Improvements in Appliances for Cutting off the Current from Electric Elevator Motors and for Arresting the Fall of the Car.
Year: 1899

page_text: Date of Application, 1st Sept., 1899-Accepted, 2nd Dec., 1899
Improvements in Appliances for Cutting off the Current from Electric
Elevator Motors and for Arresting the Fall of the Car.
We, JAMES HENRY JOHNSON, residing at No. 25, South 12th Street, in the
City of Newark, County of Essex, State of New Jersey, U.S.A., Engineer, and
WILLIAM RAYMOND WEEKS, residing at No. 40, Mt. Prospect Place, in the City
of Newark, County of Essex, State of New Jersey, U.S.A., Financial Lawyer, 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:-
The object of the present invention is to furnish auxiliary appliances for pre-
venting the fall of the car in electric elevators, whereby the electric current
may be cut off from the motor if the operator loses control of the car, and whereby
the car may be caught and arrested in its descent in case the hoisting rope should
become broken.
Electric elevators are furnished with a so-called controller for stopping the
motor and starting it in opposite directions, and with a pull-rope or other con-
nection to the moving car for working the controller.
The first improvement consists in providing a cut-out switch to cut off the
current from the controller by means of a governor upon the car if the car passes
beyond its normal limit, or moves too rapidly in the hoistway; and the second
improvement consists of a movable guide strip upon the side of the hoistway
which is crowded into the hoistway to cramp the car in its descent, if the hoisting
rope is broken.
The invention will be understood by reference to the annexed drawing, in
which Fig. 1 is a diagrammatic representation of a hoistway, car, and the required
attachments. Fig. 2 is an elevation of the car and part of the hoistway upon a
larger scale, with one governor and clamp illustrated. Fig. 3 is a vertical
elevation of the lower part of the hoistway, the view being taken in section
adjacent to the guide strip; and Fig. 4 is a vertical section on line x, x, in
Fig. 3, showing the gearing at the rear side of the guide strip.
d denotes the floors of the building, the guide posts, c¹ the car, and the
hoisting rope connected with hoisting drum el
f denotes the electric motor connected with the drum by armature shaft g¹.
The shaft is connected with the drum by a worm and wheel which are concealed
in the drawing by an enclosing casing. z¹ denotes the controller box with con-
troller lever h¹. denotes the controller wheel from which the ordinary pull-
rope is shown extended up and down the hoistway, and through the car c¹.
The rotation of the controller wheel by the pull-rope actuates the controller
lever by the cam j¹.
These are ordinary appliances and serve to operate the car normally.
The first safety appliance comprises a cut-out switch having lever / connected
with a safety rope m¹, that is extended through the hoistway adjacent to the car,
and through a clamp p actuated by hand-lever n¹ within the car as shown in
Fig. 2, and also through a clamp 9 actuated by a governor 8 on top of the
car. A shifter rod is shown supported movably in guides w upon the left hand

page_text: post b in Fig. 1, and the rope m¹ is connected to the top and bottom of such rod.
A block is secured upon the rod near the top, and a dog is attached to the
car, which contacts with such block and shifts the rod when the car reaches
the upper limit of its travel thus pulling the switch lever 7 and preventing the
car from moving further, by wholly cutting off the current from the controller z¹.
The governor is provided for further security in case the car for any reason
falls or descends too rapidly in the hoistway.
The governor is driven by rope y and connected with the clamp 7 by
levers and u. In Fig. 2, the clamps are disengaged from the safety rope m¹,
but in Fig. 1, the clamp q is pressed upon the rope and the switch is shown opened
by the pulling of the lever 7.
The positive and negative wires of the electric circuit are shown connected
with the cut-out switch and with the controller ¹, and the switch lever is so
drawn as to make the breaking of the current apparent to the eye.
One end of the rope y is fastened at the top of the hoistway, and carried over
the governor pulley r and over an idle pulley upon the car and provided with
weight at its lower end to produce a constant tension.
The weight o hangs constantly at the bottom of the hoistway, as the pulleys w
and are both supported upon the car and simply roll over the rope.
So long as the car is controlled by the pull-rope it moves at a normal speed
up or down the hoistway, but when through any accident or derangement of the
machinery the car assumes an excessive speed, the governor actuates the clamp g
and grips the safety rope m¹ which immediately pulls the cut-out switch lever 7
and cuts off the current from the controller 2.
When the car is stopped, the governor permits the clamp to open, and the
current may be restored to the system by moving the switch lever to its initial
position to close the circuit.
Should the governor fail to operate properly, the hand-lever n¹ in the car still
remains as a means for operating the cut-out switch, as it serves when moved
by the operator to press the clamp upon the rope m¹ and thus pull the lever 7.
If these appliances are operated when the car has passed the limit of safety at
the top of the hoistway, the hoisting rope may be broken before the motor is
stopped, and the car would then fall.
The movable guide strip shown in detail in Figs. 3 and 4, in such case operates
to arrest the car before it has fallen more than a few feet. A fixed guide
strips is shown at one side of the hoistway, and a movable guide strip at the
opposite side, the latter being divided into sections, four of which are shown in
Fig. 1 pivoted at their upper ends to the guide post by bolts z.
The posts are represented hollow in Figs. 3 and 4. that is, formed with
flanged metallic side beams. Only two sections are shown in Figs. 3 and 4.
Each section of the movable guide strip is strengthened by a bar e flanged
like the beams and fitted snugly between them sidewise, and such bar forms
the medium for pivoting to the beams by the bolts .
Two nuts are shown attached at intervals by bolts, to each of the beams c,
and screws e, are fitted to the nuts and connected by gears to an upright
shaft 9. which is carried in bearings secured between the beams b.
The
The outer ends of the screws are journaled in bearings upon the shaft g,
and such bearings are braced by projections 3 upon the floor beams d.
shaft is geared to a shaft k carrying rope drum m, and a safety rope n is
extended from such drum first upward and then over pulleys o' downward in the
hoistway in the path of clamps q' upon the car body c¹. Such clamps are operated
respectively by a governor and a hand-lever, like those shown for clamping
the safety rope m¹. The clamps would, in practice, be placed upon the car
at the opposite side to those employed for clamping the rope m¹. The clamps q¹
and governor are not shown in Fig. 2 of the drawing, as they would tend to
confuse the details: but the governor and part of the clamp are visible in Fig. 1.
Such governor would be actuated by a weighted rope, as described for the

page_text: governor. The rope is so applied to the drum that when the car descends
at an excessive velocity, and the rope n is gripped by the clamp 21, the descent
of the car rotates the drum m and shaft g thus turning the screws e in the nuts f,
and forcing each section of the movable guide strip into the hoistway.
Such strip cramps the car by pressure upon its shoes 2 shown in Fig. 1, and
thus arrests the car wherever it may be in the hoistway, and prevents its farther
descent. As the nuts are at different distances from the fulcrum ≈ of the
swinging guide strip s¹, the screws e should be made of different pitches, or the
gears varied in diameter, so as to advance the two nuts in proportion to their
distance from the fulcrum z. To resist the lateral pressure upon the strip, the
screw bearings are braced by supports 3 upon the floor beams, or other solid
abutment. When the car is stopped, the clamps can be opened, and the drum,
the shaft g, and the screws e returned to their initial position.
Either of the safety appliances described herein may be used in addition to
all others commonly provided.
Either the hand-clamp or the governor elamp may be used alone to control the
guide strip by the movement of the car, but greater safety is assured by providing
both.
Any device equivalent to the clamp. rope, and screw gearing can be used
for pressing the lower end of the guide strip inwardly by the movement of the
car.
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 an elevator having a hoistway and car movable therein, and an electric
motor, drum, and rope for hoisting the car, with a controller for normally regulat-
ing the movements of the motor, the safety device comprising an auxiliary switch
for cutting off the current from the said controller, a safety rope extended up
the hoistway and connected with such switch, and a governor upon the car with
clamp for gripping the safety rope, to cut off the current from the controller
when the car exceeds its normal speed.
2. In an elevator having vertical guide strips with shoes upon the car fitted
to the same, the appliances for arresting the car if falling in the hoistway, com-
prising a guide strip fixed at the upper end and movable inwardly at the lower
end, and means controlled by the movement of the car for pressing the lower
end of the guide strip inwardly to cramp the car in its descent.
3. In an elevator having vertical guide strips with shoes upon the car fitted
to the same, the appliances for arresting the car if falling in the hoistway, com-
prising a guide strip divided into sections each fixed at the top and movable at
the bottom toward the car, screws for pressing the bottoms of the sections inwardly,
a rope drum and gearing for rotating the screws, a rope extended up the hoistway
from such drum, and a governor upon the car with clamp to grip the said rope,
and thus rotate the drum and the screws to press the bottoms of the sections
inwardly when the car moves at an abnormal speed.
4. In an electric elevator of the type described, the automatic safety devices
substantially as and for the purposes herein before described and as illustrated by
the drawings hereto annexed,
Siened at Va 10 Tall Cut
001
T
THOMAS SEXTON CRANE,
Agent for Applicant.