Year: 1888

page_text: the nature of my invention to be as follows:
-
This invention has for its object to provide any ordinary lift cage or platform
with simple and reliable means for automatically stopping the cage, when the rope
breaks.
•
My improved safety apparatus chiefly comprises a flat vertical main bar attached
at the top to the rope and situated above the middle of the cage; an expansible
parallelogram or trellis composed of a pair of upper arms or sides and a pair of
lower arms, the vertical main bar mentioned above forming one of the diagonals; a
sliding frame connected with the main bar, the expanding trellis, and the upper part
of the cage, in a special manner; and a pair of vertical rails attached to the inside,
of the uprights or guide posts of the lift and serving as guides for the sliding frame
mentioned above. The two upper arms of the expanding trellis are connected with
each other and with the vertical main bar by a pivot or bolt situated near the top of
the main bar. The opposite end of each of the upper arms is pivoted to the upper
and outer extremity of the corresponding lower arm, and the lower arms are con-
nected at their point of intersection (or crossing point) by a pivot passing through a
vertical slot of the vertical main bar. The lower arms extend downward beyond
their point of intersection right and left of the main rail and carry at their lower
ends a pair of friction rollers adapted to come in contact with the vertical guide rails
of the lift. The pivot connecting the two lower arms in the centre of the vertical
main rail is secured in the upper part or cross beam of the sliding cage, and the said
guide frame has a pair of curved slots for guiding the axles of the friction rollers in
a circular path.
The sliding frame is formed of two parallel plates covering the expanding trellis
and the vertical bar, and bent at both ends (right and left) around the right and left
edge of the guide rails. The connection between the upper part of the cage, and

page_text: the safety appliance, is formed by a stud or bolt fixed in the vertical main bar and
projecting below the upper cross beam of the cage, and by a pair of studs fixed in
the cage frame (near its upper right and left corner) and passing through a
pair of vertical slots of the sliding frame. If the rope breaks, the parallelogram
will collapse by its own weight, so as to press the friction rollers against
the guide rails. This action may be accelerated by a spring which rests against
the upper cross beam of the cage and tends to press the vertical main bar
downward.
The bulging of the vertical guide rails is prevented by the bent extremities of the
guide frame.
Dated this 29th day of February 1888.

page_text: I, OTTOMAR ERFURTH, Master Mason, of Teuchern, Germany, do hereby
declare the nature of my invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:
This invention has for its object, to provide any ordinary lift cage or platform
with simple and reliable means for automatically stopping the cage, when the rope
breaks.
In the improved safety apparatus which is illustrated by the accompanying drawings,
Figs. 1 to 4, the weight of the falling lift cage serves to arrest the latter by friction,
without requiring for this purpose the release of special mechanism, and without
producing violent shocks; and the cage, when jammed between the guide posts, may
be immediately released by simply pulling it upward.
Above the middle of the platform there is a flat main bar A, to which the
chain or rope is attached. Vertically underneath the rope the bar A carries
a bolt a serving as pivot to the upper sides B, B of an expansible trellis or
parallelogram. The lower sides E and F are connected with the upper sides by
pivots c, d, and with each other by a bolt 6 passing through a vertical slot ƒ of the
main bar A.
With the bolt 6 are connected the guide plates G which form the frame work of
the apparatus and have projections i extending behind the smooth guide rails H (see
Figs. 3 and 4) of the lift-cage. The guide plates G are provided with circularly
curved slots h for the pins or axles g of the friction rollers J secured to the lower ends
of the trellis arms E. F.
The action of this mechanism is as follows:
During the normal working of the lift cage, the central bar A is held by the rope,
while the load or the weight of the cage pulls the bar downward. The sides of the
movable parallelogram are thereby pulled apart; that is, the distance between pivot a
and bolt will increase, and a considerable clearance will be produced between the
rollers J and the vertical guide rails H.
If now the rope breaks, the central bar A will at once drop under the influence of
its own weight and that of the lift cage; the trellis B, E and F will collapse, whereby
the rollers come in contact with the smooth guide rails H and are retarded in their
down-motion.
The entire load of the lift cage now acts as a brake-power, so that during the
further down-motion the rollers J will be jammed fast against the rails, and stop the
cage without shock.
To prevent the slide rails H from bending under the lateral pressure, I have provided
the plates G with projections i, as mentioned above, these projections serve as abutments,
which counteract the pressure of the friction rollers and render their clamping or
jamming effect more reliable.

page_text: The power which arrests the lift cage is always in a certain ratio to the actual
weight of the same, because the entire load of the cage acts on the central bar A
and draws the parallelogram together or presses the smooth rollers J against the
guide rails.
After the cage has fallen down, it may be lifted again with little effort, as the
upmotion of the cental bar A is sufficient to expand the trellis work and remove the
rollers from the guide rails.
If it is desired to increase the effect of the falling central bar or suspension
rail A, a spring K (Fig. 2) may be applied to the lower end of the bar A, which
spring begins to operate on the lift cage being released, so as to pull down the bar A,
and stop the apparatus rapidly, but without shock. It is not necessary, however, to
use such a spring, as the mechanism will act with sufficient safety independently of
the same.
The safety apparatus or automatic brake may be applied to any ordinary lift cage
or elevator platform.
Having now particularly described the nature of my invention and in what
manner the same is to be performed, I declare that what I claim is :
A safety apparatus or automatic brake for lift cages, in which the falling load
(after detachment from the rope or chain) is utilised as a brake-power, the said
apparatus comprising in its construction a movable central bar A or suspension rail
to which is secured a trellis work or expansible parallelogram B, E, F, by means of
bolts a, c, d, the sides E, F, of the latter being connected with each other and with
the abutment plates G by means of a bolt 6 passing through a slot f of the
rail A, and carrying at their ends friction rollers J the axles of which are
guided in slots of the guide or abutment plates G, the said rollers being
pressed. against the guide rails H, on the downfall of the central bar A and
the collapse of the trellis work, caused by the weight and load of the lift cage,
while the bending of the rails is prevented by abutment pieces i situated behind
the rails.
Dated this 90th dor of November 1888
OTTOMAR ERFURTH.
By Fairfax & Wetter,
433, Strand, London,
Agents for the Applicant.