Improvements relating to Loom Shedding and Change-box Motions.
Year: 1891

page_text: Date of Application, 11th June, 1891-Accepted, 8th Aug.. 1891
COMPLETE SPECIFICATION.
Improvements relating to Loom Shedding and Change-box Motions.
I, CLINTON ALVORD, a citizen of the United States, residing at Philadelphia, in
the County of Philadelphia, and state of Pennsylvania, one of the United States of
America, 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 :-
My invention relates to looms, and to the harness and box motion of "open shed
looms," and more particularly to the cams employed in such motions.
In certain forms of harness and box motions, in use in open shed looms, the levers
forming part of the harness and box operating connections are actuated by means of
switch cams, whose switches are controlled by a pattern chain.
In the ordinary cam, known as a "switch cam" the movements of the switches
will simply change the shape of the cam, that is from a one-up and three-down cam,
to a two-up and two-down cam, or some such combination. In other words, the
cam is still a cam, and will cause the pin or roll travelling in its groove, and carried
by one of the levers aforesaid, to move in and out during each revolution.
In a cam embodying my invention, on the contrary, so long as the switches remain
in a given position, the roll will remain, either in or out, according to the position
of the switches, and if out will move in, and if in will move out, only after the
switches have been changed in position, all as will hereinafter be made definitely
to appear.
My invention consists primarily, in a switch cam of novel construction, designed
to secure the mode of operation above set forth. It consists further, in the com-
bination with the cam, of the construction hereinafter set forth, of various associated
parts of a loom, and it consists finally, in an improved shuttle-box motion for a
loom, all as will be described hereinafter, and then be pointed out in the claims at
the close of the Specification.
Referring to the drawings:
Fig. 1-is a sectional side elevation of my harness motion detached.
Fig. 2 is a view of a modification of my cam.
Fig. 3 is a side elevation of my box-motion detached.
Fig. 4 is a partial detailed sectional view on the line W, W, of the series of
shuttle-box operating cams shown in Fig. 3.
In the accompanying drawings, 1 represents a switch-cam of my peculiar con-
struction, fast on the shaft 2. 3 is the harness-jack hung loosely on the pin 4, and
carrying the cord 5, which runs over the pulleys 6 to the harness frame 7. 8 is the
chain shaft, carrying rolls 9 and tubes 10, which operate the indicating lever 11,
hung loosely on the pin 12.
The harness-jack 3 has an arm 13 carrying an oblong shoe 14 loosely pivoted
thereon, which travels in the groove of the cam. Said cam 1 is provided with the
frog 15, carrying the contact piece 16, hung loosely on the pin 17. Frog 18 is
loosely pivoted at 19, and the two frogs 15 and 18 are joined together by the
connector 20.
The operation of my harness-motion is as follows:-
The
My switch-cam is composed of two concentric grooves, and two cam grooves,
which cross each other and open into the concentric grooves, all as shown.
spring 22 bears against a projection on the connector 20, and in yielding pressure,
retains the frogs 15 and 18 in the position shown in the full lines, Fig. 1.
The oblong shoe 14, carried on the arm 13 of the harness-jack 3, is shown in
the inner concentric groove, and it is evident that as long as the frogs remain in the

page_text: position shown in the drawings, the rotation of cam 1 will not change the
position of said harness-jack.
The cam 1 revolves once in every pick of the loom, and the pattern chain is turned
to move the indicating lever 11, just as the contact piece 16 moves within reach of
the end 23 of said indicating lever 11. When the contact piece 16, approaches the
indicating lever 11, the pattern chain moves, and if the chain be so built, a roll or
"riser" will come under the lever 11, and by the motion of said lever 11, the
contact-piece 16 will be depressed, moving frogs 15 and 18 into the dotted line
positions shown in Fig. 1, and the continued rotation of the cam I will cause the
shoe 14 to run up the cam groove, now open for it, and into the outer concentric
groove of the cam.
It is evident that so long as there are risers on the pattern chain, under the
indicating-lever 11, the shoe 14 will travel in the outer concentric groove and the
harness will stay up; but as soon as a *" sinker " appears again on the pattern chain,
and allows the indicating lever 11 to fall back into the position shown in the drawing,
the shoe 14 will run down the cam groove, and will stay down until called up again.
Thus it is noted that the "up or "down" of the harness-jack and corresponding
harness, at any pick, is absolutely controlled by the pattern chain.
"
I will now proceed to describe my box-motion.
The cams 25, (Figs. 3 and 4,) are of exactly the same style as the cam 1. The
pattern chain 81, and the indicating levers 11 and 11 work in the manner described
above, and upon the build of the pattern chain 9¹ depends the position of the levers
which work the shuttle-boxes.
The lever 26, hung loosely on pin 4', is provided with a shoe similar to 14, which
works in the groove of the first cim, and from pin 27 runs connector 28 to the com-
pound-operating lever 29. The lever 30 is similarly operated by the second cam 25,
and from the pin 31 runs the connector 32 to the compound-operating lever 29.
From the end 33 of the lever 29 runs the connector or lifter rod 34, to the shuttle
boxes 35.
The movement of the lever 26 will cause the shuttle boxes 35 to move one space,
and the movement of lever 30 will move the shuttle-boxes two spaces.
In Fig. 3 I have shown lever 26 as down, or in the inner concentric groove of its
cam, and lever 30 as up, or in the outer concentric of its cam, thus bringing
the shuttle-boxes into the third position ". The various positions that the
shuttle-boxes may occupy being shown by the letters a, b, and c, c', cl, el for
example, when the levers 26 and 30 are down, the lever 29 occupies the
position a, b, c, if both levers were up, the lever 29 would occupy the position
indicated by a¹, b¹, c¹¹¹.
In Fig. 4 I have shown a partial, detail sectional view of the series of shuttle-
box operating cams, and have also shown an outer disc or shield 36, intended to
keep the dirt away from the exposed face of the outer cam.
In Fig. 2 I have shown my cam with an additional frog 37, interposed at the
junction of the two cam grooves, and when using a cam having this additional frog,
it is not necessary to employ the oblong shoe in the cam; for the cam groove is so
closed that a roll or pin will travel from one concentric groove to the other, without
the least danger of its running down the other cam groove at the point of crossing.
The oblong shoe 14, is of such a length than when moving in one cam groove, it
cannot turn into the other cam groove at their point of crossing. The connector
20 crosses the cam groove at the bottom, so as to leave a clear passage for the
shoe 14.
I will again call attention to the peculiar feature of my cam in having two
concentric grooves, and two cam grooves, which cross each other and open into the
concentric grooves; by reason of this peculiar construction, the harness-jack, or box
lever, will remain up or down for any number of revolutions of the cam, this being
entirely controlled by the "build" of the pattern chain.
It must be understood, that 1 do not confine myself to the exact construction

page_text: shown in the drawings, neither do I confine myself to any particular number of frogs
interposed at the junction of the grooves of the cam.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
1. A cam having two concentric grooves, and two cam grooves, which cross
each other and open into the concentric grooves, substantially as described.
2. A cam having two concentric grooves, and two cam grooves, which cross each
other and open into the concentric grooves, and provided with a set of frogs for the
purpose of shutting off either of said cam-grooves from said concentric grooves,
substantially as described.
3. In a loom, the combination with a pattern chain, an indicating lever, and a set
of frogs carrying a contact-piece to work with the indicating lever, of a cam, having
two concentric grooves, and two cam grooves, which cross each other and open into
the concentric grooves, substantially as described.
4. In a loom, the combination with a harness-jack, adapted to be operated by a
cam, a harness frame, and intermediate connections between said harness jack and
said harness frame, of a pattern chain, indicating lever, and a cam provided with a
set of frogs carrying a contact-piece to work with the indicating lever, said cam
having two concentric grooves, and two cam grooves, which cross each other and
open into said concentric grooves, substantially as, and for the purpose set forth.
5. In a loom, the combination, with a series of levers adapted to be operated
by a series of cams, a box operating lever, and intermediate connections between
said cam actuated levers, and said box-operating lever, of a pattern chain, a series
of indicating levers and a series of cams, each cam provided with a set of frogs
carrying a contact piece to work with the indicating lever, and said cams having
two concentric grooves, and two cam grooves, which cross each other and open into
the concentric grooves, substantially as and for the purpose set forth.
Dated this 10th of June 1891
H. D. FITZPATRICK,
Glasgow, Agent.