Improvements in Electrical Time Switches.
Year: 1898

page_text: I, ARTHUR JOHN WHEATLEY, of "The Homestead," Chobham Road, Horsell, Woking,
in the County of Surrey, Electrical Engineer, 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 predetermined time by an electric
switch other than a balanced mercury switch.
It is used in combination with a clock or other suitable instrument for measuring
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 a spring, weight, or equivalent
device.
The cam is rotated by means of suitable gearing connected with the motion work
of a clock, and at the predetermined time slips along the spindle, and may thus be
made the means of releasing the mechanism of any electric switch driving its actuating
power from the potential energy of a spring weight or other equivalent device,
which switch may be used to complete the electric circuit. The cam is in one part
in the form of an inclined plane so that as it rotates further it regains its former
position on the spindle relatively to the pin & is then in a position to act again.
The spindle & 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.
Improvements in Electrical Time Switches.
I. ARTHUR JOHN WHEATLEY, of "The Homestead," Chobham Road, Horsell,
Woking, in the County of Surrey, 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:-
The object of my invention is to provide a mechanism whereby an electric circuit
can be completed or interrupted at a predetermined time as determined by clock-
work.

page_text: In the prior Specification No. 23,625 of 1897 mechanism for this purpose is
described the switch contact being made through mercury. According to my present
invention I employ time mechanism similar to that described in the said prior
Specification in combination with a switch in which contact is made between solid
metal, as I shall describe referring to the accompanying drawings.
Fig. 1 is a front view and
Fig. 2 is a side view of the switch according to my present invention with part of
the time mechanism described in the prior Specification above referred to, the parts
now shewn being marked by the same reference letters as in the figures annexed to
the said Specification.
Fig. 3 is a modification.
The two arms K K¹ shewn in Figs. 1 and 2 of the drawings annexed to the
Specification No. 23,625 of 1897, are operated by clock-work in the same manner as
previously described, the effect of their alternate movement being to throw over to
the one side or the other a tumbling weight a from the axis of which project two
horizontal hook ended arms b and c, the one or the other of which, according as the
weight a is on the one side or the other, catches a pin d projecting from a lever e the
upper arm of which carries a weight f, and its lower arm has an adjustable tappet g.
To an axis h which is eccentric to the pivot of e is fixed one end of a volute spring k
the other end of which is attached to the stationary framing. Free on the same axis
is a disc of insulating material to which is fixed a bar having ends m m the said
bar crossing the disc diametrically and on the same plane two shorter bars n n which
do not cross the disc. On the axis h is fixed a ratchet wheel engaged by a spring
pawl mounted on the disc l. At one side of the disc and arms is pivotted a bell
crank o having a weighted arm which keeps its other arm up against a stop, this
other arm has projecting from it a pin p in the path of the arms m and n. Insulated.
on the framing are two contact spring qr over which the bars m n rub as they
revolve. The springs being wound up, and the clock work which operates the
arms K K¹ being adjusted to the required times of switching on and off the apparatus
operates as follows:-
When the weight a tumbles over to one side the arm 6 or c which held the lever e
releases the lever which falls over to the position indicated by the dotted lines e¹,
the tappet g at its lower end is thus made to strike the weighted arm of the bell
crank o moving aside the pin p which had been holding one or other of the
bars m or n. This bar being thus released, the disc is caused by the spring k to
make a partial revolution. By this movement one of the arms m or n meeting the
pin d on the lever e carries that lever up with it until its pin d is engaged by one or
other of the hook arms b and c, the bar thus raised escaping from the pin d owing
to the fact that the pivot of e is eccentric to the axis h. When the disc has turned
a quarter of a revolution another of the bars m or n is stopped by the pin p which
has returned to its former position. By this movement of the disc either the bar mm
is bearing on the springs qr making a bridge between them and so closing the cir-
cuit, or the bars n n bear upon the springs, but as they are separately insulated,
they form no bridge, and therefore in that position of the parts the circuit is opened.
When the switch is not intended for very great currents so that the spring k may
be of moderate power, the mechanism may be simplified as shewn in Fig. 3. In
this case the lever carrying the tumbling weight a is pivotted vertically above the
plane of the bars m and n and made with two arms st forming a fork under its pivot.
According as the lever is over to the one side or the other the one or the other of
the arms st obstructs the bar m or n, allowing it to pass between the arms only
while it is itself in the act of tumbling from the one hand to the other.
Having now particularly described and ascertained the nature of this inven-
tion, and in what manner the same is to be performed, I declare that I make
no claim to the clockwork and time switch mechanism described in the Specification
No. 23,625 of 1897, but what I claim is :-
In combination with the timing mechanism described in the Specification.

page_text: No. 23,625 of 1897, the switch mechanism operated by a spring, when released by
the said timing mechanism, substantially as described with reference to the drawings.
ABEL & IMRAY,
Agents for the Applicant.