HK1116651B - Device for locking a dental instrument on a handpiece consisting of a rotating spindle, locking spring and push-button assembly - Google Patents

Description

Attachment of dental appliances to a handpiece formed by a rotating shaft-attachment spring-button assembly

Technical Field

The present invention relates to a novel dental instrument attachment.

Disclosure of Invention

It is an object of the present invention to allow the attachment of the instrument to the drive mechanism of the dental handpiece head without the use of special tools, but by using a spring-type system which is simple to implement.

The object is achieved by a dental appliance connection device of the type comprising: a main body internally supporting motorized and/or motion-transmitting means; and a tool holder head, said device being characterized in that it comprises a rotating shaft, a connecting spring and a button:

said rotation shaft being formed by a hollow shaft arranged for engagement with the motion-transmitting means of said handpiece and longitudinally crossed by a through central bore arranged for receiving an instrument head,

the connecting spring comprises a lower ring positioned around the hollow shaft and extended on the same side by two elastic arms or by a plurality of elastic arms, each arm being provided with a protruding pin and each arm having: a rest position, according to which the boss pin is inserted in an annular groove arranged on the appliance head; and a spaced position in which said boss pin is spaced from said central axis to allow said boss pin to be disengaged,

the button is in the form of a cap comprising a conical central pressing head on the lower face, the outer slope of which enables the arms of the connecting spring to be radially spread apart to disengage the male pin from the annular groove of the appliance when the user presses on the button in the direction of the appliance.

Furthermore, the arm for the connection is received in a slot provided in the rotary shaft in order to lock the rotation of the spring relative to the rotary shaft, the spring additionally being held axially between the push button and a shoulder of the rotary shaft.

Drawings

The invention will be better understood by the following description with reference to the following drawings:

FIG. 1: longitudinal section through a handpiece for dental work, which handpiece is equipped with a spring-loaded connection according to the invention.

-figure 2: longitudinal section of the connection device according to the invention.

-figure 3: fig. 1 and 2 are side views of a rotating shaft of a spring-loaded coupling device according to the present invention.

-figure 4: cross-sectional view according to line a-a of fig. 3.

-figure 5: fig. 3 is an overall view of the rotating shaft.

Figures 6, 7 and 8: a side view, a sectional view according to line B-B and a bottom view of the spring of fig. 1-4, respectively.

-figure 9: a side view of a stem of an instrument arranged to cooperate with a connection device according to the invention.

Figures 10 and 11: the longitudinal section and the section according to C-C show the appliance inserted in the connecting device according to the invention, respectively.

Detailed Description

Fig. 1 shows a dental appliance comprising a body 1 which internally supports motorized and/or motion-transmitting means (of conventional type and not shown in detail here) and a toolholder head 2.

The head 2 has a connecting device 3 according to the invention, which is formed by a rotating shaft 4, a connecting spring 5 and a push button 6 (see in particular fig. 1 and 2), and is designed to cooperate with a tool, the shank 7 of which is of the type shown in fig. 9 to 11.

The rotary shaft 4 shown in fig. 1 to 8 is formed by a hollow shaft 8, which supports a gear wheel 9 perpendicularly to its central axis 10, which gear wheel 9 is provided for normally engaging with the motion-transmitting means of the hand piece.

The hollow shaft 8 is extended at the lower surface of the gear wheel 9 by a cylindrical sleeve 11, which is provided for normally cooperating with a rolling bearing (roulette) (fig. 10, 11) or a sliding bearing (palier) (fig. 1).

The hollow shaft 8 (see fig. 5 and 2) located above the gear wheel 9 has a cylindrical lower base portion 12, immediately following upwards: an intermediate portion 13 of smaller diameter than the lower base portion and separated from the lower base portion by a peripheral shoulder 14; then a cylindrical top portion 15, of smaller diameter than the intermediate portion 13, separated from the latter by a peripheral shoulder 16.

The hollow shaft 8 is longitudinally crossed by a through central bore 17, receiving the stem 7, which is generally provided with: an annular groove 18 for axial locking by means of a male pin; and a flat 19, which is parallel to the longitudinal axis of the shaft, for locking the hollow shaft against rotation by a corresponding flat.

The hollow shaft includes a slot 20 in the top and middle portions thereof. The slit 20 passes diametrically through the top portion 15 and the central bore 17 and is open to the outside on each side. The slit is extended downwards by two incisions which open out over the entire height of the central part 13, have the same width as the slit, and have at their base a concavely curved profile 36 visible in fig. 4.

The spring 5 shown in fig. 6 to 8 is formed by a lower ring 21, which supports on the same side two diametrically opposed elastic arms 22 or a plurality of arms regularly distributed on the periphery of said ring.

Each arm has, starting from the ring, a central section 24 or 25 inclined towards the central axis 10 and ending in an upper section 26 or 27 parallel to the axis 10, each upper section ending in an inner inclined wall 23, said inner inclined wall 23 being inclined upwards by an angle α (for example 45 ° as shown in fig. 7). Each upper section 26 or 27 supports, in the direction of the central axis 10, a transverse stud 28 or 29 which is provided for snap-fitting in the annular groove 18 of the implement shank (see the assembly of fig. 4 or 10 and 11) and which comprises a plane 37 which is inclined downwards at an angle (β) (e.g. 30 ° as in fig. 7).

The ring 21 is positioned and abuts around the lower base part 12 of the hollow shaft (fig. 2), the inclined sections 24, 25 are placed externally on the middle part 13 of said hollow shaft and do not come into contact with said middle part due to the concave profile 36 of the middle part, while the sections 26 and 27 will be located in the slot 20 of the top part 15 of the hollow shaft and the protruding pin 29 will be inclined into the groove 18 of the appliance (fig. 9, 10, 11).

The push-button 6 according to the embodiment variant of figures 1 and 2 is generally in the form of a cap with a circular flat surface 30 provided with an annular peripheral skirt 31 around the shaft, said skirt 31 being delimited peripherally by a vertical collar 32, which faces the axis 10, so as to be connected, for example, to the underside of a rolling bearing 35 of the head 2 and acts as an upper axial stop for the push-button.

The button comprises a conical central pressing head 33 on the lower face, the outer slope 34 of which can be inserted between the two segments 26, 27 of the spring by sliding on the two inner slope planes 23 when pressure is applied on the surface 30 in the direction of the appliance, and the outer slope 34 can separate the segments radially outwards, thus disengaging the pins 28, 29 from the grooves and releasing the appliance.

The connection to the appliance is made by introducing and moving the tool head in the central bore 17 towards the push button. The inclined plane 37 of the pins 28, 29 facilitates the sliding of the tool head and the separation of the pins and arms as said head passes, the elasticity of the arms then enabling these arms to return to the rest position and to snap into the grooves 20.

The variants of fig. 10 and 11 show: other embodiments are possible without departing from the scope of the invention.

Also, without going beyond the scope of the present invention, it is possible to provide three or four elastic arms on the spring 5, the hollow shaft thus comprising three or four slits distributed radially by 120 ° or 90 °, respectively, or two slits with a vertical diameter.

The coupling device according to the invention is simple to implement and does not require any special tools for placing in place or removing the appliance, and the spring element is mounted on the rotating shaft without any special fixing.

Claims (5)

1. A connection device for a dental appliance, the dental appliance comprising: a main body (1) internally supporting motorized and/or motion-transmitting organs; and a tool holder head (2), said connecting means comprising a rotary shaft (4), a connecting spring (5) and a push button (6):

-said rotation shaft (4) is formed by a hollow shaft (8) which supports, perpendicular to its central axis (10), a gear wheel (9) arranged for meshing with the motion transmission means of a handpiece and which is longitudinally crossed by a through central bore (17) arranged for receiving the head of an instrument,

-said connecting spring (5) comprises a lower ring (21) positioned around said hollow shaft and extended on the same side by a plurality of elastic arms, each provided with a protruding pin and each having: a rest position in which the pin is inserted in an annular groove (18) provided on the head of the appliance; and a spaced position in which said boss pin is spaced from said central axis to allow said boss pin to be disengaged,

-said button (6) is in the form of a cap comprising, on the lower surface, a conical central pressing head (33) whose outer slope enables the arms of said connection spring (5) to be radially spread apart to disengage said pins (28, 29) from the annular groove of the appliance when the user presses on said button in the direction of the appliance,

the method is characterized in that:

-the hollow shaft (8) is extended at the lower surface of the gear wheel (9) by a cylindrical sleeve (11) provided for cooperating with a rolling bearing or a sliding bearing,

-said hollow shaft has, above said gear wheel (9), a cylindrical lower base portion (12) followed upwards by: an intermediate portion (13) of smaller diameter than the lower base portion and separated from the lower base portion by an annular shoulder I (14); then a cylindrical top portion (15) having a smaller diameter than the intermediate portion (13) and separated from the latter by an annular shoulder II (16),

-the hollow shaft comprises, on its top and middle portions, at least two slits (20), said slits (20) passing diametrically through the top portion (15) and the central bore (17) and being open to the outside on each side, said slits being extended downwards by two cuts open to the outside and to the entire height of the middle portion (13), said cuts having the same width as the slits and having a profile (36) in the shape of a concave arc,

-each arm of the spring, starting from the lower ring, comprises a central section (24 or 25) inclined in the direction of the central axis (10) and terminating in an upper section (26 or 27) parallel to the central axis (10), each of which terminates in an inner inclined wall (23) inclined upwards by an angle (a).

2. The device of claim 1, wherein said arm for attachment is received in a slot provided in said rotating shaft.

3. Device according to claim 1 or 2, characterized in that the hollow shaft comprises three slots or four slots on its top and middle part in order to cooperate with a spring having three or four arms respectively, wherein the three or four slots are radially distributed by 120 ° or 90 ° respectively.

4. Device according to claim 1, characterized in that said protruding pin (28 or 29) is provided in the upper section (26 or 27), said pin being a transverse pin supported in the direction of said median axis (10), said pin being arranged to snap into an annular groove (18) of the stem of said appliance and comprising a plane (37) inclined downwards by an angle (β).

5. Device according to claim 1, characterized in that said push-button is in the form of a cap with a circular flat surface (30) equipped with an annular peripheral skirt (31) around said central axis, said skirt (31) being delimited peripherally by a vertical collar (32) and facing towards said central axis (10) so as to be connected to the head (2) underneath a rolling bearing (35) and acting as an upper axial stop for said push-button.