Year: 1887

page_text: I, JOSEPH BUCHANAN ROBERTSON of Lurgan in the County of Armagh, Ireland,
Engineer, 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 means of driving, revolving shuttles such as are used in
many lock-stitch sewing machines, my object being to time the movement of such
shuttles suitably to that of the needle, and to provide in a simple manner for the
escape of the thread loop between the shuttle and its driver.
For this purpose, in communicating motion from the horizontal spindle which
extends along the goose neck to drive the needle, to the vertical spindle which extends
down the column of the machine and imparts motion to the shuttle, I introduce at the
angle of the goose neck with the column a pair of mitre wheels which may be of
elliptical form and are fixed obliquely on their respective spindles each in one focus as
an axis and I set these wheels so in gear that the longest radius of the one meets the
shortest radius of the other as shewn in Figs. 1 and 2 which are respectively a vertical
section and a plan of this gearing. A is the horizontal needle driving spindle in the
goose neck and B is the shuttle driving spindle extending down the column.
On these spindles are fixed the mitre toothed wheels and D each fixed obliquely
and eccentrically on its spindle, so that, assuming the spindle A to revolve uniformly,
the spindle B has a varying speed communicated to it, such that when the needle has
descended and formed a bulge of thread into which the shuttle enters, the shuttle
passes through the loop with great rapidity.
For driving the revolving shuttle, I mount it in a circular race the axis of which is
somewhat inclined to the axis of the driving spindle as shewn in vertical section by
Fig. 3 and in plan by Fig. 4. D is the spindle of the shuttle driver which has on its
upper end two or preferably three upwardly projecting horns d.
The shuttle E is fitted to revolve in a circular race the axis of which is somewhat
inclined to the axis of the spindle D. The shuttle is prevented from rising out of the
race by a covering ring F which has a downwardly projecting lip engaging inside a
corresponding upwardly projecting lip e of the shuttle. As the spindle D revolves,
نرم

page_text: one at least of the horns d is engaged in a recess of the shuttle driving it, while,
owing to the obliquity of the plane in which the shuttle revolves to that in which the
horns d revolve, there is always a clear space between the other horn or horns d and
the shuttle to allow passage of the thread loop around the shuttle.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is:
1. In a lock stitch sewing machine wherein the needle driving spindle is at right
angles to the spindle which drives the shuttle, the construction and use of oblique
eccentric mitre wheels gearing the one spindle to the other substantially as and
for the purposes set forth and illustrated by Figs. 1 and 2.
2. In a lock stitch sewing machine having a continuously revolving shuttle, fitting
the shuttle to revolve in a circular race having its axis inclined to that of the
shuttle driving spindle, and providing this spindle with projecting horns arranged
to engage successively in recesses formed in the shuttle and to retreat therefrom,
substantially as described with reference to Figs. 3 and 4.
Dated this 28th day of November 1887
ABEL & IMRAY,
Agents for the Applicant.