US1674747A - Alternating-current electromagnetically-operated device - Google Patents

Description

Jurle 26, 192s. l 1,674,747

W. C. STEVENS ET AL ALTERNATING CURRENT ELECTROMAGNETICALLY OETERATED. DEVICE lOriginal Filed July 24, 1916 ATTORNEY Patented June 26, 1928.

UNITED STATES PATENT OFFICE.

WILLIAM C. STEVENS AND ARTHUR SIMON, OF MILWAUKEE, WISCONSIN, ASSIGNORS TO THE CUTLER-HAMMER MFG. C0., OF MILWAUKEE, WISCONSIN, A CORPORATION OF WISCONSIN.

ALTERNATING-CURRENT ELECTROMAGNETICALLY-OPERATED DEVICE.

Original application led July 24, 1916, Serial No. 110,945.

1923. Serial No. 646,513.

constant magnetic flux for a given voltageimpressed thereon and in consequence it' it be designed of suiicient strength to `actuate and hold a clapper switch or the like it inherently tends to actuate the same with a very objectionable slam due to the disproportion of its magnetic flux and initial load.

The present invention has for an object to curtail the slamming tendency of such devices. x

A further object is to provide for graduation of the magnetic pull exerted upon the Other objects and advantages of the invention will hereinafter appear.

This application is a division of our application led July 24, 1916, Serial No. 110,945. y

The accompanying drawing illustrates an embodiment of the invention which will now be described, it being understood that the same is susceptible of various modifications without departing from the scope of the appended claims.

In the drawing,

Figure 1 is a front elevation of a clapper switch `constituting an embodiment of the invent-ion; and Figure 2 is a side elevation of the electromagnet employed to operate the switch.

The switch illustrated-in the drawing is of the double pole type and comprises stationary contacts 1, co-operating movable contacts 2, a magnet frame 3 having an alternating current Winding 4 mounted thereon and held in place by members 4a attached to frame 3 inthe manner indicated -at 4b. Lever 5 is mounted on said frame to carry said 'movable contacts and has a part 6 constituting anarmature for said winding, all

.CII

attracted element according to its position.`

Divided and this application iiled June 20,y

of said parts being mounted upon a suitable panel 7. The contacts 2 are pivotally mounted upon brackets 8 fixed to the lever 5 and are provided with tension springs 9 against which the electromagnet must pull after initial engagement of said contacts 2 with the contacts 1. Thus during the movement of the lever from normal position to its position representing initial' engagement of the co-operating contacts, the load upon the elect-romagnet is very much lighter than during the continued movement of the lever against the action of spring 9 and yet the electlomagnet must be suiiiciently strong to forcibly engage the contacts and hold -the springs under tension Jfor continued firm engagement of said contacts.

The magnet frame which comprises laminations assembled upon a rigid support 10. has an extended upper pole 3 and a short lower pole 3b. The Winding 4 is mounted upon the pole 3b and, slightly in advance of the outer end of said winding, said pole is provided with a perpendicular polar face 3 constituting an abutment for the armature 6. The armature 6 is also formed of laminations supported by an extension 5a of the lever 5 in such a manner as to provide for movement of said armature beneath the extended pole 3 of the magnet frame,- said lever being pivotally supported for such movement upon a spindle 11 carried by the sup-l port 10. The upper extremity of the armature 6 and the adjacent face'of the extended pole 3 are curved concentrically with the pivot of the lever and accordingly the clearance between said parts will remain constant throughout the movement of the armature, said clearance being relatively small` as compared with the maximum distance between the armature and olar face 3. Further, the pole 3is rovi ed with a plurality 'of conducting ban s or closed coils l2, similar to shading coils, arranged' thereon in planes substantially perpendicular to the path of the-flux through said pole. The face of the pole adjacent to the end of the armature is slotted to permit said coils to `loe inset therefrom and said coils are so positioned as to lie across the path of the magnetic fiux in biased position of the armature and to be lshunted progressively by the magnetic flux as the armature advances in attracted direction.

Thus with the armature in biased position, as indicated by dotted lines, and with the- Winding energized the magnetic flux passing through the extended pole- 3 will induce current in all of the coils 12 with the result of producing a magnetic fiux opposing the'mafn iux. Such opposing flux will tend to divert the main flu-x from its path through the armature and cause the latter ux to pass directly to pole 3b across the air gapbetween the two pole-s with a resulting curtailment ofl the magnetic pull exerted upon the armature and accordingly upon the contact carrying lever. A part of the main flux Will, however, pass to and throughl the armature and thence to the pole 3", or vice versa, with the result of attracting the armature and lever and as the armature advances it Will progressively exclude the ',coils 12 from the path of the main flux thereby decreasing theA opposing ux and increasing the amount of iux passing to the armature with a consequent increase in pull upon said armature. Vhen the armature 'finally abuts the pole 3** it Will exclude the coils 12 from the magnetic circuit 'of the electromagnet and 1n consequence said armature Will be subjected to the full attractive force of the electromagnet for engagement of the contacts and retention thereof in engaging relation.

The curtailment and graduation of the magnetic pull upon the armature is dependent upon the number and arrangement of coils 12 and as will be apparent, byvaryingthe number and arrangement of said coilsdifferent pull curves may be obtained.

What we claim as new and desire to securerby Letters Patent is :-x

1. The combination with a device to be operated, of an alternating current electromagnet having a magnetic frame,.an armature movable with reference to sald frame foroper'ating said device and means on said frame to opposethe passage of the effective magnetic iux to said armature when in initial position to thereby curtail the ,mag-

netic pull exerted upon ,said armature in such position.

2. The combination Witlra' device to be operated, of'an alternating current electro- 'I magnet having an armature for operating the same and having a Winding about a pole thereof to provide -a magnetic flux opposing the magnetic flux to said armature to thereby curtail the pull exerted thereon, said winding being effective only during an initial part of the movement of said armature.

3. The combination with a device to be operated, of an alternating current electro-l magnet having a magnetic frame, an armature pivotally supported by said frame for by said frame to initially curtail the eiective magnetic flux through said armature to thereby reduce the initial magnetic pull upon said armature.

4. The combination with a device to be operated, of an alternating current electromagnet having a. magnetic frame, an arma.- ture pivotally moved With respect to said fra-.me for operating said device and means fixed to said frame to oppose the passage coils thereon and a surface in uniformly spaced relation to said armature during the entire movement of the latter.

36. The combination with a device to be operated, of an alternating current electromagnet, a pivoted armature for operating said device having a terminal portion adjacent one pole of said electroma et the adjacent faces of said pole and armature being curved concentrically with respect to said pivot, said pole having slots and conducting bands in said slots arranged to direct a portion of the magnetic flux across the air gap between said pole and the other pole of the electromagnet to thereby curtail the initial pull exerted upon said armatura 7 The combination with an alternating current electromagn'et having a lon pole and a short pole, an armature mova le to` Ward andaway from said short pole in uniformly spaced relation to said long pole,

and means on said long pole to oppose the passage of the magnetic flux to said armamature, to thereby curtail the magnetic pull exerted upon saidy armature by' said short pole when in initial position. Y

8. The combination with a device to be4 operated, of operating means therefor comprising an alternating current electromagnet having relatively movable parts, and means i comprising a conductive coil so associated with the electromagnet as to provide for shunting progressively different values of the magnetic iux during relative move.-

ment of said parts.

' 9. The combination `with a device to be operating said device and means carried tive movement of said members and provide for defiecting a portion of the flux fromsuch fleeting a portion of the flux from such path path to thereby curtail the initial pull of the to thereby curtail the initial pull of the magnet. magnet, the arrangement being such that 10. The combination with a device to be the reluctance of the normal flux path is 15 5 operated, of operating means therefor comgradually decreased during continued rela- Erising an alternating current electromagnet tive movement of said members.

aving relatively movable parts, a plurality In witness whereof, we have hereunto of closed coils on one of said members to subscribed our names. increase the reluctance of the normal llux 10 path during a portion of the relative move- WILLIAM C. STEVENS.

ment of said members and provide for de- ARTHUR SIMON.

cmlrlcair or comcrloN.

mm No. 1,674. 741. 9mm ma ze, 192s. t vmmm c. sumas rr AL. l

y 1f i henny pampa im .error man in m prima mcifimimof m bove nnlbered patent requiring correcltm es iollowe:- Page 2, line 73, chil 4, for theI word "paved" reed "nov|bl,e"; eed that the seid Letters Patent should be rend with this correction therein that the eene may mfom to the record of the cue in .the 'Patent Olitec. t'

Silned and mld tliie lltll 0110i Dum, A.- D. `1928.

ne Je me (Seal) Acting Col-ieeoaer of Patente.

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