MXPA06009444A - Fired device lockout for a curved cutter stapler with a free moving trigger - Google Patents

Abstract

A linear surgical stapler adapted for applying a plurality of surgical fasteners to body tissue includes an anvil structure and a cartridge housing containing a plurality of surgical fasteners and a knife. The cartridge housing and anvil structure are relatively movable between a first spaced apart position and a second position in close approximation with one another. A firing mechanism is associated with the cartridge housing for ejecting the surgical fasteners from the cartridge housing to be driven against the anvil structure. The firing mechanism includes a slide bar at its distal end adjacent the cartridge housing. A lockout mechanism interacts with the cartridge housing for selective activation and deactivation. The lockout mechanism includes a lock tab that interferes with the slide bar of the firing mechanism moving the slide bar rotationally such that tabs on the slide bar move out of alignment with tabs on the knife during firing of the linear surgical stapler to prevent subsequent firingof the linear surgical stapler.

Description

LOCKED DEVICE LOCK FOR A CURVED BLADE COPPER WITH A FREE MOVEMENT TRIGGER FIELD OF THE INVENTION The present invention relates to surgical stapling and cutting tools adapted for use in the diagnosis and therapy of pathologies treated by stapled resection. More particularly, the present invention relates to a locking mechanism for use in conjunction with surgical stapling and cutting instruments.

BACKGROUND OF THE INVENTION Surgical stapling and cutting instruments are commonly used in the diagnosis and treatment of pathologies treated by stapled resection. The surgical stapling and cutting instruments provide a mechanism to extend the transluminal exploitation of mechanical suture devices introduced through the anal canal, mouth, stomach or service access. Although surgical stapling and cutting tools are more commonly used with rectal pathologies, surgical stapling and cutting instruments can be used in a variety of settings. With the passage of time, surgical stapling and cutting tools have been developed. These instruments generally include a support frame, an anvil attached to the support frame and a cartridge housing for transporting a plurality of staples. The instruments also include an impeller within the cartridge housing, which pushes all the staples outwardly, simultaneously into the anvil to form the staples, generally in a B-shape, suturing the tissue together. Additionally, these instruments include approach mechanisms that allow the cartridge housing and the anvil to move relative to each other to accept tissue therebetween. Finally, the instruments include a firing mechanism to move the impeller forward and form the staples against the anvil. In addition to the basic components of the stapling and cutting instruments, these products need a locking mechanism that allows the activation and / or deactivation of the approach means, in such a way that the cartridge module can be used as a clamp when it is necessary during an emergency. However, the locking mechanism is designed in such a way that the firing mechanism only works for a cartridge module that has not been used previously. Current surgical stapling instruments include a trigger bar lock that is activated by the impeller. When a new cartridge module is loaded into the instrument, the location of the impeller, as it relates to the cartridge module in the instrument, interferes with the locking arm in a way that allows the instrument to trigger staples. After the instrument fires the staples, the location of the impeller moves distally in a direction in which it no longer interferes with the locking arm. The locking arm moves to a position that now interferes with the firing bar, but prevents the firing bar from moving distally. However, the locking mechanism of the prior art does not provide a clear indication that the instrument has been fired in advance. As such, the above locking mechanism can be confused simply with an instrument that has jammed. Additionally, the above block systems require that the device survive a strong stress if the user tries to disrupt the locking mechanism. As will be discussed in more detail below, the present locking mechanism decouples the firing mechanism completely, removing any force transmission that the device may require to survive heavy loads. As such, there is a need for an improved locking mechanism that provides a clear indication that the locking mechanism has been activated and overcomes the other limitations of the prior art locking mechanisms. The present invention provides said blocking mechanism.

BRIEF DESCRIPTION OF THE INVENTION Accordingly, it is an object of the present invention to provide a surgical stapler adapted to apply a plurality of surgical fasteners to body tissue. The surgical stapler includes an anvil structure and a cartridge housing that contains a plurality of surgical fasteners and a blade. The cartridge housing and the anvil structure are relatively mobile between a first separated position and a second position in close approximation to each other. A trigger mechanism is associated with the cartridge housing to eject the surgical fasteners from the cartridge housing to be urged against the anvil structure. The firing mechanism includes a slide bar at its distal end adjacent to the cartridge housing. A blocking mechanism interacts with the cartridge housing for selective activation and deactivation. The locking mechanism includes a locking tab that interferes with the slide bar of the trigger mechanism by moving the slide bar, such that the tabs on the slide bar move out of alignment with the tabs on the blade during the shot of the linear surgical stapler to prevent subsequent tripping of the linear surgical stapler. It is also an object of the present invention to provide a surgical stapler wherein the locking tab rotatably moves the slide bar. It is another object of the present invention to provide a surgical stapler, wherein during firing of the linear surgical stapler, the firing mechanism moves the locking tab to a neutral position in the cartridge module. It is a further object of the present invention to provide a surgical stapler, wherein after the locking tab moves distally, the locking mechanism is retracted and a blade driver and locking tab remain in the distal position in the cartridge module. It is another object of the present invention to provide a surgical stapler, wherein the retraction of the firing mechanism causes the blade and the slide bar to be moved away from the locking tab and the slide rod rotated in its disengaged position. It is still another object of the present invention to provide a surgical stapler, wherein the slide bar is deflected by a spring. It is a further object of the present invention to provide a surgical stapler, wherein the locking tab is integrally formed with a cartridge housing of the cartridge module. It is still a further object of the present invention to provide a surgical stapler prior to activation of the firing mechanism, wherein the slide rod includes distally extending teeth aligned with the blade and the blade driver for subsequent contact with the latter. It is also an object of the present invention to provide a surgical stapler, wherein before activation of the firing mechanism, the locking tab engages the slide bar to ensure that the teeth are properly aligned with the blade tabs. extending proximally from the proximal end of the blade. Other objects and advantages of the present invention will become apparent from the detailed description that follows when viewed in conjunction with the accompanying drawings, which establish certain embodiments of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a perspective view of the linear surgical stapler according to the present invention. Figure 2 is a perspective view of a linear surgical stapler with the cartridge module removed. Figure 3 is a perspective view of the linear surgical stapler with the cartridge housing moved to an intermediate position. Figure 4, is a perspective view of the linear surgical stapler with the cartridge housing moved to a closed position. Figure 5 is a perspective view of the linear surgical stapler with the trigger trigger in a firing apposition. Figures 6 to 8 show the various steps involved in the activation of the present linear surgical stapler. Figures 9 to 11 show the various steps involved in the activation of the present linear surgical stapler according to an alternative modality thereof.

DETAILED DESCRIPTION OF THE PREFERRED MODALITIES The detailed embodiments of the present invention are described in the present description. However, it should be understood that the embodiments described are only examples of the present invention, which may be represented in various forms. Accordingly, the details described in the present description will not be consd as a limitation, but only as the basis for the claims and as a basis for teaching an expert in the art how to make and / or use the present invention. Referring to the various figures, a surgical insent 20 adapted to apply a plurality of fasteners for body tissue is described. The surgical insent 20 includes an anvil 122 and a cartridge housing 121 that contains a plurality of surgical fasteners. The cartridge housing 121 and the anvil 122 are relatively movable between a first separated space position and a second position in close approximation to each other. A firing mechanism is associated with the cartridge housing 121 for ejecting the surgical fasteners from the cartridge housing 121 to be urged against the anvil 122. A locking mechanism 180 interacts with the cartridge housing 121 for selective activation and deactivation of the closing mechanism. A locking mechanism 180 interacts with the cartridge housing 121 for selective activation and deactivation. The locking mechanism 180 includes a locking tab 182 which interferes with a slide bar 184 of the trigger mechanism that moves the slide bar 184 in a rotatable manner, such that the tabs 186 on the slide bar 184 move out of alignment with the tabs 188 on the blade 126 during the firing of the linear surgical stapler to prevent subsequent firing of the linear surgical stapler. Referring to Figure 1 in combination with Figures 2 to 5, there is shown a surgical stapler and the cutting insent, in particular, a linear surgical stapler 20, which is designed to staple and cut the tissue. The linear surgical stapler 20 has a handle 21 at a first proximal end and an end effector 80 at an opposite distal end. The end effector 80 is curved according to a preferred embodiment of the present invention. The right and left stural plates (often referred to as "handle plates") 34,35, respectively, connect the handle 21 to the end effector 80 of the insent (the left plate is not shown in Figure 1). The handle 21 has a cover of the right handle 22 coupled to the left handle cover (the left cover is not shown in Figure 1). The handle 21 also has a body portion 23 for holding and maneuvering the linear surgical stapler 20 (see Figures 2 to 5). The end effector 80 is a surgical fastener assembly, which includes a cartridge module 120 and a C-shaped support sture 81. The term "C-shape" is used throughout the specification to describe the concave nature of the sture. of support 81 and the cartridge module 120. The C-shape constion facilitates improved functionality and the use of the term "C-shaped" in the present specification should be interpreted to include a variety of concave shapes, which could similarly improve the functionality of the surgical stapler and the cutting insents. Although a C-shaped constion is contemplated in accordance with the preferred embodiment of the present invention, those skilled in the art will appreciate that the support sture, which can take various forms without departing from the spirit of the invention. The distal end 30 of a closure element 28 is arranged to receive the cartridge module 120. The end effector 80 also includes a safety lock mechanism 180 (best seen in Figures 6 to 8) to avoid triggering a previously fired cartridge module 120. The cartridge module 120 contains a cartridge housing 121 coupled to an anvil 122. The cartridge module 120 also includes a holding pin 125., a blade 126, a removable retaining device 160, a fabric contacting surface 127, which deploys a plurality of slots containing staples 128 in the alternating formation in one or more rows (i.e., lines of staples) ) on either side of the blade 126. The staples (not shown) are fired from the cartridge housing 121 against the surface forming the staple 129 of the anvil 122 which is facing the surface contacting the tissue 127 of the cartridge housing 121. As will be apparent from the following description, the present linear surgical stapler 20 is designed as a multiple trigger device with a replaceable cartridge module 120. However, it should be understood that several of the above-mentioned concepts of the present invention can be applied in the same way in single firing devices without departing from the spirit of the present invention. With this in mind, the operation of the different components of the blocking mechanism is described in the U.S. Patent. No. 11 / 014,910, entitled "CURVED CUTTER STAPLER SHAPED FOR MALE PELVIS" filed December 20, 2004, which is incorporated by reference in the present invention. Referring to Figures 6 to 8 (a sectional view within the support structure and the cartridge), now the components of the locking mechanism of the fired device 180 will be described. According to a preferred embodiment of the present invention, the module of the cartridge 120 is provided with a locking tab 182 which interferes with the slide bar 184 positioned on the distal end of the firing bar 43, moving the slide bar 184 in a rotatable manner, such that the tongues 186 on the slide bar 184 are located in line with tongues 188 on blade 126 before firing. When the firing transmission assembly is moved distally, the firing bar 43 moves the impeller 131 and the blade 126 toward the tissue, stapling and cutting in this way the previously determined tissue area. During firing, the firing bar 43 moves the locking tab 182 distally to a neutral position in the module of the cartridge 120. After the firing transmission assembly is retracted, the pusher 131 and the locking tab 182 it remains in the distal position in the cartridge module 120. The slide bar 184 then rotates in its disengaged position by a spring 190 because the locking tab 182 no longer forces it into its firing position. It is contemplated that the blade 126 will be moved proximally using any spring loading mechanism (not shown), which will act to move the blade 126 backwards after selectively firing or locking the hooks incorporated in the bar matching tabs. of sliding and blades. It is contemplated that the locking hooks could be similar to those used in linking the blade to the shot rod as described in the U.S. Patent Application. Serial No. 11 / 014,895 entitled "KNIFE RETRACTION ARM FOR A CURVED CUTTER STAPLER", which is incorporated herein by reference. It is further contemplated that the retraction blade could be achieved by elaborating the timing between the slide bar and the locking tab, so that the tabs on the slide bar can be hooked into the blade (or vice versa) in such a way that the rotation of the slide bar causes decoupling of the retraction hooks between the knife and the slide bar only after the knife has been retracted enough to prevent the knife from being exposed from the outside of the cartridge. The trigger bar 43 is free to move distally after which, since it will not engage or actuate either the driver 131 or the blade 126. More particularly, the tabs 186 of the slide bar 184 will not move with the trigger bar 43 because the tabs 186 of the slide bar 184 rotate in a disconnected position. The impeller 131 remains in the near forward position. More particularly, and referring to Figures 6 to 8, the locking mechanism 180 includes a locking tab 182 integrally shaped with the cartridge housing 121 of the cartridge module 120. The locking mechanism 180 additionally includes a bar of shot 43 having a slide bar 184 with forwardly extending tabs 186 or teeth, aligned with the blade 126 and the driver 131 for subsequent contact therewith. The slide bar 184 is rotatably mounted to the distal end of the firing bar 43 and interacts with the locking tab 182 to control placement of the same in a form that will be discussed in more detail below. That is, the locking tab 182 is formed and sized to engage the distal end of the trigger bar 43, in particular, the side bar 184, both before and during the activation of the linear surgical stapler 20. Prior to activating the trigger transmission assembly, and with reference to Figure 6, the locking tab 182 engages with the slide bar 184 to ensure that the tabs of the slide bar 186 are properly aligned with the blade tabs 188 that they extend backward from the proximal end of the blade 126. From the activation of the firing transmission assembly and the forward movement of the firing bar 43 (see Figure 7), the distal end of the firing bar 43, which is provided with a forwardly extending slide bar 184 having aligned tabs 186 extending therefrom, contacting the cutter 126 and impeller 131 to move blade 126 and impeller 131 forwardly in contact with anvil 122 to form staples between the impeller and the anvil. Specifically, the slide bar 184 at the distal end of the firing bar 43 makes contact with the tabs of the blade 188 extending backward from the proximal end of the blade 126. This is the alignment of the bar tabs of sliding 186 with the blade tabs 188 that allow movement of the blade 126 to cut the tissue into a desired shape. The movement of the blade 126 to its forward position ultimately results in the cutting of the fabric. In addition to moving the blade 126 and the pusher 131, the firing bar 43 also moves the locking tab 184 forward in alignment with the proximal side of the blade 126. As the firing bar 43 retracts (see FIG. 8), the housing structure of the cartridge 131 moves proximally, although the locking tab 182 remains positioned substantially adjacent the proximal end of the blade 126 and is suspended to remain in contact with the slide bar 184. Without the locking tab 182 in contact with the slide bar 184, the slide bar 184 rotates to a locked position. In this locked position, the tabs 186 along the slide bar 184 are out of alignment with the blade tabs 188. In this position, although the trip bar 43 can still be moved distally towards the blade 126 and the impeller 131, the tabs 186 of the slide bar 184 will not contact the blade tabs 188 and, consequently, the trip bar 43 does not have the ability to move the blade 126 forward towards the anvil 122. As you will appreciate surely those experts in the field, the present locking mechanism can be employed in a variety of environments without departing from the spirit of the present invention. For example, the embodiment described above could only be interpreted as a stapler, without a blade and with the tabs formed on the impeller. In addition, and referring to Figures 9, 10 and 11, a variation of the present locking mechanism can be employed in a surgical instrument that does not include a blade. According to this embodiment, the blade is removed and the locking tab is formed as part of the impeller and the impeller tabs. Although this embodiment discloses a variation of the locking tab structure described above used in conjunction with an apparatus that does not include a blade, the various components of the two embodiments could, of course, be exchanged without departing from the spirit of the present invention. Referring to Figures 9, 10 and 11, the components of this alternative embodiment of the trigger mechanism lock mechanism 280 will now be described. According to a preferred embodiment of the present invention, the cartridge module 220 is provided with a locking tab 282 that interferes with a slide bar 284 positioned at the distal end of the firing bar 43, moving the slide bar 284, such that the tabs 286 on the slide bar 284 are placed in line with the slide bars 284. tabs 288 on the impeller 231 before firing. In fact, the locking tab 282 is formed as part of the driver 231 and moves with the driver 231 during the approach and firing. When the firing transmission assembly moves distally, the firing bar 43 moves the pusher 231 toward the tissue, thereby stapling the previously determined tissue area. During approach and firing, the locking tab 282 moves distally with the driver 231 to a neutral position in the cartridge module 220. After the firing transmission assembly retracts, the pusher 231 and the locking tab 282 they remain in the distal position in the cartridge module 220. The slide bar 284 is then moved in its disengaged position by a spring 290 because the locking tab 282 no longer forces it in its firing position. The firing bar 43 is free to move distally, after which, as it will not engage or activate the pusher 231. More particularly, the pusher 231 will not move with the firing bar 43 because the bar tabs 286 Sliding members 284 are moved to a disengaged position out of alignment with the tabs 288 of the pusher 231. The pusher 231 remains in the near proximal position away from the trigger bar 43 after firing. More particularly, and with reference to Figures 6 to 8, the locking mechanism 280 includes a locking tab 282 integrally formed with the driver 231. The locking mechanism 280 additionally includes a trip bar 43 having a slide bar 284 with forwardly extending tabs 286, or teeth, aligned with the driver 231 to make subsequent contact therewith. The slide bar 284 is mounted to the distal end of the firing bar 43 in a shape that allows movement relative thereto and interacts with the locking tab 282 to control placement of the same in a manner that will be discussed later. in more detail The locking tab 282 is formed and sized to couple the distal end of the trigger bar 43, in particular, the side bar 284, both before and during the activation of the linear surgical stapler 20. Prior to activation of the transmission assembly of firing, and with reference to Figure 6, the locking tab 282 engages the slide bar 284 to ensure that the lugs of the slide bar 286 are properly aligned with the lugs of the driver 288 that extend rearward from the proximal end of the impeller 231. From the activation of the firing transmission assembly and the forward movement of the firing bar 43 (see Figure 7), the distal end of the firing bar 43, which is provided with a forwardly extending slide bar 284 having aligned tabs 286 extending therefrom, makes contact with the pusher 231 to move the pusher 231 toward front in contact with the anvil 222 to form the staples between the pusher 231 and the anvil 222. Specifically, the slide bar 284 at the distal end of the firing bar 43 makes contact with the tabs of the driver 288 that extend backward from the proximal end of the pusher 231. In this alignment of the tabs of the slide bar 286 the blade tabs 288 allow movement of the pusher 231 to trigger the staples in a desired manner. In addition to moving the pusher 231, the firing bar 43 also moves the locking tab 282 forward with the driver 231 to which it is attached. As the slide bar 43 retracts (see Figure 8), the locking tab 282 remains substantially positioned adjacent the proximal end of the driver 231 and stops to remain in contact with the slide bar 284. Without the tongue lock 282 in contact with slide bar 284, slide bar 284 moves to a locked position. In this locking position, the tabs 286 along the slide bar 284 are out of alignment with the drive tabs 288. In this position, although the trip bar 43 can still be moved distally towards the driver 231, the tabs 286 of the slide bar 284 will not make contact with the drive lugs 288 and the slide bar 43, thus, it does not have the ability to move the driver 231 forward towards the anvil 122. As will be appreciated by those skilled in the art , it is possible that the firing bar could make contact with the locking tab attached to the impeller and push the impeller slightly forward even after the slide bar has been moved. However, this can be remedied in a variety of ways by moving the locking tab out of alignment with the trigger bar after activating it or otherwise preventing the sliding bar from engaging the locking tab after the activation of it.

For example, the device could be designed in such a way that the firing bar is no longer positioned transversely to the locking tab after firing. The present invention overcomes the deficiency of the prior art in that the prior art designs mechanically prevent the firing bar from moving distally. As such and unlike the prior art locking systems, which require the device to survive a high stress if the user attempts to disrupt the locking mechanism, the present locking mechanism disengages the trigger mechanism completely, removing any force of transmission that the device could require to survive the high loads, that is, the firing bar is completely disconnected from the impeller and / or the blade after the firing thereof. This allows a wider range of materials that could be used to produce the device and structures that are less bulky, since the device does not have to survive high blocking forces. This could allow for easier manufacturing capacity and cost savings while providing the user with a compatible device in a more ergonomic way. In addition, the present locking mechanism provides clear feedback that the locking mechanism has been activated and may, therefore, not be confused with a jammed system; that is, after the system is fired, the firing bar moves freely in a way that is clearly indicative of a fired system and could not be confused with a jammed system.

Although the preferred embodiments have been shown and described, it should be understood that there is no intent to limit the present invention to said description, but instead, it is intended to cover all modifications and alternative constructions that are within the spirit and scope of the present invention.

Claims (20)

NOVELTY OF THE INVENTION CLAIMS

1. - A surgical stapler adapted to apply a plurality of surgical fasteners to the body tissue, characterized in that the surgical stapler comprises: an anvil structure; a cartridge housing that includes at least one component for the application of surgical fasteners housed therein; a trigger mechanism; and a locking mechanism for activating and deactivating the firing mechanism by disconnecting the firing mechanism of the component housed within the cartridge housing.

2. The surgical stapler according to claim 1, further characterized in that the cartridge housing contains a plurality of surgical fasteners and a blade, the cartridge housing and the anvil structure being relatively movable between a first and a second position. position in close approximation to each other.

3. The surgical stapler according to claim 2, further characterized in that the firing mechanism is associated with the cartridge housing for expelling the surgical fasteners from the cartridge housing to be urged against the anvil structure.

4. The surgical stapler according to claim 3, further characterized in that the tripping mechanism includes a slide bar at its distal end and the locking mechanism includes a locking tab that interferes with the slide bar of the tripping mechanism which moves the slide bar, such that the tabs on the slide bar move out of alignment with the tabs on the blade during the firing of the surgical stapler to disconnect the firing mechanism of the blade and prevent subsequent firing of the surgical stapler.

5. The surgical stapler according to claim 4, further characterized in that after the locking tab is moved distally, the firing mechanism is retracted and the locking tab remains in the distal position in the cartridge housing.

6. The surgical stapler according to claim 5, further characterized in that retraction of the trigger mechanism causes the slide bar to be moved away from the locking tab and the slide bar moved to its connected position.

7. The surgical stapler according to claim 1, further characterized in that the cartridge housing contains a plurality of surgical fasteners and an impeller, the cartridge housing and the anvil structure being relatively movable between a first and second separated position. position in close approximation to each other.

8. The surgical stapler according to claim 7, further characterized in that the firing mechanism is associated with the cartridge housing for expelling the surgical fasteners from the cartridge housing to be urged against the anvil structure.

9. - The surgical stapler according to claim 8, further characterized in that the trigger mechanism includes a slide bar at its distal end and the locking mechanism includes a locking tab that interferes with the slide bar of the trigger mechanism that moves the slide bar, in such a way that the tabs on the slide bar move out of alignment with the tabs on the impeller during the firing of the surgical stapler to disconnect the firing mechanism from the blade and the impeller and prevent the firing subsequent of the surgical stapler.

10. The surgical stapler according to claim 9, further characterized in that after the locking tab is moved distally, the firing mechanism retracts and the locking tab remains in the distal position in the cartridge housing.

11. The surgical stapler according to claim 10, further characterized in that retraction of the firing mechanism causes the slide bar to be moved proximally away from the locking tab and the slide bar moved to its disengaged position.

12. The surgical stapler according to claim 1, further characterized in that the trigger mechanism includes a slide bar at its distal end and the slide bar is deflected by a spring.

13. The surgical stapler according to claim 1, further characterized in that the trigger mechanism includes a slide bar at its distal end and prior to activation of the trigger mechanism, the slide bar includes teeth that extend distally aligned with the component housed within the cartridge housing of the linear surgical stapler for subsequent contact therewith.

14. The surgical stapler in accordance with the claim 13, characterized in that before activation of the firing mechanism, a locking tab engages the slide bar to ensure that the teeth are properly aligned with the tabs extending proximally formed along the component housed therein. of the cartridge housing.

15. A locking mechanism that interacts with a cartridge housing of a surgical stapler for selective activation and deactivation thereof, the surgical stapler includes an anvil structure and a cartridge housing, the surgical stapler also includes a mechanism for shot associated with the cartridge housing for ejecting the surgical fasteners from the cartridge housing to be urged against the anvil structure, the firing mechanism includes a slide bar at its distal end adjacent to the cartridge housing, characterized in that the locking mechanism comprising: a locking tab that interferes with the slide bar of the trip mechanism that moves the slide bar, such that the tabs on the slide bar move out of alignment with the tabs on a component housed within the housing of cartridge during the shot of the engra surgical punch to prevent subsequent tripping of the linear surgical stapler.

16. The locking mechanism according to claim 15, further characterized in that during the firing of the linear surgical stapler, the firing mechanism moves the locking tab distally to a neutral position in the cartridge housing.

17. The locking mechanism according to claim 16, further characterized in that after the locking tab is moved distally, the firing mechanism is retracted, and the locking tab remains in the distal position in the cartridge housing. .

18. The locking mechanism according to claim 17, further characterized in that retraction of the firing mechanism causes the slide bar to be moved proximally away from the locking tab, and the slide bar moves to its disconnected position. .

19. The locking mechanism according to claim 15, further characterized in that the slide bar is deflected by a spring.

20. The locking mechanism according to claim 15, further characterized in that prior to activation of the firing mechanism, the slide bar includes teeth extending distally aligned with the components of the cartridge housing for subsequent contact with the same. .