An Improved Electric Safety Apparatus for Lifts and Elevators.
Year: 1899

page_text: Date of Application, 14th Oct., 1899
Complete Specification Left, 13th July, 1900-Accepted, 25th Aug., 1900
PROVISIONAL SPECIFICATION.
An Improved Electric Safety Apparatus for Lifts and Elevators.
JOHN BUSH, 90, Lausanne Road, Nunhead, S.E., Engineer, and
ARTHUR DAVID JENKINS, of 131 & 133, Union Street, Borough, London, En-
gineer do hereby declare the nature of this invention to be as follows:-
This invention will consist of a safety apparatus or lock to fix the controlling
device of lifts or elevators so that the cage or car of the lift or elevator cannot
be moved away from the door, or doors of building opening to lift while the
door or gates remain open & may be made of one or two electric magnets or
solenoids which will have a sliding bar or fulcrum armiture which will be
actuated by the opening or closing of elevator lift door or gate through a
suitable switch fixed thereon; the armiture bar or lever to engage 1, 2 or more
cams, & at the same time actuate or move a reversing switch. Attached to the
armiture may be a lever with weight or spring so that when the armiture is
either drawn in or out it will retain it in position without the aid of electric
current or magnetism. Upon the gate of lift being closed the bar or fulcrum
armiture will engage 1, 2 or more clutches or cams forcing them open or
closed as the case may be thereby releasing the controlling rope, rod, wheel
lever, or bar; when the lift gate or door opens the action of the magnets will
be reversed & clutch the rope, rod, wheel, lever or bar of controlling device
rendering it immovable during the time that the cage or car door or door of
building accessible to the cage is open.
The apparatus may be fixed to the car or cage or in any place in the fift
or well hole.
11
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1000
An Improved Electric Safety Apparatus for Lifts and Elevators.
We, JOHN BUSH, of 90, Lausanne Road, Nunhead, S.E., Engineer, and
ARTHUR DAVID JENKINS, of 131 & 133, Union Street, Borough, London, En-
gineer, 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:-
According to this invention an electric apparatus is provided operated by
the doors opening from the elevator shaft into the building in such manner that
the usual starting rope, bar or other part controlling the movement of tho

page_text: cage is firmly gripped as long as the door remains open so that the cage cannot
be moved away from the doorway until the door is properly closed.
Figure 1 is an elevation from the outside of the elevator shaft and looking
inwards. The gripping mechanism (which is inside the shaft and therefore
hidden) is however shown in full lines and is about half full size whilst the door
is to a much smaller scale.
a is an electro-magnet or solenoid whose armature a¹ is fixed to the bar
or lever b fulcrummed at 6¹ and carrying rollers & engaging with two cam slots
cut in the gripping jaws c. These jaws are pivotted at c² in a three sided
box or frame & through which the usual starting rope or bar e passes. The
magnet a is energised by the battery f in the circuit of which is a switch g
(operated by a spring bolt h¹ on the door h which opens from the elevator shaft
into the building) and also a reversing switch j actuated by the bar or lever
through the rod 63. The battery f may be replaced by any other source of
electricity which may be the same or separate from that which works the
elevator. is a weighted hooked lever pivotted to the armature bar band
engaging with the catch k. is a second electro-magnet whose armature is fixed
to the lever 4. When the door is open the parts are in the
positions shown and the circuit through the magnet n is broken
at the switch ; and the circuit through the magnet 7 is broken at the
switch g. When the door is being shut the spring bolt moves the switchg
from the contact to the contact g2 and a circuit is then closed from the
battery through the wire m switch g contact g² wire magnet wire o
contact switch j and wire p back to the battery. This causes the magnet ! to
attract its armature thus releasing the lever from the catch and allowing
the bar to be forced up by its spring b. The movement of the bar b withdraws
the jaws c freeing the rope e and also shifts the switch j from the contact j'
to the contact j2 thus again breaking the circuit. In opening the door the bolt h¹
moves the switch g from the contact g2 to the contact g and a circuit is closed
from the battery f through the wire m switch g contact g wire q magnet a
wire contact switch wire back to the battery. This causes the magnet a
to attract its armature drawing down the bar 6 until the lever engages with
the catch k. This movement of the bar 6 grips the rope and shifts the switch j
from the contact to the contact 1 thus again breaking the circuit.
Figure 2 shows a similar arrangement in which two electro-magnets or sole
noids are employed to actuate the gripping mechanism. In this case the
gripping jaws care dispensed with and the rope is held by a lug 66 on the bar
which forces it against the back of the three sided box d. The spring is
replaced by the weight b and the bar bis operated by the inclines which is
pivotted at s¹ and carries the armatures of the magnets a and . In other
respects the arrangement is similar to that first described.
In place however of the pivoted bar shown in Figure 1 and 2 we prefer to
employ a sliding bar as shown in Figures 3 to 8.
Figure 3 is an elevation (partly in section) looking outwards from the elevator
shaft. Figures 4, 5 and 6 are side and end elevations and a plan of the gripping
device to a larger scale. Figure 7 shows the details of the bolt and Figure 8 a
plan of one of the switches to a larger scale.
1 is the rope by which the cage is started and stopped, 2 is a three sided
box or frame through which the rope passes, and 3 are gripping jaws pivotted
to it. These jaws are fixed to shafts 4 and are provided with teeth 5 gearing
with each other so that the jaws turn together. 6 are cams fixed to the shaft 4.
7 are rollers acting on the cams and pivotted to a fork at the end of the rod 8.
When the parts are in the position shown the rope is gripped by being forced by
the jaws 3 against the back of the box 2. 9 is a soft iron core fixed to the
rod 8, and 10, 11 are electro-magnets in which the core works so forming a 5
double solenoid. 12, 13 are the spring contacts of a switch 14, and 15 is an arm
pivotted at 16 working between them. 17 is a lug on the arm 15, and 18, 19

page_text: are pins on the rod S engaging with it. 20 is a tumbler pivotted to the arm 15,
and 21 is a spring bolt engaging with it and compelling the arm to always
remain in one or other of its extreme positions in engagement with the contact
jaws 12 or 13. 22 is one of the doors opening outwards from the elevator
shaft, and 23 is a spring bolt carried by it. 24 is a switch (shown to a larger
scale in Figure 8) in all respects similar to the switch 14 above described
but placed horizontally instead of vertically, and 25 is a lug on its arm corre-
sponding to the lug 17 of the other switch, the bolt 23 engages with the the lug
25 when the door opens and shuts, throwing over the switch arm from one
contact to the other. 26 is a bolt shown in Figure 4 engaging with the door,
and 27 is an arm against which the cage acts in passing. Normally the weight
of the bolt holds it down as shown and the ring of non-conducting material 28
carried by the bolt breaks the circuit between the contacts 29 and 30 but when
the bolt is raised the circuit is closed through it.
The object of the bolt 26 is twofold, it screws the door and it breaks the
circuit through the magnet 11. If this circuit were not normally broken at
some other point than at either the switch 14 or the switch 24 then an oscillatory
motion would be given to the core 9 by reason of the circuits through the
magnets 10 and 11 being alternately closed if any door were opened while the
others are closed. This line may also be broken by a switch or push contact
in the cage or contacts in the lift shaft which would be made by the lift cage.
It is desirable to provide a similar bolt or line cutting devices for the same
purposes in the arrangements shown in Figures 1 and 2.
31 is a source of electricity which may be the same or separate from that
which works the elevator. Normally the circuits through both the electro-
magnets 10 and 11 are broken one at the switch 14, and the other at the
switch 24, but the opening or shutting of the door momentarily closes the
circuit through the one which at that time does not contain the core 9 so
attracting it and thus moving the rod longitudinally and gripping or releasing
the rope 1 as the case may be and at the same time shifts the switch arm 15
again breaking the circuit.
The circuit through the electro-magnets 10 (when closed) is as follows:-
From the battery or other source, 31, by the wire 32, to the terminal 33 (which as
connected to the arm of the switch 24) terminal 34, wire 36, terminal 37,
wire 38, magnet 10, wire 39, contact 13, arm 15, and wire 40 back to 31. When
the door is open as shown this circuit is broken at the switch 14 for the arm 15
is not in engagement with the contact 13.
The circuit through the electro-magnet 11 (when closed) is as follows:-
Battery 31, wire 32, terminal 33, terminal 35, wire 41, terminal 42, bolt 26,
terminal 43, wire 44, terminal 45, magnet 11,, wire 46, contact 12, arm 15,
and wire 40 back to 31.
:
When the door is open as shown the arm of the switch 24 connects the ter-
minals 33 and 34 there being no connection between 33 and 35 and the circuit
through the magnet 11 is broken at the switch 24. The act of shutting the door
shifts the switch 24 and connects the terminals 33 and 35 thus closing the
circuit through the magnet 11 causing it to attract the core 9 and release the
starting rope 1 and simultaneously shift the switch arm 15 and again break
the circuit. In a similar way opening the door cases closes a circuit through the
magnet 10 which causes the rope 1 to be gripped and breaks the circuit.
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. The combination of means for gripping the starting rope or other part
controlling the movement of the cage, means for retaining the gripping device
in action, an electro-magnet or solenoid operating the retaining device, a circuit
through the magnet and a switch in the circuit operated by the door.

page_text: 2. The combination of means for gripping the starting rope or other part
controlling the movement of the cage, a lever operating the gripping device,
a catch for holding the lever in its operative position, an electro-magnet whose
armature carries or actuates the catch, a circuit through the magnet and a switch
in the circuit operated by the door.
3. The combination with the subject matter of Claims 1 and 2 of a reversing
switch operated by the movement of the gripping device whereby the circuit is
broken when the gripping device is released.
4. Electric safety apparatus for lifts and elevators substantially as described
and illustrated in the drawings.
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