THE TOILET GNOMETHE TOILET GNOME

Kimberly AlbertsKimberly AlbertsBrian LockwoodBrian Lockwood David Lomax David Lomax

John McFaddinJohn McFaddinDavid McGinnisDavid McGinnis

Chad MedlinChad Medlin

AgendaAgenda

Problem StatementProblem Statement

Design ObjectivesDesign Objectives

Conceptual DesignsConceptual Designs

Mid-Term ReviewMid-Term Review

Engineering AnalysisEngineering Analysis

Prototype/Design TimelinePrototype/Design Timeline

Comparison Prototype/Final DesignComparison Prototype/Final Design

Future ConsiderationsFuture Considerations

ConclusionConclusion

Problem StatementProblem Statement

Our goal as the Our goal as the Toilet GnomesToilet Gnomes is to produce a is to produce a product that is essential to all cohabitating product that is essential to all cohabitating

households. With a households. With a self-closingself-closing toilet seat, we toilet seat, we solve the problem of males leaving the seat in solve the problem of males leaving the seat in

the upright position and the seat spontaneously the upright position and the seat spontaneously falling during use by providing a product that falling during use by providing a product that slowly closesslowly closes the toilet seat the toilet seat after flushingafter flushing..

Design ObjectivesDesign Objectives

Universal to all toilet seatsUniversal to all toilet seats

No interference for normal use of toiletNo interference for normal use of toilet

No external power sourceNo external power source

Minimum use of moving partsMinimum use of moving parts

Slow descent when closingSlow descent when closing

Comparable cost to normal toilet seatComparable cost to normal toilet seat

Self-containedSelf-contained

Conceptual DesignsConceptual Designs

3 Subsystems of System3 Subsystems of System– Locking MechanismLocking Mechanism– Timing MechanismTiming Mechanism– Lowering MechanismLowering Mechanism

5+ Designs for each Subsystem5+ Designs for each Subsystem

Created Overall Conceptual Designs from theseCreated Overall Conceptual Designs from these– Best Locking: Spring/ball bearing, Lever, and NoneBest Locking: Spring/ball bearing, Lever, and None– Best Timing: Kitchen Timer, Falling Liquid/SandBest Timing: Kitchen Timer, Falling Liquid/Sand– Best Lowering: SpringsBest Lowering: Springs

Presented at Mid-Term PresentationPresented at Mid-Term Presentation

Mid-Term ReviewMid-Term Review

Issues/Suggestions from Mid-Term: Issues/Suggestions from Mid-Term: – Different lengths of time for toilet useDifferent lengths of time for toilet use– Resetable when new user comes in before time is upResetable when new user comes in before time is up– Possible use of washer friction for loweringPossible use of washer friction for lowering– Flush actuationFlush actuation– Possible ability to disablePossible ability to disable

Changed Design to solve issuesChanged Design to solve issues– Flush actuated instead of timing mechanismFlush actuated instead of timing mechanism– Rotary Dampers used for lowering mechanismRotary Dampers used for lowering mechanism– Equilibrium chosen as locking mechanismEquilibrium chosen as locking mechanism

Updated Design from Mid-TermUpdated Design from Mid-Term

Timer / Actuator : Timer / Actuator : Lowering of water Lowering of water in the toilet tankin the toilet tank– Allows user to control timing and Allows user to control timing and

removes some mechanical removes some mechanical complication complication

– Floater drops as tank drains Floater drops as tank drains pulling cable down with it pulling cable down with it

– Floating weight drops relatively Floating weight drops relatively large distance providing possibility large distance providing possibility for decent mechanical advantagefor decent mechanical advantage

– Still were not sure about triggeringStill were not sure about triggering

Gnome(Similar to Garden Gnome)

Leg Kicks Out To Lower Seat

Hinge AttachedTo Cable AttachedTo Weighted Float

Gnome HangsBy Suspenders

Toilet Gnome Idea CreatedToilet Gnome Idea Created

Toilet Gnome DesignToilet Gnome Design

Leg in upright position Leg in upright position when tank is fullwhen tank is fullWeighted float drops with Weighted float drops with water when toilet is water when toilet is flushed pulling on cableflushed pulling on cablePulling cable triggers Pulling cable triggers gnome to close seat by gnome to close seat by kicking toilet seat overkicking toilet seat overGnome’s leg is reset into Gnome’s leg is reset into place by opening seat place by opening seat which presses leg back which presses leg back into upright locked into upright locked position for toilet useposition for toilet use

Cable

Weighted Float

Engineering AnalysisEngineering Analysis

The sum of the moments about point P gives:

Therefore:

Analysis of the Seat:

m = mass of the seat

g = gravity

F = force from Gnome kick

P = pivot point

L = length of the seat

2

sinmgLdFM P

mg

F

L

Pivot

θ

d

d

mgLF

2

sin

Engineering AnalysisEngineering AnalysisAnalysis of the leg:

•Leg powered by torsion spring so need to know how much torque

•From diagram, torque must be larger than moment caused by force pushing over seat.

ff Ld

mgLFLT

2

sin

Lf F

Pivot

T

Spring parameters:•Coils: 5•Wire Diameter: .135 in•Wire Material: Music Wire•Young’s Modulus: 30500 ksi•Length of Each Leg: 1 in•Coil Diameter: 1 in•Overall Width: 0.675 in

•Parameters provide max torque of over 20 lb-in with rotation of 45°•Ensures ability to tip 3 lb toilet seat over when contact point is half way up seat

Lowering MechanismLowering Mechanism

Rotary Damper usedRotary Damper used

Slows descent of Slows descent of closing seat but does closing seat but does not obstruct raising of not obstruct raising of seatseat

Smooth motion Smooth motion throughout descentthroughout descent

One damper on each One damper on each side for final designside for final design

Engineering AnalysisEngineering Analysis

Max Torque: 24.75 lb-inMax Torque: 24.75 lb-in

Desired Speed: 5-10 RPM Desired Speed: 5-10 RPM

ACE F1 Series ChosenACE F1 Series Chosen

Final PrototypeFinal Prototype

Custom seatCustom seat

Gnome to attach to tank Gnome to attach to tank portion of toilet with hinged portion of toilet with hinged leg for closing seatleg for closing seat

Latching device to keep leg Latching device to keep leg in upright position when in upright position when toilet in usetoilet in use

Weight to cause triggering Weight to cause triggering when toilet flushedwhen toilet flushed

Rotary damper plus friction Rotary damper plus friction damping for smooth damping for smooth lowering of seatlowering of seat

Latching MechanismLatching MechanismLatch catches pin in leg Latch catches pin in leg when seat is raised to when seat is raised to hold leg in upright hold leg in upright position until toilet is position until toilet is flushedflushedOther end of latch Other end of latch attached to cable attached to cable coming from weight in coming from weight in tanktankPulling of cable Pulling of cable releases latch when releases latch when weight drops due to weight drops due to flushingflushing

Latch

Functioning PrototypeFunctioning Prototype

Final Design/Prototype ComparisonFinal Design/Prototype Comparison

2 smaller rotary dampers 2 smaller rotary dampers instead of one large oneinstead of one large oneLatching mechanism Latching mechanism incorporated into leg incorporated into leg instead of externalinstead of externalFloating weight made out Floating weight made out of buoyant, heavier of buoyant, heavier material than wood material than wood Gnome covered by Gnome covered by plastic coating to prevent plastic coating to prevent corrosioncorrosionRoller on end of leg to Roller on end of leg to allow smooth kicking and allow smooth kicking and easy reseteasy reset

FINAL DESIGN PROTOTYPE

Future ConsiderationsFuture Considerations

Creating changeable appearances of the Creating changeable appearances of the gnome for different holidays or seasonsgnome for different holidays or seasons

Manufacture own rotary damper to lower Manufacture own rotary damper to lower costcost

Manual override for disabling systemManual override for disabling system

Slimmer gnome to allow seat to move Slimmer gnome to allow seat to move further past vertical when in raised positionfurther past vertical when in raised position

ConclusionConclusionWent against our design objectives of being Went against our design objectives of being universal to all seats and being self-containeduniversal to all seats and being self-containedFinal design includes:Final design includes:– flush actuated timing mechanismflush actuated timing mechanism– equilibrium locking mechanismequilibrium locking mechanism– rotary damper lowering mechanismrotary damper lowering mechanism

Final design improves upon prototype with:Final design improves upon prototype with:– 2 rotary dampers2 rotary dampers– Non-corrosive part materialsNon-corrosive part materials– Locking mechanism incorporated into legLocking mechanism incorporated into leg

Future considerations include:Future considerations include:– Changeable gnome appearancesChangeable gnome appearances– Manufacturing own rotary damperManufacturing own rotary damper– Manual overrideManual override– Slimmer gnomeSlimmer gnome

QUESTIONS ?QUESTIONS ?