Wegmans Bread Tray Lift Assist Design Review 2

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

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 Specs 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 And

Finished Design

Finished Design Continued

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

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

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

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

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

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%

Ergonomics Continued Release button height: 45 inches from floor – Height based up elbow height for 95 th percentile male according to ANSUR database Tray stack height: 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

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

Simulated Floor Plan 30” 18” 36” Operator

Bill of Materials

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