Improvements in Stocks and Dies.
Year: 1892

page_text: Date of Application, 11th Apr., 1892-Accepted, 4th June, 1832
COMPLETE SPECIFICATION.
Improvements in Stocks and Dies.
1, HENRY BRINSER KEIPER, Mechanician, of 625 North Duke Street, in the
City of Lancaster, County of Lancaster, and State of Pennsylvania, United States
of America, do hereby declare the nature of my invention and in what manner
the same is to be performed, to be particularly described and ascertained in and
by the following statement :-
My invention relates to improvements in stocks and dies or screw-cutting plates
of that class in which a circular or ring collet holding two semi-circular dies,
separated by two taper-headed adjusting screws, is held in place or kept from
turning in a clamp stock, closed by means of a screw acting tangentially through
lugs or ears projecting outwards from the ends where said stock is cut open through
a side of its central ring; or, in other words, the invention may be regarded as an
improvement on what is known to the trade as "The Lightning Screw-cutting
Plates," patented in the United States of America October 24, 1871, to
John J. Grant.
The object of the invention is to produce an effective and adjustable screw-
cutting plate that will be as nearly solid as is possible, and to dispense with the
four plug or set-screws through the periphery of the collet, which now make the
proper adjustment of the dies therein a tedious and difficult operation, requiring
both skill and judgment.
The improvements consist: First, In providing the semi-circular dies now in use
with a slanting peripheral face, so that when their diametrical edges are placed
together they form the frustum of a right cone. Second, In making the collet
ring form, giving to the upper portion of the hole therein, to a depth a little less
than the thickness of the dies, a sloping inner face corresponding in size and shape
to the conical form of the dies, while the rest of said hole is cylindrical in form
and screw-threaded throughout. Third, In fitting into the threaded portion of
said hole a screw-plug or guide-disk adapted to support on its inner face the base
of the dies before mentioned, and its outer or back face is provided with recesses
to engage fingers or projections extending inwards from the stock, which pro-
jections constitute the fourth element of these improvements.
The purposes of the invention are attained by the mechanism and devices illus-
trated in the accompanying drawing, in which similar letters refer to similar parts
throughout the several views, and in which:
Figure 1 is a plan of the central portion of a screw-cutting plate embodying the
elements of this invention;
Fig. 2, an elevation from the left of Fig. 1;
Fig. 3, an elevation from the right of the portion on the left of the line x in
Fig. 1;
Fig. 4, an elevation from below of the portion above the line yy in Fig. 1;
Fig. 5, a plan of a portion of the reverse side of the stock detached from Fig. 1,
showing an inwardly-projecting finger, ear or lug in place;
Fig. 6, an elevation from below of Fig. 5;
Fig. 7, a plan of the reverse side of the collet ring detached from Fig. 1;
Fig. 8, a plan of the reverse side of the screw-plug or guide-disk detached
from Fig. 1, showing the dies in dotted and full lines in place;
Fig. 9, a plan of the dies detached from Fig. 1, being the frustum of a right
cone in form; and,
Figs. 10, 11 and 12, elevations from below of Figs. 7, 8 and 9, respectively.
The screw-cutting plate consists of a stock A. a collet B. and dies C C.

page_text: having the general form and appearance of the lightning screw-cutting plate
before mentioned, but the elements of my invention will now be clearly set forth.
In the stock A, as shown in the drawing, a a designate fingers, ears or lugs which
project inward from the stock ring, level with its back, and in line with the
handles, which, for want of space, are broken away. These fingers, ears or lugs
are adapted to fit into the recesses formed in the back of the screw-plug or guide-
disk to be hereinafter described.
In the collet B, B' designates a ring (Figs. 7 and 10), having an outside
cylindrical face adapted to fit into the central ring of the stock before mentioned,
and an inside face or wall consisting of a straight or cylindrical portion b screw-
threaded throughout, and of a sloping or conical portion ¹, narrowing gradually
from said cylindrical portion to the upper face of the collet ring, said conical
portion having a perpendicular height a little less than the depth of the dies, yet
to be described. Into the cylindrical portion is fitted a screw-plug or guide-
disk, B (Figs. 8 and 11), having axially through its centre the well-known guide
ridges, ribs or projections, and on either side thereof, in the same diametrical line,
the usual screw-threaded orifices, into which are fitted the usual taper-headed or
die-adjusting screws. These latter three elements forming no part of my inven-
tion, are not referred to by letter; but in the back of the disk, on each side of
said guide-opening, at diametrically opposite points, are formed recesses 6262,
adapted to engage the lugs aa before mentioned, when the collet is placed in
position in the stock, and the upper face of the disk is adapted to receive and hold
the base of the dies, yet to be described, when the same are placed in position
within the collet.
The dies C and C are exact counterparts and have, each at the centre of its
perpendicular diametrical face, the usual chasers or screw-cutting ribs or ridges,
and on either side thereof the usual semi-circular recesses sloping outwardly at the
upper ends and adapted throughout to receive the action of the taper-headed
screws before mentioned, whereby said dies are adjusted according to the size of
the bolt it is desired to screw-thread. These two elements being old and forming
no part of my invention, are not referred to by letter; but the dies themselves, as
shown in the drawing, are provided with outer semi-circumferential sloping
peripheral faces er, corresponding in degree of inclination with the sloping inner
face of the conical portion b¹ of the collet before mentioned, thus adapting said
dies to fit said conical portion when they are placed in position within said collet.
When the dies are placed together, as shown in Fig. 9, they form the frustum of a
right cone (Fig 12), and when placed in position on the plug-screw or guide-disk B*
(Figs. 8 and 11), and separated by the taper-headed screws, as shown, they will fill
the conical portion 61 of the collet ring (Figs. 1, 3 and 4), and will be compressed
by its conical inner face, accordingly as said screw-plug or guide-disk shall be
screwed home.
Now the several parts having been placed in position as indicated in Figs. 1, 3
and 4 of the drawing, it will be readily observed that an effective screw-cutting
plate has been constructed, forming one solid body except as the taper-headed
screws separate the dies, one that is easily manipulated or readily adjusted.
It will here be observed that I lay no claims broadly to semi-circular dies having
at their centres screw-cutting chasers and on either side thereof semi-circular
recesses to receive the action of taper-headed adjusting screws, but only to such as
have outside conical peripheral faces; to the taper-headed die adjusting screws;
to the cylindrical collet; or to the clamp stock.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :
1. In a screw-cutting plate the semi-circular dies C, C, having perpendicular
diametrical faces, screw-cutting chasers at the centre of said faces, semi-circular
grooves having outwardly sloping upper ends, one on each side of said chasers,

page_text: and the outer sloping or conical peripheral faces, substantially as hereinbefore
described, and for the purpose set forth.
2. In a screw-cutting plate the collet B, comprising the cylindrical ring B',
having an outside cylindrical face, the inside screw-threaded cylindrical portion b,
and the upwardly and inwardly sloping conical portion ; and the plug-screw or
guide-disk B3, screwed into said portion b, having the bolt-guide ridges through
the centre of said disk, the screw-threaded orifices on the same diameter, one
orifice on each side of said guide ridges, and the recesses and ², placed in
the back of said disk, all substantially as hereinbefore described, and for the
purpose set forth.
3. In a screw-cutting plate, the stock A, having the central clamp ring closed
by a clamp screw, the inwardly projecting lugs or fingers a and a, integral with the
side of said clamp ring, substantially as hereinbefore described, and for the purpose
set forth.
Dated this First day of Aneil A D
1005
Signed in the presence of:
DANIEL H. HERR.
EDWIN BOOKMYER.
HENRY BRINSER KEIPER.