Internal combustion engines

Claim 2

An internal combustion engine having: a throttle controlled induction system; an exhaust system; a valve controlled feed back conduit from the exhaust system to the induction system to feed products of combustion to fresh charge being fed to the engine; positive drive means between the throttle control and valve for moving the valve from a closed position to initially open the valve and subsequently to move the valve to a further closed position in response to opening of the throttle control, and a limited force transmitting means connected in said positive drive means whereby any obstruction to opening or closing of the valve causes breakdown of the positive drive means permitting the throttle control to be operated independently; and, means to stop movement of the valve beyond the closed positions thereof, movement of the throttle control beyond such positions being permitted by the limited force transmitting connection.

Claim 3

An engine as claimed in claim 1 wherein means are provided for holding the valve in the closed position in response to a starting operation of the engine.

Claim 4

An engine as claimed in claim 2 wherein the means for holding the valve closed comprise a solenoid operatively connected to the valve control to hold the valve closed when the solenoid is energised, said solenoid being connected in a circuit for a starter motor for the engine so that the solenoid is energised when the starter motor is operated.

Claim 5

An engine as claimed in claim 1 wherein the valve is arranged to be opened and then closed over a part of the throttle opening corresponding to a vehicle speed of 20 to 70 miles per hour.

Claim 6

An internal combustion engine having: a throttle controlled induction system, an exhaust system, a valve controlled feed back conduit from the exhaust system to the induction system to feed products of combustion to fresh charge being fed to the engine, positive drive means between the throttle control and valve for positively opening and positively closing the valve in response to opening and closing of the throttle control respectively, a limited force transmitting means connected in said positive drive means whereby any obstruction to opening or closing of the valve causes breakdown of the positive drive means permitting the throttle control to be operated independently, said valve comprising a valve body, a circular valve seat in the valve body having an outlet port therein, a rotatable valve disc having at least one aperture therein engaging the valve seat, means to press the valve disc against the valve seat and means to connect said drive means to the valve disc to rotate the disc with respect to the seat with movement of the drive means to bring the aperture in the disc into and out of register with the outlet port in the seat to open and close the valve.

Claim 7

An internal combustion engine having: a throttle controlled induction system, an exhaust system, a valve controlled feed back conduit from the exhaust system to the induction system to feed products of combustion to fresh charge being fed to the engine, positive drive means between the throttle control and valve for positively opening and positively closing the valve in response to opening and closing of the throttle control respectively, a limited force transmitting means connected in said positive drive means whereby any obstruction to opening or closing of the valve causes breakdown of the positive drive means permitting the throttle control to be operated independently, said valve comprising a valve body, a circular valve seat in the valve body having an outlet port therein, a rotatable valve disc having at least one aperture therein engaging the valve seat, means to press the valve disc against the valve seat and means to connect said drive means to the valve disc to rotate the disc with respect to the seat with movement of the drive means to bring the aperture in the disc into and out of register with the outlet port in the seat to open and close the valve.

Claim 8

An engine as claimed in claim 5 wherein the positive drive means includes a lever connected to the throttle control, the rotatable valve disc has a spindle to effect rotation thereof and the lever has an opening through which the spindle extends, there being at least one spring element supported on the lever and pressing against a flat formed on the spindle so that movement of the lever rotates the spindle and when the valve is held against movement the spring element permits the lever to rotate with respect to the spindle.

Claim 9

An engine as claimed in claim 6 wherein a coil spring is provided having outwardly extending elements at both ends thereof which are held on the lever and pressed against flats on either side of the spindle.

Claim 10

An engine as claimed in claim 5 wherein the positive drive means includes a lever connected to the throttle control, the rotatable valve disc has a spindle to effect rotation thereof and the lever has an opening through which the spindle extends, there being a plate fixed to the spindle adjacent the lever having a plurality of part spherical recesses spaced around the side thereof in which balls are located and the lever having corresponding apertures to receive said balls and spring means being provided between the spindle and lever to press the lever towards said plate so that the balls form a driving connection between the lever and plate which will permit the lever to move independently of the plate if the valve disc is held against rotation.

Claim 11

An engine as claimed in claim 5 wherein the valve seat has a slot extending across the seat to form the valve port and the disc has two diametrically spaced apertures which register with the slot in the open position of the valve.

Claim 12

An engine as claimed in claim 5 wherein the valve body and valve disc are formed from temperature resistant materials to withstand hot exhaust gases.

Claim 13

An engine as claimed in claim 10 wherein the valve body is formed from Austenitic iron and the valve disc is formed from a ceramic material.

Claim 14

An engine as claimed in claim 5 wherein the engine has a cooling system and the valve body has a passage and means to connect said passage to the engine cooling system.