I
44 BILLET GRINDERS IN A ROW SERVED WITH 9 TYPE D
V i e w a b o v shows two of the nine Type D Clones serving the swing er booths shown at the right.
This picture, taken in one of America’s l e a d i n g s te e l m ills , shows a pronounced absence of dust all along an impressive line
up of swing frame grinders. Dust is drawn into the individual booths by the rapid flow of air induced by the Roto-Clones and precipitated by their rotating impellers — af the rate o f a ton a m onth per unit.
Roto-Clone has but one moving part and requires the very minim um of m aintenance; is extremely compact and can be placed close to the equipm ent it serves — with resulting sav
ings of space and piping and power. These advantages and its high dust separating efficiency have led the operators of this same plant to purchase 16 additional Roto-Clones for other dust collecting jobs. Consult with AAF engineers about your dust problem — there’s no obligation. Send for B ulletin 272.
D raw ing show s th e s im p le construction o f an A A F - enginecred s to i n g fra m e grinder b o o th .
NORTHROP BLACK W ID O W . The P-61, d e a d ly A rm y n ig h t fig h te r is acclaim ed the larg est fig h te r
ever b u ilt. It has the range o f a medium bom ber . . . the speed and clim b o f a pursuit ship.
:M I
Æ r> I
• X* ■PESCO U N IV A C FOR AIRCRAFT . . . new h y d ra u lic bra ke in te n sifier fo r planes up to 3 0 ,0 0 0 pounds in w e ig h t. C om pact, lig h tw e ig h t, co m p le te ly p a cka g e d and p ro te c te d . The PESCO U n iv a c installed in the b ra k in g system, gives the p ilo t a m ore responsive " f e e l" . This a d d e d ease and a ccuracy o f co n tro l is o f g re a t value in g ro u n d m aneuvering. The U n iv a c operates in conjunction w ith the PESCO A ir Pump. PESCO Products C om pany, 1 1 6 1 0 Euclid Avenue, C le ve la n d 6, O h io (D ivision B o rg -W a rn e r).
In A irc ra ft H yd rau lics, Fuel Pum ps, A ir Pum ps, R e la te d A c c e s s o rie s ...
P E R F O R M A N C E P O I N T S T O F I R S T
A M E R I C A N S E A M L E S S C O O L S X - R A Y T U B E S
En g i n e e r so f the M achlett Laboratories, at Spring
dale, Conn., w o rld ’s largest manufacturers o f X-ray tubes, have found in A m erican Seamless F lexib le M etal T ubing, the solu tion to the problem o f com pact, efficient c o o lin g for X -ray tubes.
A len gth o f bronze A m erican Seam less, w ith o u t th e customary w ire b raiding, is coiled around the inner surface of the c o o lin g jacket and connected to a w ater in let and ou tlet. T h e R oen tgen tube is th en inserted in the jacket and the ends sealed.
In operation, the tube is surrounded w ith o il w h ich absorbs the heat from the tube. C oolin g w ater, flo w in g through the A m erican Seamless c o il, rem oves the heat from the o il. As w ill be seen in the illustration, the flex ib ility o f this tu b in g per
m its it to conform perfectly to the cham ber w all.
Its seamless construction elim in ates leakage prob
lem s, w h ile its th in -w all, b ello w s-lik e construction
An a c ö n dA
AM ERICAN M ETAL HOSE BRA NCH OF T H E AM ERICAN BRASS COM PA NY • G eneral Offices: W aterbury SS, Coon Subsidiary oj Anaconda Copper M ining Company • In Canada: A N AC O N D A AM ERICAN BRASS LTD., N ew Toronto, u
BUY W A R B O N D S —S aved D o lla rs m e a n S a v e d Lives
assures h ig h efficiency in heat transfer, the bellows rings h avin g the effect o f c o o lin g fins.
If you have a p rob lem in conveying liquids, gases, steam or solids . . . isolatin g vibration . . . con n ectin g m o v in g parts or com pensating for mis
alignm ent, you w ill be interested in the w ide va
riety o f "A m erican” Products for these purposes.
Send for a copy o f B u lletin N o . SS-50.
N ote how American Seamless Flexible Metal T ubing is formed from a seamless, rustless, bronze tube. In most applications one or more bronze w ire braidings are added, depending on the service for w hich it is designed.
CRATES, w ith engines, paper, or machine tools w rapped in Fibreen, give dependable, low cost protection.
B A L E S ' o r b u n d le s o f a l l shapes and sizes are w rapped with F i br een. It’s pliable.
M a a u fe ic ù v i& a o£ s i s a l k r a f t , fib r e e n , s is a l- x , SISAITAPE AND COPPER-ARMORED SISALKRAFT
Send fo r a “ w o rk in g " sam ple o f Fibreen.
See how tough if isl Keep a few ro lls in v o u r's h ip p in g room .
electrodes. W hen the preset tim e inter
val has expired, an electronic timer causes the current to increase to the full welding value, whereupon another timer operates a control valve to adm it com
pressed air to tire lower part of the top air cylinder. This air pressure is also adjustable and is a low er value than that used in the top p art of this cylinder, thereby reducing the electrode pressure to a value suitable for welding. An
other electronic tim er permits an ad
justable time lapse between the instant the welding current proper is applied and the moment the pressure is reduced.
A third preset tim er then interrupts the welding current a t end of tire welding period and causes the back pressure of tine interrupting cylinder to he exhausted, restoring full pressure to the electrodes. This is called “recom
pression”. The high pressure thus pro
duced forges the weld while it is still hot,
The length of time the recompression pressure is applied is controlled by an
other timer. Thereafter, the electrodes automatically part and the work can be removed or moved ahead to the next welding position.
For making welds around a periphery or wherever a quantity is wanted in making an assembly, a “repeat” switch ou the control panel can be set to cause the entire welding cycle to repeat auto
matically after a certain lapse of time.
For example, a typical welding cycle may require a total of 6 seconds. The repeat timer then can be set for 3 sec
onds, which means that the operator has 3 seconds to position the work for
•he next weld. Total overall cycle is
•has 9 seconds p er weld. This scheme auows maximum output from the m a
chine as the entire w elding cycle then repeats automatically as long as the op
erator holds the foot pedal down.
rrecornpression” : Purpose of the mitial precompression pressure and the Preheating current is to bring the work Pieces closely together even though
•hey do not fit perfectly. This improves ce contact and thus prevents expul-
*®n. of molten metal which may occur at . beginning of current flow if full weld- mg current is applied w ithout this con
ditioning action.
As the surfaces come in perfect con- met and the preheating current flows, e interfaces of the pieces to be welded
“e softened somewhat. A t this point, u.eu curTent is increased to th e preset 1 e °^ value and after a preset time Pse, the welding pressure is reduced.
■g. 6 shows clearly the relation be- ween pressure and current throughout
•typical welding cycle. Note th at simul-ous with interruption of the weld- I lttCU>rT.ent:> a high forging pressure is l! by the electrodes to hot work vJ.U naetal, thus assuring sound Weldsme^ an<^ uniform high-strength
Material: As mentioned previ- sm y> USeu °f the proper variable-pres- fect ™ le-c™ t cycle enables per- hav»Ve ,° k® made in pieces th a t may considerable scale or rust on their