US3099994A

US3099994A - Thermoelectric ignition safety device

Info

Publication number: US3099994A
Application number: US88566A
Authority: US
Inventors: Putz Hans; Lehnartz Robert; Feldman Ernst
Original assignee: Joh Vaillant GmbH and Co
Current assignee: Vaillant GmbH
Priority date: 1960-02-11
Filing date: 1961-02-10
Publication date: 1963-08-06
Anticipated expiration: 1980-08-06

Description

6, 1963 H. PUTZ ETAL 3,099,994

THERMOELECTRIC IGNITION SAFETY DEVICE Filed Feb. 10, 1961 2 Sheets-Sheet l Fig. 7

IN V EN TOR.

Aug. 6, 1963 H. PUTZ ETAL THERMOELECTRIC IGNITION SAFETY DEVICE 2 Sheets-Sheet 2 Filed Feb. 10. 1961 24 Fig 7 27 j Fig.4

United States Patent 3,099,994 THERMOELECTRIC IGNlTlON SAFETY DEVICE Hans Putz, Robert Lehnartz, and Ernst Feldman,

Remscheid, Germany, assignors to Job. Vaillant KG,

Remscheid, Germany Filed Feb. 10, 1961, Ser. No. 88,566 Claims priority, application Germany Feb. 11, 196i Claims. (Cl. 137-66) This invention relates to a thermoelectric ignition safety device, in particular for gas-water-heaters. As is wellknown, in a thermoelectric ignition safety device, the armature of a magnet thermoelec-trically energized by a pilot burner is pressed on the magnet poles by means of a manually actuated member, and by the energized electromagnet a valve closure body is maintained in open position against the action of a valve spring. It is well known to effect the pressing on of the magnet armature and the opening movement of the valve closure body by means of a lever as an intermediate member. With all prior art thermoelectric ignition safety devices, the difficulty arises that the force exerted by the valve spring cannot be greater than the retaining power of the thermoelectrically energized magnet.

Therefore, if a thermoelectric ignition safety device is used, one has to be satisfied with a relatively small closing force of the valve spring, which force often could not warrant for a safe sealing off. According to the inven tion this difiiculty is overcome in that making use of a lever as n intermediate memberknown per se11he supporting point of the valve closure body lies on a shorter arm of the lever, and the point of engagement of the magnet armature lies on a longer arm thereof.

With such a structure, the force of the valve spring can be larger than the retaining power of the magnet by the ratio of the lever arms. The lever can be both a one arm lever and a two arm lever or can be designed as an angle lever.

In :a particularly advantageous manner, such a thermoelectric ignition safety device can be combined with a manually operated valve system-well known per se which can be opened and closed at will and comprises a main and an ignition gas valve, and which has two coaxial plate valves, one of which is opened, by a pusher rod against the gas pressure and the other one of which is opened in the same direction by a driver after a certain stroke of said rod, in combination with contact piece non-rotatably guided in the casing and axially movable by means of a rotary control knob through a cam surface. In such a double valve structure of successful construction a thermoelectric ignition safety device of the invention can be provided in such a manner that the driver is designed as a sleeve enclosing the pusher rod and directly abutting the contact piece, and that an additional push button is provided for the actuation of the pusher rod, which axially penetrates the rotary control knob and the contact piece and which at the same time engages the lever of the ignition safety device at the shorter lever arm thereof, the lever of the ignition safety device being pivoted on the casing and passing through the pusher sleeve through a diametral slot thereof. With such a structure, the upstream plate valve acting both as an ignition gas valve and as an ignition safety valve is opened by pushing down the push button, the magnet armature being pressed on at the same time. The second downstream plate valve acting as main gas valve is, however, opened through the contact piece and the pusher sleeve by means of the rotary control knob. Thus two operating positions are provided for the rotary control knob, namely Oil and On. Provision can be made without difiiculties that push button can be pushed down only in the position Off [and is locked in the other position On. As the ignition safety valve is retained in its open position by the thermoelectrically energized magnet, if the pilot flame burns, the downstream main gas valve can be closed, with the pilot flame burning, by turning the rotary control knob into the position Off. Thus the pilot flame can be kept burning to prevent the apparatus from freezing up.

It is, however, not possible simply to extinguish the pilot flame by operation of the rotary control knob and to close the ignition gas valve.

It is well known, with thermoelectric ignition safety devices to withdraw the magnet armature from the magnet while the pilot flame is still burning in order to close the ignition safety valve. This could be realized also in a device according to this invention. This has, however, the disadvantage that the apparatus can be, again, put into operation at once. The magnet would then still retain the ignition gas valve in its open position for a certain period without the pilot flame burning, which has been extinguished in the meantime. Thereby, the resulting danger is that unburned gas might escape.

In a further modification of the invention, the thermoelectric ignition safety device is constructed in such a manner that the ignition gas valve is closed at the Off position of the rotary control knob, that, however, again putting the apparatus into operation is prevented until the armature of the thermoeleotrical-ly energized magnet has fallen off, i.e., until the thermocouple heated by the pilot flame has been cooled down.

In order to achieve this, advantageously, provision is made in a structure of the type described hereinbefore, that the push button non-rotatably guided in the rotary control knob comprises a locking bolt guided non-rotatably but axially movable against the action of a spring fixed to the casing, which bolt is coupled to the lever guiding the armature, of the thermoelectric ignition safety device, and that upon rotation of the rotary control knob into its Ofi position an axially guided in non-rotatable manner pusher rod comes into engagement with a projecting locking catch of the locking bol-t rotated with the rotary control knob and thereby moves in axial direction relatively to the lever so that the valve returns into its closing position, while the magnet armature is still rerained. Thereby the blocking of the rotary control knob effected by the locking bolt is automatically released not before then, when the lever guiding the magnet armature and the locking bolt coupled thereto have returned to their initial positions after the armature has been released.

An embodiment of the invention is shown in FIGS. 1-7 and is described hereinbelow:

FIG. 1 is a sectional elevational view of a gas controller according to the invention, and

FIG. 2 is a sectional plan View thereof.

FIGS. 3 and 4 show details of a blocking device.

FIGS. 5-7 are perspective views and show several operational positions of the locking bolt and the parts cooperating therewith.

Within a gas controller casing 1, into which the gas enters in the direction of the arrow, two coaxial valve seats 2 and 3 are provided. Valve seat 2 has a larger diameter than valve seat 3. An ignition gas passage branches olf from an annular space 4 formed between the valve seats 2, 3. Behind the valve seat 3, as viewed in the direction of the gas flow, the main gas passage 6 is arranged leading to a burner (not shown).

A pot-shaped valve closure body 7 abuts the valve seat 2, which body is held in closing direction both by the gas pressure and by a valve spring 8 resting on the gas controller casing.

Another valve closure body 9 abutting the valve seat 3 is arranged concentrically to the valve closure body 7 and is pressed towards the valve seat 3 by a valve spring 10 also in the direction of the gas pressure. The valve spring 10 is positioned within the pot-shaped valve closure body 7 and rests thereon. A spacer rod 11' inserted into a blind-end bore 14 of the valve closure body 7 passes through the valve closure body 7 in a seal 13 and extends into a control sleeve 12, which is axially guided in a seal 12' in a partition wall 1' of the casing. In the interior of this sleeve 12 a pusher rod 11 is axially guided cooperating with a spacer rod .11, and is sealed by means of a seal 11".

A rotary control knob '18 is turnably mounted on the gas controller casing 1 by means of a cap nut 1. The rotary control knob has two diametrically opposed cams 17 on the inner surface thereof which cooperate with cam surface 17' of a contact piece 15 guided non-rotatably in axial direction in the gas controller casing. If the rotary control knob 18 is turned manually through about 90 from the Off position shown to the On position, the contact piece 15 is shifted in axial direction by the cams 17 running up the cam surfaces 17', whereby two compression springs 16 resting on the partition wall 1 are put under stress. A blocking sleeve 19, shown separately in FIG. 3, is slipped over the control sleeve 12, which blocking sleeve extends into a center hole of the contact piece 15 and abuts the partition wall 1". The blocking sleeve 19 is milled out at the end extending towards the partition wall 1', so that merely fork legs 19' are produced, which between them take up flange projection 20 of the control sleeve. The flange projections 20 abut within the recess of the front face of the contact piece 15 so that, if the contact piece 15 is shifted,

th control sleeve 12 is shifted therewith, thereby, lifting the valve closure body 9 from its seat, i.e. opening the main gas valve.

Ajpush-button 21 is mounted in the rotary control knob :18, which with a hollow shaft 21 projects from the rotary control knob and is guided non-rotatably in the knob "18 by means of a fork-shaped extension 22, which is shown separately in FIG. 4. At the Off position shown of the rotary control knob 18, the push-button 21 cannot by pushed down, as the fork-shaped extension 22 strikes against the front face of the blocking sleeve 19. The blockingsleeve 19 is, however, provided with suitable recesses 19", extension 22 can enter into these recesses 19f, if the'r'otary control knob 18 is turned into an interrn ediate position, the Ignition position. Thus in this Ignition position the push button can be pushed down. A flattened locking bolt 23 is arranged in the fork- 'shaped extension 22 and is also guided non-rotatably in the rotary control knob. The locking bolt 23 shown at an enlarged scale in FIGS. -7 has a locking catch 24 at itsone end projecting the extension 22 consisting of a blade produced by milling out 24'. The end of the pusher rod 11 extendingtowards the locking bolt 23 is provided with a blind-end bore 25 and with axial slot 26 corresponding to thethickness of the locking catch 24. A threaded rod 27 is screwed into the locking bolt 23 from the front face thereof, which rod extends into the slotted end of the pusher rod 11 provided with the blind-end bore 25. A lever 28 is pivotably connected to the threaded rod at pivot 28', which lever is mounted at 29 in the gas controller casing. The lever 28 passes through the 'control sleeve 12 through a slot 30 thereof and is lead out of the gas cont-roller casing 1 through a slot 31. The

lever 28 is pivotably connected at its projecting end with the pusher rod 32 of a magnet armature 33. The pusher "rod 32 is axially guided in the casing 34 of a thermoelectric magnet.

Acompression spring 36 is housed in the shaft 21 of push button 21, which spring rests on locking bolt 23.

Additionally, a spring 37 is provided which, on the one hand rests on the locking bolt 23 and on the other hand on the blocking sleeve 19 fixed to the casing.

At the Off position of the rotary control knob 13 as shown in FIGS. 1 and .2, the locking bolt 23 is in the position shown in FIG, 6. As already described hereinbefore, at this Ofl position the push button 21 cannot be pushed down, since the fork-shaped extension .22 abuts the blocking sleeve 19.

If the rotary control knob 18 is turned into the position Ignition, where it is engaged by a catch device (not shown), the push button 21 is turned therewith so that the fork shaped extension 22 is positioned in front of the recess 19" of the blocking sleeve 19 and the locking bolt 23 has the position shown in FIG. 5. In this position, the locking catch 24 is transverse to the slot 26 of the pusher rod 11. As the lever 28 cannot perform this rotation of the locking bolt 23, the threaded rod 27 connected to the lever 28 in pivot point 28' is turned in its thread in locking bolt 23. At this Ignition position the push button 21 can be pushed down. Thereby, the locking catch 24 shifts the pusher rod 11 and opens the ignition safety valve 7/ 2 against the action of valve spring 8 by means of spacer rod 11', so that ignition gas can get through the ignition gas passage 5 to the pilot burner. At the same time, when the push button 21 is pushed down, the lever 28 is swung-out by means of the threaded rod screwed into the locking bolt, so that the armature 33 is pressed on the poles of the thermoelectrically energizable magnet 35. If now, with the push button 21 pushed down the pilot flame is ignited and in well-known manner the thermo-eurrent necessary to energize the magnet 35 is produced by the heat of the pilot-flame, the armature 35 will be retained by the magnet 35, so that lever 28 cannot return into its initial position, when the push-button is released and returns under the influence of the spring 36. With the lever 28 held in the displaced position, also the locking bolt 23 is retained by the threaded rod 27 with the spring 37 put under stress, so that the pusher rod 11 remains in its displaced position and the ignition safety valve 7/2 remains opened.

It is essential that the forces of the valve spring 8 rthnough the pusher rod 11 and the locking bolt 23 as well as the forces of the spring 37 act in the point 28' on a shorter arm of the lever 28 than the retaining force exerted by the magnet 35 on the armature 33. Therefore this retaining force can be smaller than the opposing spring forces 8 and 37' by the ratio of the lever arm. Thus the lever 28 can be retained by a relatively small 'magnetic force against the action of a relatively strong ing bolt 23 and consequently opening ignition safety valve 7/ 2, the contact piece 15 and the pusher rod 12 abutting 'ereon is displaced axially by means of the earns 17 and the cam surfaces '17 and thus the main gas valve 9/3 is opened. Now the gas is allowed to flow through the two open valves 7 /2 and 9/3 to the connecting socket 6. There a water deficiency safety valve 38 is provided in usual mmer, which is opened by a flow actuated member 40 through a pusher rod 39, if water flows therethrough. Then the gas can be ignited in the burner (not shown) by the burning pilot flame, whereby the apparatus comes into operation.

If for some reason the pilot flame is extinguished before the apparatus is put into operation, the armature of the magnet is released after a certain cooling down time, so that the lever 23 and the locking bolt 23 return to their initial position under the influence of the spring 37. Thereby the ignition safety valve returns to its closed position under the influence of the spring 8.

This device enables, however, also a closing of the ignition safety valve 7/ 2 with the pilot flame still burning, i.e. with retained armature 33 and still swung-out lever 28. If, namely, in this condition the rotary control knob 18 and thus also the locking bolt is returned into the Off position, the slot 26 of the pusher rod 11 can get into engagement with the locking catch. Thereby the pusher rod 11 is displaced under the influence of the valve spring 8 and displaces the valve closure body 7 returning into its closed position relatively to the still retained lever 28 and the locking bolt 23, so that the position shown in FIG. 7 is reached. By closing the ignition safety valve 7/2 the gas supply to the pilot burner through 5 is shut oil so that the pilot burner is extinguished. During the cooling down time lasting several seconds, the rotary control knob cannot be turned into the On position again, as otherwise unburnt gas could escape during this time. This locking of the rotary control knob 18 is provided by the engagement of the locking catch 24 into the slot 26 of the pusher rod 11, as shown in FIG. 7. If the armature 33 has been released by the magnet 35 after the cooling down of the thermocouple has taken place, the lever 28 and the locking bolt 23 can return into their initial positions under the influence 0f the spring 37, so that the locking catch 24, as shown in FIG. 6, comes out of engagement and the locking of the rotary control knob 18 is released automatically.

Invention is claimed as follows:

1. In a gas valve including a body having a main gas supply connection, a pilot burner connection and a main burner connection, and including a thermoelectric magnet means, the improvement comprising: a pilot valve including a first closure member in said body between the main connection and the pilot connection; first operating means operatively connected to the closure member and the electromagnet means to hold the closure member open when the magnet means is energized and the pilot valve is otherwise opened, said operating means including a manually operable member to permit the pilot valve to be manually opened; a main burner valve including a second closure member in said body between the pilot connection and the main burner connection; second operating means operatively connected to the second closure member and including a manually operable member to open the main valve and hold it open; and means interconnecting the firs-t and second operating means to prevent the main valve from being closed and thereafter reopened until after said magnet means has been deenergized.

2. In a gas valve as set forth in claim 1, wherein said closure members are coaxial with the second closure member being up stream, with respect to the flow of gas, of the first closure member, one of said actuating means including a sleeve and the other of the actuating means including a pusher rod positioned within the sleeve, said sleeve and rod being axially 'aligned with the closure members.

3. In a gas valve as set forth in claim 1, wherein the first operating means includes a means to provide a mechanical advantage to the magnet means in holding the closure member of the pilot valve open.

4. A gas valve including: a hollow body having a gas inlet connection, a first chamber communicating with the inlet connection and a second chamber communicating with the first chamber, said body defining a first valve seat between the inlet connection and the first compartment and a second valve seat between the first compartment and the second compartment, said two seats being coaxial, a pilot line connection communicating with the first compartment, a main burner line connection communicating with the second compartment; a first closure member seated on the first seat; a second closure member seated on the second seat; a sleeve journaled in the body coaxial with the seats with one end in juxtaposition to the seated side of the second closure member; pusher rod means journal-ed in the sleeve, extending through the second closure member and in juxtaposition to a portion of the seated side [of first closure member; means resiliently urging said closure members against said seats; a first operating means for the rod means to move the rod means axially to unseat the first closure member; a second operating means for the sleeve to move the sleeve axially to unseat the second closure member; a lever pivotally connected to the body and to the rod means; electro magnet means connected to the lever to hold the rod means in a position at which the first closure member is unseated when the magnet means is energized and the rod means is otherwise moved to said position; and means interconnecting the two operating means to prevent the sleeve from moving the second closure member to the unseated position, after both members have been unseated and the second closure member reseated, until after said magnet means has been deenergized.

5. A gas valve as set forth in claim 4, wherein the second operating means includes a rotary control knob having a cam moveable from an off position toan on position to unseat the second closure member, an axially moveable, non-rotatable cam follower operatively connected to the cam and to the sleeve; said first operating means including a push button extending through the control knob, and means operatively connecting the push button and the rod means to permit the push rod to be moved by an inward push on the button only when the control knob is at an intermediate position between the on and o positions.

References Cited in the file of this patent UNITED STATES PATENTS 2,313,890 Ray Mar. 16, 1943 2,395,470 Ewing Feb. 26, 1946 2,455,542 Weber et al. Dec. 7, 1948 2,901,034 Puttfarcken ct al Aug. 25, 1959 2,917,062 Schuchardt Dec. 15, 1959

Claims

1. IN A GAS VALVE INCLUDING A BODY HAVING A MAIN GAS SUPPLY CONNECTION, A PILOT BURNER CONNECTION AND A MAIN BURNER CONNECTION, AND INCLUDING A THERMOELECTRIC MAGNET MEANS, THE IMPROVEMENT COMPRISING: A PILOT VALVE INCLUDING A FIRST CLOSURE MEMBER IN SAID BODY BETWEEN THE MAIN CONNECTION AND THE PILOT CONNECTION; FIRST OPERATING MEANS OPERATIVELY CONNECTED TO THE CLOSURE MEMBER AND THE ELECTROMAGNET MEANS TO HOLD THE CLOSURE MEMBER OPEN WHEN THE MAGNET MEANS IS ENERGIZED AND THE PILOT VALVE IS OTHERWISE OPENED, SAID OPERATING MEANS INCLUDING A MANUALLY OPERABLE MEMBER TO PERMIT THE PILOT VALVE TO