Improvements in Weft Forks of Looms for Weaving.
Year: 1899

page_text: Date of Application, 17th Aug., 1899-Accepted, 30th Sept., 1899
COMPLETE SPECIFICATION.
Improvements in Weft Forks of Looms for Weaving.
We, JAMES MADISON BLAISDELL and DAVID WALLACE GUNN, both of 370,
Atlantic Avenue, Boston, Massachusetts, U.S.A., Manufacturers, do hereby
declare the nature of this invention, and in what manner the same is to be per-
formed to be particularly described and ascertained in and by the following
statement:-
Our invention relates to weft forks and is intended to provide a construction
which will overcome certain difficulties in the action of the weft fork and avoid
the tendency of the weft fork to miss or skip a filling thread.
The invention consists first, in providing the weft fork with a counterweight
so arranged as to balance the pivoted head when the head is in its normal or
operative position and also return the head to its normal position, without any
objectionable rebound, when it is displaced, said counterweight serving also as a
stop to limit the pivotal movement.
The invention consists, further, in the combination of such a counterweight
with means for detachably securing the tines of the fork to said head in a con-
venient manner to permit the removal and replacement of the tines without
removing the head from the slide bar.
In the accompanying drawings,
Fig. 1 is a plan view of my improved weft fork.
Fig. 2 is a vertical sectional view showing the tines in normal position.
Fig. 3 is a similar view showing the tines tipped down to the lowest limit
of their pivotal movement.
Fig. 4 is a detail view showing a front elevation of the pivoted head.
The slide bar a is of the usual construction, being recessed at the front end
and slotted to receive the pivoted head b and to permit the engagement of the
hook c, with the stop mechanism of the loom in the usual manner.
The head is pivoted between the jaws of the slide-bar upon the pivot pin 9,
and is grooved upon its upper face to receive the tines d' of the fork. These
tines are detachably secured to the head by means of the spring metal hook-
plate c, which is itself pivotally connected with the head by means of a stud
or rivet h.
The head is provided with a rearward extension or projection which engages
a recess or groove in the under face of the hook-plate c, such engagement serving
to hold the plate c from accidental displacement while permitting it to be turned
by the operator when he desires to replace a tine.
Much inconvenience has been caused heretofore by the tendency of the rebound
of the fork to miss or skip a filling thread.
To overcome this tendency we provide a weighted stop e, the weight and posi-
tion of which is such as to almost counterbalance the weight of the extension
and of the hook-plate c, when the fork is in normal position, as shown in
Figures 1 and 2. This counterbalancing gives great delicacy to the action of the
fork and makes it sensitive to slight pressure. The stop e is so positioned as to
come in contact with the stop-piece f of the slide-bar, which limits the movement

page_text: of the fork. By disposing the weighted stop in front of and below the pivotal
axis g, the stop tends to check the impact against the stop-piece f and hence
avoids the objectionable rebound, for it will be seen that as long as the stop is
in a position in front of the vertical plane passing through the pivotal axis, it
partially counterbalances the rearward extension, but when it has swung to the
rear of said plane, its weight tends to check the further movement of the fork
and to return it to normal position. On its return swing the weight also acts
as a check after it has passed the front of said vertical plane.
The advantage of a construction which permits the easy replacement of the
tines and secures delicacy of action and freedom from the objectionable effects
of rebound will be clear to those skilled in the art.
Having now particularly described and ascertained the nature of this said
invention and in what manner the same is to be performed, we declare that what
we claim is: -
1. A weft fork embracing in its construction a tine-carrying head pivotally
mounted in the slide-bar and provided with a weighted stop which serves to
limit the downward swing of the fork and which is so disposed as to check the
rebound of the fork sufficiently to prevent the fork from skipping a filling thread.
2. A weft fork embracing in its construction a tine-carrying head pivoted in
the slide-bar and provided with a weighted stop disposed in front of and below
the plane of the pivotal axis so as to act as a stop, and also by its weight to check
the rebound, substantially as described.
3. A weft fork embracing in its construction a head pivoted in the slide-bar.
said head being provided with means for detachably securing the tines to itself
and with a weighted stop which tends to counterbalance said fastening means
and to check the rebound of the fork, substantially as described.
Dated this 17th day of August 1899.
JAMES MADISON BLAISDELL.
DAVID WALLACE GUNN.
Herbert Haddan & Co.,
18, Buckingham Street, Strand, W.C., London,
Agents to Applicants.