E Z Journey Car Seat

 

Final Design Document

Prepared for:

Bruce Kennedy

Vocational Rehabilitation Services

(520) 779-4147

1510 S. Riordan Ranch St

Flagstaff, AZ 86001

 

Ben Sutcliffe

(520) 774-3176

802 W. Aspen

Flagstaff, AZ 8600

 

 

 

 

 

 

 

 

 

 


Disability Design Inc.

 

Ed Castellini

Mark Davis

Aaron Hebert

Jim Norine

 

At the College of Engineering and Technology

Northern Arizona University

 

 

 

 

 

 

 

 

 

May 8, 2000

 

Table of Contents

                                                                                                                        Page #

  1. Executive Summary                                                                           1
  2. Project Description                                                                           
    1. Problem Statement                                                                   2
    2. State of the Art Search                                                             3
    3. Design Constraints                                                                    5
    4. Design Philosophy                                                                    7
  3. Design
    1. Concept Generation, Selection, and Testing                               8
    2. Proof of Concepts/Modeling                                                     9
    3. Model Construction                                                                  11
    4. Analysis                                                                                    13
    5. Design Decisions                                                                      19
  4.  Design Execution
    1. Introduction                                                                              20
    2. Base Frame                                                                              21
    3. Rear Restraint                                                                           22
    4. Seat Hinge                                                                                23
    5. Seat Frame                                                                               24
    6. Seat Back and Seat Bottom and Harness System                      25
    7. Reclining Mechanism                                                                26
    8. Limited Tilt Mechanism                                                             28
    9. Head Rest                                                                                29
    10. Electrical Circuit                                                                       30
  5. Assembly
    1. Mechanical                                                                               31
    2. Electrical                                                                                  33
  6. Operation
    1. Seat Operating Instructions                                                       34
    2. Seat Maintenance                                                                     36
    3. Warnings/Restrictions                                                               37
  7.  Review of Progress
    1. Schedule                                                                                  39
    2. Man Hours                                                                               40
    3. Budget/Cost Tracking                                                               41
  8.  Appendices

a.       Design Matrix                                                                           A-1

b.      Ear Weld Analysis                                                                    B-1

c.       Base Assembly                                                                         C-1

1.                              Base Frame                                                      C-2

2.                              Shear Plate                                                       C-3

3.                              Ear Flange 1                                                     C-4

4.                              Ear Flange 2                                                     C-5

5.                              Angle Brace                                                     C-6

6.                              Ear Tube                                                          C-7

7.                              Safety Angle                                                     C-8

d.      Seat Frame Assembly                                                               D-1

1.                              Inner Hinge                                                       D-2

2.                              Outer Hinge                                                      D-3

3.                              Mounting Elbow                                               D-4

4.                              Seat Back Uprights                                           D-5

5.                              Seat Back Braces                                             D-6

6.                              Seat Bottom Latrals                                          D-7

7.                              Seat Bottom Stringers   and Horizontals             D-8

8.                              Shaft                                                                D-9

9.                              Seat Bottom Shear Plate                                   D-10

e.       Reclining Mechanism Assembly                                                 E-1

1.                              PreFab Parts                                                    E-2

2.                              Gear Boxes                                                      E-3

3.                              Slider Plate                                                       E-4

4.                              Pillow Blocks                                                   E-5

5.                              Lift Arms                                                          E-6

6.                              Lift Arm Ends                                                   E-7

7.                              Pin and Bracket                                                E-8

f.        Limited Tilt Assembly                                                               F-1

1.                              Limited Tilt Dimensions                                     F-2

g.       Electrical Diagram                                                                     G-1

h.       Acknowledgements                                                                  H-1

1. Executive Summary

 

Disability Design Inc. was asked to design and fabricate a seat for a handicapped student on campus to make car and airplane travel more comfortable.  A state of the art search was conducted at the beginning of this project and consisted of two phases, a product search and a patent search.  Both of these searches were conducted on the Internet.  All limiting constraints that the car seat would need to abide by needed to be determined so that they could be designed around properly.  For this project the three types of constraints would be limiting space, Federal Regulations, and the clients needs.

 

We began the design phase for this project with a very general conceptual design.  This consisted of dividing the design up into subsystems and then generating ideas for each subsystem.  The design was broken done into the following subsystems:

§         Base Frame

§         Seat Frame

§         Seat Bottom

§         Seat Back

§         Seat Hinge

§         Reclining Mechanism

§         Rear Restraint Connection

§         Anti-Roll Mechanism

§         Harness System

§         Head Rest/Switch

Once all of the ideas were discussed, a selection process narrowed down which ideas would be considered for the final design.  A modeling phase and an analysis phase provided the necessary information to make final decisions on which conceptual designs would be chosen.  It also allowed DDI to begin dimensioning certain subsystems so that other subsystems could be dimensioned around them. 

 

After extensive layout of each subsystem was done to insure precise integration, all of the dimensions were finalized and the motion of the reclining mechanism was checked.  An electrical circuit was designed and built to control the reclining mechanism through the head switches in the headrest.  Detailed drawings of the final design can be seen in appendices C-1 through F-2.  DDI also undertook the construction of the final prototype and delivery to Ben Sutcliffe. 

 

 

 

2. Project Description

2a.  Problem Statement

 

Bruce Kennedy from Vocational Rehabilitation Division of the Arizona Dept. of Economic Security asked the students of our senior level design course to design and fabricate a seat for a handicapped student on campus to make car and airplane travel more comfortable.  Ben Sutcliffe is a sophomore at NAU, majoring in psychology, who suffers from acute Cerebral Palsy and is confined to a wheelchair.  This ailment leaves Ben with almost no motor control and somewhat rigid joints.  Ben also is unable to talk so he communicates through a laptop computer that is programmed to read the input of a chin switch that Ben is able to control.  Ben has traveled the country in the past by car and plane and wishes to travel more.  Unfortunately Ben has difficulty traveling because long car trips are uncomfortable when confined to a wheelchair the entire time, and the average seat on an airplane isn’t made to accommodate his needs. 

 

Disability Design Inc. was asked to design and implement a car seat that Ben could use for long trips.  The car seat needed to be equipped with a high headrest, appropriate body stabilization devices, a reclining mechanism, and augmentative communication device mounts.  We were presented with two alternatives for solving this problem.  The recommended alternative was to design a portable seat that could be moved from vehicle to vehicle, especially cars and airplanes.  The second alternative was to design a permanent car seat in Ben’s van. 


2b.  State of the Art Search

 

The state of the art search for this project consisted of two phases, a product search and a patent search.  Both of these searches were conducted on the Internet.  The product search was conducted on the Internet because most manufacturers of adaptive technology sell a great deal of the products through their web pages.  The patent search was conducted on the Internet because NAU campus does not have a patent library.  In the event that the patent website search produced a result that was too vague to determine whether or not we would be infringing on it, the patent library at ASU would have been used. 

 

The Internet search that was conducted proved to us that nothing quite like our project had been done in the past.  There are numerous custom products available for disabled people that are made extremely versatile but nothing quite like Ben was asking for has been manufactured yet.  The following websites were searched:

 

 

A link through the Cline Library web page was used to conduct the patent search.  The website used was http://164.195.100.11/netahtml/search-bool.html.

Unfortunately, the website was not equipped to deliver a complete patent record.  This was not a problem because we were able to determine whether or not a patent described our project by reading the abstract.  Although many patents exist for wheelchair designs and children’s car seats, none exist for a car seat style chair for a disabled person.  The keywords used for the search of the general design were:

 

§         Car Seat

§         Wheelchair

§         Disabled Car Seat

§         Reclining Car Seat

§         Handicapped Car Seat

§         Adjustable Car Seat – Adult

 

As our design team moved into the design phase of the project, another patent search was conducted.  During the design phase ideas for custom parts were studied and as these parts became specific a patent search on each part was conducted.  These parts of the design will be discussed in more detail later in this report.  The keywords used for the second patent search were:

 

§         Hinge

§         Locking Pin

§         Adjustable

§         Pin Locked

§         Coupling

§         Interlocking

§         Vehicle Seat

§         Reclining Mechanism

 

Many types of adjustable hinges were found and many reclining mechanisms that are currently used in vehicle seats were found.  In the end, this search also failed to turn up any previous ideas that apply to our project or it’s specific parts.  At the end of this state of the art search our team felt comfortable that we were setting foot on new territory.

 

 

 

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