US2650581A

US2650581A - Ignition apparatus

Info

Publication number: US2650581A
Application number: US125352A
Authority: US
Inventors: Brooks H Short; Argyle G Lautzenhiser
Original assignee: Motors Liquidation Co
Current assignee: Motors Liquidation Co
Priority date: 1949-11-03
Filing date: 1949-11-03
Publication date: 1953-09-01
Anticipated expiration: 1970-09-01

Description

Sept. 1, 1953 B. H. sHQR-r Em. 2,650,581

IGNITION APPARATUS Filed NOV. 3. 1949 g .n 'n MAN/Fa mez/QM z J5@- 2 T7? Patented Sept. `1, 1953 2,650,581 IGNITION APPARATUS Brooks H. Short and Argyle G. Lautzenhiser, Anderson, Ind., assignors to General Motors Corporation, Detroit, Mich., a corporation of Dela- Ware Application November 3, 1949, Serial No. 125,352

(Cl. 12B- 117) Claims.

This invention relates to ignition apparatus having means for varying the timing oi the ignition in accordance with engine suction as well engine speed. It has been found desirable ticularly with high compression automobile engines to retard the ignition momentarily during rapid acceleration. It is, therefore, an object of the present invention to provide for momentarily decreasing the eiect of engine suction upon the control of the ignition timer during rapid acceleration while providing for the normal operation of the timer to retard the spark gradually with relatively gradual decrease of engine suction. In accomplishing this object, the engine provides for momentarily venting the pipe which connects the engine intake with a diaphragm chamber closed by a diaphragm which moves in accordance with variations of engine suction to control ignition timing.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawing, wherein a preferred embodiment of the present invention is clearly shown.

In the drawing:

Fig. l is a diagram showing a plan view of the ignition timer with its suction controller partly in section and a sectional view of the auxiliary apparatus for momentarily venting the pipe leading to the diaphragm chamber during rapid decrease in engine suction.

Fig. 2 is a chart illustrating the operation of the device.

Referring to Fig. l, a timer housing Iii supports a breaker plate Il which supports a circuit breaker lever i2 carrying a rubbing block i3 for engagement by an ignition timer cam I4 which is connected with an engine driven shaft by a device responsive to engine speed for varying the angular relation of the cam I4 relative to the engine driven shaft which has an extension i5 on which the cam I4 is rotatable.'

In the timer shown in Fig, l, the direction ci rotation of the cam I4 is counterclockwise, therefore the speed responsive device will effect displacement of cam I4 relative to shaft extension I 5 in a counterclockwise direction as engine speed increases. The lever I2 is urged counterclockwise about a pivot post I6 attached to the plate I2 by a leaf spring I1 iiXed to the lever and to a bracket I8 which a wire I9 connects with a terminal 20. Bracket I8 is connected also with a wire 2| connected with a condenser in a case 22, said condenser having one foil connected with wire 2| and the othery foil with the case 22 which is grounded by a supporting bracket 23 which a screw 24 attaches to the plate Il which in turn is connected to ground by ,a flexible wire 24 soldered or brazed at 25 to the housing il and connected with a terminal clip 28 in contact with a screw 21 threaded into the plate II. Lever i2 which is insulated .frem Post I6 and ,plate H wries a contact 28 for engaging a contact 29 iixed to a bracket 33 supported by a plate II. The condenser in case 22 is therefore in parallel with the

contacts

28 and 29.

The suction controller 33 of the ignition timer comprises two shells 3i and 32, the iianges of which clamp the periphery of a diaphragm 33, the center portion of which is attached to a link 34, a washer 35, a cup 36 by a rivet 31. Link 34 is pivotally connected with plate II by the screw 21. A compression spring 38 is conned between the cup 35 and a bushing 35il which is threaded into a bushing 40 attached to the shell 32. The connection between the engine intake and the suction chamber between shell 32 and diaphragm 33 is provided by a pipe `4i having a restriction 42. As engine suction increases, the diaphragm 33 moves right and the plate II, which is supported for rotation about the axis or" cam I4, rotates clockwise to advance the ignition timing. When engine suction decreases, spring 38 pushes diaphragm 33 left and the ignition is retarded.

Between the engine intake and the restriction 42, pipe 4I is connected by pipe 43 with a suction chamber 44 located between a shell 45 and diaphragm 41, the periphery of which is clamped between flanges of shell 45 and a shell 43. Rivets 43 connect diaphragm 41 with a washer 49 and a rod 50 guided for longitudinal movement by a flange 5I of shell 4E. Hole 52 extends through washer 49 and diaphragm 41 and into the rod 53 and connects with a small bleed hole 53 leading into the chamber between shell 43V and diaphragm 41. The hole in shell 45, which receives a rod 50, is covered by a diaphragm 55, the periphery of which is clamped between the shell and the flange 56 of a bracket 51 secured by rivets 58. Shell 51 provides a valve seat 59 for a ball valve 63 retained on the seat by spring f3! which is located by a pin 62 attached to a shell 33 supported by bracket 51 and having a vent hole 64. The valve 60 is moved from its seat by leit movement of a rod 35 attached to a plunger 6E received in a bore 61 of bracket 51, said bore being connected by pipe 63 with pipe 4i between restriction 42 and the suction device 33.

During moderate change in engine speed producing moderate change in engine suction, the diaphragm 41 remains practically in fixed position as shown, the bleed hole `53 providing for equalization of pressure on both sides of the diaphragm 41. Therefore, during relatively gradual increase in engine suction, the diaphragm 33 will move to advance ignition timing as indicated by curve A in Fig. 2; and, during relatively gradual decrease of engine suction, the ignition is retarded as indicated by curve B. Vi/"hen engine speed is increased relatively rapon a relatively level road, the suction in pipe il, between restriction 42 and the engine will be greater than the pressure on the left Y- Since the small hole 53 is too small to side. eiiect balance of pressure in a relatively short time, the diaphragm l wil move momentarily toward the left. Therefore, rod 5e will press against diaphragm 55 and cause left movementof the plunger S6 to move ball valve 6G from its seat 53 thereby connecting pipe [il with vent through the pipe t3, bore 6l, shell di and vent hole 6K3. Therefore, there will be a reduction of suction at the right of diaphragm 33 thereby permitting the spring 38 to effect momentary or abrupt retard of engine suction as represented by line C in Fig. 2. Restriction s2 limits the rate of venting of that portion of pipe di between this restriction and the engine when ball valve 65 opens and hence the rate of venting chamber 4d, so that the time required for equalization or pressure through the hole 53 will not extend unduly beyond the required interval of momentary spark retarding. At the end of the period of rapid acceleration, the suction on both sides of the diaphragm fil will have become equalized so that diaphragm 4l will return to normal position to allow the spring El to force valve @t on its seat 59.

While the embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted.

lv'hat is claimed is as follows:

l. Ignition apparatus comprising a timer having an engine driven timer cam, a circuit breaker operated thereby for controlling ignition timing,

a plate supported for rotation about the aXis of the cam and supporting the breaker, a rst suction operated device for rotating the plate and comprising a suction chamber connected with the engine intake and closed by a diaphragrn connected with thefplate and a spring opposing movement of the diaphragm with increasing engine suction to rotate the plate in a direction to advance ignition timing, said spring operating to retard ignition timing when suction decreases, and a separate suction actuated means operating in response only to sudden decrease in engine suction effective on said means for momentarily venting the suction chamber to obtain ignition retard during rapid engine acceleration.

2. Ignition apparatus comprising a timer having an engine driven timer cam, a circuit breaker operated thereby for controlling ignition timing, a plate supported for rotation about the axis of the cam and supporting the breaker, a suc= tion operated device for rotating the plate and comprising a suction chamber connected with the engine intake and closed by a diaphragm connected with the plate and a spring opposing movement of the diaphragm with increasing engine suction to rotate the plate in a direction to advance ignition timing, said spring operating to retard ignition timing when suction decreases, and a device for venting the suction chamber and including a vent valve, a spring biasing the valve into normally closed position, a chamber having a movable partition and connected on one side of the partition with the engine intake, means connected with the partition and located on the other side thereof for trans mitting motion to the valve to open it when presn sure on the iirst mentioned side of the partition is greater than pressure on said other Sid@ there of, and a duct through the partition providing for equalization of pressure on both sides of the partition within a time commensurate with `relatively gradual rates of change of engine suction, said duct providing a restriction such that pressure equalization lags behind pressure increase on the first 'mentioned side of the partition when engine suction is suddenly reduced.

3. In combination with ignition apparatus movable to advance and retarding positions of timing; a suction operated device for actuating the apparatus and comprising a suction chamber connected with the engine intake and closed by a diaphragm connected with the apparatus and a spring opposing movement of the diaphragm with increasing suction to move the apparatus in a direction to advance ignition timing, said spring operating to retard ignition timing when suction decreases; a restriction in the connection between the device and the engine intal-:e and an independent suction operated means connected around the restriction and operating in response only to sudden decrease in the engine suction eiective on said suction operated means for momentarily venting the suction chamber to obtain ignition retard during rapid engine acceleration.

4. In combination With an ignition apparatus movable to advance and retard positions of timing, a suction Voperated device connected with the engine intake and operable to move the apparatus to advance and retard positions of timing in accordance with engine suction, said device comprising a suction chamber connected with the engine intake and closed by a diaphragm connected with the apparatus and a spring opposing movement of the diaphragm with increasing engine suction to operate the apparatus to advance ignition timing, said spring operating to retard ignition timing when suction decreases; a restriction in the connection bctween the suction operated device and the engine intake; and a suction operated valve connected around the restriction for venting the suction operated device momentarily to atmosphere upon sudden decrease in the engine suction which is eiiective to control the operation of said valve.

5. In combination with an ignition apparatus movable to advance and retard positions of timing; a suction operated device connected with the engine intake and operable to move the apparatus to advance and retard positions or" timing in accordance with engine suction, said device comprising a suction chamber connected with the engine intake and closed by a diaphragm connected with the apparatus and a spring opposing movement of the diaphragm with increasing engine suction to operate the apparatus to advance ignition timing, said spring operating to retard ignition timing when suction decreases; a restriction in the connection between the suction operated device and the engine intake; and a suction responsive by-pass means around the ree striction for venting the suction operated device momentarily to atmosphere upon sudden decrease in the engine suction which is effective to control the operation of said by-pass means.

BROOKS H. SHORT. ARGYLE G. LAUTZENHISER.

References Cited in the file of this patent UNITED STATES PATENTS Y Number