IMPROVEMENTS IN POWER LOOMS
Year: 1862

page_text: LETTERS PATENT to David Abercrombie, Mechanic, in the Employment
of Messieurs Alexander Paul and Company, of Glasgow, in the County
of Lanark, North Britain, for the Invention of "IMPROVEMENTS IN
POWER LOOMS."
Sealed the 19th September 1862, and dated the 22nd March 1862.
PROVISIONAL SPECIFICATION left by the said David Abercrombie,
at the Office of the Commissioners of Patents, with his Petition, on
the 22nd March 1862.
I, DAVID ABERCROMBIE, Mechanic, in the Employment of Messieurs
Alexander Paul and Company, of Glasgow, in the County of Lanark, North
Britain, do hereby declare the nature of the said Invention of "IMPROVEMENTS
IN POWER LOOMS," to be as follows, that is to say :-
This Invention relates to improvements in power looms for weaving fabrics,
such as "tarletans," having what are termed "cords" formed, as far as,
regards the weft, by throwing two or more shots in the same shed. Hitherto.
in looms arranged for weaving such goods with ordinary shedding movements.
and with shifting shuttle boxes on one side only, the contrivances used for.
keeping the shed open whilst the successive "cord" shots are thrown have
been such as to require three or other odd number of shots to be laid in the
shed, and as only two or other even number of "cord" shots can be thrown at
once, the odd shot has been made with the ordinary or ground weft, or with
that which the pattern requires to follow or precede the "cord" shots. By the
present Invention, however, the odd shot in the "cord "shed is avoided, and
the shed is kept open when required by very simple means, the contrivance
being also applicable to looms having shifting shuttle boxes on both sides, or
with arrangements for varying the order of picking, in which application the

page_text: improved contrivances may be made to keep a shed, open an odd or an even
number of times as may be required.
In a loom provided with one modification of the improved contrivances the
cams or tappets for actuating the shedding levers or treadles are carried by the
low or second-motion shaft, as usual, but instead of being fixed thereon, they
are formed or fixed upon a tubular boss mounted loosely on the shaft. During
the plain weaving action the tappets are carried round in the ordinary way by
means of a clutch, but when the shed has to remain open more than one shot,
the clutch is thrown out of gear at the moment when one of the tappets has
depressed its treadle, and the tappet and treadle remain down, and the shed
remains open as long as the clutch remains out of gear. The clutch is shaped
so as to gear in either of two opposite positions, and it can be thrown into
gear so as to cause the tappets to resume their action after a half turn, or
after a whole turn of the shaft, or after any required number of half turns.
Thus if the motion of the tappets is arrested for one half turn, the shed will
remain open whilst the "cord" shuttle passes across the loom and back again
and lays in two shots, immediately after which the changing of the shed will
be resumed, and the next shot will be laid in a new shed. Various con-
trivances, actuated by or dependent upon the pattern mechanism, may be used
for shifting the clutch at the proper periods. When the shed is to be kept
open for two shots only, the following simple arrangements may be adopted:―
A bell-crank lever is employed to shift the clutch acting upon it by means of
a forked end applied to a groove formed round the boss at the clutch. The
other end of the lever has jointed to it a hooked link, which when the clutch
is to be shifted out of gear is, by the pattern mechanism or by the shifting
shuttle box 'details, brought into the way of a lever acted upon by a tappet or
arm fixed on the low shaft; and as this arm comes round at the proper
period the bell-crank lever is by these means made to shift the clutch out of
gear. At the next half turn the clutch returns into gear by the action of a
spring, and as long as the clutch is to remain in gear a spring keeps the
hooked link clear of the lever, which would otherwise shift it.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed,
by the said David Abercrombie in the Great Seal Patent Office on the:
22nd September 1862.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, DAVID'S
ABERCROMBIE, Mechanic, in the Employment of Messieurs Alexander Paul'

page_text: and Company, of Glasgow, in the County of Lanark, North Britain, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-second day of March, in the year of our Lord
One thousand eight hundred and sixty-two, in the twenty-fifth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said David Abercrombie, Her special licence that I, the said David Aber-
crombie; my executors, administrators, and assigns, or such others as I, the
said David Abercrombie, my executors, administrators, and assigns, should
at any time agree with, and no others, from time to time and at all times
thereafter during the term therein expressed, should and lawfully might make,
use, exercise, and vend, within the United Kingdom of Great Britain and
Ireland, the Channel Islands, and Isle of Man, an Invention for "IMPROVE,
MENTS IN POWER Looms," upon the condition, amongst others, that I, the said
David Abercrombie, my executors or administrators, by an instrument in
writing under my, or their, or one of their hands and seals, should par-
ticularly describe and ascertain the nature of the said Invention, and in what
manner the same was to be performed, and cause the same to be filed in the
Great Seal Patent Office within six calendar months next and immediately.
after the date of the said Letters Patent.
NOW KNOW YE, that I, the said David Abercrombie, do hereby declare
the nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement in writing, reference being had to the accompanying Drawings, and
to the letters and figures marked thereon, that is to say :-
My said Invention relates to improvements in power looms for weaving
fabrics, such as "tarletans," having what are termed "cords," formed as far as
regards the weft by throwing two or more shots in the same shed. Hitherto
in looms arranged for weaving such goods with ordinary shedding movements
and with shifting shuttle boxes on one side only, the contrivances used for
keeping the shed open whilst the successive "cord" shots are thrown have
been such as to require three or other odd number of shots to be laid in the
shed, and as only two or other even number of "cord" shots be thrown at
once, the odd shot has been made with the ordinary or ground weft, or with
that which the pattern requires to follow or precede the "cord" shots. By
the present Invention, however, the odd shot in the "cord" shed is avoided,
and the shed is kept open when required by very simple means, the con-
trivances being also applicable to looms having shifting shuttle boxes on both
sides, or with arrangements for varying the order of picking, in which applica-

page_text: tion the improved contrivances may be made to keep a shed open an odd or
an even number of times, as may be required.
And in order that my said Invention, and the manner of performing the
same, may be properly understood, I have hereunto appended a Sheet of
explanatory Drawings, to be herein-after referred to in particularly describing
my improvements.
Figures 1 and 2 are elevations, at right angles to each other, of a modifica
tion of the improved contrivances, and Figure 3 is a plan, whilst Figures 4
and 5 represent detached parts, and are herein-after more particularly referred
to. The same reference letters are used to mark the same parts in all the
Figures.
In the modification represented the cams or tappets A of the ordinary kind
for actuating the shedding levers or treadles B, are carried by the low or
second-motion shaft C, as usual, but instead of being fixed thereon they are
formed or fixed on a tubular boss D, mounted loosely on the shaft C, between
a collar E and a piece F, both fixed on the shaft. During the plain weaving
action the tappets A are carried round in the ordinary way by means of a
clutch G, but when the shed has to remain open more than one shot, the
clutch G is thrown out of gear at the moment when one of the tappets A has
depressed its treadle B, and the tappet and treadle remain down, and the shed
remains open as long as the clutch remains out of gear. In the Drawing the
parts are shown in the position suitable for the clutch being moved, but the
clutch is shown in gear, with the parts as they are when acting in the ordinary
way of plain weaving. The clutch G, shown detached in Figure 4, is formed
with two diametrically opposite projections which slide in guide openings in
the piece F, fixed on the shaft A, and each projection fits' or gears in either of
two opposite openings in a disc H, formed or fixed on the tappet boss D, and
shown separately in Figure 5; thus, when the clutch is out of gear it can be
thrown into gear again so as to cause the tappets to resume their action
after an interval of half a turn, or after one of a whole turn, or after any
required number of half turns. As the low shaft makes a half turn for
every pick, it follows that if the motion of the tappets is arrested for one
half turn, the shed will remain open whilst the "cord" shuttle passes across
the loom and back again, and lays in two shots, immediately after which
the changing of the shed will be resumed, and the next shot-will be laid in a
new shed.
Various contrivances actuated by or dependent on the pattern mechanism
may be used for shifting the clutch at the proper periods. When the shed is
to be kept open for two shots only, the simple arrangements represented in

page_text: the Drawing may be adopted. A bell-crank lever I, J, is employed to shift
the clutch G acting upon it by means of a forked end I, applied to a groove
formed round the boss of the clutch. The other end J of the lever has jointed to
it a hooked link or arm K, which when the clutch G is to be shifted out of gear
is, by the pattern mechanism or the shifting shuttle box details, and through the
intervention of a cord L,.brought into the way of a lever M, jointed upon the
loom framing N. This lever M is lifted at each turn of the low shaft C by a
tappet or wiper P fast on that shaft, and when the hooked link K is drawn
over in the way of the lever M, the wiper P coming round at the proper
period, causes the lever M to lift the link K, and through it to turn the
lever J, I, thereby throwing the clutch G out of gear. At the next half turn
the clutch G returns into gear by the action of a spring Q applied to the
lever I, J, and the pattern cord L being released, a spring R keeps the link K
out of the way of the lever M, as long as the clutch is to remain in gear. To
keep the tappet piece D, A, H, steady whilst the clutch G is not in gear with
it, there is formed or fixed on the arm. I of the bell-crank lever a projecting
piece S, which when the lever moves the clutch G out of gear, at the same
time elevates a lever T jointed to the framing, and causes it to bear against
the bottom of the disc H, a spring U on the lever T assisting to prevent the
disc and tappets from turning.
Having thus particularly described my said Invention, and the manner in
which the same is or may be performed, I have to state that I do not restrict
myself to the precise details herein described or delineated, but that what
I believe to be novel and original, and claim as the Invention secured to me
by the herein-before in part recited Letters Patent, is the actuating of the
treadles or shedding levers of a power loom by cams or tappets driven by
means of a clutch, which can be kept out of gear during one or more picks,
and so cause a shed to be kept unchanged during two or more picks, substan-
tially as herein-before described.
In witness whereof, I, the said David Abercrombie, have hereunto set
my hand and seal, this Nineteenth day of September, in the year of
our Lord One thousand eight hundred and sixty-two.
DAVID ABERCROMBIE. (L.s.)