ME $154-$ Homework $3(20$ points$)$

PROBLEM $1$: Your task is to design a simple mechanism to drive the windshield wipers of a

car using the graphical synthesis techniques you learned. Please use the scaled down version of

the wiper shown below to accommodate the entities within a reasonable space. The two wipers

are run by a single constant speed motor $($neglect the speed adjustment for this design$).$ The

wipers are pivoted $($a grounded pin joint$)$ to the body of the car at the points shown. You can

attach your mechanism at any point below the ground $($so that you can hide the components of

the mechanism from plain sight$).$ The mechanism also should be a quick return on with a time

ratio $1$:$1\mathrm{.}5.$ Note that the sketch below is not to scale.

$($a$)$ Show all the work, including the construction line $(6$ pts$)$

$($b$)$ In a separate drawing clearly draw your final mechanism only $(2$ pts$)$

$($c$)$ Check the Grashof condition to make sure that a constant speed motor can drive it $(2$ pt

$($d$)$ Using graphical methods, measure the minimum transmission angle of your mechanism

$(2$ pts$)$

$($e$)$ Based on the numerical value of your transmission angle, is yours an efficient

mechanism? Provide the rationale for your answer $(1$ pts$)$