Specifications

Proposed Concept

The proposed design concept is a ramp composed of foldable sections with telescopic legs. Each section will span 6 feet horizontally and 6 inches vertically and fold into a box shape, within which the legs are stored. This shape will facilitate the easy transport of the ramp sections. One or two people should easily be able to lift each section. The material chosen for the device is aluminum which is light but strong. The device must be able to hold 750 pounds which exceeds the maximum weight of a power wheelchair and large individual. The ramp will be modular, meaning that the legs of each section can be extended to a multitude of different lengths allowing for varying ramp configurations for differing applications or stage heights. The figure to the right illustrates this concept by displaying two ramp sections attached to each other at varying heights,

Design Specifications

Purpose

The folding accessibility ramp will be easy to deploy, light weight, able to stand up to a harsh environments and convenient for temporary accessibility needs.

Functions

The folding accessibility ramp will perform the following functions:
- Transport a passenger in a wheelchair up four vertical feet
- Have adjustable configurations
- Abide by all Americans with Disability Act (ADA) Accessibility Guidelines

Application Site Characteristics

The location site where the folding accessibility ramp shall be used has the following characteristics.
- Physical Characteristics
  - Ability to connect to a flat walled vertical surface: 0 - 48 in. in height
  - Ramp can be placed on top of any solid surface ie. (Grass, concrete, gravel, dirt, wood, tile, carpet, metal, etc.)
  - Storage van cargo space: 100 cubic feet
- Environmental Characteristics
  - Outdoor Environment
  - Temperature range: 0° - 120°F
  - Humidity range: 20% - 80%
  - Rain: 0 - 1.5 inches per hour
  - Wind: 0 - 30 mph

Performance Requirements

The foldable accessibility ramp shall meet the following requirements.
- System Envelope
  - Maximum running slope: 8.33%
  - Maximum Cross slope: 2%
  - Minimum clearance width between hand rails: 36 in.
  - Handrail height: 34 in. - 38 in
  - Handrail diameter: 1.25 in. - 2 in.
  - Toe kick height: 4 in.
  - Maximum footprint per ramp section 75 in. x 45 in.
- Weight
  - Maximum section weight: 100 lbs
  - Maximum allowable sectioned load: 750 lbs
- Setup Time
  - 1 person per ramp section: 5 minutes or less
  - 1 person per six section ramp: 35 minutes or less
- System Restraints
  - Tie downs required for winds over 15 mph
  - Tied downs quickly interface with ramp section and secured to ground with metal stakes
  - Operation: operator able to secure in 15 minutes or less
  - Number of tie downs per section: 2
- Operational Life
  - System life: 10 years
  - Deployment cycles: 10,000 (Ten Thousand)
- Deployment Sound
  - Maximum level: 80 dB.

Processed Materials

The foldable accessibility ramp shall be made of the following materials.
- 6061 Aluminum
  - Tensile Strength: 35,000 psi.
  - Density: 0.098 lb./in.3
  - Stock Dimensions: 36” x 48” x 0.125” (sheet), 12” x 48” x 0.125” (sheet), 2.25” OD x 0.125” wall (tube), 72” x 2” x 0.125” (bar), 2.25” x 24” (rod)

creating an inclined surface. The legs of any section can be extended to be the same height to create a flat landing or to facilitate a turn in the overall length of ramp being used for the application. This ramp design will adhere to the Americans with Disabilities Act guidelines to ensure user safety. This design satisfies the problem and fills the current gap in the market by creating a truly portable ramp capable of wheelchair transport above 4 feet. This concept will augment existing portable platforms by providing a stable, portable, and easily stowable transport solution for the mobility impaired.

Discussion

Due to time and economic restraints, creating a full scale device is not feasible. The two prototypes will only demonstrate some of the specifications listed above. The scaled functional prototype will showcase the device's purpose, functionality, some physical characteristics and the system envelope. The full scale leg prototype will validate the maximum weight each leg is capable of supporting. Some other specifications such as section weight and storage volume were validated using SolidWorks. All other specifications would be difficult to certify without testing the physical device. The team is confident if the ramp was actually created it would easily meet all listed specifications.