This invention relates to fixtures for heat treating furnaces and more
particularly to fixtures having one or more tiers, as desired. Present Invention
relates to heat treatment fixture for holding the thin circular specimen in large
quantity during heat treatment operation. The present improved invention of
heat treatment fixture made very light & the Material used in the items is
Stainless steel.
BACKGROUND OF THE INVENTION
Heat treatment of metals refers to change in the metal’s mechanical
properties. The heat treatment process involves increasing the temperature of
the mental to a specified level and holding the metal at that temperature for a
period of time. The temperature of the metal is then reduced, to some
predetermined temperature range. Unequal heating or unequal cooling of the
metal could cause the metal specimen being heat treated to expand or contract
at different rates over its length, causing the specimen to warp. During heat
treatment thin metal specimen shows some different set of problems like sticking
with each other at elevated temperature. The warping and sticking of thin metal
specimen could be so extensive as to render the thin metal specimen unusable.
It is therefore an object of the present invention to provide a heat treating
fixture which will clamp the thin circular metal specimen firmly in place to prevent
warping, but allow lateral expansion and contraction as the metal specimen is
heated and cooled. The heat treatment fixture of present invention also
separates the thin circular metal specimen with ceramic washer to prevent the
chances of sticking with each other at elevated temperature. The present
improved invention of heat treatment fixture is constructed to allow for holding of
thin circular metal specimen in bulk quantity in one setting to reduce the cycle
time for manufacturing.
Annexure‐II
SUMMARY OF PRESENT INVENTION
In accordance with one aspect of present invention is to provide a heat
treatment fixture with a plurality of support levels for work pieces, which is
assembled from threaded rod.
In accordance with second aspect of present invention is to provide a heat
treatment fixture for heat treating furnaces with which the cycle time is greatly
reduced by reason of the low fixture mass and low specific heat of the material
and which will have a longer life than that of fixtures heretofore available.
In accordance with another aspect of present invention is provided a heat
treatment fixture for heat treating furnaces which, by reason of its decreased
weight as compared with those heretofore available, makes for greater ease of
handling for introduction into the furnace and for removal.
In accordance with yet another aspect of present invention is to provide a
heat treatment fixture for holding and separating the thin circular specimen to
prevent the warping and sticking at elevated temperature.
In accordance with yet another aspect of present invention is to provide a
more rigid heat treatment fixture to hold the thin circular specimen on place
. In accordance with another aspect of present invention is to provide a
lighter heat treatment fixture.
Other objects and advantageous features of the heat treatment fixture will
be apparent from the description and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The features and advantages of the present invention will become more apparent
and descriptive in the description when considered together with figures/flow
charts presented:
Fig. 1 is a Front view of the Heat Treatment Fixture.
Fig. 2 is a Side view of Heat Treatment Fixture.
Fig. 3 is a View from the Direction –Z of Heat Treatment Fixture.
Fig.-4 is a Special Nut which clamped the stator plate.
Annexure‐II
DETAILED DESCRIPTION
Referring to fig. 1, 2 & 3, present invention is a improved heat treatment
fixture 9 used to hold the thin circular metal specimen 10 separated by ceramic
washer 7 and adapted for use on heat treatment furnace. The fixture 9 is
designed to hold the thin circular metal specimen 10 in large quantity in one
setting to reduce the cycle time.
Heat treatment fixture 9 for holding and separating the thin circular metal
specimen 10 comprises a main plate 1 made of non magnetic stainless steel
having ten counter bore hole 11 used to position and hold the ten holding bar
3.holding bar 3 holds the thin circular metal specimen 10.
Heat Treatment Fixture 9 Comprises a Side Plate 2 of non magnetic
stainless steel. Main plate 1 also hold the side plate 2 rigidly with the help of one
Allen head screw 4 and two dowel pins 5.Side plate 2 facilitate the resting of heat
treatment fixture in heat treatment furnace.
Heat Treatment fixture 9 comprises a holding bar 3 of non magnetic
stainless steel which hold the specimen 10 sandwiched between two Ceramic
washers 7. Holding bar 3 are fixed with main plate 1 through ten counter bore
holes 11 fabricated in the main plate 1. Holding bar 3 is press fitted in counter
bore holes and locked with Dowel pin 8.
A special nut 6 made of non magnetic stainless steel is used to clamp thin
circular metal specimen 10 in holding bar 3 between a pair of ceramic washer.
The special nut is tightened in the holding bar 3 on the thread made on end of
holding bar 3.
Heat Treatment fixture 9 comprises a ceramic washer 7 of Ceramic. it
plays an important role and used between two Specimen 10 to avoid the Sticking
of Specimen 10 with each other during heat treatment process.
The Heat Treatment fixture 9 as described has low fixture mass of about
one half to one fifth the weight of conventional fixtures, and the low specific heat
of the material permits much more rapid heating and. cooling, both these
characteristics contributing to reduction of furnace cycle time and consequent
savings.

WE CLAIMS:-
Accordingly, the description of the present invention is to be considered as illustrative only and is for the purpose of teaching those skilled in the art of the best mode of carrying out the invention. The details may be varied substantially without departing from the spirit of the invention, and exclusive use of all modifications which are within the scope of the appended claims is reserved. We Claim

1. The heat treatment fixture is constructed to hold the thin circular metal Specimen for heat treatment adapted to be positioned on heat treatment furnace. The fixture comprising:
- Main Plate having counter bore holes adapted to hold the holding bar and provision for fixing the side plate with main pate.
- Ten holding bar used to hold and support the thin circular metal specimen and arranged in three vertical lines. Holding bar is press fitted in counter bore holes and locked with dowel pins.
- Special nut to clamp thin circular metal specimen on holding bar.
- Ceramic washer to separate the thin circular metal specimen on holding bar during clamping to prevent sticking at elevated temperature.
2. The heat treatment fixture for thin circular metal specimen of claim 1 wherein, the connection between holding bar and main plate are detachable.

3. The heat treatment fixture for thin circular metal specimen of claim 1 wherein, the material of the fixture is non magnetic stainless steel.

4. The heat treatment fixture for thin circular metal specimen of claim 1 wherein, the thin metal specimen is separated by ceramic washers. ,TagSPECI:As per Annexure-II