Improvements in or connected with Lifts.
Year: 1896

page_text: Date of Application, 30th Jan., 1896-Accepted, 4th Apr., 1896
COMPLETE SPECIFICATION.
Improvements in or connected with Lifts.
I, EMIL KIEBITZ of 33 Thränsberg Magdeburg in the Empire of Germany,
Engineer, do hereby declare the nature of this 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 an improved safety lift which differs essentially
from the forms of construction hitherto employed, as the action of its safety device
for preventing any unauthorised descent is radically different from that of the
so called "clutch devices." These latter being attached to the cage or car as
inoperative auxiliary or extra parts which usually allow free movement to the cage
or car, their action for checking the movements of the latter within its guides can
only be brought into play by the interpolation of a third power (springs, air
cushions or the like), and if this third power from any cause does not act, the
device becomes ineffective, and thus only works intermittently and conditionally,
whereas by my invention the safety device forms a constructive part of the cage or
car, constantly arresting the power of movement of the same unless such device be
maintained in a suitable rotation, and said movement is itself directly dependent on
the safe working condition of the operating parts (ropes, chains, bands or the like).
As soon as one of these latter breaks, or even is strained (weighted) beyond the
regulation degree, the movement of the safety device entirely ceases and any
possibility of a free dropping or descent of the cage or car is removed without
bringing into action a third power, or in other words directly and unconditionally.
The invention will now be described with reference to the accompanying
drawings.
The improved safety device consists of a cylindrical drum B having a spiral R R
running at a given pitch round its periphery and forming a single, or more,
threaded screw, the axis of rotation being parallel to the direction of movement of
the lift, whether the latter be vertical or inclined.
This drum B forms an integral part of the cage or car A (as may be seen in
Figures 1 1 1 of the drawings) and is mounted in the same in such a way that it
almost touches a guide bar C, whilst the thread or spiral R projects into slots or
recesses S in the guide bar C, the distance apart of these slots corresponding to
the pitch of the thread R, so that no movement of the cage or car can take place
unless the drum B simultaneously rotates with it, and the thread R thereby passes
through the slots S. In order to avoid friction the thread R in passing through
the slots S must not directly encounter the latter, but there must remain in each
case a small interstice which must be calculated according to circumstances, which
inay be easily obtained by a correct arrangement of the lifting parts.
It may be here stated that this arrangement gives a false impression as to the
action of the drum B, namely, that the cage or car A is pushed up and down by
the screw action of the thread R R. Ropes, chains, bands or the like serve as
usual for the actual carrying and lifting of the load, but with this difference from
the arrangement at present employed, namely, that these drawing or carrying
means must not be attached to a fixed point (such as o Figures 14 and 24) of the
cage or car, as the drum B could not in such case rotate and would be held fast
with the cage or car by the thread R in the slots S of the guide rail C, but they
must be carried over a running pulley (or if preferred over several) mounted on the
cage or car, which pulley conveys the rotation imparted to it by this means in any
suitable way either directly or indirectly to the drum B in such a way that when

page_text: the ratio of speeds is correctly arranged the thread R will cause no hindrance to
the up or down movement of the cage or car, whilst if by the breakage or
stretching of the carrying parts, a stoppage or even only a delayed movement of
the drum takes place, the thread R will immediately retard or entirely stop further
movement.
In the accompanying drawings, two examples of means for conveying the
movement of the running pulley to the drum B are shown.
Figures 1 1 1 (which as already stated are primarily intended to show the
connection between the cage or car, screw drum and guide bar) show the use of
one running pulley L (with indirect transfer) the rotation of the shaft a produced
by means of the cord P and the pulley L being transferred to the drum shaft by
means of a vertical shaft W, bevel gearing E D and a pair of spur wheels be.
In the second case, as shown in Figures 24 and 20, the running pulley is directly
mounted in a horizontal position on the drum B as a rope pulley N over which two
ropes P and P2 are conveyed in symmetrical arrangement by means of guide
rollers 31 M in such a way that a rotation of the drum B is produced in a
corresponding direction on being drawn up or let down.
In each case it is assumed that the cage A is itself prevented from rotating
by means of at least two guides C and C and guide pieces F F attached to the
cage.
If the direction of movement be not vertical but (as shown in Figure 5A) an
oblique or inclined one, a pair of rails C in place of the guide C is employed, the
guide pieces F being here replaced by flanged wheels F, the cage being formed like
a car. The rotation of the spiral or screw drum B is operated in this case in
similar way to that described with reference to Figure 1^.
If the form of lift construction hereinbefore described be thus directly protected
by the serew drum B from unauthorised descent, the case might still arise of the
supporting means (and thus the lift itself) attaining a greater speed than is
admissible such as in consequence of an accident to the engine or by inattention on
the part of the enginemau. In order to provide for this somewhat dangerous
contingency and to prevent the lift exceeding a certain maximum velocity the
action on brake devices of a centrifugal governor arranged in the drum B and
operated by the same, is utilised.
The centrifugal force produced by the rotating bodies Z may act (as shown in
Figure 3) by means of elbow levels K K and brake block H against a ring G
attached to the bottom of the lift cage and thus causes at least a retardation of the
movement of the drum which however as already explained would thereby have the
effect of immediately jamming the thread R in the slots S and thus render
stationary the drum and the cage or, as shown in Figure 4, a centrifugal regulator
formed by the parts Z and K' may act by means of a bar T, links V V and brake
blocks hanging to the frame of the lift cage, thus producing against the
guides C and C a direct braking of the whole cage.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. A cage or car for vertical or oblique travelling lifts having revolubly attached
to it a cylindrical drum (B) which is provided with
a) one or more threads or spiral ridges (R) on its outer periphery, adapted to
project into slots (S) formed in a guide (C) in such a way that any
unauthorised falling or descent of the cage or car (A) is prevented and the
cage only allowed to move up and down when the drum itself makes a
suitable rotation, produced solely by the movement of the suspension means,
the threads (R) thereby passing without friction through the slots (S), and
b) an arrangement within its interior of means for setting in action any
suitable regulating or braking device adapted to limit the speed of
movement of the lift.

page_text: 2. In a vertical or oblique travelling lift the combination with the cage or car
of a revoluble drum threaded on its periphery adapted to engage a slotted guide
and means for transferring movement from the lifting rope (P) to the drum (B)
characterised by the use of a running pulley (L), the rotation of which is imparted
by means of its shaft (a), bevel gearing (ED), a vertical shaft (W) and spur
gearing (b c) to the drum (B) substantially as herein before described with reference
to Figures 14, 18 and 1° of the accompanying drawings.
3. In a vertical or oblique travelling lift, the combination with the cage or car,
of a revoluble drum threaded on its periphery, adapted to engage a slotted guide
and means for transferring movement from two lifting ropes to the drum, charac-
terised by the use of a running pulley mounted horizontally as a belt pulley (N)
on the druni shaft, over which pulley the ropes (P1 P2) crossing each other are
carried and guided by guide pulleys (M and M2) arranged on the lift cage frame,
so that the drum (B) is set in rotation substantially as herein before described with
reference to Figures 24 and 2B of the accompanying drawings.
4. In a lift having a revoluble screw threaded drum such as described, a brake
device characterised by the arrangement of a brake ring (G) on the car or
cage (A) and centrifugal balls (Z), elbow levers (K) and brake blocks (H) which, on
a given maximum speed being exceeded, effect a braking of the revoluble
druin (B) against the cage or car (A) thereby also releasing the lift rope from its
running pulley, whereby the car is brought to a standstill or retarded by the
threads or spiral ridges (R) jamming in the slots (S) of the guide (C) substantially
as hereinbefore described with reference to Figure 3 of the accompanying
drawings.
5. In a lift having a revoluble screw threaded drum such as described, a brake
device characterised by the arrangement of a centrifugal governor (Z' K') in
the drum (B) and a slide bar (T), links (V) and brake blocks (H') on the cage
or car frame and coupled to said governor which on a given maximum speed being
exceeded effect a firm braking of the whole car or cage (A) against the guide
bars (C and C¹) substantially as herein before described with reference to Figure 4
of the accompanying drawings.
Dated this 29th day of January 1896.
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Agents for the Applicant.