IMPROVEMENTS IN LOOMS FOR WEAVING
Year: 1866

page_text: LETTERS PATENT to Thomas Sagar, Machine Maker, and Thomas
Richmond, Manufacturer, both of Burnley, in the County of Lancaster,
for the Invention of " IMPROVEMENTS IN LOOMS FOR WEAVING."
Sealed the 1st January 1867, and dated the 4th July 1866.
PROVISIONAL SPECIFICATION left by the said Thomas Sagar and Thomas
Richmond at the Office of the Commissioners of Patents, with their
Petition, on the 4th July 1866.
We, THOMAS SAGAR, Machine Maker, and THOMAS RICHMOND, Manu-
facturer, both of Burnley, in the County of Lancaster, do hereby declare
the nature of the said Invention for "IMPROVEMENTS IN LOOMS FOR WEAVING,"
to be as follows:-
Our Invention consists in an improved "letting-off motion" for looms in
weaving. Our improved letting-off motion is similar to the escapement move-
ment of a clock, with the exception that the back detent must be loose or
free to work backwards as well as forwards, but it is prevented from working
beyond a given point forwards by a stop; the front detent may be either the
same or fixed. Upon the yarn beam or at the end thereof we place a ratchet
wheel; the escapement movement we fix upon the vibrating or shedding
warp bearer, and in working when the shed is opened for the passage of the
shuttle the tension put upon the warp causes the shedding bearer and the

page_text: escapement movement to vibrate the back detent, the latter holds the ratchet
wheel, but still allows it to oscillate and adjust itself to the requirements of
the shed.
The operation of letting off the yarn is effected as follows:-As the cloth
is being continuously wound up it increases the tension on the yarn, and
depresses the shedding bearer or other substitute, and carries the front detent
of the escapement movement down into the ratchet wheel, and at the same
time lifts the back detent out of the ratchet wheel and allows the weel to
move forwards a tooth, and give out a corresponding quantity of yarn. The
ratchet wheel is now held by the front detent, but at the next revolution of
the crank shaft the front detent is lifted out of the ratchet wheel by the
ordinary shedding bearer, cam, or other equivalent, when the back detent
descends into the ratchet wheel and holds the beam until more yarn is wanted,
the whole operation having moved the ratchet wheel one tooth forward. The
front detent is only brought into contact with the ratchet wheel when the
yarn is let off. The shedding lever which comes against the cam only does so
when the front detent is depressed into the ratchet wheel, as it is not required
to act except at that time. Attached to the shedding bearer we apply a
weight or spring for the purpose of withdrawing the shedding bearer lever
It will be seen
from the cam and giving the required tension to the warp.
that the yarn beam is at perfect liberty to move backwards at all times
excepting when the front detent is depressed into the ratchet wheel.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Thomas Sagar and Thomas Richmond in the Great Seal
Patent Office on the 3rd January 1867.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, THOMAS
SAGAR, Machine Maker, and THOMAS RICHMOND, Manufacturer, both of
Burnley, in the County of Lancaster, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fourth day of July, in the year of our Lord
One thousand eight hundred and sixty-six, in the thirtieth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto
us, the said Thomas Sagar and Thomas Richmond, Her special license
that we, the said Thomas Sagar and Thomas Richmond, our executors,
administrators, and assigns, or such others as we, the said Thomas Sagar
and Thomas Richmond, our executors, administrators, and assigns, should

page_text: at any time agree with, and no others, from time to time and at all times
thereafter during the term therein expressed, should and lawfully might
make, use, exercise, and vend, within the United Kingdom of Great
Britain and Ireland, the Channel Islands, and Isle of Man, an Invention
for "IMPROVEMENTS IN LOOMS FOR WEAVING," upon the condition (amongst
others) that we, the said Thomas Sagar and Thomas Richmond, our
executors or administrators, by an instrument in writing under our, or their, or
one of our or their hands and seals, should particularly describe and ascertain
the nature of the said Invention, and in what manner the same was to
be performed, and cause the same to be filed in the Great Seal Patent Office
within six calendar months next and immediately after the date of the said
Letters Patent.
NOW KNOW YE, that we, the said Thomas Sagar and Thomas Rich-
mond, do hereby declare the nature of our said Invention, and in what
manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement (that is to say) :-
Our Invention consists in an improved letting-off motion acting on the
principle of the escapement movement of a clock.
And in order that our Invention may be fully understood and readily carried
into operation, we will proceed to describe the accompanying Sheet of
Drawings, reference being had to the figures and letters marked thereon.
Figure 1 is an end elevation and Figure 2 is a view of part of the back
of a loom to which our improvements are applied; the Drawings are made
to a scale of two inches to one foot, and the parts required to complete the
loom which are not shewn in the Drawings are constructed in the ordinary
manner.
a is the frame side; b, the crank shaft, on the end of which is the
shedding bearer cam c; d is the shedding lever fixed on the end of the
vibrating or shedding warp bearer e, attached to which is the front detent f
carrying the stud h, on which works the back detent g; i is the warp or yarn
beam to which is fixed the ratchet wheelj; the detent 9 is made to take
into the teeth of the ratchet wheel j by means of the spiral spring k, one
end of which is attached to it, the other end being secured to the vibrating
warp bearer 6, and the detent f is made with a projection which extends
beneath the detent 9 for the purpose of lifting it out of contact with the teeth
of the ratchet wheel ; when required; the detent f is also furnished with a
stop piece m which limits the height to which the detent g can be raised; the
shedding lever d may be held out of the range of action of the shedding cam c
by a spring or otherwise until depressed by the motion of the vibrating warp

page_text: bearer e; or the shedding lever d may be placed loose on the end of the
vibrating warp bearer e, as shewn in Figures 1 and 2, in which case a spiral
spring n is secured to the under side of it, and also attached to the shedding
warp bearer e by means of the adjustable bolt o and bracket p, the bracket p
being fixed on the end of the shedding warp bearer e, and furnished with a
slot in which the bolt o can be moved up and down, and fixed by a winged
nut, the object of which will be explained hereafter. A weight may be used
instead of the spiral spring n, but we prefer to use the spring. We have
shewn only one dentent moveable in Figures 1 and 2, but both detents may be
made moveable by similar means to those described.
The mode of operation is as follows:-The loom having been put in motion
and the shed formed by the usual means, the tension on the warp threads
causes the vibrating warp bearer e to accommodate itself to the opening and
closing of the shed, the detent f vibrating with it while the detent g remains
in contact with the teeth of the ratchet wheel j, thus allowing the warp beam i
to oscillate and take up any slack yaru produced; when, however, a certain
amount of tension on the warp threads has been obtained through the taking-
up roller winding on the woven cloth as it is produced, the vibrating warp
bearer e becomes so depressed that the detent f descends into the teeth of the
ratchet wheel at the same moment that the projection in rising liberates
detent g from the ratchet wheel j, and allows the ratchet wheel j, and
with it the warp beam i, to move round so as to "let off" a certain amount of
yarn, but when the warp beam has moved round the distance of one tooth of
the ratchet wheel j it is arrested by the detent f being in the teeth of the
ratchet wheel j, and at the next revolution of the crank shaft b, the cam e,
acting on the shedding lever d, elevates the vibrating warp bearer 6, and with
it the end of the detent f, which is in contact with the ratchet wheel j, the
other end, on which is the projection?, being depressed so as to allow the spiral
spring to draw the detent 9 instantly into contact with the ratchet wheel j,
thus arresting any further motion of the warp beam i; the amount of tension
required to depress the vibrating warp bearer e, so as to allow the "letting-off
motion" to act, can be regulated to suit the quality of cloth to be produced
or the number of picks to the inch required by moving the adjustable bolt o
in the slot in the bracket p, the position shewn in Drawings being that
which requires the greatest tension on the warp threads.
g
By the foregoing description it will be apparent that the "letting off" is
accomplished with regularity whatever quantity of yarn is on the warp beam,
being entirely governed by the tension put on the yarn by the taking-up
motion.

page_text: Figure 3 shews a modification of our Invention in which we dispense with
the shedding bearer cam, the shedding lever and front detent, using only the
back or moveable one. In this view similar letters of reference are placed or
similar parts to those in Figures 1 and 2.
a is the frame side; e is the vibrating warp bearer; g is the moveable
detent working on the stud h fast to the fixing q, which is bolted to the vibrating
warp bearer e; the fixing q is furnished with the projection and stop piece m,
described in reference to the front detent in Figures 1 and 2; k is the spiral
spring for keeping the detent 9 in contact with the ratchet wheel j; and p is
the bracket with the slot for adjusting the bolt o, to which is attached one
end of the spiral spring m, the other end being fastened to the frame side
instead of to the shedding lever.
The mode of operation is as follows:-The loom being put in motion the
tension of the yarn causes the vibrating warp bearer e to accommodate itself
to the opening and closing of the shed, the detent g remaining in contact with
the ratchet wheel; until the "taking-up motion" causes the tension of the
yarn to depress the vibrating warp bearer e so far as to elevate the pro-
jection 7, causing it to come in contact with the detent g, and liberate it from
the ratchet wheel j, thus allowing the warp beam i to "let off" by moving
round to the extent of one tooth of the ratchet wheel j; the extra tension on
the
yarn being now removed the spiral spring n elevates the vibrating warp
bearer e, depressing the projection I, allowing the spiral spring k to act on the
detent g, which taking into the teeth of the ratchet wheel j arrests the further
motion of the warp beam i.
Figure 4 shews another modification of our Invention in which both detents
f and g are moveable on the stud h, and act on the same side of it. k is the
spring for keeping the detents ƒ and g in contact with the ratchet wheel j;
is the projection on the bracket q which lifts the detents out of contact
when required; m is the stop piece before described in reference to Figures 1,
2, and 3. When the tension on the yarn depresses the vibrating warp
bearer e sufficiently to cause the projection to liberate the detents f and g
from the ratchet wheel j, the warp beam i "lets off" a quantity of yarn,
which by removing the tension on the warp threads allows the vibrating warp
bearer to be elevated, depressing the projection so that the spring k can
bring the detents again into contact with the ratchet wheel j, the detents f
and g acting alternately on the ratchet wheel j.
Having thus described the nature of our Invention, and shewn three
methods of carrying the same into operation, we declare that we claim as of our
Invention the improved letting-off motions shewn and described acting on the

page_text: principle of the escapement movement of a clock, having one or both detents
moveable, or any modification of the same whereby the peculiar features of
our Invention are retained.
In witness whereof, I, the said Thomas Sagar, have hereto set my hand
and seal, this First day of January, One thousand eight hundred and 5
sixty-seven.
THOMAS SAGAR. (L.S.)