IMPROVE- MENTS IN LOOMS FOR WEAVING AND IN MECHANISM CONNECTED THEREWITH
Year: 1877

page_text: PROVISIONAL SPECIFICATION left by Robert Kyle at the Office of the
Commissioners of Patents on the 26th June 1877.
ROBERT KYLE, of Glasgow, in the County of Lanark, North Britain.
"
"IMPROVE-
MENTS IN LOOMS FOR WEAVING AND IN MECHANISM CONNECTED THEREWITH."
This Invention has reference to a new or improved general construction of
dobby or pattern-shedding mechanism of looms for weaving, for hanging the
heddle leaves and actuating them in a positive manner, both up and down, as
determined by the ordinary chain of pattern cards, all without the complication or
use of counter or re-acting springs or weights, and in a better and more simple
manner than heretofore, bringing the warp threads all into an even plane in both
the up-and-down warp threads or parts of the shed, and is particularly applicable
to the hand looms of weavers employed in the getting up of patterns where a great
variety of changes in these and the power of making them are required, with the
greatest possible simplicity and ease, with perfect accuracy of result.
""
And the nature and novelty of the Invention consist all as follows:-The "dobby'
is portable, having all its essential moving parts and pattern mechanism carried on
a small frame of its own (consisting of two side frames bound together by cross stays
near the top and bottom), set or secured to the top cross beams of the loom over
the middle of the set of heddles it is to work, somewhat similar to the manner of
placing the jacquard. mechanism over the shedding harness of the loom. The
essential working parts of this "dobby" consist of two vertically reciprocating short
horizontal cross drawing bars, which are guided by antifriction pulleys near their
ends and reciprocated in the same vertical slotted guides formed up the centre of
the side frames, and set transversely over the centre of the leaves of the heddles,
which they carry and raise direct by one set of cords or wires led up from the upper
lathes of each leaf of the heddles, pulled down by cords led down from their lower
lathes to the outer ends of two sets of corresponding jacks or levers, one placed
below each end of each leaf, and pulled down by a second set of cords or wires led
up from the other or inner ends of these levers, both sets being carried right up to
the said drawing or shedding bars of the "dobby" frame.
These two sets of upper direct lifting and the central drawing-up cords (from the
levers below, which pull down the heddle leaves) pass up between two pairs of small
guide rollers carried in bearing brackets projecting down from the side frames, so

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that the said two cords or wires for actuating each heddle leaf, from the front one
backwards, are carried up parallelly through hooking and unhooking holes formed
along each side of the lowest drawing bar as a catch bar, or comb," or holey-
board," a little broader than the upper drawing bar to which the upper ends of all
the cords or wires are fixed, after the pair from each heddle pass up through two
eyes in one of a set of pattern needles ranged and worked horizontally in their
guide rails, secured on opposite sides of the two side frames of the "dobby" to control
the action of each leaf separately by an ordinary pattern chain of cards, and its
square or polygonal carrying barrel and rocking frame worked on one side of the
frame by a bell-crank lever actuated from the upper draw bar, all so that each
needle controls the hooking of one or other of the two threads passing through it
and the lower drawing bar, so as to be caught by the latter, on the one side or the
other, so that when it is pulled up it will either raise or pull down its heddle leaf
by a positive action, the upper carrying bars moving in an opposite direction to
lower the cord which is not caught and raised by the lower drawing bar.
These two heddle cord-drawing bars are set and actuated in an improved manner
to give them the said reverse reciprocating action of approaching and receding from
each other at the same time and in different degrees at the front and back ends, to
suit and give the differential shed required by the heddles as their leaves recede
backwards in the loom, by a rocking shaft working in journal bearings in the top
part of the side frames considerably above the middle of the upper of the two
drawing bars, which are connected at their ends by connecting rods to oppositely
set or angled levers, keyed or otherwise fixed on the projecting or overhanging ends
of the said rocking shaft, all outside of the two side frames, the ends of the upper
bar working out through open or slotted frames or connecting rods fixed on the
ends of the lower drawing bar, connected above by its connecting rods before
-mentioned.
The upper rocking shaft (which gives motion to all the working parts of the
dobby) is by one arrangement actuated by a band-pulley keyed on it, with two
bands attached to it at their one end and wound round. or over it in reverse
directions, having their other free ends, or a wire or cord from them, led down and
attached to the free ends of two treadle levers fitted below the weaver's feet, when
applied to hand looms, so as to be worked and controlled by the action of his feet
with great ease and simplicity, while actuating the lathe and picking mechanism
with his one hand and changing the shuttles with the other, both levers being
depressed each pick, the one bringing the two heddle cord-drawing bars together to
form the shed, and the other separating them again to free the cords and allow the
pattern cards and needles to select and change the leaves to form a new shed.
For power looms, however, these treadle levers or a single lever worked positively
both up and down could be made to actuate the rocking shaft by two.cams, or one,
on one of the main shafts of the loom, or other lever arrangement and motion could
be taken from these shafts to oscillate the rocking shaft of the dobby when that is
applied to motive-power looms.