Sophisticated Design Automatic Tailgate Final Presentation December 5, 2001 Ted Akiskalos June Doan Tarek Elshazly Maggie Kim David Nimitz Sharon Ramey

Objective To build an automatic system that will facilitate the operation of a truck tailgate

Goals and Constraints To develop an automatic truck tailgate that is: Cheap Robust Compact Reliable Not a major interference to truck load Easy to use

Overall Design

Agenda Part Drawings - Locking Mechanism - System Cover - Bracket Engineering Analysis Prototype Presentation

Locking Mechanism

Parts (con’t.) System Cover

Parts (con’t.) Bracket Front View Back View

Parts Detaching Pin Cable DetachableCable Secure 0.5” 1.5” 0.4” 1.5” 0.6” 2” 6” 1/14” Front View Side View 2” 6” Spool 2” Cable Eyelet

Engineering Analysis To find weight of tailgate: FTFT W FxFx FyFy L F T = Force required to lift the tailgate from the edge (30lb) W = Weight of the tailgate F x & F y are the reaction forces in the X and Y axis, respectively L= Length from hinge to end of tailgate L/3 o

L Engineering Analysis (con’t.) To find tension in cable: To find added force in x direction: W FyFy L/3 T 45 o 1” FxFx W = Weight of the tailgate (90lb) F x & F y are the reaction forces in the X and Y axis, respectively T = Tension in the cable L= Length from hinge to end of tailgate l= Length from hinge to attachment point of cable o l

Measuring the Tension in the Cable

Engineering Analysis (con’t.) Motor requirements Distance connection point on tailgate travels: Work required: Power required: Torque needed: T r Spool

Motor 16” 20” x Open tailgate Closed tailgate D=3/8” 17” 4” Engineering Analysis (con’t.) Hole extension  20” 16” x 4” 90-  Triangle created in open position: To solve for hole extension, x:

Hole Extension

Fabricating Spool

Motor and Drive Mechanism Mounted on Truck

Installing a Support Bracket for Spool

Preliminary Cable, Pin Assembly

Completed Cable, Pin Assembly

Fitting the Cover to the Side of the Bed using a Template

Securing the Cover

A Pin used to Keep the Spring in Place

Lower Limit Switch

Mounting Switch under a latch

Wiring a circuit

Differences Design Operate from cab with handle L-bracket to mount motor only Cover for motor only Larger spool Use existing latch Gravity only force Circuit Raised by slight angle Momentary push button Four pole/double throw relays Rod holding limit switch Possible to have tailgate half open Prototype Operate from existing tailgate latch L-bracket and two straight brackets to mount motor and align spool Cover for motor and circuit; brackets added Smaller spool Removed springs from latch Spring Force Circuit Manual activation Push and hold button Single pole/double throw relays Rubber clasp, extension holding switch Safety feature added to prevent this