IMPROVEMENT IN PRESSES FOR MOLDING GLASS INSULATORS
Year: 1884

page_text: COMPLETE SPECIFICATION.
We, LAWRENCE BRICKETT GRAY, and JOSEPH HAч, of the City of Boston, and
State of Massachusetts, in the United States of America, merchants, do hereby
declare the nature of our Invention for IMPROVEMENT IN PRESSES FOR MOLDING
GLASS INSULATORS, and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement.
According to our Invention, we construct the plunger of a press, for molding
glass insulators, in such manner, that a glass insulator may be pressed into a
suitable mold, so as to form a continuous screw-thread within the opening of the
insulator, and then, by contracting the screw-thread of the plunger, permit its
removal therefrom by a single upward movement, without disturbing the screw-
thread thus formed; as heroinafter moro fully described, and specifically set forth
in the claim,
Reference being had to the annexed Drawings in which :-
Figure 1 represents a side elevation of a plunger constructed according to our
Invention. Figure 2 represents a vertical sectional elevation of the same.
Figure 3 represents a horizontal cross-section of the screw-threaded portion.
Figure represents a vertical sectional elevation, showing a portion of the screw-
thread in a contracted position. Figure 5 represents a cross-section of the same.
Figure 6 represents a vertical sectional elevation, taken at a right angle to the
view shown in Figure 4. Figure 7 represents a similar view showing opposite
portions of the screw-thread contracted. Figure 8 represents a horizontal cross-
section of the saine.
A represents a cylindrical shell or case, having a small opening through the uppor
end, within which is fitted to slide freely, the plunger-rod B, to the enclosed portion
of which is pivoted the upper end portions of the adjustable actuating-bars C, by
means of the short hinge pieces E, which are adapted to turn, or fold, from a
horizontal to a vertical position, as the said plunger-rod B is drawn upward, the
incline outward face portions contact with the incline faced lugs D, formed upon the
case A, as shown in Figures 2 and 4.
The said bars C being provided at their lower end portions with a screw-
thread H, which is thus withdrawn inwardly or centrally, so as to clear the
screw-thread formed thereby, in the interior of the insulator, as shown in Figures +
and 5; and when contracted, a further upward movement of the said plunger-
rod B, actuntes the pivoted levers L, the lower ends of which are pivoted to the

page_text: bars K within the said case A, and the inward upper ends of which contact with
the projections G, formed upon opposite sides of the said plunger-rod B, and
thereby force inwardly or centrally the lower ends of the said bars K, the outward
faces of which are provided with a screw-thread F; and thereby removo the said
screw-thrend portions F', from the screw-thread formed thereby within an insulator;
the said screw-thread portious F, being contracted into the position shown in
Figures 7 and 8.
The downward or reverse movement of the said plunger B, returns the sectional
screw-thread portions Fund E, into the expanded positions shown in Figure 1.
By means of our Invention above described, a glass insulator may be pressed in
a mold so as to form a scrow-thread within the opening thereof, in a very
expeditious manner,
Having now particularly described and ascertained the nature of our said
Invention, and in what manner the same is to be performed, we declare that what
we claim is :-
The combination with the shell or case A, of the sliding plunger B having the
actuating-bars C pivoted thereto by the hinge-piece E, and provided with a screw-
tbread H, the lever L, pivoted to the case, and pivoted to the bars K, and provided
with a screw-thread F, substantially as described.