UNITED STATES PATENT OFFICE
THOMAS C. DUFFIELD, OF BRIDGETON, NEW JERSEY
MACHINE FOR PRODUCING GLASS INSULATORS.
SPECIFICATION forming part of Letters Patent No. 723,589, dated dated March 24, 1903.
Application filed November 8, 1902, Serial No. 180,516. (No Model.)
all whom it may concern:
it known that I, Thomas C. Duffield of Bridgeton, in the County
of Cumberland and State of New Jersey, have invented certain
Improvements in Machines for Producing Glass Insulators, of which the
following is a specification.
invention relates to certain improvements in that class of machines for
producing glass insulators in which a threaded spindle is plunged into a
practically closed mold containing a mass of semifluid glass to give to
the insulator formed therein an
internal thread, as will hereinafter fully appear.
carrying out my invention I provide the machine with a central column
and a table adapted to rotate about the same, upon which are seated a
series of molds, and a second table situated above the first and
arranged to have a rotary movement in common with it.
This second table supports over each mold a spindle with an
external thread at its end adapted when plunged into a mass of molten
glass contained in a mold to provide the same with a threaded cavity.
The said spindles have also a second thread situated above the first and
of a similar pitch, which, in connection with a half-nut adapted to be
brought into contact therewith, admits of the spindles being unscrewed
from their molds and the glass insulators contained therein.
The second table also carries devices for shaping the upper part
of the insulators and means for supporting the same, together with the
threaded spindles and their immediate attachments and connections. The
central column is provided with a single arm or bracket which supports
means for depressing the devices for shaping the upper part of the
insulators, together with the spindles, whereby the insulators are
threaded as the molds are successively brought under them.
With this construction an insulator is completed whenever a
glass-charged mold is brought under the spindle-depressing devices and
the same actuated, and the threaded spindles may be unscrewed from the
insulators at any time after they have been moved from under the said
depressing devices or at any time before the molds are again brought
under them. The
output of the machine is therefore increased, for the reason that
considerably more time is allowed which to unscrew a threaded spindle
from an insulator than is required to charge a mold with fuel melted
glass, close the mold, and plunge the end of a threaded spindle into the
mold and the glass confined therein, in as will hereinafter fully
the further description of the said invention which follows reference is
made to the accompanying drawings, forming a part hereof, and in which--
Figure 1 is a central partly-sectional elevation of the improved
2 is a section of Fig. 1, taken on the dotted line X X, with certain
parts thereof omitted. Figs. 3, 4, 5, and 6 are enlarged details of the
machine and hereinafter described.
Referring now to the drawings, 1 is a wheeled platform or truck
supporting the socket 2, in which rests the stationary column 3. The
socket, 2 is provided at its upper end with an exterior flange 4,
having in its face a. circular groove of a semicircular cross-section,
in which are placed antifriction-balls 5.
6 is a circular table with an upwardly-extending hub 7, adapted
to turn loosely about the column 8.
It is provided with a circular groove like the one in the flange
of the socket 2 and rests on the antifriction-balls, as shown in Fig.
1. As it is
necessary that the table 6 should have an intermittent rotary movement
affected by hand and be held firmly and accurately in place at each stop
or when an insulator is molded, it is provided with the holes 9, which
are equidistant apart, and the end of the spring-supported bolt 10 is
adapted to enter each one of the said holes in succession, and so hold
the said table from passing beyond the stopping-point. The bolt 10 is
withdrawn from a. hole by means of the treadle 12, when the table may
be again rotated. 13
13 are the molds proper, in which the insulators are formed. They are
preferably ten in number, and by reference to Fig. 5 it will be seen
that they are each in two parts or sections hinged together and the
opening and closing of the sections is ejected by the handles 14, as is
common in molds of this class. A hinged latch 15 (a well-known device
having a handle 16) is used to lock the mold during the molding
operation, Each mold is hinged at 17 (see Fig. 1) to a base-plate 19,
fastened to the table 6, and the base-plate, which, is practically a part
of the mold, as it forms the top of the insulator, rests in a hole 20 in
the table, and the holes 20 are on radial lines passing through the
holes 9, before referred to.
is a second table fastened to the hub 7 of the first one 6 and at some
considerable distance above it.
Referring now particularly to Fig. 2, it will be seen that the
second table 23 is provided with ten pivoted forked carriers 24, each
one of which is adapted its be yieldingly held in a radial position,
with its forked end directly over the center of the mold 13, by means of
a spring 25 and a stop 27.
29 is a lug or projection at one side of the central column 3 to
deflect each carrier from a radial position and move its forked end from
over the mold beneath for a limited time as it approaches the place
where stands the operator, who is termed a "presserman" for a
purpose hereinafter described.
The forked end of each carrier is provided with a circular plate
30, having a cylindrical projection on its upper side, and at the end of
the projection is a collar 33, which is made larger in diameter than the
said projection in order to form the annular peripheral recess 35.
means whereby the plate 30 is attached to the-forked end of the carrier
consists of two fixed rods 37, which are secured in the said plate and
extending downward pass loosely through the carrier and are fastened in the flange of a plunger 39, hereinafter described.
Spiral springs 40 wound around the rods 37 and confined endwise between the circular plate 30
and the upper surface of the forked ends of the carrier, serve to
sustain the said plate in its highest position above the carrier and at
the same time draw the plunger into contact with the under side of that
is a circular follower with a beveled edge adapted to enters
correspondingly-shaped recess 43 in the upper face of the body of the
mold 13, and it is provided with a circular groove, which forms the
rounded edge of the flange of the insulator, as will hereinafter appear.
This follower is arranged to slide vertically of the plunger 39, before
referred to, and is suspended from the flange of that device by the
bolts 46. The normal position of the follower with reference to the
plunger is shown in Figs. 1 and 4.
the above descriptions it will be understood that the spiral springs 40
sustain the plate 30, and the rods around which the said springs are
wound or coiled support the plunger 39, and that the said plunger
follower 42 thorough the agency of the bolts
is a spindle which passes loosely through the plate 30 and the plunger
39 and is held when elevated by friction produced between of the
spring-bolt 50, which bears against the
spindle, as shown in Fig. 3. The lower end of the spindle 49 is
threaded, so that when it is plunged into a mass of semifluid glass and
that substance closes around it the hole so formed will be provided with
an internal thread. The upper end of the said spindle, which has a
conical point, is also provided with a thread corresponding in pitch
with that of the thread at its lower end.
is a, crank-handle whereby the spindle 49 is turned to unscrew it from
the insulator, as hereinafter described.
53 is a lever (see Fig. 6) pivoted at 55 to the face of the
collar 33 of the circular plate 30, and it is provided with not less
than one half-thread 57, adapted to engage with the thread on the upper
end of the spindle 49 and when so engaged performs the office of a nut.
leave described the threaded spindle as an entirety; but as the lower
end has to be heated before use to precept chilling the semifluid glass
in the mold when plunged therein and has at times to be reheated it is
made removable; but as this feature is not new I have not shown the
spindle in two parts with means for their connection.
is a fixed arm or bracket extending horizontally from the upper end of
the column 3 and toward the front of the machine, which is denoted by Y
and where the presserman or principal operator stands. The end of the
arm 59 is bored, the hole being directly over the center of a mold when
the came is in front of the presserman, and in the said hole is placed
the vertically sliding shaft 60. This shaft has a conical depression at
its lower end, so as to fit over the point of the spindle 49, and fixed
to its upper end is a cross-head 62, the ends of which, 63, are
connected by links 64 to an overbalanced hand-lever 65, fulcrumed at 67
to the arm 59. 69
69 are rods adapted to slide vertically in holes in the arm 59 and
through a flange 70, forming a part of the cross-head 62. Nuts 72 at the
ends of the rods 69 limit their down-ward movement independently of the
73 are collars tm the rods 69, and 75 75 spiral springs coiled about the
said rods and extending between the collars 73 and the under side of the
flange of the cross-head 62.
lower extremity of each rod 69 is turned inward to form a hook 77, and
the two hooks are adapted, under circumstances hereinafter described, to
enter the groove 35 of the plate 30.
hooks 77 are always in front of the presserman, and therefore engage
with or take hold of each plate 30 as it and its connections come to the
front of the machine, and it is by them that each plate, with its
plunger 39 and follower 42, is successfully forced down, so that the
last two devices enter the mold proper beneath prior to the plunging of
the threaded spindle into the semifluid glass therein.
The following is a description of the operation of making
insulators by means of the present machine: Supposing the various parts
or elements of the machine to be in the relative positions shown in
Figs. 1 and 2, the gathering boy by means of a, gathering-rod Insects a,
charge of soft glass into-the mold situated to the right of the
presserman, the entrance to which mold is exposed by the Inner end of
the carrier above it coming in contact with the projection 29 on the
column 3. The charge is severed from the gathering-rod by the presserman,
who by experience knows the quantity of glass necessary to form an
insulator. The presserman then turns the table in the direction
indicated by the curved arrow in Fig. 2 so as to bring the charged mold
directly in front of him and its plate 30 into engagement with the hooks
77 of the rods 69, when the table is automatically stopped by the
spring-bolt countering one of the holes 9. The presserman then pulls
down the over-balanced hand-lever 65, which depresses the rod 69
through the agency of the links 64, the cross-head 62, and the springs
75, and the hooked ends of the rods 69 being then in the groove 33 of
the plate 30 that device is carried down, together with the plunger 39,
containing the threaded spindle, and the follower 42, the last-named
device falling by the force of gravity alone, it being loose on the
plunger and sustained only by bolts 46. In this operation the follower
is seated in the recess 43 in the body of the mold and the plunger
forced into the mold, the spiral springs 40 being compressed in the
operation, with the flange of the plunger resting on the follower, as
shown in Fig. 3. At the conclusion of this part of the operation the
lower end of the shaft 70 comes In contact with the upper end of the
threaded spindle 49, and the latter is forced down and plunged into the
mass of semifluid glass confined in the mold, and the glass, finding no
means of escape, closes around the spindle and is thereby provided with
an internal thread. This completes the operation of forming the
insulator, and the pressman then releases the overbalanced hand-lever
and turns the table until the next mold, with its carrier and
connections, is brought to the front, when the operation as described is
repeated. As spun as possible after a mold containing a completed
insulator has passed from the presserman a boy pulls around the lever
53, so as to bring the half nut or thread forming a part of the said
lever into engagement with the upper thread of the spindle 49.
The boy now unscrews the threaded spindle from the glass
insulator in the mold by means of the crank-handle 52, the half-nut on
the lever 53 enforcing the proper movement of the spindle in the soft
glass and preventing any strain being placed on the thread thereof.
will be understood that this unscrewing operation may be performed at
any time after the mold has, passed from the presserman, and the spindle
has not to be connected with any extraneous unscrewing devices
whatsoever Consequently the rapidity of forming insulators is much
claim as my invention--
a machine for making internally-threaded bliss insulators, a rotary
table having a series of molds seated thereon, and a follower, a
plunger, and a threaded spindle with an unscrewing appliance situated
over each mold with means to yieldingly support them in an elevated
position, combined with a single depressing mechanism having a fixed
position, under which the melds with their threaded spindles and
attachments as described are successively brought, and whereby, in its
actuation, a mold is covered by its follower and plunger, and a threaded
spindle plunged therein, substantially as specified.