GB1594390A

GB1594390A - Dental appliance having a plurality of instruments

Info

Publication number: GB1594390A
Application number: GB2542878A
Authority: GB
Original assignee: Kaltenbach and Voigt GmbH
Current assignee: Kaltenbach and Voigt GmbH
Priority date: 1977-07-27
Filing date: 1978-05-31
Publication date: 1981-07-30
Also published as: JPS5426093A; IT7853586V0; CH629952A5; DE2733916C3; FR2398489A1; DE2733916B2; FR2398489B1; DE2733916A1; JPS5746855B2

Abstract

Each of the instruments is assigned a removal signal generator and a logic circuit, each of these logic circuits being connected by means of a single logic line (8) to the assigned removal signal generator (3). Each of the logic circuits (4) generates an activation signal for the assigned instrument (1, 101) and delivers a blocking signal to the logic line when a removal signal from the relevant removal signal generator is present and at the same time no blocking signal is present from the other logic circuits. Each logic circuit (4) contains a memory or executes a storage function in which or by means of which the signal state prevailing during application of a removal signal on the logic line (8) is stored. The stored signal state is critical for the logic decision in an evaluation circuit as to whether to generate an activation signal or a blocking signal. <IMAGE>

Description

(54) A DENTAL APPLIANCE HAVING A PLURALITY OF INSTRUMENTS (71) We, KALTENBACH & VOIGT GmbH & CO., a German Kommanditgesellschaft, of Bismarckring 39, 7950 Biberach/Riss, Federal Republic of Germany, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:: This invention relates to a dental appliance having a plurality of dental instruments each removably mounted at respective instrument-receiving stations, an instrument-removal datum source and a logic circuit associated with each instrument, and a common line linking the logic circuits together, in which each datum source is arranged to issue an instrument-removal signal upon removal of the respective instrument from its station, and each logic circuit is arranged to receive an instrument-removal signal from a respective datum source and to transmit a blocking signal to the linking line and to supply an actuation signal which allows the respective instrument to operate when no blocking signal is available on the linking line from the other logic circuits.

A dental appliance of the above type is disclosed in German Auslegeschrift No. 26 36 957, (though this had not been published as at the priority date of the present application), in which, upon removal of a working instrument, the remaining instruments are on subsequent removal blocked. Thereby it is possible to clean or change the implement of the remaining instruments without risk, but only until the working instrument is put back into the holding arrangement. When the working instrument is put back into the holding arrangement, the remaining instruments commence to operate. If a fresh working instrument is to be selected, all instruments of the appliance must be laid back into their holding system. Then, with fresh removal of the selected working instrument, all other instruments are blocked via the common working line.

The present invention has been developed primarily, though not exclusively, with a view to ensuring that, in a dental appliance of the type described hereinabove, upon return of a removed dental instrument the remaining removed instruments cannot start up in undesired fashion. If, however, one of the removed instruments is to be selected as a fresh working instrument, then this is to be possible by simple actuation of the associated instrumentremoval datum source.

According to the invention, there is provided a dental appliance having a plurality of dental instruments each removably mounted at respective instrument-receiving stations, an instrument-removal datum source and a logic circuit associated with each instrument, and a common line linking the logic circuits together, in which:: each datum source is arranged to issue an instrument-removal signal upon removal of the respective instrument from its station; each logic circuit is arranged to receive an instrument-removal signal from a respective datum source and to transmit a blocking signal to the linking line and to supply an actuation signal which allows the respective instrument to operate when no blocking signal is available on the linking line from the other logic circuits; and each logic circuit comprises a respective store for storing the signal condition obtaining on the linking line, after the issue of an instrument-removal signal, and is arranged to evaluate the stored signal condition for the logic decision as to whether an actuation signal and a blocking signal are to be generated.

In an embodiment of dental appliance according to the invention, the individual logic circuits are subjected to a fixed value corresponding to the instantaneous value of the signal condition on the linking line at the instant in time of removal of the associated instrument.

This fixed value is not again changed until the datum source associated with this instrument is actuated, whether by replacement and renewed removal of the instrument or manually, in which case the instrument does not require to be replaced.

Since each logic circuit, simultaneously with generation of an actuation signal, for the associated instrument, also transmits a blocking signal to the common linking line for the other instruments, but generates actuation signal only when no blocking signal is present on the linking line, it is necessary to ensure that the blocking signal generated by the logic circuit itself remains without influence during the logic decision. In the device described in German Auslegeschrift No. 26 36 957, this is made possible by employing a recognition circuit. This measure can, of course, also be employed in the present case for mastering the problem mentioned. According to the further preferred feature of the present invention, another possibility consists in that evaluation of the stored signal condition is effected in delayed fashion relative to the instant in time of storage.This means that at the instant in time of the logic decision having to be made by a logic circuit, as yet there is not generated by the logic circuit itself a blocking signal the influence of which on the logic decision would require to be eliminated. On the contrary, the blocking signal is delayed by the logic circuit, i.e. it is not generated until the decision has already been reached and can no longer be influenced by this blocking signal.

A possibility for practical carrying into effect of this idea may reside in the generation of an instrument-removal signal which has two chronologically spaced signal components whereof the first brings about setting of the store and the second action for the logic decision.

If, as known, each signal datum source of the appliance has change-over means which, on extraction of the associated instrument, is changed-over from a first into a second switching position, then the first signal component of the instrument-removal signal can be generated due to leaving the first switching position and the second signal component due to reaching the second switching position.

An especially simple and space-saving development to correspond to present-day techniques may furthermore consist in that each logic circuit comprises a JK master-slaveflipflop having two preparatory inputs, an inverting position input, an inverting reset input, a pulse input and also two complementary outputs, in that the two preparatory inputs are connected with the linking line, in that the inverting position input or the inverting reset input is fixed on a first logic condition, in that the inverting reset input or the inverting correcting input is normally fixed on the second logic condition and on occurrence of the first signal component of an instrument-removal signal is changed-over to the first logic condition, in that the pulse signal input is fed at least to the second signal component of the instrument-removal signal, and in that the actuation signal is extracted from one of the two outputs.

The construction and the mode of operation of the JK master-slave-flipflop is described for example in the periodical "Elektrotechnik" 53, volume 18, of 15th September 1971, pages 31/32 and also in volume 19 of 6th October 1971, pages 49/50. Furthermore, this flipflop is disclosed in the application booklet "Halbleiterschaltbeispiele" Verlag Siemens, 1970, pages 8/9. Finally, attention is also drawn to DIN 40 700.

If, as indicated hereinabove, each datum source has change-over means, then a further development may consist in that the change-over switch fixes in the first switching position the inverting reset input of the inverting correcting input of the JK master-slave-flipflop on the second logic condition and on reaching the second switching position feeds a switching surge to the pulse input.

As already disclosed in German Auslegeschrift No. 26 36 957, the actuation signal generated by a logic circuit may be employed simultaneously as blocking signal for the remaining logic circuits. For the carrying into effect of this idea in the present case, it is proposed that the output of the JK master-slave-flipflop from which the actuation signal is extracted shall be connected via a one-way transmission circuit with the linking line. The one-way transmission circuit transfers the actuation signal generated by the JK masterslave-flipflop as blocking signal to the linking line, but does not allow blocking signals generated by other logic circuits to reach the output of the JK master-slave-flipflop.

The individual circuit elements of the appliance can be carried into effect in electrical, pneumatic or hydraulic form. The designations employed for the individual circuit elements are to apply to all three possibilities.

On electrical design of the logic circuit, the one-way transmission circuit may be a diode.

An example of embodiment of the invention is described hereinbelow with reference to the drawing which shows a diagrammatic circuit of electrical design.

The appliance may comprise a plurality of instrument of which only two (i.e. the instrument 1 and the instrument 101) are shown. The circuit elements associated with each instrument are identical, so that only the circuit element associated with instrument 1 is to be described in detail.

Associated with instrument 1 is an instrument - receiving station, comprising a deposition unit 2, and datum source 3 which issues an instrument-removal signal upon removal of the instrument from its station. The datum source 3 transmits the signal to a logic circuit 4. The logic circuit 4 can, in the event of corresponding logic conditions being available, generate at its output an actuation signal fed to a power supply circuit 5 for the instrument 1. The actuation signal causes the power supply circuit 5 to supply the instrument 1 with energy, so that this instrument is able to start up. The function of the instrument 1 can normally also be controlled with a starter (omitted from the present circuit for the sake of simplicity).

The logic circuit 4 also feeds a blocking signal to a linking line 8 common to all circuit elements, via a one-way circuit 7.

The logic circuit 4 thus generates an activation and a blocking signal if signal is fed to it from the datum source 3 and if there is no blocking signal on the common linking line 8. In order to ascertain the latter, one input of the logic circuit 4 is connected with the linking line 8.

The datum source 3 has a change-over switch 9 adapted to be changed-over between a first switching contact 10 and a second switching contact 11. If the instrument 1 is disposed on the depositing unit, the change-over switch 9 is connected with the first switching contact 10. If the instrument 1 (as shown) is extracted from the depositing unit, then the change-over switch 9 is connected with the second switching contact 11. The second switching contact 11 is connected via a resistor 14 with a line 12 carrying high potential H.

This potential H corresponds to a first logic condition. The switching contact 11 is furthermore connected via a capacitor 20 and a resistor 15 with the line 12. The common connecting point between the capacitor 20 and the resistor 15 is connected via a resistor 16 with a line carrying low potential L. This low potential L corresponds to a second logic condition.

The logic circuit 4 has a JK master-slave-flipflop 6. This has two preparatory inputs J, K, a correcting input S, a reset input R, a pulse input T and also two complementary outputs Q, Q. The activation signal is extracted from the output Q. For this purpose, the output Q is connected with the input of the energy supply circuit 5 and the one-way signal circuit 7.

The correcting input S is connected via a resistor 17 with the line 12 and is consequently fixed on the first logic condition H. The input R is connected on the one hand via a resistor 18 with the line 12 and on the other hand with the switching contact 10 of the extraction signal datum source 3. The two preparatory inputs J and K are connected with the common linking line 8. The pulse input T is connected with the capacitor 20 of the extraction signal datum source 3 and also via a resistor 16 with the line 13. The output Q is not used. The connecting line 8 is connected via a resistor 19 with the line 12.

The one-way transmission line 7 is constituted by a diode 20.

For the JK master-slave-flipflop, the following conditions apply: 1) S and R must not both be on L, 25 Q and Q always have different (inverse) logic conditions, 3) If R is on L, H appears at Q in every case, independently of what condition obtains at J, K or T, 4) If R (and S) are on H, there occurs at the next negative Pulse edge T, as a function of the logic conditions at J and K, the logic condition at Q which may be read-off from the following table: LOGIC TABLE J K Q L L Logic condition remains unchanged L H H H L L H H Logic condition is changed (inverted) The circuit operates as follows:: It is initially assumed that instrument 1 is on the depositing unit 2 and that (on - sic) instrument 101 and all remaining instruments (not shown) are disposed on their deposit unit. In this case, the change-over switch 9 is connected with the switching contact 10, whereby R is on L. Thereby, according to the above condition 3, logic condition H appears at Q. This means that logic circuit 4 generates neither an activation signal nor a blocking signal. Consequently, the common linking line 8 is, via the resistor 19, on H. This means that here again there is no blocking signal which would correspond to the logic condition L.

The instrument 1 is then to be taken from the deposit unit 2. When the change-over switch 9 leaves the switching contact 10, then R is applied via the resistor 18 on H. The two preparatory inputs J and K receive logic condition H from the linking line 8. When the change-over switch 9 reaches the switching contact 11, then a negative pulse is fed to the pulse input T via the capacitor 20. Therefrom, there occurs change-over of the logic condition at Q to L. This logic condition L corresponds to the activation signal inducing the energy supply circuit 5 to start up the instrument 1. Additionally, this logic condition L is, via the diode 20 which now switches to passage, transferred as blocking signal to the linking line 8. Consequently, the linking line 8 is now on L. Thus, also at the preparatory inputs J and K there is L.However, it is noteworthy that thereby the logic condition at Q is no longer influenced.

If, then, the instrument 101 is taken from its holding system, then the logic condition L is at the preparatory inputs J and K of its flipflop 106. Thereby, according to the Logic Table no change-over of the logic condition can take place at the output Q of the flipflop 106.

Thus, also on extraction the instrument 101 remains inoperative.

If, then, instrument 101 remains extracted and instrument 1 is laid-back, then instrument 101 can according to condition 4 not start up for as long as no negative pulse edge occurs at the pulse input T of its flipflop 106. If the extracted instrument 101 is to be employed as working instrument, then consequently it is merely necessary to replace it on its depositing unit 102, in order to change-over the change-over switch 109 once between its two switching positions 110 and 111. The result of this is that there occurs at pulse input T a negative pulse edge which then (as stated) results in starting up of the instrument 101.

WHAT WE CLAIM IS: 1. A dental appliance having a plurality of dental instruments each removably mounted at respective instrument-receiving stations, an instrument-removal datum source and a logic circuit associated with each instrument, and a common line linking the logic circuits together, in which:: each datum source is arranged to issue an instrument-removal signal upon removal of the respective instrument from its station; each logic circuit is arranged to receive an instrument-removal signal from a respective datum source and to transmit a blocking signal to the linking line and to supply an actuation signal which allows the respective instrument to operate when no blocking signal is available on the linking line from the other logic circuits; and each logic circuit comprises a respective store for storing the signal condition obtaining on the linking line, after the issue of an instrument-removal signal, and is arranged to evaluate the stored signal condition for the logic decision as to whether an actuation signal and a blocking signal are to be generated.

2. A dental appliance according to claim 1, and arranged so that evaluation of the stored signal condition is effected in delayed fashion relative to the instant in time of storage.

3. A dental appliance according to claim 2, in which the instrument-removal signal has two chronologically spaced signal proportions whereof the first brings about setting of the store and the second brings about evaluation for the logic decision.

4. A dental appliance according to claim 3, in which each datum source has change-over means which, on removal of the associated instruments, is changed-over from a first into a second switching position, and the first signal proportion of the instrument-removal signal is generatable by leaving the first switching position and the second signal proportion by reaching the second switching position.

5. A dental appliance according to claim 3 or 4, in which each logic circuit comprises a JK master-slave-flipflop having two preparation inputs (J, K), an inverting position input (S), an inverting reset position (R), a pulse input (T) and also two complementary outputs (Q, Q); the two preparation inputs (J, K), are connected to the common linking line; the inverting correcting input (S) or the inverting reset input (R) is fixed to a first logic condition (H); the inverting reset input (R) or the inverting position input (S) is normally fixed on a second logic condition (L) and, on occurrence of the first signal proportion of an instrument-removal signal is changed-over to the first logic condition (H); there is fed in use to the pulse signal input (T) at least the second signal proportion of the removal signal; and the actuation signal is extractable from one of the two outputs (Q,Q).

6. A dental appliance according to claim 5, in which the change-over means fixes in the

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. instrument 101 and all remaining instruments (not shown) are disposed on their deposit unit. In this case, the change-over switch 9 is connected with the switching contact 10, whereby R is on L. Thereby, according to the above condition 3, logic condition H appears at Q. This means that logic circuit 4 generates neither an activation signal nor a blocking signal. Consequently, the common linking line 8 is, via the resistor 19, on H. This means that here again there is no blocking signal which would correspond to the logic condition L. The instrument 1 is then to be taken from the deposit unit 2. When the change-over switch 9 leaves the switching contact 10, then R is applied via the resistor 18 on H. The two preparatory inputs J and K receive logic condition H from the linking line 8. When the change-over switch 9 reaches the switching contact 11, then a negative pulse is fed to the pulse input T via the capacitor 20. Therefrom, there occurs change-over of the logic condition at Q to L. This logic condition L corresponds to the activation signal inducing the energy supply circuit 5 to start up the instrument 1. Additionally, this logic condition L is, via the diode 20 which now switches to passage, transferred as blocking signal to the linking line 8. Consequently, the linking line 8 is now on L. Thus, also at the preparatory inputs J and K there is L.However, it is noteworthy that thereby the logic condition at Q is no longer influenced. If, then, the instrument 101 is taken from its holding system, then the logic condition L is at the preparatory inputs J and K of its flipflop 106. Thereby, according to the Logic Table no change-over of the logic condition can take place at the output Q of the flipflop 106. Thus, also on extraction the instrument 101 remains inoperative. If, then, instrument 101 remains extracted and instrument 1 is laid-back, then instrument 101 can according to condition 4 not start up for as long as no negative pulse edge occurs at the pulse input T of its flipflop 106. If the extracted instrument 101 is to be employed as working instrument, then consequently it is merely necessary to replace it on its depositing unit 102, in order to change-over the change-over switch 109 once between its two switching positions 110 and 111. The result of this is that there occurs at pulse input T a negative pulse edge which then (as stated) results in starting up of the instrument 101. WHAT WE CLAIM IS:

1. A dental appliance having a plurality of dental instruments each removably mounted at respective instrument-receiving stations, an instrument-removal datum source and a logic circuit associated with each instrument, and a common line linking the logic circuits together, in which:: each datum source is arranged to issue an instrument-removal signal upon removal of the respective instrument from its station; each logic circuit is arranged to receive an instrument-removal signal from a respective datum source and to transmit a blocking signal to the linking line and to supply an actuation signal which allows the respective instrument to operate when no blocking signal is available on the linking line from the other logic circuits; and each logic circuit comprises a respective store for storing the signal condition obtaining on the linking line, after the issue of an instrument-removal signal, and is arranged to evaluate the stored signal condition for the logic decision as to whether an actuation signal and a blocking signal are to be generated.

first switching position the inverting reset input (R) or the inverting position input (S) on the second logic condition (L) and, on reaching the second switching position, feeds a switching pulse to the pulse input (T).

7. A dental appliance according to claim 5 or 6, in which the output (Q) of the JK master-slave-flipflop from which the actuation signal is extractable is connected via a one-way transfer circuit with the common linking line, so as to feed thereto the actuation signal as a blocking signal.

8. A dental appliance according to claim 7, in which each logic circuit is electrically operated, and the one-way transfer circuit is a diode.

9. A dental appliance according to any one of the preceding claims, in which the circuit components are electrically, pneumatically or hydraulically operable.

10. A dental appliance according to claim 1 and substantially as hereinbefore described with reference to, and as shown in the accompanying drawing.