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Show ; ItmAutmpiik Simplified LESSON NO. 108. Tires. : A knowledge of the construction of the tires of the car will unquestionably result in their better care aud therefore there-fore longer life. The tires used on pleasure cars are universally of the pneumatic and double tube type. On heavy cars, such as electrics and :ng, and the casing which serves a twofold two-fold purpose; it resists the pressure of the air in tho tube, and supplies a wearing surface. The ' ' tube ' ' In simply an endless rubber tube, equipped with an automatic auto-matic valve, through which the air can be pumped. Figure 1 of the illusf ration shows & ( T r,o.,uLni r i g o TIG 1 ' i 1 I'" $ FG. - Fig 5 valve pluuger, by comprising the small rubber washer T, will prevent the air leaking out around tho valve plunger. The flange K is held against the washer by t lie pressure of I lie ai r in the tube, and not by the spring shown, the spring acting more as a guide. When it is desired t let air out of the tire, the plunger S is pressed in, which will press the flange U- a w a y from its wa slier and so let the air escape es-cape around the plunger. When the i ire is being blown up, the pressure on top of the flange K will be greater than that in the tube and so the flange will be pressed down just as it is wlmn the plunger is pressed down, and o allow the air to enter around the plunger. The moment pumping is stopped the pressure inside the tube will be greater than that outside, and the flange will again be pressed against the washer and so prevent the escape otM'ho air. A "slow leak," that rs, when the tire becomes flat over night or in two or three days, is usually due to a defect de-fect in Hie valve-inside, the rubber washers be in g worn or lorn. Jieplac-i Jieplac-i ng the valve-inside (it- costs 5 cents), is the remedy. Vou can tell when the valve is leaking by putting a drop of water or saliva on the mouth of the valve. Tf it leaks the saliva will form in bubbles. Screwing the valve-inside iu a little harder will often remedy I he t rouble, but' too much strength must not be used in doing this. .Do not use a pair of plyers. Figure 2 is a picture of the valve-cap. valve-cap. Note the rubber washer A. Some-, time.1 this washer becomes reversed or out of posit ion, aud v hen the cap is screwed onlo the valve, this washer will press on the plunger and so cause the tit- io leak. It: should be looked at every time the cap is put on. In addition lo a cover to keep out dirt, and 1n help in preventing the escape of the air, thv valve-cap is a tool for removing and replacing the ' ' val vr- in sides. Note the notches in Hie top part of Hm can. Tf this thinner thin-ner t"p part, is inserted into the valve, the notches will grip prongs of. (lie screw of the 1 alvo-insidc and so give a means to unscrew it. J- bin re Z si i o vs a c ross-scc t ion of a tvpical ca.-ii- or idinc A is the fabric. If is in the fabric, that Hie strcnglh of Hie tire is, and anv weakness weak-ness in it w.l result- jn thr tube bursting burst-ing t h rough i 1 . This is what ha ppeus when the tire 1 ' blows -out . " B is the rubber or 'tread' of tire, the function func-tion of which is to ,(n vc the tire u Ion g-wea ri ug and grour.d crip ling sur-f sur-f a re. a h o to 'j-i ve a certain amomi t ol eusliioning action and a protection for the fabric. As any defect in Ihe fabric will ca use a blow-out of the t i re, ea re of tires resolves itself into preventing any harm to it. Thus Ihe protecting rub ber or tread must be kept- free from holes, so that dirt and moisture cannot get at tho fabric, and the tire must be kept fairly well inflated, so as Jo prevent pre-vent the constan t bending of the fabric, fab-ric, which would result from a soft tire. The rims must be kept free of rust ami grit or the fabric will quickly wear at. the rim, resulting in what is termed a "rim-cut." A large proportion propor-tion of "blow outs" are due to the latter lat-ter cause. , Tires are made with three types of "beads," which is the portion marked C! in Fig. 3, namely, clincher, quick detachable de-tachable clincher and t ra igli t side or bead. When a tire is purchased the type must be specified, and owners own-ers would do well, therefore, to know the typo they require. Figure 3 shows the plain clincher tire. At first glance this would appear ap-pear to be the same as the Q. T). clincher, Fie. 4, but differs in that the bead is soft, and can be stretched enough to go over the rim. while the Q. 1), clincher has a stiff bead, there being a number of steel cables running run-ning through the beads, as shown in lig. -1, in ruanv makes. As the outside of the two tires looks almost alike, mistakes in their purchase pur-chase are often made. It is practically impossible to get Hie stiff bead Q. D. tire over the regular plain clincher rim, while if the soft-bead tire is used on a uuick del m dm bin riui, there is a J danger of the tube being ' ' pinched ' ? under the bead. Figuro 5 shows the straight-side tire. Obviously this could not be used on a clincher rim, nor could the clincher tire be put on its rim. Inventors and designers have given much thought to making tires as strong as possible and to make them puncture proof. Thus we have the Silvertown Cord tire, in which cords take the place of the fabris, and a number of makes of tires, in which steel inserts arc molded into the rubber to prevent punctures. "In purchasing a tire it is best to go by reputation or the experience of others, as the eye is a poor guide even to experienced t ire men. There must be just, the right thickness of rubber over the fabric, too' much being be-ing as bad. When the rubber is too thick the tire will bend in certain spo's only, with a resultant weakening of these spots. It is also well to avoid new make of tires having heavy anti-l skid knobs. It. has cost some of Hie ' older makers of tires using these knob;- i a fortune to find the correct propnv tinning and shape for the knobs, as ' because of the bending of the more flexible portion around the knobs, the i fabric would crack around them. 1 trucks, solid tires are used, but the use of the single tube tire has been entirely en-tirely abandoned. The double-lube, or as it would bettor bet-tor be termed, the tube and casing tire, - consist of two members: the tube, the purpose of which is to hold the air, but which has no strenglh, and would burst under te air pressure required, 'C it -were n reinforced by the cas- the valve, which is almost universally universal-ly used. 1-1 ere A is the bodv of t lie valve or the alve stem. B, including the spring and parts O, I', K, T. etc., is called the valve inside. The action of the valve is as follows: The screw O, by pressing the rubber washer P against the shoulder c of flic valve stem, will prevent the air leaking out of the side, while the fiance l of the |