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Trigger to Trigger Lockout and Return Assist for RF Bipolar Transection Device

IP.com Disclosure Number: IPCOM000243030D
Publication Date: 2015-Sep-09
Document File: 5 page(s) / 391K

Publishing Venue

The IP.com Prior Art Database

Abstract

An RF sealing and dissecting device with 2 triggers, where one trigger closes a jaw and the other advances a knife, needs to have a mechanism that insures one trigger is prevented from movement until the other is fully thrown. This is to ensure that the jaws are closed before the knife fires. It would also be desirable for knife trigger to automatically return to its starting position if the closure trigger is moved back to its starting position. If the operator unlatches the closure trigger the knife trigger should return. This ensures the knife is never exposed when the jaws are open. It would also be helpful if the trigger locking mechanism would assist with the knife return, especially when the knife travels down an articulated shaft. The assisted return would be more helpful at the start of the stroke where the knife return spring is weakest and tapper off its effect at the end of the knife stroke where the knife return spring is the strongest.

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Page 01 of 5

Trigger to Trigger Lockout and Return Assist For RF Bipolar Transection Device

Problem:

An RF sealing and dissecting device with 2 triggers, where one trigger closes a jaw and the other advances a knife, needs to have a mechanism that insures one trigger is prevented from movement until the other is fully thrown. This is to ensure that the jaws are closed before the knife fires. It would also be desirable for knife trigger to automatically return to its starting position if the closure trigger is moved back to its starting position. If the operator unlatches the closure trigger the knife trigger should return. This ensures the knife is never exposed when the jaws are open. It would also be helpful if the trigger locking mechanism would assist with the knife return, especially when the knife travels down an articulated shaft. The assisted return would be more helpful at the start of the stroke where the knife return spring is weakest and tapper off its effect at the end of the knife stroke where the knife return spring is the strongest. So a single mechanism that does the following would be desirable:

1. Prevents the knife trigger from firing until the jaws are closed or jaw closure trigger is fully fired


2. Assists with the knife return especially in the first part of the knife stroke


3. Forces the knife to return when the closure trigger is released

Solution:

One solution is to accomplish all three is to use a spring assisted lever arm that works with the 2 triggers. The lever arm would start in a position that prevents the knife trigger from firing. Features on the closure trigger would interact with the lever arm so that when the closure trigger moves up it also moves the lever arm up to unlock the knife trigger. The lever arm would be moved up to a second unlock position and stay there. The knife trigger once moved would then hit the spring biased lever arm as it starts to travel. The lever arm would then put a return assist load on the knife trigger at this point.


Page 02 of 5

The knife trigger would have a cam surface that interacts with the lever arm so that as the trigger is rotated the force from the lever arm tappers off and the lever arm stroke is limited. Finally there are...