'PATENT COOPERATION TREATY PCT INTERNATIONAL SEARCH REPORT (PCT Article 18 and Rules 43 and 44) Applicant's or agent's file reference FOR FURTHER see Notification of Transmittal of International Search Report (Form PCT/ISA/220) as well as, where applicable, item 5 below. PHFR020119W0 International application No. International filing date (day/month/year) (Earliest) Priority Date (daylmonthlyear) PCT/IB 03/04832 29/10/2003 08/11/2002 Applicant KONINKLIJKE PHILIPS ELECTRONICS N. V. This International Search Report has been prepared by this International Searching Authority and is transmitted to the applicant according to Article 18. A copy is being transmitted to the International Bureau. This International Search Report consists of a total of 4 sheets. It Is also accompanied by a copy of each prior art document cited in this report. 1. Basis of the report a. With regard to the language, the international search was carried out on the basis of the international application in the language in which it was filed, unless otherwise indicated under this item. the international search was carried out on the basis of a translation of the international application furnished to this Authority (Rule 23. 1 (b)). b. With regard to any nucleotide and/or amino acid sequence disclosed in the international application, the international search was carried out on the basis of the sequence listing : contained in the international application in written form. filed together with the international application in computer readable form. furnished subsequently to this Authority in written form. furnished subsequently to this Authority in computer readble form. the statement that the subsequently furnished written sequence listing does not go beyond the disclosure in the international application as filed has been furnished. the statement that the information recorded in computer readable form is identical to the written sequence listing has been furnished 2. zu Certain claims were found unsearchable (See Box f). 3. 2 Unity of invention is lacking (see Box II). 4. With regard to the title, the text is approved as submitted by the applicant. the text has been established by this Authority to read as follows : RECEIVER, TRANSMITTER, METHOD AND SYSTEMS FOR PROCESSING A NETWORK DATA UNIT IN THE NETWORK STACK 5. With regard to the abstract, the text is approved as submitted by the applicant. the text has been established, according to Rule 38. 2 (b), by this Authority as it appears in Box III. The applicant may, within one month from the date of mailing of this international search report, submit comments to this Authority. 6. The figure of the drawings to be published with the abstract is Figure No. as suggested by the applicant. None of the figures. because the applicant failed to suggest a figure. because this figure better characterizes the invention. Form PCT/ISA/210 (first sheet) (July 1998)

RECEIVER, TRANSMITTER, METHOD AND SYSTEMS FOR PROCESSING A NETWORK DATA UNIT IN THE NETWORK STACK The invention relates to an arrangement for supplying power to a tire sensor that is situated in the interior of a tire, and to a suitable tire valve.

A great deal of effort is currently being put into the introduction or improvement of tire sensors for motor vehicles. The point of contact between the vehicle and the ground is important to the behavior of the vehicle when driven and tire sensors measure different physical parameters directly at it. Important items of information about the state of the tire and about the dynamics of the vehicle when driven, which help to increase the technical safety of the vehicle, can be obtained with the help of such sensors.

Tire sensors are generally arranged in the protected interior of the tire.

Important physical parameters, such as tire pressure and the temperature of the inflating medium, are directly accessible there.

The bulk of tire sensors transmit the values measured by wireless means.

Electrical power is required both for this and for the operation of the sensors. Because of the movement of the wheels, it is not possible to make use of a supply of electrical power from the vehicle's electrical system along conventional wires. The solution that seems obvious at first sight, namely to supply the power required by means of high-frequency alternating electromagnetic fields, comes up against serious technical problems. These are the result of, amongst other things, statutory restrictions on the power than can be transmitted, of the rotary movement of the wheel and its movement on the suspension, and of the materials of the tire and rim that have a screening action.

A choice that is often made is to supply the tire sensor from a battery. In practice however, the ambient conditions that exist in a vehicle tire are very unfavorable for batteries. The conditions that prevail there include an extreme range of temperatures and severe vibration and shaking. Condensation and sweating and the formation of ice occur there. Also, because it is difficult to predict what use is going to be made of a vehicle, there is a wide range of variation in the amount of power that has to be supplied.

Because of the high cost and complication of reaching the batteries inside the tire, the requirements for reliability and working life are considerable. It has been known for up to 10 years'serviceability in the tire without a change of battery to be demanded.

If the many-year life aimed for for the battery is in fact to be achievable to the desired degree, the least that it calls for is a battery capacity of very generous size and a battery that is very ruggedly constructed and is, to a high degree, gas and liquid-tight. What are also required are very durable materials, electrolytes of low corrosiveness and electrochemical combinations of substances that are particularly stable over long periods and when exposed to temperature.

These demands always compel the designer to allow considerable reserves of safety when designing and selecting the battery. The disadvantageous consequences are high costs and increased masses in the wheel. Another thing that is unfavorable for the true aim of tire monitoring is that the transmitted power of the tire sensor and/or the frequency with which it communicates have to be restricted to an excessive degree, simply in order to relieve the strain on the battery of the sensor to a high degree.

It is an object of the invention to specify a power source for a tire sensor arranged in the interior of a tire, which power source is easily replaceable.

This object is achieved in accordance with the invention by arranging a power source outside the tire and by designing the tire valve of the tire to connect the power source to the tire sensor electrically. Provision is preferably made in this case for the power source to be arranged in a sub-unit that can be plugged and/or screwed onto the tire valve. It is particularly beneficial in this case if the sub-unit that can be plugged and/or screwed onto the tire valve at the same time forms a cap that seals off the inflation opening of the tire valve. In this case, the making of the plugged or screwed connection also closes electrical contacts from the cap-also referred to below as the battery cap-to the tire valve.

However, provision may also be made in the arrangement according to the invention for the power source to be situated in the wheel trim cover and for electrical connections from the power source to be pluggable and/or screwable onto the tire valve.

Other mounting points on the wheel are also conceivable.

The invention allows various power sources to be used, such as, for example, an electrochemical primary battery, an electrochemical secondary battery, or a fuel-cell of small size. The latter may advantageously be supplied from the gas used to inflate the tire.

Hydrocarbons compatible with the materials involved may be used for this purpose.

However, fuel-cells employing integral solid materials may also be used.

A tire valve that is advantageous for the invention is one in which the valve is constructed from electrically conductive and insulating materials and in which conductive sub-units of the tire valve that are isolated from one another are provided to conduct the

electric current. Provision is preferably made in this case for the tire valve to comprise two concentric, electrically conductive sleeves and for the sleeves to be isolated from one another by an insulating sleeve.

In an advantageous embodiment of the invention, the electrically conductive wheel rim forms a part of the electrical circuit for supplying power to the tire sensor.

In another embodiment, provision is made for the tire sensor to be fastened to the tire valve in the interior of the tire and for the supply of at least part of the electrical power to the tire sensor to take place through the fastening of the tire sensor.

In another refinement of the invention, the tire sensor contains a further power source which assumes responsibility for supplying the tire sensor at times. This may, for example, be made use of to keep the tire sensor operating even during a temporary removal of the sub-unit.

In an advantageous embodiment, provision may be made for a sub-unit that contains the power source to be replaceable by undoing and remaking a screwed connection or by releasing and remaking a latching plugged connection. In both cases, the sub-unit may be suitable for manual replacement with regard to its size and the force that needs to be exerted for undoing/releasing and remaking.

The invention also covers various refinements for identifying the tire and/or the power source. In this way, in a first one of these refinements, means may for example be provided for an initializing transmission of data between the tire sensor and a device on the vehicle once the power source has been connected to the tire sensor.

In another refinement for this purpose, means are provided for a concluding transmission of data between the tire sensor and a device on the vehicle once the power source has been disconnected from the tire sensor.

In tire monitoring systems, it is often necessary for the fitted position of a tire to be distinguished (e. g. front or rear, left or right) in the context of wireless communication.

It may also be necessary for a given wheel to be identified as belonging to one's own vehicle.

By means of identifiers (addresses, codes, frequency parameters, etc. ) in the transmission signal, it is possible for the sensors on different vehicles or the sensors on one's own vehicle to be distinguished.

For this purpose, provision may be made in the arrangement according to the invention for the initializing transmission of data to report the fitted position of the tire to the device on the vehicle and for it to cause the fitted position of the tire to be stored there and/or for the concluding transmission of data to cause the stored fitted position to be deleted.

The invention also provides an opportunity for the initializing transmission of data to be arranged as an exchange of data on the'association of a given tire sensor with a given vehicle.

In a further, advantageous embodiment, the tire sensor is arranged to transmit the state of the power source to a device on the vehicle. In this way, the driver can be notified by the tire monitoring system of the failure of a battery cap or of a severe decline in operating voltage from it, thus giving him an adequate lead time for replacement. As well as the power supply from the battery cap, the tire sensor may also have another power source that can act as a temporary replacement if the battery cap fails. What may be considered as temporary replacement means are in particular capacitors of high capacitance or small storage batteries.

Provision may also be made for color coding identifying a time of manufacture and/or a time of expiry and/or a time-span to be visible on a sub-unit containing the power source. It becomes possible in this way for the sub-unit to be replaced in good time.

To serve as anti-theft protection, there may be provided in the arrangement according to the invention means that irreversibly damage the sub-unit if the latter is removed from the wheel, to rule out the possibility of its being re-used. This should not interfere with the inflatability of the tire. What are suitable for this are, for example, tabs around the stem of the valve which latch irreversibly into place ahead of the cap and which, if forcibly severed, break an electrical conductor in the cap or destroy the thread of the cap. In the case of plugging or screwing on, use could be made of a ring of locking pawls or latching hooks that, together with a matching ring carrying ratchets or latching holes, allows fitting to take place in only one direction (screwing/plugging on of the cap) and in the other direction (unscrewing/withdrawal of the cap) purposely destroys the cap and/or irreversibly breaks the electrical contact.

In another embodiment of the anti-theft safeguard, a pin may be removed from the cap after it has been screwed/plugged on and may release a spring or pawl that latches irreversibly into place. The pin may even be a guiding part of the cap thread in the valve thread. Once the pin has been removed, the cap can no longer be unscrewed or can no longer be pulled off without applying force. The cap has to be damaged in the event of removal.

This can be done by fairly powerful pulling and bending or may be assisted by a preformed tab for pulling off-similar to those used on packaging. The intention is for the cap to be removable without aids in this way, but to be no longer capable of being used.

Theft may also be made more difficult by so arranging the tire sensor that a failure of the power supply to the sensor, that the removal of the sub-unit from the wheel would involve, triggers the vehicles'alarm system, and/or by providing the sub-unit with a memory for an identifier, by transmitting an associating identifier between the tire sensor and the sub-unit at the time of the initial entry into use, and by causing the supply of power from the sub-unit to take place only after this identifier has been checked. The identifier is checked in the event of later use to then rule out the possibility of sensors other than that originally logged on being provided with a supply.

Identifiers in the signals are also used to enable individual ones of a plurality of sensors to be addressed and interrogated at separable times or to enable them each to be woken up to a fully operational state separately from one another. The separability by means of identifiers is also essential when a monitoring system communicates with a plurality of tire sensors by means of one common antenna and one transmitting and receiving system.

In connection with such identifiers, provision is often made for identifying data present in the sensor to be registered by the vehicle. It is also possible for the sensor to be explicitly set to an identifier that is valid for it or for it to be initially trained to an identifier.

The registration and/or the training communication of the identifiers can be combined with the initial and/or the renewed making of the power supply connection.

This operation should be performed directly on the vehicle with the wheels fitted. The external battery cap permits this procedure.

By means of the proposed solution, it is possible, after a tire change, for the tire sensors to be logged on to the vehicle, by briefly screwing up and unscrewing the battery caps in a given sequence. The sequence gives the fitted positions.

A fresh or renewed notification too of identifiers to the sensor may be the result of the plugging or screwing on of the battery caps. For the setting up of valid identifiers, the monitoring system may explicitly require the user of the vehicle to fit a new battery cap, or refit an existing one, to a given wheel. As a result of the breaking and reconnection of the voltage supply, the temporary removal of the battery cap may cause the existing identifier to become invalid and/or to be deleted, because the existing identifier may originate from a different position in which the wheel was fitted. A break of the above kind requires only a brief manipulation when wheels are being changed.

When a wheel is placed in store and it makes no sense for the sensor to continue operating, the battery cap is simply removed. It can be replaced by a simple

protective cap with no battery. Winter tires that are left mounted on their rims during the summer will serve as an example to illustrate the point. Much the same is true of a spare wheel that is carried with the vehicle but may, if required, not be monitored.

The battery cap may be of multi-piece construction. In this way, one or more small standard batteries (e. g. button cells) may be fitted in a cap in such a way as to be replaceable and the cap then performs the functions of fixing in place mechanically, making contact and providing protection against water and dirt.

The battery cap can be manufactured as a standardized mass-produced product. Due to the less demanding requirements it can be produced at a considerably lower cost than a battery in the tire. Like other consumable items used in motor vehicles (bulbs, fuses), it can be sold though automobile repair shops and dealers or filling stations. The battery cap can be fitted without any further instruction even by unskilled vehicle users themselves.

In the course of regular vehicle inspections in repair shops, the battery cap can be replaced as a precaution as a function of the state in which it is or after a given period in use. If a power source has become exhausted, a special function in the tire monitoring system may trigger an indication that directs the driver to replace the sub-unit. This being the case, a quick reaction is possible to a spontaneous failure of the battery.

The battery caps may be given a guaranteed period for which they can be used, which is applied in the form of a readable date of manufacture or expiry. Also possible are cyclically repeated color codes, similar to the badges used in some continental European countries for the statutory main vehicle test and emission test. The battery caps may be visually adapted to the design of the rims.

The conductors or valve components for the supply of power to the sensor may also be used for other purposes. They may, for example, form part of an antenna system.

It would be conceivable for a different operating voltage to be applied for servicing or checking purposes. In this way, a tire inflating and sensor calibrating system, which is connected anyway to the inflation opening of the tire valve, could set the sensor to a calibration mode by means of a higher external supply voltage. Linked to this, a check on the operation of the sensor could be carried out at the same time. Data from or to the sensor could also be transmitted via the inflation valve in the form of electrical signals.

An inflation opening in the battery cap itself can even allow the tire to be inflated with the cap screwed on-through the latter. It makes senses for there then to be a "cap on the cap", i. e. a further cap that serves solely as a closure on the additional inlet

opening in the battery cap. The battery cap then resembles a short extension of the valve, of the kind that is used in an even longer form on, for example, twin tires. The aim, however, is not (simply) to extend the duct for inflation but to accommodate the power source.

In another scheme for use, provision may be made for the cap to be replaced at each inflation, and access to the tire valve is only seldom necessary anyway due to the use of the sensor. The previous regular manual check on tire pressure at the tire valve now becomes the responsibility of the sensor system. Irrespective of this, a sudden break in the supply to the tire sensor may trigger a car alarm system that has been set to the active state.

The battery caps may also be used in place of conventional batteries in other applications, for example as batteries for remote car keys. The tire valve through which the power is conducted may be designed to fit the tire sensor. The sensor and tire valve may also be combined into one common sub-unit. German patent DE 43 03 582 C2 (Achterholt) describes the combination of a sensor and tire valve. There however, in contrast to the solution proposed here, the power source is arranged in the sensor and in the interior of the tire. There is no provision in this document for easy replacement of the power source.

Nor is the proposed solution comparable to a valve cap as claimed in DE 43 03 591 C2 (Achterholt likewise). There, the tire pressure is measured by the cap outside the tire.

The tire valve does not conduct any electrical power and there is no internal sensor. The valve cap elucidated in the document is also not very suitable for measuring the internal temperature in the tire.

The tire valve according to the invention should be designed to be compatible with conventional tire valves, so that no changes will be needed to air pumps, wheel covers, wheel trims or rims.

The invention also covers a tire valve in which electrical conductors extend from a part of the tire valve that points into the interior of the tire to a part of the tire valve that is situated outside the tire. In this case, there are preferably two concentric, electrically conductive sleeves provided, the sleeves being electrically isolated from one another by an insulating sleeve.

These and other aspects of the invention are apparent from and will be elucidated with reference to the embodiments described hereinafter.

In the drawings: Fig. 1 shows an embodiment.

Fig. 2 shows an embodiment of a tire valve having a battery cap.

Fig. 3 shows another embodiment of a tire valve having a battery cap.

Fig. 4 shows an embodiment having a battery cap that is safeguarded against theft.

Fig. 1 is a diagrammatic cross-sectional view showing an arrangement according to the invention together with part of a tire 1 and part of a rim 2. A tire sensor 3 is fastened in place in the interior of the tire together with the tire valve 5. From the latter an electrical connecting conductor 4 leads to the sensor sub-unit 3. The tire valve 5 passes through a hole in the rim 2. The valve cap 6 contains a small cylindrical battery 8 to supply power to the sensor. This cap can be plugged or screwed onto the tire valve 5 without any aids. When this is done, two electrical contacts 7-shown diagrammatically here as spring contacts-are closed at contact surfaces on the tire valve.

Fig. 2 shows an embodiment of the supply of current by parts of the tire valve and by a battery-equipped valve cap. In the diagrammatic view in section the items relevant to the invention have been emphasized. Components that relate to operation as a tire valve have merely been indicated. Also, the representation is not entirely to scale.

In the hole in the rim 9, of which latter only portions are shown in the region of the said hole, is a latching sealing ring 10. This is composed of rubber or soft plastics material. The sealing ring 10 has been drawn onto the electrically conductive outer sleeve 11 at a narrowing of the diameter of the sleeve and, in the hole in the rim, seals off the pressurized interior of the tire against the tire valve. The sealing ring 10 is pressed in from the inside of the rim, together with the tire valve, and due to its configuration, latches in the hole.

The outer sleeve 11 and the battery cap 13 are connected together by a screwed connection 12. The outer thread is situated on the outer sleeve 11 in this case and the inner thread on the battery cap 13. The battery cap 13 is electrically conductive and is made of metal.

The screwed connection 12 makes one of the electrical contacts between the battery cap 13 and the outer sleeve 11 of the tire valve. To stop water from penetrating to the region occupied by the battery, a sealing ring 14 is provided between the battery cap and the tire valve. It remains in the cap and is made of rubber or soft plastics material. When the battery cap 13 is screwed on, it is pressed against the sealing surfaces on the tire valve and deformed. Provided on the tire valve is an outside thread 15 to receive conventional-

batteryless-valve caps. At this point, the tire valve is compatible with conventional tire valves to allow use to be made of inflation points, air pumps and pressure gages.

Situated in the battery cap 13 is a battery 16. It is shown here in the form of a so-called button cell. One pole of the battery is connected via contact surfaces 17 to the battery cap 13. An electrical connection to the outer sleeve is made in this way. The other pole makes direct contact with the inner sleeve 21. This takes place at the contact surface 18 at the outer end-face of the inner sleeve 21.

In the internal cavity in the inner sleeve is situated a valve core having a conventional mechanism 19. For automobiles, it has become customary for this self-sealing valve core to be screwable into the valve-stem sleeve-the inner sleeve in this case-as a separate sub-unit. An insulating sleeve 20 isolates the conductive inner sleeve 21 from the conductive outer sleeve 11. It may, for example, take the form of a hollow truncated cone which is thicker towards the outer end, thus causing a slight wedge action to take place between the two sleeves enclosing it. The configuration given to the two sleeves may assist in this action. The inner sleeve 21 and the insulating sleeve 20 may be pressed in from the outside to give a seal.

Use may be made in addition of a clamping action from the interior of the rim.

A clamping nut 24 on an outside thread 25 on the inner sleeve 21 is used for this purpose.

The clamping nut 24 is secured against coming loose by a bendable locking tab 23 on the inner contact washer 26. An outer contact washer 27 on the outer sleeve is pressed into place with the sleeve. The two contact washers are reliably isolated from one another by an insulating washer 22. The tire sensor is connected to the inner and outer contact washers 26 and 27.

The two washers may already be part of the sub-unit formed by the tire sensor and when that is the case may be of other forms. The tire sensor sub-unit may, for example, be held in place by the clamping nut 24. The place of the clamping nut may be taken by inward-clamping shaped parts that perform a comparable function.

Batteries of conventional sizes that meet the requirements of the usual sensor systems can be accommodated in the cap. In the case of the cylindrical form, what this means in most cases is 8-18 mm in height and 5-21 mm in diameter, i. e. volumes of 0.5-2. 5 cm2 and battery weights of between 3 and 15 g. Rated capacities of 80 mAh-1200 mAh can be obtained in this way. Voltages of between 1.2 V and 3.3 V are supplied by a single cell and voltages of up to approximately 6 V by cells connected in series. In this case, the cap battery

can generally be designed in the optimum way to have a far lower capacity that a battery for the interior of the tire.

In mass-production, the valve structure may be further optimized in comparison with that shown. Conventional tire valves from different manufacturers have quite a lot of special design features, as dictated by their method of manufacture and intended purpose. Such special features have been deliberately ignored here because they do not affect the principle of the invention. The conventional design features of tire valves can often be allowed to continue to exist, if the given design is extended to include two concentric, conductive sleeves.

Fig. 3 shows an embodiment of tire valve having a battery 16'that is enlarged in comparison with Fig. 2 and having a correspondingly enlarged battery cap 13'. The volume of the battery shown is approximately the same as that of a tire-sensor battery as currently used in volume production. However, because the battery is easily replaceable, it is possible for a smaller one, such as, for example, is shown in Fig. 2, to be used. Also, the battery cap is extended beyond the thread 12 in the embodiment shown in Fig. 3, thus enabling the rim of the battery cap to rest on the edge of the sealing ring 10', which is shaped to match, with a sealing action-at the sealing point 28 that extends round in a circle.

Fig. 4 shows an embodiment of the tire valve having a battery cap 13"that is provided with anti-theft protection and air passages. In this embodiment the battery cap is connected to the tire valve by a circumferential ratchet 12'and latching springs 29 that are distributed circumferentially. The part of the battery cap that holds the latching springs is divided into a plurality of segments 37 by longitudinal slots that cannot be seen in Fig. 4. The cap is fitted by plugging it onto the ratchet 12'and then screwing it onto the thread on the inner sleeve 21. Provided for this purpose is a conductive bush 31 having a matching inside thread, which bush 31 is held fitted in the valve cap by an insulating ring 32. The battery cap 13"can be removed by forcibly unscrewing it and finally by pulling it off, by force if necessarily, in the course of which the top part of the battery cap 13"will be deformed.

At the time of removal, the latching springs 29 are unable to ride up over the circumferential ratchet 12', thus causing the latching springs 29 to exert an outward pressure on the segments 37, as a result of which these in turn are bent outwards at the intended bend points 36. Due to the material selected and the thickness of the desired bend points 36, bending back and refitting is not possible.

The battery cap 13"also has air passages 34 that allow the tire to be inflated with the battery cap fitted. The inflation opening in the battery cap can be closed off with a

normal closure cap 33. To allow air to be released from the tire, there may be provided in the battery cap a plunger 35 that presses the displaceably mounted battery against the plunger of the valve mechanism. An insulating ring 38 and a conical spiral spring 30 are provided for mounting the battery. At the side of the battery 16, contact surfaces 17 form the electrical connection to the outer shell 36 of the cap. The connection is continued via the latching springs 29 to the outer sleeve 11 of the valve. As an alternative, a ring of conductive rubber that is in contact with the bottom of the battery 16 may be used in place of the insulating ring 38.

List of reference numerals (1) Tire (shown in part in section) (2) Rim (shown in part in section) (3) Tire sensor (4) Electrical connection between tire valve and tire sensor (5) Tire valve (6) Battery cap (7) Electrical contacts between battery and tire valve (8) Battery (9) Rim (portions shown in the region of the hole in the rim) (10) Latching sealing ring between rim and tire valve (10') Sealing ring, similar to 10 but also with sealing action for the battery cap 13' (11) Outer sleeve, electrically conductive (12) Screwed connection between battery cap and outer sleeve (12') Circumferential ratchet in place of the screwed connection 12 (13) Battery cap, electrically conductive (13') Battery cap, similar to 13 but of an enlarged form (13") Battery cap, similar to 13 but of a form having anti-theft protection and air passages (14) Sealing ring between battery cap and tire valve (15) Outside thread to receive conventional valve caps (16) Battery (16') Battery, similar to 16 but of enlarged capacity and form (17) Contact surface between one battery pole and the battery cap (17') Contact surface, similar to 17 but arranged at the side of the battery (18) Contact surface between one battery pole and the inner sleeve of the tire valve (19) Conventional valve mechanism (20) Insulating sleeve between outer and inner sleeves (21) Inner sleeve, electrically conductive (22) Insulating washer between the contact rings (23) Contact ring and locking means for the clamping nut

(24) Clamping nut on the inner sleeve (25) Clamping thread on the inner sleeve (26) Inner contact ring and electrical connection to tire sensor (27) Outer contact ring and electrical connection to tire sensor (28) Sealing point with battery caps 13'and 13" (29) Latching springs (30) Conical spiral spring bearing against bush 31 and one battery pole (31) Conductive bush having an inside thread (32) Insulating ring for mounting the bush 31 (33) Closure cap (34) Air passages, shown as arrows indicating the direction in which air flows (35) Displaceable plunger below the battery (36) Desired bending point (37) Segments to receive the latching springs, separated around the circumference by longitudinal slots.