Pivoting springy mechanism that opens and closes pressed electrical contacts ...

FIG. 5

EQ 1 k = Fx(B2) - Fx (BP

Ax

EQ 2 Ax = 2L [sin (B2) - sin (B1)]

EQ 3 k = Fx (B2) - Fx (BP

2L [sin (B2) - sin (B1)]

EQ 4 Fy = 2Fa [cos (B)]

EQ 5 Fx = Fa [sin (B)]

EQ6 Fx = 2

Fx tan (B)

EQ 7 Fx = % tan (B) Fy

EQ8 Fx (B1) = % tan(B1) Fy(B1)

EQ 9 Fx (B2) = 1/2 tan (B2) Fy (B2)

EQ 10 k = tan(B2) FvfB21 - tanfBH FvfBIl

4L [sin (B2) - sin (B1)]

EQ 11 AY = L cos (B1) - L cos (B2)

EQ12 L= Ay

cos(B1) - cos(B2)

EQ 13 k = rtantB21 FWB2) - tanfBH FvfBDI fcosfBH - cos(B2H

4 [sin (B2) - sin (B1)] AY

EQ14 set Fy(B1) = Fy(B2) =Fy(min)

EQ15 k = [Fy(min)] TtanrB2> - tan(B1ti TcosfBD - cosfB2)1

4AY [sin (B2) - sin (B1)]

FIG. 6

S1 -» Select Fy (MIN) and AY in eq. 15 as design constraints

52- > Choose B1, B2 in eq. 15 such that Fx < Fy from eq. 8 and 9

53- » Calc. k from equation 15

54-» Calc. L from equation 12

55- > Fx (B1) = k A xo = 1/2 Tan (B1) Fy (MIN)

FIG. 7

51- » Fy(MIN) = 60 pounds, Ay = 0.20 inches

52- * B1 = 20 degrees, B2 = 29 degrees

53- > k = 6.45 pounds per inch

54- > L = 3.1 inches

55- * Axo = 1.693 inches

FIG. 8