AN IMPROVED CON- STRUCTION OF TRENAIL
Year: 1867

page_text: LETTERS PATENT to Edward Joseph William Parnacott, of Leeds, in the
County of York, Engineer, for the Invention of "AN IMPROVED CON-
STRUCTION OF TRENAIL."
Sealed the 4th February 1868, and dated the 6th August 1867.
PROVISIONAL SPECIFICATION left by the said Edward Joseph William
Parnacott at the Office of the Commissioners of Patents, with his
Petition, on the 6th August 1867.
I, EDWARD JOSEPH WILLIAM PARNACOTT, of Leeds, in the County of York,
Engineer, do hereby declare the nature of the said Invention for "AN
IMPROVED CONSTRUCTION OF TRENAIL," to be as follows:-
This Invention relates to a novel construction of trenail suitable for fixing
chairs to railway, sleepers, and capable while being driven of cutting its way
into the wood.
The trennil is made hollow of iron tube, and the. head is swelled or coned
outwardly by means of a punching tool. The lower end is bevilled off to a
cutting-edge to enable the trenail to cut into wood, and by means of pressure
the lower end is coned-inwardly, a shoulder being formed within the frenail.
Cross-cuts are made through the cutting-edge to allow-it-to-expand in the act
of driving the trenail into the solid wood. In that case the trenail becomes

page_text: filled with the severed or displaced wood. When, however, the trenail is
applied to a bored hole, by simply driving a rod down the trenail the lower
end may be expanded to fill the bored hole..
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Edward Joseph William Parnacott in the Great Seal Patent
Office on the 6th February 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, EDWARD
JOSEPH WILLIAM PARNACOTT, of Leeds, in the County of York Engineer, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Sixth day of August, in the year of our Lord
One thousand eight hundred and sixty-seven, in the thirty-first year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Edward Joseph William Parnacott, Her special licence that I, the
said Edward Joseph William Parnacott, my executors, administrators, and
assigns, or such others as I, the said Edward Joseph William Parnacott, my
executors, administrators, and assigns, should at any time agree with, and no
others, from time to time and at all times thereafter during the term therein
expressed, should and lawfully might make, use, exercise, and vend, within
the United Kingdom of Great Britain and Ireland, the Channel Islands, and
Isle of Man, an Invention for "AN IMPROVED CONSTRUCTION OF TRENAIL,"
upon the condition (amongst others) that I, the said Edward Joseph William
Parnacott, my executors or administrators, by an instrument in writing under
my, or their, or one of their hands and seals, should particularly describe
and ascertain the nature of the said Invention, and in what-manner the same
was to be performed, and cause the same to be filed in the Great Seal Patent
Office within six calendar months next and immediately after the date of the
said Letters Patent.
NOW KNOW YE, that I, the said Edward Joseph William Parnacott,
do hereby declare the nature of my said Invention, and in what manner the
same is to be performed, to be particularly described and ascertained in and
by the following statement, reference being had to the Drawing hereunto
annexed, and to the letters and figures marked thereon (that is to say):-
This Invention relates to a novel construction of trenail suitable for fixing
chairs to railway sleepers, and capable while being driven of cutting its way
into the wood.

page_text: is a side view, and Fig. 2 a longi-
It is made hollow of iron tubing,
In the accompanying Drawing Fig. 1
tudinal section of the improved trenail.
and for a head the tube is swelled out or coned outwardly to the form shown
by driving a punching tool into the upper end of the tube; or when thought
desirable a collar may be welded to the tube, as shewn at Fig. 3, thus forming
a cheese-headed trenail. The trenail may also be formed without a head, but
having in lieu thereof a continuous external taper. The lower end is bevilled
off to a cutting edge a, a, to enable the trenail to cut into wood, it being
reduced to that shape by the use of dies and pressure, and finished in a lathe
or otherwise, as thought desirable. The displaced metal (see Fig. 2) forms
a shoulder b, b, within the trenail, and at the same time a hollow conical
surface c, c, is produced. The shoulder b and the conical surface c perform a
most important duty, inasmuch as they permit of the expansion of the trenail
within the sleeper, as will be presently explained. In order, however, to
provide for this action taking place cross cuts d, d, are made through the
cutting edge. It will now be understood that as the trenail is driven into the
solid wood.the hollow cone as it becomes choked with the severed or displaced
wood will expand laterally and offer an effectual preventative to.the working
loose of the trenail. When however it is intended to apply the trenail to a
bored hole the shoulder 6 comes into use, for by simply driving a pin such as
that shewn at Fig. 4 down the hollow trenail the lower end of the pin will
press against the shoulder and cause the end of the trenail to expand laterally,
as shewn in the sectional view, Fig. 5, and fill the bored hole in the sleeper.
Having now set forth the nature of my Invention of "An Improved Con-
struction of Trenail," and explained the manner of carrying the same into
effect, I wish it to be understood that under the above in part recited Letters
Patent I claim, forming trenails with a cutting edge, and capable of receiving
a lateral expansion, in the manner and for the purpose above described.
In witness whereof, I, the said Edward Joseph William Parnacott,
have hereunto set my hand and seal, the Fourth day of February,
in the year of our Lord One thousand eight hundred and sixty-
eight.
E. J. W. PARNACOTT. (L.S.)