US1798522A - Automatic spark control - Google Patents

Description

March 31, 1931. s. A. COLLINS AUTOMATIC SPARK CONTROL Filed April 1, 1929 2 Sheets-Sheet 1 INVENTOR LSZA. Collins,

S S E N H W ATTORNEY March 31, 1931. s. A. COLLINS AUTOMATIC SPARK CONTROL Filed April 1, 1929 -2 Sheets-Sheet 2 l i W f.

Patented Mar. 31, 1931 UNITED STATES SAMUEL A. COLLINS, OF ONEGO, FLORIDA AUTOMATIC SPARK CONTROL Application filed April 1, 1929. Serial 110. 351,718.

My invention relates to internal combustion engines, and more particularly to an aufull range of advance, from full retard to full advance, in accordance with load and speed, regardless of the load-speed at which point advancement starts.

Other advantages and objects pertaining to the invention will be more fully described and claimed in the following specification and drawings, in which:

Figure 1 is a view in elevation of my im proved device attached to the carburetor of an internal combustion engine,

view

Figure 2 is a longitudinal sectional of the device of Figure 1,

Figure 3 is a perspective view of the breaker cam,

Fi re 4 is a view partly in section of modifled orm, v

Figure 5 is a vertical sectional view of Figure 4.

In carrying out my device, I provide a breaker cam 1 rotatably mounted on the upper end of a timer shaft 2 and held thereon by means of a lock ring 3. For causing the rotation of the breaker cam 1 to automatically advance and retard the spark, I provide a governor weight 5 that is held on the timer shaft 2 b 'means of a pin 6. The governor weight5 as a yoke shaped member 7, which is an integral part of the governor weight 5. The yoked shaped member 7 engages a pin 8 carried by the breaker cam 1 for rotating the breaker cam.

Mounted on the timer shaft '2 and adapted for sliding engagement therewith is an upper sleeve 9 and a lower sleeve 10 supporting between them a governor spring 11. The governor weight 5 pivotally supports a pair of rollers 12 for engagement with the top surface of the sleeve 9 for compressing the governor spring 11 as the weight 5 swings toward the horizontal position.

For automatically retarding the spark upon the opening of the throttle, I provide a pair of cams 13 attached to a shaft -14. The shaft 14 is connected to the throttle valve 15 of carburetor 16 by means of a rod 17 and arm 17a. To .the opposite end of the throttle valve 15 is a rod 18 leading to the gas operating pedal or lever. The shaft 14 for operating the cams 13 are mounted in the lower end of the timer shaft housing 19.

Thusit will be seen in the operation of my device, that with the increase of the speed of the motor, the timer shaft 2 will be rotated at a correspondingly greater rate of speed thereby rotating the governor weight, and the centrifugal force causes the weight to swing outward and to assume a nearly horizontal position, the yoke member 7 engages the pin 8 rotating the breaker cam a certain degree for automatically advancing the spark. As the speed decreases, the weight will, of course, assume its normal position, which is as shown in Figure 1 of the drawings, and the degree of spark will be normal.

The governor spring 11, that is held between the two sleeves 9 and 10, ofi'ers a cerso tain amount of resistance to the swinging action of the governor weight 5. The rollers 12, engaging the top surface of the spring sleeve 9, force the sleeve 9 downward acting against the pressure of the spring as the weight swings and rotates. Thus it will be seen that the governor spring determines how soon and at what speed advance of the spark will begin.

The automatic retarding of the spark is governed by the opening and" closing of the throttle. As the throttle valve'15 is opened,

the rod 17 acts on the shaft 14 through the medium of the arm 17a, forcing the cam 13 against the spring sleeve 10 thereby. compressing the spring 11 from the bottom. The increase of tension onthe spring '11 delays the advance of spark under heavy loads,

but never altering the amount of advance between ull retard and full advance. 10$

' forms.

In the modified form of my invention, shown in Figures 4 and 5, the breaker cam 1 has a forked finger 5?) made as an integral part thereof. The governor weight 4 is fixed to the timer shaft 2 by means of a pin 7b. The governor weight 4 carries a pin 66 which engages the forked finger 5?) for causing the rotation of the cam 1 to automatically advance and retard the spark.

Mounted on the timer shaft 2 and adapted for sliding engagement therewith is an upper sleeve 10?) and a lower sleeve 11?), supporting between them governor springs 12?; and 13b. The governor weight 4 is connected to the upper spring sleeve 101) by two arms 8? The arms 8?) are attached to the spring sleeve 10?) by two bush screws 95.

For automatically retarding the spark upon the opening of the throttle, I providea yoke 16?) attached to the shaft 17 b. The shaft 176 is connected to the throttle valve of the carburetor by means of an arm 18 and rod 196.

The lower sprin sleeve 11?; has a channel therein, in which tlie fingers of yoke 16b engage. The movement of yoke 16?) is accomplished by the opening and closing of the throttle.

The operation of my modified form, as shown in Figures 4 and 5 is practically the same as that described in the preceding As the speed of the motor increases, the rotation of the timer shaft 2 increases and the governor weight 4 is caused to swing toward a horizontal position. As the governor weight 4 moves toward the horizontal position the pin 66 engages the forked finger 56 rotating the cam 1 forward to automatically advance the spark. As the speed decreases,-the weight will of course, assume the full retard position as best shown in Figure4.

horizontal position a certain resistance is offered through spring sleeve 10?) and spring 12?). The spring 125 is only large enough to move freely on timer shaft 2, but allows full advance at moderate speed with only slight throttle opening.

The action of the throttle valve is the same as in the preceding forms except that as the throttle is opened, arm 18?) will be drawn downward causing shaft 17 b to rotate thereby lifting spring sleeve llb by means of yoke 16?). The lifting of lower spring sleeve 11?) first increases the tension of inner governor spring 13?), and continued movement quickly takes up the slack in outer governor spring 12?) and makes higher motor speed necessary in order to reach full advance, but never alters the number of degrees ofadvance possible when suflicient speed is reached.

It will thus be seen that I have devised an automatic spark that is controlled by two factors working together; namely, the speed As the governor weight 4 moves toward the of the motor and the degree of throttle opening. As an example, we have an engine pulling a steep grade, the throttle is opened to its fullest extent yet the speed of the motor does not increase and an automatic retarding of the spark is accomplished. Upon reaching the top of the grade, the throttle is still open and the motor has increased its speed, due to the fact that the load of the motor has decreased, and the spark is caused to advance.

Having thus'described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. An automatic spark control for combus tion engines comprising a shaft rotatable synchronously with .the' engine, a breaker cam rotatably mounted on said shaft for controlling the spark, a governor mounted on said shaft for controlling the relative position of said cam to said shaft and means operable by the throttle of said engine for controlling the movement of said governor, whereby the position of said cam relative to said shaft is varied in accordance with the engine speed and the throttle opening.

2. An automatic spark control for combustion engines comprising a shaft rotatable synchronously with the engine, a breaker cam rotatably mounted on said shaft,'a centrifugal governor mounted on said shaft for controlling the relative position of said cam to said shaft and spring means operable by the throttle of said engine for controlling themovement of said governor, whereby the position of said cam relative to its shaft is varied in accordance with the speed of the engine and the amount of the throttle opening.

3. An automatic spark control for combustionengines comprising a shaft rotatable synchronously with the engine, a breaker cam rotatably mounted on said shaft for controlling the spark, a centrifugal governor mounted on said shaft for controlling the relative position of said cam to said shaft, a collar on said shaft and movable by said governor, and means operable by the throttle for controlling the movements of said governor consisting of a spring adapted to oppose the movement of said collar and means for compressing said spring, whereby the position of said cam is varied in accordance with the speed of said engine and the opening of said throttle.

SAMUEL A. COLLINS.

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