Detent feature for articulation control in surgical instrument

1. An apparatus comprising:

(a) a body;

(b) a shaft assembly extending distally from the body, wherein the shaft assembly defines a longitudinal axis;

(c) an articulation section attached to a distal end of the shaft assembly;

(d) an end effector located distally relative to the shaft assembly, wherein the end effector is connected to the articulation section; and

(e) an articulation drive assembly, wherein the articulation drive assembly is configured to drive the articulation section to deflect the end effector relative to the longitudinal axis from a non-articulated configuration to an articulated configuration, wherein the articulation drive assembly comprises:

(i) a rotatable housing rotatably coupled to the body,

(ii) one or more pins extending through the rotatable housing,

(iii) one or more drive screws slidably coupled to the one or more pins,

(iv) a static member fixed relative to the body, wherein the static member comprises a cap defining one or more pin holes, wherein each pin hole of the one or more pin holes is coupled to a respective pin of the one or more pins, and

(v) an indication feature configured to indicate when the end effector is deflected into the non-articulated configuration, wherein the indication feature comprises:

(A) a ridge extending from an exterior surface of the rotatable housing, and

(B) a cantilever arm defining a slot configured to house the ridge when the end effector is in the non-articulated configuration, wherein the cantilever arm is directly fixed to the cap and extends along a longitudinal direction from the cap.

2. The apparatus of claim 1 , wherein the slot defines an open end configured to longitudinally receive the ridge without flexing the cantilever arm.

3. The apparatus of claim 1 , wherein the ridge is configured to deflect the cantilever arm when the rotatable housing rotates the ridge into or out of the slot.

4. The apparatus of claim 3 , wherein the cantilever arm is configured to provide a tactile response to the ridge rotating into or out of the slot.

5. The apparatus of claim 3 , wherein the cantilever arm is configured to provide an audible response to the ridge rotating into or out of the slot.

6. The apparatus of claim 3 , wherein the cantilever arm is configured to provide a frictional braking force in response to the ridge rotating into or out of the slot.

7. The apparatus of claim 3 , wherein the body defines a cutout configured to house the cantilever arm when deflected by the ridge.

8. The apparatus of claim 1 , wherein the cantilever arm comprises a camming projection extending from the static member, wherein the camming projection and the ridge are configured to interact with each other when the end effector is deflected into the non-articulated configuration.

9. The apparatus of claim 8 , wherein the camming projection is resilient such that the ridge is configured to deflect the camming projection relative to the rotatable housing from a natural position to a flexed position.

10. The apparatus of claim 9 , wherein the camming projection is configured to provide a tactile response against the rotatable housing when moving from the flexed position to the natural position.

11. The apparatus of claim 8 , wherein the ridge comprises a radial contour.

12. The apparatus of claim 1 , wherein the end effector comprises at least one electrode operable to apply RF electrosurgical energy to tissue.

13. The apparatus of claim 1 , wherein the rotatable housing is configured to house a portion of the shaft assembly.

14. The apparatus of claim 13 , wherein the rotatable housing is configured to rotate relative to the shaft assembly.

15. The apparatus of claim 13 , wherein the shaft assembly is configured to translate relative to the rotatable housing.

16. An apparatus comprising:

(a) a body;

(b) a shaft assembly extending distally from the body, wherein the shaft assembly defines a longitudinal axis;

(c) an articulation section attached to a distal end of the shaft assembly;

(d) an end effector located distally relative to the shaft assembly, wherein the end effector is connected to the articulation section; and

(e) an articulation drive assembly, wherein the articulation drive assembly is configured to drive the articulation section to thereby deflect the end effector relative to the longitudinal axis from a non-articulated configuration to an articulated configuration, wherein the articulation drive assembly comprises:

(i) a housing rotatably coupled with the body, wherein the housing further comprises a radially extending ridge,

(ii) a cap coupled with the housing, wherein the cap is fixed to the body, wherein the cap defines a shaft through hole, wherein a portion of the shaft assembly extends longitudinally through the shaft through hole, and

(iii) a resilient indication feature directly attached to the cap and extending longitudinally from the cap toward the ridge, wherein the ridge is configured to flex the resilient indication feature to snap against the housing in response to the end effector deflecting into the non-articulated configuration.

17. The apparatus of claim 16 , wherein the resilient indication feature comprises a slot configured to house the ridge when the end effector is in the non-articulated configuration.

18. The apparatus of claim 17 , wherein the resilient indication feature is configured to provide a frictional braking force against the housing when the ridge is housed within the slot.

19. An apparatus comprising:

(a) a body;

(b) a shaft assembly extending distally from the body, wherein the shaft assembly defines a longitudinal axis;

(c) an articulation section attached to a distal end of the shaft assembly;

(d) an end effector located distally relative to the shaft assembly, wherein the end effector is connected to the articulation section; and

(e) an articulation drive assembly, wherein the articulation drive assembly is configured to drive the articulation section to thereby deflect the end effector relative to the longitudinal axis from a non-articulated configuration to an articulated configuration, wherein the articulation drive assembly comprises:

(i) a cap fixed to the body, wherein the cap defines a shaft through hole, wherein a portion of the shaft assembly longitudinally extends through the shaft through hole,

(ii) a rotatable housing rotatably coupled to the cap, wherein the rotatable housing comprises a ridge, and

(iii) a resilient indication feature formed with the cap such that the resilient indication feature is directly attached to the cap, wherein the resilient indication feature extends longitudinally from the cap, wherein the resilient indication feature is configured to interact with the ridge to provide a tactile response in response to the end effector deflecting into the non-articulated configuration.