Improvements in Dobbie Looms.
Year: 1893

page_text: Date of Application, 27th Apr., 1893
Complete Specification Left, 29th Jan., 1894-Accepted, 3rd Mar., 1894
PROVISIONAL SPECIFICATION.
Improvements in Dobbie Looms.
1, JAMES MUIR of 117 Greenhead Street, Glasgow, Power Loom Manufacturer,
do hereby declare the nature of this invention to be as follows:-
This invention relates to dobbie looms and has for its object to obtain two shots.
to each card in the present single lift positive or non-positive dobbies..
:
In carrying out my invention I fit on the wyper shaft a cam wbich bears against
a roller or equivalent carried on one end of a connecting rod. The other end of
the connecting rod is pinned to a bell-crank or other suitable lever and this lever is
connected by means of a link or equivalent to a moveable needle-board. The.
arrangement is such that the movements of the cam cause, by means of the:
connecting rod and bell-crank, the needle-board to reciprocate. The cam movement
causes the needles to take the first row of holes in the card for the first shot, and
the other row of holes in the second shot.
The card cylinder is turned by means of a pawl and ratchet or equivalent catch
operated from the needle-board.
:
A 1900
H. D. FITZPATRICK,
70, Wellington Street, Glasgow, Agent.
Improvements in Dowvid
1, JAMES MUIR, of 117 Greenhead Street, Glasgow, Power Loom Manufacturer;
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 dobbie looms and has for its object to obtain two
or more shots to each card in the present single lift positive or non positive
dobbies.
j
In carrying out my invention under one arrangement I fit on the wyper shaft or.
an auxiliary shaft a cam which bears against a roller or equivalent carried on one:
end of a connecting rod. The other end of the connecting rod is pinned to a bell-
crank or other suitable lever and this lever is connected to a moveable needle-
board. The arrangement is such that the movements of the cam cause, (by means
of the connecting rod and bell-crank or other lever), the needle-board to reciprocate.
The cam movement causes the needles, if there are two shots to each card, to take
the first row of holes in the card for the first shot, and the other row of holes in the
second shot.
And in order that my said invention may be properly understood I have hereunto
appended two explanatory sheets of drawings, whereon,
:
Fig. 1 is a front elevation of the mechanism, as it appears wlien titted on a
"dobbie" loom.
Fig. 2 is a plan of the mechanism.
Fig: 3 is a front elevation of a modified arrangement of the mechanism.
Fig. 4 is a side elevation of the' mechanism Fig. 3.
Fio 4ª is a view of the cam mechanism as it appears when the card drum is

page_text: Figs. 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 and 15 are detail views.
Referring to the drawings whereon the same reference letters wherever repeated
indicate the same or similar parts.
"
A is the loom framing and B; B¹ the frame of the "dobbie mechanism. C is
the usual "Jacquard" drum or cylinder and D the needle board. E is the bottom
shaft of the loom.
-
The mechanism shown in Figs. 1 and 2' is for giving four shots to each card and
it consists of a shaft F which is driven by the gear wheels b, c from the shaft E, and
has a four throw cam a on it, see enlarged view Fig. 5 where 1, 2, 3, 4 are the
steps of the cam and the difference in height of each step, measured radially, corre
sponds to the distances between the rows of holes in the card. The cam bears
against a roller d carried on the lower end of the connecting rod e. The upper end
of this rod is pinned to the short arm of a lever-f,-fulcrumed-to-the top-rail of the
loom, and the long arm of which is connected by a rod 9 to one end of a short
lever h. This lever h is rigidly secured by a set screw or otherwise to a horizontal
-bar which is carried in holes or bearings in the side frames B, B. Pinned or
secured rigidly by set screws to the horizontal bar i are two slotted arms j, j¹ (see
Fig. 2 and enlarged view Fig. 7). The needle board D has secured to it two bent
lugs k, k, the ends of which enter the slots in the arms j, j'. As will be seen the
arrangement is such that there is a complete connection between the cam a and the
needle board D and the latter, which works in guides 1, l' (see Figs. 10 and 11) on
the side frames B, B1, is made to rise and fall at the proper times by the motion of.
said cam.
m is a spring which tends to pull up the long arm of the lever fand thereby
keep the roller d in contact with the surface of the cam a.
On the bar is a cam n having an indentation n' in its periphery (see Fig. 9).
The bent catch or tail part o' of the pawl o (see Fig. 8) works against the surface
of the cam.
This pawl, as shown at Figs. 1 and 2, is pivotted on a stud inserted in
the side frame B¹.
p, Figs. 10 and 11, are the needles in the needle board..
The cylinder or drum C has at each of its four edges a raised part or rib C¹ see
Figs. 1 and 2.
A card with four rows of holes is shown at Fig. 7.
The operation of the mechanism is as follows:-
At each revolution of the gear wheel b, which is driven from the pinion c, the
roller d and rod e are raised and lowered, by the four-throw cam a, working in con-
junction with spring m, four times, and, of course, the intermediate levers and
connections cause the needle board D to be raised and lowered simultaneously the
same number of times. The first throw of the cam causes the needle-board to be
raised to such a height that the needles can enter the upper row of holes in the
card for the time being opposite them. The second throw of the cam causes the
needle-board to rise to just a sufficient height to bring the needles opposite
the second row of holes in the card. The third throw brings the needles opposite the
third row of holes in the card and the fourth throw brings them opposite the fourth
or lowest row. As will be seen in the enlarged view at Fig. 5 the cam.a is made
so as to give the proper motion to the needle board.
The card cylinder C is turned after every fourth shot, i.e. after the needles have
entered the bottom row of holes in the card, by means of the cam n on the
rocking bar i. When the cam a has just finished its last throw the cam n has
been turned almost the full limit of its movement and the tail part o¹ of the
pawl o has entered into the nick or recess n' with the result that the catch on
the end of the pawl o is lowered down into position to turn the card drum at
the completion of its backward oscillation. The turning of the drum is effected
by one of the ribs C₁ striking against or being, caught by the catch on the
pawl o.
In Fig. 1 the drum is represented as just being, caught by the catch
and in Fig. 3 the drum is shown as having been turned a quarter of a revolution
so as to bring the next succeeding card opposite the needles. The spring

page_text: piston to (Fig. 4) retains the drum in position when turned. As long as the
tail part o' of the pawl is out of the recess of the cam n, the pawl is held up
clear of the card drum. In this manner it will be seen that the card drum is
turned after every fourth shot.
H is the usual card drum actuating lever.
The same mechanism is suitable for giving two shots to each card but in this case
the two throw cam G, Fig. 6, is substituted for the four throw cam a. The
pinion e and cam wheel b may be dispensed with and the cam G be fitted on the
shaft E and made to operate the roller d and rod e direct.
In the modified arrangement of the mechanism shown at Figs. 3 and 4, which is
adapted to give four shots to each card on the present single action vertical
dobbies, the rod e is connected to an arm g¹ sccured rigidly to the cross shaft.
or bar 9. This shaft has an arm or crank ŕ on it, to which is pinned a pawl r
The bent end (see Fig. 13) of this pawl catches in the teeth of the ratchet sl
(see Figs. 13 and 14) which is cast in one with the cam t. The cam revolves on a
studs inserted in a bracket arm cast in one with the side frame B.
As will be seen, Fig. 14, the cam is made with eight steps, four on the upper
edge and four similar ones on the lower edge, so as to give four shots at each semi-
revolution.
There is also on the stud sa leather washer t', an iron washer t' and a jam
nut t, for giving the necessary friction to the cam. As will be seen more
particularly at Figs. 13 and 15 the cam has on its back side eight projecting pins
which correspond with the number of teeth in the ratchet s and the number of
steps in the cam. A small roller u on a lever u¹, pivotted at its lower end to the
side frame B, is capable of entering the spaces between the pins and locking the
cam in position at each throw. is a spring which at one end is secured to
the frame B and at its other end to the lever u. The spring tends to press the
roller u into the spaces between the pins and make it serve the purpose of a brake
or stop. The spaces between these pins should exactly correspond to the lengths
of the steps of the cam.
In this case the slotted arms i, j, into the slots of which the lugs k, k¹, of the
movable needle board D enter, are, as before, rigidly pinned to the cross bar i.
This bar has rigidly secured to it a bent or cranked arm provided with a friction
roller which rests on the cam t.
The cam a and connections, by means of the cranked arm v, cross bar i, slotted
arms, and lugs k, l, give the requisite rising and falling motion to the needle
board D.
To each of the slotted arms j, j', is attached a spring from the top of the dobbie
to assist in the raising of the needle board and to keep the roller in contact with
the cam.
Whenever the highest part of the periphery of the cam t, pushes back the crank
arm it lowers the slotted arms j, j and also the needles to the bottom row of holes
in the card drum, and, also, by means of the rod and extension o of the
pawl o, lowers the latter into position to turn the card drum on its backward
movement.
The invention can be applied with equal facility to both horizontal and vertical
dobbies the only difference being in the shape of the levers.
When it is desired to have four shots to each card, four rows of holes are made
in the cards, as shown at Fig. 7, and when it is desired to have three or two shots,
three or two rows of holes are made in each card. In each case one row of holes is
made for each shot.
The cams a or t are so made as to give the necessary number of shots to each
card.
Of course if so desired the cam t Fig. 14 may be made with only four steps so as
to give only four shots per revolution.
Parts of the mechanism can be altered without departing from the principle of
the invention.

page_text: Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what I
consider novel and desire to claim is :-
1. The combination with a dobbie loom of mechanism, substantially as herein-
before described for giving two or more shots to each card.
2. The combination with a card drum, of loom cards having two or more rows of
holes in them, à movable needle board, and cam and lever mechanism for recipro-
cating said needle board, substantially as hereinbefore described with reference to
the drawings annexed.
3. The general arrangement and combination of parts of the mechanism for
giving two or more shots to each card, substantially as hereinbefore described and
shown under modifications on the drawings annexed.
Dated this 26th day of January 1894.
H. D. FITZPATRICK,
70, Wellington Street, Glasgow, Agent.