IMPROVEMENTS IN CHAIN HARROWS
Year: 1857

page_text: LETTERS PATENT to William Colborne Cambridge, of Bristol, Agricul-
tural Implement Maker, for the Invention of "IMPROVEMENTS IN CHAIN
HARROWS."
Sealed the 23rd October 1857, and dated the 23rd April 1857.
PROVISIONAL SPECIFICATION left by the said William Colborne Cam-
bridge at the Office of the Commissioners of Patents, with his Petition,
on the 23rd April 1857.
I, WILLIAM COLBORNE CAMBRIDGE, of Bristol, Agricultural Implement
Maker, do hereby declare the nature of the said Invention for "IMPROVEMENTS
IN CHAIN HARROWS," to be as follows:-
The object of this Invention is to render chain harrows more efficient in
their action than heretofore. In all the chain harrows in use there are three
great defects, namely, 1st, that the wooden bars which are employed to keep
the harrow expanded give the harrow such rigidity laterally as effectually to
prevent it from adapting itself to the unevenness of the land on which it may
be employed; 2nd, that the harrows are made with the links following each
other, the effect of which is that they cut deep trenches at too great distances
apart; and, 3rd, that in cleaning couch or stubble land the back or end of
the harrow in emptying itself rolls up and laps over, & thereby ceases to act.
In order to remove these defects, I propose to make several links in one

page_text: piece, and to couplo these pieces together (breadthways of the harrow) by
joints. The harrow will thus be kept expanded to its full width, but it will
at the same time be allowed to yield to any unevenoss or inequality of the
surface. The links composing the harrow I so arrange that one row will not
follow the preceding one in the same line, but will work between the lines
formed by the preceding row of links. By this arrangement the land is cut
much finer and more effectually pulverized than by the old construction of
chain harrows. To the botton or end of the harrow I propose to fix a set
of the jointed link pieces, which will keep it stretched out to its full width,
and prevent it from rolling or lapping over when it empties itself of the couch
or stubble.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Colborne Cambridge in the Great Seal Patent Office
on the 23rd October 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
COLBORNE CAMBRIDGE, of Bristol, Agricultural Implement Maker, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
l'atent, bearing date the Twenty-third day of April, in the year of our Lord
One thousand eight hundred and fifty-seven, in the twentieth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
William Colborne Cambridge, IIer special license that I, the said William
Colborne Cambridge, my executors, adñiors, and assigns, or such others as
I, the said William Colborne Cambridge, my executors, administrators, and
assigus, should at any time agree with, and no others, from time to time
aid 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 Inven-
tion for "IMPROVEMENTS IN CHAIN HARROWS," upon the condition (amongst
others) that I, the said William Colborne Cambridge, by an instrument in
writing under my hand and seal, should particularly describe and ascertain
the nature of the said Invention, and in what manrer 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.

page_text: NOW KNOW YE, that I, the said William Colborne Cambridge, 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):-
The object of this Invention of "Improvements in Chain Harrows" is to
render these implements more efficient in their action than heretofore. In
all the chain harrows in use there are three great defects, namely, first,
that the. horizontal transverse wooden or iron bars which are employed to
keep the chains of the harrow extended impart to the harrow such rigidity
laterally as effectually to prevent it from adapting itself to the unevenness of
the land on which it may be employed; second, that the harrows are made
with the links following each other in the same lines, the effect of which is
that they cut deep trenches in the ground at too great distances apart, and
do not effectually harrow the land; and, third, that in cleaning couch or
stubble land the back or end part of the barrow in emptying itself is liable to.
roll up and lap over, and thereby cease to act at that part.
In order to remedy these defects, I propose to dispense with the horizontal
transverse wooden or other rigid bars, and in place thereof to employ a
flexible or jointed bar composed of two or more lengths, cach consisting of several.
links formed in one piece, and coupled together (breadthways of the harrow)
by joints, which will admit of their bending lengthways, but not of crowding
up, as would be the case with the links of an ordinary chain. The implement
will thus be kept expanded to its full width, but it will at the samo time be
allowed to yield laterally to any unevenness or inequality of the surface of the
ground. The links composing the harrow are. so arranged that one row. of
links will not follow the preceding ones in the same lines, but will. work.
between the lines formed by the preceding row of links. By this arrange-
ment the land will be cut much finer and more effectually pulverized than by.
the old construction of chain barrows. To the bottom or end of the harrow
I also propose to fix a set of the joined link pieces, which will keep the links
stretched out to the full width of the harrow, and will prevent any of tho
links from rolling or lapping over when the harrow empties itself of the conch
or stubble.
In the accompanying Drawing I have shewn various views of a chain.
harrow constructed according to my improvements. Fig. 1 is a plan view of
the harrow; Fig. 2 is a side elevation or edge view; and Fig. 3 is an end
view, shewing how, by the application of my improvements, the harrow is.

page_text: allowed to adapt itself to the curve or undulation of the land. a, a, is the
traction bar, to which the horses or animals employed to drag the implement
are attached by ropes or chains in the usual manner; b, b, are a series of long
links which connect the chains of the harrow to the traction bar a. One,
two, or more of these long links may be removed, if desired, and dynamo-
meters attached in their place. The first section of the harrow is marked
c, c, c, and may be composed of iron links of greater weight than those of the
other two sections marked d, d, and e, e. If desired, the three sections may
be made of links of different weight, as is sometimes now done in chain
harrows. The several sections c, d, and e of the harrow are connected
together, and are also kept extended by the flexible transverse bars f.f.f
which aro constructed of three or more lengths of iron rod twisted, as shewn
in the Drawing, into something of the form of rigid chains; the three several
lengths of these twisted rods are jointed together, as at g, g, so as to form one
long length the width of the harrow, which is kept extended thereby, but yet
admits of the links of the sections of chain c, d, and e resting on the surface
of the ground, as shewn in Fig. 3. It will also be seen that the sections of
the harrow are so connected and arranged that the vertical links of the
section d do not follow and run in the lines made by the vertical links of
the preceding section c, but they make for themselves lines of their own. It
will also be seen that the vertical links of the third section e run between
the links made by the links of the section d. By this means the land is more
effectually pulverized and acted upon than if the links of all the sections ran
in the same lines as heretofore.
Having now described my Invention of Improvements in Chain Harrows,"
and having explained the manner of carrying the same into effect, I would
observe that I do not mean or intend to confine myself to any particular form
of link of which to construct my improved harrow, nor to the particular form
or mode of constructing the flexible transverse extension bars f,f, as these
parts may be varied somewhat in construction without departing from the
nature and object of my Invention; and I would further remark, that although
I have stated that I sometimes propose to construct the several sections of the
harrow with links of different weights, I do not mean to lay any claim thereto,
as this contrivance forms no part of my present Invention; but that which
I consider to be new in my improved chain harrows, and therefore desire to
claim as the Invention secured to mo by Letters Patent, as aforesaid, is,—
First, the use and application of the flexible transverse bars f.f, for the
purposes above set forth.

page_text: Second, I claim arranging the several sections of the harrow in such a
manner that the vertical links thereof shall not run in the lines produced by
the links of the section immediately preceding.
In witness whereof, I, the said William Colborne Cambridge, have
hereunto set my hand and seal, the Twentieth day of October, in the
year of our Lord One thousand eight hundred and fifty-seven:
Witness,
J. W. MOFFATT,
66, Chancery Lane.
WC. CAMBRIDGE. (L.S.)