IMPROVEMENTS IN SAFETY APPARATUS FOR HOISTING CAGES
Year: 1876

page_text: LETTERS PATENT to Carl Pieper, of Dresden, Saxony, for the Invention of
"IMPROVEMENTS IN SAFETY APPARATUS FOR HOISTING CAGES." A com-
munication from Carl Eickhoff and Robert Eickhoff, and Reinhold Ardelt, of
Bochum, Prussia.
Scaled the 18th May 1877, and dated the 2nd December 1876.
PROVISIONAL SPECIFICATION left by the said Carl Pieper at the Office of
the Commissioners of Patents on the 2nd December 1876.
CARL PIEPER, of Dresden, Saxony.
"IMPROVEMENTS IN SAFETY APPARATUS For
HOISTING CAGES." A communication from Carl Eickhoff' and Robert Eickhoff, and
Reinhold Ardelt, of Bochum, Prussia.
The object of the present Invention is to provide a safety apparatus for hoisting
cages, which is more certain in its action than the apparatus hitherto designed,
and which causes the cage to be stopped gradually, i.c., without a sudden jerk, in
case the rope to which it is attached breaks.
The main parts of this apparatus are shown by the accompanying Drawing, in
Figures 1 and 2.
A is one of the lateral cross heads of the cage, and B the corresponding wooden
guide of the framework of a shaft or of an elevator. To the cross head A two
plates C, C, are attached, which serve as guides for the two wedges D, D. To the
upper end of each of the wedges is hinged the piece E with rack inside into which
the pinion F gears, and to this pinion are fixed the two wheels G, G, having sharp
teeth on their periphery. The bolt H on which the pinion F and the wheels Ġ
turn is fixed to a spring I fastened on the inside of the cross head A. On the
bolt H there is yet a roller K, which by the pressure of the spring I bears against
the wedge L constituting a part of a cross head fixed to the suspension rod to which
the rope is attached. The suspension rod passes loose through the main cross head
of the cage and supports it when the cage is in working order. In a slot of each of
the wedges D there is a wheel M with sharp teeth turning on a pin N. As long as
the cage is properly suspended by the rope the wedge L is in its top position, and
keeps the two rollers K, K, apart so as to prevent the wheels G, G, from touching

page_text: the guide B. If however the rope breaks the springs I, I, pressing the rollers K, K,
against the wedge L force it down and then press the wheels G, G, against the
The
guide B, causing their teeth to enter more or less into the wood of the same.
cage is at the moment beginning to fall; consequently the wheels G, G, will turn in
the direction of the arrows, and the pinions F, F, lift the racks E, E, together with
the wedges D, D. The latter sliding with their back on the inclined part of the
guide plates C, C, are jammed with their face against the guide B, thereby acting
as brakes. With the wedges the wheels M, M, are raised, and at the same time
shifted within the wedges towards the guide B, as the pins N, N, on which the said
wheels turn rise in the slots O, O, which are inclined somewhat more than the back
of the wedges D, D. Consequently the teeth of these wheels also enter into the
wood of the guide B, the wheels revolve and being forcibly pressed against the
pins N, the friction between the wheels and the pins not only creates a further
resistance against the descent of the cage, but it also tends to push the wedges D, D,
upwards and against the guide.
The described apparatus acting as a powerful brake gently arrests the downward
motion of the cage.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Carl Pieper in the Great Scal Patent Office on the 29th May 1877.
CARL PIEPER, of Dresden, Saxony. "IMPROVEMENTS IN SAFETY APPARATUS FOR
HOISTING CAGES." A communication by Carl & Robert Eickhoff, and Reinhold
Ardelt, all of Bochum, Prussia.
The object of the present Invention is to provide a safety apparatus for hoisting
cages, which is more certain in its action than the apparatusses hitherto designed,
and which causes the cage to be stopped gradually, i.e., without a sudden jerk, in
case the rope to which it is attached breaks.
This apparatus is shown on the accompanying two Sheets of Drawings.
Fig. 1, Sheet 1, is a front view; Fig. 2, a side elevation; and Fig. 3, a plan of
top of the cage with the improved arrangement.
A is one of the lateral cross heads of the cage, and B the corresponding wooden
guide or conductor fixed to the framework of a shaft or of an elevator. To the
outside of each of the cross heads A. two plates C, C, of special shape are attached
(see Figs. 1 and 3), which serve as guides for the two wedges D, D, the faces of the
latter being by preference smooth. To the upper end of each of the wedges is
hinged the piece E with a rack inside with which the pinion F is kept in gear, as
it is enclosed in the piece E. To the said pinion are fixed the two wheels G, G,
having sharp teeth on their periphery. The bolt H on which the pinion F and the
wheels G turn is fixed to the top of a spring I fastened on the inside of the cross
head A. On the bolt II there is yet a roller K, which by the pressure of the spring I
bears against the wedge L. constituting a part of a cross head P fixed to the
suspension rod Q to which the rope is attached. The suspension rod passes
loose through the main cross head of the cage and supports it when the cage is in
working order. In a slot of each of the wedges D there is a wheel M with sharp
teeth turning on a pin N. Whilst out of action this wheel does not project over
the front of the wedge D, but as the slots O cut into the cross head A and into the
plate Care inclined somewhat more than the back of the wedge D, the pin N
sliding in these slots, whilst the wedge is being raised shifts the wheel M inside of
the wedge and causes it to project over its front. To allow for such shifting the
holes for the pin N in the wedge are made of suitable length, as shown in the
Drawings. Of course the entire arrangement is the same on both sides of the cage.
As long as the cage is properly suspended by the rope the wedge L is in its top
position and keeps the two rollers K, K, apart so as to prevent the wheels G, G,

page_text: same.
from touching the guide B. If however the rope breaks the springs I, I, pressing
the rollers K, K, against the wedge L, force it down and then press the wheels G, G,
against the guide B, causing their teeth to enter more or less into the wood of the
The cage is at the moment beginning to fall; consequently the wheels G, G,
will turn in the direction of the arrows and the pinions F, F, lift the racks E, E,
together with the wedges D, D. The latter sliding with their back on the inclined
part of the guide plates C, C, are jammed with their faces against the guide B,
thereby acting as brakes. With the wedges 1), D, the wheels M, AI, are lifted, and
being at the same time shifted within the wedges towards the guide B, as explained
above, the teeth of the said wheels also enter into the wood of the guide, the wheels
consequently revolve, and being forcibly pressed against the pins N, the friction
between the wheels and the pins not only creates a further direct resistance against
the descent of the cage, but it also tends to push the wedges D, D, upwards and
against the guide.
Instead of the straight springs I represented in the Drawings, spiral springs
enclosed in a tube R may be used, as shown in Figs. 4 & 5, the tube being held by
brackets screwed to the cross head A. The rollers K in this case revolve within the
forked end of a rod S inside of the tube R, and the spiral spring acts on a shoulder
of the said rod, the latter being connected on the outside of the tube to a rod with
forked end carrying the wheels G and the pinion F. The wedge L passes through
two slits in the tube R. This wedge may be replaced by a knee-lever joint, as
shown in Fig. 6. The effect of this device will be fully understood from the
Drawing.
The arrangement of the springs and other parts may be varied in different
manners without deviating from the principle of the Invention, and if considered
advantageous, an extra spring may be combined with the suspension rod Q, so as
to press the same down in case of need with more force than is to be obtained from
the springs I together with the wedge L only.
The described apparatus acting as a powerful brake gently arrests the downward
motion of the cage, whilst the apparatusses commonly in use, either stop the
cage suddenly, and thereby often cause as much damage as a fall to the bottom of
the mine, or the teeth of their excentrics, levers, &c., upon catching into the wood of
the guides abrade the same, and being filled with the abraded chips, no more
prevents the lescent.
So far wooden guides or conductors only have been taken into account, but the
apparatus inay also be used with guides constructed of bars of iron. Its general
arrangement in this case remains the same as described for wooden guides, but the
wheels G and M must be made of steel, well hardened, and they must be provided
with small and very sharp teeth fit to bite into the iron guide. The friction of the
wedges D on the iron being less than on wood, they should be made less tapered
than in the former case, and the slots less inclined against the back of the
wedges.
The Figures 7 and 8 show the apparatus applied to wire rope conductors; these
being generally placed at the four corners of the cage, the safety apparatusses have
to be arranged accordingly. In the design represented there is but one wedge D
with its appertaining parts to each conductor B', so that the wedge coming into
action friction is caused between it and the conductor on one side, and between the
latter and the guiding bracket U on the other. The wheels M and G are provided
with small and sharp teeth as required for guides of iron bars, and they should be
grooved to suit the shape of the wire rope conductor; also the wedge D must be
similarly grooved. The wheels G may be kept out of action whilst the winding
rope is intact, simply by connecting the bolts H or the top of the springs I to the
head of the suspension rod Q by means of chains V. The rod Q may in this case
also be provided with a spring X for forcing it down if the rope breaks.
An arrangement similar to that of Figures 7 and 8 may also be used for guides
or conductors made of double T iron, the guiding brackets on the hoisting cage
embracing the outer flanges of the said conductor, as shown in plan by Fig. 9.

page_text: Another modification applicable to guides of wood or of iron bars of any suitable
section consists in the use of only one wedge D with the wheels and other parts con-
nected, instead of the double arrangements of Figures to 6, the cage being
provided with a guiding bracket opposite to the wedge D for resisting the pressure
of the same when it comes into action and for causing additional friction.
Having thus explained the nature of the said Invention, and the manner of
carrying it out in practice, as communicated to me by my correspondents, I claim as
new and essential features of the same,-
(1). In a safety apparatus for hoisting cages, the roller K, the pinion F, the wheel G,
the spring I, the rack E, and the wedge 1) combined, either singly or in pairs with
the wedge L, Figures 1 to 5, or any equivalents of these parts, as and for the purpose
specified.
(2). In a safety apparatus for hoisting cages, the combination of the pinion F, the
wheel G, the spring I, the rack E, the wedge D, and the chain V, Figures 7 and 8,
or any equivalents of these parts, as and for the purpose described.
(3). In either of the apparatusses of claims 1 and 2, the combination of the
wedge D with the toothed wheel M, the pin N of which slides in slots O, as
described and for the purpose specified.
In witness whereof, I, the said Carl Pieper, have hereunto set my hand and
seal, this Twentieth day of March, in the year of our Lord One thousand
eight hundred and seventy-seven.
CARL PIEPER. (L.S.)