FIELD OF THE INVENTION
The present invention relates to an apparatus for separating laminations for
generator or motor stator core for de-stacking.
BACKGROUND OF THE INVENTION
During assembly of a stator core of an electric generator or motor it is necessary
that a single lamination be removed from a stack of laminations for further
processing operation.
In the known method of assembly of electrical generator or motor, a single
lamination of a generator or motor stator core is separated and lifted (de-
stacked) manually from stacked laminations and arranged in annular layers to
form the packets.
Various methods have been previously employed for separating laminations or
thin sheets of metal and de-stacking them.
In one method (Refer Patent No. WO 2012/109123), a method of separating
parts stuck together comprises of placing the parts in a vibratory apparatus and
vibrating the parts with vibrating head.

In another method (Refer Patent No. US 39998448), two vertically aligned
elevators, each being adapted to support a stack of blanks, are used to elevate
the blanks to a magnetic blank separator and conveyor. The magnets are
positioned adjacent to the edge of the stack to impart an opposite polarity to
adjacent blanks jn the stack for separation.
In yet another method (Refer Patent No. US 5304029), several mechanisms are
used to separate the laminations. Then laminations are titled first in one
orientation and compressed from the side and then tilted in reverse orientation
and compressed again to apply shearing forces in different directions between
individual laminations.
In yet another method (Refer Patent No. US 5498305), the apparatus includes a
channel, an impeller and a cutter adjacent the outlet of the channel positioned to
contact the edge at which two laminations are adhered adjacent the line of
adhesion between the laminations, thus separating the laminations.
In yet another method (Refer Patent No. US 6146086), the transformer
lamination separation apparatus includes a magnetic fanner arrangement on the
sides of laminations wherein at least one magnet is an electromagnet, a striker
plate and an oscillating mechanism.

In yet another method (Refer Patent No. WO 93/23321), a method of sheet
separation or de-stacking comprises the steps of two separator devices are
brought into contact with opposite edges of the stack and that the sheet is
subjected by each separator device to a force with a first component at right
angles up the stack and second component in the plane of sheet and from the
separator device in towards the stack.
OBJECTS OF THE INVENTION
It is therefore, the object of the present invention to propose an apparatus for
separating laminations for generator or motor stator core and a method of
lamination separation using permanent bar magnets placed in the vertically
moving positioning pins so that the robotic gripper or any other device can pick
up only one lamination at a time.
SUMMARY OF THE INVENTION
Accordingly, there is provided an apparatus and a method for separating the top
and subsequent bottom generator or motor stator core lamination in a stack of
laminations so that the top lamination is lifted (de-stacked) from the stack of
laminations, only single laminations is lifted by the lifting device such as robotic
gripper.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Figure 1 is a view of an apparatus showing a stacking table, two vertically
moving positioning tapered pins, two permanent bar magnets mounted on left
and right side of each positioning pin, and a mechanism to move the positioning
pins vertically.
Figure 2 is a side view of the vertically moving tapered positioning pin and the
two permanent bar magnets mounted on left and right side of tapered
positioning pin.
Figure 3 is a front view of the vertically moving tapered positioning pin and the
two permanent bar magnets mounted on front and rear of tapered positioning
pin.
Figure 4 is a top view of the vertically moving tapered positioning pin and the
two permanent bar magnets mounted on sides of tapered positioning pin (the
rear magnet is no visible in this view).
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to an apparatus and a method and for separating
the generator or motor stator core laminations so that when the laminations are
lifted from the stack of laminations, only single lamination is lifted by the lifting
device such as robotic gripper.

The embodiment of the present invention, the apparatus consists of two tapered
pins 1 mounted below the stacking surface of the stacking table 7 that move
vertically through holes in the stacking table and also travel through the holes in
the laminations. At the bottom part of tapered positioning pins, a mechanism 8,
9 such as rack-pinion, worm-gear or any other mechanism driven by electric,
hydraulic or pneumatic or any other means (not shown) is mounted to enable
the pins to move vertically through the stacking table and lamination holes. The
lamination stack 6 is positioned on stacking table by inserting them through the
positioning pins 1. Each positioning pin has two permanent bar magnets 2
mounted on the sides so that the mounting of the magnets does not interfere
with the insertion or removal of the laminations 6.
In the embodiment of the present invention, the laminations 6 are stacked on
the stacking table 7. Due to magnetic effect, the top lamination 3 is separated
from the next bottom lamination 4 thus creating a gap between the topmost
lamination 3 and subsequent (2nd top) lamination 4. Due to the magnetic effect,
the separation is also caused between 2nd top laminated 4 and subsequent (3rd
top) lamination 5. The separating gap decreases with increased count of
laminations from the top. Due to creation of gap between top and subsequent
bottom lamination, the robot gripper or any other automated or manual device
using electromagnets or vacuum cups lifts up only a single lamination at a time
thus avoiding double lamination pickup. When the top lamination is lifted by a
robotic gripper or any other automatic or manual means, the vertically traveling
positioning pins 1 are simultaneously lowered using mechanism 8, 9 so that the
separating effect is caused between next topmost lamination and subsequent
bottom lamination.

WE CLAIM:
1. An apparatus for separating a top lamination form the other laminations in
a stack of laminations to enable lifting only the single top lamination to
form annular layers of superimposed laminations for use in generator or
motor stator core, comprising :
a stacking table, two vertically moved tapered positioning pins, two
magnets mounted on the sides of each positioning pin, and means to
cause vertical movement of the positioning pins.
2. A method of separating a top lamination from subsequent bottom
lamination in a stack of laminations by using two vertically moving tapered
positioning pins with two magnets mounted on the sides of each
positioning pins.

ABSTRACT

The invention relates to an apparatus for separating a top lamination form the
other laminations in a stack of laminations to enable lifting only the single top
lamination to form annular layers of superimposed laminations for use in
generator or motor stator core, comprising a stacking table, two vertically
moved tapered positioning pins, two magnets mounted on the sides of each
positioning pin, and means to cause vertical movement of the positioning
pins.