The Iron Age 1937-09-23: Vol 140 Iss 13

FRITZ FRANK President VAN DEVENTER Editor Managing Editor Editor Emeritus Machinery Bditer Art Bditor Metallurgical Bditor Associate Editors Consulting Editor Washington Editor Resident District Editors Pittsburgh Chicago Cleveland Detroit Editorial Correspondents England Boston Hamburg, Germany Milwaukee San Francisco SANDERSON ROUNTREB, JR. Toronto, Ontario Birmingham Buffale Owned and Published CHILTON COMPANY Publication Offices Editorial and Chestnut and 56th Executive Offices Philadelphia, Pa. 239 West New York, N. Y. OFFICERS AND DIRECTORS MUSSELMAN, President FRITZ FRANK, Executive Vice-President STEVENS, Vice-President JOSEPH HILDRETH, GRIFFITHS, EVERIT TERHUNE, ERNEST HASTINGS, WILLIAM BARBER, Treasurer JOHN BLAIR MOFFETT, Secretary JOHN VAN DEVENTER JULIAN CHASE THOMAS KANE CHARLES BAUR CARROLL BUZBY BAUR, General Advertising Manager DIX, Manager Reader Service Member, Andit Bureau Circulations Member, Associated Business Papers Indexed the Arts Index. Published every Thursday. Subscrip- tion Price: United States and Pos- sessions, Mexico. $6.00 Can- ada, $8.50 Foreign, $12.00 year. Single copy, cents. Cable Address, ADVERTISING Emerson Findley, 621 Union Cleveland B. L. Herman, Chilten Bidg., Chestnut & 56th Sts., Philadelnhia. Pa. H. K. Hottenstein, $02 O’is Bidg., Chicago Leonard, 239 39th New York Peiree Lewis, 7316 Woodward Ave.. Detroit Cc. H. Ober, 239 W. 39th St.. New York W. B. Robinson, 428 Park Bidg., Pittsburgh D. C. Warren, P. 0. Box $1, Hartford, Coan. RON Contents SEPTEMBER 23, 1937 Economic Experimenters Machine Tools Railroad Repair Shops Plastics Are Growing .............. Driving Clutches and Cut-Off Couplings Charts for Determining Weights Pipes and Rods Unusual Cantilever Ore Bridge Automotive Industry Statistics Metal-Working Activity Rate Activity Capital Goods Washington News NEWS CONTENTS Plant Expansion and Equipment Buying Just Between Two Copyright Chilton Company from press shops continually verify the excellence Bethlehem cold-rolled sheets: drawing record has been excellent less scrap, good margin all sheets worked sat- isfactorily performance consistently This excellence part due the VisControl process for making steel. This exclusive development, used only Bethlehem, makes possible new high uniformity ductility. Com- bined with Bethlehem’s large and mod- ern cold-strip mill, the rigid inspections, the careful workmanship, VisControl has made possible the production sheets which materially reduce percentage failures. Uniformity Bethlehem cold-rolled sheets bettering production records everywhere this steel being used. Whether for automobiles, furniture, re- frigerators, other products, try these sheets. You will with the results. with BETHLEHEM ROLLED SHEETS i 4 | if q if 3 rif a 34—THE IRON AGE, September 23, 1937 P 4 > THE IRON AGE ... September 23, 1937 ESTABLISHED 1855 Vol. 140, No. Economic Experimenters XPERIMENTS economics are not new. They back the Garden Eden. Adam found himself placed agrarian economy. Like some our present Government dependents, did not care much for work. Adam was perfectly satisfied sit the shade palm tree and swap gossip with the lions, tigers and other inhabitants. When wanted meal, there was always bunch bananas hand awaiting his convenience. But not with his better half. Eve had that well developed bump curiosity which has marked the economic experimenter all ages. She was willing try anything once, even forbidden apple. was Eve's experiment with the apple that shifted the human race, much existed then, from agrarian industrial economy. For, thereafter, Adam had earn his living the sweat his brow. had work, having lost his mem- bership ticket the Paradise Association). Economic experiments have larger repercussions than ordinary mechanical phys- ical experiments. They affect nearly everybody. The scientist experimental engineer restricts his experimenting small lots quantities. The economic experimenter does not try out his idea upon the few thousand inhabitants small island see works before putting into effect large scale. His unit hundred million more human guinea pigs. Perhaps that the reason why for the last 400 years, until the post-World War Russian experiment, there has been practically attempt anywhere compel economic shifts government fiat. light laughing matter hold the present and future destinies millions upon millions one's hands. Rulers have approached such responsibilities the past with fear, trembling and prayer. Economic changes there have been, and plenty them, but not mandate ukase. They have come through natural evolution which reveals need through government encouragement subsidies, but they have been permissive and not man- datory. Perhaps the reason why the world has the today that too many human guinea pigs recently have been undergoing, willy nilly, many assorted economic in- oculations command and masse the hands experimenters willing try any- thing once. | HEN making study the equipment railroad machine shops, little com- parison should made with in- dustrial shops where products are made for sale. The railroads are selling transportation, and their machine shops are for the repair and maintenance the equipment needed supply the transporta- tion. The efficiency the equip- ment the railroad shops must, therefore, studied entirely from this viewpoint. While increas- ing number replacement parts are being manufactured pro- duction basis, many operations still remain which cannot classi- fied. The main objective classi- fied repair shop return the locomotives service quickly 36—THE IRON AGE, September 23, 1937 achine Tools Railroad possible. They are earning money while undergoing repairs and reconditioning. impor- tant that the machine tools modern and efficient perform their various duties and keep pace with the erecting gang. The vari- ous units must repaired and reconditioned and reach the erect- ing floor the proper time. Machine Tools Available for Modern Locomotives Modern machine tools for rail- road shops have been developed with increased weight and power keep pace with the heavier lo- comotives now service. Many repair shops are inefficient today because the modern locomotives are being reconditioned with equip- ment designed for operations the lighter power units years ago. Néw locomotives were pur- chased many railroads without giving any consideration the proper equipment for their repair and maintenance. poor economy use old machine tools operations re- quiring high degree accuracy. Many parts not accurately ma- chined only lead expensive fail- ures. Modern tools first-class condition should used such operations. the other hand, there are many tools suitable for use railroad shops which would considered useless industrial shops. Such machines may not have regular operator and are only used certain jobs not re- quiring particular work. The ex- | i | + penditure for new tools these cases would not justified. There has been great improve- ment during recent years the material used for cutting tools. The power, weight and rigidity modern machine tools have been greatly increased enable the machines take advantage these improvements. Modern de- sign has done much decrease the time and labor required operate the machines. Ease control has been the watchword modern de- sign. Special-purpose machines for var- ious railroad operations have been developed greatly facilitate rail- road repairs. The accuracy the operations performed many these machines direct result the accurecy built into the ma- chine and does not depend upon the skill the operator. For ex- ample, the new quartering and turning assures that the crankpins the exact quarter and ac- curately positioned for the stroke the engine. Also, that they will Repair Shops turned without taper, with their axes and the axis the axle accurate parallelism. Materials Handling Methods Important The efficiency operations repair shop greatly dependent upon the arrangement and grouping the various ma- chine tools and the methods handling the material through the shop. evident that greater economy will result from arrang- ing the machines that loco- motive part will moved from one another without back travel until all machining operations are completed. This saves time and labor, and reduces long-crane hauls minimum. Considerable sav- ing can also effected local- izing detailed repair work into sub-departments. The importance adequate facilities must not over- looked. The departments which the parts are heavy and awkward handle are particularly depen- dent upon electric traveling cranes. Much time lost when single crane tied one end the bay and needed the other. Jib cranes and hoists should provided for handling parts and off the machine tools, that the main traveling cranes will not tied serving individual tools but will kept free for general distribution materials and parts. Many classified repair shops are without adequately equipped tool rooms and suffer from the lack proper tools, gages, jigs and fix- tures. Roundhouse Repair Equipment Suitable and adequate repair equipment the various round- houses great importance perform the running repairs neces- sary locomotives pe- When roundhouse iso- lated point does not have full equipment, necessary tie the locomotive while the parts are shipped another point for repair operations. The investment necessary for suitable repair equipment the roundhouse small item comparison the loss from idle locomotives awaiting their parts. Classified Shop Schedules Upset Roundhouse Repair Work Unless their equipment excess the requirements for classified repairs, the repair work the parts sent from the various roundhouses often disrupts the schedule repairs the classi- fied shops. There single ele- ment which can completely upset shop schedules and increase classified repair costs the re- moval such work machines take care running repairs and then the replacing the classified work. For this reason just important have full running repair facilities roundhouse adjacent classi- MeCALL riods general classified repairs. has been the practice many railroads transfer older equip- ment from the classified shops the various roundhouses, the roundhouse obtaining the equip- ment being the one whose foreman happened making the most noise about his requirements that particular time. Such prac- tice has resulted much anti- quated equipment the round- houses. There are some machine tools, when not too old, that will perform satisfactorily when trans- ferred roundhouse, but all other equipment should modern, the roundhouse shop plays important role keeping the loco- motive service and increasing the mileage between classified re- pairs. ° fied repair shop have them point. Locomotives tied over the pits roundhouse while parts are being machined distant shop valuable space which may needed any time. The demands for running repair work cannot accurately anticipated, scheduled provided for ad- vance. the number tives handled roundhouse in- creases, the demands facilities will increase faster rate the chance for simultaneous comes greater. order prevent expensive operating delay, conges- tion yards and serious financial loss, adequate equipment for the (CONTINUED PAGE 124) THE IRON AGE, September 23, — | ¢ 4 od | | EPLACING plywood, this plastic case almost foot and half long, encloses pounds electrical equipment. It’s electro-cardiograph used heart diagnoses, called the Sanborn Cardiette. LEFT ARNHAM Dispenser Co. molds this entire tomato juice dispenser from phenolic plastics. Condensation from ice made the use water- resistant scarlet Durez imperative. 38—THE IRON AGE, September 23, 1937 ABOVE OLDED phenolic radio cabinets have all but displaced veneered wood cases the table radio field, due greater design possibilities and re- sistance dampness and humidity. Pilot’s, above, shows the trend toward larger and stronger moldings. LEFT RESIST rusting and chipping, and because plas- tics are warm the touch, Art Chrome Corp. picks black phenolic material for this hair rinse tray. BELOW RAYS for refrigerator crispers and coffee-sets are recent plastic innovations, where durability sur- face counts. Molds are stacked the press, boost- ing output. | Are Growing men who tend strictly business are apt to- day think plastics terms their pre-depression uses, which ran mostly insulators and small elec- trical parts. sure, small parts still consume the bulk plastics out- put, but these synthetic materials are broadening their applications into larger structural parts way con- nected with insulation. Strengths plastics have improved considerably since 1930, but more im- portant the greater knowledge among designers how design stronger moldings. Telephone hand- set bases are now being molded phenolic plastics, and the higher strength materials are not even re- quired, because inside fillets and ribs are said give adequate strength resist the standard test three-foot drop without cracking. The foot-and- half-high radio cabinet, shown oppo- site, supports the weight man standing squarely top. these pages present review recent developments the field molded phenolic plastics. —Photographs General Plastics’ Durez ABOVE EICH Electric’s Reid says, “The modern Phone couldn’t made anything but plastics.” a ABOVE LOCK cases are older plastic plications, ideal because multiple cavities can grouped one mold, producing finished cases the Above, Telechron’s direct-reader. LEFT ECORDING instruments, espe- cially for corrosive industrial at- mospheres, find plastic cases rust-proof, resistant steam, acids, alkalies. Shapes, surface treatments and colors can varied. BELOW OOVER CO. used fourteen plas- tic parts and brighten its new One-Fifty cleaner, phe- nolic plastics being extremely light weight. Best new use was chip- proof plastic hood which eliminated costly factory refinishing chigped and scratched demonstrators. — 4 4 4 THE IRON AGE, September 23, 1937—39 Driving Clutches and Cut- hensive series the Economics Industrial Power Transmission CLUTCHES form means quickly con- necting disconnect- ing one rotating mem- ber drive from another, making possible stop ma- chine, group machines, with- out shutting down the prime mover. Clutches serve two distinct pur- poses; they permit driving pulley disengaged will, they serve connect disconnect two abutting transmission shafts desired. the latter case they are commonly known couplings.” Clutch mechanisms may broadly classified, design and con- struction, under seven heads: Positive, jaw clutches Expanding ring clutches Contracting band clutches Cone clutches Dise clutches Free-wheeling clutches Magnetic clutches. all these types except the first, friction, the grip one plain surface another under external pressure, the medium whereby the driving member temporarily coupled the driven member. 40—THE IRON AGE, September 23, 1937 Couplings FRANCIS JURASCHEK Consulting Editor, The Iron Age ° the positive, jaw clutch type, however, male and female hub members interlock positively, and friction-grip forms part the coupling. Three general forms positive type clutches are available. the first, sliding sleeve mounted free- the transmission shaft carries one end hub cut with alternat- ing lugs and lug-pockets its face. similarly cut hub keyed the shaft position adjoining the sleeve. sleeve moved longitudinally the shaft that the lugs and lug-pockets fit the corresponding lug-pockets and lugs the fixed hub, interlocking results, and the sleeve (with its pulley, sprocket gear) caused rotate with the shaft. With- drawing the sleeve permits the shaft rotate freely while the sleeve remains rest. Used cut-off coupling, the sleeve fast- ened one shaft and the hub the other. second form the hub faces are cut into spiral, opposing jaws, that when rotating one direc- tion they interlock positively, but when rotating the other direc- tion they slide apart and release the engagement. third form external gear one hub enters and meshes with the teeth internal gear the other hub. this form friction ring may introduced make preliminary sliding engagement order bring the driven hub the speed the driving hub and thus effect final gear meshing without damage the teeth. Once the gears are mesh the engage- ment positive, and the friction surfaces not carry any part the load. Positive clutches their widest application shafts rotat- ing slow speeds; that is, from 200 r.p.m. When used shaft cut-off couplings and the engagement may made with both shafts rest this limitation does not apply strictly. However, not common practice operate the square-jawed type clutch speeds over surface feet per minute (measured the mean diameter the jaw-teeth), the spiral-jawed type speeds over 200 surface feet per minute (cor- responding roughly 300 r.p.m. for outside diameter clutch). Expanding Ring Clutches One the oldest forms fric- tion clutch, the expanding ring type, has single pair friction surfaces the form annular rings, concentric with the shaft. operates somewhat like internal expanding brake automobile wheel. arrangement causes friction-surfaced ring expand within encircling fric- tion-surfaced band fixed the driven member, whereupon the two if 4 } iq if 5 | it a ‘ 4 { | | | | | i 4 | 4 — surfaces grip and rotate together. Reverse action the toggles causes the inner ring contract, break- ing the grip and permitting the in- ner member remain rest while the outer continues turn. The design makes necessary have large diameter clutch transmit even fair amounts power, compensate for the small surface width the expanding ring. The high surface speeds resulting from large diameter clutches cause rapid wear the friction surfaces when engaging and disengaging; conse- quently this form friction clutch only used for the transmission low powers low medium Contracting Band Clutches This type the opposite the expanding ring type operation, although the design quite dif- ferent. The surface ring generally quite wide, and con- siderably less diameter than the expanding ring type just described. This ring consequently called “drum.” The outer friction surface made the form wide split shoe, almost completely encircling the inner drum. toggle causes this band contract over the drum and grip tightly the en- gaged position, causes ex- Table Service Classifications CLASS A—Uniform Load AGITATORS for liquids li- quid stocks. BLOWERS, centrifugal. CONVEYORS, uniformly load- fed, except re- ciprocating. COOKERS, cereal. GENERATORS. ELEVATORS, BUCKET, uni- formly loaded fed, all FEEDERS, disc type. KETTLES, brew. LINE SHAFTS, light duty. MACHINES, all types with uni- form loads, non-reversing. PUMPS, centrifugal. SCREENS, rotary, uniformly fed. COMPRESSORS, centrifugal, reciprocating more cyl- linders) CONVEYORS, not uniformly loaded fed, all types except reciprocating. ELEVATORS, BUCKET, not uniformly loaded fed. FEEDERS (under bins, hop- pers, etc.) apron, belt, screw, rotary vane. GRINDERS. HOISTS. KILNS, DRYERS, rotary. LINE SHAFTS, heavy service. MACHINES, all types with moderate pulsating load, non- reversing. MILLS, ball, pebble, tube. PUMPS, reciprocating BEATERS more cylinders). Table Service Factors CLASS B—Moderate Shock Load CLASS C—Heavy Shock BOAT PROPELLERS COMPRESSORS, reciprocat- ing (single cylinder). CONVEYORS, reciprocating. CRUSHERS. FEEDERS, reciprocating. MACHINES, all types with severe impact loads speed variations and reversing types MILLS, hammer, rolling. Steam Engine 4,6 Source Power Gas Oil AClass Service Type Load Electric Motor cyl. Gasoline Steam Turbine Engine Engine Table - d Fic. handy guide for the selection friction clutches normal requirements. the selection friction clutch proper size and capacity for any service, ample margin capacity over actual requirements the best assurance long life and low maintenance cost. Clutches are always rated nominal horsepower capacity for smooth loads and uniform power flow, Class Table above. When the power source does not provide uniform torque the driven mechanism does not present uniform load, the normal power requirement should multiplied the service factor shown Table obtain conservative clutch selection. Unusual service conditions, including speeds over 600 and clutch engagements averaging two minutes less, require special engineering recommendations. (Tables courtesy Co.) Spiral Jaw Clutches applied Sprocket Wheels Left-Hand Clutch Clutch Drives Wheel Left-Hand Clutch Right-Hand Clutch Drives Clutch Fic. 2—Spiral jaw clutches applied sprocket wheels. THE IRON AGE, September 23, ii pand the disengaged position, permitting the drum remain rest while the driving member turns. Neither the expanding ring nor the contracting band types clutch are commonly used shaft cut-off couplings; generally they are made integral part the pulley, sprocket gear which the shaft. Cone Clutches Cone clutches are midway be- tween the ring band type fric- tion clutches (in which the friction surfaces are parallel and con- SHAFT AND KEY also the double and triple dry-plate clutches, developed solely permit the single-plate principle em- ployed for larger powers without increasing the clutch diameter point where centrifugal force be- comes serious disadvantage) has bell housing containing heavy interior flange which friction blocks, usually hard maple asbestos, are set radially. This bell housing fastened the driven shaft pulley sleeve. The driving shaft carries hub terminating flat, circular disk. When, means toggle arrangement, this disk pressed firmly against the friction flange the bell hous- Fic. 3—Diagram the Link Belt double cone type friction clutch shaft coupling. centric with the shaft), and the dise plate type clutches (in which the friction surfaces are plane right angles with the shaft axis). the single cone clutch, cone-shaped friction sur- face the sliding member engages with similar, oppositely placed friction surface the fixed mem- ber. the double cone type, two opposed conical surfaces the fixed member are gripped corresponding opposite surfaces coming together the sliding member. Cone clutches are not commonly used for large power ap- plications for high speeds. Disk Clutches The disk friction clutch far the most popular type use today. great extent, large diameter single plate clutches are preferred for lineshafting use. For machine tools and general machinery appli- cations the large single plate clutch rapidly giving way the small, compact multiple disk clutch, either dry running oil. The single dry-plate clutch (in which category must included 42—THE IRON AGE, September 23, 1937 ing, friction-grip coupling ef- fected. The grip not completed instantly; some slip always occurs the driven shaft sleeve gradually brought the speed the driving shaft. reverse action the toggles backs the disc away from the friction flange far enough eliminate all possibility drag. The standard automobile clutch single plate friction clutch normally held engagement springs. Depressing the clutch pedal momentarily disengages the disk and friction flange surfaces. Adjustments are seldom required since the springs tend take inequalities wear. industrial practice the clutch remains en- gaged disengaged until the posi- tion the shifter lever manually changed, and there possibil- ity securing the automatic ad- justments inherent the automo- tive clutch. Industrial single plate (or dou- ble triple plate) dry-disc clutches, arranged sleeve clutches cut-off couplings, range size from inches diameter, for capacities from 1000 hp. 100 For use where abrasive substances, lint, inflammable vapors are present, similar type clutch totally en- closed Sizes range with capacities for the single plate model ranging from 100 hp. 100 r.p.m., and from 200 hp. for the double plate model. The multiple clutch has un- dergone many vicissitudes. one time was made with more plates discs thin steel, run- ning oil. was never used ex- tensively for industrial lineshaft work, because the difficulty completely separating the plates when the axial pressure was re- moved, resulting excessive drag, and because was dis- sipate the heat produced bring- ing the driven load the speed the driving shaft—particularly when the clutch be- ing engaged and disengaged. How- ever, the theory overcoming the low coefficient friction smooth steel steel, running oil, the use large number plates series, with corresponding low axial pressure exerted, combined with the relatively small diameter the resulting clutch, and the con- sequent limitations power loss due the centrifugal effect large mass rotating high speed, was intriguing that equipment manufacturers kept experiment- ing boldly. The results those ex- periments have yielded new types multiple disc clutches, both wet and dry, which caused veritable landslide their favor regards machine tool and general machinery applica- tions. For machine tool work espe- cially there has been developed small, compact clutch with many hardened steel discs running high speed bath oil, giving surprisingly small space large power-transmitting capacity, flexi- bility, sensitiveness and complete freedom from attention any kind other than that required keep the oil level constant. Various types are now available for shaft sizes from 9/16 in. di- ameter, with capacities from hp. 500 r.p.m. Free-Wheeling Clutches Two purposes are served the free-wheeling clutch: Two dif- ferent pieces equipment may operated intermittently from one ig if | | | | | | | | i 4 4 | | | i prime mover, Two prime mon load that either prime mover may stepped without af- fecting the operation the other. Whenever the driving shaft such \ | q a ABOVE 4—The Conway single plate friction clutch applied sprocket wheel. RIGHT 5—The Conway overload release clutch automatically cuts out the drive when condition occurs. clutch tends rotate faster than the driven, the clutch mechanism engages, and causes the driven member pull into step. When- ever the driven member tends rotate faster than the driver, how- ever, the clutch “free-wheels,” and power longer applied the driving shaft comes rest even though the driven member con- tinues run because power ap- plied from another point. Further- more, where intermittent power im- pulses are transmitted heavy flywheel, such clutch will engage only when the power impulses are produced, and will free-wheel dur- ing the periods when the flywheel completes the operating cycle. Slow speed free-wheeling clutches are generally the ratchet type. When the shaft drives, the ratchets engage the teeth ring gear, but when the driven member rotates faster than the driving shaft, the ratchets trail over the gear teeth. Higher speed clutches are generally the eccen- tric cam type, sliding friction springs throwing these cams mesh with gear the driving position, and out mesh the free-wheeling position. Clutch Quills pulley mounted clutch sleeve develops stresses the shaft beyond the bearing exactly like those cantilever bridge. the load the pulley great advisable give bearing support the pulley sleeve independently transmission shaft runs without contact. When the clutch hub the transmission shaft and that the quill are engagement, the quill pulley, with its load, rotates. When the clutch disengaged, the transmission shaft rotates freely within the quill, without having support the load the quill, its pulley and the Clutch Service Characteristics clutch for any given situation re- quires the consideration certain fundamental service conditions. There such thing uni- versal clutch—that is, one type clutch equally well adapted all conditions use. Some are excel- lent low speeds but have grave defects high speeds. The num- ber engagements per day, per hour, per minute has decided influence the type selected. After all, not economic use high-priced clutch developed for heavy loads and high speeds, for use where these conditions are not encountered. Some clutches are satisfactory clean atmospheres but should not used where dust, abrasive grit, lint explosive fumes are present. Certain types, with projecting points, must pro- tected reduce the safety haz- ards when used common loca- tions. Finally, power capacity require- ments are invariably the most im- portant factors. Starting torque ° ° ° the shaft supports. This com- must considered, maximum monly done means quill, which simply extended clutch sleeve the form hollow shaft adequately supported its own bearings, and through which the loads, and speed operation. The power transmitting capacity any friction clutch falls off rapidly low speeds compared with its capacity high speeds; but there THE IRON AGE, September 23, 1937—43 ° ° 4 7 4 are natural limitations the ef- fective speed operation any type. Only one who thoroughly familiar with clutch design, con- struction and application com- petent decide what size clutch economically best for given job. Magnetic Clutches Industrial power transmission has found valuable ally the magnetic clutch. machine op- ‘erations have grown heavier, haz- ards have continued multiply for the operator. has become in- creasingly necessary for manage- ment provide accurate, speedy and positive control all times. Safety for the workman, and pro- tection for both machines and the materials worked upon demands that such controls make possible the instant stopping massive moving parts, within fraction field that the magnetic clutch, and with the clutch-brake unit, have played important role. Essentially the magnetic clutch single multiple dise friction built-in electromagnet, through system control operated push buttons conveniently located. The magnet incorporated the driv- ing member disc, behind friction surface, and the driven dise friction-faced armature. Formerly, was the custom add most magnetic clutches shoe and band brake, provide positive mechan- ical braking safety feature and positive the driven machine should interruption the electrical circuit occur. Now, however, successful and positive- acting electromagnetic disc brake has been developed part the clutch mechanism, that declutch- ing and stopping are obtained simultaneously one operation. second and almost equally vital function the magnetic clutch lies its use high- torque starting device. Whenever heavy machinery, heavy line- shaft loads must started through clutch mechanical design, the load acceleration must controlled manually the operator. the clutch thrown too slowly great deal heat will gener- ated between the friction surfaces before they are finally brought condition positive grip, and ex- cessive clutch wear results, requir- ing constant adjustment. the other hand, the clutch thrown 44—THE IRON AGE, September 23, 1937 too rapidly the friction surfaces either grip instantly, causing heavy stresses the machines and shafts, often causing the motor stall breakage occur, the friction surfaces slip under great pressure, causing the generation great deal heat, and excessive wear. But with the magnetic clutch the engagement the friction surfaces controlled automatically the flowing the clutch magnetical- engaged and the brake mag- netically disengaged. the instant the circuit broken the magnetic attraction both parts ceases, and the clutch mechanically disen- gaged while the brake mechani- set. The magnetic clutch, either with without the magnetic dise brake, has been used very successfully be- i Fic. in. Dodge split friction clutch installed overhead lineshaft. slip the magnet and its arma- ture; the grip gradually in- creased the magnet builds its hold the armature until finally, the speed the driven member becomes approximately the same that the driving member, the friction grip becomes positive. one well-known clutch and brake combination the design both parts similar, but the operation reversed. The clutch magnetically engaged, and mechanically disengaged through the operation positive-acting springs which come into play when the electrical circuit broken and the magnetic attraction ceases; the brake normally set through the action similar springs, the pres- sure which overcome the magnet when the electrical circuit closed. Thus, when the current tween motor having “across-the- line” starting characteristics and high starting torque machine, either directly connected con- nected through reduction gear. likewise coming into extensive use integrally built-in clutch machine, and for general clutch service lineshafting. High Starting Torque Mention should “made here that, addition the mechanical- actuated friction clutches which require manual control under high starting-torque conditions oper- ation, and the magnetic clutch which provides automatic control under similar conditions, there has been developed mechanical clutch which provides automatic control through the action centrifugal force. This clutch serves the dou- if } | | | | I | | | , q ble purpose providing high starting-torque coupling and somewhat flexible connection. design combines certain features the multiple dise wet-plate type and the double friction cone. op- eration use made the shear stresses developed oil films be- tween resilient friction rings the absorb the heat generated the frictional contacts. Clutch Sleeves According the conditions service clutch sleeves six dif- ferent types may used: 1—A bored and reamed cast iron sleeve adapted for moderate pow- 8—Large brake press equipped with Dodge Diamond friction clutch flywheel. slippage medium. starting this slippage high because the conical rings are separated thick film oil. speed increases the in- ner rings are thrown outwards centrifugal force against the outer rings, reducing the thickness the interposed oil film, until slippage ceases and metal metal contact established. .Since the rings are er, shaft speeds 250 r.p.m., belting in. width, and where clutch runs the engaged most the time. Lubrica- tion with grease. 2—A cast iron sleeve lined with babbitt metal adapted for mode- rate power, shaft speeds 350 r.p.m., belting in. width, and where clutch runs the en- 9—Stearns 5-in. combination magnetic clutch and brake unit. flexible and freely co-adjustable, all portions the contacting surfaces are brought equally into play. The oil protects these surfaces from wear, and also acts coolant gaged position most the time. Lubrication with grease. 3—A cast iron sleeve equipped with loose, split bronze bushing provided with radial holes through its walls permit grease lubricant flow from channel the sleeve proper the shaft adapted for heavy power, shaft speeds 500 r.p.m., belting in. width, and where clutch runs disengaged for moderate periods. 4—A cast iron sleeve equipped with tight bronze bushing pro- vided with capillary plugs feeding oil from chamber the sleeve proper the shaft adapted for moderate power, shaft speeds 600 r.p.m., belting in. width, and where clutch disen- gaged for long periods. 5—A cast iron sleeve equipped with bronze bushings into which are fitted graphite rings requires lubrication after the initial oil- ing and adapted for moderate power, shaft speeds 400 r.p.m., belting in. width, and where clutch runs disengaged for moderate periods. 6—A cast iron sleeve equipped with internal ball roller bear- ings, using soft grease, adapted for moderate power, shaft speeds 1800 r.p.m., belting any width, and where clutch runs dis- engaged for long periods. Welding Wire Output Growing ORE than 140,000,000 Ib. steel welding wire were pro- duced during 1936, enough make strong weld 134,000 long, estimated the Ameri- can Iron and Steel Institute. The total production steel welding wire 1936 represented increase about 480 per cent over the 1932 output 24,150,000 which compares with in- crease about 250 per cent over the same period the production steel ingots. consequence, the amount welding wire pro- duced per ton ingot increased from 1.79 Ib. per ton 1932 2.95 Ib. last year. The growth welding recent years has presented new and growing market for products the steel industry that many articles which are now produced welding together steel sheets, plates, bars and other rolled prod- ucts, were formerly made other means. THE AGE, September 23, 3.0 Zinc 2.5 Cast Brass Nickel Copper) Silver 2.0 Gold Platinum 1.0 1.0 0.5 0.5 Inside Outside Lbs. per Diameter Diameter Stee! (B) CHART 46—THE IRON AGE, September 23, 1937 Paper Rubber Mica Lbs. per Feet per ft. 1000 Ibs. (E) (F) { } 5 j | 4 | 2.5 100 4 | i j ae } / | THE weight any pipe round rod can determined instantly use the accompany- ing charts. believed that these charts employ new mathematical principal, heretofore unknown— that subtracting diameters obtain weights directly. CHART use Chart No. place ruler straight edge across the inside diameter scale and the out- side diameter scale the pipe question. The weight per ft. the pipe will shown directly where the ruler crosses scale the desired pipe steel. the pipe some other metal than steel, the ruler should swung around the point found scale through the index mark scale for the material desired. Where the ruler crosses scale the Ib. per ft. weight the pipe. The reciprocal this figure the number ft. 1000 Ib. pipe will noted that the index mark for brass covers wide space scale This because the exact weight the alloy brass can- not determined until the ratio copper and zinc known. All the possible combinations brass fall within the space scale within the two marks. will also noted there index mark scale for steel. not necessary use this mark for determining weights steel pipe inasmuch these weights can read directly scale However, the steel index mark provided order secure read- ings scale should these desired. matter fact the direct readings scale are not taken, but the index mark for steel used, will found that scale All charts copyrighted Eugene Caldwell. ° ° EUGENE CALDWELL* General Manager, Wrought Washer Mig. Co., Milwaukee ° reads exactly the same scale for the steel index mark. find the weight solid round rod wire, the ruler should placed zero scale indi- inside diameter. order read scale directly per ft., the inside and outside diameters scales and should read inches. However, di- ameters are feet, the answer scale must multiplied 144. For exceptionally small pipe rods the values scales and words the both scales can considered one. this case two decimal places must pointed off the left the answer ob- tained scales and and two decimal places added the right For example, suppose the weight pipe in. o.d. and in. i.d. desired. The ruler placed across This gives answer per ft. scale However, inasmuch one decimal place was added each the outside and inside di- ameters, two decimal places must pointed off the answer, mak- ing the correct answer 0.52 per ft. Two decimal places must added the answer ft. per 1000 Ib. scale making the correct answer 1900 ft. per 1000 Ib. For large pipe rods the values scales and can increased times. other words the both scales can considered 100. this case two decimal places must added the right the answer obtained scales and and two decimal places pointed off the left scale For example, suppose the weight pipe in. o.d. and in. i.d. desired. The ruler placed per ft. However, in- asmuch one decimal place was dropped off each the outside and inside diameters, places must added the answer, making the correct answer 5200 Ib. per ft. Two decimal places must pointed off the left the answer ft. per 1000 ib. found scale making the correct answer 0.19 ft. per 1000 Ib. Care should taken use the same units for both scale and scale For instance the weight pipe in. outside diameter and in. inside diameter can- not found placing rule The answer obtained would bear mathematical relation the correct answer. CHART Following Page Chart will find the weight practically any pipe within very THE IRON AGE, September 23, 1937—47 ° | | | close limits accuracy regardless how large how small, simply described. However, for certain range diameters pipe some accuracy Inside Outside Diameter Diameter (A) (B) 48—THE IRON AGE, September 23, 1937 sacrificed. This range where the outside diameter greater than in. and the inside diameter less than in. take care this range Chart (below) has been provided. For example, suppose the weight desired pipe 2.5 in. out- side diameter and in. inside diameter. The values scales and Chart cannot reduced 1/10 for the reasons previously described. Nevertheless the values read directly Chart II, 320- 100 300 aper 280- Fibre 260 240 Mica 220 120 200 180 Zinc Cast 160 Bras = Nicke/ 18 Bronze 140 120 220 Gold Platinum 240 260 280 300 320 Lbs. per ft. Lbs. per Steel per ft. (c) (E) (F) CHART j q t ba, f } | j } if if | | | . 4 3 the answer being found 16.2 lb. per ft. Where both outside and inside diameters are below one in., the weight can found directly Chart using 1/10th the values Chart both with equal accuracy. The values scales and Chart can increased decreased exactly the same manner previously described for Chart selecting the correct combination Chart II, the Outside Diameter (A) weight any pipe can found with extreme accuracy. CHART Seamless tubing usually desig- nated the outside diameter and the wall thickness. course the inside diameter can found subtracting twice the wall thick- ness from the outside diameter. Then the weight can found using Charts Nos. and II. Lbs. per ft. Steel CHART Cast Iron However, this not necessary when Chart III used. ruler straight edge placed across the outside diameter scale and the wall thickness the curved crosses scale the cor- rect value the weight Ib. per ft. per ft. the outside diameter and wall thickness must taken inches. However, the same varia- 200 190 180 170 160 150 140 130 120 Aluminum Rubber 100 Lbs.per per Foot 1000 Ibs. (E) THE IRON AGE, September 23, 4 8 40 | Gold 4 Bronze Copper! 100 Stee/ | 120 160 180 190 | | tions for very small pipe very large pipe previously described for Chart No. apply equally Chart No. III. The weight solid rod any outside diameter can found placing the ruler tangent the curved scale will seen that from any outside diameter tangent the curved scale touches scale half the outside diameter, inasmuch this the 2.0 0.5 Outside Diameter IRON AGE, September 23, 1937 value necessary equal the inside diameter. will also seen that for any pipe the ruler passes through two values wall thickness the curved scale one greater than half the outside diameter and the other less than half the inside di- ameter. The former only interest mathematically and should disregarded. The larger wall thickness (greater than half the outside diameter) gives the weight Lbs. per Steel CHART solid rod from which has been subtracted negative weight wall thickness extending beyond the center the rod itself—im- possible conception. CHART Chart has been provided give greater accuracy for certain ranges diameters and should used the same manner pre- viously described for Chart Lbs. per Foot ibs. ‘ if iJ So P< 1? Bronze 1.0 Mica- Aluminum Paper | Generat view ore bridge South works Steel Corp., looking east. Unusual Cantilever Ore Bridge for Carnegie-lllinois South Works handling bridge No. located the north vessel dock for blast furnaces Chicago South works the Steel Corp., has recently been completed. Due conditions, the bridges this dock are cantilever structures rather unusual dimensions. Bridge No. traveling crane 523 ft. in. long operating 20- gross ton (45,000 Ib.) ore bucket. The usual capacity the buckets tons. The south cantilever 181 ft. long, the center span 188 ft. and the north cantilever 155 ft. long: The base rails trolley ft. above base rails trucks. The are spaced ft. cen- ters and the base the towers ft. centers. The towers the bridge are mounted turntables with expansion rollers one tower and the whole assembly carried two trucks spaced 188 ft. apart, each having spring-supported wheels and travels standard gage tracks. The height from the base rail top chord the bridge ft. The ore bucket operates maximum speed 175 ft. min.; the trolley speed 350 ft. and the bridge ft. min. The bridge also swings deg. either side its normal centerline, making possible move the extreme end one canti- lever 134 ft. ahead the other. The bridge electrically operated 230-volt direct and controlled one man located the trolley cage. The whole ture propelled four motors mounted the trucks, and the power transmitted all the wheels through double spur gear reducer units and two lines float- ing shafts connected with geared couplings worm gear speed re- ducers, which are fastened, al- ternate positions, the wheel axles. The motors are mounted, one each end both trucks. Each mo- tor drives axles and wheels, one-half the wheels under each truck. Two brakes are used for each unit, one applied the motor armature shaft and one the first spur gear shaft. The bridge equipped with eight spring set safety clamps each gripping the track rails with force 100,000 each. The safety clamps are op- erated with four separate motors and reduction gears mounted the top the trucks. guard against over-skewing, the bridge pro- vided with two automatic limit switches, one set for deg. and one for deg. either side the normal position the bridge. also provided with anemome- ters which shut off the current when the wind velocity exceeds miles hour. The trolley, cage and bucket unit traveling the full length the bridge, and loaded with ore this unit weighs about 330,000 carried ten spring-supported wheels and operated four mo- tors, two for the bucket and two for the trolley. The trolley pro- vided with magnetic rail sanders, automatic slowdown and stopping controls. The ends the bridge are also equipped with draft gear spring trolley bumpers compressing about Ib. before closing, and capable withstanding the im- pact, due full load and speed the trolley. The superstructure this bridge unique design. The heavy load the trolley unit produces high stresses the bridge due the long cantilevers. There are also considerable sway and torque stresses added when the bridge operated. The problem was design structure strong and rigid without too heavy for economical operation. High tensile steel was therefore used the truss members where saving weight could accom- plished, and the center center chords varied approximately with the intensity the stresses. The THE IRON AGE, September 23, | - bottom chord the trusses, being compression member, was placed the plane the track stringers, except for the five panels each tower, and held place the stringer bracing and cross trusses. “K” web system was adopted for the trusses because its more effi- cient distribution shearing stresses, and being short, adds the stiffness the bridge. The track stringers were made continuous over their supports prevent loose rivets their end connections and reduce the deform- ation the track. order provide more efficiency for sway and torque loads, two systems lateral bracing are used, one the top chord and one the middle intersection the truss diagonals, above the trolley clearance. The chord components the stresses the iower lateral system are trans- mitted through truss diagonals the top and bottom chords the bridge, and there cross brac- ing all panel points between the two systems, the bridge will resist torque stresses addition bet- ter distribution the lateral stresses, The bents the towers support- ing the bridge were figured two hinged arches because they are open crosswise from floor top trolley clearance. The tower legs are supported box-loading gird- ers. 52—THE IRON AGE, September 23, 1937 Each turntable assembly consists two cast steel bearing castings ft. long planed top and bottom for roller bearing. They are firmly braced and the assembly held place bronze bushed steel cast- ing placed over in. diam. pin which connected the truck girders below. The two expansion roller nests the south tower consist in. diam. bronze bushed rollers each held place angle frames. The maximum travel the south tower spaced ft. in. centers, with necessary cross girders, king pin frame and machinery supports. bottom lateral bracing was used, but cross frames each axle transmitted the lateral force horizontal girder placed top the trucks. This horizontal girder riveted the girder flanges and prevents dirt from accumulating the machinery below. provided with trap doors for access the machinery. was very important that the trucks true aline- ment, and they were therefore riv- right angles the track, due skewing the bridge about ft. The tower above held place for lateral motion four in. diam. rollers fastened the turn- table below and running the edge the track plates the load- ing girders above. The turntable roller nests both towers are ft. diam. each consisting 8-in. conical rollers ft. long. They are all bronze bushed and each roller ad- justable for radial position. They are held firmly place with channel frame connected the ro- tating centers with bronze bushed cast steel bearings the in. diam. king pins. The roller nests rest radial tread plates con- nected the cross girders the trucks. The main trucks are made structural steel, consisting two plate girders about ft. long and ORTH cantilever arm new ore bridge South works Carnegie- Steel Corp. eted complete the shop and the bottom flange milled for bear- ing the wheel castings. The holes for these castings were drilled wide iron templet insure the proper alinement the wheels and machinery. The bridge provided with 10-ton electric repair hoist and has stairs, walks and ladders all places necessary for operation and inspection the bridge. order prevent dirt and ore dust from accumulating, which would cause corrosion the steel, the bridge was designed and detailed make self-cleaning and all mem- bers accessible for painting. The general design this bridge was under the direction Brown, chief engineer South works and Hall, chief engineer the Steel Corp., Chicago district. The structural steel was fabricated and erected the American Bridge Co. said H t { +25 | | 4 | ia unusual and effective m