Improvements in Electrical Switches.
Year: 1898

page_text: Improvements in Electrical Switches.
I, ALFRED WATSON, of Hockley Street, in the City of Birmingham, Electrical
Engineer, do hereby declare the nature of this invention to be as follows:-
This invention has reference to detail improvements in the construction of
electrical switches, principally of the tumbler fly-action type in which circuit is
made and broken by means of a rocking contact arm, taken into contact with
the terminals of the circuit wires by the action of a pivoted tumbler or lever
whose foot end is caused to wipe to and fro along the top side thereof, whilst
circuit is broken by the said arm being lifted out of contact by the expansion of
a spring (compressed by the closing) acting upon its underside.
The primary object of the present invention is to reduce the cost of manufacture
and dispense with the cross pin usually employed as the centre on which
the operating tumbler lever is pivoted and to prevent any lateral play or twist
of the said lever when in use. This it has heretofore been proposed to accomplish
by making the seating or bearing for the ball joint of the said lever in two
socketted cup-like parts, with the bottom of the one provided with a cross gap
or slot, through which the toe or acting end of the tumbler lever extended and
was thereby guided and prevented from twisting when making its rocking
movement.
arm.
I now propose to attain this purpose in a still simpler manner and to further
reduce the cost of manufacture by the arrangements hereinafter described.
The tumbler lever is made generally in the usual form with a spherical middle
part intermediate of the operating end and the toe impinging upon the contact
This said middle part is located within an elevated bearing of an inverted
cup figure, with a hole in the top through which the operating end extends
whilst the bottom is quite open or unenclosed. The ball joint part is retained
within this inverted seating, and the lever itself guided in the rectilinear traverse
of its acting toe along the fly-action spring contact bar by the impinging part
or tip of the said toe being gapped, bifurcated or channelled to take over and
closely embrace a parallel sided rib or longitudinal extension preferably formed
upon the top surface of the block of insulating material which intervenes between
the tumbler and the contact arm for the purpose of preventing metallic contact
between these parts and consequently short-circuiting.
The top surface of the confining and guide rib is provided with a wearing or
running strip of steel or other metal to prevent the wearing away of the insulating
material by the traverse of the forked end of the tumbler along the said rib.
The inverted and elevated bearing cup is also outside screwed to take the cover
of the switch.
By this arrangement, the tumbler is prevented from lateral twist and is
guided in its rectilinear rocking movement when making and breaking contact
without the employment of a cross pin or a guide slot in the bottom of a confined
bearing.
As another form, the top of the contact arm may be channelled, or provided

page_text: with a guide groove, slot or equivalent, into which the toe end of the tumbler
lever takes and is guided in its traverse and prevented from twisting by the
sides of the channel, groove or slot, it being understood that the said channel
is of such a section as to correspond with the section of the lever end.
Another modification consists in providing the toe end of the tumbler lever
with a rolling contact or roller, the periphery of which is grooved or channelled,
somewhat like a sheave pulley but with the groove having square sides, and taking
upon and working along a rib or longitudinal extension upon the top face of the
contact arm, whereby twisting of the lever is prevented and the lever retained
in its joint seating without the employment of a cross pin. The same result
may be attained by making the roller end with a plain periphery and arranged to
work within a parallel sided groove or channel or slot formed along or attached
to the top side of the contact arm.
A further modification of my improvements consists in making the middle or
joint part of the tumbler lever flat (instead of spherical as in the preceding
forms) and arranging it to work, within an elevated bearing or bridge having a
slot or gap of nearly the same width as the flat part of the tumbler, which is
thus prevented from twisting (although no joint pin is used) and guided in its
movement by the sides of the slot or bearing, whilst it is retained in position by
being confined between the bridge and the top of the contact arm, it being
understood that the distance between the said bridge and arm is about equal to
that between the centre and toe of the lever and that the said lever is prevented
from being pushed outwards from its seating by suitable confining shoulders or
stops upon it coming against the underside of the slot sides. The toe end of the
lever, in this form, may be either plain or rollered:
Dated this 14th day of December 1908
ALFRED WATSON.
By Henry Skerrett,
Agent for Applicant.
Pprovements in Flectrical Switches.
I, ALFRED WATSON, of Hockley Street, in the City of Birmingham, Electrical
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 has reference to detail improvements in the construction of
electrical switches, principally of the tumbler fly-action type in which circuit is
made and broken by means of a rocking contact arm, taken into contact with
the terminals of the circuit wires by the action of a pivoted tumbler or lever
whose foot end is caused to wipe to and fro along the top side thereof, whilst
circuit is broken by the said arm being lifted out of contact by the expansion of
a spring (compressed by the closing) acting upon its underside.
The primary object of the present invention is to reduce the cost of manufacture
and dispense with the cross pin usually employed as the centre on which
the operating tumbler lever is. pivoted and to prevent any lateral play or twist
of the said lever when in use. This it has heretofore been proposed to accomplish
by making the seating or bearing for the ball joint of the said lever in two
socketted cup-like parts, with the bottom of the one provided with a cross gap
or slot, through which the toe or acting end of the tumbler lever extended and

page_text: was thereby guided and prevented from twisting when making its rocking
movement.
I now propose to attain this purpose in a still simpler manner and to further
reduce the cost of manufacture by the arrangements hereinafter described.
Figure 1 of the accompanying drawing represents an elevation of a tumbler
switch (with the cover removed) constructed according to one form of my invention
and with the parts in their circuit breaking positions.
Figure 2 is a longitudinal section, with the parts shown in the same positions
as indicated in Figure 1 whilst Figure 3 is a similar section as Figure 2 but shows
the parts in their circuit making positions.
Figure 4 is a part vertical section of Figure 3 upon the dotted line c, but with
the base of the switch in elevation.
Figure 5 is a horizontal section of Figure 4 upon the dotted line showing
the contact maker in plan.
Figures 6 and 7 represent two different sectional views of the elevated bearing
of the tumbler lever separately.
Figure 8 is a partial section and Figure 9 a front elevation of the said tumbler
lever separately.
Figures 9, 10 and 11 respectively represent a side elevation, a plan and an end
view of the contact maker separately.
The same letters of reference indicate corresponding parts in the several figures
of the drawings.
The tumbler lever a is made generally in the usual form with a spherical middle
part al, intermediate of the operating end a³, and the toc a", impinging upon the
contact arm b. This said middle part is located within an elevated bearing c
of an inverted cup figure, with a hole c', in the top through which the operating
end extends whilst the bottom c², is quite open or unenclosed. The ball joint part
is retained within this inverted seating, and the lever itself guided in the
rectilinear traverse of its acting toe along the fly-action spring contact bar by
the impinging part or tip of the said toe being gapped, bifurcated or chanelled
at d, to take over and closely embrace a parallel-sided metal rib or longitudinal
extension e, fitted upon the top surface of the block of insulating material f,
which intervenes between the tumbler and the contact arm for the purpose
of preventing metallic contact between these parts and consequent short-
circuiting.
The inverted elevated bearing cup is outside-screwed to take the cover of the
switch.
By this arrangement, the tumbler is prevented from lateral twist and is
guided in its rectilinear rocking movement when making and breaking contact
without the employment of a cross pin or a guide slot in the bottom of a confined
bearing.
As another form which is represented in Figure 12, the insulating block f,
itted upon the contact arm b, may be channelled, or provided with a guide groove,
lot or equivalent such as into which a toe end c, of the tumbler lever a takes
and is guided in its traverse and prevented from twisting by the sides of the
channel, groove or slot, it being understood that the said channel is of such a
ection as to correspond with the section of the lever end.
Another modification represented in Figure 13, consists in providing the toe
nd of the tumbler a, lever with a rolling contact or roller e, the periphery of
hich is grooved or channelled at e, somewhat like a sheave pulley but with
he groove having square sides and taking upon and working along a rib or
ongitudinal extension d upon the top face of the contact arm, whereby twisting
f the,lever is prevented and the lever retained in its joint seating without the
mployment of a cross pin. The same result may be attained by making the
oller end with a plain periphery and arranged to work within a parallel-sided
roove or channel or slot forined along or attached to the top side of the contact
I'm.

page_text: A further modification of my improvements is represented' in Figure 14 and
consists in making the middle or joint part a', of the tumbler lever a, flat (instead
of spherical as in the preceding forms) and arranging it to work within an
elevated bearing or bridge e having a slot or gap c¹, of nearly the same width, as
the flat part of the tumbler, which is thus prevented from twisting (although no joint
pin is used) and guided in its movement by the sides of the slot or bearing, whilst it is
retained in position by being confined between the overhanging top, of the said
bridge and the top of the contact arm, it being understood that the distance
between the said bridge and arm is about equal to that between the centre toe
of the lever and that the said lever is prevented from being pushed outwards from
its seating by suitable confining shoulders or stops upon it coming against the
underside of the slot sides. The toe end of the lever, in this form, may be either
plain or rollered.
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 —
First In electric tumbler switches, the employment of a tumbler or operating
lever having a gapped or forked inner or acting end adapted to take and work
over a rib or its equivalent provided on the contact arm, whereby the said lever is
prevented from twisting laterally and is guided in its rectilinear rocking move-
ment (when making and breaking contact) without the employment of a cross
pin through the lever or a guide slot in the bottom of its elevated bearing,
substantially as described and set forth in Figures 1 to 11.
Secondly In electric tumbler switches, the employment of a tumbler or
operating lever whose inner or acting end takes and works within a channel slot or
equivalent formed or provided upon or within the contact arm, substantially as
and for the purpose described and set forth in Figure 12.
Thirdly In electric tumbler switches, the employment, at the inner end
of the tumbler or operating lever, of a grooved roller with the groove of the same
taking onto a rib or its equivalents provided on the contact arm, and along which
the said roller runs substantially as and for the purpose described and set forth in
Figure 13.
Fourthly-In electric tumbler switches, the employment of a tumbler lever
which is made flat at its joint or middle part and works within an elevated bearing
having a slot or gap such as c', of the same width as the flat part of the tumbler
and an overhanging confining part, such as ², substantially as and for the purpose
described and set forth in Figure 14.
Dated
unis 17th day 01 July 1000.
ALFRED WATSON.
By Henry Skerrett,
24, Temple Row, Birmingham, Agent for Applicant.