Sophisticated Design
Automatic Tailgate
Week Four Deliverables
September 12, 2001
Ted Akiskalos
June Doan
Tarek Elshazly
Maggie Kim
David Nimitz
Sharon Ramey
Cable Truck
Advantages:
Aftermarket
Installation,
Efficient, Reliable,
Operational if motor
breaks, Cheap,
Compact, Easy to
Use
Pulley
Motor
Unlocking
Cable
Disadvantages:
Easily damaged,
slow, hard to
weatherproof, risk of
cable being cut
Manual
Switch
Detachable
Cable
A release lever inside the cab of the truck will start the motors, much like the release mechanism used to pop
trunks and hoods in cars today. The original locking mechanism of the truck will be used. Once the lever is
pulled the motors will begin to unwind the cable which will be routed through pulleys at the end of the bed and
hold the tailgate as gravity pulls it down thus slowing the speed of opening. There will be a manual switch at
the end of the bed to begin the raising of the tailgate.
Hydraulic System
Advantages
Disadvantages
•reliability
•cost
•quickness
•high power
consumption
•powerful
•compact
•dangerous
•easy to use
A hydraulic system would provide sufficient power to raise and lower the tailgate without any effort
from the user. The hydraulic system consists of three main systems; a power system, a control system,
and a transmission system.
Worm Gear
Advantages
•Compact
•Cheap
•No visible parts
•No load interference
•Easy to use
Spur Gear
Motor
Disadvantages
•Large torque
•High-wear
•Slow
Switch
Worm Gear
•Motor/tailgate lock-up
The design being proposed uses a worm gear, shown in Figure 3, to lower and raise the tailgate of a pick-up
truck. The three main components of this design are a spur gear, a worm gear, and a rotating motor. The
spur gear component transmits torque to the tailgate to accomplish the goal. The function of the worm gear
component is to convert one form of rotational motion from the motor to the spur gear. The motor is used
to power the worm gear. The advantages of this design are that it is compact, cheap, and easy to use. It
also has no visible moving parts and it doesn’t interfere with the load being applied to the tailgate. The
disadvantages of this design are the large force required to power the worm and spur gears, the high wear
that would result from its use, and the lock up that would occur in the tailgate if the motor became locked.
Tethered Featherweight Tailgate
Advantages:
•Low cost
•Compact
•Robust
•Little interference with
load
•Efficient (no power
consumption)
•Purely Mechanical
•Safe (no powered
components)
Disadvantages:
•Not powered (passive
design)
•Higher part count
Truck Bed
Retaining
Rod
Torsional
Spring
Bolts
Cable
Spool
Truck Tailgate
Pulleys
Mounting
Beams
Featherweight Tailgate
Advantages:
•Compact
•Robust
•Cheap
•Efficient
•No interference with load
•Purely mechanical
•Safe (no powered
components)
•Modular
Disadvantages:
•Not powered (passive
design)
Truck Bed
Retaining Rod
Torsional
Spring
Truck Tailgate
Half and Half Design
Hinge
Handle/Latch
Hinge
Advantages
•no weight to support
•no power requirements
•cheap
•reliable
•no interference w/ load
Disadvantages
•requires significant modification
•reduces effective bed area
•reduces strength of tailgate
Axle
Axle
Rear View
Gears/Levers
The purpose of this design is to reduce the required force to open and close the tailgate of a pick-up truck. It consists of the tailgate (split in half),
the handle that operates the latch and a gear system that serves as a mechanical connection between the two halves of the tailgate. Each half is
hinged vertically at the side of the truck. Thus, the tailgate pivots around a vertical axis, which minimizes the required operating force since
there’s no lifting required. The latch locks the right half to the bed as well as to the other half. Even though only the right half is manually
operated, the left half follows the right half’s motion precisely thanks to a gear and lever system, similar to the one found in school bus doors. The
major advantage of this design is that it eliminates the need to manually support the weight of the tailgate. Furthermore, since it is human
powered, there are no power requirements from the vehicle. It only involves mechanical systems and therefore, it is relatively cheap and very
reliable. Finally, it completely satisfies one of the requirements set forth for the project, which is not to interfere with the load. On the other hand,
the most significant disadvantage is that it requires significant modifications to the truck, which prevents after market installation. It also
eliminates the option of driving with the tailgate open while carrying bulky objects. Finally, it reduces the structural integrity of the tailgate.
Immediate Objectives
• Patent/ Product Search
– Patent description
– How it relates
• Begin Design Selection
– Quality Function Criteria
– Final Concept