Piano World Home Page Forums Our Most Popular Forums Piano Tuner-Technicians Forum Cont. Hickman Piano Action Discussion

Ok, since the old thread went OT about the Hickman Action, I am starting this thread. The old thread is here

https://www.pianoworld.com/forum/ubb...memade%20Piano%20Action.html#Post1982166

I did a little sleuthing about the Hickman action through my player piano friends. He wrote back with this:

One of the most interesting features of the Hickman action was a lever on the bass cheek block, which allowed for adjustment of the "feel" or "touch" (gram weight) of the action. The downside was the materials
available for manufacture (in 1929 -1930) -- we are sure the shortcomings could be overcome with today's
materials... anyway, an annoying "clicking" (somewhat like the Steinway Teflon cauls of the 1960s,
though not as bad) killed the production.

Interesting info.


I wonder if anyone is interested in making a prototype modern Hickman -- or if someone else made it would be interested in trying it in their piano?

Apparently in the 1990's a Hickman action was constructed:

http://www.mmdigest.com/Archives/Digests/199908/1999.08.21.03.html

I get down around Allentown occasionally. I'll se what my schedule is like and what contacts I can make next time.

I still don't see a reset function at the point of escapement as in the conventional grand action. Perhaps before complete release of the key, but not at let-off (escapement.) Then again the purpose doesn't seem to have been an improvement in the functioning of the action, only an improvement in the manufacture and adjustment.

You can see the action cycle here:
http://www.mmdigest.com/Tech/HickmanAction/

In other of the mmdigest.com pages you can read that it was actually used in a public concert.

The action couldn't be outplayed -- which I guess is one reason it was installed in the players. (Can you imagine people turning their tempo control to max and then complaining that the piano wouldn't play? ) Also, there is clearly less inertia in the design.

I played a piano many years ago that had a Hickman action. I did look at the action.

I wish I knew more at that time, I would have spent more time looking it over.

That piano may still be with the same owner, I might give him a call.

I have my doubts that the description of how the action works is accurate. At paragraph "P9" at this site:

http://www.mmdigest.com/Tech/HickmanAction/analysis.html

I quote:

"With a very loud blow, the downward motion may continue beyond the normal rest position, and the moving hammer will fetch up against the stop rail, where the stop rail felt will absorb any remaining hammer energy."

The backcheck might not ckeck the hammer on a very loud blow? And after the shank hits the stop rail felt... What the... ?

And then on "R2":

"The toggle can not transmit upward force until it is completely straight."

No, the toggle cannot transmit upward force until it is reset to the left. There is not an adequate explanation how the toggle resets.

You can't believe everything you read!

I suspect that there may be a way to adapt this for a vertical action.

Continuing with the info I have been able to gather....a major piano manufacturer has been studying the Hickman action and is probably working on ways to incorporate some or all of it's functions in their pianos.

Oh come on! I saw it on the internet, it must be true!

No, but it was an actual functional action. I have examined and operated the Hickman model that the PTG has at their home office/museum. There's no doubt it works.

Some years ago, I played on old M&H model A that was outfitted with the Hickman action. The piano dated from the 30s if my memory serves me well. Despite not having been regulated for many years and despite the piano having received heavy use at a school, the action felt really nice. Also, its down weight was adjustable by means of a lever. (How's that for being way ahead of its time!)

The verbiage in the cited web site might not be perfect, but, nevertheless,it does give a good general description of how the action works. Clarence Hickman was a brilliant inventor who, among other things, also invented the Bazooka. If you Google his name you'll find lots of links.

Here is what I found from the original patent:

http://www.patentstorm.us/patents/6232537/description.html

”After the hammer 81 has struck the string 38 it rebounds and rotates downwardly until a hammer tail 86 of the hammer 81 is caught by a backcheck 120 mounted to the key frame 12. While the key 24 is depressed all the way to the stop position and the hammer 81 is caught by the backcheck 120, the spring 98 is poised to reset the lower link 62 of the jack 60. When the key 24 is released the hammer tail 86 is released and the repetition lever 72 is impelled upwards due to the force in the spring 98. The lower link 62 is rotated back to the reset position where the second joint 142, third joint 146, and the fourth joint 148 are aligned and the upper link 66 and the lower link 62 are linearly aligned and locked up such that the jack 60 functions as a solid column. At this point, the key is fully released and is ready to be depressed or struck again.”

I take this to mean that this is not a fully repeating action, otherwise it would not say ”At this point, the key is fully released and is ready to be depressed or struck again.” It would say something like before the key is fully released... I do not believe the jack resets at the point of escapement. Not that it doesn’t work well, just that it does not repeat like a conventional grand.

I disagree, from the diagram and this description it does seem like this will repeat. The wording is bad, but the last sentence makes a distinction between the key being "fully released", and the key being "depressed". I think this would be the difference between the key releasing the hammer from check, which allows the repetition lever to reset the jack, and the player lifting fully off the key.

Huh? "At this point, the key is fully released and is ready to be depressed or struck again.” Sounds like it means just what it says. Nothing relates to repetition at all. Not that it won't repeat. Upright actions repeat when played normally due to momentum. Momentum, again during normal play, might make the Hickman action repeat also.

How does one depress a fully released key? The only way that sentence makes any sense is if 'fully released' and 'depressed' mean different things.
Plus, you did look at the page here http://www.mmdigest.com/Tech/HickmanAction/analysis.html didn't you? The descriptions might not be particularly clear, but it's pretty obvious that repetition was the goal, and it was achieved. In the R3 position, the jack has straightened so that it can exert upward pressure on the hammer again, but the key isn't fully depressed.

What boggles me is that people can read something and think that trumps actual experience. Living people on this forum -- and elsewhere -- have actually seen and played the thing. As a matter of fact its repetition is superior. As I wrote in an earlier post on this thread, that is one reason why they put it in players: it can't be outplayed by a human or by a machine set to max tempo.

Can anyone explain what resets the jack before the key is completely released? Nothing I have read explains this.

Hah! I found it.

Take a look at where the spring attaches to the lower link. In the patent sketch it is shown to the right of the linkage centerline. In the animation it is shown on the centerline. But on the photo of the model it is shown to the LEFT of the centerline. That is what makes the jack reset at the point of escapement. There is torque applied to the lower link to rotate the link, not just elongate the links.

I can attest to the fact that the action repeats very nicely.