Illustrated Sourcebook of Mechanical Components Part 5 pdf

Locking & Clamping 9-19 3 STAMPED SPRING snaps onto clevis before final assembly and acts as detent against the flat errd and top surfaces of metal handle.. u Corner turned WIRE HANDL

8 Detents for Clevis Mountina w

When handles are mounted in clevises they often need to be held in one or more

positions by detents Here are ways to do this

Irwin N Schuster

CAST OR MILLED clevis features an adjust-

able tensioning device, which varies the fol-

lower load Handle can be extruded section

Locote from defen t depressions

CLEVIS MACHINED from hexagonal stock can be drilled to receive a ball detent, whicl~

acts in rammed surfaces cast in handle

CAST HANDLE is drilled to accept a com- mercial “bullet” catch, which detents in the

milled internal surface of the clevis flanges

WELDED CLEVIS is relieved to improve

spring characteristics Punched holes receive

steel rivet head which acts as the detea!

ten 1’5

cu?

/

Drive pin

Locking & Clamping 9-19

3 STAMPED SPRING snaps onto clevis before

final assembly and acts as detent against the

flat errd and top surfaces of metal handle

Detent position I

# /

m

lower, actuated by a spring, which seats

against a pivot pin in the bar and rod handle

u

Corner turned

WIRE HANDLE acts as spring and follower

io sheetmetal clevis, in which cammed sur-

faces and positive stops are made by bending

4 Locking Fastener Designs

Crosspin 4

U-spring

Quick-operating fastener has internal cam action to draw up or

release a 300-lb force with only a quarter-turn o f wrench

Cam surface Flexible retainer

Springy all-plastic quarter-turn fastener w i t h stylish head de- sign can take sharp impact forces and resist corrosion

Locking & Clamping 9-2 1

Quarter-turn-fastener concept with through-core bolt makes

it easy t o attach honeycomb panel to a frame or structure

Outer section forced

into panel hole

Knock-in fastener can be pushed easily into square-punched

hole Center is then knocked in t o make receptacle for screw

8 Control Mountings

When designing control panels follow this 8-point guide and check for

Frank William Wood JR

-v*y-

A

LOCKING Control will stay fixed in spite of vibration

or attempts to force shaft too far Washer at right has two

tabs; one fits in the panel, the other in the control bushing

Left washer has a boss which fits into a cutout in the panel

and around a pin projecting from the control body

SEALING against dust or wa-

ter Boot seals between shaft and

bushing and between bushing and panel With control behind panel

rubbergrommet seals only ode place

HAND-ROOM at front of the panel

Space knobs at least one inch apart Extend-

ing knob to save space puts it where the oper-

ator can bump into it and bend the shaft

5 Best rule i s to keep shaft as short as possible

WCIT” CONTROL KNOBS One a p

proach is to ground them by installing a brush against the shaft Another solution is to iso,

late the control by an insulated coupling or a plastic knob having recessed holding screws

Locking & Clamping 9-23

RESETTING to match controls to panel ACCESSIBILITY behind the panel

markings For crude adjustments a set-screw Easy access reduces down time and mainte-

is enough Where matching is critical a three- nance costs especially if one man can do most piece vernier coupling permits more accurate jobs alone Here, technician can’t replace a calibration warning light without dismantling other parts

LIMIT STOPS that are strong enough

not to bend under heavy-handed use Other-

wise setting will change when stop moves

Collar and grooved knob permit adjustment;

tab on bracket doesn’t

GUARDS to prevent accidental actua-

tion of switches Bell-shape guard for push- buttons is just finger-size U-shape guard sep-

arates closely spaced toggle switches, and a

swinging guard holds down special ones

Control-Locks Thwart Vibration

Critical adjustments stay put-safe against accidental turning or deliberate fiddling

with them

Frank William W o o d JR

1 S P L I T Y O K E clamps on shaft when

eccentric squeezes ends of yoke together

Knurled knob is handy for constant use, and

eliminates need for tool Another advantage

is high torque capacity But this design needs

considerab1.e space on panel

2 FINGER springs into place between gear teeth at turn of cam Although gear lock is

ideally suited for right-angle drives, size

of teeth limits positioning accuracy

3 SPLIT BUSHING tightens on control shaft, because knurled knob has tapered thread Bushing also mounts control to panel, so requires just one hole Lever, like knob, does away with tools, but locks tighter and faster For controls adjusted infre- quently, hex nut turns a fault into an ad- vantage Although it takes a wrench to turn the nut, added difficulty guards against knob- twisters

4 C O N S T A N T DRAG of tapered collar on

shaft makes control stiff, so it doesn’t need

locking and unlocking Compressed lip both

seals out dust and keeps molded locking nut

from rotating

Locking & Clamping 9-25

5 T O N G U E slides in groove, clamps down

on edge of dial If clamp is not tight, it can

scratch the face

6 SPOT-BRAKE clamp

is self-locking, which means i t takes two hands

to make a n adjustment, one to hold the clamp open and one to turn the dial

Low-Cost Latches

These latches cut costs where appearance is a secondary consideration

L Kasper

r

Slyt ond formed

SLIT AND FORMED box side de- pends upon spring action of box metal and latch plate for engagement in latch- plate hole A box that i s too stiff will require a relatively flexible latch plate for ease of operation

FOLDED LEAF-SPRING end is an- other positive, spring-action ' latch Here, however, the leaf spring itself provides spring action - box can be as heavy as desired without interfering with opening or closing Careful align-

went of spring and notch is necessary

BAYONET ACTION of forwed-wire spring in lid is again automatic upon closing Spring must be manipulated for opening unless a lead is deliberately designed into the lid notch so that open- ing force can overcome holding-force

Locking & Clamping 9-27

SPIRAL SPRING holds the lid in a

manner similar t o the previous latch

arrangement, Spring action comes from

tension windup rather than cantilever

and so design is suitable for boxes where

a long latch spring is not possible

FINGER RING is here provided by

forming the spring to do double duty -

it not only perEorms as the latch spring

hut provides finger hold for withdraw-

ing the box from a narrow shelf or desk

drawer Disadvantage is that protrud-

ing spring takes extra space

LATCH SPRINGS projecting through

the box tup provide for stacking by

engaging a slot in the bottom of the

box above Several boxes can thus be

carried without risk of sliding The lid

can be hinged or completely removable

LATCH SPRING foriiied into shape of

a handle is suitable for long, narron

hoxe, ‘The 5tiape of the handle section permit5 several boxes to be stacked and carried safeh

CARRYING-HANDLE is attached to

the latch spring wliich is attached to

its center with a spacer between Press the handle to release the catch

LATCH BAR a t rear falls into slot

when drawer is %lid fully in To with-

draw the box must be raised at the rear

b? tilting on the front edge W e c t is

a self-locking, secret-opening drawer

locking & Clamping 9-29

SWIVEL HANDLE is attached b)

shudder screw at pivot point ‘Tu with-

draw the drailer, tilt the handle ahotit

the pivot point until the latch is dis-

enpaged from rlot in runner

DOUBLE-BAYONET notch in one lid

\naps over Vspring in other lid to hold

hox closed Presr spring to open T h k

Qpe of latch i4 verj witdhie for long,

Ilarrow houe5

NOTCHES are specball) shaped to hold

ewer over instrument housing Siniplj

lift cuver and slide out support leg, tu

reiiiove cover If tit of legs and rlide,

is made fairly tight, accidental reniov-

al or tampering is improhahlr

Hinged Lids That Separate

Keyslots, lid grooves, open hooks, sliding pins, and other features let

hinged lids be completely removed

L Kasper

KEYSLOTTINO one leaf of

the hinge is a simple way to

provide for separation of the

lid from the box

Shoulder screws (one not shown)

Slof or groove for binge leaf slide unfil Lid locates lifted and won?

/-/ cannot siip out

3 OPEN HOOK is formed by

partly uncurling one leaf To

disassemble the lid it must

be opened through 180 dcg

Locking & Clamping 9-3 1

FLAT PLATES are hook and pin that act as efficient but low-cost hinge for rigid lids Round off pin corners

SLIDING PIN is popular way of niaking lids separable Locating pins must be pro- vided if lid does not fit in box

SPRING-TYPE LEAF niust have enough clearance to ac- cept retaining plate thickness unless spring is very light

Hinge bars, notched lids, spring hing pins and other ways of providing for detachable lids

L Kasper

7

8

HINGE-BAR A N D HOOK

make strong and low-cost

hinge, separable when lid i s

opened through 90 deg

N O T C H E D L I D a c c e p t s

hooked part of hinge plate

when lid is opened beyond 90

deg Only one plate is needed

SHOULDER SCREW in hinge

plate needs to be loosened to

only slightly more than the

thickness of lid to detach it

Slighfly more fbon

l i d muferial fhickness

locking & Clamping 9-33

L O O P E D HINGE P I N is

sprung over spacer When the

loop is palled off the spacer

the pin ends retract

H O O K E D M E M B E R i s

slipped under pin in position

shown When lid is opened

latch can he turned to lock pin

H E A D E D PINS are driven

into eurled lid edge Heads are

same diameter as the curl Lid

slides when opened 270 deg

IJ f O f / / d

8 Stops for Panel Doors

They protect hings from overtravel and hold doors in working positions

Frank William Wood JR

BEADED C H A I N provides as many positions as there

a r e beads Keyhole slot allows repositioning

Locking & Clamping 9-35

4

W R A P A R O U N D back of bar comes to a stop against

the cross-rod Slots permit adjusting bar for different

door opening

5

DOG-LEG on end of segment butts against door frame

6

CABLE pulls taut on end collars, which screw back

and forth for slight adjustment

Panel-Stops leave Hands Free

They hold open panel doors while repairs or adjustments are made

Frank William Wood JR

I Ribbon /’’’

spring

1

CAM rubs on spring-loaded pressure plate Resulting friction

holds panel oDen a t any position Tubular spring-holder has

helical instead of ribbon spring

2

N O T C H E D BAR catches on flat spring a t only a few positions Serrations increase number of positions Heavier flat spring holds by friction at any position

3 SLIDER jams when pulled against spring case, but sIides freely after

raising the panel slightly releases pres- sure Spring holds panel shut

4

D E T E N T S a t both ends of swinging bar cup spring-loaded balls

Rod snaps into holes for more positive hold, but must be pulled

out to release Both methods will hold panel shut

5

FRICTION WASHERS hold panel in any position, but are sus-

veptible to vibration Tiglitenirig down on spring washer adjusts

cli*ag for weight of panel Kiiurled kiiol) in place of nut allows

tightening a t desired position

Locking & Clamping 9-37

0

6

CLIP can hold panel door in only one posi- tion-open Push on clig to release

Better Looking Sheetmetal Joints

Improve their appearance with overlapping beads, backing strip, push-in trim strip,

stick-on decals, recessed joints, inverted channels, and painted band

Frank William Wood JR

Both edge lines are

visible Also forms

dusf trap

could &e used

here as shown in No 2

0 INVERTED-CHANNEL JOINT

metal

or Extruded metal or

8 Interlocking Sheetmetal Fasteners These eight sheetmetal parts join sheetmetal quickly with the simplest of tools, few screws

or bolts

L Kasper

way i w long slqt while butting sheets are being positioned Aftenvards it slips down over lower sheet

SQUEEZE CLIP holds two overlapping

sheets, together The, eads of ,the clip are

pushed @?ugh parallel slots, then bent

over much like a staple

CUP carries a bar on both sides of divider Here bars $tick bpiabovq the top, but deeper catout will lowet them u n a they are4luph or-sunk

ESS supports shelf b e p e e n yprights Bq

mating +tli n+tcFe-&gag2'it-acti iid a key

t o beep $helf fro^ sfid1 g-badk dnd'foiah;'

*and iroyidss positibe F ocation.1

Locking & Clamping 9-4 1

BRACKETS provide instantly mobile rack

space for boxes To install or remove,

squeeze sides together and push hooked

ends through slots

FLANGE HOLDER does double duty by holding up shelves on both sides of a parti- tion Angular corners allow it to fit through small slit when tilted

CLAW holds top sheet between two end

pieces Tail snaps into slot, then claw Is

hammered over edge With notched edge,

top is even with sides

n

BAR clamps divider in place Extruded holes provide a recess for screws so that they stay flush with upper surface of hori-

zontal sheet

Lanced Metal Eliminates

Separate Fasteners

15 ways in which sheetmetal tabs, ears and lugs can serve to

fasten and locate

B E N T - O V E R T A B holds together up to four layers of sheet-

metal Designing tahs to stress in shear increases holding strength

tab can be riveted

T H E S E T A B S both locate and hold disk in tubing

When necking locates disk, tab only holds-again by wedge action

Locking & Clamping 9-43

I

9

L I P A N D T A B S combine to join round bar and tubing

For longer bars, tabs fit into grooves Bar can

rotate inside tube if tabs a r e pressed lightly into groove

L A N C E D S H E L L secures rubber in

bumper or instrument foot

13

L Sbeef me fa/ insert

CORNER R E l NFORCE M E N T grips

wood, plastic or fiber with lanced teeth

Similarly, lanced nameplates or labels

attach easily t o equipment or instru-

ment panels by pressing into the sur-

face

M E T A L REINFORCEMENTS and mounting pads grip plastic better if lanced

INTERLOCKING SLOT and tab connects two pieces of tubing Joint is

permanent if inner tubing has thick wall If inner tube has thin wall, tab can be depressed and tubes pulled apart if desired hole However, for angular shapes,

LANCED F L A P S provide large contact areas for brazing or soldering sheet- metal fins to bars and pipes An alternate method for round bars or

pipe i s a n embossed collar around the

flaps a r e easier to make

Lanced Sheetmetal Parts

Federico Strasser

1 C A P T I V E N U T allows blind assembly on panel

too thin to tap Nut is held firmly, cannot get lost,

€/ectr;cal

3 T E R M I N A L made of flat spring stock presses wire

lead tightly in lanced t a b , yet releases easily

2 SPACERS spparate panels with fewer parts and with less weight than extra strips or filler materials

4 T A B S fit into slot to align in one direction as well

as fasten Matching tab and slot on other side

would align plate in second direction

Locking & Clamping 9-45

5 SLIDE rides on projecting tabs At same time, tabs

act as limit stops Length of slot determines how

far the slide c a n trarel

7 REINFORCEMENT RIBS of three different de-

signs all give support for wall bracket, yet retain

one-piece construction

blades

9 L A N C E D B L A D I N G results in one-piece construc-

tion of lightweight cooling fan for small motors,

6 RAISED TABS are bearings and supports for rotat-

ing shaft in light-duty applications Tabs will also guide sliding rod or bar Bent-up end of plate can take place of a tab

8 SPRING ANCHOR-possible variations: tab with hole, or tab with only one notch for spring that pulls

t o side

10 CONTINUOUS STRIP is lanced while flat, then cut t o length and rolled into a sprocket Small sketches suggest ways to avgid a separate hub

Joining Circular Parts

without Fasteners

Fig I-Fastenin:: for a rollccl

cirrnlar srcgion Tab< arc in-

tcsgral with dirc*t: onr tab

liein:: longcr than thc other,

m i d bent o \ c r on aosembly

Fig 5-Similar to Fig 4 for sup- Fig 6-For supporting of rods or Fig 7-Eniboised shcv-t inctal porting elrctrical vires Tab is tubes Installation ran be either bracket to hold rod., tnbes or

integral with plate and crimped prriiianent or temporar? Sheet rablrs Tension i s *ultp!icd IJ\

m e r on assembly metal bracket is held 1ty bent tabs screw threaded into lower plate

Fig IO-Plate i* embossed and tabs bent over o n assembly If two platcs

are used I i a ~ i n g tab edges ( B ) a piaiio-t,pe hinge i s formed ( A ) and (B)

can be conibincd to form a quirk release door mechanism A cablr is

passed throiigli the eye of the hinge bolt, and a IiandIe attached to the cable

Fig 14 Strap fastener to hold a circular section tight against a structural

shape Lock can be made from square bar stock (A) or from sheet metal

(B) tabbed as shown Strap is Bent over for additional lochiiig Slotted

holes in sheet should be spared equal to rod dia to prevent tearing

Fig 11-Rods and t u l ~ r c can be supportrrl by sheet n i c d t n h s Tah

is wrappied around circular section and bent through plate

Fig 15-C clamp support usually

uw d for tuhing Serrated wedge i s

hammc.rrd tight ; serrations keep

v edge f nlor king