US1126762A - Lifting-magnet controller. - Google Patents

Description

C. T. HENDERSON. LIPTING MAGNET CONTROLLER. APPLICATION FILED APR.29, 1912.

El.. E EL? Patented Feb. 2, m5.

4 SIAEETS-*SHEET 1.

l un' 0. T. HENDERSON. LIFTING MAGNET CONTROLLER.

APPLICATION FILED APR. 29, 1912.

Patented Feb. 2, 1915.

4 SHEETS-SHEET 2.

(L L HENDERSN. LIFTING MAGNET CONTROLLER.

APPLIUATIOE FILED APR. 29, 1912.

1,126,762. Patented Feb. 2, 1915.

` 4 SHEETS-SHEET 3. j Je l d fr C. T. HENDERSON.

LIPTING MAGNET CONTROLLER.

APPLICATION FILED APR.29,1912.

Patented Feb. 2, 1915,

4 SHEETS-SHEET 44 'rnn sTA'rns PATENT CLARK T. HENDERSON, MILWAUKEE, WISCONSIN, ASSIGNOR T0 THE CUTLER- HAMMER MFG?.v C0., 0F 'MILWAUKEE WISCONSIN, A CORPORATION OF 'WIS- 'consist LIFTING-MAGNET CONTROLLER.

Specification of Letters Patent.

Patenten nel). e, i915.

Application led April 29, 1912. Serial No. 693,844.

circuit controllers.

It is particularly applicable to controllers for electro responsivey lifting may be used in other relations. It is one object of my invention to provide a controller for causin a lifting magnet to quickly Arelease an dropM-its load when desired.

A further object of my invention is to provide a controller for establishing a back discharge path forl the magnet winding upon interruption of its circuit to reduce the arcing-at the circuit breaking points.

` A still further object of my invention is to provide means for insuring the controller against such operations as might cause injury thereto or to the controlled device.

My invention has various other objects and advantages which will be'hereinafter clearly and fully set forth., Y

For the purpose of disclosing the nature and characteristic features of .my invention, l shall describe Vthe embodiment thereof illustrated inl the accompanying ydrawings. it should be understood, however, that my invention is not limited to the specific embodiment thereof chosen for the purpose of illustration.

ln the accompanying drawings, Figure i. is a front elevation of the controller, a pormagnets, but

tion oir' the inclosing casing removed andv withcertain parts shown in section. Fig.-

2 is a top plan view of Fig. l. Fig. 3 1s a side elevation loit the upper portion of Fig. l. Fig. l is a sectional view taken on line lL-ll Fig. Il, ,and Fig.l 5 isy a sectional view taken on line --5 Fig. l. Fig. 6 is a combined schematic and diagrammatic View of the controllerl and oneuform of circuit connections adapting the same to lifting magnet service.

The 'various parts ci the controller showna're mounted within a casing. rlhis casing is provided with a back l and bottom 2 lpreferably formed integrally and of cast iron and with atop 3 preferably formed of cast 1ron and secured to the back l by any suitable means. This section of the casing is providedl with-suitable supporting lugs or ears 4.- 'lhe remaining sides of the casing' are preferably' formed of a sheet metal plate 5 adapted to be secured to the back ot the casing by the usual devices 6.

Secured to the back l of the casing and extending substantially the entire length thereof is an insulating switch supporting panel 9. Mounted upon this panel and extending transversely thereof are four switches, -1l-12 and 13. These switches are all of the same construction and accordingly a description'of one will suffice for all.`

Referring to Fig. 5, each switch comprises an arm 14 ulcrumed on a pin l5 carried by `a bifurcated bracket 16 secured to the inis' adapted to be engaged by an arcing 'contact 22 on the switch arm 14. "The arcing.

contactA 22 is preferably mounted upon the extremity of a spring 23 secured to the arm l-i bysUitable means such .as a bolt 24 and screw 25, Conned between the spring arm 23 and arm' lll is a iiexible conductor 26 which extends around the pivot l5 to a binding post 27 on-thebracket i6. rEllis provides an electrical foonnection between the v'bracket 16 and bothhcontactsof the switch arm. The bracket-16 is provided with a suitable terminal post 28. Both the main contact brush 18 and the carbon block 21 directly engage the Contact holder 19 which is of conducting material and provided with a suitable. terminal post 29. The contacts are so disposed that upon inward movement` of the arm it Contact is first made between thev arcing contacts and then between the main contact 17 7and brush 18. Upon outward movementio the arm contact is lirst broken between main contact 17 and brush The y arcing contacts.

18 and then between the arcing contacts. VThe arm 14 is biased outwardly by a spring 30 set into the insulating base and bearing against said arm.

The switches are preferably provided with individual blowout devices and are so illustrated. These blowout devices are all of the same construction. As best illustrated in Figs. 3 and 5, each of these blowout devices comprises an electromagnet 32 supportedbe-- tween the extremities of two magnetic plates 33 and v34 secured at their inner ends by suitable means such as bolts. 35 to the insulating 'panel 5. The supporting plates 33 and 34 form pole pieces for the magnet32 and are disposed on opposite sides of the An insulating chute or barrier 36 is provided between each pair of plates 33 and 34 for the well-known purpose. These chutes or barriers may be conveniently .secured in place by means of bolts 37 passing through the same and through said plates. l

One terminal oi' each of the blowout devices is adapted to be connected to the terminal post 29 of the stationary contact support while its opposite terminal is adapted to be connected to one of the terminal posts 38 provided upon the supportingv panel 5. The terminal posts 38 are adapted to be connected to outside circuits. Thus, uponclosure of each switch a circuit is established from the binding post 28 through the switch arm and stationary contacts thence through the ,blowout magnet to terminal 38.

` rEhe switches 10-11-12 and '13 are adapted to be operated by. revoluble cams 40-41-42 and 43 respectively, mounted upon a shaft 44 extending longitudinally through the casing. The shaft 44. is revolubly mounted in suitable'bearings 45 provided in the top and bottom of the casing and is provided with a suitable operating handle 46.

Each of the cams preferably comprises an insulating disk secured to asuitablesupport 47 iixed to the shaft by suitable means such as a pin 48. The cams engagel rollers 49 suitably mounted on the switch arms 14. rl`he cams are so constructed and so arranged upon the shaft 44 that when the shaft is in normal position the switches 10 and 11 will be closed and the switches 12 and 13 opened. When the shaft is revolved to the right, switch 11 is opened and switch l2 closed. When the shaft is revolved tothe left ythe switch 10 is opened and the switch 13 is closed. Further, the cams are so designed that when the shaft is revolved to the right, theswitch 12 will be closed before the switch 1l is -opened and upon return movement the switch 11 will be closed before the switch 12 is opened. Likewise when the shaft is revolved to the left, the switch 13 will be closed before the switch 10 is opened madres and upon return movement the switch 10 will be closed before the switch 13 is opened. The purpose of this sequence of operation will later be explained.

As 4will be later more fully explained, when the device is used for controlling an electro-responsive lifting magnet the switches 10 and l1 when closed establish a back discharge circuit for the magnet winding. When the shaft is revolved to the right, the opening of the switch 11A breaks the back discharge circuit while the closure of switch 12 connects the magnet to a power circuit. 'When the shaft is revolved. to the leftfto close switch 13 and open switch`10, the 4baclr discharge circuit is opened and the magnet connected to the supply circuit but 'in' such aI manner as to reverse the polarity.

rlhe purposeof reversing the polarity of the magnet 4is to cause it to repel its load therethereof. I

ln practice it is desirable to only maintain by insuring a quick release or dropping the connectionsv for reversing the polarity of the magnet for a moment. Otherwise tlie magnet might drop its load and then immediately pick up the same. l, accordingly, prefer to bias the shaft from release or dropping position to od position so that the controller will remain in dropping position only so long as the operator holds it in such position. rlhere is no occasion for biasing the controller from lifting position to od position. ln fact, such a provision might prove dangerous. ln practice it is very' much preferred to positively insure the rev tention or" the'controller in lifting position until it is positively moved away from such position. l, accordingly, desire to provide means to this end. Still further, vl desire to provide means Afor positively limiting the movement of the controller from dro ping position4 to o position to prevent trie same from moving too far and unintentionally establishing lifting connection or bringing the contacts for establishing lifting con nections .into such positions that arcing Iwould result. The controller shown is provided with means for accomplishing all these results and l shall now. describe said' means.

@n the upper end of' the shaft 44 l have provided a disk 50 which may be secured to of the controller from odi to lifting position' fio.

ideama does not aieot the spring. A lug 53 projecting downwardly from the top of the casing coperates with shoulders 5a and 55 provided on the disk 50, to limit the rotation of the shaft in both directions from ol position. lt stops the shaft in lifting position and dropping position.

A spring pressed lever 56 carrying a roller 57 cooperates with a notched section of the disk to releasably lock the shaft in normal position and in lifting position. rlhe lever 56 is fulcrumed upon a pin 58 projecting downwardly from the top of the casing and is yieldingly held in engagement with the notched periphery of the disk by a tension device. rl`his tension device includes a rod 59 suitably secured to the back of the casing and projecting between the bifurcations of a tail piece 60 of the lever 56. rlhe rod 59 carries a helical spring 6l confined between a washer 62 bearing against the tail piece 60 of the lever 56 and a washer 63 on said rod retained in place by nuts 6%. The spring 6l is of the expansion type.y

rl`he disk 50 is providedwith a notch 65 into which the roller 57 of the lever 5t is adaptedto enter when the controller is in od position and with a notch 66 into which the roller is adapted to enter when the controller is in lifting position. Thus the controller is insured against accidental movement from` either its od position or its `lifting position.

While the entry of the-roller 57 into the notwch would tend to stop the controller in oil position when returned to such .position by the spring 52 it might under some conditions tail to so stop the controller.V l

accordingly prefer to provide a more positive stop which l shall now describe.

The operating handle of the controller instead o being rigidly iixedto the sha-ft is ulcrumed upon a horizontal pin 68 supported byl a device 69 fixed to the shaft by means of a pin 70. This permits of a vertical movement of the handle. rlhe stop device coperates with this handle. lt comprises a member 7l secured as by means of bolts 72 to the top of the casing. The' member 7l is recessed to receive the shank of the handle and to permit movement thereof fromA one extreme position to the other. rthe recessed portion of the member 7l is however, so formed as to require a vertical movement of the handle in its travel from one extreme position to the other.

0n one side of the central position of the handle, the member 7l is provided with a cam member 73 which raises the handle as it is moved from its central position to its extreme lett hand position. @n the opposite side of the central position of the handle the member 7l is provided with a stop member 7 6` directly in the path oit the shank of the haridtlgl/fI when in its elevated position.

'lo clear this stop the handle must be moved downwardly and in practice l prefer to provide only a small clearance between the handle shank and the stop 7 6 to necessitate downward movement of the handle to its full extent to free the same from said stop. Also in practice l prefer to provide the stop 76 with a cushioning spring 77 for taking the impact of the handle. 1

Vln operation the handle is free to move either fromits central position or from its extreme right hand position to its extreme left hand position vwithout interruption. Assume now that the handle is in its eX- treme left hand-position and is released by the operator. rlhe return spring will then move the shaft and handle back toward the central oft position and in so doing will drive the shank on the handle against the stop 76. This arrests the movement of the handle inthe central od position. rlhe shaft is at this time relieved of the tension of the return spring. Accordingly the shaft will come tq rest and the handle will drop to the position' shown in lig. l, in which position it is free to be moved in either direction. rllhe stop 76 thus insures the shaft, and handle lagainst accidental movement beyond the central od position, but without iny any wise interfering with the manual operation thereof.

Referring now to l? ig. 6 one application of the controller will be described. ln this :figure the controller is shown schematically. lt controls the circuits of an electro-responsive litting magnet 80 also schematically illustrated. rlChe controller serves to establish the following circuit connections for the magnet winding. rl`he controller is shown in od position in which the switches 10 and l1 are closed. rlhe switches lO-ll complete a closed loop across theF terminals of the magnet winding. rl`his'oircuit may be traced from the lett hand terminal of then magnet vwinding by conductor 81 through the switch l0, by conductor 82 through the switch ll, by' conductor 83 through a resistance R to the opposite terminal of the magnet winding. IThis circuit provides what is known in theart as a back-discharge path for the winding to prevent excessivey arcing at the switch contacts when the magnet is disconnected "from the supply circuit. Assume now that the controller be moved to its extreme right hand or lifting position, the switch il will be opened and the switch i2 closed. This connects the magnet winding to the supply circuit L-LC The circuit et the magnet winding may now be traced from line li to conductor 82 through switch l0 by conduct-or 8l through the magnet winding by conductors 80 and 8lthrough the switch l2 to line L. The magnet is thus energized for lifting. Return ot the controller to the central ed position causes the switch I1 to irst close therebyreestablishingthe back-discharge circuit and said connections and to insure the establishment of said closed loop prior to disconnecthen causing the switch- 12 to open to dis-- tion of the translating device from circuit.

connect the magnet winding from circuit. This denergizes the magnet. In some cases the residual magnetism is suiiicient to cause the load to stick to thei magnet after circuit is opened, thereby rendering the discharge of the load uncertain. If there is any tendency of the load to stickit can be readily overcome by continuing the movement of the controller to its extreme left hand position. This results in opening theswitch 10 and closing the switch 18. Thereupon the magnet winding is again connected to the supply circuit but in such a-manner that its polarity is reversed. This will be obvious 'from tracing the circuit ofthe magnet winding which now extends from line L to conductor 82 through switch 11 by conductor 83 through resistance R, by conductor 84 through the magnet winding by conductor 85 through resistance R, thence through switch 18 to line L. This circuit it will be observed causes the current to iow through the magnet winding in, an opposite direction to that previously described and accordingly causes a reversal'of the polarity of the magnet winding causing it to quickly drop its load. For this purpose only a comparatively small current is required and hence the inclusion ofthe resistances R and R. In factasmall current for reversal is much preferred as the magnet would immediately pick up its load after dropping the same if supplied with a full amount fof current.

What I claim as new and desire to secure by Letters Patent is as follows 1. A controller having a plurality of switches operable to connect a translating device to a supply circuit for causing a iiow of current therethrough in either direction and further operable to connect the translating device in a closed loop, and means insuring the establishment of said closed loop prior to disconnection of the translating device from circuit. o

2. A controller provided with a plurality of switches operable to connect a translating device to a supply circuit to cause a How of current therethrough in either direction and further operable. to connect the translating device in a closed loop, and a common operating member for all of said switches insuring the establishment of said closed loop prior to disconnection of. the translating device from circuit.

3. A controller comprising a plurality of switches operable to connect a translating device. to a supply circuit and to reverse the connections between the translating device and the supply circuit, and further operable to connect the translating device in a closer circuit, and a single device for mechanically operating said switches to establish all of '4. A controller comprising: a plurality of switchesl operable to connect'a translating device to a supply circuit and to reverse the .connections between the translating device .and the supply circ'uit, to reverse the polarity yof the former, and further. operable to connect the translating device in a closed circuit, anda single device for 'mechanically operating `said, switches to establish all of Vsaid connections and to insure the establishment of said closed loop prior to disconnection`of the translating device from circuit, said device being-movable in opposite directions from an intermediate position to connect the translating. device in circuit and control the direction of flow 'of current therethrough, and when in said `intermediate position to cause the establishment of said closed loop. Q

5. In combination, a. lifting magnet and means operable to connect the magnet winding to a supply circuit, to reverse the polarity of the magnet qwinding and to connect the magnet winding in a closed loop.

6. In' combination, a lifting magnet, means operable to connect the magnet winding'to a supply circuit, to reverse the polarity thereof and to connectthe magnet winding in a closed loopand'means coperating with said former means to insure the establishment of said closed loop prior to disconnection of the magnet winding from circuit. 7. In combination, a lifting-magnet and la plurality of switches, certain of said switches when closed connecting the magnet winding to the' supply circuit, certain of said switches when closed reversing the polarity of the magnet winding, and certain of said switches when closed establishing a closed loop includingv the magnet winding.

8. In combination, a lifting magnet, a plurality of switches, certain of said switches when closed connecting the magnet windini to the supply circuit, certain of said switches when closed reversing the polarity of the magnet winding, and certain. of said switches when closed establishing a` closed loop including the magnet winding, and a common operating member for all of said switches insuring the establishment of said closed loop prior to disconnection of the magnet winding from circuit.

9. In combination, a lifting magnet, a plurality of switches, certain of said switches when closed connecting the magnet winding to the supply circuit, certain of said switches when closed reversing the polarity of the magnet winding, and certain of said switches when closed establishing a closed loop including the magnet winding, and a common operating member for all of said switches insuring the establishment of 4said closed loop prior to disconnection of the magnet winding from circuit, said memlating device to the supply circuit to reverse the polarity of the translating device, and

ber when moved to reverse the polarity of-two of the same when closed vconnecting the the magnet winding, tending to return to a position `to disconnect the magnet winding from circuit.

10. In a circuit controller in combination, four switches, `and a common operating member therefor having three positions in each of which it closes a pair of switches and allows another pair to open, said operating member always insuring closure of a certain pair of said switches prior to the opening of either one of the other two switches.

11. ln a controller in combination, four switches, two of said switches when closed being. adapted to connect a translating device to a supply circuit, two of said switches when closed connecting the translating device to the supply circuit but reversing the connections between the same and `two of said'switches when closed connecting the translating device in a closed loop, and a common operating member for said switches movable to close the' same in pairs to estab-` lish all of the aforesaid connections.

121 lna controller in combination, four switches, two of said switches when closed being adapted to co'nnect the translating device to a supply circuit, two of said switches when closed connecting the translating device tothe supply circuit but reversing the connections between the same and two of said switches when closed connecting the translating device in a closed loop, and a common voperating member for said switches movable to close the same in pairs to establish all ot the aforesaid connections, said member insuring closure of the last mentioned pair oic switches prior to the opening of either of the remaining two switches.

13. ln a controller in combination, four switches, two of the same when closed being adapted to connect a translating device to a supply circuit, two of `the same when closed being adapted to connect the translating device to the supply circuit to reverse the polarity of the" translating device, and two ot the same when closed connecting the translating device in a closed loop, and a common operating memberfor all of said switches adapted when in initial position to close the last two mentioned switches, when moved in one direction from normal position to close the irst mentioned pair of switches, and when moved in the opposite direction :rom normal position to close the second mentioned pair of switches.

14. ln a controller in combination, four switches, two ot the same when closed being adapted to connect a translating device to a supply circuit, two of the same when closed being adapted to connect the transtranslating device in a closed loop, and a common operating member for all of said switches adapted when in initial position to close the last two mentioned switches, when moved in one direction from normal position to close the irst mentioned pair of switches and when moved in the opposite direction from normal position to close the second mentioned pair oi switches, said member operating said switches through cams, and said cams being so designed as to insure closure of the third mentioned pair of switches prior to the opening of either of the other two switches.

15. ln combination, a switch controlling member movable between predetermined points, means biasing said member from one of said points to an intermediate position, andmeans for positively checking the operation of said member at said intermediate position when said member is moved by said biasing means, said member when brought to rest at said intermediate position being automatically freed for continued operation.

16. ln combination, a switch controlling member movable between predetermined points and biased from one of said points to an intermediate point, and means coper-y ating with said membernto permit uninterrupted manual operation or" said member from one extreme point to the other, but positively stopping said member at said intermediate position upon automatic operation thereof.

17. ln combination, a switch controlling member movable between predetermined points and a device associated therewith permitting free movement of said member in one direction :trom one of said points to the other, `but having a portion adapted to block the reverse movement of said member at an intermediate pointunless said member is adjusted during its movement to clear said portion. p

18. :in combination, a lifting magnet, means for connecting the magnet winding to a supply circuit to obtain a ilow of current therethrough in either direction, means for establishing a closed loop across the terminals of said winding prior to disconnection thereoi3 from circuit, and a resistance for said closed loop, said iirst mentioned means connecting said resistance in series with the magnet winding under predetermined conditions.

19. ln combination, a lifting magnet, means for connecting the magnet winding to a supply circuit to obtain a iow of current therethrough in either direction, means for establishing a closed loop across the terminals of said winding prior to disconnection thereof from circuit, and two resist- In witness whereof, I have hereunto subances, said first mentioned means connectscribed my name in the presence of two Witing both resistances in series with themagmesses.

`net winding under predetermined condic CLARK T. HENDERSON. 5 tions and said second mentioned means con- Witnesses:

necting one of said resistances in said closed F RANK H. HUBBARD,

loop. J EANETTE S. BROCK.

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