WE Governor Spring Clutch Operation

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This is the governor clutch before (over oiled that turned to hard sticky tar) and after cleaning.



Looking the spring clutch while turning the governor shaft showed what happens when dialing a number and then releasing the finger wheel to allow it to return to its normal stop.

Looking at the clutch spring, you can see both ends of the spring. It is a square metal spring material slipped over the "clutch shaft" (a silver colored shaft). The ends of the spring are circled in red.



The assembly seems to be like this. The silver shaft has a bearing axel on the bottom (blue arrow), as shown, which fits into the gear train cage plate (not shown).

Just above the axel is a collar (green arrow) that keeps the bottom the the spring on the shaft. The pre-coiled spring is slipped over the shaft. The governor gear is then slipped over the shaft and a brass collar (yellow arrow) is press fit onto the shaft to keep the spring and gear in their proper place.

The rest of the silver shaft with a couple of washer is inserted through other gear train cage plate, the governor raceway is added on the other side of the plate and governor fly wheel (brakes) are press fit onto the shaft to hold the clutch/governor assembly in place.

The square metal spring is wound clockwise.

The spring is loose on the silver shaft but seems to have a length that just fills the entire shaft from the bottom collar to the gear. The gear is sitting loose on the gear end of the spring.

When the gear is turned to the right (black arrow), clockwise, the governor fly wheel does not turn, the clutch is not engaged. The gear is "opening up" the spring allowing the finger wheel to be turned to a desired number without forcing the governor bakes to operate. The governor stands still when dialing a number.

When the finger wheel is released, the governor gear is turned to the left (maroon arrow), counter clockwise, the clutch engages. This engagement is by way of the gear turning in the same direction the spring is would causing the spring to tighten of the silver shaft and thereby operating the governor fly wheel, controlling the dialing speed by expanding the fly wheel brakes to control the speed of the dial.

When the dial comes to its normal rest, the spring that was held tight against the silver shaft relaxes a bit allowing the next number to be dialed without operating the governor.

It's an ingeniously simple clutch with very tight specifications so that the governor gear is allowed to engage and release the clutch with each number dialed.

The last image is an approximate cross section drawing of the governor spring clutch.



Since I did not take this clutch apart, and never would due to the press fit parts, the cross section is a close approximation (not to scale) based on what is seem in the images and what I observed during operation of the clutch.

WE changed to design of their gear train with each new dial model number but I suspect that all WE spring clutches that look similar to this operate in the same way. Other manufacturers probably use other types of clutches to end up with the same governor response.

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The specs on that square wound spring between the bottom collar and the governor gear is so close, the tolerance so tight, that the governor gear only has to move about a half of a gear tooth revolution to tighten the spring around the silver shaft to engage the clutch, to tighten the spring around the silver shaft. The use of square windings puts 100% of the spring area in contact with the silver shaft almost immediately, with no slippage.