The Iron Age 1938-11-03: Vol 142 Iss 18

FRITZ FRANK President VAN DEVENTER Editor Managing Editor News Editor Editor Emeritus Machinery Editor Art Bditor Metallurgical Bditor Associate Editors JURASCHEK Consulting Editor Washington Editor MOFFETT Resident District Editors Pittsburgh Chicago Cleveland Editorial Correspondents London, England Cincinnati FRAZAR Boston Hamburg, Germany Milwaukee San Francisco SANDERSON ASA ROUNTREE, JR. Toronto, Ontario Birmingham ALLISON toy EDMONDS Newark, N. J. St. Lowis TURNER, JR. Buffalo NOVEMBER 1933 Speaking Monopoly Investigations Owned and Published Electric-Furnace Brazing Pre-Planning—Key Handling Economies Editorial and Executive Offices Fundamental Data for Pulley Selection Chestnut and 56th Sts., 239 West 39th Philadelphia, Pa. New York, Motor Controllers and Industrial Lighting Equipment Cc. A. MUSSELMAN, President FRITZ FRANK, Executive Vice-President International New Truck Plant FREDERIC STEVENS, GEORGE GRIFFITHS, Vice-President the Assembly Line EVERIT TERHUNE, Vice-President WILLIAM BARBER, Treasurer JOHN BLAIR MOFFETT, Secretary Washington News JOHN VAN DEVENTER, JULIAN CHASE, THOMAS KANE, CHARLES BAUR, THE NEWS BRIEF Weekly Ingot Operating Rate Rate Activity Capital Goods Cc. S. BAUR, General Advertising Manager DIX, Manager Reader Service Plant Expansion and Equipment Buying Member, Audit Bureau of Circulations Member, Associated Business Papers Indexed the Industrial Arts Index. Published every Thursday. Subscrip- tion Price: United States and Pos- sessions, Mexico, Cuba, $6.00; Can- ada, $8.50; Foreign, $12.00 a year. Single copy, 25 ee Sabie Address, Just Between Us Two ‘‘Tronage, N. Emerson Findley, 621 Union Bldg., Cleveland B. L. Herman, Chilton Bidg., Chestnut & 56th on ma | d Ad +i ™ 3 ottenstein, 802 Otis Bidg., Chicago H. E. Leonard, 239 W. 39th St., New York Peirce Lewis, 7310 Woodward Ave., Detroit C. H. Ober, 239 W. 39th St., New York W. B. Robinson, 428 Park Bldg., Pittsburgh . " D. C. Warren, P. 0. Box 81, Harftord, Conn. Copyright 1938 by Chilton Company (Inc.) Contents bethanized wire takes them its stride BETHANIZING has, effect, made new material available the manufacturer wire products: zinc-coated wire obtainable any coating weight that may called for service conditions. zinc-coated wire that will stand practically any fabricating operation without impairing the protective value the coating, regardless its weight. The electrolytic bethanizing process im- poses limit the weight zinc that can put wire. And two the unique char- acteristics the zinc applied this method —secure bonding the wire and high duc- the way for the drastic forming. Also great importance are the uniform thickness the coating and its extreme purity —99.99 per cent. These features assure maximum protection for the weight zinc. For whatever purpose you may use corro- sion-resisting wire, highly probable that bethanized wire will the job better more economically. Bethanized wire available soft low carbon and high carbon, basic- and acid-open-hearth steel grades wire. 28—THE IRON AGE, November 1938 : 7 7 7 q THE IRON AGE ... NOVEMBER 1938 ESTABLISHED 1855 Vol. 142, No. FTER the elections are out the way, there will political implications con- nected with it, are going have monopoly investigation. will conducted, are told, spirit fair-minded economic re- search and study and not campaign make newspaper headlines arouse class antagonism. That's fine. will all welcome the opportunity have the question settled whether bigness means badness. And find out whether there are powerful tions our midst that are exploiting the American consuming public. record both sides the question. will not just try show the bad things that some the big fellows may have done; will attempt also reveal the benefits the public that have come from bigness. this investigation approached and conducted fair way, will look and How big should company corporation permitted be? Big enough best serve the public interest. The interests the consuming public. When corporation any other organization gets beyond that point, getting too big. the Ford Motor Co. too big, the Steel Corp. American Tel. Tel., General Motors? The customers who are served such companies are the ones who could give the best evidence this point. Does the chap who steps the starter but- ton his car say himself: would get more for money the maker were limited employing 30,000 workers instead When you make long dis- tance call, does the thought occur you that you would get much better service went through independent systems instead through one? course, find that there some huge monopoly this country which has competition and therefore can and does raise the price its products its con- nc. sumers year after year, should something about it. And approaching this monopoly investigation spirit fairness, why not add hat government itself the list organizations under scrutiny? Government has now become the biggest business that have. has competition. And the one ble only big business which has been continuously raising the price its product its consumers. re. 7 = pa | ELECTRIC-FURNACE APILLARY some queer interesting tricks. For instance, two clean glass plates are immersed water and held closely together, the water wi!l wet the glass and rise column between the plates. How- ever, glass plates are immersed mercury wetting takes place, and the column liquid actually de- pressed below the surface the mer- cury. This illustrated Fig. and respectively. Water and mercury not behave the same, however, with all materials. For example, paraffin plates are im- mersed water, wetting results, and get depressed column the same with glass mercury. Also, amalgamated zinc plates are immersed mercury, good wetting results and the The smaller the gap between the the higher the Obviously, then, wish have liquid drawn between two surfaces, the liquid must wet the surfaces and the surfaces should very close one another. Capillary Attraction Furnace- Brazing Now what does all this have with electric-furnace brazing? Well, has been found that assemblies with clean surfaces are put together such fashion that their joints are snug and tight, brazing metal such copper applied near the joints will melt and wet the parent metal such steel and creep into the joints ca- pillary attraction, providing suitable controlled atmosphere maintained within the furnace other precau- tions are taken assure that the sur- faces will stay clean and free from oxides, further illustrate the principles capillary attraction, and its rela- tionship furnace brazing, Figs. and have been prepared, using India ink and strips glass spaced apart with different gaps, held po- sition with sealing wax. Fig. shows the relationship be- 30—THE IRON AGE, November 1938 near the joints brazed, the brazing metal first melts, then wets the parent metal and, finally, creeps into the joints capillary attrac- tion. Both the wetting and the creeping are basic phenomena; understanding them will far eliminate unsatisfac- tory results due improper sur- face preparation and improper fitting parts brazed. The present article the fourth the series Mr. Webber; the previous ones appeared THE IRON AGE Sept. Sept. 15, and Sept. 22, respectively. tween the wetting action and capillary attraction, and illustrates the desir- ability cleanliness metal surfaces within joints furnace brazed. and were pieces glass in. wide in. long, fastened pieces glass in. wide in. long. The strips glass. were held intimate contact throughout their length and immersed about in. India ink glass dish. The surfaces glass were chemi- cally cleaned remove oil films and assure good wetting, dipping the glass hot sulphuric acid and potas- sium dichromate, and rinsing dis- tilled water. The surfaces glass were fairly clean, but fingerprints were purposely impressed strips glass assure the presence oil films. The result obvious. the ink climbed high could uniformly wetting the glass. the ink climbed until reached prints, where wetting-became difficult. However, passages around the finger- prints were soon established, and the ink continued creep upward, going around small oil spots its way. pencil points the prints. the ink metal instead, the bond would not expected have maximum strength tightness where the surfaces were unclean. Why Uniform Fits Are Desirable Fig. 47, all pieces glass were chemically cleaned assure good wetting, but various gaps were used between the strips, show the effect the width the gap upon the height the ink column, and trate the desirability having form fits assemblies furnace brazed. The spacings the glass strips were follows: uniform contact (no gap) through- out. uniform gap 0.001 throughout. tapered gap from bottom top: Intimate contact (no gap) 0.020 in. gap top. tapered gap from left right: In- timate contact (no gap) left, 0.020 in. gap right. thin film the top the small glass strip. the ink climbed high its surface tension could draw through the uniform gap 0.001 in. the ink started climb from the bottom where there was gap, but soon reached level where the gap was wide that the surface ten- sion could pull higher. The width the gap this point was about 0.006 the ink rose short distance above its surface, between the glass strips which were touching the left and were 0.020 in. open the right, but soon stopped climbing along the right edge. continued climb along the left edge, however, until reached the top, and the height the column between the left edges adjusted itself the varying width the gap. Influence Gap Behavior Brazing Metals demonstrates that the dis- tance flow brazing metal Capillary Attraction and Wetting Action Explained pillary attraction directly depea- dent upon the width the gap, that the travel becomes greater the gap diminishes, and that uniform clean gap will give uniform bond. Also, that gap can become wide completely stop the flow, and that line contact non-uniform contact, rather than uniform contact through- out joint, will result non-uni- form bond. not illustrated here, but worthy consideration when study- Good wetting —_ Clean plates mercury Clean glass plates water Amalgamated zinc plates mercury Paraffin plates water 45—Capillary attraction does some interesting though queer tricks. Be- tween two clean glass plates immersed cause wetting. Immersed mercury, wetting takes place, and the column depressed. Paraffin plates water, however, will behave like glass mer- cury, and amalgamated zinc plates mercury, like glass water. ing the behavior brazing metals, that viscous pasty will bridge wider gaps than will those low viscosity. The temperature, na- ture gravity the liquid also are factors. Fig. and have been prepared illustrate exaggerated man- ner how the foregoing lating gaps within joints can ap- brazed products. WEBBER Industrial Department, General Electric Co., Schenectady, Fix. 48, shown lever with hub prepared for furnace braz- ing approved manner, with snug joints throughout. All corners are square that they fit closely and leave gaps. shown how the copper creeps uniformly through- out all joints and leaves fillets the extremities. Gap Principle Applied Brazed Products shows similar assembly with the exception that there gap one corner within the joint, which might occur due rounded corner one the parts. shows fillet which has formed this gap, and has prevented the brazing metal from bonding the rest the joint. shows how rounded corner the hub, caused blunt tool, can keep the shoulder from fitting snugly against the lever, and this way form gap which fillet occurs, ink between glass demonstrates capillary attraction and having faces within joints metal parts fur- shown chemically- clean glass; and fairly clean glass: note poor wetting fin- ger-printed area end the pencil point. The principle illustrated Fig. the assemblies prepared for electric- furnace brazing, and well keep mind. Actually, very small gaps sometimes are responsible for the in- terruption the flow the brazing metal, and the cause this interrup- tion not always apparent su- perficial examination. the brazing metal does not flow through the joint, gap one condition look for. Fig. illustrates the proper way provide sleeve fit typ- ical assembly having head pressed into shell. With this arrangement the brazing metal will make strong, tight, uniform bond. However, the only line contact will result, and the bond cannot depended upon for either strength tightness. Best re- sults can counted upon from good workmanship directed give formly snug joints. Surface Condition Parent Metal Important electric-furnace brazing the wet- ting action little different than the case water glass, because are dealing with metals ele- vated temperatures and most cases THE IRON AGE, November 4 iss ht, § =. a the attraction between metal and the parent metal ciently great cause tween the two. However, the condi- tion the surface the parent metal has great deal with the behavior the brazing metal from the standpoint wetting tendency creep ball up. These tendencies depend upon the relative surface tension—whether there suf- ficient attraction the surface the parent metal draw metal out thin film, whether the surface tension the brazing metal sufficient draw into balls lumps the surface the parent metal compared with lack attraction the surface draw One’s first thought might that the molten brazing metal would creep best highly-polished surface, but can said that exactly the oppo- site true. The brazing metal will creep best and farthest clean roughened surface. For instance, molten will wet clean polished steel, but not have much tendency creep out its surfaces and distribute evenly the presence the protec- tive atmosphere the furnace. How- ever, this surface should rough- ened shot blasting, rough grinding, rough machining, pickling, some other process, the copper will spread out thin film and tend dis- tribute itself evenly over the surface. This because the liquid drawn through the tiny scratches and pores 32—THE IRON AGE, November 1938 Effect the width gap between strips glass upon capillary attraction. intimate contact (no gap) throughout; uniform gap in. throughout; tapered gap, 0.020 in. top, 0.000 in. bottom; and ta- pered gap, 0.020 in. left. the surface capillary attraction. The reader can easily demonstrate this effect for himself, and other phases the wetting action, with some ink and several grades paper. Ink and Paper Analogy Wetting Action Fig. 50, for example, illustrates the wetting action ink five different grades paper, which although not identical performance with respect brazing metals parent metals, can somewhat likened certain conditions encountered furnace brazing. Studying the wet- ting action this manner will least give one understanding some the results obtained with the furnace-brazing process. drop ink was placed each the ten pieces paper shown, F Before Furnace Brazing bond) Fillet After Furnace Brazing while all were the horizontal plane, and then the back panel was raised ninety degrees into the vertical plane. This allowed the ink creep out draw together sur- force gravity vertical sur- Effect High Mutual Solubility piece blotting paper. The ink soaked into neously upon striking its surface, and was completely absorbed the body the paper that was unable spread. This can likened some extent the action copper nickel, relatively high-melting silver solder copper, similar combina- tions where the metals are mutually soluble high degree. Because this great mutual solubility, usu- ally desirable supply number reservoirs brazing metal joint when the parent metal likely ab- sorb the brazing metal readily, rather than expect the brazing metal creep appreciable distances can accomplished machining one more grooves the tenon re- tain wire rings; drilling feeder holes the joint, filled with slugs; including foil within the joint practicable. Fig. 50, does not illustrate, how- ever, another effect high mutual solubility the brazing metal and the parent metal, namely the “freezing” the brazing metal due pick- metal. This also retards the flow the brazing metal and sometimes stops its penetration into joint leaves collections the surfaces the Good bond throughout all joints Uniformly snug contact through- out joint, and gives good bond throughout. Gaps and interrupt capil- larity and result complete bond. | ii 7 7 Square corners Rounded corner corners Square corners Rounde corner 7 Provide sieeve fit for good capillarity 1G. 49—Here, too, uniformly snug con- tact throughout the joint, will give strong, tight bond. However, with only line contact, spotty contact, neither strength expected. Avoid line bond Before After Furnace Brazing Furnace Brazing parts instead allowing the excess creep out freely into thin film. High Creep Ability noted for its highly absorbent prop- erties. Because extremely thin, very little ink was required soak through it, and the remainder has spread widely because the capillary attraction. This can likened the action copper clean low-carbon steel with matte finish, where the copper oaly slightly soluble the steel and penetrates only “skin deep,” but has great ability creep the surface capillary attraction. like manner, copper plating such matte surface will tend retain its brazing cycle. readily wetted the ink but neither absorbed all nor drew out over its surface. The surface tension the ink held the drop position even the vertical plane. Copper sil- ver solder, for instance, sometimes behaves this manner steel the wetting action not caused unclean surfaces, impure furnace atmosphere, insufficient flux, ete. another grade cardboard. Although was wetted the ink, the ink drew itself together instead creeping out the horizontal plane, but the surface tension the ink was not sufficiently hold the drop intact the plane, which resulted down- ward flow. This action likened some extent copper highly-polished steel, where sometimes found that the brazing metal gets beyond control and runs downward, forming collections which solidify projections low portions assemblies. Some- times this property can used great advantage, while other times better avoided. Example Poor Wetting Action has very effectively resisted the wet- ting action the ink, allowing the surface tension the ink draw the ink together into small drop when resting the horizontal plane, and run freely down the vertical sur- face. This can likened the very poor wetting action copper * steels which have protective surface films oxides chromium, manga- nese, vanadium, aluminum, silicon. formed impurities the controlled atmosphere, and explains the necessity preventing removing such oxide films. Copper electroplating highly-pol- ished low-carbon steel commonly balls furnace, making difficult impos- sible retain uniform coating copper where desired. haves this manner steel surfaces impure protective atmosphere badly contaminated with excessive water vapor, oxygen, carbon diox- ide, compared with the amount hy- drogen carbon monoxide present. The former have oxidizing while the latter have reducing ef- fect. With badly furnace atmosphere the surface ten- sion the copper relatively high compared with the negative wetting action the oxidized surfaces the parent metals, which causes the cop- highly reducing atmosphere the sur- face tension the copper relatively low compared with the good wetting action, which encourages the brazing metal creep the steel. Oxidized Surfaces Avoided Surfaces low-carbon steel which are oxidized become reduced the hydrogen the furnace atmosphere the copper-brazing temperature, leav- ing clean white matte finish which serves excellent means for dis- tributing the copper. Steels with oxi- dized surfaces are generally avoided 1G. 50—Drops ink various grades paper behave somewhat like brazing metals parent metals with different surface characteristics. blotting paper; facial tissue; poster-board; bristol-board; and cellophane. THE IRON AGE, November Uniform bond steel surface Copper wire ring Bare steel surface (pickled matte finish) Bare steel surface (polished) Copper wire ring Before Furnace Brazing Copper coated. and down these rough steel surfaces steel Copper crept this matte surface Bare steel. The copper did not creep over this polished surface After Furnace Brazing 52—The assembly left, prepared for brazing, has copper wire rings the joints. The view right shows how the copper creeps rough surfaces but not smooth ones. making assemblies furnace brazed, however, because oxides with- the joints are not duced those exposed, and some trouble might expected getting good bond. Surfaces which are rusted will also reduced the furnace atmosphere. Parts which have been unintentionally exposed the weather previous their furnace brazing, and re- sult have become rusted, necessarily spoiled. Cases have been known where such assemblies have brazed with apparent ill effects. Here again the reduced oxides form matte finish which readily holds and draws the copper. More copper than usual should applied such assem- blies during preparation, for its absorption the faces well the joints. Effects Surface Condition Creep Copper The effects the surface condition the creep copper actual fur- nace-brazed assemblies are illustrated Figs. and 52. Fig. 51, the assembly was made section hot-rolled bar stock, copper brazed punching cold-rolled steel. The assembly was similarly made except that the bar was rough-machined be- fore assembling instead having the rough-oxide surface Prep- aration for brazing consisted plac- ing copper-wire rings around the bars 34—THE IRON AGE, November 1938 near the joints the bottom. ‘The two assemblies are shown they came from the brazing furnace. Assembly completely covered with copper, the molten metal having been drawn upwards distance in., then horizontally rough-cut top which dia- meter. The mill scale the surface the bar has been reduced the hydrogen the furnace atmosphere, leaving pure iron which has been im- pregnated with the copper and can seen the illustration having the same rough surface the original iron oxide. will observed that practically copper fillet left the joint because the copper has been drawn away. There was ample cop- per, however, supply the needs the joint because the assembly well bonded which has noticeable fillet the joint. The cop- per crept upwards about in. the rough-machined steel bar and left outline which can seen the illustration. the bar had been finish-machined the would have been but short distance, and had been polished this up- ward creep would have been nil. Fig. shows assembly before and after being furnace brazed, and respectively, which the cop- per did not creep polished surfaces but crept readily the adjoining pickled and scratched surfaces. The cup the top had been scratched the die, leaving tiny grooves which have drawn the copper upward, The pickled surface the tube, has drawn the copper downward from the joint the top and upward from the joint the bottom. However, the cap the bottom, being made well-finished cold-rolled steel, has polished surface which has not been scratched the die, and instead running down over the polished sur- face the copper has clung fillet the joint, and has also crept upward the pickled tube. The copper has also, course, crept into the joints capillary Clean Surfaces Give Best Wetting Action For best wetting action faces assemblies should perfectly clean. Heavy oil drawing com- pounds should removed, such hot caustic wash, vapor “de- tetrachloride occasionally used for cleaning parts. Light oil can sometimes left the parts, particularly the oil dis- tills readily and leaves carbon de- posit which would For particular work, however, even light oil should avoided sible. Dirt the assemblies within the joints is, course, objectionable be- cause the condition not improved either the heat the reducing atmosphere and hinders the wetting action. Lead-bearing lubricants particularly should avoided because general their presence completely prevents the creep brazing metal into the joints. Bars, rods, and tubing rolled drawn with such lubricants have skin which offers poor response the wetting action and this skin should ground, machined, scaled off before employing such stock assemblies which are electric- furnace Furnace-brazed joints with lead them are extremely weak and brittle. Surfaces Shot Blasted From the wetting standpoint, sand- blasted surfaces have been found much less satisfactory blasted surfaces, the explanation being that sand particles embed themselves within the surface. Consisting silica, the embedded particles repel the molten copper and impair the wetting action the steel surface. Shot-blasted surfaces, the other hand, are easily wetted because the abrasive, clean, consists simply iron. Care should taken, however, 7 | | f | | | 7 a q see that only clean shot grit used, free from the foreign materials has been previously used for Steel uncoated other jobs, such removing porcelain with copper see that the coolant clean and all over sure that the finished surfaces will not removed have these impurities ground into Copper coated Furnace Time and Temperature Affect Wetting naturally has important effect the wetting action, because the wet- two furnace-brazed assemblies reacted differently the creepage ting and alloying action improves copper because the one left had its original mill scale while the one right had the temperature increases. course machined surface. the temperature must above the melting point the brazing metal, surfaces wetted, before assembly, the latter subject oxidation ts. and the melting the instead requiring that the flux run protective atmospheres, due the in- into the joints from the outside clusion some such element zinc, generally selected capillary attraction. Also, should which oxidizes readily. from overall standpoint. Some cover uniformly the brazing metal (TO CONTINUED) manufacturers, for example, copper braze low-carbon steel assemblies while others copper braze 2040-2100 Turbine-Gear Shop will installed service the entire ing area. heating and temperature time also ONSTRUCTION new large control system that will provide the fects the wetting action, particularly crane bay the western end uniform temperature essential for the with respect the distance creep the present gear-cutting shop the the the brazing metal. there River Works the General Electric process mixing fresh air and re- tendency creep, the distance Co., will completed Nov. circulated air will automatically sly erally will increase with time. new building, which will provide controlled thermostats. nts The alloying action between brazing deal more floor space and addi- nse metal and parent metal is, course, tional machinery for the marine-gear kin function both temperature and division, has completely welded steel Yarnall Heads led time. for production and Engineering Trustees quality. ft. high clear, with overall Yarnall-Waring Co., the machine dent United Engineering Trustees, Oxides Removed Flux reduction gear rotors 16% ft. New York, which the Engineering Oxides which form the diameter and many tons weight. the research organiza- parent metals brazing metals and Features construction include use tion. Other officers were named nd- usually can special glass the north and follows moved satisfactorily suitable flux south walls admit light but exclude Henry Lardner, White En- applied during the heat sun rays. Brick with hollow gineering New York, furnace brazing. this done, tile will back windows double president; Albert Roberts, secretary. lves flux should chosen which will melt glazed construction. stated that Minerals Separation North America and become active temperature construction this type will provide Corp., New York, second vice-presi- cles lower than the melting point the insulating air space equivalent dent; Woodrow, vice-president the brazing metal, that the flux will brick wall. Upper windows will the Consolidated Edison Co., New remove the oxides and provide clean hollow glass blocks for York, treasurer; vice surfaces when the brazing metal melts ft. continuous president the Turner Construction the and ready wet them. Wherever length the building. Co., New York, assistant treasurer. possible, for best results, the flux overhead electric traveling John Arms continues secre ver, should spread uniformly over the crane with all modern equipment, tary. THE IRON AGE, November 1938—35 | Key Handling increased capacity, became ap- parent that manufacture washing machines must moved new site the Bridgeport works. preliminary sur- vey the products handled and the layout the building occupied showed that scientific study and pre-planning potential mate- rials-handling problems real dividends. True, earlier home- laundry manufacture had given some consideration floor layout rela- 2—Washing handling materials, but the Bridgeport. equipment itself with only passing regard economical movement materials. Although chutes and con- veyors had been generously utilized and bulkier parts had been stored mezzanine floor that they could fed down the assembly lines, this preliminary survey showed that there were further possibilities for improve- ments. about this time the company was upon materials handling. works committee was coordinating the efforts individual plants. general materials handling committee each plant was concentrating upon the local situation. And even the home laundry method ling and storing gear cases cartons. 7 this was tion the eral ocal 7 7 Economies ave equipment section Bridgeport had formed its own committee for special- ized study its own problems. Before moving the new washing- machine manufacturing quarters, complete study the building was made. First, was decided lay out the building with just much empha- sis economical materials handling the location strictly manufac- turing equipment. Plans were made locate stocks they could con- sumed most economically. Space for different stocks was allotted with eye minimizing the total fabrication joh, The new location had high ceilings that tiering pallet loads, with the aid fork trucks, was indicated. the other hand, was seen that han- dling equipment must easily port- able and flexible facilitate moving the varied units comprising the fin- ished product. With the exception the main as- sembly conveyor lines, was decided that fork trucks, conjunction with scientifically designed pallet loads, would form the basis all materials handling. Main aisles were established and the layout was completed accordance with Fig. All the bulkier items raw material and work-in-process— such tubs, crates, motors cases, car Small surplus washer warehouse truck shipments ° ° Supervisor Production Appliance and Merchandise Department, General Electric Co., Bridgeport, Conn. ° ° Truck sub Car materials Appliance warehouse floors layout department Bridgeport Works for fork truck and conveyor assembly handling. ‘ storing gear cases ° fe les he AVE. me ‘la- ing zed cover disks, skirt and leg assemblies, and variety steel items were studied detail. This study included all aspects receiving the material. was necessary take cognizance the different problems involved when materials came from vendors pallets, when they were placed after receipt Bridgeport, truck, and when they were adaptable fork-truck handling. was seen, with but one two exceptions, that everything could moved trucks—particularly adequate aux- iliary equipment could developed. Next the optimum location, the allot- ment required spaces, and the com- plete handling operations were estab- lished. all cases, accurate time studies were made and absolute cost records all known handling methods were made. Examples Improvements Washing machine motors, manu- factured another G-E plant, are packed units 100 (Fig. before shipped Bridgeport. Further, these motors are kept unit load until deposited the washing machine as- sembly line. fork truck does the handling the load. The special pallets and separators are ac- cumulated and returned the motor- IRON AGE, November plant after the motors have been incorporated the finished washing machine. shows the old method handling and storing gear cases while process. They were received bulky cartons—which had open- ed, emptied, and disposed of. Today another method Fig. indicates the savings. Upon com- pletion inspection the gear cases the plant, approximately four miles from the G-E shop, cases are these portable racks and transported street truck. addi- tion this immediate “unit-forming” advantage, such racks serve other pur- poses. Rollers make easy push them short distances hand; they can handled tiered use fork trucks. Similar racks have been developed for other units such wringer as- semblies. Completed tub covers may placed such racks. Sixty covers may now moved unit (Fig. 5). the materials-handling men. after pallets were initiated, 6—Pallet unit-loads activators previously received from the vendors. Fic. 5—Sixty completed tub covers handled unit portable rack. < = shape and size the units made pack- aging and handling difficult (Fig. 6). Fig. shows pallet units activa- tors they are received from vendors today. For storage purposes, one unit tiered four corner spindles another pallet unit. All piles activa- tors except the four corner ones are held place means spindles about 1/3 the length the corner spindles, with wooden rounding the necks all the activators the top level. Surprisingly simple packs designed for odd-shaped parts with little study. the left the activators are standard tote boxes work-in-process parts pallets. good practice establish standard box quantities for all stand- ard parts and either store definite quantity sets parts for assem- bly one pallet confine the use one pallet particular part sub- assembly. unusual system making de- liveries the assembly lines has been Numbers have been assigned all delivery stations, and the truck operators quantities what parts each station. The frequency the de- scheduled daily output. operator sees going run out material, throws switch which turns green light the aisle the sta- tion-number sign. The truck operator, after making the delivery, switches the conveniently located light off without leaving the truck. stations where very bulky parts —such tubs and crates—are sup- plied, good use has been made short lengths roller conveyors. These conveyor lengths are fastened the floor right angles the assembly line. They are long enough hold two pallet loads that when oper- ator finishes the material the first pallet, simply removes the empty pallet and pulls the second one into place, proceeding his work without delay. Live pressed-steel tote boxes, impor- tant for their part tiering, were developed with the cooperation one the largest manufacturers steel materials-handling equipment. The trend definitely toward use more them, new applications are found. Finished products the type pro- duced this plant either handled and stored pallets, or, the pack permits inserting each fork under the top crate, they can Fic. 7—Pallet unit-loads activators received from the vendors today. transported and tiered storage with out the use pallets. The customary industrial applica- tions handling cumbersome dies be- tween die storage and the presses and the moving equipment during the expansion ironer manufacturing facilities, fork trucks have afforded many intangible savings. Savings Savings recorded fell into one the following classifications: (1) saving labor; (2) saving space better utilization existing space; (3) de- cided reduction spoilage; (4) high- utilization manufacturing equip- ment; (5) better housekeeping; (6) ease checking inventories. New and Steel Statistics Include Czechoslovakia the latest edition the Iron and Steel Industries,” which covers 1937 and has just been issued the British Iron and Steel valuable new tables have added. These additional statis- tics cover Brazil. Czechoslovakia, and Canada. The tables regarding Czechoslovakia are special interest this time, when much that iron and steel industry being transferred Germany. They show that 1937 Czechoslovakia had record outputs pig iron and ferro alloys and steel, the respective totals being 1,675,000 tons and 2,318,000 tons. Czechoslovakia’s exports aggregated 479,276 tons, total second only that 1929. The largest purchaser was the Netherlands, with 48,797 tons. The United Kingdom’s amount was 20,855 tons, while Germany was very low the list with 8,928 tons. Czecho- slovakia imported 8,113 tons from the United Kingdom and 11,057 tons from THE IRON AGE, November Fundamental Methods and Equipment In- dustrial Power Transmission. the general power transmission scheme, wherever belts are em- ployed, the pulleys have nearly al- ways been looked upon simply necessary evil. The belt itself has al- ways been regarded the power transmitting medium; the pulleys mere accessories thereto. This hardly fair, when one con- siders how intimately the transfer the power from driving driven shaft concerned with the shape, size, weight, general construction and fric- tional characteristics the face RIGHT 2—A Dodge heavy duty, split- steel pulley with malleable iron hub, detail construction. 40—THE IRON AGE, November the pulleys employed. may con- ceded that the belt itself the major problem, but the minor problem pulley selection intimately and inextricably bound with that major problem that pulley design cannot ignored the utmost economic values are derived from any belting drive. The last chapter this series dealt briefly with the characteristics various types pulleys, and suggested the principal conditions under which each type finds its major applications. Further consideration given here certain fundamental tors affecting those applications. Two these factors are primary importance; speed and surface grip. IG. Diagram turbulence caused rotational move- ment pulley. ngineering Data Two other factors are lesser portance; weight and shape. And, finally, two are distinctly minor importance under most conditions service, yet must considered care- fully under other conditions the drive- tension, and the method fastening the pulley the shaft. All the engineering factors concern- ing pulley application selection may referred one another these matters, and clear conception their importance should help determining the economic values this that type pulley any given The subject not difficult one, except that clear thinking the matter often unusual. will approached, therefore, from some- what elementary standpoint, order keep the reasoning ground. The vital element pulley speed not the number revolutions per minute the pulley whole, but the speed the pulley rim feet per minute. Every pulley principles flywheel. matter how light may be, must have some weight. And because that weight stores energy while energy character which tends act centrifugally, burst the rim. The energy contained any balanced rotating mass calculable familiar formula; that is, the product the weight the mass the square the radius gyration (the radius gyration this case being taken the distance from the center the mass the imaginary point which, for mathematical pur- poses, the weight the mass may considered concentrated). evi- dent, therefore, that the energy the pulley varies not only total weight, but the square the radius eter the energy will about four times that pulley one ft. diam- eter any given speed rotation. Again, pulley one ft. diameter will have rim speed 3.1416 500, 1570.8 ft. per min., when the pulley rotating 500 r.p.m.; while pulley ft. diameter the same speed will have rim speed 3141.6 | | 4 | \ | hes ~ | : For Pulley Selection per min. But while the rim speed merely doubled when the diameter doubled, the forces tending dis- rupt the rim are quadrupled. Thus, the higher the rim speed the greater the strain put upon the pulley rim, ind this strain must limited the RIGHT Steel rimmed, iron spider, flanged pul- leys paper-ma- chine drive. The seldom seen nowa- days. material strength construction. The formula usually applied pulleys can, for ordinary purposes, simplified neglecting the weight the arms and hub, and considering only the weight the rim. Then becomes the square the mean radius LEFT 3—A Reeves all-wood drive pulley, showing de- tail multiple-arm construction. FRANCIS JURASCHEK Consulting Editor, The Iron Age the rim; that is, one-half the sum the squares the inside and out- side rim radii. The entire formula for computing the energy 5872.86 where the square ~ pounds the number revolutions per min- ute the pulley. Manifestly, the greater becomes, the greater the tendency the pulley rim burst due the centrifugal action this contained energy. But, assuming the remains constant, increasing the the pulley multiplies these structive internal forces geometrical ratio; hence the easiest way set practical limit the safe speed any pulley limit the rim speed. Pulley rim speeds for solid cast iron pulleys should not exceed 4,000 ft. per min.; for split cast iron pulleys, 4,500 it. per min.; construction cast iron pulleys, 5,500 ft. per min. For iron spider wood rim pulleys the rim speed should not nor mally exceed 6,000 ft. per min., but special construction iron spider wood rim pulleys may run speeds not exceed 9,000 ft. per min. The safe rim speeds under normal operating conditions for steel split pulleys should not exceed 5,000 ft. per min., while laminated THE IRON AGE, November ‘ pulleys may have safe limit high 12,000 ft. per min. For solid wood (laminated construction pulleys, 5,000 ft. per min. usually accepted the safe limit; for pressed fibre paper pulleys, 5,000 ft. per min.; for lami- nated compressed paper pulleys, 6,000 ft. per min.; and for compressed wood (Sprucolite) pulleys, 6,500 ft. per min. These are all safe speeds under nor- 7—Cast iron V-belt pulleys with Dayton cog- belt driving large press. 5—Below, heavy cast iron pulley for flywheel effect: above, light pressed steel pulley the transmission shaft. mal operating conditions; periods they may exceeded; and wood rim pulleys have been used suc- cessfully sustained rim speeds excess 29,000 ft. per Windage Losses Still another item which has direct connection with pulley speed item windage losses. Windage may defined the loss power trans- mitted caused the drag the air turbulence due the fan-effect the two ways; the rush the outer rim surface the pulley, and the churning the air the arms con- necting the rim and the hub. These effects are roughly indicated the sketch Fig. Both effects are negligible low pulley speeds, but high speeds may easily become major importance. The rim turbulence begins appreciable rim speeds over 2,500 ft. per min., and increases square the speed. That is, the speed doubled, the horsepower losses due this effect are The design the pulley will have little effect here, since the loss caused the rim surface, and all rim surfaces are more less alike. The arm turbulence varies consider ably with the design and construction the pulley, and especially the arms. greater pulley where the ratio diameter face width large, and less the face width comes equal greater than the diameter. (An overhanging rim cuts down the volume movement the air churned the arms, but the same time increases the windage loss due rim turbulence.) The loss energy due the fan-effect the pulley arms increases the cube the pulley speed; that is, when the pulley r.p.m. doubled, the arm tur- bulence losses are multiplied eight. Robert Drake tested six different types construction pulleys, and found that the total windage losses the type having the greatest losses, 3,000 ft. per min. rim speed, was five times great the type having the least losses when the ratio face case pulleys having face-to-diam- eter ratios the maximum windage loss the type having the greatest loss was only times that the type having the least loss, oper ating the same speed. Drake says that pulley windage losses are unim- portant where the less than 2,000 ft. per min., but that where belts operate 4,500 5,500 ft. per metal grinding and wood- working jobs, windage losses may run 2.5 3.0 per cent the total input power. Drake also sponsor for the following table, showing the great crease total windage losses due increased speed the case in. diameter in. face steel pulley especially designed for low windage loss: Rim Speed, Windage 2 000 106 O07 2,000 0.22 1,000 212 5000 1.00 8,000 218 1.76 Surface Grip The resistance slipping any two areas contact the product the normal pressure between these sur- faces, and the coefficient friction. That is, the frictional resistance But the coefficient friction the case belt and pulley must taken the mean between the cient friction the belt surface and that the pulley surface. Leather belting may taken varying be- tween 0.27 and 0.60 for oak tannages, Typical Rockwood drive hung from small paper pulley motor shaft, and large iron pulley transmission shaft. and between 0.50 and 1.10 for minera! tannages, while rubber between 0.30 and the type considered. average ten- sion the belt (say 100 pounds) and allowing one per cent slip between the belt and the pulley full load, may assumed that the following average friction will hold for the pulley face; cast iron, 0.46; laminated wood, 0.56; laminated paper, 0.76. Under normal conditions, then, well worn-in, oak-tanned leather belt with friction coefficient 0.50 oper- ating 100 tension and 2000 ft. per min. belt speed over cast iron pulley with coefficient Chalmers, texrope drive, illustrating capacity application the V-belt prin- ciple. s | nt Cs | will 0.50 0.46 develop Ib. per sq. in. area are contact. The significance this point cannot appreciated until the whole matter stated different way. Consider once more the equation, pf. must evident that for any required with respect each other. That is, high value requires only low value requires only low value This latter statement the nubbin the argument. the coefficient friction between the belt and the pulley may made high, the tension the belt may kept low. the evil effects tight belts granted, then that combination belt which gives the highest coefficient friction will permit the operation the drive the least belt tension, other things being equal. things may, for most practicable pur- contact the belt and the pulley, and the speed belt travel feet per minute. Manifestly, the greater the are contact, the greater the total area belt and pulley surfaces contact with each other, and the great- the total resistance whence arrive expression for working limit for are contact. Normally, the least contact the smaller pulley should not less than 120 degrees. For less than this value the slipping increases very rapid- ly. the horsepower transmitted 180 degrees contact (both pul- leys having the same taken 100 per cent, the horsepower transmitted 120 degrees con- tact will vary from about per cent, according the coefficient friction between the two surfaces. But the speed the belt likewise enters the problem. high belt speeds centrifugal force must considered. This tends throw the belt away from the pulley face throughout the entire arc contact, thus breaking the frictional grip and permitting large increase slip. small tent this compensated for in- creased tension the belt, but not entirely. Thus still another limiting factor derived. Under normal con- ditions and with the usual types belts and pulleys, belt speeds about mile minute should not ex- ceeded. Lesser speeds will transmit more horsepower slipping less. has been intimated, mal operating conditions pulley 44—THE IRON AGE, November 1938 which weighed nothing all would Since must have weight have strength, may thus in- ferred that the pulley which combines the least weight with strength the ideal desired. But the attainment the least weight with great strength must not sacrifice other characteristics, such cient friction. And, times, may highly desirable bring into play the flywheel, effect pulley, which case weight must kept mind. Weights pulleys increase materi- ally sizes increase, and not direct proportion. Most equipment makers’ catalogues give pulley weights for size. For quick reference the following figures are illuminating: Solid Cast Iron Pulleys in. diam. arm pulley weighs 2.5 per in. face width from in. in. diam. arm pulley weighs per in. face width from in. in. diam. arm pulley weighs per in. face width from in. Pulleys per in. face width from in. in. diam. pulley weighs Ib. per in. face width from in. per in. face width from in. Wood Rim, Iron Center Pulleys per in. face width from in. in. diam. pulley weighs Ib. per in. face width from in. in. diam. pulley weighs Ib. per in. face width from in. in. diam. pulley weighs Ib. per in. face width from in. may seen, pulley weights vary both the material and the size. larger the size and the heavier the weight, the more must the WR’ flywheel effect considered. takes considerable energy put heavy pulley motion, wise, once motion, considerable re- sistance must overcome bringing the drive rest once more. certain types machinery this ob- viously advantage; for transmis- sion pulleys lineshafts decreases the overall efficiency the drive using power. The shape pulley rim (that is, whether crowned flat) has distinctly minor influence the drive efficiency. But the shape the pulley hody may seriously affect the windage losses high speeds. The less the arms are shaped like paddles, the less will they stir air-turbulence, and the more the rims overhang the arms, even when those arms shaped, the less the turbulence effect. other words, where possible design the pulley shape decrease windage losses, such will transmit more power high speed operation. This applies course large diameter pulleys, for the usual small diameter pulleys have solid webs and not pronounced wind- age losses. the matter drive-tension, all that can done make sure that the web arms are desi