Year: 1886

page_text: I GEORGE KIRK of Rashcliffe Iron Works, Huddersfield in the County of York
Machine Maker 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 an improved shedding motion or dobby for operating
the healds or heddles of looms; and it has for its object to simplify the construction
of the shedding motion and enable the loom to be worked at a much greater speed,
and with greater certainty than heretofore.
The invention consists essentially in an improved combination of mechanism
whereby the whole of the heddles are locked when at "full shed" by the
draw bars.
The invention also consists in the knife and catch mechanism whereby the draw
bars are operated.
The invention also consists in other details of construction as hereafter set forth.
I will proceed to describe the Invention with reference to the accompanying
drawings forming part of this specification wherein Figure 1 represents an end
elevation of the shedding motion, the heddles being omitted. Figure 2 is a front
elevation of the shedding motion, and heddles. Figure 3 is a plan of the same,
omitting the heddles. Figure 4 is a separate view of one of the 1 or jack levers in
its mid position Figure 5 is a detail view showing the double hooked catch levers
and draw bars and the draw knives in cross section.
Figure 6 shows the means of actuating the pattern chain cylinder seen from the
opposite side of Figure 2.
The same letters of reference indicate the same parts in all the figures.
A are the 1 or jack levers to the arms of which the respective heddles are
connected at top and bottom as usual. B are the draw bars by which the jack
levers A are oscillated and locked when in either of their two extreme positions.
C are oscillating double catch levers pivoted to the draw bars and acted on by the
draw knives Di D' as hereafter described. The draw knives D1 D2 work between
horizontal slides on the frame and are actuated by pairs of crossed links E jointed
to a cross head frame F carried by a vertical guide rod G working in guides in the
frame and actuated through a crank pin and connecting rod by oval gear X on the
low shaft. I is the pattern chain composed of rollers or bowls threaded on rods at
suitable positions spaced by smaller distance pieces. K are the lifters or feelers

page_text: resting on the pattern chain and connected by the needles or wires L each with the
tail arm c of one of the double catch levers C. Each of these levers C is pivoted at
about the middle of its length as at c* to a corresponding draw bar B and is
provided with upwardly turned catches or hooks c¹ c' one at each end.
These hooks (which I will distinguish as the front and back catches respectively)
are brought, the one or the other, into the path of the corresponding knife D¹ or D'
according to their corresponding feelers is or is not raised by the pattern chain,
their normal position being such that the back catch c³ is raised. The one knife D¹
acts on the front catches c¹ to move the draw bars out and the other on the back
catches c² to move them in, Each draw bar B is provided with two downward
projections 61, 62, having oppositely inclined edges and each jack lever A has two
upwardly projecting horns a¹ a one at either side of its axis a and in the same
plane as the inclined projections on the corresponding draw bar, the relative
distances apart of the inclines b¹, 62, and horns a¹, a, being such that when the
draw bar is half drawn and the jack lever is at the middle of its oscillation (as
shown in Figure 4) the inclines just pass between the horns. To bring the inclines
into the same plane with the horns, in order to enable the former to act on the
latter as hereafter described, the draw bars are thickened (as shown in Figure 3)
and a recess is formed in the thickened part for the top member of the jack lever
to work in. This member is formed with a quadrant slot through which passes a
fixed cross bar b which also passes through straight slots 6* in the draw bars for
the latter to work on. Each draw bar is engaged by a pawl M jointed to the
framework and whose V end falls into one or other of two V notches m in the
draw bar for the purpose of retaining the adjacent draw bars in the locked position
whilst any one bar is being moved, the pawl being overcome when the knife
engages with the catch lever of the draw bar.
The operation of the locking mechanism is as follows:-Referring to Figures 1.
2 and 3: The jacks A which correspond to all the heddles H except one are shown
as having been pushed in by knife D' acting on hooks of their catch levers, and
as being locked by 63, as, abutting together; whilst the draw bar B* and jack A*
which correspond to heddle H* are shown as having been drawn out by knife D¹
acting on hook c¹ of the catch lever and locked by 61, a¹, abutting.
I have shown in Figure 2 two different jacks but it will be understood that
Figure 2 might be supposed to represent the two extreme positions of one and the
same jack and draw bar.
.
In the motion of the draw bar in either direction the inclined edge of 6¹ or b³ in
advancing strikes the horn a¹ or a³ as shown in figure 4 and produces the oscillation
of the jack lever in the desired direction.
The pattern chain barrel is propelled intermittently by the ratchet N and pawl P
actuated from the cross head F through the connecting rod Q (as shown in figure 6)
the movement of the barrel being checked by a V notched wheel R and pawl rat
the opposite end of the barrel (as shown in Figure 2) Wheel R is provided with a
handle for the purpose of bringing the chain to any desired position.
Instead of a pattern chain composed of bowls, lugs with pegs or holes may be
used in their stead.
The purpose of using oval gear X for working the crosshead F is to render the
speed of the draw knives more uniform by compensating for the decrease of speed
during the ascent of the cross head which would otherwise occur owing to the
oblique position of the links E.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed I declare that what
I claim is
1 The combination and arrangement of mechanism constituting the shedding
motion for looms substantially as herein described and shown in the drawings.
2nd In a shedding motion for looms the combination with the jack levers and
their horns of the draw bars with their inclined projections, the projections being

page_text: arranged to act on the horns in the manner herein described and shown in the
drawings for the purpose of moving and locking the heddles.
3rd In a shedding motion for looms the combination of the double hooked catch
levers pivoted to the draw bars and of a pair of draw knives working to and fro in
the same plane simultaneously but in opposite directions substantially as described
and shown in the drawings.
4th In a shedding motion for looms the combination of mechanism consisting of
the oval gear crosshead cross links and draw knives substantially as herein
described and shown in the drawings.