CN115227315A

CN115227315A - Secondary triggering safety mechanism for cutting anastomat

Info

Publication number: CN115227315A
Application number: CN202110438781.2A
Authority: CN
Inventors: 王海涛; 杨卫民
Original assignee: Changzhou Kangdi Medical Stapler Co Ltd
Current assignee: Changzhou Kangdi Medical Stapler Co Ltd
Priority date: 2021-04-23
Filing date: 2021-04-23
Publication date: 2022-10-25

Abstract

The invention relates to a secondary firing safety mechanism for a cutting stapler, the cutting stapler (100) being provided with a cutting knife arranged within a hollow housing, the cutting knife being configured to be movable proximally and distally along an axial direction of the housing, characterized in that the secondary firing safety mechanism is provided with a secondary firing safety disc (130) arranged at an outer peripheral side of the housing and movable in conjunction with the movement of the cutting knife, and a blocking pin (140) arranged within a through hole (128) in the housing wall, the blocking pin being configured such that: during a firing event, the blocking pin is biased by the biasing member away from the cutting blade and does not protrude from the through hole to inside the housing to allow the cutting blade to advance proximally and then retract distally proximally; when secondary firing is desired, the secondary firing safety tab urges the blocking pin against the biasing force of the biasing member such that the blocking pin at least partially protrudes from the through hole to the inside of the housing to prevent proximal distal advancement of the cutting blade.

Description

Secondary triggering safety mechanism for cutting anastomat

Technical Field

The invention relates to a secondary triggering safety mechanism for a cutting anastomat. In particular, the present invention relates to a secondary firing safety mechanism for a single-use cutting stapler.

Background

Cutting staplers are widely used in a variety of minimally invasive procedures, such as for the excision, transection and anastomosis of tissue in open procedures for abdominal, gynecological, pediatric and thoracic surgery. Cutting staplers are typically configured to clamp tissue to be resected or transected between two jaw members, with a cutting knife extending between the jaw members to resect or transect the tissue. To effect anastomosis of tissue incisions, one of the two jaw members typically includes a staple cartridge in which staples are stored, while the other typically includes an anvil which cooperates therewith. Such cutting staplers are typically disposable. After the cutting stapler is used (i.e., the cutting knife is fired) once, there are no more staples in the cartridge. If the doctor mistakenly uses the cutting anastomat for the second time, the risk that only the cutting knife cuts the tissue and the tissue incision is not sutured occurs, and medical accidents such as operation failure and the like are easily caused. For this reason, the cutting stapler needs to be provided with a safety mechanism for preventing the secondary triggering of the cutting knife. For example, there are cutting staplers provided with a secondary firing safety mechanism comprising a sleeve member provided with a firing adjustment through hole, a firing safety block and a spring plate provided on an inner core inside the sleeve member, and the like. However, it remains desirable in the art to provide an improved after-fire safety mechanism, or more alternative after-fire safety schemes, so that a manufacturer or user may select the appropriate after-fire safety mechanism for a particular application, manufacturing process, etc.

Furthermore, in practice, a firing test is required before the cutting stapler is shipped for sale or medical use. Due to the secondary triggering safety, the cutting anastomat which is tested and triggered once can not be used for secondary triggering. At this time, the second firing safety needs to be reset after the test. For example, prior art cutting staplers reset the secondary firing safety mechanism by externally depressing the firing safety block through the firing adjustment through hole of the cannula member. However, there is a problem that the impact safety block is distorted due to uneven pressing force. If the triggering safety block is distorted after resetting, the secondary triggering safety mechanism can not be ensured to play a role correctly in the subsequent medical use process.

Disclosure of Invention

In order to overcome at least one of the above-mentioned drawbacks existing in the prior art, according to a first aspect of the present invention, there is provided a secondary firing safety mechanism for a cutting stapler provided with a cutting knife arranged within a hollow housing, the cutting knife being configured to be movable proximally and distally along an axial direction of the housing, characterized in that the secondary firing safety mechanism is provided with a secondary firing safety disc arranged on an outer peripheral side of the housing and movable in conjunction with the movement of the cutting knife, and a blocking pin arranged within a through hole in a wall of the housing, the blocking pin being configured such that: during a firing, the blocking pin is biased away from the cutting blade by a biasing member from protruding from the through hole to inside the housing to allow the cutting blade to advance proximally and then retract distally proximally; when secondary firing is desired, the secondary firing safety tab urges the blocking pin against the biasing force of the biasing member such that the blocking pin at least partially protrudes from the through hole into the housing interior to prevent proximal distal advancement of the cutting blade. By utilizing the secondary triggering safety mechanism of the cutting anastomat, the secondary triggering of the cutting knife can be reliably prevented, and the condition that only the cutting knife cuts the tissue and the tissue incision is not sutured is avoided; and the structure and the reset of the secondary triggering safety mechanism are simple.

According to a preferred embodiment, the secondary firing safety catch comprises an elongated body extending in the axial direction of the housing, which housing is correspondingly provided with an axial groove in the peripheral side wall which is longer than the elongated body. In this way, the elongated body can be housed in a slidable manner along the axial groove between a distal end position and a proximal end position on the peripheral side of the housing.

According to a preferred embodiment, the elongated body of the secondary firing safety disc is provided with a cantilevered arm movable under the action of external forces perpendicularly to said axial direction, said cantilevered arm being provided at a free end with a first tab configured to protrude inside said housing from an axial through slot provided at the bottom of the axial groove, and said cutting knife is provided with a corresponding second tab. Such first lug and second lug can be used for realizing the interlock between cutting knife and the secondary percussion rupture disc.

According to a preferred embodiment, the first tab of the double firing safety plate is in a triangular configuration with the inclined plane proximal and the vertical plane distal, and the second tab of the cutting knife is in a triangular configuration with the inclined plane distal and the vertical plane proximal. The first bump and the second bump are simple in structure and convenient to manufacture.

According to a preferred embodiment, the first and second lugs are configured such that: when the cutting knife advances from the near side to the far side in the primary firing process, the inclined surface of the second lug of the cutting knife presses the inclined surface of the first lug of the secondary firing safety piece towards the axial through groove, so that the first lug retracts towards the axial through groove to allow the cutting knife to pass through; and when the cutting knife after the primary firing withdraws from the far side to the near side, the vertical surface of the second lug of the cutting knife abuts against the vertical surface of the first lug of the secondary firing safety piece, so that the secondary firing safety piece moves to the near side together with the cutting knife until the secondary firing safety piece reaches the near side end position. Like this, through the interlock between the first lug of secondary trigger insurance spare and the second lug of cutting knife, just can realize the "activation" of secondary trigger insurance mechanism. As used herein, "activated" means that the secondary firing safety mechanism is thereafter capable of preventing secondary firing of the cutting blade.

According to a preferred embodiment, the elongated body is provided with a stepped portion comprising, in order in a direction from the proximal side to the distal side, a first step portion of lowest height, an inclined portion obliquely rising from the first step portion towards the distal side and connected between the first step portion and a second step portion, and said second step portion having a height greater than the first step portion but lower than the rest of the elongated body. By such a stepped portion being integrally provided on the secondary firing safety, the effect of blocking the secondary firing of the cutting blade can be achieved in a simple manner in cooperation with the blocking pin.

According to a preferred embodiment, the first step of lowest height is located below the blocking pin when said secondary firing safety is in the distal end position, so that said biasing member biases the blocking pin away from the cutting blade, such that the blocking pin does not protrude from the through hole to the inside of the housing. At this time, the blocking pin, which does not protrude from the through hole to the inside of the housing, allows one shot of the cutting blade.

According to a preferred embodiment, when the secondary firing safety is in the proximal end position, a second step having a height greater than the first step but less than the remainder of the elongate body is located below the blocking pin to urge the blocking pin against the biasing force of the biasing member to at least partially protrude from the through hole into the housing interior to prevent proximal distal advancement of the cutting burr. At this time, the blocking pin protruding from the through hole to the inner side of the shell prevents the cutting knife from passing through, thereby preventing the secondary percussion of the cutting knife.

According to a preferred embodiment, the cutting burr is provided with a third cam which is able to pass over the blocking pin when the secondary firing safety is in the distal end position, so that the cutting burr is advanced proximally distally and withdrawn distally proximally; the blocking pin blocks passage of the third tab when the secondary firing safety is in the proximal end position to block proximal distal advancement of the cutting blade.

According to a preferred embodiment, the secondary firing safety mechanism of a cutting stapler that has been fired once can be reset as follows: hooking a cantilevered arm of a secondary firing safety with a hook through an adjustment opening on an outer sleeve of the cutting stapler, pulling the cantilevered arm outward to release an abutment between a first tab of the secondary firing safety and a second tab of the cutting knife, and then pulling the cantilevered arm distally after the abutment is released to move the secondary firing safety to its distal end position. The secondary triggering safety mechanism of the cutting anastomat can be simply and reliably reset, and related parts of the cutting anastomat are not easily damaged in the resetting process.

According to a preferred embodiment, the biasing means is a compression spring in a compressed state, and the blocking pin is a metal pin captured between the coils of the compression spring.

Further features of the invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings.

Drawings

The present invention will now be described in detail hereinafter with reference to the accompanying drawings. It is to be understood that the figures are not necessarily to scale; in addition, components shown in one drawing may be omitted from other drawings for ease of illustration. The drawings are only for purposes of illustrating exemplary embodiments of the invention and are not to be construed as limiting the scope of the invention. In the drawings:

FIG. 1 is a perspective view schematically illustrating an implement assembly of a cutting stapler 100 in accordance with an exemplary embodiment of the present invention;

fig. 2 is an exploded perspective view schematically illustrating components of an actuating assembly of the cutting stapler 100;

fig. 3 is an enlarged view of a portion a of fig. 2;

FIG. 4 is a close-up view of the secondary firing safety 130 schematically illustrated in its distal-most distal position P1;

FIG. 5 is a close-up view schematically illustrating the secondary firing safety 130 in its proximal-most distal position P2;

FIG. 6 is a cross-sectional view schematically illustrating an initial state of an actuating assembly of cutting stapler 100 prior to first use;

fig. 7 is an enlarged sectional view of a portion B of fig. 6;

fig. 8 is a sectional view schematically showing a state after the cutting knife 120 of the cutting stapler 100 is fired once;

fig. 9 is an enlarged sectional view of a portion C of fig. 8;

FIG. 10 is a cross-sectional view schematically illustrating the cutting blade 120 after completion of the cut as it is being pulled back into contact with the secondary firing safety 130;

fig. 11 is an enlarged sectional view of a portion D of fig. 10;

FIG. 12 is a cross-sectional view schematically illustrating a state when the cutting burr 120 is pulled back to the proximal end position P2 and the blocking pin 140 is in a blocking position capable of blocking the cutting burr 120 from being fired again; and

fig. 13 is an enlarged sectional view of a portion E of fig. 12.

Detailed Description

Exemplary embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It is to be understood that the description of the various embodiments is illustrative only and is not intended to limit the technology of the present invention in any way. It is also to be understood that the embodiments disclosed herein can be combined in various ways to provide further additional embodiments.

It should be understood that throughout the drawings, like reference numerals refer to like elements. In the drawings, the dimensions of some of the elements may be modified, exaggerated or reduced for clarity; or some components may be omitted or shown in somewhat schematic form in order to highlight certain components.

Unless otherwise indicated, all terms used in the specification have the meanings commonly understood by those skilled in the art. Well-known functions or constructions may not be described in detail for brevity and/or clarity.

As used in this specification, the singular forms "a", "an" and "the" may include the plural forms as well, unless expressly specified otherwise. The terms "comprising," "including," and "containing" when used in this specification specify the presence of stated features, but do not preclude the presence or addition of one or more other features. The term "and/or" as used in this specification includes any and all combinations of one or more of the associated listed items.

In the description, when an element is referred to as being "on," "attached" to, "connected" to, or "contacting" another element, etc., it can be directly on, attached to, connected to, or contacting the other element or intervening elements may be present.

In the specification, the terms "first", "second", "third", and the like are used only for distinguishing the respective components, and are not intended to limit the order and function of the respective components. Further, "second" or "third" etc. subsequent components may be provided without providing or employing "first" etc. prior components.

In the specification, "proximal" refers to the side of the operator that is closer to the cutting stapler 100, while "distal" refers to the side that is further away from the operator (i.e., closer to the patient).

In the specification, "left", "right", "upper", "lower", "outer", "inner", and the like are referred to directions in the drawings unless otherwise specified. It should be understood that spatial relationships such as "left", "right", "upper", "lower", "outer", "inner", and the like are intended to describe the relationship of one feature to another in the drawings. It should be understood that the spatial relationship terms encompass different orientations of cutting stapler 100 in use or operation in addition to the orientation depicted in the figures.

First, a cutting stapler 100 according to an exemplary embodiment of the present invention, and in particular, an executing assembly of the cutting stapler 100 configured to cut and staple tissue will be described with reference to fig. 1-2. The actuation assembly of cutting stapler 100 includes a pair of clamping members 110 configured to be closed relative to each other to sandwich tissue to be cut and to be opened relative to each other. Specifically, the pair of holding members includes a cartridge member 111 in which staples for stapling are stored, and a staple abutment seat 112 opposed to the cartridge member 111. The actuation assembly of cutting stapler 100 also includes a cutting knife 120 configured to cut (e.g., excise or transect) tissue, and a drive sleeve 121 configured to drive the cutting knife 120 along its longitudinal axis, the drive sleeve 121, in turn, being operatively connectable to an actuation source, such as an actuation lever (not shown), of the cutting stapler 100. The cutting blade 120 is a sheet-like member arranged in a plane orthogonal to the plane of the clamping surface 113 of the cartridge member 111 and the plane of the clamping surface 114 of the anvil 112. The cartridge member 111 and the anvil 112 are provided with a first slot 115 and a second slot 116, respectively, for receiving a cutting knife 120 advancing towards the tissue to be cut. Normally, the cutting blade 120 and its driving sleeve 121 in a standby state are accommodated in a cylindrical housing consisting of an upper half-shell 122 and a lower half-shell 123 opposite to each other. The upper and

lower housing halves

122, 123 are in turn received in a sleeve 124. The cartridge member 111 and anvil 112 are operably connected to the upper and

lower housing halves

122 and 123, respectively, via an adapter joint 117, a swivel head pin 118, and a connecting tab 119, etc.

Next, the secondary firing safety mechanism of the cutting stapler 100 will be described in detail. As shown in the enlarged partial view of fig. 3, the secondary firing safety mechanism includes a secondary firing safety 130. The secondary firing safety 130 is configured to include an elongated body 131 extending in the axial direction of the lower housing half 123 (i.e., the forward-rearward movement direction of the cutting blade 120) and two arcuate arms 132 extending laterally from the elongated body 131 to both sides. Together, the two arcuate arms 132 form a semi-circular ring orthogonal to the elongate body 131. As shown in fig. 4 and 5, in the peripheral side wall of the lower half-shell 123, there are provided an axial groove 125 formed by cutting away a portion of the lower half-shell 123 and a circumferential groove 126 orthogonal to the axial groove 125 for accommodating an elongated body 131 and an arc-shaped arm 132, respectively, of a secondary firing safety 130. In fig. 4 and 5, the ferrule 124 located outside the lower housing half 123 is removed for ease of illustration. However, in the assembled state, the double firing safety 130 will be clamped with some play between the lower half-shell 123 and the sleeve 124. The axial length of the axial recess 125 is greater than the axial length of the elongate body 131 of the double firing safety 130 so that the elongate body 131 is able to move within the axial recess 125 in the axial direction of the lower housing half 123. Also, the width of the circumferential groove 126 in the axial direction is larger than the width of the arc-shaped arm 132 in the axial direction, so that the arc-shaped arm 132 can move within the circumferential groove 126 in the axial direction of the lower half shell 123. The circumferential groove 126 serves to define two end-of-travel positions of the secondary firing safety 130 relative to the lower housing half 123, a distal end position P1 (see fig. 4) and a proximal end position P2 (see fig. 5), as will be described further below. The arcuate arms 132 may also be provided with hooks 133 at free ends configured to be hooked to corresponding locations on the lower housing half 123 for movably attaching the secondary firing safety 130 to the lower housing half 123.

The elongate body 131 of the secondary firing safety 130 is provided with a cantilevered arm 134 at the distal end. The cantilever arms 134 can move within a certain range in a direction perpendicular to the axial direction (i.e., a radial direction of the housing, or an up-down direction) by an external force. The sleeve 124 is provided with an adjustment opening (not shown) for resetting the secondary firing safety mechanism at a position corresponding to the cantilevered arm 134. The cantilevered leg 134 is provided at a proximal free end with a first tab 135 projecting upwardly from an inner side surface of the elongate body 131. Furthermore, at the bottom of the axial groove 125 of the lower half-shell 123, a through axial through slot 125' is provided (see fig. 4, 5). The first tab 135 is configured to protrude into the housing through the axial through slot 125'. The first tab 135 can have a triangular configuration with an inclined face on the proximal side and an upright face on the distal side. Correspondingly, a second tab 127 protruding downwards and configured to be able to interact with the first tab 135 is provided on the cutting knife 120. The second tab 127 can also have a triangular configuration with an inclined face on the distal side and a vertical face on the proximal side. The interaction of the first and

second bumps

135 and 127 will be described further below.

In addition, the elongate body 131 of the secondary firing safety 130 is also provided with a stepped portion at the proximal end, as shown in fig. 3. The stepped portion includes, in order in a proximal to distal direction, a first stepped portion 136 having a lowest height and being substantially horizontal, a slanted portion 137 obliquely rising from the first stepped portion 136 toward the distal side and connecting between the first stepped portion 136 and a second stepped portion 138, the second stepped portion 138 having a height greater than the first stepped portion 136 but still lower than the rest of the elongated body 131, and a shoulder 139 formed between the second stepped portion 138 and the rest of the elongated body 131. At a position in the lower housing half 123 overlapping the axial groove 125, a through hole 128 formed through the sidewall of the lower housing half 123 is also provided. Blocking pins 140 (e.g., metal pins) are disposed within through holes 128 in the wall of lower housing half 123. Furthermore, the biasing means is configured to always bias the blocking pin 140 in a direction away from the inside of the lower housing half 123 (i.e. away from the cutting burr) (i.e. downwards in fig. 6-13). The biasing means may be two compression springs 141 in compression, the blocking pin 140 being clamped between the coils of the two springs 141 at both sides. During operation of the cutting stapler 100, the blocking pin 140 housed within the through hole 128 of the lower half-shell 123 is only movable in a direction perpendicular to the axial direction (i.e., the vertical direction in fig. 6-13) with respect to the lower half-shell 123, and is not movable in the axial direction with respect to the lower half-shell 123. The thickness of the blocking pin 140 is configured to be slightly less than or equal to the difference in height between the first step 136 and the rest of the elongated body 131, but higher than the difference in height between the second step 138 and the rest of the elongated body 131, i.e. the height of the shoulder 139. As shown in fig. 7, the cutting blade 120 is further provided with a third protrusion 129 protruding downward at the proximal side of the through hole 128. The third tab 129 may also have a triangular configuration with an inclined face on the proximal side and a vertical face on the distal side. The third protrusion 129 of the cutting knife 120 and the second protrusion 127 protrude downward to substantially the same height. The blocking pin 140 will cooperate with the previously described stepped portion and the third tab 129 to prevent the cutting blade 120 from being fired again to move in the distal direction after one firing, as will be described in more detail below.

The structure of the actuating assembly of cutting stapler 100 has been described above in connection with fig. 1-5 and the like. It should be noted, however, that only the components of the cutting stapler 100 that are associated with the secondary firing safety mechanism are described herein. However, the actuating assembly of the cutting stapler 100 may also include many other components in addition to those described above, the structure and function of which are known to those skilled in the art and will not be described in further detail herein.

Next, the action mechanism of the secondary-fire safety mechanism will be described in detail.

First, as shown in fig. 6 and 7, in an initial state before the first use of the cutting stapler, the cutting knife 120 and its driving sleeve 121 are located at their proximal end position within the housing, and the cartridge member 111 and the anvil 112 are in an open state. At this point, the secondary firing safety 130 is in its distal tip position P1 (see fig. 4), the second tab 127 of the cutting knife 120 is proximal to the first tab 135 of the secondary firing safety 130, the blocking pin 140 is biased downward by the compression spring 141 to retract into the through hole 128 and rest on the first step portion 136 of the secondary firing safety 130, which is the lowest in height, and the third tab 129 of the cutting knife 120 is proximal to the blocking pin 140.

Next, as seen in fig. 8 and 9, as the cutting knife 120 is driven by its drive sleeve 121 to move further in the distal direction, the second tab 127 of the cutting knife 120 passes over the first tab 135 of the secondary firing safety 130, and the third tab 129 of the cutting knife 120 passes over the blocking pin 140 from between the two compression springs 141 and also over the first tab 135 of the secondary firing safety 130, whereby the cutting knife 120 reaches its distal most end position. Note that since the inclined surface of the first tab 135 is located proximally, as the cutting blade 120 moves proximally distally, the passing second tab 127 and third tab 129 each press downwardly against the inclined surface of the first tab 135, causing the cantilevered arms 134 and the first tab 135 to move back downwardly to allow the second tab 127 and the third tab 129 to pass. The cutting knife 120, which is located in its most distal position, can perform a cutting operation on the tissue to be cut, which is now clamped by the closed cartridge member 111 and the anvil 112.

Next, after the cutting operation is completed, the operator will pull back the cutting blade 120 proximally. Fig. 10, 11 schematically illustrate the cutting knife 120 as it is being pulled back into contact with the secondary firing safety 130. At this point, the vertical face of the downwardly projecting second tab 127 of the cutting knife 120 has just abutted the vertical face of the upwardly projecting first tab 135 of the secondary firing safety 130, the third tab 129 of the cutting knife 120 is located just above the blocking pin 140, the blocking pin 140 is located on the first step 136, and the secondary firing safety 130 is still in its distal tip position P1.

Finally, as the operator further pulls back the cutting knife 120 proximally, the secondary firing safety 130, with its first tab 135 in abutment with the second tab 127 of the cutting knife 120, will move proximally along with the cutting knife 120 until the secondary firing safety 130 reaches its proximal-most end position P2, as shown in fig. 12, 13. In this process, the inclined portion 138 (see fig. 3) will first pass under the blocking pin 140 biased downward by the compression spring 141, and the gradually passing inclined portion 138 will compress the compression spring 141 upward, so that the blocking pin 140 moves upward until the second stepped portion 138 having the greatest height is located under the blocking pin 140 and the blocking pin 140 at least partially protrudes from the through hole 128 toward the inside of the lower half casing 123. Thereafter, the operator withdraws the cutting stapler 100 from the operated site of the patient.

Thus, one firing of cutting stapler 100 is completed. Since the cutting stapler 100 is disposable, the used cutting stapler 100 should be discarded. Should the operator inadvertently and incorrectly re-use such a cutting stapler 100 that has been fired once, the cutting knife 120 will move distally from the condition shown in fig. 13. After the cutting burr 120 is slightly moved distally from the state shown in fig. 13, the third tab 129 of the cutting burr 120 will contact the blocking pin 140 protruding from the through hole 128 to the inside of the lower half-shell 123. The protruding blocking pin 140 prevents the third tab 129 of the cutting burr 120 from passing, thereby preventing the cutting burr 120 from moving further distally.

By utilizing the secondary triggering safety mechanism of the cutting anastomat 100, the secondary triggering of the cutting knife 120 is reliably prevented, and the condition that only the cutting knife cuts the tissue and the tissue incision is not sutured is avoided.

Next, the resetting of the secondary firing safety mechanism will be described in detail.

Before the cutting anastomat leaves a factory for sale or medical use, a triggering test needs to be carried out, and a secondary triggering safety needs to be reset after the triggering test, otherwise, the cutting anastomat after being triggered once by the test cannot be used for secondary triggering. The cutting stapler 100 according to the present invention is once fired by the manufacturer according to the above procedure before shipment, and thus the secondary firing safety mechanism of the cutting stapler 100 will be in a state as shown in fig. 13. The manufacturer then extends a specially designed hook (not shown) from a correspondingly provided adjustment opening in the sleeve to hook the cantilevered leg 134 of the secondary firing safety 130, pulling the cantilevered leg 134 outwardly to release the abutment between the first tab 135 on the cantilevered leg 134 and the second tab 127 of the cutting burr 120. The manufacturer also pulls the cantilevered arm 134 distally after the abutment is released to move the secondary firing safety 130 to its distal tip position P1. In this way, the secondary firing safety 130 will return to the initial state as described in fig. 6 and 7, i.e.: the second tab 127 of the cutting knife 120 is located proximal to the first tab 135 of the secondary firing safety 130, the blocking pin 140 is biased by the compression spring 141 downward into the through hole 128 to rest on the first step portion 136 of the secondary firing safety 130, and the third tab 129 of the cutting knife 120 is located proximal to the blocking pin 140. The cutting stapler 100 after the secondary firing safety mechanism is reset can be fired again for use.

According to the secondary triggering safety mechanism of the cutting anastomat 100, the resetting of the secondary triggering safety mechanism can be simply and reliably carried out, and related parts of the cutting anastomat are not easily damaged in the resetting process.

While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.

Claims

1. A secondary firing safety mechanism for a cutting stapler, the cutting stapler (100) being provided with a cutting knife (120) arranged within a hollow housing, the cutting knife (120) being configured to be movable proximally and distally along an axial direction of the housing, characterized in that the secondary firing safety mechanism is provided with a secondary firing safety tab (130) arranged at an outer circumferential side of the housing and movable in conjunction with the movement of the cutting knife (120), and a blocking pin (140) arranged within a through hole (128) in the housing wall, the blocking pin (140) being configured such that: during a firing, the blocking pin (140) is biased by a biasing member away from the cutting blade (120) from protruding from the through hole (128) inside the housing to allow the cutting blade (120) to advance proximally distally and then retract distally proximally; when secondary firing is desired, the secondary firing safety tab (130) urges the blocking pin (140) against the biasing force of the biasing member such that the blocking pin (140) at least partially protrudes from the through hole (128) to the inside of the housing to prevent proximal distal advancement of the cutting blade (120).

2. The double firing safety mechanism for cutting staplers as claimed in claim 1, wherein said double firing safety tab (130) comprises an elongated body (131) extending along the axial direction of the housing, said housing being correspondingly provided in a peripheral side wall with an axial groove (125) longer than said elongated body (131), said elongated body (131) being configured to be housed at the peripheral side of the housing in a manner slidable along said axial groove (125) between a distal tip position (P1) and a proximal tip position (P2).

3. The secondary firing safety mechanism for cutting staplers as claimed in claim 2, wherein the elongated body (131) of the secondary firing safety disc (130) is provided with a cantilevered arm (134) movable perpendicular to the axial direction under the action of external forces, the cantilevered arm (134) being provided at a free end with a first cam (135), the first cam (135) being configured to protrude inside the housing from an axial through slot (125') provided at the bottom of an axial groove (125), and the cutting knife (120) being provided with a corresponding second cam (127).

4. The double firing safety mechanism for cutting staplers as claimed in claim 3, wherein the first tab (135) of the double firing safety tab (130) has a triangular configuration with an inclined plane proximally and a vertical plane distally, and the second tab (127) of the cutting knife (120) has a triangular configuration with an inclined plane distally and a vertical plane proximally.

5. The secondary firing safety mechanism for a cutting stapler of claim 4, wherein the first tab (135) and the second tab (127) are configured such that:

as the cutting knife (120) advances proximally and distally during a firing, the ramped surface of the second tab (127) of the cutting knife (120) presses the ramped surface of the first tab (135) of the secondary firing safety tab (130) toward the axial channel (125 ') such that the first tab (135) retracts toward the axial channel (125') to allow the cutting knife (120) to pass; and

when the cutting knife (120) after one firing is withdrawn from the far side to the near side, the vertical surface of the second lug (127) of the cutting knife (120) abuts against the vertical surface of the first lug (135) of the secondary firing safety piece (130), so that the secondary firing safety piece (130) moves to the near side together with the cutting knife (120) until the secondary firing safety piece (130) reaches the near side end position (P2).

6. The double firing safety mechanism for cutting staplers as claimed in claim 3, wherein said elongated body (131) is provided with a stepped portion comprising, in order in a proximal to distal direction, a first step portion (136) of lowest height, a sloping portion (137) rising obliquely distally from the first step portion (136) and connected between the first step portion (136) and the second step portion (138), and said second step portion (138) having a height greater than the first step portion (136) but lower than the rest of the elongated body (131).

7. The secondary firing safety mechanism for cutting a stapler according to claim 6, wherein when the secondary firing safety (130) is in a distal tip position (P1), the first step (136) of lowest height is located below the blocking pin (140) so that the biasing member biases the blocking pin (140) away from the cutting knife (120) such that the blocking pin (140) does not protrude from the through hole (128) to the inside of the housing.

8. The double firing safety mechanism for cutting a stapler of claim 6, wherein when the double firing safety (130) is in the proximal terminal position (P2), a second step (138) having a height greater than the first step (136) but less than a remainder of the elongated body (131) is located below the blocking pin (140) to urge the blocking pin (140) against the biasing force of the biasing member such that the blocking pin (140) at least partially protrudes from the through hole (128) inside the housing to prevent the cutting knife (120) from advancing proximally and distally.

9. The secondary firing safety mechanism for cutting a stapler according to any of claims 3 to 8, wherein the cutting knife (120) is provided with a third cam (129), said third cam (129) being capable of passing over a blocking pin (140) when the secondary firing safety (130) is in a distal tip position (P1) for the proximal distal advancement and the distal retraction of the cutting knife (120); when the secondary firing safety (130) is in a proximal end position (P2), the blocking pin (140) blocks passage of the third tab (129) to block proximal distal advancement of the cutting blade (120).

10. The double firing safety mechanism for a cutting stapler of any one of claims 3-8, wherein the double firing safety mechanism of a cutting stapler that has been fired once can be reset as follows: hooking a cantilevered arm (134) of a secondary firing safety (130) with a hook through an adjustment opening on an outer sleeve of the cutting stapler, pulling the cantilevered arm (134) outward to release abutment between a first tab (135) of the secondary firing safety (130) and a second tab (127) of the cutting knife (120), and then pulling the cantilevered arm (134) distally after the abutment is released to move the secondary firing safety (130) to its distal tip position (P1).