Grips for Injector Testing Systems

Instron | Autoinjector | Provisional Patent

Overview

I designed two sets of universal jaw faces to accommodate a wide range of autoinjector pens. These jaw faces feature custom mounting points to ensure precise functionality and fit. They facilitate critical tasks such as aligning and measuring cap removal force, activation force, needle depth, click detection, injection time, delivered volume, and needle guard lock engagement.

 

Solutions

  • Durable Design: Upgraded from 3D-printed to machined components for enhanced durability and scalability.

  • Versatile Compatibility: Standardized geometry to support up to “80” device configurations.

  • Customizable Features: Added mounting holes for custom inserts and ESG-compatible attachments.

  • Enhanced Grip: Applied spray-on Surfalloy coating for improved grip performance.

Challenges

  • Standardize custom gripping solutions into a versatile product.

  • Ensure secure alignment and holding of specimens.

 

Analysis & Validation

FEA ❖ Design Validation Testing ❖ GD&T

Design & Development

Concept Generation ❖ CAD ❖ Prototyping ❖ DFM ❖ DFA

Manufacturing

Material Selection ❖ Supplier Coordination

Communication

Cross-Functional Collaboration ❖ Client Interaction ❖ Documentation

3D Printed to Machined

The jaw faces were initially 3D-printed to meet the custom-fit requirements for specific devices. The challenge was to replicate their functional design while transitioning to a machinable solution. By redesigning the components for AISI 303 stainless steel, I delivered a scalable, durable, and aesthetically refined product that met functional and production requirements

 

Fits “80” Devices

With autoinjectors varying widely in shape and size, the jaw faces were engineered to accommodate the team’s identified critical and major devices. The grips feature two distinct sections: a default V-shape for general use and a customizable geometry that can be post-machined to suit specific needs.

 

Easy to Assemble

I developed a minimalist, intuitive design for the jaw faces, ensuring ease of assembly. The reversible design allows the jaw face to be flipped, enabling users to switch between different gripping sections based on testing requirements, enhancing versatility and efficiency.

 

Aligns Testing Devices

When the pneumatic grips close, the upper and side jaw faces moves the autoinjector into vertical alignment prior to testing.

 

Analysis

Finite element analysis was employed to validate the safety and performance of the jaw faces under operational conditions. Simulations evaluated the forces applied when the pneumatically actuated grips closed onto a device, ensuring they could withstand high pressure. Additionally, the analysis helped understand factor of safety and determine whether a specific torque specification was necessary for fastening the jaw faces securely.

 

Final Product

Impact:

  • Standardization: Reduced unique upper grips from 12 to 2 (83% reduction) and side grips from 18 to 1 (94% reduction).

  • Scalable Design: Converted custom 3D-printed parts to standardized machined components for broader applicability.

  • Improved Grip Performance: Enhanced gripping capability, minimizing slippage and reducing wasted specimens.

  • Future-Proofing: Added flexible mounting points to support future ESG requirements.