Improved Electro-magnetic Picking Mechanism for Looms.
Year: 1897

page_text: Date of Application, 27th Aug., 1897-Accepted, 8th Jan.,
1898
[Communicated from abroad by FRANZ EUGEN KLEIN, of Schnorrstrasse, 44111
Dresden, in the Empire of Germany, Engineer.]
Improved Electro-magnetic Picking Mechanism for Looms.
I, WALLACE FAIRWEATHER, C.E., of 62 Saint Vincent Street, in the City of
Glasgow, Chartered Patent Agent, do hereby declare the nature of this invention
and in what manner the same is to be performed, as communicated to me, to be
particularly described and ascertained in and by the following statement:-
This Invention relates to the driving of weaver's shuttles by the aid of
electricity. Mechanism of this kind is generally so constructed that a row of
electro-magnets is arranged below the shuttle race and come successively into.
operation so as to act upon the iron shuttles. The closing of the circuit is
effected by a contact drum or by another device independent of the shuttles.
According to this Invention a powerful action can be exerted on the shuttle,
when at the same time an electro-magnet is arranged in the said shuttle and is
subjected to the action of the electro-magnets arranged below the shuttle race.
This arrangement will answer the purpose for direct as well as for alternating
currents. For direct currents, the closing of the circuit of the electro-magnets
below the shuttle race and of that of the electro-magnet in the shuttle is effected
by the latter as it is being shot.
•
:
This shuttle may be provided with contact rails sliding upon contact pins placed
in the warp, in such a manner that whichever electro-magnet of the shuttle race
happens to be under the shuttle at the time is inserted in the circuit and
periodically attracts or repels, as it changes its direction, the electro-magnet of
the shuttle.
'
...
The difficulty to be overcome is to place these contact pins before each weft
in such a manner in the warp, that the shed may not be interfered with.
If there are simply dressed or twisted chain threads, it will be sufficient to well
polish the contact pins and-to round them off at the top. If there are several
threads between two reeds or slays or if the chain threads can be easily separated,
Buch separation will have to be prevented by a special construction or arrangement
of these contact pins.
In all cases the contacts can be utilized as guiding pins. In the working of the
shuttle actuated by the electro-magnetic mechanism hereinafter described, it is
advisable to spread over the electro-magnets under the shuttle race as far as the
position of rest of the shuttle, which arrangement however does not apply to
shuttle changing mechanism or arrangements. A special contrivance must be
therefore devised whereby the shuttle may come, as it leaves its position of rest
in order to make or weave the next chain, within the influence of the electro-
magnets of the shuttle race, and for this purpose the swells are so arranged. as
not to merely receive the blow from the shuttle but to store up at the same time
the working capacity or power of the shuttle as it leaves the shed by means of
a spring, clips and releasing means and to yield such force to the shuttle where-
with to begin the next weft shot.

page_text: This arrangement of the swells has moreover the advantage of economizing a
considerable amount of power by utilizing the striking or hitting force of the
shuttle which has hitherto had an injurious effect on the picking mechanism of
looms..
One of the advantages of the whole arrangement consists further in the 5
possibility of weaving very wide material. The shuttle moves throughout all the
points of its race with equal or uniform speed, while it cannot jump out of its
race, such a contingency being prevented by the contacts which are used as guide
pins.
The accompanying drawings show by way of example the application of this 1
invention to a weaving loom wherein the electro-magnets arranged below the
shuttle race act successively upon the electro-magnet of the shuttle alternating in
one direction so as to drive this shuttle. The electro-magnets are supplied by a
continuous or direct current.
There are moreover various manners of carrying out the construction and
various arrangements of contact pins.
In these drawings, fig. 1 is a front view of the batten or lathe partly in section
parallel to the reed or separator, fig. 2 being a top view of the lathe Figs. 3, 4
and 5 are vertical sections, perpendicular to the plane of the reed and made
through the lathe, showing the various positions of the chain theads. Fig. 6 is
a single reed thickened at the bottom, such as should be used for the construction
of the contacts about to be described. Figs. 7 and 8 are diagrams showing the
electric connections of the electro-magnets of the shuttle race and of the shuttle
for the loom, when a direct current is used. Figure 9 is a second modification of
the connections for a direct current. Figure 10 shows the connections for a three
shunt alternating current. Figs. 11, 12 and 13 show the arrangement of the
contacts when dressed or twisted chain yarn is used. Figs. 14 and 15 show a
modification of the arrangement illustrated in figs. 11, 12 and 13.
64
On account of the analogy of the arrangement with an electric motor, the
electro-magnet A of the shuttle will be hereinafter caller the
"
armature while 3
the electro-magnets 131, B³, 133.
Bn of the shuttle race will be hercin-
Bu
after designated as "field magnets." These field magnets B1, B2, B³.
are arranged directly under the shuttle race and extend close to the upper surface
of the same. They are excited by currents, one after the other; these currents
passing through the coils C, C³, C³
Cn, when the shuttle actuates the
contacts E¹, E², E³
En which is effected by the contact rails
F, F, FJ
Fn. At the same time the current passes through the
coil D of the armature A. Figs. 7 and 8 illustrate best of all the manner in
which the shuttle is set in motion by the electro-magnets. Assuming that the
armature A is in the position shown in fig. 7, the current enters, as it leaves the
main circuit of the lathe, the coils C of the field magnets 134, and passes around
the same, whence it proceds through the contact E, the contact rail F³ and the
contact maker G into the armature A through which it circulates and passes
thence through the contact maker G and the rail in order to reach the coils (
through the contact E afterwards returning to the main circuit on leaving the
field magnet B³.
3
4
5
From the direction of the circulation through the field and armature electro-
magnets it results that B and A are south poles and B' and A' are north poles.
There occurs accordingly a repelling action between A and B and an attraction
between A and B on the one hand and between A and 13 on the other hand.
The horizontal components of these forces are added together and impart a motion
to the shuttle towards the right hand side. In that position of the armature
wherein the pile pieces A and B as well as A and B are exactly one above the
other the contacts E and E are out of circuit and the shuttle moves further on
account of the momentum acquired. A moment afterwards when the armature 5
reaches the position shown in fig. 8 for instance, the contacts E³ and E are in
contact with the rails F¹ and F³. The current circulates now through the field

page_text: magnets in the same direction as before but passes through the armature in an
opposite direction. A and B are south poles, A and B north poles. A repelling
action takes place between A' and 133 on the one hand and between A and B on
the other hand, while an attraction occurs between A and B. The horizontal
components of these forces act again in the direction of the shuttle motion and
accelerate the same.
When the rail F³ comes into contact with the contact E, the current circulates
for a moment through the field magnets B3 and 135 in the same direction.
B becomes according a south pole and attracts A. At the next moment the
bobbin C is thrown out of circuit so that only B and B act on the armature.
The field magnets B, B; B', B³, 133; 1ª, 13³; Bª, B³, B*; B³, B* .
Bn
act successively and in a similar manner on the shuttle so as to propel the same,
while each time as the poles of the armature pass those of the field magnets, the
former change their direction.
The shuttle passes over the shuttle race until it arrives beyond the contacts
when the current is broken off until the next weft shot. By reason of the speed
acquired the shuttle reaches the swells, after having previously passed along the
guide H (Figs. 1 and 2) which depresses the head J of the contact maker project-
ing out of the shuttle (Figs. 2, 7 and 8) and thus places the same in such a
position, that at the next weft the motion of the shuttle must be in a reverse
direction. A similar guide H³ (figs. 1 and 2) brings the head J and with it the
contact maker G back into the starting position when the weft shot towards the
left hand side is completed.
With reference to the arrangement of the bobbins of the field magnets and of
the armature a great number of variations is possible. Fig. 9 shows another
arrangement of the bobbins C of the field magnets. The analogy of this arrange-
ment with an electro-motor admits of a great number of arrangements of the
electro-magnets and of ways of making the connections. If the connection shown
in figs. 7, 8 and 9, are designated as connections "in series," the corresponding
induced current connections may be next worthy of consideration. In this case
the field magnets are excited by a peculiar current and hence the con-
tacts E, E, F
En will be directly connected with the circuits a
and b. Instead of an armature with two poles, a multipolar arinature may
be used with suitable connections. Obviously the arrangement could be made to
answer for alternate instead of continuous or direct currents, the field magnets
being excited by a continuous current while the armature would be supplied with
the alternate current by the aid of suitable contacts. The arangement would then
have the properties of a synchronous electric motor with alternate currents.
When the current used has three alternations or directions the analogy with an
asynchronous triple alternation motor is thorough. Fig. 10 shows the connections
for a rotary current with three alternations. The currents are conveyed to the
field magnets B through the circuits a, b, c while the shuttle is
provided with a short circuiting armature A. No contact is needed for the
armature and the shuttle is provided with conical rollers in the usual manner.
If guiding pins are needed they must be analogous to the contacts.
Obviously any of the usual multi-current motors can be used, and in particular
the electro-magnet of the shuttle may be considered as a field magnet and
supplied with the current, while the electro-magnets of the shuttle race may be
considered as an armature and may be provided with a short circuiting coil. "The
same applies to the arrangement which is analogous to asynchronous motors with
a single current.
There remains now to be described the construction and arrangements of the
contacts. Figs. 1 to 6 show the construction of the contacts when the separation
of the chain threads is to be prevented. This is effected by arranging the pin
shaped contacts E in the central plane of the field magnets B close behind a
reed L of special form and thickened. This reed L is shown on an enlarged
scale in fig. 6. The chain threads & on the right and on the left hand side of the

page_text: reed L can be drawn, for shed making purposes, over the points of the contact E
without there being any risk of the chain threads being separated. In fig. 2 and
fig. 4 the position of the chain threads d¹ is shown just as they are drawn over the
contact E.
The chain threads da, figs. 2 and 5, represent the endings of the shed formation.
In this position the chain threads d³ which are in close proximity to the reed L
are parallel, as the reed L has the same thickness below as other reeds. The
guiding of the shuttle is effected by the contacts E in a side groove R made of
insulated material wherein the contacts F1, F2, 13, are arranged (figs. 2, 5 and 12).
After the weft is shot through and while the lathe is coming back, the chain
threads are raised by the shuttle race, whereupon the weft threads d are acted upon
by the reed plate, this being done to prevent the formation of gaps in the fabric
by placing a part of the plate above the thickening of the reed L, fig. 3. To
prevent the shuttle from being clamped as well as to obtain a good contact, the
contact rails of the shuttle or the contacts E could be so arranged as to be slightly
resilient.
When the chain threads cannot become separated, the reed can be constructed
in the same manner as in ordinary weaving looms. The contacts E which may
assume the form of rounded off and polished pins can be directly fixed to the reed
plate (Figs. 11, 12 and 13); the guiding of the shuttle and the supply of electric
current taking place sidewise in a groove or channel. Or the contacts could be
so arranged as to guide the shuttle between them and the reed plate or frame
(Figs. 14 and 15). In all these constructions the contact pins or rails can be
rendered slightly flexible to make sure of the contacts. The form of the contacts
may be varied, they may even assume the shape of rollers forming "roller
contacts". The contacts may be likewise arranged in many ways, for instance
the contact pins could be introduced from above into the shed in the same manner
as the field magnets may be made to act on the shuttle from above. The arange-
ment of the contact pins can moreover be such that damaged contacts can be
rapidly replaced by new ones by the aid of a handle.
For weaving metallic threads or for wire looms, the contacts E could be
covered with insulated material at the parts which come in contact with the chain
threads. When the shuttle has shot through the shed it passes beyond the sphere
of influence of the field magnets and reaches the swells, where the propulsive force
of the shuttle cocks the spring S. The light blow is taken up by the mass of the
spring bolt and hence the small leather disc u suffices to receive the shuttle.
Stop or trigger mechanism consisting of the lever v fulcrumed at k, of the
trigger w pivoted at i, of the springs m and n and of the knife serves to maintain
by the aid of the bolt t the springs in tension. Usually the knife is in the
position shown in figs. 1 and 2, so that the lever and the fulcrum or pivot of the
picce placed on the latter should be firmly fixed. The latter piece acts in
common with the spring m as an eccentric brake. The pressure transmitted by
the piece or trigger upon the fulcrum i causes the lever v to oscillate, which
oscillation is arrested by the knife r. Whenever the shuttle has to be shot anew
through the shed, it is sufficient to withdraw the knife by means of a device
connected with the mechanism of the loom, when the lever vis free to turn, the
fulcrum is raised in consequence thereof and the bolt is released. After the
bolt has shot the shuttle through the shed it has reached its extreme position,
fig. 2, and the spring n brings the lever v back into its normal position so that the
knife may also return into its former position.
To enable the shuttle after it has cocked the spring to remain at a standstill
while bearing tightly against the head u of the bolt t, a spring y is arranged to
bear normally against the pin = (figs. 1 and 2), while it firmly holds the shuttle
by the aid of the pin o and the hole whenever this shuttle presses against the
spring s. As soon as the bolt is released, the spring y abuts against the pin z,
the pin o is withdrawn from the hole p and the shuttle is released. The fixing
and releasing of the shuttle may be likewise carried out for shuttle changing

page_text: mechanism with somewhat modified mechanism. The trigger mechanism and the
releasing can be arranged in any other suitable manner or may be replaced by
suitable ratchet and pawl mechanism.
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:-
-
1. Electro-magnetic picking mechanism for the shuttles of weaving looms,
characterized by the propulsive action of the electro-magnets, arranged below the
shuttle race, upon the electro-magnet contained in the shuttle, which action is
such that the shuttle acts as an armature while the electro-magnets of the shuttle
race act the part of the field magnets of an electro-motor and vice versa.
2. Actuating the electro-magnetic picking mechanism for the shuttles of
weaving looms such as above claimed, by means of a continuous current, wherein
the operation, in the proper direction, of the electro-magnet of the shuttle and of
the shuttle race by the flying shuttle is performed by contacts reaching the shed.
3. Actuating the electro-magnetic picking mechanism for the shuttles of
weaving looms such as set forth in claim 1 by means of alternate currents, wherein
this current is conveyed either to the electro-magnets of the shuttle race or to
that of the shuttle, while the electro-magnet or magnets of the other part form a
short circuiting coil.
4. An electro-magnetic picking mechanism for the shuttles of weaving looms
of the kind mentioned in claims 1 to 3 wherein the shuttle is driven from its
position of rest on to the influential zone of the magnetic field by means of spring
mechanism.
Dated this 26th day of August 1897.