Welcome to the ABA! Bell Talk Forums Large Bells Question about yoke design

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    • #11759
      halanb
      Participant

      Jackbell, Neil, Harry, Carl, Towerguy, et al. – Dumb (?) question for the Big Bell guys from a Small Bell guy.

      The picture of the William Blake bell earlier today for some reason got me wondering about yoke design. Yokes swoop down so that the ends are lower than the top of the bell, thus moving the pivot points closer to the combined center of gravity of the bell, yoke, and clapper. My question concerns if there is a formula for the percentages of weight above and below the pivots, say, 30% above and 70% below? Does this vary from one founder to another? Does this vary with size (weight) of a bell? Are there differences between church, school, and locomotive bells? My assumption is that the pivots are closer to the center of gravity as the size/weight increases, so as to make the bell easier to ring.

      The first set of pictures shows a Meneely 17″ bronze, a Stuckstede 34″ bronze, and a Sheffield 37″ steel. It seems to me that the pivots for the (100 lb?) Meneely are relatively higher than for the (800 lb?) Stuckstede.

      Yet the pivots for the Sheffield steel bell seem even higher??? I don’t know anything about relative weights of bronze vs. steel bells. Are steel bells cast with thinner metal so they do not need as much extra allowance for weight?

      The second set of pictures is of two fairly large bronze bells. The sizes are unknown, but the photos are the same scale so relative size is accurate. Again, it seems to me that the pivots for the larger/heavier bell are relatively lower.

    • #16360
      jackbell
      Participant

      It’s an interesting observation. Some foundries cast yokes of 3 pieces with adjustable pivots that could be raised or lowered to fit several sizes of bells thus reducing the number of different molds needed for yokes. I’ve seen these on Coffin (Cincinnati), Caughlin (St Louis) and a few others I can’t recall. I imagine some makers used physics in their bell designs and others just went with what looked good.

    • #16361
      hjlong3
      Participant

      The English Change Ringing Bells have a low pivot at the center of gravity to allow a complete swing of the bell with little effort. Railroad bells have a rather high pivot as it was undesirable to have a complete swing of the bell. Many Italian or Spanish bells have a large counter weight in the yoke that in effect shifts the center of gravity to make it easier to swing a heavy bell. In the US, I believe that the pivot point of most large bells was unique to the founder and probably had little plan, but I might be wrong. John Eachus would know the answer.
      Harry Long, MD

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