Patent Description:
Examples of endoscopic surgical instruments include surgical staplers. Some such staplers are operable to clamp down on layers of tissue, cut through the clamped layers of tissue, and drive staples through the layers of tissue to substantially seal the severed layers of tissue together near the severed ends of the tissue layers. Merely exemplary surgical staplers are disclosed in <CIT>; <CIT>; and <CIT>.

Surgical staplers may also be used in open procedures and/or other non-endoscopic procedures. By way of example only, a surgical stapler may be inserted through a thoracotomy and thereby between a patient's ribs to reach one or more organs in a thoracic surgical procedure that does not use a trocar as a conduit for the stapler. For instance, the vessels leading to an organ may be severed and closed by a stapler before removal of the organ from the thoracic cavity. Of course, surgical staplers may be used in various other settings and procedures.

<CIT> discusses various embodiments relating to a surgical cutting and fastening instrument that has an end effector with an anvil that can pivot between open and closed positions relative to an elongate channel that can support a staple cartridge therein. The anvil may be opened and closed by a drive system. Various embodiments employ a powered drive system for opening and closing the anvil and powering a knife and staple drive assembly used to cut tissue and deploy the staples in the cartridge. Other embodiments employ a mechanical system to open and close the anvil and employ a powered system to power the knife and staple drive assembly. In various embodiments, the drive assembly serves to axially and laterally align anvil relative to the elongate channel. The anvil is constructed to move in a substantially parallel path relative to the elongate channel during closing. The elongate channel is stamped or otherwise formed from sheet metal or the like and pivot holes may be punched therein.

<CIT> discusses a surgical stapling anvil for use with a surgical instrument. The anvil comprises an anvil body comprising a tissue-facing surface and a longitudinal cavity. The longitudinal cavity comprises a first cavity portion configured to receive at least a portion of a cutting edge of a firing member of the surgical instrument therethrough, a second cavity portion configured to receive an anvil-engaging portion of the firing member therethrough, and a third cavity portion comprising a first angular surface which flares outward relative to the second cavity portion. The anvil further comprises an anvil cap comprising a first section positioned within a portion of the second cavity portion and a second section positioned within the third cavity portion, wherein the second section comprises a second angular surface corresponding to the first angular surface, and wherein the first angular surface and the second angular surface are welded together.

<NPL>) Discusses how in the last 30years, the concept of manufacturability has been applied to many different processes in numerous industries. This has resulted in the emergence of several different "Design for Manufacturing" methodologies which have in common the aim of reducing productions costs through the application of general manufacturing rules. Near net shape technologies have expanded these concepts, targeting mainly primary shaping process, such as casting and forging. The desired outcomes of manufacturability analysis for near net shape processes are cost and lead/time reduction through minimization of process steps (in particular cutting and finishing operations) and raw material saving. Product quality improvement, variability reduction and component design functionality enhancement are also achievable through near net shape optimization. Process parameters, product design and material selection are the changing variables in a manufacturing chain that interact in complex, non-linear ways. Consequently, modeling and simulation play important roles in the investigation of alternative approaches. However, defining the manufacturing capability of different processes is also a "moving target" because the various near net shape technologies are constantly improving and evolving so there is challenge in accurately reflecting their requirements and capabilities. In the last decade, for example, computer-aided design, computer numerical control technologies and innovation in materials have impacted enormously on the development of near net shape technologies. This article reviews the different methods reported for near net shape manufacturability assessment and examines how they can make an impact on cost, quality and process variability in the context of a specific production volume. The discussion identifies a lack of structured approaches, poor connection with process optimization methodologies and a lack of empirical models as gaps in the reported approaches.

<NPL>]) discusses how a large percentage of surgical instruments and medical devices contain precision engineered miniature and micro metal components produced from a wide variety of expensive - and often precious - raw materials. Manufacturers are focused on reducing these raw material costs, and, at the same time, looking for ways to save labor intensive assembly costs while improving yield and component reliability. It goes on to compare the pros and cons of screw machining (or Swiss machining), stamping, metal injection molding, and cold forming (or cold forging), and provide examples of how cold forming can improve production efficiency, quality and cost of ownership in medical device manufacturing.

The accompanying drawings incorporated in and forming a part of the specification illustrate several aspects of the present invention, and together with the description serve to explain the principles of the invention; it being understood, however, that this invention is not limited to the precise arrangements shown but defined by the appended claims.

For clarity of disclosure, the terms "proximal" and "distal" are defined herein relative to a human or robotic operator of the surgical instrument. The term "proximal" refers the position of an element closer to the human or robotic operator of the surgical instrument and further away from the surgical end effector of the surgical instrument. The term "distal" refers to the position of an element closer to the surgical end effector of the surgical instrument and further away from the human or robotic operator of the surgical instrument. In addition, the terms "upper," "lower," "lateral," "transverse," "bottom," "top," are relative terms to provide additional clarity to the figure descriptions provided below. The terms "upper," "lower," "lateral," "transverse," "bottom," "top," are thus not intended to unnecessarily limit the invention described herein.

In addition, the terms "first" and "second" are used herein to distinguish one or more portions of the surgical instrument. For example, a first assembly and a second assembly may be alternatively and respectively described as a second assembly and a first assembly. The terms "first" and "second" and other numerical designations are merely exemplary of such terminology and are not intended to unnecessarily limit the invention described herein.

<FIG> depict a first exemplary surgical stapling and severing instrument (<NUM>) that is sized for insertion through a trocar cannula or an incision (e.g., thoracotomy, etc.) to a surgical site in a patient for performing a surgical procedure. Instrument (<NUM>) of the present example includes a handle portion (<NUM>) connected to a shaft (<NUM>), which distally terminates in an articulation joint (<NUM>), which is further coupled with a first exemplary end effector (<NUM>). Shaft (<NUM>) may be constructed in accordance with at least some of the teachings of <CIT>.

Once articulation joint (<NUM>) and end effector (<NUM>) are inserted through the cannula passageway of a trocar, articulation joint (<NUM>) may be remotely articulated, as depicted in phantom in <FIG>, by an articulation control (<NUM>), such that end effector (<NUM>) may be deflected from the longitudinal axis (LA) of shaft (<NUM>) at a desired angle (α). Articulation joint (<NUM>) and/or articulation control (<NUM>) may be constructed and operable in accordance with at least some of the teachings of <CIT>; and/or <CIT>.

End effector (<NUM>) of the present example includes a lower jaw (<NUM>) and a pivotable anvil (<NUM>). Lower jaw (<NUM>) may be constructed in accordance with at least some of the teachings of <CIT>. Anvil (<NUM>) may be constructed in accordance with at least some of the teachings of <CIT>; <CIT>; and/or <CIT>.

Handle portion (<NUM>) includes a pistol grip (<NUM>) and a closure trigger (<NUM>). Closure trigger (<NUM>) is pivotable toward pistol grip (<NUM>) to cause clamping, or closing, of the anvil (<NUM>) toward lower jaw (<NUM>) of end effector (<NUM>). Such closing of anvil (<NUM>) is provided through a closure tube (<NUM>) and a closure ring (<NUM>), which both longitudinally translate relative to handle portion (<NUM>) in response to pivoting of closure trigger (<NUM>) relative to pistol grip (<NUM>). Closure tube (<NUM>) extends along the length of shaft (<NUM>); and closure ring (<NUM>) is positioned distal to articulation joint (<NUM>). Articulation joint (<NUM>) is operable to communicate/transmit longitudinal movement from closure tube (<NUM>) to closure ring (<NUM>). Handle portion (<NUM>) also includes a firing trigger (<NUM>) (shown in <FIG>). An elongate member (not shown) longitudinally extends through shaft (<NUM>) and communicates a longitudinal firing motion from handle portion (<NUM>) to a firing beam (<NUM>) in response to actuation of firing trigger (<NUM>). This distal translation of firing beam (<NUM>) causes the stapling and severing of clamped tissue in end effector (<NUM>), as will be described in greater detail below.

<FIG> depict end effector (<NUM>) employing an E-beam form of firing beam (<NUM>). As best seen in <FIG>, firing beam (<NUM>) includes a transversely oriented upper pin (<NUM>), a firing beam cap (<NUM>), a transversely oriented middle pin (<NUM>), and a distally presented cutting edge (<NUM>). Upper pin (<NUM>) is positioned and translatable within a longitudinal anvil slot (<NUM>) of anvil (<NUM>). Firing beam cap (<NUM>) slidably engages a lower surface of lower jaw (<NUM>) by having firing beam (<NUM>) extend through lower jaw slot (<NUM>) (shown in <FIG>) that is formed through lower jaw (<NUM>). Middle pin (<NUM>) slidingly engages a top surface of lower jaw (<NUM>), cooperating with firing beam cap (<NUM>). Firing beam (<NUM>) and/or associated lockout features may be constructed and operable in accordance with at least some of the teachings of <CIT>.

<FIG> shows firing beam (<NUM>) of the present example proximally positioned and anvil (<NUM>) pivoted to an open position, allowing an unspent staple cartridge (<NUM>) to be removably installed into a channel of lower jaw (<NUM>). As best seen in <FIG>, staple cartridge (<NUM>) of this example includes a cartridge body (<NUM>), which presents an upper deck (<NUM>) and is coupled with a lower cartridge tray (<NUM>). As best seen in <FIG>, a vertical slot (<NUM>) is formed through part of staple cartridge (<NUM>). As also best seen in <FIG>, three rows of staple apertures (<NUM>) are formed through upper deck (<NUM>) on one side of vertical slot (<NUM>), with another set of three rows of staple apertures (<NUM>) being formed through upper deck (<NUM>) on the other side of vertical slot (<NUM>). As shown in <FIG>, a wedge sled (<NUM>) and a plurality of staple drivers (<NUM>) are captured between cartridge body (<NUM>) and cartridge tray (<NUM>), with wedge sled (<NUM>) being located proximal to staple drivers (<NUM>). Wedge sled (<NUM>) is movable longitudinally within staple cartridge (<NUM>); while staple drivers (<NUM>) are movable vertically within staple cartridge (<NUM>). Staples (<NUM>) are also positioned within cartridge body (<NUM>), above corresponding staple drivers (<NUM>). Each staple (<NUM>) is driven vertically within cartridge body (<NUM>) by a staple driver (<NUM>) to drive staple (<NUM>) out through an associated staple aperture (<NUM>). As best seen in <FIG> and <FIG>, wedge sled (<NUM>) presents inclined cam surfaces that urge staple drivers (<NUM>) upwardly as wedge sled (<NUM>) is driven distally through staple cartridge (<NUM>). Staple cartridge (<NUM>) may be constructed and operable in accordance with at least some of the teachings of <CIT>; and/or <CIT>.

With end effector (<NUM>) closed as depicted in <FIG> by distally advancing closure tube (<NUM>) and closure ring (<NUM>), firing beam (<NUM>) is then advanced in engagement with anvil (<NUM>) by having upper pin (<NUM>) enter longitudinal anvil slot (<NUM>). A pusher block (<NUM>) (shown in <FIG>) is located at the distal end of firing beam (<NUM>) and pushes wedge sled (<NUM>) as firing beam (<NUM>) is advanced distally through staple cartridge (<NUM>) when firing trigger (<NUM>) is actuated. During such firing, cutting edge (<NUM>) of firing beam (<NUM>) enters vertical slot (<NUM>) of staple cartridge (<NUM>), severing tissue clamped between staple cartridge (<NUM>) and anvil (<NUM>). As shown in <FIG>, middle pin (<NUM>) and pusher block (<NUM>) together actuate staple cartridge (<NUM>) by entering into vertical slot (<NUM>) within staple cartridge (<NUM>), driving wedge sled (<NUM>) into upward camming contact with staple drivers (<NUM>), which in turn drive staples (<NUM>) out through staple apertures (<NUM>) and into forming contact with staple forming pockets (<NUM>) (shown in <FIG>) on the inner surface of anvil (<NUM>). <FIG> depicts firing beam (<NUM>) fully distally translated after completing severing and stapling of tissue. Staple forming pockets (<NUM>) are intentionally omitted from the view in <FIG>; but are shown in <FIG>. Anvil (<NUM>) is intentionally omitted from the view in <FIG>. In some versions, anvil (<NUM>) pivots about an axis that is defined by a pin (or similar feature) that slides along an elongate slot or channel as anvil (<NUM>) moves toward lower jaw (<NUM>). In such versions, the pivot axis translates along the path defined by the slot or channel while anvil (<NUM>) simultaneously pivots about that axis.

Instrument (<NUM>) may otherwise be configured and operable in accordance with any of the teachings of any of the patent references cited herein. Additional exemplary modifications that may be provided for instrument (<NUM>) will be described in greater detail below. The below teachings are not limited to instrument (<NUM>) or devices taught in the patents cited herein. The below teachings may be readily applied to various other kinds of instruments, including instruments that would not be classified as surgical staplers. Various other suitable devices and settings in which the below teachings may be applied will be apparent to those of ordinary skill in the art in view of the teachings herein.

In some conventional manufacturing processes, lower jaw (<NUM>) of instrument (<NUM>) may be machined from a single solid block of material (e.g. metal). As a result, this machining of lower jaw (<NUM>) may be time consuming and expensive, both of which are undesirable. Conventional machining techniques, being reductive in nature, may also be considered as being inefficient since they may create waste in the material that is removed from the single solid block of material. Additionally, in some instances, considerable machining may impart undesirable stresses into lower jaw (<NUM>). As a result, it is desirable to manufacture lower jaw (<NUM>) using a faster, more efficient, and more cost-effective process or system of processes to further enhance lower jaw (<NUM>). Additionally, it may be desirable that specific portions and features of lower jaw (<NUM>) have tight tolerances to aid in the use of instrument (<NUM>), while other specific portions and features of lower jaw (<NUM>) may have looser tolerances where the precise dimensions are of lesser significance. As such, it is desirable to manufacture an exemplary lower jaw (<NUM>, <NUM>) that is efficient, cost effective, and sufficiently robust to interchangeably function with end effector (<NUM>) of instrument (<NUM>) described above.

As described below, lower jaw (<NUM>, <NUM>) may be used in place of lower jaw (<NUM>) of instrument (<NUM>). Similar to the operation of instrument (<NUM>), where anvil (<NUM>) pivots relative to lower jaw (<NUM>), anvil (<NUM>) pivots relative to lower jaw (<NUM>, <NUM>). As such, anvil (<NUM>) and lower jaw (<NUM>, <NUM>) may clamp tissue similarly to the clamping performed by anvil (<NUM>) and lower jaw (<NUM>) shown in <FIG>. Similar to lower jaw (<NUM>), lower jaw (<NUM>, <NUM>) is also configured to receive a staple cartridge, similar to staple cartridge (<NUM>) shown in <FIG>. Additional details of lower jaw (<NUM>, <NUM>) are described below with reference to the following figures.

<FIG> show an exemplary lower jaw blank (<NUM>) that is configured to be transformed into a lower jaw (<NUM>, <NUM>) shown in <FIG> and <FIG> respectively, through one or more manufacturing processes as described below. Lower jaw (<NUM>, <NUM>) is similar to lower jaw (<NUM>) of end effector (<NUM>), with notable differences indicated below. As previously indicated, instrument (<NUM>) includes a body (shown as handle portion (<NUM>)), shaft (<NUM>) extending from the body, and end effector (<NUM>) in communication with shaft (<NUM>). End effector (<NUM>) is operable to compress, staple, and cut tissue. Lower jaw blank (<NUM>), once transformed into lower jaw (<NUM>, <NUM>) is configured to be used in place of another lower jaw (e.g. lower jaw (<NUM>)) to form a portion of end effector (<NUM>).

As shown in the perspective views of <FIG>, lower jaw blank (<NUM>) includes a U-shaped body portion (<NUM>) and outwardly extending flanges (<NUM>, <NUM>) extending outwardly from U-shaped body portion (<NUM>). U-shaped body portion (<NUM>) includes a bottom wall (<NUM>) interposed between opposing side walls (<NUM>, <NUM>). Side walls (<NUM>, <NUM>) taper outwardly at outwardly tapering portions (<NUM>, <NUM>). As shown, side walls (<NUM>, <NUM>) do not include any apertures or cutouts at this manufacturing stage. More specifically, <FIG> show respective top, bottom, left side, and distal end views of lower jaw blank (<NUM>) prior to any features being formed into opposing side walls (<NUM>, <NUM>). As shown, bottom wall (<NUM>) includes a proximal aperture (<NUM>) and a distal elongated aperture (<NUM>) that extend completely through inner and outer surfaces (<NUM>, <NUM>) of bottom wall (<NUM>).

As shown in the distal end view of <FIG>, side walls (<NUM>, <NUM>) extend vertically at right angles from bottom wall (<NUM>), which is horizontally oriented. However, other angles between bottom wall (<NUM>) and side walls (<NUM>, <NUM>) are also envisioned. More specifically, outwardly extending flange (<NUM>) extends from side wall (<NUM>) and includes opposing upper and lower planar surfaces (<NUM>, <NUM>) shown in <FIG>. Similarly, outwardly extending flange (<NUM>) extends from side wall (<NUM>) and includes opposing upper and lower planar surfaces (<NUM>, <NUM>). As shown in <FIG>, thickness (t) of lower jaw blank (<NUM>) is generally constant. However, thickness (t) may vary if desired. One or more stamping operations may be used to impart one or more additional features in bottom wall (<NUM>) and side walls (<NUM>, <NUM>) as will be described in greater detail below.

While not shown, lower jaw blank (<NUM>) may be initially transformed from an initial flat planar sheet into U-shaped body portion (<NUM>) and outwardly extending flanges (<NUM>, <NUM>) using one or more manufacturing processes (e.g. one or more sequential stamping operations). Instead of or in addition to one or more stamping operations, lower jaw blank (<NUM>) may be formed using additive manufacturing, selective laser melting, direct metal laser sintering, and/or metal injection molding. Certain manufacturing processes (stamping, additive manufacturing, selective laser melting, direct metal laser sintering, and/or metal injection molding) may result in looser tolerances than desired. In view of the tight tolerances desired for manufacture of instrument (<NUM>), it is desirable to refine at least certain specific portions of lower jaw blank (<NUM>) to improve the dimensional accuracy of lower jaw blank (<NUM>).

<FIG> show an exemplary lower jaw (<NUM>) after at least one manufacturing process is performed to lower jaw blank (<NUM>). As shown in the perspective views of <FIG>, outwardly extending flanges (<NUM>, <NUM>) have been removed using at least one manufacturing process (e.g. one or more stamping operations). Lower jaw (<NUM>) includes a U-shaped body portion (<NUM>) that includes a bottom wall (<NUM>) interposed between opposing side walls (<NUM>, <NUM>). The inside of U-shaped body portion (<NUM>) forms a channel configured to receive a staple cartridge. Side walls (<NUM>, <NUM>) taper outwardly at outwardly tapering portions (<NUM>, <NUM>). Additionally, bottom wall (<NUM>) includes a proximal aperture (<NUM>) and a distal elongated aperture (<NUM>) that extend completely through inner and outer surfaces (<NUM>, <NUM>) of bottom wall (<NUM>). Proximal aperture (<NUM>) and distal elongated aperture (<NUM>) are connected by a longitudinally extending channel (<NUM>).

Side walls (<NUM>, <NUM>) include one or more apertures and cutouts. As shown in <FIG> and <FIG>, side wall (<NUM>) includes a proximal aperture (<NUM>) and a distal cutout (<NUM>). Similarly, side wall (<NUM>) includes a proximal aperture (<NUM>) and a distal cutout (<NUM>). One or more manufacturing processes (e.g. one or more stamping operations) may be performed to impart proximal apertures (<NUM>, <NUM>) and distal cutouts (<NUM>, <NUM>) to the intermediate state of the lower jaw, where the intermediate state occurs at a point in time between lower jaw blank (<NUM>) and lower jaw (<NUM>)). Additionally, as shown, side walls (<NUM>, <NUM>) also include inwardly tapering portions (<NUM>, <NUM>), recessed portions (<NUM>, <NUM>), and apertures (<NUM>, <NUM>).

<FIG> shows a left side view of lower jaw (<NUM>) including proximal aperture (<NUM>) and distal cutout (<NUM>), with proximal aperture (<NUM>) and distal cutout (<NUM>) being mirror images thereof. Proximal aperture (<NUM>) is described in detail below; however, the principles and accompanying features apply equally to proximal aperture (<NUM>). <FIG> shows a detailed view of proximal aperture (<NUM>) after being formed but prior to be machined, while <FIG> shows a detailed view of proximal aperture (<NUM>) of <FIG> after having been machined. Proximal aperture (<NUM>) is generally kidney shaped. As shown in <FIG>, proximal aperture (<NUM>) has a near net shape with an initial area (A1) defined by the continuous solid line. As used herein, "near net shape" means that the initial forming operations create an intermediate (near net) shape that is very close to the final (net) shape, which reduces the need and associated cost of significant surface finishing. These initial forming operations may include, for example, stamping, additive manufacturing, selective laser melting, direct metal laser sintering, and/or metal injection molding.

As shown in <FIG>, proximal aperture (<NUM>) has a machined shape with a machined area (A2) defined by the continuous solid line, with the dashed line denoting the near net shape shown in <FIG>. As shown, only distal portions of proximal aperture (<NUM>) are machined, such that the remainder of proximal aperture (<NUM>) is not machined. As shown in <FIG>, only upper, middle, and lower distal surfaces (256a, 258a, 260a) are machined which results in upper, middle, and lower distal surfaces (256b, 258b, 260b) after the machining operation(s). As shown in <FIG>, proximal aperture (<NUM>) has a machined area (A2) that is greater than initial area (A1), since material is removed from upper, middle, and lower distal surfaces (256a, 258a, 260a) to form upper, middle, and lower distal surfaces (256b, 258b, 260b). However, it is also envisioned that the entire initial perimeter (P1) of the proximal aperture (<NUM>) may be machined if desired to produce a machined perimeter (P2). For example, this may be beneficial if tighter tolerances are required for desired operation.

<FIG> show distal cutout (<NUM>). More specifically, <FIG> shows a detailed view of distal cutout (<NUM>) after being formed but prior to be machined, while <FIG> shows a detailed view of distal cutout (<NUM>) after being machined. Similar to proximal aperture (<NUM>, <NUM>), distal cutout (<NUM>) is a mirror image of distal cutout (<NUM>). As a result, the principles and accompanying features described for distal cutout (<NUM>) apply equally to distal cutout (<NUM>). As shown in <FIG>, distal cutout (<NUM>) includes a bottom wall (262a), a proximal wall (264a), and a distal wall (266a), forming a generally rectangular shape. As shown in <FIG>, distal cutout (<NUM>) has near net shape with an obtuse interior angle (θ1). More specifically, near net shapes produce an obtuse angle between bottom and proximal walls (262a, 264a) and an obtuse angle (θ1) between bottom and distal walls (262a, 266a).

As shown in <FIG>, distal cutout (<NUM>) has a machined shape with approximately <NUM>-degree interior angles (θ2). In other words, the near net shape of distal cutout (<NUM>) with obtuse interior angles (θ1) obtained using at least one stamping process, are machined into machined shapes with approximately <NUM>-degree interior angles (θ2). More specifically, distal cutout (<NUM>) is machined to have a <NUM>-degree angle (θ2) between bottom and proximal walls (262b, 264b) and <NUM>-degree angle (θ2) between bottom and distal walls (262b, 266b). Additionally, top edges (268a, 270a) of <FIG> surrounding distal cutout (<NUM>) are machined to top edges (268b, 270b) of <FIG>. As shown, the machined shape is the finalized shape, however more manufacturing operations may be performed if desired.

<FIG> show a second exemplary lower jaw (<NUM>). Lower jaw (<NUM>) comprises a U-shaped body portion (<NUM>), a bottom wall (<NUM>), opposing side walls (<NUM>, <NUM>), a tapering portion (<NUM>), a proximal aperture (<NUM>), inner and outer surfaces (<NUM>, <NUM>) of bottom wall (<NUM>), proximal apertures (<NUM>, <NUM>), an inwardly tapering portion (<NUM>), and an aperture (<NUM>). Proximal apertures (<NUM>, <NUM>) are formed and subsequently machined using a method similar to that described with respect to proximal apertures (<NUM>, <NUM>).

As shown in <FIG>, lower jaw (<NUM>) does not include distal cutouts, similar to distal cutouts (<NUM>, <NUM>) described above with respect to lower jaw (<NUM>). However, if desired, distal cutouts may be imparted similar to distal cutouts (<NUM>, <NUM>) of lower jaw (<NUM>). As shown in <FIG>, outer surface (<NUM>) of bottom wall (<NUM>) includes a recessed portion (<NUM>) that extends longitudinally. Recessed portion (<NUM>) terminates proximally at proximal aperture (<NUM>) and distally at a distal wall (<NUM>).

Recessed portion (<NUM>) is configured to receive a lower longitudinally extending back member (<NUM>) having proximal and distal ends (<NUM>, <NUM>). Projections (<NUM>, <NUM>) of lower longitudinally extending back member (<NUM>) extend distally from distal end (<NUM>) of lower longitudinally extending back member (<NUM>). Lower longitudinally extending back member (<NUM>) is configured to provide additional support for bottom wall (<NUM>). Outer surface (<NUM>) of lower longitudinally extending back member (<NUM>) may extend flush with outer surface (<NUM>) of bottom wall (<NUM>). Lower longitudinally extending member (<NUM>) may be coupled to outer surface (<NUM>) of bottom wall (<NUM>) before, during, or after machining of the at least one feature (e.g. proximal apertures (<NUM>, <NUM>)). For example, lower longitudinally extending back member (<NUM>) may be welded to outer surface (<NUM>) of bottom wall (<NUM>).

<FIG> shows a method (<NUM>) of manufacturing lower jaw (<NUM>, <NUM>) of end effector (<NUM>) of surgical instrument (<NUM>) that includes at least three steps (<NUM>, <NUM>, <NUM>). As shown, at step (<NUM>), the method includes providing a lower jaw blank (<NUM>) that includes U-shaped body portion (<NUM>). U-shaped body portion (<NUM>) includes bottom wall (<NUM>) interposed between opposing side walls (<NUM>, <NUM>). As previously described, lower jaw blank (<NUM>) may be formed using one or more manufacturing processes (e.g. one or more sequential stamping operations performed by a stamping machine). Instead of or in addition to one or more stamping operations, lower jaw blank (<NUM>) may be formed using additive manufacturing, selective laser melting, direct metal laser sintering, and/or metal injection molding.

At step (<NUM>), the method also includes forming the at least one feature (e.g. proximal apertures (<NUM>, <NUM>, <NUM>) and/or distal cutouts (<NUM>, <NUM>)) into at least one of side walls (<NUM>, <NUM>). The feature (e.g. proximal apertures (<NUM>, <NUM>, <NUM>)) and/or distal cutouts (<NUM>, <NUM>)) has a near net shape. The feature (e.g. proximal apertures (<NUM>, <NUM>, <NUM>) and/or distal cutouts (<NUM>, <NUM>)) may be formed using a variety of manufacturing processes, (e.g. one or more sequential stamping operations performed by a stamping machine (<NUM>)). The manufacturing processes used to form the at least one feature (e.g. proximal apertures (<NUM>, <NUM>, <NUM>) and/or distal cutouts (<NUM>, <NUM>)) into at least one of side walls (<NUM>, <NUM>) may be the same or different.

At step (<NUM>), the method includes subsequently machining the feature (e.g. proximal apertures (<NUM>, <NUM>, <NUM>) and/or distal cutouts (<NUM>, <NUM>)) to have a machined shape. If two or more features are imparted, the features may be imparted simultaneously or sequentially. For example, a first feature may be formed in the first side wall through a first manufacturing process, and subsequently a second feature may be formed in the second side wall through a second manufacturing process. Non-machined portions of lower jaw (<NUM>, <NUM>) have a first surface finish and machined portions of lower jaw (<NUM>, <NUM>) have a second surface finish. The second surface finish is finer than the first surface finish. For example, the second surface finish may be substantially finer than the first surface finish. Step (<NUM>) may be performed using a variety of machining tools, for example, using a lathe (<NUM>), which may be manually operated or automated.

<FIG> shows a method (<NUM>) of manufacturing lower jaw (<NUM>, <NUM>) of end effector (<NUM>) of surgical instrument (<NUM>) that includes at least four steps (<NUM>, <NUM>, <NUM>, <NUM>). At step (<NUM>), the method includes stamping lower jaw blank (<NUM>) to include a U-shaped body portion (<NUM>). U-shaped body portion (<NUM>) of lower jaw blank (<NUM>) includes bottom wall (<NUM>) and opposing side walls (<NUM>, <NUM>). As previously described, U-shaped body portion (<NUM>) may be formed using one or more manufacturing processes (e.g. one or more sequential stamping operations performed by a stamping machine (<NUM>)). Instead of or in addition to one or more stamping operations, U-shaped body portion (<NUM>) may be formed using additive manufacturing, selective laser melting, direct metal laser sintering, and/or metal injection molding.

At step (<NUM>), the method also includes stamping proximal aperture (<NUM>, <NUM>) of side wall (<NUM>, <NUM>). Proximal aperture (<NUM>, <NUM>) has a near net shape with first area (A1). One or more sequential stamping operations may be performed by a stamping machine (<NUM>), that may be the same or different from stamping machines (<NUM>). A variety of other manufacturing processes may be used instead of, or in addition to, stamping.

At step (<NUM>), the method also includes stamping side wall (<NUM>, <NUM>) to include proximal aperture (<NUM>, <NUM>). Proximal aperture (<NUM>, <NUM>) has a near net shape with first area (A1). Stamping proximal aperture (<NUM>, <NUM>) may happen before, simultaneously with, or after, the stamping of proximal aperture (<NUM>, <NUM>). For example, a first feature (e.g. proximal aperture (<NUM>, <NUM>)) may be formed in side wall (<NUM>, <NUM>) through a first manufacturing process, and subsequently a second feature (e.g. proximal aperture (<NUM>, <NUM>)) may be formed in the side wall (<NUM>, <NUM>) through a second manufacturing process. The first and second manufacturing processes may be the same or different. One or more sequential stamping operations performed by a stamping machine (<NUM>), that may be the same or different from stamping machines (<NUM>, <NUM>). A variety of other manufacturing processes may be used instead of or in addition to stamping of proximal aperture (<NUM>, <NUM>).

At step (<NUM>), the method also includes subsequently machining proximal apertures (<NUM>, <NUM>, <NUM>, <NUM>) to have machined shapes with second areas. Second area (A2) is less than first area (A1). As shown, only distal portions (e.g. distal surfaces (256a, 258a, 260a) of proximal apertures (<NUM>, <NUM>, <NUM>, <NUM>) are machined into distal portions (e.g. distal surfaces (256b, 258b, 260b)) such that remainder of proximal apertures (<NUM>, <NUM>) are not machined. It is envisioned that the machining of proximal aperture (<NUM>) may happen before, simultaneously with, or after the machining of proximal aperture (<NUM>). Non-machined portions of lower jaw (<NUM>, <NUM>) have a first surface finish and machined portions of lower jaw (<NUM>, <NUM>) have a second surface finish. The second surface finish is finer than the first surface finish. For example, the second surface finish may be substantially finer than the first surface finish. Step (<NUM>) may be performed using a variety of machining tools, for example, using a lathe (<NUM>), which may be manually operated or automated.

While method (<NUM>) is described with respect stamping and subsequent machining of proximal apertures (<NUM>, <NUM>, <NUM>, <NUM>), these principles apply equally to distal cutouts (<NUM>, <NUM>) and other features, where improved tolerances are desired. The exemplary methods (<NUM>, <NUM>) using near net shapes reduce the need for costly machining by providing lower jaw (<NUM>, <NUM>) already having one or more features already imparted.

Claim 1:
A method (<NUM>, <NUM>) of manufacturing a jaw (<NUM>, <NUM>) of an end effector (<NUM>) of a surgical instrument (<NUM>), the method (<NUM>, <NUM>) comprising:
(a) providing (<NUM>, <NUM>) a jaw (<NUM>) that includes a U-shaped body portion (<NUM>), wherein the U-shaped body portion (<NUM>) includes a bottom wall (<NUM>) interposed between first and second opposing side walls (<NUM>, <NUM>);
(b) forming (<NUM>, <NUM>, <NUM>) at least one feature (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) into at least one of the first and second side walls (<NUM>, <NUM>), wherein the at least one feature (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) comprises a first proximal aperture (<NUM>, <NUM>) in the first side wall (<NUM>) and a second proximal aperture (<NUM>, <NUM>) in the second side wall (<NUM>) and the at least one feature has a near net shape, and
(c) subsequently (<NUM>, <NUM>) machining the at least one feature (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) to have a machined shape;
wherein only distal portions (256a, 258a, 260a) of the first and second proximal apertures (<NUM>, <NUM>, <NUM>, <NUM>) are machined such that the remainder of the first and second proximal apertures (<NUM>, <NUM>, <NUM>, <NUM>) are not machined; and
wherein non-machined portions of the jaw (<NUM>, <NUM>) have a first surface finish and machined portions of the jaw (<NUM>, <NUM>) have a second surface finish, wherein the second surface finish is finer than the first surface finish.