Patent Description:
It is well known from the prior art, for example from <CIT>, to use a torque wrench for connecting a replaceable instrument tip to a hand piece. For example, the instrument is a dental instrument, and the instrument tip is a scaling tip that is used for removing plaque and/or tartar from teeth by scaling. Replaceable instrument tips allow applying types of instruments differing from each other with respect to their specifications and/or their use status by using one common hand piece. However, for avoiding damages of the instrument tip and/or hand pieces by applying an inappropriate high torque during connecting, the torque wrench limits the torque used for connecting the instrument tip and the hand piece on one hand. On the other hand the torque wrench makes sure that the instrument tip is not connected to the hand piece too loose. For example, the torque wrench guarantees a proper connection of the instrument tip and the hand piece for transferring an ultrasonic movement generated by an activator unit of the hand piece to the instrument tip.

<CIT> concerns an abutment clip for use in a dental implant system. <CIT> deals with a dynamometric key, disclosing the preamble of claim <NUM>, designed in particular for fixing an insert on a handpiece. A similar subject matter is shown in <CIT>.

Usually, it is provided that the torque wrench is equipped with the instrument tip that is about to be used by the hand piece. Subsequently, the instrument tip is fixed to the hand piece by using the torque wrench.

Further, it is known to provide a transparent housing surrounding the instrument tip being mounted on or attached to the torque wrench, wherein the housing is structured at its outside in order to improve gripping the torque wrench during connecting the instrumental tip to the hand piece. The transparent housing allows identifying the instrument tip being currently equipped to the torque wrench by looking through the housing.

It is an object of the present invention to provide a torque wrench being further improved compared to the known torque wrenches from the state of the art, preferably in view of their handling and their support to identify the instrument tip being currently equipped to the torque wrench.

This object is achieved by the torque wrench according to claim <NUM>, the system of torque wrench and instrument tip according to claim <NUM> and a method for connecting the instrument tip to the hand piece according to claim <NUM>.

Preferred embodiments are incorporated in the dependent claims, the description and the figures. According to the invention, a torque wrench for connecting a replaceable instrument tip, such as a scaling tip for example, to a hand piece that carries the replaceable instrument tip in operation, preferably to form a dental instrument, is provided, comprising.

Thus, it is possible to realize a contact between the guiding structure and the instrument tip, wherein the contact supports aligning, when the instrument tip is moved towards to the receiving region. Furthermore, the insertion direction corresponds to a longitudinal direction of the base body of the instrument tip, being fixed to the receiving region. Due to the tapered structure of the second front side, the torque wrench can be shifted in a direction slanted or even perpendicular to the insertion direction or longitudinal direction of the receiving region. As a consequence, a probability for injuring the user during depositing the torque wrench on the hand piece is reduced and the user might even insert the instrument tip with closed eyes. Furthermore, it is provided that the guiding structure is part of the second front side of the base element.

Preferably, the housing has an inner surface and outer surface being parallel to each other over a complete primary region extending from the base element to at least an end of the instrument tip, in particular pointed at the end of the instrument tip, when the torque wrench is equipped with the instrument tip.

In contrast to the state of the art, the torque wrench according to the present invention has an inner surface and an outer surface being fully parallel to each other over the complete primary region, in particular along a complete circumference surrounding the instrument tip, i. <NUM> ° and in particular concentric to each other. As a consequence, when the housing is transparent, there is no beam displacement, when the user takes a look at the instrument tip through the transparent housing. Therefore, no distorted image is visually detected by a user that tries to identify the instrument tip being arranged at the receiving region of the torque wrench. This supports the user to quickly identify the instrument tip equipped to the torque wrench. Contrary, these distorted images are realized by such housings known from the prior art that has a structured outer surface in order to simplify gripping the torque wrench. Further, the guiding structure of the present invention supports the user by inserting the instrument tip into the receiving region. In particular, the guiding structure is configured such that the instrument tip is shifted, for example laterally, to the proper position by the guiding structure, when the instrument tip is moved towards the receiving region. Thus, it is possible to support the handling of the torque wrench when it is equipped with the instrument tip and reduce a probability to injure the user by the instrument tip during aligning the instrument tip relatively to the hand piece.

Preferably, the housing surrounds the instrument tip being arranged at the receiving area such that the housing surrounds the complete instrument tip and/or is arranged concentrically to the instrument tip. Thus, the housing protects the instrument tip and the user against injury by the instrument tip. For example, the housing is cylindrical and has openings at its front ends. In particular, the primary region extends over the whole housing. Furthermore, the receiving area is configured as a recess, in particular a recess in form of a hole reaching through the complete base element, wherein the base element has a first front side and a second front side being opposite to the first front side. The shape of the recess in a plane being parallel of the first front side and/or the second front side corresponds to a base body of the instrument tip that is arranged inside the base element. In particular, the base body of the instrument tip and the base element of the torque wrench are configured complementary, for example in a sense of a key-lock principle. The base element has a mainly cylindrical shape being surrounded by the housing. Furthermore, the base element comprises the torque wrench mechanism, such as a torque wrench mechanism disclosed in <CIT>, of which content related to the torque wrench mechanism is explicitly referred to herewith.

According to a preferred embodiment it is provided that a first length is assigned to the primary region extending from the base element to at least the end of the instrument tip and a second length is assigned to a maximal width or distance of an opening defined by the inner surface, wherein the second length is larger than the first length, in particular the second length is <NUM> to <NUM> times, preferably <NUM> to <NUM> times and more preferably <NUM> to <NUM> times bigger than the first length. As a consequence, a comparable large first front side of the base element is provided that simplifies looking from a top view perspective. Furthermore, it is possible to provide information regarding the instrument tip and/or the torque wrench on the first front side. Furthermore the primary region extends from the first front side to the end of the housing, in particular the end of the housing being located on the side of the end of the instrument tip protruding from the first front side.

In another preferred embodiment of the present invention it is provided that the torque wrench is individualized for connecting to a certain type of instrument tip. Thus, it is advantageously possible to use the torque wrench only for one type of instrument tip or a group of instrument tips such that information relating to the instrument tip, such as its identification number, can be placed or located on the torque wrench. Preferably, the individualizing is realized by the key lock principle between the base body of the instrument tip and the base element of the torque wrench. For example, the size and/form of the recess forming the receiving region is adapted correspondingly.

According to a further preferred embodiment of the invention, it is provided that the torque wrench has an identification, such as a sign, for visually identifying the instrument tip inserted into the torque wrench. Thus, it is possible to simplify identifying the type of the instrument tip in use. For example, an identification information is engraved into the torque wrench, in particular in the base element or a secondary region of the housing that differs from the primary region of the housing. It is also conceivable that the information is located on the first front side. Another possibility might be using a colour code such that the colour code corresponds to a certain type of instrument tip and the housing and/or the base element of the torque wrench is coloured correspondingly, wherein the housing is preferably still transparent.

In another preferred embodiment of the present invention, the housing is at least partially free, preferably fully free, from deformations. Thus, it is advantageously possible to avoid a distorted view on the instrument tip and/or the torque wrench mechanism by looking through the housing. It also conceivable to include at least one deformation in a secondary region of the housing being different from the primary region. For example, the secondary region extends from the first front side to at least the second front side of the base element. Thus, it is advantageously possible to have deformation supporting gripping in a region irrelevant for the view on the instrument tip. Another benefit is that the user gets to used to grip the housing in the secondary region. As a consequence, a probability for soiling the housing in the primary region by finger prints is reduced. Another benefit of a complete transparent housing without any deformation is supporting the user by identifying possible dust residues. As a consequence, an optimal hygiene and trans-contamination is guaranteed.

According to the invention, it is provided that the torque wrench has a reference marking for determining a status of the instrument tip connected to the receiving region. Thus, it is possible for the user to identify the current status of the instrument tip. In particular it is provided that the reference marking is a reference for identifying the length of the instrument tip. In particular, a projection of the instrument tip on the reference marking, preferably from a defined point of view, can be used for identifying the use status of the instrument tip. Preferably, the reference marking is located on the first front side of the base element of the torque wrench and the user needs to look from a defined top view perspective, such as located around <NUM> from the first front side, along a direction perpendicular to the first front side.

According to a preferred embodiment, it is provided that a reference marking is a ring, in particular extending concentrically to the inner surface, the outer surface and/or the receiving region. Preferably, the ring is dimensioned such that a thickness of the ring measured radially supports identifying the use status of the instrument tip. In particular, the ring is configured such that a projection of the instrument tip onto the reference marking extends radially to the outer circle of the ring, when the instrument tip is new. When the instrument tip is shortened to a critical limit, the projection of the instrument tip on the reference marking extends only to the inner circle. As soon as the inner circle is reached the instrument tip should be changed.

Preferably, the torque wrench is made from a material being compatible with a sterilization method used for the instrument tip. As a consequence, it is possible to sterilize the instrument tip, when it is mounted to the torque wrench, together with the torque wrench without removing the instrument tip from the torque wrench. The sterilisation might be performed manually, for example by using an ultrasound bath. It is also conceivable that the sterilization is performed semi automatically, by using a thermodesinfication machine, or automatically in a device designed for cleaning and sterilizing. For example, the torch wrench and the instrument tip are exposed to a steam, chemicals and/or temperatures that supports sterilization and/or disinfection of the instrument tip.

Preferably, the instrument tip is an integral part of the torque wrench. Thus, there is no need for mounting the instrument tip to the torque wrench. Instead, the torque wrench is part of the dental instrument, when the instrument tip is arranged on the hand piece and only the housing is removed for the treatment.

In another preferred embodiment is provided that the housing has a secondary region surrounding the base element, wherein a third length is assigned to the secondary region that is smaller than a complete height of the base element. Consequently, the base element protrudes relatively to the housing and the protruding part of the base element can be used for realizing an identification such as a label. Further, the user can grip a part of the torque wrench being arranged next to the interface area of the torque wrench and thus simplifies handling, in particular when the torque wrench is moved relatively to the hand piece.

Another aspect of the present invention is a system comprising a torque wrench according to the invention and an instrument tip for a hand piece. Preferably, the torque wrench being equipped with the instrument tip is stored in a tray of sachet.

In particular, the activator unit generates an ultrasonic movement of <NUM>,<NUM> to <NUM>,<NUM>.

Another aspect of the present invention refers to a method for connecting an instrument tip and a hand piece that carries the replaceable instrument tip in operation defined by a torque wrench according to the present invention, comprising.

Another aspect of the present invention refers to a torque wrench for connecting a replaceable instrument tip, such as a scaling tip for example, to a hand piece that carries the replaceable instrument tip in operation, preferably to form a dental instrument, is provided, comprising.

Wherever not already described explicitly, individual embodiments or their individual aspects and features can be combined or exchanged with one another without limiting or widening the scope of the described invention, which is disclosed in the appended claims, whenever such a combination or exchange is meaningful and in the sense of this invention. Advantages which are described with respect to one embodiment of the present invention are, wherever applicable, also advantageous of other embodiments of the present invention.

In the <FIG> a torque wrench <NUM> for connecting a replaceable instrument tip <NUM> to a hand piece that carries the replaceable instrument tip <NUM> in operation is shown in a side view (<FIG>), in a cross sectional view (<FIG>) and in a perspective view (<FIG>). For example the replaceable instrument tip <NUM> is a scaling tip, i. an instrument tip <NUM> that is used to clean teeth by scaling, and in particular in the mounted state the hand piece and the instrument tip <NUM> form a medical instrument, preferably a dental instrument.

Such an instrument tip <NUM> might be formed by a cylindrical metallic body that is bend and/or twisted, wherein the metallic body tapers to a sharp or pointed end <NUM>. In operation, i. during using the instrument for removing tartar and/or plague from the teeth, the instrument tip <NUM> is mounted on a hand piece for carrying the instrument tip <NUM> during the operation, wherein the instrument tip <NUM> is arranged on one front end of the hand piece (not shown). For removing tartar and/or plaque from the teeth the hand piece having the instrument tip <NUM> is lead to the teeth such that the instrument tip <NUM> is in contact with the surface of the teeth. Preferably, the hand piece comprises an activator unit for activating a movement, in particular an ultrasonic movement, of the instrument tip <NUM> connected to the hand piece. This ultrasonic movement supports removing spots, plaque and/or dentine tartar. The instrument tip <NUM> might be used subgingival or supragingival.

In particular, the hand piece is constructed such that the activator unit transfers the ultrasonic movement to the instrument tip <NUM> being located at the front end of the hand piece. For example, the activator unit comprises a piezo element for realizing the ultrasonic movement. The hand piece might further comprise a cooling unit such a cooling circuit including a water inlet and/or outlet, for cooling the hand piece during its operation. It also conceivable that the hand piece has a power supply for providing energy to a light source such as a LED.

The scaling during operation typically wears the instrument tip <NUM> out. Consequently, the instrument tip <NUM> is a consumption item that is renewed from time to time. Thus, the instrument tip <NUM> is configured replaceable and is no integral part of the hand piece. Another benefit of a replaceable instrument tip <NUM> is changing between different types of instrument tips <NUM> by using the same common hand piece. In particular, the instrument tip <NUM> and the hand piece are connected to each other via interface areas being respectively assigned to the hand piece and the instrument tip <NUM>.

For connecting the instrument tip <NUM> to the hand piece and/or for disconnecting the instrument tip <NUM> a torque wrench <NUM> is used. As a consequence, it is possible to apply the proper torque that does not destroy the hand piece, in particular a corresponding interface area of the hand piece, and simultaneously guarantees that the instrument tip <NUM> is connected not too loose for transferring the ultrasonic movement from the hand piece to the instrument tip <NUM> properly.

The torque wrench <NUM> presented in <FIG> comprises a base element <NUM> having a recess forming a receiving region <NUM> for placing the instrument tip <NUM> inside the receiving region <NUM>. Besides the receiving region <NUM> the torque wrench <NUM> has a torque wrench mechanism for applying a certain torque when connecting the instrument tip <NUM> to the hand piece. In particular, a spring <NUM> surrounding the base element <NUM> represents a part of the torque wrench mechanism. Such a torque wrench mechanism is described for example in <CIT>, of which content concerning the torque wrench mechanism is incorporated explicitly herewith.

In the embodiment presented in <FIG> the base element <NUM> mainly has a cylindrical form, wherein in a mounted state the instrument tip <NUM> protrudes from a first front side <NUM> of the cylindrical base element <NUM>, when the torque wrench is equipped with the instrument tip <NUM> and a second front side <NUM> opposite to the first front side <NUM> includes a guiding structure <NUM> that supports connecting the instrument tip <NUM> to the hand piece. For equipping the hand piece with a certain instrument tip <NUM>, the instrument tip <NUM> is inserted inside the hole forming the receiving region <NUM>. In particular, the instrument tip <NUM> extends through the base element <NUM>, in particular the whole base element <NUM>, when the torque wrench <NUM> is equipped with the instrument tip <NUM>, wherein preferably the pointed end <NUM> of the instrument tip <NUM> faces away from the first front side <NUM>. Furthermore the torque wrench <NUM> and the instrument tip <NUM> are connected with each other via a coupling mechanism <NUM>, preferably a coupling mechanism <NUM> based on a key lock principle. For example, the instrument tip <NUM> has a mainly cylindrical base body <NUM> at its end being opposite to the pointed end <NUM>, which is used for removing tartar and/or plaque, and the base body <NUM> comprises a key lock region <NUM>' having a preferably non-circular cross section. This lock region <NUM>' having a different cross section interacts with a corresponding recess in the base element <NUM> at the second front side <NUM> for forming the coupling mechanism <NUM>. In particular, it is provided that the instrument tip <NUM> is inserted into the hole, i. the receiving region <NUM>, by entering the hole at the second front side <NUM>. The instrument tip <NUM> might be fixed to the torque wrench <NUM> via a clip or a magnet.

To limit the risk of an injury, it is provided that the second front side <NUM> of the base element <NUM> has the guiding structure <NUM> for aligning the instrument tip <NUM> during inserting the instrument tip <NUM> into the torque wrench, in particular the receiving region <NUM>. In particular, the torque wrench <NUM> is moved towards the receiving region <NUM>, for example manually, and the guiding structure <NUM> shifts the torque wrench <NUM> and/or the instrument tip <NUM> laterally. The guiding structure <NUM> is preferably realized by a corresponding curvature, for example concave curvature, of the second front side <NUM> of the torque wrench <NUM>. In particular, the guiding structure <NUM> forms an opening that tapers along a direction parallel to the insertion direction D, in particular in a direction pointing to the first front side <NUM> of the torque wrench <NUM>. In particular the insertion direction D corresponds to a longitudinal direction of the receiving region <NUM>.

Furthermore it is conceivable that the guiding structure <NUM> is concentric to the base body <NUM> of the instrument tip <NUM> extending from the second front side <NUM>, when the torque wrench <NUM> is equipped with the instrument tip <NUM>. For example, the guiding structure <NUM> forms a funnel or chute. Preferably, the guiding structure <NUM> has a first height H1 extending parallel to the insertion direction D and a relation between the first height H1 and the whole height H2 of the base element <NUM> measured along the insertion direction D has a value between <NUM> and <NUM>, preferably between <NUM> and <NUM> and more preferably between <NUM> and <NUM>.

Moreover, it is preferably provided that the torque wrench <NUM> is individualized to a certain type of instrument tip <NUM> and/or a certain sub-ensemble of types of instrument tips <NUM>. This might be realized by adapting the receiving region <NUM>, i. the hole, corresponding to an outer surface of the instrument tip <NUM>, in particular the outer surface of the base body <NUM> of the instrument tip <NUM>. As a consequence, it is possible to label the torque wrench <NUM> with an individual identification that identifies the type of the instrument tip <NUM> being installed at the torque wrench <NUM>. For example, a name of the instrument tip <NUM> is engraved into a portion of the base element <NUM> of the torque wrench <NUM> being visually ascertainable, such as the first front side <NUM>. It is also conceivable that the base element <NUM> has a colour code, wherein each colour or colour combination is assigned to a specific type of instrument tip <NUM>.

Further, the identification of the instrument tip <NUM> being inserted into the torque wrench <NUM> is supported by a transparent housing <NUM> that surrounds the part of the instrument tip <NUM> extending or protruding from the first front side <NUM> of the base element <NUM>. Due to the transparent housing <NUM> it is advantageously possible to simultaneously protect the instrument tip <NUM>, in particular the part of the instrument tip <NUM> that extends from the first front side <NUM> and that is thinner than the base body <NUM> of the instrument tip <NUM>, and see and identify the instrument tip <NUM>. Preferably, it is provided that the housing <NUM> has a shape being concentrically to the base element <NUM> of the torque wrench <NUM> and/or the hole forming the receiving region <NUM>. Furthermore, the housing <NUM> has an inner surface <NUM> and an outer surface <NUM>, wherein at least in a primary region <NUM> extending from the first front side <NUM> of the base element <NUM> to the end <NUM> of the instrument tip <NUM> the inner surface <NUM> and the outer surface <NUM> are fully or completely parallel to each other. Preferably, the primary region <NUM> extends from the first front side <NUM> of the base element <NUM> to the end <NUM> of the housing <NUM> in a direction perpendicular to the first front side <NUM> or parallel to the insertion direction D. It is also conceivable that primary region <NUM> extends over the whole housing <NUM>. Realizing the inner surface <NUM> and the outer surface <NUM> of the housing <NUM> completely cylindrically and parallel to each other means that there no deformation incorporated into the housing <NUM> that usually are intended to simplify gripping of the housing <NUM> and therefore the torque wrench <NUM>. It is also conceivable that the housing <NUM> has at least one deformation in a secondary region <NUM> of the housing <NUM>, wherein the secondary region <NUM> extends from the first front side <NUM> to at least the second front side <NUM> of the base element.

In particular, it is provided that a first length L1 is assigned to the primary region <NUM> extending from the base element <NUM> at least to the end <NUM> of the instrument tip <NUM>, preferably exactly to the end <NUM> of the instrument tip <NUM>, and a second length L2 is assigned to a maximal distance of an opening defined by the inner surface <NUM>, wherein the second length L2 is larger than the first length L1, in particular the second length L2 is <NUM> to <NUM> times, preferably <NUM> to <NUM> times and more preferably <NUM> to <NUM> times bigger than the first length L1. These dimensions and in particular a first front side <NUM> corresponding to the opening, simplifies taking a look from above on the instrument tip <NUM>. Further, it is possible to provide information of the used instrument tip <NUM> on the first front side <NUM> of the base element <NUM> being comparable large. Preferably, the secondary region <NUM> has a third length L3 being smaller than the first length L1, preferably <NUM> to <NUM> times smaller.

In <FIG> a component suitable for being mounted on the torque element <NUM> of the <FIG> or to another torque wrench <NUM> is shown. In particular, the component is shown isolated from the torque wrench <NUM> (top) as well as mounted on the torque wrench <NUM> (bottom). The component mainly comprises a ring <NUM>, in particular a ring <NUM> made from plastic that is placed concentrically onto the first front side <NUM> of the base element <NUM>, in particular concentrically to the receiving region <NUM> and/or the base body <NUM> of the instrument tip <NUM> being equipped to the torque wrench <NUM>. For mounting the ring <NUM> at the first front side <NUM>, the ring <NUM> comprises protrusions <NUM> for realizing a force and/or form fitting fixing. In the embodiment presented in <FIG> the protrusions <NUM> corresponds to an arc shaped or circular curvature extending perpendicular to the plane of the ring <NUM> and the two protrusions <NUM> are arranged opposite to each other. In the mounted state each of the protrusions <NUM> is located between two bridging member <NUM> such that the protrusions <NUM> are jammed or clipped between the bridging members <NUM> that mainly extend parallel to the first front side <NUM>. The mounted ring <NUM> represents a reference marking <NUM> that can be used to identify the status of the instrument tip <NUM> being equipped to the torque wrench <NUM>. In particular, a thickness <NUM> of the ring <NUM> measured in a radial direction relative to the receiving region <NUM> represents the reference marking <NUM> for identifying the status of the instrument tip <NUM>.

The illustration at the bottom side of the <FIG> represents a top view on the torque wrench <NUM> being equipped with the ring <NUM> and the instrument tip <NUM>. The instrument tip <NUM> is orientated in a predefined way. For example the shape of the base body <NUM> of the instrument tip <NUM>, i. its non-circular cross section, and the corresponding recess at the second front side <NUM> of the base element <NUM> pre-defines the orientation of the end <NUM> of the instrument tip <NUM>. In a case of a squared cross section, there are for example four orientation of the instrument tip <NUM> extending from the first front side <NUM> possible.

Claim 1:
Torque wrench (<NUM>) for connecting a replaceable instrument tip (<NUM>) to a hand piece that carries the replaceable instrument tip (<NUM>) in operation, comprising
- a base element (<NUM>) having a receiving region (<NUM>) for placing the instrument tip inside the receiving region (<NUM>) at least during connecting the instrument tip (<NUM>) to the hand piece,
- a torque wrench mechanism for applying a certain torque when connecting the instrument tip (<NUM>) to the hand piece and
- a housing (<NUM>) surrounding the instrument tip (<NUM>) being arranged in the receiving region (<NUM>), the housing being preferably transparent,
-- wherein the torque wrench (<NUM>) has a guiding structure (<NUM>) for aligning the instrument tip (<NUM>) during inserting the instrument tip (<NUM>) into the receiving region (<NUM>), and
-- wherein the guiding structure (<NUM>) tapers along a direction being parallel to a longitudinal direction of the receiving region (<NUM>), wherein preferably the guiding structure (<NUM>) has a concave shape, for example a conical shape, characterized in that the torque wrench (<NUM>) has a reference marking (<NUM>) for determining a status of the instrument tip (<NUM>) connected to the receiving region (<NUM>).