Pull Apart Testing for Unique Products Inc.
One Piece E-Zee Lockout Devise
Testing was conducted by Anderson Associates Consulting Engineers Inc. on 10 individual E-Zee Lockout Safety Lockout devices.
These lockout devices were of mixed construction with an aluminum body, a steel cable and an aluminum screw key (see photograph 1).
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The steel cable was passed through a hole in the aluminum body until it protruded 1to 2 inches (25.4 mm to 50.8 mm). The locking key was turned to crimp the steel cable in the aluminum body. The locking key was turned until the key snapped off by design.
In Photograph 2 the red arrows show how the pull apart test was conducted.
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A manually operated fixture was designed and built to perform the pull apart tests (Photograph 3 -blue arrow).
An electronic S-Type load cell and data logging software were used to measure and record data (Photograph 3 -yellow arrow).
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The load cell was rated to 5,000 lbs. and calibrated on March 2, 2012 to ASTM E4 with 1% tolerance. The load was applied by turning a nut on a threaded shaft (Photograph 3 - green arrows).
Pull apart testing was carried out at room temperature. As there are no known applicable standards for the specified testing. Testing was conducted using standard laboratory material testing protocols.
Photographs 4, 5 and 6 depict the typical failure modes.
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In Photograph 4, the steel cable is shown having pulled out from the screw crimp end (red arrow) on the aluminum body. In Photograph 5 the steel cable partially failed as it pulled out from the screw crimp end (red arrow) on the aluminum body.
Photograph 6 is a view depicting lockout device 9 after the pull apart test. The steel cable failed approximately 23,4inches (69.9 mm) from the screw crimp end.
Actual test results are listed in the following table:
| Lockout Device # |
Maximum Pull Apart Force in lbs. |
Observations |
| #1 |
709 |
Steel cable pulled away from screw crimp |
| #2 |
757 |
Steel cable pulled away from screw crimp |
| #3 |
681 |
Steel cable pulled away from screw crimp |
| #4 |
555 |
Steel cable pulled away from screw crimp |
| #5 |
738 |
Steel cable partially failed and pulled away from screw crimp |
| #6 |
830 |
Steel cable pulled away from screw crimp |
| #7 |
713 |
Steel cable pulled away from screw crimp |
| #8 |
671 |
Steel cable pulled away from screw crimp |
| #9 |
914 |
Steel cable failed 2% inches (69.9 mm) from screw crimp |
| #10 |
934 |
Steel cable failed 2% inches (69.9 mm) from screw crimp |
The average pull apart force was 750 lbs. The mean pull apart force was 723 lbs. The range was 555 to 934 lbs. units are Imperial.
Graph 1 represents the data set for the pull apart test of lockout device 1. The screw crimp retained the steel cable until 705 lbs. of force was applied.
The cable began to slide out with resistance in the range of 240 lbs. to 427 lbs. The graph profile was typical for the other samples, with the exception of tests where the cable failed.
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