An Improved Let-off Motion for Looms for Weaving.
Year: 1899

page_text: PROVISIONAL SPECIFICATION.
An Improved Let-off Motion for Looms for Weaving.
I, REGIS DE BEAL, of 89, Rue Mulatiere, St. Etienne, France, do hereby
declare the nature of this invention to be as follows:-
The object of this invention is an apparatus whereby the tension of the
warp as it is delivered from beams of looms can be regulated in such a manner
as to give a regular tension during the whole duration of the work in spite of
variations in the diameter of the delivery cylinders or warp beams.
The apparatus consists of a shaft which can revolve in bearings bolted to a
flat iron bar arranged on the loom; to this bar straps are fixed to which are
secured the axles upon which the delivery cylinders or warp beams revolve;
upon the base of each delivery cylinder a bevel wheel is arranged and is operated
by a corresponding wheel keyed upon the above mentioned shaft; at the end
of this shaft a toothed wheel is keyed and gears with a pinion fixed upon an
intermediate shaft upon which latter a ratchet wheel is keyed and a lever, con-
nected with the loom, is also arranged, said lever having a pawl which is main-
tained in engagement with the aforesaid ratchet wheel by means of a spring.
This lever, in its movement, strikes an axle fixed to a compensating arrange-
ment which consists of an oscillating lever carrying, at the one end, a fork
between the branches of which a revoluble roller of oval form is carried and is
caused to press constantly against the surface of the yarn placed on the first
warp beam by the action of a spring which actuates the other end of the
oscillating lever.
The diminution of the diameter of the warp beam, during the work, displaces
the axle of the compensator, against which the above named lever strikes, in
such a manner that the pawl of this lever engages, from the commencement
of the work to its finish, with a gradually increasing number of the teeth
(from 1 to 5) of the ratchet wheel so as to allow the warp beam an increasing
amplitude of rotation the result of which is that an equal quantity of yarn is
always delivered.
An Improved Let-off Motion for Looms for Weaving.
I, REGIS DE BEAL, of S9, Rue Mulatiere, St. Etienne, France, do hereby
declare the nature of this invention and in what manner the same
ig
[Price Sd.]

page_text: to be performed to be particularly described and ascertained in and by the
following statement:-
The object of this invention is a let-off motion or apparatus whereby the
tension of the warp as it is delivered from the warp beams of looms can be
regulated in such a manner as to give a regular tension during the whole
duration of the work in spite of variations in the diameter of the delivery
cylinders or warp beams.
In order that my said invention may be properly understood I have hereunto
appended two explanatory sheets of drawings, whereon:-
Fig. 1 is an end view of the let-off motion.
Fig. 2 is a plan view of same and showing the arrangement of the warp
beans.
Figs. 3 and 4 are detail views.
The apparatus consists of a shaft d which can revolve in bearing brackets f
bolted to a flat iron bar e arranged on the loom; to this bar straps are fixed
to which are secured the axles g upon which the delivery cylinders or warp
beams 6 revolve. The number of warp beams will vary according to the length
of the loom. In Fig. 2 the left hand warp beam is shown filled with yarn
whilst the right hand one is shown empty. Upon the end of each warp beam b
a bevel wheel e is arranged and is operated by a corresponding wheel r keyed
upon the shaft d. The yarn starting from the warp beam passes round a
suitable roller and upwards over guide pulleys i, 1, (see Fig. 4) and thence
to the loom. A regulating pulley is placed between the pulleys i, i, and the
yarn, as shown, passes under it. A counter-weight is attached to the pulley .
The pulley and counter-weight are for the purpose of retaining the yarn
always at the proper tension. Each warp beam lias a similar system of pulleys
arranged in connection with it.
At the end of the shaft is keyed a toothed wheel a which gears with a
pinion fixed upon an intermediate shaft o. On the end of the shaft o is a
horizontal lever which is provided with a pawl m maintained in engagement
with the teeth of the ratchet wheel 2, on the shaft o, by means of a spring.
This lever is provided with an adjustable slide n which is connected, by any suit-
able means, with a moving part of the loom in such manner that it is raised
at regular intervals and thereafter allowed to fall again.
.
A lever, fulcrumed, at , upon a small stud fixed in the frame of the loom,
has, at its one end, a fork in which an oval shaped roller is held. A
spring p, suitably held in place on the loom, is attached to a hook on the other
end of the lever and acts on the lever in such manner as to constantly press
the roller against the under surface of the yarn on the last warp beam. The
lever has an arm fitted to it at right angles in such manner as to check, as
hereinafter described, the drop of the lever l
The apparatus operates as follows:-
The motion of the loom causes the lever to rise, at intervals, and in rising
to actuate, by the pawl m, the ratchet wheel and thereby revolve the warp
beam to a certain extent, by means of the wheels r¹, a, r, e, and deliver a certain
quantity of yarn. After each rise of the lever it is allowed to fall back again
and the extent of its fall is regulated by the position of the arm j. Now it will
be evident that as the yarn unwinds from the warp beam it will decrease in
diameter and as it decreases the roller k, being pressed against the yarn on the
beam by the spring p, will rise. As the roller krises so will the opposite end
of the lever fall with the result that the lever will be allowed a greater and
greater fall in exact proportion to the amount of yarn withdrawn from the warp
beam. As the downward movement of the lever increases so will the amount
of movement of the ratchet wheel and the warp beam be increased for the
reason that the pawl m will take an increasing number of teeth at each upward
movement. It will thus be seen that in proportion as the diameter of the warp
j

page_text: beam decreases its amount of rotation will be increased so that the same length
of thread is always delivered.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I consider novel and desire to claim is :-
A let-off motion for looms constructed and operating substantially as herein-
before described with reference to the drawings annexed.
Dated this 24th day of November 1899.
H. D. FITZPATRICK,
100, Wellington Street, Glasgow, Agent.