Improvements in Treadle Mechanism for Sewing Machines and the like.
Year: 1896

page_text: Date of Application, 8th Oct., 1896-Accepted, 12th Dec., 1836
Communicated from abroad by THE SINGER MANUFACTURING COMPANY, OL
New York, in the United States of America, Sewing Machine Manufacturers.]
Improvements in Treadle Mechanism for Sewing Machines and
the like.
I, WILLIAM HARVEY INSLEE, Manager of The Singer Manufacturing
Company, Kilbowie, Dumbartonshire, do hereby declare the nature of this
invention and in what manner the same is to be performed as communicated
to me to be particularly described and ascertained in and by the following
statement :-
My invention has for its object to provide a treadle mechanism for sewing
machines and the like, in which all the treadle mechanism and also the driven
crank shaft will be supported by the brace which connects the legs or side-frames
of the stand or table, and also to so arrange the treadle mechanism in relation
to the driven crank shaft that a dead centre is avoided, whereby the operator
is enabled to drive a machine at a high speed and with a minimum expenditure
of power. To this end I provide the said brace with suitable supports or legs
on which a crank shaft, having two cranks and a pulley or driving wheel, is
mounted preferably by centre screws, and to the lower part of said brace 1 pivot
two treadle levers which are connected by two pitmen with the two cranks of
the driving shaft, the treadle levers being preferably provided with pivoted or
rocking foot pieces having convex and corrugated upper surfaces.
In a modification of the invention in which the crank shaft operated by the
treadle mechanism is carried transversely of the machine the pitmen are placed
in such relation to each other and to the crank shaft and treadle levers that
the pitmen will at no time be parallel to each other thus avoiding a dead centre.
In the accompanying drawings Fig. 1 is a front elevation of a sewing machine
stand embodying my invention. Fig. 2 is a plan view of the same with the table
omitted, and Fig. 3 is a detail view of the treadle levers, pitmen and crank shaft.
Fig. 4 is an end elevation, Fig. 5 a back elevation and Fig. 6 a plan of a sewing
inachice embodying a modification of my invention, and Figs. 7 and 8 are detail
views showing the relative position of the pitinen due to different positions of the
crank.
Referring particularly to Figs. 1, 2 and 3, A denotes the legs or side frames of
the stand supporting the table B on which the sewing machine, or other similar
machine to be driven is mounted. C is the cross-brace bolted at its upper and
lower ends to the said legs or side-frames and serving to hold the latter strongly
and accurately in place. The brace C is provided at its rear side with projecting
lugs c by which is supported, preferably by centre screws c', the double crank-
shaft D carrying the driving wheel or pulley d.
E denotes the twin treadles or treadle levers pivotally supported in the lower
part of the brace C, said levers, as herein shown, being hung on centre screws c
and on a double-cone-pointed pin beld in a lug on the lower cross-rod of the
brace, and being preferably provided at their forward or operating ends with
pivoted foot-pieces e having corrugated and convex upper surfaces. The rear

page_text: arms of the treadle levers are connected by pitmen F with the two cranks d',
which cranks are situated diametrically opposite each other on the driving or
crank-shaft.
It will thus be seen that the entire treadle mechanism, comprising the alternately
working treadles and the double-crank shaft operated therefrom, is supported by
the brace so that all of the parts of said mechanism will always maintain their
relative positions unaffected by any springing or warping of the table B which
might disturb such relative arrangement were the double treadles or the crank
shaft mounted in the legs or side-frames of the stand or on rods or parts connecte!
therewith.
It will also be seen that the arms or lugs c projecting rearwardly from the
brace C, about midway of the height thereof, afford means for supporting the
double crank shaft clear of the brace so that there will be room for said shaft to
work behind said brace without requiring said shaft to be lowered to a point which
would be objectionable.
In this modification the crank shaft D is journalled lengthwise of the machine
and the treadle mechanism consisting of the treadle levers E and pitmen F are s.)
arranged in relation to said crank shaft that the treadle levers act obliquely on the
crank shaft as shown at Fig. 3 and a dead centre is impossible.
Referring to Figs. 4 to 8 of the drawings, the crank shaft D carrying the
driving pulley d is in this modification placed transversely of the machine instead
of longitudinally as in Figs. 1, 2 and 3, and is carried by a bracket C depending
from the table. The pitmen are connected between the crank shaft D and the
treadle levers E in such a manner that the pitmen F are at no time parallel to
each other the axis of the joint to the crank being at right angles to that of the
joint connected to the treadles. One position of the pitmen F in relation to each
other and to the cranks d' is shown particularly at Fig. 7 in which it is apparent
that even if one pitman is in a line with the crank i.e., in a dead centre, the other
pitman must stand at an acute angle to the former. If the cranks d¹ and con-
sequently the treadle levers E are in horizontal positions the pitmen F will either
stand nearly parallel to each other as shown at Fig. 5 or will cross each other as
shown at Fig. 8.
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. The combination with the legs or side-frames A, and the brace C connecting
the same and provided with the rearwardly projecting arms or lugs c, of the
crank-shaft supported by said arms or lugs behind and clear of said brace and
having the wheel or pulley d and two cranks d, the two treadle levers E, mounted
in the lower part of said brace, and the pitmen connecting said levers with said
cranks.
2. The combination with the legs or side-frames A, and the brace C connecting
the same and provided with the rearwardly projecting arms or lugs c, of the
crank-shaft supported by said arms or lugs behind and clear of said brace and
having the wheel or pulley d and two cranks d¹ the two treadle levers E, mounted
in the lower part of said brace, and the pitmen connecting said levers with said
'cranks, said treadle-levers having the pivoted foot pieces e.
3. The combination with the legs or side-frames A, and the brace C connecting
the same and provided with the rearwardly projecting arms or lugs c, of the
crank-shaft supported by said arms or lugs behind and clear of said brace and
having the wheel or pulley d and two cranks d', the two treadle-levers E mounted
in the lower part of said brace, and the pitmen connecting said levers with said
cranks, said treadle levers having the pivoted foot pieces e having convex and
corrugated or roughened upper surfaces.
4. The combination with the treadle levers E mounted in the lower part of the
brace C of the two pitmen F connected thereto and to the cranks d¹ on the crank

page_text: shaft D carried trans ersely of the rocking axis of the treadles and operating
substantially as described.
Dated this 7th day of October 1896.
WALLACE FAIRWEATHER,
Of the Firm of Cruikshank & Fairweather,
Chartered Patent Agents,.
62 St. Vincent Street, Glasgow, Agent for the Applicant.