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 AnalysisDeflection seen by max force of Forks

W

Max Deflection:

0.0152 inch

Deflection and Force AnalysisDeflection seen by max force of top bar

F

Max Deflection:

0.01477 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 MikeDesigned with factor

safety involvedAsked 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 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

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”

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