Improvements in Apparatus for Raising and Lowering Arc Lamps.
Year: 1898

page_text: Date of Application, 29th Apr., 1898
tate Specification Left. 24th Jan., 1899-Accepted, 25th Feb.,
1899
PROVISIONAL SPECIFICATION.
Improvements in Apparatus for Raising and Lowering Arc Lamps.
We, WILLIAM JAMES DAVY, Engineer, of Horsell Road Works, Ronald's Road,
Highbury, and GEORGE THOMAS-DAVIES, Engineer, of 53, Primrose Mansions,
Battersea Park, both in the County of London, do hereby declare the nature of
this invention to be as follows:-
This invention for improvements in apparatus for raising and lowering arc
lamps relates to hoisting apparatus enclosed in the post from which the lamp is
suspended and controlled through a small hole in the base of the lamp column
and prevented from lowering by a ratchet device, and has for its object improved
means for throwing the ratchet out of gear when desired to lower the lamp.
Now, according to this invention, the insertion of the socket or operating part
of the handle sufficiently far into or upon the first motion shaft of the hoisting
apparatus automatically throws the pawl or pawls out of gear.
In one way of carrying out this invention, the round shaft of the handle fits
into a socket of the first motion shaft of the hoisting gear and is prevented from
turning in the socket by a feather or key. The end of the round shaft is conical
and if forced sufficiently inwards it acts on the ends of pawl levers to automati-
cally force them outwards and the pawls out of gear for example it may be
forced between the ends of two adjacent pawl levers and separate the two ends
or it may force the said end aside. The conical cam end of a socket fitting on
manner. If a key or feather is
0 a spindle may be made to act in the same
employed it is essential that the key or feather shall be well engaged before the
pawls are thrown out of
gear.
.
1000
L A
WHEATLEY & MACKENZIE,
40. Chancery Lane, London, W.C., Agents
Improvements in Apparatus for Raising and Lowering Arc Lamps.
We, WILLIAM JAMES DAVY, of Horsell Road Works, Ronald's Road, Highbury,
and GEORGE THOMAS-DAVIES, Engineer, of 53, Primrose Mansions, Battersea
Park, both in the County of London, do hereby declare the nature of this inven-
tion and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement:-
This invention for improvements in apparatus for raising and lowering arc
1 to hoisting apparatus enclosed in the post from which the lamp is

page_text: suspended and controlled through a small hole in the base of the lamp column
and prevented from lowering by a ratchet device, and has for its object improved
means for throwing the ratchet out of gear when desired to lower the lamp.
Now, according to this invention, the insertion of the socket or operating part
of the handle sufficiently far into or upon the first motion shaft of the hoisting
apparatus automatically throws the pawl or pawls out of gear.
In one way of carrying out this invention, the round shaft of the handle fits
into a socket of the first motion shaft of the hoisting gear and is prevented from
turning in the socket by a feather or key. The end of the round shaft is conical
and if forced sufficiently inwards it acts on the ends of pawl levers to automati-
cally force them outwards and the pawls out of gear for example it may be
forced between the ends of two adjacent pawl levers and separate the two ends
or it may force the said end aside. The conical cam end of a socket fitting on
a spindle may be made to act in the same manner. If a key or feather is
employed it is essential that the key or feather shall be well engaged before the
pawls are thrown out of gear.
In the accompanying sheet of illustrative drawings, Fig. 1 is a side elevation
of a winch mechanism for raising and lowering arc lamps, constructed according
to this invention and Fig. 2 is a longitudinal section and Fig. 3 a back end
elevation of the same. Fig. 4 is a detail view.
The drum a is mounted on the boss b of a plate e fixed inside the pillar sup-
porting the arc lamp. The hoisting cord is fixed to and wound round the drum a
and passes up within the pillar to the head of the lamp. The drum a is retained
on the boss 6 by the screws d screwing into the boss and having cylindrical ends
working in a groove e on the boss. The drum a is provided at one end with
ratchet teeth f into which gear the counterweighted pawls pivotted to the
plate cat i.
As shown there are two pawls h set to get half a tooth apart, this
being the well known equivalent of having double the number of ratchet teeth.
The pawls have arms or levers that pass down towards the axis of the
drum as clearly shown in Figs. 1, 2 and 3, and that have projections s shown
in Fig. 4. The drum a is provided with a long boss m having a groove n and bored
to the same diameter as the boss b. The round shaft of the handle P is pro-
vided with a feather or key r and has its inner end rounded.
In use the shaft o is inserted into the boss m of the drum a and first the
feather takes into the groove n and connects the shaft to the drum so that
the drum can be wound up. When desired to lower the lamp the shaft o is
inserted still further so that its rounded end passes between the projections s and
opens out the arms or levers 7 and forces the pawls h out of gear with the ratchet
wheel so that the drum can then be turned in the reverse direction to lower the
lamp.
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 apparatus for raising and lowering arc lamps, causing the insertion of the
operating part of the handle into the hoisting gear to connect to the drum and
the further insertion to throw the pawls out of gear, substantially as described.
2. The improved apparatus for raising and lowering arc lamps substantially as
described with reference to the drawings.
Dated this 24th day of Januar 1899
WHEATLEY & MACKENZIE,
40, Chancery Lane, London, W.C., Agents.