US1897703A

US1897703A - Ignition timing device for low speeds

Info

Publication number: US1897703A
Application number: US571005A
Authority: US
Inventors: Mallory Marion
Original assignee: Mallory Research Co
Current assignee: Mallory Research Co
Priority date: 1931-10-26
Filing date: 1931-10-26
Publication date: 1933-02-14
Anticipated expiration: 1950-02-14

Description

1933- M. MALLORY ,897,703

IGNITION TIMING DEVICE FOR BOW, SPEEDS Filed 061?. 25'. 1951 take manifold with Patented F514, 1933 UNITED STATES amen IALLOBY, 01

PATENT OFFICE IGNITION TIIIIG DEVICE FOR LOW SPEEDS Application .llled October 28, 1981. Serial 10. 571,005.

This invention relates to a control device for ignition timers, with particular reference to conditions when the engine is idling or operating at low speeds.

In order to insure a smooth and steady operation when the engine is idling, it is necessary for the timer to be set so thatthe spark will occur when the crank is to past dead center. With such setting, when the throttle is opened, if the initial spark advance depends primarily u n a centrifugal governor, no advance wi 1 take place until there.

has been a considerable increase in s and as a consequence the pick-up will be s ow. On the other hand, if the spark is initially set where it should be for the best after the throttle is opened, the idling operation of the engine Wlll be unsteady or perha s stopped altogether.

ith the above facts in mind, it is the object of the present invention to provide an improved device for controlling the timing at low speeds and particularly to provide for an immediate advance of the timing when the throttle begins to open. With such a device, the timer may be set for an extreme retardation of the spark when the throttle control means is in position for idling and yet, the moment the throttle begins to open, the spark will be advanced immediately so as to insure a quick pick-up. The subsequent control of the timing as the speed of the engine increases may be cfiected entirely by the action of the vacuum in the intake manifold or by any of the other usual devices which have been heretofore used. 'The present embodiment of my invention will be-more particularly described in connection with the accompanying drawing, which is a sectional view of the timer and in the invention associated therewith.

As illustrated in the drawing, the timer comprises a housing 1 within which is a cam 2 mounted on the timer shaft 3 and adapted to actuate the circuit breaker 4. Associated with the timer is an arm 5 which is movable to and fro to advance or retard the times of i 'tion as will be readily understood by those amiliar with the art. A rod 6 is connected at erformance 12 in the cylinder 8 is adapted to act on the piston 7 to maintain an extreme retardation of the timing mechanism when the engine is idling.

The throttle valve 13 is secured to a ivot pin 14 to which there is also secured a ever 15 which is held against a stop 16 by a spring 17 to maintain the throttle valve in closed or idling position except when it is positively opened by other means. For opening the throttle valve a control arm 18 is journaled on the pin 14 andhas a connection 19 with the accelerator. In order to open the throttle valve, the control arm 18 is moved about its pivot with the lug 20 engaging the end of the ever 15. The arm 18 also has a lug 21 which is connected by a rod or wire 22 with the valve 11. When the arm 18 is released, a spring 23 acts on the valve ll to close the same and at the same time to swing the arm 18 away from the lever 15 as the latter engages the stop 16 with the throttle valve 13 closed; When the throttle control arm is. released for idling, therefore, there is a lost motion of the arm 18 which must be taken up as the accelerator is again 'moved to open the throttle valve. p

From the foregoing description, it will be understood that when the throttle control is in idling position as illustrated in the drawing, the valve 11 will be closed and the timing mechanism, then controlled entirely by the action of the spring 12, will be in its extreme retarded position. .With the-throttle closed, even though the engine is idling,-

there will be ahigh vaccum in the intake passage 10 but, with the valve 11 closed, this vacuum will have no effect upon the piston 7 and with the maximum retardation of the timing, the idling operation will besmooth. As the accelerator is actuated to open the throttle, the lost motion between the arm 18 and the lever 15 will first be taken u and just as soon as the throttle valve begins to open, the valve 11 will open the port 9, providing a free communication between the intake assageway 10 and the interior of the cylin er 8. The suction produced in the passage 10 by the operation of the engine will then be communicated to the piston 7 and will actuate the latter in opposition to the spring 12 to advance the timmg and since,-with the throttle inany given position, the increas ng speed of the engine will cause an increasing vacuum in the intake passage, the timing will be pro essively advanced. If the throttle valve, owever, is suddenly opened wide, there will be comparatively little vacuum in the passageway 10 and there will be a correspondingly limited advance of the timing until the speed of the engine increases and the compression in the cylinders decreases. This prevents a spark knock such as frequently occurs with timers as heretofore constructed, when the engine is traveling at low or moderate speed and the throttle is suddenly o ened.

\Vhile I have described in detail the present form of the invention, it is to be understood that the same includes all such modifications that may fall within the scope of the appended claims.

What is claimed is:

1. The combination with an ignition timer mechanism, of a member connected with said timer mechanism and movable back and forth to vary the timing, a throttle valve, an arm having a connection for controlling the throttle valve, with a lost'motion between the idling position of said arm and the position where it begins to open the throttle, and means actuated by said arm as the throttle begins to open, to act on said member to ad- Vance the timing before there is any material increase in the engine speed.

2. The combination with an ignition timer mechanism, of a member connected with said mechanism and movable back and forth to vary the timing, a throttle valve, an arm having a connection with the throttle valve for o ening it, with a lost motion between the i ling position of said arm and the position where 1t begins to open the throttle valve, and means actuated by said am as the throttle valve begins to open to causethe vacuum in the intake passe of the engine to act on said member to a vance the tlming before there is any material increase inthe engine speed.

3. The combination with an ignition timer mechanism, of a piston connected with said mechanism and reciprocable to vary'the timing, means operable by itself on said lston to causemaximum retardation when t e ongine is idling, a throttle valve, an arm having a connection with the throttle valve, with a lost motion-between the idling position of said arm and the position where it begins to openthe throttle valve, and means actuated by said arm, as the throttle valve to open, to act on said member to advance the timing before there is any material increase in the engine speed.

4. The combination with an ignition timer mechanism, ofa piston connected with said mechanism and pneumatically operable to advance the timing, a cylinder'for. guiding said piston and having a port leading from the cylinder to the intake passage of the engine, a valve normally closing said port when the engine is idling, a throttle valve, an arm having a connection with the throttle valve for controlling the same, with lost motion between the idling position of said arm and the position where it begins to open the throttle valve, and means actuated by said arm to open the first mentioned valve as thethrottle valve begins to open. 1

5. The combination withthe ignition timing mechanism and the intake. manifold of an internal combustion engine, of a member connected with said timing mechanism and movable back and forth to vary the timing, a passageway leading from said member to the intake manifold, a valve for said pa ssageway, a spring acting directly upon said valve and operable by itself to close said valve, a throttle valve, control means forsaid throttle valve, and a connection between said control means and the first mentioned valve for opening the same as soon as the control a means is actuated ,to open the throttle.

In testimony whereof I have hereunto signed my name to this s ecification.

' MARI N MALLORY.

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