Core plug block heater and method

Information

  • Patent Grant
  • 6472637
  • Patent Number
    6,472,637
  • Date Filed
    Thursday, May 17, 2001
    23 years ago
  • Date Issued
    Tuesday, October 29, 2002
    21 years ago
  • Inventors
  • Original Assignees
  • Examiners
    • Walberg; Teresa
    • Dahbour; Fadi H.
    Agents
    • Rader, Fishman & Grauer PLLC
Abstract
In accordance with the present invention, the heater provides a core plug having one open axial end and one closed axial end to define a hollow housing. During installation, the closed end of the housing is secured into an engine core bore, such that at least a portion of housing projects inwardly of the bore and is immersed in engine fluid. Independently, a heating element, adaptable to an external power supply, is releasably inserted inside the hollow housing. Heat is therefore conducted directly through the housing directly to the engine fluid and the engine itself. A quick-release retaining member is installed to retain the heating element within the housing while still allowing free rotation of the heating element therein. The free rotation of the heating element allows an electrical connector from an external power source to interconnect with the heating element completely independent of the final orientation of the heating element inside the core plug or the end orientation of the core plug within the engine bore. The present invention therefore functions as both an immersion and a dry heater while simplifying installation and replacement.
Description




FIELD OF THE INVENTION




The present invention relates to engine block heaters, and more particularly, to a combination of a core plug and block heater with a removable, free rotating heating element cartridge.




BACKGROUND OF THE INVENTION




Engine block heaters are well-known in the prior art, and are generally of two types. An immersion-type block heater includes a heating element inserted through an engine bore such that the heating element is “immersed” into an engine coolant or fluid. Upon an electrical connection to the heating element, heat from the element warms the engine fluid directly, permitting improved starting of the engine in extreme cold. The heating element is typically placed within an open-ended housing, which is threadedly inserted into the engine bore, providing a direct access channel for the heating element to contact the fluid. To prevent fluid leakage between the heating element and the housing, the heating element is permanently welded or soldered into the housing. Because the heating element is permanently fixed within the housing, replacement of the heating element requires replacement of the entire heater and drainage of the fluid.




Alternatively, a housing, with the permanently fixed heating element extending therein, is inserted into the engine bore through an O-ring sealer, mounting the O-ring between the housing and the interior walls of the bore. The O-ring is designed as a seal to prevent fluid from escaping through the bore around the loose interface formed between the surface walls of the housing and the bore. In this heater configuration, a fastener secures the housing, inserted through the O-ring, in a fixed position to an exterior surface of the engine block. The housing, and correspondingly the heating element, do not rotate within the bore because such rotation may distort the O-ring sealer, opening gaps between the housing and bore surfaces from which fluid may leak.




To install or replace an immersion heater, all engine fluid must be drained, and in some cases, if used, the O-ring must be replaced. Further, the use of O-ring, over a period of time under high temperatures, results in an addition disadvantage for the O-ring may permanently set to the bore, or otherwise deteriorate, thereby failing to provide a sufficient seal and allowing engine fluid to leak through the bore and soil the electrical connection between the heating element and an external power source causing the heater to malfunction. Likewise, the O-ring may fail to seat properly during installation, causing an insufficient seal leading to the loss of engine fluid. Additionally, aftermarket installation of an immersion-heater is cumbersome and time consuming, requiring drainage of the engine fluid before the heater may be installed or the heater and/or the heating element replaced.




A second type of engine block heater is referred to as a “dry” or “cartridge-type” heater. Instead of being inserted through a bore that taps an engine fluid chamber, the dry heater is threadedly inserted into a bore specially drilled into a portion of the engine housing adjacent to but not intersecting the fluid chamber. Alternatively, the heater is placed in the bore by a fastener that mounts the heater in a fixed position to an external surface of the engine block. In either application, the heater, within the bore, does not directly contact the coolant. When an electrical connection is made to the dry heater, heat is conducted directly into the walls of the engine, and from there, indirectly to the engine coolant. While the dry heater eliminates engine fluid leaks, its effectiveness and efficiency is reduced because of the relatively large thermal mass (i.e. the engine block and/or head) that must be heated prior to heating the fluid within the engine.




In both types of heaters, electrical power is provided to the heating element by means of a power cord/connector combination that engages the heating element. One part of the connector combination is usually permanently mounted to the heating element. As may be appreciated, the final orientation of the heater-mounted connector portion is highly dependent upon the rotational orientation of the heating element after threaded interconnection to the engine block. In particular, thread start and stop points may vary significantly between engines, and even between engines of the same type due to manufacturing variances. Thus, a final heater-mounted connector orientation may vary significantly between identical engines. Moreover, the cord-mounted connector portion has limited positions in the confined space about the engine to effect interconnection between the cord and the heating element, thereby increasing the difficulty of connecting the heater to a power supply for operation.




Accordingly, an engine block heater is needed that overcomes the aforementioned difficulties and limitations.




SUMMARY OF THE INVENTION




To overcome the difficulties associated with block heaters, the present invention provides a generally annular cylindrical core plug having one open axial end and one closed axial end to define a hollow housing. A portion of the housing exterior is threaded for engagement with a corresponding threaded core bore of an engine that extends from an outer surface of the engine to an interior fluid chamber. Additionally, the housing exterior may include a sealing flange for sealingly engaging the outside perimeter of the engine core bore.




During installation, the closed end of the housing is inserted into the bore, and the housing is threadedly secured in place such that at least a portion of housing projects inwardly of the bore and is immersed in engine fluid inside the chamber. At any time after installation of the housing, a heating element is inserted into a housing cavity. The heating element has a radial diameter slightly smaller than the radial inner diameter of the housing cavity for easy insertion and rotation therein. Once inserted, a quick-release fastener is installed to retain the heating element within the housing while still allowing free rotation of the heating element.




The heating element of the present invention is therefore dry inserted within the housing so that no direct contact exists between the heating element and the engine fluid. As a result, the heating element does not need to be permanently welded into the housing or no O-ring is required to seal the interface between the surfaces of the bore and the housing, thereby removing the possibility of leaks therebetween. If desired, a flange may be formed on the exterior of the housing adjacent the threaded portion to tightly fit against the outer surface of the engine, thereby sealing the bore against leakage.




Additionally, since the heating element is retained within the housing only by the quick-release fastener, the heating element is free to rotate 360 degrees within the housing. Any electrical connector attached to the heating element is likewise free to rotate, making orientation of the electrical connector from the external power source easier, especially within confined spaces. The free rotation of the heating element allows the electrical connector to interconnect with the heating element completely independently of the final orientation of the heating element inside the core plug or the end orientation of the core plug within the engine bore. Upon application of electrical current, the heating element heats, thermally expanding the materials that constitute the heating element. This thermal expansion increases the diameter of the heating element, forcing the exterior walls of the heating element against the internal walls of the housing cavity to lock the heating element in place within the housing and to provide a direct transfer path of heat conductance from the heating element to the housing to be radiated directly to the engine fluid and the engine block. The present invention therefore has the advantages of an immersion heater, namely the ability to directly warm the engine fluid to quickly and efficiently heat the engine, and a dry heater, which provides simplified installation and replacement of the heater while minimizing the possibility of fluid leakage.











BRIEF DESCRIPTION OF DRAWINGS





FIG. 1

is a front view of the core plug and cartridge heater installed in an engine block.





FIG. 2

is a cross sectional view of the core plug and cartridge heater of FIG.


1


.





FIG. 3

is a top view of the core plug and cartridge heater of FIG.


1


.





FIG. 4

is an assembly view of the core plug and cartridge heater installed in the engine block.





FIG. 5

is a perspective front view of an alternative embodiment of the core plug and cartridge heater.





FIG. 6

is a side view of the core plug and cartridge heater of FIG.


5


.





FIG. 7

is a perspective front view of an alternative embodiment of the core plug and cartridge heater.











DETAILED DESCRIPTION





FIGS. 1 and 2

show a generally annular cylindrical core plug heater


10


defined by a core plug


11


and a heating element


40


. Core plug


11


comprises a hollow housing


12


. Housing


12


provides exterior walls


14


extending between an open axial end


16


and a closed axial end


18


. Interior walls


20


define an interior cavity


22


of the housing. Interior cavity


22


is generally annularly cylindrical in shape. Housing


12


is made of brass or any other known heat-conductive material. Core plug


11


is shown as a generally annular cylindrical housing


12


. The Plug


11


may also take alternative shapes to conform to an engine core bore


28


. Bore


28


extends through an engine


29


from an interior fluid chamber


36


to an exterior surface


32


of the engine.




Exterior walls


14


includes a threaded portion


24


, threaded for engagement with engine bore


28


of engine block


29


. Threaded portion


24


provides threads that extend around a surface of walls


14


and is adapted to matingly engage a corresponding set of threads


30


formed in engine bore


28


. A torquing collar


34


defines a top portion of housing


12


. The closed axial end


18


of housing


12


is inserted into bore


28


, and housing


12


is threadedly secured in place in bore


28


such that at least a lower portion


26


of housing


12


projects inwardly through bore


28


into fluid chamber


36


and is immersed in engine fluid, such as engine coolant or oil. The engagement of threaded portion


24


with engine bore


28


effectively seals the bore, preventing the escape of fluid from chamber


36


while providing access to the fluid for direct heating by core plug heater


10


.




In the illustrated embodiment, open axial end


16


of housing


12


is defined by torquing collar


34


. Collar


34


has a fixed geometric shape (e.g. hexagonal) and is designed to receive a fastening device, such as a socket, for threadedly driving housing


12


about threads


24


and


30


into position in engine bore


28


. The described shape of collar


34


is not imperative to the invention, and any shape of collar


34


or a housing


12


without collar


34


could be designed to accommodate various methods for securing core plug


11


within bore


28


. Likewise, threads


24


and


30


as shown can be replaced with other methods known in the art for sealingly securing a plug in a bore, such as cementing or soldering plug


11


into a sealing engagement within bore


28


.




Additionally, a sealing flange


37


may extend from walls


14


of housing


12


. Flange


37


sealingly engages exterior surface


32


about an outside perimeter


38


of bore


28


, providing an additional barrier against leakage of fluid from engine


29


through bore


28


. Flange


37


also serve as a stop against over-threaded insertion of plug


11


into bore


28


and sets the proper position of lower portion


26


of housing


12


within chamber


36


.




A heating element


40


of the present invention is a dry cartridge-style heater insertable into interior housing cavity


22


. Heating element


40


is defined by sleeve


42


. Sleeve


42


provides a body


39


, extending between an end portion


44


and a top portion


45


, with a radial diameter slightly smaller than the radial inner diameter of cavity


22


for easy insertion and rotation therein. In cavity


22


, end portion


44


of sleeve


42


resides adjacent to closed axial end


18


of housing


12


. A connector receptacle


46


axially extends from top portion


45


of body


39


through the open axial end


16


of housing


12


. Connector receptacle


46


has a diameter smaller that the radial diameter of sleeve


42


. In one embodiment, top portion


45


of body


39


resides substantially within cavity


22


. Alternatively, as shown in

FIG. 5

, body


39


and connector receptacle


46


may extend beyond cavity


22


through open axial end


16


.

FIG. 3

shows connector receptacle


46


formed in a heart-shaped configuration, but it could be formed in any configuration to receive the shape of an electrical connector


70


.




As shown in

FIG. 2

, sleeve


42


encases a heating coil


50


. Heating coil


50


comprises a metallic tube


52


molded into an U-shaped configuration. A wire runs throughout tube


52


. A thermally conductive powder, such as magnesium oxide, fills tube


52


, snugly packed about the wire. Electrical conductors


60


extend axially in parallel from each leg of the U-shaped tube


52


and are interconnected by the wire. Electrical conductors


60


include a pair of terminals


62


commonly known in the art and also may include a ground pin


64


. A metallic material, such as aluminum is then casted or molded around tube


52


encasing the tube to form sleeve


42


with connector receptacle


46


and also setting the orientation of electrical conductors


60


, extending axially therefrom. A machining process may be utilized to smooth or refine the shape of sleeve


42


after casting to adapt sleeve


42


for insertion into housing


12


or to receive electrical connector


70


.




When activated, heating element


40


heats, thermally expanding the materials that constitute the heating element. This thermal expansion increases the diameter of sleeve


42


, forcing its exterior walls against internal walls


20


of housing cavity


22


to lock sleeve


42


in place within the housing and to provide a direct transfer path for heat conductance from the heating element to the housing to be radiated directly to both the engine fluid and engine block


29


. Because housing


12


extends directly into fluid chamber


36


and directly contacts the engine fluid, heating element


40


through housing


12


has a direct heat transfer path to warm the fluid, thereby providing substantially the same heat transfer and warming capabilities of an immersion heater of the same size and thermal properties. The direct contact between housing


12


and bore


28


also provides heating element


40


to directly warm engine block


29


through the conductance of heat from sleeve


42


through the thermally conductive walls of housing


12


to the engine block.




Because housing


12


is closed at axial end


18


, the heating element need not be permanently soldered or welded to the walls of cavity to seal against leakage of fluid. Moreover, no O-ring is required to seal the interface between the bore walls and the housing, thereby removing the possibility of leaks therebetween, which is a common problem with prior engine heaters that contact engine fluid. Additionally, because O-ring seals degrade over time due to engine heat and frictional stresses, fluid leaks through the bore retaining the immersed heating element commonly occur. Elimination of an O-ring reduces both engine and heater maintenance and the potential for heater malfunction from fluid leakage through a failed O-ring, which may contaminate electrical conductors


60


, leading to heater failure. The elimination of the O-ring or the permanent seal between the housing and the heating element also provides flexibility in the insertion and orientation of the heating element to adjust to receive the electrical connection to power the heating element. Additionally, the presence of housing


12


permits the ease of installation and/or replacement of heating element


40


, by avoiding the burdensome task of draining engine fluid prior to the installation or repair of conventional fluid-immersed engine heaters.




As shown in

FIG. 4

, electrical connector


70


generally comprises connector body


72


, cord


74


, and a terminal plug


76


. Connector body


72


provides a socket that receives electrical conductors


60


to form an electrical connection between heating element


40


and electrical connector


70


. The shape of connector body


72


matches the shape of connector receptacle


46


to be snugly received within the receptacle.




Connector body


72


is provided with a rubber or other insulating cover to protect electrical conductors


60


from adverse environmental conditions. Terminal plug


76


is adapted to connect to an external electrical power source


78


. Cord


74


is designed to deliver electricity from the external electrical power source, through the union of connector body


72


and electrical conductors


60


to provide the necessary power to heating element


40


. Generally, cord


74


is long enough to extend from engine


29


to outside a vehicle to enable terminal plug


76


to be received into an electrical socket available in a garage or alternative power source, like a generator, located remote from the vehicle in which engine


29


resides. Alternatively, as shown in

FIG. 7

, electrical connector


70


may also comprise a conduit pair


71


and a socket


73


. Conduit pair


71


are tubular members, which replace connector receptacle


46


, that extends through top portion


45


of sleeve


42


. Conduit pair


71


carry a pair of wires that connect to conductors


60


inside the conduit or connect directly to the wire that runs through the heating element. Conduit pair


71


supports an elbow


75


design to orient electrical connector


70


away from heater


10


but generally parallel and in proximity to engine block


24


to accommodate the positioning of electrical connector


70


in the generally confined engine compartment. Conduit pair


71


connects to socket


73


. Socket


73


provides terminals to receive a plug


72


on a power cord


74


supplying electrical power from an external power source such as an electrical outlet in a garage or on a generator. Socket


73


is made of plastic, rubber or other insulating material to protect the terminals therein from dirt, grime and the elements and may be designed in any configuration to conform to the shape of plug


72


. Overall, electrical connector


70


is design to serve as an elongated extension from heater


10


to enable a user easier access to connect heater


10


to the external power supply at a location remote of the heater.




A quick-release retaining member


80


retains heating element


40


within housing


12


. As shown in

FIGS. 3 and 4

, retaining member


80


takes the form of retaining spring


81


, a resilient wire formed of a generally circular body


82


terminated with a pair of arms


84


. In an unbiased position, circular body


82


possesses a radial diameter slightly larger than the radial diameter of cavity


22


of housing


12


. Arms


84


extend generally perpendicular to the plane in which circular body


82


resides and are separated by a pinch gap


86


. Arms


84


provide easily accessible grip points to bias spring


81


by pushing arms


84


together to reduce the size of pinch gap


86


. The minimized pinch gap


86


reduces the radial diameter of circular body


82


to a diameter less than that of cavity


22


of housing


12


. In such a biased state, retention spring


81


can be placed around connector receptacle


46


and above top portion


45


of sleeve


42


and into an upper region of housing cavity


22


. Once inside cavity


22


, releasing arms


84


pushes circular body


82


radially outwards to transfer the spring's bias against interior walls


20


of cavity


22


. Inside cavity


22


, spring


81


engages interior walls


20


in a position adjacent to top portion


45


of body


38


, thereby prohibiting axially longitudinal movement of heating element


40


within cavity


22


, but enabling heating element


40


to rotate independently of the engine within the cavity during installation. Because heating element


40


, in a non-operational state, has a radial diameter only slightly smaller than the radial diameter of housing cavity


22


, partial surface contact between the wall of sleeve


42


and interior walls


20


of cavity


22


exists, frictionally engaging sleeve


42


to retain heating element


40


within housing


12


and to prevent undesirable spinning of heating element


40


in the cavity during vehicle operation, which may over time damage or degrade the element from unnecessary movement within the housing. To overcome the surface friction between sleeve


42


and interior walls


20


of cavity


22


, a moderate torquing force, that can be applied through manual band adjustment, is sufficient to rotate heating element


40


within cavity


22


to orient element


40


to position connector receptacle


46


in a manner to simplify or optimize the interconnection of heating element


40


to electrical connector


70


.




In an alternative embodiment,

FIGS. 5 and 6

show the retaining member as a spring clip


90


. Spring clip


90


is comprised of a curved extension


92


, a body


94


, a retaining lip


96


and a release tab


98


. Curved extension


92


interconnects body


94


with top portion


45


of sleeve


42


. Curved extension


92


is received into a notch


99


in top portion


45


to frictionally secure or lock clip


90


to heating element


40


. Alternatively, curved extension


92


could be secured to sleeve


42


by a variety of methods including solder, a weld, or other physical fasteners. Curved extension


92


connects with retaining lip


96


by body


94


. Retaining lip


96


is a curved tight-radius portion that curves towards housing


12


to provide a retaining surface


97


designed to engage a second flange


100


extending around exterior surface


14


of housing


12


between collar


34


and closed axial end


18


. Tab


98


connects to lip


96


to terminate clip


90


in a direction opposite to retaining surface


97


formed by lip


96


.




Upon the insertion of sleeve


12


within cavity


22


, clip


90


engages flange


100


. Flange


100


is shaped so that lip


96


snaps over or about the flange to retain heating element


40


inside cavity


22


. More specifically, clip


90


is biased to extend over flange


100


to place retaining surface


97


in frictional engagement with a lip or edge


101


of flange


100


. Because flange


100


extends around housing


12


, clip


90


may be positioned at any location about housing


12


, thereby permitting sleeve


42


to freely rotate in cavity


22


to orient connector receptacle


46


to positions to aid in its connection to the outside power source as discussed herein. Tab


98


provides an easily accessible grip point to bias clip


90


for attachment to flange


100


or to provide a quick-release to unbias the clip, disengaging it from housing


12


. Tab


98


also provides an easy-to-locate release point to permit the quick disengagement of the clip and a handle to aid in the removal of heating element


40


, tasks that could otherwise be difficult and time consuming to accomplish because of the tight confines about the engine in the vehicle engine compartment and the low-observability of the components therein resulting from the engine block's orientation.




Overall, retaining member


80


, be it spring


81


or clip


90


, increases the ease of installation and replacement of heating element


40


in a confined engine compartment and decreases the time needed to secure/unsecure the heating element by eliminating the commonly employed but labor-intensive fastening methods such as screws, bolts, or solder, which require precision tools to affect retention and are difficult to operate in confined areas.




Because heating element


40


is retained within housing


12


only by quick-release retaining member


80


, heating element


40


remains rotatable 360 degrees within housing


12


upon the application of sufficient force to overcome the frictional surface forces between sleeve


42


and cavity walls


20


that retain heating element


40


in position within the housing. The rotation of the heating element permits free orientation of connector receptacle


46


and electrical conductors


60


to receive electrical connector


70


. This flexibility of orientation of the connector receptacle provides mobility and freedom to position electrical connector


70


within confined spaces about engine


29


, permitting connector body


72


of electrical connector


70


to interconnect with the heating element completely independent of the final orientation of the heating element inside housing


12


or the end orientation of core plug


11


within bore


28


. The rotatability of heating element


40


independent of engine configuration also permits the use of core plug heater


10


in a wide variety of engines and eliminates the need for separate heater models specifically designed to orientate the connector receptacle in a select position based on the engine or vehicle model to facilitate the interconnection of the heating element to the external power source because of varying engine configurations or space constraints within a vehicle's engine compartment.




Upon application of electrical current, heating element


40


thermally expands to contact walls


20


in cavity


22


. This thermal expansion increases the diameter of sleeve


42


, forcing its exterior walls against internal walls


20


of housing cavity


22


to lock sleeve


42


in place within the housing and to provide a direct transfer path of heat conductance from the heating element to the housing to be radiated directly to both the engine fluid and engine block


29


. Because housing


12


extends directly into fluid chamber


36


and directly contacts the engine fluid, heating element


40


through housing


12


has a direct heat transfer path to warm the fluid. The direct contact between housing


12


and bore


28


also permits heating element


40


to directly warm engine block


29


through the conductance of heat from sleeve


42


through the thermally conductive walls of housing


12


to the engine block. Heat is therefore conducted directly through housing


12


to the fluid in chamber


36


, while a portion of heat is also conducted simultaneously to engine


29


itself from the contact between housing


12


and bore


28


. Thus, the present invention functions as both an immersion heater directly warming the engine fluid and a dry heater that directly warms the engine block itself.




Core plug heater


10


enables an improved methodology for installing and repairing/replacing an engine heater. By separating housing


12


from heating element


40


, the engine bore sealing component, plug


11


, is installed in the engine bore


28


independently of the more fragile and expense heating element


40


. Housing


12


may be inexpensively installed during engine assembly and later equipped with the heating element if the vehicle's purchaser requests such option. Housing


12


is secured in engine bore


28


through the use of threads or other securing/retaining methods and partially projects into fluid chamber


36


. Housing


12


effectively seals engine bore


28


, prohibiting the escape or leakage of fluid from chamber


36


. A sealing flange


37


may extend from housing


12


to mate with exterior surface


32


of engine


29


about outside perimeter


38


of bore


28


, providing an additional barrier against leakage of fluid through the bore. Flange


37


also serve as a stop that sets the proper position of lower portion


26


of housing


12


, extending into chamber


36


for active heating of the fluid therein.




If desired, heating element


40


is releasably inserted into housing


12


. The insertion of heating element


40


does not require drainage of fluid chamber


36


or the addition of further sealing members, such as an O-ring, to prevent leakage of fluid from the chamber. A retaining member


80


retains heating element


40


in housing


12


.




The use of quick-release retaining member


80


, such as retention spring


81


or clip


90


, increases the ease of installation and replacement of core plug heater


10


in confined engine compartments and decreases the time needed to secure/unsecure heating element


40


by eliminating conventional labor-intensive fastening methods such as screws, bolts, or soldering, which require precision tools to affect retainment that are difficult to operate in confined areas. Since retaining member


80


does not secure heating element


40


in a fixed position, heating element


40


is rotatable 360 degrees inside housing


12


independent of the engine or its configuration. This freedom of rotation provides indefinite arrangements for positioning connector receptacle


46


to receive the electrical connector


70


, which provides power to heating element


40


upon interconnection with electrical conductors


60


. Because of different engine configurations and confined space within engine components, flexibility in the orientation of connector receptacle to receive electrical connector


70


simplifies interconnection between heater


10


and the external power supply regardless of the engine configuration or engine or vehicle model.




The above described advantages of the core plug heater invention are by no means meant to limit the scope of the invention. Though the invention has been described with respect to the preferred embodiments thereof, many variations and modifications will become apparent to those skilled in the art. It is therefore the intention that the claims be interpreted as broadly as possible in view of the prior art, to include all such variations and modifications.



Claims
  • 1. An engine block heater for heating an engine, comprising:a generally annular cylindrical core plug secured in an engine bore, having one open axial end and one closed axial end to define a hollow housing with an interior first diameter; and a heating element insertably received within said housing, said heating element having a second diameter smaller than said first diameter such that said heating element may rotate independently within said housing relative to said engine to orient said heating element to receive an electrical connection from an external power source.
  • 2. The heater of claim 1, wherein said closed axial end is inserted within said bore such that at least a portion of said housing is immersed in an engine fluid.
  • 3. The heater of claim 1, wherein said heating element further includes an electrical conductor that is orientated through rotation of said heating element to receive an electrical connection from said exterior power source.
  • 4. The heater of claim 1, wherein said heating element is retained in said housing by a retaining member that does not impair said rotation of said heating element in said housing.
  • 5. The heater of claim 4, wherein said retaining member retains said heating element by engaging an interior wall that defines said interior first diameter of said housing.
  • 6. The heater of claim 4, where in said retaining member retains said heating element by engaging an exterior surface of said housing.
  • 7. The heater of claim 1, wherein said heating element rotates 360 degrees relative to said housing.
  • 8. The heater of claim 1, wherein said heating element thermally expands within said housing.
  • 9. The heater of claim 8, wherein said thermal expansion locks said heating element in place within said housing.
  • 10. The heater of claim 8, wherein said thermal expansion prevents said heating element from rotating in said housing.
  • 11. The heater of claim 8, wherein said thermal expansion improves contact between said heating element and said housing to aid in heat conductance from said heating element to said housing for the purpose of heating the engine.
  • 12. An engine block heater for contacting fluid within an engine, comprising:a housing having one open axial end and one closed axial end to define a cavity defining a first diameter, wherein said housing about said closed axial end is adapted to be positioned in the engine to contact the fluid; and a heating element insertably and releasably received within said cavity, said heating element having a second diameter smaller than said first diameter of said cavity such that said heating element is rotatable within said cavity to position said heating element independently of said position of said housing relative to the engine.
  • 13. The heater of claim 12, wherein said housing seals against a leakage of the fluid from the engine.
  • 14. The heater of claim 12, wherein said heating element radiates heat to directly warm both the fluid and the engine simultaneously.
  • 15. The heater of claim 12, wherein said heating element further includes an electrical conductor orientated through rotation of said heating element to receive an electrical connector from an exterior power source.
  • 16. The heater of claim 12, wherein said heating element is retained in said housing by a retaining member that does not impair said rotation of said heating element therein.
  • 17. The heater of claim 16, wherein said retaining member retains said heating element by engaging an interior walls that defines said interior first diameter of said housing.
  • 18. The heater of claim 16, wherein in said retaining member retains said heating element by engaging an exterior surface of said housing.
  • 19. The heater of claim 12, wherein said heating element rotates 360 degrees relative to said housing.
  • 20. The heater of claim 12, wherein said heating element thermally expands within said cavity.
  • 21. The heater of claim 12, wherein said thermal expansion locks said heating element in place within said cavity.
  • 22. The heater of claim 12, wherein said thermal expansion prevents said heating element from rotating in said cavity.
  • 23. The heater of claim 12, wherein said thermal expansion improves contact between said heating element and said housing to aid in heat conductance from said heating element to said housing for the purpose of heating the engine.
  • 24. A method for installing an engine block heater into a fluid chamber of an engine, comprising the following steps:inserting a housing having one open axial end and one closed axial end defining an interior cavity through a bore in the engine block such that said closed axial end of said housing enters the fluid chamber; securing said housing in said bore; releasably inserting a heating element into said interior cavity of said housing; retaining said heating element in said housing with a quick-release retaining member; rotating said heating element in said housing to connect said heating element to a power source.
  • 25. A method as in claim 24, wherein said retaining member is insertable inside said cavity adjacent to said heating element.
  • 26. A method as in claim 24, wherein said retaining member engages an outside surface of said housing.
  • 27. A method as in claim 24, wherein said heating element further includes an electrical conductor orientated through said rotation of said heating element to receive an electrical connector from said power source.
  • 28. A method as in claim 24, wherein said securing said housing in said bore further comprises sealing said bore to prohibit a leakage of fluid from said bore.
  • 29. A method as in claim 24, wherein said heating element thermally expands to improve contact between said heating element and said housing to aid in heat conductance from said heating element to said housing for the purpose of heating the engine.
RELATED APPLICATION

This application claims priority to U.S. Provisional Application No. 60/204,977, filed on May 17, 2000, the contents of which are incorporated herein in its entirety.

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Number Date Country
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