Improvements in Electrical Motor Fittings for Transmitting Motion to Light Machinery.
Year: 1894

page_text: PROVISIONAL SPECIFICATION.
Improvements in Electrical Motor Fittings for Transmitting Motion
to Light Machinery.
I, HENRY LEA, of Bennetts Hill, in the City of Birmingham, Civil Engineer,
do hereby declare the nature of this invention to be as follows:-
This invention has reference to the construction and arrangement of fittings for
applying electric motors to sewing machines, burnishing, buffing and lapping
machines and small lathes; the object of the invention being to combine in one
piece of mechanism, a device for 1. releasing a brake; 2. starting the electric
motor; and 3. tightening the driving belt or engaging the clutch or friction
pulley for setting in motion the machine; the said cycle of operations being
reversed when it is desired to stop the machine; the whole of these operations
being controlled by the movement of one lever, rod or cord, actuated by the foot
or knee or hand of the operator.
I will first describe my invention as applied to drive a sewing machine, the
electric energy being derived from ordinary electric lighting connections. I arrange
an attachment to suit an ordinary electric wall socket or lamp holder and I convey
the current therefrom by wires to an electric motor of any suitable construction.
I fix the motor upon a special bracket rocking upon a horizontal hinge pin. I mount
upon the motor spindle a pulley suitable for driving the sewing machine by means
of a cord or belt. Upon the rocking bracket I provide a brake pad or shoe which
when the bracket is pulled over by means of a spring is applied to the rim of a
brake wheel fixed upon the spindle of the sewing machine. The ordinary hand
wheel of the machine answers the purpose very well. Upon the rocking bracket
I also arrange a contact piece in such a manner that when the bracket is rocked or
pulled over against the pull of the spring by means of a starting lever, rod or cord,
the contact piece establishes a connection between two springs and thus completes
the electric circuit whereby the motor spindle is set revolving. I make my contact
piece of such a length that it is free to move up and down between the springs to
allow the rocking bracket to put the necessary tension upon the belt.
The normal
position of the parts is as follows-The brake pad or shoe is pressed against the
brake wheel, the driving belt is slack, and the electric circuit is broken. The
motor and the machine are therefore at rest.
When the starting lever or rod or cord is moved either by the hand or by the
foot, the cycle of operations which my combination effects is first to release the
brake, secondly to complete the electric circuit, and thirdly to tighten the belt.
The machine is thus set in motion and continues to work as long as the starting
lever or rod or cord remains unaltered. When it is desired to stop the machine
the starting lever or rod or cord is moved or released and the cycle of operations is
reversed, namely, first the driving belt is slackened, secondly the electric circuit
is broken and thirdly the brake is applied. The belt being slack the momentum of
the motor causes it to continue to revolve for some little time, but the machine
itself is almost instantaneously stopped.
Instead of making the bracket to rock upon a horizontal hinge pin, I sometimes
arrange it so as to slide to and from the spindle of the machine, the cycle of
operations being performed in the same manner as hereinbefore described. In
order to maintain the necessary tension upon the starting lever or rod or cord while.

page_text: the machine is at work I make use of the pressure of the foot or knee of the
operator, or I employ a pawl engaging with ratchet teeth. The release of either
of these will cause the machine to stop.
Sometimes I mount my bracket so as to swivel upon a vertical pin, the cycle of
operations remaining the same as hereinbefore described.
I make the shape of my bracket and the method of carrying it to suit the table or
base of the machine to, which it is to be applied. When applying it to a treadle
sewing machine or a treadle lathe, I detach the treadle from the crank and attach
it to a rod, cord or chain so that when the treadle is depressed by the foot the
bracket is pulled over or outwards and the machine is started, and when the treadle
is relieved of pressure the machine is stopped.
I apply my invention to other kinds of machines such as lapidaries lathes,
polishing machines, and such like, modifying the method of mounting and carrying
the bracket to suit the type of frame base or table of the machine to which it is
to be applied. I do not limit the application of my invention to any particular
form of motor or of device for making electric contact.
Dated this 26th day of October 1904
MARKS & CLERK,
18 Southampton Buildings, London, W.C., and
13 Temple Street, Birmingham, Agents for the Applicant.
Improvements in Electrical Motor Fittings for Transmitting Motion
to Light Machinery.
I HENRY LEA of Bennetts Hill in the City of Birmingham Civil Engineer, do
hereby declare the nature of my said 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 has reference to the construction and arrangement of fittings for
applying electrical motors to sewing machines for transmitting motion, and to other
light machinery.
And in order that this my said invention may be more clearly understood, I will
now proceed to describe the same with the aid of the two accompanying sheets of
drawings which shew my invention as applied to a sewing machine.
The same letters of reference denote the same parts in every figure in which
they occur.
Figure 1 (Sheet 1) represents an end view of the apparatus when in such a
position that the running parts are at rest.
Figure 2 (Sheet 1) represents an end view of the apparatus when in such a
position that the running parts are in motion.
Figure 3 (Sheet 2) represents, a back view of the apparatus corresponding to
Figure 1.
a, is the table of an ordinary sewing machine bis the arm of the sewing machine.
This carries the bearings in which the cam shaft c, revolves. On the shaft c, and
secured to it is the usual small fly wheel d. e, is a grooved pulley also secured to
the shaft c.
The above mentioned parts are all found in ordinary sewing machines.
fis an electric motor of the proper size to drive the sewing machine when supplied
with electric energy at such a pressure as is usually employed for ordinary house
electric lighting.
To the spindle f¹ of the electric motor, I secure a pulley f which has a very
deep groove in its periphery (see Figure 3),

page_text: An endless band g, connects the pulley on the electric motor with the pulley e,
on the shaft of the sewing machine, so that the sewing machine may be driven by
the electric-motor f.
n,
I affix the electric-motor f to one arm of a rocking bracket which is jointed
to the base plate by a fulcrum pin h¹. This rocking bracket h, has a brake
shoe firmly secured to it by the arm h. The extremity *, of the vertical
arm of the rocking bracket h, is connected to the table by means of a strong
helical spring. To the underside of the horizontal arm h³ of the rocking bracket
I secure an electrical contact piece k. I affix a corresponding forked spring
contact piece 1, to the base of plate m, to which is also secured the terminal
socket and the enclosed resistance frame o. The base plate m, is attached to the
sewing machine table a, by the hinges m' m' so that if the driving band g is.
removed the whole of the apparatus may be turned down to the right (Figures 1
and 2) out of the way. This is done when it is required to turn back on its hinges
in the usual way the sewing machine for cleaning. p. is a cord connecting the
outer end of the horizontal arm of the rocking bracket with the usual treadle
of the sewing machine q. 9. are covered wires for supplying the electric energy
to the electric motor. r, is the twin flexible conductor by means of which the
electric energy is conveyed from any suitable point (such as a wall socket, or a
lamp socket) to the terminal socket n, of my apparatus.
OPERATION.
The action of the apparatus is as follows. I will suppose that the sewing.
machine is at rest, but that the apparatus is connected up by means of the flexible.
conductor, r, to the source of electric energy so that it is ready to be set in motion..
The parts will then be in the position shewn in Figures 1 and 3.
The rocking
bracket h, has then one of its arms vertical or nearly so and the other upon
which the electric motor rests, is horizontal. The rocking bracket h, is constrained'
to assume this position by the action of the helical spring j.
The brake-shoe h² presses against the rim of the fy-wheel d of the sewing
machine which it keeps at rest. The brake-shoe ³, also acts as a stop to prevent.
the spring, from pulling the rocking bracket h, too far towards the sewing
machine. The driving band g, now lies quite slack in the grooves of the pulleys/
and e, and the electrical contact piece k, being clear of the corresponding contact.
piece 7, no electric energy can pass through the electric motor f, which is therefore
at rest.
If now it is desired to set the sewing machine in motion, the treadle (not shewn
in the drawings) is depressed and held down. This pulls down the cord or rod p..
which is connected to the rocking bracket hat and the various parts of the
apparatus then assume the position shewn in Figure 2, and the three following:
actions take place immediately one after the other in the following order.
First. The brake-shoe ' is removed from the fly wheel of the sewing machine.
Second. The electrical contact piece k, is forced into the forked spring contact
piece, thus putting the electric motor f into circuit through the regulating;
resistance o. The forked spring contact piece 1, allows the contact piece k, to
move down between its arms far enough to allow the rocking bracket h, to put the
necessary tension on the belt g. The electric motor is thus set in motion.
Third. The band g, is tightened to such a degree that it will transmit power
from the electric motor to the pulley e, causing the shaft c, and wheel d, to rotate
giving motion to the sewing machine."
The parts remain in this position and the sewing machine continues to run so long
as the treadle is held down.
When it is desired to stop the machine the operators foot is removed from the
treadle.
The helical spring j is thus allowed to act and it restores the parts to the position
shown in Fig. 1, thus repeating the cycle of operations caused by drawing down the.

page_text: cord, but in the reverse order, namely first slackening the driving band
breaking the electrical contact and third applying the brake to the wheel.
g, second
The effect of slackening the driving belt is that, although the sewing machine is
instantly stopped by the brake yet the electric motor is not instantly stopped,
but although the supply of electric energy is stopped the electric motor continues
to run by its own momentum for a short time, till gradually brought to rest by
friction.
The gradual cessation of the motion is very desirable to avoid injury to the
electric motor.
I can apply this my invention to any ordinary sewing machine driven by the foot
of the operator all the alteration necessary being to affix the apparatus constituting
my invention and to remove the connecting rod under the table and also the driving
band which connects the wheel under the table with the pulley on the cam shaft,
and to connect the cord p. to the treadle, so that pressure on the treadle pulls down
the cord. The electrically driven machine can be easily reconverted into a foot
driven machine, electrical apparatus being either retained or removed as most
convenient.
My invention may be applied to a sewing machine driven by the operators hand,
but in that case a grooved pulley must be secured to the cam shaft of the sewing
machine, and a treadle, or equivalent devise must be provided whereby the cord p.
may be pulled down or other means provided to produce the same effect ou the
rocking bracket.
I have described and illustrated the means by which I usually carry my invention
into effect as applied to a sewing machine, but I can apply my invention to other
light machinery and I may vary the configuration and arrangement of parts and
substitute equivalents, while not departing from my said 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
:
1. In improvements in electrical motor fittings for transmitting motion to light
machinery. The combination of "A rocking bracket affixed to a sewing machine,
and carrying an electric motor to drive the said machine, substantially as herein-
before described and illustrated by the drawings.
2. The combination of a brake-shoe secured to the rocking bracket, substantially
as hereinbefore described and illustrated by the drawings.
3. The combination, of a spring to the rocking bracket in the one direction, and
a cord to move it in the other, substantially as hereinbefore described and illustrated
by the drawings.
4. The combination of a pair of electric contact pieces, one being affixed to the
rocking bracket substantially as herein before described and illustrated by the
drawings.
5. The combination of a slack driving band capable of being tightened by the
pull of the cord on the rocking bracket substantially as hereinbefore described, and
illustrated by the drawings.
6. The general construction combination and arrangement of the aforesaid parts,
substantially as and for the purposes hereinbefore described in the foregoing
Specification and illustrated by the accompanying sheets of drawings.
Dated 29th July 1895.
THOS. KENDRICK,
3 Cherry Street, Birmingham, Agent for said Applicant.