Safety Clutch Mechanism for Mine Cages and the like.
Year: 1899

page_text: Date of Application, 22nd Nov., 1899-Accepted, 22nd Nov., 1900
. COMPLETE SPECIFICATION.
Safety Clutch Mechanism for Mine Cages and the like.
We, WALTER FEHLENBERG, Merchant, and RICHARD SCHULZ, Miner, both of
Herne, Wesphalia, Germany, do hereby declare the nature of this invention an
in what manner the same is to be performed to be particularly described and
ascertained in and by the following statement:-
My invention relates to improvements in safety devices for mine cages and lifts,
employed for arresting the descent of the mine cage or lift when the hoisting
chain or cable breaks.
My invention consists in novel features of construction hereinafter described and
claimed.
In order that my invention may be fully understood I will proceed to describe
it with reference to the accompanying drawings, in which :-
Fig. 1 is a front elevation of the upper part of a cage and adjacent parts showing
my improved clutch mechanism.
Fig. 2 is a top plan view thereof.
Fig. 3 is a side elevation of the same.
Fig. 4 is a detail end view of a central buffer.
Fig. 5 is a detail side view of the same partly in section.
Fig. 6 is a perspective view of a corner pocket.
Fig. 7 is a perspective view of a clutch lever frame.
2 are the shaft timbers, and n are the central guide-bars, 3 is the hoisting
chain or rope connected by chains 4 with the cage or lift. Connected with the
hoisting chain or rope by means of a short chain care rods e supporting an
upper plate lower plate 6 and a spring e compressed between the plates by the
weight of the cage or lift on the central supporting bar d on which the cage
or lift is suspended. i are four separate two armed clutch-levers whose upper
ends engage with the lower plate so as to be tripped there by when the hoisting
chain breaks and unloads the spring.
The clutch levers aro pivotted to the upper bars d of the cage or lift, by means
of rods or shafts p. At the four upper corners of the cage or lift are pockets o,
each containing buffers o¹, of soft clastic rubber, located over the lower arms k of
the clutch levers and open towards the sides of the shaft. To these pockets o
are hinged flaps o against which the lower arms of the clutch levers are adapted
to come in contact. The bearings of the clutch levers are so arranged that if.
the hoisting chain or rope is broken their lower arms describe the segment of a
circle upward, that is to say the ends of the lower arms move from underneath
the pockets upward and therefore of course move outward. In consequence of this
they move outside of the cage or lift. 3 are central pockets each having hinged
flaps of and containing buffers o of soft elastic rubber formed with flanges of
adapted to bear on and embrace the guide bars n. Each pair of clutches arranged
on one side are connected with one another by means of a cross-bar s of angle shape,

page_text: the arms of which project upward diagonally from the connecting points. The
tops of these cross-bars are adapted to bear against the flaps of of the central pocket.
The operation of my improved safety clutch is as follows:-
-
If the hoisting chain or rope breaks the spring e is released and presses down
the lower plate b, so that the four two-armed clutch levers are rocked, the lower
arms move out of the angle irons m to the cage or lift, and place themselves under
the flaps o² of the corner pockets containing the rubber buffers o¹. The bearings
for the cushions are sloped off at the bottom so that there is an equal contact on
the whole lower surface of the cushions or buffers.
When
Simultaneously with the rocking of the clutch levers their lower arms press up
the cross bars, the arms of which come in contact with the flaps of of the central
pockets and press their buffers o outwardly against the guide bar n so that
the flanges of of the buffers embrace the central bar. The guide bars are so arranged
that they offer as large a contact surface as possible to the central rubber buffers
and the bearing is preferably set so that the contact with the cushions commences
at the point of rotation and increases in front, in consequence of which an in-
creased projection of the mass of the pressed buffers results. As all the pockets
are only open in front it is obvious that the buffers can only yield in that direction.
It is also to be noted that the corner buffers can serve for braking together with
the central cushions, as the rubber presses against the shaft timbers; or they may
be used merely as elastic bearings for the clutch levers. As the cage or lift slides
down further, all the rubber buffers are compressed and are pressed more and more
against the sides of the shaft and against the guide bars, which causes increased
friction as the cage or lift moves downward. The central cushions, which as
already mentioned, hold the guide bars as closely as possible, instantly begin
to produce their braking actions at the least compression from this part before
the speed at which the cage or lift is falling has increased to any extent.
the buffers are compressed to their maximum point, the lower arms k come out
of the cage or lift so far that they rest over the ledges projecting inwardly from
the shaft timbers. The corner buffers are preferably arranged so that the clutch
levers when they come into contact with the corner buffers already project from
the cage or lift, and when these rest on the next ledge immediately bear thereon,
and as the cage or lift slides further down they are thrust upward. As at the same
time the cushions are more strongly compressed, they act as a still stronger brake
on the shaft timbers. In consequence of this the lower arms k can only move
slowly over the ledges without causing a sudden blow against them and thus the
bending or breaking of the clutch levers is avoided even with iron ledges. Should
there still be any jolting it is sufficient to lessen the counter pressure of the buffers
to obviate this. As only the buffers, and without strong pressure, are connected
with the shaft, and there is no engagement with the clutch levers, none of these
parts can be broken. This clutch mechanism is not only operated by the breaking
of the rope, but also by its slipping or jerking whether the cage or lift is travelling
up or down. As the rubber buffers are readily re-placeable, it rests with the person
in charge to see whether they are renewed at the right time, and do not become
sufficiently worn to render them useless.
Having now particularly described and ascertained the nature of my said in-
vention and in what manner the same is to be performed, I declare that what
I claim is
1. The combination, with a cage or lift of the corner pockets, the hinged flaps
beneath the corner pockets, the buffers located in the corner pockets, and the
clutch levers pivotted to the cage or lift and having their lower arms adapted to
bear upwardly against the hinged flaps, substantially as described.
2. The combination with a cage or lift of the central pockets, the hinged flaps
beneath the central pockets, the buffers located in the central pockets, and the
clutch levers pivotted to the cage or lift, having lower arms and an engular cross
bar adapted to bear upwardly against the hinged flaps, substantially as described.

page_text: 3. The combination with a cage or lift of the corner pockets, the hinged flaps
beneath the corner pockets, the buffers located in the corner pockets, the central
pockets, the hinged flaps beneath the central pockets, the buffers located in the
central pockets and the clutch levers pivotted to the cage or lift having lower arms
adapted to bear against the flaps of the corner pockets, and an angular cross-bar
adapted to bear upwardly against the hinged Haps of the central pockets, sub-
stantially as described.
4. A cage or lift substantially as described and shewn in the accompanying
drawings.