IMPROVEMENTS IN LOOMS FOR WEAVING
Year: 1881

page_text: PROVISIONAL SPECIFICATION left by the said Theophilus Hanson at the
Office of the Commissioners of Patents on the 4th March 1881.
THEOPHILUS HANSON, of Bradford, in the County of York, Mechanic.
"IMPROVEMENTS IN LOOMS FOR WEAVING."
This Invention relates to improved appliances to be employed in connection with
mechanism for effecting a positive motion to the heald staves in their downward as
well as in their upward movement; that is to say, a "positive dobby," and the
apparatus is so constructed as to raise and depress any one or more of the heald
staves and healds required, and to securely lock and hold such staves and healds in
such position until the pattern being woven requires a change.
Mechanism for the purpose aforesaid comprises draw bars and jacks having the.
usual cords or other connections with the heald staves. The knives according to
one arrangement work in pairs and are connected to one end of a forked lever
having its fulcrum about midway its length. At the extremity of each prong or leg
of the said forked lever is an antifriction bowl. The bowls act alternately (as the
forked lever is operated by the knives) upon the upper jacks levers, so as to depress
and raise the latter and healds as required. The upper jack levers are provided
with curved or waved races in which the antifriction bowls act, and the races are
so constructed that when one or other of the antifriction bowls has depressed its
end of the jack lever the antifriction bowl enters a hollow or curved end of the
race nearest the fulcrum of forked lever, forming a lock, and so bolding securely the
healds until a change in the pattern requires the healds to be moved, the knives
moving as described in pairs. In order to prevent the knife not required to be used
for the time being from engaging with the draw bar, duplicate pegs or cards, hole
and blank are employed; the recesses for the draw bars are made in the under or
lower edges of the knives. The eccentric for operating the peg a card mechanism
is constructed so as to "bold up" and afford the required dwell whilst the knife
not in operation passes its draw bar. According to another arrangement I employ.
instead of the knives in pairs a single knife, having recesses for the draw bars in
its upper and lower edges, the peg or card mechanism acting upon the said knife
so as to bring its upper or lower recess into position for the upper or lower draw
bar, according to the pattern being woven, there being a grate and a lug on the
knife so as to prevent the knife falling off the top draw bar.

page_text: admits of the notches K' therein being made wide enough only for the reception
of the draw bars J, J, (provision for play being unnecessary) so that the levers
N and V and the knives K are all held steadily and firmly in position until a
change is necessary. At Z, Z, are the cords connecting the upper and lower
heald staves with the levers V, V, and the lower jack levers Z', Z¹.
Having thus fully described the nature and particulars of this my said
Invention, together with the manner in which the same is to be performed
or carried into practical effect, I would have it understood that I disclaim "what
is described in Leeming's Patent, No. 2366, A.D. 1876." What I do claim is,-
The forked lever N and the lever V in combination, and as herein described
and illustrated by Drawings annexed.
In witness whereof, I, the said Theophilus Hanson, have hereunto set my
hand and seal, this Seventh day of March, in the year of our Lord One
thousand eight hundred and eighty two.
THEOPHILUS HANSON. (L.S.)