Wegmans Bread Tray Lift Assist

1. Wegmans Bread Tray Lift Assist Design Review 2

2. Wegmans Bread Tray Lift Assist • Goal:Improve ergonomics for operator during the task of stacking loaded bread trays at the Wegmans Bakery

3. And Specs Needs • Enable good ergonomic practices in terms of lifting and body position • Meet Wegmans safety requirements in terms of mechanical operation and physical aspects • Meet Wegmans requirements in terms of cleaning and food contamination risks • Ease of use for operator • The unit should be durable and reliable • Maintain a loading height at 33 inches • Allow for food to descend no closer to the floor than ½ foot • Allow max load of 5 trays at 115 lbf

4. Updated Design

5. Whole Assembly

6. Updated Design Continued

7. Lift Tray Cart • Features: • V groove wheels • Redesigned as skeleton • Cotter Pin • End Caps • Gussets • Double Support Bar • Locating Wedge

10. Start Air goes into cylinder 3 way valve opens to pressure line Forks lower Dolly and trays loaded Forks lock Is switch activated Restart Process Button pressed No Yes No Yes Forks raise to home position

11. 3 way valve Air from line Muffler Air regulator Adjustable needle valve Emergency relief ball valve Air cylinder (2 inch bore and max of 125 lbs to lower requires ~40psi)

12. 5th has been placed and is descending Line is unpressurized 3 Way Normally Open to Atmosphere Push-Valve

13. 5th tray has fully descended Line is pressurized Switched pressed, wheels on ground

14. Piston Pressurized, lowering piston slowly Forks lower, trays in contact with floor only

15. Filled until 40 psi is reached and cylinder is locked in down position

16. Open to ATM closed to pressurized line Compressed air released to ATM

17. Piston raises, acting as air damper Open to ATM again

18. Deflection and Force Analysis Deflection seen by max force of Forks W Max Deflection: 0.0171 inch

19. Deflection and Force Analysis Deflection seen by max force of top bar F Max Deflection: 0.00166 inch

20. Problems and Solutions from Last meeting • End Caps on Forks • Brush Guard System • Removable forks (use in place) • Hard stop at 2 inches (normal use leaves 2.75 inch clearance) • Dolly Sliding off • Hand Guarding • Piston Failure • Foot being crushed by forks

21. Updated Risks Updated Mitigations • Designed with factor safety • BOM finished and ready to order • Verify with Mike • Designed with factor safety involved • Asked operators what they want/expect • Springs failing • Materials not arriving on time/correct material • Air drop installation • Air piston damper failing • Not used correctlyor at all

22. Ergonomic Analysis • NIOSH Lifting Equation: • When setting tray on ground: 1.7 • With Bread Tray Lift Assist: 1.4 • Analysis of only 36 inch and below • Percent improvement: • 17.6%

23. Ergonomics Continued • Release button height: 45 inches from floor • Height based up elbow height for 95th percentile male according to ANSUR database • Tray stack height: 30-36 inches from floor • Based upon height of hand at rest calculated from ANSUR database • Reduces bending at waist • Lower risk of back strain • No detriment to higher lifts • Additional suggestion: add anti-fatigue mat to floor where operator stands

24. Safety Features • Bright colored forks for visibility • Powder Coated Yellow • Hard stop for forks at 2 inches above floor • Prevent foot from being crushed in a failure situation • Removable forks removes collision hazard when device is not in use

25. Simulated Floor Plan 30” 30” 18” 36” Operator

26. Bill of Materials

27. Next Steps • Procurement of materials • Regulator • Floor Location • Air Drop • Planning shop fabrication time • Receiving • Air Cylinder Maintenance • Build and Test