WO2023167993A1

WO2023167993A1 - Advancing a toothed rack of a surgical handle assembly

Info

Publication number: WO2023167993A1
Application number: PCT/US2023/014366
Authority: WO
Inventors: David Thomas MOY JR.; Andrew MARECKI; Leon Amariglio
Original assignee: Lexington Medical, Inc.
Priority date: 2022-03-04
Filing date: 2023-03-02
Publication date: 2023-09-07

Abstract

The present disclosure includes apparatuses for a surgical handle assembly. An example apparatus includes a toothed rack, a movable handle member, a driving pawl configured to engage the toothed rack and advance the toothed rack in a linear distal direction in response to a movable handle member advancing in a proximal direction and a latch configured to engage the toothed rack and advance the toothed rack in a linear proximal direction in response to the movable handle member advancing in a distal direction. The toothed rack comprises a recessed portion that the latch is configured to contact, which causes the latch to rotate away from the toothed rack.

Description

ADVANCING A TOOTHED RACK OF A SURGICAL HANDLE ASSEMBLY

Technical Field

[0001] The present disclosure relates generally to a surgical handle assembly, and more particularly, to advancing a toothed rack of a surgical handle assembly.

Background

[0002] A surgical handle assembly can be used in a number of surgical devices. One example includes use as a surgical stapler. A surgical stapler is a fastening device used to clamp tissue between opposing jaw structures to join tissue using surgical fasteners. Surgical staplers can include two elongated members used to clamp the tissue. One of the elongated members can include one or more reloadable cartridges and the other elongated member can include an anvil that can be used to form a staple when driven from the reloadable cartridge. A surgical stapler can receive one or more reloadable cartridges. An example of reloadable cartridges can include having rows of staples having a linear length. A row of staples can have a linear length between 30mm and 60mm, for example. A staple can be ejected by actuation of a movable handle member that is a part of the surgical handle assembly of the surgical stapler.

Brief Description of the Drawings

[0003] Figure 1A is a schematic diagram of a surgical stapling apparatus including a surgical handle assembly and a reloadable cartridge assembly in an unclamped position in accordance with a number of embodiments of the present disclosure.

[0004] Figure IB is a schematic diagram of a surgical stapling apparatus including a surgical handle assembly and a reloadable cartridge assembly in a clamped position in accordance with a number of embodiments of the present disclosure. [0005] Figure 2A is a schematic diagram of a surgical handle assembly in an unclamped position including a movable handle member, a button, a toothed rack, a driving pawl, a latch, a disengagement mechanism, and a safety latch in accordance with a number of embodiments of the present disclosure.

[0006] Figure 2B is a schematic diagram of a surgical handle assembly in a clamped position including a movable handle member, a button, a toothed rack, a driving pawl, a latch, a disengagement mechanism, and a safety latch in accordance with a number of embodiments of the present disclosure.

[0007] Figure 2C is a schematic diagram of a surgical handle assembly in a clamped position including a movable handle member, a button, a toothed rack, a driving pawl, a latch, a disengagement mechanism, and a safety latch in accordance with a number of embodiments of the present disclosure.

[0008] Figure 2D is a schematic diagram of a surgical handle assembly in an unclamped position including a movable handle member, a button, a toothed rack, a driving pawl, a latch, a disengagement mechanism, and a safety in accordance with a number of embodiments of the present disclosure.

[0009] Figure 2E is a schematic diagram of a surgical handle assembly in an unclamped position including a movable handle member, a button, a toothed rack, a driving pawl, a latch, a disengagement mechanism, and a safety in accordance with a number of embodiments of the present disclosure.

[0010] Figure 2F is a schematic diagram of a surgical handle assembly in an unclamped position including a movable handle member, a button, a toothed rack, a driving pawl, a latch, a disengagement mechanism, and a safety in accordance with a number of embodiments of the present disclosure.

[0011] Figure 2G is a schematic diagram of a surgical handle assembly in an unclamped position including a movable handle member, a button, a toothed rack, a driving pawl, a latch, a disengagement mechanism, and a safety latch in accordance with a number of embodiments of the present disclosure.

[0012] Figure 2H is a schematic diagram of a surgical handle assembly in a clamped position including a movable handle member, a button, a toothed rack, a driving pawl, a latch, a disengagement mechanism, and a safety latch in accordance with a number of embodiments of the present disclosure.

[0013] Figure 3 is a schematic diagram of a safety latch, a button, and a disengagement mechanism in accordance with a number of embodiments of the present disclosure.

[0014] Figure 4A is a schematic diagram of a toothed rack in accordance with a number of embodiments of the present disclosure.

[0015] Figure 4B is a schematic diagram of a toothed rack in accordance with a number of embodiments of the present disclosure.

Detailed Description

[0016] The present disclosure includes apparatuses for a surgical handle assembly. An example apparatus includes a toothed rack, a movable handle member, a driving pawl configured to engage the toothed rack and advance the toothed rack in a linear distal direction in response to a movable handle member advancing in a proximal direction and a latch configured to engage the toothed rack and advance the toothed rack in a linear proximal direction in response to the movable handle member advancing in a distal direction.

[0017] Use of the surgical handle assembly with a surgical stapler coupled to a reloadable cartridge can advance the reloadable cartridge to a clamped position in response to the driving pawl advancing the toothed rack in the linear distal direction and the reloadable cartridge can advance to an unclamped position in response to the latch advancing the toothed rack in the linear proximal direction. [0018] For example, a user can move the movable handle member from a most distal position to a most proximal position. This movement can cause the driving pawl to engage the toothed rack, drive it distally to cause the elongated members of the reloadable cartridge assembly to clamp and can cause the latch to enter a slot in the toothed rack. While the toothed rack is moving distally, a safety latch can move downward and upward in response to the movement of the toothed rack and the latch can move into engagement with the toothed rack such that the toothed rack cannot be moved distally either with the movable handle member or manually by the user using retract grips. At this stage, the user can either push a button such that staples can be delivered or release the movable handle member to cause the elongated members of the reloadable cartridge assembly to unclamp. [0019] If the user does not push the button, but instead releases the movable handle member, the movable handle member can move in a distal direction and stop at a position between the most distal position and the most proximal position. In response to the movable handle member moving in the distal direction, the latch can engage the toothed rack and can drive the toothed rack in the linear proximal direction causing the elongated members of the reloadable cartridge assembly to unclamp.

[0020] In some examples, the user can move the movable handle member from the position between the most distal position and the most proximal position to the most proximal position. The elongated members of the reloadable cartridge assembly can clamp in response to the user moving the movable handle member from the position between the most distal position and the most proximal position to the most proximal position. Alternatively, the user can move the movable handle member from the position between the most distal position and the most proximal position to the distal most position and then, upon moving the movable handle member in the proximal direction, clamp the elongated members of the reloadable cartridge assembly.

[0021] In a number of embodiments, the surgical handle assembly with the surgical stapler coupled to the reloadable cartridge can deploy a number of staples. The reloadable cartridge can deploy the number of staples in response to a user pressing the button and moving the movable handle member in the proximal direction. In some examples, the movable handle member can be in the most proximal position or a position between the most proximal position and the most distal position when the button is pressed by the user.

[0022] The button can include a first slanted surface. When the button is pressed and the button is in a pressed position, the first slanted surface of the button can cause a safety latch to move in a downward direction. Once the safety latch is in a lowered position, the safety latch can no longer engage the toothed rack to prevent the toothed rack from moving further in the linear distal direction such that the staples can be delivered.

[0023] The button can also include a second slanted surface. When the button is pressed and the button is in the pressed position the second slanted surface of the button can contact a disengagement mechanism and cause the disengagement mechanism to move in a downward direction. As the disengagement mechanism moves downward, it can contact the driving pawl and move the driving pawl and latch in a downward direction to prevent the driving pawl and the latch from engaging the toothed rack.

[0024] In a number of embodiments, the movable handle member can be coupled to a spring. The spring can bias the movable handle member to the most proximal position. In response to the disengagement mechanism preventing the latch from engaging the toothed rack, the spring can bias the movable handle member to the most distal position without advancing the toothed rack in the linear proximal direction. Without advancing the toothed rack in the linear proximal direction, the reloadable cartridge can stay in the clamped position.

[0025] A user can advance the movable handle member from the most distal position to the most proximal position. The driving pawl can reengage with the toothed rack and advance the toothed rack in a linear distal direction in response to the movable handle member advancing in the proximal direction. The safety latch, in the lowered position, can no longer engage the toothed rack to prevent the toothed rack from moving further in the linear distal direction such that the staples can be delivered.

[0026] When the user has finished delivering staples, the user can manually move the toothed rack in the linear proximal direction. In some examples, the user can manually move the toothed rack in the linear proximal direction by engaging retract grips on both sides of the surgical handle assembly and pulling the retract grips in the linear proximal direction to cause the toothed rack, the button, the safety latch, the disengagement mechanism, the driving pawl, and the latch to return to a start position. [0027] In a number of embodiments, the surgical handle can be constructed in accordance with US 10,433,842, which is incorporated herein by reference and shows, among many embodiments, a switch configured to provide two or more modes of operation for the movable handle member.

[0028] In the following detailed description of the present disclosure, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration how one or more embodiments of the disclosure may be practiced. These embodiments are described in sufficient detail to enable those of ordinary skill in the art to practice the embodiments of this disclosure, and it is to be understood that other embodiments may be utilized and that process, electrical, and structural changes may be made without departing from the scope of the present disclosure.

[0029] As used herein, designators such as “X”, “Y”, “N”, “M”, etc., particularly with respect to reference numerals in the drawings, indicate that a number of the particular feature so designated can be included. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used herein, the singular forms “a”, “an”, and “the” can include both singular and plural referents, unless the context clearly dictates otherwise. In addition, “a number of’, “at least one”, and “one or more” (e.g., a number of pivot points) can refer to one or more pivot points, whereas a “plurality of’ is intended to refer to more than one of such things. Furthermore, the words “can” and “may” are used throughout this application in a permissive sense (i.e., having the potential to, being able to), not in a mandatory sense (i.e., must). The term “include,” and derivations thereof, means “including, but not limited to”. The terms “coupled” and “coupling” mean to be directly or indirectly connected physically or for access to and movement of the movable handle member, as appropriate to the context.

[0030] The figures herein follow a numbering convention in which the first digit or digits correspond to the figure number and the remaining digits identify an element or component in the figure. Similar elements or components between different figures may be identified by the use of similar digits. For example, 106 may reference element “6” in Figure 1 , and a similar element may be referenced as 206 in Figure 2A. As will be appreciated, elements shown in the various embodiments herein can be added, exchanged, and/or eliminated so as to provide a number of additional embodiments of the present disclosure. In addition, the proportion and/or the relative scale of the elements provided in the figures are intended to illustrate certain embodiments of the present disclosure and should not be taken in a limiting sense.

[0031] Figure 1A is a schematic diagram of a surgical stapling apparatus 100 including a surgical handle assembly 102 and a reloadable cartridge assembly in an unclamped position in accordance with a number of embodiments of the present disclosure. In the example, the surgical stapling apparatus 100 can include a surgical handle assembly 102 and a reloadable cartridge assembly 103.

[0032] As shown in the example of Figure 1A, the reloadable cartridge assembly 103, e.g. a disposable loading unit, can be releasably secured to a distal end of an elongated body of the surgical handle assembly 102. In this example, the reloadable cartridge assembly 103 can include a first elongated member 107 and a second elongated member 109. The reloadable cartridge assembly 103 can be in a clamped position when the first elongated member 107 and the second elongated member 109 are clamping tissue and/or contacting each other. The reloadable cartridge assembly 103 can be in an unclamped position when the first elongated member 107 and the second elongated member 109 are not clamping tissue and/or are not in contact with each other.

[0033] In a number of embodiments, one of the elongated members can house one or more staple cartridges. The other elongated member can have an anvil that can be used to form a staple when driven from the staple cartridge. As mentioned, a surgical stapling apparatus 100 can receive reloadable cartridge assemblies having rows of staples. In a number of embodiments, third party reloadable cartridge and/or reloadable cartridge assemblies may be used with the surgical handle assembly 102 and embodiments of surgical handle assembly 102 may be configured to receive the same. [0034] The surgical handle assembly 102 coupled to the reloadable cartridge assembly 103 can advance the reloadable cartridge assembly 103 to the clamped position in response to the user actuating the movable handle member 104 of the surgical handle assembly 102 in a proximal direction. The user can also advance the reloadable cartridge assembly 103 to the unclamped position in response to the user actuating the movable handle member 104 in a distal direction.

[0035] In a number of embodiments, the surgical handle assembly 102 coupled to the reloadable cartridge assembly 103 can deploy a number of staples. The reloadable cartridge assembly 103 can deploy the number of staples in response to the user pressing a button 106 and moving the movable handle member 104 to the most proximal position. The button 106 can be pushed from either the right-hand side or the left-hand side of the surgical handle assembly 102. The movable handle member 104 can be in the most proximal position when the movable handle member 104 cannot move further in the proximal direction.

[0036] When the button 106 is pressed the reloadable cartridge assembly 103 is no longer prevented from delivering the number of staples. Once the button 106 is in the pressed position the number of staples can be ejected in response to the user actuating the movable handle member 104 in the proximal direction.

[0037] When the button 106 is pressed the movable handle member 104 is free to move to the most distal position. The movable handle member 104 is in the most distal position when the movable handle member 104 cannot move further in the distal direction. When the button 106 is pressed it also allows the reloadable cartridge assembly 103 to stay in the clamped position even when the movable handle member 104 moves to the most distal position.

[0038] A user can advance the movable handle member 104 from the most distal position to the most proximal position. Since the user has pressed the button 106 and the reloadable cartridge assembly 103 is no longer prevented from delivering the number of staples, the number of staples can be delivered in response to the user advancing the movable handle member 104 in the proximal direction.

[0039] When the user has finished delivering staples, the user can return the surgical handle assembly 102 and the reloadable cartridge assembly 103 to a start position. Tn the start position, the button 106 can be in an unpressed position, the movable handle member 104 can be in the most distal position, and the reloadable cartridge assembly 103 can be in an unclamped position. The user can return the surgical handle assembly 102 and the reloadable cartridge assembly 103 to the start position by engaging retract grips 105 on both sides of the surgical handle assembly 102 and pulling the retract grips 105 in the linear proximal direction. In some examples, the retract grips 105 can be used in response to the surgical stapling apparatus 100 failing to unclamp.

[0040] The surgical handle assembly 102 is described with the surgical stapling apparatus 100 example throughout the present disclosure for ease of understanding and illustration. However, embodiments are not limited to use with a surgical stapling apparatus 100.

[0041] Figure IB is a schematic diagram of a surgical stapling apparatus 100 including a surgical handle assembly 102 and a reloadable cartridge assembly 103 in a clamped position in accordance with a number of embodiments of the present disclosure.

[0042] As shown in the example of Figure IB, the reloadable cartridge assembly 103, e.g. a disposable loading unit, can be releasably secured to a distal end of an elongated body of the surgical handle assembly 102. In this example, the reloadable cartridge assembly 103 can include a first elongated member 107 and a second elongated member 109. The reloadable cartridge assembly 103 can be in a clamped position when the first elongated member 107 and the second elongated member 109 are clamping tissue and/or contacting each other. The reloadable cartridge assembly 103 can be in an unclamped position when the first elongated member 107 and the second elongated member 109 are not clamping tissue and/or are not in contact with each other.

[0043] In a number of embodiments, one of the elongated members can house one or more staple cartridges. The other elongated member can have an anvil that can be used to form a staple when driven from the staple cartridge. As mentioned, a surgical stapling apparatus 100 can receive reloadable cartridge assemblies having rows of staples. In a number of embodiments, third party reloadable cartridge and/or reloadable cartridge assemblies may be used with the surgical handle assembly 102 and embodiments of surgical handle assembly 102 may be configured to receive the same.

[0044] The surgical handle assembly 102 coupled to the reloadable cartridge assembly 103 can advance the reloadable cartridge assembly 103 to the clamped position in response to the user actuating the movable handle member 104 of the surgical handle assembly 102 in a proximal direction. The user can also advance the reloadable cartridge assembly 103 to the unclamped position in response to the user actuating the movable handle member 104 in a distal direction.

[0045] In a number of embodiments, the surgical handle assembly 102 coupled to the reloadable cartridge assembly 103 can deploy a number of staples. The reloadable cartridge assembly 103 can deploy the number of staples in response to the user pressing a button 106 and moving the movable handle member 104 to the most proximal position. The button 106 can be pushed from either the right-hand side or the left-hand side of the surgical handle assembly 102. The movable handle member 104 can be in the most proximal position when the movable handle member 104 cannot move further in the proximal direction.

[0046] When the button 106 is pressed the reloadable cartridge assembly 103 is no longer prevented from delivering the number of staples. Once the button 106 is pressed the number of staples can be ejected in response to the user actuating the movable handle member 104 in the proximal direction.

[0047] When the button 106 is pressed the movable handle member 104 is free to move to the most distal position. The movable handle member 104 is in the most distal position when the movable handle member 104 cannot move further in the distal direction. When the button 106 is pressed it also allows the reloadable cartridge assembly 103 to stay in the clamped position even when the movable handle member 104 moves to the most distal position.

[0048] A user can advance the movable handle member 104 from the most distal position to the most proximal position. Since the user has pressed the button 106 and the reloadable cartridge assembly 103 is no longer prevented from delivering the number of staples, the number of staples can be delivered in response to the user advancing the movable handle member 104 in the proximal direction. [0049] When the user has finished delivering staples, the user can return the surgical handle assembly 102 and the reloadable cartridge assembly 103 to a start position. In the start position, the button 106 can be in an unpressed position, the movable handle member 104 can be in the most distal position, and the reloadable cartridge assembly 103 can be in an unclamped position. The user can return the surgical handle assembly 102 and the reloadable cartridge assembly 103 to the start position by engaging retract grips 105 on both sides of the surgical handle assembly 102 and pulling the retract grips 105 in the linear proximal direction. In some examples, the retract grips 105 can be used in response to the surgical stapling apparatus 100 failing to unclamp.

[0050] The surgical handle assembly 102 is described with the surgical stapling apparatus 100 example throughout the present disclosure for ease of understanding and illustration. However, embodiments are not limited to use with a surgical stapling apparatus 100.

[0051] Figure 2A is a schematic diagram of a surgical handle assembly 202 in an unclamped position including a movable handle member 204, a button 206, a toothed rack 208, a driving pawl 210, a latch 212, a disengagement mechanism 214, and a safety latch 216 in accordance with a number of embodiments of the present disclosure.

[0052] The surgical handle assembly 202 can be in a home unclamped position when the movable handle member 204 is not being actuated by the user and the reloadable cartridge assembly (e.g., reloadable cartridge assembly 103 in Fig. 1) is in an unclamped position. The movable handle member 204 is not being actuated by the user when the movable handle member 204 is in the farthest distal position the movable handle member 204 can travel.

[0053] The driving pawl 210 can be coupled to the movable handle member 204. In some examples, the driving pawl 210 can be coupled to the movable handle member 204 via a pin, which can allow the driving pawl 210 to pivot and engage or disengage from the toothed rack 208. The toothed rack 208 can be in a home position when the toothed rack 208 is in a linear most proximal position. When the toothed rack 208 is in the home position, the driving pawl 210 can be disengaged from the toothed rack 208.

[0054] The latch 212 can be coupled to the driving pawl 210. The latch 212 can pivot via a pin coupling the latch 212 to the driving pawl 210. In some examples, the latch 212 can pivot to engage or disengage from the toothed rack 208. When the toothed rack 208 is in the home position, the latch 212 can be disengaged from the toothed rack 208.

[0055] The latch 212 and/or the driving pawl 210 can be disengaged from the toothed rack via the disengagement mechanism 214. The disengagement mechanism 214 can contact the driving pawl 210 to disengage the driving pawl 210 and/or the latch 212 from the toothed rack 208 in response to a user pressing the button 206. However, when the toothed rack 208 is in the home position, the disengagement mechanism 214 may not contact the driving pawl 210.

[0056] In some examples, pressing the button 206 can disengage the safety latch 216. When the button 206 is pressed one of the one or more slanted surfaces (e.g., slanted surfaces 322-1, 322-2 in Fig. 3) of the button 206 can contact one or more slanted surfaces (e.g., slanted surface 326-1, 326-2 in Fig. 3) of the safety latch 216 and cause the safety latch 216 to move in a downward direction. In the lowered position, the safety latch 216 cannot engage the toothed rack 208 to prevent the toothed rack 208 from moving further in the linear distal direction such that staples can be delivered.

[0057] The safety latch 216 can prevent a user from accidentally ejecting staples. For example, the safety latch 216 can make a user press the button 206 in order to eject staples. In Figure 2A, the safety latch 216 is biased upward which can prevent staples from being ejected if a user were to actuate the movable handle member 104 to the proximal direction.

[0058] Figure 2B is a schematic diagram of a surgical handle assembly 202 in a clamped position including a movable handle member 204, a button 206, a toothed rack 208, a driving pawl 210, a latch 212, a disengagement mechanism 214, and a safety latch 216 in accordance with a number of embodiments of the present disclosure.

[0059] The surgical handle assembly 202 can be in an index clamped position when the movable handle member 204 is fully actuated by the user and the reloadable cartridge assembly (e.g., reloadable cartridge assembly 103 in Fig. 1) is in a clamped position. For example, the movable handle member 204 can be fully actuated by the user squeezing the movable handle member 204 in a proximal direction from the most distal position, shown in Figure 2A, until the movable handle member 204 cannot travel any further in the proximal direction.

[0060] As previously described in Figure 2A, the driving pawl 210 can be coupled to the movable handle member 204 via a pin, which can allow the driving pawl 210 to pivot and engage or disengage from the toothed rack 208. For example, the driving pawl 210 can be configured to engage the toothed rack 208 and advance the toothed rack 208 in a linear distal direction in response to the movable handle member 204 advancing in the proximal direction. In some examples, the surgical handle assembly 202 can advance the reloadable cartridge assembly (e.g., reloadable cartridge assembly 103 in Fig. 1) to a clamped position in response to the driving pawl 210 advancing the toothed rack 208 in the linear distal direction.

[0061] The latch 212, as previously described in Figure 2A, can pivot from the driving pawl 210 to engage or disengage from the toothed rack 208. When the toothed rack 208 is in the index position, the latch 212 can engage the toothed rack 208.

[0062] The disengagement mechanism 214 can contact the driving pawl 210 to disengage the driving pawl 210 and/or the latch 212 from the toothed rack. In Figure 2B, the disengagement mechanism 214 is not in contact with the driving pawl 210.

[0063] The driving pawl 210 can be disengaged from the toothed rack 208 in response to a user pressing the button 206. The button 206 can include one or more slanted surfaces (e.g., slanted surfaces 320, 322 in Fig. 3). When the button 206 is pressed one of the one or more slanted surfaces of the button 206 can contact a surface of the disengagement mechanism 214 and cause the disengagement mechanism 214 to move in a downward direction As the disengagement mechanism 214 moves downward, the disengagement mechanism 214 can contact the driving pawl 210 and move the driving pawl 210 and the latch 212 in a downward direction to prevent the driving pawl 210 and the latch 212 from engaging the toothed rack 208. In Figure 2B, the button 206 is not in a pressed position.

[0064] In some examples, pressing the button 206 can disengage the safety latch 216. When the button 206 is pressed one of the one or more slanted surfaces (e.g., slanted surfaces 322-1, 322-2 in Fig. 3) of the button 206 can contact one or more slanted surfaces (e.g., slanted surface 326-1, 326-2 in Fig. 3) of the safety latch 216 and cause the safety latch 216 to move in a downward direction. In the lowered position, the safety latch 216 cannot engage the toothed rack 208 to prevent the toothed rack 208 from moving further in the linear distal direction such that staples can be delivered.

[0065] As previously described in Figure 2A, the safety latch 216 can prevent a user from accidentally ejecting staples. For example, the safety latch 216 can make a user press the button 206 in order to eject staples. In Figure 2B, the movable handle member 204 is in a most proximal position, but staples are not ejected because the safety latch 216 is in an upward position preventing the toothed rack 208 from moving further in the linear distal direction. The toothed rack 208 can include an opening, for example a slot. The safety latch 216 in the upward position can enter the opening of the toothed rack 208, as shown in Figure 2B. In some examples, the safety latch 216 engaged in the opening of the toothed rack 208 can maintain the surgical handle assembly 202 in a clamped position.

[0066] Figure 2C is a schematic diagram of a surgical handle assembly 202 in a clamped position including a movable handle member 204, a button 206, a toothed rack 208, a driving pawl 210, a latch 212, a disengagement mechanism 214, and a safety latch 216 in accordance with a number of embodiments of the present disclosure.

[0067] The surgical handle assembly 202 can be in a clamped position between a most distal position and a most proximal position when the movable handle member 204 is partially actuated by the user and the reloadable cartridge assembly (e.g., reloadable cartridge assembly 103 in Fig. 1) is in a clamped position. In some examples, the movable handle member 204 can remain in the position between the most distal position and the most proximal position without any assistance from the user. This position can be, but is not limited to, halfway between the most distal position and the most proximal position.

[0068] As previously described in Figure 2A, the driving pawl 210 can be coupled to the movable handle member 204 via a pin, which can allow the driving pawl 210 to pivot and engage or disengage from the toothed rack 208. When the toothed rack 208 is between the linear most proximal position and the linear most distal position, the driving pawl 210 can be disengaged from the toothed rack 208. For example, the driving pawl 210 can be disengaged from the toothed rack 208 to allow the toothed rack 208 to move in a linear proximal direction in response to the movable handle member 204 moving in a distal direction.

[0069] The latch 212, as previously described in Figure 2A, can pivot from the driving pawl 210 to engage or disengage from the toothed rack 208. In the clamped position, where the movable handle member 204 is between the most distal position and the most proximal position, the latch 212 can engage the toothed rack 208. The latch 212 can cause the toothed rack 208 to advance in the linear proximal direction in response to the user moving the movable handle member 204 in the distal direction. In some examples, the reloadable cartridge assembly (e.g., reloadable cartridge assembly 103 in Fig. 1) can move to an unclamped position in response to the toothed rack 208 advancing in the linear proximal direction.

[0070] The disengagement mechanism 214 can contact the driving pawl 210 to disengage the driving pawl 210 and/or the latch 212 from the toothed rack 208. In Figure 2C, the disengagement mechanism 214 is not in contact with the driving pawl 210.

[0071] The latch 212 can be disengaged from the toothed rack 208 in response to a user pressing the button 206. The button 206 can include one or more slanted surfaces (e.g., slanted surfaces 320-1, 320-2, 322-1, 322-2 in Fig. 3). When the button 206 is pressed one of the one or more slanted surfaces of the button 206 can contact one or more slanted surfaces (e.g., slanted surface 324-1, 324-2 in Fig. 3) of the disengagement mechanism 214 and cause the disengagement mechanism 214 to move in a downward direction. As the disengagement mechanism 214 moves downward, the disengagement mechanism 214 can contact the driving pawl 210 and move the driving pawl 210 and the latch 212 in a downward direction to prevent the latch 212 from engaging the toothed rack 208. In Figure 2C, the button 206 is not in a pressed position.

[0072] In some examples, pressing the button 206 can disengage the safety latch 216. When the button 206 is pressed one of the one or more slanted surfaces (e.g., slanted surfaces 322-1, 322-2 in Fig. 3) of the button 206 can contact one or more slanted surfaces (e.g., slanted surface 326-1, 326-2 in Fig. 3) of the safety latch 216 and cause the safety latch 216 to move in a downward direction. In the lowered position, the safety latch 216 cannot engage the toothed rack 208 to prevent the toothed rack 208 from moving further in the linear distal direction such that staples can be delivered.

[0073] The safety latch 216 can prevent a user from accidentally ejecting staples. For example, the safety latch 216 can make the user press the button 206 in order to eject staples. In Figure 2C, the safety latch 216 is in an upward position that would prevent staples from being ejected if a user were to actuate the movable handle member 204 in the proximal direction. The toothed rack 208 can include an opening, for example a slot. The safety latch 216 in the upward position can enter the opening of the toothed rack 208, as shown in Figure 2C. In some examples, the safety latch 216 engaged in the opening of the toothed rack 208 can maintain the surgical handle assembly 202 in a clamped position.

[0074] Figure 2D is a schematic diagram of a surgical handle assembly 202 in an unclamped position including a movable handle member 204, a button 206, a toothed rack 208, a driving pawl 210, a latch 212, a disengagement mechanism 214, and a safety latch 216 in accordance with a number of embodiments of the present disclosure.

[0075] The surgical handle assembly 202 can be in an unclamped position with the movable handle member 204 between a most distal position and a most proximal position when the movable handle member 204 is partially actuated by the user and the reloadable cartridge assembly (e.g., reloadable cartridge assembly 103 in Fig. 1) is in an unclamped position. In some examples, the movable handle member 204 can remain in the unclamped position between the most distal position and the most proximal position without any assistance from the user. The unclamped position with the movable handle member 204 between the most distal position and the most proximal position can be, but is not limited to, halfway between the most distal position and the most proximal position.

[0076] As previously described in Figure 2A, the driving pawl 210 can be coupled to the movable handle member 204 via a pin, which can allow the driving pawl 210 to pivot and engage or disengage from the toothed rack 208. In the unclamped position with the movable handle member 204 between the most distal position and the most proximal position, the driving pawl 210 can engage the toothed rack 208. For example, the driving pawl 210 can engage the toothed rack 208 to allow the driving pawl 208 to advance the toothed rack 208 in a linear distal direction in response to the movable handle member 204 moving in the proximal direction towards the index position.

[0077] The latch 212, as previously described in Figure 2A, can pivot from the driving pawl 210 to engage or disengage from the toothed rack 208. The latch 212 can be biased by a spring to engage the toothed rack 208. During unclamping, the latch 212 engages toothed rack 208 at an engagement location 230. In some examples, the spring can bias the latch 212 in an upward direction. In the clamped position with the movable handle member 204 between the most distal position and the most proximal position, the latch 212 can engage the toothed rack 208. The latch 212 can advance the toothed rack 208 in a linear proximal direction in response to the user moving the movable handle member 204 in the distal direction to unclamp.

[0078] The disengagement mechanism 214 can contact the driving pawl 210 to disengage the driving pawl 210 and/or the latch 212 from the toothed rack 208. In some examples, in the unclamped position with the movable handle member 204 between the most distal position and the most proximal position, the disengagement mechanism 214 does not contact the driving pawl 210.

[0079] The driving pawl 210 can be disengaged from the toothed rack in response to the user pressing the button 206. The button 206 can include one or more slanted surfaces (e.g., slanted surfaces 320-1, 320-2, 322-1, 322-2 in Fig. 3). When the button 206 is pressed, one of the one or more slanted surfaces of the button 206 can contact one or more slanted surfaces (e.g., slanted surface 324-1, 324-2 in Fig. 3) of the disengagement mechanism 214 and cause the disengagement mechanism 214 to move in a downward direction. As the disengagement mechanism 214 moves downward, the disengagement mechanism 214 can contact the driving pawl 210 and move the driving pawl 210 and the latch 212 in a downward direction to prevent the driving pawl 210 and the latch 212 from engaging the toothed rack 208 such that latch 212 is no longer in contact with engagement location 230. In Figure 2D, the button 206 is not in a pressed position. [0080] In Figure 2D, the safety latch 216 is in the lowered position. In some examples, the safety latch 216 in the lowered position can engage the toothed rack 208 to prevent the toothed rack 208 from moving further in the linear distal direction from the index position.

[0081] Figure 2E is a schematic diagram of a surgical handle assembly 202 in a clamped position including a movable handle member 204, a button 206, a toothed rack 208, a driving pawl 210, a latch 212, a disengagement mechanism 214, and a safety latch 216 in accordance with a number of embodiments of the present disclosure.

[0082] In Figure 2E the surgical handle assembly 202 can be transitioning to a ready to fire position and the movable handle member 204 can be in a position between the most distal position and the most proximal position.

[0083] When the surgical handle assembly 202 is transitioning to a ready to fire position, the latch 212 can be disengaged from the toothed rack 208 in response to the user pressing the button 206. The button 206 can include one or more slanted surfaces (e.g., slanted surfaces 320-1, 320-2, 322-1, 322-2 in Fig. 3). When the button 206 is pressed one of the one or more slanted surfaces of the button 206 can contact one or more slanted surfaces (e.g., slanted surface 324-1 , 324-2 in Fig. 3) of the disengagement mechanism 214 and cause the disengagement mechanism 214 to move in a downward direction. As the disengagement mechanism 214 moves downward, the disengagement mechanism 214 can contact the driving pawl 210 and move the driving pawl 210 and the latch 212 in a downward direction to prevent the latch 212 from engaging the toothed rack 208. In Figure 2E, the button 206 is in a pressed position.

[0084] In Figure 2E, pressing the button 206 can also disengage the safety latch 216. When the button 206 is pressed one of the one or more slanted surfaces (e.g., slanted surfaces 322-1, 322-2 in Fig. 3) of the button 206 can contact one or more slanted surfaces (e.g., slanted surface 326-1, 326-2 in Fig. 3) of the safety latch 216 and cause the safety latch 216 to move in a downward direction. In the lowered position, the safety latch 216 cannot engage the toothed rack 208 to prevent the toothed rack 208 from moving further in the linear distal direction such that staples can be delivered.

[0085] Figure 2F is a schematic diagram of a surgical handle assembly 202 in a clamped position including a movable handle member 204, a button 206, a toothed rack 208, a driving pawl 210, a latch 212, a disengagement mechanism 214, and a safety latch 216 in accordance with a number of embodiments of the present disclosure.

[0086] The surgical handle assembly 202 can be in a ready to fire position when the movable handle member 204 is not being actuated by the user and the reloadable cartridge assembly (e.g., reloadable cartridge assembly 103 in Fig. 1) is in a clamped position. The movable handle member 204 is not being actuated by the user when the movable handle member 204 is in the most distal position.

[0087] In the ready to fire position, the driving pawl 210 can be disengaged from the toothed rack 208, the latch 212 can be disengaged from the toothed rack 208, and the disengagement mechanism 214 may not contact the driving pawl 210. [0088] The latch 212 can be disengaged from the toothed rack 208 in response to the user pressing the button 206. The button 206 can include one or more slanted surfaces (e.g., slanted surfaces 320-1, 320-2, 322-1, 322-2 in Fig. 3). When the button 206 is pressed one of the one or more slanted surfaces of the button 206 can contact one or more slanted surfaces (e.g., slanted surface 324-1, 324-2 in Fig. 3) of the disengagement mechanism 214 and cause the disengagement mechanism 214 to move in a downward direction. As the disengagement mechanism 214 moves downward, the disengagement mechanism 214 can contact the driving pawl 210 and move the driving pawl 210 and the latch 212 in a downward direction to prevent the latch 212 from engaging the toothed rack 208. In Figure 2F, the button 206 is in a pressed position.

[0089] In some examples, pressing the button 206 can disengage the safety latch 216. When the button 206 is pressed one of the one or more slanted surfaces (e.g., slanted surfaces 322-1, 322-2 in Fig. 3) of the button 206 can contact one or more slanted surfaces (e.g., slanted surface 326-1, 326-2 in Fig. 3) of the safety latch 216 and cause the safety latch 216 to move in a downward direction. In the lowered position, the safety latch 216 cannot engage the toothed rack 208 to prevent the toothed rack 208 from moving further in the linear distal direction such that staples can be delivered.

[0090] The safety latch 216 can prevent a user from accidentally ejecting staples. For example, the safety latch 216 can make the user press the button 206 in order to eject staples. In Figure 2F, the safety latch 216 is in a downward position that would allow staples to be ejected if a user were to actuate the movable handle member 204 in the proximal direction.

[0091] Figure 2G is a schematic diagram of a surgical handle assembly 202 in an unclamped position including a movable handle member 204, a button 206, a toothed rack 208, a driving pawl 210, a latch 212, a disengagement mechanism 214, and a safety latch 216 in accordance with a number of embodiments of the present disclosure.

[0092] The surgical handle assembly 202 can be moving from an unclamp position, described in Figure 2D, to a start position, Figure 2A, when the disengagement mechanism 214 is lowered in response to a user pressing the button 206. [0093] When the movable handle member 204 is in the position between the most distal position and the most proximal position, the driving pawl 210 can be disengaged from the toothed rack 208, the latch 212 can be disengaged from the toothed rack 208, and the disengagement mechanism 214 can be in contact with the driving pawl 210.

[0094] The latch 212 can be disengaged from the toothed rack 208 in response to the user pressing the button 206. The button 206 can include one or more slanted surfaces (e.g., slanted surfaces 320-1, 320-2, 322-1, 322-2 in Fig. 3). When the button 206 is pressed one of the one or more slanted surfaces of the button 206 can contact one or more slanted surfaces (e.g., slanted surface 324-1, 324-2 in Fig. 3) of the disengagement mechanism 214 and cause the disengagement mechanism 214 to move in a downward direction. As the disengagement mechanism 214 moves downward, the disengagement mechanism 214 can contact the driving pawl 210 and move the driving pawl 210 and the latch 212 in a downward direction to prevent the driving pawl 210 and/or the latch 212 from engaging the toothed rack 208. In Figure 2G, the button 206 is in a pressed position.

[0095] In Figure 2G, the safety latch 216 is biased downwards by the disengagement mechanism 214, such that the one or more slanted surfaces (e.g., slanted surfaces 322-1, 322-2 in Fig. 3) of the button 206 will not contact the one or more slanted surfaces (e.g., slanted surfaces 326-1, 326-2 in Fig. 3) of the safety latch 216 and the safety latch 216 will not move in the downward direction when a user presses the button 206.

[0096] Figure 2H is a schematic diagram of a surgical handle assembly 202 in a clamped position including a movable handle member 204, a button 206, a toothed rack 208, a driving pawl 210, a latch 212, a disengagement mechanism 214, and a safety latch 216 in accordance with a number of embodiments of the present disclosure.

[0097] The surgical handle assembly 202 can be in a firing mode, as shown in Figure 2H, able to fire staples when the movable handle member 204 is fully and/or partially actuated by the user and the reloadable cartridge assembly (e g , reloadable cartridge assembly 103 in Fig. 1) is in a clamped position.

[0098] When the surgical handle assembly 202 is firing, the driving pawl 210 can engage the toothed rack 208, the latch 212 cannot engage the toothed rack 208 to advance the toothed rack 208 in a linear proximal direction, and the disengagement mechanism 214 cannot contact the driving pawl 210.

[0099] In Figure 2H, the button 206 is in an unpressed position. In some examples, pressing the button 206 can disengage the safety latch 216. When the button 206 is pressed one of the one or more slanted surfaces (e.g., slanted surfaces 322-1, 322-2 in Fig. 3) of the button 206 can contact one or more surfaces (e.g., slanted surface 326-1, 326-2 in Fig. 3) of the safety latch 216 and cause the safety latch 216 to move in a downward direction. In the lowered position, the safety latch 216 cannot engage the toothed rack 208 to prevent the toothed rack 208 from moving further in the linear distal direction such that staples can be delivered. [00100] The safety latch 216 can prevent a user from accidentally ejecting staples. For example, the safety latch 216 can make the user press the button 206 in order to eject staples. In Figure 2H, the safety latch 216 cannot engage the toothed rack 208 to prevent the toothed rack 208 from moving in a linear distal direction and staples can be ejected as the user continues to actuate the movable handle member 204 in the proximal direction.

[00101] Figure 3 is a schematic diagram of a safety latch 316, a button 306, and a disengagement mechanism 314 in accordance with a number of embodiments of the present disclosure.

[00102] The safety latch 316 can include one or more slanted surfaces 326-1, 326-2, the button 306 can include one or more slanted surfaces 320-1, 320-2, 322-1, 322-2, and the disengagement mechanism 314 can include one or more slanted surfaces 324-1, 324-2.

[00103] The one or more slanted surfaces 320-1, 320-2 of the button 306 can contact one or more slanted surfaces 324-1, 324-2 of the disengagement mechanism 314 to activate the disengagement mechanism 314 and move the disengagement mechanism 314 in a downward direction. For example, the slanted surface 320-1 of the button 306 can be a parallel surface to the slanted surface 324-1 of the disengagement mechanism 314 and can contact the slanted surface 324-1 of the disengagement mechanism 314 and/or the slanted surface 320-2 of the button 306 can be a parallel surface to the slanted surface 324-2 of the disengagement mechanism 314 and can contact the slanted surface 324-2 in response to a user pressing the button 306.

[00104] The one or more slanted surfaces 322-1, 322-2 of the button 306 can contact one or more slanted surfaces 326-1, 326-2 of the safety latch 316 to move the safety latch 316 in the downward direction. For example, the slanted surface 322-1 of the button 306 can be a parallel surface to the slanted surface 326-1 of the safety latch 316 and can contact the slanted surface 326-1 of the safety latch 316 and/or the slanted surface 322-2 of the button 306 can be a parallel surface to the slanted surface 326-2 of the safety latch 316 and can contact the slanted surface 326-2 of the safety latch 316 in response to a user pressing the button 306.

[00105] In some examples, the safety latch 316 can include one or more notches 328-1, 328-2. The one or more notches 328-1, 328-2 can each include one or more slanted surfaces to each create an indentation in the safety latch 316. When the button 306 is pressed towards the ready to fire position, as shown in Figure 2F, the button 306 is latched inside the 328-1 notch or the 328-2 notch of safety latch 316. For example, if the button 306 is pressed from a first side of the surgical handle assembly (e.g., surgical handle assembly 202 in Fig. 2A-2H), the button 306 will latch with the 328-1 notch and if the button 306 is pressed from a second side of the surgical handle assembly, the button 306 will latch with the 328-2 notch.

[00106] The latching of the button 306 with the 328-1 notch or 328-2 notch can create a noise. For example, the noise can be a clicking noise audible to a user. The noise can alert the user that the disengagement mechanism 314 has biased the safety latch 316 in a downward direction to disengage the safety latch 316 from the toothed rack (e.g., toothed rack 208 in Fig. 2A-2H) and the surgical handle assembly (e.g., surgical handle assembly 202 in Fig. 2A-2H) is now in a firing mode. [00107] In some examples, the latching of the button 306 with the 328-1 notch or the 328-2 notch can create a physical cue. For example, the physical cue can be a click that can be felt by a user. The physical cue can alert the user that the disengagement mechanism 314 has biased the safety latch 316 in a downward direction to disengage the safety latch 316 from the toothed rack (e.g., toothed rack 208 in Fig. 2A-2H) and the surgical handle assembly (e.g., surgical handle assembly 202 in Fig. 2A-2H) is now in a firing mode.

[00108] In some embodiments, resulting from the placement and size of various components, the latch (e.g., latch 212 in Fig. 2A-2H), as it moves from the configuration shown in Fig. 2D, through the configuration shown in Fig. 2E, and then to the configuration shown in Fig. 2F, can catch on the toothed rack and can remain in a vertical position. In some examples, the latch can be pivotably attached to a driving pawl (e.g., driving pawl 210 in Fig. 2A-2H) and spring loaded so that the end of the latch is biased in an upward direction away from the driving pawl. In some instances, after the button 306 has been pressed and the user begins moving movable handle member (e.g., movable handle member 204 in Fig. 2) proximally, the driving pawl can be relatively horizontal. As the latch is biased in an upward direction, if one were to consider an imaginary line between the pivot point for the driving pawl and the pivot point for the latch on the driving pawl, it would be at an approximate 90-degree angle with a compressive force on the latch from upward movement of the latch into the toothed rack. This approximate 90-degree angle results in the latch not being able to move in the proximal direction and the latch being caught on the toothed rack.

[00109] Figures 4A and 4B are schematic diagrams of a toothed rack 408 in accordance with a number of embodiments of the present disclosure. In a number of embodiments, the toothed rack 408 includes recessed portion 432 positioned proximally of engagement location 430. The recessed portion 432 provides an initial proximal force to a tip of a latch (e.g., latch 212 in Fig. 2A-2H), allowing the latch to move to a position slightly proximal of vertical, after which a spring force from a driving pawl spring can then fold the latch away from the toothed rack 408. The recessed portion 432 is configured to have a proximally facing acute angle 434 with respect to the longitudinal axis of the toothed rack 408. Recessed portion 432 is shown with an asymmetrical concave downward shape. However, the recessed portion 432 can be a curved shape or a combination of slanted faces connected by curved locations. The recessed portion 432 can be recessed relative to a bottom of the toothed rack 408 that is positioned between two rows of teeth.

[00110] In some examples, after the button (e.g., button 206 and 306 in Fig. 2A-2H and Fig. 3, respectively) has been pressed and the user begins moving a movable handle member (e.g., movable handle member 204 in Fig. 2) proximally, the driving pawl (e.g., driving pawl 210 in Fig. 2A-2H) can be biased in an upward direction causing the tip of the latch to contact the recessed portion 432. A force vector can be perpendicular to a tangent line at a contact point between the latch and the recessed portion 432 resulting in both downward and proximal forces applied from the recessed portion 432 onto the latch causing the latch to rotate to a position just proximal of vertical. For example, the latch can rotate away from the toothed rack 408 in response to the latch contacting the recessed portion 432.

[00111] The depth of recessed portion 432 can be minimized to prevent adversely affecting the strength of toothed rack 408. The recessed portion 432 can be located such that the tip of the latch will contact the distal portion of the recessed portion 432 after the user has pressed the button. In some embodiments, the distal end of recessed portion 432 is located just distal to the engagement location 430 where the latch interfaces with the toothed rack 408 when the toothed rack 408 is positioned as shown in Figure 2E.

[00112] In a number of embodiments, after the user has moved movable handle member to a proximal most position to cause reloadable cartridge assembly (e.g., reloadable cartridge assembly 103 in Fig. 1A-1B) to move to a clamped position, the user can release movable handle member and allow movable handle member to move partially back toward a distal most position. Then the user can either push the button to place the movable handle member in a ready to fire mode or move the movable handle member distal to unclamp the reloadable cartridge assembly. If the button is pressed, the driving pawl and latch can be pulled downward by a disengagement mechanism (e.g., disengagement mechanism 214 and 314 in Fig. 2A-2H and Fig. 3, respectively) and away from toothed rack 408 and the latch can be allowed to rotate to a position just proximal of vertical in response to contacting the recessed portion 432.

[00113] Although specific embodiments have been illustrated and described herein, those of ordinary skill in the art will appreciate that an arrangement calculated to achieve the same results can be substituted for the specific embodiments shown. This disclosure is intended to cover adaptations or variations of one or more embodiments of the present disclosure. It is to be understood that the above description has been made in an illustrative fashion, and not a restrictive one. Combination of the above embodiments, and other embodiments not specifically described herein will be apparent to those of skill in the art upon reviewing the above description. The scope of the one or more embodiments of the present disclosure includes other applications in which the above structures and processes are used. Therefore, the scope of one or more embodiments of the present disclosure should be determined with reference to the appended claims, along with the full range of equivalents to which such claims are entitled.

[00114] In the foregoing Detailed Description, some features are grouped together in a single embodiment for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the disclosed embodiments of the present disclosure have to use more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed embodiment. Thus, the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate embodiment.

Claims

What is claimed is:

1. A surgical handle assembly apparatus, comprising: a toothed rack comprising a recessed portion proximal to an engagement location; a movable handle member; a button; and a latch configured to: engage the toothed rack at the engagement location and advance the toothed rack in a linear proximal direction in response to the movable handle member advancing in a distal direction; and contact the toothed rack at the recessed portion and rotate in response to the button being pressed.

2. The apparatus of claim 1, wherein a reloadable cartridge assembly advances to a clamped position in response to a driving pawl advancing the toothed rack in a linear distal direction.

3. The apparatus of claim 1, wherein a reloadable cartridge assembly advances to an unclamped position in response to the latch advancing the toothed rack in the linear proximal direction.

4. The apparatus of any one of claims 1-3, wherein the recessed portion is positioned between two rows of teeth included in the toothed rack.

5. The apparatus of any one of claims 1-3, wherein the latch is biased in an upward direction.

6. The apparatus of any one of claims 1-3, wherein the latch is configured to rotate to a position proximal to vertical in response to contacting the toothed rack at the recessed portion.

7. A surgical handle assembly apparatus, comprising: a toothed rack comprising a recessed portion proximal to an engagement location; a disengagement mechanism configured to disengage a latch from the toothed rack; and the latch configured to: engage the toothed rack at the engagement location and advance the toothed rack in a linear proximal direction; and contact the toothed rack at the recessed portion and rotate in response to the disengagement mechanism disengaging the latch from the toothed rack.

8. The apparatus of claim 7, wherein the disengagement mechanism is further configured to disengage a driving pawl from the toothed rack.

9. The apparatus of claim 7, further comprising a button to activate the disengagement mechanism.

10. The apparatus of any one of claims 7-9, further comprising a movable handle member.

11. The apparatus of claim 10, wherein the toothed rack advances in the linear proximal direction in response to the movable handle member advancing in a distal direction.

12. The apparatus of claim 10, wherein the surgical handle assembly ejects one or more staples in response to disengaging a safety latch and the movable handle member advancing in a proximal direction.

13. A surgical handle assembly apparatus, comprising: a toothed rack comprising a recessed portion proximal to an engagement location, wherein the recessed portion is configured to provide a proximal force to a latch; a movable handle member; and the latch configured to: engage the toothed rack at the engagement location and advance the toothed rack in a linear proximal direction in response to the movable handle member advancing in a distal direction; and contact the toothed rack at the recessed portion and rotate in response to receiving the proximal force from the recessed portion.

14. The apparatus of claim 13, further comprising a reloadable cartridge assembly coupled to the toothed rack.

15. The apparatus of claim 14, wherein the reloadable cartridge assembly ejects one or more staples in response to activating a disengagement mechanism and advancing the movable handle member in a proximal direction.

16. The apparatus of claim 1 , wherein the toothed rack moves in a linear distal direction.

17. The apparatus of claim 14, wherein the reloadable cartridge assembly moves to an unclamped position in response to advancing the movable handle member in the distal direction.

18. The apparatus of claim 17, wherein the toothed rack moves in the linear proximal direction.

19. The apparatus of claim 13, wherein a driving pawl and the latch are coupled via a pin.

20. The apparatus of claim 13, wherein the recessed portion comprises a concave shape.