An Improved Automatic Warp Letting-off Motion for Looms.
Year: 1894

page_text: Date of Application, 24th Feb., 1894
Complete Specification Left, 22nd Nov., 1894-Accepted, 22nd Dec., 1894
PROVISIONAL SPECIFICATION.
An Improved Automatic Warp Letting-off Motion for Looms.
I, EDWARD HOLLINGWORTH, of the Firm of Hutchinson, Hollingworth and
Company, Limited, of Dobcross, in the County of York, Loom Manufacturers, do
hereby declare the nature of this invention to be as follows:-
The object of this invention is to provide an automatic warp letting-off motion,
sensitive, steady and efficient in its action.
In carrying out my invention I utilise the oscillatory motion of the back swing
bearer, because as is well understood the back bearer oscillates a little in two
directions according to the tightness or slackness of the warp passing over.it.
employ a ratchet wheel secured on the worm shaft gearing with the worm wheel on
the warp beam, and there is mounted loosely on the same shaft, a catch box carrying
one or two pawls gearing with the teeth of the ratchet wheel, when not kept out of
gear by a shield the movement of which shield being governed by the slackness or
tightness of the warp.
The catch box, together with the pawls, have a continuously up and down
movement imparted to them from the slay or other convenient source, and if the
shield did not interpose between the pawis and the ratchet wheel, the said ratchet
wheel would be partially revolved at each revolution of the loom, and thus the same
quantity of warp would be let off at each pick whether the weft required it or not,
but by the use of this shield the teeth of the ratchet wheel are only exposed, to be
taken hold of by the pawls when the tension of the warp requires slackening. The
shield is carried by a lever arm placed loosely on, the worm shaft, the opposite end
of the said lever arm being connected by vertical rod to another lever, the free end
of which is moved up and down by the back bearer, the latter being oscillated by
the slackness or tightness of the warp, therefore if the tension on the warp is great,
the back bearer rocks in such a manner as to cause the shield to lower, thereby
exposing one or more teeth to the action of the pawls, the effect of which is, that
the ratchet wheel is operated and warp let off, but if the said warp is too slack the
action of the back-swing will cause the shield to rise and cover up the teeth of the
ratchet wheel or expose fewer teeth to the action of the pawls, so that a less
quantity of warp for the time being is let off the beam. By the combined use of
the ratchet wheel and pawls, together with the shield operated by the back-swing,
a steady efficient and sensitive motion is constructed, letting-off the warp just in
proportion at which it is required by the weft or weave whereby the formation of
thin or thick places in the fabric will be avoided.
If in case the weaver requires to turn back the warp beama fter pulling out
weft, I employ a cord passing over a pulley, one end of such cord being connected
to the shield rod or lever, and the other end of said cord being extended to the
front of the loom to be within easy reach of the weaver who on pulling the cord
forward raises the shield so as to cause the pawls to be free from the teeth of the
ratchet wheel whereby the worm shaft is free to be turned back to tighten the
warp to its proper tension after pulling out weft, and whether this operation has
left the warp slack or overtight the shield would find its proper place and govern
the pawls according to the tension of the warp.
Dated this 22nd day of February 1894.

page_text: COMPLETE SPECIFICATION.
An Improved Automatic Warp Letting-off Motion for Looms.
I, EDWARD HOLLINGWORTH, of the Firm of Hutchinson, Hollingworth and
Company, Limited, of Dobcross, in the County of York, Loom Manufacturers,
do hereby declare the nature of this invention and in what manner the same is
to be performed, to be particularly described and ascertained in and by the
following statement:-
The object of this invention is to provide an automatic warp letting-off motion,
sensitive, steady and efficient in its action.
In carrying out my invention I utilise the oscillatory motion of the back swing
bearer, because, as is well understood, the back bearer oscillates a little in two
directions according to the tightness or slackness of the warp passing over it.
I employ a ratchet wheel secured on the worm shaft gearing with the worm
wheel on the warp beam, and there is mounted loosely on the same shaft, a catch-
box carrying one or two pawls gearing with the teeth of the ratchet wheel, when
not kept out of gear by a shield, whose movement is governed by the slackness or
tightness of the warp. The catch-box, together with the pawls, have a continuously
up and down movement imparted to them from the slay or other convenient source,
and if the shield did not interpose between the pawls and the ratchet wheel, the
said ratchet wheel would be partially revolved at each revolution of the loom, and
thus the same quantity of warp would be let off at each pick whether the weft
required it or not, but by the use of this shield the teeth of the ratchet wheel
are only exposed, to be taken hold of by the pawls when the tension of the warp
requires slackening.
Such being the nature and object of my invention I will now proceed to describe
the same more fully, and for such purpose make reference to the accompanying
sheets of drawings illustrative thereof, wherein :-
Fig. 1 is sectional elevation of such parts of a loom as are necessary to shew the
application thereto of my present invention.
Fig. 2 is an enlarged front elevation of the catch-box having combined therewith
my improved shield."
Fig. 3 is end view of Fig. 1 and Fig. 4 a plan view.
A represents the loom framing, B the crank shaft, C the warp beam, D the back
roller attached to the swing bearer E capable of swinging upon a fulcrum F, the
sid back roller being forced underneath the warp by means of weights and levers
(not shewn) connected to the vertical rod G. The end H of the back swing bearer
is provided with an adjustable screw I resting upon the end of the lever J working
on fulcrum L, the opposite end of said lever being connected by vertical-rod M to
a bell crank lever N placed loosely on the horizontal shaft O which has a worm P
on one end gearing with a worm wheel on the warp beam C. On the worm shaft O
there is fastened a ratchet wheel Q and there is also on the said worm shaft a
catch-box composed of radial arins or toothed segments R and R' mounted loosely
on the said shaft, and gearing with a toothed segment S working on a stud in
bracket S¹. The segment S is made with a tail piece or lever arm T attached by
rod U to the lathe sword or other oscillating part of the loom, whose movement
gives a continuously oscillating motion to the segment S, and through said segment
to the radial arms R, R' to which the pawls V and V₁ are pivoted, whereby the
latter are moved backward and forward alternately and act upon the ratchet
wheel Qand consequently impart rotary motion to the warp beam.
As, however, such arrangement would cause the warp beam to let off
the same quantity of warp at each backward and forward motion of the
tail T, I employ a shield W, the movement of which shield is governed by
the slackness or tightness of the warp, that is to say, when the warp is slack

page_text: the shield W is moved into a position intermediate of the teeth of the ratchet
and the pawls V and V, consequently the let off of the warp is temporarily
stopped, so that the slack warp may be taken up. This is accomplished by the
movement of the back bearer E, (owing to the slackness of warp,) swinging in
the direction of arrow a, whereby the pressure of the set screw of the swing
bearer is increased on the toe of the lever J consequently the rod N ascends
in the direction of the arrow b, in doing which, the shield is placed between
the ratchet and pawls, whereupon the motion of the ratchet wheel is temporarily
stopped and with it the worm wheel P and the warp beam. It will therefore
be seen that if the tension of the warp is great, the back bearer rocks in such
a manner as to cause the shield to lower, thereby exposing one or more teeth to
the action of the pawls, the effect of which is, that the ratchet wheel is operated
and warp let off, but if the warp is too slack the action of the back swing will
cause the shield to rise and cover up the teeth of the ratchet wheel or expose
fewer teeth to the action of the pawls so that no warp or a less quantity of
warp for the time being is let off the beam.
By the combined use of the ratchet wheel and pawls, together with a shield
operated by the back swing, a steady, efficient and sensitive motion is constructed,
letting off the warp just in proportion to what is required by the weft or
weave, consequently the formation of thin or thick places in the fabric are
avoided.
.
A slight modification is shewn in Figs. 5 and 6 which shews that instead of
the catch-box and pawls V, VI, being operated by segment S and tail T from
the lathe sword, the said catch-box can be operated by rod Z from any con-
tinuous moving part of loom. In this case the pawls move backwards and
forwards together and one is therefore set a tooth or more behind the other as
shewn.
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 claim is:
For letting off warp in looms for weaving, the employment therein of a catch
box and pawls, together with a ratchet wheel in combination with a shield
governed by the slackness or tightness of warp acting on and through the back
swing bearer, all arranged and operating in the manner substantially as herein
shewn and described.
Dated this 21st day of November 1894.