Firing deck insert for internal combustion engines
AssigneeSpencer Heads, Inc.
InventorBoyd La Russell Spencer
Life of this patent
Estimating the term…
Abstract
An internal combustion engine including a coolant jacketed body surrounding a combustion cylinder with a tubular wall extending through the coolant jacket and surrounding an ignition device exposed through a firing deck area to said cylinder, has a circular recess axially of said ignition device and encompassing said firing deck area with an axially disposed, internally threaded bore extending from said recess into said tubular wall, and a circular plate insert having an axially disposed, externally threaded boss threadable into said bore to axially secure said insert within said recess, the diameter of said insert being less than the diameter of said recess to enable expansion by heat absorption of said insert independently of and without transmitting stress and strain to said engine body.
Claims11
A replaceable firing deck insert for an internal combustion engine having a coolant jacketed engine body including at least one combustion chamber and having a firing deck surface with a critical area surrounding an ignition device and subject to thermal stresses, the ignition device being sealed from the coolant jacket by a generally tubular shaped wall structure and the firing deck surface having a circular counterbore recess in the critical area thereof and disposed axially of the ignition device, and having an axially disposed internally threaded bore extending into the tubular wall structure, said insert comprising a circular body to be nested in and to conform to the counterbore recess with peripheral clearance and to cover at least a portion of the critical area of the firing deck surface, the diameter of said insert being slightly smaller than that of the counterbore recess with the peripheral edge of said insert spaced from the peripheral wall of the counterbore recess and providing the peripheral clearance as an expansion area for said insert to accommodate absorption by said insert of heat and strain independently of the engine body, and a centrally disposed externally threaded boss of reduced diameter extending axially from the inner surface of said insert body and threadable into the internally threaded bore in the engine body for securing the insert and body together, the thickness of said insert being substantially equal to the depth of the counterbore with the exposed surface of said insert generally contiguous with and conforming to the engine body surface surrounding the counterbore, said boss having an axially disposed opening therethrough and including a portion defining a seat for the ignition device and an opening for exposing the ignition device to the combustion chamber, whereby said insert body is centrally fixed by said boss relative to the point of combustion in the chamber but is free to expand radially from said boss as it absorbs heat of combustion without stress or strain.
In an internal combustion engine, an engine having a coolant jacketed engine body including at least one combustion chamber and having a firing deck surface with a critical area surrounding an ignition device and subject to thermal stresses, the ignition device being sealed from the coolant jacket by a generally tubular shaped wall structure and the firing deck surface having a circular counterbore recess in the critical area thereof and disposed axially of the ignition device, and an axially disposed internally threaded bore extending into the tubular wall structure, and an insert comprising a circular body nested in and conforming to said counterbore recess with peripheral clearance and covering at least a portion of the critical area of the firing deck surface, the diameter of said insert being slightly smaller than that of said counterbore recess with the peripheral edge of said insert spaced from the peripheral wall of said counterbore recess and providing the peripheral clearance as an expansion area for said insert to accommodate absorption by said insert of heat and strain independently of said engine body, and a centrally disposed externally threaded boss of reduced diameter extending axially from the inner surface of said insert body and threadable into the internally threaded bore in said engine body for securing the insert and body together, the thickness of said insert being substantially equal to the depth of said counterbore recess with the exposed surface of said insert generally contiguous with and conforming to the engine body surface surrounding said counterbore recess, said boss having an axially disposed opening therethrough and including a portion defining a seat for said ignition device and an opening for exposing the ignition device to the combustion chamber, whereby said insert body is centrally fixed by said boss relative to the point of combustion in said chamber but is free to expand radially from said boss as it absorbs heat of combustion without stress or strain.
Dependencies are inferred from the claim text.