US1341020A - Rotary circuit-interrupter - Google Patents

Description

H. 0. PUTT.

' ROTARY CIRCUIT INTERRUPTER.

APPLICATION FILED FEB. 5, 1918.

1,341,020, Patented May 25, 1920.

UNITED STATES? HARLIE OGDEN FUTT, 0F ELKIdAR/l, INDIANA.

ROTARY CIRCUIT-INTERRUPTER.

Specification of Letters Patent.

Patented May 25, 1920.

Application filed February 5, 1918. Serial No. 215,442.

To all whom it may concern:

Be it known that I, I-IARLIE OGDEN PUTT, a citizen of the United States, residing at Elkhart, in the county of Elkhart and State of Indiana, have invented a new and useful Rotary Circuit-Interrupter, of which the following is a specification.

In all mechanical circuit interrupters, the function of closing the contact points is accomplished by spring tension or by cam action applied to an oscillating contact which is normally open, while the opening or separation of the contact points is accomplishedin the rotary type--by causing the contact arm to strike a cam surface, or, in the revolving cam type, by causing the cam to strike the contact arm or by holding the contact arm normally open by means of a stiff spring.

In either of the two above types of interrupter, the function of closing the contacts by spring tension only, results in imperfect contact at high magneto speeds unless excessively stiff spring tension is employed, in which case the contact points, cam surfaces, etc., are rapidly worn. Also at high speeds the spring tension is somewhat neutralized by centrifugal force, in the case of the rotary type, and when the cam releases the contact arm permitting contacts to close, the arm rebounds or chatters, causing a break, or a series of breaks in the generated electrical wave or current.

At high speeds the force of impact of the cam and contact arm tends to cause contact points to open too far, thereby detracting from efficiency and life of contact points and other wearing parts. At low speeds the action is more or less slow, whereas a quick break or separation of the contact points is desirable.

The object of my invention is to provide a rotary'circuit interrupter which has none of these defects, thereby attaining higher efficiency and longer life.

The closing of the contact points, in my invention, is positively secured or accomplished by cam action, while the opening or breaking of circuit is accomplished by spring tension and centrifugal force acting on a contact arm.

The spring tension is just sufiicient to quickly open contact points at low magneto speeds, While at high magneto speeds this action is accelerated by centrifugal force acting on the contact arm. in addition to the normal spring tension, thereby securing an automatic adjustment of contact arm tension at any magneto speeds. Breaking of tension spring would not render interrupter inoperative, as the centrifugal action on contact arm would act to open the contact, irrespective of spring tension, in fact the interrupter may be operated with this tension spring entirely eliminated, but better results are secured at low magneto speeds by the use of this spring. I

Rebound, or chattering of contact points is entirely eliminated and positive contact secured with a minimum of spring tension and consequently less wear, thereby adding to efficiency and longer life of the mechanism.

The degree or distance of separation of the contact points is uniform at all speeds. There is no hammering or pounding of contact points.

The construction is extremely simple, accessible and efficient, and can be manufactured cheaply.

In the accompanying drawings, Figure 1 is a section on line 1 1 of Fig. 2, showing interrupter and cam; and Fig. 2 is a sectional view of Fig. 1 on line 22 of Fig. 1, showing manner of attachment or assembly to magneto armature shaft.

Like characters designate like parts throughout the several views.

Referring to the drawings, C in Fig. 1 is the cam of cylindrical form, which is capable of being oscillated, or may be rigidly secured o the magneto. Two cam-releasing and cam-engaging portion such as suitable depressions or slots, C and C are provided diametrically opposite in one end of cam cylinder, or when only one break per revolution of armature is desired, then only one slot or depression is employed. The width of these cam-releasing and cam-engagin portions determines the degree that the contacts remain open, and can be readily cut to meet any requirement.

The inner surface corners of the elements and C are to be slightly beveled. D is the contact arm pivoted or journaled at E which carries a tension spring G secured by screw F. The opposite end of spring G is secured to post H by means of screw F The tension of this spring operates to open contact points. K is a fiber block or other suitable wear-resisting material inserted in and rigidly fastened to arm D.

.L is a flat spring screwed or riveted to arm D at one extremity and carrying a contact point P at the other extremity. Q, is the insulated bracket which carries adjustable contact screw M which is locked in position by locknut O and loekscrew N. This bracket is rigidly attached to interrupter disk J by means of insulated screw R and collector stem or screw S. Screw S is in electrical connection with bracket Q. T is the adjustable stop screw which screws into post H and is locked in position by locknut T and controls throw of contact arm D. V is a retaining spring having one extremity fastened to post id, and the other bearing against contact arm D at its fulcrum point. This spring merely holds arm D on its journal, and can be swung around permitting arm D to be removed from its journal by removing screws 1* and F The interrupter disk or body J is preferably provided with a taper boss, which fits into armature shaft and is held in place by means of collector stem or screw S, which has a taper fit in insulated bracket Q. The design of arm D is such as to cause centrifugal force to act in conjunction with spring G in direct proportion to the speed of rota tion.

The operation is as follows: At slow magneto speeds the fiber block K engages cam surface causing contact points to close against action of spring hen fiber block K reaches slot in cam, spring it throws arm D outward thereby opening contact points, and they remain open while block K passes over slot in cam to opposite sector, when block K again engages cam surface and thereby closes contact points, spring L acting resiliently on contact points and arm D,

The adjustment of contact screw M and stop screw T is such as to permit contact points to open the required distance when fiber block K is not engaged by cam G.

The suddenness or rapidity of break is determined by the abruptness of the cam slot, where the fiber block K leaves it, but a slight bevel will not detract from electrical efficiency, and will prevent block K sticking or catching on cam when rotated in reverse direction. As the speed of rotation increases, the centrifugal action on arm D operates with spring G to cause a correspondingly quick break, while the cam surfaces force a positive make or closing of contact points without chatter or rebound, and by virtue of the resilient action of spring L all undue wear is eliminated from contact points and fiber block K and other wearing parts.

lVhat I claim is:

1. In a rotary circuit interrupter, the combination of a hollow cylindrical casing having one or more cam slots therein, contact carrying members mounted within said eas ing, one of said members having an operative contact with the inner surface of the cylindrical casing to normally maintain the contact points in closed relation, said member being pivotally mounted to permit of its being swung outward by centrifugal force during the period determined by the aforesaid cam slots whereby the rapidity of the break of contact is proportional to the effect of centrifugal force acting on the pivoted contact arm.

2. In combination with the apparatus disclosed in claim 1, a spring operatively connecting the contact carrying members and having a tension just suliicient to quickly open contact points at low magneto speeds independent of centrifugal force.

8. In a rotary circuit interrupter, the combination of a cylindrical member having one or mbre cam slots, a collector stem, an interrupter disk mounted to but insulated from the stem, a contact arm pivotally mounted to the disk and carrying a fiber block to engage the cam slots, means for limiting the pivotal movement of the contact arm said means including an adjustable stop screw, an insulated bracket mounted to the interrupter disk and carrying an adj ustable contact member, an opposing spring contact member carried by the contact arm, and means to open the circuit at low magneto speeds resiliently connecting the contact arm and the above-mentioned means for limiting the pivotal movement of the contact arm whereby to close the circuit by cam action and to open it by centrifugal force and spring tension.

4. In a rotary circuit interrupter, the combination of a cylindrical member having opposite cam slots, a collector stem, an interrupter disk mounted to and insulated from the stem, a contact arm pivotally mounted to the disk, a post carried by the interrupter disk, an adjustable stop screw carried by the post and adapted to limit the centrifugal movement of the contact arm, an insulated bracket mounted to the interrupter disk, an adjustable contact member carried by said bracket, an opposed resiliently mounted contact member said member being carried by the contact arm, and a fiat spring connecting the contact arm with the post carried by the interrupter disk said spring being adapted to reinforce the centrifugal action in throwing the contact arm outward on entering cam slots, substantially as and for the purposes described.

5. In a rotary circuit interrupter, the combination of a hollow cylindrical casing having one or more cam slots therein, a pivoted contact-carrying member having an operative slidable engagement with the inner surface of the aforesaid cylindrical casing, means for limiting the pivotal movement of said member, a second contact carrying ele ment, a spring having one end rigidly mounted and having the other end aiiixed to the contact carrying member first mentioned, said spring being resiliently ten sioned to open the contacts by its resilient action at low magneto speeds while admitting of a more rapid operation by centrifugal force at high speeds, substantially as described.

6. In combination with the apparatus described in claim 5, means for adjusting the pivotal movement of the first mentioned pivoted contact carrying member.

7. In a rotary circuit interrupter, the combination of a hollow cylindrical casing having one or more cam-releasing and cam-engaging portions, contact-carrying means mounted within the aforesaid casing and in operative contact with its inner surface to normally maintain the contacts closed, said means being operable by centrifugal force to open and close the contacts during the period it moves past the cam-releasing and cam-engaging portions of the cylindrical casing, whereby the quickness of break of contact is controlled by and proportional to the centrifugal force acting on the pivoted contact arm.

8. In combination with the apparatus disclosed in claim 7, resilient means in operative engagement with the contact-carrying means and adjusted to quickly open the contacts at low magneto speeds independent of centrifugal force.

9. In a rotary circuit interrupter, the combination of a hollow cylindrical cam having one or more cam-releasing and cam engaging portions to admit of a pivoted contact member swinging outwardly and subsequently being swung inwardly by the aforesaid cam, a pivoted contact member having an operative slidable engagement with the inner surface of the aforesaid hollow cylindrical cam, means for limiting the pivotal movement of said contact member, resilient means controlling the operation of the contact member to a limited degree and arranged to open the contacts by its resilient action at low magneto speeds and admitting of a more rapid operation of the contact element by centrifugal force at high speeds, for the purposes described.

10. In combination with the apparatus described in claim 9, means for adjustably regulating the operation of the pivoted contact element.

11. In a rotary circuit interrupter, means carrying an electrical contact member, means carrying a cooperating electrical contact member, a member carried by said last mentioned means adapted to slidably engage a cam to positively maintain the electrical contacts in closed relation for definite periods in the operation of the device, the said cam member, and resilient means attached to the means carrying the cooperating electrical contact member and tensioned to afford the desired control of the opening of the contact points and the breaking of the circuit at low magneto speeds.

HARLIE OGDEN PUTT.

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