JPS6343850B2 - - Google Patents

Description

Detailed Description of the Invention Technical Field The present invention relates to a key identification device, and in particular to a lock or keyhole member into which a plurality of independent keys entrusted to a predetermined waiter can be inserted, and a keyhole member that can be inserted into the lock. a supply control unit which can be activated by fully inserting said key; and at least one soft iron identification code element or code member mounted within said key when said key is fully inserted. The switch includes a switch means which is made operable by the presence of the lock and is opened and closed by the code member, and a permanent magnet facing the switch means and separated by a keyhole of the lock, and the number of counters equal to the number of different keys is connected to the switch. The present invention relates to a key identification device which is adapted to be selectively activated by a means and is suitable for use in a device for dispensing food and drinks in a restaurant or the like and recording the amount of food supplied.

Background Art A device of this type is already known (German Patent No. 1524601). In this known device, gas-filled switches are used as switches connected to the individual counters, in which the air gap formed by the keyhole is magnetically activated by a code member made of soft iron. It is designed to close when the circuit is formed.

This type of food and drink supply recording device (as well as devices with serving-only locks in general) has proven to be convenient. However, with the modern development of coffee dispensing devices, the known serving locks have become an obstacle to attempts to make the devices as compact as possible. In other words, in order to prevent the magnetic fields of each permanent magnet from interfering with each other and causing a malfunction of the counter, a certain distance must be maintained between the permanent magnet and the switch. It is impossible to downsize a large volume without changing the structure. Additionally, the above device is also relatively expensive due to the use of the protective gas filled switch.

Summary of the Invention The present invention aims to solve the above-mentioned difficulties and provide a more compact and inexpensive key identification device.

The present invention uses a Hall power generation element as a switch coupled to a counter, and in order to block the magnetic field lines of the permanent magnet, an adjustment magnet is provided on the opposite side of each Hall power generation element to the side facing the permanent magnet. By arranging them, the above-mentioned difficulties are solved.

Hall power generation elements have the advantage of generating Hall voltage even in a relatively weak magnetic field. Therefore, the permanent magnets used in the device of the invention do not need to be powerful, so the lock of the device is compact. If the above-mentioned switch using a permanent magnet in a known device is simply replaced with a Hall power generation element, the non-negligible strength generated by the permanent magnet will be generated at the position of the Hall power generation element even if the key is not completely inserted. magnetic fields are present, which may not solve the problem of false counting pulses in some cases. This is because the Hall power generation element outputs a measurable Hall voltage even in a weak magnetic field.

In the device known from Swiss Patent No. 549845, a detection device is used which has a reading terminal with a reed contact in a predetermined position, and a small magnet is used to polarize this reading terminal beforehand. Although placed near the lead contacts, this measure also did not facilitate solving the problems associated with the use of Hall power generating elements. In the known detection device, at least one permanent magnet is arranged in the key as a code member, and the presence of the permanent magnet at a predetermined position in the lock causes the detection of the permanent magnet located at that position in the lock. This is because the reed contacts in the lock are activated depending on the direction of magnetization. In the device of the present invention, a code member made of soft iron is used, and a permanent magnet and an adjustment magnet are arranged at each predetermined position within the lock. This adjustment magnet is for partially eliminating the magnetic lines of force of the permanent magnet. In previously known devices, only one permanent magnet is arranged at each predetermined position and, due to the nature of the key used, no additional adjustment magnets are used. In this regard, the documents already cited do not mention at all the problem that the magnetic field of the permanent magnet arranged in the lock needs to be effectively nullified for the required purpose.

In order to reliably prevent a Hall voltage from occurring even when the code member made of soft iron is not present, resulting in a false counting signal being sent to the counter,
The adjustment magnet is arranged. The magnetic field generated by these adjusting magnets cancels the magnetic field generated by the opposing permanent magnet, and when the code member is not inserted, the magnetic field strength at the position where the Hall power generating element is arranged is reduced. When the code member is actually set to zero and the code member is inserted, lines of magnetic force act to penetrate the Hall power generating element.

Therefore, when the code member is not inserted, the Hall voltage output from the Hall power generation element is zero or negative, and when the code member is inserted, a positive Hall voltage is output.

It is appropriate to use a commercialized integrated circuit incorporating a Hall power generation element, which is configured to send counting pulses to the counter by a control signal, that is, a Hall voltage, from the Hall power generation element. .

Another advantage of the device of the invention is that the recording function of the device is virtually temperature independent, since the properties of the Hall-generating element exhibit virtually no temperature dependence over a wide temperature range. This has particular implications for coffee and tea dispensing devices used at food and beverage points. This is because this type of device generally operates at high temperatures, and as a result, conventional devices may malfunction and result in erroneous recording. The key attached to the small lock in the device of the present invention is, of course, small and does not cause any inconvenience when carried. The device of the present invention is resistant to external disturbances such as temperature changes, and is therefore less likely to fail. The manufacturing costs of the device according to the invention are low because the components and components used are inexpensive.

In the device of the present invention, the adjustment magnet is smaller than the permanent magnet, and the distance between it and the Hall power generation element is smaller than the distance between it and the permanent magnet. Due to the difference in size between the adjustment magnet and the permanent magnet and the asymmetrical arrangement of the two, the desired magnetic field at the location of the Hall power generation element can be achieved even though less space is required for arranging the adjustment magnet. state is realized.

Furthermore, it is preferable that the distance between the adjustment magnet and the corresponding Hall power generation element is adjustable, which makes assembly and adjustment of the device particularly simple. In this way, the selection of the adjusting magnet and the adjustment of its position can be controlled, since mechanical tolerances can be compensated for and the electrical properties can be adjusted in the desired way by suitably adjusting the position of the adjusting magnet. This gives rise to the advantage of having some leeway.

Embodiment One embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 shows a food and drink supply recording device used, for example, in coffee shops, restaurants, and the like. From the storage tank 2, the beverage, for example coffee, is transferred to the conduit 3,
A tap 6 is reached via a supply control unit 4 and a suitable conduit 5. The supply control unit 4 is connected to a keyhole member or lock 8 operated by a key 7. Furthermore, a counter 9 is connected to the lock 8.

This device performs its function as follows. That is, a coffee cup is placed under the stopper 6, and then a key 7, which may also be formed in the form of a ballpoint pen or the like, is inserted into the lock 8 in order to activate the limit switch. This activates the supply control unit 4,
A predetermined amount of drink from the storage tank 2 is poured into the coffee cup via the conduits 3, 5 and the tap 6. When the supply control unit 4 has finished operating, the counter 9 is also put into a standby state and is ready to count new signals. Which number counts depends on the type of key inserted, in other words, the position of the soft iron code member mounted in the key so as not to be visible from the outside. In restaurants, etc., all the servers involved in this device have their own keys, and each key has a soft iron code member mounted in a different position from the others, so it corresponds to the server using the device. A fixed counter is activated. Thus, at checkout, it is clearly known which waiter took out how many cups of coffee or other drinks from the device.

FIG. 2 schematically shows a longitudinal section of the lock 8. The lock 8 has a cylindrical keyhole 10, and in order to activate the supply control unit 4, the key 7 must be inserted into the keyhole 10 until it comes into contact with the adjusting screw 7'. A permanent magnet 11a is placed on one side of the keyhole 10.
~11f are juxtaposed. At the bottom of the keyhole 10,
A pair of permanent magnets 12', 12'' are arranged opposite each other in the diametrical direction of the keyhole.

The permanent magnet 12' cooperates with a differential magneto-resistive element 13 arranged above it and consisting of two field plates having a magneto-resistance change characteristic. Differential magnetoresistive elements are well known and will not be specifically described here. The differential magnetoresistive element 13 is connected to the supply control unit 4
is combined with When the key 7 is completely inserted into the keyhole 10, the permanent magnet 1 is held by the soft iron piece 14 made of soft iron.
A magnetic circuit is formed in the gap between 2' and 12'', and a control signal is generated through a differential magnetoresistive element 13. The differential magnetoresistive element, together with an operational amplifier cooperating with it, is regulated by a piece of soft iron 14. The switching action is such that the soft iron piece 14 is conductive only when it is on the field plate closest to the possible adjustment screw 7'.If the soft iron piece 14 is on the other field plate or between the two field plates,
Alternatively, if the width of the soft iron piece is so large as to exceed both field plates, no switching action occurs at all.
Since the switch point is precisely set in this manner, it is ensured that when the key is inserted, the recording switch consisting of the Hall element has already been activated before the dispensing of the drink begins.

A hole 15 is provided at an appropriate position on the side of the keyhole 10 opposite to the side where the permanent magnet is arranged,
Adjustment magnets 16a-16f are arranged within the holes so as to be movable in the radial direction of the keyhole. Hall power generation elements 17a to 17f are arranged at positions slightly away from the adjustment magnets 16a to 16f toward the keyhole. Each Hall power generating element is typically incorporated into an integrated circuit that includes a voltage stabilizer and an amplifier. Inside the key 7, there is a soft iron piece 1 at the tip.
4, a code member 18 made of soft iron is installed. In the embodiment shown in FIG. 2, when the key 7 is completely inserted, the code member 18 is located between the Hall power generation element 17c or the adjustment magnet 16c and the permanent magnet 11c facing them. It is set up to be located. A magnetic circuit is formed in the space within the cylindrical keyhole 10 by the soft iron code member 18, and as a result, lines of magnetic force emitted from the permanent magnet 11c penetrate the Hall power generation element 17c. The integrated circuit activated by the supply control unit 4 sends one counting pulse to the counter 9c connected to this integrated circuit when the Hall power generation element 17c in the integrated circuit is penetrated by the magnetic field line. Permanent magnet 12', 1
2'', a differential magnetoresistive element 13 and a soft iron piece 14, and coupled to the feed control unit 4, the limit switch or sensing means not only serves the function of controlling the coffee feed, but also simultaneously controls the feed control unit 4. all integrated circuits are placed in a standby state via the soft iron code member, so that the integrated circuit closest to the soft iron code member sends one counting pulse to its associated counter.

FIG. 3 shows a cross section of the lock 8. As shown, the soft iron code member 18 has an annular shape. This code member 18 is inserted into a predetermined position within the key 7 made of plastic, for example. The key 7 is surrounded by a coating 19, so that it is difficult to confirm the position of the code member 18 from the outside. This makes it difficult to forge these keys. Adjusting magnet 16c is movable within hole 15 in the direction of compound arrow P. When the key 7 is not inserted, the adjustment magnet 16c deflects the magnetic field generated by the permanent magnet 11c in the vicinity of the Hall power generation element 17c, and in the Hall power generation element 17c, the adjustment magnet 16c deflects the magnetic field toward the negative side. influence in a way that causes The adjustment magnet 16c is arranged in such a way that only the magnetic field lines of the magnet penetrate into the Hall generator 17c and as a result this produces a negative voltage. All tolerances (electrical and mechanical) are compensated by proper arrangement of the adjustment magnets. Without the adjustment magnet, the positive Hall voltage would simply increase when the key was inserted.

The function of the Hall power generation element is generally well known and will only be briefly explained here. When a magnetic field perpendicular to the direction of the current is applied to a semiconductor thin plate through which the current is flowing, an electric field is created in the thin plate in a direction perpendicular to the current, thus creating a hole between the sides of the thin plate. A voltage U _H is generated. By measuring the Hall voltage U _H , it is also possible to confirm the strength of the magnetic field or the presence of the magnetic field. In this embodiment, the Hall power generating element forms part of an integrated circuit particularly suitable for generating control pulses. When the circuit is activated to pass current through the semiconductor, a pulse is output by a magnetic field of a predetermined intensity in a predetermined direction. If there is no magnetic field or the magnetic field is not oriented in the required direction, no pulses will be output.

In order to clarify the mode of operation of the device of the invention,
This will be further explained below with reference to Figures 4a and 4b. FIG. 4a briefly shows the state of the lines of magnetic force when the code member made of a piece of soft iron is not inserted between the Hall power generation element 17 and the permanent magnet 11. The relative positions of the permanent magnet 11 and the adjustment magnet 16 depend on the magnetic field they generate within the Hall power generation element.
B _L can be adjusted to give a Hall voltage equal to zero. In the illustrated embodiment, current flows in the Hall power generation elements 17a to 17f in a direction perpendicular to the paper plane of the accompanying drawings. FIG. 4b shows the state of the magnetic lines of force when the soft iron code member 18 is inserted. The soft iron code member 18 forms a magnetic circuit between the Hall power generation element 17 and the permanent magnet 11, thus creating a magnetic field B _W that penetrates the Hall power generation element, and as a result, the Hall power generation element generates a Hall voltage U _H greater than zero. arise. By detecting this voltage, one counting pulse can be output that is sent to the counter 9c.

If the adjusting magnet 16 were not present, the Hall generator 17 would be located in the magnetic field generated by the permanent magnet 11 and would be penetrated by the magnetic lines of force, even if only slightly, so that the Hall voltage would be greater than zero.
U _H will occur. As a result, it becomes extremely difficult to determine whether or not a soft iron code member has been inserted. In order to prevent the Hall voltage from exceeding a predetermined voltage value when a soft iron code member is not inserted, the position and magnetization strength of the permanent magnet 11 must be set extremely strictly. The tolerances allowed for keyholes and keys will be extremely small. However, since the adjustment magnet is arranged in the device of the present invention, the state in which the soft iron code member is “inserted” and the state in which it is “not inserted” can be clearly distinguished, thus preventing malfunction of the device. has been done. There are less stringent restrictions on the properties and tolerances of the members used as code members.

Of course, the polarity of the magnet, the resulting direction of the magnetic field, the direction of the current flowing through the Hall-generating element, and the sign of the Hall voltage U _H as a result of these combinations can of course be chosen arbitrarily.

The present invention is not limited to the above embodiments. For example, the key 7 does not need to be cylindrical, and may be flat. In this case, the soft iron code member 1
8 can be manufactured to have a plate shape. The form of the switch for controlling the supply control unit 4 and activating the Hall power generation element is not limited to the one used in the above specific example, but may be a mechanical switch that is activated when pressed with the tip of a key. It is also possible to use a limit switch. In order to make the adjustment magnet 16 adjustable, it is also possible to take measures different from the embodiments described above. For example, eccentric devices, adjustment screws or the like may be used. One long permanent magnet is permanent magnet 11a, 11
It is also possible to perform all the functions of 11b, 11c, 11d, 11e, 11f, and 12''.
It is not necessary to directly attach only one dedicated counter to each integrated circuit. By arranging a different number of code members for each key, or by appropriately arranging the code members and using a decoder, the maximum It is possible to drive as many as ²⁶ - 1 = 63 counters.

Effects of the Invention As is clear from the above, according to the key identification device of the present invention, when identifying a key in which a code member made of soft iron, that is, an identification code element is embedded, a permanent magnet is attached to one inner wall of the keyhole. while arranging the magnetic sensing elements facing each other with the keyhole in between,
Furthermore, this magnetically sensitive element is used as a Hall power generation element, and an adjustment magnet is arranged behind it to cancel the field from the permanent magnet, thereby preventing the Hall power generation element from malfunctioning when the identification code element is not present. Ori,
A key identification device that operates reliably despite being small and inexpensive can be obtained.

[Brief explanation of drawings]

FIG. 1 is a schematic front view of one embodiment of the invention;
Figure 2 shows the first system including the feed control unit and counter.
3 is a cross-sectional view of the lock used in the device shown in FIG. It is a figure which schematically shows the state of the magnetic field lines when it is not inserted and when it is inserted. Explanation of symbols of main parts, 1... Food and drink supply recording device, 2... Storage tank, 3, 5... Conduit, 4...
... Supply control unit, 7 ... Key, 7' ... Adjustment screw, 8 ... Lock, 9 ... Counter, 10 ... Keyhole, 1
1a to 11f... Permanent magnet, 12', 12''... Permanent magnet, 13... Differential magneto-sensitive resistance element, 14... Soft iron piece, 15... Hole, 16a to 16f... Adjustment magnet, 17a to 17f... ...Integrated circuit including Hall power generation element, 18... Code member made of soft iron, U _H ... Hall voltage.

Claims (1)

[Scope of Claims] 1. A keyhole member 8 having a keyhole 10 into which the key 7 is to be inserted, including a soft iron identification code element 18; detection for detecting that the key 7 is completely inserted into the keyhole 10; means 12', 12'', 13, 14; permanent magnets 11a to 11f arranged in order within the inner wall of the keyhole along the central axis direction of the keyhole; and means arranged in order opposite to the permanent magnets; and magnetically sensitive switch elements 17a to 1 that are sensitive to a magnetic field as long as the detection means detects complete insertion of the key into the keyhole.
7f; and counters 9a to 9f connected to the magnetically sensitive switch element; the magnetically sensitive switch element is comprised of a Hall power generation element; A key identification device characterized by comprising adjustment magnets 16a to 16f that sandwich and oppose the magnetic pole faces of the permanent magnets, have magnetic pole faces of the same type as the magnetic pole faces, and block the magnetic lines of force of the permanent magnets. 2. The key identification device according to claim 1, wherein the adjustment magnet has a smaller shape than the permanent magnet and is provided closer to the Hall generator. 3. The key identification device according to claim 1, wherein the position of the adjustment magnet is adjustable in a direction across the keyhole.