IM- PROVEMENTS IN LOOMS FOR WEAVING
Year: 1870

page_text: PROVISIONAL SPECIFICATION left by George Lucas at the Office of the
Commissioners of Patents, with his Petition, on the 15th September
1870.
I, GEORGE LUCAS, Pattern Maker, of Accrington, in the County of
Lancaster, do hereby declare the nature of the said Invention for "IM-
PROVEMENTS IN LOOMS FOR WEAVING," to be as follows:-
:-
This Invention relates to the employment of apparatus for "letting
off" the yarn from the yarn beam, and its construction, which is as
follows: A stud in the side frame of the loom carries one end of a
horizontal lever, the latter extends (under the crank shaft and is operated
by an eccentric thereon) to near the back of the loom, to this end of the
said lever is attached a vertical one on which are catches for actuating
catch and gear wheels, these impart the required motion to the yarn
beam. The upper end of the vertical lever carries a short arm on which
is a finger or projection for purpose herein-after described. The yarn
from the beam is passed over a roller extending across the loom under
a second roller over a third roller forward to the healds. The second
roller above referred to is suspended by the yarn which it serves to keep
in a state of tension when and after "letting back." The necks of this

page_text: shaft are received in the clip ends of two arms extending from a cross
shaft, this I term the "weight shaft," on which is also an arm and
projection immediately over or opposite the short horizontal lever and
finger or projection herein-before described; near each extreme end of
the weight shaft and attached thereto is a lever the other ends of which
carry vertical rods on which are a number of weights varied according
to the nature of the yarn or tension required.
The action of the apparatus is as follows:-Each revolution of the
crank shaft will through the eccentric operate the horizontal lever and
this in turn the vertical lever, the catches thereon acting on the teeth
of the catch wheel impart through the agency of gear wheels the desired
motion or intermittent motion in a positive and certain manner. When
necessary from any cause to "let back" the yarn the tension roller and
the clip arms connected therewith descend, and as the bosses of the arms
are secured_on_the_weight_shaft a partial-rotation-of-that-shaft-takes-
place, bringing the projection on the arm on the said weight shaft to
bear on the finger or projection on the short horizontal lever (above
described), this and the levers and catches connected therewith are
depressed so that the eccentric on the crank shaft ceases to operate the
said levers and catches and the beam no longer gives off yarn, whilst
the "let back" yarn is being woven the necessary tension is maintained
by the tension shaft, and when this is raised to its original line or
position the weight shaft will have completed its return partial rotation
and the levers and catch will operate the beam as before. The weights
employed prevent or detect any tampering with the loom as a number
corresponding with the number of weights in the vertical weight rods is
supplied to the attendant on the loom. A friction plate is employed in
connection with the catch and gear wheels so as to retard and steady the
beam when letting back and when the catches are out of contact with
the catch wheel.