JPS59176602A - Measuring probe - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a probe used in a measuring device, and more particularly to a probe that detects contact between a button and an object to be measured. Such probes are applied to orthogonal slides that perform measurements within a rectangular coordinate frame.

One object of the invention of this application is to provide a measurement probe that can repeatedly and accurately detect an object.

Another object of the invention of this application is to provide a measurement probe which, in addition to the above-mentioned characteristics, further has a cylindrical structure.

The probe is arranged to contact an object to close or open an electrical circuit, and an indicator lamp is provided to indicate the status of the circuit. Generally, the probe is configured to open the circuit, and when the probe is not in contact with an object, an indicator lamp lights up, making it easy to detect that the probe is not operating properly.

The present invention is provided with a probe for pushing the button, the housing, and the device in the direction of a rest position associated with the housing, so that the button can be moved within a limited range from said rest position. A device is provided for detecting the displacement of the scissors which have been displaced and taken different orientations with respect to the housing.

In a preferred embodiment of the invention, the needles are arranged at substantially equal angles.
11 m of members, the needle being pushed into a fixed rest position relative to the housing, each member having a respective V
engaging both sides of the V-shaped groove, the limited deflection of the nail from the rest position being oriented UF with respect to the housing, and at least one of said members being engaged with at least one side of one side of said V-shaped groove. A device is provided to detect the deflection of the needle when it is no longer in contact with the needle.

Such a device for detecting the limited runout of a nail may, for example, cause an electrical circuit to be turned on when the needle is in its rest position, the circuit passing from one V-shaped groove to the next adjacent groove; Each member forms a closed circuit between opposite sides of its respective V-shaped groove.

In another embodiment of the invention, the button is pressed into contact with two axially disposed V-shaped grooves in the rest position.
↑ 1's curved wing itself is pushed by J, which engages with the inclined surface, 13, 21's limited deflection from the 1-ho position changes the direction of the swing of the kite relative to the housing, ka<L,
TNI L, which makes contact with at least one side of the CvTV-shaped groove 1 m? A device is installed to detect the runout of the machine.

To describe an example of this invention with reference to the drawings below, in Figures 1 to 3, the probe 1 is
3 Turn right □. Three members 4 extend radially from 13, a3, and the button 3 is located at 1 (one part G acts on a spring 5 J, the other is fixed in the housing 2 41 and 1C is moved to the resting position). C-spring biased. In this rest position, each member 4 engages on both sides 6°7 of each V-shaped groove 8. It is formed between a pair of ball bearings 9 and 10.

The end 13 of the nail 3 extending through the housing 2 is disposed with a properly centered ball 14.

In the above configuration, the probe 1 is connected to a coordinate measuring device (not shown), such as a rectangular coordinate frame or a spherical polar coordinate frame, and can move in space in any direction so as to detect the boundary of the object to be measured. The contact engagement between the ball 14 and the object is caused by the spring 5
The nail 3 is displaced away from the rest position against the spring force of.

In this way 1. While t3 is being displaced, the position or orientation of the button 3 relative to the housing 2 becomes different.

The displacement is detected when the button 3 is in the rest position, forming an electrical circuit 15 which is turned on, for example. Each ball bearing 9.10 is connected to the insulator 16 by The circuit is insulated from the housing 2 as well as from the housing 2.
Formed in series from the glyph groove 8 to the adjacent cat one after another, with a value of 13
Each member 4, which is insulated from the other members 4, forms an open circuit between the sides 6.7 of each V-shaped groove 8. When the hook 3 is displaced from its rest position, the member 4 leaves contact with at least one side of each V-shaped groove 8, thereby causing the circuit 15 to
Indicator lamp 1 that is always turned on with power supply 18 after shutting off
7? jLight it.

The circuit is broken, although this is not shown, but at this time, if the coordinates of the probe are read and a command is given to the device to record it, an input pulse is sent to a known automatic switching device that can be used in this way. It will be done. 1 microphone 1” second time pulse is Hatake 1i 1! It is known that C makes it possible to measure j.

A gap 19 is provided between the button 3 and the housing 20, which gap 19 allows a limited displacement of 21 within the housing 2. Kushi 3 away from the resting position
If the displacement η is elastically received by the compression of the spring 5, the inertia of the probe at the time of measurement becomes 113.
damage to the product can be avoided. If the inertia of the probe is problematic, for example it will be difficult to prevent the axis 2o of 213 from bending after a reading has been taken, this can be solved by providing the button with a breaking device known per se. .

In making the probe, it is necessary to ensure that each component is in good contact with each of the ball bearings of each phase. This means that the part 2'1 of each member 4 that is fitted to the needle 3 is covered with glue (covered and insulated), the probe is assembled there C, and the cover plate 22, which is moved by the holder of the spring 5, is attached to the 11 Installation is easy. When the glue hardens and the circuit is connected to the power supply 18, the indicator lamp 1
A lighting of 7 indicates that all three switches are in contact with each other.

In this way, it is ensured that no disadvantages arise due to manufacturing tolerances related to the depth of the bore in which each ball bearing 9, 1o is installed. To ensure that the center of the ball 14 is in the desired position with respect to the probe, the ball 14 and its associated shaft 20 are configured to be mounted to the needle 3 after the arrangement of the member 4 has been fixed. be able to.

The shaft 20 of it 3 is attached by a spigot 24 to the shaft which engages the hole formed in the counterbore. The center of the sphere 14 is set at θ]3 while the probe and the sphere 14 are held firmly in the assembly jig.
The spigots 1 to 24 are aligned with the housing 2 by loosely fitting them into the counterbores and gluing them.

The holes 26 for the ball bearings 9, 10 are located in the housing 2 with a smaller diameter than the diameter of each ball bearing, so that incorrect ball bearings can be easily removed and replaced during assembly.

The axis of the needle 3 shown in Figure 1 is coaxial with the detector, but this is not necessary for the operation of the device; for example, when measuring a cylinder bore, the ball and axis are placed in the radial direction of the position shown. It will become clear that this is preferable.

If the housing 2 is filled with electrical insulating oil, the operation of the probe can be improved. The rubber garter 27 prevents oil from leaking along the shaft 3.
, C has sufficient elasticity so as not to be pushed when the probe is placed in a limited rest position.

The connection between the two grooves 8 is the groove 28 of the housing 2.
be placed appropriately within. ■Ball bearings to prevent shape disease
It will be appreciated that the use of is for convenience and that each set of ball bearings could be replaced by a pair of mutually inclined needle rollers.

In this embodiment, the rest position of the needle 3 and the displacement from this rest position are limited by the same device and are detected.

FIGS. 4 and 5 show another embodiment of the invention, in which three human body circular shapes respectively cooperate with V-shaped grooves formed in the same manner as described in FIGS. 1 to 3. The needle is on the right with legs 81, 82, and 83. 1 of 3 legs
The two legs 83 extend laterally and support the measuring ball 14. This embodiment has advantages in situations such as the measurement of cylindrical holes.

6 to 8 show further embodiments of the invention, in which the probe 1 has a needle 3 disposed within a housing 2. FIG. Hairpin spring glued to insulator 91 2
The insulator 91 is insulated by two strips 92 and 93 (J3 is fixed to one end 90 of the A91).As shown in FIGS. 94 and the platform part 95 to which the strips 92, 93 are glued.The insulator 91 made of polyester resin is glued with another polyester resin in the housing 2.2 Navy blue needle [1-La 96°97 and 9
8.99 is connected to both sides 112 and 113 of the V-shaped groove to form two V-shaped grooves.

The fifth needle roller 100 is bonded to the insulator 91 at an angle of about 45° with respect to the axis 101 of the probe '1.

In the above configuration, the spring 5 passing through the diametrical hole 102 of it 3 has the cylindrical part of the hook 13 in contact with the two V-shaped grooves, and the curved end 103 in contact with the inclined surface of the needle 100. The rest positions of U, f, and +3 are determined by pressing the keys so that the The contact engagement between the ball 1/I at the end of the hook 3 and the object to be measured displaces the hook 3 and bends the direction of the button 3 with respect to the housing 2, causing the needle [1 - at least 1 A J that allows you to enjoy the buttons from one side to the other.

Therefore, set up an electric circuit between the needle roller and the button (C).
By this, it is possible to detect when the button is moving away from the rest position, and each contact point 1 between the button and the needle roller can be detected.
．． 1 Operates as a switch that opens and closes an electric circuit. Five needle rollers 96, 97, 98, 99, and 100 are bonded to an insulator 91 using polyester resin, separated by N, and electrically insulated. The button 3 extends through a cylindrical portion 104 which is insulated from the rest of the tl by a cylindrical sleeve 105 of Borini resin.

An electrical circuit for detecting when a button has broken contact with one of the needle rollers runs from conductor 106 to needle roller 96, it 3, to needle roller 98, to needle [1].
- La 99, cylindrical part 104 of needle 3, 'needle [Cola 9
7. The conductor 107 is connected in series to the AC power source and the indicator lamp (not shown).

The two conductive wires 106 and 107 are mechanically supported with respect to the probe by a rubber cap 119 fixed to the probe by screws 108.

Since any axial movement of ♀ 13 causes the curved end 103 to cooperate with the inclined needle roller 100, breaking the electrical connection between one of the other needle rollers and the needle,
It is not necessary to connect the contact between the fifth needle roller 100 and the needle 3 in series with the electrical circuit described above.

In this example, a V-shaped groove of λ1 is formed and covered with a needle for positioning the hook at the eye stop point.
Although it may be convenient to use a laser, it will be readily apparent that other positioning means can be used. For example, each needle roller can be replaced by a rectangular metal strip.

Needle rollers are commercially available and are preferred because of their high precision surface finish, hardness, and low frictional forces against button movement, which improve probe sensitivity.

The present invention contemplates that any device that reliably determines the position of 11 may be used in place of the needle rollers, and that the point contact between the shuttlecock and each needle roller may be made into a line contact.

As a modification (not shown), the fifth needle roller 10
0 can also be placed perpendicular to the axis 101 of the probe to limit the measurement capabilities of the probe to two dimensions.

FIG. 9 shows yet another embodiment in which the arrangement of needle rollers 96, 97, 98, 99, 100 is the same as that in FIG. All you have to do is position the needle.

The electric circuit 15 is located below the conductors 112 and 113 (needle 3 in the drawing).
It is formed by the A7 pin 5 and the conductive wire 113 to the nail 3 and the contact point 110 located at the rear of the pin 3. The switch formed by the sword 3 and the contact 110 is shut off by any displacement of the elephant 13 from its rest position. Therefore, any displacement can be detected via the electric circuit 15.

During the measurement of the object in the embodiments described above, a series of readings are taken at various locations around the object to facilitate input data for a computer programmed to compare the reference object and the measurement object. The information that will be created will be brought to you. The measuring probe according to the invention can therefore be used to measure objects such as pipes of gas turbine engines or cylinder blocks of internal combustion engines.

The probe described in (a) above is equipped with a detector having an electrical switching device, but the electrical switching device can be replaced with a fluidic switch or other switch, or the detector can be replaced with a device other than a switch. should be obvious. For example, each detector is equipped with an optical projection device that magnifies any misalignment between two pointers that provides an indication of needle movement.

It will also be apparent that any of the embodiments described above can be filled with oil in a manner similar to that described in FIGS. 1-3.

Above, J, Uni, J
: Then, when the button comes into contact with an object (object), the displacement of the button is Wl-, and then when the sword leaves the object, the action of the engaging element, the converging surface, and the biasing means is J, Since the flywheel accurately returns to its original body position (position relative to the fixed member), accurate detection of the object can be repeatedly performed.

Further, according to the invention set forth in claim 2, a signal is generated based on the contact distance between the engagement element and the converging portion for accurately returning the needle to the rest position. , the structure of the measurement probe is simple.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of a probe constructed according to the present invention;
Fig. 2 is a cross-sectional view taken along the line ■-■ of Fig. 1, Fig. 4 is a cross-sectional view of another probe, Fig. 5 The figure is a cross-sectional view of the probe in FIG. 4 taken along the v-v line, FIG. 6 is a cross-sectional view of another probe constructed according to the present invention, and FIG. 7 is an enlarged view taken along the vu-vu line in FIG. FIG. 8 is an enlarged sectional view taken along the line ■--■ in FIG. 7, and FIG. 9 is a longitudinal sectional view of another embodiment. 1... Measurement probe, 2... Housing, 3... Needle,
5... Spring, 8... V-shaped groove, 9, 10... Ball bearing, 14... Ball, 15... Electric circuit, 16... Insulator, 17... Indicator lamp, 18...Power supply, 91.
...Insulator, 92.93...Strip C, 94...V-shaped groove, 96.97.98.99.100...Needle roller. Applicant's agent Kiyoshi Inomata Figure 1 Uku Figure 8 Procedural Amendments Director-General of the Special Wis Office Kazuo Wakasugi 1 Indication of matter f1 1982 Patent Application No. 37190 2 Determination of the title of the invention Searcher 3 Person making the amendment Relationship to the case Patent applicant Rolls Royne MI971) Limited 4 Agent's ``Claims'' column, ``Detailed Description of the Invention'' column and 1° Brief Description of Drawings'' column in the specification. Hini Drawing 8 Contents of amendment (1) The entire text of Mei II will be corrected as shown in the attached sheet. There are no changes to the contents other than those listed as subject to amendment. (2) Figure 1 of the drawings has been corrected as shown in the attached sheet, and Figure 2,
Figure 3, Figure 4, Figure 5, and Figure 6 have been deleted, and Figure 7 has been deleted.
Figures 8 and 9 are attached to Figures 2 and 3 as indicated in red on the attached sheet.
Figure 4. Description 1, Title of the invention Measuring probe 2, Claims (1) Comprising a fixed element and a movable element having a needle for detecting a measurement target, the fixed element and the movable element described in t are relative to each other. the fixed element supports the movable element at three spaced apart positions and further comprises means for generating a signal when the needle is in a predetermined positional relationship with respect to the object to be measured; Either one of the movable element and the fixed element has a pair of converging surfaces that converge with each other at each of the two spaced apart positions, and the other of the movable element and the fixed element has a pair of converging surfaces at each of the two spaced apart positions. has an engaging element capable of engaging both of the pair of converging surfaces, each of the pair of converging surfaces converging in a first direction and resisting movement of the engaging element in a second direction. and allowing the engaging element to move in a third direction, the first, second and third directions being orthogonal to each other, and further configured to allow the movable element to move in the first direction. biasing means adapted to force the engagement element into contact with both of the pair of converging surfaces to form a rest position for the movable element by forcing the engagement element into contact with the fixed element; When a force is applied to said needle, it moves from said rest position against said biasing means, and then when no force is applied to said needle, said biasing means and retractor move.
A measuring probe characterized in that the convex surfaces cooperate to return the movable element to the rest position. (2) the engagement element at each of the positions;
At least one of the backs of the converging surface constitutes a pair of electrical contacts, and the means for generating the signal changes the contact state of one of the electrical contacts by moving the movable element. 2. A measuring probe according to claim 1, further comprising electrical circuit means whose conduction state changes when the electrical contact changes, said electrical contacts forming part of said means for generating said signal. 3. Detailed Description of the Invention The present invention relates to a probe used in a measuring device, and particularly to a probe that detects contact between a needle and an object, that is, a measurement target. Such probes are applied to orthogonal slides that perform measurements within a rectangular coordinate frame. One object of the invention of this application is to provide a measurement probe that can repeatedly and accurately detect an object. Another object of the invention of this application is to provide a measurement probe having a simpler structure in addition to the above characteristics. The probe is arranged to contact an object to close or open an electrical circuit, and indicator lights are provided to indicate the status of the circuit. Generally, the probe is configured to open and close a circuit, and when the probe is not in contact with an object, an indicator lamp lights up, making it easy to detect if the probe is not working properly. According to the invention, a probe is provided having a needle, a housing and a device for pushing the needle in the direction of a rest position relative to the housing, the needle being displaced within a limited range from said rest position relative to the housing. A device is provided to detect this displacement when different directions are taken. In a preferred embodiment of the invention, the needle is pushed into contact with two axially disposed V-shaped grooves in the rest position, and the curved end of the needle is pushed into engagement with the ramp. , the limited deflection of the needle from the rest position changes the direction of deflection of the needle relative to the housing, thus taking it out of contact with at least one side of one of the V-grooves. A device is provided to detect the deflection of the needle. Such a device for detecting limited deflection of a needle may have an electrical circuit which is turned on, for example, when the needle is in its rest position, and which circuit passes from one V-groove to the other to each The members form a closed circuit between opposite sides of each V-shaped groove. 1 to 3 show embodiments of this invention,
The probe 1 has a numbered button 3 in the housing 2. The needle 3 extends through the housing 2 and has a centrally located ball 14 attached to its end 13. Two strips 9 with hairpin springs glued to an insulator 91
2.93 to the insulator 91 at one end 90. As shown in FIGS. 1 and 2, the insulator 91 has a cylindrical shape and has a V-shaped groove 94 extending over the majority and a platform portion 95 to which the strips 92, 93 are adhered. Zuru. An insulator 91 made of polyester resin is glued with another polyester resin in the housing 2. Two sets of needle rollers 96.97 and 9'8.99 are located on both sides 112. of the V-shaped groove. ．． 113 to form and cover two V-shaped grooves. The fifth needle roller 100 is bonded to the insulator 91 so as to form an angle base of about 45° with the axis 101 of the probe 1. 5 needle rollers 96.97.98.99°100
are adhered to an insulator 91 by polyester resin, and are separated from each other and electrically insulated. The needle 3 has a cylindrical part 104 insulated from the rest of the button by a cylindrical sleeve 105 of polyester resin. The spring 5 passing through the diametrical hole 102 of the needle 3 pushes the cylindrical part of the needle 3 into contact with the two V-shaped grooves and the curved end 103 into contact with the sloping surface of the needle roller 100. Deciding where to rest. In the above configuration, the probe 1 is connected to a coordinate measuring device (not shown), such as a rectangular coordinate frame or a spherical polar coordinate frame, and is movable in space in any direction to detect the boundaries of the object to be measured. The contact engagement between the ball 14 at the end of the needle 3 and the object to be measured displaces the needle 3 from its rest position against the force of the spring 5 and changes the orientation of the needle 3 relative to the housing 2, causing the needle to Move the needle away from at least one of the rollers. Therefore, by providing an electrical circuit between the needle roller and the needle, the movement of the needle away from the rest position can be detected, and each point of contact between the needle and the needle roller acts as a switch to open and close the electrical circuit. . An electrical circuit for detecting when a needle has broken contact with one of the needle rollers runs from conductor 106 to needle roller 96 to needle 3 to needle roller 98 to needle roller 9.
9, cylindrical part 104 of needle 3, needle roller 97, conducting wire 1
It is connected in series with the power source and the indicator lamp 17 via the terminal 07. When the shank 3 is displaced from its rest position, the needle 3 or its cylindrical part 104 is no longer in contact with one side of each V-shaped groove 8;
With this, the circuit 15 is cut off and the display lamp 17, which is normally lit, is turned off by the power supply 18. The two conductors 106, 107 are mechanically supported to the probe by rubber snaps 119 secured to the probe by screws 108. Since any axial movement of the needle 3 causes the curved end 103 to cooperate with the inclined needle roller 100, breaking the electrical connection between one of the needle rollers and the needle, the fifth needle roller It is not necessary to connect the contact between 100 and nail 3 in series with the electrical circuit described above. A circuit break is used to provide an input pulse to an automatic switching device, not shown, which is known per se and which can then be used to provide a command to the device to read and record the coordinates of the probe. It is known that pulses of 1 microsecond duration allow highly accurate measurements. A gap is provided between the needle 3 and the housing 2, this gap allowing a limited displacement of the needle within the housing 2. When the needle 3 is displaced away from the rest position, this is elastically received by the deformation of the spring 5.
Damage to the needle 3 can be avoided due to the inertia of the probe during measurement. If the inertia of the probe is a problem, for example it will be difficult to prevent bending of the needle 3 after a reading has been taken, but this can be solved by providing the needle with a breaking device known per se. Although it is convenient in this embodiment to use needle rollers to form a pair of V-shaped grooves for positioning the needle in the rest position, it will be readily apparent that other positioning means may be used. For example, each needle roller can be replaced by a rectangular metal strip. Needle rollers are commercially available and are preferred because they have a high precision surface finish, hardness, and low frictional forces against needle movement, improving the sensitivity of the probe. The present invention contemplates that any device that reliably positions the needles can be used in place of the needle rollers, and that the point contact between the needle and each needle roller can be made into a line contact. If the housing 2 is filled with electrical insulating oil, the operation of the probe can be improved. This prevents sparks in the contact area which could lead to deterioration of the contact area. A rubber gutter can be provided to prevent oil from leaking along the girder 13. As this rubber gutter, one having sufficient elasticity so as not to interfere with the seating of the probe in the rest position can be used. In the embodiment described above, the rest position of the needle 3 and the displacement from this rest position are limited and detected by the same device. As a modification (not shown), the fifth needle roller 10
0 can also be placed perpendicular to the axis 101 of the probe to limit the measurement capability of the probe to two dimensions. FIG. 4 shows another embodiment, in which the needle roller 96
．． The arrangement of 97, 98, 99, 100 is similar to that of FIG. 1, and in combination with spring 5 it is only necessary to position the sword in the rest position. Electric circuit 15 includes conductor 112 and needle 3
It is formed by a contact point 110 located on the lower side (behind the needle 3 in the figure), the needle 3, the hair pin 5, and the conducting wire 113. The switch formed by the needle 3 and the contact 110
is interrupted by any displacement from its rest position. Therefore, any displacement can be detected via the electrical circuit 15. During the measurement of the object in the embodiments described above, a series of readings are taken at various locations around the object to facilitate input data for a computer programmed to compare the reference object and the measurement object. Information that can be created will be provided. The measuring probe according to the invention can therefore be used to measure objects such as pipes of gas turbine engines or cylinder blocks of internal combustion engines. The probe described in (a) is equipped with a detector that connects to an electrical switching device, but the electrical switching device can be replaced with a fluid switch or other switch, or the detector can be replaced with a device other than a switch. should be obvious. For example, each detector is equipped with an optical projection device that magnifies any misalignment between two finger buttons that provides an indication of needle movement. It will also be clear that the embodiment of FIG. 4 described above can also be filled with oil in a manner similar to that described in FIGS. 1-3. As described above, according to the invention recited in claim 1, when the needle comes into contact with an object (target object), displacement of the needle is allowed, and when the needle leaves the object, the engagement element Since the button accurately returns to its original body position (position relative to the fixed member) by the action of the converging surface and the biasing means, accurate detection of the object can be repeatedly performed. Further, according to the invention set forth in claim 2, a signal is generated based on the contact/separation between the engagement element and the convergent river, which function to accurately return the needle to the rest position. , the structure of the measurement probe becomes simple. 4. Brief description of the drawings Figure 1 is a longitudinal cross-sectional view of a probe constructed according to the present invention;
FIG. 2 is an enlarged sectional view taken along line 1--2 in FIG. 1, FIG. 3 is an enlarged sectional view taken along line 1--2 in FIG. 1, and FIG. 4 is a longitudinal sectional view of another embodiment. 1... Measurement probe, 2... Housing, 3... Needle,
5... Spring, 15... Electric circuit, 17... Display lamp, 18... Power supply, 91... Insulator, 92.93
...Strip, 94...■-shaped groove, 96.97.98.
99.100...Needle roller. Applicant's agent Kiyoshi Inomata Figure q

Claims (2)

[Claims] (1) It comprises a fixed element and a movable element that supports the measuring object detection lever 21, the fixed element and the movable element move relative to each other, and the fixed element is arranged at three locations separated from each other. The movable element is supported at the position, and further includes means for generating a signal when the button is in a predetermined positional relationship with respect to the object to be measured, and either the movable element or the fixed element is arranged in the spaced apart position. A pair of converging surfaces that converge to each other are provided at each of at least two positions, and the other element between the movable element and the fixed element is
[At each position there is an engaging element that can engage both of the pair of converging surfaces, the pair of converging surfaces converge in the first direction, and the engaging element is in the second direction. W[
- [2 the first, second and third directions are perpendicular to each other; bringing an engagement element into contact with both of the pair of converging surfaces to form a rest position for the movable element;
said movable element is moved from said rest position against said biasing means when a force is applied to said needle, and then when said force on said H is no longer applied said biasing means and converging means; A measurement probe characterized in that surfaces cooperate to return the nJ moving element to the rest position. (2) at each of said positions, said engagement element and at least one of said converging surfaces constitute an electrical contact of said signal; and said means for generating said signal comprises: comprising electric circuit means for changing the conduction state when the movable element moves to change the contact state of one of the upper power distribution contacts, the electric contact forming a part of the means for generating the signal; A measurement probe according to claim 1, characterized in that: