Year: 1886

page_text: Date of Application, 1st Sept., 1886.
Complete Left, 1st June, 1887.
Complete Accepted, 1st July, 1887.
1 WILLIAM PORTER WARD, of 46, Holborn Viaduct, in the City of London,
Merchant, do hereby declare the nature of this invention :-
This improvement relates to the manufacture of a screw or bolt which has a thread
or series of thread segments adapted to engage with a nut having either a right
or a left hand thread, or with two nuts having reverse threads.
The improvement consists in forming a blank for a screw or bolt with arc-shaped
portions and intermediate flattened, grooved, or hollowed out portions, in cutting
either a right hand or a left hand screw thread upon this blank or its arc-shaped
portions, and in subsequently subjecting the screw or bolt to the action of dies
whereby the screw-thread will be so chamfered off that it will be adapted to engage
with a nut having a right or a left hand screw thread, or with two nuts having reverse
threads.
W. P. WARD.
By A. M. & Wm. Clark,
53, Chancery Lane, London,
Patent Agents.

page_text: COMPLETE SPECIFICATION.
Improvements in the Manufacture of Screws or Bolts.
I, WILLIAM PORTER WARD of 46 Holborn Viaduct in the City of London
Merchant, do hereby declare the nature of this invention (a communication to me
from abroad by Clinton Furbish of 81 Beekman Street New York, United States of
America) 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 the method of manufacturing a screw or bolt having a
more or less mutilated thread which is adapted to engage both a right and a left handed
threaded nut, or with either of them.
The improvement consists in first forming a blank for a screw or bolt of approxi-
mately elliptical cross-section, or of approximately cylindrical section but flattened,
grooved, or hollowed along two diametrically opposite lines; in cutting either a right
hand or a left hand screw thread upon this elliptical or flattened blank, or upon the
portions of major diameter thereof; or in cutting the screw thread upon a cylindrical
blank and afterwards cutting flats or grooves whereby the thread is removed along
opposite sides; and in subsequently subjecting the screw or bolt to the action of dies
whereby the screw thread or segments of screw-thread will be so chamfered off
towards the minor diameter of the elliptical or flattened bolt, that a nut having a right
or a left hand screw thread or, as would generally be the case in practice, two nuts
having reverse threads may be screwed thereon.
In the accompanying drawings, figure 1 is a side view, and figure 2 an end view,
of a bolt blank of elliptical section. Figure 3 is a side view, and figure 4 a
cross-section, of the bolt having the simple thread cut upon it. Figure 5 is a side
view, and figure 6 a cross section, of the finished bolt. Figure 7 is a face view of one
of the dies used in the manufacture of the bolt. Figure 8 is an end view of a pair of
the dies.
Similar letters of reference designate corresponding parts in all the figures.
I take a bolt blank A, of approximately elliptical cross-section (the diametrically
opposite parts a being on the major diameter and the intermediate flattened parts a' on
the minor diameter of the ellipse) and I cut a right or left handed thread a² upon it
in the usual way of cutting a screw thread. This thread is of full depth at the
portions a of the bolt blank which are the operative portions, and has little or no depth
at the intermediate portions a².
Or, I may, as above mentioned, cut the thread upon a cylindrical blank and
then cut flats or grooves along opposite sides of the threaded blank.
In either case, the operative portions a of the thread are so short circumferentially
of the bolt, that either a right or a left hand screw threaded nut can be used on
the bolt, if the thread or segments of thread be chamfered as next described.
To enable the use, upon the bolt, of a nut having a thread the reverse of that
which is cut upon the bolt, the screw thread or segments of screw-thread on the bolt
are chamfered off towards the minor diameter of the bolt in order to there enlarge

page_text: the space between adjacent convolutions of the thread. The chamfers spoken of are
lettered a. These chamfers a³ are produced by subjecting the bolt to the action of
dies B whereby they are pressed in the thread. The dies may be operated in any
suitable press.
These dies are formed with threads of the form shewn in
figures 7 and 8, being counter-parts of the intended finished form of the bolt-that
is to say they each correspond in form to half the section of the bolt blank (the
meeting faces of the dies coinciding with the major diameter of the bolt blank) and
they have a female thread corresponding to the thread first cut upon the bolt blank but
so modified towards the bottom of the cavity in the die as to produce the chamfer,
indicated by the letter a³ in figures 5 and 6, on the working face at one end of each
thread segment and on the rear face at the other end of each seginent.
By this improvement, the described bolt is produced both economically and in such
manner that the thread will possess great strength. The portions a of the bolt may
be of the shape of arcs of the same circle or of an eclipse.
Having now particularly described and ascertained the nature of the said invention
and in what manner the same is to be performed, I declare that what I claim is ;-
The method of producing a screw or bolt which is adapted to receive both a
right-handed and a left-handed threaded nut, consisting in forming a threaded bolt of
the form herein described, and in chamfering portions of the thread by means of dies,
substantially as specified.
W. P. WARD.
By A. M. & Wm. Clark,
53, Chancery Lane, London,
Patent Agents.