Brown movement 271 uses a vibrating lever carrying two pawls which act alternately on a ratchet bar, producing nearly continuous rectilinear motion.
Two-pawl Continuous Rectilinear Ratchet Bar Interactive Calculator
Enter tooth pitch, pawl-action rate, an arithmetic effectiveness factor and target travel. Outputs are ideal mean calculation—not a prediction of contact, missed engagement, force, holding, strength or safety.
Equation Used
- Each entered pawl action has ideal pitch scale p.
- The effectiveness factor is an assumed multiplier; it does not predict successful engagement or mechanical efficiency.
- Rate is pawl actions per minute.
- Target time assumes constant mean ideal rate.
- Pawl contact, springs, tooth geometry, lever dimensions, holding behavior, force, wear, strength, release and safety are omitted.
Brown Movement 271
Henry T. Brown's movement 271 states that vibrating the lever carrying two pawls gives a nearly continuous rectilinear motion to the ratchet bar. The drawing and animation show the two pawls acting alternately from the same lever.
What This Calculator Represents
The tool multiplies an entered tooth-pitch scale by an entered pawl-action rate and an entered effectiveness factor. It does not infer lever cycles, contact success or equipment performance.
Entered-Rate Arithmetic
ideal advance per minute = p × n × eta
mean advance per action = p × eta
ideal target time = target / v
n is the entered number of pawl actions per minute. eta is an assumed multiplier, not a calculated mechanical efficiency.
Worked Arithmetic Example
For entered pitch 10 mm, 60 pawl actions/min and 100% entered effectiveness, the ideal mean rate is 10 mm/s, ideal advance is 600 mm/min and mean advance is 10 mm per action. A 100 mm target corresponds to 10 seconds at that constant ideal rate.
Assumptions and Limits
- Source-backed: a vibrating lever with two attached pawls acting alternately on a ratchet bar.
- Calculated: entered pitch/rate/effectiveness calculation.
- Not calculated: tooth or pawl geometry, spring behavior, contact timing, missed engagement, lever dimensions, force, holding, friction, wear, strength, release, equipment capacity or safety.
Frequently Asked Questions
Is rate a complete lever-cycle rate?
No; it is entered pawl actions per minute.
Is effectiveness predicted?
No.
Does the model prove each pawl advances one full pitch?
No.
Does it calculate holding capacity?
No.
Are springs and contact included?
No.
Can it size a load-bearing device?
No.
References
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