US1962931A - Automatic control device for ignition timers - Google Patents

Description

June 12, 1934. M. MALLORY 1,962,931

AUTOMATIC CONTROL DEVICE FOR IGNITION TIMERS Filed Oct. 19, 1931 2 Sheets-$heet 1 Jane" $2, 1934. i m. MALLORY ,9

AUTOMATIC CONTROL DEVICE FOR IGNITION TIMERS Filed Oct. 19, 19:51 2 Sheets-Sheet 2 14 which actuates the circuit breaker 15.

Patented June .12, 1934 AUTOMATIC ooN'moL DEVICE FOR IGNITION rmnns Marion Mallory, Toledo,. Ohio, assignor to The Mallory Research Company, a corporation of 1 Delaware Application October 19, 1931, sci-a1 No. 569,690 1 Claims. (01. 123-111) This invention-relates to a device for automatically controlling the timing of the ignition in internal combustion engines in accordance with the various conditions of operation.

} Automatic ignition timing devices, as heretofore used, have depended upon an increase in the speed of the engine or upon an increase in 4 the degree of vacuum in the intake passageway for initially advancing the spark. In order to 1 insure a smooth and steady operation when the engine is idling, it is necessary to set the timer so that the spark will occur when the crank is 5 to past dead center. With such setting, when the throttle is first opened, if the initial 1 spark advance depends directly or indirectly upon an increase in speed, the'pick up will neces-' sarily be slow. 0n the other hand, if the spark is initially set where it should be for the best performance after the throttle is open, it will cause the operation of the engine to be jerky when idling or perhaps to stop altogether.

With the above facts in mind it is the object of the present invention to provide a double acting control device, preferably a device which will retard the timing only when the engine is idling with the throttle closed, permitting it to advance immediately to normal as soon as the throttle is opened, so as to insure a quick pick up, and which will thereafter gradually advance the timing as the vacuum in the intake passageway increases or as the speed of the engine'increases.

My invention will be more particularly described in connection with the accompanying I drawings, in which Figure 1 is a sectional view of the timer with the control device associated therewith;

Figure 2 is a section taken on the line 2---2 of Fig. 1;

Figure 3 is a view similar to Fig. 1 but showing a modified form; and Figure 4 represents a chart showing the spark advanced as the throttle is opened and the speed of the engine increases.

As shown in the drawings the invention is associated with an ignition timer comprising a housing 10 formed with. a bearing 11 for the timer shaft 12. As shown in Figs. 1, 2 and 3 a sleeve 13 is mounted for relative circumferential movement on the shaft 12 and is provided with a cam relative position of the sleeve 13 and cam 14 with reference to the timer shaft 12 is controlled through the medium of a circular plate 16 which is secured to the sleeve by screws 17 or other suitable means.

In the form of the invention shown in Figs. 1 and 2 a plate 18 is secured to the shaft 12 andis provided with a stud 19 which projects into an arcuate slot 20 formed'in the plate 16. A spring 21 is mounted on the plate 16 and bears against 00 v the stud 19 so that it has a tendency to advance the plate 16 in its relation to the timer shaft as the latter rotates in a right hand or clockwise direction as indicated by the arrow.',

In order to modify the operation of the timer as affected by the spring 21, the|housing 10 is formed with an extension 22, within which is a reciprocable brake member 23 adapted, under predetermined conditions, to engage and retard the rotation of the disk 16. The brake member 7 23 has a stem 24 which extends into a'housing or cylinder 25 secured to the extension 22 and is there provided with a piston 26. The brake is urged toward engagement with the disk 16 by a' spring 27 the tension of which may be adjusted by a thumb screw 28. In addition to the spring 3 r 27, the piston 26 may be acted upon by suction through either of the passageways 29 or 30 which, by means or a three-way valve 31 are selectively placed in communication with the intake pas sageway 32 of the engine through a connecting conduit 33.

For shifting the valve 31, the latter is provided with. a crank arm34 which is connected by a link 35 to a. crank arm 36. The throttle valve 37 is secured to a pin 38 on which the crank 36 is mounted. A lever 39 is secured to the pin 38 and a spring 40 connected therewith urges the valve to a closed or idling position with the lever engaging a stop pin 41. The crank 36 has a lu 42 which engagesthe other end of the lever 39 to open the throttle valve. The crank 36, how-- ever, has a lost motion connection with the lever 39 and in closing the throttle is moved tothe position shown in broken lines in Figs. 1 and .3, while the lever 39 stops as soon as it engages the stop pin 41.

but a centrifugal governor is substituted for the spring 21. This centrifugal governor comprises a weight 43 eccentrically pivoted on a plate 44, secured to the timer shaft 12. The outer end of this weight has a lug 45 which projects through an arcuate slot 46 inthe plate 44 thus limiting the movement of the weight in either direction about its pivot. The lug 45 also projects into an eccentric slot 2min the plate 16 so that,'wlth the timer shaft rotating in a right hand or clockwise direction indicated by the arrow, the out passage 32 of the engine.

vIn the operation of the inventionas illustrated,

when the throttle is closed with the crank arm 36 in the position shown by broken lines, the valve 31 will be in such position that the passageway 29 will be in communication with the intake With the throttle closed, a high vacuum willbe established in the intake passageway and augment the eifect of the spring 27 on the piston 26, causing the brake member 23- to bear against the disk 16 with such force that the sparkhas a maximum retardation. In order to obtain the most favorable results, the setting is such that this maximum retardation causes the spark to occur when the crank is 5 or 10 past dead center.. As the crank arm 36 is advanced to the full line position shown in Figs. 1 and 3 to open the throttle, the passageway 29 is cut off from the intake 32 and there is then no pressure of the brake upon the disk 16 except that caused'by the spring 27. This permits the spark to advance immediately about 20, as indicated by the line 51 in Fig. 4, as soon as the throttle commences to open. This insures a quickpick' up and, as the throttle is opened wider for an increase in speed, thepas'sageway 30 is brought .into communication with the intake 32 and the increased vacuum, as the speed of the engine increases, gradually counter-acts the effect of the spring 27, the brake member 23 bears with less and less pressure against the disk 16, gradually advancing the spark, as indicated by the line 52 ill 1 mg. 4, until the pressure of the brake upon the disk 16 ceases altogether and the timing reaches the maximum advance permitted by the slot 20 or 20".

From the foregoing description, it will be seen that I have provided a timer controlling device which may be initially set so that, in idling, the

spark will occur after the crank passes dead center, thus insuring a smooth and steady operation, and yet, the moment the throttlestarts to open, the spark is immediately advanced sufficiently to insure a quick pick up, after which .the

spark is advanced gradually in accordance with I the amount of vacuum in the intake passageway as determined by the speed of the engine and the position of the throttle.

It will be understood that the invention is not limited to the structure shown and described but includes all-such modifications as may fall in the scope of the appended claims.

What is claimed is:

1. In an ignition'timer, means including a brake for effecting an extreme retardation of the timing while the throttle is in idling position, and means to lessen the frictional resistance of the brake for effecting an immediate advance of the timing through a substantial angle as soon as the throttle starts to open and before there has been any appreciable increase in speed.

2. In an ignition timer, a timershaft, a circuit breaker cam having a relative circumferential movement thereon to vary the timing, 9. spring Withtending to advance the cam, a brake tending to retard it, means constantly acting on the brake and operable by itself to efiect an intermediate timing, and supplementary means for modifying the efiect of said constantly acting means to cause a progressive release of the brake as the speed increases and to increase the pressure of the brake when the engine is idling.

3. In an ignition timer, a timer shaft, a circuit breaker cam having a relative circumferential movement thereon to vary the timing, a spring tending to advance the cam, a brake tending to retard it, means constantly acting on the brake and operable by itself to effect an intermediate timing, and supplementary means for rendering the vacuum of the engine intake passage efiective to progressively lessen the effect of the brake as the speed of the engine increases and to increase the eflectiveness of the brake when'the engine is constantly acting on the piston to apply the brake with moderate force to effect an intermediate timing, and means for rendering the vacuum of the engine intake passage eifective upon the piston to progressively diminish the pressure of the brake as the speed of the engine increases and to increase the pressure of the brake when the engine is idling. I I

5. In an ignition timer, a timer shaft, a circuit breaker cam having a relative circumferential movement thereon to vary the timing, centrifugal means tending to advance the cam, a brake tend ing to retard it, means constantly acting on the brake and operable by itself to .eifect an intermediate timing, and supplementary means for modifying the effect of said constantly acting means to cause a progressive release of the brake as the speed increases and to increase the pressure of the brake when the engine is idling.

6. In an ignition timer, a timer shaft, a cir- 1 cuit breaker cam having a relative circumferential movement thereon to vary the timing, centrifugal means tendingto advance the cam, a brake tending to retard it, means constantly acting on the brake and operable by itself to effect an intermediate timing, and supplementary means for rendering the vacuum of the engine intake passage effective to progressively lessen the effect of the brake as the speed of the engine increases and to increase the effectiveness of the brake when the engine is idling. v I 7. In an ignition timer, a timer shaft, a circuit breaker cam having a relative circumferentialmovement thereon to vary the timing, centrifugal means tending to advance the "cam, a brake tending to retard it, a;piston connected with the brake, means constantly acting on the 1 piston to apply the brake with moderate force to effect an intermediate timing, and means for rendering the vacuum of the engine intake passage efiective upon the piston .to progressively diminish the pressure of the brake as the speed i of the engine increases and to increase the presresistance of said brake to effect an immediate g advance of the timing through a substantial airbreak, means to utilize suction from the engine to decreasevthe effect of said friction means as the speed increases and to increase the effect of said friction means at idling speeds, and means including a lost motion connection to cut off said suction means at idling speeds to lessen the resistance of said friction means to eifect an immediateadv'anceoftheflmingthrougha substantial angle immediately before the throttle is opened and before therehas been any appreciable increaseinspeed.

v 10. In an ignition timer, a timer shaft, a circuit breaker cam having a circumferential movement relative thereto to vary the timing, means tending to advance the cam, means including a brake tending to retard the cam,- and means to utilize suction from the motor to add to or subtract from the effective resistance of said brake means.

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