predetermined distance (d1). In certain instances, the predetermined distance (d1) can be any distance selected from a range of about 0.001 inch to about 0.010 inch. In certain instances, the predetermined distance (d1) can be any distance selected from a range of about 0.003 inch to about 0.008 inch. In certain instances, the predetermined distance (d1) can be about 0.004 inch, for example. In certain instances, the predetermined distance (d1) can be about 0.005 inch, for example.

Referring now primarily toFIG. 7A, a protrusion or projection50extending through an opening or aperture44of the electrically conductive layer42may be spaced apart from the perimeter wall44aof the opening44to prevent, or at least reduce, electrical arcing between the protrusion50and the electrically conductive layer42. In certain instances, as illustrated inFIG. 7A, the perimeter wall44aof the opening44may be disposed around, or at least partially around, the protrusion50, wherein a predetermined distance (d2) is maintained between the protrusion50, or at least the electrically conductive portion50aof the protrusion50, and the wall44aof the opening44.

Although the electrically conductive portion50ais spaced apart from the perimeter wall44a, current may still be conducted between the electrically conductive portion50aand the electrically conductive layer42through tissue disposed therebetween, as illustrated inFIG. 7A. In such instances, the conducted current may be employed to treat, seal, and/or cut the tissue disposed, or at least partially disposed, between the electrically conductive portion50aand the electrically conductive layer42, for example.

In certain instances, the predetermined distance (d2) can be any distance selected from a range of about 0.001 inch to about 0.010 inch. In certain instances, the predetermined distance (d2) can be any distance selected from a range of about 0.003 inch to about 0.008 inch. In certain instances, the predetermined distance (d2) can be about 0.004 inch, for example. In certain instances, the predetermined distance (d2) can be about 0.005 inch, for example.

FIG. 8illustrates a perspective view of a second jaw27of the end effector10of the surgical instrument2ofFIG. 1, according to one embodiment.FIG. 9illustrates a partial cross-sectional view of the second jaw27ofFIG. 8, according to one embodiment. As illustrated inFIG. 8, the second jaw27is similar in many respects to the second jaw23(FIG. 5). For example, like the second jaw23, the second jaw27includes the conductive layer42, the conductive layer48a, the non-conductive layer46′, and the protrusions50. Also, like the second jaw23, the protrusions50of the second jaw27may extend from the conductive layer48athrough the non-conductive layer46′, for example. Also, like the jaws22a,23, tissue is captured between the jaws22a,25, as illustrated inFIG. 9.

Referring toFIGS. 8-10, a protrusion or projection50of the second jaw27may extend from the conductive layer48aand can be partially surrounded by an electrically non-conductive barrier49extending from the non-conductive layer46′. In certain instances, as illustrated inFIG. 8, the barrier49can be disposed, or at least partially disposed, between a protrusion or projection50and the electrically conductive layer42to prevent, or at least reduce, electrical arcing between the protrusion50and the electrically conductive layer42. An electrically conductive surface51of the protrusion50may remain exposed to permit current to flow between the protrusion50and the electrically conductive layer42through tissue disposed, or at least partially disposed, therebetween, for example. In certain instances, the tissue connecting the electrically conductive surface51and the electrically conductive layer42may create a passage for current to flow between the protrusion50and the electrically conductive layer42. In at least one example, the conducted current can be employed to treat, seal, and/or cut the tissue disposed, or at least partially dispose, between the electrically conductive surface51and the electrically conductive layer42.

In certain instances, referring primarily toFIG. 10, a protrusion or projection50of the second jaw27may be partially enclosed within the barrier49of the non-conductive layer46′. In various instances, the protrusion50may comprise a semi-cylindrical shape comprising a first base53and a second base55, as illustrated inFIG. 10, for example. The barrier49may comprise crescent shape configured to separate, or at least partially separate, an arcuate portion of the semi-cylindrical protrusion50from the electrically conductive layer42to prevent, or at least reduce, electrical arcing between the semi-cylindrical protrusion50and the electrically conductive layer42. The second base55may extend, or at least partially extend in a first plane which is perpendicular, or substantially perpendicular, to a second plane defined by the first base53, for example. In certain instances, the first base53can be flush with an outer surface49aof the barrier49, for example.

In certain instances, the first base53and/or the second base55are exposed, as illustrated inFIG. 10. Said another way, the first base53and/or the second base55may not be enclosed by the non-conductive layer46′. Yet said another way, the first base53and/or the second base55can contact tissue captured between the first jaw22aand the second jaw27. In such instances, the captured tissue may create a passage for current to flow between the electrically conductive layer42and the first base53and/or the second base55. In at least one example, the conducted current can be employed to treat, seal, and/or cut the tissue connecting the electrically conductive layer42and the first base53and/or the second base55.

One or more of the switches described herein may comprise mechanical switches, electro-mechanical switches, and/or solid state switches. In certain instances, one or more of the switches of the present disclosure may comprise open, inactive, and/or non-conductive positions, states, and/or configurations. In certain instances, one or more of the switches of the present disclosure may comprise closed, active, and/or conductive positions, states and/or configurations. In certain instances, one or more of the switches of the present disclosure can be transitioned from the open, inactive, and/or non-conductive positions, states, and/or configurations to the closed, active, and/or conductive positions, states and/or configurations to close and/or activate one or more circuits associated with such switches, for example.

While this disclosure has been described as having example designs, the present disclosure may be further modified within the spirit and scope of the disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the disclosure using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this disclosure pertains.

The entire disclosures of: