NL2031241A

NL2031241A - Cursor arrangement

Info

Publication number: NL2031241A
Application number: NL2031241A
Authority: NL
Inventors: Lamminen Vesa-Matti
Original assignee: H Vesala Oy
Priority date: 2021-03-15
Filing date: 2022-03-10
Publication date: 2022-09-27
Also published as: NL2031241B1

Abstract

The disclosure of embodiments of the invention shows a miniature transmitter device (1) for a drilling cursor arrangement arranged to transmit an alignment signal (16), (17), 5 whereby the drilling point is determined by a receiver device (2) arranged to locate said alignment signal (16), (17), and thus to determine the drilling point. The disclosure of embodiments of the invention also discloses a drilling cursor system having at least one miniature transmitter device (1) according to an embodiment of the invention and at least one receiver device (2) for receiving an alignment signal (16), (17) of the miniature trans- 10 mitter device (1 ).

Description

CURSOR ARRANGEMENT

FIELD OF THE INVENTION Embodiments of the invention relate generally to alignments through structures. More particularly, embodiments of the invention relate to the positioning of drillings through wall structures or other structures in buildings and the electronic location of penetration points by means of an electronic device arrangement.

BACKGROUND OF THE INVENTION Various construction and renovation work often involves drilling or other penetrations through site structures such as walls or floors. The purpose may be to lead cables or pipes from one space to another. Drillings and penetrations are naturally intended to be aligned in such a way that making them, for example by drilling, does not unnecessarily damage the structure or other objects on the invisible side of the structure nor pipes and wiring or other structures already inside the structure. Achieving this requires prepara- tions.

Itis known per se to measure distances and heights on both sides of a structure in relation to a known point. In some cases, other mechanical means may be used, such as acous- tics or small test drillings, to determine the drilling point on either side of the structure. Drill guide devices for aligning penetrations and the like are also known. Other names, such as concrete scanner, are also used for similar products.

One embodiment of providing such a device at its simplest may be based on permanent magnets, such that the magnet is placed at a drilling site on the first side of the structure and a corresponding location on the other side is detected by a magnetic field responsive detector, like a second magnet or magnetic field strength meter.

A principle similar to passive RFID transponders with receivers is also known, but has not been found to be useful for alignment purposes due to their short operating distance rel- ative to the size of the devices.

In addition, drilling cursors are also known, which are mostly electronic devices based on electromagnetism or radio technology. With such a device, alignment can be done faster and more accurately than with devices based on mechanical methods.

According to the prior art, a drilling cursor per se usually consists of a transmitter and a receiver. In this case, the transmitter is placed at the drilling site in the structure, e.g. on the wall on the first side of the structure. The transmitter switched on transmits a magnetic signal at a certain frequency. The corresponding point is then located on the other side of the structure by a receiver that recognizes the transmitter signal and is able by using indicator lights and often sound signals to guide the user to move the receiver towards the alignment point, where the transmitter and receiver are aligned on different sides of the structure. The receiver may also have a display that indicates the distance between the transmitter and receiver increasing the reliability of positioning/alignment. The re- ceiver may have a special marking hole through which the found alignment point can be marked on the structure.

The operating distance between the transmitter and receiver of electronic drilling cursor devices may be up to 200 cm, but the alignment accuracy is generally strongly dependent on the distance, for example between 1 and 10 cm, where the latter number indicates the accuracy at the maximum locating distances of the device used. The usual alignment distance is a few tens of centimeters, whereby alignment accuracy of a few centimeters is usually sufficient.

Electronic drilling cursors generally work well for alignments made through wood struc- tures and, for example, stone and concrete structures. Metal structures, on the other hand, may weaken or even prevent alignment because they strongly attenuate the mag- netic signal. Some electronic drilling cursors use in addition to the magnetic signal a radio path, whose operation may also be impeded if there is a wide uniform metal barrier in the structure between the transmitter and receiver.

Sizes of the transmitter and receiver units of known electronic drilling cursor devices are generally suitable for hand holding and handling, i.e. having width of 50-100 mm, height of 100-200 mm and thickness of 20-50 mm.

The most advanced devices may have additional features such as metal detectors or electric field detectors.

However, there are problems with device solutions of the prior art. One problem with the prior art devices based on permanent magnets is their operating distance, which is at most e.g. 20 cm for devices of a practical size. Also, based on the permanent magnet, it is not possible to easily manufacture a receiver that would guide the user to move the receiver in the correct direction during positioning. In this case, the alignment is usually based on finding the maximum strength of the magnetic field, which is not very accurate. In addition, the field of a permanent magnet is susceptible to distorting factors, such as metal rebars or frame beams, which are often present in wall and floor structures. As a result, the misalignment can be significant.

Electronic drilling cursors of the prior art are general purpose.

In terms of their operating distance and size they are suitable for many different sites, where the user operates both the transmitter and receiver by hand.

One disadvantage of the prior art general purpose electronic drilling cursors is the me- chanical size of their transmitter devices.

The hand-held device does not usually fit inside the structures, but is placed on the surface of the structure.

For this purpose, for example, a fixing mass or a mechanical support, such as a piece of wood, may be used.

Metal hangers, such as screws or nails, cannot be used because they distort the magnetic field and may cause misalignment with the receiver.

A device mounted on the wall may also fall and be damaged.

Also, a device mounted visibly on the exterior wall of a building can be stolen if left unattended.

Another disadvantage of the prior art electronic drilling cursors is the multi-step nature of the work.

Once the location to be drilled is first selected on the first side of the structure, the transmitter device is attached to the selected location in the structure as described above.

One must then move to the other side of the structure and locate the transmitter using the receiver.

If the drilling point is unproblematic, one can return to the first side, mark the drilling point at the transmitter location, remove the transmitter from the struc- ture, and drill.

Often, however, it is desired to drill from the side, where the receiver was used to protect the more sensitive surface of the structure.

In this case, the alignment is first marked on the wall, the transmitter device is taken off in front of the drilling line from the first side of the structure and then return to the second side to drill.

Similar disadvantages are also associated with drillings in which a certain depth of cavity is made at a desired point in the structure, and also when it is desired to avoid hitting a part of the structure embedded in the structure, for example a possible water pipe inside the wall.

In some cases, drilling must be done even on both sides of the structure to keep surface damages to a minimum on both sides.

In this case, a procedure has to be used in which the drilling is done only partially through the structure on one side and then on the other side, trying to hit the same point, where the first drilling ended.

It is known to those skilled in the art that it is difficult to align the two opposite drillings, especially precisely so that the smallest possible shoulder structure is left at the junction of the drilling points.

A third weakness of the prior art electronic drilling cursors per se is that the equipment practically always consists of one transmitter and one receiver.

In some situations, there is a need to perform several similar alignments in succession, serial alignments, where the use of a single pair of devices easily means a multiple need to move around the structure, multiplying the time required for change of sides when using a single pair of alignment device.

A fourth weakness of the prior art electronic drilling cursors is that the alignment must be performed at the same time from start to finish. This means that there must be access to both sides of the structure at least for marking the drilling site, even if the drilling itself is not necessary to be done immediately. In the case of, for example, private residences or otherwise closed sites, access to the other side of the structure may be completely blocked, even for an indefinite period.

SUMMARY OF THE INVENTION The purpose of the embodiments of the invention is to solve the problems according to the prior art or at least to alleviate them by means of the drilling cursor devices of the new drilling cursor arrangement, which, in particular, extend the use and application of elec- tronic drilling cursors to situations, where this is not currently possible with the prior art equipment.

However, embodiments of the invention are not limited merely to devices for aligning drillings, but can also be applied to other devices that aim to align through structures or measure distance also for other purposes than drilling alone.

The object of the invention is achieved by means of a miniature transmitter device of a drilling cursor device arrangement according to the independent claim.

In the drilling cursor arrangement according to the invention, the drilling cursor devices are a miniature transmitter device and a receiver device for receiving a signal from a transmitter device.

The miniature transmitter device of the drilling cursor arrangement according to the in- vention is characterized in that the miniature transmitter device is arranged to transmit an alignment signal to a receiver device for locating said alignment signal to determine a drilling point.

In the miniature transmitter device of the drilling cursor arrangement according to one embodiment of the invention, the alignment signal is an electromagnetic signal, a mag- netic signal, a radio signal or a combination thereof. The signal may also be a burst signal implemented as an electromagnetic signal, a radio signal or a magnetic signal.

The miniature transmitter device of the drilling cursor arrangement according to one em- bodiment of the invention has at least one of the following: a battery, a capacitor, an excitation coil, a transmission coil and a radio transmitter.

In a miniature transmitter device of a drilling cursor arrangement according to one em- 5 bodiment of the invention, the miniature transmitter device has an LC resonant circuit for selectively limiting the frequency band of the excitation signal.

The drilling cursor arrangement according to the invention is characterized in that it has a miniature transmitter device according to one embodiment of the invention and a re- ceiver device for receiving an alignment signal transmitted by a miniature transmitter de- vice.

The drilling cursor device system according to the invention is characterized in that it has a miniature transmitter device according to one embodiment of the invention among min- lature transmitter devices, and at least one receiver device for receiving an alignment signal of the miniature transmitter device.

The drilling cursor device system according to one embodiment of the invention further comprises at least a miniature transmitter device centralizer and/or alignment means for positioning the miniature transmitter devices in determined positions relative to each other according to the alignment means.

According to one embodiment of the invention, the transmitter device is dimensioned smaller than the devices according to the prior art and shaped to fit in a drilling hole. In this case, the device is smaller at least in one dimension than a handheld device known per se.

Due to its size, the miniature transmitter can be used in a new way so that it is placed inside the structures and even in the penetration points themselves, i.e. in the drillings.

This also reduces the risk of the device being stolen, as it is not easily noticed even in a visible place.

According to one embodiment of the invention, the drilling cursor device system has a plurality of miniature transmitter devices. According to one embodiment, these can be aligned with each other, for example by means of alignment means using fastening means 18b attached to the alignment means, for example, to form a line shaped as a straight line, arcuate, broken line and/or conical cutting surface sideline, without limiting to these shapes per se. The alignment means may be a semi-rigid, bendable or jointed ruler with slots for miniature transmitters. The positions can be adjusted, for example, by screw locking at different points on the line of the alignment means.

The miniature transmitter according to embodiments of the invention is active, i.e. its op- eration is mainly based on its own energy source. Even if it were possible in itself to implement a completely passive transmitter device, such would not allow the same ben- efits as an active miniature transmitter.

A miniature transmitter insertable inside the structure offers several advantages over the use of prior art devices. One important advantage is the improvement in alignment accu- racy when the alignment distance shortens due to the structure and dimensioning of the miniature transmitter. This is especially emphasized in situations, where drilling should be done on both sides of the structure to minimize surface damages. In the procedure made possible by the embodiments of the invention, the device is used so that the first drilling can be extended almost through the structure. The miniature transmitter can then be pushed a suitable distance into the drilling, for example to the bottom, and the location of the transmitter is located on the other side of the structure. Because the positioning depth is small, possible interference factors in the structure, such as metal, do not cause misalignment as easily. In addition, since the depth of the second drilling is small, it is easy to hit the first drilling hole. The procedure has the advantage, especially when the drilling is performed at an inclined angle, whereby the mutual accuracy of the holes is considerably improved by the procedure according to an embodiment of the invention. The miniature transmitter that can be pushed inside the structure makes it possible to identify and mark various hidden penetrations with the receiver device even without open- ing them. The purpose may then be to search for objects which must not be drilled, or not to form a groove damaging the object.

Another essential advantage over the prior art is that the miniature transmitter according to the invention can be equipped with minimally space-consuming and inexpensive bat- teries. Even with them, the miniature transmitter remains ready for operation even for years, because it can be activated just by the receiver device. For this reason, the time between the start and completion of a positioning job is not limited to the one-time dura- tion of the device's battery-consuming transmission mode, as with prior art devices.

A third advantage over the prior art is the new method of mutual operation of the trans- mitter device and the receiver device in this field of technology. It is possible to manufac- ture the receiver device for use with a miniature transmitter according to an embodiment of the invention in such a way that the receiver device remains, where applicable, similar to prior art devices due to compatibility of operations, but is adapted to receive and use the signal of a transmitter according to an embodiment of the invention to position the drilling point. In this case, the same receiver device can operate flexibly both with the miniature transmitters and with a conventional handheld transmitter, or with another transmitter device designed to be compatible with it. Thanks to the optimized design, it is possible to manufacture the miniature transmitter inexpensively. In this case, a large number of miniature transmitters can be used accord- ing to the drilling cursor device system simultaneously and cost savings can still be achieved, for example in the form of saving the working time required for changing the sides of the structure to be drilled. One such use is to install miniature transmitters at the ends of cables to be taken into buildings. The cables with their transmitters are intention- ally left hidden in the building structures to wait for later deployment. During the deploy- ment phase, each miniature transmitter is located by a receiver device and the cables can be drilled out of the structure, for example. According to one embodiment, the minia- ture transmitter devices of the drilling cursor arrangement are configured as system ele- ments to use their own characteristic signal encoded in frequency, pulse duration and/or other signal characteristics so that the receiver is able to differentiate the signals of the receivers, whereby, for example on curved surfaces the positioning will be easier, even if the devices are fan-shaped closer to each other in the direction of the receiver due to the curvature of the mounting surface of the transmitters.

BRIEF DESCRIPTION OF THE DRAWINGS Examples of embodiments according to the invention will now be described in detail with reference to the accompanying drawings, in which: Figure 1 shows an exemplary embodiment of a miniature transmitter and a receiver de- vice, Figure 2 shows, as an exemplary embodiment, the structural solutions of the miniature transmitter, Figure 3 shows an example of a partial arrangement of the circuit board of the miniature transmitter according to an embodiment, Figure 4 shows an exemplary embodiment of the interaction between the miniature trans- mitter and the receiver device, Figure 5 shows an exemplary embodiment of a miniature transmitter device system, and Figure 6 shows an example of a centralizer of the miniature transmitter device according to an embodiment of the invention as an element of the miniature transmitter device sys- tem.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

Although the following examples illustrate the structure/geometry of some of the devices according to an embodiment of the invention, one skilled in the art will recognize from the embodiments of the invention that the dimensioning and structural geometry may also differ from the examples shown.

Fig. 1 shows an example drawing of a miniature transmitter 1 according to an embodiment of the invention and a receiver device 2 according to the prior art, the user interface of which shows an alignment marking hole, directional arrow indicators used in alignment, and a distance display.

A key part of the miniature transmitter in the example is its cylindrical protective housing

3. In a preferred embodiment of the invention, the protective housing is made of a plastic which practically does not prevent the transmission of electromagnetic fields, which is advantageous for the invention. As is known to those skilled in the art from the embodi- ments of the invention, other materials may alternatively be used in place of the plastic, provided that their mechanical and magnetic properties are suitable for the miniature transmitter. One useful material according to the embodiment is a glass fiber reinforced epoxy resin. A third preferred material is austenitic stainless steel. The austenitic material conducts the magnetic flux poorly, which is advantageous for the invention. According to an em- bodiment of the invention, the eddy currents generated in the magnetic field of the steel can be minimized by using grooves in the protective housing or other preferred design of the device according to the embodiment or by limiting the steel parts to only part of the protective housing and using other material, like epoxy resin, in magnetically essential locations. As an example of the dimensions of the protective housing of the miniature transmitter device according to the embodiment of the invention, a length of 120 mm and a diameter of 15 mm can be used. The thickness of the wall between the interior and the outer sur- face of the protective housing can be, for example, 2 mm according to an embodiment, but not limited to said value. The invention does not limit the dimensions of the protective housing, i.e. they may be smaller or larger than this, and the selected embodiment may have objectives other than minimizing the size of the protective housing, such as tightness and weather resistance. According to an embodiment of the invention, a centralizing body, a centralizer 19 (Fig. 6), can be connected to the miniature transmitter device in order to centralize the minia- ture transmitter device in the middle of a hole larger than its diameter. According to one embodiment, such a centralizer is a tubular rack with a sleeve for the device, the sleeve having radial wings extending outwards from the device for setting and/or adjusting the distance by means of wings adjustable in length. According to one embodiment, the wings of the centralizer 19 (Fig. 6) are formed as flexible finger-like pieces which adapt to the size of the opening by themselves, for example by bending. According to an embodiment of the invention, the protective housing of the miniature transmitter device is jointed, whereby the miniature transmitter device can be placed in holes other than completely straight, even with dimensional accuracy, in accordance with the limitations of jointing, in particular by means of a suitable centralizer. In the example of the embodiment of the invention shown in Fig. 2, a pull loop 4 is made at the end of the protective housing 3 of the miniature transmitter device. The purpose of the loop is to allow the miniature transmitter to be pulled out of the penetration, drilling hole or the like by means of a suitable hook 5. An exemplary embodiment of the invention does not limit the geometric dimensions of the loop or hook solely to those shown in the figure, or the fact that the loop and hook can be interchanged. Instead of a loop or hook, other mechanical gripping or fastening means, such as a thread or string, can be used. In an alternative preferred embodiment, a special reinforcement part 6 is provided at the end of the protective housing 3, by means of which the protective housing prevents the drill from hitting it so that the protective housing 3 and the components inside it do not break despite the impact. Preferably, the reinforcement part is of the same material as the protective housing, but may also be a thicker material or may be another stronger material, such as steel. The reinforcement feature can also be connected to the pull loop

4. In one embodiment of the invention, a fastening mechanism 7, which is a female thread, is provided at one end of the protective housing of the miniature transmitter. An exemplary embodiment of the invention does not limit the shape or size of the fastening mechanism solely to that shown, but may also be another mechanism suitable per se. These can be a pull loop similar to 4, a male thread, a bayonet or some other quick clamping body, such as a wedge-based threaded sleeve mechanism known in the penetrations or a rotatable three-jaw chuck. One use of a female thread-based fastening mechanism is to attach thrust cables known to those skilled in the art to a miniature transmitter, whereby the transmitter can be pushed long distances into cavities, pipes or drilling holes. This mode of operation is reminiscent of the use of tubular probes known in the art, with the difference that the use of a miniature transmitter is not as strongly limited in battery life as known tubular probes, which typically run out of batteries within a few hours unless removed and turned off.

Another preferred way of using the fastening mechanism is to fasten the miniature trans- mitter to the cable with it. In this case, the end of the cable to be inserted into the cavities, pipes or drilling holes with its miniature transmitter can be left in the structures to wait for positioning and drilling out and deployment for up to years.

A third preferred use of the fastening mechanism is to connect an accessory to the min- iature transmitter. Such an accessory may be a protective housing for the cable con- nector. According to an embodiment of the invention, the centralizer 19 can also be used, where applicable (Figure 6). According to one variant of the embodiment, the centralizer can be integrated with a protective housing.

In another alternative preferred embodiment, the miniature transmitter is made in dimen- sions and impact resistance suitable for blowing use. This is reminiscent of the use of tube probes known to those skilled in the art, where the probe is blown into a tube, to be localized, with compressed air.

In the exemplary embodiment of the invention shown in Figure 3, there is a circuit board 8 inside the protective housing of the miniature transmitter. The circuit board contains the components essential for the intended use of the device according to the embodiment of the invention and the associated components essential for electrical operation, which are the battery 9, the capacitor 10, the excitation coil 11, the transmitter coil 12 and the radio transmitter 13. It will be apparent from the embodiments of the invention to those skilled inthe art that the examples do not limit the features of the components, such as their size or mutual placement within the protective housing, to the exemplary embodiment only. In a preferred embodiment of the invention, the battery 9 acts as the main energy source for the miniature transmitter. The example is not intended to limit the size or capacity of the battery, but it can be optimized according to the embodiment selected.

The battery can be replaced by the user so that the protective housing 3 is designed to be opened and reclosed. Alternatively, the housing may be permanently closed, whereby the battery cannot be replaced by the user. This is especially in case when it is desired to minimize the manufacturing costs of a miniature transmitter for an intended use, where, for example, they are used in large quantities at the same time or it is necessary to provide housing with a very tight seal. According to one embodiment, the housing is arranged to comply with a grading of electrical equipment according to IEC 60529, the IP code of which may be, for example, IP44, IP65, IP66, IP67 or other, however, it is selected ac- cording to the intended environmental conditions to provide an appropriate tightness.

In one embodiment of the invention, where the batteries are not user-installable, the per- manently installed batteries are connected to the rest of the circuit for conformity reasons only by the user. This is done by turning the activation screw 14 inside the fastening mechanism 7 at the back of the protective housing to the bottom. The screw closes the contacts on the circuit board, after which the miniature transmitter is ready for operation. The activation mechanism may also be in itself in accordance with one of the known ingress protection grading. In another preferred embodiment, the battery 9 is replaced by a storage cell. The storage cell may be preloaded during manufacture. The storage cell can be recharged inductively without opening the miniature transmitter, which is known per se in conjunction with mod- ern mobile phones. Alternatively, an opening or connection is provided in the protective housing 3, through which the battery can be recharged by a suitable charging device. In a third preferred embodiment, the energy source of the miniature transmitter is two- phase, so that the battery 9 is the primary energy source as long as its capacity is suffi- cient, which can be, for example, up to 10 years under favorable conditions. The miniature transmitter can then be reactivated at the time of positioning by inductively or otherwise charging energy to its capacitor 10, which acts as a temporary energy store. The operat- ing time of the next transmission mode may be short, but sufficient to perform alignment. However, if necessary, this charge-transmission cycle can be easily repeated. The align- ment distance may also be limited, but for the selected embodiment it is sufficient for the site.

The energy receiving element of the inductive charging of the above embodiments can advantageously be an excitation coil 11 or some other component made for the same purpose. The receiving device 2 can advantageously act as a charging device, i.e. device generating energy magnetically. In this case, the inductive field transmitting the energy can be the same as the excitation signal 15 shown in Fig. 4. The charging device can of course also be another suitable device. Also so-called harvester can be used, which may be based, for example, on the vibration/deflection of a piezoelectric crystal, to recover the energy of the mechanical vibrations and/or to collect the energy of the RF fields.

In yet another embodiment of the miniature transmitter, an RFID-type functionality known in the art is provided in connection with the excitation signal receiving excitation coil 11, which affects the excitation signal 15. In this case, the receiver device 2 detects a reflec- tion corresponding to the frequency of the excitation signal or a modulation caused to the excitation signal, which indicate that there is a miniature transmitter at close range. The embodiment allows short range alignment.

Thus, in the illustrated embodiment of the invention, the excitation coil 11 acts as an ele- ment of the wake-up mechanism of the miniature transmitter. In the idle mode, the min- iature transmitter does not transmit anything per se and thus does not consume energy from the battery 9, or the consumption is so low, leakage current like, that the intended embodiment of the device is not limited/prevented, or is further ensured as described above.

In the exemplary embodiment shown in Fig. 4, in the operation mode the receiver device 2 is arranged to transmit an excitation signal 15, which is an 80 kHz magnetic signal (H- field). The exemplary embodiment shown does not limit the frequency of the excitation signal per se, but it can be almost any frequency suitable for the application to which the excitation coil 11 responds.

The excitation signal may also be time phased.

When the receiver device 2 switched on is brought in the vicinity of the miniature trans- mitter 1, a current is induced in the excitation coil 11, which by means of other compo- nents excites, i.e. actuates, the miniature transmitter into the active state.

According to one embodiment of the invention, the excitation coil 11 may advantageously be part of an LC resonant circuit, which increases the excitation sensitivity and the fre- quency selectivity.

The excitation signal can also be a radio field (V field), whereby the excitation coil has been replaced by a suitable radio receiver block.

In the exemplary embodiment shown, the excitation coil 11 has a shape directing the magnetic field so that it is the most sensitive to the excitation signal coming mainly from the direction of the axis of the coil.

This is advantageous when several miniature trans- mitters are placed in close proximity to each other, for example according to a miniature transmitter device system.

In this case, the user of the receiver device can best control, which miniature transmitter in each case wakes up from the idle mode by moving the receiver device only at the point of the structure, where the miniature transmitter to be located is assumed to be located.

The switched-on miniature transmitter 1 described in the embodiment shown returns to the idle mode in a few seconds when the excitation signal 15 disappears.

This is advan- tageous if several miniature transmitters are placed in close proximity to each other and several of them have unduly woken up and thus prevented the location of a particular device.

However, the exemplary embodiment of the invention does not limit the time of return to the idle mode, but in some other embodiments, a long autonomous running time may be useful.

In the exemplary embodiment shown, the miniature transmitter triggered by the excitation transmits a magnetic positioning signal 16 by means of a transmission coil 12. The trans- mission coil is made so that its size and shape provide a magnetic field with a favorable strength and directional pattern.

In the exemplary embodiment shown, the directional pat- tern is narrow and axial with the protective housing 3, which improves the ability of the receiver device 2 to distinguish the location signals of the miniature transmitters placed close to each other.

In this case, it is possible to locate two miniature transmitters trans- mitting the positioning signal at the same time, even if the distance between the transmit- ters is small.

In this case, the same transmission with transmitters can also be used, and encoding of the transmissions with a transmitter-specific signal is not necessarily re- quired.

In another variant of the embodiment, the magnetic field of the positioning signal may be wide in shape or may be directed differently in relation to the protective housing of the transmitter.

According to one embodiment, the frequency of the positioning signal is about 8 kHz, which is a sufficiently different frequency in relation to the excitation signal 15, being advantageous to prevent mutual interference.

The frequency can naturally be ad- vantageously selected according to the desired embodiment.

In one exemplary embodiment shown, the miniature transmitter triggered by the excitation also transmits the radio signal 17 by the radio transmitter 13. The frequency used may, by way of example, be 433 MHz, which is the frequency range allowed for small devices.

The receiver device 2 includes a radio receiver operating on the same frequency.

The radio signal contains modulated phase information supplementing the magnetic location signal 18. The phase information allows the receiver device to prevent erroneous align- ment displays in situations, where the phase of the magnetic signal is reversed relative to the receiver device so that it could not otherwise be easily detected.

The invention does not impose any restrictions on the other use of the radio signal 17. In another preferred embodiment, it can be used to identify different transmitter types.

In this case, the characteristic identification code or similar signal included in the radio signal indicates the type of transmitter in question.

The receiver device 2 can adjust its own operation according to the type of transmitter, for example, so that the distance of the transmitters to the receiver device can always be displayed correctly, regardless of the level of the positioning signal.

Since the separate transmitters do not have to strive for the same magnetic transmitting power, it makes it possible to optimize the size of the batteries and components of the miniature transmitters described in the exemplary em- bodiments shown.

In a third preferred embodiment, the radio signal 17 can be used as a separately detect- able indicator that a compatible miniature transmitter is waking up in the vicinity of the receiver device 2. This is advantageous, for example, when the miniature transmitter to be located supports the two-phase power supply described above and its batteries are depleted.

In this case, the receiver device 2 can be optimized to transmit the excitation signal 15 for a time and with the greatest possible power as long as no response is detected.

When the radio signal is detected, it is possible to quickly switch to the receiving mode of the magnetic alignment signal.

In this case, due to the limited energy of the miniature transmitter, a short magnetic alignment burst signal is possibly sufficient to per- form the alignment.

Naturally, this sequence can be repeated several times during a sin- gle alignment task.

In the exemplary embodiment shown, the operation of the excitation signal 15 and the features related to its receiving are described advantageously for the miniature transmit- ter 1. In embodiments of the invention, it is not desired to limit the variation of the excita- tion signal 15, but one skilled in the art will recognize from the embodiments of the inven- tion that in the normal or larger size range of conventional drilling cursors, the excitation signal may also be used in other preferred ways within the scope of the exemplary em- bodiments claimed.

According to an embodiment of the invention, the drilling cursor device system has a plurality of miniature transmitter devices 1. According to one variant of the embodiment, these can be aligned with each other, for example, by an alignment means 18 using fas- tening means 18a, 18b attached to the alignment means 18, for example, to form a line shaped as a straight line, arcuate, broken line and/or conical cutting surface sideline, without limiting to these shapes per se.

The alignment means 18 may be a semi-rigid, bendable or jointed ruler with slots 18a for miniature transmitters.

The positions can be adjusted, for example, by screw locking 18b at different points on the line of the alignment means.

Figure 5 illustrates an exemplary system according to an embodiment of the in- vention, where a plurality of miniature transmitters 1 and a receiver 2 reside on opposite sides of an obstacle to be drilled, for example a wall.

In this example, the miniature trans- mitters 1 are connected by fastening means 18a, 18b to an alignment means to which a line shape is set.

The line may also be closable, like the ellipse illustrated as a conic section example, or a broken line, like at the bottom of the wall.

The miniature transmitters may be attached to the alignment means by a holder 18a having a screw locking 18b to hold the miniature transmitter in line set with the alignment means to correspond to the drilling points in the wall.

The alignment means with its miniature transmitter devices can be fastened to the wall with screws, nails to hang on a cable or rope, or can be supported otherwise (for example with a floor stand) against the wall.

Figure 6 illustrates the centering of a miniature transmitter device according to the inven- tion by means of a centralizer 19 in a drilling hole or a preform thereof (dashed line).

Claims

Conclusions

A miniature transmitter device for a drilling cursor array, characterized in that the miniature transmitter device (1) is arranged to transmit an alignment signal (16), (17), to locate said alignment signal (16), (17) with a receiver device (2 ) to determine a drilling point.

A miniature transmitter device (1) for a drilling cursor array according to claim 1, characterized in that the alignment signal (16), (17) is an electromagnetic signal.

A miniature transmitter device (1) for a drilling cursor array according to claim 1, characterized in that the alignment signal is a magnetic signal (16).

A miniature transmitter device (1) for a drilling cursor array according to claim 1, characterized in that the alignment signal is a radio signal (17).

A miniature transmitter device (1) for a drilling cursor array according to claims 1 to 4, characterized in that it comprises at least one of a battery (9), a capacitor (10), an excitation coil (11), a transmitter coil (12) and a radio transmitter (13).

A miniature transmitter device (1) for a drilling cursor array according to claims 1 to 5, characterized in that the miniature transmitter device (1) has an LC resonant circuit for improving the frequency band selectivity of the excitation signal (15).

Alignment arrangement for drilling, characterized in that it comprises a miniature transmitter device (1) according to any one of claims 1 to 6 and a receiving device (2) for receiving an alignment signal (16), (17) transmitted by the miniature transmitter device ( 1).

A drill cursor system, characterized in that it comprises a miniature transmitter device (1) for a drill cursor arrangement according to any one of claims 1 to 6 of the miniature transmitter devices (1), and at least one receiver device (2) for receiving a miniature transmitter alignment signal (16), (17).

Drill cursor device system according to claim 8, characterized in that it further comprises at least a centering device (19) for the miniature transmitter device (1) and/or alignment means (18) for positioning the miniature transmitter devices in a certain position relative to each other according to the alignment means (18).