GB2230085A - Gas hobs - Google Patents

Abstract

In a gas hob having a pivoted cover 10 and a safety device capable of interrupting the gas supply when the cover is closed, a gas valve 1 controls the gas supply to the gas burners and has a vertical rod 2 biased upwardly, downward movement of which rod causes valve opening, the cover 10 is provided with a cam 5 which, when the cover is open, causes downward movement of a slidably mounted inclined pin 3, which causes rotation to the position shown in Fig. 2 of a hooked member 9a against the bias of springs 13, the member 9a being pivotally mounted on a plate 6 which is fixed to said rod 2. At this position of member 9a, pressure on a push button 2a causes the rod 2 to open the valve 1, whereupon the member 9a adopts the position shown in Fig. 3 to prevent upward movement of rod 2 until cover 10 is moved from the open position. <IMAGE>

Description

"SAFETY DEVICE FOR GAS RANGES HAVING A COVER" The present invention relates to a safety device for gas ranges or cookers and in particular a valve for preventing gas flowing when cover is down.

It is known that sometimes it may happen that at least one burner of a gas range is left inadvertently alight and then the cover is let down onto the flame which, even if small and thereby of a poor appearence so as to justify the oversight, in the long run may cause an overheating of the cover, which especially if it is of glass, may break or even burst with serious danger for the people standing near, being in addition cause of damages to the objects.

Of course a situation of danger also occurs when the flame has gone out for any reason and the gas supply cock of the corresponding burner has not been closed, whereby the gas flow continues, also with closed cover, which means during all the period in which the appliance is not used, thus giving rise to extremely dangerous concentrations of gas.

Various safety devices are known, among which the one described and claimed in the patent application No. 19786 A/87 in the name of the same applicant, thanks to which it is impossible, with Lowered cover, to rotate the control knobs of the gas range to the open position of the associate gas cocks being Locked in the "Off" position by a suitable slidable bar which can be moved so as to set free the knobs only with the cover up. With gas flowing from at least one burner (and the flame presumably Lighted) the cover could not be completely Lowered, but it is not excluded that the actuating parts of the valve are so sized to Leave the cover only slightly lifted, namely to an extent not immediately noticeable, whereby the above mentioned effects of overheating and possible burst could however occur. On the other hand the safety regulations in force in some countries order that the gas flow is certainly stopped already before the cover is completely laid down.

Therefore it is the object of the present invention to provide a device which automatically stops the gas supply upon lowering of the cover, before the latter is completely down and that allows the gas to be fed again, with lifted cover, only upon an intentional manual intervention.

The device according to the invention comprises a gas stop valve, normally closed, placed at the inlet of the pipe feeding gas to the cooker burners, being provided with a valve rod normally biased by springs to a forward position of closure of the valve, said rod having mounted thereon fixedly a plate on which there is hinged a member with a hook -shaped extension resiliently connected to a stationary portion of the device for cooperating with one end of a pin which is slidable in a direction inclined and not in the same plane with respect to the said rod, the other end of said pin being engageable with a cam provided on the cooker cover in its lifted position whereby, with cover down, there is no interference and the valve is in its normal condition of closure while, with cover completely up, said cam pushes the pin to engage said extension so as upon lowering the valve rod as a consequence of an operation from the outside, the zone of engagement between pin and hook is located at a recess defined between the hooked element and its extension, such as to keep at a Lowered position hook, plate and rod against the recovery force of the latter and the consequent maintenance of the valve in an open condition.

Therefore, only upon a willful manual intervention onto the upper end of the valve rod, formed as a push button, the gas supply will be reinstated by operation of the control knobs. It should be appreciated that the above-mentioned push button is positioned on the plane of the gas range toward its rear side so as to be hardly reachable by children and substantially inaccessible when cover is down.

However, even if such a push button could be anyhow pressed with lowered cover, the slidable pin or stem, not been engaged in this case by the cam, would have its inner end so positioned to sLip on the convex portion of the hooked member extension thus allowing the rotation thereof and lifting again of the support plate and valve rod, under the action of the return springs of the latter and of the hooked member itself.

These and other features of the present invention will be clear to those skilled in the art from the following detailed description of a preferred embodiment thereof, even by way of a non-limiting example with reference to the annexed drawings in which: FIGURE 1 shows a cross-sectional view of the device according to the invention mounted in a gas range of which only the cover can be partially seen; FIGQRQ2 1 shows a cross-sectional view, taken from the opposite side with respect to Fig. 1, of the same safety device with lifted cover; and FIGURE 3 shows the same view of Fig. 2 upon pressing the push button for the valve opening.

With reference to the drawings, the device according to the invention has been shown directly fixed between a gas inlet pipe 11 and the so-called "ramp" feed hose 11 a of the gas range, for supplying with gas the various burners, the whole at a position immediately underlying a hinge 15 of cover 10, in a side-rear zone of cooker, which has not been shown in the drawings.

The device comprises, within a housing and sheltering structure designated 7 and 7a in the drawings, the valve 1 of the type known as "ON-OFF" cock normally closed, with a control rod 2 extending itself from the valve body and normally biased resiliently upward by springs (not shown) to keep valve in a closed condition. The device aLso comprises a pin or stem 3 mounted askew with respect to the rod 2 on the housing portion 7a, being free to slide in a sleeve 4.

A plate 6 parallel to pin 3 is fixed on the rod 2, integrally therewith, which carries on the side facing the pin 3 a substantially rectangular member 9, pivotally mounted in 8 and provided with an extension 9a which is hook-shaped so as to show an outer convex portion and a recessed zone of connection with member 9. The free end of extension 9a is resiliently bound to a stationary point of the device, such as housing 7a, by means of tension springs 13.

The cover 10 and preferably its rear edge, outerly with respect to the hinge 15, is provided with a cam-shaped member 5 for cooperating with the outer end of the stem 3 only when cover 10 is completely up. Therefore, as shown in Fig. 1, when the cover is down there is no interference between the cam and the pin 3, the opposite end of which is pushed upward by the hooked member 9, more precisely by its extension 9a under the action of springs 13.

In this situation the rod 2, having at its upper end an actuating push button 2a protruding from the plane 12 of the cooker, is practically inaccessible owing to the lowered cover, but even if push button 2a could be pressed, the rod would return again to its normal lifted position under the thrust of the springs within the valve body 1 as soon as the push button 2a is released, and this because the inner end of pin 3 would slide freely without any interference with the convex portion of extension 9a, while the member 9 rotates about 8 under the different action exerted by springs 13 during the downward movement and upward return of rod 2.

With reference to Figs. 2 and 3 the situation is shown when cover 10 is up. In this case the cam 5 pushes pin 3 to the inside of the device through the sleeve 4. Thus the inner end of pin 3 acts onto the hooked extension 9a and causes member 9 to rotate about axis 8 against the action of the springs 13 which are under tension. It will be noted that in this situation the hook-shaped member 9 is rotated with respect to the vertical in a direction opposite to the rotation of Fig. 1.

Making now reference to Fig. 3, it is observed that upon pressing downwards the push button 2a, the rod 2 carries in its downward stroke plate 6 and member 9, while the pin 3 is kept stationary in its retracted position which is forced to hold by the thrust exerted by cover 10 through cam 5. In this way, as the plate 6 moves downwards, the member 9 rotates under the friction exerted by springs 13 thus causing the extension 9a to slide on the end of pin 3 until the latter is Locked in the zone where said extension adjoins the actual member 9 which by this time has reached a vertical position.

If now the push button 2a is released, the rod 2 does not come back to the lifted position correspond ing to the valve 1 closed, as the whole system plate 6, member 9 and extension 9a is Locked in this position by engagement of pin 3 in the recess between member and extension. The downward rotation of cover 10 will set free the rod 3 thus causing that the latter can move upwards, being unlocked, under the action of springs 13, until reaching the position shown in Fig. 1.

From the foregoing it descends that, unlike the known safety devices, the present invention provides for a situation in which gas feed is normally excluded and this is rendered possible, as long as the gas range cover is up, only as a consequence of a direct and willful operation.

It should be appreciated that the above-mention ed safety device can be applied to already existing cookers by means of a simple adaptations and modifications such as perforation of the upper plane for allowing the push button rod passing therethrough, application of a cam onto the cover and possible shifting and adaptation of the connection between gas inlet pipe and "ramp" hose.

Possible additions and/or variations could be carried out by those skilled in the art to the above-mentioned and illustrated embodiment of the safety device according to the invention without departing from the scope of the invention itself.

Claims (6)

1. A safety device for gas ranges with cover (10) comprising a gas-stop valve (1), normally closed, placed at the inlet of the gas flow feeding pipe (11, 11a), being provided with a valve rod (2) normally pushed by springs to an outward position of closure of the valve, characterized by the fact that fixedly mounted on said rod (2) there is a plate (6) on which a member (9) is hinged in (8) with a hook shaped extension (9a) resiliently connected through springs (13) to a stationary portion (7, 7a) of the device for cooperating with an inner end of a pin (3) which is slidable inclined and not on the same plane with respect to said rod (2), the outer end of pin (3) being engageable by a cam (5) provided on the cover (10), when this is up, whereby with cover down there is no interference and the valve (1) is at its normal condition of closure, while, with cover (10) completely lifted, said cam (5) pushes the pin (3) to engage said extension (9a) so that, upon lowering of rod (2) as a consequence of an operation from the outside, the engagement zone between pin (3) and hook (9, 9a) is located at a recess zone defined between the member (9) and its extension (9a), thus keeping at lowered position hook (9), plate (6) and rod (2) against the resilient recovery force of the Latter with consequent holding the valve (1) in its open condition.

2. A device according to claim 1, characterized by the fact that said plate (6) is substantially parallel to said pin (3) and said member (9), substantially rectangular, is pivotally mounted thereon in (8) on the side facing said pin (3), being provided with its hooked extension (9a) in correspondence with the inner end of said pin.

3. A device according to claim 1 or 2, characterized by the fact that said pin (3) is freely slidable with negligible friction in a sleeve (4) which is mounted on an inclined portion of housing (7a) of the device.

4. A device according to one or more of the preceding claims, characterized by the fact that the upper end of said rod (2) is shaped as a push button (2a) and extends itself from the plane (12) of the gas range without interfering with the cover (10) in its lowered position.

5. A device according to claim 1, characterized by the fact that, with cover up and rod downward, said hooked member (9) is at a substantially vertical position in correspondence with engagement kith inner end of said pin (3) which causes the rod (2) to be locked at its lower position.

6. A safety device for gas ranges with cover, substantially as above described and shown.