FIELD OF INVENTION

The present invention relates to an improved means for manufacturing insulating frames with high accuracy and high productivity for large size exciters. More particularly, the invention relates to an improved means and method for manufacturing insulating frames with less effort, reduced man-power enhancing quality and productivity.
BACKGROUND OF THE INVENTION
Insulating frames which is used to make pole of exciters. Exciter is used to produce necessary direct current for turbo generator system.
Plurality of insulating frames are used in field coil assembly. Field coil assembly is mounted on stator of exciter. Bunch of conductors are held with the help of insulating frames. Conductors are fitted into window made in insulating frames. Variety of insulating items are used as a supporting structure for different ratings of exciters. These insulating items are made of epoxy laminated glass fabric base sheet.
There is requirement of high accuracy in dimension of window made in insulating frame during assembly of conductor. In the existing practice there was no arrangement to hold insulating frames on bed of milling machine. Therefore,

manufacturing of the insulating frame was done by taking tolerance in length and width of window made in insulating frame which could be maintained during grinding. But during the process, enormous problems were faced like additional man-power was required to maintain dimensions of window made in insulating frame. Quality of finished product was affected because in absence of no proper arrangement to machining of window made in insulating frame which ultimately causing less productivity because of increase of cycle time of manufacture and in case of failure during quality control check further increasing cycle time, as well as increased material wastage because of high rejection rate.
Thus there was a need for improved means to manufacture these insulating frames with high accuracy and high productivity.
OBJECTS OF THE INVENTION
Therefore, it is an object of the invention to propose an improved means for manufacturing insulating frames with high accuracy and high productivity for large size exciters, which is capable of reducing cycle time of manufacture and hence enhancing productivity.
Another object of the invention is to propose an improved means for manufacturing insulating frames with high accuracy and high productivity for large

size exciters, which is able to enhance quality of the product reducing high rejection rate.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Fig. 1: Shows the base unit and the upper support as the means for
machining insulating frame placed on the base unit.
Fig. 2: Shows the base unit.
Fig. 3: shows the upper support.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION
The arrangement or means (20) comprises of a base unit (10) and a work holding unit (30). The job is placed on the base unit (10). The base unit is fixed to a machine bed with standard T-slot passing through the hole (12) of a plurality of protrusion (11) made at the middle of the two arms of the base unit (10). This restricts and totally lock the rotational degree of freedom of the base unit (10). The base unit (10) is held in the said machine bed in a way to provide enough strength to hold against vibration, machining forces and tendency of migrating or rattling in the T-slot that contributes to the reduced job quality and finish.

The length of the threaded means fixing on the base unit (10) on the machine bed should be such that top face of threaded mean is always below the top face (T) of the step section 21. The depth (D) of the step section (11) is also machined accordingly to comply with the requirement. This is to ensure that when the parallelopiped job is placed in step section (21) of the base unit (10), free end face of the said threaded mean (12) do not protrude out of step section (21). Step height ‘d1’ of step section (21) and the depth ‘d’ of the upper work support (30) is maintained as 20mm.
Referring to figure 2 U-shaped base unit (10) serves as the base of the means (20) for holding insulating frame or job. The base unit has threaded holes (28) at the two ends of the top face of the base unit (10) and threaded holes (25) and (27) at the front part of the base unit (10) to match with holes (13) and (14) of the upper support (30) for fixing the upper support with base unit when the job is placed on the base unit (10). The base unit (10) is machined in such a way that a step or collar (24) is configured on the base unit (10) which additionally help in rigidly holding the job against machining forces and vibrations.
Figure 3 shows a L-shaped work support (30) with holes (13, 14) for fixing with threaded holes (27, 28) and (25, 28) of the base unit (10).

Figure 2 shows the means (20) that consist of the base unit (10) and the upper support (30) when the job is placed on the base unit (10) to be held tightly and rigidly by the upper support (30). The step ‘d’ of the L-shaped upper support (30) is made exactly equal to the depth ‘24’ of the step section of the base unit (10) so that the support (30) sits on the base unit (10) properly.

WE CLAIM
1. Improved means (20) for manufacturing insulating frames with high
accuracy and high productivity for large size exciters, the said means consisting of;
a base unit (10) as the base of the means (20) for holding insulating frame for machining;
an upper support (30) to clamp the insulating frame on the base unit (10); wherein,
a slot protrusion (11) is configured at the middle of the two arms of the U-shaped base unit for providing easy access into standard T-slot of a machine bed for locking and arresting rotational degree of freedom of the base unit (10), when the base unit (10) is provided with a step section (21) with a step height ‘d1’, wherein the L-shaped upper support (30) having a depth ‘d’ that matches with the height ‘d1’ of the base unit step section (21) wherein the upper support has holes (13) and (14) matching with threaded holes (27, 28) and (25, 28) of the base unit for fixing the work support rigidly on the job insulating frame being disposed on the base unit wherein the job placed on the base unit (10) takes rigid support by the collar (24) of the step section (21) of the base unit.

2. The means as claimed in claim 1, wherein the depth ‘d’ and step height ‘d1’
is 20mm.