US2474086A - Breaker point refacing device - Google Patents

Description

June 21, 1949. c, ow, 5 2,474,086

BREAKER FOINT REFACING DEVICE Filed July 3, 1947 2 Sheets-Sheet 1 IIIH lfl ,I & a 71 A I j I P5 ea 6/ I4 1 1.4

7 My 3 1 '6 5 m INVENTOR. ///R 4M 6- 541974010 fie.

June 21, 1949. H. c. BARTLOW, sR 2,474,086

BREAKER POINT REFACING 'DEVICE Filed July 5, 1947 2 Sheets-Sheet 2 INVENTOR. flue/4M 62 Emenqw [1a Patented June 21, 1949 UNITED STATES PATENT OFFICE 3 Claims.

This invention relates to a device for grinding and trueing breaker points of distributor heads which form a part of the ignition system of internal combustion engines.

The contact faces of breaker points frequently become pitted and worn due to arcing of the electric current so as to necessitate the removal or refacing of the points after a period of use. Attempts have been made to reface the breaker points by filing or grinding the same without removal thereof from the distributor head but due to the limited space available for performing such operation, the refacing thereof has not been satisfactory and generally new breaker points are inserted as the only means of insuring satisfactory operation of the ignition system.

In order to overcome the disadvantages incident to filing or grinding of the breaker points when in position in the distributor head and yet to achieve perfect alignment of the faces thereof,

the present invention comprehends a device in which the breaker points are held in position corresponding to that of actual operation and by which they may be aligned with a cam corresponding to the point cam by which they are moved into and out of contact and when so aligned are then refaced to remove the worn or pitted surfaces thereof by grinding the same in contact with the side face of a rotary grinding wheel whereby the contact faces of the breaker points are disposed in parallel alignment and will flatly engage to insure contact throughout their extent and eliminate arcing of the current.

Another object of the invention is the provision of a reciprocatory carriage for mounting thereon the breaker point arms carrying the breaker points and which carriage is provided with means for advancing the points by increments toward the grinding wheel.

Still another object of the invention is the provision of a device of the indicated character in which the breaker points may be expeditiously refaced and trued.

With the foregoing and other objects in View, reference is now made to the following specification and accompanying drawings in which the preferred embodiment of the invention is illustrated.

In the drawings:

Fig. 1 is an end view of a breaker point refacing device constructed in accordance with the invention and illustrating the same affixed to the base of a grinding wheel.

Fig. 2 is a View in side elevation thereof on a reduced scale.

Fig. 3 is an enlarged fragmentary view taken approximately on line'33 of Fig. 1 showing one of the breaker point arms held in position thereon and with a fragmentary portion of the grinding wheel shown in outline.

Fig. 4 is a similar view showing the other breaker point arm in position thereon with a fragmentary portion of the grinding wheel shown in outline.

Fig. 5 is a fragmentary sectional view taken approximately on line 5-5 of Fig. 3.

Fig. 6 is a sectional view taken approximately on line 6--6 of Fig. 5.

Referring to the drawings by characters of reference, the device includes a bracket l0 provided with a slotted arm II for adjustably attaching the same by means of a thumb screw l2 to the base l3 of an electric motor A coupled to a grinding wheel 13.

The bracket 10 also includes spaced upwardly extending apertured ends [4 and M in which the opposite ends of a longitudinally extending rod [5 are secured. Mounted on the rod for pivotal swinging movement as well as longitudinal reciprocatory movement is a carriage l6 consisting of a flat plate I1 having apertured ears l8 and I8 through which the rod I5 slidably extends. The rod l5 also extends through a block l9 having its longitudinal side faces located at right angles to the rod and having an annular recess opening through one side face thereof with a reduced circular aperture 2| opening through the opposite side face to thereby provide an inwardly directed peripheral flange 22 which is slidably fitted in an annular recess 23 formed in the periphery of a cylindrical projection 24 formed integrally with the ear l8 and projecting outwardly therefrom.

Secured to the block l9 in longitudinal alignment with the rod I5 is a screw 25 having its outer end slidably protruding through the end M of the bracket ID. A knurled thumb wheel 26 threadedly engages the screw 25 between the end [4 of the bracket Ill and an apertured offset plate 21 secured to the outer face of the end i l through which plate the screw 25 slidably protrudes. By this construction the carriage I6 is swingable on the rod I5 and is attached to the block [9 for movement therewith longitudinally of the rod l5 by manual rotation of the thumb wheel 26.

The plate ll of the carriage I5 is swingable toward and away from the grinding wheel for refacing and trueing the breaker points which are aflixed to the outer ends of breaker arms. In order to mount the breaker point arms on the plate I! the same is provided with a stud 28 projecting outwardly therefrom and adjacent the stud the plate I! is provided with a cam element 29 having oppositely disposed peripheral cam faces 30 and 31 with the high part 32 of the cam located between said cam faces. The cam element 29 with the cam faces 30 and 3| corresponds to the point ca m of the distributor head by which the breaker point arms are moved to bring the contact points into and out of contact. The cam element 29 is centrally apertured and is secured to the plate I! by a screw 33 by which the same may be removed and replaced by a different cam element in the event that a different type of point cam is employed in the distributor head in which the breaker points are to be refaced.

The stud 23 is provided with a collar 34 forming an enlargement at the base thereof so as to snugly receive the apertured upper end of one of the breaker point arms while the reduced upper end of the stud is adapted to snugly receive the apertured upper end of the opposite breaker point arm.

As illustrated in Fig. 3 of the drawings, one of the breaker point arms indicated by the reference character C is shown in position on the upper surface of the plate I! with the collar 34 and stud 28 protruding through the opening therein. The breaker point arm is secured in position on the plate 11 by means of an arm 35 mounted for swinging movement on a screw stud 36 projecting upwardly from the upper face of the plate 11 and on the upper end of which is threadedly engaged a knurled thumb nut 31. The arm 35 is provided with a set screw 38 having a pointed end which is adapted to engage against the upper surface of the breaker point arm by tightening the thumb nut on the screw stud 36 for holding the breaker point arm in position. Before securing the same in position the breaker point D thereof is aligned with the forward edge of the cam face 39 as indicated by the broken line in Fig. 3. This sets the breaker point D at the location with reference to the cam element 29 that the same occupies when engaged by the movable breaker point in the distributor head. In Fig. 4 of the drawings, the oppositely disposed movable breaker point arm E is shown in position on the stud 28 with the spring arm F thereof tensioned against the thumb nut 31 and with the cam follower lug G disposed against the high part 32 of the cam element 29. This positions the breaker point H thereof in alignment with the forward edge of the cam face 3!] corresponding to the position of said breaker point when in contact with the oppositely disposed breaker point C in the distributor head. When the breaker point arms are thus disposed on the upper surface of the plate [1, the plate i1 is swung upwardly on the rod l5 as the pivot and the thumb wheel 26 are rotated to move the side face of the grinding wheel B against the breaker points to reface the same.

What is claimed is:

1. In a device for grinding and trueing breaker points, a base, a grinding wheel mounted for rotation on said base, a bracket affixed to said base and having a pair of spaced ends, a rod afiixed to said ends, a carriage mounted on said rod for pivotal swinging and longitudinal reciprocatory movements, said carriage including a plate having an upwardly projecting stud for receiving the apertured ends of breaker point arms with the arms disposed upon said plate and having a cam element affixed thereto and provided with cam faces corresponding to the cam of the distributor head which actuates said breaker point arms when in use, said breaker point arms being adapted to be rotated on said stud to align the breaker points thereof with one of the cam faces of said cam element, clamping means for securing said breaker point arms in aligned position on said plate, a screw affixed at one end to said carriage and slidably mounted in one of the ends of said bracket, a thumb wheel threadedly engaged on said screw for imparting sliding movement to said carriage on said rod to thereby move the breaker points into engagement with said grinding wheel wh n the carriage is swung towards the wheel.

2. In a device for grinding and trueing breaker points, a base, a grinding wheel mounted for rotation on said base, a rod supported by said base, a carriage mounted on said rod for pivotal swinging and longitudinal reciprocatory movements, said carriage including a plate having an upwardly projecting stud for receiving the apertured ends of breaker point arms with the arms disposed upon said plate and having a cam element affixed thereto and provided with cam faces corresponding to the cam of the distributor head which actuates said breaker point'arms when in use, said breaker point arms being adapted to be rotated on said stud to align the breaker points thereof with one of the cam faces of said cam element, clamping means for securing said breaker point arms in aligned position on said plate, a screw affixed to said carriage for imparting reciprocatory movement thereto to thereby move the breaker points into engagement with said grinding wheel when the carriage is swung towards the wheel.

3. In a device for grinding and trueing breaker points, a base, a grinding wheel mounted for rotation on said base, a rod supported by said base, a carriage mounted on said rod for pivotal swinging and longitudinal reciprocatory movements, said carriage including a plate having an upwardly projecting stud for receiving the apertured ends of breaker point arms with the arms disposed upon said plate and having a cam element affixed thereto and provided with cam faces corresponding to the cam of the distributor head which actuates said breaker point arms when in use, said breaker point arms being adapted to be rotated on said stud to align the breaker points thereof with one of the cam faces of said cam element, clamping means for securing said breaker point arms in aligned position on said plate, and means for moving said carriage on said rod to thereby move the breaker points into engagement with said grinding wheel when the carriage is swung towards the wheel.

I-IIRAM C. BARTLOW, SR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,416,366 Lindholm May 16, 1922 1,422,097 Greenfield July 11, 1922 1,688,212 Van Dervort Oct. 16, 1928 2,125,709 Bauer Aug. 2, 1938 2,144,095 Zwick Jan. 1'7, 1939 2,248,262 Wilhide July 8, 1941

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