An Improved Tension Apparatus, applicable to the Driving Bands of Sewing and other Machines.
Year: 1891

page_text: Date of Application, 23rd Oct., 1891--Accepted, 28th Nov., 1891
COMPLETE SPECIFICATION.
An Improved Tension Apparatus, applicable to the Driving Bands
of Sewing and other Machines.
I GEORGE EDWARD RIDGWAY of Peel Causeway in the County of Chester
Draper, 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 :-
This invention is designed principally to be applied to sewing machines worked
by a treadle and its object is to keep the driving band at such an even state of
tension that it will not be so tight as to cause unnecessary friction upon the bearings
of the machine, but at the same time it will have such a grip upon the grooved
pulley that it will not slip or lose power.
I may here observe that by using a slack band in connection with my improved
tension apparatus more power will be gained as a slack band grips a larger portion
of the circumference of the pulley than a tight band would do.
The nature of my said invention and the manner in which the same is to be per-
formed or carried into practical effect will be readily understood on reference to the
annexed drawings and the following explanation thereof.
Fig. 1 is a side view drawn full size and
Fig. 2 a front view of my improved tension apparatus as applied to an ordinary
sewing machine.
a represents in section part of the table of the sewing machine, and ƒ is a portion
of the driving band on the "slack" side.
At a convenient position I make a square hole through the table through which
I pass a square bodied screw bolt b, fitted with a winged nut c. d is a thin steel
spring of suitable width bent or doubled at one end as shown at Fig. 1 and provided
with two holes through which the round part of the bolt 6 passes so as to secure it
to the table. At the other end of this spring is formed a notch in which is mounted
a grooved pulley e in the groove of which the driving band fruns.
The centre ping upon which the grooved pulley e revolves may be attached to
the forked end of the spring in any convenient manner but I prefer to flatten the
ends of the pin on one or both sides and fix the same to the spring by screws
as shown.
The tension of the driving band may be increased or decreased at any time by
turning the winged nut c.
It will be evident that for some sewing machines it may be more convenient to
attach the spring d to some part of the frame instead of to the table as shown, and
also that in applying my invention to the driving bands of other machines different
methods of attaching the fixed end of the spring may be adopted without departing
from the principal feature of my invention.
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 :-
The combination of the flat steel spring bent and fixed at one end with a
grooved pulley carried in a notch or fork at the other end, substantially in the
manner and for the purpose hereinbefore particularly described and represented by
the drawings annexed.
GEO. DAVIES & SON,
4, St. Ann's Square, Manchester, Agents for the Applicant.