IMPROVEMENTS IN SCREW BOLTS
Year: 1876

page_text: LETTERS PATENT to Edward Thomas Periam, of Birmingham, in the County
of Warwick, Manufacturer, for the Invention of "IMPROVEMENTS IN SCREW
BOLTS."
Scaled the 15th August 1876, and dated the 1st April 1870.
PROVISIONAL SPECIFICATION left by the said Edward Thomas Periam at
the Office of the Commissioners of Patents on the 1st April 1876.
EDWARD THOMAS PERIAM, of Birmingham, in the County of Warwick, Manu-
facturer. "IMPROVEMENTS IN SCREW BOLTS.
My Invention has reference to screw bolts used for connecting together parts of
machinery and for other like purposes. The said screw bolts have a head at one
end and are wormed or screwed on the other end. Screw nuts are fitted to the
screwed ends of the said screw bolts, and when the said screw bolts are used, say for
connecting parts of machinery, the screw bolt is passed through holes in the parts to be
connected and the screw nut is screwed home on the screwed end of the screw bolt.
The parts to be connected are thus grasped between the head of the screw bolt and
the screw nut screwed on the end of the screw bolt.
The jarring or vibratory motion to which many kinds of machinery and articles
are subjected, in which screw bolts are used, frequently causes the screw nut to be
skaken loose, or even wholly unscrewed, thereby occasioning great inconvenience,
and in some cases serious accident; and the object of my Invention is to prevent
the accidental loosening of the screw nut referred to.
My said Invention consists in inaking a slit or division in the screwed end of the
screw bolt, the said slit or division dividing the screwed end of the bolt longi-
tudinally into two equal parts; or I make in the screwed end of the screw bolt two
longitudinal divisions crossing each other at right angles, the intersection of the
two slits being in the axis of the screw bolt; or I make two longitudinal parallel
slits in the screwed end of the screw bolt, the two parallel slits being parallel to
and on opposite sides of the axis of the screw bolt; or I make two pairs of the
said parallel slits, one pair crossing the other pair at right angles.
In using screw bolts made according to my Invention, the bolt is passed through
When the screw nut
the parts to be connected and the nut is screwed thereon.
has been brought to the required position on the screwed end of the screw bolt, a
chisel or chisel-pointed tool is inserted in the slit and struck with a hammer; the
[Price Gd.1

page_text: two halves of the screw are thereby slightly separated, and the screw nut is so
tightly fixed on the screw bolt that it cannot be unscrewed excepting by the
application of considerable force by a screw wrench or spanner, and is not shaken
loose by any amount of vibration to which it may be subjected.
Where two or more slits are made in the end of the screw bolt, each of the said
slits may be expanded by means of a chisel-pointed tool.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Edward Thomas Periam in the Great Seal Patent Office on the 21st
September 1876.
EDWARD THOMAS PERIAM, of Birmingham, in the County of Warwick, Manu-
facturer. "IMPROVEMENTS IN SCREW BOLTS."
My Invention has reference to screw bolts used for connecting parts of machinery
and for other like purposes. The said screw bolts have a head at one end and are
wormed or screwed on the other end. Screw nuts are fitted to the screwed ends of
the said screw bolts, and when the said screw bolts are used, say for connecting
parts of machinery, the screw bolt is passed through holes in the parts to bo
connected and the screw nut is screwed home on the screwed end of the screw bolt.
The parts to be connected are thus grasped between the head of the screw bolt and
the screw nut screwed on the end of the screw. bolt.
The jarring or vibratory motion to which many kinds of machinery and articles
are subjected, in which screw bolts are used, frequently causes the screw nut to be
shaken loose, or even wholly unscrewed, thereby occasioning great inconvenience,
and in some cases serious accident; and the object of my Invention is to prevent
the accidental loosening of the screw nut referred to.
My said Invention consists in making a slit or division in the screwed end of the
screw bolt, the said slit or division dividing the screwed end of the bolt longi-
tudinally into two equal parts; or I make in the screwed end of the screw bolt two
longitudinal divisions crossing each other at right angles, the intersection of the
two slits being in the axis of the screw bolt; or I make two longitudinal parallel
slits in the screwed end of the screw bolt, the two parallel slits being parallel to
and on opposite sides of the axis of the screw bolt; or I make two pairs of the
said parallel slits, one pair crossing the other pair at right angles.
In using screw bolts made according to my Invention, the bolt is passed through
the parts to be connected and the nut is screwed thereon. When the screw nut
has been brought to the required position on the screwed end of the screw bolt, a
chisel or chisel-pointed tool is inserted in the slit and struck with a hammer; the
two halves of the screw are thereby separated, and the screw nut is so tightly fixed
on the screw bolt that it cannot be unscrewed excepting by the application of
considerable force by a screw wrench or spanner, and is not shaken loose by any
amount of vibration to which it may be subjected.
Where two or more slits are made in the end of the screw bolt, each of the said
slits may be expanded by means of a chisel-pointed tool.
Figure 1 of the accompanying Drawing represents in side elevation, and Figure 2
in end elevation, a screw bolt made according to my Invention; that is, having at
its end a cross slit or division & which divides the screwed end of the bolt longi-
tudinally into two equal parts. It is preferred to make the said slit or division a
taper, as represented. The said slit a is made in the screwed end of the bolt by a
circular saw, but it may be made in other ways.
Figure 3 represents in elevation, and Figure 4 in section, the said screw bolt after
a screw nut b has been applied to the screwed end of the bolt, and securely fixed
thereon by expanding or separating the parts of the slit or divided end a of the
bolt; that is to say, after the screw nut 6 has been screwed to the required position

page_text: on the screwed end of the bolt, a chisel or chisel-pointed tool is inserted in the
slit a and struck by a hammer, so as to slightly separate the parts of the slit end
and expand them in the nut, and thereby fix the said nut very securely on the bolt,
the said nut being incapable of being shaken loose by any vibration to which it may
be subjected.
Figure 5 represents in elevation, Figure 6 in section, and Figure 7 in end
elevation, a large screw bolt made according to my Invention, the screw nut b
being fixed on the bolt by the expansion of the split end of the bolt; in this
arrangement two parallel slits c, c, are made in the bolt, the said slits being parallel
to and on opposite sides of the axis of the screw bolt. In fixing the nut bon the
scrowed end of tho bolt each of the slits c, c, is expanded or separated by a chisel-
pointed tool, as herein-before described.
Although I have represented the screw bolt as having a single slit, or a double
slit, or two parallel slits, for the purpose of permitting the screwed end of the bolt
to be expanded in the nut, yet I do not limit myself thereto, as the screwed end of
the bolt may be otherwise divided with like effect. For example, instead of the
single slit a, Figures 1, 2, 3, and 4, two slits crossing each other at right angles may
be employed, as represented in the end elevation of a screw bolt, Figure 8; or,
instead of making two parallel slits c, c, as in Figures 5, 6, and 7, more than two
parallel slits may be made; or two pairs of the parallel slits c, c, one pair crossing
the other pair at right angles, may be employed. The last described form of slit
bolt is represented in end elevation in Figure 9. The screw nuts may be removed
from the screw bolts made according to my Invention by the application of con-
siderable force by the use of a screw wrench or spanner.
By slitting or dividing the end of the screw bolt according to my Invention, the
use of cotters or keys passed through the bolts and made to bear against the back
of the screw nuts are dispensed with.
Having now described the nature of my Invention and the manner in which the
same is to be performed, I wish it to be understood that I claim as my Invention
the improvements in screw bolts herein-before described, and illustrated in the
accompanying Drawing, that is to say, making in the screwed end of the screw
bolt a longitudinal slit or division, or two longitudinal slits or divisions crossing
each other at right angles, or two or more parallel slits, or two pairs of parallel slits,
one pair crossing the other pair at right angles, for the purpose and substantially
as described and illustrated.
In witness whercof, I, the said Edward Thomas Periam, have hereunto set my
hand and seal, this Nineteenth day of September, in the year of our Lord
One thousand eight hundred and seventy-siv
Witness,
RICHARD SKERRETT,
Clerk to George Shaw,
Birmingham.
EDWARD THOMAS PERIAM. (L.S.)