This invention relates to a device for inspecting the keyway symmetry in the crankshaft of a motorcycle.
The. crankshaft is part of the petrol engine of a two wheeler which forms an assembly with the connecting rod and piston to transfer the motion.
In the crank-halt there is a keyway which acts m a drive to convert the •notion on to the magneto assembly.
The key way in the crankshaft is manufacture by keyway nulling operation.
The symmetrv of this keyway was inspected bv attribute so far. This method of inspection has resulted in accepting wrong components which affects the quaiity and productiyty.
When the crankshafts are being produced setting needs to he done to ensure that the keyway symmetrical with respect to the diameter within specifications. This is being done through inspection in standards room
which consumes more time
The known type of inspection shown in Fie J (A & B) consists of two assemblies (1 and ii) top and bottom, The top assembly (i) is a bracket which is mounted with guide bush 1 and centre 2 with spring 3 along with lifting lever 4. The bottom assembly ( ii) is & movable centre 5 and guide bush 6 with orienline. pin 7 and keyway symmetry checking pin and guide hush 8 and 9 (attribute, type) located at the right side of the bracket.

This type of inspection has the following disadvantages. In the event of tool change there is a need to check the symmetry of the key way Geometrical accuracy of the crankshaft is ensured by inspecting the symmetry and its value which can be checked by the attribute method. Consequent to this The inspection time increases, thereby reducing the productivity.
Therefore the device herein is proposed to provide an alternative solution which will overcome the above disadvantages.
For solving the aforem entioned problems, the present invention, provides an absolute measurement device.
The invention will now be explained with reference to Fig. 2 (C & D) which illustrate bv wav of example and not bv way of limitation one of the possible embodiments of the device proposed herein.
The embodiment consists of two blocks lefthand 1 and riehthand 2 with
centre members .1 and 4 guided and connected to base plate 5 by any known means, such a.s, the screws 6. The digital dials 7 and 8 are mounted with dial holder 9 and 10 on the left and right side of the blocks 1 and 2 on the top with screws 11.
A set of custom, designed slip 12 provided lo insert into the component keyway A ball cage 13 with guide bush 14 and stem 15 is provided to take up the rest of the symmetry inspecting slip and it is connected to base plate 5 with screws: 16 and linear adjustability by means of slots on the base plate. A clamp screw 17 is provided on the stem 1 5 to clamp the dips.

A digital indicator is provided with holder 18 and mounted on the base plate- to inspect the symmetry of the keyway in the crankshaft. An orienting pin 19 is provided for orienting the key way axis as reference to the centre members.
The device proposed herein includes checking of symmetry and depth of keyway absolute measurement thereby solving the abovementioned
problem.
THE terms and expression:- are of description and not of limitation having regars to the scope and ambit of this invention.

We Claim :
I. A device for inspecting the- keyway symmetry in the crankshaft of a motorcycle comprising two left hand and right hand blocks orovided with
two centre members fixed to abase plate; two digital dials mounted with two dial holders on either side of the said blocks on the lop: slips lor insertion into the crankshaft keywav: a ball cage with guide bush and stem; a clamp screw provided on the stem to clamp the slips: a digital dial indicator with, mounted on the base plate to inspect the symmetry of the keywav of the crank shafty and an orienting pin for orienting the kev way axis as a reference with respect to the said centre members.

2 A device for inspecting the keyway symmetry in the crankshaft of a
motorcycle substantially as herein described and illustrated with
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reference to the accompanying drawings.
Dated this the 9th day of December 2005