US2988939A - Breaker point adjusting tools - Google Patents

Description

June 20, 1961 sc L E 2,988,939

BREAKER POINT ADJUSTING TOOLS Filed Jan. 26, 1959 I N V EN TOR. JOHN E. SCH/L LER BY ATTORNE Y United States Patent c e 2,988,939 a r I BREAKER POINT ADJUSTING TOOLS John E. Schiller, 4821 W. Hampton Ave., .5

- Milwaukee, 'Wis; 3 w

Filed Jan. 26, 1959,Ser.No.788,9'18

. 1 Claim. ,(Cl. 81- 3) s 1 This invention relates to tools for adjusting the breaker pointsor contacts of an enginejignition timer or distributor.

" A type of ignition distributor a breaker point mechaengaged in the notchand pocket, the screw-driver being then turned to angularly shiftthe point-carrying plate and thus adjust the gap between the breaker points. In practice, the use of a screw-driver forthis purpose is generally unsatisfactory since after the desired point gap is set with the aid of a feeler it is found difficult to hold the screw-driver in fixed position and any inadvertent tipping or shifting of the screw-driver before or during clamping of the point-carrying plate will result in changing the gap, making it necessary to repeat the operation until the proper gap adjustment is obtained.

An object of the invention is to provide an improved and conveniently manipulated tool of simple and inexpensive construction which will facilitate accurate adjustment of breaker points to establish a predetermined gap between them.

Another object is to provide a tool of this character including a readily mounted replaceable end member presenting fulcrum-engaging and notch-engaging surfaces.

The invention further consists in the several features hereinafter described and claimed.

In the accompanying drawing,

FIG. 1 is an elevational view on an enlarged scale of a breaker point adjusting tool of the invention, parts being broken away and parts being shown in section;

FIG. 2 is a bottom end view of the tool;

FIG. 3 is an enlarged fragmentary top view of a breaker point mechanism, showing the tool applied thereto, the tool shank or shaft being shown in transverse section;

FIG. 4 is a fragmentary sectional elevational view taken generally on the line 4-4 of FIG. 3, and

FIG. 5 is a fragmentary sectional view taken generally on the line 5-5 of FIG. 4.

In the drawing, the numeral designates generally a breaker point adjusting tool of the invention. The tool comprises a shaft or shank 11 having at its upper end a handle 12 of any suitable type and having at its lower end a downwardly projecting pivot projection or trunnion 13 and a radially projecting finger or blade 14. The pivot projection 13- and blade 14 are preferably formed on a flat insert plate 15 which snugly fits in a parallel-sided slot 16 extending diametrically in the lower end of the shank 11 and is suitably secured or clamped therein, as by a cross rivet or screw 17. The slotted lower end of the shank is enlarged to form a cylindrical head 18 coaxial therewith, the head having a flat bottom face 19 the plane of which is perpendicular to the axis of the shank. The lower edge 20 of the insert plate 15 is fiat and coplanar with the bottom face 19 except for the pivot projection 13 which extends downwardly from the face 19 at right Patented June 20, 1961 angles thereto. The pivot projection 13 has a rounded or semi-cylindrical bearing surface 21 at the side thereof remote from the finger or blade 14, the axis of the hearing surface" being substantially coaxial with the tool shank. "In order to cooperate with existing breaker point mechanisms, one type of which is hereinafter described, the pivot projection or trunnion 13 of the tool is relatively narrow, about 5 inch. To provide adequate strength this projection is made of oblong cross-section in the plane of theplate, as seen in FIG. 2. The radial finger or blade 14 extends in the plane of the insert plate and is of outwardly tapered or wedge-shaped cross-section in a plane normal to the axis of the tool, as best seen in FIG 2. The finger or blade is adapted to cooperate with an angularly shiftable point-carrying member of a breaker point mechanism, as hereinafter described.

3 'In FIGS. 3, '4, and 5, the tool 10 is shown to be applied to a known type of ignition distributor 22 which comprises a housing. 23 having mounted therein an angularly shiftableflistr ibutor plate assembly 24 through which a rotary multiple-lobe cam 25 projects. The assembly 24 comprises an apertured base plate or disk 26 pivotally mounting thereon a point-carrying plate or lever 27. In somednstanc'es, as for an eight cylinder engine, the disk also" mounts thereon a second point-carrying plate 27, shown in broken lines at the left-hand side of FIG. 3. Each plate 27, which rests flatwise on the disk 26, has secured thereto a vertical pivot stud 28 parallel to the cam axis and interengageable with the disk, as usual, and the plate 27 is adjustably clamped to the disk by one or more screws 29 which pass through slots 30 in the plate and into threaded openings 31 in the disk. Each plate 27 is provided at an end portion remote from the pivot stud 28 with an upstanding flange or ear 32 which rigidly carries a contact or breaker point 33. An oscillatable spring-loaded arm 34 is pivotally mounted on the pivot stud 28 of the plate 27 in insulated relation thereto, and at its free end portion carries a contact or breaker point 35 which cooperates with and is spring-urged against the stationary breaker point 33. A rubbing block 36 of nylon or other suitable material secured to the arm 34 is engageable by the rotary cam 25 for periodically separating the arm-carried point from the stationary point. The plate 27 and swingable arm 34 form the usual subassembly which is clamped to the disk 26 by the screws 29.

The gap between each pair of the breaker points 33 and 35 in their open condition is adjusted by angularly shifting the point-carrying plate 27 about its pivot stud 28, the gap being set by means of a feeler, not shown. A notch 37 is formed in an edge 38 of the plate 27 near the point-carrying flange 32, and an opening 39 is formed in the disk 26 below the notched portion of the plate. The notch 37 extends radially with respect to the pivot stud 28, and the opening 39, which is here shown to be generally triangular but may be of various other shapes, has a rounded corner portion or pocket 40 spaced from the notch. This construction was devised to permit the opposite edges of the blade of a screw-driver to be engaged in the notch 37 and fulcrum-forming pocket 40, the notched pivoted plate 27 being angularly shiftable by turning the screw-driver, and the plate being thereafter clamped in its adjusted position.

However, it has been found difficult to effect accurate adjusting of the point gap to a predetermined dimension by means of a screw-driver, since a slight tipping of the screw-driver before or during tightening of the screws 29 will change the adjustment. Also, in some cases the disk opening 39 is inaccurately punched, making it necessary to use a screw-driver which is too narrow to properly engage in the plate notch 37 and pocket 40. Furthermore, the sharp edges of an ordinary screw-driver have a tendency to cut buns in the notch 37 and opening 39.

The tool of the present invention avoids these disadvantages and is applied by inserting the pivot projection 13 thereof into the disk opening 39 at the pocket 40 and entering .the laterally projecting tapered finger tor .blade 14- :into the tapered plate notch 37, the rounded pivoted projection 13 being then seated in the fulcrum-forming pocket 40 of the opening, and the flat bottom face 1-9 -,of the tool head and insert -plate resting squarely on the flat top face of the disk. With the plate clamping screws 29 in loosened condition, and with the rubbing block .36 of the spring-loaded arm on a nose of the rotary cam, a feeler, not shown, of selected thickness held in one hand is inserted between the breaker points, and thedisk-supported tool, which is held in the other hand, is rotated in one direction or the other until both of the points engage the feeler, the flat bottom face 19 of the tool being maintained in flatwise abutment with the disk. The feeler is then removed, and the screws 29 are tightened by a screw-driver while the adjusting tool is held in its selected position, insuring the proper gap between the points. The breaker points of the other breaker subassembly-are then adjusted in a similar manner to provide the same point gap. .11 is noted that the lateral finger 14 of the tool is not required to enter the plate opening 39, so that this opening need not extend to the root of the plate notch 37. The cylindrical head 18, from which the finger 14 projects at one side,

is ,of sufficiently small diameter so that it will clear the .nearby cylindrical wall of the distributor housing 23 The distance between the plate notch 37 and the fulcrum-forming pocket 40 of the disk opening may be different in various breaker plate mechanisms. These variations can be accommodated by providing the tool with different sizes of insert plates .15.

I claim:

A breaker point adjusting tool, comprising a shaft adapted to be turned and having a lower ,end portion with a flat bottom face and with a diametrically extending slot, said bottom face being adapted to abut against the upper surface of a distributor base plate, an insert plate ,fitting in said slot and having .a bottom projection and ,a lateral projection, and means for rigidly but removably securing said insert plate in said slot, said bottom projection having a lateral bearing surface remote from said lateral projection and adapted to seat laterally against a fulcrum surface of the base plate, and said lateral projection being adapted to engage in a notch of an angularly shit-table point-carrying plate releasably clamped on said base plate.

References Cited in the file of this patent UNITED STATES PATENTS 1,424,275 Bates et al. Aug. 1, 1922 1,525,128 Heise Feb. 3, 1925 2,501,561 Clay Mar. 21, 1950 2,773,529 Valenti Dec. 11, 1956 FOREIGN PATENTS 184,680 Switzerland Aug. 17, .936

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