US2303771A - Breaker point assembly - Google Patents

Description

Dec. 1, 1942. w. s. THOMAS BREAKER POINT ASSEMBLY Filed Oct. 2, 1940 gown/rm William if/zomas,

Patented Dec. 1, 1942 UNITEE STATES PATENT OFFICE.

BREAKER POINT ASSEMBLY William S. Thomas, Montoursville, Pa., assignor of ninety-five per cent to Howard S. Reese,'Williamsport, Pa, and five per cent to Christian K. Nielsen, Washington, D. C.

Application October 2, 1940, Serial No. 359,445

1 Claim. (Cl. 200-30) This invention relates to electrical contact mounting of the arms I2 and I 3 is Well underpoints, especially applicable to ignition systems stood and a detailed description is unnecessary of internal combustion engines and it consists to the full understanding of the invention. The

in the constructions, arrangements and combiarm I3 is spring-actuated as at I4, holding the nations herein described and claimed. ubbing block I5 into enga e h a Cam It is well known to those skilled in the autoi7.

motive as well as other fields, that the present The arm I2 is provided with a breaker point day construction of breaker points presents a I8, the contact face I9 of which is tapered or source of motor failure due, in most cases, to incl ned with respect to the lon itudinal axis formation of pitting between the contacts. When in e a d the arm I3 embodies a breaker point pitting between the contacts occurs, one of the 23 ha a C eX CO aC face 2| a d contacts will have a tit formed thereon, while to en a h po n 8 s shown n F re the other will have a pit and unless the tit and y the con ru t n of r a r p ints as shown,

pit are actually aligned during closing of the it will be obvious that the convex face 2| by contacts, the contacting surface is insuflicient to 3.3 reason of its convexity Will tend o p o a transmit currents for proper operation of th sliding or wiping actionon the tapered contact engine, with consequent loss of power as n face I3, thereby reducing liability of formation as liability of complete failure of the engine. of h and ts t p In 2Midition, the

It is therefore the cardinal object of the insurfaces of the breaker points will prevent oxivention to provide a novel construction of con- 1m dation of the contact faces, as well as maintain tact points in which a sliding or wiping action the faces free of foreign matter which would is inherent between points, thus eliminatin the interfere with proper operation of the distributor.

formation of a tit or pit on the contact points, While I have shown and described the convex which consequently reduces the failure of a spark ea point as in m u d o the a inasystem employing the onta ts, 2.? and the tapered contact is on the arm l2, re- More specifically, it is an object of th inversal of the contacts is possible, without devention to provide a pair of cooperating eonparting from the eficiency of the assembly. tacts, one of which has a convex face comple- The breaker p0 ts I 8 and 0 will be cut from mental to a tapered surface of the other contact, y n i a ba s of tungst of p oper lengt s, thereby providing a wiping or cleaning effect be- :31) and as Shown, the point W1111 include a S tween the contacts durin opening d closing 22 for rigid mounting upon the arm I2, and movements f th cgntacts the point 20 will have a length to frictionally Additional objects, advantages and features of fit between p a g s 23 of the arm I3, invention will be apparent from the following where it is Spot-welded or otherwise secured. description considered in conjunction with the 235 The breaker assembly, namely, the arms l2 accompanying drawing, wherein and it are to be made in sizes and so constructed Figure 1 is a top plan View of a distributor as to readily replace similar arms of standard with the cover removed, ha ing m i ti distributers, thereby permitting installation of installed therein. the assembly upon distributers already in use.

Figure 2 is a vertical section through the disn) In Figures 5 d 6, a modified m Of y tributer casing, showing the breaker points in breaker as m y s s wn, in w ch he sw n end i ti ing arm I3 is provided with a spring for mount- Figure 3 is a perspective view of one of the ing of a breaker point o produce a greater breaker arms illustrating the contact having a S g or wipi g effect than is possible in the di 45 first form described.

Figure 4 is a similar view of the other contact. In t m f the a m l2 and a r p i Figure 5 is a view similar to Figure 1, illusit remain as first described, but the arm I3 trating a modified form of one of the breaker is of shorter length and has fixed inwardly of arms. the free end thereof, as at 24, a flat steel leaf Figure 6 is a perspective view of the breaker 5O spring 25. The spring 25 will include parallel arm shown in Figure 5. flanges 25 corresponding to the flanges 23 for There is illustrated a distributor casing In of mounting of the breaker point 20. conventional form, having an assembly plate I I The relation of the points I8 and 28 will be for mounting of an adjustable contact arm I2 the same as before described, but in operation,

and a cam actuated swinging arm I3. The the spring I4 being of greater strength than the leaf spring 25 a decided sliding or wiping action between the contacts is obtained.

I have particularly described the invention as applied to a breaker assembly for a distributer, but obviously, the construction is applicable to many make-and-break devices for electrical circuits.

While I have shown and described preferred forms of the invention, this is by way of illustration only, and I consider as my own, all such modifications in structure as fairly fall within the scope of the appended claim.

I claim:

An ignition timer for internal combustion engines comprising a fixed arm and a movable arm, said movable arm having a flat leaf spring fixed inwardly of the free end of the arm and projecting therebeyond, a contact carried adjacent the projecting end of the spring, a contact carried by the fixed arm complemental to the first named contact, one of said contacts having a tapered face cooperative with an arcuate face of the other contact, whereby a sliding action is effected between the contacts at and during the period of contacting engagement and means for intermittently moving the movable arm.

WILLIAM S. THOMAS.

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