Improved Means of Working and Controlling Electric Elevators.
Year: 1893

page_text: Date of Application, 15th July, 1893
Complete Specification Left, 14th Apr., 1894-Accepted, 2nd June, 1894
PROVISIONAL SPECIFICATION.
Improved Means of Working and Controlling Electric Elevators.
I MICHAEL HOLROYD SMITH of 161 Trinity Road Upper Tooting London S.W.
Mechanical and Electrical Engineer do hereby declare the nature of this invention
to be as follows:-
This invention relates to that class of electric elevators where the motor is
stationary operating the cage through the medium of ropes, chains, racks, screws,
rams or equivalent devices.
In all elevators the movement of the cage must be controlable by the attendant
within the cage.
To control an electric motor a reversing switch and rehostat have to be employed
if these be placed in the cage they add to the weight, & necessitate a number of
wires with sliding or other connections.
It is preferable that the switch and rehostat be stationary and located near to
the electric motor, but it has hitherto been difficult to operate them from the
moving cage & satisfactorily fulfill the essential conditions.
In this my invention I take two ropes cords, belts, wires or chains and attach
one end of each to the top of the cage then pass the cords over separate pulleys
secured at or near the top of the lift space, thence downward clearing the cage,
to or near the bottom of the lift space each cord passing round a separate shackle
pulley thence upward into or by the side of the cage the ends of the cords
being wound in opposite directions round a wheel or cylinder upon one shaft or
spindle.
The cords thus form two distinct loops, one end of each being attached to the
cage the other ends being round a drum or cylinder within the cage.
It follows that if the ropes or cords are of equal length and equally wound
round the cylinder that the bottom loops holding the shackle pulleys will hang in
the same horizontal plane, and that if the drum or cylinder be turned one of
these ropes will be shortened lifting its shackle pulley & one lengthened lowering
its shackle pulley, also that the relative positions of the shackle pulleys are not
affected by the movement up or down of the cage the ropes being free to run like
a blind cord over the top & bottom pulleys.
It is also obvious that the ropes or cords are stationary relative to the cage not
passing rapidly through it as is customary with bydraulic hoists.
From the shackles of the shackle pulleys I pass a cord round a drum attached
to the spindle of an electric switch, it follows that as the shackle pulleys are
alternately lifted & lowered the drum of the switch will be turned from right to
left and the switch operated. This arrangement permits of considerable movement
of the switch. If however only small movement of the switch is required then
bars or levers can be used in lieu of drums or cylinders.
. To the spindle or drum of the switch I attach oue end of a belt, cord or chain
and to the other end a weight or spring, if the drum be turned in either direction
the belt will be wound thereon raising the weight or extending the spring, and as
soon as the force turning the drumi is removed the weight or spring will bring the
drum back to its normal position and the switch to zero. This device can be
attached either to the switch drum or to the drum of the operating handle within
the cage or to both.
By applying clamps or buttons to either or both of the operating cords above
mentioned and fixing stops near the top & near the bottom of the lift space in

page_text: suitable positions, it is obvious that the ascent & descent of the cage will bring
these clamps or buttons into contact with the stops and the pull thus made upon
the ropes will operate the switch and stop the movement of the cage.
The arrangement above described lends itself to the ready application of a speed
governor that will operate the switch should the travel of the cage exceed a
predetermined speed.
Dated this the 14th day of Jul 1802
4
COMPLETE SPECIFICATION.
Improved Means of Working and Controlling Electric Elevators.
I MICHAEL HOLROYD SMITH of 161 Trinity Road Upper Tooting London S. W.
Mechanical and 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 relates to that class of electric elevators where the motor is
stationary operating the cage through the medium of ropes, chains, racks screws
or equivalent devices.
In all passenger elevators the movement of the cage must be controlable by the
attendant within the cage.
The object of this invention is to operate and control a stationary switch &
rehostat from the moving cage, and will be better understood by reference to the
following drawings all of which are merely diagramatic and are not shown as
actual working drawings but simply to indicate the nature of my invention so that
those skilled in the art may understand the same.
Figs. 1. 2 and 3 are diagrams of an elevator shaft showing the cage & its
attachments.
Figs. 4 and 5 are side elevations of the switch and operating device indicated in
Fig. 3.
Fig. 6 is a diagram showing how the operating cord may be diverted.
Like letters or numbers refer to like parts in all the drawings.
A is the cage B the main hauling rope or ropes passing over suitable pulleys to
the winding drum of the electric motor. C, C are cords ropes belts or chains,
attached to the cage A by means of compensating springs & adjusting screws,
and passing over pulleys D D at the top of the lift space thence downwards,
clearing the cage, to or near the bottom of the lift space each cord passing round
a separate shackle-pulley E E' thence upwards into or by the side of the cage, the
ends of these cords being in Figs. 1 & 2 attached to a cross lever pivoted in the
centre and in Figs. 3 and 4 wound in opposite directions round a drum G & secured
thereto. The shackle pulleys E E' are in Figs. 1 & 2 attached to opposite ends of
a centrally pivoted lever H, in Figs. 3 & 5 to cords or chains . a wound in opposite
directions round a drum or cylinder J. On the shaft or spindle of lever H &
drum J is secured the arm of an electric switch K.
It will be seen that the cords C C¹ form two distinct loops one end of each being
atached to the cage the other ends being attached to the drum or lever. It follows
that if the cords are of equal length and equally wound round the drum on the
cage (or attached to the lever) that the bottom loops holding the shackle-pulleys
will hang in the saine horizontal plane and that this will not be affected by the up
or down movement of the cage, the cords being free to run like blind cords over the
top & bottom pulleys. But it is also obvious that if the drum or lever be turned one
of these cords will be shortened lifting its shackle-pulley and the other lengthened
lowering its shackle-pulley & thus operate the switches attached to the stationary
drum or lever. This will be clearly seen by reference to Fig. 2, therefore the
movement of the switch K can be made to coincide with the movement of the

page_text: handle L attached to the lever for drum G in the cage & by moving to right or
left the cage may be made to go up or down.
Levers may be employed where only small movement of the switch is required
and drums where many points of a rehostat have to be covered.
As a provision against accident through neglect on the part of the attendant the
spindle or drum J of the switch K may have attached to it one end of a belt, cord
or chain, M having at the other end a weight N or spring. If the drum be turned
in either direction the belt will be wound thereon raising the weight or extending
the spring, and as soon as the force turning the drum is removed the weight or
spring will bring the drum back to its normal position and the switch to zero.
Where levers are used I employ two weights O. O Figs. 1 & 2 attached to the
ends of the levers by chains so adjusted that the weights will rest upon the floor
(or other support) when the lever is in its normal position, but to move the lever
to right or left one or other of the weights will have to be lifted.
Springs could be used in lieu of weights and the device could be attached to
either the stationary or moveable drum or switch or to both.
Should it be inconvenient to fix the switch-drum (or lever) under the cage at the
bottom of the lift space, the whole order can be reversed and the switch placed at
the top and the pulleys D D' at the bottom, or the switch can be placed clear of
the lift space and the cords or chains from the shackle-pulleys E E¹ led round
guide pulleys P. P' as indicated in Fig. 6, this is capable of many modifications.
By applying clamps or buttons to either or both of the operating cords C. C¹
and fixing stops near the top and bottom of the lift space in suitable positions it is
obvious that the ascent and descent of the cage will bring the clamps or buttons
into contact with the stops, and the pull thus made upon the cords will operate the
switch and stop the motor working the cage.
If it is desired to automatically stop the cage at any intermediate floor modifi-
cations of well known devices can be applied. A method is illustrated in Fig. 1
where the operating leverf is made hollow & in the hollow a bolt can be slided by
the knob R, when the knob is central the ends of the lever will respectively engage
with the stops 1. 1' at the bottom or top of the lift space, by sliding the bolt to left or
right it may be made to engage with stops 2. 21 3. 3¹ as required.
Fig. 4 is an enlarged & more detailed view of an operating handle & drum within
the cage & Fig. 5 is an enlarged and more detailed view of a stationary switch.
I do not confine myself to the details shown.
Having now particularly described & ascertained the nature of my said inven-
tion. and in what manner the same is to be performed I declare that what I
claim is
1. The combination of loop-cords and shackle-pulleys with levers or drums as &
for the purpose herein illustrated and described.
2. The automatic cut out herein described & illustrated.
M. HOLROYD SMITH.