EP0486796A1

EP0486796A1 - Gas cock with modular safety device

Info

Publication number: EP0486796A1
Application number: EP91116905A
Authority: EP
Inventors: Mario Zucco
Original assignee: IMIT SpA
Current assignee: IMIT SpA
Priority date: 1990-11-19
Filing date: 1991-10-04
Publication date: 1992-05-27
Also published as: IT9022131U1; IT220286Z2; IT9022131V0

Abstract

Gas cock with modular safety device designed for gas stoves with cooking top of limited height and comprising a hollow tubular body (10) having a square form and consisting of two arms (12,13) communicating together and arranged at a mutual angle of 90°.

One (13) of said arms contains the opening and closing control device while the other (12) arm contains the operating device (24) and the magnetic safety valve (22). The hole (15') for passage of the gas in placed between the operating device (24) and the magnetic safety valve (22).

Description

The present invention relates to a gas cock with magnetic safety device.
More specifically the present invention relates to a gas cock with magnetic safety device particularly suited for gas stoves with cooking top of limited height.
One particularly serious problem in the production of gas cocks with modular safety concerns their dimensions. Indeed, there is a requirement to make gas stoves or burners with ever smaller cooking tops, since the present tendency is to allow rather reduced spaces for the rooms where appliances are installed. Very often these specific rooms are even replaced in small apartments by simple cooking spaces included in a larger room.
The considerable reduction of space for appliances has led to the manufacture of extremely compact equipment which sometimes incorporates in a single block several appliances. For example, beneath the conventional cooking top on which there are various gas burners and electric hot plates there is installed the dishwasher or oven and both units may have reduced capacity.
From this point of view it is easy to understand that, while functional characteristics remain unchanged, achievement of a reduction even of only a few millimetres in the height of one of the units allows better utilization of the remaining ones.
Besides the widespread gas stoves with cooking tops whose standard height is 40mm, similar tops with height of no more than 30mm are spreading. This realization however conflicts with the requirements deriving from the sizing of the gas cocks installed thereon. Said cocks, indeed, in addition to the devices necessary for opening and closing the gas supply duct, include adequate safety systems which automatically stop gas delivery in case of accidental extinguishing of the flame. To achieve this, known cocks are provided with a magnetic valve housed in the body thereof. This requirement necessarily leads to an increase in the size of the cock body, the valve being conventionally aligned with the operating pushbutton.
The object of the present invention is to provide a particularly compact gas cock.
Specifically the object of the present invention is to provide a gas cock including an opening and closing device for the gas supply duct and a particularly compact safety valve which can be used on gas stoves or burners with cooking tops of extremely limited height.
Another object of the present invention is to provide a gas cock easy and economical to make and which would not require the use of skilled manpower nor complex technologies.
Generally these and other objects are obtained in accordance with the present invention by means of a gas cock in which the opening and closing control device is arranged at a 90° angle in relation to the magnetic safety valve. In particular the gas cock of the present invention comprises a hollow tubular body having a square form consisting of two orthogonal arms communicating together, in one of said arms is inserted the opening and closing control device and in the other the magnetic safety valve and an operating device.
The opening and closing control device comprises a sliding rod which, when operated manually, makes contact with the free end of the operating device which acts on the magnet to activate it and opens the valve for passage of the gas. When the magnet is deactivated the valve closes and blocks opening of the gas to prevent flow of gas.
To better understand the functional and construction characteristics and advantages of the gas cock in accordance with the present invention it will now be described in detail with reference to the figures in the annexed drawings which represent a preferred form of embodiment by way of nonlimiting example of the present invention and wherein:

FIG. 1 shows a schematic view of the cross section of the gas cock of the present invention, and
FIG. 2 shows a schematic view of a part of FIG. 1 which illustrates in particular the rod of the opening and closing control device and the device which operates the safety valve.

With reference to the figures the gas cock of the present invention comprises a hollow tubular body (10) having a square form and comprising a longitudinal arm (12) and a transverse arm (13) communicating together and arranged at an angle of 90° with each other.
Said hollow tubular body (10) may be preferably made in a single piece and preferably by casting in brass or some other suitable material.
The longitudinal arm (12) is provided at its free end with a ring nut union (14) in the central part of a union (42) for connection thereof to a gas supply and, near said central part, an annular recess (15) which defines a central hole (15') for passage of the gas. Said longitudinal arm (12) is closed at the end opposite the end with the ring nut (14) by a plug (16) whose structure is defined better below.
In the cavity of the transverse arm (13) is inserted the opening and closing control device. The free end of said transverse arm (13) is closed by a riser (18) in which is inserted and projects the control rod (20) of said control device. The end of the rod (20) corresponding to the internal part of the riser (18) has a blind hole (21).
The control device comprises a hollow body (30) with longitudinal truncated cone cross section inserted in the cavity of the transverse arm (13), which also has a longitudinal truncated cone cross section but in a direction opposite that of the body (30) so as to mate exactly, and fixed to said arm by the riser (18).
Along the longitudinal axis of the cavity of said truncated cone body (30) there runs a rod or shaft (26) provided at one end with a pin having smaller diameter and delimited by a ring nut (29), and at the opposite end a tapered cam (28) whose base has a diameter greater than that of the cavity of the hollow body (30).
In its central part said hollow body (30) has an annular cavity (31) which defines a central hole (31') which acts as a guide for the sliding of the rod (26).
Said rod (26) is inserted in the cavity of the body (30) and through the central hole (31') in such a manner that its pin (27) penetrates in the blind hole (21) of the control rod (20) and its tapered cam (28) is in contact with the free edge of the hollow body (30).
A return spring (32) inserted in the rod (26) is arranged between the ring nut (29) and the cavity (31) and ensures the elastic position of the rod (26) with the tapered cam (28) in contact with the free edge of the hollow body (30).
A seal ring (33) (O-ring) arranged between the spring (32) and the cavity (31) ensures sealing between the rod (26) and the hole (31').
The recess (15) divides the cavity of the longitudinal arm (12) in two chambers of which one (38) communicates with the cavity of the transverse arm (13) and the other (37) is provided with the union (42) for connection to the gas supply. In the chamber (37) is arranged the magnetic valve (22) and in the chamber (38) the operating device (24).
The magnetic valve (22) comprises a magnet and an axially sliding stem (48) provided with a sealing disc (44) at the free end. Said disc (44) closes the hole (15') through which passes the gas.
The stem (48) is kept in advanced position and hence completely closing the hole (15') by a compression spring (46) arranged between the magnetic valve (22) and the sealing disc (44).
The operating device (24) consists of a pin provided on the outer surface with guide finning (36) arranged preferably at an angle of 120° or 90° from each other. Said finning (36) grazes the inner wall of the chamber (38) and thus keep said operating device (24) aligned during its axial sliding.
The pin of the operating device (24) has the end (40) corresponding to the tapered cam (28) with truncated cone form and the opposite end (25) of smaller diameter than that of said pin so as to pass through the hole (15') through which the gas passes. The truncated cone end (40) of the operating device (24) is aligned with the tapered cam (28) of the rod (26) so that said cam (28) can make contact with said end (40) by axial sliding of said rod (26). A spring (47) ensures the position of the operating device (24) with the end (25) outside the hole (15'). The closing plug (16) of the longitudinal arm (12) is preferably shaped in such a manner as to create with its front (34) a shoulder for the tapered cam (28) at the moment said cam comes into contact with the tapered end (40) of the operating device (24).
The rod (26) with the cam (28) as well as the pin (24) with finning (36) can be made of thermo-plastic materials, steel or some other suitable material although a preferred embodiment calls for brass.
The finning (36) does not bring about an undesirable decrease of the passage of gas in the cylindrical chamber (38).
Operation of the gas cock in accordance with the present invention is as follows: in closed position the rod (26) is held in position away from the truncated cone end of the operating device (24) by the return spring (32). In this position the base of the tapered cam (28) is pressed against the edge of the hollow body (30) and closes the passage.
The magnet (22) is not activated and the disc (44) closes the hole (15') through which the gas passes due to the effect of the spring (46). The gas let into the cylindrical chamber (37) in which is arranged the magnet (22) does not pass into the chamber (38), the hole (15') being closed and sealed by the disc (44).
To open the cock the rod (26) is made to slide axially against the elastic resistance of the spring (32) until the tapered cam (28) makes contact with the end (40) of the operating device (24) and pushes its end (25) axially against the disc (44) through the hole (15').
In this manner the magnet (22) is energized and draws the stem (48) into a retracted position. The hole (15') is thus open and the gas can pass through it and reach the chamber (38) and thence the burner (not shown). The stem (48) and hence the disc (44) remain automatically in this retracted position when in the magnet (22) there circulates sufficient current obtained by means of a thermocouple excited by the heat of the flame. Said thermocouple is of known type and is arranged near the burner (not shown) to receive immediately the heat released by the flame.
Should there be an accidental lack of gas, the flame is extinguished and the thermocouple is no longer able to produce the current for the magnet (22). The magnet is thus deactivated and the disc (44) is pushed by the spring (46) and closes the hole (15') to prevent the gas from entering the chamber (38)

Claims

Gas cock with modular safety suitable for gas stoves with cooking tops of limited height and comprising an opening and closing control device and a magnetic safety valve (22) characterized in that said opening and closing control device is arranged at an angle of 90° with the magnetic safety valve (22).
Gas cock in accordance with claim 1 characterized in that an operating device (24) is arranged between the opening and closing control device and the magnetic safety valve (22).
Gas cock in accordance with claim 1 or 2 characterized in that it comprises a hollow tubular body (10) having a square form and consisting of two arms (12,13) communicating together and arranged at an angle of 90° with each other, the opening and closing control device being arranged in one (13) of the two arms and the operating device (24) and the magnetic safety valve (22) in the other arm (12).
Gas cock in accordance with claim 3 characterized in that the hollow tubular body (10) is made of brass in a single piece by casting.
Gas cock in accordance with any of claims 3 to 4 characterized in that the arm (12) containing the magnetic safety valve (22) is provided near its central part with an annular recess (15) which defines a central hole (15') for passage of the gas and said recess (15) dividing the cavity of the arm (12) in two chambers (37,38) of which one (38) communicates with the cavity of the other arm (13) and contains the operating device (24) and the other (37) the magnetic safety valve (22).
Gas cock in accordance with any of the above claims in which the opening and closing control device comprises a hollow body (30) with longitudinal truncated cone cross section inserted in the cavity of an arm (13) and said hollow body (30) being provided in its central part with an annular cavity (31) with a central hole (31'), a riser (18) for fixing said hollow body (30) to the arm (13), a rod (26) provided at one end with a tapered cam (28) whose base has a diameter greater than that of the cavity of the hollow body and inserted in a sliding manner in said hollow body (30) and in said central hole (31'), and a return spring (32) which keeps the tapered cam (28) in contact with the free edge of the hollow body (30).
Gas cock in accordance with any of the above claims in which the magnetic safety valve (22) comprises a magnet, an axially sliding stem (48) provided at its free end with a sealing disc (44) and a spring (46) which holds said disc (44) in contact with the hole (15') through which the gas passes.
Gas cock in accordance with any of the above claims from 2 to 7 in which the operating device comprises a pin provided with guide finning (36) on its surface and having one end (40), corresponding to the tapered cam (28), of truncated cone form and the opposite end (25) of smaller diameter than that of the pin in such a manner as to pass through the hole (15') through which passes the gas, an elastic means (47) holding the end (40) aligned with the tapered cam (28).
Gas cock in accordance with claim 8 in which the guide finning (36) is arranged at an angle of 120° or 90°.
Gas cock in accordance with any of the above claims from 3 to 9 in which the arm (12) is provided at its free end with a ring nut union (14) and is closed at the opposite end by a plug (16) having a front shoulder (34) for the tapered cam (28).