Tulsa daily world. [volume] (Tulsa, Indian Territory [Okla.]) 1905-1919, 1917-10-07
AUTO LESSON No. 5S.
The Sfccrinn Gcar


We have seen how the wheels each
turned on their separate pivot when
the automobile is steered and have
now to see the merchanism by which
the steering is done from the drivers S
hand wheel.
In Fig. /, the construction OF the
front axle is again shown. Here A,
the part which comprises the axle
of tha wheel. The hub, thru which the
pivot pin tcalled the king pin) passes
and tie rod arm 2, is called the
steering knuckle. You will note that
the steering knuckles of the two
wheels are connected by q rod (B), A.,
called the tie rod. or reach rod, in
such "A way that when one wheel is
turned, the other will also be turned,
and because sof sthe angle, of the tie
rod arms, both wheels will be turned
the proper amount. Obviously, then,
the steering mechanism need only op-
crate on one of the wheels.
When the driver sits on the right
hand side of the car. the car is said
TO be Of right-hand drive, and the
steering mechanism Is usually con-
nected to the right-hand wheel. while
II he sits on the left-hand side (nOw
the most common). the car Is OF left
hand drive and the mechanism oper-
ates on the left-hand wheel
When the car is OF left-hand drive,
the left wheel steering knuckle. in
addition to the @tie-rod arm. has an
arm (C) fastened to 1t, to which u
rod or link (E) Gig. 81, called the
drag link is fastened. the other end
Of this drag link, being fastened to
the steering arm (F). You will
note that when the steering arm Is
moved so as to swing backward or
forward on its center Co, that the
wheels will be made to turn. We
have, therefore, next to see how the
steering arm is moved.
While the construction OF the steer
ing knuckle, tie rod, drag link and
steering arm Is nearly the same for all
cars, there is considerable variation
In the design and construction Of the
steering mechanism proper In the
majority of cars the steering arm is
operated by means OF a worm and
worm wheel.
Figure 4 shows detail of the worm
wheel. (M) is the worm (N) the
worm wheel and CD the steering arm
The worm Is connected to a hollow
shaft to the other end of which shaft
Is connected the steering hand wheel
You will be able to see how, when
the hand wheel is turned, 1t turns the
worm, which, in turn, will make the
worm wheel revolve, and so swing
the steering arm back or forth.
Study this worm and worm wheel
for moment. What will happen
when they become worn? Why. there
will be back LASH" or play, In the
hand wheel. How can this play be
taken out you ask. The simplest way
would be to take off the steering arm,
from its square-ended shaft and then
turn the hand wheel until the shaft
has made a half Of revolution, and
put back the arm. This, you will no.
tice will bring the back portion OF
the worm wheel, marked (A). into
mesh with the worm. AS this portion
of the worm wheel has not yet been
used, doing this will be the same as
installing anew worm wheel.
Play In the hand wheel will also
result from the thrust bearings CID
and UD, becoming worn, so that the
worm can move up and down. To take
out this play, the nut (K) Is screwed
down. when this Is done. however,
both wheels must be lacked, and tests
made of the hand wheel so a sto be
sure that 1t does not bind. In most
cars the nut (K) is locked" by hav-
ing the top portion Of the worm hous-
ing split and clamped around the nut.
To turn the nut. therefore. the upper
housing bolts will first have to be
loosened little.
In some cars. the wear Of the worm
and worm wheel can be taken up by
setting the worm wheel closer to the
worm. TO accomplish this. the shaft
Of the worm wheel Is set in eccentric
bearing, which bearings can be turned
and so press the shaft and its worm
wheel closer to the worm. Figure 9
shows one OF these bearings. Care
must be taken to turn both Of the
bearings, which will be found on each
side Of the worm wheel, an equal
amount, and also to see that there is
no "binding." as explained for the
thrust bearing adjustment.
You may have noticed In cntalogs
the expression: "Irreversible Worm
and Worm Wheel" BY this Is meant
that the wheels can be turned only by
turning the hand wheel, they being
sort Of locked" In the position set by
the hand wheel. This Ia accomplished
by having the pitch of the worm quite
small: that IL, the teeth come near to
taking the shape OF rings or Of q spi-
raj of many turns to the foot Of length.
Obviously. were the teoth to be rings.
instead Of a spiral. pressing the steer
Ing arm would simply presss the teeth
Of the worm wheel against those of
tho worm. hut there could he No move
nent Of either. BY having the teeth