The invention relates to a device for cooling cutting tools during operation according to the preambles of claim 1.

Irrigation systems are used to cool cutting tools during operation, in particular during surgery. To this effect the state of the art uses devices like foot pedals with which it is possible to control the motor of a pump delivering the irrigation liquid during operation of the cutting tool.

A dental handpiece being provided with longitudinal passages therein for compressed air to drive a the drive turbine and for a cooling liquid is known from WO 92/10144 SENEY. The pressurized cooling liquid is provided to the handpiece from a remote pressure source which is not mentioned in detail.

The invention is based on the objective of providing a device permitting the actuation of the driving means as well as pressurization of the dispensing means with the same compressed fluid being available in the operating room if a compressed-air tool is used.

The invention solves the posed problem with a device for cooling cutting tools during operation that displays the features of claim 1.

The advantages achieved by the invention are essentially to be seen in the fact that, thanks to the device according to the invention

- the driving means as well as the pressure acting on the cooling liquid are controllable by means of a single control means;

- the actuation of the driving means as well as pressurization of the dispensing means is effectable with the same fluid such that no further energy source and pressurization means as engines or pumps are necessary;

- the device is uncomplicatedly configured via diverting the compressed air for pressurization of the cooling liquid; and

- no assistant person is necessary to control the flow of the cooling liquid.

Additional advantageous embodiments of the invention are characterized in the subclaims.

In a preferred embodiment the device comprises a first connecting means for being connected to a compressed fluid source P, e.g. a compressed air source which is available in the operating room.

Preferably, the pressurization of the container is effected by means of compressed fluid supplied from the compressed fluid source P. In case of using a common compressed air driven driving means no further energy supply is necessary.

In a further embodiment the container is compressible and preferably configured as a flexible bag. Thus, a common flexible bag available in the operating room may be used.

In another preferred embodiment the activation of said dispensing means is effected by means pneumatic pressure. This permits the advantage that compared to the known complicated prior art devices which are using a separate hand-activated pump acting on the container the invention permits a container directly being compressed by pneumatic force controlled by the control means.

In a further embodiment the control means comprise a control valve, e.g. a foot controlled valve.

In yet a further embodiment the control means further comprise a) a second connecting means for being connected to a first compressed-fluid tube supplying the driving means; c) a third connecting means for being connected with a second compressed-fluid tube supplying the dispensing means; and d) a branching for diverting the flow of compressed fluid to the second and third coupling means after passing the control valve.

This embodiment permits the advantage of a simple bifurcation of the compressed fluid supply.

In another embodiment the dispensing means comprises a tube clamping device acting on said tube connected to said container.

In yet another embodiment the device additionally comprises a flap valve. This permits the advantage that the flap valve together with the tube clamping device avoid a depressurization of the container when the cooling circuit is shortly interrupted. Thus, the device is more efficient since the container has not to be filled again upon activating the device again such permitting a shorter reoperating period of the device.

In still another embodiment the device additionally comprises a pressure collar for acting on said container for said cooling liquid.

In a further embodiment the control means comprise a on-off valve for control of the flow of compressed fluid through the second compressed-fluid tube which is connected to the pressure collar.

In another embodiment the device is provided with an exhaust tube being connectable to the driving means and being bifurcated, therewith permitting the actuation of the on- off valve by means of the exhaust compressed fluid. This permits the advantage that the flow of cooling liquid is not limited to the use of a control means operated by foot but may as well be used in a device having the control valve integrated in the driving means.

In a further embodiment the container for the cooling liquid is positioned at a higher location than said cutting tool, so that said cooling liquid is subject to both said pneumatic pressure and the force of gravity.

In yet a further embodiment the device additionally comprises an on-off switch for switching on or off the dispensing means independently from the control means. This permits the advantage that by means of the on-off switch the flow of cooling liquid may

be interrupted when the surgeon does not need any cooling liquid, e.g. in case of an interference with visibility through the cooling liquid.

The invention and additional configurations of the invention are explained in even more detail with reference to the partially schematic illustration of several embodiments.

Shown are:

Fig. 1 a diagrammatic view of an embodiment of the device according to the invention;

Fig. 2 a diagrammatic view of a further embodiment of the device according to the invention;

Fig. 3 a diagrammatic view of another embodiment of the device according to the invention;

Fig. 4 a diagrammatic view of yet another embodiment of the device according to the invention; and

Fig. 5 a diagrammatic view of a further embodiment of the device according to the invention.

Fig. 1 depicts an embodiment of the device 1 according to the invention together with a surgical drive means 3 being operated by a compressed fluid, e.g. compressed air and being provided with a cutting tool 9. The control means 2 is provided with a first connecting means 23 being connected to a compressed fluid source P by means of a preferably flexible input tube 16. Compressed air system are usually available in any operating room. A preferably flexible, first compressed-fluid tube 17 connects the control means 2 to the drive means 3, said first compressed-fluid tube 17 being connected to the second connecting means 24 of the control means 2. Furthermore, the device 1 comprises a dispensing means 4 with a container 5 for storing a cooling liquid 13, said container being connected to the environment of said the cutting tool 9 by means of a preferably flexible tube 6 for transporting said cooling liquid 13 during operation. The dispensing means 4 are being connected to a second connecting means

24 at the control means 2 by means of a second compressed-fluid tube 18. Thus, the drive means 3 as well as the dispensing means 4 are activated by means of the same control valve 14 which is configured as a single foot switch or foot control equipment. In the embodiment shown here, the dispensing means 4 comprises a compressible container 5, e.g. a flexible bag for storing a cooling liquid 13 and which is connected to the environment of said cutting tool 9 by a preferably flexible tube 6 for transporting said cooling liquid 13 to said cutting tool 9. The compressible container 5 is being compressed by means of a pressure collar 10 which is actuable through compressed air flowing through the control means 2. In order to actuate the drive means 3 together with the pressure collar 10 by means of the control valve 14 a branching 19 is inserted bifurcating the compressed air between the outlet of the control valve 14 and the second and third connecting means 24;25.

The embodiment shown in fig. 2 differs from the embodiment shown in fig.1 only therein, that the branching 19 is inserted between the inlet of the control valve 14 and the first connecting means 23. Further, the control means 2 comprise an on-off valve 20 actuated through the control valve 14, the on-off valve 20 being provided between the branching 19 and the third connecting means 25. Furthermore, a tube clamping device 7 is attached to the tube 6 connected to the container 5 and which is apt for transporting the cooling liquid 13 to the cutting tool 9. The tube 6 is squeezed together by means of a spring 21 included in tube clamping device 7 upon depressurizing the second compressed-fluid tube 18 by closing the on-off valve 20 via the control valve 14. Upon opening the on-off valve 20 via the control valve 14 compressed air may flow through the second compressed-air tube 18 and through a second branching 22 connected to the tube clamping device 7 such opening the tube clamping device 7 against the force of the spring 21.

The embodiment shown in fig. 3 differs from the embodiment shown in fig. 2 only therein, that it further comprises a flap valve 8 being situated in the second compressed-fluid tube 18 between the pressure collar 10 and the second branching 22. The integration of the flap valve 8 permits to keep the pressure collar 10 under pressure when the pressure of the compressed air is reduced by means of the control means 2. Since upon reduction of the pressure by means of actuating the control valve 14 the

tube clamping device 7 squeezes the tube 6 for the cooling liquid 13 therewith closing the outlet of the container 5 the pressure is also kept in the container 5.

The embodiment shown in fig. 4 differs from the embodiment shown in fig. 3 only therein, that it additionally comprises an independent on-off switch 11 permitting to switch on or off the dispensing means 4 independently from the control means 2. Between the on-off switch 11 and the first branching 19 a pressure reducer 27 is inserted in order to protect the container 5, i.e. the flexible bag from bursting.

Fig. 5 depicts an embodiment the differs from the embodiment show in fig. 3 only therein, that the control means 2';2" are divided in two parts, the first part including the control valve 14 is attached to the driving means 3 while the second part including the on-off valve 20 is separated. The on-off valve 20 is actuated by means of exhaust compressed air flowing through an exhaust tube 15 connected to the driving means 3 and being guided to the on-off valve 20 via a bifurcation 26 in the exhaust tube 15.