Note: Descriptions are shown in the official language in which they were submitted.
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The present invention relates to an apparatus for
automatically extracting objects, either individually or
in groups, from containers. The apparatus includes a
stand, beneath which or in the vicinity thereof at least
one container having the objects to be extracted can be
positioned; an extractor arm disposed movably on the
stand in the area above the container; a device for
axially extending and retracting the extractor arm; and
a device for guiding the extractor arm grasping element
toward various areas inside the container.
Known automatically operating extra~tor apparatus of this
general type have a vertically disposed extractor arm
which can be driven in a coordinate system in a horizontal
plane and is extendable and retractable in the direction
of its longitudinal axis.
Modern receptacle containers, especially those which must
be very sturdily built so as to transport heavy objects,
have an upper rim, drawn partway inward at least in some
areas, conse~uently making it difficult to remove objects
from the lower side areas and the corners using the known
extractor apparatus. It may therefore happen with the
known apparatus that individual objects cannot be extract-
ed from the container.
Accordingly, it is an object of the present invention to
improve an extractor apparatus of the type discussed
above such that satisfactory emptying of the containers
is assured.
In accordance with the present invention, ~his object is
attained by provision of an apparatus which includes a
holding device for the extractor arm which is connected
to the frame via a cardan joint suspension system, by a
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drive mechanism for the longitudinal displacement of the
extractor arm relative to the holding device, and further
drive mechanisms for pivoting the holding device in vari-
ous planes which are at angle to one another.
In the apparatus according to the present invention it is
possible to guide the extractor arm obliquely into the
corners or underneath the upper edge of the container, so
that all areas of the ccntainer interior are readily
accessible to the extractor arm. Furthermore, the cost
of construction is less due to the use of the cardan sus-
pension of the extractor arm.
Moving the holding device of the present invention in the
area of the cardan joint suspension system is accomplished
by two drive mechanisms for pivoting the holding device in
lS two vertical planes at right angles to one another.
The cardan joint suspensi-on of the holding device may have
a horizontal, pivotable supporting beam supported in the
stand as well as a cross beam supported on the supporting
beam, the holding device being suspended on the cross beam.
On the supporting beam, rigid supporting arms may be
provided on both sides of the holding device of the ex-
tractor arm, the supporting arms being located in the
pivoting plane of the holding device, which is defined by
the cross beam. A drive mechanism for pivoting the hold-
ing device about the cross beam is disposed between thetwo supporting arms. Due to the type of suspension used,
movement of the extractor arm into all the areas of the
container is made possible by relatively simple means.
A drive mechanism for piuoting the holding device about
the cross beam is accomplished by a threaded spindle which
is rotatable with the aid of a motor and a nut supported
on a spindle, such that the nut is not rotatable relative
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to the holding device; the nut being connected to the
holding device via a carrier rod, and both connecting
points being articulated joints.
Pivoting the holding device about the supporting beam is
achieved by pxoviding a drive mechanism which at one end
engages the stand and at the other end engages at least
one of the supporting armsO The drive mechanism for
pivoting the holding device about the supporting beam
also includes a threaded spindle which is axially station
ary relative to the stand and drivable by means of a motor,
and a nut seated on a spindle, which is joined via a toggle
link to a respective supporting arm.
The extractor arm of the present invention is expediently
guided longitudinally displaceably on the holding device,
A carried is movable via a threaded spindle with the aid
of a motor acting as the drive mechanism for the extractor
arm. The extractor arm is preferably supported by its own
weight at the top on the carrier, so that when the extrac-
tor arm meets any resistance, a free-wheeling effect
results; in other words, the extractor arm is not driven
any longer.
Trip cams for actuating counting switches may be provided
on the threaded spindles, so that the extractor arm can ~e
moved into a precisely prespecified position by various
specified numbers of rotations of the threaded spindles.
The extractor arm is preferably controllable in accordance
with prespecified programs, and the drive motors are
switched on and off via the counting switches.
The particular program, according to which the holding
device supporting the extractor arm is moved, may be ad-
justed to various container sizes and shape~ and also to
various types and shapes of objects to be extracted.
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If the apparatus is provided for extracting magnetizable
objects, an electromagnet may be provided as the grasping
element of the extractor arm. This electromagnet is pre-
ferably suspended by a cardan joint.
The present invention is illustrated in the drawings by
way of example and described in detail below.
In the drawings:
Figure l is a front elevational view of an apparatus for
the automatic extraction of individual objects from
containers; and
Figure 2 is a side elevational view of the apparatus.
Referring to Figure l of the drawings, the automatic
extractor apparatus substantially includes a stand 1, an
extractor arm 2 suspended on the stand by a cardan joint
and a receiving area 3 in the lower portion of the stand
l below the extractor arm 2, for a container 4 that is to
be emptied.
The stand l is incorporated with sturdy steel beams 5 and
is provided with a protecting sheathing on its outside,
not shown in detail in the drawing, which can be opened
at the side or top for the insertion of a container 4.
I~ide the &tand 1, or ~terally ~eside it, a col~lecting
container 6 is provided for the objects individually ex-
tracted from the container 4. With the aid of an inclined
hoist 7, the objects are delivered to an outlet chute 8.
Alternatively, other conveying and sorting devices are
also conceivable.
An upper supporting beam 9, which is supported at the top
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on the stand 1, serves to effect the cardan suspension o~the extractor arm 2. Approximately in the centre of the
supporting beam 9, a short cross beam 10 is supported,
and a holding device 11 for the extractor arm 2 is sus-
pended onlthe cross beam 10. The centre line of the crossbeam 10 extends precisely at right angles to the centre
line of the supporting beam 9.
On the opposite sides of the centre line of the cross beam
10, spaced apart from the cross beam, respective support-
ing arms 12 and 13 are secured to the supporting beam 9.
In the outset position, the supporting arms 12 and 13 hang
vertically downward, similar to the extractor arm 2.
Between the two supporting arms 12 and 13 is disposed athreaded spindle 14, which is drivable via step-down gear
15 with the aid of an electric motor 16. The gear and
the motor are secured on the supporting arm 12. A nut,
not shown in detail in the drawing, is seated on the
threaded spindle 14. The nut is not able to rotate rela-
tive to the holding device 11 and is connected to the
holding device via a carrier rod; both connecting points
are embodied as articulated joints, so that when the hold-
ing device 11 pivots, the differences in level between the
articulation points on the holding device 11, and the nut
can be compensated for.
A threaded spindle 17, which is stationary relative to the
stand 1 and is drivable via a step-down gear 18 by means
of an electric motor 19, serves to pivot the holding
device 11 about the supporting beam 9. All that is visible
in the drawing of the threaded spindle 17, as in the case
of the threaded spindle 14 extending crosswise to it, in
the drawing is an outer sheathing surrounding each spindle.
A nut 20 is seated on the threaded spindle 17 protruding
out of the sheathing at the bottom. ~ccordingly, only the
lower portion of the nut 20 is visible. The nut 20 is
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joined via a toggle link 21 to a bearing tang 22, which is
provided on the side of the supporting arm 13 oriented to-
ward the threaded spindle 17.
Also provided on the holding device 11 is a threaded
spindle 23, which is drivable with the aid of an electric
motor 24. A nut 25 is seated on the threaded spindle 23
and a carrier 26 cooperating with the extractor arm 2 is
disposed on the nut 25. The extractor arm 2 rests with a
support plate 27 on the carrier 26, so that wha~ rests on
the support plate 27 is the weight of the extractor arm 2,
perhaps reduced by a dead weight, not shown. When the
carrier 26 is lowered, it carries the extractor arm 2
along with it due to its own weight. When the grasping
element 28 at the bottom of the extractor arm 2 meets an
object that is to be extracted, the extractor arm 2 comes
to a stop, while the carrier 26 can still move some dis-
tance beyond. This free-wheeling effect has the result
that the extractor arm 2 can be placed upon some object
to be extracted while exerting no more than its own weight,
optionally reduced by the counterweight provided. As a
res~llt, extremely gentle handling of the objects that are
to be extracted is assured.
If magnetizable obJects are to be removed from the
container 4, the grasping element 28, which is disposed
such that it can be removed and replaced, can be an
electromagnet. This magnet is likewise suspended b~ a
cardan joint at the lower end of the extractor arm 2, so
that no matter what the position of the extractor arm 2,
the magnet can always be placed precisely vertically upon
an object that is to be extracted.
The actuation of the apparatus is effected via a program-
mable control unit, not shown in the drawing. The extrac-
tor arm 2 is moved in such a manner that it scans the
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cross section of the container in a grid pattern, line by
line, and at a specified number of positions in each line.
The grid pattern is adjustable in accordance with the
size of the objects that are to be extracted. The down-
ward movement of the extractor arm 2 is terminated immedi-
ately after the grasping element 28 is in place on an ob-
ject. The lowermost position prior to touching the bottom,
as the container becomes empty, i5 programmed for all pos-
sible depths to which the arm may plunge. Upon each
lifting movement, it is possible to monitor whether objects
have been taken up with the arm. If there is a nil indi-
cation, the extractor arm 2 moves into the next programmed
grid position. Positions ~hich are recognized, at the
maximum plunging depth, as being empty are not approached
again.
Control is effected via actuation of the three electric
motors 16, 19 and 24; the times at which these motors are
switched on and off are determined with -the aid of count-
ing switches, which are actuated with the aid of cams
seated on the threaded spindles. Alternating-current
braking motors are preferably used as the electric motors.
Due to the cardan joint suspension of the extractor arm
2, it can be pivoted in any arbitrary position. Since
the extractor arm is suspended over the container opening,
it can be driven steadily obli~uely as it approaches the
inner rim areas and corners of the container, so that it
can readily reach into all areas, moving past the upper
inwardly drawn container rim. Once the extractor arm 2
has grasped an object, it can pivot laterally toward the
left, as shown in Figure 1, and deposit the object in the
collecting container 6.
In the exemplary embodiment shown in the drawing, the
cardan joint suspension of the extractor arm 2 is not
directly above the centre of the container 4 but is instead
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shifted somewhat toward the side of the collecting
container 6, so that the lateral pivoting angle in both
directions can be exploited to the fullest and the maxi-
mum pivoting angle can be kept small, The pivoting angle
for reaching the collecting container is exactly the same
size as the pivo-ting angle for approaching the opposite
rim of the container 4.
As will be understood by those skilled in the art, various
changes and modifications may be made without departing
from the scope of the invention and the invention is,,not
to be considered limited to what is shown in the drawings
and described by way of ~xample.
