Improvements in Time-stamp Motors.
Year: 1899

page_text: PROVISIONAL SPECIFICATION.
Improvements in Time-stamp Motors.
We, THE EMPIRE CASH REGISTER LIMITED, of Monument Square Chambers,
in the City of London, and NORMAN COLLINS, of same address, Engineer, do
hereby declare the nature of this invention to be as follows:-
This invention relates to motors for time-stamps" wherein the mechanism,
by means of which the successive alterations in the progressively changing
portion of the stamp face are effected, remains at rest except at predetermined
intervals when said mechanism is required momentarily to operate; and our
invention has for object to enable the change in the stamp face to be effected
by a virtually instantaneous movement and thus to avoid the disadvantage
(commonly experienced in connection with "time-stamps ") of the type partially
changing position of alignment during the time when they should be at rest.
A further object of our invention is to provide motor mechanism for time-
stamps in which a single train of wheel work is employed instead of two.
trains as heretofore, and thus to materially reduce the complexity and cost of
such mechanism.
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"
According to this invention the successive changes in the stamp face are
produced or controlled (through suitable devices) by the corresponding partial
and very rapid rotary movements of a wheel mounted upon (say) the hour arbor
of a clock train, said wheel being capable of limited angular motion relative
to the arbor, by which it is only actuated at the required instants through the
medium of a strong spring made fast at one end to the arbor so as to be put in
tension by the continuous rotation of the latter during the intervals in which
the wheel itself is prevented from rotating.
The means by which the wheel is alternately held stationary during a pre-
determined interval, and released so as to make a rapid partial rotary movement
under the impulse of the spring, are preferably as follows:-Upon the periphery
of the wheel are a series of teeth equally spaced at somewhat wide intervals
apart, one or another of these teeth being normally kept (by the action of the
spring which actuates the wheel) pressed against the one or the other of two
spring detents mounted upon the frame of the mechanism and so placed relatively
to the teeth that when one detent engages a tooth, the other is midway between
two teeth. Mounted upon, and continuously driven by, the arbor is a cam disc
carrying as many cams as there are teeth on the wheel, the cams acting on the
detents alternately so as to bring one detent into the path of a tooth when
the other detent is released from the same, or from another, tooth of the wheel.
By this means, supposing a six-toothed wheel and a six-cam disc to be mounted
upon the hour arbor of the clock train, the wheel will remain stationary during
successive intervals of five minutes each and will be rotated, at the conclusion
of each interval, through an angular distance equal to half that separating two
adjacent teeth, such rotary movement being practically instantaneous.
It will be evident that by increasing or diminishing the number of teeth and
cams, the length of the intervals during which the wheel remains stationary

page_text: may be correspondingly diminished or increased; the same results being also
attainable by mounting the wheel and cam disc upon an arbor rotating more or
less rapidly than the hour arbor.
Dated this 15th day of August 1899
A. M. & WM. CLARK,
Chartered Patent Agents, 53, Chancery Lane, London.
Improvements in Time-stamp Motors.
We, THE EMPIRE CASH REGISTER LIMITED, of Monument Square Chambers,
in the City of London, and NORMAN COLLINS, of same address, 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: —
This invention relates to clockwork motors for shifting the type or type wheels
of time-stamps' "wherein the mechanism, by means of which the successive
alterations of the movable type or type wheels which constitute the progressively
changing portion of the stamp face are effected, remains at rest except at pre-
determined intervals when said mechanism is required to operate; and our
invention has for object to enable the alteration of the stamp face to be effected
by a virtually instantaneous movement and thus to avoid the disadvantage
(commonly experienced in connection with the type wheels of "time-stamps ")
of the type occupying an intermediate position out of proper printing alignment
at the moment when the impression is made, this improvement being obtained
conjointly with the employment of a single clock train instead of two trains as
usual heretofore, whereby the complexity and cost of the mechanism is materially
reduced.
According to this invention the successive changes in the stamp face are
produced by very rapid partial rotary movements of a wheel loose upon (say)
the hour arbor of the clock train, said wheel being connected to the arbor
through the medium of a spring and being permitted to rotate only at pre-
determined intervals by the action of an escapement operated by the train itself
through the medium of a cam or equivalent mechanical movement, such partial
rotation being produced by the stress acquired by the spring during the intervals
in which the wheel is prevented by the escapement from rotating.
Reference is to be had to the accompanying drawings forming part of this
specification wherein Figure 1 is a face view and Figure 2 an edge view of one
arrangement of one form of cam operated escapement, and Figure 3 is a face
view of another form of escapement for determining the sudden change of position
of the movable type wheels of a time stamp.
A is the hour arbor of a clock-train which is represented in dotted lines in
Figure 1. B is an escapement wheel loose upon or concentric with said arbor.
C is a cam wheel fast on the same arbor and connected with B by a spring D
attached to B at d and to C at d. EE are spring detents engaging with the
escapement wheel B and actuated by the cams c of the cam wheel against which
the detents bear by projections e e¹.
The means by which the wheel is alternately held stationary during a pre-
determined interval, and released so as to make a rapid partial rotary movement
under the impulse of the spring, are preferably as follows:-Upon the periphery
of the wheel B are a series of teeth b spaced at intervals of 60° around the
circumference of wheel B, it being assumed that the change of the type stamp

page_text: is to be made every five minutes, the number and spacing of these teeth depend-
ing on the intended frequency of the change to be made, and on the rate of
rotation of the spindle by which the escapement is operated. The two spring
detents E E are mounted upon the frame of the mechanism and are so placed
relatively to the teeth b that when one detent is in engagement with a tooth,
the other detent is midway between two teeth so that when the detent E is
disengaged the wheel B will be free to rotate through an angular distance equal
to half the pitch of the teeth. The cam disc C has as many cams c as there are
teeth b on the wheel B, the cams c being spaced to correspond to the spacing of
teeth and the angular relation of the detents to the cams being similar to that
above mentioned in respect of the angular relation of the detents to the teeth 6,
so that the detents E E¹ will be alternately disengaged from the teeth of the
wheel B, the detent which for the time being is not so disengaged remaining in
position to be encountered by the tooth next succeeding that by which it was
previously encountered and so on for the two detents alternately. By this
means, supposing a six-toothed wheel B and a six-cam disc C to be mounted
upon the hour arbor of the clock-train, the wheel B will remain stationary
during intervals of five minutes each and will be rotated, at the conclusion of
each interval, through an angular distance equal to half the pitch of the teeth b,
such angular movement which is practically instantaneous being produced by
the stress acquired by the spring D in the five minutes interval in consequence
of the progressive rotation of C whilst B is held stationary.
It will be evident that by increasing or diminishing the number of teeth and
cams, the length of the intervals during which the wheel remains stationary
may be correspondingly diminished or increased; the same results being also
attainable by mounting the wheel and cam disc upon an arbor rotating more or
less rapidly than the hour arbor.
In Figure 3 the detents E E are the pallets of an anchor escapement F
pivoted at f and oscillated by an eccentric cam G turning in a slot in the
escapement lever, the eccentric being carried by an arbor H driven from the
bour arbor through gear so proportioned as to cause the eccentric to revolve once
in ten minutes. In this case the spring is attached to an arm J fast on the
hour arbor in lieu of cam wheel C.
In both cases the wheel B is attached or geared to the type wheel for denoting
intervals of five minutes (or other unit of time) the connection between said
units wheel and the hour wheel being made by the usual transferring mechanism.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, we declare that
what we claim is:-
1. In a time stamp the combination with the movable type wheels and with
the clock-train, of escapement mechanism interposed between the trains and the
type wheels, the escapement wheel being actuated through the medium of a
spring by the continuous movement of the clock-train and being released
periodically by a cam or equivalent operated by the clock-train so as by its
sudden movement to effect the sudden shifting of the type wheels, substantially
as specified.
2. The respective arrangements of time-stamp type wheel shifting mechanism
constructed and operating substantially as described and illustrated in the respec-
tive figures of the drawings.
Dotad this fith dor of Tuna 1000
A. M. & WM. CLARK,
Chartered Patent Agents, 53, Chancery Lane, London.