Ryan Brandt, Benjamin House, Matt Coffman, Bryce Tanner (California State University, Chico)
ABSTRACT
The Adaptive Seating for Single Rider Golf Carts project, sponsored by Beneficial Designs Inc., approached the problem that current single rider golf carts on the market lack the appropriate seating to safely and effectively position a person with mid-level paralysis in a partially standing, golfing position. The aim of the project was to create an inexpensive modular replacement for common single rider golf cart seats that would safely position a person in an effective golfing stance. This article presents the design overview, methodologies, and results of the project.
BACKGROUND
Since the birth of the Americans with Disabilities Act (ADA) in 1990, America has sought to make the world it lives in accessible regardless of individual ability. The game of golf is one example of a sport that is all but unavailable to someone without the use of their legs. As a solution, single rider golf carts are widely available at many golf courses, however they are designed for someone who has trouble standing on their own, not someone who has no use of their legs. This presented the problem of designing a seating system which could be mounted on these carts and support the golfer into a partially standing position to golf.
DESIGN SPECIFICATIONS
Peter Axelson of Beneficial Designs Inc. put forth the design requirements and asked that all designs comply with the Rehabilitation Engineering and Assistive Technology Society of North America (RESNA) wheelchair and seating standards. The final design had to move a golfer from the sitting to a partially standing position and include a system to stabilize the pelvis, legs, and torso during game play. The design had to be made so that it could be easily attached to a common single rider golf cart and needed to be sized appropriately to fit a reasonable percentage of golfers.
METHODS/APPROACH
The final concept chosen to prototype is best described as a pivoting three piece seat with a dynamic torso support and harness designed to support a golfer without back muscles, to rotate their upper body through a golf swing.
Figure 1. The adaptive golfing seat
It consists of a bottom piece that is rigidly attached to a set of parallel links on each side. These links are connected to the back support at one end and to the foot support at the other. An electromechanical linear actuator is attached to the back support and moves the golfer from the seated position to a partially standing golf stance. The factors driving the design were function and manufacturability, at a reasonable cost. The components were designed so a fabricator would be able to construct the system using standard manufacturing techniques.
DISCUSSION/OUTCOMES/PERFORMANCE
The seat operates in two stages of motion. Stage 1 describes the range of motion between 0 degrees (seated/horizontal) and 30 degrees tilted forward.
Figure 2. Golf seat, stage 1 motion completed
Stage 2 corresponds to seat motion between 30 degrees and 70 degrees from the seated position.
Figure 3. Stage 2 motion completed
During Stage 1, an electric linear actuator raises and therefore inclines the sitting surface about a pivot point 6 inches behind the front of the seat.
Figure 4. Side view of golf seat in the seated position
This lifts the back of the seat and lowers the foot support, which contacts the ground when the sitting surface has reached an angle of 30 degrees of forward tilt from horizontal.
Figure 5. Side view of completed stage 1 motion
If a golfer desires a seat angle between 30 and 70 degrees to golf, the actuator can lift the seat into Stage 2. During Stage 2 motion, the seat pivots about a second pivot point located at the front of the seat, which allows the foot support to stay stationary on the grass while the sitting surface continues to increase in slope.
Figure 6. Side view of completed stage 2 motion
The linear actuator is controlled via a jog switch to extend or collapse it. For golfers without back muscles, a removable flexible spine support has been implemented into the design to provide compensation. This composite rod works with a chest harness in opposition to the abdominal muscles of the golfer. It allows the golfer to lean forward and rotate their upper body to golf. Then the composite rod returns the golfer’s torso to the upright seated or standing position after game play.
A proof of concept prototype was taken to Beneficial Designs facility for verification that it met the sponsors’ functional specifications. The design functioned as desired, completing the sit-to-stand motion and effectively supporting the user in a semi-standing, golfing position. User feedback verified that the sitting surface is capable of tilting forward from 0 and 70 degrees from horizontal. It was determined that personal comfort lies in the 0 and 55 degree range.
During development of the prototype, discussion with adaptive sports professionals has determined the design will be beneficial to a wider range of people with disabilities than anticipated. The Hagen Oaks Golf Complex in Sacramento, CA, is ready to evaluate the prototype with the Surviving Strokes Program to determine how it will work for stroke survivors.
COST/IMPLICATIONS
The primary goal of this project was to create a functional partially standing seating system to enable golfers with mobility and standing impairments to partially stand and golf. It needs to be available at a reasonable cost. The total cost for all parts and components on this project was approximately $750, excluding labor. All parts and components were made with standard sized rectangular steel tubing, sheet metal, and fasteners.
RESULTS/RESOLUTION
There is a need for a cost effective adaptive seat for single rider golf carts that allow people with mid-level paralysis the ability to golf. The problem was defined, concepts were generated and a design solution was created. This design allows the user to move from a golf cart-operating position to a partial standing golfing position and then back again in a short period of time and is adaptable to a variety of mobility platforms. The system will be tested to ensure that it complies with the RESNA Wheelchair and Wheelchair Seating Standards.
ACKNOWLEDGMENTS
The design team would like to thank the faculty of California State University, Chico, Department of Mechanical and Mechantronic Engineering and Manufacturing Technology for their support over the last year. We would also like to acknowledge Peter Axelson for bringing the project to us and continually providing input that has guided the development of this project.