Penn State / Ingersoll-Rand Design Project

Ergonomic Redesign of a Die Grinder Test

Team Members: Blaise Cackovic, George DeGroft, Stephen Ellner, Nathaniel Krumpe, Brian Lucot, Kyle Markell

Project Sponsor: Ingersoll Rand Tool and Hoist Division, Athens PA

Faculty Coach: Professor Tedric A. Harris

Course: ME415W Spring 2001

  Background

The LG1 Die Grinder line at Ingersoll-Rand's Athens plant produces thousands of pneumatic die grinders each year.  Each tool must pass a rigorous series of quality tests before packaging and final shipment.  During the first test, the tool is manually threaded onto an air line, tested for vibration and speed, and then removed. The rotary motion needed to connect and disconnect the tool is time consuming and may cause repetitive motion trauma in the operator's wrists. Quick attach components tested in the past did not allow sufficient airflow and were subsequently rejected.

Problem statement: Develop a quick, ergonomically correct method for attaching the tool to the air supply line

  Design Criteria

  • Connector must provide an ergonomically correct way to attach the die grinder to the air supply line. This method should reduce or eliminate cumulative trauma disorders experienced by operators.
  • Connector must be able to provide the necessary airflow to allow the tool to reach its rated RPM.
  • New design should increase the test throughput
  • Design should be cost-effective.

   

The design solution alone (left) and attached to the IR Cyclone HC150 die grinder (right)


  Solution

The final design incorporated the use of a threaded collar which screws on to the outer diameter of the die grinder.  A sealing flange with an O-ring is compressed between the collar and die grinder fitting to provide an airtight seal. The advantages of the new design are:

  • Ergonomic - Our solution requires only 1 turn as opposed to 9.

  • Effective -  The airflow is more than sufficient to deliver the required RPM.

  • Efficient - Due to the fewer required turns, it takes much less time for the operator to test the tools.

  • Economic - At a cost of $240, this is an economic solution compared to a previous device that costs $500.