IMPROVED DRIVING GEAR FOR SEWING MACHINES
Year: 1884

page_text: I JOHN FARRAN of 45 Clifton Street Old Trafford Manchester in the County
of Lancaster Mechanician do hereby declare the nature of my invention for
"IMPROVED DRIVING GEAR FOR SEWING MACHINES" (which invention has been
partly communicated to me from abroad by Lyman C. Perkins of the City of
Pennsylvania in the United States of America, and is partly my own invention) to
be as follows :—
This invention is intended to be used as a substitute for the crank motion
usually employed for driving sewing machines, the advantages being that the
motion is easier and the machine cannot be driven in the wrong direction.
The driving wheel of the sewing machine is operated by clutch gears on opposite
sides of the hub, each gear being driven by a strap connected at one end to the
drum of the clutch and at the opposite end to a treadle lever hung to the main
frame. The improved clutch gear is constructed as follows.
The axle on which the driving wheel turns is secured to the main frame so as to
be incapable of movement independently thereof, and the drum to which the
driving strap is connected is free to turn on the axle, and to the hub of this drum
is clutched a hub to which are hung the inner ends of a series of pawls, the outer
ends of which are adapted to engage with an internal rack inside a drum, the hub
of which is screwed or otherwise securely fastened to the hub of the driving wheel.
Each of the pawls has a transverse opening to receive a plug and a spring, the
tendency of the spring being to force one of the said plugs against the inner face of
the drum and the other against a plate bolted to the drum.
These spring plugs serve to impart a certain retaining friction which prevents
the pawls from dropping down and disengaging with the teeth of the ratchet in
the backward movement of the hub. The first result of this backward movement
is to draw the pawls inward until their ends are free from the teeth in which
position they remain without change until the motion is reversed, whereupon the
first result is the throwing out of the ends of the pawls until they engage with

page_text: the teeth, by this means the objectionable clicking noise which accompanies the
backward movement of an ordinary pawl and ratchet clutch is effectually
overcome.
The retraction of the drum and pawl hub is effected by a spring. This spring is
connected at the inner end to the hub of the drum and at the outer end to a bolt
which is secured by suitable nuts to a plate fixed to the axle, so that the inner end
of the spring is the moving end, the spring winding and unwinding from the inside
so as to avoid the objectionable scraping of the convolutions of the springs against
each other which results when the inner end of the spring is fastened and the outer
end movable.
A bolt is adapted to a slot in the plate so that the spring can be tightened
and there is a washer which prevents the access of dust or moisture to the spring.
A washer interposed between the drum and the plate similarly prevents the access
of dust or moisture to the gearing of the clutch and the plate and washer each
have an opening for the reception of a bolt which secures the spring to the plate
and both the washer and the plate is moved to tighten the spring.
GEORGE DAVIES,
Agent for the Applicant,
4, St. Ann's Square, Manchester.

page_text: I JOHN FARRAN of 45 Clifton Street Old Trafford in the County of Lancaster
Mechanician do hereby declare the nature of our invention for "IMPROVED DRIVING
GEAR FOR SEWING MACHINES" 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 intended to be used as a substitute for the crank motion usually
employed for driving sewing machines, the advantages being that the motion is
easier and the machine cannot be driven in the wrong direction.
The driving wheel of the sewing machine is operated by clutch gears on opposite
sides of the hub, each gear being driven by a strap, connected at one end to the
drum of the clutch and at the opposite end to a treadle lever hung on the main
frame.
The improved clutch gear is constructed in the manner hereinafter set forth
reference being bad to the annexed drawing in which Fig. 1. is a vertical section
of the clutch gear complete. Fig. 2 is a transverse section on the line 1. 2 on
Fig. 1. Fig. 3 is a transverse section on the line 3. 4.-Fig. 4. a face view of
Fig. 1.-and Fig. 5. a view of part of Fig. 2 with some of the parts in a different
position.
M. is the axle on which the driving wheel turns, this axle being secured to the
main frame so as to be incapable of movement independently thereof.
The drum P to which the driving strap n is connected is free to turn on the
axle, and to the hub g of this drum is clutched a hub p to which are hung the inner
ends of a series of pawis S, the outer ends of which are adapted to engage with an
internal rack T in a drum V, the hub r of which is screwed or otherwise securely
fastened to the hub s of the wheel B.
Each of the pawls S has a transverse opening Fig. 1 for the reception of plugs t,
and a spring u the tendency of the spring being to force one of said plugs against
the inner face of the drum V and the other against a plate W, bolted to the drum.
These spring plugs serve to impart a certain retaining friction which prevents the
pawls from dropping down and engaging with the teeth of the rack T on the
backward movement of the hub p The first result of this backward movement is
to draw the pawls inward until their ends are free from the teeth, as shown in
Fig. 5. in which position the pawls remain without change until the motion is
reversed whereupon the first result is the throwing out of the ends of the pawls
until they engage with the teeth. By these means, the objectionable clicking noise
which accompanies the backward movement of an ordinary pawl-and-ratchet clutch
is effectually overcome.
The retraction of the drum p and pawl hub is effected as usual by a spring Y.
This spring is connected at the inner end to the hub q of the drum P, and at the
outer end to a bolt w which is secured by suitable nuts to a plate X secured to
the axle M so that the inner end of the spring is the moving end, the spring
winding and unwinding from the inside, so as to avoid that objectionable scraping
of the convolutions of the spring against each other which results when the inner
end of the spring is fastened and the outer end movable.

page_text: The bolt wis adapted to a slot w¹ in the plate X (see dotted lines Fig. 4) so that
the spring can be tightened as desired and between the plate X and an outer
plate X intervenes a washer z which fits snugly to the inside of the flange of the
drum P and prevents the access of dust or moisture to the spring.
A washer ý interposed between the drum V and plate W similarly prevents the
access of dust or moisture to the gearing of the clutch.
The plate X and washer x each have an opening for the reception of the
bolt w which secures the spring Y to the plate X both the washer and plate X¹
turning on the hub of said plate X when the bolt wis moved to tighten the
spring Y.
Having now particularly described and ascertained the nature of our said
invention and in what the same is to be performed I declare that what we
claim is
1. The combination in a ratchet clutch for driving sewing machines of the
drum V, having an internal rack, the driving drum P and a hub p connected to
said driving drum and carrying pawls S and two spring-plugs t, t projecting from
the opposite sides of each pawl and forming a frictional retainer therefor as set
forth.
2. The combination of the drum V, and its rack, the drum P and the pawls, and
a retracting spring connected at the inner end to the hub of the said drum P and
at the outer end to a fixed plate as specified.
3. The combination of the pawl drum retracting-spring bolt w and plate X,
having a slot w¹ for the adjustment of the bolt as described.
4. The combination of the driving drum the fixed plate X the cover plate X' and
the protecting-washer as set forth.
5. The combination of the driving drum, the drum V on the driving wheel and
the washer y as set forth.