IMPROVEMENTS IN UNIVERSAL SAFETY APPARATUS FOR ELEVATORS AND THE LIKE APPARATUS
Year: 1878

page_text: LETTERS PATENT to Frank Wirth, of the Firm of Wirth and Company, Patent
Solicitors, at Frankfort-on-the-Main, in the Empire of Germany, for the Inven-
tion of "IMPROVEMENTS IN UNIVERSAL SAFETY APPARATUS FOR ELEVATORS
AND THE LIKE APPARATUS." A communication from Leopold Lebrecht Stieler,
Civil Engineer, of Stolp, in the Empire of Germany.
PROVISIONAL SPECIFICATION left by the said Frank Wirth at the Office of
the Commissioners of Patents on the 4th May 1878.
FRANK WIRTH, of the Firm of Wirth and Company, Patent Solicitors, at
Frankfort-on-the-Main, in the Empire of Germany. "IMPROVEMENTS IN UNIVERSAL
SAFETY APPARATUS FOR ELEVATORS AND THE LIKE APPARATUS. [A communication
from Leopold Lebrecht Stieler, Civil Engineer, of Stolp, in the Empire of Ger-
many.]
My said Invention consists of an improved apparatus for preventing elevators
or "lifts" and similar apparatus from falling in the event of the rope breaking.
My said improved safety apparatus consists of two excentric wheels on the same
axle, having between them a third wheel excentric in the opposite direction, this
latter being placed in the centre of a metal bar, which being projected from the
elevator passes through two guides running from the top to the bottom and
fastened to the wall; the end of the bar passing through the guides is provided
with a wooden shoe-piece, overlapping the guides on each side; it will thus be
seen that upon the wheels turning towards the guides they will become wedged
between the latter and the wooden shoe on the inside; the wheels are held in their
normal position by straps or like devices passing up to the head piece, this piece
being allowed some play in a bearing slot; thus, should the rope part the head
piece will fall as far as the slot will allow it, thus liberating the wheels, which
being driven by a spring will turn toward and be wedged between the guides.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Frank Wirth in the Great Seal Patent Office on the 4th November
1878.
FRANK WIRTH, of the Firm of Wirth and Company, Patent Solicitors, at
Frankfort-on-the-Maine, in the Empire of Germany. "IMPROVEMENTS IN UNIVERSAL
SAFETY APPARATUS FOR ELEVATORS AND THE LIKE APPARATUS." A communication
from Leopold Lebrecht Stieler, Civil Engineer, of Stolp, in the Empire of Ger-
many.
My said Invention relates to an improved apparatus for preventing elevators or
lifts and similar apparatus from falling in the event of the rope breaking.
It is well known how dangerous elevators are when they are not provided with
safety apparatus, this consideration and numerous accidents have caused it to be
now customary to provide clevators with a safety apparatus; but an apparatus has
until now not been invented which can be attached to any existing elevator.
My Invention is represented in the accompanying Drawing in which,―
Figure 1 is a side elevation; Figure 2, a plan; and Figure 3, a front elevation
of the same.
The said Invention is represented as attached to an ordinary elevator chair, but
it can equally well be used on any of the existing apparatus.
My Invention comprises mechanism consisting of three excentrics, working in
opposite directions, and a catch shoe and catching rails.
The two excentric catch rolls a are wedged on the toe ends of the excentric
'connecting bar, which is fitted to turn in the journals b of the connecting fork d,
attached to the back of the elevator chair c. The catch arm e passes around the
excentric bar between the two excentric catching rolls a, and further connects the
catch shoe fand bar g with bolts.
The catch rails are placed vertically on each side of the catch arm & at the
back of the elevator c, and are attached to the flooring joists or wall in any con-
venient manner.
The safety apparatus is represented in the Drawing in a passive state, so that the
elevator chair can be drawn up or let down at will.
con-
The vertically movable hanging bolt i, together with the brace k, which is
nected with the lifting rope, are drawn up before the elevator chair begins to lift,
by which movement the two straps or cords n, attached to the excentric apparatus
and to the brace k, draw the catch rolls a and catch shoe faway from the catch
rails, and in doing which the spring p is stretched by means of the carrier o.
The rod serves to carry the catch arm c, but a cord or strap can be used in
place thereof. The pin q serves to prevent the rolls a from being too much turned,
and thus causes the springs p to be always at the same pressure.
g
The instant the lifting rope snaps, the brace k, with bolt i, slips down through
the vertical slot 1, and the excentrics are driven by the spring p in the direction
of the arrow in Figure 1, and at the same time the catch shoe fis drawn against
the catch rails from the opposite side to the excentrics, the shoe and excentrics
thus firmly holding the rails cause the elevator chair to remain stationary.
To loosen the elevator chair from the rails, after a breakage has occurred, it is
only necessary to remove the wedge a² of the catch shoe.
It will be understood that the catch rails can be equally well made of iron or
wood.
The said excentric rolls and catch shoe may be provided with rough or toothed
surfaces, or even covered with india-rubber or left plain. In place of the common
flat spring pa spiral spring may be used, the excentrics a can be provided with
weights at r, in which case the clutching operation is effected without the aid of
the spring p.
Having thus fully described the said Invention, and the manner of performing

page_text: the same, I wish it understood that my Invention may be applied to an elevator
chair not only as shewn in the Drawing but also below the bottom of the chair,
the manner of operating the same however remains the same. And that my Inven-
tion can be used not only on elevator chairs with one back but also on double-sided
elevators, in which case the mechanism is placed on both sides instead of only on
one side, the principle of my Invention however, as shewn and described, remains
the same, and I claim,―
First. The excentric rolls and excentric connecting rod and lever bar forming a
set of excentrics working in opposite directions, as above set forth.
Second. The connecting arm, with the wedge, movable journals, bolts, and
removable shoe, as above described.
Third. The catching rails in connection with my said apparatus as above
described.
Fourth. The connection of the rolls with the brace bolt, small straps or strings,
as and for the purpose set forth.
Fifth. The employment or adaptation of the above-named parts to form the
safety apparatus, substantially as described.
In witness whereof, I, the said Frank Wirth, have hereunto set my hand and
seal, this First day of November, in the year of our Lord One thousand
eight hundred and seventy-eight.
FRANK WIRTH, (L.B.)