CERTAIN IMPROVEMENTS IN LOOMS FOR WEAVING
Year: 1854

page_text: LETTERS PATENT to Arthur Dobson, of Belfast, in the County of Antrim,
Ireland, Bleacher, for the Invention of "CERTAIN IMPROVEMENTS IN LOOMS
FOR WEAVING."
Sealed the 3rd April 1855, and dated the 13th October 1854.
PROVISIONAL SPECIFICATION left by the said Arthur Dobson at the
Office of the Commissioners of Patents, with his Petition, on the
13th October 1854.
I, ARTHUR DOBSON, of Belfast, in the County of Antrim, Ireland, Bleacher,
do hereby declare the nature of the said Invention for "CERTAIN IMPROVEMENTS
IN LOOMS FOR WEAVING" to be as follows:-
My improvements consist in giving a positive motion to the vibrating rail
of a loom from the tappet or other shaft which gives motion to the heddles.
The vibration of the rail has hitherto generally been effected by the tension of
the warp, which is counterbalanced by a spring or weight. The object of my
One
Invention is to render the action of the vibrating rail more efficacious.
mode of carrying my Invention into operation is by a tappet on the tappet
shaft acting on a lever, which is connected to a lever fixed on the fulcrum
shaft of the vibrator; this tappet depresses the lever and the vibrating rail"
when the shed is closed, and the lever and vibrating rail are raised by a
spring when the shed is opened. The rising of the vibrating rail, being at all

page_text: times equal to the opening of the shed, keeps the warp at a uniform tension.
In addition to the vibrating rail, I place a shaft between the fulerum shaft and
the vibrating rail; a cross rail, lined below with vulcanized india-rubber or
other suitable material, is supported in spring boxes above this intermediate
shaft. This cross rail is pressed on to the warp when the shed is opened to
secure and hold the warp. When the shed is closed, the intermediate shaft
is depressed, thereby setting the warp free to be drawn forward in the usual
manner. I also propose in sonic cases to work the vibrating rail by an
excentric on the crank shaft.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Arthur Dobson in the Great Seal Patent Office on the
13th April 1855.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ARTHUR
DOBSON, of Belfast, in the County of Antrim, Ireland, Bleacher, send greeting.
WHEREAS Iler most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Thirteenth day of October, in the year of our Lord
One thousand eight hundred and fifty-four, in the eighteenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Arthur Dobson, Her special license that I, the said Arthur Dobson,
my executors, administrators, and assigns, or such others as I, the said Arthur
Dobson, 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 "CERTAIN IMPROVEMENTS IN
LOOMS FOR WEAVING," upon the condition (amongst others) that I, the said
Arthur Dobson, by an instrument in writing under my hand and seal, 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 imme-
diately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Arthur Dobson, 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 Specification
thereof, reference being had to the accompanying Drawings (that is to say):

page_text: My said Invention consists of improved combinations of machinery for
imparting a positive motion to the vibrating rail of a loom, which motion
can be regulated according to the shed; also in the application of certain parts
by which the warp is held when it is separated to form the shed, by means
of which improvements the injurious strains on the warp are diminished or
avoided, and a more uniform cloth is produced than heretofore.
I have in the said Drawings given Figures for shewing how my improve-
ments may be constructed, similar parts in each of the Figures being marked
with similar letters of reference.
Figure 1 of the said Drawings is a side elevation of the principal parts of a
loom to which my improvements are applied; Figure 2 is another view of the
same, in which the parts constituting my improvements are represented in
another position. a is the crank shaft; b, the tappet shaft; c, the warp beam;
d, the fulcrum shaft of the vibrator; z, the heddles; e, the breast beam; f, the
taking-up roller; and g, the cloth beam. These and all the other parts of the
loom which are not shewn in the Drawings are made in the ordinary manner.
To the crank shaft a is fixed an excentric h, which gives motion to the lever i,
fixed to. the fulcrum shaft d of the vibrator, by means of the link j. To the
shaft d are fixed two levers k, which support the vibrating rail and the inter-
mediate shaft m, above which is the cross rail n, the lower surface of which is
lined with vulcanized india-rubber or other suitable material; this cross rail
is supported in the spring boxes o. p is a cross shaft, over which the warp is
taken before it passes through the, heddles z. In Figure 1 the parts are shewn
in the positions they occupy when the shed is open; and in Figure 2 they are
shewn in the positions they assume when the shed is closed. The mode of
operation is as follows:-The warp, which is indicated by the lines g. on
leaving the warp beam c is taken over the fulcrum shaft d, and over the inter-
mediate shaft m, then under the vibrating rail 7, and over the cross shaft p,
from whence it is taken in the ordinary manner through the heddles. When
the shed is open, as in Figure 1, the intermediate shaft m presses the warp
against the cross rail n, thereby securing the length of yarn in the loom from
the influence of the back strain on the warp beam, and enabling the shed to
be formed with facility,.and consequently without injury to the warp; but as
soon as the shuttle has been thrown across the open shed, the excentric h,
acting as before described on the lever i, depresses the vibrating rail and
intermediate shaft m, which then assume the position shewn in Figure 2. The
warp is thus liberated from between the intermediate shaft m and cross rail n,
and is consequently free to be drawn off the warp bean by the blow of the
reed striking home the weft, and by the action of the taking-up motion. The

page_text: _position of the cross shaft p is so regulated that the depression of the vibrating
rail tightens the warp when the shed is closed; consequently when the rail
is elevated, the warp is slackened at the required time to allow the shed to be
opened. This provision for tightening and slackening the warp is particularly
beneficial in weaving linen or other yarns, which from their want of elasticity
are liable to break when subjected to sudden jerks. It will be apparent to
.any practical weaver, that by varying the point of attachment of the link j
to the lever i, more or less motion may be given to the vibrating rail l to suit
the shed required. The excentric h is fixed to the crank shaft a by means of
a set, screw, in order that the ascent and descent of the vibrating rail may be
regulated according to the cloth that is being woven. For a medium quality of
cloth, the descent of the vibrating rail commences when the reed has performed
from one-half or three-fifths of its stroke towards the cloth. I would also
remark that instead of an excentric, such as that marked h, a double tappet
fixed on the shaft b may be used for giving motion to the vibrator.
Having thus described the nature of my Invention, and the manner of
performing the same, I wish it to be understood that I do not confine myself
to the precise details herein set forth; but what I claim is, the improved com-
.binations of machinery shewn and described for imparting a positive motion
to the vibrating rails of looms, also the parts marked m and n for holding
the warp when it is separated to form the shed.
In witness whereof, I, the said Arthur Dobson, have hereunto set my
hand and seal, this Twelfth day of April, in the year of our Lord One
thousand eight hundred and fifty-five.
Witness,
H. B. BARLOW,
Manchester.
ARTHUR DOBSON. (L.S.)