Machine Drawing

298 Machine Drawing

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d:\N-Design\Des18-2.pm5

Exercise

Figure 18.23 represents the details of a swivel machine vice. Assemble the parts and draw,

(i) sectional view from the front, (ii) view from above and (iii) sectional view from the left, with

cutting plane passing through the axis of the clamping bolts.

18.3.11 Drill Jig

A jig is a work holding and tool guiding device which may be used for drilling, reaming, boring

and similar operations in mass production.

Figure 18.24 shows the details of a drill jig used to produce six holes, spaced equally in a

circular flange. The design allows for quick loading and unloading of work pieces. For unloading,

the top nut 6 is loosened, the latch washer 8 swivelled out of zone and then the jig plate 3 is lifted

to remove the work piece from its seating.

M20

54 f 54

f 50 5×45°

2

25

f 40

f 60 3 HOLES, M6 EQUI-SP

SLOTTED CHEESE HEAD

SCREW B M6×50

4

30

35

84

98

M20

5

f 216

5×45°

f 17

16 25

f 54 M12

6 HOLES,

DIA 25

30°

60°

42

f 160

3×45°^5

f 60

f 40

8

f 110

f 156

3×45°

20

40

1

12

f 17

(^842)

R12

R33

R32

R54

R15 M12

15

3×45°

f 24

3

f 16

36

f 25

f 18

257

CASE HARDENED

9

Part No. Name Matl Qty

1 2 3 4 5 6 7 8 9

Base plate

Stem

Jig plate

Screw

Stud

Nut M20

Bush case hardened

Latch washer

Screw

Cl

MS

Cl

MS

MS

MS

Steel

MS

MS

1 1 1 3 1 1 6 1 1

Parts list

3

2

Fig. 18.24 Drill jig

It may be noted that the jig plate is so designed, that the nut overall size is less than the

size of the central hole. This makes the loading and unloading easy, without totally removing the