CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of and priority to U.S. Provisional Patent Application Serial No. 63/278,586 filed November 12, 2021, the entire disclosure of which is incorporated by reference herein.

FIELD

[0002] This disclosure relates to surgical stapling devices and, more particularly, to a surgical stapling device having a knife and a firing lockout mechanism.

BACKGROUND

[0003] Surgical stapling devices that eject staples to resect or transect tissue during surgical procedures are well known. These stapling devices are available in a variety of configurations including linear, curved, and circular, for performing open and endoscopic surgical procedures. Linear surgical stapling devices for performing open surgical procedures typically include an anvil section, a cartridge receiving section, a staple cartridge, and a firing assembly. The anvil section and the cartridge receiving section are coupled together and movable from an open position to a clamped position to clamp tissue between the staple cartridge and the anvil section. The staple cartridge is releasably secured within the cartridge receiving section, and the firing assembly is movable within the cartridge receiving section to eject the staples from the staple cartridge and to cut the tissue clamped between the staple cartridge and the anvil section.

[0004] These stapling devices often include a lockout assembly that prevents reclamping of the stapling device after the stapling device has been fired. In certain linear surgical stapling devices, the lockout assembly includes a knife guard that shields the knife and is movable after firing to a position to prevent reclamping of the stapling device. In such devices, the lockout may be susceptible to binding when staples come into contact the lockout assembly.

[0005] A continuing need exists in the art for a stapling device having a lockout assembly that is less susceptible to binding. SUMMARY

[0006] This disclosure is directed to a surgical stapling device having an anvil section, a cartridge section, a staple cartridge, a clamping lever, and a firing assembly. The anvil section is coupled to the cartridge section and is movable in relation to the cartridge section between open and clamped positions in response to operation of the clamping lever. The staple cartridge is releasably supported on the cartridge section and includes a lockout assembly and a knife assembly. The knife assembly includes a knife bar having a cutting blade for cutting tissue clamped between the anvil and cartridge sections. The lockout assembly includes a lockout member that movable from an unlocked position to a locked position and is positioned to shield the cutting blade in both positions. The lockout member is configured to prevent binding of the lockout member after the stapling device is fired to ensure movement of the lockout member from the unlocked position to the locked position. In the locked position, the lockout member prevents movement of the anvil section in relation to the cartridge section to the clamped position.

[0007] Aspects of the disclosure are directed to a stapling device stapling device including an anvil section, a cartridge section, a firing assembly, a clamp member, and a staple cartridge. The anvil section has a proximal portion, a distal portion, and spaced beams. The proximal portion of the anvil section includes a hand grip, and the distal portion of the anvil section includes an anvil plate that is supported on the spaced beams. The cartridge section includes a channel member that defines a channel having a proximal portion and a distal portion. The channel member is adapted to be coupled to the anvil section to facilitate movement of the anvil section in relation to the cartridge section between open and clamped positions. The firing assembly is supported within the proximal portion of the channel and includes a drive beam and a trigger. The clamp member is supported on the cartridge section and is movable from an unclamped position to a clamped position to move the anvil section in relation to the cartridge section from the open position to the clamped position. The staple cartridge is releasably supported within the distal portion of the channel of the channel member of the cartridge section and includes a cartridge body, staples, pushers, an actuation sled, a knife assembly, and a lockout assembly. The cartridge body has a proximal portion and a distal portion and defines a central knife slot and staple receiving pockets positioned on opposite sides of the central knife slot. Each of the staple receiving pockets receives one of the staples and one of the pushers. The actuation sled is positioned within the proximal portion of the cartridge body and is movable through the cartridge body into engagement with the pushers to eject the staples from the staple receiving pockets. The knife assembly includes a knife bar having a cutting member that includes a member body having a distal edge and a cutting blade formed on the distal edge of the member body. The cutting blade is positioned within the knife slot and has an exposed portion that extends above the cartridge body. The lockout assembly includes a lockout member that is pivotably coupled to the proximal portion of the cartridge body and is movable from an unlocked position to a locked position. The lockout member has a base portion that defines a knife slot and includes a blade guard positioned on each side of the knife slot of the base portion. The knife slot of the base portion of the lockout member receives the drive beam of the firing assembly. The blade guards are positioned and configured to shield the exposed portion of the cutting blade when the lockout member is in the unlocked position while leaving the member body of the cutting member exposed. In the locked position, the lockout member obstructs movement of the anvil section in relation to the cartridge section from the open position to the clamped position.

[0008] Other aspects of the disclosure are directed to a staple cartridge including a cartridge body, staples, pushers, an actuation sled, a knife assembly, and a lockout assembly. The cartridge body has a proximal portion and a distal portion and defines a central knife slot and staple receiving pockets positioned on opposite sides of the central knife slot. Each of the staples is received one of the staple receiving pockets of the cartridge body. Each of the pushers is received within one of the staple receiving pockets of the cartridge body and supports one of the staples. The actuation sled is positioned within the proximal portion of the cartridge body and is movable through the cartridge body into engagement with the pushers to eject the staples from the staple receiving pockets. The knife assembly includes a knife bar that has a cutting member that includes a member body having a distal edge and a cutting blade formed on the distal edge of the member body. The cutting blade is positioned within the knife slot and has an exposed portion extending above the cartridge body. The lockout assembly includes a lockout member that is pivotably coupled to the proximal portion of the cartridge body and is movable from an unlocked position to a locked position. The lockout member has a base portion that defines a knife slot and includes a blade guard positioned on each side of the knife slot. The blade guards are positioned and configured to shield the exposed portion of the cutting blade when the lockout member is in the unlocked position while leaving the member body of the cutting member exposed.

[0009] In aspects of the disclosure, the staple cartridge includes a biasing member that is positioned to urge the lockout member towards the locked position.

[0010] In some aspects of the disclosure, the lockout member includes a blocking portion having a support block formed on each side of the knife slot of the base portion, and each of the support blocks has an engagement surface that is positioned to engage one of the spaced beams of the anvil section when the lockout member is in the locked position to prevent movement of the anvil section in relation to the cartridge section from the open position to the clamped position.

[0011] In certain aspects of the disclosure, the blocking portion has a distal portion positioned over but spaced from the knife bar when the lockout member is in the unlocked position and positioned distally of the knife bar when the lockout member is in the locked position.

[0012] In aspects of the disclosure, the distal portion of the blocking portion of the lockout member has an arcuate inner surface that faces the knife bar and a linear outer surface.

[0013] In some aspects of the disclosure, the base portion of the lockout member includes pivot members that are coupled to the cartridge body to pivotably couple the lockout member to the cartridge body.

[0014] In certain aspects of the disclosure, the biasing member includes a torsion spring that is positioned about one of the pivot members.

[0015] In aspects of the disclosure, the knife assembly includes a support member that supports the knife bar.

[0016] In some aspects of the disclosure, the support member is positioned within the cartridge body proximally of the actuation sled and is movable into engagement with the actuation sled to advance the actuation sled through the cartridge body.

[0017] In certain aspects of the disclosure, the knife bar includes a hook member that is configured to be coupled to the drive beam of the firing assembly when the staple cartridge is positioned within the channel of the channel member. [0018] In aspects of the disclosure, the knife bar includes a retainer that engages the lockout member when the lockout member is in the unlocked position to retain the lockout member in the unlocked position.

[0019] Other aspects, features, and advantages will be apparent from the description, the drawings, and the claims that follow.

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Various aspects of the disclosure are described herein below with reference to the drawings, wherein:

[0021] FIG. 1 is a side perspective view of a surgical stapling device according to aspects of the disclosure in a clamped pre-fired position;

[0022] FIG. 2 is a perspective exploded view of the surgical stapling device shown in FIG. 1 ;

[0023] FIG. 3 is a side perspective view of a staple cartridge and shipping wedge of the surgical stapling device shown in FIG. 2;

[0024] FIG. 4 is an enlarged view of the indicated area of detail shown in FIG. 5;

[0025] FIG. 5 is a side perspective view of a proximal portion of the staple cartridge shown in FIG. 3;

[0026] FIG. 6 is a side perspective exploded view of the staple cartridge shown in FIG. 2;

[0027] FIG. 7 is a side perspective view of a lockout member of the staple cartridge shown in

FIG. 6;

[0028] FIG. 8 is a cross-sectional view taken along section line 8-8 of FIG. 7;

[0029] FIG. 9 is a perspective view from the proximal end of the lockout member shown in

FIG. 7;

[0030] FIG. 10 is a bottom perspective view from the distal end of the lockout member shown in FIG. 7;

[0031] FIG. 11 is a side perspective view from below of the lockout member shown in FIG. 7;

[0032] FIG. 12 is a side perspective view from above of the lockout member shown in FIG. 7;

[0033] FIG. 13 is a cross-sectional view taken through the proximal portion of a channel member and staple cartridge of the surgical stapling device shown in FIG. 2 in a pre-fired position;

[0034] FIG. 14 is a side perspective view of the stapling device shown in FIG. 1 with the anvil section separated from the cartridge section after the stapling device has been fired;

[0035] FIG. 15 is an enlarged view of the indicated area of detail shown in FIG. 14; [0036] FIG. 16 is a side perspective view of the surgical stapling device shown in FIG. 1 with the cartridge section having a spent or fired staple cartridge as an anvil section is attempted to be coupled to the cartridge section;

[0037] FIG. 17 is a cross-sectional view taken along section line 17-17 of FIG. 16; and

[0038] FIG. 18 is a side perspective, cutaway view of the central portion of the stapling device shown in FIG. 16.

DETAILED DESCRIPTION

[0039] The disclosed surgical device will now be described in detail with reference to the drawings in which like reference numerals designate identical or corresponding elements in each of the several views. However, it is to be understood that aspects of the disclosure are merely exemplary of the disclosure and may be embodied in various forms. Well-known functions or constructions are not described in detail to avoid obscuring the disclosure in unnecessary detail. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the disclosure in virtually any appropriately detailed structure.

[0040] In this description, the term “proximal” is used generally to refer to that portion of the device that is closer to a clinician, while the term “distal” is used generally to refer to that portion of the device that is farther from the clinician. In addition, the term “clinician” is used generally to refer to medical personnel including doctors, nurses, and support personnel. Further, directional terms such as “front”, “rear”, “upper”, “lower”, “top”, “bottom”, and similar terms are used to assist in understanding the description and are not intended to limit the disclosure.

[0041] This disclosure is directed to a surgical stapling device that includes an anvil section, a cartridge section, a staple cartridge, a clamping lever, and a firing assembly. The staple cartridge is releasably supported on the cartridge section and includes a lockout assembly and a knife assembly. The anvil and cartridge sections are coupled together and movable from an open position to a clamped position in response to movement of the clamping lever from an unclamped position to a clamped position. The firing assembly is coupled to the knife assembly when the staple cartridge is received within the cartridge section and is movable between a retracted position and an advanced position to eject staples from the staple cartridge and to cut tissue clamped between the staple cartridge and the anvil section. The lockout assembly is supported on the staple cartridge and is movable from an unlocked position to a locked position to prevent reclamping of the anvil and cartridge sections after the stapling device has been fired. The lockout assembly includes a lockout member that is configured to prevent binding of the lockout member to ensure movement of the lockout member from the unlocked position to the locked position after the stapling device is fired and the anvil and cartridge sections are moved to the unclamped position.

[0042] FIG. 1 and 2 illustrate a surgical stapling device shown generally as stapling device 10. The stapling device 10 defines a longitudinal axis “X” (FIG. 1) and includes an anvil section 12, a cartridge section 14, a clamping lever 16, a staple cartridge 18, a shipping wedge 19 (FIG. 2), and a firing assembly 20. The cartridge section 14 includes a channel member 22 that has a proximal portion 24 and a distal portion 26 and defines a channel 22a that extends through the proximal and distal portions 24 and 26. The proximal portion 24 of the channel member 22 receives the firing assembly 20, and the distal portion 26 of the channel 22a receives the staple cartridge 18 in a manner to facilitate replacement of the staple cartridge 18 and reuse of the stapling device 10. The proximal portion 24 of the channel member 22 includes arms 27 that extend upwardly towards the anvil section 12 and define open ended recesses 27a. A central portion of the channel member 22 includes upwardly extending flanges 29 that define circular cavities 29a.

[0043] The anvil section 12 includes spaced beams 12a and 12b (FIG. 18), an anvil hand grip 28 supported on a proximal portion of the beams 12a and 12b, and an anvil plate 30 supported on a distal portion of the beams 12a and 12b. The anvil plate 30 defines a knife slot 30a and faces the cartridge section 14 when the anvil section 12 and the cartridge section 14 are coupled together. The anvil section 12 also includes protrusions 34 that are centrally located on the anvil section 12 and pivot members 36 that are located on a proximal portion of the anvil section 12. The pivot members 36 are received within the recesses 27a of the arms 27 of the channel member 22 to pivotally support the proximal portion of the anvil section 12 on the proximal portion of the cartridge section 14 and facilitate movement of the anvil section 12 in relation to the cartridge section between open and clamped positions. The protrusions 34 are received within the circular cavities 29a of the flanges 29 of the channel member 22 when the anvil section 12 is coupled to the cartridge section 14. In aspects of the disclosure, the pivot members 36 have a tear-shaped configuration although other configurations are envisioned. In the clamped position of the anvil and cartridge sections 12 and 14, the anvil plate 30 is in juxtaposed relation to the staple cartridge 18.

[0044] The clamping lever 16 is pivotally supported on a proximal portion of the cartridge body 14 and is movable between an unclamped position and a clamped position. The clamping lever 16 includes centrally located flanges 40 that are spaced from each other and positioned on opposite sides of the cartridge section 14. Each of the spaced flanges 40 defines a recess 41 that receives one of the protrusions 34 of the anvil section 12 when the clamp lever 16 is pivoted from an unclamped position to a clamped position to move the protrusions 34 of the anvil section 12 further into the cavities 29a of the flanges 29 of the channel member 22 to move the anvil section 12 into juxtaposed alignment with the cartridge section 14 and to clamp tissue between the anvil plate 30 and the staple cartridge 18.

[0045] FIG. 2 illustrates the firing assembly 20 which includes a trigger 42 and a longitudinally extending drive beam 44. The trigger 42 is rotatably supported on a proximal portion of the drive beam 44 and includes a thumb engagement member 42a positioned on each side of the stapling device 10. The thumb engagement member 42a is rotatable between two positions to facilitate actuation of the stapling device 10 from both sides of the stapling device 10. The pivotable trigger 42 is coupled to a proximal portion of the drive beam 44 and is movable longitudinally within the proximal portion 24 of the channel 22a of the channel member 22 of the cartridge section 14 to advance the drive beam 44 from a retracted position to an advanced position. The drive beam 44 includes a distal portion that is adapted to engage a knife assembly 50 (FIG. 4) of the staple cartridge 18 when the staple cartridge 18 is received within the distal portion 26 of the channel member 22. In aspects of the disclosure, the distal portion of the drive beam 44 includes a hook-shaped portion 52 that extends upwardly towards the anvil section 12 and defines a slot 52a having an open upper end as viewed in FIG. 2. In aspects of the disclosure, the drive beam 44 includes a longitudinally extending rib 44a formed along a lower end of the drive beam 44. The rib 44b adds rigidity to the drive beam 44 to prevent buckling of the drive beam 44 during firing of the stapling device 10. In certain aspects of the disclosure, the rib 44a can be formed by rolling the lower end of the drive beam 44 upwardly. Alternately, the rib 44a can be formed on or applied to drive beam 44 using a variety of different techniques.

[0046] A lock member 58 (FIG. 2) is supported within a central portion of the channel 22a of the channel member 22 of the cartridge section 14. The lock member 58 defines a slot 60 (FIG. 2) that receives the drive beam 44 to facilitate movement of the drive beam 44 between the retracted and advanced positions. The lock member 58 is pivotable between a locked position in which the lock member 58 is engaged with the drive beam 44 and an unlocked position in which the lock member 58 is positioned to allow the drive beam 44 to move through the slot 60. In aspects of the disclosure, the lock member 58 is pivotable from the locked position to the unlocked position in response to placement of a staple cartridge 18 within the channel 22a in the distal portion 26 of the channel member 22 of the cartridge section. In some aspects of the disclosure, a biasing member (not shown) is engaged with the lock member 58 to urge the lock member 58 towards the locked position.

[0047] FIGS. 2-4 illustrate the staple cartridge 18 which includes a cartridge body 66, the knife assembly 50, an actuation sled 68, pushers 70, staples 72, and a lockout assembly 74. The cartridge body 66 includes a tissue contact surface 66a that defines a centrally located knife slot 76 and staple receiving pockets 78 that are positioned on opposite sides of the knife slot 76. The knife slot 76 extends through the staple cartridge 18 from a proximal end of the staple cartridge 18 to a position adjacent a distal end of the staple cartridge 18. The knife assembly 50 is movable through the knife slot 76 from a retracted position to an advanced position when the drive bar 44 (FIG. 2) of the firing assembly 20 is advanced from a retracted position to an advanced position to cut tissue clamped between the anvil plate 30 and the staple cartridge 18.

[0048] Each of the staple receiving pockets 78 receive one of the staples 72 and one of the pushers 70. In aspects of the disclosure, the staple receiving pockets 78 are aligned in two or more rows on the opposite sides of the knife slot 76, e.g., three. The actuation sled 68 is supported within the cartridge body 66 and includes a central rib 80 (FIG. 4) and cam surfaces 82 positioned on opposite sides of the central rib 80. The central rib 80 is received in the knife slot 76 of the cartridge body 66 and the cam surfaces 82 are aligned with the pushers 70. The actuation sled 68 is movable from a retracted position to an advanced position within the cartridge body 66 in response to movement drive beam from its retracted position to its distal position into engagement with the pushers 70 to eject the staples 72 from the staple receiving slots 78 of the cartridge body.

[0049] The staple cartridge 18 also includes a staple guard 80 that is secured to a lower portion of the cartridge body 66 to retain the staples 72 and the pushers 70 within the staple receiving pockets 78 of the cartridge body 66. In aspects of the disclosure, the staple guard 80 is secured to the cartridge body 66 with a connector 82 that includes spaced flexible detents 82a. the detents 82a extend through cutouts 84 defined in the staple guard 80 and slots 86 formed in a distal portion of the cartridge body 66 to secure the staple guard 80 to the cartridge body 66 in snap-fit fashion.

[0050] The shipping wedge 19 (FIG. 3) is secured to the tissue contact surface 66a (FIG. 4) of the cartridge body 66 and is provided to retain the knife assembly 50 in a retracted position and retain the staples 72 within the cartridge body 66. In aspects of the disclosure, the shipping wedge 19 includes fins 19a (FIG. 2) that are received in the knife slot 76 of the cartridge body 66 to secure the shipping wedge 19 to the cartridge body 66. When the shipping wedge 19 is secured to the cartridge body 66, the shipping wedge 19 covers the staple receiving slots 78. The shipping wedge 19 includes a stop member 19b (FIG. 2) that is positioned to prevent advancement of the knife assembly 74 until the shipping wedge 19 is removed from the cartridge body 66. The shipping wedge 19 includes lateral extensions 19c positioned on a distal portion of the shipping wedge 19 and serrations 19d positioned on a proximal portion of the shipping wedge 19 that can be grasped by a clinician to remove the shipping wedge 19 from the staple cartridge 18.

[0051] The knife assembly 50 includes a support member 90 and a knife bar 92. The knife bar 92 includes base 94, a cutting member 96 that extends upwardly from the base 94, a hook member 98, and a retainer 100. The knife bar 92 is secured to the support member 90 such that the knife assembly 50 is movable as a single construct through the cartridge body 66. The cutting member 96 includes a member body 96b that extends upwardly from the base 94 and has a cutting blade 96a that is formed on a distal edge of the member body 96. In aspects of the disclosure, the cutting member 96 extends from the base at an angle such that the uppermost end of the cutting blade 96a is position distally of the lowermost end of the cutting blade 96a. The hook member 98 of the knife bar 92 is formed on a proximal portion of the knife bar 92 and extends downwardly. The hook member 98 is received within the slot 52a (FIG. 2) defined by the hook-shaped portion 52 of the drive beam 44 when the staple cartridge 18 is received in the distal portion 26 of the cartridge section 14. The retainer 100 of the knife bar 92 is positioned on a central portion of the knife bar 92 and extends proximally to define a retaining slot 100a that receives a portion of the lockout assembly 74 to retain the lockout assembly 74 in a locked position as described in further detail below. For a more detailed description of the components of the stapling device described above, see, e.g., U.S. Patent No. 8,505,801 to Ehrenfels et al.

[0052] FIGS. 4 -12 illustrate the lockout assembly 74 which includes a lockout member 102 and a biasing member 104. The lockout member 102 has a base 108 and a blocking portion 110 that is secured to a central portion of the base 108. The base 108 defines a longitudinal slot 114 (FIG. 9) and includes side walls 108a, an upper surface 108b, pivot members 116, laterally extending wings 118, and cutting blade guards 120. The pivot members 116 are formed on a distal portion of the base 108 and extend outwardly from the side walls 108a. The pivot members 116 are received in openings 122 defined in the proximal portion of the cartridge body 66 of the staple cartridge 18 to pivotally couple the lockout member 102 to the cartridge body 66 such that the lockout member 102 is movable from an unlocked position to a locked position.

[0053] The laterally extending wings 118 are formed on a proximal portion of the base 108 of the lockout member 102 and extend outwardly of the side walls 108a of the base 108 of the lockout member 102. When the lockout member 102 is in the unlocked position, the wings 118 rest on the beams 12a and 12b of the anvil section 12 to minimize deflection of the lockout member 102.

[0054] In aspects of the disclosure, the proximal portion of the base 108 of the lockout member 102 includes support blocks 119 that are symmetrically positioned on opposite sides of the longitudinal slot 114 on the proximal end of the base 108 of the lockout member 102. The support blocks 119 include engagement surfaces 119a that are substantially vertically oriented and face proximally when the lockout member 102 is in the unlocked position and are substantially horizontally oriented and face the anvil section 12 when the lockout member 102 is in the locked position (FIG. 18). The support blocks 119 include engagement surfaces 119a that engage the beams 12a and 12b of the anvil section when the lockout member 102 is in the locked position and the anvil section 12 is coupled to a cartridge section 14 having a spent or fired staple cartridge 18 to prevent reclamping of the stapling device 10. The increased surface area provided by the engagement surfaces 119a minimizes deflection of the lockout member 102 when the lockout member 102 is in the locked position and an attempt is made to attach an anvil section 12 to the cartridge section 14.

[0055] The cutting blade guards 120 are formed on opposite sides of the longitudinal slot 114 on the distal portion of the base 108 of the lockout member 102. In aspects of the disclosure, the cutting blade guards 120 are triangular and have proximal walls 120a that extend in the direction of the cutting blade 96a of the cutting member 96 of the knife bar 92. The cutting blade guards 120 are positioned on opposite sides of the cutting blade 96a to shield the cutting blade 96a. In aspects of the disclosure, the cutting blade guards 120 or positioned distally of the member body 96b of the cutting member 96 to minimize any likelihood of staples becoming wedged between the cutting blade guards 120 and the cutting member 96 of the knife bar 92.

[0056] The blocking portion 110 includes a body 124 having a proximal portion 124a, a distal portion 124b, and a central portion 124c (FIG. 7). The central portion 124c (FIG. 7) is coupled to or integrally formed with the base 108 of the lockout member 102. The distal portion 124b of the blocking portion 110 has an arcuate inner surface 125a and a linear outer surface 125b. The arcuate inner surface 125a has a triangular configuration and includes a central ridge 125 c and angled walls 125d that extend outwardly from the central ridge 125 c. The distal portion 124b of the blocking portion 110 and extends over but is spaced from the cutting member 96 of the (FIG. 6) when the knife bar 92 when the lockout member 102 is in the unlocked position. The proximal portion 124a of the blocking portion 110 of the lockout member 102 has a distal extension 126 that defines a cavity 126a that receives the retainer 100 of the knife bar 92 when the knife bar 92 is in its retracted position. Receipt of the retainer 100 within the cavity 126a of the lockout member 102 retains the lockout member 102 in the unlocked position.

[0057] The biasing member 104 of the lockout assembly 74 is positioned to urge the lockout member 102 towards the locked position. In aspects of the disclosure, the biasing member 104 includes a torsion spring that is positioned about one (or both) of the pivot membersl l6 of the lockout member 102 to urge the lockout member 102 towards the locked position. Alternately, it is envisioned that the biasing member 104 may have a variety of configurations.

[0058] FIG. 13 illustrates the proximal portion of the cartridge assembly 14 in a pre-fired condition with the firing assembly 20 and the knife assembly 50 in retracted positions. In the prefired condition, the retainer 100 of the knife bar 92 is received within the cavity 126a of the blocking portion 110 of the lockout member 102 to retain the lockout member 102 in the unlocked position. In the unlocked position, the upper portion of the cutting blade 96a is shielded by the cutting blade guards 120 and the lower position of the cutting blade 96a is positioned within the longitudinal slot 114 of the lockout member 102. The distal portion 124b of the blocking portion 110 of the lockout member 102 is positioned over a portion of the member body 96b of the cutting member 96 when the lockout member 102 is in the unlocked position.

[0059] When the stapling device 10 (FIG. 1) is fired by pressing on one of the thumb engagement members 42a of the pivotable trigger 42 to move the firing assembly 20 and the knife assembly 50 to their advanced positions, the retainer 100 of the knife bar 92 is removed from the cavity 126 of the lockout member 102 to release the lockout member 102. When the lockout member 102 is released, the biasing member 104 of the lockout assembly 74 rotates the lockout member 102 in a counterclockwise direction as indicated by arrow “A” in FIG. 15 towards the locked position. In the locked position, the distal portion 124b of the blocking portion 110 of the lockout member 102 extends downwardly from above the knife assembly 50 to a position in front or distally of the cutting blade 96a of the knife bar 92 of the knife assembly 50 to shield the cutting blade 96a of the knife bar 92. It is noted that movement of the lockout member 102 from the unlocked position to the locked position is obstructed by the anvil section 12 when the stapling device 10 is in the clamped position. Thus, the lockout member 102 will not move to the locked position until the stapling device 10 is unclamped, i.e., the clamping lever 16 is moved to the unclamped position to space the anvil section 12 from the cartridge section 14.

[0060] When the stapling device 10 (FIG. 1) is fired and the knife bar 92 is moved to its advanced position, the actuation sled 68 (FIG. 13) is engaged by the support member 90 (FIG. 4) of the knife assembly 50 and advanced through the cartridge body 66 into engagement with the pushers 70 to eject the staples 72 (FIG. 4) from the cartridge body 66. As the knife bar 92 of the knife assembly 50 moves through the knife slot 76 of the cartridge body 66, the cutting blade 96a of the cutting member 96, which projects above the cartridge body 66, cuts tissue clamped between the anvil section 12 and the cartridge section 14.

[0061] After the knife assembly 50 reaches its advanced position, the firing assembly 20 is returned to its retracted position by pushing or pulling the pivotable trigger 42 in a proximal direction. It is noted that the actuation sled 68 is not coupled to the knife assembly 50 and as such will remain in the distal portion of the cartridge body 66 when the firing assembly 20 and knife assembly 50 are returned to their retracted positions. When the knife assembly 50 reaches its retracted position, the retainer 100 of the knife bar 92 is no longer aligned with the cavity 126 of the lockout member 102 which has pivoted towards the locked position. As such, the lockout member 102 can rotate to its locked position when the stapling device 10 is moved to the unclamped position. As illustrated in FIG. 13, the arcuate surface 125a of the blocking portion 110 of the lockout member 102 is spaced proximally of the cutting member 96 when the lockout member 102 is in its unlocked position. The lockout member 102 will not move to the locked position after the stapling device 10 is fired until the anvil section 12 is spaced from the cartridge section 14 a sufficient distance from the cartridge section 14 to allow the lockout member to pivot. It is noted that the shape of the arcuate surface 125a of the lockout member 102 including the angled walls 125d directs staples that may be positioned between the cutting member 96 and the arcuate surface 125a outwardly of the arcuate surface 125a to prevent the staples from becoming trapped between the lockout member 102 and the cutting member 96 which may obstruct movement of the lockout member 102 from the unlocked position to the locked position. [0062] FIGS. 14 and 15 illustrate the stapling device 10 with the anvil section 12 separated from the cartridge section 14 after the stapling device 10 has been fired and the firing assembly 20 and the knife assembly 50 are returned to their retracted positions. Separation of the anvil section 12 from the cartridge section 14 allows the lockout member to rotate from the unlocked position towards the locked position and is accomplished by moving the clamping lever 16 in the direction indicated by arrow “B” in FIG. 14 to the unclamped position as is known in the art. When the lockout member 102 is in the locked position, the proximal portion 124a of the blocking portion 110 of the lockout member 102 extends upwardly from the proximal end of the staple cartridge 18 and the distal portion 124b of the blocking portion 110 of the lockout member 102 extends downwardly to a position in front of an exposed portion of the cutting blade 96a (FIG. 17).

[0063] FIGS. 16-18 illustrate the stapling device 10 as the anvil section 12 is attempted to be coupled to a cartridge section 14 having a spent or fired staple cartridge 18. As described above, after the anvil section 12 is separated from the cartridge section 14 and the lockout member 102 is pivoted to the locked position, the proximal portion 124a of the lockout member 102 projects upwardly from the cartridge body 66 of the staple cartridge 18. When an anvil section 12 is coupled to a cartridge section 14 having a spent staple cartridge 18, the proximal portion of the blocking member 110 of the locking member 102 is received between the spaced beams 12a and 12b of the anvil section 12 (FIG. 18) and the engagement surfaces 119a of the support blocks 119 of the lockout member 102 engage the beams 12a and 12b to prevent reclamping of the stapling device 10. In some aspects of the disclosure, the proximal portion 124a of the blocking member 110 of the lockout member 102 defines an abutment surface 150 that engages an inner surface 152 (FIG. 17) of the anvil section 12 to assist in preventing approximation of the anvil section 12 with the cartridge section 14.

[0064] Persons skilled in the art will understand that the devices and methods specifically described herein and illustrated in the accompanying drawings are non-limiting exemplary embodiments. It is envisioned that the elements and features illustrated or described in connection with one exemplary embodiment may be combined with the elements and features of another without departing from the scope of the present disclosure. As well, one skilled in the art will appreciate further features and advantages of the disclosure based on the above-described embodiments. Accordingly, the disclosure is not to be limited by what has been particularly shown and described, except as indicated by the appended claims.