Ratcheting Mechanism for Surgical Stapling Device

• US 20090230170A1
• Filed: 03/04/2009
• Published: 09/17/2009
• Est. Priority Date: 03/12/2008
• Status: Active Grant

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: Tyco Healthcare Group LP (Medtronic Plc)
• Inventors: Milliman, Keith L.
• Granted Patent: US 8,733,611 B2
• Time in Patent Office: Days
• US Class Current: 227/176.100
• CPC Class Codes: A61B 17/068 Surgical staplers , e.g. containing multiple staples or clampsstaplers containing only one staple A61B17/10; magazines or containers for staples A61B17/105; for performing anastomosis A61B17/115; staplers in general B25C5/00
• CPC Class Codes: A61B 17/0684 having a forming anvil staying above the tissue during stapling
• CPC Class Codes: A61B 17/0686 having a forming anvil staying below the tissue during stapling
• CPC Class Codes: A61B 17/1114 of the digestive tract, e.g. bowels or oesophagus
• CPC Class Codes: A61B 17/115 Staplers for performing anastomosis in a single operation
• CPC Class Codes: A61B 17/1155 Circular staplers comprising a plurality of staples
• CPC Class Codes: A61B 2017/00407 Ratchet means
• CPC Class Codes: A61B 2017/00477 Coupling A61B2017/0046 takes precedence
• CPC Class Codes: A61B 2017/00685 Archimedes screw
• CPC Class Codes: A61B 2017/07221 curved
• CPC Class Codes: A61B 2017/07257 characterised by its anvil
• CPC Class Codes: A61B 2017/07278 characterised by its sled or its staple holder
• CPC Class Codes: A61B 2017/07285 characterised by its cutter
• CPC Class Codes: A61B 2017/2837 with a locking ratchet
• CPC Class Codes: A61B 2017/2923 Toothed members, e.g. rack and pinion
• CPC Class Codes: A61B 2017/2927 the angular position of the head being adjustable with respect to the shaft
• CPC Class Codes: A61B 2090/0811 for the position of a particular part of an instrument with respect to the rest of the instrument, e.g. position of the anvil of a stapling instrument

Abstract

A surgical stapling device comprising a housing, an elongated portion, an end effector, and a movable handle disposed in mechanical cooperation with the housing and movable between a first open position and a second approximated position for affecting a function of the end effector. A ratchet mechanism is disposed in mechanical cooperation with the movable handle and is configured to substantially prevent the movable handle from moving towards its first open position until the movable handle reaches a predetermined position

Claims

1. A surgical stapling device comprising:

a housing;

an elongated portion extending distally from the housing;

an end effector, at least a portion of the end effector being disposed in mechanical cooperation with a distal portion of the elongated portion;

a movable handle disposed in mechanical cooperation with the housing, the movable handle being movable between a first open position and a second approximated position for affecting a function of the end effector; and

a ratchet mechanism disposed in mechanical cooperation with the movable handle, the ratchet mechanism configured to substantially prevent the movable handle from moving towards its first open position until the movable handle reaches a predetermined position, the ratchet mechanism including;

a rack having rack teeth and a cam surface, the rack being disposed in mechanical cooperation with the housing;

a pawl having pawl teeth and being disposed in mechanical cooperation with the movable handle, the rack teeth and the pawl teeth being configured for engagement with each other; and

a spring disposed in mechanical cooperation with movable handle and being configured to bias at least one of the pawl and the rack towards the other such that the pawl teeth and the rack teeth are in engagement with one another,

wherein the cam surface is configured to disengage the pawl teeth and the rack teeth upon the cam surface contacting the pawl for facilitating movement of the movable handle towards its first open position.

2. The surgical stapling device of claim 1, wherein the end effector is configured for ejection of staples therefrom upon movement of the movable handle from its first open position towards its second approximated position, and wherein the ratchet mechanism is configured to substantially prevent the movable handle from moving towards its first open position until at least one staple has been ejected from the end effector.

3. The surgical stapling device of claim 2, wherein the cam surface of the rack moves the pawl away from the rack after at least one staple has been ejected from the end effector.

4. The surgical stapling device of claim 1, further including a knife, the knife configured for distal translation upon movement of the movable handle from its first open position towards its second approximated position, and wherein the ratchet mechanism is configured to substantially prevent the movable handle from moving towards its first open position until the knife has been distally translated.

5. The surgical stapling device of claim 4, wherein the cam surface of the rack moves the pawl away from the rack after the knife has been distally translated.

6. The surgical stapling device of claim 1, wherein the cam surface of the rack moves the pawl away from the rack when the movable handle reaches the predetermined position.

7. The surgical stapling device of claim 1, wherein the spring is a compression spring and wherein the spring is configured to bias the pawl teeth into engagement with the rack teeth.

8. The surgical stapling device of claim 1, further including an override disposed in mechanical cooperation with the pawl, the override configured to allow a user to disengage the pawl teeth from the rack teeth before the movable handle reaches the predetermined position, wherein disengagement of the pawl teeth from the rack teeth allows the movable handle to be moved towards its first open position.

9. The surgical stapling device of claim 1, further including a link disposed in mechanical cooperation with the rack and being pivotably coupled to the housing.

10. The surgical stapling device of claim 1, wherein the rack is pivotably coupled to the movable handle.

11. The surgical stapling device of claim 1, wherein the predetermined position of the movable handle is between about 0.01 inches and about 0.05 inches away from its second approximated position.

12. The surgical stapling device of claim 1, further including a clip disposed in mechanical cooperation with the ratchet mechanism, the clip configured to releasably maintain the pawl teeth and the rack teeth in a disengaged position.

13. The surgical stapling device of claim 12, wherein the clip is automatically disengaged when the movable handle reaches its first open position.

14. The surgical stapling device of claim 1, wherein the end effector includes an anvil assembly and a shell assembly, the anvil assembly including an anvil head and an anvil center rod, the shell assembly supporting a plurality of staples, the anvil assembly being movable in relation to the shell assembly between spaced and approximated positions.

15. A surgical stapling device comprising:

a housing;

an elongated portion extending distally from the housing;

an end effector disposed adjacent a distal portion of the elongated portion and including an anvil assembly and a shell assembly, the anvil assembly including an anvil head and an anvil center rod having a proximal end and a distal, the anvil head being supported on the distal end of the anvil center rod, the shell assembly supporting a plurality of staples, the anvil assembly being movable in relation to the shell assembly between spaced and approximated positions;

a movable handle disposed in mechanical cooperation with the housing, the movable handle being movable between a first open position and a second approximated position for affecting a function of the end effector; and

a ratchet mechanism disposed in mechanical cooperation with the movable handle, the ratchet mechanism configured to substantially prevent the movable handle from moving towards its first open position until the movable handle reaches a predetermined position.

16. The surgical stapling device of claim 15, further including an approximation mechanism including an anvil retainer for supporting the anvil assembly, the anvil retainer including an annular shoulder configured to engage the anvil center rod to fasten the anvil center rod to the anvil retainer.

17. A ratchet mechanism for use with a surgical stapling device, the ratchet mechanism including:

a rack having rack teeth and a cam surface,

a pawl having pawl teeth, the rack teeth and the pawl teeth being configured for engagement with each other; and

a spring disposed in mechanical cooperation with one of the pawl and the rack, the spring being positioned to bias at least one of the pawl and the rack towards the other to engage the rack teeth and the pawl teeth,

wherein the cam surface is configured to disengage the pawl teeth and the rack teeth upon the cam surface contacting the pawl and wherein the ratchet mechanism is configured to substantially prevent a movable handle of the surgical stapling device from moving towards a first open position until the movable handle reaches a predetermined position.

18. The surgical stapling device of claim 17, further including an override disposed in mechanical cooperation with the pawl, the override configured to allow a user to disengage the pawl teeth from the rack teeth before the movable handle reaches the predetermined position, wherein disengagement of the pawl teeth from the rack teeth allows the movable handle to be moved towards its first open position.

19. The surgical stapling device of claim 17, wherein the rack is pivotably coupled to the movable handle of the surgical stapling device.

20. The surgical stapling device of claim 17, wherein the predetermined position of the movable handle is between about 0.01 inches and about 0.05 inches from a second approximated position of the movable handle.