Improvements in Screw Bolts and in Dies for Making same.
Year: 1890

page_text: Date et Application, 11th Nov., 1890-Accepted, 13th Dec. 1840
COMPLETE SPECIFICATION.
Improvements in Screw Bolts and in Dies for Making same.
I CHARLES DAKE ROGERS of 21 Stevens Street, Providence, in the State of Rhode
Island United States of America Works Superintendent do hereby declare the nature
of this invention and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement :-
In the production of tyre-bolts as heretofore practised, it has been usual, so far as I
am aware, to make the portion of the shank contiguous to the head substantially plain
or smooth. An objection to such former bolts is that the smooth portion possesses but
little holding capacity laterally when inserted into the wooden rim or felloe of a wheel.
Another objection is that the continual running of the wheel over uneven surfaces,
coupled with a slight shrinkage of the wood, produces a jarring movement which acts
to loosen the bolt and at the same time causes a rattling noise. I would state that the
hole bored through the wood for the bolt becomes gradually enlarged by wearing away
or upsetting the fibres of the wood contiguous to the bolt, the same being due largely
to the jar or vibrations of the wheel in running, as stated, and to the rotation of the
bolt within the hole; but with the body of the bolt fluted as herein described there is
sufficient engagement with the wood to prevent or greatly diminish the tendency
to turn.
The object I have in view is to produce a stronger tyre-bolt than commonly made,
and one which is devoid of the objections before referred to. To that end, my present
invention consists of a tyre-bolt having the surface of its shank portion, intermediate
of the head and threaded portions, provided with a series of longitudinally arranged
ribs and grooves or flutings. My invention further consists of a novel form of die
arranged to simultaneously form on the bolt-blank the screw-thread and the said
flutings. My invention is more especially adapted to the "rolling" process; that is
to say, the blanks are introduced singly between a pair of suitably arranged recipro-
cating dies provided with ribs and grooves which at one and the same operation
impress or form the screw-threads and flutings into the blank's surface. It would, I
think, be impossible with any machinery now known to form on the surface of a bolt
at any reasonable expense the screw-thread and flutings which I have described, but
by means of a die about to be described it can be done at an insignificant cost.
In the accompanying sheet of drawings, which illustrate my improvements, Fig. 1
is a side elevation of the bolt or screw-blank; Fig. 2 is the same after it has been
acted upon by the dies which form the screw-thread and flutings; Fig. 3 shows the
bolt provided with a nut; Fig. 4 is a cross-sectional view, taken on line xa of Fig. 3,
showing the arrangement of the peripheral ribs and grooves formed in the bolt's
surface; Fig. 5 is a similar view, showing another form of flutings; Fig. 6 is a side
elevation of the die, adapted to produce the said screw-thread and grooves; as drawn,
the figure represents the front or working face; Fig. 7 is an end view; and Fig. 8
shows a partial plan view of the die.
In the several figures, a indicates the bolt or screw itself, the same having at one
end a head and at the other end a screw-threaded portion t; the shank portion s
ntermediate of the head and screw-threaded portions is provided with a series of
ongitudinally arranged ribs r and grooves; these I prefer to make well-rounded both
at the top and bottom transversely, substantially as shown in Fig. 4, although other
orms may be made as shown in Fig. 5.
The die used is indicated by B. The upper portion of its working face is provided
vith a series of parallel ribs m and grooves m' alternating with the ribs. The lower
portion of the die's face is provided with a series of inclined parallel ribs b and grooves c
aving a V-shape form. As drawn, the ribs and grooves are substantially uniform
ross-sectionally at any point throughout the length of the die.
D

page_text: In rolling the bolts a, the headed blanks a', Fig. 1, are introduced singly between
a pair of the dies B, which are reversely arranged and separated laterally a distance
somewhat less than the diameter or size of the wire, or plain portion of the blank.
Now, upon reciprocating the dies towards each other the blank is seized between them,
the continued movement of the dies impress the fluting ribs m and threading-ribs b
into the blank's surface simultaneously (the blank meanwhile turning on its axis) until
at the end of the operation the dies pass each other and allow the now fluted and
screw-threaded screw or bolt a to drop from them.
In thus rolling the screw the metal is expanded radially so that the diameter taken
across the fluted or screw-threaded portions exceeds that of the normal size of the
shank a¹.
Obviously, the form and number of the flutings may be varied as desired; so also
in like manner the form of the screw-threads may be modified. As drawn, the threads t
indicate a fine pitch or "machine-thread"; the threads may, however, be coarser,
substantially like wood screws, without departing from the spirit of the invention.
Any such change or variation must first be effected by a corresponding change in the
form of the ribs and grooves of the dies. The transverse ribs upon the die by their
engagement with the metal prevent any slipping or displacement of the blank between
the dies.
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 :-
1. The herein described die for making bolts provided with transverse ribs and
grooves over a portion of its surface to produce longitudinal ribs and grooves or
flutings over a portion of the body of the blank, combined with ribs and grooves on
another portion of the die and nearly at right angles to the said transverse ribs to
form screw-threads on the lower or entering end of the blank.
2. A bolt having its shank provided at its entering end with spiral ribs and grooves
arranged to form a screw, and the portion between the screw and the head provided
with longitudinal ribs and grooves, or flutings, substantially as described.
Dated the 10th day of October 1800
CHARLES DAKE ROGERS,
Philip M. Justice,
Inventor.
55 & 56, Chancery Lane, London, Agent for the Applicant.