EP2742288B1

EP2742288B1 - System comprising a safety valve and a connector member for electrically connecting a thermocouple to the safety valve in a gas cooking hob

Info

Publication number: EP2742288B1
Application number: EP12762396.5A
Authority: EP
Inventors: Wei Yu
Original assignee: Ningbo Bicai Industry Co Ltd; Whirlpool Corp
Current assignee: Ningbo Bicai Industry Co Ltd; Whirlpool Corp
Priority date: 2011-08-10
Filing date: 2012-08-02
Publication date: 2019-07-10
Anticipated expiration: 2032-08-02
Also published as: WO2013021321A1; EP2742288A1; CN202182238U

Description

The present invention relates to a system comprising a safety valve and a connector member for electrically connecting a thermocouple to the safety valve in a gas cooking hob, in accordance with the introduction to the main claim. For safety during use, a gas cooking hob is known to present members for interrupting the gas flow to each burner when a burner flame is lacking (during use). These members comprise a thermocouple positioned at the burner to generate an electrical signal when it senses the flame. This signal is fed to an actuator (generally an electromagnetic actuator) of the gas safety valve in order to maintain this latter open and enable gas to flow to the burner while flame is present at said burner. If the flame should disappear during use (for example because extinguished by a liquid spilling from a container placed on the burner), the thermocouple no longer generates the electrical signal and the actuator, in the absence of this signal, closes the valve (which is opened by a usual knob positioned on the cooking hob).
To connect the thermocouple to the actuator, a connector member is used comprising an insulating body supporting a first and a second electrical connector which cooperate with corresponding electrical connection elements of the thermocouple and with the valve actuator simultaneously. This enables the electrical signals generated by the thermocouple to be transferred to the actuator.
The electrical connectors of the connector member have defined positions within the insulating body: the first electrical connector is located in an axially more internal position than the second within said body, generally in a position close to or along the body axis. In a preferred embodiment, the first electrical connector is completely contained within the insulating body, while the second electrical connector normally has an end which projects from said insulating body by jutting from a portion contained therein.
In this manner, those portions of the first and second connector positioned in a first end of the connector member cooperate with the safety valve actuator.
In particular, the first connector has an at least partially tubular shape and is usually arranged to cooperate at its first end with a pin of the actuator of the valve, the other or second end cooperating with a corresponding first connection element of the thermocouple.
The second electrical connector cooperates at a first end with a metal collar of the magnetic actuator and at its second end, projecting from the insulating body, with a second connection element of the thermocouple. Various embodiments of such a connector member are known. For example, EP619460 describes a connector member in which the insulating body supports internally the second electrical connector, which in this manner encloses it completely. The first electrical connector is positioned within an axial seat of the insulating body. During use, a metal part or collar of the magnetic actuator becomes positioned between the insulating body and the second connector, such as to connect to this latter. A male terminal of the actuator is instead connected to the first electrical connector positioned within the insulating body. EP619460 , to which reference should be made, also describes the safety valve actuator, which can be similar to that used in the present invention.
This solution, which comprises a connector member provided with securely supported electrical connectors, has the advantage of enabling easy and quick connection to the valve actuator, but requires considerable care in its construction. In this respect, it must allow correct positioning of the actuator metal collar, between the insulating body and the second electrical connector, to avoid an electrical connection which is electrically unstable or which can fail with the passage of time due to oxidation of the contacting surfaces. The second connector can in fact easily deform during connection, so loosening its mechanical connection and making the electrical connection with the actuator unstable.
In addition, because of the method of connection between the connector member and the actuator, this latter must have predefined dimensions to be able to connect securely to the second electrical connector, i.e. it requires precise coupling.
WO2004/088205 describes instead a connector member in which the second electrical connector is removably coupled to the insulating body after the connection has been made between the connector member and the actuator. This solution, in which the electrical connectors are hence not securely coupled to the insulating body, overcomes the dimensional and tolerance problems in constructing the member described in EP619460 ; however it is more complex and fitting the connector member to the actuator takes more time time. Moreover this solution comprises parts which are separate before utilization but which must always be ready for use; this involves a greater difficulty in handling and preparing the member under examination compared with the case of a corresponding member in which all the electrical connectors are securely associated with the insulating body.
An object of the present invention is to provide a connector or connection member for electrically connecting a thermocouple to an actuator of a safety valve in a gas cooking hob which represents an improvement with respect to known solutions.
More specifically an object of the present invention is a thermo-electric protection assembly connection, between a thermocouple and an electromagnetic valve, comprising an electrode (positive/male/plug) connector and an electromagnetic valve external connector, wherein the (positive/male/plug) electrode connector is plugged into an aperture of an external connector of the electromagnetic valve.
In preferred configuration, the present invention relates to a thermo-electric assembly protection connection, between the thermocouple and the electromagnetic valve in which the external diameter of the (positive/male) electrode connector is shorter than the bore diameter of the internal aperture of the electromagnetic valve external electrodes, in the range between 0.05 and 0.2 mm.
A particular object of the invention is to provide a connector member which is compact, is simple to handle and use while connecting to the thermocouple and the corresponding actuator, and which enables best utilization of the housing space provided for it in current cooking hobs (which are increasingly less deep).
Another object is to provide a connector member of the stated type which the electrical connection contacts achieved at the valve actuator are secure, such that these contacts cannot loosen with time because of the method used to couple the connector member to the actuator and/or because of temperature variations of the environment in which said member operates.
Another object is to provide a connector member of the stated type in which the electrical components are optimally protected (and better than in known solutions) from dust and from any other dirt which is able to arise in the cooking hob and reach the member.
A further object is to provide a connector member of the stated type which is of lower cost than known solutions.
These and other objects which will be apparent to the expert of the art are attained by a connector member in accordance with the accompanying claims.
The present invention will be more apparent from the accompanying drawings, which are provided by way of non-limiting example and in which:

Figure 1 is an exploded perspective view of a connector member according to the invention;
Figure 2 is a perspective view of the connector member of Figure 1 in the assembled state;
Figure 3 is a view of the connector member of Figure 2 seen from above;
Figure 4 is a section on the line 4-4 of Figure 3;
Figure 5 is a lateral view of the connector member connected to a safety valve; and
Figure 6 is a longitudinal section through the member and through part of the valve shown in Figure 5.

With reference to said figures, a connector or connection member of the invention is indicated by 1. It presents a first end 3 arranged to cooperate with an actuator 15 (of known type, for example of electromagnetic type) for a gas safety valve 16 (also of known type and hence not described) of a gas cooking hob, and a second end 4 arranged to cooperate with corresponding electrical connection elements of a thermocouple (not shown).
The member comprises a body 2 of insulating material (of known type) presenting a central part 7 in which a through hole 6 is provided between said ends 3 and 4, preferably along its longitudinal axis W, an end 8 thereof being preferably of cylindrical shape at said first end 3. On a side of said central part 7 a recess 9 is formed extending from the first end 3 to the second end 4 of the body 2 and preferably having a cross-section in the form of a portion of a circular sector.
The through hole 6 houses a first metal electrical connector 10, a second metal electrical connector 11 being positioned in the recess 9. The first connector 10 is preferably completely contained in the central part of the body 2, whereas the second connector 11 projects via its second end 13 at least from the second end 4 of said body 2. In a preferred embodiment the second connector 11 also projects from the first end 3 of the body 2, as shown in Figure 4.
Advantageously, the compact shape of the body 2 comprises an external portion 80 such as to completely or partially enclose the first and second connector with the exception of its second end 13, so protecting the connectors 10 and 11 at least when the connector member is connected to the actuator 15 of the gas safety valve 16 (see Figure 6). In an advantageous embodiment, the second connector 11, even though slightly projecting from the external portion 80 (visible in the detailed view of Figure 4), is virtually enclosed and protected by the body 2. In a further advantageous embodiment, said external portion 80 presents incisions 70 enabling an elastic component to be introduced in coupling the connector member to the actuator 15, or enabling a polarized coupling with corresponding elements (not shown) present on the actuator 15.
More particularly, the first electrical connector 10 presents a first end 20 and a second end 21 to be disposed in proximity to the corresponding ends 3 and 4 of the body 2. The first end 20 of this first connector 10 is tubular and is arranged to cooperate with a pin 23 (or similar member) of the actuator 15 which, preferably, penetrates into the internal through hole 6 of the first connector 10 (see Figure 6). Said first connector 10 presents projecting lateral lugs 25 acting as limit stops for the insertion of said connector into the through hole 6. Specifically, the lugs 25 are arranged to abuttingly cooperate against an internal annular step or groove 27 of said hole 6, to hence block insertion of the connector into it.
The second end 21 of the first electrical connector 10 is arranged to cooperate with a usual fixing member or cable terminal (not shown) of an electric cable which connects the connector under examination to a corresponding electrical connection element of the thermocouple (not shown). This second end 21 is close to the second end 4 of the body 2, and is preferably inside this latter so as to be protected by it against impact or contact with any members positioned in the cooking hob in proximity to the valve 16.
The second electrical connector 11 has a first end (or portion for connection to the actuator) 30 close to said first end 3 of the body 2; from this first end 30 or connection portion there extends a portion or arm 32 terminating in a second end 13. The first end or portion 30 is partly housed in a larger cross-section end part 35 of the recess 9, within the body 2; the arm 32 is positioned within a smaller cross-section part 36 of this recess 9 opening at the second end 13 of the second electrical connector 11, and preferably projects from this latter.
The first end 30 of the second connector 11 has a shape, also preferably cylindrical, which is open on one side (indicated by 30A in Figure 1) and is mounted on the corresponding end 8 of the body 2. The coupling between the body 2 and the second connector 11 is facilitated by the cylindrical shape of the end of the body 2 and of the corresponding shape of the end 30 of the second connector 11.
The end 30 preferably presents an aperture on one side, advantageously a longitudinal slot (indicated by 30A in Figure 1) to enable it to be elastically coupled when mounted on the end 8.
In addition the first end 30 cooperates with an end annular portion 40 of the aperture 15 (of known type, shaped for example as a metal collar) which is disposed preferable about the connector 11 in that part of greater cross-section 35 of the recess 9 (see Figure 6) so as to be electrically in contact therewith.
Electrical contact between the second connector 11 and the annular end portion 40 of the actuator is achieved by mechanical contact with the internal surface of said annular end portion. This makes the electrical contact achieved in this manner more stable than electrical contacts in which the second connector 11 is external to that actuator part with which it cooperates (as is the case, for example, of the solution described in EP619450 ), said stability being demonstrated with the passage of time by the absence of slack between those contacting parts subject to possible temperature variations undergone by them by virtue of the working environment.
The second end 13 of the connector 30 is arranged to cooperate with a cable terminal (or the like, not shown) positioned at the end of an electric cable (not shown) which connects the thermocouple to the member 1.
As will be apparent from the aforegoing, the invention offers a connector member 1 in which, under working conditions, the first end 30 of the second connector 11 is shaped such that, by physical contact, a stable electrical contact is formed with the actuator 15, i.e. when the member 1 is connected to the actuator 15 of the safety valve 16, the first end 30 of the second connector 11 disposed in contact with one end 8 of the insulating body 2 and lies in physical contact with the surface inside the metal collar 40 of the actuator 15, hence ensuring the connection and lasting stability of this contact.
The second electrical connector 11, except for its end 13 which has to suitably project from the insulating body 2, can be completely enclosed by said body 2.
It should also be noted that all the electrically contacting surfaces between the connectors 10 and 11 and said actuator, lie within the insulating body 2 and are hence protected by this latter, in particular against dust or possible dirt which may penetrate into the cooking hob and onto the connector member 1.
The shape of the external portion 80 of the insulating body 2 can be such as to facilitate its grip and insertion during installation by the operator.
Moreover, this member is compact, is easy to handle during its coupling to the thermocouple and the gas valve actuator 15, hence reducing the time of this operation, and is less costly than similar solutions of the state of the art.
For the completeness of the description in regard to the preferred configuration of the electric connectors (the thermocouple and the electromagnetic valve) and in regard to their preferred dimensions, reference is made to the "Brief description of the drawings" section, to the "Embodiment" section and to the drawings of the priority document CN 201120289240 .
In conclusion, a particular embodiment of the invention has been also described. The main beneficial effect associated with the present invention consists in the reduced volume of the thermocouple connector, which also provides protection from the electrode oxidation. In fact, this product takes the (positive/male/plug) electrode connector plugged into the electromagnetic valve external electrodes when the electromagnetic valve external electrodes have the established requirements, the external diameter of the positive electrode connector will be smaller.
Other embodiments can be obtained in the light of the preceding description by combining the described features, and they are therefore to be considered as falling within the scope of the invention as defined by the accompanying claims.

Claims

System comprising: a safety valve, a connector member (1) for electrically connecting a thermocouple to said a safety valve (16) of a gas cooking hob, the connector comprising an insulating body (2) connected to an actuator (15) of said safety valve (16), said insulating body (2) supporting electrical connectors (10, 11) to be connected to corresponding electrical connection elements of the thermocouple and to cooperate with said actuator (15), the first connector (10) being disposed within said body (2) and the second connector (11) having a connection portion (30) establishing electrical contact with said actuator (15), characterised in that said connection portion (30) of the second connector (11) is disposed on an end (8) of the insulating body (2) and is in physical contact with a surface inside a metal collar (40) of the actuator (15), so ensuring connection and the stability of this contact.
System as claimed in claim 1, characterised in that the insulating body (2) comprises a through hole (6) to contain the first electrical connector (10), said hole being preferably formed along the longitudinal axis (W) of said body (2), and a recess (9) formed on a side of the hole (6) and arranged to contain the second electrical connector (11), said recess presenting an end part (35) to contain said second connector (11), an end (13) of said second connector (11) projecting from the insulating body (2).
System as claimed in claim 2, characterised in that the through hole (6) is provided in a central part (7) of the insulating body (2), from which said end (8) extends cylindrically at said first end (3) of said body, about said cylindrical end (8) there being positioned the connection portion or first end (30) of the second connector (11), between this latter portion and the insulating body, within the end part (35) of the recess (9), there being disposed an end annular portion (40) of the actuator (15) in contact with said connection portion (30).
System as claimed in claim 2 or 3, characterised in that the end part (35) of said recess (9) presents a cross-section which is widened with respect to a lesser cross-section part (36) of said recess, to contain a portion or arm (32) of the second connector, at a first end of which the connection portion (30) is positioned and of which the second end (13) projects from a second end (4) of the insulating body (2).
System as claimed in any one of the preceding claims, characterised in that said connection portion (30) is open longitudinally on a side (30A) so as to be elastically deformable.
System as claimed in any one of the preceding claims, characterised in that the first electrical connector (10) is positioned within the through hole (6), said first connector (10) presenting projecting lateral lugs (25) arranged to cooperate with an internal step or groove (27) and acting as a limit stop for its insertion into the through hole (6).
System as claimed in claim 6, characterised in that the first connector (10) comprises a first end (20) arranged to cooperate with the actuator (15) and a second end (21) arranged for connection to the thermocouple, the first end (20) being cylindrical.
System as claimed in any one of the preceding claims wherein, when in use, the connection portion (30) of the second connector (11) is substantially enclosed by the insulating body (2), by means of an external portion (80) of said body (2), except for its second end (13).
System as claimed in claim 8, wherein said external portion (80) presents an incision (70) for introducing an elastic component into the coupling of said member.
System as claimed in claim 8 or 9, wherein said external portion (80) of the insulating body (2) presents a shape such as to facilitate its grip and insertion during installation by an operator.