US1319543A - Best available copy - Google Patents

Description

E. A. WATSON.

DYNAMO ELECTRIC MACHINE.

APPLICA'HON min ml. 3|. 1917.

1,319,543. Patented Oct. 21,1919.

Fig.3

mas/v roe imam Ansley Wald-022 A TTOQNEYJ UNITED STATES PATENT OFFICE.

ERNEST ANSLEY WATSON, 0F COVENTRY, ENGLAND, ASSIGNOR, BY MESNE ASSIGN- MEN'I'S, TO THE C. L. I. MANUFACTURING COMPANY LIMITED, 0F BIRMINGHAM,

ENGLAND.

DYNAMO-ELECTRIC MACHINE.

Specification of Letters Patent.

Patented Oct. 21, 1919.

Application filed January 31, 1917. Serial No. 145,697.

To all whom it may concern:

Be it known that I, ERNEST ANSLEY WAT- SON, a subject of the King of Great Britain and Ireland, residing at Victoria Works West Orchard, Coventry, in the county of Warwick, England, have invented certain new and useful Improvements Relating to Dynamo-Electric Machines, of which the following is a specification,

This invention has for its object to construct an improved dynamo-electric machine for the generation of low tension current for lighting or lighting and starting purposes, and high tension current for ignition purposes, on motor road and other vehicles driven by internal combustion engines, the machine being of the type in which there are combined with the generator field winding, an additional windlng serving as a secondary of a high tension ignition system, and a contact mechanism rotating synchronously with the engine for intermittently making and breaking the circuit of the field winding.

The invention comprises the provision in the machine of a magnetic shunt or leakage circuit common to the flux of the wound pole and the opposing flux associated with the armature.

Referring to the accompanying sheet of explanatory drawings Figure 1 is a cross section; and

Fig. 2 a longitudinal section showing diagrammatically a dynamo constructed in accordance with this invention;

Fig. 3 is a dia am; of connections.

In carrying t e invention into effect as shown, the ordinary field winding a of a low tension generator suitable for lighting or li hting and starting purposes is surrounded y another winding 6 which serves as a secondary of a high tension ignition system. Any suitable mechanism such as that ordinarily employed on magnetos is provided for interrupting the field winding, and such mechanism is rotated synchronously with the en ine. The arrangement shown consists 0% a fixed contact 0 and a movable contact d. The latter is mounted on a spring arm (3 actuated by a cam f on a wheel 9 driven by a pinion h on the shaft 2' of the armature 7'.

For the production of a spark, a com ara tively small flux change suflices, provi ed it occurs with sufficient rapidity. The com bination above described would not result in an efficient ignition apparatus because the inductance associated with the armature would tend to resist a rapid change of flux in the field winding. To avoid this it is necessary to produce a magnetic path which is associated with the field winding only and is independent of the armature. Such a path is obtained by the arrangement of an air gap or leakage path or shunt on each side of the pole piece In and the adjacent part of the frame Z. While these paths are not narrow enough to seriously interfere with the flux from the core m to the armature, they do insure a definite amount of flux passing from the pole tips to the frame. There are thus two paths for the core flux, one which includes the armature through which the greater part of the core flux passes and a second across the leakage paths or shunts which takes a relatively small amount of the flux. The latter circuit is independent of the armature and consequently the flux associated with it can change with the necessary rapidity to produoe a spark in the secondary or high tension current circuit when the current in the field winding is interrupted.

Further in ordinary automobile current generators the demagnetizing magneto-motive-force associated with the armature is usually considerable. The leakage flux due to this magneto-motive-force, or some of it, also crosses the above mentioned leakage paths but does not enter the core m when the winding a is energized. When the winding a is interrupted, the demagnetizing magneto-motive-force tends to reverse the flux through the main core m and hence increases the rapidity of falling of the main flux and therefore assists in the process of flux change necessary for the spark.

In the arrangement shown the core m is laminated and formed integrally with a laminated portion Z of the frame. This portion is removable and is attached to the solid main portion Z in any convenient man-- ner. The vole piece it is secured to the main portion of the frame by cross bolts n of non-magnetic material such as brass and the leakagepaths are filled with blocks 0 of nonmagnetic material such as brass, these also being secured by the bolts a.

Any suitable cut-in and cut-out device is arranged at p to prevent discharge of the battery through the armature j, and a switch is provided at r. In the diagram at Fig. 3 the battery is indicated by 8, the sparking plug by t and the lamps by u. A condenser "u is provided to suppress sparkin at the interrupter of the field winding. 1* igh tension current taken from the winding 11 by a terminal as w. Any mnvcuient additional means may be employed in the generator for producing automatic regulation of the current or voltage. Obviously two or more field windings may be use without departing from the invention. when the enerator is required to operate as a motor for engine starting purposes any suitable provision is made for temporarily convert-- ing the generator into a series motor. For ignition in multi-cylin-der en ines a distributor is combined with the igh tension system of the machine.

The invention is not limited to any particular mechanical details as these may be varied to meet different requirements.

Having thus described my invention What I claim as new and desire to secure by Letters Patent is I 1. In dynamo electric machines, the combination of an armature, a magnetic frame consisting in art of a solid main portion and a detacha le laminated portion, a laminated core formed integrally with said lami- Ila-ted orti'on of the frame, a pole piece secured o the main portion of t e frame and abutting against the said core, said pole piece being spaced from said frame, to provide a magnetic shunt between the ends of the pole piece and the adjacent parts of the a field winding acting as a primary winding and a secondary winding on the core, an interrupter in the primary Winding, and means "For actuating the interrupter from the armature, substantially as described.

2. In a dynamo electric machine, a magnetic frame, an armature disposed within the frame at one end thereof, a core carried by the frame at the opposite end thereof, a pole piece carried by the core, said pole piece being spaced from the frame to pro vide a magnetic shunt, nonana 'netic blocks dis osed in the space between t 1e pole piece ant the frame, and securing means arranged lo pass through the frame, the blocks and the pole piece for holding the parts together.

In a dynamo electric machine, a magnetic frame, an armature disposed within. the frame at one end thereof, a core carried by the frame at the opposite end there of, a pole piece carried by the core said pole piece being spaced from the frame to provide a magnetic shunt, non-magnetic blocks dis osed in the space between the pole piece an the frame, securing means arranged to pass throu h the frame the blocks and the pole piece or holding t e parts together, a primary field Winding on the core, a secondary field Winding superposed on said primary winding, an interrupter in the primary Winding, and means for actuating the interrupter from the armature.

In. testimony whereof I have signed my name/co this s ecification.

ERN ST ANSLEY WATSON.

frame copier of this patent may be obtafnel hifl'we cents each, by addressing the Commissioner 0? Patents, Washington, D. C.

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