IMPROVEMENTS IN SAFETY-APPARATUS FOR LIFTS
Year: 1884

page_text: I, MORITZ MARTIN, of Bitterfeld, Prussia, manufacturer, do hereby declare the
nature of said invention for "IMPROVEMENTS IN SAFETY-APPARATUS FOR LIFTS,"
to be as follows:-
My invention relates to safety-apparatuses for lifts, serving to automatically stop
the lift in case of breakage of the winding-rope, and its object is to render the
tension of the springs of the apparatus independent of the weight of the lift and
its charge.
The apparatus consists of a shaft carrying toothed eccentrics adapted to catch
into the wooden guiding-posts, and springs by which the shaft may be so rotated
as that the eccentrics will be pressed against the posts. On the shaft there is,
moreover, & ratchet-wheel with which engages the short arm of a lever, to the long
arm whereof is attached the winding-ropo; and the parts are so arranged that the.
ratchet-wheel is prevented from being rotated by the springs as long as the lever is
pulled upon by the rope; whereas, when the lever is let free, the springs will put the
wheel in rotation. Consequently, in case the rope breaks, the lever, losing its
hold, is tilted by the ratchet-wheel, and the springs press the eccentrics against
the posts.
In order to prevent the lever from disengaging with the ratchet-wheel when the
lift, at the lower end of its course, settles on the supports provided therefor, and
the rope becomes slack, a fixed stop or abutment is required, having such position
that, when the lever is about to tilt, it will come in contact with the said stop and
be prevented from leaving the teeth of the wheel. In some cases there may be a
movable piece on the lift arranged to settle on the stop or stops and be raised
thereby, relatively to the lift, so as to be brought close to the levers.
Dated this twenty seventh day of June 1884.

page_text: I, MORITZ MARTIN, of Bitterfeld, Prussia, manufacturer, do hereby declare the
nature of my invention for "IMPROVEMENTS IN SAFETY-APPARATUSES FOR LIFTS,"
and 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 safety-apparatuses for lifts, serving to automatically stop
the lift in case of breakage of the winding-rope, and its object is to render the
tension of the springs of the apparatus independent of the weight of the lift and
its charge.
A lift provided with my improved apparatus is shown on the annexed sheet of
drawings in two different modifications. Fig. 1 is a sectional side-view of a lift
with a single apparatus, and Fig. 2 a plan of the latter. Fig. 3 shows in side-view,
partly in section, and Fig. 4, in plan, a lift with double apparatus. Fig. 5 is a
sectional front elevation of a part of the same.
The apparatus consists in the first place of the shaft f, the toothed eccentrics a
and the springs b. These parts are old. The shaft fis mounted in bearings, either
at the bottom of the lift, as in Fig. 1, or at the top, as in Figs. 3 and 4. The
eccentrics a, adapted to catch into the guiding-posts 8, are keyed on the shaft, and
the springs bare fastened with one end to the shaft and with the other to a part of
the lift.
In addition to the said pieces the shaft carries a ratchet-wheel p, and to the
lift is pivoted a lever h, having a short arm forming a pall that engages with the
teeth of the wheel p, and a long arm to which is attached the winding-medium,
consisting in a rope, a strap or a chain. In the lift Fig. 3, each of the two levers h
is connected by a short chain to the winding chain z. To put the apparatus into
working order, the shaft f is turned by a key or other instrument, so as to
impart to the springs the tension required for enabling them, when released, to
press the eccentrics against the guiding-posts. The springs are then kept in their
state of tension by the pall-end of the lever bearing against a tooth of the ratchet-
wheel, and the lever is maintained in the proper position by the pull of the winding-
rope. But, if the winding-rope breaks, the lever h, not being held any more, is
tilted by the power of the springs transferred through the ratchet-wheel on the
short arm of the lever, the wheel becomes disengaged, and the springs turn the
shaft so as to drive the eccentrics with their teeth into the wooden guiding-posts.
With this arrangement the greatest power with which the springs may act, is not
limited to the weight of the lift, but it depends upon the proportion between the
lengths of the two arms of the lever h. Now as these lengths can be varied while
the weight of the lift remains the same, it follows that, for actuating the eccentrics,
a greater power may be stored up in the springs than is possible with other
constructions of the same kind.
In order to prevent the lever h from disengaging with the ratchet-wheel when
the lift, at the end of its descent, settles on the ground-timbers of the lowest floor,
and the rope becomes slack, a stop or abutment must be provided for, which keeps
the lever in its proper position. With the apparatus Fig. 1 this abutment is
formed by a portion w of the foundation, the height whereof is such that the lever

page_text: will be close to it when the lift rests on its supports. In the apparatus Figs. 3 to 5
the device serving to retain the levers in gear with the ratchet-wheels, consists in
the cross-beam i, movable on, and guided by two bolts m, and in two stops o fixed
to the posts 8 at such height that, just before the lift settles on the ground-timbers,
the beam i will strike on the said stops and be raised, relatively to the lift, by so
much as is required to bring the same close to the levers h. The beam is then in
a position to serve as support for the levers when the chain z becomes slack.
On the bolts m there are springs n serving to press down the beam i as soon as
the lift rises again. Moreover the bolts are connected by a cross-piece m¹ serving
to prevent the levers from being drawn beyond the horizontal position.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is
1, In a safety-apparatus for lifts, the combination with a shaft f, the springs b
and the toothed eccentrics a, of the ratchet-wheel p keyed on the shaft f, and the
lever h, attached by its long arm to the winding-medium, and engaging by its short.
arm with the said ratchet-wheel, substantially as described.
2, The combination with a shaft f, springs b, eccentrics a, ratchet-wheel p and
lever h, of a stop or stops, having such position as to prevent the lever h from dis-
engaging with the ratchet-wheel p when the lift is at the bottom of its course, and
the winding-medium is slack, as and for the purpose described.
F
MORITZ MARTIN.
By his Agent, Carl Pieper.