IMPROVEMENTS IN INCANDESCENT ELECTRIC LAMPS
Year: 1883

page_text: PROVISIONAL SPECIFICATION left by John Clayton Mewburn at the
Office of the Commissioners of Patents on the 27th November 1883.
Communicated to him from abroad by Josef Kahn and Ignaz Bräuer both of
Vienna Austria.
JOHN CLAYTON MEWBURN of 169 Fleet Street in the City of London Patent
Agent and Consulting Engineer, "IMPROVEMENTS IN INCANDESCENT ELECTRIC
LAMPS [communicated to him from abroad by Josef Kahu and Ignaz Bräuer
both of Vienna Austria]
"1
sure and
This invention consists of improvements in incandescent electric lamps and
chiefly relates to arranging their supports or holders so that a
uninterrupted electric contact is established between the light giving body within
the lamp and the conducting wires outside.
The characteristic feature of the improved supports or holders is that there is a
metal ring which bears against the lower tapering or pear-like part of the globe or
Bask of the lamp; this ring is supported by springs and has a constant tendency to
press upwards so that as soon as the contact hooks of the lamp holder are hooked
into their corresponding loops they are pressed against each other;
uninterrupted contact between the hooks and loops is thus ensured and liability
to accidental breaking of the current from loosening of the hooks in their loops is
prevented.
an
In one modification of the invention the lamp holder is composed of a supporting
block of wood or other suitable material; the upper portion of this block is
surrounded by a loop to which three spiral springs are soldered and to the upper
ends of these springs is fixed the metal ring which bears against the lower portion
of the lamp globe as above explained. The two contact hooks form the upper
ends of two small spiral springs which are in metallic communication with the
terminals.
In another modification there are only two springs to support the metal ring,
and the two contact books are so arranged that the plane passing through them is
at right angles to the plane of the springs so that the lamp is held up from four
symmetrically arranged points of the support. The contact hooks are metal pins
passing in a slanting direction through the supporting block and formed with
hooks at the upper ends, their lower ends serving as terminals. The`number of

page_text: the springs which support the ring may of course be increased or diminished and
their spirals may extend the whole length of the springs or only a portion of the
length the remaining portion being a straight fixed connection. The pin which as
already mentioned is formed with a hook at its upper end has at its lower end a
nut having a hole bored through it; the conducting wire communicating with the
contact hook is passed through this hole and by then turning the nut the wire is
twisted round the pin and a rigid conducting connection thereby established.
In another modification two flat springs are employed to support the metal ring,
the two contact books being arranged symmetrically on both sides of the springs
in a line at right angles to the plane of the springs.
In another modification there is only one supporting spring and this is placed in
a hollow or recess of the supporting block. The metal ring is carried by a bow
fitted upon a bolt or pin which pin is soldered or screwed to a disc. This disc fits
in the hollow or recess of the block. The spring bears at its lower end against
the bottom of the recess and at its upper end against the lower face of the disc.
In order to always keep the spring in some degree of tension the pin has a flange
working in an extension of the hollow; one or more pins are passed through the
support so that when the flange has reached the desired highest limit it comes
against these pins and is topped so that upward movement of the pin and
consequently of the bow and ring is limited. The disc and the flange serve as
guides to the pin and keep it in a position exactly corresponding with the centre
of the supporting block. The two contact hooks are placed at right angles to the
plane of the arms of the bow.
In order to prevent waste of light from the lamps when they are placed
overhead or near a wall or other surface they are provided with reflectors shaped
to approximately fit that portion of the globe which is uppermost or next the
said wall or other surface as the case may be and this reflector is secured in
position by the metal ring before described. For example if the lamp is suspended
with the tapering portion or neck of the globe uppermost and the light is required
below it the reflector is in the form of a cap tapered at the top to fit the tapering
portion of the globe and the metal ring of the holder embraces it and holds it in
position. If the lamp is in a wall bracket the reflector is in the form of a hood
and has a narrow neck to fit the tapering portion of the globe; in this case also
the metal ring holds the hood in position. Or if desired the outside of the globe
may be formed into a reflector by being coated with a reflecting varnish or
amalgam.