IMPROVEMENTS IN LIFTS
Year: 1883

page_text: LETTERS PATENT to Herbert John Haddan, of Kensington, Middlesex, for an
Invention of IMPROVEMENTS IN LIFTS communicated to him from abroad by
R. Liebig, of Leipzig, in the kingdom of Saxony
PROVISIONAL SPECIFICATION left by the said Herbert John Haddan at
the Office of the Commissioners of Patents on the 15th June 1883.
HERBERT JOHN HADDAN, of Kensington, Middlesex, “IMPROVEMENTS IN
LIFTS," a communication to me from abroad by R. Licbig, of Leipzig, in tho
kingdom of Saxony,
This invention has for its principal object to simplify the construction of lifts
without diminishing their safety.
For this purpose I provide the inside of the guide-posts, along which the
platform or cage travels, with teeth, and the underside of the platform with two
toothed arms or catches, placed opposite the teeth of the guide-posts, so that either
the right or the left of the said catches engages between the teeth when the
platform is tilted.
This tilting of the platform takes place whenever one of the two ropes or chains,
from which its ends or sides are suspended, breaks. Consequently the breaking of
such a chain or rope causes one of the catches to fall between the teeth of the
corresponding guide-post, thereby preventing the further descent of the platform.
In order to utilize as much as possible the space above the platform I place the
girders or beams and stays which support the same, under the platform, and attach
the chains or ropes on the sides. The platform may be provided with a removable
railing, if desired.

page_text: when safety.
In describing this invention reference will be made to the accompanying drawing
of which Fig. i is a front elevation of a lift embodying this invention, Fig. 2 a side
elevation and Fig. 3 a plan, while Fig. 4 represents the position of the cage after the
rupture of one of the chains.
Lifts of hitherto known constructions are generally provided with complicated
brake and stop mechanisms which considerably increase the cost, and do not always
work with complete security.
The principal feature of the present invention consists in a completely safe
arrangement for arresting the cage in case of a breakage which is obtained by
fixing in the pit of the lift and on each of the guide posts, along which the
cage travels, a rack Z arranged in such manner that when the chain or rope
breaks a set of pawls fixed to the platform of the carriage engages into the teeth
of the rack and thus prevents the fall of the cage (see Fig. 4).
It is well known that the two chains of a lift never break simultaneously and
consequently in the moment of rupture of one of the chains the own weight of the
cage causes the same to be tilted, whereby one of the pawls K fixed to both sides
of the cage or platform comes into operation, that is to say, engages into the teeth
of the contiguous rack Z and absolutely prevouts the fall of the cage.
In order to render the upper side of the platform free from any obstruction the
girders or beams and stays which support the same are placed under the platform,
while the chains is arranged on both sides of the cage.
The railing G fixed on the platform is adapted to be removed when required.
The remainder of the mechanism of the lift represented in the drawing, viz the
wheel-work for raising or lowering the cage may be made to suit local conditions
and the carrying capacity of the cago.
CLAIMS
1. In lifts the combination of fixed racks Z, with pawls K secured to the cage
or platform and adapted to take into the racks when the cage or platform is
placed oblique in consequence of the rupture of a chain or cord, substantially as
described.
2. The arrangement of the girders or beams supporting the platform, and of the
railing substantially as described.
In witness whereof I the said Herbert John Haddan have hereunto set my hand
and seal this 11th day of December A.D. 1883.