Gardner D. Hiscox movement 138i shows a stroke-driven toggle arrangement. As the toggle links pass their center line to the dotted position, the wheel completes a second revolution.
Two Revolutions for One Stroke Interactive Calculator
Enter an illustration wheel radius, an illustration toggle-link scale and a number of input strokes. The calculator applies the stated two wheel revolutions per stroke; the dimensions do not create a force or constrained-linkage solution.
Equation Used
- One entered stroke means one complete input stroke cycle.
- The historical caption is taken as defining two wheel revolutions per input stroke.
- Entered wheel radius and link scale control only the schematic proportions and their displayed ratio.
- The solid and dashed toggle positions identify the historical over-center topology but are not a dimensionally solved linkage.
- Velocity, acceleration, dwell, toggle singularity, force, torque, contact, bearing loads, friction, backlash, strength, wear and safety are omitted.
Hiscox Movement 138i: Toggle Links Passing Center
Hiscox's plate shows a wheel at the left, a rocking upper member, toggle links, a fixed lower pivot and a horizontal stroke member. His caption says the toggle links pass their center line to the dotted position and thereby make a second revolution of the wheel.
The illustrated motion passes through toggle links and the rocking member.
What This Calculator Represents
The tool applies the source's stated timing count: two wheel revolutions for every entered complete input stroke. The two dimension controls change only the illustration and report their entered ratio.
The timing count does not determine torque, loads, dimensions, clearances or operating limits.
Wheel Revolution Count
wheel revolutions = 2 × entered input strokes
revolutions per stroke = 2
The ratio is not Hiscox's transmission ratio and does not affect the two-revolution count. The source is undimensioned.
Worked Timing Example
For two entered input strokes, the source-stated timing gives four wheel revolutions. Entered illustration values of 40 mm link scale and 20 mm wheel radius display a 2.00:1 illustration ratio only.
Model Boundary
- Historical description: the pictured toggle-over-center topology and two wheel revolutions per stroke.
- Calculated: timing count and an entered illustration ratio.
- Not calculated: a dimensionally constrained linkage, position law, velocity, acceleration, dwell, singular force, torque, bearing load, friction, backlash, strength, wear, fatigue, application duty or safety.
What determines loads near the toggle center?
Toggle force and wheel torque depend on the link dimensions, pivot positions, input force and position through the stroke. The historical timing count supplies none of those load values, so this calculator does not estimate peak force, wear or service life.
What is needed to evaluate a physical mechanism?
A complete dimensioned linkage and its input motion are needed to determine positions, travel and loads through the over-center region. Materials, joints, bearings and clearances must then be evaluated for that design. The illustration controls do not supply these specifications or maintenance limits.
Frequently Asked Questions
Is this a 2:1 gear reducer?
No. Hiscox shows toggle links rather than a gear pair.
What passes the center line?
The toggle links pass through their aligned position to the dotted position shown in the source.
Does link scale determine the two-revolution timing?
No; it is an illustration control only.
Is torque doubled?
This calculator does not establish a torque ratio.
Is the linkage dimensionally solved?
No. Hiscox provides no dimensions.
Can this size a press or pump drive?
No.
References
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