Improved Mechanism for Regulating the Stopping of Lift Cages.
Year: 1897

page_text: Date of Application, 9th Aug., 1897
Complete Specification Left, 30th Apr., 1898- Accepted, 9th July, 1898
PROVISIONAL SPECIFICATION.
Improved Mechanism for Regulating the Stopping of Lift Cages.
We, SIEMENS BROTHERS & COMPANY, LIMITED, of 12, Queen Anne's Gate,
Westminster, S.W., Electrical Engineers, do hereby declare the nature of this
invention (as communicated to us from abroad by Messrs. Siemens & Halske, of
Markgrafen Strasse 94, Berlin, S.W., Germany, Electrical Engineers), to be as
follows:-
Electrically worked lift cages with automatic stopping gear, in particular those
for raising heavy loads and working at high speeds, suffer from the disadvantage
that the cages when carrying a heavy load, do not stop at the same point as that
at which they stop with a lighter load; in the former case they stop at too low a
level, and in the latter case at too high a level, so that difficulties arise in loading
and unloading owing to this difference of levels.
The present invention relates to mechanism whereby an accurate stopping action
of the lift cages can be attained whether with light or with heavy loads, such
mechanism being actuated by the difference in the strain put upon the hauling
rope resulting from loads of different weight.
For this purpose, a moveable roller is pressed by a weight or spring laterally
against a part of the hauling rope in such manner that every alteration of the
strain of the rope will cause a corresponding change in the position of the roller
and this motion of the roller is caused by means of intermediate mechanism, to
actuate the stopping gear of the lift at an earlier or a later moment according
to whether the lift cage carries a light or a heavy load.
The said mechanism can be variously arranged for carrying out the purposes
of the invention. According to one arrangement, the said roller is mounted on a
three armed lever one arm of which is weighted so as to press the roller, mounted
on another arm, against the hauling rope, thereby deflecting this to a certain extent
sideways. The third arm of the lever engages with a fork in an annular groove of
a tubular sleeve which rotates with but can move longitudinally on a shaft
and which carries a drum with a wide helical slot into which projects with a con-
siderable amount of play an arm on a second shaft lying in the axial line of the first
one.
This second shaft carries a pulley round which passes a vertical endless steering
cord on which is fixed at one point a button or stop, with which a fork carried by
the lift cage comes in contact as the latter rises, the fork being thus made to actuate
the cord and thereby to turn the second shaft. The arm on this shaft in turning
comes in contact with the side of the wide helical slot of the drum and thereby
effects the turning of the first shaft, which imparts motion to the stopping gear
of the electro-motor that winds the hauling rope, such stopping gear being of any
suitable known construction. If the cage carries a heavy load the resulting
greater tightening of the hauling rope causes the before mentioned roller and
its lever to move, so as to slide the sleeve and drum into a position relative to the
arm in the slot, that such arm and its shaft must turn through a certain angle

page_text: before it comes in contact with the side of the slot and thereby turns the first
shaft so as to switch off and stop the electro-motor. When on the other hand
the cage only carries a light load, the slackening of the strain on the hauling
rope will allow the roller and its lever to move in the contrary direction, thereby
shifting the drum so that the arm only has to turn through a small angle before
it actuates the drum and the stopping shaft, so that by this means the switching
off and stopping of the electro motor is effected quicker than when the cage
carries a heavy load.
In order to prevent any motion of the lift cage while loading or unloading
through accidentally moving the steering cord, the weighted lever carrying the
pulley is at that time locked in position by its end being engaged with teeth on
a pivotted bar, which, when the steering cord is moved for setting the lift cage
in motion, is shifted out of gear with the roller lever by means of a cam on the
second shaft.
Total 4 041
1007
Improved Mechanism for Regulating the Stopping of Lift Cages.
We, SIEMENS BROTHERS & COMPANY LIMITED, of 12, Queen Anne's Gate,
Westminster, S.W., Electrical Engineers, do hereby declare the nature of this
invention (which has been communicated to us from abroad by Siemens & Halske,
of Markgrafen Strasse 94, Berlin, S.W., Germany, Electrical Engineers), and
in what manner the same is to be performed to be particularly described and
ascertained in and by the following statement:-
Electrically worked lift cages with automatic stopping gear, in particular those
for raising heavy loads and working at high speeds, suffer from the disadvantage
that the cages when carrying a heavy load, do not stop at the same point as that
at which they stop with a lighter load; in the former case they stop at too low a
level and in the latter case at too high a level so that difficulties arise in loading
and unloading owing to this difference of levels.
The present invention relates to mechanism whereby an accurate stopping
action of the lift cages can be attained whether with light or with heavy loads,
such mechanism being actuated by the difference in the strain put upon the haul-
ing rope resulting from loads of different weight.
For this purpose a moveable roller is pressed by a weight or spring laterally
against a part of the hauling rope in such manner that every alteration of the
strain of the rope will cause a corresponding change in the position of the roller
and this motion of the roller is caused by means of intermediate mechanism, to
actuate the stopping gear of the lift at an earlier or a later moment according
to whether the lift cage carries a light or a heavy load.
The said mechanism can be variously arranged for carrying out the purposes
of the invention.
On the accompanying drawing is shewn one such arrangement; Figure 1 shews
a diagrammatic elevation partly in section, and Figures 2 and 3 shew respectively
an enlarged plan and longitudinal section of the regulating appliance.
a is the before mentioned moveable roller which is mounted on the end of a
three armed lever carried on a fixed axis P; the one arm c of this lever carries
a weight b which causes the roller a mounted on the short arm of the lever to
be pressed laterally against the hauling rope R so as to deflect this to a certain

page_text: extent out of the straight line. The third arm d of the lever has its forked
lower end engaged with a circular groove e on the tubular shaft f with which is
combined a cylinder g. This cylinder has a slot formed in it, in a helical direc-
tion relatively to the axis of the shaft, and into this slot projects the end of an
arm fixed on a shaft k arranged in line with the shaft h on which the tubular
shaft can slide longitudinally, being prevented by a groove and feather i from
rotating thereon. The slot of cylinder g is of such a width that the shaft k can
turn through a certain angle relatively to shaft f, such angle being limited by.
the arm coming in contact with the one or the other side of the slot. The
shaft carries at its right hand end a rope pulley n and the shaft h carries at
its left hand end the rope pulley o; connected by means of the rope p to the
pulley of the stopping mechanism r of the electro motor E that works the
winding drum D of the lift. The pulley q carries a face cams for actuating
the levert that works the brake B of the motor. Round the pulley n on shaft k
and around a second pulley at the top of the lift, is stretched the endless steering
cord m at one point of which is fixed a stop v with which a forked arm u carried
by the lift cage c comes in contact when the latter has risen to the corresponding
height. The action of the apparatus so far as it has been described is as follows;,
When the loaded cage rises the strain put upon the hauling rope R will tend to
straighten the deflected lower part and consequently to press the moveable roller a
downwards raising the weighted arm c of the lever to a corresponding extent, and
moving the arm d to the right, whereby the shaft f and cylinder g will also be
shifted to the right. When the cage C has risen to the point at which the fork u
bears against the stop v, the steering cord m will be moved upward thereby. By
the consequent rotation of the shaft k the arm / will after a certain lapse of time,
come in contact with the edge of the slot at the point w, and will turn the shafts fi
cage ceases to rise. If on the other
hand the cage Cascends without a load, the roller a will be pressed
upward by the weight, as the rope R, being less strained will yield to the
pressure; the lever d will thereby shift the shaft f and cylinder g to the left, so
that on the pulley n being rotated by the action of the cord m stop v and fork u
as before the arm will bear against the edge of the slot at the point z and will
turn the shafts f and h and pulley o so as to stop the lift.
and h and pulley until the
0
It will be seen that in this case the time which elapses between the commence-
ment of the turning motion of and the moment when it comes in contact with
the point of the cylinder and begins to turn the pulley o, will be shorter than
in the case when the cage is loaded, and consequently the stopping of the motor
and applying of the brake will take place sooner when the cage is empty than
when it is loaded. When the cage C descends, the reverse action will take place,
with the difference that the points of contact between the arm and the slot of
the cylinder will be at different points on the opposite edge thereof.
In working the apparatus it will be seen that for starting the upward motion
of the cage, the steering cord m must be moved downward by hand, and for start-
ing it downward the cord must be moved upward. In order, when loading or
unloading the lift cage, to prevent any alteration of the position of the latter
owing to the downward or upward motion of the pulley a it is necessary after
stopping the cage, to hold the lever cin a fixed position. This is effected by means
of the locking arm y, which is suspended at its upper end from a fixed point and
is acted upon by a spring tending to cause rack teeth formed thereon to engage
with the end of the lever c. The lower end of arm y bears with a roller against a
face cam z on the shaft k this cam being so formed that when the shaft k is
turned into the position for stopping, as above described, the cam allows the
army to be drawn into engagement with c, as shewn, while when the shaft k is
turned for starting the cam pushes the arm out of engagement. It will be evident
that the weight on lever arm c might be replaced by a spring, and also that
the apparatus may be otherwise modified without departing from the essential
features of the invention..

page_text: Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed we declare that what we
claim is:
1 Mechanism for regulating the stopping of lift cages according to the load
thereon consisting of the arrangement of a roller pressed by a weight or spring
laterally against the hauling rope so as to deflect it, the motion imparted to the
roller consequent upon variations in such deflection due to variations in the load
of the lift being made to effect the shifting of the connection between the steering
gear of the lift and the stopping mechanism of the motor in such manner that for
a heavy load the stopping gear is brought into action at a later moment by the
steering gear than with a light load, substantially as described.
2 In mechanism for regulating the stopping of lift cages such as is referred
to in the First Claim, mounting the pressing roller a upon a weighted lever c
an arm of which is engaged with a shaft f sliding on a shaft / connected to the
stopping mechanism, the shaft f having a slotted cylinder g in the slot of which
is an arm on the steering shaft k rotated by the motion of the steering rope m.
the shaft and slotted cylinder being shifted longitudinally relatively to the
arm by the variations in the position of the pulley a consequent on variations
in the strain on the hauling rope substantially as and for the purpose described.
3 In mechanism for regulating the stopping of lift cages such as is referred
to in the Second Claim holding the lever c carrying the pressing roller a in a
fixed position when the lift has stopped by means of a locking arm y actuated by
a cam on the steering shaft k in such manner that when the shaft is stationary
the arm locks the lever c but when the shaft is rotated by the steering rope for
starting the lift cage, the arm is moved out of engagement with the lever sub-
stantially as and for the purpose described.
Dated this 30th day of April 1898