IMPROVEMENTS IN MANDRELS AND DIES FOR MANUFACTURING LEAD ARMORED CABLES
Year: 1884

page_text: I, RICHARD SOLOMON WARING of Pittsburg, County of Allegheny, State of
Pennsylvania, United States of America, Electrical Engineer do hereby declare the
nature of my Invention for "IMPROVEMENTS IN MANDRELS AND DIES FOR
MANUFACTURING LEAD ARMORED CABLES" and in what manner the same is to
be performed to be particularly described and ascertained in and by the following
statement
This Invention relates to mandrels and dies for manufacturing lead armored
cables and is illustrated in the accompanying Drawing in which:
Figure 1 is an end view of my improved mandrel looking upon the nipples or
point of the same.
Figures 2 and 3 are sectional elevations of the mandrel the sections being taken
in the lines X X and X¹ X' of Figure 1.
Figure 4 is a side elevation of the mandrel.
•
Figures 5, 6 and 7 are transverse sectional views, the sections being taken Y Y,
Y Y and Y2 Y2 of Figure 4.
Figure 8 is a plan view of the die to be used with my mandrel.
Figures 9 and 10 are sectional views of dies showing different forms of openings
in the die.
Figure 11 is an end view of a modified form of mandrel.
Figure 12 is a longitudinal section on the line X X Figure 11.
Figure 13 is a transverse section on the line Y Y, Figure 12.
Figure 14 is a longitudinal section of one of the nipples on the line X'X¹
Figure 11.
In laying telegraph, telephone and other wires for electrical purposes it is
frequently essential that the conductors should be protected from the induced
currents from other wires in close proximity and from moisture and other injurious
external agencies. It has been found by experiment that the best means by which
the conductors can be protected from these and other injurious agencies is to cover.
and surround them with a thin covering of lead. The most practicable method of
applying this covering, is to form a tube or pipe around the conductors in a lead
press, the conductors being drawn through the core of the press, and the lead
pressed around it as it leaves the core. Conductors have been heretofore enclosed
[Price-fd1

page_text: in lead pipes as above stated but the capacity of the presses has been limited to the
formation of a single cable at a time.
The object of my Invention is to increase the capacity of the presses now in use
and to provide means whereby the lead is caused to flow more readily around the
end of the core and around the conductor emerging therefrom, and my Invention.
consists in general terms in the construction and combination of my improved core
and die, as hereinafter set forth and claimed.
The
A is a body of steel or other suitable metal in which is formed a socket a which
is partly threaded at a¹ to attach it to the core- bar D of a press. On the end of
the body A are formed three or more teats or projections a³, through which are
formed passages a³ which communicate at their lower ends with the socket a.
body A is cut away at a forming a curved inclined surface to guide the lead to
and around the teats a² which are similarly cut away at their outer ends a³ for the
purpose of guiding the metal from around the body of the teats to the conductors
emerging from their ends. Thus by cutting away the mandrel at a and the teats
at as the direction of flow of the metal is gradually changed and the great pressure
required in changing the flow abruptly is obviated. By separating these teats and
causing them to project some distance above the body A of the core, the lead can
flow completely around these teats thus furnishing a supply of metal on every side
and ensuring an equal pressure all around the teats and the conductor, during the
formation of the cable and obviating all danger of injuring the insulation of the
conductor by a greater pressure on one side than on the other.
By cutting away the teats at a short nipples are formed around which the
passage in the lead pipe for the conductors is formed thereby preserving insulation
of the wires from injury by the direct pressure of the lead.
In connection with the above described core I use the die B shown in Figures 8, 9
and 10 in which are formed the openings b which may be of any desired form, oval,
round, angular etc., adapted to form the exterior shape to the lead covering. These
openings bare enlarged at their upper ends to form basins or receptacles into
which the lead flows before being forced around the nipples whose ends are
adjusted so as to project into these basins. The side walls of these basins may be
either vertical as shewn in Figure 9, or may flare outward from the opening bas
shown in Figure 10. By flaring the side walls as shown in Figure 10, the lead
is guided gradually into these basins.
In place of the single wire passage in each teat a² I may form several of such
wire passages as for instance five as shown in Figures 11 to 14. The four outside
passages being arranged in a position corresponding to the angles of a quadri-lateral
the central passage being located at the intersection of the diagonals of this
quadri-lateral.
Along the tapering sides of the teats a² and between the wire passages a³ are
cut grooves & which extend to the point of the teats. The wall of the central
passage does not extend to the same height as the walls of the outer passage and
there is thus formed a recess fin the end of the teat, which recess is connected with
the external grooves d by narrow channels e cut in the walls connecting the
adjoining nipples. The grooves d direct the flow of lead into the outer spaces
between the outside wire passages and the channels e afford passages through
which the lead can flow from the grooves d around the inside spaces of the outer
wire passages and against the central wire. It will be seen that in the above
described construction that the lead is forced against the central wire with equal
pressure on all sides and that therefore a central nipple is not necessary to support
and hold the central wire in place, it not being subjected to any unequal pressure.
By omitting this central nipple I am enabled to arrange all the wires in much closer
proximity than if a nipple for the central wire were used for in the latter construction,
the nipples for the outside wires would have to be sufficiently removed from the
central nipple to allow of the formation of grooves between these outside and
central nipples for the flow of lead around the central nipple, and as a consequence
of this spreading of the nipples the walls of lead between the wires of the cable

page_text: would be much thicker than is necessary to prevent induction and a complete
sealing of the wires and the cable would be therefore much heavier and less
flexible.
It will be further observed, that by the relative arrangement of the wire passages
combined with the side grooves d and the channels e, almost all of the mandrel
around each outside wire is exposed to the direct contact and pressure of the lead
as it flows upon the exterior surface, and that the lead is formed into tube like
enclosures around the outside wires before it leaves the mandrel, thereby preventing
undue pressure of the lead upon the wires which if too great would cause injury
by stripping off or breaking the insulating covering of the wires. It is not necessary
to so protect the central wire as it is in a great degree protected from the pressure
of the lead by the surrounding nipples.
Having now particularly described and, ascertained the nature of my said
Invention and in what manner the same is to be performed, I declare that what
I claim is
First. The core A for a lead press having three or more teats a² with passages
therethrough in combination with a die having an equal number of openings,
substantially as set forth.
Second. The mandrel A for a lead press having three or more teats a² with a
passage through each teat and having the incline guiding surface.a³, substantially
as set forth.
Third. The mandrel A for a lead press having the inclined guiding surface a¹,
and provided with three or more teats a² each teat having a wire passage a³, and
an incline guiding surface a substantially as set forth.
Fourth. The mandrel A. for a lead press having three or more teats a², each teat
having a passage therethrough, and an inclined guiding surface a in combination
with a die B having a like number of openings b provided with flaring sides,
substantially as set forth.
Fifth. A mandrel A for a cable press having a teat or projection on its end, with
separate wire passages through both the mandrel and teat, the outside wire passages
extending beyond the central wire passage, the teat having the longitudinal grooves d
extending between the outside wire passages to the point, and having the channels e
connecting the grooves with the central recess f, substantially as set forth.
Sixth. A mandrel A for a cable press having a tapered body and a teat or
projection on its end, with five separate wire passages through both the tapered
body and teat and arranged in positions corresponding to the intersection and ends
of the diagonals of a square, the teat having grooves d extending between the
outside wire passage to the point, the channels e connecting the grooves with the
recess and the central recess fin its end, substantially as set forth.
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