IMPROVE- MENTS IN LOOMS
Year: 1883

page_text: PROVISIONAL SPECIFICATION left by the said Thomas Crabtree at the
Office of the Commissioners of Patents on the 17th August 1883.
THOMAS CRABTREE of Shipley in the County of York, Loom Maker IMPROVE-
MENTS IN LOOMS
This Invention relates to certain improvements in the method of the treading of
healds and warp threads for weaving, whereby greater certainty in the action of
the parts is ensured than is the case with machines hitherto in use.
In order to accomplish my object I construct an ordinary framework and fit the
same to the loom in the ordinary position. In this framework I mount a shaft and
centre upon the same any required numbers of L levers. The upper end of each
Llever is connected with suitable draw knives: the lower end of each L lever is
forked, and two bowls are centred within the fork. Between the two bowls I
introduce the upper end of a lever which lifts the healds directly, or over pulleys:
but in either case, without the aid of weights or springs. The upper end of this
lever is of such configuration that the locking of the Healds in proper tension,
top and bottom, is accomplished by the motion of the lower end of L lever up
or down.
In case of making the motion positive with the same advantages as to the
locking of the healds top and bottom by the motion itself, I use a lever for the
purpose of lifting the bealds shaped 1, the upper portion of which has the same
configuration as the lever before mentioned which operates the healds over pulleys.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Thomas Crabtree in the Patent Office on the 15th February
1884.
THOMAS CRABTREE of Shipley in the county of York Loom Maker "IMPROVE-
MENTS IN LOOMS
This invention relates to certain improvements in the method of the treading of
the healds and warp threads in looms for weaving, whereby greater certainty in
the action of the parts is ensured, than is the case with machines as hitherto
constructed; and consists in mounting to the framework of the apparatus a series
of bell crank levers, which are in direct connection with the corresponding series of
draw knives and levers of the configeration to impart to the healds the desired
motion. In order that my invention may be more clearly understood, I havo
appended drawings illustrative thereof, in which Figure 1 represents the sectional
side elovation of a machine fitted up according to my invention, one side frame
plate, being removed in order to more effectually show the working parts.
The apparatus is fixed to the loom in the ordinary working position and the
connections between my improved levers and the heald staves, are of the ordinary
description. The side frame plate is indicated by the letter A, in which are formed
the slots B and B' in these slots slide, the reciprocating draw bars C and C¹ which
are connected by the bars D to the oscillating lovers E. One of these lovers is
connected by rod R to an eccentric or crank arm mounted on the bottom shaft of
the loom, by which I am enabled to obtain what is known as a double lift positivo
motion.
Between the side frame plates is secured a grate F and a cross bar G which
serve as guides for the draw knives H, and mounted on stationary shaft J are n
number of bell crank levers K each of which is in connection with a draw knife
and one of my improved levers M, the bottom part of each lever at M is connected
to the healds in tlie usual manner.
The lag cylinder N is of the ordinary construction, and actuated in the usual
manner, and when any of the pins P in the lags N₁ raise the corresponding
levers L; the needles S, and the draw knives H will lower until the bottom
recess in cach draw knife thus lowered is in contact with the bottom reciprocating
draw bar C which will give motion to the said draw knives, and cause the boll
cranks K and levers M in connection therewith to oscillate and actuate the healds.
Those draw knives which have not been lowered will be actuated by the top draw
bar C, in the opposite direction, and thus form the "shed" for the shuttle.
When the bell cranks are working on the portions of the levers, as shown by
detail Figure 2 and 3 at M² and M³, the healds are then stationary at the highest
and lowest portions of their movements, thus by the configuration given to the
levers at M and M³ the healds keep the shed open for a longer period, than is
accomplished by machines of the ordinary construction, thereby giving more time
For tlie shuttle to pass through the "shed."
Figure 4 represents a 1 lover with the upper portion constructed according to
my invention, and which is mounted in the machine in the manner as before
described in reference to levers M.
Having now described my invention, and in what manner I carry the same into
effect, I hereby declare that I make no claim to the use of boll crank levers acting
in combination with other levers by means of pins or bowls working in slots of the

page_text: latter so shaped as to provide for the necessary movements and dwell, as this
arrangement has been proposed, but I claim :-
The combination of the slotted bell crank levers H, with the levers M having
arms engaged in the slots of the levers H, and so shaped as to provide for the
necessary movements and dwell, substantially as, and for the purpose, herein set
forth.
In witness whereof I the said Thomas Crabtree have hereunto set my hand and
seal this fifteenth day of February in the year of our Lord one thousand eight
hundred and eighty four.
THOMAS CRABTREE (L.S.)