1. SofaKing: The Lazy-Man Futon Chris Wooldridge Loren Hankla Ankur Desai JT Stukes Barrett Evans John Pendley

2. Agenda Problem Statement Functional Requirements Design Partition Solution Engineering Analysis Prototype Conclusions Questions

3. Problem Statement Futons can be bulky and difficult to adjust Create a method to transform the futon with minimal user effort Mechanism must be cost efficient Must be able to endure normal everyday use by an adult

4. Functional Requirements Single hand operation (maximum of 20 lbs of force) Reliable in terms of life expectancy of design Safely move back and forth without fast moving parts Futon should not hit wall or floor when converting Minimize areas where fingers or clothing may get caught No sharp corners or edges “Lock” mechanisms to prevent accidental shifting Aesthetically pleasing Fairly lightweight

5. Design Partition User Interface: The mechanism the user will access to adjust the futon Sit-up Mechanism: This will transform the futon from the down position to the up position Lay-Down Mechanism: This will transform the futon from the up position to the down position Moving from Wall Mechanism: This will allow the user to open the futon without having to move the entire unit away from the wall

6. Solution: The Lazy-Man Futon

7. The Lazy-Man Futon

8. Locking Mechanism: Upright

9. Locking Mechanism: Down

10. Total System: Down

11. Engineering Analysis

12. Bolt Shear Stress Calc. Single Shear Equations Double Shear Equations SAE Grade 5 bolts – Bolt Shear Strength 120,000 psi

13. Beam Deflection Calculations Frames will be made from 1 inch O.D. tubing. The thickness of each tube will be 0.3 inches Lower Frame will be designed to support two adult males. Each male is assumed to weigh less than 200 lbs. Maximum beam deflection shall be calculated and checked

14. Beam Deflection Calc. Moment of Inertia for Tubular Beam

15. Summary of Beam Deflection

16. Torsion Spring Design Torsion Spring should require no more than 20lbs to lower upper rail Mattress should not weigh more than 40 lbs. Similar mattress weighed 35 lbs. Weight of frame is calculated to be less than 30 lbs. Weight of Individuals shall be supported by the Locking Mechanism, not the torsion springs.

17. Weight of Upper and Lower Frame Length of Tubing = 328 inches Density of Steel = 490 lbs / ft 3 Weight of Frame = 40.5 lbs

18. Loading of Upper Frame

19. Torsion Spring Design Balance moments about pin connection to calculate necessary strength of spring Minimum spring strength necessary to prevent back from moving equals 0.8125 (lbs – in/deg). d = Wire size (inches) D = Mean diameter (inches) Torsion Spring. N = Number of active coils (front side) Rt = Rate of Torsion (Inch-lbs./Rev.) S = Stress (lbs. /sq. inch) M = Moment (Inch-lbs.) P = Load (lbs.)

20. Range for Spring Constant Converted: Minimum Spring Constant – 9.75 (lb-in/deg) Maximum Spring Constant – 12.0 (lb-in/deg)

21. Constructing the Prototype

22. The Lazy-Man Prototype

23. Spring: Upright and Down

24. Sliding Mechanism: Drawer Slides

25. Lazy-Man Futon Videos Links:

26. Conclusions A viable design was for a futon that can easily be adjusted was created SofaKing feels that there is a place in the market for such a product Several additional considerations to the design should be made in terms of materials –Bolts appeared to be much stronger than needed –Metal tubing may be thicker than necessary –SofaKing feels that there is a place in the market for such a product

27. Questions?