Improvements in and connected with Electric Clocks."
Year: 1896

page_text: "Improvements in and connected with Electric Clocks."
I, WILLIAM WHITEHEAD, of 4, Corporation Street, Manchester, in the County of
Lancaster, Engineer, do hereby declare the nature of this invention to be as
follows;-
This invention relates to improvements in and connected with that type of
electric clocks wherein the tooth or pin wheel or disc is rotated by a pawl actuated
by the arm of an armature which is under the influence of a weight or spring and..
operates the switch, the object of my improvements being to render the said type
of electric clocks absolutely reliable and certain in action.
To this end I employ in. connection with the said. tooth or pin wheel or disc,
two pawls in lieu of one, hereinafter termed the "thrust pawl" and "pull pawl"
respectively, the teeth or pins of the said wheel or disc representing preferably each
one minute.
The said "thrust pawl" is directly pivoted to the said armature arm and the
pull pawl" indirectly, i.e. to the longer arın of a rocking lever fulcrumed to the .
said armature arm. The said pawls are tied together by means of a coiled spring.
which serves to retain the same always in contact with the teeth or pins of the said
wheel or disc. The long arm of the said rocking lever is formed with a projection
having at its upper end a lip and the short arın is placed under the influence of the
weight or spring which furnishes the power to work the clock. On the free end of
the aforesaid armature arm I pivot another lever which at its end has a pin, bearing.
against the underside of the said armature arın and causing it to remain parallel
with the latter until the aforesaid lip contacts with the inner end of the last named
lever. Immediately after the "pull pawl" has engaged its tooth or pin the said
armature is attracted, its arm lifts the "thrust pawl" to the next following tooth
or pin and the "pull pawl" on the said rocking lever engages the adjacent wheel
or disc tooth or pin. The said pawl is then in position for its maximum amount of
pull, but as the tooth or pin wheel or disc rotates, it alters its position, whilst the
"thrust pawl" is descending and finally arrives in position for its maximum amount
of thrust, which occurs when the "pull pawl" leaves its tooth or pin, thus equalizing
the work of the two pawls. When the armature arm has risen to near its highest.
position, the inner end of the lever pivoted to the free end of the armature arın
contacts with the lip on the said rocking lever which causes the outer end of the .
lever pivoted to the free end of the armature arm to fly up and operate the arm of,
the switch and thus break contact.
The switch which I preferably use consists of a hatchet pivoted between centres
and retained out of contact by a back pawl.
The said back pawl is furnished with a spring which serves to throw off the switch
at the right moment and also to assist in raising the free end of the back pawl.
when breaking contact,

page_text: When working a series of time stamps or other apparatus through one switch I
duplicate the number of hatchets in the switch and their contacts on an insulated
base.
F. BOSSHARDT & Co.,
Agents to Applicant.
"Improvements in and connected with Electric Clocks."
I, WILLIAM WHITEHEAD, of 4, Corporation Street, Manchester, in the County of
Lancaster, Engineer, do hereby declare the nature of this invention and in what
manner the same is to be perforined, to be particularly described and ascertained in
and by the following statement:
This invention relates to improvements in and connected with that type of
electric clocks, wherein the tooth or pin wheel or disc is rotated by a pawl actuated
by the arm of an armature, which is under the influence of a weight or spring and
operates the switch, the object of my improvements being to render the said type
of electric clocks absolutely reliable and certain in action.
And in order that any invention may be more fully understood I have caused to be
appended hereunto two sheets of drawings marked with letters of reference
indicating like parts in the various figures, Fig. 1, sheet 1, being a side view, Fig. 2
an end view and Fig. 3 a plan of my improvements in electrical clocks. Fig. 4 is a
plan of a modification of the switch. Figs. 14, 1, and 2, sheet II, are respectively
side views and an end view showing various positions of the working parts during
the cycle of action.
-
In carrying out my invention and referring to Figs. 1, 2, & 3, a is the magnet,
b its armature, b¹ the arm of the armature, c, c the centres between which the
armature is mounted, d the clock frame, e, e¹ the tooth or pin wheel or disc, fits
arbor.
"
In connection with the tooth or pin wheel or disc e, I employ two pawls f & f,
in lieu of one as hitherto hereinafter termed the "thrust pawl" and "pull pawl
respectively, the teeth or pins e¹ of the wheel or disce representing each one or more
minutes, in the present instance one minute.
The "thrust pawl" is directly pivoted to the armature arm 61 and the
"pull pawl" f indirectly, i.e. to the longer arm of a rocking lever g, fulcrumed to a
lug g¹ on the armature arm b', another lug g* being formed on the latter to guide the
lever g. The pawls f&f are tied together by a coiled spring (or each separately
placed under the influence of a spring) which serves to retain the said pawls always
iu contact with the teeth or pins e of the wheel or disc e. The long arm of the
rocking lever g is formed with a projection g2 having at its upper end a lip g³ and the
short arm is placed under the influence of the weight be, see dotted lines Fig. 1, or
under that of a spring, see full lines, the tension of which latter can be altered by
means of the nut 6 and which weight or spring furnishes the power to work the
clock. To the free end of the armature arm 6 I pivot another lever / which at its
inner end has a pin engaging in a recess formed in the underside of the arm b' so
as to remain parallel with the arm buntil the lip g³ contacts with the inner end of
the lever h.
The switch which I preferably use, see Fig. 2, consists of a lever i carrying
a hatchet ; pivoted between centres and retained out of contact with a contact arm
by a back pawl k. The latter is furnished with a spring which serves to throw off
the hatchet at the right moment and also to assist in raising the free end of the
back pawl to its former position.

page_text: The position of the pawls f&f and of the other working parts, as shown in
Figs: 1 & 2, is that just after the armature 6 has been attracted by the magnet a and
the circuit broken:
After this operation the spring 2 (or weight) immediately begins to pull the
armature arm b¹ down. Fig. 1, sheet II, showing the same when half way and Fig. 1B,
when arrived in its lowest position. During this movement the armature arm bi
lowers the "thrust pawl" whilst the "pull pawl" f is raised by the lever g. until
the armature arm &¹ and lever g contact with each other in position shown in Fig. 14.
As the armature arm b' arrives in its lowest position, Fig. 1B, its free end depresses
the back pawl k, which releases the hatchet lever i and causes its hatchet to fall
and make contact with the arm . This causes the circuit to be closed and the
magnet a to attract the armature b and raise its arm.b. During the rise of the
armature arm b¹ the latter and the rocking lever 9 separate again, the lip g³ on
the projection g² contacts with the lever h just before the armature arm 6 has arrived
in its highest position causing the outer arm of the lever h to fly up, as shown in
dotted lines Fig. 1, and thereby strike the batchet lever i and bring its hatchet, out
of contact with the arm thus breaking the circuit, the hatchet lever i, ³ being then
retained in its raised position by the back pawl k.
Immediately after the armature has been attracted the "pull pawl" has taken
up its position under its tooth or pin el, the arinature arm b¹ lifts the "thrust pawl"f
to the next following tooth-or pine and the "pull pawl" on the rocking lever g,
engages the adjacent wheel or disc tooth or pin e. The "pull pawl" is then in
position for its maximum amount of pull, but as the tooth or pin wheel of disc e
rotates, it alters its position, whilst the "thrust pawl" is descending and finally
arrives in position for its maximum amount of thrust, which occurs when the
"pull pawl" leaves its tooth or pin e', owing to the long arm of the lever g
contacting with the armature arm, thus equalizing, the work of the two pawls f¹, f²,
and ensuring uniform working of the clock.
Referring to Fig. 4 when working a series of time stamps or other apparatus
through one switch I duplicate the number of hatchets in the switch and their
contacts on an insulated base as will be readily understood.
.
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-
"In and connected with electrical clocks."
1st. In combination with a clock wheel or disc e, e', and armature b, bl, a rocking
lever g pivoted to the armature arm b' and placed under the influence of a weight or
spring 62 and two pawls f, f, the "thrust pawl" of which is pivoted to the
armature arm b' and the "pull pawl" to the rocking lever g, which pawls are
adapted to engage the teeth or pins el on the wheel or disc e, and thereby rotate the
latter, all substantially as and for the purpose set forth.
2nd. In combination with the armature arm b, specified in the preceding claim, a
two arined lever h pivoted to the free end of the said arm, the inuer end of which
lever is controlled by a lip gs on the rocking lever g and the outer end adapted to
operate the batchet switch, all substantially as and for the purpose set forth.
Dated this 24th day of April 1807
F. BOSSHARDT & Co.
4, Corporation Street, Manchester. Agents to Applicant.