IMPROVEMENTS IN WEAVING
Year: 1856

page_text: LETTERS PATENT to Alexander Drew, of Glasgow, in the County of
!
Lanark, North Britain, and Matthew Gray, of Bonhill, in the County
of Dumbarton, North Britain, Calico Printers, for the Invention of
"IMPROVEMENTS IN WEAVING."
Sealed the 8th August 1856, and dated the 30th May 1856.
PROVISIONAL SPECIFICATION left by the said Alexander Drew and
Matthew Gray at the Office of the Commissioners of Patents, with their
Petition, on the 30th May 1856.
We, ALEXANDER DREW, of Glasgow, in the County of Lanark, North
Britain, and MATTHEW GRAY, of Bonhill, in the County of Dumbarton, North
Britain, Calico Printers, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN WEAVING," to be as follows, that is to say:-
This Invention relates to a means of weaving checked or cross-over cloth
in power looms, the object of the improvement being to produce such cloth
by means of a single shuttle, such shuttle being passed more than once
through the same warp shed whilst the warp remains motionless, and thereby
causes two or more plies of the weft to be woven as one ply. In this manner.

page_text: a cord will be shown in the cloth; or: the. cloth will have the appearance of
being woven by two different sizes of.weft. "Checked or cross-over cloth of the
kind to which this Invention refers is usually woven by means of two shuttles,
each containing a different. size of yarn; the two shuttles being moved into
proper positions, and driven across the warp, as may be required, by means
of a jacquard machine or other contrivance. The objection to this mode of
checking is that the loom cannot be made to run as quick as a plain weaving
loom, whilst it is at the same time much more liable to get out of order.
A loom with the present improvements can, however, be made. to weave at
the same speed as a plain weaving loom with very little additional liability to
getting out of order. The apparatus employed for carrying out this Invention
consists of the tappet which ordinarily moves the heddles, but is in the present
case made loose upon the shaft, and fitted with a pronged clutch on one end
of it. On the same shaft is fitted and fixed another clutch for the purpose
of driving the tappet when wanted, this clutch being made to move out of or
into gear by means of a pronged lever in the ordinary way. Near the tappet
shaft is placed a wheel, with its axis at right angles to the tappet shaft, and
having teeth or cogs on the outer extremity of its side. This wheel is moved
to the extent of one tooth at each revolution of the tappet shaft by means of
a small crank fixed on the shaft. Upon the periphery of the wheel just
referred to are fixed plates or projections according to the pattern of cloth
wanted. As the wheel is. moved round by the small crank, the projections are
made to bear upon the pronged lever, and to put the clutch into gear, so as
to drive the tappet or wyper; and when the projection releases the pronged
lever; the clutch is again put out of gear by the pressure of a spring. The
arm of the pronged lever is so constructed as to bear upon the tappet to
prevent it from moving whilst the clutch is out of gear, and to keep the
tappet in such a position as, will leave the warp open to allow the shuttle to
pass to and fro without the warps being crossed. To catch the weft thread
at each throw of the shuttle, it is necessary to cross one or more threads of
the warp at each edge of the cloth, to prevent the weft from following the
shuttle when it recrosses the warp. To accomplish this, a lever is arranged
at each side of the warp, and is moved in a vertical direction án eccentric,
fixed on the upper or crank shaft of the loom; one or more threads of warp
are made to pass through the point of this lever, by the motion of which the
thread is made to cross every weft thread that is laid by the shuttle. In this
manner a cord is formed in the body of the cloth. When the loom is making
the cord, it is necessary that the taking-up motion should be stopped or
retarded, and this is attained by means of levers connected to the centre

page_text: or shaft on which the pronged lever moves. These levers are made to lift
the catches which propel the takingup beam when the clutch is put out of
gear, and to thus stop the onward motion of the cloth. It will be obvious
to the practical weaver that the herein-before described apparatus may be
modified in various ways; but the essential feature of the Invention is, the so
arranging the tappet movement for working the heddles, that one, two, or
more weft shots may be thrown into a single shed of the warp at any desired
intervals, according to a predetermined pattern, this result being attained by
rendering the tappets inoperative in changing the warp shed when more than
one weft is to be thrown in.