assembly drawings part-3

8/13/2019 Assembly Drawings Part-3

1/19

Fig. 18.20 Revolving centre

M34


2/19

78

8

10 19 R32

2 HOLES, M8

8 8R32

48

2 PINS

46 6

5192 HOLES,

DIA 7 82100

2718

104 51

6110 10 DIA 6

3 10

2410

10R72 PINS, DIA 6PCD 51 6

13

22

18 2

8

30 14103

119162

aParts listPart No.1

123456789

NameBodyBearing ball seatPivot platePivotSleeveCover plateSet screw M813Cover bolt M625Ball 13

Matl

14 HOLES, M6, PCD 78 4 HOLES,

DIA 7 619

438

5 7 4 6 3 2Qty111111241

8 9 b

HCSHCSHCSHCSHCSHCSMSMSHCS

6 16 22 78

Assembly

Drawings

293Fig. 18.21 Floating reamer holder


3/19

294 Machine Drawing

centre 3. The sleeve is positioned in the barrel by the cover 5. Another cover 2 is fixed on the frontside of the barrel by means of the screws 8 to retain the radial bearing in position.

ExerciseAssemble the parts of the revolving centre, shown in Fig. 18.20 and draw a half sectional viewfrom the front.

18.3.8 Floating Reamer HolderA reamer provides a ready means of sizing and finishing a hole after drilling or boring. However,greater accuracy is ensured when the reamer is carried in a holder, which allows it to float or tohave a certain latitude of free movement. If the reamer is rigidly held and if there is any smallerror in the alignment, the reamer will be unable to follow the bored hole, resulting in inaccuracy.The floating reamer holder, by permitting a certain amount of freedom, allows the reamer tofollow the axis of the hole it is reaming.

The details of a floating reamer holder are shown in Fig. 18. 21a. The sleeve 5 is rigidlyfixed in the pivot 4 by the set screws 7. This assembly is fitted into the body 1, by making use ofthe pivot plate 3, bearing ball seat 2 and the steel ball 9. This ensures floating condition for thereamer holder. This assembly is held in place by the cover plate 6 to the body of the holder.Figure 18.21b shows the assembly drawing of the floating reamer holder.ExerciseThe details of a floating reamer holder used on a lathe are shown in Fig. 18.21a. Assemble theparts and draw the following views to a suitable scale:

(i) Half sectional view from the front, with top half in section, and(ii) View from the left.

18.3.9 Machine ViceThe details of a plain machine vice are shown in Fig. 18.22. It consists of the base 1 which isclamped to the machine table using two T-bolts. The sliding block 3 is fixed in the centre slot ofthe base by means of the guide screw 4. The movable jaw 2 is fixed to the sliding block with fourscrews 8 and 7. One of the serrated plates 5 is fixed to the jaw of the base by means of screws 6 andthe other to the movable jaw by the screws 7. One end of the guide screw is fixed to the base bymeans of the washer 9 and nut 10 (not shown in figure). The movable jaw is operated by means ofa handle (not shown) which fits onto the square end of the guide screw.

ExerciseFigure 18.22 shows the details of a machine vice. Assemble the parts and draw, (i) sectional viewfrom the front, (ii) view from above and (iii) view from the left. Use suitable scale.

18.3.10 Swivel Machine ViceA machine vice is a work holding device, used in machines such as drilling, milling, etc. Aswivelling type machine vice permits swivelling about its vertical axis, so that the work may beclamped at any angular position required in the machining operation. T-bolts (not shown) areused through the base plate, to fix the vice to the machine table.

Figure 18.23 shows the details of a swivel machine vice. It consists of the swivel body 1which is fixed to the base plate 3 by two bolts 6. The heads of the bolts are so shaped, that they canslide freely in the circular T-slot of the base plate. The graduations marked in degrees on theflange of the base plate, facilitate setting of the swivel body at any desired angle.

The swivel body has a fixed jaw at one end. The movable jaw 2 is mounted on the swivelbody by the screw 4. After the screw is inserted fully, it is held in position by a nut and pin to prevent its axial motion. Thus, when the screw is turned, the movable jaw slides on the swivelbody guide ways. Steel jaw plates 5 are fitted to jaws by machine screws.


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45OIL HOLE, DIA 10

12 35

45 M8

112

3559

94

5038

23 1216

47 376535

32

OIL HOLE,DIA 5

50

12 10

112 2 HOLES,DIA 15

16683130

57

704 HOLES, M8

62 SQ THD,DIA 253 LH

23

176100 66 50LH SQ THDDIA 253

20

R8023

R20

100 10035 12

4

50 215393

75 6 6

4 HOLES, DIA 8CSK DIA 16

3512M8 15

32Parts listPart No.

1234

56789

10

NameBaseMovable jawSliding blockGuide screw

Serrated plateCSK Screw 34 longCSK Screw 30 longCSK Screw 50 longWasher 206

Nut M20

MatlCICICIMS

MSMSMSMSMSMS

Qty1111

242211

38

2

112

176 22

10611218 46 R6

12

4625M20R5 3

12

AssemblyDrawings

M82452 HOLES, DIA 8CSK DIA 16

38

45

12 1765 6 7 8

Fig. 18.22 Machine vice

295


5/19


6/19

Assembly Drawings 297

24 12

16

190126

24 120 M1050

62 R2222

21

R10 10

R10 203 50 60

16 4233

5888

M123526

292

4216

R

152SQ THDDIA 254

262

1214 10 142

25 12 28

254

R50

8238 32 32

3

Parts listPart No.

123456

NameBodyMoving jawSwivel baseScrew rodJaw plateClamping bolt

MatlCSCSCIMSHCSMS

Qty111122

Fig. 18.23 Swivel machine vice

6

22

80

18 14 SP3


7/19

298 Machine Drawing

ExerciseFigure 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, withcutting 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, boringand similar operations in mass production.

Figure 18.24 shows the details of a drill jig used to produce six holes, spaced equally in acircular 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 liftedto remove the work piece from its seating.

M20

SLOTTED

CHEESE HEADSCREW BM650

30

545

54 84545

98 35

M12

32

M20

25 56 HOLES,DIA 25

3 HOLES, M6 EQUI-SP

60

4

345

3042

5

345

12

820

40

1

3458 42 3

25

Parts listPart No. Name

Base plateStemJig plateScrewStudNut M20Bush case hardenedLatch washerScrew

MatlClMSClMSMSMSSteelMSMS

Qty111311611

7 123456789

R33 R15

4R5

152R336

M12

2R12

CASE HARDENED9

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

16 25


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nut from the stud 5. It may further be noted that the work piece is machined at the requiredsurface before loading in the jig. This is so, because, certain machined surfaces of the work piecemay be used for locating it in the jig.

ExerciseAssemble the parts of the drill jig shown in Fig. 18.24 and draw, (i) sectional view from the frontand (ii) view from above.

18.3.12 Indexing Drill JigFigure 18.25 shows the details of an indexing drill jig used to drill six holes in the work piece (13).

The jig consists of the bracket 1, on the top of which is fixed the jig plate 2. The plain drillbush 6 and the slip bush 7 are located in the jig plate. The plain bush is fixed with interference fitin the plate, whereas the slip bush is provided with sliding fit in the plate and is removed tofacilitate loading of the job. The job is located in the jig by means of the locater 3 which is fastened to the bracket 1 by means of the nut 11. Quick loading and unloading of the job is carried out bymeans of the quick acting knob 4. Two holes are drilled on the job through the bushes 6 and 7. The location of the remaining holes, which are at 90 intervals is obtained by the simple indexingmechanism provided by the ball catch assembly 5. The ball catch assembly consists of a M.S platewhich is fastened to the bracket by means of the socket headed screws 10. The required indexingis obtained by means of the spring 9, loaded ball 8, which is a part of the ball catch assembly.

After the first operation, when the job is rotated in clockwise direction, the ball catch assemblyfacilitates location of the job at intervals of 90 rotation.

ExerciseThe details of an indexing drill jig are given in Fig. 18.25. Draw, (i) sectional view from the front,(ii) view from above and (iii) view from the right.

18.3.13 Self-centring ChuckThe self-centring chuck is a work holding device mounted on the headstock spindle of a lathe. It

automatically centres the workpiece by the three jaws, moving simultaneously to and from thecentre. Regular shaped objects such as rounds and hexagons are quickly held and centred in threeaw self-centring chucks.

Figure 18.26a shows the two views of a self-centring lathe chuck. The details of the assemblyare given in Fig. 18.26b. It consists of a face plate 1, and the scroll plate 3 is fitted into the circularrecess at the back of the face plate. Three pinions 4 are mounted in position in the face plate suchthat, their teeth engage with those on the back of the scroll plate. The back plate 2 is fastened tothe face plate by six screws 7. This assembly is fastened to the flange 5 by three socket headedscrews 8. The three jaws 6 are then engaged with the scroll plate. By rotating any one pinion bya chuck key (not shown), the three jaws move in the radial direction either to or from the centre.The threaded hole in the flange facilitates the mounting of the chuck in the threaded headstockspindle.

ExerciseFigure 18.26b shows the details of a self-centring lathe chuck. Assemble the parts and draw to1 : 1 scale, the following:

(i) The view from the front, as seen from the side of the jaws, and(ii) The half sectional view from the right. Consider suitable local section for showing other

details.18.3.14 Four Jaw ChuckFour jaw chuck is a device used to hold jobs accurately on a lathe. Unlike three jaw self-centringchuck, it can hold both regular and irregular shapes of objects.


9/19

30013.5 2 Nos M6SOCKET HEADED

SCREW10

3618

1.518

1830

15 1548

M1224 4815

MachineDrawingM12

96 3

4 Tilt angle torelease knob15

18 405

18

4 HOLES, DIA 4.5

5427

13.5X

1218

2.520 1 5

18 28 31 18A

13.5 2 HOLES,DIA 4.548

1890

18

Ballcatch 9 6

7

18 13

XX X

824

3 HOLES, M696

Detail at A

3 HOLES, DIA 17C-BORE

18 Parts listPart No.

1234567

Name Matl Qty1111111

Part No.89

10111213

NameBall 5SpringSocket head screw

Nut, M12Dowel pin, 535Workpiece

MatlMS

SteelMSMSMS

Qty11512

ClBracketMSJig plateMSLocatorMSQuick acting knob

Ball catch assembly MSHCSDrill bushHCSDrill slip bush

122 HOLES,

DIA 548

18

22.5 27

18

92 42

76

58

Fig. 18.25 Indexing drill jig


10/19


8 5 7 2 1 3 6arts listPart No.

12345678

NameFace plateBack plateScroll platePinionFlangeJawSocket head screwSocket head screw

MatlMSMSMCSMCSClMCS

Qty11131363

4

Fig. 18.26a Self centring chuck

10

3041

171320

421

8

22

017

3 HOLES, M6PCD 50

3 HOLES,DIA 10 PCD 140

R5 R11 1

120

1604060125

58 TEETH12 PITCH 3

60

3.5 TURNSSQ 4 SPIRAL

Fig. 18.26b Details of self centring chuck (contd.)

9306412 41030 11

24

3 HOLES, M6DEEP 30PCD 140

4124

1254


11/19

3024 4 R10

1203H20

3 HOLES, DIA 10PCD 140

OLRE

BO0

6CD5

IA, D 0 PCES

1DIA

3 HOLES, DIA 6 CBORE DIA 10

R30X

18

811

MachineDrawing

5 888

88 8R18

20

2010

8

R9Y 20 323 12

56 R1013

6

R70R45 R25

PCD 25

6 25 22 1256M6

54

24

Y

3 HOLES, M6 EQUI-SP

R112 X

XX

11

M5020 70

M1010

35 10

4

6 R6

3 52050 8 12 TEETH

12 PITCH

Fig. 18.26b Details of self centring chuck

767

16

19

10 464

YY

45


12/19


The isometric view of a four jaw chuck is shown in Fig. 18.27a. It consists of a cast ironbody 1, in which is located the screws 3 and the jaws 2 which engage with each other with squarethreads. The screws are held in position by the locators 4 which prevent their axial movement aswell. When the screws are operated by means of a chuck key (not shown), the jaws move towardsor away from the centre. Thus, the four jaws can be moved independently to grip the job firmly.The locators are fixed to the body by means of screws 5. The body of the chuck is fixed to the backplate by means of four M 18 bolts. The details of the chuck are illustrated in Fig. 18.27b.

3

2

4

1

Fig. 18.27a Four jaw chuck

ExerciseThe details of a four aw chuck are shown in Fig. 18.27b. Assemble the parts and draw, (i) the viewfrom the front, as seen from the side of the jaws and (ii) the half sectional view from left.

Also consider suitable local section for showing other details.

18.4 VALVES AND BOILER MOUNTINGS

18.4.1 Gate ValveA valve is used on a fluid line to check or control the fluid flow. It may be operated by the pressureof the fluid or by hand. A number of designs of valves are available; however the gate valvepermits the whole area of the passage for the flow of fluid, when fully opened. This minimizes anyenergy loss in the fluid flow.

Figure 18.28 shows the details of a gate valve. The wedge valve 4 in this design is guided bythe control screw 5. When fully opened, the wedge valve clears-off the passage in the valve body 1for the flow of fluid. The inside union 8 is slipped onto the stem from below. This is placed in theunion 2 and screwed. The wedge valve is threaded on the stem and the assembly is placed in the valve body and screwed. The gland is placed from the top of the stem so that it enters the union.It is fixed in position by the union ring 3. Finally, the hand wheel 6 is placed on the square end ofthe screw and fixed in position by means of a nut (not shown). The gate valve may be fixed for any direction of the fluid flow.


13/19


14/19

3

52M36

18

M18

13

5

10

8 327 1 6

12 50

60M2614 R3

1

1110 3

36 1 112 9

11013

R44R4

SQ. THDDIA 7

1013 5

M3

8

4 2

17

1512

9 Parts listPart No.

12345678

NameValve bodyUnionUnion ringWedge valveStemHand wheelGlandInside union

MatlBrassBrassBrassBrassBrassCl

BrassBrass

Qty11111111

3496 M18

3

1418

4

SQ. THD DIA7

78

9 102

M16

23

R3

R3

4

AssemblyDrawings

51

Fig. 18.28 Gate valve

305


15/19

306 Machine Drawing

ExerciseFigure 18.28 shows the details of a gate valve. Assemble the parts and draw to full scale, (i)sectional view from the front, (ii) the view from above and (iii) the view from the left.

18.4.2 Screw Down Stop ValveSimilar to any other valve, this valve is also used in a fluid line to control the fluid flow. In thefully open position, valve gets lifted by 5 mm from the seat to allow the fluid flow from left to right.

Figure 18.29 shows the details of the screw down stop valve. The sleeve 5 is mounted on the stem 8 by means of actuating screw 9. Valve seat 11 is attached to the collar 6 with the screw 12and then the collar 6 is screwed onto the sleeve 5, completing the valve assembly. Screwed sleeve10 is located in the bonnet 2 and this assembly is screwed onto the valve body 1 after slipping ontothe stem assembly. Gland 4 is located on the bonnet through the stem and packing 7 (not shownin figure) is used between the bonnet and gland, to stop any leakage of fluid. Gland is secured bythe cap nut 3. Hand wheel 13 is mounted on the stem, using the nut 14.

During operation of the hand wheel, the screw 9 either lifts the vlave, opening the fluidpassage or screws down the valve, closing the fluid passage. Hence, the name actuating screw.

ExerciseFigure 18.29 shows the details of a screw down stop valve. Assemble the parts and draw,(i) sectional view from the front and (ii) view from above.

18.4.3 Non-return Valve (light duty)Valve is a device used for regulating the flow of fluid. In the non-return valve, the pressure of thefluid allows the flow in one direction only.

When the inlet pressure of the fluid is greater than the pressure at the top of the valve, it gets lifted and allows the fluid to flow past. However, as the fluid pressure builds-up more at thetop; the flow ceases and the fluid will not be permitted in the reverse direction, due to shutting ofthe valve automatically. It is used in boiler feed water system.

Figure 18.30 shows the details of a non-return valve. The fluid enters at the bottom of the

valve and leaves from the side. It consists of a body 1 with flanges at right angle, for the purposeof mounting the same. The valve seat 3 is introduced into the body from top and secured in place by set-screw 6. The valve 4 is also introduced from top and located in the valve seat. The valveseat allows free sliding of the valve in it. The studs 5 are first screwed into the body and afterplacing the cover 2, it is tightened with nuts.

As water with pressure enters at the bottom of the valve, the valve gets lifted in the valveseat, allowing free flow of water through the exit. However, the amount of lift of the valve iscontrolled by the cover.

ExerciseThe part drawings of a non-return valve are shown in Fig. 18.30. Assemble the parts and draw,(i) half sectional view from the front, (ii) view from the left and (iii) view from above.

18.4.4 Non-return ValveWhen a valve is operated by the pressure of a fluid, it is called a non-return valve, because, due tothe reduction in the pressure of the fluid, the valve automatically shuts-off, ensuring non-returnof the fluid. Figure 18.31a shows a brass/gun metal valve with a bevelled edge on the valve seat. The isometric view of the inverted valve shows the details of the webs. However, in the non-returnvalve, a separate valve seat is not provided.


16/19

4 7

M32

R52

510

415

M4

613

10105 3

M18R4 2

R4 10

M206

913

6 R45

R2513 1

R3R3

3

10 6

5M15

3

213

M45

83 4

658

40 4

12

M4

1380

M18

17112

13 14

M12

Parts listSl. No.

1234567891011121314

NameValve bodyBonnetGland tightening nutGlandSleeveCollerStuffing box packingStem with screwActuating screw endScrewed sleeveValve seatScrewHand wheel

Nut

Matl.CI

BrassMS

BrassMSMS

AsbestosMSMS

BrassGMMSCIMS

Qty.11111111111111

M1516

1.5

8

10 4 3 12 1253 27 16

2

M4

2127 273 5

2

AssemblyDrawings

M4 9

M12M32

11

M12

22

11 10 15

Fig. 18.29 Screw down stop valve 307


17/19

308 Machine Drawing

6 HOLES, M16 PCD150

20

12 620

20

50 12

6 HOLES, DIA 187

3PCD 150

14012 40

12

20

1401

2

45

6 3 7 545

22

25 R100

8012 M10

38

45

3

SET SCREWEND 4

3 WINGS,THICK 8

M10

6

28M16

5

Parts listNo.123456

NameBodyCoverValve seatValveStud with nutSet screw

Matl QtyBrass1Brass1Bronze 1Brass1MS6MS1

Fig. 18.30Non-return valve (Light duty)

Fig. 18.31a Valve and the seat

20

TO SUITDIA 10

4860R10

0


18/19


19/19

310 Machine Drawing

Figure 18.31b shows the details of a non-return valve. Fluid flow enters the valve at A(inlet) and leaves the valve at B (outlet). The gland bush 3 and the gland 4 are first assembled and screwed onto the spindle 2 and assembled into the valve body 1 at C. By operating the spindle, thefluid outlet B is either closed or kept open. The valve 5 is positioned in the body through thepassage D and it is kept floating. The valve stop 6 is screwed into the body at D and is used to control the amount of lift of the valve. The fluid inlet connection to the valve is made at A.

When the spindle is operated and the outlet is open; due to the pressure of the inlet fluid,valve is lifted and passage is established from A through B. When the pressure of the incomingfluid is reduced, the valve automatically shuts-off the inlet passage, ensuring non-return of thefluid in the opposite direction.

ExerciseThe details of a non-return valve are shown in Fig. 18.31b. Assemble the parts and draw thefollowing veiws to a suitable scale:

(i) Sectional view from the front, taking the section through Y-Y, and,(ii) Sectional view from above, considering section through X-X.

assembly drawings part-3

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