IMPROVEMENTS IN LINEN AND OTHER FABRICS, AND IN LOOMS FOR MANUFACTURING THE SAME
Year: 1875

page_text: PROVISIONAL SPECIFICATION left by Charles James Webb at the
Office of the Commissioners of Patents, with his Petition, on the
12th May 1875.
I, CHARLES JAMES WEBB, of Randalstown, in the County of Antrim,
in the Kingdom of Ireland, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN LINEN AND OTHER FABRICS, AND IN LOOMS FOR
MANUFACTURING THE SAME," to be as follows:-
-
This Invention has for its object the manufacture of a variegated
pattern of cloth by simply spacing the threads (more especially the
weft) at uneven distances apart. This is effected easily in the warp by
omitting a thread at intervals in the reed, such as by putting one thread
instead of two in every split where thin places are desirable. In the
weft it is accomplished by causing the ratchet wheel on the shaft
driving the cloth roller to revolve at intervals through the space of two
or more ratchet teeth (instead of one as is customary), for each stroke of
the reed against the weft. This periodical increase in speed of the cloth
roller can be accomplished in several different ways.
•
The plan I prefer as simplest and best is as follows:-I drive the cloth
roller in the usual way by a ratchet wheel keyed on the same shaft as
the pinion which drives the spur wheel of the cloth roller shaft.
1

page_text: The paul driving the ratchet wheel is also fastened as usual to a
slotted lever pivotted above on a pin in the gabel of the loom, but the
speed driving this lever instead of being rigidly fastened to the lath
sword of the loom is unconnected to it, except by link motion as
hereafter described. On the lath sword projecting backwards I place a
bracket supporting bearings of a ratchet wheel and cam, firmly bolted or
cast together. (These for convenience sake I will call the new ratchet
wheel and the cam). Pivotted to the extremity of this bracket I place
a pair of levers or links standing vertically upwards, and pivotted again
to them, the link carrying at its other extremity the spud before
mentioned. It also carries a stud working on or in the aforesaid cam,
which latter is so shaped that as it revolves it occasionally raises the
stud, and consequently the spud at the other end of the lever a
considerable height; these occasions being when it is desired to increase
the travel of the cloth roller, and thus make the weft more open.
Fastened to a link pivotted on the axis of the new ratchet wheel at one
end, and at the other to a link pivotted to the frame, I fix the paul of
the ratchet wheel in such a manner that as the lath sword oscillates and
presses against the weft shot, the new ratchet wheel shall be rotated to
the extent of one tooth and no more. The teeth in the ratchet wheel
being exactly the same in number as the threads of weft in the repeat
of the desired pattern.
To alter the variation in the weft all that is required is to change or
alter the cam, the increase or discrease of the distance of the highest
part of the cam from the axis regulating the height of the spud in the
slot of the oscillating shaft, and with it the throw of the paul driving the
main ratchet wheel, and (consequently) the speed of the train of wheels
actuating the cloth roller also.