Improvements relating to Let-off and Tension Regulating Mechanism for Looms.
Year: 1894

page_text: Date of Application, 20th Jan., 1894
Complete Specification Left, 19th Oct., 1894-Accepted, 1st Dec.. 1894
PROVISIONAL SPECIFICATION.
Improvements relating to Let-off and Tension Regulating Mechanism
for Looms.
RICHARD WILBY, Let-off Motion Maker, Exchange Buildings Marsh, Hudders-
field, do hereby declare the nature of this invention to be as follows:-
This invention relates to that class of warp let off motions for looms such as
described in the Specification of my Patent No. 11367", the object of the present
invention being to make the working parts of such mechanism as few and simple as
possible in order that its cost may not debar its use on cheap narrow looms such as
the Lancashire cotton looms.
My improved method of operatively connecting by bevil wheel teeth the two
arms of the T shaped lever to the lower arms of the two L levers of my ratchet
mechanism which improvement is described in my Patent Specification 6288°³
enables me to get twice the length of stroke of the pawls as with my original peg
This
and slot arrangement as described and shewn in my Patent 113679.
lengthened stroke on most looms gives quite sufficient motion with a single acting
ratchet mechanism therefore for the purpose of lessening the cost of such warp
let-off mechanisms and making them more simple, instead of using a double ratchet
mechanism having two levers, two pawl pendants, two pawls and a broad ratchet
wheel as described and shewn in my Patent Specifications 113679 and 628893 I use
a single stroked ratchet mechanism having only one ✓ lever one pawl pendant one
pawl, and a narrow ratchet wheel and I always take care to fix the oscillating
lever carrying the pawl on the shaft on that side of the ratchet wheel as will
cause the pawl to operate the ratchet wheel during that half of the pick when the
slay is approaching the fell of the cloth.
This
proper timing of the delivery of the warp might also be achieved by having
right and left hand worms and wheels to suit both hands of looms but as two kinds
of warp beam wheels would be perplexing to the loom tuners or tasklers I prefer
the above method.
By thus causing the warp to be delivered during that half of the pick when the
slay is approaching the fell of the cloth I am enabled to use a very simple and
effective method of regulating the ratchet mechanism by the back bearer of the
loom which method may be appropriately termed the open shed method of
regulating as by this method of regulating it is at the time of open shed that the
back bearer puts the pawls into engagement with the teeth of the ratchet wheel
when warp is required to be delivered.
The means and method I employ in this system of regulating the letting off I will
now describe.
By means of a spring attached to some part of the pawl mechanism a convenient
form of which is a coiled spring placed concentric on the axial stud of the pawl
lifting arm 20 see Figs. 2 & 3 in my Specification 11367% I cause the said
spring to press upward on the said arm with just sufficient force to promptly lift
the pawl and keep it lifted when not acted upon by the back bearer of the loom as
will be presently described. The pawl is therefore normally out of gear when not
acted upon by the back bearer of the loom. The arrangement of parts by which
the back bearer is made to operate the pawl into gear at the tiine' of open shed when
warp is required to be delivered is as follows.
I provide the back bearer at or near that end where the ratchet mechanism is
applied to the loom with an hanging arm having a hole near its lower end through

page_text: which hole a thin rod or wire passes, the rod being provided with a nut or shoulder
at the back of the arm so that when the arm moves backward it comes against the
shoulder and pulls the rod. This rod is connected to one arm of a small L shaped
lever which is pivoted to the loom frame, the lever simply being used to change
the direction of the motion given to the rod by the hanging arm
bearer. To the other arm of the lever is attached another thin rod which passes
downwards to the ratchet mechanism and is attached to that end of the spring
aforementioned which presses the arm 20 upward.
on back
Or the motion changing lever can if desired be pivoted to the bearing bracket
of the ratchet mechanism and its second arm coupled direct to the said spring so
that when a pull is given to the rod by the hanging arm on back bearer it acts on
the spring relieving it from the pawl lifting arm which arm is then allowed to fall
thereby permitting the pawl to fall into engagement with the teeth of the ratchet
wheel.
The modus operandi of the delivery of the warp by this open shed method of
regulating is as follows. Starting with the back bearer in such an angular position that
its hanging arm does not come into contact when the shed is fully open with the nut
or shoulder on the rod the pawl by the action of the spring remains out of gear and
no delivery of warp takes place, this condition of things as the weaving proceeds
brings the back bearer gradually forward in its angular position and causes the
hanging arm to pull the rod each time the shed is opened and so through the
medium of the L lever, pawl lifter, and pawl pendant, (see Figs. 2 and 4
Specification 113679) permits the pawl to fall into gear and deliver warp at each
pick of the loom so long as the hanging arm on back bearer so continues to pull the
rod each time the shed is opened, but as the delivery of warp (even when the warp
beam is nearly empty) is arranged to be quicker than is required in the weaving
when the pawl happens to be put into gear each succeeding pick the back bearer
gradually gets backward in its angular position causing the hanging arm to cease
coming into contact with the nut or shoulder on the rod and permitting the pawl to
remain out of gear with its ratchet wheel which stops the delivery of the warp to
be again started in the manner described above when the back bearer is brought
forward a very small fraction of an inch and again stopped when the hanging arm
on back bearer ceases to pull the rod.
The reason why I connect the rod or the arm of the lever (as the case may be)
to the spring which keeps the pawl out of gear instead of attaching it direct to the
pawl lifting arm is for the purpose that when the back bearer is required to move
further forward than is necessary to put the pawl into gear it can do so without
deranging the parts the spring yielding the necessary amount.
With this single ratchet mechanism it is not necessary to have a steel ribbon
spring 23 fixed on the underside of arm 20 as described and shewn in my
Specification 1136792. The arm must be made long enough and must be curved
near the end concentric to the shaft with a radius equal to the distance of the upper
surface of the arm from centre of shaft when the arm is raised half way of its
vertical travel. This curvature is for the purpose of allowing the pawl pendant to
glide over the curved part in its own free circular path which condition is essential
for the proper working of the pawl into and out of gear. Also the double action
spring 27 with its two knife edges 24 and 25 (see above Patent Specification) are
not necessary to the successful working of this single acting mechanism so that the
above described arrangement of letting off mechanism coupled with the above
described means and method of regulating the said mechanism is cheaper and more
simple than the double mechanism and the fewness of its parts and the simplicity of
its working have been specially designed to bring its cost low enough for the
mechanism to be applied to the Lancashire cotton looms.
Dated this 20th day of January 1894.

page_text: COMPLETE SPECIFICATION.
Improvements relating to Let-off and Tension Regulating Mechanism
for Looms.
RICHARD WILBY Exchange Buildings Marsh, Huddersfield, Warp Let-off
Motion Maker, 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 :-
This invention relates to improvements in that class of warp let-off motions for
looms, such as described in the Specification of my Patent bearing date June 17th
1892, and No. 11367. The object of the present invention being to reduce the
number of the working parts contained in the above mentioned, let-off motion, and
to make these parts as simple as possible, so that its cost may not debar its use on
cheap and narrow looms, such as the Lancashire cotton looms.
The character of these improvements will hereafter be fully described, and set forth.
In order to assist in the complete understanding of my invention by those skilled
in the art to which it relates, I have annexel hereto a sheet of explanatory
drawings.
Fig. 1 is a side elevation of a loom with the improved ratchet mechanism affixed
thereto, whilst
Figs. 2, 3, 4, 5, & 6, are views of details, which will be fully described.
In referring to these, I have made use of numerals for those parts represented
in the drawings which are similar to those described in my original Specification
No. 11367, whilst for those parts which generally speaking constitute the subject
matter of my present invention, I have designated by letters.
In order to reduce the number of working parts in the above mentioned let-off
motion, instead of making the ratchet mechanism double acting as shewn in my
former Specifications 11367%, & 628893, I make the said ratchet mechanism single
acting with only one pawl 9, and one oscillating pawl lever 7, as shewn in
Figs. 1 & 4.
One of the arms 10° of the T shaped lever 10 shewn in the above numbered
Specifications Figs. 5 & 9 respectively, is dispensed with, as herein shewn in Fig. 6
and in many cases where it is convenient, 1 dispense with this lever 10 altogether,
by coupling or connecting the arm 7 of the pawl lever 7 as herein shewn in
Figs. 1, & 2, by a link, or connecting rod a, direct to a bracket b, which bracket
I fix to the slay sword 16, either in front, or behind its axis as the case may*
require. The up aud down motion of this bracket b when the loom is in action,
gives through the medium of the link a an oscillating motion to the pawl lever 7,
and pawl 9, which motion is in the same plane as the circular motion of the worm
shaft 4.
When my improved let-off motion is applied to fustian looms, where the
great number of picks to the inch of fabric permits of the use of two worms
between the warp beam, and the ratchet mechanism, and which causes the latter to
be fixed to the loom at right angles to the usual way, and causes the motion of the
pawl lever 7 to be in the same plane as that of the slay sword 16, I get the
required motion for the pawl lever 7, by coupling the upright portion of same
direct to the slay sword 16 by a short connecting rod, or link similar to that
marked a in Fig. 1.
My next improvement is to dispense with the steel ribbon springs 23, which are
fixed on the ends of the pawl lifting arms 20, on both the double acting ratchet
mechanism described in my original Specification 113679, and on the single acting
ratchet mechanism herein described. In place of the said springs, I make the
I have
curved parts 23 of the pawl lifting arms 20, integral with the said arms.
found that by having one pawl set so as to just clear the teeth of the ratchet
wheel 6, when the other pawl is in gear, there is no danger of the pawls being kept
continually in gear, by one of the pawls becoming locked at the commencement of

page_text: its stroke, before the other has got freed from its tooth, and therefore with this
arrangement, elasticity in the arms 20 is not required. There is another advantage
in having one pawl set a little higher than the other, which is that the lower set
pawl does all the letting off when a full warp beam is in the loom, but when the roll
of warp yarn has got about half used up, and requires the warp beam turning
quicker, then the other pawl begins to assist in the letting off.
To steady the action of the pawls on both double acting, and single acting
ratchet mechanisms, I fix a peg c in each pawl pendant 18 see Fig. 2, in such a
position, that the peg comes against the underside of the pawl stud 8, and acts as a
stop in the upward direction, when the pawl 9 is raised sufficiently clear of the teeth
of the ratchet wheel 6.
The pawl lifting lever 20, Figs. 4 & 5, must be pivoted on one side of the ratchet
mechanism, instead of at the back as heretofore, which position renders the use of
the motion changing lever mentioned in this Provisional Specification unnecessary,
and permits the said pawl lifter 20 Figs. 1, 4, & 5, to be put in direct connection
with the back bearer 33 of the loom, by the rod d, so that a pull given to the said
rod by the banging arm m of the back bearer 33, Fig. 1, operates the pawl 9 into
engagement with the teeth of the ratchet wheel 6 when warp is required to be
delivered.
As shewn in Fig. 3, the regulating rod d, is provided with a slot E at its lower
end, which slot works on a peg F, Figs. 4 & 5, said peg being firmly secured in the
pawl lifter 20 at a point a little behind, and below its axis G, as shewn in
Figs. 1, 4 & 5.
On the lower end of the rod d Fig. 3, is placed a spiral spring H, the upper end
of which is fastened to the rod d by a pin I, or other means, while the lower end of
the spring is connected under tension to a fixed part K Figs. 1 & 4 of the ratchet
mechanism, above the axis of the pawl lifter 20. The spring H is purposely
coupled to a point above the axis of lever 20, in order that the said spring may by
its oblique pull assist the lever 20 to fall when the rod d is pulled by the hanging
arm m of the back bearer 33 Fig. 1. The upper part of the rod passes through a
hole in the banging arm m of the back bearer as shewn in Fig. 1, and the rod d at
this part is provided with a thread, on which thread are a nut, and lock nut N,
situate at the back of the arm m, or instead of the thread, and nuts, the end of the
rod may be provided with a shoulder, and a provision made elsewhere on the rod for
adjusting its length, by any one of the well known means. The spring H on the rod d,
must be connected to the fixed part K, by the link L (see Figs. 1 & 3) with such a
tension, as will cause the rod d to press against the peg F with just sufficient force
to cause the lever 20 to promptly lift the pawl 9 and keep it lifted when the rod d
is not acted upon by the hanging arm m of the back bearer 33. The pawl 9 is
thus normally kept clear of the teeth of the ratchet wheel 6, by the spring H, and
is only permitted to fall into engagement with the said ratchet wheel, when the
hanging arm m comes against the nuts N and pulls the rod d. The single acting
ratchet mechanism herein described must be made to operate the ratchet wheel
during that half of the pick when the slay is approaching the fell of the cloth, in
order that the active stroke of the mechanism will commence when the shed is open,
and consequently when the back bearer 33 is comparatively motionless, which
arrangement will cause the regulation of the delivery of the warp to be steady, and
certain, and a sufficient length of stroke must also be given to the pawl lever 7, as
will enable the mechanism to deliver warp quick enough when the warp beam is
nearly empty.
The modus operandi of the delivery of the warp by the herein described means
and method of regulating, is as follows:-
Starting the loom with the back bearer 33 in such an angular position that the
hanging arm m Fig. 1, does not come in contact with the nut, or shoulder N, on the
rod d at the time of open shed, under such conditions the pawl 9 being kept
normally out of gear with the ratchet wheel 6, no warp will be delivered.
This condition of things as the weaving proceeds, gradually brings the back

page_text: bearer 33 forward in its angular position, or arc of vibration, and causes the
hanging arm m to come against the nuts N, and to pull the rod d each time the
shed is opened, and so through the medium of the pawl lifter 20, and pawl
pendant 18 Fig. 4, permits the pawl 9 to fall into gear with the ratchet wheel 6,
and deliver warp at each pick of the loom, as often as the hanging arm m on
back bearer 33 continues to pull the rod d at the time of open shed, but as the
delivery of the warp (even when the warp beam is nearly empty) is arranged to be
quicker than is required in the weaving when the pawl 9 happens to be put into
gear each succeeding pick of the loom, the back bearer gradually gets backward in
its angular position, or are of vibration, and immediately it has got back a
predetermined amount, say a twentieth part of an inch, the hanging arm in ceases
to pull the rod d, and therefore permits the pawl 9 to remain out of gear with its
ratchet wheel 6, which stops the delivery of the warp, to be again started in the
manner described above when the are of vibration is brought forward a twentieth
part of an inch, and again stopped when the hanging arm m ceases to pull the
rod d.
The slot E in the regulating rod d in combination with the spring H Fig. 3 are
for the purpose of providing an elastic connection between the ratchet mechanism,
and the vibrating back bearer of the loom, and they allow the back bearer to move
forward in its arc of vibration, after the pawl 9 has been operated into gear by the
rod d which arrangement permits of a large amplitude of vibration of the back
bearer, without deranging the parts, or interfering with the proper regulating of
the ratchet mechanism, conditions which are very essential on looms having a plain
weave, and consequently having a large arc of vibration of back bearer.
I would have it understood, that the details of my invention may be slightly
modified, without departing from the essential features of the invention, as will be
obvious to the practical engineer.
Having now particularly described, and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
:-
Ist. In a warp let-off motion for looms of the nature set forth in my Patent
No. 11367 and herein shewn, and described, the use in combination therewith, of
the rod d provided with nut, or shoulder N, slot E, and spring H, also peg F in
pawl lifting lever 20, and hanging arm m on back bearer 33, the whole being used
for the purpose of getting an elastic regulating connection between the pawl lifting
lever 20, and the vibrating back bearer 33 of the loom, which connection will
communicate a slight motion to the said pawl lifter 20, whenever the arc of
vibration of pivoted back bearer 33 changes forward (from a given arc) a
predetermined amount, this motion being communicated through the pawl
pendant 18, to the pawl 9 so as to operate said pawl into gear with the ratchet
wheel 6, substantially as herein described and shewn.
2nd. In a warp let off motion for looms, of the nature set forth in my
Patent 11367, and herein shewn, and described, the improved method of keeping
the pawl 9 normally suspended out of gear from its ratchet wheel 6, by the tension
spring H, so that warp can only be delivered from the beam when the rod d is
pulled by the hanging arm m of the back bearer 33, the said spring by being
connected to a point above the axis of the pawl lifter 20, being made to assist in
operating the pawl 9 into gear, whenever the pull on the rod d relieves the
pressure of the spring H, from the peg F, substantially as herein described, and
shewn.
3rd. The several improvements in warp let-off motions for looms, constructed,
and arranged substantially in the manner described, and shewn in the accompanying
drawings, and for the purposes set forth.
101 3
1004
RICHARD WILBY.