WO2010063037A1

WO2010063037A1 - A thermostat

Info

Publication number: WO2010063037A1
Application number: PCT/ZA2008/000113
Authority: WO
Inventors: Traugott Salzman Ernst
Original assignee: Individual
Current assignee: Individual
Priority date: 2008-11-25
Filing date: 2008-11-25
Publication date: 2010-06-03
Anticipated expiration: 2011-05-25

Abstract

An improved thermostat (10) generally comprises the components of a conventional thermostat, typically of the type generally utilized in the cooling systems associated with internal combustion engines or the like, the thermostat also including a mechanism adapted to release the obstruction posed by the thermostat when a predetermined critical temperature is reached in the cooling system; one embodiment of the invention foresees a bimetallic release mechanism (26) adapted to release an obstructive mechanism (16) to the flow-path of cooling fluid when a critical temperature is reached; another embodiment foresees the use of a mechanism utilizing a material, typically a eutectic alloy or the like, to reach a "melting" point at which it mechanically deforms sufficiently to allow release of obstruction-causing components when a critical temperature is operatively reached.

Description

A THERMOSTAT

Technical Field

This invention relates to an improved thermostat and more particularly to such a thermostat suitable for use in cooling systems of conventional motor vehicles or the like, particularly motor vehicles equipped with internal combustion engines.

Background Art Applicant has identified difficulties experienced with conventional thermostats such as those that are activated / deactivated by means of a valve arrangement urged into a normally closed position by a helical coil spring or the like. This conventional thermostat requires the internal heat of such a cooling system to which it is applied to rise beyond a predetermined level upon which the valve arrangement will open and allow cooling fluid pass there through.

This conventional thermostat arrangement accordingly depends on the internal heat and flow experienced with the cooling system to activate / deactivate the thermostat.

It is a common difficulty experienced with the aforementioned conventional thermostats that the valve arrangement as referred to fails, restricts coolant flow to a cooling mechanism and accordingly the heat build-up in such a cooling system rises beyond desirable levels which in turn leads to damage to other parts of the engine to which such a cooling system is applied. One such difficulty is experienced where the valve arrangement becomes stuck due to calcium build-ups or the like about the valve seat.

Another reason for failure of the thermostat is that it is not tested and/or serviced at regular intervals and accordingly metal fatigue leads to the coil spring obtaining different qualities than it had when installed and accordingly fails to allow the valve arrangement to open when so required in use.

In this specification the following terms will carry the following meanings:

Eutectic: A eutectic will be meant to be a mixture of two or more crystalline substances which has a lower melting point than that of any of its constituents.

Alloy: An alloy is a combination, either in solution or compound, of at least two or more elements, at least one of which is a metal.

Binary alloy: An alloy with two components.

Ternary alloy: An alloy with three components. Quaternary alloy: An alloy with four components.

It is accordingly an object of this invention to provide an improved thermostat, which will at least alleviate some of the disadvantages of the known devices.

Summary of the invention

According to a first aspect of the invention an improved thermostat comprises a conventional thermostat including a bimetallic activatable mechanism adapted to open a flow path through the thermostat upon the latter experiencing predetermined temperatures.

According to a first preferred embodiment of the first aspect of the invention the bimetallic mechanism comprises a substantially elongate bimetallic member operatively associated with a matched aperture, the bimetallic member being adapted to operatively open the aperture with which it is associated upon experiencing a predetermined temperature, the aperture being so disposed relative to the conventional thermostat that it will allow a passage of a substantial volume of fluid there through upon being opened. According to a second preferred embodiment of the first aspect of the invention the conventional thermostat comprises at least two concentric rings with the operative inner one containing the conventional thermostat mechanism and being fluid-tightly interconnected about it's periphery to the second, larger, concentric ring. The connection also comprising a hinge interconnection between the two rings and substantially opposite thereto a latch mechanism being capable of activation/deactivation by a bimetallic release device; the release device being adapted to release the inner concentric ring upon experiencing predetermined temperatures. It will be appreciated that upon deactivation of the inner concentric ring, the conventional thermostat will be capable of being hinged to a substantially "open" position and accordingly allow for fluid-flow through the thermostat arrangement.

According to a second aspect of the invention an improved thermostat comprises a conventional thermostat including a closed aperture, the aperture being closed by a material comprising a substantially low, predetermined melting point.

Further according to the second aspect of the invention the melting point of the material is approximately 110° degrees centigrade. Still even further according to the second aspect of the invention the material comprises an eutectic alloy with substantially low melting point.

It will be appreciated, that the predetermined temperature as referred to, will be selected such that, where the cooling system or related components of an internal combustion engine or the like, to which the thermostat is operatively applied, reaches critical levels, such melting point will be reached and accordingly the aperture to which the material is applied will fall open due to the melting and subsequent mechanical failure of the material at that temperature, and accordingly allow cooling fluid to flow through the thermostat arrangement.

It will even further be appreciated that applicant has attempted, with both the aforementioned aspects of the invention, to provide a mechanism to effect and "overriding" safety feature to the conventional thermostat when it fails in use.

Description of the drawing

One preferred embodiment of the invention will now be described by way of example only with reference to the accompanying drawing which depicts a conventional thermostat comprising a hinge and latch mechanism when viewed in perspective from it's side. Description of a preferred embodiment of the invention

According to a preferred embodiment of the invention an improved thermostat 10 comprises conventional thermostat components in the form of a helical spring and valve arrangement 12 contained in a housing 14 in a conventional manner. Arrangement 12 and 14 is generally referred to by reference numeral 16. Combination 16 is operatively secured to an apertured, concentric ring plate 18 which is associated with an outer concentric ring 20, matched with the conventional outer dimensions of the conventional thermostat combination 16.

Plate 18 and accordingly outer plate 20 is adapted to seal about their overlapping peripheries in a fluid-tight manner in use.

Ring 18 is hingedly interconnected to ring 20 by means of a conventional pivot arrangement 22 at a predetermined location on it's periphery. Approximately directly opposite the disposition of pivot arrangement 22, a latch mechanism 24 is provided and serves to secure that portion of the internal periphery of ring 20 to the outer periphery of ring 18. Mechanism 24 comprises a bimetallic pin 26 passing through latch arrangement 24 to effectively hold arrangements 18 and 20 secured to each other in use.

The one end of pin 26 is operatively secured to the exposed face of ring 18 and the other end is passed through latch arrangement 24. The arrangement being such that, where a predetermined temperature (a critical temperature to a cooling system to which thermostat 10 is operatively applied) is reached, pin 26 will, due to the specific qualities of it's bimetallic nature, deform to such an extent that it will move out of latch arrangement 24 and accordingly operatively disengage the latter.

This action of pin 26 will accordingly cause ring 18 to be capable of pivotal movement about pivot arrangement 22 and will cause combination 16, and accordingly plate 18, to pivot to a position where it will not pose an obstruction to fluid-flow over arrangement 10.

It will be appreciated that the temperature at which pin 16 will deform will be selected such that ring 18 and accordingly the obstruction it carries, will be caused to fall away in use and allow cooling fluid to flow through arrangement 10 at a point just prior to that where critical damage may be suffered to the component parts of an engine or the like (not shown) to which thermostat 10 is applied in use. It will further be appreciated that such a temperature will also be so selected as to not allow for combination 16 to fall away as referred to in the normal course of events as the latter will accordingly be allowed to function in it's normal conventional manner.

The objective of the applicant is therefore to provide an "overriding" safety mechanism to serve in allowing fluid-flow over thermostat 10 where a conventional thermostat combination 16 malfunctions and subsequent damage may be suffered to the engine or the like to which such a thermostat is operatively applied.

It will still even further be appreciated that there are no doubt many variations in detail possible with an improved thermostat 10 according to the invention without departing from the scope and/or spirit of the appended claims.

Claims

1. An improved thermostat comprising a conventional thermostat including a bimetallic activatable mechanism adapted to open a flow path through the thermostat upon the latter experiencing predetermined temperatures.

2. An improved thermostat as claimed in claim 1 including a bimetallic mechanism comprising a substantially elongate bimetallic member operatively associated with a matched aperture, the bimetallic member being adapted to operatively open the aperture with which it is associated upon experiencing a predetermined temperature, the aperture being so disposed relative to the conventional thermostat that it will operatively allow passage of a substantial volume of fluid there through upon being opened.

3. An improved thermostat including a conventional thermostat comprising at least two concentric rings, the operative inner one containing the conventional thermostat mechanism and being fluid-tightly interconnected about it's periphery to the second, larger, concentric ring.

4. An improved thermostat as claimed in claim 3 comprising a hinge interconnection between the two rings and substantially opposite thereto a latch mechanism being capable of activation/deactivation by a bimetallic release device; the release device being adapted to release the inner concentric ring upon experiencing predetermined temperatures.

5. An improved thermostat comprising a conventional thermostat including a closed aperture, the aperture operatively being held closed by a material comprising a substantially low, predetermined melting point.

6. An improved thermostat as claimed in claim 5 including a material with a predetermined melting point of approximately 110° degrees centigrade.

7. An improved thermostat as claimed in claims 5 and 6 including a material comprising an eutectic alloy with a predetermined substantially low melting point.

8. An improved thermostat as claimed in claims 5, 6 or 7 including a material with a melting point selected from predetermined critical temperatures for internal combustion engines.

9. An improved thermostat substantially as described hereinbefore with reference to the accompanying drawing.