IMPROVE- MENTS IN DOBBIES OR SHEDDING MOTIONS FOR LOOMS
Year: 1884

page_text: We RICHARD Lowcock of Greengate Mills Salford in the County of Lancaster
Manufacturer and WILLIAM SKERRATT of 8 Gordon Street Lower Broughton in the
same County Mechanic do hereby declare the nature of our Invention for IMPROVE-
MENTS IN DOBBIES OR SHEDDING MOTIONS FOR LOOMS to be as follows:-
The object of this invention is to produce a double lift machine for figured or
fancy weaving.
In carrying out our invention instead of the usual eccentries which only give
single lifts I apply a S link to open and close the knives or levers simultaneously
for operating the jacks which raise and lower the heddles This S link being
mounted on a fixed centre and provided with slots which embrace bowls upon the
sides of the knives and thus impart motion to such knives as the S link is oscillated
on its axis.
An arm branching from this S link is connected by a rod to a lever carrying a
bowl working in a cam groove so arranged and "timed" as to give a double lift to
such lever for every revolution of the cam. This cam forms a feature in my
invention and consists of a groove somewhat in the form of the figure 8 and is so
designed to give the double lift required. This invention further relates to the
dispensing with springs and to a novel application of mechanism for causing the
hooks on the slide rods to catch the top or bottom knife as required by the peg or
pattern chain and consists in the application to each hook and slide rod of a
weighted double armed lever which is arranged to fall down on to the hook and to
cause the same to catch or be placed upon the top knife when the three armed lever
is raised by the peg on the pattern chain coming in contact with it.
It will be readily understood that except when the pegs on the pattern chain
come in contact with their respective three armed levers the hooks are constantly
pressed by the latter on to the bottom knife.
In this manner I not only dispense with all springs but I secure that no breakage
of the mechanism shall take place owing to the hooks catching the same in either
rising or falling.

page_text: We RICHARD LOWCOCK, of Greengate Mills, Salford, in the county of Lancaster,
Manufacturer, and WILLIAM SKERRATT, of 8 Gordon Street, Lower Broughton, in
the same county Mechanic, do hereby declare the nature of our said invention of
"IMPROVEMENTS IN DOBBIES OR SHEDDING MOTIONS FOR LOOMS," and in what
manner the same is to be performed to be particularly described and ascertained
in and by the following statement :—
The object of this invention is to produce a double lift machine for figured or
fancy weaving and will be best understood by reference to the accompanying
drawing, upon which Fig 1 represents a back view of our improved dobbie or
shedding motion and Fig 2 an end or side sectional view of Fig 1 on the line a-b.
In carrying out our invention instead of the usual eccentries which only give
single lifts we apply a S link A to open and close the knives or levers B and B¹
simultaneously for operating the slide rods and jacks which raise and lower the
heddles. This S link being mounted on a fixed centre C and provided with slots B'
which embrace bowls B³ upon the sides of the knives and thus impart motion to
such knives as the S link is oscillated on its axis. An arm A¹ branching from this
S link is connected by a rod A² to a lever D carrying a bowl D¹ working in a cam
groove so arranged and "timed" as to give a double lift to such lever and hence
to the S link and knives for every revolution of the cam E-This cam E forms a
feature in our invention and consists of a groove E¹ somewhat in the form of the
figure 8 as illustrated and is so designed to give the double lift required.
It will be apparent that for every revolution of this cam E that the knives B
and B are operated twice and hence the necessary double shedding motion is
obtained.
This invention further relates to the dispensing with springs and to a novel
application of mechanism for causing the hooks F on the slide rods G which operate
the jacks and heddles to catch the top knife B or bottom knife B¹ as required by
the peg or pattern chain H carried by the chain roller H in the ordinary manner
and operated at the required speed by the star wheel H2 and intermittent wheel H*.
This part of our invention consists in the application to each hook F and slide
rod G of an arm I mounted upon the rod I connected by a slot I² to a pin on the
upper arm J¹ of a three armed lever J carried upon the rod J2. This upper arm J¹
is arranged to advance the arm I towards the hook F and to cause the same to
catch or be placed upon the top knife B when the three armed lever J is raised by
the peg on the pattern chain H coming in contact with it as seen more clearly in
Fig 2.
The action of this improved, dobbie or shedding motion is as follows:-
Each slide rod being fitted with its own three armed lever as aforesaid
it will be readily understood that except when the pegs on the pattern chain H
come in contact with their respective three armed levers J the hooks F are constantly
pressed by the weight of the latter resting upon them on to the bottom knife B¹
and thus the heddles appertaining to such slide rods are raised whilst those heddles
the hooks of which are pressed on to the upper knife by the pegs on the pattern
chain as aforesaid are lowered,

page_text: In this manner we not only dispense with all springs but we secure that no
breakage of the mechanism shall take place owing to the hooks catching the same
in either rising or falling.
We wish it to be understood that we make no claim to slide rods and hooks for
operating the jacks and heddles nor to the application of a peg or pattern chain for
operating the hooks in a dobbie or shedding motion as the same are well known.
Having now particularly described and ascertained the nature of our said
invention, and in what manner the same is to be performed, we declare that what
we claim as our improvements in dobbies or shedding motions for looms are as
follows:-
1st The use and application of the double lift cam and S link for so operating
the knives as to obtain a double lift substantially as and for the purposes herein-
before described and illustrated on the accompanying drawing.
2nd The employment of an arm in conjunction with three armed levers for
operating the hooks upon the slide rods and whereby springs are dispensed with
substantially as herein before described and illustrated on the accompanying
drawing.