Mechanized Legless Classic Rocker

1
Mechanized Legless Classic Rocker

• Team 7
• Tom Dabrowski
• Sarah Philo
• Adam Rauwerdink

2
Outline

• Specifications
• Physical challenges
• Mechanics of rocking
• Potential mechanisms
• Competitor products
• Project constraints
• Design summary
• Budget
• Marketing
• Conclusion

3
Specifications

• Rocking mechanism
• Comfortable speed
• Does not surpass tipping angle (varying user
  weight)
• Does not require permanent attachment to floor
• Control
• Simple power switch for user
• Control of audio by user
• Caretaker has master control for all power and
  for music track and volume
• All easily accessible and with high ease of use
• Audio
• Internal speakers
• Input from CD player accessible to caretaker

4
Physical Challenges

• Users have wide array of physical and mental
  limitations
• Cerebral palsy, Multiple sclerosis, varying
  levels of paralysis
• Coordination
• Muscle control
• Mental abilities and attentiveness
• Seizures of varying intensity (some CP)

5
Mechanics of Rocking

• Equilibrium, all in line
• Center of curvature of rocker
• Center of gravity of chair and occupant
• Point of contact with ground
• No moment

6
Mechanics of Rocking (cond)

• Chair rotated
• Restoring moment from force of gravity
• Moment taken about point of contact with ground

MIa Moment (Moment of Inertia) x (Angular
Acceleration) -mg(R-h)sin(?)mh2a

• Frequency of rocking
• Dependent on radius of curvature and occupant
  center of gravity

7
Mechanics of Rocking (condd)
www.exoticoutdoors.com/swing.pdf
8
Potential Mechanisms

• Rack-and-pinion styled
• Motor turns stationary small gear over a long,
  linear piece attached to chair back
• Counterweights
• Like an elevator system
• Linear Actuator
• Rod extends, pushes up on chair back
• Rod returns, pulls down chair back

9
Competitor Products/Previous Projects

• Electronic and Mechanical Assistant Technologies
  Motorized Rocking Chair

• NSF Project Rensselaer Polytechnic Institute
  1989 The Mechanical Rocking System

10
Competitor Products/Previous Projects (cond)

• Various non-mechanized legless rockers, available
  at many major retailers (Wal-Mart, Target, etc)
• Numerous patents granted for mechanized rocking
  systems
• Single instances (web forums)

11
Project Constraints

• Safety
• If 120V power is being used, must be completely
  isolated from possible shock and from chair
  fabric
• Angle and speed of rocking must not cause tipping
• Environmental
• Must be durable and capable of surviving moderate
  abuse
• Should be able to withstand spilling of liquids
  and be easily cleaned
• Economic
• Pre-built chair must be purchased

12
Project Constraints (cond)

• Control
• Caretaker must be capable of having master
  control of the rocking
• Audio volume, track, and master power are also to
  be under caretaker control
• Construction
• Internal frame of chair will vary with models
• Ability to build off of frame will be dependent
  on this

13
Design Summary
14
Budget

• 750 from National Science Foundation
• Chair prices (30-100)
• Quality (frame, fabric)
• Accessories (speakers, audio input)
• Motor (16-50)
• Power, RPM
• Actuator (100-150)
• Power, length
• Speakers (40-100s)
• Wattage, size, quality
• Accessories
• Amplifier (100) probably excessive
• Subwoofer
• Linkage bars, brackets, mounts
• Frame material
• Maximum Total 500 (rest for error analysis)

15
Marketing

• Target special needs consumers who wish to enjoy
  a relaxing experience
• No physical input needed to rock
• Music enhances overall experience
• Classic-Rocker
• Simplicity
• Basic controls
• Simple controls for caretakers

16
Conclusion

• Will provide self-rocking motion for those with
  physical disabilities
• Reliable, easy to use, and safe rocking mechanism
• Final product will include implanted audio system
  to enhance the experience
• Caretaker will have master control over all parts
  of the chair
• Complete product will be sturdy self-contained
  unit that is easy to maneuver