Note: Descriptions are shown in the official language in which they were submitted.
~C98;~5;35
The invention relates to a crane unit consisting of a
carriage having downwardly-directed guide columns on which a
guide frame is adapted to travel vertically and a load-pick-up
frame adapted to move vertically in the said guide frame.
A crane unit of this kind is known as a stacking crane
~German Patent 1 068 267). In this piece of equiprnent, the
carrier for the load-pick-up means is adapted to move up and
down guided in columns, so that, when the crane travels, the
said pick-up means does not collide with objects on the shop
floor. This unit can be controlled only manually ~y the crane
operator who is responsible for guiding it accurately to the
pick-up stations. There exists, however, a need for crane
installations of this ~ind in which the crane must reach the
pick-up stations very accurately b~ remote control. This
problem arises, for example, in plants where noxious vapours
are present and the crane therefore has to be controlled without
direct vision.
It is the purpose of the invention to provide a crane
unit, of the type mentioned at the beginning hereof, in such a
manner that it moves to the pick-up stations automatically and
with extreme accuracy, even in the event of certain dimensional
deviations arising, for example a settling of the structure of -
the crane. One application presenting these requirements is,
for instance, in electrolyzing plants where the plates must be
suspended in, or removed from the tanks. In this case, the said
plates must be moved accurately, without striking any objects
and without coming into contact with each other during
transportation. -
The present invention provides a crane unit comprising a
carriage having downwardly-directed guide columns on which a
guide frame is adapted to travel vertically, a loa~-pick-up frame
adapted to move vertically in the said guide frame, and means for
accurate alignment of the pic~-up frame with stationary pick-up
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stations comprising co-operating centering parts arranged upon
the guide frame and the pick-up stations, respectively, the said
centering parts entering into engagement and serving to guide
the guide frame laterally relative to the pick-up station when the
guide frame is in the lowered postion, and actuating a device
which allows the pick-up frame to descend in the guide frame.
This ensures that the said pick-up frame can be moved into its
lowermost position only when the guide frame, in which the pick-
up frame is adapted to move, has assumed a position which
predetermines the correct terminal position. If, however, the
guide frame for any reason whatsoever, fails to engage correctly
with the centering parts, it is impossible for the said pick-up
frame to descend to its terminal position, and the load suspended
is therefore thus protected from damage.
In one form of the invention, the centering parts may
be a centering mandrel, vertically adjustable against the force
of a spring, and a centering receiver. Arranged upon the
centering mandrel is a switch rod for a part actuating a switch
which controls the movement of the pick-up frame in the guide
frame. The said switch is connected to a hoist motor and
ensures that the pick-up frame is not lowered in the guide frame
unless the centering mandrel is correctly positioned in the
centering receiv~r. The centering mandrel and the switch rod are
held in the ready position by means of a spring. The centering
mandrel is guided displaceably in relation to the switch rod in
a centering tube, against the force of a spring. Moreo~er,
secured to the said switch rod is a sliding ring with a sliding
guide for a double-ended sliding lever. Mounted at the end of
the said
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8~535
lever remote from the sliding guide is a switch-roller co-
operating with a switc~-stop on the guide column in the
direction in which the centering mandrel is raised. The sliding
lever raises the centering mandrel as soon as the guide frame
reaches the upper terminal pssition. This ensures that the
mandrel does not present problems by proiecting beyond the
profile of the crane carriage when the latter is in motion.
The sliding lever, and the parts co-operating therewith, may
also be otherwise designed.
10In the preferred form, the guide frame is provided at
one lateral end with centering parts and is adapted to be placed
upon a support on the side opposite the said centering parts.
This support may be a roof-shaped part for a matching abutment
secured to a transverse beam on the ^guide frame, the said roo- -
shaped support also serving as a centering means for the side of
the guide frame facing the centering mandrel in the direction of
travel of the carriage.
The guide frame is adapted to be placed upon vertically
adjustable support points which permit accurate alignments of
the guide frame for setting down the load.
one of the support points is provided with an actuating
means~ displaceable against the force of a switch-spring, for a
switch which alsa reports to the hoist motor when the guide
frame has been set down correctly upon the support points, and
which allows the pick-up frame to be lowered only when a report
is received, from this side of the rame al80, to the effect that
the said frame has been correctly set down.
Preferably, the pick-up frame runs in the guide frame
on guide rollers and rails at the bottom o which are located
83S3~5
recesses for the release of the guide rollers. In the same way,
the guide frame runs in the carriage guide frames by means of
rollers arranged one above the other and running on rails, the
said rails having recesses at the bottom for the release of the
said rollers, and being used to provide guidance during raising
and lowering. The said recesses raise this guide when the lowering
operation comes to an end, allowing the parts to tilt freely in
relation to each other, when the centering means described above
enter the relevant parts and the roof-shaped support.
In the case of a load consisting of a plurality of
plates suspended for transportation vertically and parallel with
each other, one of the plates, ~or instance the cathode plate of
a zinc-recovering unit, is arranged upon a spacing gripper-
device on the pick-up frame. m e gripper device is in the form
of downwardly directed combs adapted to swing in and out and
- located on the two sides o~ the pick-up frame upon which the
vertical lateral edges o~ the plate~ lie. The ends o~ the combs
are each connected, through a multi-articulated drive, to the
pick-up frame in such a manner that when the plates pivot
upwardly, the combæ release. In the upwardly-pivoted position
they do not interfere when the cathode plates are inserted into
narrow electrolysis tanks.
Another gripper device i5 in the form of gripper rails
which move so as to clamp and expand, and have downwardly- -
directed gripping loops. ~he ends of these rails are hinged
b~ means o~ rods to double-ended levers which are connected in
turn, through a common shaft, to a motor.
According to another preferred feature of the invention,
the pick-up frame may be provided with a longitudinal-displacement
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device in the form of a spindle motor for ~he gripper devices.
This device shifts the gripper devices, after the cathode
plates have been set down and released, by the distance of one
cathode, so that ~hose cathode plates a~ the side of the plates
just inserted can be picked up.
According to still another preferred feature, the
pick-up frame is suspen~ed from two pairs of cables which are
guided over deflecting rollers by a cable drum driven by a hoist
motor. one of the pairs of cable is connected~to the pick-up
frame by means of a rocker and thus allows statically-determined
placing of the pick-up frame upon its support. The cables pass
through the guide frame. Arranged between the pidk-up and guide
frames are shock-absorbers whi~h ensure that the guide frame is
raised smoothly when it is lifted with the pick-up frame.
one of the said deflecting rollers is mounted upon
the crane carriage with an interposed overload -protection deviceO
This switches off the hoist motor in the event of excessive
hoisting forces, for example if the material being lifted becomes
jammed or if parts of ~he carriage become caught in the steel
structure of the shop. Also provided is a slack-cable indicator
which detects unpredicted han~-ups of the pick-up frame during
its descent~ and immediately switches the hoist motor off to
prevent further slackness in the cable.
The capacity of the crane unit may be increased by the
provision of two carriages each having a pick-up frame, the
said carriages being hinged together by means of distance-rods
and bolts. This hinged connection makes it possible for one
carriage to lead the other. The said carriages travel, with the
pi~k-up ~rame, in the area above the electrolysis baths, on
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branch tracks on which are arranged switch-actuating lugs ~or
initiators secured to the carriage~. These initiators and
actuating lugs switch of the motors driving the carriages as
soon as they arrive above predetermined baths.
The carriage frame equipped with guide columns may
be connected, by means of a turntable, with the longitudinal
members of the carriage running on wheels on the crane tracks
and branch tracks.
The turntable makes it possible to rotate the cathode
plates into the correct position for insertion into the
electrolysis baths and strippers, and to turn the said plates
through 180 before inserting them into the baths, depending
upon the bath and the circuit.
The position of the cathode plates in the electrolysis
baths is governed by the design of the cathode heads and the
circuit in the electrolyte.
When the crane unit is used to ~ervice electrolysis
baths, insulators are arranged between the individual components,
i.e. between:
a) the support points at the baths, the centering
means and the transverse beams;
b) the pick-up frame, the stationary point of the
cables, and the rocker:
c) the hoist motor with its cable drum, the
deflecting rollers and the guide columns, on
the one hand, and the carriage frame on the
other hand.
An exemplary embodiment of the invention is explained
hereinafter in greater detail, and i5 illustrated in the
8~535
drawings attached hereto, wherein:
Fig. 1 is a plan view of a portion of a zinc~
~lectrolyzing installation with a crane unit arranged thereabove;
Fig. 2 is a section along the line II-II in Fig. l;
Fig. 3 is a section along the line III~II in Fig. 2:
Fig. 4 shows one of the carriages in Fig. 3 to an
enlarged scale;
Fig. 5 is a side elevation of the carriage in Fig. 4;
Fig. 6 is a view from X in Fig. 4 to an enlarged
scale:
Fig. 7 is a view from Y in FigO 4 to an e~larged
scale, but with the centering mandrel retractedt
Fig. 8 shows the centering means in Fig. 7 to an
enlarged scale, but with the centering mandrel in its lower
terminal position:
Fig. 9 is a plan view of a load-pick-up frame;
Fig. 10 is a section along the line X-X in Fig. 9.
Fig. 1 shows a crane unit for transporting cathode
plates between electrolysis baths 3 and strippers 4. The
complete installation comprises 30 rows each having ~ourteen
baths 3 and two strippers 4. In a~ installation o~ this size,
the crane unit covers an area of about 150 m in length and
about 30 m in width. Crane beams 8 of crane 7 running in front
of baths 3 on a crane track 5 are parallel with branch tracks 6
which run over the rows of baths 3 and may be locked thereto.
The installation has two cranes 7 and ~our carriages 9, each
~wo connected to~e~her by distance rods 10.
Each crane 7, with each double carriage 9/ i~ re~uired
to service each double row 9~ baths, ie in spite o~ di~erent
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positiona~ tolerances in a total of 420 baths, the cran~ unit
is desiqned that cathode plates can be correctly removed from,
or inserted into, each double row of baths with each double
carriage 9.
According to Fig. 2, wheels 13 are mounted on
longitudinal girdexs 12 of carriage 9, whereby the said carriage,
driven by tractor 27 can travel on girders 8 of crane 7 or on
branch tracks 6. Girders 12 carry~ on a turntable 14, a
carriage frame 15 havin~ vertical guide columns 16. ~s shown
in Fig. 5, these columns have guide rails 17, with discontinuities
18, on which a guide frame 28 runs on rollers 29. Turntable 14
allows cathode plates 1 to be rotated into the correct position
for insertion into the baths 3 or strippers 4. The said
turntable also allows the said plates to be rotated through 180
before being inserted into the baths, depending upon the bath
and the circuit. The position of cathode plates 1 in baths 3 is
predetermined by the design of cathode plates 2, shown in Fig. 5 7 :-
and of the circuit In the electrolyte.
Special requirements obtain with respect to electrical
safety. The circuit used to d~Ive carriages 9 is separated from
current-carrying baths 3 by two insulator planes. On the one
hand, deflecting rollers 22~ hoist motor 19, and the cables 21
are completely insulated from the upper part of carriage 9 by
~nsulators 70 shown in Figs. 4 to 8. On the other handy rollers
29 and guide frame 28 are insulated from p~ck-up frame 53 by
insulators 70. The lower part~ of guide frame 28 are also
insulated from baths 3 by insulators 70.
Fig. 3 shows two carriages 9 united in the form of a
parallelogram by means of distance rods 10 and bolts 11. ~he
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~S3~35
two carriages, located on one o~ cranes 7, travel xespec~ively
on two adjacent branch tracks 6, each of the interconnected
aarriages being designed to serv~ce one row of baths 3. The
hinged connection allows each carriage to assume a 50 mm
mechanical lead over the other. This arrangement compensates,
to a certain extent, in conjunction with a positioning control,
~or the tolerances between the baths, and the restriction to
50 mm ensures that the width of the carriage track does not alter
unduly.
Guide columns 16, on each cæriage frame 15, carry a
guide frame 28 which can be set down, with an abubment 35, on a
support point 32 andg with two vextically adjustable support
points 33, 34, on brackets 73 on bath 3.
According to Figs. 3 and 4, each carriage 9 has a hoist
motor l9 with a cable drum 20 whence cables 21 run, over
deflecting rollers 22, through guide frame 28, to a load-pick-
up frame 53. The left-hand pair of cables runs over a cross
member 24, equipped with an overload safety device, to a rocker
23 secured to pick-up frame 53, while the right-hand pair of
cables is connected to pick-up frame 53 at a fixed point 71.
The overload safety device switches the hoist motor
o~f in the event of excessive hoisting forces, e.g. if the
cathode plates jam or parts of the carriage catch in the steël
structure of the shop. The said safety device also report a
slacX cable if, for any reason, guide ~rame 28, or pick-up frame
53 running therein, becomes jammed unexpectedly on its way down.
m e procedure for centering carriages 9 over the baths,
described hereinafter, is al o used in locating cathode plates 1
over the input magazines on strippers 4.
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~8~535
Fig. 4 also shows a positioning control which comes
into effect when a carriage 9 arrives over a bath 3 into which
a cathode plate 1 is to be inserted, or from which it is to be
removed. The said control has a plurality of initiators 25,
arranged on one of the carriage girders 12, for the provision
of information, the said initiators cooperating with switch-
actuating lugs 26 secured to branch tracks 6, and thus
controlling tractor 27.
This initiator control ensures that each carriage 9
is positioned on track 6, above corresponding bath 3, with a
, theoretical holding accuracy of ~ 10 mm. This tolerance is
often exceeded in practice in the case of electrolysis baths,
for instance if subsidences or bending produce~ changes in the
branch tracks which prevent accurate vertical lowering of pick-
up frame 53.
As shown in Fig. 5, guide frame 28 runs on roller~ 29,
on rails 17 fitted to guide column 16 on carxiage frame 15.
When pick-up frame 53 is lowered, guide frame 28, which rests
thereon, is also lowered. Shortly before the lower terminal
position is reached9 and when a centering mandrel 30a on guide
frame 28 is in guiding contact with a centering receiver 31
arranged on bath 3, rollers 29 arrive in the vicinity of
discontinuities 18 in guide rails 17. In the event o* any
inaccuracies in the design of the shop and/or in the positional
tolerances of the baths, this allows guide frame 28 to be set
down, without the use of force, with millimetre accuracy, and
also permits precision positioning o~ pick-up frame 53 above the
desired bath. As shown in Fig. 8, centering mandrel 30a enters
centering receiver 31. As shown in Fig. 6, abutment 35 descends
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onto a roof-shaped support point 32 arranged on the side of
the bath opposite to centering receiver 31. Support point 32
constitutes a centering device on this side of guide frame 28
which extends in the dixection of travel of carriage 9.
Insulators 70 are arranged between abutments 35 and
transverse member 28b between columns 28a on guide ~rame 28.
Columns 28a have chambers 41 which facilitate the entry of
pick-up fr~me 53, from below, into guide frame 28, during
assembly or subsequent repair.
Supports points 33, 34, arranged in Fig. 7 at the side
of centering receiver 31, have adjusting nuts 40 for accurate
vertical adjustment. Previously mentioned rocker 23 permits
statically determined lowering of guide frame 28 onto the three-
point support.
Support point 33, shown in Figs. 7 and 8, is located
upon a supporting bracket 73 and comprises a switching device ;
having a switch shaft 36, a switch-spring 37, and a means 38 for
actuating a switch 39 which reports the correct placement of
guide frame 28 upon the support points, to the control unit of
the hoist motor, and initiates the lowering of pick-up frame 53
into guide frame 28.
When guide frame 28 is set down in guide column 16 of
carriage 8, sliding connection 42, shown in Figs. 7 and 8, comes
into action and shifts centering mandrel 30a, with the aid of
spring 45, downwardly from its neutral position into its
operative position. Sliding connection 42 comprises a lever 43
which, in its operative position, secures centering mandrel 30a
positively, by means of a sliding ring 44, aga~nst displacement
in an upward direction, in order to prevent any unexpected
vertical force, greater than the force of spring 45, from forcing
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mandrel 30a upwardly in a manner not provided for in its
normal functioning, for example as a result of improper setting
down, forcible bending, or corrosion of parts due to lack of
lubrication.
Centering rnandrel 30a is also equipped with a control
device which reports unscheduled vertical forces acting upon
the automatic equipment. Excessive vertical force moves
centering mandrel 30a, with its shaft 30b, against the force
of switch spring 47, in centering tube 72, thus actuating switch
50 through rod 48 extending to switching part 49.
When guide frame 28 is raised, a roller 51 on lever 43
strikes a switch-stop 52 secured to guide column 16, thus
returning mandrel 30a to its neutral position. This ensures
that the said mandrel does not project downwardly from the
profile of carriage 9 and thus strike obstacles inadvertently.
All of the foregoing arrangements serve to ensure that guide
frame 28 is lowered correctly onto the relevant supports points
32, 33, 34 for a given bath 3. Insulators 70 are also æranged
between support points 33, 34 and transverse member 28b located
between columns 28a on guide frame 28.
When pick~up frame 53 is lowered, guide frame 28 is
correctly positioned over the bath and provides precision
centering for the insertion of cathode plates 1 in the said
bath. In the example described hereina~ter, carriage 9 brings
along a set of cathode plates 1, places them in one of the baths
and takes all of the cathode plates adjacent the said inserted
plates 1 to stripper 4. Only each second cathode plate 1 must
be removed from the bath~ since otherwise a short-circuit is
produced.
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83~35
During transportation by the crane, ca~hode plates
1 are spaced accurately apart by means of mul~i-articulated
drives 54 shown in Fig. 5 arranged laterally on pick-up frame
53, the said drives having two combs 55. These combs remain
in the holding position until the bottom edges of the cathode
plates are engaged between the cathode plates in the bath and
the anodes. Drives 54 then raise combs 55 into the position
shown in dotted lines and pick-up ~rame 53 is lowered still
further, Nhen it has almos~ reached its teminal position,
cathode heads 2 have to be engaged in busbars 56. To this end,
pick-up frame 53 is guided in frame 28 until cathode heads 2
are about 1 cm above the corresponding precision-cen~ering
means 57 on bath 3. Guide rollers 60 on pick-up frame 53 move
into recesses 58 out of contact with guide rails 59 on frame 28,
and cathode heads 2 are thus introduced into precision-centering
means 57 in busbars 56, as shown in Fig. 4, and are thus
conn~cted~to the electrolyzing circuit, whereupon pick up ~rame
53 releases itself from cathode heads 2.
Fig. 9 is a plan view of pick-up frame 53. For the
purpose of releasing the load, held by the frame, a motor 66
rotates a shaft 63, causing gripper rails 61 to expand and
release ~he set down cathode plates, the said expansion being
achieved by means of double-ended lever 64 and rods 65 shown in
Fig~ 10. A spindle motor 67 then moves the gripper rails in
the direction of the longitudinal axis of the bath until they are
able to seize all cathode plates 1 adjacent those just inserted.
Gripping loops 62 are secured to gripper rail~ 61, as shown in
Fig. 4, in order to ensu~e a correct pick-up when gripper rails
61 close.
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3535
As soon as cathode plates 1 have been raised ~ar
enough out of bath 3, multi~articulated drives 54 move combs
24 towards cathode plates 1 and position them. Each drive 54
is controlled by a slipping clutch, not shown, in such a manner
that, although the edges of cathode plates l are guided, they
are not crushed. Further raising causes pick-up frame 53 to
carry guide frame 28, by means of shock-absorbers 68 shown in
Fig. 4, into the uppermost position~ Carriage 9 then travels
on branch track 6 to girder 8 of crane 7 which moves ~he said
carriage, with cathode plates 1, to strippers 4.
A description has been given of the way in w~ich a
carriage inserts a batch of cathode plates 1 into an
electrolysis bath 3 and takes the adjacent batch plates to the
strippers. It is also possible, however, for the carriage to
arrive empty, to remove the "left" or rright" -hand cathode
plates selectively from a bath, in which all of the cathode
plat~s are located, and to take them to ~he strippers. The
carriage may also arrive with a batch of cathode plates, insert
them into one of the baths, and then pro~eed empty to an adjacent
bath in order to remove a batch of cathodes therefrom.
Since if a bath is completely emptied, a short circuit
is produced, carriage 9 is equipped with a cathode position
sensor. Using the principle o the switch described under 36
to 38, this reports when there are no cathode plates in the
bath other than those seized.
The mechanical equipment of the crane unit maXes it
possible, even in the case of a large number of baths with
different positional tolerances, to mechanize, by remote control,
the centering, removal and insertion of cathode plates, and thus
to automate the entire operation.
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