US2729725A - Breaker point assembly for internal combustion engines - Google Patents

Description

Jan. 3, 1956 A. c. RUSSELL 2,729,

BREAKER POINT ASSEMBLY FOR INTERNAL COMBUSTION ENGINES Filed Sept. 13. 1954 United States Patent BREAKER POINT ASSEMBLY FOR INTERNAL COMBUSTION ENGINES Andrew C. Russell, Shawnee, Okla. Application September 13, 1954, Serial No. 455,483 3 Claims. (Cl. 200-166) This invention relates to the field of internal combustion engines and, more particularly, to improvements in breaker point assemblies for use in the distributor mechanisms forming a part of such engines.

It is the principal object of this invention to provide a breaker point assembly of improved construction which gives a more positive making and breaking action upon the electrical circuit controlled and which permits the passage of greater amounts of electrical current through the assembly during periods when the circuit is made than has heretofore been possible with practicable, prior devices used for the same general purpose. Experimental tests have conclusively demonstrated that the use of the improved breaker point assemblies of this invention not only increase the power available from an internal combustion engine, but also increase the running time or mileage which may be had from a given amount of fuel.

Obviously, one of the larger fields of application for this invention is in connection with the distributor mechanisms of automobiles and other motor vehicles, although it is to be understood that the usefulness of the invention extends to any internal combustion engine utilizing a distributor mechanism having a rotatable cam for operating a breaker point assembly.

Another of the very important objects of this invention is to provide a breaker point assembly which results in substantial economies in manufacture by virtue of the fact that the working parts of the assembly have been simplified and a substantial portion of same may be formed in one operation as a unitary body of plastic material or the like.

Other important objects of the invention, including certain important details of construction rendering the assembly uniquely wear-resistant, simplifying replacement of parts when same does become necessary and achieving other advantages which will become clear, will be fully explained or become apparent as the following description of the invention progresses.

In the accompanying drawing:

Figure l is a fragmentary view of a distributor mechanism of an internal combustion engine showing the cam forming a part of such mechanism and the assembly of this invention in elevation;

Fig. 2 is a cross-sectional view taken centrally through the main block portion of the assembly on line II-II of Fig. 4;

Fig. 3 is a sectional view taken centrally of the block portion of the assembly at right angles to the section of Fig. 2 on line III-III of the latter;

Fig. 4 is a top plan view of the assembly taken on line IV-IV of Fig. 1;

Fig. 5 is a fragmentary view of the body of the assembly in its initial condition after manufacture and before the cam-follower portion thereof has been bent into its operative position; and

Fig. 6 is a fragmentary, top plan view of a modified form of the assembly of this invention.

The problem of increasing the current flow through 2,729,725 Ce Patented Jan. 3, 1956 the electrical ignition circuits of an internal combustion engine during periods of make of the breaker point assemblies used in the distributor of the engine, has long challenged the manufacturers of automobiles and other internal combustion engine devices. Difficulty has always been experienced with prior types of breaker point assemblies, in that, the current which could be conducted by same during the make portion of the cycle was limited or the structure provided with a view to increasing such current was impractical and not conducive to positive making and breaking action. Moreover, attempts to improve upon the conventional types of breaker point assembly in common use, have been so complicated as to be either impractical in operation or prohibitive from the standpoint of manufacturing cost.

It is these problems and difficulties which the present invention overcomes by providing a breaker point assembly of increased simplicity and operational efficiency.

Referring first to Fig. l, the numeral 10 generally designates a distributor mechanism of an internal combustion engine. Mechanism 10 conventionally includes a base 12 and a rotatable cam 14.

The breaker point assembly of this invention is broadly designated by the numeral 16 and includes a body generally designated 22 and contact structure broadly designated 24.

Body 22 is preferably formed of a strong, wear-resistant, insulating plastic material, such as nylon or the like, and includes a main, block-like portion 26, a mounting portion 28, and an extension portion 30. Portions 26, 28 and 30 are preferably integral with each other so that the body 22 is of unitary nature and may be formed by a single manufacturing operation such as is well known in the art of plastics fabrication.

The main body portion 26 is substantially rectilinear in configuration and is provided with a straight, elongated bore 32 passing therethrough, bore 32 having a portion of its length of reduced diameter as at 34. Mounting portion 28 extends from the main body portion 26 as most clearly illustrated in Fig. 1 and is provided with a number of perforations 36, 38 and 40 adapted to coincide with the usual fastening means 42, 44 and 46 which are conventionally provided upon the base 12 of distributor 10 for the mounting of a breaker point assembly therewithin. It may be noted that perforations 36 and 38 are preferably elongated to permit adjustment of the position of assembly 20 relative to the cam 14 through swinging of mounting portion 28 about the pivot provided by fastening means 46.

As best indicated in Fig. 5, the extension portion 30 of body 22 may initially extend essentially straight out- Wardly from one face 48 of main body portion 26. However, extension portion 30 includes a section of decreased thickness as at 50, so that extension portion 30 may be bent to the position illustrated in Fig. 1 disposing a projection 52 of portion 30 for engagement with cam 14 and an opposed surface 54 of portion 30 in partially covering, spaced relationship to the end of bore 32 adjacent face 48 of main body portion 26. Due to the decreased thickness of section 50 of extension portion 30 and the fact that the body 22 is formed of slightly flexible material, it will be clear that extension portion 30 may swing toward and away from face 48 of body portion 26 as projection 52 rides upon cam 14.

Electrical contact structure 24 includes a stationary plate 56 of electrically conducting material rigidly mounted upon a face 58 of body portion 26 opposite to face 48 of the latter by any suitable fastening means 60, such as screws threaded into main body portion 26. Secured to plate 56 are a plurality, in the illustrated embodiment a pair, of contacts 62 and 64 which are preferably rigidly secured to plate 56 in spaced relation to one another by any suitable means such as a rivet-like flange 66. Contacts 62 and 64 are preferably of highly conductive material and may be of copper, silver or the like. Such contacts 62 and'6'4 are, except for the portions 66 thereof provided for riveting or fastening to plate 6, substantially cylindrical in configuration and are each provided with a flat end face 68. Electrical connection to contacts 62 and 64 is accomplished by conductive means 70 coupled with plate 56 in any suitable manner as by soldering to a lug 72 engaged and held by one of the fastening screws 60.

Electrical contact structure 24 also includes an elongated rod 74 reciprocably mounted within bore 32 of main body portion 26 and extending from the latter at each end thereof. Rod 74 is preferably of enlarged diameter as at 76 adjacent the end thereof proximate face 54 of extension portion 30. Enlarged portion 76 of rod 74 is slidable within the main part of bore 32, while the remainder of rod 74 is slidably journaled in the reduced diameter portion 34 of bore 32, it being noted that plate 56 is provided with an opening 78 adapted to clear rod 74 without electrical contacting engagement with the latter. An elongated element 80 is secured in any suitable fashion upon the opposite end of rod '74 and rigidly carries a plurality of contacts corresponding to the contacts 62, 64, etc., in the illustrated embodiment a pair of contacts 82 and 84 respectively opposite contacts 62 and 64. Contacts 82 and 84 may be secured to element 80 as by a rivet flange 86 or in any other suitable manner. Contacts 82 and 84, like contacts 62 and 64, are preferably formed of highly conductive material and are each provided with a fiat face88 of substantial area directly opposed to the flat face 68 of the corresponding contact 62 or 64.

A strong compression spring 90 is disposed within bore 32 and around the smaller diameter portion of rod 74. The ends of spring 90 respectively bear against the enlarged portion 76 of rod 74 and a shoulder 92 presented adjacent the zone 34 of decreased diameter-of bore 32. It will be clear, therefore, that spring '90 yieldably biases rod 74 in a direction to move contacts 82 and 84 into engagement with contacts 62 and 64 respectively and to move enlarged portions 76 of rod 74 into engagement with face 54 of extension portion 30 of body 22.

Main body portion 26 is provided with a straight, elongated, lateral passage 94 communicating with bore 32 adjacent face 48 of the portion 26 and extending therefrom toward the surface 96 of body 22 which bears against base 12 of distributor when the assembly 20 is mounted as shown in Fig. 1. Within passage 94, as shown in Fig. 3, there isprovided an elongated contacting member 98 which is reciprocable toward and away from enlarged portion 76 of rod 74, the latter being provided with a vertical groove 100 adapted to receive the end of contactingelement 98. Element 98 is biased toward rod portion'76 by a compression spring 102, which at its opposite end, bears against a screw plug 104 threaded into main body portion 26.

Screw plug 104 also carries a star washer 106 adapted to engage and make electrical contact with base 12 of distributor 10 when the assembly 20 is in place. It is to V be understood that base 12 will normally'be of conductive metallic material constituting the grounded side of the system, so that electrical connection with contacts 82 and 84 is madethrough base 12, start washer 106, metallic screw plug 104, metallic spring 102, metallic contact element 98, the enlarged portion 76 of metallic rod 74, and the metallic supporting element 80 which carries contacts 82 and 84. The riding of contact element 958 7 within .groove 10 0. of rod portion 76 therefore accomplishes two purposes, first, by. Virtue of the biasing effected by spring 102 and the electrical path just mentioned, it serves to ground rod 74 and thereby contacts 82 nd 84 f he ass mbly .0, and ec n y, it p e en s rotation of rod 74 and thereby serves to maintain con? tacts 32 and 84 in alignment with stationary contacts 62 and 64.

An alternate form of construction is illustrated in Fig. 6 wherein is provided a bore 132 that is polygonal in cross-section rather than round as was the case with bore 32 of the first described embodiment of the invention. In this modified form, the rod 74 is provided with an enlarged portion 176 which is of polygonal cross-section corresponding with that of the polygonal bore 132. Such construction serves to maintain alignment between the contacts 82 and 84 and the contacts 62 and 64 by preventing rotation of the rod 74, without the utilization of a groove 100 having an element 93 riding therein. It will be understood however, that an element 98 will be provided as above described for bearing against the rod portion 176 to establish electrical grounding contact therewith.

it will now be apparent that simple, practical, structure has been provided in combination by'this invention by which all of the above-mentioned objects and advantages may be fully enjoyed. It will also be obvious that certain minor modifications or changes could be made from the exact details illustrated and described without departing from the true spirit and intention of the invention.

Accordingly, it is to be understood that the invention 7 shall be deemed limited only by the scope of the appended claims.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:

1. As an article of manufacture, a blank for use in a breaker point assembly, said blank comprising a unitary body of insulating material having a main, block-like portion provided with a bore therethrough, and a cam follower extension portion integrally attached to said main portion and provided with a zone of reduced dimension adjacent the extremity thereof attached to said main portion, said extension portion being bendable at said zone thereof and of dimensions for disposition of a part thereof remote from its said extremity in spaced alignment with one extremity of said bore, whereby said extension portion is adapted to extend between an external cam and one extremity of a contact-carrying element forming a part of said assembly and shiftably mountable in said bore, to be oppositely engaged by said cam and said element, and to swing about said zone thereof toward and away from said extremity of the bore for shifting the element responsive to the cam. V a

2. As an article of manufacture, a blank for use in a breaker point assembly, said blank comprising a unitary body of plastic, insulating material having a main, substantially rectilinear, block-like portion provided with a straight, elongated bore therethrough, and an elongated cam follower portion initially extending from said main portion in one direction and having a zone of reduced thickness at which it may be bent to dispose the longitudinal axis of said cam follower portion in a different direction with a part of the latter adjacent its free end spaced from said main portion and in alignment with said bore.

3. In an article as set forth in claim 2, wherein said body includes a mounting portion integral with said main portion and extending therefrom, said mounting portion being provided with perforations adapting thesame for securement to the base of a conventional distributor mechanism.

References Cited in the file of this patent UNITED STATES PATENTS Chermendy Feb. 1, 1938

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