Year: 1887

page_text: Date of Application, 29th' June, 1887
Complete Left, 29th Mar., 1888
Complete Accepted, 29th June, 1888
I, JAMES GRIEVE LORRAIN, of Norfolk House, Victoria Embankment, London,
W.C., Consulting Engineer, do hereby declare the nature of this invention to be as
follows:-
In my previous specification accompanying my letters patent No. 8181, dated
21st June 1886, I described a form of chronoscope, or electric clock as it is more
frequently though perhaps less correctly termed inasmuch as the essential parts which
usually exist in ordinary clocks are entirely absent.
My present invention consists of improvements or modifications in the details of the
form of chronoscope just mentioned.
The first improvement or modification consists in the employment of continuous
currents to actuate the chronoscope, instead of alternating or reversed currents as
specified in my said previous specification. The next improvement or modification is
to employ an electromotor which, instead of having one of its parts an electromagnet
and the other a permanent magnet, has both parts electromagnets. This modifica-
tion entails the use of a commutator which I fix on the spindle carrying the moveable
part (the said moveable part being hereinafter referred to as the armature) of the said
electromotor, or to any convenient part in mechanical connection therewith. The
said armature moves upon an axis or spindle in a vertical or a horizontal plane. In
the case where
moves in a horizontal plane its spindle is vertical and carries a worin
or endless screw working in a worm wheel forming one of the train of wheels
actuating the hands. In the case where the armature moves in a vertical plane its
spindle is horizontal and carries a toothed wheel forming one of the train of wheels
actuating the hands. Another improvement or modification consists in the employ-
ment of a different form of mechanical brake or detent to take the place of the magnetic
brake referred to in my above mentioned previous specification. This detent consists
of a gripping device acting upon a pin or pins, or the equivalent thereof, attached to
the spindle of the electromotor, or to a part in suitable mechanical connection
therewith. A convenient form of gripping device consists of a plate of soft iron,
or of a plate of any other convenient material with a piece of soft iron affixed thereto,
077

page_text: with a more or less zigzag groove or slot cut therein, and of such form that the pin
on entering the said groove or slot will press the plate upwards, bringing it within the
range of a small electromagnet fed by the current actuating the chronoscope, and
arranged either in series with or in a shunt to the electromotor. The plate being so
raised and detained in its raised position by the electromagnet, the pin will then come
upon the side of a vertical part of the said groove or slot so as to stop its motion and
bring the armature of the electromotor to rest. As soon as tho current ceases to flow
through the electromagnet holding up the said plate, the plate will drop by gravity, so
that the pin will then be in such position (when the next transmission of the electric
current takes place) that the armature of the electromotor, with which it is in
sufficiently rigid mechanical connection, will be in the proper position for again
producing a movement. In conjunction with this form of mechanical brake I may
sometimes employ the form of mechanical brake referred to in my said previous
specification. In action I arrange that each transmission of the clectric current sent
from the master clock through the chronoscopes has a duration of a second or more,
so as to allow the momentum of the armature to expend itself and the armature to
come to rest before the electromagnet of the detent allows the plate to drop. It will
be seen that at each transmission of the electric current an angular movement of the
electromotor, or more strictly speaking of its armature, will take place, and the hands
be advanced a definite amount.

page_text: Improvements in Electric Clocks.
I, JAMES GRIEVE LORRAIN, of Norfolk House, Victoria Embankment, London, W.C.,
Consulting Engineer, 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:
In the specification accompanying my Letters Patent No. 8181 dated 21st June
1886, I described a form of electric clock. My present invention consists of
improvements or modifications in the details of this previous invention.
The first improvement or modification consists in the employment of continuous
currents to actuate the electric clocks instead of alternating or reversed currents as
specified in my said previous specification. The next improvement or modification
lies in the employment of an electromotor which instead of having one of its parts
an electromagnet and the other a permanent magnet has both parts electromagnets.
This modification entails the use of a commutator which I fix on the spindle carrying
the movable part (the said movable part being hereinafter referred to as the armature)
of the said electromotor or to any convenient part in mechanical connection therewith.
The said armature moves upon an axis or spindle in a vertical or a horizontal plane.
In the case wherein it moves in a horizontal plane its spindle is vertical and carries
a worm or endless screw working in a worm wheel forming one of the train of wheels
actuating the hands. In the case wherein the armature moves in a vertical plane
its spindle is horizontal and carries a toothed wheel forming one of the train of wheels
actuating the hands. Another improvement or modification consists in the employment
of a different form of mechanical brake or detent to take the place of the inagnetic
brake referred to in my above mentioned previous specification. This detent consists
of a gripping device acting upon a pin or pins or the equivalent thereof attached to
the spindle of the electromotor or to a part in suitable meclianical connection therewith.
A convenient form of gripping device consists of a plate of soft iron, or of a plate of
any other convenient material with a piece of soft iron affixed thereto, with a more
or less zigzag groove or slot cut therein.and of such form that the pin on entering
the said groove or slot will press the plate upwards, bringing it within the range
of a small electromagnet fed by the current actuating the electric clock, and arranged
either in series with or in a shunt to the electromotor. The plate being so raised,
and detained in its raised position by the electromagnet, the pin will then come upon
the side of a vertical part of the said groove or slot so as to stop its notion, and bring
the armature of the electromotor to rest. As soon as the current ceases to flow
through the electromagnet holding up the said plate, the plate will drop by gravity,
so that the pin will then be in such position (when the next transmission of the

page_text: electric current takes place), that the armature of the electromotor, with which it is
in sufficiently rigid mechanical connection, will be in the proper position for again
producing a movement.
Having thus described the nature and object of my invention for Improvements
in Electric Clocks, I shall now proceed to explain in detail one or more ways in which
it is to be or, may be, performed or carried into effect: and in order that this more
detailed description may be more readily understood I have annexed hereunto sheets
of drawings illustrative of my invention and have inserted in the same figures and
letters of reference corresponding with those in the following explanation. In the
said sheets of drawings similar letters of reference refer to similar parts.
:
Figure 1 is a view of my complete Electric Clock as seen from behind. A is the
front plate serving to support the wheels, the detent and other parts. B is the field
magnet, or fixed part of the electromotor, and the armature or moveable part
thereof. The spindle D, with and around which the armature moves, is in this case
vertical, and bears towards its upper end worm E which gears into the first of the
train of wheels actuating the hands. F is the commutator, and G the commutator
springs or brushes serving for the passage of the electric current to and from the
electromotor. At the upper end of the spindle, and at right angles thereto, a pin H
is fixed (being passed through D so as practically to constitute two separate pins);
and suitably placed to receive and engage this pin is the gripping device or plate J
(shown in this case as formed of a non-magnetic material and having a piece of soft
iron K affixed to its upper part). Above K, and in close proximity thereto, is the
small electro-magnet L, whose poles are shown projecting through the upper part of
the supporting piece M.
Figure 2 shows the electromotor in plan with the commutator removed, and fixed
in its position in the frame of the Electric Clock.
Figure 3 is a plan view showing the upper part of the spindle and the gripping
plate in the positions which they occupy relatively to one another when the parts
are in their normal position that is to say during the intervals between the several
transmissions of the electric current.
Figure 4 is an enlarged view of the electromagnet and the gripping device in the
position occupied at the moment when, as is hereinafter described, the pin has entered
the zigzag slot of the gripping plate, and raised the latter into position to be attracted
and held up by the electromagnet.
Figure is an enlarged view of the same parts when at rest in their normal position,
when it will be seen that the pin H is at the end of the long horizontal part of the
slot and free to commence its movement as will be hereinafter described.
These figures, namely 1 to 5 inclusive, illustrate a case wherein the armature moves"
in a horizontal plane and I shall now explain the action of my invention as illustrated
in these figures. The electromotor is one of a well known form whose action is well
understood and therefore need not be explained here. Its armature would
continuously rotate as long as the current of electricity passed through it, but, as
such continuous rotation is not desired in this case, the function of the detent is to
prevent movement through a greater angular distance than 180°. 1 have drawn the
parts in the position shown in Figure 1 in order that the pin H may be clearly shown ;
but I desire it to be understood that this is not the normal position which it occupies
when the electromotor is at rest-that normal position being at right angles, or nearly
so, to the position shown in Figure 1 and which is more clearly represented in
Figure 5, it being understood that the pin and the armature are in the same vertical
plane with one another or nearly so. Let us assume now that a current is passed
through the electromotor when the parts are in their normal position, namely as
shown in Figures 3 and 5. As soon as the current passes, the armature begins to
move, carrying the pin H in the direction shown by the arrow (Figure 3), the gripping
plate being in its normal position as shown in Figures 1 and . The limb of the
pin being in the long horizontal slot is free to move out of engagement with the
gripping plate, whilst the opposite limb 2 is moved. round so as to strike the nose j

page_text: of the gripping plate, which nose, being curved in a suitable direction, causes the
gripping plate to be raised during the onward movement of the pin which then strikes
against the shoulder and so expends all or most of its energy. The gripping plate
being thus raised the soft iron piece K on its upper surface is brought within range
of the electromagnet L, which, being active during the passage of the current, causes
the gripping plate to be held up. When the limb 2 of the pin H has struck the
shoulder it may rebound but the gripping plate being still held by the electro-
magnet in its raised position it will in rebounding strike against the vertical part,
but, the current being still on, the armature will still be pulled in its original
direction, so that the pin will be carried on to actual contact with the shoulder 73
again, and will come to rest. there. The current is maintained for such a length of
time as to allow the parts to come to rest, when the current being no longer
transmitted from the master clock the electromagnet L ceases to sustain the gripping
plate, and the latter is allowed to fall, when the pin will again be in the long
horizontal slot j' as shown in Figure 5, and ready for another movement through an
angle of 180° at the next transmission of the electric current. At each movement the
worm E, acting through the train of wheels, moves the. hands of the clock. through a..
definite angular distance as required..
The commutator F, consisting of two conducting segments insulated from one
another, is of the usual form employed with this type of electromotor.
I sometimes find it convenient to provide the gripping plates with an adjustable
balance weight as shown at O in Figures 1, 3, 4 and 5, for the purpose of regulating
the action of the gripping device.
The form of gripping plate already described has a slot for the pin to travel in but
it will be understood that a groove may be substituted; in which case the pin is made
of sufficient length for its end to travel in the groove, and the gripping plate, instead
of being flat as illustrated, is bent round so as to be concentric as it were with tho
armature spindle..
Figure 6 represents an Electric Clock the armature of which moves in a vertical
plane, in which case its spindle is provided with a pinion gearing directly into the
first of the train of wheels actuating the hands. In this figure the parts are shown in
elevation as seen from behind, the back plate being removed. The action in this case
will be readily understood from what has preceded.
Figures 7, 8, 9 and 10 illustrate a detent which I find it convenient to employ with
this form of Electric Clock. Figures 7 and 8 are back views of the detent, the former
figure illustrating the gripping plate before it is raised to the electro magnet, and the
latter illustrating it when held up by the electromagnet. Figure 9 is a front view of
the gripping plate, and Figure 10 is a plan. With this form of detent I employ a
pin similar to that hereinbefore referred to but bent at right angles towards the
extremities as shown in the separate view of the pin in Figure 11. In
Figures 7, 8, 9 and 10 the gripping plate is shown as made of soft non-magnetic
material for the purpose of silence with metallic parts attached thereto where the wear
and tear is greatest. The action in the case of the form of detent shown in
Figures 7, 8, 9 and 10 will be readily understood from the description given of the
action in the case of the form of detent shown in Figures 1, 3, 4 and 5.
It will be seen that at each transmission of the electric current an angular
movement of the electro-motor, or inore strictly speaking of its armature, takes place,
and the hands are advanced a definite amount. In practice I find it convenient to
transmit the electric current from the master clock every half minute; and I arrange
the train of wheels in accordance with this so that the long haud is moved one
one-hundred-and-twentieth (th) of the circumference of the dial, the short hand
being moved through'a proportionate angular distance. I also find it convenient to
maintain the flow of the current at each transmission for a period of two and a
half seconds in order to allow the parts to come to rest before the gripping plate is
allowed to drop.
I arrange iny. Electric Clocks as referred to in, my., previous,, Specification.
.

page_text: Number 8181 of the year 1886; but instead of employing a master clock transmitting
alternating or reversed currents as therein referred to 1 employ a master clock
transmitting direct or continuous currents, that is transmitting currents all of which
are in the same direction. It must be understood however that a master clock
transmitting currents alternately in a reverse direction would actuate my Electric
Clocks satisfactorily.
I desire it to be understood that I do not limit myself to the form of electromotor
shown, as almost any kind of electromotor will answer my purpose: and it is not
necessary for me to limit the angular movement of the armature to 180°. Thus if
I employ a single pin projecting in one direction only from the spindle I may make
the angular movement equal to 360°, the train of wheels being of course altered to
suit or by again altering the train of wheels and by having three pins projecting
at angular distances of 120° from each other I might employ a movement through an
angular distance of 120°, and so on.
In my provisional specification I stated that in conjunction with the form of
mechanical brake herein described I may employ the form of mechanical brake
referred to in my previous Specification Nuniber S181 of the year 1886, but in
practice I do not find this to be necessary as the form of mechanical brake herein
described is quite satisfactory in its operation.
In practice I find that a suitable material of which to construct the gripping plate 2
is what is known as hard vulcanized fibre provided it be made sufficiently stout;
though when noise is not objected to the gripping plate may be more conveniently
made of brass or iron, in which case it will wear better and last longer. In all cases
however where the gripping plate is made of non-magnetic material a piece of soft
iron must be attached to the upper part to enable it to be attracted and held up by 2
the electromagnet.
Care should be taken not to have the electromagnet of the detent too strong as
it would be in such case liable to attract the gripping plate before the pin had moved
trom the slot or groove.
Having now particularly described and ascertained the nature of my said Inven- 3
tion and in what manner the same is to be performed I declare that what I
claim is
1. The Improvement in Electric Clocks consisting in the combination of an
electromotor capable of being actuated by continuous currents and capable of rotating
or moving in an angular direction at each transmission of the electric current and a
detent serving to arrest the movement of the electromotor when it has travelled
through its required angular distance and to allow it to make its next movement
in the same angular direction as before when the next transmission of the electric
current takes place.
3
2. The Improvement in Electric Clocks consisting in the employment of a detent 4
acting substantially in the manner and for the purpose set forth.
3. The Improvement in Electric Clocks consisting substantially in the form of
detent illustrated in Figures 1, 3, 4 and 5.
4. The Improvement in Electric Clocks consisting substantially in the form of
detent illustrated in Figures 7, 8, 9 and 10.
5. The Improvement in Electric Clocks consisting in the employment of a gripping
plate having a zigzag slot and a pin engaging therein substantially as and for the
purpose set forth.
4
6. The Improvement in Electric Clocks consisting in the combination of the plate J
whether formed of a magnetic material or having a piece of magnetic material affixed 5
thereto the pin H and the electromagnet L substantially as and for the purpose
set forth.
7. The Improvement in Electric Clocks consisting in the combination of the plate J

page_text: whether formed of a magnetic material or having a piece of magnetic material affixed
thereto the pin H the electromagnet L and the adjustable device Ů.
8. The Improvement in Electric Clocks consisting in the arrangement and the
combination of parts substantially as set forth with reference to Figures 1, 2, 3, 4
and 5.
9. The Improvement in Electric Clocks consisting in the arrangement and the
combination of parts substantially as set forth with reference to Figure 6 and having
combined therewith a detent substantially as set forth with reference to Figures 7, 8, 9
and 10.