US2195328A - Magneto-electric generator - Google Patents

Description

March 26, 1940. Q R, EATQN 2,195,328

IIAGNETD-ELECTRIC GENERATOR Filed Aug. 5, 1957 2 Sheets-Sheet 1 March 26, 1940. G. R. EATON 2,195,328

IAGNE'rELEcTRIc GENERATOR Filed Aug. 5, 19:57 2 sheets-sheet 2 Patented Mar. 26, 1940 UNITED STATES PATENT OFFICE MAGNETO-ELECTRIC GENERATOR Application August 5,

4 Claims.

My invention relates to a magneto generator of the type used by telephone subscribers for signaling a central oice particularly those subscribers associated with what are commonly yknown as rural lines which lines are usually of such length that the `resistance is too high to permit the use of central battery equipment.

The present trend of telephone equipment is toward lighter and more compact equipment and an object of my invention is the construction of a highly eflicient generator which is light in weight and small in size.

A feature of my invention is the provision of a generator in which the operating mechanism is entirely enclosed.

Another feature of my invention is a generator so constructed that the permanent magnets are held in place by the cover plates and the supporting frame which completes the magnetic circuit.

Another feature resides in the use of short bar magnets, which are preferably of special composition, on opposite sides of the rotor whereby a concentrated magnetic field is provided by a `small amount of magnetic material.

Another feature of my invention is the use of an internal gear so as to reduce the overall dimensions of the generator.

Still another feature of my invention is a special lever mechanism associated With the crank shaft for operating the contact springs which control the automatic shunt common in generators of this type.

Other features not specifically enumerated .above will be apparent from a perusal of the following specification and claims.

In the accompanying drawings,

Fig, 1 is a side View of my magneto generator with the side cover plate removed.

Fig. 2 is an end view with the cover removed and part of the larger gear web broken away to show the pinion gear.

Fig. 3 is a sectional view taken along the line 3--3 in Fig. 2.

Fig. 4 is a sectional in Fig. 2.

Fig. 5 is a sectional view along the line 5-5 in Fig. 1.

Fig. 6 is a sectional view along the line 6-8 in Fig. 8.v

Fig. 7 is a sectional view along the line 1-1 in Fig. 2.

Fig. 8 is an end View of the commutator disc.

Fig. 9 is ank Interior view of the large gear and view along the line 4-4 1937, Serial No. 157,459

are composed of magnetic material. An end plate I3 is fastened to the bottom member II and top member I2 by means of screws and this end plate I3 has a thickened portion I4 (Fig. 3) provided with an orifice in which is secured a bearing I5.

The armature comprises an H-shaped core I6 and Winding I'I which is placed upon the round bridge member I8. The round core member differs materially from the oblong core which is usually used in generators of this type and its use greatly facilitates the winding of the armature and thus reduces the cost of, construction. The edges I9 and of the core I6 are arcuate-shaped so that the armature is substantially cylindrical in form. Circular metallic end plates 2l and 22 are secured to the ends of the core I6 by means of screws 23. The plate 22 has a stub shaft 24 secured to its center, which shaft enters the bearing I5. Secured in any suitable manner` to the plate 2I at its central point is a shaft 25 which extends through the bearing 26 and has a pinion gear 21 securedto its end. The respective shafts 24 and 25 support the armature and permit it to be rotated. The shafts are parallel to the arcuate-shaped core pieces I 9 and 20 and at right angles to the bridging member I8. Rotatably supported on the shaft 28 is a hub 29 which is also rotatably secured in the bearing mounted in a recess in the frame member. Rigidly secured to the outer end of the hub 29 is a web or disc 29 to the outer circumference of which is secured the internal gear LG the teeth of which mesh with the teeth of the pinion 21.

Formed in the inner end of the hub 30 is cam notch 3 I. Pin 32 extends through shaft 28 within the notch 3I. A crank C has threaded engagement with the end of shaft 28 and when the shaft is rotated by crank C, pin 32 will slide along the cam surfaces of the notch 3l to displace the shaft 28 relative to the hub 29, but engagement of the inner screw threaded end of the crank C with the web 29 will so limit the longitudinal movement of shaft 28 that pin 32y will be unable to move beyond the top of the notch 3I. Thus upon turning crank C, the shaft 28 is iirst displaced longitudinally until the end of crank C engages web 29 after which the internal gear LG is rotated with the crank. Gear LG acts through pinion 2'! to impart rotary movement to the core I6.

The shaft 2B has a reduced end portion 33 which extends into a bearing 34 in the frame F. Upon the initial rotation of the shaft 28, it moves longitudinally, as above explained, and the shoulder 33' of the shaft engages the lever 35 (Figs. 3 and 4) through an oriiice in which the reduced end 33 of the shaft passes.

Lever 35 is provided centrally with an orice through which the screw 38 (Fig. 4) passes. The frame F is provided with a hump 31 at the point where screw 36 enters so as to permit the lever to pivot at this point. Upon initial operation of the crank, the upper end of lever 35, as seen in Fig. 4, is moved to the right and the lower end 38 is moved to the left.

The end 38 of the lever 3% engages a plunger 39 which is adapted to move longitudinally through an orifice in the supporting ir-ame F to operate a contact spring c purposes hereinafter described. A spring member secured by means of rivets I2 to the lever S5. This spring member' is bowed in such a manner that its ends rest against the supporting frame F but its center portion is raised therefrom so that the end 38 of the lever 3E normally is held away from the supporting frame F and the other end of the lever 35 is maintained against the shoulder S3 o the cranl; shaft The springs nl@ and ifi are normally engaged to complete the usual automatic shunt circuit when the generator is idle. rIhe springs 4G and 45 are normally separated but are closed when the generator is operated to complete the electrical circuit for the armature winding. When the rotation of the crank is stopped, the spring 4I forces the crank to the left in Fig. 4 and the upper or lever .follows the shoulder 33. The contact spring 4d presses the plunger 39 against the lever arid the spring c disengages the spring E and again engages ie spring 44.

An extension 46 of contact spring .it

i (Figs. 2 and 7) engages a spring iember fil which rests within an insulating bushing 5d secured within an orifice provided in the supportiro rrame F. The other end of spring engages a ce. oon block which is thereby spring presse into engagement with a coilector disc @9. This collector disc 4B consists of a circular copper disc which is held in position upon an insulating disc by tab members 5i which t in grooves in the insuiating disc and are then turned over to maintain the discs in position relative to other. The insulating disc is secured to th" I of the armature and one end or" tf l' passes through an orifice in the end plate the insulating disc 5U and the collector This end is electrically connected at 53 to the collector uy means of solder'. The ot ier end or the winding ii' is connected to the end plate of the armature which is in electrical engagement with the trarne F oi the generator through the stub shaft 24. The contact springs do, dfi,

and from each other and from the su by means of insulating bushings l.; 56 secures them in position. A terminal 7 which has electrical engagement with 'the Contact spring 45 provides the other terminal for the generator output.

The bottom member I I and the top member I2 of the supporting frame, as shown in Fig. l0, are provided with ledges 58 and a shoulder portion 59. The permanent magnets 5&1 are of the bar type and rest on the ledges 58 and against the shoulder 59 in which position they are maintained by their magnetic attraction for the pole pieces, a side plate or cover 6I of nonmagnetic material is secured to the supporting frame F by means of screws S2 and also prevent the displacement of the magnets 6G. The member I2 has an arcuateshaped portion 63 which is concentric with the edge i9 of the armature core member I6 and the bottom member II has a similarly shaped portion 64 which is concentric with the edge 2U of the armature core member I6. The space between the pole pieces and the armature is very small so as to increase the output of the device. The magnetic circuit of the generator is completed by the members I l and I2 which extend between the permanent magnets ED located on opposite sides of the armature. Like poles of the magnets 6U must extend in the same direction so that the lines of force will pass through the arcuateshaped portions of members II and I2 and the core I6. The arcuate portions are substantially as deep as the thickness of the arcuate portions of the core members so that when the armature is in the position shown in Fig. 10, practically all of the magnetic lines of force will pass through the iron of the core rather than through the air and the electrical output will be very high.

A iront plate 65 is secured to the frame F by means of screws 65 to cover the mechanism located in the front of the supporting frame. The plate 65 is provided with an orice through which the reduced portion of the crank shaft 28 passes. A terminal member El is secured to the frame F to provide the second terminal for the electrical circuit. This circuit may be traced from terminal 57, contact springs 45 and 4U, spring 4i', brush 48, commutator A9, wire 53 to the winding of the armature, end plate 22, shaft 2d and frame F to terminal 61.

The bar magnets are preferably oi the cast typo of special aluminum alloy and the device has been found to give good results when the armature is composed of the 45-55 per cent nickel, iron mixture.

Having thus described my invention, what I claim is new and desire to secure by United States Letters Patent is:

l. In a generator of the character described, a supporting frame comprising front portion, a cover for said portion, a large gear having a hub portion, a driving shaft resting in said hub portion and bearing in said cover Ynd having its rearwardly extending end ter inating adjacent the front portion of said frame and having limited rotation within said hub portion and longitudinal movement in said bearings, a pivoted lever located in said front portion and having one end associated with said shaft, spring means for maintaining said shaft and lever in their normal position, means for moving said shaft and lever to their alternate position at the initial rotation of said shaft, and a pair of contact springs perable upon movement of said lever.

2. In a generator of the type described, a supporting frame comprising an end portion and rearwardly extending members, en armature rotatable between said extending members, a large gear having a hub portion, a pinion gear in mesh with said large gear and connected to said armature, a driving shaft resting in said hub portion andbearing in said cover and said frame adjacent said end portion and having its rear- Wardly extending end terminating thereat, and having limited rotation within said hub portion and longitudinal movement in said bearings, a pivoted lever having one end associated with said shaft, spring means for maintaining said shaft and lever in their normal position, means for moving said shaft and lever to their alternate position at the initial rotation of said shaft, and a pair of contact springs operable upon movement of said lever. i

3. In a generator, a frame, an internal gear having a hub rotatably supported in said frame, a shaft rotatably and longitudinally movable in said hub, said hub having a cam recess in the inner end thereof, a projection onsaid shaft extending into said recess, means for limiting the longitudinal movement of said shaft relative to said hub preventing said projection passing out of said recess, an armature rotatably supported in said frame, said shaft terminating short of said armature, a lever positioned between the gear and the end of the armature arranged to be engaged and displaced by said shaft upon longitudinal movement thereof, a set of contact springs arranged to be actuated by said lever upon displacement thereof.

4. A generator of the character described including a supporting frame comprising a front `portion and rearwardly extending members, a

gear located in said front portion, a drive shaft for said gear having its rearward end bearing in said front portion and terminating thereat, a 1ever positioned between said gear and said bearing and arranged to be displaced by said shaft, a set of contacts arranged to be actuated by said lever upon displacement thereof, an armature rotatably mounted Within said rearwardly extending members, and means connecting said gear to said armature.

. GEORGE R. EATON.

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