Year: 1888

page_text: 1, ALBERT LYMAN PARCELLF, a citizen of the United States, of Boston, Suffolk
County, Massachusetts, now residing in New York, County and State of New York,
USA, Electrical 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
-
My present invention has special reference to Electric Clocks of the character
shown in Letters Patent granted to me in England, No 5328 on the 12th day of
April, 1887, though not necessarily confined to clocks of that particular type
In the accompanying drawings,
Figure 1 is a front view,
and
Figure 2 a side elevation of so much of the clock mechanism as is necessary to
illustrate some features of my invention
Figure 3 is a diagram view illustrating the switch mechanism and the arrangement
of circuit
Figure 4 is a side elevation illustrating one very simple form of clock train
Figure is a front diagram view, and
Figure 6 a side elevation illustrating another feature of my invention
Figure 7 is a diagram view showing my improved arrangement of circuits in
connection with an ordinary rigid pendulum
Figure 8, detail view showing a rotary switch, and
Figure 9, a detail view showing an arrangement for locking the train against
accidental movement
All of the features illustrated in the drawing may of course be combined in a
single time piece, though they have not been so shown
Referring to Figures 1, 2, 4 and 6, the pendulum A in vibrating, rocks a lever a,
whose fork end embraces the pendulum, the opposite or upper end being connected
with a rock shaft a¹ This rock shaft may be split or slotted at b, Figure 2, and
carries an arm 6', which may be adjusted endwise and clamped in the slot by a set
screw The end of the arm 6', engages with a notch in the rocking anchor lever B,
in the manner shown in Figure 1, and well understood, so that the arm b¹, 18

page_text: detached from the train at a given point in the vibration of the pendulum irrespective
of the amplitude of vibration The movement of the anchor lever B is limited by
stops Pawls on the rocking lover B ongigen ritchot wheel C on a spindle of
the clock train which is thereby driven a uniform distance at each vibration of the
pendulum
The
In the drawings the pendulums are ill shown hanging in their central position
In Figure 3, which shows the circuit connections, the arm ituro D on the end of
the pendulum is moving with the pendulum in the direction of the arrow and is about
to come into the field of the driving magnet E, the circuit of which is closed
pendent pivoted oscillating switch Ghas its under fice curved on the arc of a circle
of which the pivot g is the centro The pendulum works between adjustible screws
carried by posts on the switch, and by their adjustment the extent of movement of
the switch may be regulated Three contacts are shown fixed in the curved fice of
the switch The middle one is connected through the coil of the motor magnet E
with one pole of the battery. B B while the outer contacts are both connected with
the same pole of the bittery through resistance Rh A pivoted brush H preferably
weighted at one end, (or a spring might be used) is connected with the opposite pole
of the battery and bears agunst the curved fice of the switch The circuit is shown
closed from one pole of the battery through the brush, central contact of the switch,
and magnet E to the opposite pole of the battery The pendulum in starting is
assumed to move to the right ind brings the imiture into the field of the magnet
The continued movement of the pendulum now under the attractive influence of the
motor magnet swings the switch to the right, and causes the brush H to pass off of
the middle cont ict on to the left hand contact, thus breaking the circuit through the
motor mignet E and short circuiting the battery through the resistance R
Preferably, the contact of the brush H with the curved fice of the switch is such
that the short circuit is completed before the circuit of the motor magnet is broken,
the bittery circuit is therefore nover open This is a material advantage in working
with some forms of buttery The pendulum having reached the end of its vibration
and the motor magnet being no longer energized, returns by its own gravity and
resilience and completes its vibration on the opposite side of the central line, moving
the switch and ti insferring the bush to the night hind resistance contact I have
found in practice that it is unnecessary to have a motor magnet upon oach side of the
centre of vibration, although of course, two magnets may be used if desued
The form of switch illustrated swings easily, presents a minimum of resistance to
the movement of the pendulum and as the cont icts on its curved face are constantly
rubbed by the brush H they are kept clean and bright and the curved face being
upon the underside of the switch, there is no tendency for dust to accumulate
thereon I prefer to employ weighted brush because uniform pressure upon the
fice is obtained With spring the power will vary more or loss on account of
weir, or changes in temperature, &c
The manner of pivoting the brush and the special form of clock trun illustrated
in Figures 1 and 2 are special features of my invention and are presently described
In all the Figures, A* indicites a bob, which may be a cylindrical cup filled with
shot, sand or other suitable material by which the weight of the pendulum may be
adjusted with exactness
In Figures 5 and 61 have shown a flexible non-resilient pendulum suspended from
a post A¹, and carrying a suitable bob It may be made of any flexiblo material,
such as webbing, woven from various substances, or it may be of leather At the
top it is shown suspended by two short suspension springs r, clamped in the post A¹,
and attached to a metal piece on the upper end of the pendulum A plate y of metal
may be placed on each side of the flexible pendulum at the point where it comes_in
contact with the switch devices and driving mechanism A pendulum of this
character is not matori illy affected by heat or cold and no means of compensating for
changes in temperature are necessary The material forming the pendulum could be
prepared or treated so as not to absorb or be affected by dampness or by variations of
temperature The form of switch shown in these figures is similar to that above

page_text: described, except that there are two contacts in the face of the switch instead of three
The circuit of the battery will therefore be open a part of the time In these figures
another manner of driving the pendulum is shown The magnet E instead of acting
upon an armature upon the end of the pendulum has a pivoted armature e carrying a
light spring finger which is drawn against the bob of the pendulum at the proper time
to give it a return impulse, for instance, suppose the pendulum is moving to the right
as seen in the figure when it has reached the full extent of its swing it will hive
moved the switch so that the circuit of the magnet will be completed through the
brush and the left hand contact, and the sping drawn up gunst the pendulum, thus
giving a return impulse to it The circuit rem uns closed until the movement of the
pendulum to the left operates the switch and opens the circuit, when the armature falls
back to its original position The two positions of the spring ire indicated by full and
dotted lines Uniform impulses are therefore given to the pendulum respective of
the power of the battery The spring is prefei ibly long and light, and I have found
in practice a piece of watch spring sufficient for the purpose of driving a hewy second
pendulum The magnet, its irm iture, and the sping are adjusted for sy one half the
power of the battery, and as the battery is only used to pull the spring up against the
pendulum the force of the impulses is uniform, depending as it does upon the spring
and not upon the strength of the bittery A spring on each side the pendulum might
be used The circuit connections shown are such that when the pendulum is in the
central position the battery is closed through the re-ist inco R The bob may be
adjusted as on an ordinary pendulum, and the stop agunst which the irmature e works
may be covered with felt or cork to prevent noise
-
In Figure 7, I have shown in ordinary rigid pendulum provided with bob and
arinature, and suspended by a short sping is usu il The pendulum works between
the adjustable screws of a sliding switch, having three contacts connected in the sime
minner as shown in Figure 3 The bush, however, is of a different character, it is
inide to slide endwise in suitable supporting block 2, ind is adjusted by means of
screw, for the purpose of regulating it iccur itely with reference to the switch contact
This figure merely illustrates the application of my improved arrangement of circuit
to a rigid pendulun
Figure 8 shows rotary switch on the sime irbor as the driving ritchet wheel of
the cloch train It consists of a hub having alternate conducting strips, to he
connected to the battery, and intervening insulated spices A weighted brush such
as described, may be used with this switch
In the construction here shown, 1 cross
arm T is secured on the end of the rock shaft a', ind a gravity pawl p, engiging the
teeth of the ratchet wheel, is carried on cach end of it The movement of the
pendulum causes one or the other of the piwls to engage the itchet wheel and drive it
forward step by step In this figure the driving lever instead of being forked enters
an aperture in the pendulum, in ordinary rigid pendulum such as that shown in
Figure 6 being shown in this figure Stops for throwing the pawls out of engagement
with the ratchet wheel may be employed if desired is shown and described in my
patent No 5328 of the 12th April, 1887, above mentioned
In Figure 9, the driving ratchet wheel is actuated by pawls upon a pivoted inchoi
lever rocked by a rod 6', on the rock shift, is already described Ordinarily, however,
when a ratchet wheel is employed the bands may by accident be moved and in the case
of tower clocks, some arrangement for preventing this is desirable because the snow
and wind are liable to move the hands An arrangement for locking the hands is
shown in this figure On the same arbor with the ratchet wheel another wheel F,
having radially projecting teeth is mounted A pallet lever on the rocking spindle of
the anchor lover ongages the teeth of the wheel F The pillets do not in any way
interfere with the driving of the tr un, but they enter between the teeth of the whol
and lock the train against movement in either direction The pallets gradually enter
and withdraw from the teeth as the ratchet wheel is rotated and at no time is the train
free to move except in response to the vibrations of the pendulum Of course the
construction of these locking devices may be varied
In my improved clock the pendulum is disconnected from the train when it his been

page_text: driven given distance irrespective of the battery or propelling power and irrespective
of the amplitude of vibration of the pendulum The running of the trun is therefore
absolutely uniform, and further since the resilient flexing pendulum describes a cycloid il
arc and is practically isochronous under all degrees of amplitude required in a clock,
the clock runs continuously with unchanging time By driving the pendulum by i
battery of strength greater than that required for driving the trun and giving it an
amplitude of vibration in excess of that required for driving the trun, important
results are obtained, for instance, should the battery fail, the pendulum will continue
to drive the train for a consider ible length of time before its amplitude becomes too
small Further, the pendulum does all of its work during the central part of its
swing when it is moving with its greatest vigor Practically the pendulum is a free
vibrator, such little work as it has to do being performed by it it the most advantageous
point in its vibration The switch offers but very slight resistance to the pendulum,
and since the arc described by the switch and that part of the pendulum which actuates
it as well as that of the lever a, and that part of the pendulum which drives it, all
coincide or have the same direction the entire mechanisin runs smoothly
In practice much care is required to ensure a perfectly uniform contact between the
brush and the face of the switch If the pivot of the brush is not placed in the
proper relation to the face of the switch one portion or edge only of the brush
may bear upon the switch, thus giving an imperfect contact, and causing unequal
wear
In use also, even if the switch and brush are properly related, the contact surfices
are liable to become impured either by reason of unequal wouring of parts of the
brush or switch, or of the brush bearing
Whether the brush be a pivoted one, such is shown, or not, it should be capable of
rocking transversely to accommodate itself readily to the face of the switch By thus
constructing the brush special care in making and mounting it and its bearing pin are
avoided and the surf ices of contact will not vary in use
One practical manner of mounting the brush is illustrated in the drawing It is
cut out on top for the reception of the bearing pin, and 15 pivotally hung thereon by
a transverse pin Sufficient play being allowed it will rock transversely to
accommodate itself to the fice of the switch This structure is simple, practical
and efficient
The trun illustrated in Fig 1 and 2, is provided with sweep seconds hand W,
actunted in the following manne
One of the two pawls b2b drives the wheel ( it each vibration and as will be
plain from the drawing eich piwl acts on cach tooth in the wheel There being
The
30 teeth in the wheel it will therefore receive 60) impulses in each revolution
spindle of the wheel extends to the frout of the clock-face and caries a sweep seconds
hand which is moved over 1 seconds spice on the dial at each actuation of the wheel C
The minute hand is driven in proper time by the gears C³, C³, C³, C³, and the hour
hand by the gears c', c², c³, and e, as will be plain from the drawings to any one
familiar with movements of tlus character
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 The combination, in an electric clock, of an electrically driven pendulum, the
driving magnet which operates said pendulum, its battery and circuit, the moving
switch, actuated by the driven pendulum, the electrical contacts thereon, and circuit
connections whereby the driving magnet is intermittently energized to vibrate the
pendulum without opening the battery circuit
II The combination of the electrically driven pendulum, the driving magnet its
battery and circuit, switch devices actuated by the pendulum in its vibration, a brush
and contacts on the switch, and branch or short circuit through which the battery
is short circuited when the pendulum is at and near the limit of its swing, substantially
as set forth

page_text: III The combination of the electrically driven pendulum, the driving magnet, its
battery and circuit, switch devices actuated by the pendulum, three switch contacts,
the middle one being connected through the magnet with one pole of the battery and
the other two connected with the same pole of the battery outside of the magnet,
and the switch brush connected with the opposite pole of the battery
IV The combination of the electrically driven pendulum, switch devices inter-
mittently operated by the pendulam, the driving magnet and its battery and circuit,
and weighted or gravity brush which bears on the switch
V The combination of the electrically driven pendulum, electric switch devices
actuated thereby, electric contacts on the under or bottom face of the switch, and a
brush which be ɩrs on the contacts
VI The combination of the clectrically driven pendulum, the pendent pivotted
Switch, the contact or contacts on its curved bottom face, and brush bearing
thercon
VII The combination of an electric clock pendulum, formed of a strip of flexible
non-resilient material, electro-magnetic devices for driving it, and mechanism
actuated thereby
VIII A clock pendulum formed of flat tipe or web of flexible non-resilient
material adapted to be suspended at one end and weighted at the other
IX In an electric clock, the combination of pendulum, switch devices actuated
thereby, driving magnet which is intermittently energized by the action of the
switch devices, and a spring intermittently drawn against the pendulum by the
magnet to impart impulses of vibration to the pendulum
X The combination with a vibrating pendulum, of a spring intermittently drawn
against the pendulum to impart impulses of vibration to the pendulum
✗I The combination of a pendulum composed of non-resilient flexible material,
a spring intermittently operated to impart impulses of vibration to the pendulum
ind olcctro-magnetic devices controlled by the pendulum for oporating the spring
XII The combination, in an electrical clock, of a vibrating pendulum, electro-
magnetic devices for driving it, a clock train driving wheel (C), driving devices by
which the wheel is driven by the pendulum, and locking devices which prevent the
movement of the train driving wheel except by the action of the pendulum
XIII The combination of a driven pendulum, a clock train actuated thereby,
clock train driving devices, and locking devices which prevent the movement of the
train except by the action of the pendulum
XIV The combination with the notched driving or anchor lever (B) of the
end wise adjustable arm or rod (64)
XV The combination of the notched driving or anchor lever (B), the rock
shaft, and the end wise adjustible arm or intermediate lever carried by the
rock shaft
XVI The combination of the switch and the transversely rocking brush, for the
purpose set forth
XVII The combination of the pendulum, the pivoted rocking switch, and the
pivoted and transversely rocking brush bearing thereon, substantially as set forth
XVIII The combination of a clock-trun, a driven pendulum, the train driving
wheel, the duplicate wheel-actuating devices operated by the pendulum in its
vibration and each acting on each tooth of the train-driving wheel, and a sweep
seconds band carried by the train-driving wheel spindle, substantially as set forth
Dated this 11th do of Anal 1000