for Lanterns or Lighting Means.
Year: 1886

page_text: for Lanterns or Lighting Means.
I, ROOKES EVELYN BELL CROMPTON Engineer of the Arc Works Chelmsford
Essex do hereby declare the nature of my invention for IMPROVEMENTS IN RAISING
LOWERING AND SUPPORTING APPARATUS FOR LANTERNS OR LIGHTING MEANS to
be as follows :—
My improvements relate to the design and construction of poles, masts, or
brackets, used for the suspension and fixing more particularly of electric are lamps,
but they may be used for any other large lamps required to be raised and lowered
to and from elevated positions. They have for their object a simple method of
hoisting large lanterns to a central position at the top of the poles or masts instead
of the lanterns being hoisted to a davit or arm fixed to one side of the pole as
heretofore has been the case.
This last arrangement has the disadvantage of unsymmetrical appearance, álso
the wind pressure on the pole is not central, also that the pole itself casts a deep
and broad shadow on the ground.
To effect the above object I propose to fix to the top of the wooden or iron pole
or mast a curved arm or davit forged out of flat bars of steel or other rigid
material, the arm being presented edgeways to the light so as to throw a minimum
of shadow. This curved arm is so contrived and shaped that when seen on a side
view it is somewhat like the letter C. On the outside of the upper part of the
curve I place a cradle which can run on rollers or grooved wheels from a point
midway or exactly above the central line of the post out to the end of the arm
which is of sufficient length to carry the cradle to a point so far clear of the post
that the lantern can be hoisted to this point without touching the post. This
upper part of the curved arm is sloped from the centre part outwards in such a
manner that the cradle left to itself will of its own weight run outwards to the
outermost position of the arm.
i
I generally hoist the lantern to this cradle by wire rope or ropes or chains passing
over a sheave free to revolve on the cradle, and again over another sheave fixed

page_text: free to revolve to the curved arm itself, the axis of this last sheave being at a point
approximately at the same level as that of the sheave on the cradle and so far
away from the centre line of the post as to allow the cradle to come up to this
centre line without fouling or interfering with the 2nd sheave. The wire rope
may be led direct from this 2nd sheave either down to a windlass fixed at a
convenient position near the foot of the post or a downhaul and counterweight
arrangement may be used. To hold the cradle at its outermost position during the
time the lamp is being hoisted I attach the upper ends of one or more guide wires
to it the lower ends of which are secured to adjustable attachments at or near the
foot of the pole.
The action of hoisting the lantern is as follows:
The adjustable attachments above mentioned are so actuated as to pull the guide
wires downwards and so tend to keep the cradle in its lowest and hence outermost
position. The lantern having arms which run on the guide wires is then hoisted
by the windlass or by other suitable means and is guided securely clear of the post
by the guide wires. The hoisting is continued until the shackle or stop on the
lantern comes bard up against the sheave on the cradle. If the guide wires are
then slightly slackened by easing off the adjustable attachments at the foot and
the action of hoisting be still continued, the hoisting wire will draw both cradle
and lantern together up the inclined portion of the arm until the required central
position is reached. The guide wires can then be set up sufficiently tight and the
operation is complete; the lantern remaining suspended and secured centrally
above the top of the pole.
The action of lowering is the reverse of the above. By easing off the hoisting
wire at the same time that the guide wires are slightly tightened the lantern is
first drawn outwards until it reaches the extremity of the arm, and is then free to
be lowered clear of the pole.
I prefer to actuate the attachments which tighten or slacken the guide wires at
the foot of the pole by attaching these guide wires to the end of a pair of levers
which can be worked in the desired manner by a treadle or foot lever thus leaving
the hands free to work the hoisting windlass or downhaul or I can apply screw
"gear or springs which can be arranged to be automatic in their action, or eccentrics
can be employed, or I can use any other well known means for alternately
tightening and slackening these wires in a ready and convenient manner.
For hoisting and suspending the lanterns when used for electric lamps I some-
times use the conductors themselves which convey the electricity to the lamps.
I form these conductors of insulated cables the core of which consists of many
strands of fine wire twisted together so as to ensure great flexibility and thus
allow them to roll safely and without undue wear round sheaves of comparatively
small diameter.
.
I sometimes attach one end of a pair of conductors to the lantern, and make the
length of these approximately equal to the half height of the post. I carry them
over the sheave of a movable pulley, and attach the free ends to a position half
up the post. I hoist the lantern by attaching a separate hoisting arrangement to
the moveable pulley over which the bight of the cables or conductor passes.
way
Sometimes I lead the cables themselves over the sheaves on the moveable cradle
and again over the sheave on the curved arm. I hoist the lantern by heaving
down a pulley under and through which these cables are passed, their outer ends
being secured as before to a position about half way up the post. It will be
obvious that in both these cases we lose power on the hoisting as the moving
pulley only passes through half the space that the lantern does.
Sometimes I hoist by a separate wire but lead the cables themselves through the
sheaves as before, but instead of hauling down the last named pulley I attach a
counter weight to it, so that when I hoist by means of this separate wire, the
counter weight descends and keeps the cables tight as before thus preventing them

page_text: swaying in the wind, but avoiding putting on them the entire hoisting strain as
will be the case in the first two methods proposed.
In some cases I dispense altogether with flexible or moveable conductors, but
provide suitably formed terminals so placed and contrived that they engage and
make proper contact with the lamp only when it is hoisted in its central position
at the top of the pole.
With this latter arrangement I find it convenient to provide a second pair of
contact terminals at a convenient position near the foot of the pole in order that
the lamp may be trimmed adjusted.

page_text: for Lanterns or. Lighting Means.
I ROOKES EVELYN BELL CROMPTON Engineer of the Arc Works Chelmsford
Essex 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 :-
My improvements relate to the arrangement and construction of poles, masts or
brackets used for the suspension and fixing of Electric Arc Lamps.
They have for their object a simple method of hoisting electric are lanterns to a
central position at the top of the poles or masts instead of such lanterns being
hoisted to a davit or arm fixed to one side of the pole as heretofore has generally
been the case.
This last mentioned arrangement has the disadvantage of unsymmetrical appear-
ance also the wind pressure on the pole is not central, also that the pole itself casts
a deep and broad shadow on the ground.
To effect the above object I propose to fix to the top of the wooden or iron pole
or mast a curved arm or davit forged or made out of flat bars of steel or other
suitable rigid material, the arm being presented edgeways to the light so as to
throw a minimum of shadow.
This curved arm is so contrived and shaped that when seen on a side view it is
somewhat like the letter C. On the outside of the upper part of the curve I place
a cradle which can run on rollers or grooved wheels from a point practically midway
or exactly above the central line of the post out to the end of the arm which is of
sufficient length to carry the cradle to a point so far clear of the post that the
electric arc lantern can be hoisted to this point without touching the post.
This upper part of the curved arm is sloped from the centre part outwards in
such a manner that the cradle left to itself will of its own weight run outwards
to the outer end of the arm.
In the accompanying drawing a lamp post according to my Invention is shewn,
a is the post which is shewn of wood, on the top is fixed a bent steel crook b. b.
with its top sloping so that the carriage c will run down to the outer end when
left to itself. The electric arc lamp d is supported by the twin cable ; which also
carries the current to the lamp.
The cable passes over the pulley h which is fastened to the frame c but left free
to turn on its own axis, it then passes over the pulley i which is fixed to the
crook bb but is left free to revolve, it then passes round the counterbalance
pulley k and up to the point where it is fixed; two arms e are fixed to the lamp
and the guide ropes ff pass through the ends.
The action of the whole is as follows:
The electric arc lamp is used in the position shewn in Figure 1, the electric
T

page_text: lamps the guides ff are first tightened, this is accomplished by putting down the
lever o shewn in Figures 2 and 3 which are elevation and plan of the platform.
This lever is shewn up in Figure 1 and in Figures 2 and 3, it is shown down so
as to draw the guide ropes ff tight.
The lever o is attached to the short levers p p which are connected by a screw
attachment q with the guides ff. When ff are tightened and the pull down r
Figure 1 is slackened, the frame c with the lamp & run out to the end of the
crook to the position shewn dotted in Figure 1.
On further slackening r the counterbalance pulley k runs up being less than
twice the weight of the lamp. The lamp thus descends clear of the post.
To raise the lamp the guides are tightened and the pulley is hauled down, the
lamp thus rises to the position shewn by the dotted line in Figure 1.
The lever o is then raised to the position shewn full in Figure 1 and the lamp
runs up the slope till it is over the centre of the post as shewn, the down haul is
then made fast.
Various modifications of arrangement of apparatus for raising and lowering
lanterns according to this my invention will be obvious but I have described the
method that I now consider best.
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:
In apparatus for use in raising lowering and supporting electric arc Lamps the
arrangement or construction and use of
1. Apparatus for raising the lamp to a position centrally above its supporting
pole substantially as set forth.
2. A davit curved or formed as described carrying a moving cradle to which is
fixed the hoisting sheave operated as herein described.
3. A cradle operated by means of side stays attached to it at top and to a lever
arrangement at bottom substantially as described.
Dated the 25th day of October 1886.
.
TIM
AdAAd
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