US1619960A - Electric controller - Google Patents

Description

1 March 192? J. E. SEDERHOLM 6 9 960 ELECTRI C CONTROLLER Filed 5 Sheets-Sheet 1 To MAIN LINE OOOO I N YEN TOR 3 JQHNE'JEDERHOLM DISCHARGE REsy-s TANCE Erma/(4Q UNLoAmNe,

Ir Ton/Yin:

"b MA NET RESISTANCE March 8,1927. 1,619,950

J. E. SEDERHQLM ELECTRIC CONTROLLER Filed March 3. 1922 Sheets-Sheet 2 Mafch 8, 1927.

1,619,960 .1. E. SEDERHOLM ELECTRIC CONTROLLER Filed March 5, 1922 5 Sheets-Sheet 5 To MAIN LINE To MAGNET I N YEN TO B JOHN ii JQDERHOLM DISCHARGE RESISTANCE UNLOADING; RESISTANCE Patented Mar. 8, l9li7n stares BATE-NT QFFlQEo JOHN E. SEDERT-IGLIE, OF ST. Pfi'UL, MIIINESQTA, ASSIGNOB T0 AHERICAN HOIST 82; DERRICK GGMPANY. OF ST. EAUL, MINl-IESOTA, A EARTNEBSHIP COMPOSED 0F OLIVER CROSBY, T. Z. JOHNSON, AND W. O. \VASEBURN.

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Application filed. March 3, 1922.

This invention relates to improvements in electric cont-rollers designed particularly for use in connection with lifting magnets, though capable of use for many other purposes.

Electric controllers, particularly those adapted for use with lifting magnets, must be positive in performance and the possibility of accidental openingot their contacts must be obviated or at least. minimized Furthermore, such controllers must be constructed to stand up under very hard service conditions in operating lifting magnets and also give maximum protection to the wind 9's 0? the magnet. The destructive arcing ot contacts must be prevented and discharge protection must be aiior'ded the lifting magnet. Such protection must be attained without the dangerous introduction of the usual fuses or circuit-breakers into the circuit of the lifting magnet. As is well known, fuses often blow without apparent cause and circuit-breakers often function from excessive vibration. In either case, no discharge protection is afforded the magnet. The danger res des not only in damage or injury usually resultant tron such sudden unexpected release or" the lifted load but also in damage to the magnet windings and to the load or either.

In this improved controller two magnetic blowout coils have beenprovided, one for each oi the two lines. Further, each of the two lines is provided with two contact openinns and preferably all such openings are nitrated as much as feasible and set in aight line. These coils are so located that he controller case which is preferably of iron. "forms one of: the magnetic circuits wh le the other path of the magnet lines of r rcc passes through the line of contact fingers. These blowout coils are also clesigned to function as choke coils and are constructed to carry a limited amount of current. These blowout coils are easily interchan 'eable and replaceable giving an added advantage to the controller of adaptability to variant duties and of variant capacities. The above-mentioned obviation or minimizing or accidental contact opening is effected by positive locking 0r contacts so that opening through vibration or accidental striking against the operating lever will not pull the Serial No. 540,817.

cont-acts out of their operative lifting position. This positive locking is eiiectedby he provision of a locking pin. at the operating end of the controller. to lock the contacts in lifting position. This pin also gives a quick make-and-break or snap action of contacts.

The object therefore of the invention is to provide an improved electric controller.

More specific objects or" the invention are to provide a controller by means of which electric circuits may be made and broken without forming any are; to provide a controller with t-wo powerful magnetic blowers; to provide an instantaneous make and break of the controller contacts; to provide reliable and etlective discharge clips and resistance; and to provide suitable resistance for the re verse current in dropping the load from the magnet.

(Ether objects or" the invention will appear from the following detailed description. taken in connection with the accompanying drawings, in which- 4 Figure 1 is an elevation of my improved controller, with the outer casing removed;

Fi 'ure 2 is a vertical section on line 22 m oi: Figure 1;

Figure 3 33 a plan view; Figure 4 is a horizontal section on line 4t of Figure 2';

Figure 5 is a vertical section on line 55 of Figure 4;

Figure 6 is a similar view on line 6-6 of Figure 4; and

Figure 7 is a detail section on line 7 of Figure 2.

The casing of the device is preferably provided by a one-piece or integral casting forming the back wall 2 and the top and bottom, or upper and lower end walls 8 and 4. This casing is also preferably provided with lugs 5 by means of which the coninsulatinolining 7 and having its vertical edges secured to the edges or" the rear wal 2 by suitable screws 8. While the casin may be or" any desired form it preferred to make its outwardly projecting part of curved form (Figures 3 and 4).

A bar 9 having journals 10 and 11 is ar ranged in a vertical position in the casing. The journals 10 and 11 are preferably mounted to rotate in bearings in the upper and lower walls 3 and 4. The bar 9, thus supported, is capable of being oscillated on its vertical axis, for the purpose hereinafter stated. A block 12 is arranged upon the up per journal 11 of the barl) and is secured rigidly to said journal preferably by suit able set screw 13. This block is preferably circular in cross-section and is provided upon its edge with three depressions 15 (Figures 2 and 7) adapted to be engaged by the rounded end of a spring-bolt 16 disposed in a suitable socket in the wall ofthe casing and pressed outwardly toward said block by a compression spring 17.

A crank arm 18 is mountedto turn freely upon the journal 11 and is provided with a handle 19. This crank is held upon said journal by means of a set screw 20 engaging an annular groove 21 in said journal. The crank arm 18 is provided with a pair of lugs 22 extending downwardly beyond the plane of an integrally projecting arm 14 on the block 12. A tension spring 23 is connected to the end of the arm 14 and to alug 24 provided on the end of the crank arm 18. Bosses 18 are provided on the top wall 3 to limit the horizontal movement or throw of the crank arm 18.

The bar 9 is preferably provided upon one side thereof with parallel flanges 25, (see Figure 4) and the space between said flanges forms a groove in which is secured a lcngitudinally extending block or bar 26 of insulating material.

Contacts 27 and 28 (see Figure 5) are preferably secured upon the outer edge of the bar 26. Each of these contacts is preferably of U-shapeand is secured to the bar 26 by suitable screws 29. Each contact also preferably provided at the free end of each of its arms with broad contact block pie senting a contact surface 30. T hcse contact surfaces are adapted to engage suitably dis posed contact blocks. Secured upon the rear wall of the casing are the longitudinally es:- tending bars 31 and 31 of insulating material (see Figures 4 and 5). The bar 31 l Secured to it a series of metal conductin plates 32 32132 and 32 (see Figures 1 and 2) while the b r 31 has :1 corresponding series of plat-es 32 32 and 32. Secured to said plates are the spring contact fingers 33 preferably arranged in pairs. each carrying contact blocks 34. These blocks are disposed for engagement by the contact blocks (Figure 4) as hereinafter set forth. A wall or separator 30 of insulating material is provided at each end and also between each pair of contact fingers to prevent arcing between said fingers. These walls are held in place by recesses or slots provided in bars 31, 31*, Figure 4 and also bar 35, hereinafter described.

The vertically extending bar 35 of insulating material, preferably secured to the end walls 3 and 4 of the casing by suitable screws 36 (Figures 2 and 4), is arranged parallel withthe oscillating bar 9, and substantially at the outer wall of the casing. This bar has supported thereon the two pairs of oppositely extending curved clips 3'? and 37 held in place by bolts 38 and 38, Figure 1. These bolts also form connecting means for electric conductors as hereinafter described.

Extending through one wall of the casing preferably the lower wall 4, are several pairs of conductors, consisting preferably of usual insulated wires, each provided with an ordinary connecting clip 39. These wires preferably extend through insulating bushings 40 arranged in openings in the wall of the casing. As indicated in Figure 6 the wires41 and 42, connect with the main line or source of elect dc power. The conductors 43. and 44 connect with a lifting magnet, or any other device that it is desired to operate by an electric current passing through this controller. Conductors 45 and 46 connect with a discharge resistance and conductors 47 and 48 with an unloading resistance. The conductor 41, extending from'the main line, connects with the plate 32 through a suitable magnetic blow-out coil 49, and the other main lineconductor 42 connects with the plate 32 through a similar blow-out coil 50. a

The conductor 43 is connected to the plate 32 and the conductor 44 is connected to the plate 32 The conductor 47 is connected to the plate 32 and the conductor 48 to the plate 32 The conductor45 is connected to the bolt 38 that is connected with the 37, while a. conductor 51 extends from the plate 32 and is connected with a boltw38 havingelectrical connection with the clips 37 Plates 32 and 32 are permanently con nected by conductor 52. Plates 82 and 32 are permanently connected. by conductor Plates 32 and 32 are permanently connected. by conductor Opcmtica.'lhe top Wall of the casing S is preferably provided upon its outer surface with the words Lift. Drop. indicating the three po which the oscillatory bar 9 car tacts 26 and 2'? may be turned 18 and handle 19.

Assuming that the bar 9 stands in the position shown by full lines in Figure 4 the contact blocks or surfaces 30 on the swingthe conov the ing contacts 27' and 28 will be in electrical engagement with the blocks 84 carried by the contact springs 33 on the lift side of ,6118; use.

e contr l er-i circuit. will then; be los d from the. generator through th CQ hl t012t2-a the; blow-out coil 50, plate 32?, its spring; 33

and block 34-, the swinging contact 28, block; 234, spring 33,,plate 32, conductors 54: andwill be energized and may beemployed for lifting and transporting-any desired metallic articles.

Assum ng now that it is desired. to deenergize the magnet in order to cause-it to release the article or articles held by it, the handle 19 and crank arm 18 will therefore be swung from the position indicated by dottedlinesopposite the word Lift in Figure 3, to the position shown by dotted lines opposite the word-Drop in the same figure. Asthe block 12 is held in a stationary position by the spring bolt. 16, (Figure 7),, the bar 9 will also remain in a stationary position until the crank arm 18 has been swung a sufficient distance to cause one of the lugs 22 on the crank: arm to, engage the lug 14 on the block 12'.- This movemento't' thc crank arm, while the block remains Stilt-i011? ary, will put the spring 23. under tension. As further-movement of the crank arm will, by the engagement of thelug 22 with the lug 14, cause the block 12 tobe turned with the crank arm, the rounded end Qfthespring bolt 16 slipping out of the recess 15 in the edge of the block 12;. The tension of the spring- 28. will act to give a quick quarter turn to the bar- 9, turningit to the position indicated in dotted lines in Figure 3 opposite the word Qii.

As soon as the swingingcontacts 2? and 28 carried by the bar 9 are moved away'fitoni the contact blocks 34 carried by the Springs 33 the circuit already described through the magnet will be broken, and an arc will he formed between the contact blocks 30 and 34. Under the action of the coils 49 and 5d,.

there will be no injuryto the contact blocks- 30 and 34.

The Spring 23 being under tension when the block'12fis released fromthe spring bolt 16, will quickly turn the bar 9 so as to bring said bar into the intermediate position shown by the dotted lines in Figure 4, the second recess 15 on the edge of the block 12 being engaged by the spring bolt 16, which stops the movement of the bar 9, and holds said bar in a stationary position. As the operator continues the movement of the handle 19 and the crank arm 18, while the block 12 remains stationary, the spring 23 is again put under tension and, when the lug 22 eng se h 1-ug:1 he b o k 12, th w parts will move; together and the block 12 will be released from the spring bolt 16. The tensi n at the spring 23, will then quickly throw the lug 14 forward, turning the'block 1-2' and bringing the parts into the position shown by dotted lines at the left in Figure 4. The blocks 3901 the contacts 27 and 28 are thus brought into electrical contact with the blocks 34 on the spring contact lingers-33 carried by the plates 32 32, 32 and 32 As the contact block 30 carried by the swinging contact 28 are moved away from the blocks 34 carried by the springs 33 connected with thenlates- 32 and 32, they come into contact with the clips 3? and 37. Connection is then made through said clips and the movable contact 28 bringing the discharge resistance which is to be connected with the conductors 45 and 46 into direct circuit with the magnets, whereby the dis charge current of the magnet is absorbed in the discharge resistance. The circuit is as follows; One side of the magnet, conductor 44, conductor 51, spring clips 37, swinging contact 28, clips 3?, conductor 45 through the discharge resistance, conductors 46 and 43. to the other side of the magnet.

When the-movable contacts 2? and 28 are brought into connection with the contact on tne springs carried by the slates 32", 32, 32 and 32", the unloadingresistance connected with the conductors 47 and 48, will be brought into circuit with the magnet and the-polarity of the current through the magnet will be reversed, thereby bringing the magnet to zero and causing the load to be immediately dropped by the-magnet.

This circuit is as follows; One sideot the main line, conductor 42 blow-out coil 50, conductor 48, through unloading resistance connected with the conductors 47 and 48, conductor 47, plate 32 through its spring and. block, through block 30, swinging contact 29-, plate 3 2 with its spring and block, conductor 43 through the magnet, conductor 44, plate 32 with its contact block, swinging contact 28, plate 32* through its spring and block, conductors 52- and 41, blowout magnet 49, and conductor 41, to: the other side of the main line. It will be noticed that the current in this case traverses the ma gnot inthe opposite direction froniwhich it does when the arm 18 is thrown to the lift position.

As soon as the magnet has dropped the load the operator will turn the handle and crank arm 18 into the position indicated by dotted lines after the word Off in Figure 3, and the bar 9 will then stand in the neutral position indicated by the dotted lines at the center in Figure I claim as my invention:

1. In an electric controller the combine tion with a casing, insulating blocks supported at intervals around the interior walls of the casing, an insulating bar journaled in sulating blocks and the insulating bar respectively, insulating strips substantially horse shoe-shaped to leave space for t'he'oscillation of the journal bar, said strips being located between the contacts and supported at each endand middle por'ion by said insulating blocks, sa d insulating strips being spaced from the casing, and blow-out coils on the end of thecasin and connections therefrom i C:

to said cont-acts extending through the space between said strips and the casing.

3. In an electric controller the combinaion with a. casing having a back, a top, and bottom, and havingthe front thereof subitau ially semi-cylindrical, of an oscillatable ar ournaled in the top and bottom of said fusing, ll-shaped contact members carried by oscillatahle bar and adapted to engage Jigrr said with contacts disposed within the sweep of bar as it is swung from one extreme pouition to the other, a plurality of insulating bars carrying contacts thereon mounted in said casing and having the cont-acts thereof so disposed as to be within the sweep of the contacts of said oscillatable bar, substantially semi-circular insulating separators mounted in slots'in said last named insulatingbars and disposed between contacts to prevent arcing therehetween. I

4- In an electric controller the combination with a casing having a back, a top, and a bottom, and having the front thereof substantially semi-cylindrical, of an oscillatable bar journaled in the top and bottom of said casing, U-shaped contact members carried by s id oscillata-hle bar and adapted to engage with contacts disposed within the sweep of said bar as it is swung from one extreme position to the other, a plurality of insulating bars carrying contacts thereon mounted in said casing and having the contacts thereof disposed to be within the sweep of the contacts of said os'cillatable oar, substantially semivircular insulating separators mounted in slots in said last named insulating bars and disposed between contacts to prevent arcing therebetween, and a pair of blow-out coils disposed in line with part of said cont acts, the magnetic circuit of said coils including said casing.

In an electric controller, a semi-cylindrical casing, a bar journaled the ends of the casing, an insulating bar attached to a side of the journal bar and having pairs of contacts attached thereto, insulating blocks attached to the flat side of the casing and a third insulating block to the semi-cylindrical portion of the casing intermediatethe first-mentioned blocks, said blocks having contacts thereon to co-act with the contacts on the insulating bar, horseshoe-shaped insulating strips having their diametrically ppesite ends attached to the two blocks at the flat side of the casing and also supported by third insulating block intermediate the first two blocks, said strips extending between contacts supported on the insulating blocks, and journal on the journal bar extending through the casing at one end, and means on the journal exterior of the casing for quick making and'breaking of the circuits through the contacts.

6. A controller comprising a casing, an 0s cillat-ing contact maker, insulating blocks on opposite sides of the casing, and athird insulating block, midway of the sweep of the contact maker as it oscillates in the casing, contact plates carried by each of the first mentioned insulating blocks, each plate carrying a plurality of contacts, a plurality of contacts carried by the intermediate insulating block and extending in opposite directions from said third insulating block, the contacts being so arranged that as the oscil latable contact maker is oscillated the contacts thereon will engage successively the

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