Improved Drop Shuttle Box Changing Mechanism for Looms.
Year: 1892

page_text: Date of Application, 10th Dec., 1892—Accepted, 21st Jan., 1893
COMPLETE SPECIFICATION.
Improved Drop Shuttle Box Changing Mechanism for Looms.
I FRIEDRICH HOFMANN, of Barracone, near Turin in the Kingdom of Italy,
Manager of Weaving Factory 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 improved drop shuttle box changing mechanism for
power looms and has for object to ensure the bringing of the shuttle boxes to their
proper positions without shock, even when working at a high speed.
Reference is to be had to the accompanying drawings, forming part of this Speci-
fication, wherein
Figure 1 is a sectional elevation shewing the improved mechanism.
Figure 2 is a perspective view of a part thereof.
Figures 3, 4, 5, and 6, are diagrams illustrating its operation.
Figures 7, 8, 9, and 10, shew the four pattern cards corresponding to the four
positions of the mechanism.
The same letters of reference denote like parts in all the figures.
The mechanism receives its motion from the shaft a which by a cam c oscillates
the lever to which is attached the rod d carrying the griffe e which is thereby
raised at each revolution of shaft a. An eccentric also fixed on shaft a imparts
through the medium of connecting rod and lever the necessary horizontal
oscillations to the pattern card cylinder i for the purpose of rotating the cylinder,
changing the pattern cards and moving the cylinder towards and away from the
needle box which contains four spring needles 1, each needle being in connection
with one of the lifting hooks m', m², m³, m². These hooks m¹, m², m³, m², are
actuated in the usual way, by the pattern cards acting through the needles those of
the hooks to whose needles perforations in the pattern cards coincide remaining in
position to be engaged by the griffe e whilst the remainder of the hooks are forced
back so as not to be engaged thereby. The hooks m¹ to m³ are arranged behind
one another as shewn in Figure 1 and work at the upper part through the needle
box k and at the lower part in the guide n. m² and m² constitute one pair and m³
and m another pair of hooks, the two hooks of each pair being connected by chains,
bands, or cords, with and acting oppositely on a chain drum of which there are
two pl p² corresponding respectively to the two pairs of hooks. To each of the
chain drums is attached an eccentric q' or q², each drum and its respective eccentric
being rotatable independently of the other upon a stationary shaft o and each chain
drum has formed upon it two notched projections a¹², each in the plane of the
corresponding hook rod. At every ascent of the one or other hook of a pair, the
eccentric q' or 2 connected with the drum thereby actuated is rotated through a
semicircle so as to be brought either from its lowest to its highest position or vice
versa, according to which hook of the pair is actuated. The two eccentrics q¹
and 92 are connected by links to the drop box lever s, the link being
connected to the middle of the lever at t¹ and the link r² with the end t² of the lever,
the connection in both cases being made by a spherical joint and the socket of the
joint t¹ being guided in transverse vertical slots u in a guide bracket having a
longitudinal vertical slot in which the levers is guided whereby both lateral and
longitudinal motion of said lever are prevented. The standard wo jointed to the
ends of the lever s carries the drop box which is raised and lowered to four
different positions by the eccentrics g¹ and q² being brought to the various relative
positions shewn diagrammatically in Figures 3, 4, 5, and 6, the eccentrics in their
various positions acting on the levers and bringing it to the various heights and
inclinations shewn. For instance the position of the eccentrics and lever in

page_text: Figure 3 is produced by raising the hooks m² and m* and that shewn in Figure 4
by raising hooks m² and m³, whilst those shewn in Figures 5 and 6 are produced by
raising wires m¹ m³ and m³ m³ respectively, the operation of the hooks being deter-
mined as before stated by the perforations of the pattern cards shewn in Figures 7,
8, 9, and 10. From these figures it will be seen that for each position of the shuttle
box, the simultaneous raising of one hook of each pair is requisite. If the same
hook be raised twice in succession, it will not cause the drum in connection with it
to rotate the second time but will only uselessly pull its chain. The height of the
shuttle box is accurately determined by the engagement with the chain drums of
the hook rods which are not raised. For this purpose the lower ends of the hook
rods are bevelled and those which are not raised by the griffe, ride upon the corre-
sponding cam-like projections on the chain drums and each drops into the notch a
or 2 which is presented to it, when the other hook of the pair has been raised to
such a height as to cause the eccentric attached to that drum to perform a half-turn.
The weight of the shuttle box is counterbalanced by a spiral spring y, Figure 1,
connected to the lever s by a chain passing over, and engaging with an eccentric
pulley mounted on the guide bracket of the levers, the eccentricity of the pulley
compensating for the variable height of the lever s.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is;
A drop box changing mechanism for power looms in which the raising and
lowering of the shuttle box cells is effected by two pairs of lifter hooks actuated
by jacquard mechanism and acting those of each pair in opposite directions upon
an eccentric, the two eccentrics oscillating independently and being coupled to a
lever whose inclination and height is thereby varied as described, the height of the
shuttle box being accurately determined by the engagement of the unraised lifter
hook rods with the notches of the chain drums when the half-turn of the drum is
completed substantially as specified.
Dated this 10th day of Dreamhan 1902.
F. HOFMANN,
By A. M. & Wm. Clark,
53, Chancery Lane, London, Chartered Patent Agents.