KR20060128897A - Elastic belt-shaped device for fixing a dental tool to a handpiece head - Google Patents

Abstract

The invention relates to a device for fixing a dental tool to a tool holder arrangement which rotatably fixes and actuates a dental tool or instrument around a drive shaft (6), is incorporated into a dental handpiece head (4) and is coupled to a movement transmission unit integrated into the arm of said handpiece. The inventive device is characterised in that it mainly consists of a deformable and elastic clamping-unclamping element which is embodied in the form of a belt (25), whose at least one part is provided with a section introducible into an annular throat or groove embodied in the top part of the tool and holding said tool by clamping forces and which is also provided with means for producing unclamping forces for cancelling clamping forces, thereby releasing the tool. In other variants, said elastic belt can be embodied in the form of a parallelogram or ring or split catch.

Description

ELASTIC BELT-SHAPED DEVICE FOR FIXING A DENTAL TOOL TO A HANDPIECE HEAD}

The present invention relates to an apparatus for attaching a tool to a dental hand piece.

Many devices for attaching a dental tool in a hand piece are known, specifically these devices are designed to hold and hold the tool in the head, and the tool is rotated and guided by separate means. Examples are devices such as those described in EP 0 174 695. In general, such a device utilizes radial movement of a shoe-shaped mechanical element operating in cooperation with a groove shape formed in the handle of the tool, the shoe-shaped mechanical element being installed in the handle, the shoe-shaped part Is fixed or returned by the spring system.

These embodiments are bulky and large in head size, due to the fact that they use many components.

However, due to the development of microscopic dental field, small tools are needed.

It is an object of the present invention to provide a tool attachment device which is capable of producing handpiece heads that are detachable and can be used in straight and reverse bends, and which are small in size and inexpensive.

This object is an attachment device for attaching a dental tool to a tool receiving assembly for attaching and rotating a dental tool about a drive shaft, the tool receiving assembly being incorporated into the head of the dental hand piece and the tool receiving assembly Connected to a motion transfer assembly incorporated into the handle of the hand piece, wherein the attachment device consists of a resilient and deformable tightening and loosening means in the form of a belt, wherein at least a portion of the belt is provided on top of the tool and holds the tool with a clamping force A section is provided which is coupled to a recessed groove or annular slot, wherein the clamping and unwinding means are achieved by the present invention consisting of an attachment device, characterized in that it comprises a unwinding force applying means that counteracts the clamping force to loosen the tool.

Preferably, the clamping force is due to the elasticity of the material or the elasticity of the hand piece, and is preferably forced in a direction perpendicular to the axis of the tool at points facing in the radial direction.

According to one embodiment, the belt made of deformable elastic material presents a form of parallelogram with a central area provided to securely hold the head of the tool in the slot, wherein the large diagonal of the parallelogram has two ends at two ends. It is provided as a protrusion to ensure that it extends obliquely beyond the cover of the head, and the two protrusions consist of a means of directly applying force by hand to release the belt.

Furthermore, the belt includes a separator provided at the base of the protrusion and seating on the periphery of the housing provided in the head to receive the attachment device.

According to a further embodiment, the elastic belt is in the form of a parallelogram and has a central area provided to hold the tool firmly and comprises two ears located on the same surface and forming protrusions perpendicular to the plane of the belt, The two ears constitute a means for applying a clamping force through the middle portion of the barrel pinion located at the head of the hand piece.

According to this embodiment, the attachment device further comprises a push button presenting a plurality of element parts, wherein the plurality of element parts

An elastic ring at the bottom to hold the push button to the head,

An intermediate elastic region acting as a return spring for the push button,

An internal cylindrical insert that causes the elastic belt to deform when the push button is pressed to separate the tool.

Further, the insert has an inner conical shape to interact with the conical flange of the ear of the belt.

According to one of these and / or other embodiments, the parallelogram shaped belt also has a conical portion formed underneath the central area.

According to another embodiment, the deformable elastic belt shows the form of an elastic split ring.

More specifically, this split ring comprises an upper cylindrical flange extended by a conical intermediate portion and a transverse locking jaw formed by a segment facing towards the drive shaft.

In this embodiment, the push button has a fitting ring at the bottom to interact with the slot of the barrel pinion that rotates the tool.

Further, the attachment device of the present invention can be applied to any type of hand piece, whether straight or inverted bend hand piece, in the form of a hand piece having a unitary body provided by the non-limiting embodiment of the detailed description below. It is not limited.

The invention will be more readily understood by the following description with reference to the accompanying drawings.

1 is a schematic perspective view of a hand piece of the present invention.

Figure 2 is a longitudinal cross section of the hand piece of Figure 1;

Figure 3 is a longitudinal cross sectional partial view of a non-limiting embodiment of the present invention.

Fig. 4 is a perspective view showing a partial cross section of another non-limiting embodiment that includes tightening and loosening means in the form of a hand loosen rhombic elastic belt;

5 is an axial cross-sectional view of FIG. 4;

FIG. 6 is a partial transverse cross-sectional view of the head of FIG. 4 shown at the height of the elastic belt. FIG.

Fig. 7 is a perspective view showing a partial cross section of the hide of Fig. 4;

8 is an axial cross-sectional view of another non-limiting embodiment that includes tightening and loosening means in the form of an elastic belt that can be released by operation of a push button.

Fig. 9 is a perspective view showing a partial cross section of the embodiment of Fig. 8;

Fig. 10 is a perspective view showing the elastic belt of Figs. 8 and 9;

11 is an axial cross-sectional view of another non-limiting embodiment including tightening and loosening means in the form of a split ring.

12 and 13 are perspective views of the push button of FIG.

Figures 14 and 15 are perspective views of the tightening and releasing means of the split annular clip of Figure 11;

Figure 16 is a perspective view of the push button of Figure 3;

hand Piece of  Concept for the body

Reference is first made to the non-limiting embodiments of FIGS. 1-3.

As shown in the drawings in a non-limiting embodiment, the hand piece 1 according to the invention consists of a unitary body 2, as long as it serves as a handle 3 having a linear axis. And a portion consisting of a head 4 to attach and drive the tool 5, the drive shaft 6 being aligned in line with the axis 7 of the handle or between 90 and 180 degrees, preferably Preferably it may be formed at a predetermined angle between 100 degrees and 130 degrees.

The body is formed of a cover 8, i.e. an outer case, which may or may not be a single piece, which may be electrically insulated, for example thermosetting material (preferably polyetherether ketone, hereafter referred to as PEEK). Head from a connection 9 provided at the end of the handle, which can be made of a polymer and a thermoplastic resin, and which combines the handle and the mechanical component parts of the head with electrical connection means to interact with an external motor (not shown). It is possible to transfer electrical energy and movement up to the tool 5 fixed in (4).

The reversely curved hand piece 1 according to the invention shown in FIGS. 1 to 3 shows two axes 6, 7, which are inherently possessed by each bearing to ensure the most stable output. It is possible to limit the possibility of friction, which is why in this case the ball bearings are integrated in the cover. This type of reverse bending hand piece device is particularly helpful for root canal treatment (endodonty) with an apex locator.

Thus, the hand piece of the present invention, which is connected to the motor, can, for example, cause a rotational movement in the tool 5 (eg root canal tool), and can even be used for detection of the tip by this means. It can also carry current. The electrical connection between the motor and the hand piece can be made by any connection means, for example, between the attachment ring for the motor and the attachment groove 10 of the socket 11. (Or by means of a foldable button, for example.) The doctor holds the insulation cover 8 by hand and the tip at the end of the head 4 is located in the patient's mouth. In this configuration, a series of mechanical motorized and electrical element components are configured in the handle as follows: current flows from the socket 11 into a fixed outer race of the first bearing 12 and from the first spring ( 13), then to the fixed outer race of the second bearing 14, then to the ring 15 axially held at the first locking jaw in the cover 8, and then to the cover 8. It flows into the spring 16 which is axially maintained in the 2nd locking jaw.

The first bearing 12 and the second bearing 14 support the transmission shaft along the longitudinal axis 7 of the handle, ie the first axis of the hand piece 1, the springs 13, 16 being compression springs and compression The coil of the spring is arranged outside the transmission shaft 7.

In this step, current flows across the handle portion or hand piece 1 bent in the reverse direction.

Alternatively, one can consider the conductive wires leading from the tip of the motor end to the part in contact with the tool 5.

The head 4 of the hand piece bent in the reverse direction with the second axis, ie the drive shaft 6, supports two ball bearings (possibly obliquely in contact). That is, these two ball bearings are the upper bearing 17 and the lower bearing 18, the outer race of the upper bearing interacts with the second spring 16 of the handle, and the action in the axis of the lower bearing is the elastic washer With the help of (19).

In this type of bearing assembly, the ball of the bearing is always in contact with the outer race and the inner race of the bearing, thus ensuring electrical connection between the fixed part and the moving part.

The barrel pinion 20 mounted to the drive shaft 6 includes a tooth 21 which engages with the teeth 22 of the output pinion 23 of the handle.

The barrel pinion 20 is conductive and integral with the inner race of the bearing, ensuring that electricity is conducted to the tool 5 and mechanically driven. The current delivered to the end of the tool will delimit the tip under the influence of the resistance change taking into account the external insulation of the push button 55 and the cover 8 provided on the head 4. This will be explained in more detail below.

Design of means for clamping and releasing attachments and tools in the head

The matter described here is a preferred embodiment of the means for attaching the tool to the head 4 and the means for tightening and releasing the tool, but not limited thereto.

During endodontic treatment, for example, easy access to the molar can ensure both comfort and quality service for both doctors and patients. This is because the object is to propose a tool receiving assembly 24 composed of mechanically driven component parts of the head that should be as small and compact as possible.

Applicant achieved the object by recognizing the following facts.

The compact and bulky new tightening and unwinding means 25 is part of the attachment assembly and consists of a deformable elastic belt 25 (may or may not be made of plastic material (e.g. PEEK)), The loosening function can be ensured, the loosening function is achieved by hand operation from the belt towards the center and the tightening function is performed by loosening this operation.

The inner housing 26 of the head houses the tool receiving assembly 24 and the means for tightening and loosening 25, which housing 27 can be closed by a stopper, ie by the cap 28 or by a push button. Open at the head through.

This solution can be more readily understood by reading the description of the two embodiments provided below.

First, the first embodiment is described with reference to FIGS. 4 to 7, wherein the loosening is controlled by applying the belt directly by hand.

The housing 26 of the tool receiving assembly 24 shows on the one hand the lower cylinder 29 which is coaxial with the drive shaft 6 and whose diameter is adapted to receive the barrel 30 of the barrel pinion 20. And on the other hand similarly shows an upper cylindrical part 31 coaxial with the drive shaft 6, having a larger diameter and adapted to receive the teeth 21 of the pinion barrel, and the tool as well as the clamping and unwinding device. Means for connecting are described below.

The discharge opening 27 in the upper part of the housing 31 is closed by a plug, ie a cap 28. The cap is preferably made of the same material as the lid 8 but is not necessary.

The upper part of the housing 31 similarly has a side opening which flows into the inner housing 33 of the handle 3 so that the teeth of the barrel pinion 20 can engage with the teeth of the output pinion 23 of the handle 3. And (32).

The barrel pinion rotates freely in the head, and it is ensured that the axis standard is between the base 34 of the housing top forming the jaw and the front face 35 of the stopper. The axial degree of freedom of the barrel pinion is therefore hundreds of millimeters.

The rotational motion of the output pinion 23 is transmitted to the barrel pinion 20 and then to the tool 5 by way of a plane 36 provided on the tool which interacts with the plane provided on the inner diameter 38 of the barrel pinion. do.

As claimed in the embodiments of FIGS. 4-7, the clamping and unwinding means is a lozenge provided with a central area 39 to secure the head 40 of the tool at the height of the annular closing slot 41 provided at the top of the tool. It necessarily includes a belt 25 made of deformable elastic material exhibiting form.

In order to allow the two ends to extend radially beyond the lid of the head 4, a large lozenge of a lozenge is provided, the two projections 42 are each located in the notches 43 of the head, and each notch 43 is On the one hand it reaches the upper part 31 of the housing and on the other hand it reaches the opening 27 which receives the plug.

At the same time, the tool is released by acting directly on the two projections 42 directly towards the center, and when released, the tool is tightened.

The flange 44 of the notch 43 can impede the rotation of the belt and the belt is headed by a separator 45 provided near the protrusion 42 and supported by the edge 46 of the upper portion of the housing 26. Is located in the center of the.

The axial standard of the belt is on the one hand by the jaw 47 provided on the base 48 of the axial cavity 49 of the stopper which receives the head 40 of the tool, and on the other hand of the notch. Guaranteed by the base 50.

In this way, the belt does not contact the rotating part of the barrel pinion.

In the free state, the belt interacts with the upper locking jaw 51 of the annular slot of the tool head such that the tool is restricted in the first axial direction, the restriction in the second axial direction being the transverse end 53 of the plane of the tool. Is ensured by the plane 52 of the barrel pinion interacting with the.

Loosening the tool is performed by applying two radially opposed pressures to the protrusion 42 facing toward the rotation axis. These two pressures form orthogonal components to unwind the tool. By applying pressure directly and simultaneously to both ears of the belt (eg with thumb and index finger) it can be tightened at the mouth, for example compared to a push button. Since the conical portion 64 is provided below the central region 39 of the belt, it is possible to attach the tool without applying pressure to both ears of the belt, and with the tool moved axially, the belt is radially elastically moved. It is moved and the belt is returned to its original form to ensure the clamping function.

Hereinafter, a second embodiment of the tightening and loosening means will be described with reference to Figs.

The elastic belt 25, which is in the shape of a rhombus and has a central area 39 for fixing the tool, is also provided in that the ear portions 54 form projections perpendicular to the plane of the belt and are located on the same plane. It differs from the conventional belt in that the position is maintained axially and radially by the barrel pinion as shown in Figs.

For this effect:

The two ends of the belt traverse two edge gaps 61 provided on the upper flange 62 of the barrel pinion, which gaps are radially opposite and are arranged in the plane crossing the drive shaft 6.

The two ears 54 are prevented from turning by the two notches 63 in the flange.

Furthermore, the head of the present invention is distinguished from the previous head in that the plug is replaced (for ease of manufacture), for example by a push button 55 with a metal insert.

As claimed in this embodiment, a push button, for example made of polyetheretherketone (PEEK), presents a plurality of elemental parts as follows.

An elastic ring 56 formed at the bottom that limits the axial freedom of the barrel pinion and holds the push button in the head 4

An intermediate elastic region 57 which acts as a return spring for the push button

When the push button is pressed, the tool is released by adjusting the deformation of the elastic belt. For this purpose, the push button is pressed to compress the spring 57 and the inner conical part 59 of the insert 58 is the complementary conical flange of the belt ear. Inner cylindrical insert 58, which will interact with 60

The radial element in the ear 54 of the belt causes another radial deformation perpendicular to the main element. This deformation causes the tool to loosen.

Pressing the push button allows the tool to fit into the head, and the tool can be fitted by the conical device 64 at the bottom of the central region 39 of the belt without pressing the push button.

The structure of this belt makes it possible to assure that it is tightened by the centrifugal force effect during rotation.

Concept of push button

Compact design is an area of continuing research in the field of medical devices, such as the head of an inclined hand piece. New materials, such as thermoplastic or thermoset materials, meet this challenge. By considering the mechanical, physical and chemical properties of such materials and at the same time, the mechanisms disclosed previously can be reconsidered by reducing the number of parts of the component, improving quality and reducing assembly costs; These plastic parts can be machined or injection molded. Not only can of course be designed compact, but by using such a plastic material it is lighter, can be slid against dynamic devices, is more resistant to sterilization or disinfection, and its elasticity is improved. This is why plastic materials are used to produce dental hand pieces. The push and release of the push button on the head of the hand piece is a common practice in which the clamping and loosening functions are performed. By this principle, the push button can be integral with, for example, a dynamic assembly for endodonty (rotation, vibration, etc.) and can be integral with a fixed push button which is not affected by the dynamic assembly.

The head of the hand piece in which a bur (dental machine for shaving or puncturing) is located has already been presented as an example in connection with FIGS. 2 and 3.

It should be noted once again that the body of the head 4 fits well with the rotating barrel pinion 20 which is rotated by the output pinion 23 of the handle, whether or not unitary with the handle 30. do. The barrel pinion is freely rotated and connected at the shaft, which is ensured, for example, by ball bearings.

Of course, as shown in Figs. 5 and 7, a solution for inserting a plain bearing or casting a plain bearing to the body of the head without using a ball bearing may be devised.

The rotational motion of the bur can be transmitted by combining the plane 36 provided on the barrel pinion 4 with the plane 37 of the tool. The on-axis criterion of the tool is ensured by the locking jaws of the barrel pinion and by the locking jaws in the complementary plane of the tool.

Using this common description as a starting point, the two types of push buttons of the present invention can be distinguished.

Push button integrated with dynamic assembly

The push button is designated 55 in FIGS. 3 and 16 and is known as the tool receptacle, the gist of which is the permanent contact between the rotary lock assembly and the push button. In the stationary state, the push button 55 (e.g. made of polyetheretherketone (PEEK)) is centered relative to the axis 6 while setting limits on the axis relative to the elastic split ring 65 Let's do it. The ring 65 is cylindrical in shape externally and its inner wall comprises an upper flange with a conical inclined portion 71 and an intermediate portion in the form of a transverse locking jaw 66 facing towards the shaft 6. The engaging jaw 66 of the resilient ring 65 holds the tool 5 in the axial direction by engaging in the annular slot 41. The push button 55 is guided radially at the inner diameter 38 of the barrel pinion by one or more sectors 87 arranged below, with each sector terminating at the conical end to press the elastic ring 65 respectively. . The axial movement of the push button 55 is limited between the upper and lower ends of one or more gaps 68 formed in the upper body of the barrel pinion and interacts with one or more rings 67 provided on the bottom of the push button. The elastic ring 65 forces the push button 55 in the axial direction to return to the original position. Since it is radially elastic, by the slot 69 provided between the ring and the sector 87, the ring 67 allows the push button to be clipped and engaged in the barrel. When the push button 55 is pressed, the tool 5 is released by the conical component 70 engaged in the complementary conical inclined surface 71 of the resilient ring to release the locking jaw 66. The fitting of the tool into the barrel pinion is automatic without the need to press the push button by means of the conical part 73 provided at the bottom of the elastic ring at the end of the locking jaw 66. In Fig. 3, the tightening and loosening means is a split elastic ring, which ring is opened along the radial plane seen in the cross section of Fig. 3, and the loosening force applying means is constituted by a conical inclined portion 71.

Push button independent of dynamic assembly

While holding the tool by hand, it is a technical necessity to separate the push button and the fastening means.

This embodiment is represented by the example in Figs.

In the non-operational state, with or without moving pushbuttons, the conical resilient clip 72 holds the tool 5 on the axis with an arm 73 (e.g. six arms), Each arm is terminated by a locking jaw 79 facing the axis 6. The clip 72 is integral with the rotating barrel pinion by engaging the peripheral protrusion 74 of the clip with a corresponding opening 76 formed in the barrel pinion. A fully traversing slot 77 in the clip allows the clip to be engaged and detached at the inner diameter of the barrel pinion, so that the required elasticity is transmitted radially.

The push button 55 is held in shaft and centered by an elastic blade 75 which fits into the cap at the opening 27 of the head; This blade provides axial elastic freedom (along axis 6) of the push button when assembled under tension in the head body. 12 and 13 show the blade 75 constrained in position and shows the fitting groove 80 at the end of the blade for fitting the push button 55 into the opening 27. Pressing the push button by hand in the axial direction switches the pressing force, causing the conical base 78 of the push button to move in the axial direction and interacting with the complementary cone portion 82 of the inner conical cavity of the clip arm. Become; The tool is released by the aforementioned separation of the arm and separation of the locking jaw 79. When the pressurization by hand is released, the push button returns to the initial position because each cone of the two element parts 55, 72 is no longer in contact. According to the solution of Figs. 11 to 15, the clamping and loosening means is an elastic conical clip 72, and the locking jaw 79 of the clip is coupled to the groove or annular slot of the tool, and the loosening force applying means is the clip 72. ) Consists of a conical portion 82 which is conical, with the slot 77 deforming the clip radially.

Idea for lubrication

Referring to Fig. 8, which is a cross-sectional view of Fig. 9 in an axial direction, the head includes a cavity 83 that surrounds the barrel of the barrel pinion or is provided on the side of the barrel and contains solid grease. Solid oil is discharged every time through the hole 84 from the separating wall 85 between the barrel and the cavity to lubricate the barrel.

Concept for Assembly

The cover 8 is made of a plastic material such as electrically insulated polyetheretherketone (PEEK) or a small piece of material (e.g. metal injection molding, MIM for short) containing a metal content with electrical conductivity. ) Can be produced as a single piece. This cover includes the following configurations:

In other words, the lid comprises a first housing 26 in the head and a second housing 33 in the handle, wherein the first housing 26 for attaching the tool receiver and the tool along the drive shaft 6 has two openings. Open through to one side of the head, the opening 27 of at least one of the two openings being dimensioned to fit all of the component parts of the head as well as the assembly thereof; The second housing has a straight shaft 7, which is open at the distal end of the handle on the one hand through the opening 81 and at the base end of the head in the first housing 26 via the side opening 32 on the other hand. Open to allow interaction between the mechanical elements of the head and the components of the handle. Further along the rectangular axis called handle axis 7 the opening 81 is sized so that not only all components of the handle therein but also the assembly can be fitted. In order to produce the reversely curved hand piece, a cover is provided, the shafts 6 and 9 of which are inclined, for example, from 90 degrees to 180 degrees, preferably from 100 degrees to 130 degrees. Further, in order to manufacture a straight hand piece, the axes 6 and 7 must be parallel and moved from each other so that the openings in the head 27 can be used to assemble the parts of the internal components and to plug the push buttons. You may need to be able to.

This concept is particularly advantageous because it offers the following possibilities:

-Reduce the number of bearings or remove them

-Can reduce the cost of the handpiece

-Reduced hand piece dimensions

-Point to facilitate cleaning (smooth contour)

-Improved hygiene (single product, no boundary)

Claims (16)

An attachment device for attaching a dental tool to a tool receiving assembly for attaching and rotating the dental tool relative to the drive shaft 6, the tool receiving assembly 24 being integrated into the head 4 of the dental hand piece and Also in the attachment device which is connected to the electric assembly installed on the handle 3 of the hand piece 1, The attachment device comprises elastic and deformable tightening and loosening means in the form of belts 25, 56, 65, wherein at least a portion of the belt is coupled to a groove or annular slot provided in the top of the tool for holding the tool by the clamping force. Wherein said clamping and releasing means comprises means for applying a squeezing force to offset the clamping force to loosen the tool. The method of claim 1, Attachment device, characterized in that detachable with respect to the tool receiving portion (24). The method according to claim 1 or 2, The belt 25 made of deformable elastic material exhibits the form of a parallelogram with a central area 39 provided to securely hold the head 40 of the tool in the slot, the large diagonal of the parallelogram having two ends. Is provided to ensure that the two projections 42 extend obliquely beyond the cover of the head 4, the two projections constituting means for directly applying a force by hand to release the belt. . The method of claim 3, The belt (25) is characterized in that it comprises a separating portion (45) provided at the base of the projection (42) and seated on the edge (46) of the housing (26) of the head. The method of claim 3, The resilient belt 25 having a central area 39 provided for firmly holding the tool in the form of a parallelogram comprises two ears 54 which are located on the same plane and form projections perpendicular to the plane of the belt, wherein And the two ear portions constitute a means for applying a clamping force through an intermediate portion of the barrel pinion located at the head of the hand piece. The method of claim 4, wherein Attachment device, characterized in that the ear portion comprises a conical flange (60). The method according to any one of claims 3 to 6, And the belt has a conical portion (64) formed at the bottom of the central region (39). The method according to claim 5 or 6, The attachment device further includes a push button formed of a plurality of components, The plurality of components are: An elastic ring 56 at the lower end which holds the push button on the head 4, An intermediate elastic region 57 which serves as a return spring for the push button, An inner cylindrical insert 58 which deforms the tool by deforming the elastic belt when the push button is pressed. The method according to any one of claims 6 to 8, The insert (58) is characterized in that it has an inner conical shape (59) to interact with the conical flange (60) of the ear of the belt. The method according to claim 1 or 2, The resilient belt formed of the deformable material has a split ring comprising annular engaging jaws 66 and 79 adapted to engage the annular slot 28 in the tool and a conical portion 71 for interacting with the conical portion of the push button. (65) or the attachment device characterized by the form of a split annular clip (72). The method of claim 10, And the split ring comprises a conical part (73) provided on the bottom surface of the split ring for fitting the tool. The method of claim 11, And a push button (55) axially guided by one or more sectors (87) arranged on the bottom surface and respectively terminated by conical ends (70). The method of claim 11, And an push button (55) comprising an elastic blade (75) cut in the cap and terminated by the fitting slot (80) and the conical base (78). The method according to claim 1 or 2, And a push button for applying a releasing force to the tightening and releasing means. The method of claim 14, And the push button is integrally formed with the tool receiving portion. The method according to claim 14 or 15, And the push button is held by the clip in the opening of the head.

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