US2001579A - Generator regulating device - Google Patents

Description

Patented Mayv 14, 1935 omaaroa aaoum'rmo DEVICE Bennett M. Iieece. Cleveland, and Dale 8. Cole, Cleveland Heights, Ohio, asslgnors to The Leece-Nevllle Company, Cleveland, Ohio, a

corporation of Ohio Application November 28, 1931, Serial No. 577,836

3 Claims.

- This invention relates to generating systems of the type provided on vehicles for lighting, battery charging, and other purposes, and more particularly to an improved form of regulating device for such a system.

An object of the present invention is to provide an improved form of regulator of the vibratory contact type wherein destructive sparking at the contacts is reduced to a minimum.

Another object of the invention is to provide an electromagnet having a core element disposed in an air-tight envelope and a make and break device associated with said core.

A further object of the invention is to provide a regulating device having a coil disposed around an air-tight envelope, and a core for the coil, which is positioned in the envelope andiincludes a vibratory member.

Other objects and advantages of the invention will be apparent from the following description when taken in conjunction with the accompanying sheet of drawing, wherein Fig. 1 is a diagrammatic view representing a generating system embodying the regulating means of our invention.

Fig. 2 is a sectional view, of somewhat diagrammatic form, representing another regulating device constructed according to our invention.

Fig. 3 is a similar sectional view taken through another regulating device of our invention, and

Fig. 4 is a transverse sectional view taken substantially on line 4-4 of Fig. 1.

Detailed reference will now be made to the accompanying drawing, wherein we have illustrated the regulating device 01 our invention as embodied in a generating system of the type commonly provided on motor vehicles for auxiliarypurposes. The invention is not to be regarded, however, as being limited to this particular use, 'nor to the specific arrangements illustrated in the drawing.

Our regulating device, as herein disclosed, represents an improvement over the regulating device of the Leece Patent No. 1,540,698, dated June 2, 1925, and over the regulating device disclosed in our application Serial No. 572,042, iiled October 30, 1931.

Our improved regulating device is especially useful in connection with a generating system of the type provided on motor vehicles, such as that illustrated in Fig. l of the drawing, comprising a generator III having main brushes II and II for supplying current to the load conductors l3 and I4, and a shunt iield l5 adapted to be energized from a third brush it disposed between the main brushes H and I2. The current supplied to the load conductors l3 and 44 by the main brushes may be utilized for any desired purpose, such as lighting, battery charging and other uses.

The regulating device itself comprises an electromagnet having coils or windings l1 and I8, which are disposed around an air-tight envelope I 8 containing a make and break device, and which are adapted to be energized from the generator in. These coils are in additive relation and function in the manner described in detail in the patent referred to above.

For the purpose of disclosing the present invention it is pointed out briefly that the coil I1 is a shunt coil having its ends permanently connected to the main brushes II and I2 by means oi! the conductors 20 and 2|, and the coil I8 is an operating coil having its ends connected to the main brushes II and 12 in such a manner that its circuit may be ailected or altered by the make and break device within the envelope i9. As explained more fully in the patent referred to above, the operating coll l8, upon being energized by the generator Ill, actuates the make and break device within the envelope, while the shunt coil II, responding to changes in the voltage output 01' the generator, controls or regulates the rate of operation or the make and break device.

The envelope, about which the coils of the electromagnet are arranged, may be of any appropriate construction, such as a tube of glass, or any other suitable non-magnetic material, which is evacuated and hermetically sealed. The make and break device disposed within this envelope comprises stationary and movable core members 22 and 23, of magnetic material, and a pair of cooperating contact elements 24 and 25. The core element 22 and the contact element 24 are 'held substantially immovably within the envelope, preferably by supporting conductors 26 and 21 which extend through, and are sealed in, the end walls of the envelope. The contact element 25 is movable toward and away from the stationary contact 24, and is carried by the movable core element 23. This movable core element is preferably so shaped that it conforms to the cross sectional shape of the envelope, and will be guided during its movement by engagement with the inner surface of theenvelope wall. If desired the sides of the movable core members may be depressed or undercut, as indicated at 24' so as to reduce the friction between this member and the wall of the envelope when the device is operated in a horizontal position. As shown in Fig. 1 of the drawing,

this movable core member may be of substantially U-shape, having a transverse bottom wall portion 28 forming a seat for one end of the coil spring 29. This coil spring is disposed between the'movable core member and the stationary core member 22 for the purpose of nor mally urging the contact element 25 toward the contact element 24. If desired the stationary core member 22 may be provided with a spring centering projection of suitable shape, such as the projection 30 illustrated in the drawing.

Regulation of the voltage of the generator I is obtained, in this instance, by controlling the excitation of the shunt field I5. Variation in the excitation of the shunt field is obtained by providing a resistance unit 3|, of suitable value, which is adapted to be intermittently connected into and short-circuited from the field circuit by the contact elements 24 and 25. To this end the resistance 3| is shown in Fig. l as being arra .iged in parallel with the contact elements 24 and 25 with its terminals connected to the conductors 26 and 21 by means of the conductors 32 and 33. The conductor 26 is connected with the main brush H by conductor 34, while the conductor 21 is connected to one end of the winding |8 by means of conductors 35 and 36, and to one end of the shunt field |5 by means of the conductor 31. Thus the circuit for the coil l8 may be traced from main brush through conductor 34, and then through core members 22 and 23 and spring 29 to contact element 25. Whenever the contact element is moved into engagement with the contact element 24, the circuit for the coil |8 is completed through conductors and 36, the coil itself, and through conductor 2| to main brush l2.

From the circuit arrangement as just described, it will be seen that as the speed of the generator increases, the strength of the magnetic field, produced by the coils I! and I8, is increased with the result that the movable core element 23 is attracted toward the stationary core element 22 thereby separating the contact elements 24 and 25. Separation of these contact elements interrupts the passage of current through the envelope so that all of the exciting current for the shunt field l3 must pass through the resistance 3|. With the resistance 3| connected in series with the field winding, in this manner, the ampere turns of the latter are materially reduced and consequently the voltage of the generator tends to drop. The decreasing generator voltage causes a corresponding decrease in the magnetization of the coils IT and |8, thus allowing the spring 29 to move the core member 23 away from the core member 22. This separating movement of the core members brings the contact element 25 into engagement with contact element 24, thereby establishing a current path through the envelope and short-circuiting the resistance 3| out of the field circuit. The removal of this resistance from the field circuit results in the field strength being increased and the magnetization of the coils H and I8 being again increased correspondingly. The increase in the strength of the magnetic field produced by the coils I1 and I8, again causes the core member 23 to be moved and the contact elements 24 and 25 to be opened, and the resistance member 3| again out into the field circuit. It will be understood, of course, that during the operation of the device the movement or vibration of the core member 23 takes place very rapidly and the resistance 3| is cut into, and

short-circuited from, the field circuit at a corresponding rate. The electromagnet consisting of the coils l1 and I8, and the make and break device contained in the envelope, thus responding to the voltage of the generator, control the excitation of the generator field to thereby maintain the generated voltage at a substantially constant value.

In Fig. 2 of the drawing, we have shown a regulator wherein the arrangement of the core elements is somewhat different from that illustrated in Fig. 1. In this arrangement the core, which is provided for the coils and 4| surrounding the envelope 42, comprises a stationary member 43 of magnetic material and a movable member 44. This movable member is in the form of a disc comprising a comparatively small body of magnetic material, and carries a movable contact element 45. A coil spring 45 disposed between the core members tends to separate the latter, thereby urging the contact element 45 toward a stationary contact element 46.

In making the movable core member in the form of a disc comprising a relatively small mass of magnetic material, as shown in this figure, the effect of gravity and external vibration upon this member will be almost negligible. comparative lightness of this movable core member increases the efliciency of the operation of the device when the same is set at an angle other than vertical, by tending to reduce the friction between this member and the walls of the envelope.

In Fig. 3 of the drawing, we have shown still another arrangement wherein the electromagnet is provided with an external magnetic core 5|, which is so disposed relative to the air-tight envelope 52 as to cause a strong magnetic circuit through the stationary and movable core members 53 and 54 contained within the envelope. In this arrangement the stationary core member 53 is made relatively long so as to provide a magnetic path within the envelope which will have very little reluctance. The movable core member 54 may be in the form of a relatively light disc of magnetic material which is urged away from the stationary core member by a coil spring 55. A contact element 56 carried by the movable core member cooperates with a stationary contact element 51 under the infiuence of the spring and under the influence of the magnetic field produced by the winding.

In the regulator constructions, which we have illustrated and described, the air-tight envelopes may be evacuated to such an extent that they contain an atmosphere of very low pressure, after which they are permanently sealed, or they may be evacuated and then charged with an inert gas, such as nitrogen, to provide the same with an atmosphere having desired characteristics. During the operation of a regulating device of this kind, the inert gas, contained within the envelope, or the rarefied air contained therein, as the case may be, tends to prevent oxidation of the contact elements when sparking occurs, with the result that the useful life of these elements is materially prolonged. Moreover, in the arrangement which we have provided, the air-tight enclosing envelope protects the contact elements against moisture, foreign material, and the meddling of unexperienced persons. This envelope also renders the operation of the device less subject to interference by external shocks or vibrations.

It will be understood, of course, that in the regulating devices illustrated and described, the

Likewise the A coiled spring, which is disposed between the core members, is formed of current conducting material so as to complete the path through the core members and contact elements arranged within the envelope. For most eillcient operation our regulating devices are preferably arranged with the axis of the envelope in a vertical position, but this is not essential and if desired the devices may be mounted and operated with the envelope extending in an inclined or a horizontal position. Although we have shown our regulating means embodied in a generating system of the threebrush type, obviously the same can be used as well in a generating system wherein the tenninals oi the shunt field are connected to the main brushes.

While we have illustrated and described our invention in a detailed manner,it should be understood that we do not intend to limit ourselves to the precise details of construction and arrangements of parts illustrated and described, but regard our invention as including such changes and modifications as do not involve a departure from the spirit of the invention and the scope of the appended claims.

Having thus described our invention, we claim:

1. In a vibratory electromagnetic device of the character described the combination of an airtight envelope, a magnet coil disposed around said envelope, 2. contact in said envelope, a core for said coil stationarily supported in said envelope, and a vibratory member in said envelope responsive to changes in the magnetization of said core and normally biased toward engagement with said contact for vibratory cooperation with the latter.

2. In a vibratory electromagnetic device of the character described the combination of an airtight envelope, a magnet coil disposed around said envelope, a contact in said envelope, a core for said coil stationarily supported in said envelope, a vibratory member in said envelope between said core and said contact responsive to changes in the magnetization of said core, and a spring interposed between said core and said vibratory member for biasing the latter toward said contact, said spring establishing an electrical connection between said vibratory member and the core.

3. In a vibratory electromagnetic device of the character described the combination of an elongated air-tight tubular envelope of non-magnetic material, a magnet coil disposed around said envelope, an elongated core for said coil stationarily supported in said envelope, a vibratory member axially movable in said envelope in response to magnetization of said core by said coil, cooperating contacts in said envelope, one of said contacts being relatively stationary and the other being carried by the vibratory member, and a spring electrically connecting said vibratory member and said core and normally biasing the vibratory member in a direction to close said contacts.

BENNE'I'I M. LEECE. DALE S. COLE.

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