Improvements in the Screws and Screw Nuts of the Stay Rods and Swivels or Stay Fasteners of Telegraph Poles, which Improve- ments are also Applicable to the Screws and Screw Nuts of other Articles Exposed or Liable to be Exposed to the Weather.
Year: 1888

page_text: Date of Application, 23rd June, 1888
Complete Specification Left, 12th Mar., 1889
Complete Specification Accepted, 13th Apr.. 1885
Improvements in the Screws and Screw Nuts of the Stay Rods and
Swivels or Stay Fasteners of Telegraph Poles, which Improve-
ments are also Applicable to the Screws and Screw Nuts of
other Articles Exposed or Liable to be Exposed to the Weather.
I HOWARD COCHRANE JOBSON of Wolverhampton Street Dudley in the County of
Worcester Civil Engineer do hereby declare the nature of this Invention to be as
follows:-
In the screws and screw nuts of the stay rods and swivels or stay fasteners of
telegraph poles as ordinarily made the screw threads of the said screws and nuts have
the form of the thread of an ordinary Whitworth screw that is of a V shape or are
flat on the top that is the summit of the thread on the rod bolt or spike and the
hollow is V shaped.
In consequence of the sharp angles at the bottom of the trough between the
threads there is a great tendency in the screw and screw nut to retain any water
which may have fallen on them as in the case of rain. The retention of water or
moisture results in the more rapid rusting or oxidization of the iron of which the
screws and nuts are made and not only necessitates their more frequent renewal but
also interferes with their use the corrosion causing the thin V shaped threads to
rapidly rust away leaving no hold for the nut in screwing up.
My invention has for its object to prevent these inconveniences and consists in
making the screw thread square at top and giving to the trough between the threads
a semicircular figure in cross section or an analogous figure such as a semi-ellipse
or a parabola or hyperbold. By making the trough of these figures any water getting
into the trough readily passes along its curved bottom and escapes and the screw
corrodes very slowly and there is little or no tendency to the fixing of the screw nut
in consequence of corrosion. The screw thread in the nut has preferably a shape the
counterpart of that of the screw on the rod swivel or stay.
My invention is especially applicable to telegraph and railway work.
Dated this 23rd day of June 1888
W. T. WHITEMAN,
Agent for the Applicant.

page_text: Improvements in the Screws and Screw Nuts of the Stay Rods and
Swivels or Stay Fasteners of Telegraph Poles, which Improve-
ments are also Applicable to the Screws and Screw Nuts of
other Articles Exposed or Liable to be Exposed to the Weather.
I HOWARD COCHRANE JOBSON of Wolverhampton Street Dudley in the County of
Worcester Civil Engineer 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:—
In the screws and screw nuts of the stay rods and swivels or stay fasteners of
telegraph poles as ordinarily made, the screw threads of the said screws and nuts
have the form of the thread of an ordinary Whitworth screw, that is, of a ✓ shape
or are flat on the top, that is, the summit of the thread on the rod bolt or spike and
the hollow is V shaped.
In consequence of the sharp angles at the bottom of the trough between the
threads there is a great tendency in the screw and screw nut to retain any water
which may have fallen on them as in the case of rain. The retention of water or
moisture results in the more rapid rusting or oxidation of the iron of which the
screws and nuts are made and not only necessitates their more frequent renewal but
also interferes with their use, the corrosion causing the thin V shaped threads to
rapidly rust away leaving no hold for the nut in screwing up.
My invention has for its object to prevent these inconveniences and consists in
making the screw thread square at top and giving to the trough between the threads
a semi-circular figure in cross section or an analogous figure such as a semi-ellipse or
a parabola or hyperbola. By making the trough of these figures any water getting
into the trough readily passes along its curved bottom and escapes and the screw
corrodes very slowly and there is little or no tendency to the fixing of the screw nut
in consequence of corrosion. The screw thread in the nut has preferably a shape the
counterpart of that of the screw on the rod swivel or stay.
My invention is especially applicable to telegraph and railway work.
Figures 1 and 2 represent elevations of screws the threads of which are constructed
according to my invention; Figure 3 represents in section a screw nut or screw box
also constructed according to my invention to be used with the screw represented in
Figure 2: Figure 4 represents the screw and screw nut Figures 2 and 3 applied to a
stay rod; Figure 5 represents the screw and screw nut Figures 2 and 3 applied to a
double swivel and Figure 6 represents screws and screw boxes of the kind represented
in Figures 2 and 3 applied to a right and left handed screw of a screw connection.
In Figure 1 the trough between the square top threads of the screw is semi-
elliptical in cross section and is marked a and in Figure 2 the trough between the
square top threads of the screw is semi-circular in cross section and is marked b.
The screw thread in the nut Figure 3 has a shape the counterpart of that of the screw

page_text: Figure 2 on which it is to be fitted as represented in the Drawing. By the square
top thread of a screw I mean a thread the summit of which is cylindrical as
represented in the Drawing such threads being commonly called "square top" in
contradistinction to the ordinary angular or V shaped top of the thread.
The several screws represented in Figures 4, 5 and 6 and their screw nuts or boxes
are of the kind represented in Figures 2 and 3.
Instead of making the trough between the threads of the screw semi-elliptical or
semi circular in cross section as represented in the Drawing the said trough may be
made of the figure of a parabola or hyperbola but I prefer to use the forms of trough
represented in the drawing.
It will be understood that by making the trough of the screw thread of the figures
described and represented any water getting into the trough readily passes along its
curved bottom and escapes. In consequence of the facility with which the water
can escape from the thread the screw corrodes very slowly hence there is little or no
tendency to the fixing of the screw nut by corrosion. The other advantage herein-
before pointed out also results from the use of screws and screw nuts of the
construction described and represented.
-
Having now particularly described and ascertained the nature of my inven-
tion and the manner in which the same is to be performed I declare that what
I claim is:
The improvements in the screws and screw nuts of the stay rods and swivels or
stay fasteners of telegraph poles and the screws and screw nuts of other articles
exposed or liable to be exposed to the weather hereinbefore described and illustrated
in the accompanying Drawing, that is to say, making the threads of the said screws
square at top and giving to the trough between the square top threads a semi-circular
or semi-elliptical figure or of an analogous figure in cross section and making the
screw thread in the nut the counterpart of that of the screw for the purposes and
substantially as described and illustrated.
Dated the Seventh day of March 1889.