US1250904A - Circuit-breaker. - Google Patents

Description

B. M. LEECE.

CIRCUIT BREAKER.

APPLICATION mu) AUG.23, 191s.

1, 250,904. Patented Dec. 18, 1917.

UNITED STATES PATENT OFFICE.

BENNETT 1a. LEECE, or CLEVELAND, 01110, ASSIGNOR tro riiii Manon-NEVILLE comrm, or CLEVELAND, OHIO, A CORPORATION or OHIO.

CIRCUIT-BREAKER.

Specification of Letters Patent.

Patented Dec. 18, 1917.

Application filed August 23, 1916. Serial No. 116,407.

or make and break devices adapted especially for use with ignition systems.

The principal ob 'ect of the invention is to provide a make and break device which is simple in construction and durable, and whose efliciency is not affected by the speed of the engine, 11. 6., is as efficient at high as at low speeds of operation.

As is well known, practically all ignition systems utilize a circuit breaker or timer provided with a stationary contact and a movable contact, together with means for shifting the movable contact into and out of engagement with the stationary contact. Generally the movable contact is shifted in one direction by a cam or other positive actuating device, and in the opposite direction by a spring. While many of these make and break devices are efficient, they are not entirely satisfactory in action at high speeds of operation, for the reason that at high speeds the spring which shifts the movable contact in one direction does not act quickly enough. This defect or disadvantage is particularly serious with so-called battery ignition systems, whose primary voltage is substantially constant and does not increase with the speed of operation as does the primary voltage of an ignition system employing a magneto as its source of current.

The above mentioned defect or disadvantags is overcome by my invention wherein means are provided for ositively actuating or moving the movab e contact in both directions.

In applying my invention in practice,,the movable contact is carried by a holder consisting preferably of a pivoted member which is arranged to be shifted in both directions by the rotary cam, although the cam is provided primarily to shift the contact in one direction while a spring is provided primarily to shift the contact in the reverse direction. This pivoted member and the cam are so arranged, however, that the latter can also shift the contact in said reverse direction so as to assist the spring, or act in place thereof, in the event the spring cannot be relied on for the purpose intended, as, for example, at high speeds of operation when the spring, due to its inertia, does not respond quickly enough to function in the proper manner. Preferably, the parts are so arranged that at lowspeeds the cam shifts the movable contact in one direction and the spring shifts it in the reverse direction, but when the speed reaches an amount such that the spring cannot be relied upon, the cam shifts the contact in the direction that the spring tends to shift it, but acts more quickly than the spring so that good contact is assured at high speeds as well as low speeds. I wish to be understood, however, that it is within the scope of my invention to have the cam shift the contact in the direction that the spring tends to shift it even at the lowest speeds.

My invention may be further briefly summarized as-consisting in certain novel details of construction and combinations and arrangements of parts which will be described in' the specification and set forth in the appended claims.

In the accompanying sheet of drawings I have shown a construction wherein the cam is ordinarily or primarily arranged to open the circuit, and the spring is arranged to close the circuit with the cam assisting the spring to close the circuit if the spring does not act quickly enough, although it is obvious that the reverse arrangement could be employed wherein the cam primarily or normally closes the circuit and the spring opens the circuit, with the cam assisting the spring if it does not open the circuit quickly enough.

In the said sheet of drawings Figure 1 is a plan view of the circuit breaker with the cup or casing which normally incloses the operating parts removed, the contacts being separated the maximum amount by the cam; Fig; 2 is a side view of the same; Fig. 3 is a sectional view; Fig. 4 is a plan view of the contact members and cam with the contacts about to be closed by the spring assisted by the cam; and Fig. 5 is a similar view with the contacts in engagement, or the circuit closed.

Referring now to the drawings, 10 represents a disk constituting a support for the contacts, and mounted on a stationary base 11 with respectto which the disk can be adjusted to advance or retard the spark by an adjusting lever 12. Extending centrally through the disk 10 and base 11 is an operating shaft 13 to which is secured a cam 14. As here shown, the cam is a six-point cam intended for a six-cylinder engine, the

.points consisting of projecting rounded ribs 14:.

The contacts of the breaker include a stationary contact 15 formed on, or carried by an adjustable screw mounted in a post 16, extending upwardly from an insulated segment or arc-shaped strip 17. to which a conductor 18 is connected. The other contact to be referred to presently, may be grounded in the customary manner.

A movable contact which is adapted to be moved into and out of engagement with the stationary contact 15, is shown at 19. This contact 19 is carried by a pair of leaf springs orfiexiblc members 20 and 21, the latter being somewhat shorter, and hence somewhat stiffer than the former to which the contact 19 is directly connected. These two springs, or spring members are c0nnected near their outer ends by a rivet 22 which normally holds the two spring members a predetermined distance apart, but allows the st-ifier member 21 to yield slightly, or to move along the shank of the rivet for a purpose to be explained. The inner ends of the contact carrying springs 20 and 21 are connected by one or more pins or rivets 23 to a pivoted holder 21, pivotally mounted between its ends on afixed pin 25, extending upwardly from the disk 10. A spring 26, which is secured to an upright post 27 projecting upwardly from the disk 10, holds the pivoted member 24 downwardly in proper position on the pin 25. A rather stiti spring 28, which is secured at one end to the post 27, and at its other end bears'on the head of rivet tends to keep the contacts in engagement, or to move the contact 19 into engagement with the stationary contact 15,-

so as to close the circuit after the circuit has been opm' d by the cam.

It will be observed that the pivoted member 24 is substantially L-shaped inasmuch as it has two arms which extend away from the pivotal axis at substantially right angles to each other, the said arms embracing, so to speak, a portionof the periphery of the cam. At the ends of the two arms are a pair of rollers29 and 30, which are designed to be alternately engaged by the ribs'lt of the cam so as to successively open and close the circuit.

The operation of the circuit breaker construction above described is as follows:

Assuming that the cam is rotating in the direction indicated by the arrows in Figs. 1, 4 and as each lug or rib 14 of the cam engages the roller 29, it rocks the pivoted member 24, separating the contacts against the tension of the contact closing spring 28. \Vhen the holder 21 is rocked by the engage ment of a point of the cam with roller 29, roller 30 is moved inwardly so as to be in the path of movement of another of the ap-' preaching ribs or points of the cam, so that in the event that the spring 28 does not close the circuit quickly enough, said approaching rib or point of the cam will strike the roller 30, and thus positively rock the holder 24 in the reverse direction, thus closing, or assisting the spring 28 to close the circuit.

In Fig. 1 the parts are shown in the positions which they occupy at the instant that the contacts are separated the maximum distance by the engagement of the cam with roller 29. In Fig. 4 the parts are shown .in the positions they occupy when the cam is about to rock the member 21 in the reverse direction to close the circuit, or to assist the spring 28 in closing the circuit, while in Fig. 5 the contacts are shown in engagement.

It is not essential that the cam be provided with the projecting points or ribs 14, as an ordinary square, hexagonal or octagonal cam may be employed. I. prefer, however, to use the arojecting ribs as the cam points, for I am t us enabled by varying the shape or size of the ribs,'to vary their effective spacing and heights so as to modify the action of the cam. For example, the cam may in this manner be caused to close the circuit, or to assist the spring in closing the circuit at the lowest speeds as well as at the highest speeds, or it can be made to have a circuit closing effect only at speeds above a predetermined limit. In the latter event, at lower speeds of operation the spring would be relied on solely to close the circuit, and the cam would come into action to assist the spring at speeds such that the spring might not act quickly enough to close the circuit at an instant such that the predetermined dwell of the contacts with the circuit closed would be obtained. In any event, with the present construction good contact is secured at high speeds as well as at low speeds, a sutficiently long dwell or period of engagement of the contacts to secure proper energization of the coil which is used in connection with the circuit breaker being assured for all speeds of operation.

Not only is there an ample period ofdwell at all speeds, but the construction is such that the contacts remain clean and smooth for a long period of time, for the reason that as the holder rocks on its axis, the point or points of connection of this holder with the springs 20 and 21 are moved slightly toward and from the contact 15, and this causes a wiping action of the contact 19 on the contact 15, each time the contacts are separated and also each time they are moved into engagement with each other.

Although obviously the two springs 20 and 21 are not essential to the principal features of this invention, for the purpose of supporting or carrying the movable contact 19, they are nevertheless preferable. By connecting these springs by the rivet 22 (or equivalent device) the spreading action of the springs is, of course, limited, and inasdo not involve a departure from the spirit and scope of my invention, such, for example, as the reversal of the action of the circuit opening cam 14 and circuit closing spring 28.

Having thus described my invention, what I claim is:

1. In a circuit breaker for ignition systems, a movable contact, a movable member adapted to be shifted to shift said contact, and a cam adapted to successively engage difierent points of said member for positively shifting the movable contact in one direction to close the circuit and for positively shifting the same in the opposite direction to open the circuit.

2. In a circuit breaker for ignition systems, stationary and movable contacts; a cam for shifting the movable contact in one direction; yieldable means for shifting said movable contact in the reverse direction; and means whereby the cam may shift the movable contact in the reverse direction.

3-. In a make and break device for ignition systems, a movable contact; a cam for shifting the inovable contact-in one direction; a spring for shifting the contact in the reverse direction; and means whereby the cam may shift the movable contact in the same direction that it is shifted by the spring.

4. In a make and break device for ignition systems. a movable contact; a movable support for the latter; and a cam in operative relation to two different points of said support so as to first shift the same in one direction and then in the reverse direction to successively cause the opening and closure of thecircuit.

5. In a circuit breaker, movable and sta tionary contacts; a spring normally tending to shift the movable contact in one direc tion; and means independent of said spring for shifting the movable contact in the same direction when a predetermined speed of operation is reached.

6. In a make andbreak device, a movable contact; a cam for shifting the movable contact in one direction; a spring for shifting the movable contact in the reverse direction; and means whereby under certain speed conditions said cam shifts the movable contact in said reverse direction.

7. In a circuit breaker, a movable contact; a'movable holder for the movable contact; a cam; said holder having two portions which are engaged by the cam to successively shift the movable contact toward and from the stationary contact.

8. In a circuit breaker, a movable contact; a cam; a pivoted member carrying the movable contact, said member being pivoted between its ends and having both end portions adjacent the cam so that both said portions can be successively engaged by the cam to cause both the closing and opening of the circuit.

9. In a circuit breaker, a movable contact,

BENNETT M. LEECE.

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