Improvements in Loom Dobbies.
Year: 1890

page_text: Date of Application, 14th Jan., 1890-Accepted, 7th June, 1890
COMPLETE SPECIFICATION.
[Communicated from abroad by GEORGE WILLIAM STAFFORD, of Providence, Rhode
Island, United States of America, Manufacturer.]
Improvements in Loom Dobbies.
I, HENRY HARRIS LAKE, of the firm of Haseltine, Lake & Co., Patent Agents,
Southampton Buildings, in the County of Middlesex, 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 that class of shedding mechanism for looms known as
dobbies."
The dobby form of shedding mechanism has to a considerable extent taken the
place of the cam and treadle motion because it is lighter and consequently admits of
a higher rate of speed, and its capacity for readily producing a variety of patterns
though short of that of the " Jacquard is still far greater than that of the cam
and treadle.
In the accompanying drawing,
"
Figure 1 shows a front elevation of the dobby.
Figure 2 is a top or plan view of the same.
•
Figure 3 shows a front elevation partly in section of the working parts of the dobby,
the frame being left out.
Figure 4 is a top view of the ratchet wheels on the shaft of the pattern cylinder and
the pawls that move them.
Figure 5 shows a vertical section of the pattern cylinder and chain with a pair of
the plate levers that are operated by them.
Figure 6 is an end view of the parts shown in Figure 5.
Figures 7 and 8 show modifications of the compound harness lever.
Figure 9 shows a part of the lever D and the mode of holding it in place in
the frame.
B is the front frame of the dobby a similar one being placed opposite or on
the back of the machine and the two frames connected together by cross bars.
These two frames support the moving parts of the apparatus between them on shafts
and bars having bearings in both frames.
E is one of an upper series of harness levers to each of which one of the cords a
are attached that convey the motion of the levers to the top of the corresponding
heddle frames.
The series of horizontal harness levers D are placed side by side on the shaft a² the
number of the upper set E and also of the lower set D being equal to that of the heddle
frames used in the loom. d is the motive shaft of the dobby, it receives a rocking motion
by means of an arm attached to the end of the shaft, this arm being connected by means
of a rod and gearing to the main shaft of the loom. A lever fast on the end of the
shaft d, is connected on at both its upper and lower arm by the rods o, o¹ to
the lifters r, which in turns are connected by the rods s s¹ to the depressors y, y¹
the said lifters and depressors sliding in slots in the side frames of the dobby.
The lever B, and rods o, o', and s, s have their counter-parts on the other side
of the dobby, that both ends of the lifters and depressors may be moved back and
forward in the slots by the rocking of the shaft d.
A vertical jack lever J is pivoted to each of the levers D at j.
Each jack has a long hook latch h h pivoted to each end.
These latches are
nade with hooks on the under sides of their free ends, which are placed so as to

page_text: come over the lifter r, and are kept in place by means of rack bars extending from
one frame of the dobby to the other.
A series of plate levers 1, are hung loosely on the rod 6, the number of them
being equal to that of both the upper and lower latches, and each alternate latch
has a vertical double stirrup m, of wire, the loop on the upper end of which
hooks over the inner end of the plate lever and its lower end extends down
and catches into a latch ¹ below, so as to raise it when that end of the plate lever
is raised.
The inner end of the remaining plate levers 1 bear against the under side of the
latches h of the upper series.
The pins in the pattern chain n' are so placed that a row will come under the
outer end of each plate lever 1, and raises it as the chain passes over the
wheel d² and they are inserted or left out in the rows as the pattern to be woven
may require.
Check bars p, p' having concave sides are placed diagonally across the frames
from front to back above each set of latches and in proximity to the outer ends
thereof, so that when the latches are clear back against the stop bars t, t¹ their
free ends when raised by the descent of the outer end of the plate levers 1, 11
which occurs when no pins are present in the pattern chain bar under them, will
catch into the concave side of the said check bar and prevent the ends of the jack
levers to which they are attached from being moved outward, or into an improper or
disarranged position by the friction of the adjoining latches or levers or otherwise,
during the action of the adjacent parts.
One advantage of these improvements consists in the use of double harness levers
which provide a way for increasing or decreasing the amount of motion of one lever
with regard to the other. This admits of a shortening in of the horizontal lever when
its extreme or usual length would contract the alley way between the looms or
interfere with the drop of the pattern chain. The harness levers E, D are shown in
Figures 1, 3, 7 and 8, they are held on separate pivots or shafts at the side of the
loom. The upper levers E, operate in a vertical position with the cords a attached to
their upper ends, which passing over sheaves on the top of the loom are carried down
and made fast to the top of the harness frame the lower levers D operate in a
horizontal position with a cord a' attached to their free ends which after passing down
around sheaves fastened to the floor or loom frame, are carried up under the loom and
made fast to the bottom of the harness frame. These two levers E D are connected
together by a plate s¹ which is attached by working pivots or studs at each end to the
levers and by placing these pivots nearer to or farther from the pivots on which those
levers swing, the motion communicated from levers D to the levers E may be
increased or diminished as required.
For convenience the lever D has been made the moving lever upon which the jack
levers are pivoted. A part of the lever above the shaft a² is carried up in a curved
form to receive the stud j which passes through a projection on the back of the jack
lever J this projection being provided for a purpose hereinafter explained.
To cause the lifters to raise the back harness frames higher than the front ones to
obtain the same angle in the shed, the back ends of the lifters operating the back
harnesses are made to move farther than the other ends that operate the front
harnesses by placing the studs in the levers that moves the back harnesses farther
from the shaft d, than the studs that move the front harnesses. The stop bars t, t¹ are
placed at the same angle to receive the back ends of the hook latches and jack levers J
as that of the lifters when clear back. The check bars p, p² (see Figure 2) are also
placed at the same angle across the dobby frames to receive the front ends of the hook
latches and hold them without loss of motion when the depressers carry back the jack
levers p; we are aware that it is not broadly new to impart an angular movement to
the bars employed for lifting the harnesses of looms in effecting the shedding of the
warp, but we are not aware that the check bars that hold the front ends of the latches

page_text: in place whilst the jack levers are being pushed back by the depressers at the other
end have ever heretofore been placed in a diagonal position as described whereby the
principle of the "angular movement" is made practicable for positive motion
dobbies.
These improvements consist also in a modification of the pawl mechanism that
operates the pattern cylinder, and also of the plate levers that are raised by the pins
in the pattern chain and also in a modification of the mode of pivoting the jack levers
on the harness-levers to maintain the position of the lower latch hooks when they are
not in motion, and allow of a relative increase of the motion of the harness levers.
The two ratchet wheels H H¹ Figure 4 are put on the shaft of the pattern cylinder
where one has heretofore been used, and two pawls K K' are employed to operate the
ratchet wheels. One of these pawls K¹ is pivoted to the rocker lever B₁ below its
shaft & and the other pawl K is pivoted to the rocker lever above its shaft, by which
it will readily be seen that one of the pawls moves the pattern cylinder while the
other pawl is going back from having moved it. The result of this that there are
two short motions given to the pattern cylinder one by the inward movement of the
upper part of the rocker lever B and the other by the inward motion of the lower
part of that lever. These two short motions equal in extent the one long motion
formerly given by one pawl pivoted on one arm of the rocker lever, and the advantage
gained by using the two short motions is that whereas with one long motion it was
necessary to indicate for two latch hooks, an upper and a lower one, at the same time
because both of them were likely to be required before another long motion of the
pawl would be made, with the two short motions it is necessary to indicate for only
one of the two latch hooks before mentioned at each motion, thereby avoiding the
trouble liable to be met with from indicating for a latch hook before it is needed, as
in case of a positive motion dobby the hook indicated in advance would be free of its
check bar and be liable to be moved by the friction of the harnesses in motion and
other causes before it was time for the lifter to move it.
The plate levers are in pairs one of each pair to indicate for an upper latch hook,
which it raises by its inner end extended up into contact with said upper latch hook
for that purpose, and the other for one of the lower hooks which it operates by means
of a wire m connecting the lever with the hook, and one of each pair has the
projection o on its underside by which the pin n' in the pattern chain raises it, placed
just far enough in advance of the like projection o¹ of the other one of the pair that as
one row of latchhooks is raised by one of a pair of levers the other one of the pair will
be dropped by the row of pins just passed. This is shown in Figure 5 where the
pin n' in the bar s has just raised the lever and the lever l has just been dropped by
a pin in the same bar. In addition to the greater security of the hooks already
mentioned I am also enabled to shorten the pattern chain one half in certain cases
which would require with the usual arrangement twice as many chain bars with single
rows of pins to produce the result I obtain with two rows of pins in a bar and the
levers constructed and operating as described.
The modifications of the harness levers shown in Figures 7 and 8.show modes of
connecting the two levers below their bearings instead of above as in Figure 1.
Figure 7 shows projections on the lower ends of the two levers connected together by
a link and Figure 8 shows an extension of the lever that raises the harnesses, curved
down under the bearing of the lower lever and furnished with gear teeth that engage
with gear teeth on the under side of the latter lever to convey motion from one lever
to the other. Figure 9 is an enlarged view of a part of the lever D showing the
shaft a², and the locking bar d, with the projection b, on the top of lever D.
In attaching dobbies for weaving wide goods in the usual construction it is
customary to give more motion to the knives or lifters than in looms for weaving
narrow goods, in order to give sufficient motion to the harness levers. To shorten
this extended movement of the lifters the jack levers J can be shortened to bring the
point where the power is exerted on the jack lever nearer the point where it is
pivoted to the harness-lever; but in proportion as the jack lever is shortened the

page_text: rising movement of the lower end of the jack lever, which occurs when the latch hook
at the upper end thereof is engaged and moved outward by the upper lifter, increases.
This upward movement of the jack-lever raises the pivot end of the lower latch and
tilting said latch on the loop or bend of the wire m'as on a fulcrum, tends to lower
the hooked end thereof into engagement with the lower lifter r¹ and thus occasion
outward movement of said latch and the lower end of the jack lever with said lifter at
a time when such movement is not desired. To overcome this upward movement, I
make a projection von the jack lever J which projection has an opening therein for
the reception of the stud or pin j in the harness lever which constitutes the pivot of
the jack lever. This carries the centre of motion of the jack lever out of line with the
end pivots of the latch hooks, the effect of which is to produce a falling movement of
the jack lever while the upper end thereof swings outward, and prevents any upward
movement of the lower end of the jack lever that is in contact with stop-bar t¹.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed as communicated to me
by my foreign Correspondent I declare that what I claim is :—
i
First. The combination of a check bar placed in a diagonal position as described
with the stop bar having its inner surface inclined to conform to the angular position
of the check lifters and depressors having more extent of motion at one end than at
the other end, as described.
Second. The combination with a harness frame and operating connections there-
from, of two levers pivoted at the loom side and having their adjacent ends connected
to move together and in the same direction cords connecting them with the harness
frames said connections being connected with the free end of said levers.
Third. The combination with the harness frame and cording connected with the top
and bottom thereof; of a compound harness lever composed of two simple levers pivoted
at the loom side and having their adjacent ends connected to move together in the
same direction whereby the said two levers affect the movement of the harness frame,
said cording being connected with the free ends of the said levers and also connected
with the harness frames.
Fourth. The combination of two simple levers connected together, and with the
harness frame as described, the jack levers pivoted to said simple levers, booked
latches pivoted to the opposite ends of said jack levers pattern devices for controlling
the position of said latches, and lifters and depressors operating in connection with
said levers, and latches.
Fifth. In a shedding mechanism for looms a series of plate levers arranged in pairs,
one of each pair having the projection by which it is raised by the pins in the pattern
chain, placed in advance of the similar projection on the other lever of the same
pair, combined with a pattern-chain cylinder provided with mechanism for moving
it to indicate for the operation of top and bottom hook latches separately.
Sixth. In a shedding mechanism for looms the combination of a pattern cylinder
provided with two ratchet wheels, with a series of plate levers arranged in pairs one
of each pair having a projection by which it is raised by the pins in the pattern
chain, placed in advance of the similar projection on the other lever of the
same pair.
Seventh. The combination with a harness lever of a jack lever pivoted thereto
and having latch hooks pivoted at opposite ends of the same, the pivot by which the
jack lever is connected with the harness lever being placed outside of the line passing
through the pivots of the said latch hooks as described.
Eighth. In a loom the following instrumentalities: a series of harness frames,
harness levers, cording connected to the free ends of said levers, connections on jack
levers mounted on one set of said harness levers, hooks attached to the opposite ends
of said connection, a pattern mechanism to select which of said hooks shall be next
engaged and moved, stop bars and check bars place diagonal to the frame supporting
them to engage with the said hooks when at one extreme of their movement and

page_text: when held by the pattern chain out of engagement with the lifters, lifters having
more motions at their back ends than at their front ends, to engage the said hooks,
means to operate the said lifters, and devices acting positively to carry the ends or
connections on jack levers, back against the stop bars and place the hooks so that they
may engage with the said bars as described.
Dated this 14th day of January 1890
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, Agents for the Applicant.