Improvements in Shedding Motions of Looms for Weaving.
Year: 1889

page_text: Date of Application, 18th Jan., 1889
Complete Specification Left, 18th Oct., 1889-Accepted, 18th Jan., 1890
PROVISIONAL SPECIFICATION.
Improvements in Shedding Motions of Looms for Weaving.
We, FRANK LEEMING, Machine Maker, and ROBERT WILKINSON, Foreman, both
of North Vale Works, Bradford, in the County of York, do hereby declare the nature
of this invention to be as follows:-
This invention relates to improvements in apparatus for purpose aforesaid, and the
object being to dispense with many of the complicated parts heretofore used, and at
the same time to ensure a direct action, whether the improvements are applied to
what is known as the "positive" or the "negative" shedding motion.
According to this our said invention, on a cross bar of the dobby which serves as a
fulcrum are a series of heavy ended levers, the heavy ends of which rest on the "pegs
or "lags" of the pattern mechanism, the other end of each lever is formed into two
curved fingers, one below the other, the top one of which operates the top "knife,"
and the lower one the bottom knife. These "knives" are actuated as ordinary by the
draw bars, and their ends are secured by a pin to two racks, both of which are geared
in a toothed wheel on the end of a rod, or bar, the other end being fixed to the
shedding lever. Stop pieces are provided to prevent the racks overrunning.
The action is as follows:-When there is no peg under the heavy ended levers,
they fall, consequently their opposite ends rise, and so raise the knives, that their
holding notches may come in contact with the draw bars, and if one knife is
drawn forward, the rack operates the toothed wheel, connecting rod, or bar, and
shedding lever, and the shod is open.
A spring attached to the shedding lever draws back the rack, knife, and con-
nections, when released from the draw bar, and if, say, the bottom knife, and rack
are drawn forward, at the time the top knife and rack are returning, the shed
will still remain " open" as the forward movement of one rack, and the backward
movement of the other, acting on the toothed wheel being equal, the centre of
the toothed wheel, and therefore the connecting rod, or bar will remain stationary
This motion will continue so long as there is no peg in the lattice, under the
heavy ended lever, when a peg raises the latter its opposite ends are clear of
the knives, which fall below and their notches clear of the draw bars, so that
the shed is not changed until a change in the indicating mechanisın.
One end of the racks are extended so as to allow just sufficient space, between
the end, and the holding notch of the knife, that the draw bar may enter the
notch, and at the backward movement, the draw bar will, by coming in contact
with the end of the rack, force the latter back against its top piece, and the
motion is "positive," and so dispensing with the requirement of a spring.
A stop piece is provided at the opposite end of the knives, to the racks, into
which the knives fall when not held by the draw bars, when acted upon by the
draw bars the knives rest on the top of the stop piece which forms a bed on
which they are drawn.
Dated this 17th day of January 1889.

page_text: COMPLETE SPECIFICATION.
Improvements in Shedding Motions of Looms for Weaving.
We FRANK LEEMING, Machine Maker, and ROBERT WILKINSON, Foreman both
of North Vale Works, Bradford, in the County of York, do hereby declare the
nature of this invention and in what manner the same is to he performed, to be
particularly described and ascertained in and by the following statement :-
"
This invention relates to improvements in apparatus for purpose aforesaid, the
object being to dispense with many of the complicated parts heretofore used, and
at the same time to ensure a direct action, whether the improvements are applied
to what is known as the " positive or the negative" shedding motion.
According to this our said invention on a cross bar of the dobby which serves
as a fulcrum are series of heavy ended levers, the heavy ends of which rest on
the "
pegs
or lags of the pattern mechanism, the other end of each lever is
formed into one or two curved fingers, one below the other, the top one of which
operates the top catch or draw hook, and the lower one the bottom catch. These
catches or hooks are actuated as ordinary by the draw bars and their ends are
secured by a pin to two racks both of which racks are geared in a toothed wheel
on the end of a rod, or bar the other end being fixed to the shedding lever.
Stop pieces are provided to prevent the racks overrunning.
Stop pieces are provided at the opposite end of the catches to the racks into
which the catches fall when not held by the draw bars and thus preventing the catches
moving When acted upon by the draw hars the catches rest on the top of the stop
pieces which form beds on which they are drawn.
Such being the nature and object of this invention the following is a complete
description of same reference being had to the accompanying drawings in which:-
Fig. 1 is a side elevation of our improved shedding motion as applied to “spring”
dobbies.
"
Fig. 2 is a side elevation of extended rack for use in positive dobbies.
Fig. 3 is a side elevation of the heavy ended and double fingered tumbler lever,
drawn about full size.
Fig. 4 is a side elevation of connecting bar and guide piece.
Fig. 5 is a side elevation of rack with guide bar in section.
Fig. 6 shews the method of attaching the draw hooks to the racks.
Fig. 7 is a side elevation of wheel.
According to this our said invention, on a cross bar 1 of the dobby which serves as
a fulcrum are a series of heavy ended levers 2, the heavy ends 3 of which rest on the
"
pegs or "lags" 4 of the pattern mechanism, the other end of each lover is formed
into one or two curved fingers 5.6 one below the other the top one 5 of which operates
the top catches or draw hooks 7 and the lower one 6, the bottom catches 8. These
catches or hooks 7. 8 are actuated as ordinary by the draw bars 9. 10 and their ends
are secured by a pin 11 to two racks 12. 13 both of which racks 12. 13 are geared in
a toothed wheel 14 on the end of a rod, or bar 15, the other end being fixed to the
shedding lever 16. Stop pieces 17 are provided to prevent the racks 12. 13 over-
running.
The action is as follows:-When there is no peg 4 ander. the heavy ended levers 2
their heavy ends fall consequently their opposite ends and fingers 5. 6, rise and so
raise the catches or draw hooks 7. 8 that their holding notches 18 may come in con-
tact with the draw bars 9. 10 and if one catch or draw hook (say 7 in Fig. 1) is drawn
forward, the rack 12 operates the toothed wheel 14, connecting rod, or bar 15, and
shedding lever 16, and the shed is open.
A spring as ordinary attached to the shedding lever draws back the rack 12
catch 7 and connections 15 when released from the draw bar 9 and if, say the bottom
catch 8, and rack 13 are drawn forward, at the time the top catch 7 and rack 12 are
returning, the shed will still remain "open" as the forward movement of one rack 13
and the backward movement of the other 12 acting on the toothed wheel 14 being

page_text: equal, the centre of the toothed wheel 14 and therefore the connecting rod or bar 15
will remain stationary. This motion will continue so long as there is no peg 4 in the
lattice, under the heavy ended levers 2 when a peg 4 raises the latter levers their
opposite ends 5. 6 are clear of the catches or draw hooks 7. 8 which fall below their
notches 18 clear of the draw bars 9. 10, so that the shed is not changed until a change
in the indicating mechanism.
In positive dobbies we use a separate tumbler lever 2 for the top 7. and one for the
bottom draw hooks one end of the racks 12. 13 are extended (see Fig. 2) so as to
allow just sufficient space between the end 19 and the holding notch 18 of the catch
or draw hook 8 that the draw har 10 may enter the notch 18, and at the backward
movement, the draw bar 10 will, by coming in contact with the end 19 of the rack 13,
force the latter back against its stop piece 17 and the motion is "positive" and so
dispensing with the requirements of a spring as in spring or negative" dobbies.
Stop pieces 20 are provided at the opposite end of the catches 7.8 to the racks 12. 13,
into which the catches 7.8 fall (see Fig. 2) when not held by the draw bars 9. 10 and
thus prevent the catches 7. 8 moving. When acted upon by the draw bars 9. 10.
the catches 7. 8 rest on the top of the stop pieces 20 which form beds on which they
are drawn (see Fig. 1).
"
By the use of the above described appliances we obtain a direct pull from the draw
bars to the shedding levers and the catches, racks connecting bar move in a parallel
line whatever amount of motion is given them, the guide bars 21 effectually preventing
the racks 12. 13. from leaving the parallel position in relation to each other.
The catches 7. 8 are attached to the racks 12. 13 by a pin 11 (see Fig. 6) which is
formed circular, with the top and bottom edges cut away so that the pin 11 is
narrower longitudinally than it is vertically and by turning the catches 7. 8 they can
be withdrawn from the holding pins 11 but when in their working positions cannot
be detached. The broad part 21* of the connecting bar 15 (see Fig. 4) serves
as a guide and steadying piece between one pair of racks 12. 13 and wheel 14 and
another.
Having now particularly described and ascertained the nature and object of our
invention and in what manner the same as to be performed we declare that what
we claim is.
1). The improved construction of heavy ended tumbler lever having the curved
finger 5. 6. as and for the purpose herein described and illustrated by Fig. 3 of the
accompanying drawings.
2). In spring dobbies the tumbler lever 2 catches or draw hooks 7. 8. racks 12. 13
wheel 14 and and connecting bars 15 all in combination as and for the purpose herein
set forth and as illustrated by Fig. 1 of the accompanying drawings.
3). In positive dobbies the tumbler levers 2. 2 catches or draw hooks 7. 8 extended
racks 12. 13 draw bars 9. 10 stop wheel 14 and connecting bar 15 pieces 20 all in
combination as and for the purpose herein described and substantially as illustrated by
Figs. 1. and 2 of the accompanying drawings.
4). The improved construction of joint or attachment between the draw hooks 7. &
nd racks 12. 13. as herein described and as illustrated by Fig. 6 of the accom-
anying drawings.
Dated this 16th day of Andalio 1000