US2264531A - Electromechanical apparatus - Google Patents

Description

Dec. 2, 1941. P. P. HORNI ELECTROMECHANICAL APPARATUS Filed June 7, 1938 Pau/B/[oml INVENTOR AT RNEY Patented Dec. 2, 1941 UNITED STATES PATENT OFFICE ELECTROMECHANIGAL APPARATUS Paul P. Horni, Newark, N. J.

Application June 7, 1938, Serial No. 212,312

3 Claims.

This invention pertains to armatures and more particularly to the arrangement of an armature in relation to the core or cores of an electromagnet. Heretofore it has been the practice to employ metallic pieces with flattened surfaces to engage the pole face of an electromagnet. To prevent the residual magnetism from holding the armature against the pole face after the electromagnet has been de-energized, it is customary to provide a non-magnetic metallic member, such as a sheet of brass, between the armature and the pole face.

In utilizing the fiat armature to engage the pole face of the electromagnet, difficulties are frequently encountered. An instance of this is shown in the case where the armature may be dropped back from the pole face when the electromagnet is de-energized. The armature, however, is within the effective range of the electromagnet and is frequently so adjusted that a line surge will cause the armature to be snapped up into its attracted position.

In certain types of apparatus, for instance, fire alarm signaling transmitters, the adjustment of the armature in relation to the pole face is extremely critical, since any operation of the armature, when it is not required, may cause an extra electrical impulse in the signaling system. Furthermore, any operation of the armature when it is not required may cause the entire transmitted signal of a fire alarm system to be of no benefit, since a wrong signal could not be used for confirming a prior or following signaling cycle, which is required under the rules for proper operation of fire alarms for signal initiating stations. Furthermore, a line surge which would attract an armature when said armature is not required to be attracted, might cause the entire signal transmitter to be totally disabled.

From the foregoing it is pointed out that it is therefore essential that the armature be so constructed that a minimum amount of difiiculty will be encountered in adjusting the armature in signalling apparatus of the general type to which this invention is particularly adaptable.

In utilizing the fiat type of armature the nonmagnetic metallic member which is placed intermediate the armature and the pole face provides the equivalent of an air gap for the purpose of reducing the effect of the residual magnetism. However, in utilizing this flat type of armature, the armature frequently when moved into its attracted position will rigidly engage the pole face and have no mechanical freedom to permit cooperation with other parts of the device which are used in conjunction with the armature and its engaging lever arrangements. In electro-magnet devices of this type, the nicety of adjustment between the armature and its pole face is provided by moving the pole face of the electromagnet, which pole face is a part of the core of said electromagnet. This feature is not always desirable and it is pointed out that the present invention definitely eliminates the aforementioned objectionable features.

It is an object of this invention to provide a signal armature so constructed that a minimum amount of difficulty will be encountered due to abnormal line surges.

A further object of the invention is to provide an armature which is capable of adjustment in relation to a pole face, when said armature is in its fully attracted or portative position.

Another object is to provide an armature having a non-magnetic bracket supporting said armature with means constituting a part of said armature for limiting the flux flowing therethrough.

A further object is to provide an adjustable armature in combination with a resiliently mounted pole face constructed to provide a special concentrated magnetic field.

Further and other objects will be apparent to those skilled in the art from a perusal of the drawing and following specification.

For a better understanding of the invention, reference may be had to the accompanying drawing in which:

Figure 1 is a front view shown in section taken on the lines AA of Figure 2.

Figure 2 is a partial side view of the apparatus disclosing the relation of the armature and its corresponding pole face.

Figure 3 is a view partly shown in section to show construction of the armature.

Figure 4 is an enlarged end view taken on lines BB of Figure 3.

Figure 5 is a top view of Fig. 1 showing one of the electromagnets and certain of its associated parts in cross section.

Referring particularly to Figure 1, an armature 6 is held in a bracket 1, said bracket being split and having an adjusting screw 8 which is utilized to draw the opposing sides of the bracket together so as to securely hold the armature 6 of magnetizable material in a fixed position in relation to the non-magnetic bracket arm 9. The non-magnetic bracket arm 9 is pivotally mounted in journals l0l0' said bracket arm being of material such as brass or copper, having low, if any, magnetic properties. While it is not essential to show any of the operating mechanism of the gear train, it is felt that one gear II is sufficient to indicate a moving part which places the armature up into the effective range of the flux of the electromagnet. The gear l is pivoted on a shaft I2 shown dotted and is journaled in side frames l3-l3. The screws |4--|4 carry the journals |-|0 which screws may be any convenient means for providing journals for the pivotal member I5 which is securely connected to the bracket arm 9. The backs of the hubs 32-32 of of pole pieces |6|6 impinge resilient spiders I'I-l'l which spiders engage the front of the ends of the armature 6 in order to limit the flux due to excessive line surges. Thisis quite clearly shown in Figure 5 which is a top view.

In Figures 4 and 5 it can be seen that the hub 25 is so positioned and adjustably mounted as to permit adjustment of the armature toward or away from the pole faces X. This nicety of adjustment is afforded by the loosening of the screw 8 and a slight twist in either one direction or the other of the armature 6.. It will be apparent that with the eccentric hub 25, the copper members 24-24 may be spaced from said pole faces or moved so that they frictionally engage the pole faces when said armature is in its operative position as displaced by movement of engaging pin 2| against the shoulder of engaging surface 22.

possible since the cores connected to the pole faces X, are movable within the coil spools and usually have some limiting meanson the rear thereof to prevent the cores from sliding out when the armature is removed.

, The weight I9 is adjustable on the bracket arm 9, said weight being dependent upon gravity to cause the armature to be pulled away from the pole pieces |'6|6'.

Normally, the armature is retracted so that the bracket arm 9 rests against the stop pin 20, which pin limits the movement inone direction of the bracket arm.

In operation the movement of the gear train in the direction of the arrow will cause the pin 2| to engage the underneath surface 22 of the lower end of the bracket arm 9. The continued movement of the gear H and its pin 2| will move against the cam surface 22 and cause the bracket arm 9 and its corresponding armature 6 to be moved within the effective range of the flux of the electromagnet. Ordinarily,' if there is current flowing through the coils |8-|8, the armature B will be attracted before the pin 2| can completely move the armature into its extreme mechanically displaced position. However, if there is no current in the coils l8-l'8', then the pin 2| must completely move the bracket arm 9 and its corresponding armature 6 to th fully mechanically displaced position, that is, so that the armature substantial'lyengages the pole pieces 16-16. After the pin 2| moves past the shoulder 23, the effect of the gravity attracted member I9 will cause the armature to fall away from its pole faces and rest with arm 9 against the stop pin 20. p 7 7 From the foregoing it is pointed out that the armature through the medium of the mechanism provided herein, may be moved from aposition beyond the effective range of the flux of the electromagnet into the effective range of the flux of the electromagnet, and contiguous with the pole pieces IB-IB. It is also clear now, that in the absence of mechanical support, or magnetic support for the armature, the gravity actuated weight l9 will cause the armature 6 to fall away from its corresponding pole faces. 7

In Figure 3 we observe that the armature 6 has copper rings 24-24 which areconcentric with the armature 6. A hub 25 is provided on armature 6 intermediate its opposing ends and positioned eccentrically with reference to its longitudinal axis. Bracket surrounds hub 25, as shown in Fig. 4. This eccentric hub is provided to permit the proper mechanical adjustment between the actuated' position of the armature per se and, the pole pieces Iii-l6". A restricted flux path26 is provided intermediate the opposing In Figure 4, the end view more clearly shows the bracket 1 with the armature 6 having its copper member 24 shown dotted. The hub 25 is shown gripped within the bracket 1-.

The spools of coils Iii-l8" in Fig. 5 having the pole pieces |'6-l6" through the centers thereof engage a support member 3|] of magnetizable material which support 30 is secured to side frames I3-I3 by screws 33-33. Nuts 31-3 I threaded on the cores of pole pieces |6, |5 abut the'far side of support 30 against which they are held tightly by the spring resistance of thespiders which spiders engage the backs of hubs 32-32 of the pole pieces Iii-l6". Thus the spools of coils |B-|8' are held tightly back against the bracket 30. By this means, the pole faces of the pole pieces |6-|'6" will always remain substantially the same distance from the support 30 as determined by adjustment of nuts 3|, 3|", so that as the bracket arm 9 pivoted at Iii-I0 is mechanically urged toward the pole faces X by rotation of the pin 21 on gear H, the fully mechanically displaced position of the armature caused by mechanical motion of the gear train, will always bring the non-magnetic copper rings 24-24 to just about touchthe pole faces X. Angular adjustment of armature 6 in bracket 1 adjusts its position with reference to pole pieces Iii-l3, so that when the pin 21 of gear causesthe bracket arm it to urge the armature 6 toward the pole pieces- |6-|-6", the armature copper rings 24-24 will not presstoo tightly against the pole faces X to prevent the pin 2| from sliding past the shoulder 23.

It is further pointed out that thel'toothed pm tuberance X shown in Figs. 2 andg5 definitely has for its function a reduced poleface area to cause concentration of the emanating from the core of the electromagnet. The round armature 6 will have an area nearest to the toothed part X, which area on the armature 6 will tend to restrict the path. The peculiar arrangement of the restrictedarea X and the round armature 6, in combination, has-an effect which is highly desirable for the particular work'which the present invention is designed to effect; In this regard it is indicated that the limiting or restricted surfaces of the toothed members. X and the round; armature 6 infront of the pole faces areparticularly effective in that when. the. armature is dropped back out of the normal. effective magnetic range so that the bracket am 9 engages the pin 20-, line surges: have a minimum effect in attracting the'armatu're. However, the areas 6 and X are such that when the armature comes within the effective magneticfiarea,

fectively picked up by the electromagnet.

While the rotation of the armature may cause the armature to be slightly lowered or raised it is pointed out that at all times when the armature is mechanically urged to its fully mechanically displaced position, the copper rings 2424' of the armature 6 just about touch the pole faces X. Consequently, the armature adjusting is for a mechanical function rather than a magnetic function. The adjusting by angularly orienting the armature is necessary to permit the pin 2| carried by gear H to urge the copper rings 24-24 up to the pole pieces without binding. If the copper rings are forced against the pole pieces, and no resilient play of the pole pieces is provided as by resilient spiders H, the pin 2| will bind on the portion 22 which is at the lower end of the bracket arm 9. If this results, the pin 2| will not be able to continue its progress and the gear II will bind and stop. If the gear stops, the entire gear train will stop and the fire alarm transmitter will no longer be in op eration, resulting in a failure of the fire alarm transmitter which will be unable to send in its coded signal. The adjustment of the armature position and the action of resilient spiders |'l' avoid these operating difliculties.

Heretofore this desirable quality was entirely lacking in signaling apparatus wherein the armature was without the effective range of the electromagnet, and was mechanically moved into the effective range to be attracted by said electromagnet. This present invention has proven highly satisfactory in commercial use and without an equal in its particular field of electromechanical devices of the nature for which this invention has been set forth.

From the foregoing it is pointed out that it is no longer necessary to move the pole face in relation to the armature, which operation usually consumed a great deal of time, and did not provide a nicety of adjustment that is accomplished with the present invention. This nicety of adjustment is necessitated since any frictional engagement between the armature and the pole faces frequently resulted in no-operation of the device since the pin 2| on the gear II was unable to ride past the shoulder 23. If the pin 2| were unable to pass the shoulder 23 it is clear that the rotation of the gear ll would be stopped and the mechanism prevented from rotating further.

From the foregoing it will be clear that there are many advantages to the present invention which are not definitely pointed out in the objects but will be more definitely set forth in the claims.

While specific details of the system have been herein shown and described, the invention is not confined thereto as changes and alterations may be and may become apparent to those skilled in the art without departing from the spirit thereof as defined by the appended claims.

Having thus described the invention What I claim as new and desire to secure by Letters Patent of the United States is:

1. In a signal transmitter, an electromagnet having a pole piece, a movable cylindrical armature cooperating therewith, an eccentric cylindrical hub as part of said armature, the axis of said hub and the axis of said armature being laterally spaced but substantially parallel one to the other, a bracket having a cylindrical housing for said hub, pivot means supporting said bracket, and metallic non-magnetic means secured to said armature to prevent the armature per se from engaging the pole pieces, whereby rotation of the armature within the bracket housing will vary the distance between the bracket and the electromagnet when the armature is in its portative position.

2. In a signal transmitter, an electromagnet with a pole face and a movable cylindrical armature cooperating therewith, pivot means for said armature but spaced therefrom, a cylindrical hub as part of said armature, a bracket pivoted on the pivot means and having a cylindrical housing portion remote from said pivot means, the housing portion of the bracket carrying the cylindrical hub portion of the cylindrical armature with the cylindrical axis substantially parallel to the electromagnet pole face, the hub portion being eccentric to the pole face engaging part of the armature, whereby rotation of the hub Within the housing adjusts the armature relative to the pole face of the magnet.

3. In a signal transmitter, an electromagnet with a pole piece, a movable cylindrical armature cooperating therewith, an eccentric hub on said armature, pivot means, a bracket supported by said pivot means having a housing for said eccentric armature hub, means to permit rotation of said hub within said housing, and mechanical means to urge one end of said armature carrying bracket toward the pole pieces of the electromagnet, whereby rotation of the armature within the bracket housing will vary the distance between the bracket housing and the electromagnet when the armature is urged mechanically to its portative position.

PAUL P. HORNI.

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