Circular Stapler Handle Assembly With Spring-Linked Firing Lockout

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Solution Overview

Problem

Existing circular staplers face issues with lockout mechanisms that impact operator experience and can lead to accidental firing or casing damage due to vigorous handling.

Innovation Solution

A handle assembly with a first handle component and a second handle, linked by a slider controlled by a compression spring, ensuring the stapler can only be fired when the handles are properly aligned, preventing accidental firing and protecting the casing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a lockout mechanism is added to prevent accidental firing, then safety is improved, but operator experience deteriorates and casing damage risk increases

Engineering Contradiction:
ImprovesafetyVSAvoidoperator experience
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The handle assembly transitions from a static locked state to a dynamic unlocked state through rotational movement. The first handle component rotates relative to the second handle component, dynamically changing the position of the first limiting structure to either engage or disengage from the second limiting structure, thereby controlling the compression spring's ability to push the slider into the second handle component.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The handle is divided into two separate handle components that can rotate relative to each other. This segmentation allows the safety mechanism to be controlled by the operator through rotational movement, improving ease of operation while maintaining safety through the compression spring and slider mechanism.

Inventive Principle:
Principle #1Segmentation

2Reliability

If a lockout mechanism is added to prevent accidental firing, then safety is improved, but the risk of casing damage increases

Engineering Contradiction:
ImprovesafetyVSAvoidcasing damage
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The compression spring acts as an intermediary between the slider and the second handle component. It provides a controlled, gradual force rather than a sudden impact, reducing the risk of casing damage while maintaining the safety function. The spring absorbs excess force and prevents direct transmission of impact to the casing.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The compression spring provides cushioning before the slider contacts the second handle component. This beforehand cushioning prevents sudden impacts that could damage the casing, while still ensuring the safety mechanism functions properly to prevent accidental firing.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

3Reliability

If the handles are rigidly connected, then operational reliability is improved, but adaptability deteriorates

Engineering Contradiction:
Improveoperational reliabilityVSAvoidhandle positioning flexibility
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The connection between the two handle components is dynamic rather than rigid. The first handle component can rotate relative to the second handle component, allowing the system to adapt to different operational positions while maintaining reliability through the compression spring and slider safety mechanism.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The relative position parameter between the two handle components can be changed through rotation. This allows the handle assembly to adapt to different operational requirements while the compression spring and slider mechanism ensure that safety conditions are met before firing.

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Prevents accidental stapler firing and protects the casing from damage by allowing controlled operation through a spring-actuated linkage mechanism.

Implementation Method 1

a compression spring configured to be located between the first limiting structure and the second limiting structure... when the slider is free from a force exerted by the indicator lever, the restoring force of the compression spring actuates the slider to return

Methodology Applied
Scientific EffectCompression spring: Spring

Implementation Method 2

a first torsion spring configured to be sleeved on the first pin, and two ends of the first torsion spring configured to be respectively in contact with the casing of the stapler and the second handle

Methodology Applied
Scientific EffectTorsion spring: Torsion Spring

Data Source

PatentEP3733091B1Handle assembly and anastomat comprising same
Publication Date: 2026.03.04 TOUCHSTONE INTERNATIONAL MEDICAL SCIENCE CO LTD
  • EP3733091B1 patent drawingFigure 1
  • EP3733091B1 patent drawingFigure 2
  • EP3733091B1 patent drawingFigure 3

AI summary

A handle assembly and an anastomat comprising same. The handle assembly comprises: a first handle member provided with a sliding slot (41), a first sliding block (42) being slidably provided in the sliding slot (41), one end of the sliding block (42) being provided with a first limiting structure (43), a second section (412) of the sliding slot (41) being provided with a second limiting structure (44), and a compression spring (45) being provided between the two limiting structures (43, 44); and a second handle (2), a first end of the second handle (2) being rotatably connected to the first handle member, and the sliding block (42) moving toward the second section (412) of the sliding slot (41) under external force. When the first handle member is rotated in a first direction, the compression spring (45) is deformed, and the sliding block (42) abuts against the second handle (2) and pushes the second handle (2) to rotate; and when the sliding block (42) is released from the external force, the compression spring (45) pushes the sliding block (42) to reset. According to the handle assembly, a handle is divided into the first handle member and the second handle (2), and the linkage state of the two is controlled according to the moving position of the sliding block (42); the sliding block (42) may be reset under the action of the compression spring (45) after being released from the external force, and the position of the compression spring (45) is limited by means of the first limiting structure (43) of the sliding block (42) and the second limiting structure (44) of the first handle member.