Designers: Vivek Patel, Eric Yuan, Tom Backeris, and Jeffery Wang
Client Coordinators: Tracey Craven, OE Enterprises
Supervising Professors: Kevin Caves and Richard Goldberg
INTRODUCTION
OE Enterprises is a local community rehabilitation program that employs people with disabilities for contract work. One of the contract jobs at this location involves cutting 24” lengths of metal bands from a large spool of metal. The current technique requires unwinding the metal from a 120-pound spool, measuring the correct length, and making the final cut with a band saw. Because our client, Dee, has cerebral palsy, it is difficult for him to unwind and measure the metal bands because of his limited strength, dexterity, and cognitive function. Additionally, it is unsafe for him to operate a band saw from a seated position in his wheelchair.
We developed an easily operable device for our client that can unwind, measure, cut and collect 24” strips cut to a tolerance of ½”. The device consists of three components. The first component is a feeding and measuring mechanism that eliminates the issues of physical stress and potential injury to employees from pulling sharp metal strips from the heavy spool. The second component is a cutting mechanism that employees can safely and easily operate with one arm, eliminating the need to use a band saw. In addition, there is a cut prevention mechanism that does not allow the user to initiate a cut until they have unwound exactly 24” of metal. Finally, the third component of the device is a hands free mechanism to collect the cut strips, which requires no additional work from the client.
Figure 1: The Cutting Edge Device: Left picture is the turntable and metal spool; Right picture is cutting device (a) First pipe guide (b) Rubber wheel flush on bed castor wheels (c) Second pipe guide (d) Extended lever arm (e) Sliding wooden ramp (f) Safety shield.
STATEMENT OF IMPACT
We made a visit to OE Enterprises to test the functionality of the device. Dee had a smile on his face after making a few cuts and was very satisfied with its ease of use. One staff member at OE commented that employees found the use of the device to be entertaining, resulting in a more positive and efficient work environment. Another staff member said, “This device worked very well to help Dee achieve something that he could not otherwise achieve and I think it’s something that could be used by most anybody in the workshop.” Before delivering our device to OE Enterprises, none of the employees could accomplish this task. Dee is very excited to begin using the device and abandon his current job of collating paper.
TECHNICAL DESCRIPTION
The overall design of the project simplifies the process of feeding, cutting, and collecting the metal strips with small amounts of force required in each step. The different components are shown in Figure 1. The spool of metal weighs 120 pounds. It rests on a horizontal turntable (Figure 2). The turntable is made of plywood and mounted on a 6” ball bearing lazy Susan, which greatly reduces the amount of friction. This allows for the band to be pulled from the edge of the reel with less than 5 pounds of force. The metal strip must be initially loaded by a staff member. Once loaded, the operator will not have to move the spool. The metal strip is fed through a guide (a) and under a rubber wheel (b). When the user rotates the wheel, the metal strip is fed through the system, into another guide (c) past the cutting shears (d), and on to an inclined wooden sliding track (e). As the metal strip is fed onto the ramp, it eventually hits the metal piece at the end of the ramp. The ramp then slides upwards as the user continues to turn the rubber tire, feeding out more of the metal strip. The ramp slides up 7” until it reaches its maximum extent where the total length of the metal strip reaches exactly 24”. At this point, the user pulls the extended handle (Figure 1d) to cut the metal and the strip falls off the ramp into a bucket located under the base, as the ramp slides back into its original position. The extended handle decreases the force required by a factor of three. In order to prevent a cut before a full 24 inches of metal has been fed out, a metal rod attached to the ramp prevents the user from cutting until the sliding ramp is fully extended.
Three acrylic shields surround the shear blades, preventing users from accidentally getting their fingers near the blades (Figure 1f). Because of the feeding mechanism design, the user also does not have to even touch the sharp metal during the feeding and cutting process.
The total cost of this device is $365.
Figure 2: Client with the Cutting Edge device