|
To all whom it may concern: Be
it known that we, LUTHER C. BALDWIN,
and JOHN C. THURSTON, both of
Manchester, in the county of Hillsborough and State of New Hampshire, have
invented a new and useful Improvement in Insulators for Telegraph-Wires,
of which the following is a specification. Our
invention relates to improvements in insulators for telegraph-wires, in
which the insulator is connected to the bracket-pintle or supporting-pin
by partially turning the insulator after the supporting-pin is inserted
therein, instead of by means of screw-threads. The
object of our invention is to provide means for preventing the insulator
from being turned on its supporting-pin when they are put together for
use. Our
invention consists in a cup of some non-conducting material, preferably
glass, having its interior shaped to receive the supporting-pin, in
combination with a pin adapted to be inserted and turned, and then farther
inserted to lock and form a firm bearing for the inverted cup,
substantially as hereinafter fully described, reference being had to the
accompanying drawings, in which-- Figure
1 is an elevation, with the insulating-cup in section, showing the pin
inserted as far as it will go without being partially turned.
Fig. 2 is a similar view, showing the pin in place, and so locking
the cup as to prevent its being withdrawn without first partially
separating the cup and pin, and partially turning one on the other.
Fig. 3 is a longitudinal cross-section through the insulating-cup;
and Fig. 4 is a bottom view of the insulating-cup. The
best way now known to us for carrying out our invention is to turn a knob
or bulge, a, on the top of the pin A and make two sides of this knob flat.
Turn the pin from the knob to near the lower part, a', to a tapering form.
The diameter of this tapering part at a2 in Fig. 2 is greater
than the longest diameter of the knob a.
The lower part, a', of the pin is made either in the usual round
form or in a bracket shape for inserting into a hole or for being spiked
to a post. The upper part, b, of the interior of the insulating-cup B is made to fit snugly the upper end, a, of the pin A--that is, it is made into a shallow chamber having two straight sides and round ends. This chamber is best made as shallow as possible, since its depth |
 |
|
|
determines
the distance the insulating-cup may be moved on the pin by an upward
strain before the knob in the pin arrests its further movement. Just below the chamber b a circular chamber, b', is made, its
diameter and depth being such as to allow the knob a to turn in it.
Below the chamber b' the interior of the cup is made oval at b2
the shorter diameter of the oval being the same ns the diameter of the
tapering part of the pin at the line a in Fig. 2, and the longer diameter
being slightly greater than the longest diameter of the knob a on the pin
A. The oval shape at b2
expands gradually until it forms a circle at b', the diameter of which is
the same as the diameter of the tapering part of the pin at a2
in Fig. 2, which, as above stated, is slightly greater than the longest
diameter of the knob a. This shape gives the cup a firm bearing on the pin
at a2 and causes a partial contact between the two up to a3
when the pin is in place, as shown in Fig. 2. The
manner of inserting the pin will be readily understood by referring to
Fig. 1, in which it is shown in the position to allow the knob a to pass
through the oval-shaped part of the cup, and the knob having passed this
part and ready to be turned in the circular chamber b' before being pushed
up into the chamber b’, the straight sides of which prevent the cup from
turning on the pin. We
claim as our invention-- 1.
A cup of non-conducting material having its interior shaped substantially
as described, in combination with a pin which, when partially inserted,
allows the cup to turn, and when fully inserted forms a bearing for and
prevents the cup from turning, substantially as set forth. 2.
A cup of non-conducting material having its interior formed into an upper
chamber with flat sides, a middle circular chamber, and a lower tapering
chamber oval at one end and circular at the other, in combination with a
supporting-pin having a knob with fiat sides at one end, its other end
adapted to be secured to an arm or post, and a cylindrical tapering part
between these ends, substantially as and for the purpose set forth. LUTHER
C. BALDWIN, JOHN
C. THURSTON. Witnesses: W.
A. COPELAND, G. B. MAYNADIER. |