US2487015A - Electromagnetic counting device - Google Patents

Description

Nov. l, 1949 J. i. BELLAMY 2943?@35 ELECTROMAGNTIC COUNTING DEVICE Filed Sept. 2G, 1946 2 Shee'tS-Sheei; l

NVENTOR: JOHN I. BELLAMY BY 55%" l ATTORNEY Nov. l, i949 J. n. EELLAMY 457mm ELECTROMGNETIC COUNTING DEVICE Filed Sept. 26, 1946 2 Sheets-Sheeh 2 37 FIG. G

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A4 56 L3 A3 59 :NSULATION 73 54 33 32 21 JEB AT TQRNEV Patented Nov. l, 1949 ELECTBOMAGNETIC COUNTING DEVICE John I. Bellamy, Brookfield, lll., signor to Kellogg Switchboard and Supply Company, Chlcago, Ill., a corporation of Illinois Application september ze, 194s, serial No. esente s claim. (ci. 117-353) This invention relates to electromagnetic counting devices. Its object is toprovide an improved form of electromagnetic devices for counting a received series of electrical impulses and for controlling contact sets in accordance with the number o1' impulses therein.

This invention is in the nature of a further improvement on the counting device disclosed in my prior application for Electromagnetic counting devices, Serial No. 647,896, led February 15, 1946.

The principal feature of the present invention resides in -a mechanical latching arrangement which renders unnecessary the sequence armatures oi' the previously identiiied prior application. By this latching arrangement, each armature after the first is maintained latched until the immediately preceding armature has operated and its operating impulse has subsided. An important advantage of this arrangement is that the magnetic flux required in the previous device to control the sequence armatures can be utilized herein to operate the work armatures more powerfully. such work armatures having a suitably increased cross-'sectional area for this purpose.

Other `features of the invention relate (1) to an improved construction for promoting the magnetic eiiiciency of the armatures by concentrating the iiux in their respective operating air gaps,

(2) an improved pivoting, guiding. and back-stop arrangement for the armatures, and (3) an im- .proved arrangement for providing the required number of contact sets side by side in the same plane and for rendering them readily adjustable after the deviceis assembled.

Other objects and features o1' the invention will appear as the description progresses.

Of the drawings, Figs. 1 to 9 show the construction of the improved counting device; Figs. 10 to 12 show successive operational steps; and Fig. 13 shows la wiring diagram of a simple signaling system employing the improved counting device.

More in particular, Figs. 1, 2, and 3 are respectively `a top view, a side view, and a front view of the improved counting device;

Fig. 4 is a further front view with certain parts removed;

Fig. 5 is a further top view with certain parts removed;

Fig. 6 is a partial sectional View taken along line 6--6 of Fig. 5;

Fig. 7 is -a `pantial sectional view showing how the insulating control studs are :attached to the traveling blades in the contact sets;

Figs. 8 and 9 show a modined construction of the latch springs;

Fig. 10 is an enlarged view o! the upper front pontion of the device in normal position; Fig. 1l is a similar view of the parts after the ilrst impulse has arrived and before it has terminated; and Fig. l2 shows the same Darts after the termination of the first impulse.

DETAILED DESCRIPTION A. General arrangement Referring first to Figs. 1 to 7, and more particularly to Figs. 1 to 3, the improved counting device includes a generally rectangular magnetic structure of which magnetic return plate I comprises the rear lim-b and the principal portion of the upper limb; ten armatures 4 comprise ,the remaining portion of the upper limb; two parallel electromagnets 2 comprise the lower limb; and laminated pole member 3 comprises the front limb. All the remaining parts of the structure are preferably non-magnetic, except that the screws V69 and l0, and .parts 5I and 68, in bank assembly 5 may be of steel if desired. Parts I, I2, and 3 may be of soft cold-rolled steel, but armatures I are magnetically hard. They may be made of annealed too1-steel sheet.

As seen -best in Fig. 2, each of the electromagnets includes the usual iron core I2, a square rear spool head I4, a round iront spool head I5, and a pair of concentric windings (not separately shown) wound between the spool heads. As seen best in Figs. l and 5, each of the rear spool heads is provided with four winding terminals I3, a separate pair for each of the two windings of the associated electromagnet. assembled with return Il (Figs. l and 5).

Actuating pole member 3 may be conveniently formed of a number of similar laminations secured together by rivets 26 (Figs. 1 and 4). Pole member 3 is attached to the front of the cores I2 by a pair of screws I6 which are countersunk in the overlying nonmagnetic bracket I'l, which affords a location for attaching the nine armature latches L2 to LI d which cooperate with the armatures to cause them to respond respectively to successive impulses in a series received by electromagnets 2.

Bank assembly 5, attached to return plate l. supports ten similar sets of contact members CI to CIU, one for each of the ten armatures l. External connections to the contact members may be made through their rear terminal portions 1.

plate I by a pair of screws Electromagnets 2 are B. vThe armatures The ten armatures 4' are referred to individually as armatures Al to All). They are positioned along the common pivot rod 29. on which they are freely rotatable. Pivot rod 29 is supported on the upper surface of lguide bracket 3i, and is held in place by the three overlyingarms 38 oi pivot bracketI 35. Parts l, 3l. and 35 are held in the illustrated assembled position by three rivets 89.

Eachof the armatures d comprises a main armature portion surrounding pivot rod 29, and extending forwardly therefrom, and a contactactuating tail portion 39 which extends to the rear and underlies its associated one of the contact sets Ci to C40. Pivot bracket 3B ends at the rear in an upstanding portion 8l, the top edge oi which underlies tails 39 to serve as a common backstop for the armatures.

The upturned rear portion 32 of guide bracket 3l is slotted at ten points 33 (Fig. 6) to provide individual rear guide slots for the armatures Il. The upturned front portion 3d of the guide bracket is similarly slotted at points 35 to provide individual front guide slots for the armatures d. As is shown best in Fig. 5, the front guide slots 35 extend rearwardly in the forward horizontal portion of guide bracket 36 to a point to the rear of the location of pivot rod 29 so as to receive the lower edge of the main portion of each armature t. The intervening space between any armature i and return plate l serves as the return air gap for the concerned armature f3. The parts are preferably so dimensioned that only a small amount of this air gap (.010 inch, for example) remains after any armature "i has fully operated to lie substantially parallel to return plate 0.

In the assembly oi the device, the ten arma ltures d are placed in their respective slots in upstanding portions 52 and 3, and are then secured pivotally in place by sliding pivot pin 29 endwise into position. The part 36 is made of suilciently thin stock that retaining arms 38 spring outwardly sufficiently to permit pivot rod '2S to be forced endwise into position, but are still rigid enough to retain the pin firmly in its illustrated assembled position.

C. Front pole member Front pole member 3, comprising the illustrated laminations held together by rivets 2t, may next be attached to the forward end of cores 52, by screws l, along with bracket member it, before theA assembly including latches L2 to Li@ has been attached.

As shown best in Fig. 4;, the upper edge of pole member 3 is slotted to provide teeth 25 respec tively underlying the armatures t. This arrangef ment provides a higher concentration of ux between the pole member and the armatures than is afforded by a flat, common pole face, thereby increasing the tractive force on the armatures.

The openings in pole member 3 for screws i6 are slotted vertically to permit oi vertical adjustment of the pole member. Preferably, a thickness gauge (.010 inch, for example) is inserted between armatures t and the forward portion of return plate l. Then, armatures Al and AID may be held operated by hand against the thickness gauge to bring the lower edge thereof substantially parallel to return plate l, and the pole member 3 may be brought directly into contact with the lower edge of these armatures. Screws I6 may be tightened rmly with the parts in this position, whereupon, the thickness gauge may be removed. All armatures will then be able to come directly into contact with the upper surface of pole member 3 despite normal manufacturing variations.

D. The contact bank Contact bank E may next be assembled with return plate i by three screws 'l0 which pass downwardly through the bank and enter tapped openings in the return plate. This bank assembly is arranged to beheld together as a preassernbled unit by two screws 69, which pass downwardly through cap plate 68 and threadedly engage the comparatively thick base plate 5i, within which they end. The intervening parts include comb 52 to which restoring springs 53 are integrally attached, base insulator strip 'i l, spacing insulator strip 65, and sub-assembly insulating strips Bt, tl, t6, and el to which the contact members are attached in layers. For example, as is seen best in Figs. 5 and 6, insulating strip t3 has individual contact blade 5d attached thereto at a pair of points ll, and has the laterally displaced contact plate 55 attached thereto at urther points lll, wherefore parts 63, 5d, and 55 cornprise a preassembled strip which may be placed at the indicated position in the bank assembly as a unit. The preassembling operation is prefer-1 ably accomplished by providing pairs of punched openings it in parts 5t and 55, and by using these openings as dies to cooperate with punch members employed at points "il to semiperforate strip 63 to force material therefrom into openings lo. The parts are thereby held together iirmly enough for handling as a unit for assembly into the contact bank. Each oi the other layers of contact members is similarly xed with the concerned one of the insulating strips dit, Gd, and el.

The traveling blades 56 and 5l are preferably comparatively thin and arepretensioned (bent downwardly prior to assembly of the bank strips together) to exert the desired downward pressure to maintain closed the back contacts associated respectively with the ten blades 5S.

Comb 52 and restoring springs 53 are preferably or" thin material, and springs 53 are pretensioned, by being bent downwardly a substantial amount, to provide a sumcient, but comparatively light, downward restoring pressure on tails 3Q of armature l.

Fig. which is a cross-sectional view through any traveling blade be and its attached stud 59, shows how studs be are attached to blades 5t. Each such blade 5t has a depending tongue el struck downwardly therefrom. Each stud 59 has a hole vertically therethrough of a diameter slightly less than the width of tongue t l. When any such tongue di is forced into its stud 5S, the resulting distortion of the insulating material (such as a suitable plastic or hard rubber) of the stud causes the parts to remain rmly in the illustrated assembled position. Studs 5@ are iixed with travelingblades S0 in a similar manner. The openings in the forward ends of blades di resulting from striking down their tongues El may be seen in Fig. l.

'After the preassembled contact bank 5, with its ten forwardly extending sets of contact blades Cl to Clt, and its rearwardly extending terminal portions l, has been attached, by the three assembly screws it, and before latch springs L2 to Li@ are attached, the contact sets Cl to Cid may be adjusted for operation. The height of backstop portion 3l of pivot bracket 3S is preferablyso chosen that a desired working air gap (.031 inch, for example) exists between any areA mature l and the upper face oi' pole member l when the armatures are held in their normal position by restoring springs 53. n the forward stroke of any armature, its traveling blade l engages its make-contact blade 58 when only a small amount of working air gap remains (.005 inch, for example). The thickness of the blades 58 is preferably such that the desired contact pressure is built up between blades 5l and 58 incident to a small deflection movement of the order stated. vSince the front-contact blades 58 lie uppermost in the assembly, they are readily accessible for bending up or down to secure makecontact closure at the desired point in the armature travel.

On the forward stroke of any armature, its associated traveling blade 56 should separate from its underlying back-contact blade 54 slightly before the front contact controlled by the associated traveling blade 5l closes. Such separation may occur when, for example, .010 inch of the armature stroke remains. This adjustment is accomplished for the first stackup Ci by bending individual blade 54 upwardly or downwardly as desired. Thiscan be accomplished after assembly by employing a suitable tool which grips blade 54 from the side near the base thereof, such as a spring bender commonly employed for adjusting the contact blades of telephone relays. Adjustment of the point of which the back contacts separate in contact sets C2 to CIO is controlled by raising or lowering the forward end of back-contact plate 55, seen best in Fig. 5, for this contact plate carries the nine back-contact points for the nine contact sets C2 to CIO, being provided with a single rear terminal 55. Raising and lowering of the front edge of plate 55 is accomplished by bending upwardly or downwardly support arms 13 extending alongside the cutout portion 12. Plate 55 is strengthened along the front edge by having a downwardly offset rib 15 (Figs. 2 and 5) formed therein. The above-mentioned bending of arms 13 to accomplish the desired back-contact adjustment is facilitated by slots 14, Figs. 1 and 5, into which a suitable tool may be inserted which is thin enough to pass between the concerned contact sets.

As a result of adjustment of the contact sets CI to Cin as described, a substantial clearance gap exists between the lower end of any stud 59 and the opposed face of restoring spring 53, wherefore any armature 4 executes a large portion of its forward stroke before engaging control stud 59. This arrangement provides considerable latitude in adjusting the latches L2 to ILli'l and their attached cam-spring portions 24.

E. The latches Latches L2 to L|0 may now be applied to the structure and adjusted. The latches may be formed of spring material having only suicient rigidity to reliably resist substantial bowing under the downward pressure exerted by the armatures when latched thereby. Each latch includes a main latch portion 2|, 22 and a laterally displaced rearwardly oiset camming spring portion 24, connected to the main portion by the diagonally extending portion 23. Portions 2l of latches L3 to LID lie directly behind the main portion of latches L2 to L9 respectively. In the embodiment of the device as shown in Figs. 1 to 7, L2 to LID may comprise separate members soldered or similarly secured to one or both of the plates i8 (Fiss. 1 to 3). The two plates i8 may be riveted together at points I8. The latch assembly is secured to bracket i1 by three screws 20, and may be adjusted vertically before screws 20 are finally tightened by virtue of the clearance between such screws and the vertically elongated openings in parts i8 through which they pass. The adjustment is preferably such that a forward movement of any armature A2 to AIB on the order of .005 inch occurs before its forward portion 43 encounters the end of its associated latch to compensate for manufacturing irregularities. Any latched armature should be brought to a stop by its associated latch when its unfinished forward stroke is on the order of .026 inch when the total stroke is as previously indicated.

The final adjustment steps with respect to the latches L2 to Liu include bending the lower portion 2i of each inwardly or outwardly near the base portion to insure that the upper portion 22 thereof (see Figs. 2 and 10 to 12) lies snugly against the face of vertical stop portion 4i of its associated armature 4, but with only the desired relatively light tension, and includes bending camming spring portion 24 inwardly or outwardly to a point where operation of the concerned preceding armature results finally in the forward movement of the top of the main portion of any latch member just sufficiently to reliably unlatch the associated armature. When this adjustment has been accomplished, no camming portion 24 is engaged by the camming surface 40 of the concerned armature until such armature has completed nearly half of its total forward stroke, for an outward-movement on the order of .010 to .015 inch is ample to unlatch an armature.

F. Modiyed latch construction Figs. 8 and 9 show a modified construction wherein assembly of the latches between strips i8 of Figs. 1 to 3 is facilitated by forming the even numbered latches L2 to L8 in one piece with a common interconnecting member as shown in Fig. 8, and by forming the odd numbered latches L3 to L9 in one piece with a further common interconnecting member as shown in Fig. 9. Each of the common interconnecting members is provided with a pair of openings 9 to receive rivets I9 through which they may be preassembled with strips I8, and each is provided with openings i0 through which assembly screws 20 may pass.

In the construction as shown in Figs. 8 and 9, the latches may be formed of somewhat thinner material than in the construction shown in Figs. 1 to 3 because of the stiffening effect of raised rib portions 8. Such rib portions strengthen the main portion of each latch member, while leaving their camming sidenarm portions of unimpaired flexibility. The lower end of each stiilening portion B lies a short distance above the base of the latch, leaving a flexible hinge portion 45 to permit the latch to swing out readily when released as described.

It will be understood, of course, that one of the parts shown in Figs. 8 and 9 is laid over the other, with corresponding openings 9 and i0 aligned. The main portions of latches L3 to L9 then lie in front of the laterally and rearwardly offset camming side arms of latches L4 to Lil), respectively, as is shown in Figs. 1, 3, and 5. The cannning side arms of latches L3 to L9 lie behind latches L2 to L8, respectively.

G. The counting operation about as indicated on an enlarged scale in Fig. l0.

Gl. First impulse begins n the receipt by electromagnets 2 oi the rst magnetizing impulse of a series, each of the armatures Ai to Ait is thereby attracted downwardly by the resulting magnetization of pole member il. Each armature is held in normal position only by the relatively light resti-a um.: force of restoring springs 53, keeping in mind that a substantial lclearance normally exists between each restoring spring 53 and its overlying control stud et, and that a substantial clearance normally exists between each www. arm 2d and the camming face il@ of its associated armature. accordingly, all armatures d start to move substantially together.

Before any armature has moved sumciently to encounter either its associated contact-control stud be or its associated camming spring portion 243, the forward movement of each armature .A2 to Aid is arrested, by the slightly protruding latch portion i3 thereof coming into contact with the upper end of the main portion of its associated latch L2 to Li t. The rst armature Al, however, having no latch, continues its forward movement until it comes into engagement with pole member 3 as shown in Fig. ll.

.ils the movement of the rst armature Ai continues from the point in its travel at which the slight forward premovement of the latched armatures A to Ait is arrested, its camming face dii engages the upper end of the associated carnming spring arm 2d of latch L2. This engagement may occur at midtravel of the armature, or slightly before. The further movement of armature Al toward its iinal fully operated position causes the upper end of camming spring arm 26 to be moved forwardly. This forward movement is accompanied by a flexing of arm 2Q and by a similar exing of the upper portion 22 of latch L2, resulting in latch L2 assuming a position substantially as is indicated in Fig. 11. The downward force being exerted on the upper end oi latch L2 by portion d3 of armature A2 holds the latch in the tensioned condition indicated in Fig. ll so long as the operating impulse endures. rIhis holding action may be enhanced as desired by sloping the lower surface of part di! upwardly and rearwardly, but this has not been found to be necessary with the structure as illustrated and described because of the normal rearward inclination of the prop-like latches as shown best in Fig. 2.

With the parts relatively adjusted according to the previous description, when armature Ai has completed about two-,thirds its stroke, its tail portion 39 brings restoring spring 53 into contact with stud 59, thereby immediately lifting traveling blade 5d from in engagement with the relatively rigid underlying blade ed, thereby opening the back contact represented by these two blades.

Just before armature Ai completes its strobe,

stud i0 forces traveling blade 51 into engage ment with the associated comparatively rigid blade 58, thereby closing the front contacts represented by blades B1 and 5B.

Gla. First impulse ends When the rst impulse ends, armature A! is held in its fully operated position by the residual magnetism which it retains by virtue of the composition and treatment of the material of which it is composed, notwithstanding the restoring pressure at that time exerted by the combined action of its restoring spring 53 and associated contact blades 56 to 58, and the slight restoring action of arm 24 of latch L2; Each of the remaining armatures A2 to Aid, however, not having been permitted to come close to pole member 3, is immediately restored through the short distance required to reengage upstanding backstop portion tl of pivot bracket 15. Incident to to the upper end of latch L2 by the'slightly overhanging latch yportion. lib, parts 22 and 2t of latch L2 immediately straighten out to move the upper end of latch portion 22 outwardly to a position such as is indicated in Fig. l2, wherein it is out or reach of portion t3 of armature A2. Latch Ld is maintained in this position thereafter until the device is cleared out.

G2. Second impulse begins At the beginning o .the second impulse of the series, the already operated armature Al is attracted still more ilrmly, and each of the unoperated armatures A2 to Al@ starts to move toward pole member 3 as previously described. Each of the armatures A3 to Alt is arrested (each by its associated one of the latches L3 to Lili) after it is moved only the previously described short distance, but armature A2 operates fully at this time as previously described for armature Al. its associated latch L2 having been moved outwardly, as described, to a position such as is shown in Fig. l2.

incident to its above-noted complete movement, armature A2 exes latch L3 as described for armature Ai and latch L2, thereby preparing to unlatch armature A3. Additionally, armature All., through its tail portion 3Q, actuates the contact members in contact set C2 as described for armature Ai and contact set C i.

@2a. Second impulse ends Whenthe second impulse of the instant series ends, the upper portion 22 of latch L3 is thereby released, permitting such latch to spring outwardly to an in'eective position such as is illustrated in -Fig. l2 for latch L2.

G3. Succeeding impulses en the succeeding impulses of the series arrive, the armature l corresponding to any such impulse operates as previously described and tensions the associated latch preparatory to the un- 5 latching of the next succeeding armature when such impulse ends. The counting operation is thereby continued as` described. The device is capable of counting the impulse of a series equal in number to the number o armatures d, ten being provided in the illustrated example.

Gli. Clearing out 7e mild reversed magnetization to neutralize tbe the restoring action of armature A2, and to the consequent release of the force previously applied residual magnetism of the operated armatures I, which restore immediately by virtue of the stored downward tension in the operated ones of the contact sets C| to CID, assisted by the light restoring tension of restoring springs 53.

H. The system of Fig. 13

Fig. 13 illustrates use of the improved counting device in a simple signaling system. In this system, the counting device is illustrated in circuit diagram within the rectangle label "Counter, and a relay group for controlling the operation of the system is shown within a further rectangle label Control circuit. The impulse counter is controlled over line |00, through the illustrated control circuit, to light signal lamps Si to Si selectively. The control is exercised from a remote control station, including the switch key SK and calling device CD. Calling device CD can transmit a series containing from one to ten interruption impulses. being of the type usually employed in automatic telephone systems.

In the control circuit, relay |0| corresponds to the line relay customarily employed in automatic telephone systems; relay i 02 corresponds to the slow-restoring release relay; and relay |03 is a slow-operating start relay which refrains from operating until a transmitted series of impulses has terminated.

Electromagnets 2 are each shown in Fig. 13 as having two dierentially connected windings. The lower winding is the one which receives impulses to be counted, while the upper one is the relatively low-powered demagnetizing winding used for clearing out the device.

Assume now that a desired one of signal lamps SI to S|0 is to be lighted to display a correspending signal. This operation is effected from the control station by first closing key SK and then manipulating calling device CD to transmit a corresponding series of interruption impulses over line |00. Line relay |0| responds to the closure of key SK by operating release relay 02 to prepare an impulse circuit for the counter. Being slow restoring, release relay |02 remains operated throughout the series of restorations of line relay IM incident to the assumed operation of calling device CD.

Line relay |0| restores momentarily each time calling device CD interrupts line |00. Each time it does so. it closes a circuit for the impulse'windings of electromagnets 2. by Way of the front contact of the armature of the operated release relay |02. The impulses thus delivered to electromagnets 2 causes a counting operation to occur as hereinbefore described. Accordingly, concerned ones of contact CI to C|0 are actuated successivelv. beginning with contact set CI.

Unon the-actuation of contact Ci (separation of its members 54 and 56, and closure of its members 51 and 58) incident to the receipt of the ilrst impulse of the series, a circuit is prepared for slow-operating start relay |03. This circuit 'is closed momentarily upon each reoperation of line relay |0| during the transmission of the impulse series. Being slow restoring, start relay |03 does not respond to these momentary closures of its circuit, but delays until its circuit is closed relatively permanently, when line relay |0| comes to rest in an operated condition at the end of the impulse series.

Upon operating, at the end of the transmitted impulse series, start relay |03 closes a self-locking circuit at its lower contacts, independent of the Cil ing through the armatures lower contacts of line relay |0|: prepares a clearout circuit for the counter at its upper contacts; and at its inner upper contacts, it applies ground potential to the signal conductor extending to the counter, thereby completing a lighting circuit for the one of the signal lamps Si to S|0 which corresponds to the last-operated one of the contact sets Ci to C10.

If, for example, the received impulse series contained only a single impulse, only contact set Ci has been operated. In this event, lamp Si is lighted in a circuit through the contact member 55 (common to contact sets C2 to Ci0) and the associated contact member 58 in Contact set C2. One the other hand, if two impulses have been received, contact C2 is operated along with contact set Ci. Then, lamp Si is disconnected (by the separation of member 58 from member 55), and lamp S2 is substituted, being connected to common member 55 by way of members 5l and 58 of contact set C2 and member 56 of contact set C3.

Operation of any succeeding contact set C3 to C|0 results in the disconnection of the signal lamp associated with the preceding contact set and in the substitution of the locally associated signal lamp.

When the system oi Fig. 13 is to be cleared out, switch key SK is reopened, permitting line and release relays |0 and |02 to restore successively. Incidentally, a further actuating impulse is delivered to the impulse counter during the interval required for relay |02 to restore following the restoration of relay |0| which may be avoided, when desired, by providing a pair of normally closed contacts on start relay |03 in series with the impulse windings of electromagnets 2.

Start relay |03 remains operated (through the upper contacts in set Ci, and through its own lower contacts) notwithstanding the restoration of line relay |0|. With relays |0| and 02 both restored, a clearout circuit exists through the upper contacts of relays |0| to i 03 for the lowpower demagnetizing windings of electromagnets 2. Responsive to the ow of current through these windings, the counting device clears out as previously described, all operated ones of the contact sets Ci to C|0 returning to their illustrated normal condition. When this occurs, the opening of the upper contact pair in set C| causes start relay |03 to restore to open the clearout circuit, returning the system of Fig. 13 to its illustrated normal condition.

Notice is hereby given that subject matter disclosed herein is claimed in my subsequent application for Electromagnetic counting devices, Serial No. 711,111, filed November 20, 1946, as a continuation in part of this application.

I claim:

1. In an electromagnetic structure, an electromagnet, a series of armatures and means movably supporting them side by side in a row, a pole member for the electromagnet underlying the armatures in common and shaped on its side adjacent the armatures to provide a series of raised pole-face portions operatively underlying the armatures respectively.

2. In an electromagnetic structure, an electromagnet, a series of armatures and means movably supporting them side by side in a row, a pair of pole members for the electromagnet operatively underlying the armatures in common, said supporting means including a non-magnetic plate overlappingly secured to one pole member and slotted to receive the armatures, a pivot rod passin common, and means aesaois tor. clamping the pivot rod against said nonmagnetic plate.

3. In an electromagnetic structure, an electromagnet. a series of armatures and means movably supporting them side by side in a row, a pair of pole members tor the electromagnet operatively underlying the armatures in common, said supporting means including a non-magnetic plate overlappingly secured to one pole member and slotted to receive the armatures, a pivot rod passing'through the armatures in common, and means for clamping the pivot rod against said non-magnetic plate, each armature having a'tail portion iixed therewith which engages said non-magnetic plate to dene the normal position oi the armature. 1

In an electromagnetic structure, an electromagnet, an amature and means movably sup porting it, a pair o pole members for the electromagnet operatively associated with the amature, said supporting means including a non-magnetic plate overlappingly secured to one pole member and slotted to receive the armature, a pivot rod passing through the armature and means for the pivot red agamt said nom-magnetic 5. In an electromagnetic structure. a pole member and an electromagnet for energizing it, a series otarmatures and means pivotally supporting them side by side in a row generally parallel to the near face of the pole member, and nonmagnetlc guide means providing separate guide slots for the respective armatures.

JOM I. B.

assemblers erran The following references are of record in the ille of this patent:

'fr STA'IES "5111.1'

Number Name te 592,432 MclBerty Oct. 26, 1897 767,703 Levison Aug. 16, 1904 849,4@ Webster Apr. 9, 1907 979,992 Dunham Dec. 20, 1910 991,929 Clement May 9, 1911 994,345 Suridh June 6, 1911 1,318,178 Reed Oct. Y, 1919 2,127,322 Blomberg Aug. 16, 1938 2,292,489 Stibitz Aug. 11, 1942 2,305,450 Stibitz Dee. 15, i942

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