FIELD OF THE INVENTION :
The present invention relates to an improved device of hoist brake arrangement.
More particularly, the present invention relates to an improved device for brake coil
mounting of hoist brake applicable in blast furnace skip hoist.
BACKGROUND OF THE INVENTION ;
The typical steel plant, the basic raw materials like iron ore, coke etc. are fed to the
blast furnace by means of a skip which is operated by a electrical hoist having a
brake attachment to control the motion of hoist. The brake of the skip hoist is
originally constructed by a bobbin, which is press fitted on cast iron plate. The
problem develops in the production process that on continuous usages of skip hoist
the cast iron fitting on the bobbin became loose and the entire bobbin starts
rotating. As a result the leads of the coil getting tension, and causes snapping of
lead. Secondly false rotation may cause accident at the work center. Thirdly,
damage the metallic body of the bobbin due to sudden impact.
To overcome the above adversity in the production line, an emphasis is made to
develop an improved hoist brake by modifying the existing bobbin of skip hoist brake
construction and the frequent coil burning is reduced by using DGC Copper
conductor in place of enameled and asbestos covering wire. Furthermore, a
terminal board has been introduced to protect the lead from external damage.
OBJECTS OF THE INVENTION :
It is therefore, an object of the present invention to propose an improved device for
brake coil mounting of hoist brake which will eliminate the adversity of prior art.
Another object of the present invention is to propose an improved device for brake
coil mounting of hoist brake which will increase the life time of the skip hoist brake.
A further object of the present invention is to propose an improved
device for brake coil mounting of hoist brake which is more safety and less accident
prone.
SUMMARY OF THE INVENTION :
The improved skip hoist brake construction comprising a metallic plate of one side is
machined and made a groove of 5-10 mm thick. A non-ferrous metal plate of 5-10
mm is made suitable to match with groove of metallic plate by plurality of screws. A
non-ferrous metallic sheet of 1.0-2.0 mm thickness is folded round and the folded
non-ferrous metallic sheet collar is joined on the non-ferrous metallic plate with the
help of silver brazing rod containing 25%-30% silver content. A rectangular copper
conductor is wound on the bobbin on which entire coil is fitted on the frame of the
brake and fastened rigidly by plurality of studs. The gap between bobbin and the
frame is filled with RTV-11 silicon rubber compound and made it 10-20 sq.mm is
joined parallely from the end connection of the winding and brought it outside and
terminated at two sides of the frame just 180 degree apart from each other so that it
can be operated either of side i.e. left or right as per the requirement.
Thus the present invention provides an improved device for mounting coil of a hoist
brake in a blast furnace skip hoist comprising a bobbin made of non-ferrous metal
press fitted on metallic plates ; and I of rectangular copper conductor wound on the
bobbin with at least two round silicon flexible leads joined parallely from the end
connection of the winding ; characterized in that the side walls of said bobbin is
provided with a groove of 5-8 mm for accommodating rigidly a non- ferrous metal
plate on the outer surfaces thereof; and in that said non-ferrous metal plate is rigidly
fastened with a plurality of screws.
DETAILED DESCRIPTION OF THE ACCOMPANYING DRAWING:
Fig. 1 shows isometric view of showing the crack generated on the body of the skip
hoist brake body in prior art.
Fig. 2 shows a schematic diagram of isometric view of sidewall of bobbin with
machined groove.
Fig. 3 A schematic diagram showing 5-10 mm non-ferrous metal round plate to be
inserted in the metallic plate groove.
Fig. 4 shows a schematic diagram of non-ferrous metal plate fastening with metallic
plate by means of plurality screws.
Fig. 5 shows an isometric view of terminal board in the present invention.
Fig. 6 shows existing skip hoist brake in blast furnace as per prior art.
Fig. 7 shows existing and modified skip hoist brake assembly as per new invention.
BRIEF DESCRIPTION OF A PREFERRED EMBODIMENT OF
THE INVENTION:
Fig - 2 Shows the metallic plate (4) of one side of the bobbin (1)
machined and made a groove of 5-10 mm thick (2) to fit non-ferrous
metal parts (3).
Fig - 3 Shows a non-ferrous metal plate (3) of 6-10 mm is made to
be inserted in the groove (2) of metallic plate to cover the groove (2)
which acts as a bearing material.
Fig - 4 Shows the non-ferrous metal plate (3) is in assembled
condition with metallic plate (4) and fastened with the metallic plate
(4) with plurality of screws (6) after inserting the coil.
Fig - 6 Shows a terminal board (7) on cover of the bobbin (1) and
disposed terminal point (6.6)
Fig - 6 Shows a schematic diagram of Existing body, Existing Coil
bobbin, existing bobbin assembly and existing skip hoist brake coil in
prior Art of FIg-1.
Fig-7 Shows a schematic diagram of Modified Coil bobbia
Modified bobbin assembly and modified skip hoist brake coil as per
invention.
WE CLAIM:
1. An improved device for mounting hoist brake coil in blast furnace
skip hoist, comprising:
- a bobbin made of non-ferrous metal press fitted on metallic plates;
and
- a rectangular copper conductor wound on the bobbin releasably
attached to the brake frame, the end windings of the conductor being
fastened on the frame,
- at least two round silicon flexible leads joined parallely at the end
connection of the winding and brought outside and terminated at two
sides of the frame for direct electrical connection;
characterized in that the side walls of said bobbin is provided with a
groove of 5-8 mm for accommodating rigidly a non-ferrous metal
plate on the outer surfaces thereof; and in that said non-ferrous metal
plate is rigidly fastened with a plurality of screws.
2. The device as claimed in claim 1, wherein a folded non-ferrous sheet
of 1-2 mm thickness collar is joined on the parting line of the non-
ferrous plate and metallic plate with the help of a silver brazing rod
containing 25%-40% silver.
3. The device as claimed in claim 1, wherein the gap between the bobbin
and the frame is filled with RTV - 11 silicon rubber compound in
order to make it 100% rigid.
4. The device as claimed in claim 1, wherein said non-ferrous metal
plate is formed from a metal selected from the group consisting of
brass, gun-metal, white metals.
5. The device as claimed in claim 1, wherein the metallic plates on which
the non-ferrous bobbin is press fitted is made from Cast iron, mild or
stainless steel plates.

The invention relates to an improved device for mounting hoist brake coil in
blast furnace skip hoist, comprising: a bobbin made of non-ferrous metal
press fitted on metallic plates; and a rectangular copper conductor wound on
the bobbin releasably attached to the brake frame, the end windings of the
conductor being fastened on the frame, at least two round silicon flexible
leads joined parallely at the end connection of the winding and brought
outside and terminated at two sides of the frame for direct electrical
connection. The side walls of said bobbin is provided with a groove of 5-8
mm for accommodating rigidly a non-ferrous metal plate on the outer
surfaces thereof; and in that said non-ferrous metal plate is rigidly fastened
with a plurality of screws.