Improvements in Automatic Electric Intermittent Motors for Driving the Mechanism of Recording Instruments and the like.
Year: 1893

page_text: Date of Application, 9th Oct., 1893
Complete Specification Left, 9th July, 1894-Accepted, 11th Aug., 1894
Improvements in Automatic Electric Intermittent Motors for Driving
the Mechanism of Recording Instruments and the like.
GEORGE WILLIAM FAIRALL 34 Ann Street, Tettenhall Road Wolverhampton
in the County of Stafford Electrician do hereby declare the nature of this invention
to be as follows:-
This invention relates chiefly to automatic electric driving mechanism for
recording instruments.
The electric driving is accomplished according to this invention through the
medium of a disc wheel & friction pawl of which the pawl is fixed on a lever, the
said lever is in contact with a lever which carries an armature, & by means of a
suitable electro magnet or magnets, this lever called the armature lever, is drawn
towards the magnet when electrical contact is made, as hereinafter described &
at the same time raising the first named lever, called the clutch lever carrying the
friction pawl which slides inoperatively in one direction along the periphery of the
disc, the pawl being made in the form of a spring & of a suitable shape presses
itself with sufficient firmness against the periphery of the disc, to insure that such
pawl will bite against the disc on the instant the armature is released from the
influence of the electromagnet on the other end of the clutch lever there is pivoted
a bar carrying a suitable weight to drive the mechanism, in the end of this bar
called the connecting bar, there is a slot, this bar engages with a disc through the
medium of a short arm, in the end of this arm there is a pin which works in the
slot referred to in the connecting bar as hereinafter described, & is fixed on
the axis of this disc called the contact disc, which disc has part of its circum-
ference cut away to allow a lever called the contact lever, which lever is pivoted
on an axis adjacent to the axis on which the contact disc is carried & the inner end
of such lever is normally pressed downwards by a spring & is provided with a
downward projection, which rests normally on the periphery of the disc & holds
the outer end of such lever out of electrical contact with a spring terminal, but if
such disc is moved a short distance, the lever is pressed down, so that the projec-
tion thereof falls down on the part of the disc that is cut away & the outer end of
the lever is brought into electrical contact with the spring terminal.
To complete the circuit & set the driving mechanism in motion, the projection of
the inner end of this lever, has to be drawn down upon that part of the disc where
a portion has been cut away being moved into such a position in the manner herein-
after described, so that the outer end of such lever is in electrical contact with the
terminal & as the connecting bar raises each time through the power imparted to it
by the armature lever & clutch lever the slot in the connecting bar engages with
the pin in the small arm & consequently moves up the inner end of the contact lever
& brings the outer end of such lever out of electrical contact with the terminal, the
projection of the contact lever then rests upon the top of the disc that has not
been cut away & thus the outer end of such lever is held out of contact with the
terminal, until the connecting bar returns to its normal position & the pin in the
short arm referred to is again moved sufficient distance to allow the contact lever
to fall on the part of the disc that has been cut away, & again brings such lever
into contact with the spring terminal.
Dated this 6th day of October 1992
GEORGE WILLIAM FAIRALL,
Applicant.

page_text: COMPLETE SPECIFICATION.
Improvements in Automatic Electric Intermittent Motors for Driving
the Mechanism of Recording Instruments and the like.
I GEORGE WILLIAM FAIRALL of 34 Ann Street, Tettenhall Road,
Wolverhampton in the County of Stafford Electrician do hereby declare the nature
of my 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 relates chiefly to an automatic driving mechanism for recording
instruments in which an electric current is periodically applied to raise a weight
which in its descent imparts motion to a train of clockwork, and which at the end
of its fall causes the circuit through the exciting coils of an electro-magnet to be
completed so as to attract an armature which by its movement lifts the weight the
circuit through the coils of the electro magnet being then broken. The weight
then descends and the energy of its descent is the motive power for operating the
driving mechanism. When the weight has fully descended the circuit is again
completed and the cycle of operations is repeated.
In order that this invention and the manner in which it can be carried out in
practice may be well understood I will proceed to describe with reference to the
accompanying drawing what I consider the best means for carrying it into practical
effect. The driving is shewn as applied to the clockwork illustrated by the
wheels YY the escapement wheel being shewn at Y. The driving is effected
through the medium of a disc wheel D and a friction pawl P fixed on a bell crank
lever C (called the "clutch lever") loosely mounted on the axis of the disc D one
arm of which lever C is in contact with the end of a lever L called the armature
lever which is centered at 7 and carries an arınature A influenced by an electro
magnet E (or electro magnets) energised as hereinafter described by a battery Z
or other convenient generator of current, the circuit from which is completed when
the contacts X and n bear against each other.
When the armature A is so attracted it acts on one arm of the clutch lever C so
as to raise the other end thereof carrying the friction pawl P which slides
inoperatively in one direction along the periphery of the disc D, the pawl being
made as a spring pawl and being acted upon by a spring as at p and being of a
shape to press with sufficient firmness against the periphery of the disc D to insure
that the said pawl bites against the disc on the instant the armature A is released
from the influence of the electro magnet E. On the other end of the clutch
lever C there is pivoted a bar B carrying a weight W which provides the power
to drive the mechanism. This bar B I call the connecting bar. This connecting
bar B actuates a disc T (called a contact disc) through the medium of a short
arm secured to the said disc or to the axis thereof in the end of which arm there
is a pin which works in the slot S in the connecting bar B. The contact disc T
has part of its circumference cut away as shewn at t to allow a bell crank lever N
(called the contact lever) pivoted on an axis n³ to move to bring the contact
pieces n and X together. The one end of the contact lever N is moved downwards
by a spring V and is provided with a downward projection n³ (shewn as a roller)
which is pressed by the spring V onto the periphery of the contact disc T so as to
hold the contact piece n at the other end of the said lever N out of electrical
contact with the contact spring X. If the contact disc T be moved a short distance
by the descent of the weight W so that the cut away part 3 comes opposite the
projection of the lever N the said projection n³ is pressed into the cut away
part and the lever N is operated so that the contacts X and n meet and the circuit
through the magnet E is completed the armature A is attracted and the armature
lever L acts on the clutch lever C and the weight W and bar B are raised and the
lower end of the slot S in the said bar B acts on the pin in the arm t and moves
round the disc T so that the uncut away part comes opposite the projection n³ on

page_text: the end of the contact lever N and moves the said lever so that the electrical
contacts n and X are separated. The pawl P when the lever C was operated to
raise the weight W rode over the periphery of the disc D and when the contacts n
and X are separated from the weight W begins to descend the said pawl P effects the
driving of the disc D and the gearing with which it is connected. The weight
descends until the connecting bar B returns to its lowest position when the upper
end of the slot S acts on the pin t' in the arm t which again moves the disc Ta
sufficient distance to bring the cut away part opposite the projection n when the
contact lever N moves so as again to bring the contact n and X together when the
weight W is again raised as herein before described.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed 1 declare that what I
claim is
1. In automatic intermittent motors for the purposes mentioned the employment
of a weight in combination with an electro magnet automatically and intermittently
magnetized by the fall of the weight and demagnetized when the weight is lifted
substantially as hereinbefore described.
2. An automatic intermittent motor for the purposes described the said motor
being constructed or arranged substantially as hereinbefore described and illustrated
in the accompanying drawings.
Dated the 0th day of Jul, 1901.
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, W.C., Agents.