IMPROVEMENTS IN WORKING CLOCKS AND OTHER TIMEKEEPERS, TELEGRAPHS, AND MACHINERY BY ELECTRICITY
Year: 1849

page_text: SHEPHERD, of Leadenhall Street, in the County of Middlesex, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Letters Patent under the Great Seal of the United Kingdom of Great Britain
and Ireland, bearing date at Westminster, the Sixteenth day of April,
in the twelfth year of Her reign,
did give and grant unto me, the said Charles Shepherd, my exors, admors,
and assign, Her special licence, full power, sole privilege and authority,
that I, the said Charles Shepherd, my exors, adñiors, and assigns, and such
others as I, the said Charles Shepherd, my exors, adñiors, and assigns, should
at any time agree with, and no others, from time to time and at all times there-
after, during the term of years therein mentioned, should and lawfully might
niake, use, exercise, and vend, within that part of the United Kingdom of Great
Britain and Ireland called England, Her Dominion of Wales, and Town of
Berwick-upon-Tweed, and also in the Islands of Jersey, Guernsey, Alderney,
Sark, and Man, and in all Her Colonies and Plantations abroad, my Invention
of "IMPROVEMENTS IN WORKING CLOCKS AND OTHER TIMEKEEPERS, TELEGRAPHS,
AND MACHINERY BY ELECTRICITY;" in which said Letters Patent there is con-
tained a proviso requiring that I, the said Charles Shepherd, shall particularly
describe and ascertain the nature of my said Invention, and in what manner
the same is to be performed, by an instrument in writing under my hand

page_text: and seal, to be inrolled in Her said Majesty's High Court of Chancery within
six calendar months next and immediately after the date of the said in part
recited Letters Patent, as, reference being thereunto had, will more fully
and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
Charles Shepherd, 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 thereof, reference being
had to the three Sheets of Drawings hereunto annexed, and to the letters and
figures marked thereon (that is to say) :-
My Invention relates to improvements in actuating by electricity machinery
and apparatus employed in or applicable to measuring time and telegraphic
purposes, and has for its object the attaining greater uniformity and certainty
than has hitherto been attained in the application of electricity to similar
purposes. My improvements in electrical clocks may be divided into three
several parts, and have reference to,―
First, the escapement or mode of giving the impulse to the pendulum
balance or other regulator.
Secondly, the mode of actuating the train.
Thirdly, the striking or marking audibly the hour.
In the ordinary mode of giving motion or impulse to the pendulum or
balance, it has been usual to transmit the motive power required thro' the
train of wheels constituting the clock or other train in communication with
'the maintaining power, as the weight or spring, wound up to a sufficient degree
to produce the required action for a given period. Now such mode of giving
the impulse is subject to considerable objection from any irregularity in the
train being carried through and imparted to the balance or pendulum, causing
a variation in the performance of those instruments detrimental to their
To obviate these defects in the escapement or impulse giver, there
accuracy.
have been various improvements from time to time, one of which is termed
the remontoir escapement, in which, as is well known, a spring or weight is
wound up to an uniform degree at each impulse to be given, the spring or
weight being locked on a detent, from which it is released by the motions of
the machine. The remontoir escapement has, however, been subject to the
objection that in transmitting the power from the going parts of the clock to
the winding up or imparting the required degree of tension or force to the
weight or spring, whereby to give the impulse the mechanical means, occasion-
ally fail to ensure the requisite certainty. Now my Invention in this respec
has for its object the application of electricity to the winding up of the impulse

page_text: spring or weight, whereby such escapement or the impulse given may be
rendered certain and unerring in its action. In carrying this part of my Inven-
tion into effect I employ the force of a spring, for the purpose of giving the
required impulse, instead of a weight, since, in the use of a weight, although
it may be delicately poised, the friction is variable, and will bear such propor-
tion to the impulse required as in some slight degree to diminish the accuracy
of its movement and impart a variable amount of force to the pendulum.
In the annexed illustrations I have shewn the application of the remontoir
spring to the several timekeepers, shewing only a detached view in application
of the weight on the remontoir principle.
Figure 1, Sheet A, represents a front elevation of a pendulum with an
escapement arrangement, and constructed according to my Invention; Figure
2, a side elevation; Figure 3, a plan; and Figure 4, an elevation of the back.
The pendulum rod A is suspended in the ordinary manner from the frame B
erected on the bed plate C, on which plate the escapement or apparatus for
giving the impulse is placed. This consists of a bar magnet D, supported by
the spring a attached to the bracket E, so that it has a tendency to remain in
the position shewn at Figure 3; and, on the cessation of the force applied to
the bar magnet D to it, immediately returns to its original position by the
elasticity of the spring a. The spring a from its point of junction with the
bar magnet is continued in the form of a rigid bar b, which consequently
participates in the movement of the bar magnet D. An electro-magnet F, F,
is placed on the under side of the plate C in such a position that the poles
c, c, project above the plate, and are so disposed as to exert their attractive
influence on the opposite ends of the bar magnet and cause it to oscillate,
having the spring a for a centre. A like oscillation is imparted to the bar b, the
whole extent of motion being determined by the banking or set screw d, which.
is previously adjusted to permit the movement required. G is the reinontoir or
impulse giver, which consists of a rigid bar supported by a spring e attached to
the bracket E. This spring e I prefer to form out of the solid, leaving suitable
parts at either end for the purpose of connecting it with the bar G and
bracket E. In securing it to the bracket I confine it at the extreme end by a
single screw, its position being otherwise confined by two set screws f,f,
which regulate the degree of tension to be given to the impulse spring e, which
must be always sufficient to carry the part G against the banking screw g. A
pin h on the arm 6 is raised above the level of the bar G, and which arm bat
each oscillation comes in contact. with G, carrying it to the full extent of its
motion, where the extreme end of G slips under the stone i of the detent,
where it is locked or retained until released for the purpose of giving the

page_text: impulse, the arm b and pin h returning to its original position. The detent
consists of a spring k secured at one end to the bracket 1, the head having two
rubies i and m, one on either side. The spring is banked up by a screw 'n, by
which the extent of its movement is regulated, and on which it rests, except
when raised for locking and discharging the impulse spring. The impulse
spring being thus wound up or reduced to the same degree of tension, and
permitted to return to the same point, it imparts a certain defined amount of
force to the pendulum at each oscillation. Two screws o and p are passed
through the pendulum rod A, the points of which perform the office of dis-
charging and receiving the force of the impulse spring. o is the discharging
pallet, which has a conical termination, and is so situated with respect to the
ruby m of the detent that the inclined point passing under the ruby m raises
the detent head, and consequently the ruby i which relieves the impulse spring,
at which time the pendulum will have completed its oscillation in that
direction. The impulse pallet p, which is a little in the rear of the discharg-
ing pallet, will, at the moment of discharge, have arrived close up to the point
of the bar G, receiving its pressure until it is caught on the banking screw g
where it rests until the moment arrives at which a like action is repeated.
In the construction of electric clocks I employ the pendulum simply to
measure the time, its oscillations being perfectly independent of the train or
other part of the clocks, except that it makes and breaks the currents for
actuating such; therefore a very slight amount of force only is necessary to be
expended by the impulse spring, thereby avoiding the injurious effects of
friction or other circumstance calculated to render the action of the escape-
ment variable. It will be observed that the amount of force imparted to the
pendulum is perfectly independent of the strength of the currents of electricity,
provided that the same be sufficient to excite the electro-maguet F, F, to
impart the necessary movement to the magnet D.
In connection with Figure 1, Sheet A, the battery and current wires are
represented in illustration of the course and time of the completion of the
circuit. On the frame B a piece of ivory or other insulating bracket N' is
secured, on which is supported twe brass brackets 1, 2, carrying each a
contact spring 3 and 4 (one only of which is used in effecting the vibration of
the pendulum. These springs are secured at their back ends, and have near
the front ends two set screws 5, 5, which press on extending arms of the
brackets and regulate the distance of the springs 3, 4, from the sides of the
pendulum rod (see Plan, Figure 7, Sheet B). The front ends of the springs
3 and 4 carry two platina pins 6, 7, which are so adjusted by the screws that
their points effect only a slight contact with the sides of the pendulum, where

page_text: "
pieces of platina are also placed for the purpose of ensuring a completion of
the circuit. The springs 3 and 4 are of a slight character, and are otherwise
arranged so as to prevent any unequal effect on the motions of the pendulum.
As before mentioned, one only of these springs is used in the completion of the
pendulum circuit, which in this arrangement is that on the left of Figure 1,
Sheet A, which is connected with the negative pole of the battery I by means
of a wire 8 attached to the bracket 1, while the positive pole is in commu-
nication with the coils of the electro-magnet F by the wire 9, the other coil
being in connection with the framework, which continues the circuit to the
pendulum rod; thus it will be perceived that on each oscillation of the pen-
culum to the left (as viewed in Figure 1) contact is effected by its touching
the platina pin 6, at which instant the electric circuit is completed, when the
attractive influence of the poles C, C, of magnet F will impart the movement
to the magnet D required to "wind up' or impart the desired tension to the
remontoir spring. On the pendulum breaking contact with pin 6 the current
ceases, the bar magnet being free to resume its original position; to insure
which contact between the permanent bar magnet and poles C, C, of the
electro-magnet F is prevented by the arm 6 coming in contact with the
banking screw d. From the foregoing it will be readily understood that
the "winding up" of the remontoir spring is effected at the completion of the
pendulum's oscillation to the left, while the discharge of such spring is effected
at the completion of the opposite oscillation, the impulse also taking effect at
such time, and is continued during a portion of its oscillation to the left, as
previously explained, which therefore takes place once during two oscillations
of the pendulum A. It will also be observed that the "winding up" of the
impulse spring is effected during the contact between the pendulum rod A
and platina pin 6, and therefore forms no obstruction in its oscillation towards
the right.
In Sheet B I have represented my improvements in effecting the movement
of the train in order to denote the hours or other subdivision of time, and also
the method of effecting the striking or audibly marking each particular hour.
Figure 5, Sheet B, is a side elevation of a clock train with the necessary
adjuncts for effecting the required objects; Figure 6, a lateral section of the
train at the dotted line K, K; and Figure 7, a plan of some of the parts.
The first mover consists of a pair of pallets q, q, supported on an oscillating
axis L, which pallets impart at each oscillation of the axis La movement to the
ratchet wheel M on the arbor of the seconds' hand, if the pendulum performs
its vibrations in such space of time, causing it to rotate the distance of half a
tooth at each movement of the pallets, as is well understood in clock move-

page_text: ments. To the oscillating axis L two bar magnets Q, Q, are attached, the
opposite ends of which terminate immediately over the poles of two electro-
magnets R and S, which are caused alternately to attract and repel the ends
of the bar. magnets Q, Q, and thereby transmitting the necessary motion to
the pallets. The oscillating shalf L, it will be seen, is mounted on the top of
the framework of the train, having a bracket bearing extended for the purpose
of carrying the extreme end, in order to obtain the necessary width between
the bar magnets to permit the required diameter of the coils, which with the
electro-magnets, are simply shewn in their respective positions. In the pro-
ductions of the necessary currents of electricity I employ two batteries T, U,
the positive pole of battery T being connected with contact spring 4 by wire r,
while the negative pole of battery U is similarly connected with contact
spring 3 by means of wire s. The contact springs 3 and 4, as explained in
the description of the first part, being complete, more particular mention is
unnecessary. The remaining positive pole of battery U and the negative pole
of battery T are connected. by the wire t with the coils of the electro-
magnets S, S, in such manner as to cause a current to travel round the two
arns of the magnet S in contrary direction, thereby exciting it to attract the
ends of the bar magnets on that side. From the last coil on the magnet S a
wire u is carried to the opposite coils, so wound as to induce an opposite
influence on the poles of electro-magnet R, which thereby exerts a repelling
force on those ends of the bar magnets opposed thereto simultaneously with
the attractive force of the electro-magnet S. The last coil of this magnet is
connected to the frame A by the wire v, thence completing the electric
current to the pendulum rod. The pendulum during its vibrations causes
the following action to take place:-In oscillating (say to the right, it comes
in contact with the platina point 7 of spring 4, during which contact the
electric current of battery T will be complete by means of wires r, v, and t,
including the coils of the magnets R and S, thereby inducing the attraction
and repulsion of those magnets, by which one oscillation of the bar mag-
nets Q, Q, with their supporting axis, which causes one of the pallets q, to be
withdrawn and the other to fall into and propel the wheel M round half a
tooth. On the opposite vibration of the pendulum taking place the rod A will
come in contact with the platina point of spring 3, thereby completing the
circuit of battery U. by wires s, t, and v, including the coils, as before; but in
this circuit the current is transmitted in an opposite direction, causing the
electro-magnet, which before exerted an attractive influence on the bar nagnet,.
now to repel and-"vice versa," producing an opposite oscillation of the bar
magnets Q, Q, as also the pallets q, q, the wheel M thereby completing its

page_text: motion to the extent of one tooth, which is thence transmitted through the
train in the ordinary manner. By the continued oscillations of the pendulum,
produced as before explained, the electric currents will be thus completed
alternately in opposite directions with uninterrupted and uniform succession,
thereby actuating the train with the extreme regularity attainable by the
motion of a free pendulum. The. pallets q, q, are so connected with the axis L
as, by their contact with the wheel M, they will prevent the bar magnets
oscillating so far as to come in contact with the poles of the electro-mag-
nets R and S, by which any obstruction to the opposite oscillation is prevented.
In Figures 5, 6, and 7, Sheet B, the apparatus used for effecting the
striking or marking numerally the hour or other period of time, by means of
electro-magnetism, is shewn. In the seconds' wheel M a projecting pin W is
placed, which wheel, having thirty teeth, revolves once every minute, and is
therefore in the position shewn once during every such period. Another like
pin x is fixed in a disc on the arbor of the minute hand, which, being in the
train reduced in its motion as sixty to one, arrives at the position shewn only
once every hour; these pins w and are therefore only in conjunction or in
similarly relative positions once in each hour, which takes place at the proper
time for striking the hour. On arbor y is pivoted in the framing of the
clock carrying an arm z, which is insulated from the arbor by an ivory bush in
its collar; this arm is slight and elastic in its stem, and carries a pad z¹, on
which the pin w rubs. Another arm a¹ (shewn by dotted lines in Fig. 6, is
attached to the arbor y in a position so that the pin x, in its rotation with the
minute-hand arbor, comes in contact with arm a². The eye of the arm is
connected by a spring 61 with the piece of brass, c¹ which is insulated from
the framework by the intervention of ivory or other non-conducting medium.
This spring 6 retains the arms and a¹, when not acted on by pin x, in a
position a little lower than as represented, so that the pin w revolves free from
contact with pad ¹, except when the arm a¹ is raised by the pin x, at which
time an electric circuit will be completed from the spring 61, through arm z,
to the pin w, and thence by the wheel and arbor to the framing. It is so
arranged that the pin x does not remain in contact with arm a¹ throughout
a revolution of the wheel M, so that, on the return of pin w at the succeeding
revolution, the pad z¹ will have fallen so as to prevent contact. A battery V
has one pole placed in connection with the coils of the electro-magnet W,
which again is connected by wire d' with the insulated piece of brass c¹, while
the other pole of the battery is placed in connection with the framing by
wire e'. On the break being united by the contact of pin w and pad z¹, the
electric circuit will be complete, causing the poles of the electro-magnet W to

page_text: attract an armature f¹, which armature is attached to an arm from the click
or detent X of the locking plate Y, and which is thus raised from the notch
in that plate. The click or detent X, moving on a fulcrum at g', is so
arranged that the armiture f¹ shall not come in contact with the poles of the
magnet W by reason of the detent arm striking the bracket h¹, the detent
having a preponderance of weight over the armature to cause the detent X to
return to the locking plate when required. On the arbor on which the locking
plate is fixed is also fixed a ratchet wheel Z, into the teeth of which pallets, ,
take, and by their oscillation with their arbor k¹ cause the ratchet wheel Z to
rotate step by step the distance of half a tooth, as is well understood. The
pallet arbor has an arm attached supporting a cross armiture A¹ imme-
diately over the poles of an electro-magnet B', having a circuit completed
in the following manner. The position of the coils and armatures is
represented in dotted lines in Figure 5, and also in the plan Figure 7.
I have represented a separate battery C₁ for the sake of perspicuity, the
same battery being capable of completing both circuits if of sufficient strength..
The battery C has one pole connected with the stud of spring break I, which
is insulated from the framing by a piece of ivory, while the opposite pole
is connected with the coils of the electro-magnet. B', the metallic connection
being completed by wire m¹ to the bracket h', which bracket is also insulated
from the frame of the clock. This bracket h¹ has a spring n', having a
platina pin opposed to a piece of platina on the detent arm X, but so adjusted
by a set screw that it shall only effect a contact when the detent is withdrawn.
from the locking plate by the attractive force of the electro-magnet W. The
action of the whole is this:-When the circuit of battery V. is completed by
the contact of the pin w with arm Z, the detent X is withdrawn from the
locking plate Y, which at the same time completes the circuit of battery C¹,
in so far as regards the contact of the platina point of spring n' with
the detent X, thence to the framing, and leaving the locking plate free to
rotate with its axis. The length of pad z¹ is such that it permits the bar
magnets Q, Q, to perform one oscillation before it quits or breaks the circuit,
during which time the bar magnet Q, by reason of its oscillation, strikes the
platina point of spring , which thus completes the circuit of battery C¹,
causing the current to excite the magnet B', which attracting the armiture A',
gives motion to the pallets i, i, thereby impelling the ratchet and locking
plate. The attractive force of magnet B¹ being momentary, by reason of the
short duration of contact between the bar magnet and the break, the pallets
by their superior gravity again fall and complete the distance of a tooth of
ratchet Z, this double oscillation, as will be herein-after explained, causing

page_text: one stroke of the bell. The circuit of battery V, although broken at pin W,
on the succeeding oscillations of the bar magnets Q, Q, taking place, does not
necessarily break the circuit of battery C', as the detent or catch will, if the
hour to be struck be more than one, will rest on the periphery of the locking
plate, maintaining the contact of platina pin on spring n' with the arm X; so
that, on the second succeeding oscillation of the bar magnet Q, the contact of the
break spring is again effected, and a second action of the pallets takes place,
and which is repeated until the next notch in the locking plate is presented to
the detent or catch X, which drops into it, and thereby breaking contact at the
platina point of spring n¹, preventing further action of electro-magnet B',
until conjunction of pins W and X at the next hour. On the arbor A³ a bell
hammer D¹ is suspended, which strikes the bell E at each escape of a whole
tooth in wheel Z, and, consequently, at each two seconds of time. I have
thus shewn the arbor K¹ in direct communication with the hammer, but I
prefer to employ the motion such arbor for making and breaking the circuit
of a larger battery, and separate set of electro-magnets of greater or less
attractive force, according as the sounds required may be more or less sonorous.
The locking plate Y is similar in its division to the ordinary locking plate of
striking clocks, and the ratchet wheel Z is divided so that the number of teeth
correspond with the whole number of strokes of the hammer required in
twelve hours; the notches in the periphery of the locking plate being so
disposed as to embrace severally the number of teeth required to produce the
successive numbers of the hours to be struck.
In Figures 8 and 9, Sheet B, I have represented a mode of making and
breaking the circuits, by which the chance of interruption of the currents from
oxidation of the platina points is diminished. a is a glass vessel supported
from the pendulum rod A. In this glass vessel a weight 6 is suspended, its
point of suspension being in line with the centre of motion of the pen-
dulum rod, so that it may not be actuated by such platina. Break points
c, d, are introduced through the sides of the glass vessel a, their connecting
wires being carried up, and terminate also in line with the centre of oscillation,
where, in order still further to ensure the non-interruption with the pen-
dulum's motion, two light springs are connected with the wires of the
batteries B and C, which are arranged as before explained in Figure 7. The
suspended weight being connected with the pendulum rod, and thence to the
frame from which the wire e communicates with the coils f, f,f, f, for working
the train during the oscillations of the pendulum, the glass vessel will be caused
to vibrate therewith, while the suspended weight within it remains stationary,
so that one of the platina points c or d come in contact with the weight bat

page_text: each oscillation, which thus completes the currents that travel in contrary
directions in alternate succession, producing the action of the train. The
object of the glass vessel is to contain hydrogen in order that the platina
break points may not be oxidized, pure hydrogen having little or no such
effect on that metal, thereby ensuring an interminable or greatly extended
period before interruption of the currents could take place from such cause;
a similar effect may be produced by exhaustion or other gas not acting pre-
judicially on the metal. In order to prevent any motion resulting in the
suspended weight from frequent contact with points c, d, extremely slight
springs may be affixed to the sides of the weight b, carrying the pieces of
platina for effecting the contact with points c, d. The glass vessel must of
course be capable of retaining permanently the hydrozen introduced.
In Figure 10 and 11, Sheet B, the weight is applied on the principle of the
remontoir escapement. Fig. 10 being a front elevation, with one of the sup-
porting frames removed, and Fig. 11 a side elevation of the same. a is a
weight, which is supported by its arm from an axis b, so as to produce the
least possible friction; this axis carrying also the arm c for transmitting
impulse to the pendulum rod A .d is the bar magnet, with arm e for " winding
up" or elevating the weight a at each impulse, by contact with its pin f, on
arm c; this arm being locked on the detent g, as before explained with
reference to the remontoir spring. From the detent it is discharged also as
before, and imparts the impulse produced by the gravitation of the weight a.
The weight being adjustable on its arm, may be caused to exert greater or
less force on the pendulum; the supporting arm of the weight a, although
represented in an inclined position, may be horizontal or at any other inclination.
The attractive force of the magnet h, h, is produced and interrupted as before.
My Invention also has reference to the effecting a regularity of motion in
chronometers by means of the remontoir escapement, which is represented in
Figs. 12 and 18, Sheet C; Fig. 12 being an elevation of the chronometer
frame with the parts necessary to explain the improvements, and Fig. 13 a
plan on the line a, b. The impulse or remontoir spring c is supported in a
bracket d, and is adjustable with regard to tension as before explained, while
the opposite end branches into two points e and f, which is more distinctly
represented in Fig. 14, in an enlarged under-side plan; the arme takes effect at
the proper time on the impulse pallet g in the large roller, the other arm f
taking on to the detent h, which is furnished with a discharging spring, the
same as in the ordinary escapement; an arbor i placed in the centre, on
which is affixed two bar magnets k, k, having electo-magnets A, A, so
disposed that their attractive influence on the bar magnets, k, k, will impart a

page_text: partial rotation to the arbor i; on this arbor also an arm is affixed, carrying
the "winding up" or tension pin m of the impulse spring c, the pin m being
platina and supported on a piece of brase n, insulated from arm 1, this piece
of brass being connected by a spring p with another piece of brass B insulated
from the frame, the spring p tending to draw the pieces n and B together..
Another arm C is supported by the arbor i, which arm carries a pin o for
moving a detent D for the purpose of breaking contact at the platina point q
attached to spring E, the opposing point of contact being also on a spring
arm F having a tendency to receed therefrom. The spring E is mounted on
a bracket insulated from the chronometer frame, and to which a wire from one
end of the coils of the electro-magnets A, A, is connected, the other end of the
coil being in communication with one pole of the battery G, while the other
pole of the battery is in connection with the piece of brass B. The action
is this: supposing the impulse spring to be released from the detent h, it
moves to the right and consequently comes in contact with the platina pin m,
which, during the position represented in the Drawings, is the only place at
which the electric circuit is broken; which, being thus restored, the current
passes through the impulsive spring to the frame, and thence by spring arm F
& platina points q to spring E, where it is transmitted through the coils to
the opposite pole of the battery. The electro-magnets now being rendered
magnetic, their poles attract bar magnets k, k, causing a partial rotation of
the arbor i, and consequently "winding up" the impulse spring by reason of
the force transmitted through arm and pin. m, so as to lock the impulse
spring c on the detent h; when this is completed the pin o has advanced
by the motion of the arm C so far as to force the detent D beyond the
end of spring F, which being thus released withdraws from contact with
the platina point q, thereby breaking contact, and consequently the electric
circuit; which, having ceased, permits the several parts to return to their
original position, which is effected by the force of the spring p with the ex-
ception of the impulse spring c, which remains on the detent h to discharge its
office. During the retrogade motion of the arm c the pin o lifts or draws
back the spring F so as again to lock it on the head of detent D, by which
the contact of platina points q will be effected, thereby completing that part
of the circuit in readiness for a repetition of the action. The detent D is
limited in its action by a banking screw. The arbor i, in performing
this oscillatory motion, imparts the desired motion to the train by means of
the pallets II, II, affixed thereto, and taking into the teeth of ratchet wheel I
in communication with the train of the chronometer. The locking of
the impulse is effected by a ruby placed in the detent h, the arm itself extend-

page_text: ing nearly up to the discharging pallet r, the motion of the detent being
limited in its motion by the head of the banking screws, so as just to retain
the long arm f of the impulse spring. A spring t, termed the discharging
spring, is secured to the detent which extends beyond the point of the detent,
so that the discharging pallet r, in its rotation in a direction to the left, simply
lifts the discharging spring t from the detent, allowing the pallet r to pass,
without affecting the detent h, while, supposing the motion of the balance
to be in the opposite direction or to the right, the discharging pallet will
come in contact with the spring t, but the nip being short the motion is
consequently imparted to the detent h, so as to unlock the impulse arm, at
which time the impulse pallet g will have arrived at such a position that
the short arm e takes effect upon it, and thereby giving an impetus to the
balance which is repeated at each oscillation in that direction; thereby
increasing the tension of the pendulum spring, the impulse pallet 9 leaving
the arm e, the impulse arm C coming in contact with the platina pin m
instantly completes the circuit, producing the winding up as before explained.
It will thus be observed that the maintaining power of the chronometer is
received from the electro-magnets, and regulated by the motions of a balance
actuated by means of the remontoir escapement, the movements of the chro-
nometer being perfectly isochronous with the motion of such balance.
A further improvement consists in an improved escape wheel and pallets,
which is represented at Figure 15, Sheet C, in front elevation with a side view
at Figure 16. In the ordinary escape wheel as driven by the pallets, con-
siderable friction results from a constant rubbing of the pallets at the time of
driving. In the improved escapement the pallets have less motion on the
driving tooth.
a, is the driving arm in connection with the bar magnet Q, or
other driving power. The arm a is divided into four points of contact, c, d, e,
and f, two of which, c and e, are the driving pallets, while d and fact as
detents to the wheel g. In the position shewn in the Drawing, the pallet
has just completed its stroke, having moved the wheel g from the position
shewn by dotted line, when the detent f at the same instant comes in
contact with a tooth, preventing the further progress of the wheel. On the
opposite oscillation of the magnet Q taking place, the pallet c moves the
wheel from the position shewn by color to the dotted line position, or the
distance of another half tooth, at the same time throwing out the detent f,
and bringing up the detent d, when the operation is repeated. It will thus
be seen that the centre of motion of the driving arm a being nearly in a
straight line with the driving pallets their rubbing motion on the teeth will
be very slight, and consequently lessen the friction.

page_text: The improved escape wheel and pallets just described may be applied to the
actuating of telegraphic hands or pointers in the manner of the well-known
step-by-step movement.
In obtaining power for the purpose of striking the hours, I prefer to employ
a series of small electro-magnets where great power is required; that is to say,
having ascertained the size of electro-magnet most useful; which I believe to
be formed of iron, whose cross section is about an inch by about ten inches in
length, or from pole to pole, beyond which size I do not increase the electro-
magnets, no matter how great the power required, which is increased by adding
to the series of electro-magnets.
Figure 17, Sheet G, represents a side elevation of a bell hammer arranged
with a number of electro-magnets, and Fig. 18 an end elevation thereof. It
will be seen that the cross arm of the hammer has eight armatures opposed to
the poles of a like number of electro-magnets, which attract simultaneous the
armatures and give motion to the hammer, a suitable stop preventing contact
between the armatures and magnets. Should the power required be greater
than attainable by eight magnets, I increase the length of the armatures and
add to the series of electro-magnets.
Having now described the nature of my said Invention, and in what manner
the same is to be performed, I wish it to be understood that I am aware that.
electro-magnetism has been employed as a substitute for weights, springs, and
other sustaining power in the machinery of clocks and timekeepers. I do not,
therefore, claim the exclusive use of electro-magnetism for that purpose,
except when employed as herein-after mentioned; and I hereby declare that I
claim as my Invention,―
First, the improvement in clocks and timekeepers, in which the remontoir
escapement is wound up and actuated by electro-magnetism, and retained by a
detent, as above described.
Secondly, I claim as an improvement in clocks and timekeepers the giving
audible signals by means of a locking plate and apparatus connected therewith,
actuated by electro-magnetism, as above described.
Thirdly, I claim as an improvement in clocks the making and breaking the
contact by means of an apparatus adapted and arranged as above described,
& represented at Figs. 8 & 9, Sheet B.
Fourthly, I claim as an improvement in timekeepers the arrangement and
combination of machinery shewn in Figs. 12, 13, and 14, and actuated by
electro-magnetism, as above described.
Lastly, I claim as an improvement in timekeepers and telegraphs the combi-

page_text: nation of two driving pallets and detents for giving the step-by-step motion, as
bove described.
In witness whereof, I, the said Charles Shepherd, have hereunto set my
hand and seal, this Sixteenth day of October, in the year of our Lord
One thousand eight hundred and forty-nine.
day
er, in
the year
of our Lord 1849, the aforesaid Charles Shepherd came before our said
Lady the Queen in Her Chancery, and acknowledged the Specification afore-
said, and all and every thing therein contained and specified, in form above
written. And also the Specification aforesaid was stamped according to the
tenor of the Statute made for that purpose.
Enrolled the Sixteenth day of October, in the year of our Lord One
thousand eight hundred and forty-nine.