Pivot Arm Toggle Formulae and Calculator

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Pivot Arm Toggle Formulae and Calculator

Machine Design Application, Equations and Calculators

Pivot Arm Toggle Mechanism Design Formula and Calculator

Pivot Arm clamp design with forces applied and reaction forces calculator. Force is applied at Q and maintained by the spring between the pivot arm and stop collar.

Preview: Pivot Arm Toggle Toggle Mechanism Calculator

Eq. 1
Q = P [ ( ( l + l₁ ) + ( ( l + l₁ ) / l₁ - 1 ) r · f_o / ( l₁ - h · f₁ ) ]

Eq. 2
P = Q / [ ( ( l + l₁ ) + ( ( l + l₁ ) / l₁ - 1 ) r · f_o / ( l₁ - h · f₁ ) ]

When n is designated

Eq. 3
Q = P [ ( l + l₁ ) / l₁ ] ( 1 / n )

Eq. 4
P = Q / [ ( l + l₁ ) / l₁ ] ( 1 / n )

Figure 1
Pivot Arm Toggle Mechanism

Where:

Q = force applied to handle. lbf, (N)
P = clamping force, lbf. (N)
f_o = coefficient of friction (axles and pivot pins) = 0.1 to 0.15
f₁ = coefficient of friction of pin contact surface = 0.1 to 0.15
n = efficiency coefficient, 0.98 to 0.84
l, l₁ = length as indicated. in, (mm)
h = distance as indicated. in, (mm)
r = radius of pivot hole. in, (mm)

Reference:

Handbook of Machining and Metalworking Calculations
Ron A. Walsh
2001