23-07-2024, 08:06 AM
Hi Chris
That's interesting - I haven't come across the slotted toggle variant before.
Checking back on my notes, the gap between the weights at full advance is about 3/16 inch (4.8 mm). The spring extension at rest is about 20 thou (0.5 mm) in other words not slack but not very stretched either.
The toggle geometry is quite clever. A plain spring acted on by centrifugal force would give an advance that increased with the square of the RPM - not what's wanted. The pivoted toggles compensate for this to give advance more or less proportional to RPM. I take my hat off to which ever mechanical designer dreamt that one up.
That's interesting - I haven't come across the slotted toggle variant before.
Checking back on my notes, the gap between the weights at full advance is about 3/16 inch (4.8 mm). The spring extension at rest is about 20 thou (0.5 mm) in other words not slack but not very stretched either.
The toggle geometry is quite clever. A plain spring acted on by centrifugal force would give an advance that increased with the square of the RPM - not what's wanted. The pivoted toggles compensate for this to give advance more or less proportional to RPM. I take my hat off to which ever mechanical designer dreamt that one up.