[AT] PTO-driven table saw - NOW shifter forks (LONG)
David Bruce
davidbruce at yadtel.net
Sat Mar 5 15:48:05 PST 2005
On old textile looms powered by a line shaft the "shifter fork" was
called a "shipper handle". When I was at N C State in the 70's they had
a loom set up with a belt drive powered by an electric motor - good for
a demonstration I guess.
David
Greg Hass wrote:
> Little late getting back in, but here goes...
>
> First of all, we are not talking about shifter forks in a tractor
> transmission, but those used to shift flat belts from one pulley to
> another. For many years, at an auction sale I would see old drill
> presses or power hacksaws that were flat-belt driven by what would
> appear to be two pulleys. One pulley would run the machine and the
> other would just "free-wheel" on the shaft. However, no one could
> explain to me why they were this way.
>
> About 25 years ago I visited Greenfield Village in Dearborn, Michigan (a
> suburb of Detroit) for the first time. It is about a 2-1/2 to 3 hour
> drive for us. For those of you not familiar with it, Greenfield Village
> was established by Henry Ford and covers more than 90 acres. It
> includes a working steam locomotive which pulls a tour train around the
> grounds. It also includes Thomas Edison's Meno Park, NJ laboratory,
> Edison's workshop, the Wright Brothers' bicycle shop, Noah Webster's
> home, Stephen Foster's house, several different types of machine shops,
> and many other historical and interesting exhibits. These are the
> actual buildings which were disassembled at the original locations,
> moved to the Village and reassembled. They are the actual buildings.
>
> My favorite was the machine shop (approximately 100 ft. long) with 4
> rows of machines run by 2 jackshafts which ran the length of the
> building. Both shafts were run by a steam engine located at one end of
> the building. The jackshafts were running all day, and during the tours
> they would start many of the machines for half a minute or so. (You
> don't have to take a tour. You can just pay your entry fee and wander
> around all day as you want. There is even a picnic area.) This is
> where I finally learned what the two pulleys were for.
>
> As you walked through, all of the flatbelts were running on the pulley
> that was just "free-wheeling". When the one doing the demonstration
> wanted to start the machine, he would use a shifter fork to do it.
> Basically it was just a 1-1/2 inch piece of hardwood on each side of the
> belt fastened together at one end and it had a wooden handle on it. I
> don't remember exactly where it pivoted, but the operator would reach up
> about shoulder high and move the lever sideways. The flatbelt, being
> between the forks, would be forced over to the other pulley, thus
> starting the machine. To stop the machine the process was reversed,
> forcing the belt back over to the "free-wheeling" pulley and the belt
> would just spin on it. I can remember thinking to myself at the time
> how functional yet simple this system was and how ingenious our
> forefathers were.
>
> We were also told that if any equipment used in the demonstrations in
> the village broke, they use the equipment in this machine to repair or
> make new parts because, as old as it was, it was the type of equipment
> that was originally used to make the other machines in the Village so it
> was an authentic way of doing things. Most of the people actually
> running the steam engines and the other machines were in their 80s, as
> they had originally run this type of equipment for a living. My next
> paragraph is NOT political, just plain facts.
>
> Unfortunately, about 15 years ago, for some unknown reason, one of these
> 80-something men broke a cardinal rule and wore a longer length
> bandana. It got caught in one of the belts and he was killed. MIOSHA
> came in and mandated that any running equipment had to be shielded.
> Village officials tried to get an exemption as a special because these
> were antiques as shielding would destroy the purpose and function of the
> displays, which was to show this antique equipment, how it was used, and
> how it functioned. Unfortunately, there was no talking with the
> bureaucrats, and when I was last there about 8 years ago they were no
> longer running the steam engine or the jackshafts. The two machines
> they did demonstrate were so heavily enclosed in plexiglas and shielding
> that it took the fun out of watching them. To the mechanical person
> like me, it was obvious that the machines were now being run by electric
> motors hidden up in the rafters of the building. Every machine there
> that runs, including a couple of old printing presses for their sample
> newspapers, are also so heavily enclosed that it's really no fun to
> watch them operate. BTW, the public was always blocked from being close
> enough to be endangered and the operators were trained. However, if one
> makes a choice to break the rules you really can't protect everyone
> against everything.
>
> I am just happy I was able to see everything when it was running as it
> was mean to be run and feel sorry for the millions of people who will
> never be able to see things as they originally were. However, if any of
> you trractor people are ever in the Detroit, the Village and the Henry
> Ford Museum next door all include many agriculturally related items and
> are well worth seeing. Be forewarned... it takes a day for each to see
> and explore everything. The Museum is open year-round seven days a week
> 9:30 AM - 5:00 PM, but the Village is open only April 15 - Oct. 31 seven
> days a week from 9:30 AM - 5:00 PM, and Nov. 1 - Dec. 31 Fri-Sat. only.
> (They are closed on Thanksgiving and Christmas days.) The Village is
> also open late (until 9 PM) on Saturdays from July 9-Aug 20. The
> website for info is: www.greenfieldvillage.org
>
>
> Greg Hass
>
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