An Electrical Time-switch.
Year: 1897

page_text: PROVISIONAL SPECIFICATION.
An Electrical Time-switch.
ARTHUR JOHN WHEATLEY, Engineer, 8, High Street, Harborne, Birmingham,
JOHN MELVILLE JAMES, Engineer, 39, Victoria Street, London, S.W., TOM
BOUSQUET BROWNE, Engineer, 39, Victoria Street, London, S.W., do hereby
declare the, nature of this invention to be as follows:-
-
The object of this invention is to provide a mechanism whereby any electric
circuit may be completed or interrupted or both at any pre-determined time.
It is used in combination with a clock or other suitable instrument for measur-
ing time. In its simplest form it consists of a spindle carrying at its end an
index finger or any suitable arrangement to indicate the time at which the switch
is set to act. This spindle carries a pin fixed approximately at right angles to it
and a cam wheel carried loosely by the spindle is pressed against this pin by
means of one end of a lever, the other end of which lever lies in contact with a
balanced mercury switch. The cam is rotated by means of suitable gearing
connected with the motion work of a clock, and at the pre-determined time slips
along the spindle and causes the lever to throw over the balanced mercury
switch which may be used to complete the electric circuit. The cam is in one
part in the form of an inclined plane and so as it rotates further it regains its
former position on the spindle relatively to the pin and is then in a position to
act again. The spindle and with it the pin is adjustable in a rotary manner by
hand the position of the pin determining the time at which the switch will act.
Another such combination may be arranged to interrupt the electric circuit.
Further the two cams, one for completing the circuit and one for interrupting
it, may be placed on the same spindle.
We, ARTHUR JOHN WHEATLEY, Engineer, (late of 8, High Street, Harborne),
of Board School Road, Woking, Surrey, JOHN MELVILLE JAMES, Engineer, (late
of 39, Victoria Street, London, S.W.), of 20, Minford Gardens, West Kensington,
London, and TOM BOUSQUET BROWNE, Engineer, of 39, Victoria Street, West-
minster, London, do hereby declare the nature of this invention, and in what

page_text: manner the same is to be performed, to be particularly described and ascertained
in and by the following statement:-
-
The object of this invention is to provide a mechanism whereby any electric
circuit may be completed or interrupted or both at any pre-determined time. It
is used in combination with a clock or any other suitable instrument for measur-
ing time.
In its simplest form it consists of a spindle carrying at or about its end an
index finger, or any other suitable arrangement, to indicate the time at which
the switch is set to act. This spindle carries a pin (preferably provided with a
suitable knife-edge) fixed approximately at right angles to it, and a camwheel
running loosely on this spindle is pressed against the pin by means of one end
of a lever the other end of which is arranged to throw over a balanced mercury
switch. The cam consists of a hollow flange provided with a suitably shaped
recess, and is rotated by means of suitable gearing connected with the motion-
work of a clock or other suitable instrument. The spindle, and, with it, the
pin, is adjustable in a rotary manner by hand, the position of the pin determining
the time at which the switch will act. As the cam and camwheel are rotated by
the clock, the above-mentioned recess is gradually brought round opposite the
pin and allows the whole cam and camwheel to slide bodily along the spindle
by the pressure of the above-mentioned lever, the other end of which lever simul-
taneously throws over the balanced mercury switch which is used to complete
the electric circuit. The leading edge of the above-mentioned recess is shaped
approximately at right-angles to the edge of the flange (or even a little under-
cut) while the trailing edge is in the form of an inclined plane, so that, after
having operated the switch, the camwheel gradually regains its position on the
spindle relatively to the pin and is then in a position to act again. The lever
which presses the camwheel against the pin is controlled by a suitable spring,
weight, or equivalent device.
Another such combination may be arranged to interrupt the electric circuit
by a similar lexer throwing over the switch in the opposite direction.
Further, the two cams, one for completing the electric circuit and the other
for interrupting it, may be placed on the same spindle, and in practice, this is
the method usually adopted, as the levers for operating the switch may then be
mounted on one spindle and controlled by one spring, as shewn on accompany-
ing drawings.
The invention will be understood by referring to the accompanying sheets of
drawings in which
Figure 1 is a front elevation of the mechanism as above described connected
up to an ordinary clock.
Figure 2 is a side elevation of the mechanism alone, the clock not being
shewn.
Figure 3 is a front elevation of movement only, shewing index-fingers and
milled nuts.
Figure 4 is a sectional elevation of the same through centre.
In carrying out this invention, we provide a pinion A mounted in a suitable
frame as shewn, which is driven by a wheel B and which drives the camwheels C
and which revolve freely on spindle R. The wheel B, and the various
wheels D, E, F & G which connect it with the clock, may be varied in diameter,
so that the camwheels C and C¹ may revolve at any desired speed relative to
the clock. We prefer to drive from the wheels E, F, and G, which form part
of the ordinary minute-hour reducing gear of the clock, as by this means, we
ensure synchronism between the camwheels C and C¹ and the hands of the clock.
The camwheels C and C are each provided with a hollow flange with a suitably
shaped recess H and H, and are pressed against the pins I and II by means
of the levers K and K¹ respectively, which are pivotted about the same spindle L,
and controlled by the same spring M acting between them, in such a manner

page_text: that the short ends of the levers are pressed apart and keep the cam wheels C
and C¹ close against the pins I and I. In the position shewn in drawing the
balanced switch N is shewn "off." Suppose the pin I is set to complete the
circuit at any given time by turning milled head 7. Now, when the clock has
driven the recess H' opposite the pin I', it allows the short end of the lever K¹
to press the camwheel C¹ towards the pin by the action of the spring M which
simultaneously causes the long end of the lever K¹ to travel towards the lever K,
thereby tipping over the balanced lever N which completes the electric circuit
by dropping the forked conductor into the mercury cups P and P¹. The
various parts of this switch are suitably insulated in the usual manner and may
assume many different forms as required. The same cycle of operations with
the other pin I and the other camwheel C would interrupt the circuit and bring
the mechanism back to the position shewn on drawing, as after operating, the
inclined planes cause the camiwheels to resume their former position as they are
gradually driven round by the clock.
66
"
It has been found desirable, in order to simplify the setting of the "on" and
off" positions, to arrange these on separate dials, and for this purpose, another
spindle S is provided, in addition to the spindle R on which the camwheels
revolve and to which the switching "on pin I is affixed. This second spindle $
carries a wheel T, the motion of which is transmitted to another wheel U by
means of a small pinion V which revolves. freely on the end of the pinion A
which has been turned down to receive it. The wheel U is mounted on a sleeve W
which revolves freely on the spindle R and carries the pin I, so that the position
of the pin I relative to the recess H is determined by the rotary adjustment of
the spindle S, while the position of the pin I¹ is similarly determined by the rotary
adjustment of the spindle R. Each of the spindles R and S is adjust-
able in a rotary manner, and is provided with a suitable friction device X and X'
to prevent their accidental rotation by the friction of the running wheels, but
are still readily adjustable by hand, as they are each provided at or about their
ends with index fingers Y and Y' and milled nuts Z and Z', or other suitable
device for ascertaining the position of the pins I and I¹ respectively and may
also be provided with dials over which these pointers move...
Having now particularly described and ascertained the nature of our said
invention, and in what manner the same is to be performed, we declare that what
we claim is:.
1. In an electrical time-switch, the use of the cam mechanism substantially
as and for the purposes herein before described, set forth and illustrated in the
drawings annexed.
2. The use of the cam mechanism as above described actuated by a clock or
other suitable instrument for measuring time in combination with a balanced
mercury switch.
A. J. WHEATLEY.
J. M. JAMES.
T. B. BROWNE.