aeroplanes-第22章

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or　to　the　left。



For　convenience　in　explaining　the　action；　the

planes　E　are　placed　at　right　angles　to　their　regular

positions；　F　being　the　forward　margin　of　the

plane；　and　G　the　rear　edge。　Wires　H　connect

the　ends　of　the　frame　B　with　the　respective

planes；　or　ailerons；　E；　and　another　wire　I　joins

the　downwardly…projecting　arms　of　the　two

ailerons；　so　that　motion　is　transmitted　to　both　at

the　same　time；　and　by　a　positive　motion　in　either

direction。



_Fig。　65。　Action　of　the　Gyroscope。_



In　the　second　figure；　65；　the　frame　of　the　aeroplane

is　shown　tilted　at　an　angle；　so　that　its　right

side　is　elevated。　As　the　gyroscopic　wheel　remains

level　it　causes　the　aileron　on　the　right　side　to

change　to　a　negative　angle；　while　at　the　same

time　giving　a　positive　angle　to　the　aileron　on　the

left　side；　which　would；　as　a　result；　depress　the

right　side；　and　bring　the　frame　of　the　machine

back　to　a　horizontal　position。



FORE　AND　AFT　GYROSCOPIC　CONTROL。It　is

obvious　that　the　same　application　of　this　force　may

be　applied　to　control　the　ship　fore　and　aft；　although

it　is　doubtful　whether　such　a　plan　would

have　any　advantages；　since　this　should　be　wholly

within　the　control　of　the　pilot。



Laterally　the　ship　should　not　be　out　of　balance；

fore　and　aft　this　is　a　necessity；　and　as　the　great

trouble　with　all　aeroplanes　is　to　control　them

laterally；　it　may　well　be　doubted　whether　it　would

add　anything　of　value　to　the　machine　by　having

an　automatic　fore　and　aft　control；　which　might；

in　emergencies；　counteract　the　personal　control　of

the　operator。



ANGLE　INDICATOR。In　flight　it　is　an　exceedingly

difficult　matter　for　the　pilot　to　give　an　accurate

idea　of　the　angle　of　the　planes。　If　the　air　is

calm　and　he　is　moving　over　a　certain　course；　and

knows；　from　experience；　what　his　speed　is；　he　may

be　able　to　judge　of　this　factor；　but　he　cannot　tell

what　changes　take　place　under　certain　conditions

during　the　flight。



For　this　purpose　a　simple　little　indicator　may

be　provided；　shown　in　Fig。　66；　which　is　merely　a

vertical　board　A；　with　a　pendulum　B；　swinging

fore　and　aft　from　a　pin　a　which　projects　out

from　the　board　a　short　distance　above　its　center。



The　upper　end　of　the　pendulum　has　a　heart…

shaped　wire　structure　D；　that　carries　a　sliding

weight　E。　Normally；　when　the　aeroplane　is　on

an　even　keel；　or　is　even　at　an　angle；　the　weight

E　rests　within　the　bottom　of　the　loop　D；　but

should　there　be　a　sudden　downward　lurch　or　a

quick　upward　inclination；　which　would　cause　the

pendulum　below　to　rapidly　swing　in　either

direction；　the　sliding　weight　E　would　at　once　move

forward　in　the　same　direction　that　the　pendulum

had　moved；　and　thus　counteract；　for　the　instant

only；　the　swing；　when　it　would　again　drop　back

into　its　central　position。



_Fig。　66。　Angle　Indicator。_



With　such　an　arrangement；　the　pendulum　would

hang　vertically　at　all　times；　and　the　pointer　below；

being　in　range　of　a　circle　with　degrees

indicated　thereon；　and　the　base　attached　to　the

frame　of　the　machine；　can　always　be　observed；

and　the　conditions　noted　at　the　time　the　changes

take　place。



PENDULUM　STABILIZER。In　many　respects　the

use　of　a　pendulum　has　advantages　over　the　gyroscope。

The　latter　requires　power　to　keep　it　in

motion。　The　pendulum　is　always　in　condition

for　service。　While　it　may　be　more　difficult　to

adjust　the　pendulum；　so　that　it　does　not　affect

the　planes　by　too　rapid　a　swing；　or　an　oscillation

which　is　beyond　the　true　angle　desired；　still；　these

are　matters　which；　in　time；　will　make　the　pendulum

a　strong　factor　in　lateral　stability。



_Fig。　67。　Simple　Pendulum　Stabilizer。_



It　is　an　exceedingly　simple　matter　to　attach　the

lead　wires　from　an　aileron　to　the　pendulum。　In

Fig。　67　one　plan　is　illustrated。　The　pendulum

A　swings　from　the　frame　B　of　the　machine；　the

ailerons　a　being　in　this　case　also　shown　at　right

angles　to　their　true　positions。



The　other；　Fig。　68；　assumes　that　the　machine　is

exactly　horizontal；　and　as　the　pendulum　is　in　a

vertical　position；　the　forward　edges　of　both　ailerons

are　elevated；　but　when　the　pendulum　swings

both　ailerons　will　be　swung　with　their　forward

margins　up　or　down　in　unison；　and　thus　the　proper

angles　are　made　to　right　the　machine。



STEERING　AND　CONTROLLING　WHEEL。For　the

purpose　of　concentrating　the　control　in　a　single

wheel；　which　has　not　alone　a　turning　motion；　but

is　also　mounted　in　such　a　manner　that　it　will　oscillate

to　and　fro；　is　very　desirable；　and　is　adapted

for　any　kind　of　machine。



_Fig。　68。　Pendulum　Stabilizers。_



Fig。　69　shows　such　a　structure；　in　which　A

represents　the　frame　of　the　machine；　and　B　a

segment　for　the　stem　of　the　wheel；　the　segment

being　made　of　two　parts；　so　as　to　form　a　guideway

for　the　stem　a　to　travel　between；　and　the　segment

is　placed　so　that　the　stem　will　travel　in　a

fore　and　aft　direction。



The　lower　end　of　the　stem　is　mounted　in　a

socket；　at　D；　so　that　while　it　may　be　turned；　it

will　also　permit　this　oscillating　motion。　Near　its

lower　end　is　a　cross　bar　E　from　which　the　wires

run　to　the　vertical　control　plane；　and　also　to　the

ailerons；　if　the　machine　is　equipped　with　them；　or

to　the　warping　ends　of　the　planes。



_Fig。　69。　Steering　and　Control　Wheel。_



Above　the　cross　arms　is　a　loose　collar　F　to

which　the　fore　and　aft　cords　are　attached　that　go

to　the　elevators；　or　horizontal　planes。　The　upper

end　of　the　stem　has　a　wheel　G；　which　may　also　be

equipped　with　the　throttle　and　spark　levers。



AUTOMATIC　STABILIZING　WINGS。Unquestionably；

the　best　stabilizer　is　one　which　will　act　on

its　own　initiative。　The　difficulty　with　automatic

devices　is；　that　they　act　too　late；　as　a　general

thing；　to　be　effective。　The　device　represented　in

Fig。　70　is　very　simple；　and　in　practice　is　found　to

be　most　efficient。



In　this　Fig。　70　A　and　B　represent　the　upper

and　the　lower　planes；　respectively。　Near　the　end

vertical　standards　a；　D；　are　narrow　wings　E　E；

F　F；　hinged　on　a　fore　and　aft　line　close　below

each　of　the　planes；　the　wings　being　at　such　distances

from　the　standards　C　D　that　when　they

swing　outwardly　they　will　touch　the　standards；

and　when　in　that　position　will　be　at　an　angle　of

about　35　degrees　from　the　planes　A　B。



_Fig。　70。　Automatic　Stabilizing　Wings。_



_Fig。　71。　Action　of　Stabilizing　Wings。_



Inwardly　they　are　permitted　to　swing　up　and

lie　parallel　with　the　planes；　as　shown　in　Fig。　71

where　the　planes　are　at　an　angle。　In　turning；　all

machines　skid；that　is　they　travel　obliquely

across　the　field；　and　this　is　also　true　when　the

ship　is　sailing　at　right　angles　to　the　course　of　the

wind。



This　will　be　made　clear　by　reference　to　Fig。

72；　in　which　the　dart　A　represents　the　direction

of　the　movement　of　the　aeroplane；　and　B　the

direction　of　the　wind；　the　vertical　rudder　a　being

almost　at　right　angles　to　the　course　of　the　wind。



_Fig。　72。　Into　the　Wind　at　an　Angle。_



In　turning　a　circle　the　same　thing　takes　place

as　shown　in　Fig。　73；　with　the　tail　at　a　different

angle；　so　as　to　give　a　turning　movement　to　the

plane。　It　will　be　seen　that　in　the　circling　movement

the　tendency　of　the　aeroplane　is　to　fly　out

at　a　tangent；　shown　by　the　line　D；　so　that　the

planes　of　the　machine　are　not　radially…disposed

with　reference　to　the　center　of　the　circle；　the　line

E　showing　the　true　radial　line。



Referring　now　to　Fig。　71；　it　will　be　seen　that

this　skidding　motion　of　the　machine　swings　the

wings　E　F　inwardly；　so　that　they　offer　no　resistance

to　the　oblique　movement；　but　the　wings　E

E；　at　the　other　end　of　the　planes　are　swung　outwardly；

to　provide　an　angle；　which　tends　to　raise

up　the　inner　end　of　the　planes；　and　thereby　seek

to　keep　the　planes　horizontal。



_Fig。　73。　Turning　a　Circle。_



BAROMETERS。These　instruments　are　used　for

registering　heights。　A　barometer　is　a　device　for

measuring　the　weight　o