"Threadless Corner" -- The Stearns Insulator
by Ray Klingensmith
Reprinted from "INSULATORS - Crown Jewels of the Wire", April 1979, page 5
This month I decided to cover
another insulator of the "threadless era", a patented item which, to
my knowledge, has not been found.
On November 26, 1869, Joseph B. Stearns, of
Boston, Massachusetts, applied for a patent on an improvement in the method of
attaching insulators to their supports. He was granted a patent on September 13,
1870. The patent actually involved two different, but similar, methods. I've
included a copy of the patent drawing (see fig. 1-4), and have also made four
drawings of my own (fig. 5-8)
I felt the patent drawings might be a
little confusing, and decided to draw the insulators and pins separately so that
everyone could understand the invention a little easier. Sometimes the patent
specifications get a little complicated, and this one certainly was no
exception. The insulators and pins involved were designed with corresponding
grooves and pegs in a way to lock the two together.
In his first method, Stearns
designed a regular threadless insulator. In the dome area was a small opening,
from the outside area to the pinhole inside (see fig. 1 and 5). In this small
opening was placed a small peg. Picture it, if you will, as a matchstick going
into the dome of the insulator. Fig. 5 shows a cross section of the insulator
with the peg (C) inserted. It projects into the pinhole a small distance. Figure
6 shows a pin (B) with a groove (D) the same size as the peg. To mount the
insulator on the pin one would position the pin in a manner in which the peg (C)
would enter the groove (D). The insulator would be pushed downward, allowing the
peg to follow the groove. After traveling approximately 1-1/4 inches, the peg
would reach another groove (E which traveled almost entirely around the pin. At
that point the insulator would be turned in the direction of the groove (E)
until reaching point (F), at which time it would be fully mounted. Notice the
depth of the groove from E around the pin to point F gets shallower in depth.
The pin is designed that way to cause the peg and groove to bind and become
firmly joined, to prevent the pin and insulator from coming apart.
In his other
method, Stearns had the peg (C) embedded in the pin. Imagine, if you will, a
threadless pin with a matchstick driven through its center, projecting from one
side a small amount (see fig. 8). This pin would fit an insulator as shown in
fig. 3 and 7. This insulator was a regular threadless insulator with a small
groove at one side of the pinhole. This groove (D) started at the entrance of
the pinhole and traveled upward to a point approximately one half the distance
to the top of the pinhole. At that point the groove (D) joined another groove
(E) which circled the center of the pinhole nearly the entire circumference. To
install the insulator one would place the insulator in a manner in which the peg
(C) would enter the groove (D). The insulator would be pressed downward until it
reached a point where groove E is located. At that time the insulator would be
turned almost one entire revolution, at which time it would be fastened firmly
to the pin. The groove (E) on this insulator is also shallower at the far end,
as was the groove in the other method. This allows the insulator to be firmly
attached to the pin.
This design seems very interesting and quite practicable.
Had it been invented about ten years earlier, I'm sure it would have seen some
use. However, the screw-threaded insulator was becoming popular at the time of
the Stearns invention, so it's doubtful it was a success. Probably only a small
number (if any at all) were produced. I know of none to exist; but as with many
other patented items, it would be no surprise to me if one turned up. I'm a firm
believer that if someone went to all the trouble and expense to have something
patented, then they would most likely produce at least a small amount of their
invention.
As you are reading this, Spring will be upon us, and that
means digging season. It really amazes me how few collectors have ever found
even a piece of a threadless. The only way to find something is to look, look,
look and look more. It's so much fun to try to find a rare jewel. Sure, many
places have been searched before, but there are millions of insulators waiting
to be found. Come on, grab that trusty, probably rusty (from lack of use!)
shovel and get to digging. I've got my favorite digging places, many of which
local residents told me time and time again, "Oh, you're too late. There
have been a dozen collectors here before you." Well, that doesn't stop me.
I'll find what they didn't find! Don't let the fact that other people have
searched the area stop you. I've walked over 60 miles of one line, found some
nice broken threadless, which involved a lot of scratching around, digging,
sweating, aching muscles and hard work. It involved considerable time. And what
do I have? Well, I have many fond memories of great times and experiences. I've
many more friends, friends which I'd never have made if it weren't for my "diggin's".
And, one of these days I'll find that whole threadless. In the meantime I'll be
having a great time and getting some healthy exercise.
Just thought I'd add that
last November I took my sister with me on a dig. She always talked about going
with me and finding a threadless. She had gone with me once or twice before, but
it was more of a nature trip in the past. This time it was an insulator trip.
The two of us hurried to our "site" and started digging. Of course I
explained the "right" way to look. One must have that special
technique, you know! I guess we had dug for a couple of hours when she started
finding insulators, and I found ROCKS! First she pulled up a CD 126 Brookfield
with the embossed date on the lower wire projection, then came a CD 126.4 W.E.
MFG. CO. in an unusual icy green color, similar to a sage green California.
Well, then of course came the top one third of an unembossed CD 736 threadless.
Oh well, just a mere threadless!! So as you're reading this, the two of us will
probably be out there looking for that whole one. Come on, folks, get in on the
fun. Let's see what we can find!
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