$80,000 WORKSTATION WITH NO-COST ACCESSIBILITY

Leonard L. Anderson, Robert J. (Joey) Jackson and John C. Schafers Rehabilitation Engineering Research Center Wichita, Kansas

ABSTRACT

Job accommodations for persons with disabilities are generally made by modifying a workstation that has been previously in use by another person. A totally different approach was used in the development of the workstation portrayed in this case study. A new process and machine was required to drill the mounting holes in aircraft window frames. The new machine and workstation were designed, fabricated, and set up to accommodate a person who uses a wheelchair. Since accommodations for the operator were considered from the start of the design process it can be shown that the "accommodation" in this case was made at no additional cost. Features of the workstation and its operation are discussed.

BACKGROUND

The windows located in the passenger compartment of Boeing airliners have a frame that is an aluminum forging. Installation in the fuselage structure requires that 22 mounting holes be pre- drilled in the frame. Drilling of these mounting holes was accomplished by a worker using a hand- held drill, drilling one hole at a time. The drilling process required 20 to 25 minutes per frame. A subcontractor was offered the drilling operation if time and money could be saved. The subcontractor has a history of employing persons with disabilities whenever possible. Rehabilitation engineers who had manufacturing experience were employed to design a drilling machine that would hold the frame firmly while the 22 holes were being drilled in a gang drilling operation. The machine was designed, fabricated, and put in operation under scrutiny of Boeing manufacturing personnel. The philosophy applied in the design was crucial to the success of the project. Locations for the holes, and the diameters were set with extremely tight tolerances (typical of aircraft manufacturing). It was difficult to design the machine to simply do the drilling operation, but features which accommodate a person in a wheelchair did not complicate the process of design and fabrication.

OBJECTIVE

The objective was to design a machine that would hold the window frame firmly while 22 mounting holes were being drilled automatically without moving the frame in the process. Of utmost importance was that the finished product had to meet the strict aircraft standards and tolerances.. Secondarily, but crucial, in the design process, the designers were to make the machine part of an overall workstation that could be operated by a person who uses a wheelchair. In particular, the goal was to make the workstation accessible and operable by a person who has severe disabilities.

APPROACH

Handling of the parts was a major consideration. It was determined that parts prior to drilling would be supplied to the machine operator in stacks within reach of a seated position by persons who are ambulatory. After drilling, the parts would be stacked by the machine operator and moved on by others in the shop.

Placement of undrilled parts was to be facilitated by guides with an assist from gravity. The term "funnel effect" has been used to describe the use of guides assisted by gravity. Utilization of the funnel effect is most helpful for persons who have "unsure" hands.

Twenty of the 22 holes are drilled with the drills positioned in one plane. The drill motors drilling the 20 holes were mounted on a single plate. The plate was then mounted on support structure. There are 10 air driven motors, each having a gear head which holds two drill bits. Thus, each of these drill motors drills two holes at a time. The mounting plate is positioned 15 degrees from the vertical which provides for components of gravity to assist vertically and horizontally in the placement of undrilled parts in the clamping fixture. Pneumatic powered clamps are activated by a push button close to the operator. In fact, the utilization of a programmable controller provides the capability of the machine to cycle through its entire drilling operation by pushing the one button. The two remaining holes are drilled perpendicular to the plane of the mounting plate and are positioned at the rear of the plate. The drills pass through the mounting plate to reach the part.

RESULTS

The drilling operation utilizing the new machine requires one minute ten seconds. A minimum of 19 minutes is saved for each window frame that is drilled. The design was carried out as a research project. However, accounting for engineering and fabrication time the new machine would have a cost of $80,000. The costs saved due to reduction in time will pay for the machine in less than one year. Two different persons are the main operators. One has cerebral palsy and uses a wheelchair for mobility. The other is legally blind and can use only one hand to handle parts. Both of these operators are capable of producing quality parts at the required production rate. Quality of the finished part is of utmost importance since the cost of a single part being rejected is approximately $160.

DISCUSSION

It is important to realize that an entirely new machine and workstation were required to accomplish the desired task. The employer was willing, if not eager, to employ a person who has severe disabilities. Combining these two goals in the design and fabrication process resulted in little or no cost being realized because the workstation would be accessible. In retrospect, the set up of the new workstation, and its operation, is better for all persons whether they have disabilities or not.

ACKNOWLEDGEMENTS

The authors wish to acknowledge Center Industries in Wichita, Kansas, for providing the workplace, The Rehabilitation Engineering Research Center in Wichita for supporting the research, and NIDRR for providing the funding for the research.

Leonard L. Anderson, MS Rehabilitation Engineering Research Center 2021 N. Old Manor Wichita, KS 67208 (316)688-1888 Voice and TTY (316)688-5687 FAX e-mail: llanders@shocker.ee.twsu.edu