Improvements in Double Lift Dobbies for Weaving Leno Cloth.
Year: 1893

page_text: Date of Application, 10th June, 1893
Complete Specification Left, 10th Mar., 1894-Accepted, 14th Apr., 1894
PROVISIONAL SPECIFICATION.
Improvements in Double Lift Dobbies for Weaving Leno Cloth.
We, BENJAMIN LUPTON, and ROBERT HENRY PLACE of Sandy Gate,
Burnley, in the County of Lancaster, Loom Dobby Makers, do hereby declare the
nature of this invention to be as follows:-
This invention relates to looms for weaving leno cloth, and our improvements
have reference to means to be employed for combining a leno weaving motion with
a double lift dobby. It is well known that doupe healds are employed in weaving
leno cloth and that one section of warp called the standard or idle ends " neither
rises nor falls, but another section of warp called the "crossing ends" is made to rise
and move laterally to cross over the standard ends, then to descend and move
laterally again under the standard ends, thus crossing the warp after the manner of
knitting. This constant up and down lift of the crossing ends causes considerable
friction and chafes the warp and also the healds whereby there is considerable
wear and tear. The object of our invention is to combine a leno weaving motion.
with a double lift dobby and this we effect by raising the standard ends about half
way to meet the crossing ends so that the friction on the warp and healds is con-
siderably reduced.
To do this we employ a double lift dobby such as that described in Specification
No. 1073988
According to our present invention the oscillating lever at the top of the dobby
carries a bowl which as the lever oscillates causes the bowl to act upon one end of
a bell crank form of lever, making the foot thereon to press on one of the jack
levers which causes the standard ends to rise in the shed to meet the crossing
ends.
The feet of the bell crank levers are removable so that they can be removed
when not required. Two of these bell crank levers may be employed at each end
of the dobby and they may be connected together by a cross bar to which feet
may be attached when required for the purpose of acting upon the jack levers, as
the bell crank levers are oscillated. The upper ends of the bell crank levers are
suitably bent or cammed so that when the standard ends have been raised, the
heald operating them is caused to dwell, to give time for the crossing ends to
perform their function of descending and passing underneath the standard ends,
but at a proper time the heald descends quickly so as to assist in forming a complete
and open shed.
Dated this 9th day of June 1893.
TASKER & CROSSLEY,
Halifax, Agents.
COMPLETE SPECIFICATION.
"
Improvements in Double Lift Dobbies for Weaving Leno Cloth..
We, BENJAMIN LUPTON, and ROBERT HENRY PLACE, of Sandy Gate,
Burnley, in the County of Lancaster, Loom Dobby Makers, 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 looms for weaving leno cloth, and our improvements
have reference to means to be employed for combining a leno weaving motion with
a double lift dobby.

page_text: In order that our invention may be more clearly understood, we will make
reference to the accompanying sheets of drawings illustrative thereof, wherein
Fig. 1 is elevation of a double lift dobby as shewn and described in prior Letters
In
Patent granted to the present inventors No. 1039 of 1888 and 16,342 of 1892.
this form of dobby the jack levers A raise the heald shafts B by means of the
hanging arms C which have an upward and downward motion imparted to them by
the lever D. These hanging arms do not act upon the jack levers at each
of their downward movements but only when they are selected by the pegs E
on the peg lags F.
Our present invention consists in combining a leno weaving motion with
a double lift dobby, these combined parts being shewn in Fig. 1 where G
is a bell crank form of lever capable of oscillating slightly upon the fulcrum H
on the bracket I secured to the framework of the dobby. This bell crank
form of lever G is operated by a bowl J at one end of the said oscillating
Jever G, which bowl rides over the inclined surfaces on the upper end thereof,
whereby the said lever has an oscillating motion given to it for purposes herein-
after described. On the foot of the bell crank lever is a bowl K which presses
upon a lever L pivoted at M to the bracket I to which the said bell crauk lever is
also pivoted. There is a lever L on each side of the dobby and to them is bolted
a cross bar N to which the detachable feet O are secured as shewn in front
elevation Fig. 2. The feet O press upon those jack levers A' to which the
healds are connected which operate the "standard warp" whereby the said warp
is raised in the shed to meet the "crossing end" warp threads so that the friction
and chafing of the warp upon the healds is reduced. The feet O are made in three
or more sizes to operate upon one jack le ver or upon two, three, or more adjoining
jack levers and the said feet O are notched as shewn in the drawings so as to more
surely engage upon the upper edges of the jack levers A!.
Fig. 3 shews a cross section of the bar N and one of the feet O.
The bell crank lever G in Fig. 1 is shewn as having been forced in the direction
of the arrow P and raised the healds carrying the "standard warp" half way into
the "shed." The dotted lines at R in the heald shafts shew their position at full
shed.
In Fig. 4 we have shewn that the feet O may be attached directly to the lower
end of the bell crank lever G; in this case we have dispensed with the lever
arms L. From a to b in Fig. 4 on bell crank lever G is the portion where the
healds are caused to dwell to give time for the "crossing ends to perform their
function of descending and passing underneath the "standard warp."
Fig. 5 is a diagram shewing the standard ends S and heald shafts S' to be raised
half way into the "shed to meet the crossing warp ends T attached to heald
shafts T. The doupe healds are shewn at U.
Having now particularly described and ascertained the nature of our said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim, is :-
Firstly. In double lift dobbies for weaving leno cloth, the combination therewith
of bell crank lever G lever arm L and the feet O for operating the "standard
warp substantially as shewn in Fig. 1.
"
Secondly. In double lift dobbies for weaving leno cloth, the combination there-
with of bell crank lever G and feet O for operating the "standard warp
substantially as shewn in Fig. 4.
1
2004
TASKER & CROSSLEY,
Halifax, Agents.