US1232596A - Ignition-timing device for internal-combustion motors. - Google Patents

Description

W. E. NICKERSON.

IGNITION TIMING DEVICE FOR INTERNAL COMBUSTION MOTORS 7 APPLICATION FILED MAY I9| I913- l g sga Patented Ju1y10,1917.

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W. E. NICKERSON.

IGNITION TIMING DEVICE FOR INTERNAL COMBUSTION MOTORS.

APPLICATION FILED MAY19.19|3.

1 56 Patented July 10, 1917.

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WILLIAM E. NICKERSON, F CAMBRIDGE, MASSACHUSETTS, ASSIGNOR TO EVERETT D.

CHADWICK, TRUSTEE, 0F WINCHESTER, MASSACHUSETTS.

Specification of Letters Patent.

Patented July 10, 1917.

Application filed May 19, 1913. Serial No. 768,396.

To all whom it concern:

Be it known that I, WILLIAM E. Nickna- SON, a citizen of the United States, residing at Cambridge, in the county of Middlesex and State of Massachusetts, have invented new and useful Improvements in Ignition- Timing Devices for Internal-Combustion Motors, of which the following is a specification.

My invention has for its object the provision of means whereby the ignition in an internal combustion motor of the character commonly employed in automobiles may be automatically timed in accurate correspondence with theoretical requirements by the operation of the motor itself, thus dispensing with manual control of the ignition and the disadvantages incident thereto and improving the operation of the motor in respect to efficiency and economy. This object is accomplished, according to the present in vention, by the employment of two distinct mechanisms, one controlled by or in accordance with the power demand on the motor and the other controlled by its speed, which mechanisms are so combined with the ignition device of the motor that the speed-controlled mechanism advances the ignition as the speed increases and retards it as thespeed diminishes, while the other mechanism retards the ignition as the power demand increases and advances it as the power de mand diminishes, the actual timing of the ignition under any given condition of speed and load being determined by the compounded effect of the two mechanisms above referred to. As applied to a motor provided with a manually-adjustable throttle valve and with electric spark ignition regulated by an adjustable timer, the preferred embodiment of the invention hereinafter specifically described comprises a speed-controlled mechanism of the centrifugal governor type, to which the timer is connected, and also a connection between the timer and the throttle valve whereby the ignition is regulated in accordance with the power demand as measured by the extent to which the throttle valve is opened, these parts being combined in the manner illustrated in the accompanying drawings, in which Figure 1 is an elevation of such parts of the motor and automatic timing mechanism as are sufficient for an understanding of the latter; and

Figs. 2 to 11 inclusive are diagrams illustrating difierent position assumed by the parts of the timing mechanism under various conditions.

In Fig. 1 of the drawings 2 is the cylinder casing of the motor, 3 is the carbureter, 4 is the manifold leading from the carbureter to the cylinders 5 is the throttle valve, and 6 is the ignition device, shown as a magneto having an adjustable timer 7 so arranged that an upward movement of its operating arm 8 advances the ignition and a downward movement of said arm retards the ignition. All the parts above mentioned are or may be of well known construction.

To the arm 8 is pivoted the middle portion of a lever 9 connected on opposite sides of the arm 8 with the two mechanisms for operating said arm. Of these mechanisms the one controlled by the speed of the motor consists of a centrifugal governor 10, shown as comprising inwardly and outwardly movable weights 11 connected to a sliding sleeve 12 which in turn is connected by suitable means such as a pivoted arm 13 and a link 14 to the right hand end of the lever 9. The governor 10 is provided with a belt pulley 15 or other means for rotating it in proportion to the speed of the motor by suitable connections therewith (not shown), and the connections between said governor and thelever 9 are so arranged that as the speed increases the right hand end of said lever 18 lifted. 4

The other or left hand end of the lever 9 is connected to the throttle valve 5, in the example represented, by means of a link 16 which is pivoted to one end of a rockmg lever 17 supported on the casing 2 and connected at its other end by a link 18 to an arm 19 attached to the throttle valve. This valve is also provided with means for opening and closing it manually, in accordance with the load on the motor, to \vhlch end the link 16 may be connected to a bell crank lever 20 to which is attached a rod 21 leading to any suitable throttle-operating device (not shown), the parts being so arranged that the left hand end of the lever 9 is lowered as the throttle valve is opened and raised as said valve is closed.

69 ignition. In Fig. 4 the motor is assumed to It will be evident that so long as the throttle-operating parts are maintained in a given fixed position corresponding to a predetermined amount of opening of the throttle valve 5, that end of the lever 9 to which the link 16 is connected will also be fixed in position, and hence if any change in the speed of the motor occurs while the position of the throttle valve remains unchanged, the raising of the link 16 due to an increase in speed will result in lifting the arm 8 and thus advancing the ignition, while conversely a decrease in speed will lower the arm 8 and retard the ignition. Onthe other hand, for any given speed of the motor the governor weights 11 will be located at a certain definite elevation and will maintain the right hand end of the lever 9 at a corresponding point which will be fixed so long as the speed remains unchanged, and therefore any variation in the opening of the throttle valve without change in speed will result in raising or lowering the arm 8, said arm being raised and the ignition advanced in proportion to the closing of the throttle. Consequently the actual position of the arm 8 at any given instant will depend upon the compounded efl ect of the two mechanisms connected to the opposite ends of the lever 9, each mechanism producing its own proper effect on said lever in such manner that an increase in speed or a decrease in load tends to advance the ignition while a decrease in speed or an increase in load tends to retard the ignition, thus fulfilling the conditions which theory requires for securing the combustion of the explosive mixture at i the proper time to insure the maximum development of power and the absence of injurious efiects upon the motor itself, such as are liable to occur if the mixture is ignited so late in the cycle that combustion is not completed before the exhaust valve opens.

The mode of operation of the ignitiontiming mechanism above described under various conditions of speed and load is exemplified in Figs. 2 to 11 inclusive. Of these diagrams, Figs. 2, 3, 4 and 5 show the throttle valve 5 in the same slightly-open position, and in Fig. 2 the motor 1s assumed to be at rest and hence the governor weights l1 occupy their lowest position. Under such conditions the arm 8 also occupies its lowest position and the ignition is therefore fully retarded, which is as it should be when the motor is to be started. In Fig. 3 the motor is assumed to be'running at a relatively low speed such that the governor weights 11 move outward somewhat, thus lifting the lever 9 and arm 8 andslightly advancing the be running at a medium speed at which the governor weights move outward and lift the Y 8 until the ignition is advanced still farther, while in Fig. 5, which corresponds 1 ,asaeec I without a load, the governor weights have moved outward and lifted the arm 8 until the ignition is fully advanced. Fig. 6 shows a somewhat increased throttle valve opening, but the load is assumed to be such that the motor is running at a low speed in which the governor weights occupy the same position as in Fig. 3. Under theseconditions the ignition is retarded almost to the full extent, since the lifting of the right hand end of the lever 9 is nearly neutralized by the lowering of the opposite end of said lever by the movement of the throttle-operating mechanism resulting in the wider opening of the throttle. In Fig. 7, with the same throttle valve opening, the speed of the motor is assumed to have increased until it is equal to the speed assumed in Fig. 4, with the result that the arm 8 is lifted somewhat farther than in Fig. 6 and the ignition is advanced accordingly. In Fig. 8, in which the throttle valve opening is the same as in Figs. 6 and 7, the motor is assumed to be running at the same high speed as in Fig. 5, and in this case the governor weights lift the arm 8 into the position illustrated, in which the ignition is almost fully advanced In Figs. 7 and 8, as in Fig. 6, the ignition is not advanced as far as in Figs. land 5, which show corresponding positions of the governor weights, because the wider opening of the throttle valve results in lowering the left hand of the lever 9 and thus neutralizing in part the lifting effect of the governor weights on said lever. In Figs. 9, 10

and 11 the throttle valve is shown in a quite they assume at observed that in each of Figs. 9, 10 and 11 the lowering of the left hand end of the lever 9 in correspondence with the wider opening of the throttle valve has the effect of preventing the arm 8 from being lifted by the governor weights at the different speeds asfar as it is lifted under the conditions assumed in the preceding figures, so that the ignition is advanced to a less extent. In Fig. 9 the ignition is fully retarded, in Fig. 10 it is slightly advanced and in Fig. 11 it is advanced to a medium extent. The position shown in Fig. 11- permits a further advance of the ignition withconnections between said lever and the throttle-operating mechanism, while the right hand end of said lever is set and maintained in proper position according to the speed of the motor, independently of the amount of opening of the throttle valve, the

ignition being timed by the adjustment of a but also because the extent to which it is opened is in accurate correspondence with the power demand asmeasuredby the quantity of explosive mixture necessary to be supplied per stroke in order to meet this demand, but it is to be understood that instead of a connection with-the throttle valve various other parts or characteristics ofthe motor which vary in position or otherwise in accordance with the power demand may be utilized for'the same purpose, if preferred.

The centrifugal governor herein described by way of example may also be replaced by any other suitable arrangement which is responsive to the speed of the motor and is capable of acting upon the ignition 'in' the manner previously described, and the two distinct mechanisms of which the governor and the throttle valve connections are examples may. also be combined with or caused to operate upon the ignition device in various ways, as my invention, broadly considered, is not limited to the particular mechanisms shown, or to any specific manner of combining them with each other and with the ignition device. My invention is also applicable to various types of motors and ignition devices, as will readily be understood without further explanation.

I claim:

1. In an internal combustion motor having means for igniting the explosive mixture therein, the combination with an ignition timer of two distinct mechanisms independently operated in accordance with variations in the speed of the motor and in its power demand, respectively, and a lever positively connected at different points to said mechanisms and to the ignition timer, whereby said mechanisms are reciprocally related as power and fulcrum and the timer is moved in both directions by its connection with the lever.

2. In an internal combustion motor having means for igniting the explosive mixture therein, the combination with an ignition timer and an adjustable throttle valve of means under the control of the operator for opening and closing said throttle valve, a speed-controlled mechanism, a lever pivotally connected at one point to the speedcontrolled mechanism and at another pointtothe throttle-operating mechanism, whereby said mechanisms are reciprocally related as power and fulcrum, and positive connections between a'third point on said lever and the ignition timer, whereby the latter is operated 1n both directions by the combined efi'ect of said mechanisms.

3. In: an internal combustion motor, the combination with an ignition device having an adjustable timer, of two distinct mechanisms independently operated in'accordance with variations in the speed of the motor and in its power demand, respectively, and a lever connected at its ends to said mechanisms and between its ends to the timer.

4..1n an internal combustion motor, the combination with an adjustable throttle valve and an ignition device having an adjustable timer, of a lever connected at one end to the throttle valve and between its ends to the timer, a mechanism responsive to variations in the speed of the motor, and

connections between said mechanism and the other end ofsaid lever.

In testimony whereof I have hereunto subscribed my name this 14th day of May,

1913. i WILLIAM E. NICKERSON.

,Witnesses: v E. D. CHADWIOK,

OLIVER R. MITCHELL.

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