IMPROVEMENTS IN SEWING MACHINE GEARING
Year: 1881

page_text: LETTERS PATENT to Herbert John Haddan, of the Firm of Herbert and
Company, Solicitors of Patents, of 67, Strand, in the City of Westminster,
Civil Engineer, for an Invention of "IMPROVEMENTS IN SEWING MACHINE
GEARING." A communication from abroad by Mario Irénée Lecœur, of
Darnetal, in the Republic of France.
PROVISIONAL SPECIFICATION left by the said Herbert John 'Haddan at
the Office of the Commissioners of Patents on the 11th June 1881.
HERBERT JOHN HADDAN, of the Firm of Herbert and Company, Solicitors of
Patents, of 67, Strand, in the City of Westminster, Civil Engineer. " IMPROVE
MENTS IN SEWING MACHINE GEARING." A cominunication from abroad by Marie
Irénée Lecour, of Darnetal, in the Republic of France.
The Invention relates to mechanism for giving variable speed to sewing machines
moved by mechanical motors.
The improvements consist of a friction disc imparting to a travelling pulley in
contact therewith a rotary motion proportionate to the position assumed by the
pulloy where it comes in contact with the disc.
Also in an arrangement for allowing the pulley to place itself in the centre of
the friction disc, where the spoed is practically nil.
And an arrangement of the actuating treadle for giving the operator the power
of regulating with the feet the speed of the friction pulley, and thus governing the
speed of the machine by placing the pulley on any point of the surface of the disc
which then serves as an additional fly wheel. The various parts are best constructed
of metal. The disc is mounted on an axle supplied with mitred gearing so that
power is transmitted at right angles. On the disc is a sliding rest carrying a pin,
which is received and held in the jaws of a forked lever working loosely on said
pin at one end, and pivoted to a treadle arrangement at the other. As the disc
revolves the speed is controlled by pressing on the treadle, and so the pin on the
sliding rest can be approached to or from the centre of the disc or fly wheel, and
so regulate the speed.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Herbert John Haddan in the Great Seal Patent Office on the
8th December 1881.
HERBERT JOHN HADDAN, of the Firm of Herbert and Company, Solicitors of
Patents, of 67, Strand, in the City of Westminster, Civil Engineer. " IMPROVE-
MENTS IN SEWING MACHINE GEARING." A communication from abroad by Mario
Irénée Lecœur, of Darnetal, in the Republic of France.
This Invention relates more particularly to the driving mechanism of sewing
machines, and is also applicable to other machines which should be worked at
variablo speed. It consists in an arrangement which allows of instantaneously
regulating, that is to say, increasing or slackening, the speed of such machines.
In the accompanying Drawings, Fig. 1 is a front view, Fig. 2 a side elevation,
and Fig. 3 a plan view of a mechanism embodying this Invention and forming
part of a set of machines actuated by one common motor, the sewing machine
proper being only represented by the pulley P.
Two rows of sewing machines are driven by a horizontal main shaft T placed
under the table or machine platforin, and extending from one end of the latter to
the other. At both sides of this main shaft T is arranged the intermediate gearing
which constitutes the improvements, and which consists essentially of a friction-
disc and a friction pulley.
The friction disc A is mounted on an axle a, the head of which is made bevelled
and fits exactly into a corresponding bore in the centre of the disc A, while the
opposite end is fixed in the sleeve t.
A bevel wheel a' is mounted on the shaft of the friction disc A, and gears with
another bevel wheel t¹ fixed on the main shaft T. A friction pulley B is mounted
on a shaft b provided with a square part b', which fits into a square opening in the
nave of the pulley; this arrangement allows of shifting the pulley on the shaft,
and makes the shaft turn with the pullley.
Two rings b, 61, placed at the ends of the square parts on the shaft 6 limit
the travel of the friction pulley B. The friction pulley B is kept in permanent
contact either with the surface of the friction disc A or the head of tho shaft a,
which is made flush with the disc by means of the helical spring 6, which by its
pressure on the sleeve 6 produces sufficient adherence between the disc A and
pulley B, that the former cannot turn without also turning the pulley B if it is in
contact with any point of its surface. The sleeve 6 is one of the bearings of the
shaft b, and is mounted in a slot on the brackets 6, 6, of this shaft.
The friction-pulley B is lined with leather for increasing friction. On the same
shaft b which carries the friction pulley B, a grooved pulley P¹ is mounted, which
by means of an endless cord b communicates motion to the driving pulley P of the
sewing machine.
A double pedal C with two treadles c, c¹, arranged to oscillate round a common
axle is adapted at the bottom of the apparatus within easy reach of the operator's
feet. A forked lever c¹ is also fixed on the axle c¹ of the pedal, and connected
with the friction pulley B by means of a collar c¹¹, which fits into a circular groove
in the nave or sleeve of the friction pulley. The collar c also carries two ears
which project into slots provided in the fork-branches of lever c¹¹. It is evident
that through this arrangement each oscillation of the pedal and lever, c¹¹ will cause
the friction pulley to alter its position on the shaft b in one or the other sense.
Having thus described the mechanism I will now explain its working:-
The main shaft T being set in motion it communicates motion to the friction
pulley A by means of the toothed bevel wheels. While the friction-pulley B is
in the centre of the disc in contact with the head of shaft a, it is at rest (this

page_text: position being represented in the Drawings). But as soon as the operator places
one foot, say, for instance, the left, on treadle c, the pedal and lever c begin to
oscillate, and cause the friction pulley B to recedo from the centre of the friction
disc A, which imparts to the pulley Ba speed directly proportional to the distance
of the point of contact of the pulley B from the centre of the disc A. By further
depressing the same (left) trendle the pulley B recedes still further from the centre
of the disc A, and its speed is increased. It is obvious that the limit for this
receding motion of the pulley B is the extremity of the radius of disc A. By
depressing the other (right) treadle the pulley B is brought back and caused to
again approach the centro of the disc A, or it may be brought to rest completely if
placed in the centre on the head of shaft a. The pulley B would also be brought
to rest if the centre of the friction disc were formed only by the surface of said
disc without the application of the head of shaft a, on account of the speed being
nil at the centre, but the adoption of the system illustrated in the Drawings is
advisable, as it prevents the leather lining of the pulley from being worn too soon
by friction.
The simple depression of the treadles is sufficient for instantaneously regulating
the speed of the machine, or for stopping it completely.
The above described improvements can be applied not only to sewing machines
arranged in rows and driven by a common driving shaft, but also to single machines
worked by the foot of the operator. In this latter caso the common shaft T is
replaced by a short driving shaft, which may be set in motion in the usual way,
and be made to transmit it to the intermediate regulating apparatus by means of
bevel gear, &c.; or the motor may act directly on the friction disc, which may have
the necessary driving pulleys mounted on its shaft. The intermediate regulating
mechanism may be actuated by the knees, while the machine is actuated by the
fect. The application of this Invention to such machines worked by foot has the
advantage of allowing the motion of the machine to be slackened to a more perfect
degree than can be effected by the motion of a connecting rod, while the treadles
may be actuated with the usual speed.
This Invention is not only applicable to sewing machines, but it may be applied
to other machines, which must be worked with variable speed.
By using this Invention sewing machines may be advantageously moved by
steam or other elementary power, instead of working such machines by the feet.