FR2651672A1 - TIGHTENING DEVICE COMPRISING AT LEAST ONE REMOTELY CONTROLLED CLAMP FOR DENTISTRY INSTRUMENT. - Google Patents

Abstract

Clamping device with at least one clamp which can be remotely controlled by the practitioner by means of a ring or the like for holding a dentistry instrument in a handpiece provided with means for driving said dentistry instrument in rotation , characterized in that it comprises at least one clamp (7) ensuring clamping at at least one of its ends associated with at least one second clamp arranged in series with respect to said first clamp, said second clamp ensuring clamping at one at least from its ends.

Description

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  The present invention relates to a clamping device with at least one clamp which can be remotely controlled by the practitioner by means of a ring or the like for holding a dentistry instrument in a handpiece provided with means of driving in rotation of said dentistry instrument. Dentistry instruments and more particularly rotary instruments are, for their maintenance in handpieces, provided with a shank whose dimensions are for example defined by standard ISO 1797. According to this standard, shanks of diameter 2.35 millimeters, for example, can exist with lengths of 9 or 11 or

12 or 30 millimeters.

  In the use of handpieces and particularly of straight handpieces, practitioners are led to choose both short-tail and long-tail cutters. It is therefore necessary that the clamping device is capable of ensuring a correct clamping of the tails of strawberries whether they are short or long, which implies a device which is capable of ensuring a good clamping at the front end of the handpiece. , but also at the most distant point of the strawberry tail

inside the handpiece.

  Clamping devices are of course already known.

  So for example in US Patents 3,619,904 and

  US 3,496,638, a device is proposed having this function.

  However in these two embodiments the use of a double clamp ensuring a tightening at each of its ends only solves

partially the problem.

  Indeed, if the double clamp has a length suitable for short tails, the long tails will only be clamped forward and in the middle. Conversely, if the double clamp has a length suitable for long tails, the short tails will only be properly tightened forward. Likewise, patent FR 2 336 593 in the name of the applicant proposes a device also having a clamping function. The structure of the part referenced (12) against which the tail of the tool abuts shows that this part can only accept small variations in length

tails of dental tools.

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  The object of the invention is to provide a clamping device which makes it possible to receive both short tails and long tails, with each time an optimal clamping action, and this at least in two places. In accordance with the invention, this result is obtained with a clamping device with at least one clamp which can be controlled remotely by the practitioner by means of a ring or the like for holding a dentistry instrument in a handpiece. provided with means for driving said dentistry instrument in rotation, characterized in that it comprises at least one clamp ensuring clamping at at least one of its ends associated with at least one second clamp arranged in series with respect to said first clamp , said second

  clamp ensuring tightening at at least one of its ends.

  In a particularly advantageous manner, the tightening and loosening of each of the clamps takes place simultaneously under the action of a sleeve mounted idly between the two clamps, said sleeve transmitting

  the clamping or loosening effort from one clamp to another.

  According to a particular embodiment, at least one

  clamps are of the type ensuring a clamping at its two ends.

  According to an alternative embodiment of the preceding device, provision may be made for the clamping force transmission sleeve to have, on the side of the double clamp, a female conical shape combined with a male conical shape for said clamp. so that the relative movements of the two conical shapes by translation allowing adequate clamping by the clamp at its end

  located on the side of said transmission sleeve.

  As a variant, it will be provided that the clamps are all of the double-clamping type and that they all have at their ends a male conical shape cooperating with the transmission sleeve (s) provided with corresponding female conical shapes, the ends most at exterior of all the clamps of the clamping device cooperating for their part with female ramps formed on movable spindles

  in relative translation with respect to each other.

  According to an implementation variant, the conical shapes

  above mentioned sleeves and pliers will be ogival in shape.

  According to another variant of implementation, the sleeve

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  transmission can be integrated into one of the clamps.

  To this end, at least one of the clamps clamps only at one of its ends, the transmission sleeve between said clamp and the adjacent clamp being replaced by a female conical or ogival shape formed in said clamp. single clamping, said female conical or ogival shape cooperating directly with a conical shape or

  ogival male of the adjacent clamp.

  The clamping and loosening control of the clamp device will be ensured by a cam acting on the spindle (s) inside

  which are arranged the clamps, which will be explained later.

  We will indeed better understand the invention using the

  description given below of an implementation mode given as

  non-limiting example with reference to the accompanying drawing which is a longitudinal sectional view of a clamping device according to the invention, in

  clamping position, integrated into a right handpiece.

  There is shown a right handpiece generally referenced (1) essentially composed of a body (2) disposed on a rear bushing (3) itself connected in itself known manner to means for supplying them. different fluids such as, but not limited to, water, air, etc. as well as drive means

  rotation of a dentistry tool (4) disposed in said head.

  The tool can generally be a cutter or a grinder, etc. which is rotated by the handpiece and the members which it comprises. The invention relates to holding the shank of the tool (4) in the handpiece, that is to say its tightening, respectively loosening. According to the invention, the tightening (loosening) device will essentially comprise: - an external spindle (5); - an inner spindle (6) - at least two clamps (7,8) arranged in series; - an external control assembly (9) which can be actuated by the practitioner. We will first describe the operating principle of the

  tightening / loosening of the tail by the two pliers (7,8).

  The clamps (7,8) as shown have a section substantially of trapezoids. In fact, they each have two male ramps (9,10; 11, 12) which each cooperate with a female counter ramp

  arranged on different parts.

  Thus the male ramp (9) of the first clamp (7) cooperates with a female counter ramp (13) formed inside the spindle (5) at

level of its distal end.

  Likewise, the male ramp (12) of the second clamp (8) cooperates with a female counter ramp (14) formed on the inner face of the

time zone (6).

  The ramps (14) of the spindle (6) and (13) of the spindle (5) enclose the entire tightening-loosening device and control the

  relative displacement of the clamps (7,8).

  In order to transmit the clamping force, respectively to release it, the male ramps (10,11) are biased by the female ramps (15,16) of a transmission sleeve (17) mounted idly between the two clamps

(7.8).

  The sleeve (17) is limited in its transverse movement by a cylindrical section (18) of the spindle (5) and a cylindrical section

(19) of the time zone (6).

  Thus, during the relative displacement of the spindles (5,6) the sleeve cannot move outward relative to the tail of

  the tool. It therefore applies the ramps (10,11) against the tail of the tool.

  The spindles (5,6) are slidably mounted one relative to

the other.

  The spindle (6) is fixed in translation, while the spindle (5), integral with a screwed cap (20) can move relative to the spindle (6) against a pressure spring (21) bearing on the one hand on a shoulder (22) of the spindle (6) and on the other hand on the face

inside (23) of the cap (20).

  It will be understood that when the spring (21) is in the relaxed position, the ramp (13) pushes on the clamp (7), all of the elements (7,17, 8) being placed in compression and therefore applied against the

  shank of the tool which is thus held by clamping.

  The reverse movement, that is to say the compression of the spring (21) releases the different male and female ramps from their contacts

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  respective and allows you to remove or insert the shank of the tool.

  It will be understood that the different clamp structures described above can operate on this same principle without it being necessary to explain them in more detail, all operating on a known principle of ramp / counter-ramp. Their number is not limited,

  even if optimally two pliers generally seem sufficient.

  We will now focus on describing the control system (9).

  This essentially consists of an outer ring (24) coaxial with the body (2) and movable in rotation around the latter. The ring (24) is connected by a pin, respectively a screw (25) to a cam (26) of the bell-cam type. The raceway (27) of the cam moves against a fixed pin, preferably a roller (28), the positioning of the axis (29) of which can be moved by screwing / unscrewing an accessible adjustment screw (30) from the outside (longitudinally or at an angle) in order to adjust the position of the axis and therefore of the roller. The position of the roller makes it possible to adjust the possible stroke of attack of the cam therefore

  also that of the outer time zone, as will be explained below.

  On the cam body is driven in its central part a ball bearing (31) which is made integral by its ring

exterior (32).

  We understand that the rotation of the ring causes the

  longitudinal displacement of the bearing (31) therefore of the balls (33).

  These then come into abutment against the outer face of the cap (20) and therefore push the assembly (5,20) forward to

  against the spring (21), as explained above.

  The displacement of the cam (26) also takes place against a stack of Belleville washers (34) which ensure the locking

if the ring (24) is released.

  This structure also makes it possible to avoid the various possible deteriorations by friction during the operation of the device or the rotation of the tool: - thus the fixed point constituted by the roller (28) avoids a deterioration of said fixed point because rotation of the roller on its axis; - the contact between the cam and the spindle on which it acts is ensured by the ball bearing, which avoids the deterioration of the surfaces potentially due to the command of the tightening, respectively of the loosening

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  when the spindle (5) is rotating.

  In the same vein, the cam (26) and / or the spindle (5) on which it acts will preferably be provided with a piece of hard material making the raceway for the ball (33), namely respectively a path (35) on the spindle and (36) on the cam. Of

  preferably they will be made of tungsten carbide.

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Claims (19)

  1. Clamping device with at least one clamp which can be controlled remotely by the practitioner by means of a ring or the like for holding a dentistry instrument in a handpiece provided with means for driving said instrument in rotation dentistry, characterized in that it comprises at least one clamp (7) ensuring tightening at at least one of its ends associated with at least a second clamp arranged in series with respect to said first clamp,   said second clamp ensuring clamping at at least one of its ends.   2. Device according to claim 1, characterized in that the tightening and loosening of each of the clamps takes place simultaneously under the action of a sleeve (17) mounted idly between the two clamps, said sleeve   transmitting the tightening or loosening force from one clamp to another.   3. Device according to one of claims 1 and 2, characterized   in that at least one of the pliers is of the type ensuring a clamping at its two ends.   4. Device according to one of claims 1 to 3, characterized   in that the clamping force transmission sleeve has on the side of the double clamp a female conical shape (15) combined with a male conical shape of said clamp so that the relative movements of the two forms conical in translation allowing adequate clamping by the clamp at its end   located on the side of said transmission sleeve.   5. Device according to one of claims 1 to 3, characterized   in that the clamps are all of the double-clamping type and that they all have at their ends a male conical shape cooperating with the transmission sleeve (s) provided with corresponding female conical shapes, the outermost ends of the '' set of clamps of the clamping device cooperating for their part with female ramps formed on spindles (5,6) movable in relative translation relative to each other.   6. Device according to any one of claims 1 to 5,   characterized in that the conical shapes of the sleeves and pliers are ogival in shape. - 8 - 2651672   7. Device according to any one of claims 1 to 6,   characterized in that the transmission sleeve is integrated into one of the clamps. 8. Device according to claim 7, characterized in that at least one of the clamps clamps only at one of its ends, the transmission sleeve between said clamp and the adjacent clamp being replaced by a conical shape or female warhead formed in said single collet, said female conical or warped shape cooperating directly with a conical or warped shape male of the adjacent clamp.   9. Device according to any one of claims 1 to 8,   characterized in that the clamping and loosening control of the clamp device is ensured by a cam (26) acting on the one or more   spindles inside which the pliers are arranged.   10. Device according to any one of claims 1 to 9,   characterized in that it essentially comprises: - an external time zone (5); - an inner time zone (6): - at least two clamps (7,8) arranged in series; - an external control assembly (9) which can be actuated by the practitioner. 11. Device according to claim 10, characterized in that the clamps (7,8) have a section substantially of trapezoids, that they each comprise two male ramps (9,10; 11,12) which each cooperate with a counter ramp female formed on different parts, the male ramp (9) of the first clamp (7) cooperating with a female counter ramp (13) formed inside the spindle (5) at its distal end, the male ramp ( 12) of the second clamp (8) cooperating with a female counter ramp (14) formed on the inner face of the spindle (6), which the ramps (14) of the spindle (6) and (13) of the spindle (5) enclose the entire clamping-loosening device and control the relative movement of the clamps (7,8) and that, in order to transmit the clamping force, respectively to release it, the male ramps (10,11) are requested by the female ramps (15,16) of a transmission sleeve   (17) mounted idly between the two clamps (7,8).   12. Arrangement according to claim 11, characterized in that - 9 - 2651672   the sleeve (17) is limited in its transverse movement by a cylindrical section (18) of the spindle (5) and a cylindrical section (19) of the spindle (6), the spindles (5,6) being slidably mounted one by compared to each other.   13. Device according to any one of claims 10 to 12,   characterized in that the spindle (6) is fixed in translation, while the spindle (5), integral with a screwed cap (20) can move relative to the spindle (6) against a spring pressure (21) bearing on the one hand on a shoulder (22) of the spindle (6) and on the other hand   the inner face (23) of the cap (20).   14. Device according to any one of claims 1 to 13,   characterized in that it comprises a remote control system (9) comprising an outer ring (24) coaxial with the body (2) and movable in rotation around the latter, the ring (24) being connected by 'a pin , respectively a screw (25), to a cam (26) of the bell-cam type, the   raceway (27) moves against a fixed point.   15. Device according to claim 14, characterized in that the raceway (27) of the cam moves against a fixed point preferably a roller (28) whose positioning of the axis (29) can be moved by screwing / unscrewing an adjustment screw (30) accessible from the outside longitudinally or at an angle in order to adjust the position of the axis therefore of the roller.   16. Device according to any one of claims 10 to 15,   characterized in that on the cam body is driven in its central part a ball bearing (31) which is made integral by its outer ring (32), the rotation of the ring causing the longitudinal displacement of the bearing (31) therefore balls (33), these then coming into abutment against the outer face of the cap (20) and repel   the assembly (5,20) forward against the spring (21).   17. Device according to any one of claims 10 to 16,   characterized in that the displacement of the cam (26) takes place against a stack of Belleville washers (34) which ensure the locking if the ring (24) is released.   18. Device according to any one of claims 10 to 17,   characterized in that the contact between the cam and the spindle on which   it acts is ensured by the ball bearing. - 10 - 2651672   19. Device according to any one of claims 10 to 18,   characterized in that the cam (26) and / or the spindle (5) on which it acts are provided with a piece of hard material making the raceway for the ball (33), namely respectively a raceway (35) on the spindle and (36) on the cam, preferably made of tungsten carbide.