Improvements in Vibrating Switches or Contact Breakers for Induction Coils, Bells, and the like.
Year: 1899

page_text: Date of Application, 11th Aug., 1899-Accepted, 7th Oct., 1899
COMPLETE SPECIFICATION.
Improvements in Vibrating Switches or Contact Breakers for
Induction Coils, Bells, and the like.
I, JOHN BURNS, of No. 64, Rue de Saintonge, Paris, France, Electrician, 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:.
As is well known in the vibrating switches generally employed in breaking and
making alternately the circuits of certain coils such as induction coils, the coils
of bells and other electrical apparatus, the vibrator is constituted by a flat spring
secured at one end only while its other end carries the soft iron armature which is
to be attracted by the core of the coil as the current passes through it.
The vibrators of this class are defective owing to the fact that being unsupported
from end to end they are in the first place subject to secondary vibrations which
cause abnormal closures and interruptions of the circuit, while in the second
place they are very apt to get out of order and to become warped.
To obviate these drawbacks and obtain a stable vibrating switch uniform in
its operation and not liable to get out of order I propose to place the body of the
armature, not at the free end of a flat spring secured in position at its opposite end,
but midway between the two ends of a flat spring both ends of which are fixed.
In the accompanying drawings the invention is by way of example represented
as being applied to a vertical induction coil.
Fig. 1 being a front elevation of the apparatus,
Fig. 2 a vertical section, and
Fig. 3 a plan of the same.
a designates the metal blade or lamina constituting the vibrator both ends of
which are secured to brackets and c. One end of the lamina is preferably
slotted or split as shown in Fig. 3 so as to allow for the expansions and contrac-
tions caused by variations of temperature.
In the centre the plate or blade a supports the soft iron body d forming the
armature which is to be attracted by the core e of the coil.
The main resilient plate or flat spring a preferably carries a small supplemental
flat spring secured at one end, while its other end which is free is provided
with a stud g of unoxidisable metal (such as platinum, gold, silver or the like)
which makes contact while no current is passing with the point -also unoxi-
disable of the set screw i. This screw is supported by a metal bridge j which
like the brackets b and c is secured to the lid k of insulating material, which
closes the case of the coil.
The small additional spring f, which is very flexible, serves to increase the
amplitude of motion of the armature and to ensure a more perfect contact with
the screw even though the displacement of the main spring should be very
slight.
The current from the battery is sent through the wire m to the binding post or
screw n projecting from the lid k; thence it passes through a metal lamina o to
019

page_text: the bracket and through the springs a and f to the screw and the bridge j.
Thence it proceeds through the metal lamina p to the binding screw q secured
on to the lid k and connected to one end of the primary winding r.
The current
now passes through this winding and then returns to the battery through the
binding screws and wire t.
The core e, being thus excited, attracts the armature d so that the circuit is
interrupted at gh; and as the core now discontinues to attract the armature the
flat spring a restores the contact, and so on.
The vibrator comprising a flat spring secured at both ends affords the following
advantages:
66
1. The interruptions of circuit are sharply defined and rapid and consequently
the working capacity or output" of the coil is augmented; the sparks given
off by the secondary wire are of greater length, of a more intense heat and more
numerous;
2. The vibrator is effectively prevented from getting out of order and capable
of operating in any position,
3. Frequency may be readily increased or reduced by varying the length
width and thickness of the flat spring a.
Where a small additional spring such as f is used, there arises as before stated
the further advantage that the extent of motion of the armature becomes greater
and that a more perfect contact with the screw is ensured. This supplemental
spring however is not absolutely necessary and may be omitted in which case the
unoxidisable stud 9 should be supported by the main flat spring a.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is
1. A vibrating contact breaker wherein the vibrator is constituted by a flat
spring secured at both ends substantially as and for the purpose specified.
2. A vibrating contact breaker of the class referred to in the preceding claim
wherein contact is made through the medium of a small and very flexible supple-
mental flat spring one end of which is secured to the main spring substantially
as and for the purpose specified.
3. The vibrating contact, breaker herein before claimed applicable to induction
coils or to the coils of bells or other electrical apparatus constructed substan-
tially as herein before described and illustrated in the accompanying drawings.
Dated this 11th day of August 1899.
ALLISON BROS.,
Agents for the Applicant.