AN IMPROVEMENT IN THE MANUFACTURE OF SCREWS, BOLTS, AND SIMILAR ARTICLES
Year: 1882

page_text: LETTERS PATENT to William Robert Lake, of the Firm of Haseltine, Lake,
& Co., Patent Agents, Southampton Buildings, London, for an Invention of
"AN IMPROVEMENT IN THE MANUFACTURE OF SCREWS, BOLTS, AND SIMILAR
ARTICLES." A communication from abroad by the American Screw Company
(Incorporated), of Providence, Rhode Island, United States of America.
COMPLETE SPECIFICATION filed by the said William Robert Lake at the
Office of the Commissioners of Patents on the 30th March 1882.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent
Agents, Southampton Buildings, London. "AN IMPROVEMENT IN THE MANU-
FACTURE OF SCREWS, BOLTS, AND SIMILAR ARTICLES." A communication from
abroad by the American Screw Company (Incorporated), of Providence, Rhode
Island, United States of America.
My improvement consists in providing an iron screw, bolt, rivet, nail, or similar
article with a steel core, or in other words producing a screw, bolt, rivet, nail, or
similar article having a central portion of steel and a surrounding or outside
portion of iron.
A screw composed wholly of steel is open to two objections, namely, first, the
tools employed for threading the shank wear out very fast owing to the hardness
of the steel, and the threading machines have to be run at a comparatively slow
speed; and, secondly, the screw when finished (unless it is annealed, which is
comparatively expensive and objectionable) is brittle, and therefore its head is
liable to split and the shank to break.
The object of my improvement is to strengthen an iron screw, bolt, rivet, nail,
or similar article, and yet obviate the disadvantages of one composed wholly
of steel.
In the accompanying Drawing,
Figure 1 represents in perspective an iron billet or faggot with a steel core.
Figure 9 ch

page_text: Figures 3 and 4 represent two of my improved screws, one having a flat and the
other a round head.
My improved screws, bolts, rivets, nails, or similar articles may be produced
from rods having a central portion of steel and an outer portion or covering of iron
securely attached to each other. Such a rod can be successfully made by welding or
fusing together at the proper heat rods a of iron and a central rod b of steel in the
form of a billet, as shewn in Figure 1, and then rolling the said billet into a round
rod as shewn in Figure 2. From this rod screw-blanks are formed in the ordinary
manner and the said blanks are threaded and nicked in the usual machinery.
As will be seen by reference to Figures 3 and 4, that portion of the screw which
is acted upon by the cutting tools is of iron except the extreme point and the
central portion of the head, which are of steel. In heading the blanks, the steel
flows outward with the iron, producing a head having a steel central portion which
is surrounded by iron. The walls of the nick, therefore, are less likely to be
indented by the driver than when the head is formed wholly of iron, and the said
head is stronger than if made wholly of steel, since the steel, which is comparatively
brittle, is bound about or surrounded by iron. The screw also possesses the
further advantage of a comparatively hard point surmounted by a strong shank.
Bolts, rivets, nails, and similar articles, when made with a central core of steel,
will possess advantages over those made wholly of iron or steel.
Having thus fully described the said Invention as communicated to me by my
foreign correspondents, and the manner of performing the same, I wish it understood
that I claim,
A screw, bolt, rivet, nail, or similar article having a steel core and a surrounding
iron shell welded to the said core, substantially as set forth.
In witness whereof, I, the said William Robert Lake, have hereunto set my
hand and seal, this Thirtieth day of March, in the year of our Lord
One thousand eight hundred and eighty two.