The principle of this machine consists in the combination of two
separate Jacquard machines. Two hooks (one of each machine) are
connected to one leash of the Jacquard harness, and as each machine is
operated alternately, a high speed is attained, which is the purpose
of the machine. For example: 140 picks per minute (speed of loom) only
requires 70 picks per minute from each part of the double lift double
cylinder.
In Fig. CIII. this is clearly illustrated. It shows two 12-row machines
(_E_ and _F_) combined, thus giving 24 griffe-bars for the complete
double machine, as the griffes work within each other. As explained for
double lift single cylinder, every alternate bar is connected with a
separate griffe, and these two griffes are worked alternately on the
same double lever arrangement.
_O_ to _P_ and _O´_ to _P´_, represent the two needle-boards; _P_ to
_R_ and _P´_ to _R´_, represent the two corresponding needle-boxes.
These double lift double cylinder Jacquard machines are mostly used
in the manufacture of turkey-red goods and similar table-cover
fabrics, using tie-ups similar to the one illustrated below, which is
a combination of the straight-through and point tie-up, which may be
alluded to once more by way of explanation in this particular case.
The illustration represents a double lift double cylinder machine
containing two 600 machines, which equals an ordinary 600 machine for
the tie-up.
[Illustration: Fig. CIII.]
This tie-up contains six divisions for the centre straight-through,
and requiring leashes 1 to 400 from each part of the double machine.
Leashes 1, 12, and 400 (heavy lines) only are illustrated in drawing.
The borders are constructed on the point tie-up, and require leashes
401 to 604 from each part of the double machine. The first and last
leash only are illustrated. The margins between border and selvedge
are worked by leashes 605 to 612. Centre and border are 12 rows deep,
arranged in the comber-board; the margin 8 rows deep, on account of
working it (as is generally done) on an 8-leaf satin. One complete row
in machine, (both parts), as well as in the comber-board, (illustrated
on each side in drawing), is left for the selvedge.
[Illustration: Fig. CIV.]
Fig. CIV. represents this machine (built by Thomas Halton,
Philadelphia,) attached to a Clipper loom. In this drawing both sets
of cards (one to contain the even numbers, and the other the uneven
numbers) are clearly visible, and also the double lever arrangement for
working every cylinder alternately. As the cylinders run at only half
speed, the wear on the cards is reduced to a minimum.