Improvements in Treadle-driving Mechanism.
Year: 1890

page_text: Date of Application, 4th Mar., 1890
Complete Specification Left, 4th Dec., 1890-Accepted, 10th Jan., 1891
PROVISIONAL SPECIFICATION.
Improvements in Treadle-driving Mechanism.
I, JOSEPH LITTLE, of No. 30, South Street, Exeter, in the County of Devon,
Sewing Machine Agent, do hereby declare the nature of this invention to be as
follows:-
My invention relates to improvements in treadle-driving mechanism, and its object
is to prevent the occurrence of dead points in the cranks thereof.
In carrying it into effect, I pivot a treadle upon the bottom extremity of a lever,
which has its fulcrum upon some fixed point. The opposite end of the treadle; that
is, the end farthest from the foot is pivotted to the end of the ordinary connecting
rod. But the latter is converted into a lever, by being connected, by a link, to the
top of the lever above mentioned. These two levers are preferably parallel. The
top end of the combined connected rod and lever is pivotted to the crank-pin in
the ordinary way. The points at which the link is so connected to the said levers
may be varied.
Dated this 4th day of Marah 1890
PHILLIPS & LEIGH,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Treadle-driving Mechanism.
I, JOSEPH LITTLE, of No. 30), South Street, Exeter, in the County of Devon,
Sewing Machine Agent, 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 improvements in treadle driving mechanism, such as are
used for converting the alternate motion of the foot into a rotary one in the pin of a
crank. The object of it is, Firstly, to give the foot perfect control of the crank-pin
throughout its circular path, with the natural consequence that dead points cannot
occur therein, and, Secondly, to render it possible to work the driving mechanism
with either an up-and-down motion, a swinging motion, a toe-and-heel motion, or a
combination of the two latter in any desired proportion.
The advantages of the swinging motion over the others will be patent to anyone
who is acquainted with the vast amount of mischief inflicted upon users of treadle-
driven sewing machines the driving mechanism of which demands an up-and-down
motion of the knee.
In carrying it into effect, I pivot a treadle upon the bottom extremity of a lever
which has its fulcrum upon some fixed point. The opposite end of the treadle, that
is, the end farthest from the foot, is pivotted to the end of the ordinary connecting
rod. But the latter is converted into a lever by being connected by a link to the
top of the lever above mentioned. These two levers are, preferably, parallel. The
top end of the combined connecting rod and lever is pivotted to the crank-pin in
the ordinary way. The points at which the link is so connected to the said levers
may be varied.
In order that my invention, and the best means by which the same is to be carried
into practical effect, may be thoroughly understood, I will now describe them in
detail, referring in so doing to the accompanying drawings which are to be taken as
part of this Specification and read therewith.'
Fig. 1 is a side elevation, partly in section, taken on the line y-z of Fig. 2.
Fig. 2 is a front elevation corresponding therewith.

page_text: The above figures illustrate the application of the invention to a sewing machine,
and the mechanism is proportioned to be driven by a toe-and-heel motion.
Fig. 3 is a diagram illustrating the paths of the several moving parts of the
mechanism.
Referring to Figs. 1 and 2, A is the treadle. It is pivotted at B to the lower
extremity of a lever C. This lever C has its fulcrum upon the fixed point c which is
provided in the case illustrated by a small bracket c¹ projecting from and carried by
a strut D provided for that purpose. The pivot B is developed into a horizontal bar
as shew in Fig. 2, which is cranked and provided with a centred which is the
complen nt of the aforesaid fulcrum c.
Gis a driving pulley; its axis, or that of the crank shaft if there be one, and
g the axis of the crank pin.
F is the well known connecting rod. Its lower extremity is pivotted to which
is practically the rear extremity of the treadle A, while its upper extremity is pivotted
or connected to the crank-pin in the usual way.
His a link pivotted at the points i, j; the former being a point in the connecting
rod; and the latter, the upper extremity of the lever C. The introduction of this
link provides the connecting rod F with a fulcrum i, thereby converting it into a
lever. It is referred to hereafter as the combined lever and connecting rod.
Referring to Fig. 3, the circle K is the path of the crank-pin; the elliptical
figure L, the path of the point; M. the path of the point 6; and N, the path of
the front extremity of the treadle. The arcs o and p are the paths of the points j
and B, respectively. Corresponding positions of the moving parts of the mechanism
are marked on the diagram by the Figures 1 to 8, respectively.
An analysis of this diagram will shew that the treadle, no matter what may be its
position, is always capable of exerting an operative pull upon the crank-pin, and
also, that its own travel is continuous-circular, instead of being intermittent
through an arc, thereby eliminating the possibility of the occurrence of dead points.
The variations between the motions set out in the opening paragraph are effected
by vrying the relative dimensions of the members of the combined lever and
connecting rod F and the lever C.
The longer b and c B are, relatively and respectively, to i g¹ and cj, the more
will the motion of the treadle be a swinging one. When the members are pro-
portioned as illustrated, a heel-and-toe motion of the foot will be required, i.e., the
treadle will oscillate on a moving axis, the point B. In other words, the fulcra i, c
are adjustable up and down the members F and C, respectively, and any adjustment
possi ole to the construction which is hereafter claimed may be made.
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
clain is
1 te combination of crank pin, combined lever and connecting rod, treadle pivotted
the to and having its fulcrum upon the bottom of a lever which said lever has its
ful im upon a fixed point, its opposite end being connected by a link to the fulcrum
aforesaid combined lever and connecting rod; as set forth.
of
Dated this 3rd day of November 1890.
PHILLIPS & LEIGH,
22, Southampton Buildings, W.C., Agents for the Applicant.