Instrument for manipulating and impacting a hip prosthesis cup
The bayonet-type mounting system with combined translational and rotational movements addresses the issue of unreliable plate attachment in existing instruments, ensuring secure and reliable fixation of the hip prosthesis cup in the acetabular cavity.
Patent Information
- Application Number
- FR2022006172
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2022-06-22
- Publication Date
- 2026-03-06
- Estimated Expiration
- 2042-06-22
AI Technical Summary
Existing surgical instruments for implanting a hip prosthesis cup lack reliable mounting means that securely attach the plate to the head, independent of pressure application.
The instrument employs bayonet-type mounting means with combined translational and rotational movements to securely attach the plate to the head, utilizing indexing elements and stop surfaces for reliable fixation.
The bayonet-type mounting ensures the plate is locked to the head in all directions without requiring continuous pressure, facilitating secure and reliable attachment and expansion of the cup in the acetabular cavity.
Smart Images
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Abstract
Description
Title of the invention: Instrument for manipulating and impacting a cup of a hip prosthesis
[0001] The present invention relates, in general, to surgical instruments, in particular those intended to implant a cup or "prosthetic acetabulum" in a cotyloid cavity of a patient's pelvis.
[0002] The cup is the outer shell of an acetabular implant. It is in the form of a hollow hemisphere, generally made of metallic material. This outer shell contains an inner sliding core, made in particular of high-density polyethylene. The inner sliding core is designed to receive a femoral head carried by a femoral stem implanted in the patient's femur.
[0003] To implant the cup, the surgeon typically uses a cup manipulation and impaction instrument. This instrument allows the cup to be grasped, manipulated, and impacted into the acetabular cavity of the patient's pelvis. Impaction is a procedure that contributes to fixing the cup in the acetabular cavity.
[0004] The invention relates more particularly to an instrument for manipulating and impacting a cup comprising: - an arm,
[0005] - a head, attached to one end of the arm, through which a conduit passes along an axis X,
[0006] - an expanding plate provided with a central recess by which it is adapted to to be brought over the head,
[0007] - mounting means operating between the head and the plate, and
[0008] - pressure means capable of exerting radial pressure on the mounted plate on the head, these pressure means comprising a pad that can be moved in translation along the X axis in said conduit of the head under the action of a lever mounted on the arm.
[0009] An instrument of the aforementioned type is already known, notably from documents FR2948013 and FR2994645, in which the mounting of the plate on the head is achieved simply by engaging the plate on the stud so that a counter-support surface of the plate rests on a support surface of the head.
[0010] According to document FR2994645, the bearing surface of the head and the counter-support surface of the plate are flat, and an annular projection is provided on the counter-support surface of the plate, defining a molded recess to receive the bearing surface of the head. This annular projection forms a stop means that opposes the sliding of the bearing surface of the head relative to the surface of counter-support of the plate.
[0011] However, the instruments already known have the disadvantage that the mounting means do not allow the plate to be reliably fixed on the head, independently of the pressure being applied to the plate using the stud.
[0012] In order to remedy this aforementioned drawback, the present invention proposes a new instrument for manipulating and impacting a cup in which said means for mounting the plate on the head are reinforced, independently of said pressure means.
[0013] More particularly, the invention proposes an instrument as defined in the introduction in which said mounting means are of the bayonet type comprising first means belonging to the head and second means provided in the central recess of the plate, adapted to cooperate according to two combined movements, one of translation along the X axis and the other of rotation around the X axis, of the plate to secure the latter to the head.
[0014] Advantageously, the bayonet mounting, which is characterized by a push-turn movement of the plate on the head, allows said plate to be locked on the head in all directions even if the pressure means are not actuated.
[0015] Other non-limiting and advantageous features of the handling and impaction instrument according to the invention, taken individually or in all technically possible combinations, are as follows:
[0016] -said mounting means include indexing elements belonging to the head and the plate, adapted to cooperate with each other at the end of the rotational stroke of the plate around the X axis to fix the locked position of the plate on the head;
[0017] - the indexing elements comprise at least one notch and at least one rib whose shapes correspond;
[0018] - the rotational stroke of the plate around the X axis between its engaged position and its locked position on the head, is between 50 and 60 degrees;
[0019] - said first means comprise at least one bayonet having a curved external sliding surface extending lengthwise parallel to the X axis and a flat sliding surface extending perpendicularly to the X axis, and the second means comprise, on the one hand, at least one longitudinal groove whose bottom has a shape complementary to the curved external sliding surface of said bayonet, and, on the other hand, at least one flat sliding surface extending perpendicularly to the longitudinal axis of said longitudinal groove, capable of sliding on said flat sliding surface of said bayonet;
[0020] - said mounting means comprise on the head a cylindrical surface of guide and on the plate a complementary cylindrical surface suitable for sliding on said cylindrical guide surface;
[0021] - at least two stop surfaces are provided in the central recess of the plate radial and said block includes, correspondingly, two radial stop surfaces provided on a slide and adapted to be positioned opposite said radial stop surfaces of the plate when said block is moved in translation along the X axis in said conduit of the head on which said plate is locked;
[0022] - the radial abutment surfaces of the plate are formed by the lateral surfaces in view of a slide whose bottom forms an inclined surface on which slides a complementary inclined surface of the slide of said block when the latter is moved in translation along the X axis in said conduit of the head on which said plate is locked;
[0023] - the turntable is generally in the form of a disc with a central recess is centered on the Y-axis of the disk, this disk being radially split and comprising at least one elongated radial recess extending from the central recess into a portion of the disk; and
[0024] - the plate includes a collar forming an external peripheral rim provided grip notches.
[0025] The following description with regard to the attached drawings, given by way of non-limiting examples, will make it clear what the invention consists of and how it can be carried out.
[0026] On the attached drawings:
[0027] [Fig-1] is a schematic side perspective view of a pre- the instrument's ferrule according to the invention,
[0028] [Fig.2] is a schematic side perspective view of the instrument's handle [Fig. 1] in the open state,
[0029] [Fig.3] is a view along arrow F of [Fig.2],
[0030] [Fig.4] is a cross-sectional view along plane AA of [Fig.3],
[0031] [Fig.5] is a schematic side perspective view of the instrument's handle [Fig. 1] in the closed state,
[0032] [Fig.6] is a view along arrow F of [Fig.5],
[0033] [Fig.7] is a cross-sectional view along plane AA of [Fig.6],
[0034] [Fig.8] is a schematic perspective view from below the head of the handle of the [Fig.2],
[0035] [Fig.9] is a side view of [Fig.8],
[0036] [Fig. 10] is a schematic perspective view from below the instrument's plate of [Fig. 1],
[0037] [Fig. 11] is a schematic perspective top view of the plate of the [Fig. 10]
[0038] [Fig. 12] is a side view of the plate of [Fig. 10],
[0039] [Fig.13] is a top view of [Fig.12],
[0040] [Fig.14] is a cross-sectional view along plane AA of [Fig.13],
[0041] [Fig.15] is a bottom view of [Fig.12],
[0042] [Fig. 16] is a cross-sectional view along plane DD of [Fig. 15],
[0043] [Fig. 17] is a view from below of the plate engaged in translation on the head of the the handle in the open state of the instrument according to the invention,
[0044] [Fig. 18] is a cross-sectional view along plane AA of [Fig. 17],
[0045] [Fig. 19] is a view from below of the plate in the locked position on the head of the the handle in the open state of the instrument according to the invention,
[0046] [Fig.20] is a cross-sectional view along plane AA of [Fig. 19],
[0047] [Fig.21] is a side view of the handle head in the open state with the plate in locked position cut according to plane BB of [Fig.22],
[0048] [Fig.22] is a bottom view of [Fig.21],
[0049] [Fig.23] is a partial cross-sectional view along plane BB of [Fig.1],
[0050] [Fig.24] is a view similar to that of [Fig.23] after the initiation of the closure of the lever in the arm of the instrument's handle [Fig.1],
[0051] [Fig.25] is a longitudinal cross-sectional view of the plate engaged in a cup while the pressure means stud is in the extended (non-active) position,
[0052] [Fig.26] is shown in magnifying glass view of area B of [Fig.25], and
[0053] [Fig.27] is a view similar to that of [Fig.2] with a lever-forming rod tilting of the handle screwed into the arm of the handle.
[0054] In the description that follows, by convention, the term "proximal" will designate the side of a part of the instrument located closest to a surgeon when he has the instrument in his hand, while the term "distal" will designate the opposite side of this part, located furthest from the surgeon.
[0055] In [Fig.1], a preferred embodiment of an instrument 1 for the manipulation and impaction of a cup (shown in [Fig.25]) of a hip prosthesis is shown.
[0056] This instrument 1 comprises a neck 100 and a radially expanding plate 200, mounted at one end of the neck 100.
[0057] The handle 100, more particularly represented in figures 2 to 7 and 27, is an elongated tool which includes a handle 110 and a head 180 connected to the handle 110 by an arm 120.
[0058] The handle 110 is a relatively massive part which allows the handle 100 to be gripped by a surgeon.
[0059] The head 180, as will be described in more detail later in the text, is used for mounting the plate 200 intended to be engaged in a cup 20 (see [Fig.25]) to grasp it for the purpose of impaction.
[0060] The handle 110 has at its proximal end an impaction tip 111 fixed to the handle 110 (see figures 4 and 7). This impaction tip 111 has a flat impaction surface 11 IA on which the surgeon can strike with a hammer to impact the cup attached to the plate 200, into the acetabular cavity of the patient's pelvis.
[0061] At its distal end, the handle 110 is secured by a connecting end 112 to one end 121 of the arm 120.
[0062] The arm 120 is a long and relatively thin piece compared to the handle 110 (see figures 3 and 6). It follows a curved path between its two ends. At its distal end, the arm is fixed to the head 180.
[0063] The arm 120 and the head 180 are here made of biocompatible metallic material and are welded to each other.
[0064] As shown more particularly in Figures 3, 4, 6 and 7, the arm 120 internally comprises a housing 123 which extends over most of the length of the arm 120. Indeed, this housing 123 extends from an area located near the threaded housing provided at the proximal end 121 of the arm 120 to the other end of said arm to which the head 180 is welded.
[0065] This housing 123 is a kind of through slot which opens onto two opposite sides of the arm 120 through oblong longitudinal openings 123A (see figures 3 and 6).
[0066] Inside the housing 123 is mounted pivotally a lever 130 connected to the proximal end 141 of a connecting rod 140 whose other distal end 142 is connected to a stud 170.
[0067] The lever 130 is a flat piece, one end of which, accessible from the outside of the arm 120, is pierced with a large circular opening 131 allowing the passage of a finger for the actuation of the lever 130, and the other end of which forms a base 132 for mounting the lever 130 inside the housing 123 of said arm.
[0068] The base 132 of the lever 130 includes an opening pivotally engaged on an axis 122 fixed in the housing 123 of the arm 120. It fixedly carries another axis 133 offset relative to the opening pivotally engaged on the axis 122 of the arm 120.
[0069] The lever 130 is therefore pivotally mounted in the housing 123 of the arm 120 of the handle 100 between an open position, shown in Figures 1 to 4, in which the major part of the lever 130 extends outside the arm 120 transversely to it, and a closed position, shown in Figures 5 to 7, in which a large part of the lever 130, with the exception of the pierced end of the circular opening 131 which remains accessible outside the arm 120, extends into the housing 123 of the arm 120, parallel to it.
[0070] The connecting rod 140 is also a flat part which follows a substantially curved path parallel to the path of said arm 120. The proximal end 141 of the connecting rod 140 is articulated on the other axis 133 attached to the lever 130, while the other distal end 142 of the connecting rod 140 is articulated on an axis 173 fixed to the block 170.
[0071] As Figures 8 and 25 show in particular, the stud 170 is a single-piece component with an overall T-shape, a cylindrical body 171 with axis XI, and a head formed at one distal end of this body 171 by two diametrically opposed slides 172, which project from the body 171 in a direction perpendicular to the axis XI and in opposite directions. The stud 170 includes at its proximal end, opposite its head, an axial housing 174, open at one end. The stud 170 is pierced by two circular lateral openings 175 centered on the same axis perpendicular to the axis XI of the stud 170 and opening into said housing 174 (see [Fig. 25]). The housing 174 accommodates the distal end 142 of the connecting rod 140, the axis 173 being fixedly engaged through said circular lateral openings 175 so that it passes through said distal end 142 of the connecting rod 140.
[0072] The body 171 of the stud 170 is mounted for translation in a conduit 181 which passes along an axis X through the head 180 of the handle 100. When the body 171 of the stud 170 is mounted in the conduit 181 of the head 180, its axis XI coincides with the axis X of the conduit of the head 180 (see Figures 4 and 18). The head of the stud 170, including the slides 172, is located on the free distal face 185D of the head 180, while the proximal end of the body of the stud 170, including the housing 174 which receives the distal end 142 of the connecting rod 140 articulated on the axis 173, is located in the portion of the conduit 181 of the head 180 that communicates with the housing 123 of the arm 120 (see [Fig. 18]).
[0073] Actuating the pivoting lever 130 from its open position to its closed position causes the axis 133, to which the proximal end 141 of the connecting rod 140 is attached, to move along an arc C from a position A to a position B shown in [Fig. 7]. In doing so, the connecting rod 140 moves from an extended position where it is located outside the housing 123 of the arm 120 (see [Fig. 2]) to a retracted position in which it is practically entirely housed within the housing 123 of the arm 120 (see [Fig. 5]). During its movement, the distal end 142 of the connecting rod 140 pulls the pin 170 into the conduit of the head 180 along the axis X over a distance d (shown in [Fig. 5].7]) from an extended position in which the head of the stud 170 is placed flush with the free distal face 185D of the head 180 (see figures 2 and 8) to a retracted position (shown in figures 5 and 7) in which the head of the stud 170 is raised in the channel of the head 180 and is located at a distance d from the free distal face 185D of the head 180 of the handle 100. .
[0074] As will be described in more detail later in the text, plot 170, which is de- placeable for translation along the X axis in said conduit 181 of the head 180 of the handle 100 under the action of the lever 130 mounted pivotally on the arm 120, forms pressure means capable of exerting radial pressure on the plate 200 locked on the head 180.
[0075] As shown more particularly in [Fig.4], a spring blade 150 is provided in the housing 123 of the arm 120, one end 151 of which is fixed to the arm 123 by screws 160 and the other free end 152 of which constantly presses on the connecting rod 140 to push the connecting rod into the extended position and, consequently, to keep the lever 130 in the open position.
[0076] The closing of the lever 130, achieved by pushing with a finger on the lever 130 to rotate it around the axis 122 towards the arm 120, is carried out against the action of the spring blade 150 which is pressed by the connecting rod 140 going inside the arm 120.
[0077] If the pressure exerted with the finger on the lever 130 is released, the spring blade 150 is no longer pressed by the connecting rod 140 and it pushes the latter towards its extended position which, consequently, rotates the lever 130 around the axis 122 from its closed position to its open position.
[0078] Of course, the return of the connecting rod 140 to the extended position and of the lever 130 to the open position automatically causes the reverse translational displacement of said pin 170 along the X axis in the conduit of the head 180 from its retracted position to its extended position.
[0079] Advantageously, means are provided between the lever 130 and the connecting rod 140 which cooperate with each other to ensure the correct positioning of the lever 130 in the closed position in the housing 123 of the arm 120.
[0080] Here, these means include, on the connecting rod 140, a rounded edge 145 and a notch 145A, and, on the lever 130, a rounded edge 135 of its base 132. At the end of the closing stroke of the lever 130, the rounded edge 135 of the base 132 of the lever 130, is placed against the corresponding rounded edge 145 of the connecting rod 140 and the notch 145A of the connecting rod 140 catches the rounded edge 135 of the lever 130 to hold it in contact with the rounded edge 145 of the connecting rod 140.
[0081] The locking of the lever 130 in the closed position is ensured by the connecting rod 140 which, in the retracted position, acts as a spring exerting on the lever 130 a force directed globally towards the head 180 to maintain it in the closed position.
[0082] To remove the lever 130 from its closed position, it is simply necessary to pull on it to rotate it around the axis 122.
[0083] As shown in Figures 4, 7 and 27, a threaded channel 124 is provided on one side of the arm 120 for screwing in the threaded tip of a rod 3 forming a lever for tilting the handle 100. Advantageously, during the operation With the cup impaction using instrument 1, the surgeon can use this tilting lever to slightly tilt the handle 100 in order to slightly reorient the cup in the acetabular cavity of the patient's pelvis.
[0084] As shown in Figures 10 to 16, the plate 200 is generally disc-shaped with a central recess 210 centered on the Y-axis passing through the center O of the disc. The plate 200 has a proximal face 201 and a distal face 202 that are flat with circular contours and extend perpendicularly to the Y-axis of the disc. The plate 200 has an external lateral face 203 that extends from the distal face 202 towards the proximal face 201. The shape of this external lateral face 203 is adapted so as not to interfere with the internal face of the cup 20 during the radial expansion of the plate 200 inside said cup 20.
[0085] It includes a collar 204 which extends around the proximal face 201 overhanging the external lateral face 203.
[0086] This collar 204 forms an external peripheral rim 205 provided with gripping notches 206. These notches 206 have a rounded bottom. According to the example shown, three notches 206 are provided, distributed around the perimeter of the collar 204.
[0087] When the plate 200 is engaged in the cup 20, the rear face 204A of the collar 204 rests on the peripheral front edge 22 of the cup 20 in order to ensure proper relative positioning of the plate 200 and the cup 20 (see [Fig.26]).
[0088] The plate 200 has, projecting on its outer lateral face 203, a peripheral bead 209, located just below the collar 204 (see Figures 12 and 14). As shown in Figures 25 and 26, the bead 209 is designed to engage in a groove 21 of the cup 20 during the radial expansion of the plate 200 under the action of said pressure means. This engagement allows the plate 200 to be clamped in the cup 20.
[0089] The plate 200 is made of a plastic material exhibiting a certain capacity for elastic deformation. To allow for radial expansion, the plate 200 is slotted. The slot 207 of the plate 200 extends radially along its length from the central recess 210 to the edge of the disc and vertically along the entire height or thickness of the disc.
[0090] To increase the expansion capacity of the plate 200, two elongated finger-shaped recesses 208 are provided, advantageously in the example shown, which extend radially from the central recess 210 into a part of the disk (see for example figures 11 and 15).
[0091] The plate 200 is attached by its central recess 210 to the head 180 of the neck 100 of the instrument 1.
[0092] The instrument 1 includes mounting means operating between the plate 200 and the head 180 of the handle 100 to easily and reliably secure said plate 200 to said head 180 independently of the action of said pressure means formed by plot 170.
[0093] According to a notable feature of the instrument 1 according to the invention, said mounting means are of the bayonet type. They comprise first means belonging to the head 180 and second means provided in the central recess 210 of the plate 200, adapted to cooperate according to two combined movements, one of translation along the X axis and the other of rotation around the X axis, of the plate 200 to secure the latter to the head 180.
[0094] As Figures 8 and 9 show in particular, the head 180 comprises a single-piece body centered on the X-axis of the conduit 181 which passes through the entire body. The body comprises a proximal portion 182, generally frustoconical in shape, welded to the distal end of the arm 120, and a distal portion 183, cylindrical in shape, the diameter of which is smaller than the diameter of the proximal portion 182. The distal portion 183 extends from the free, flat face 182A of the proximal portion 182. The distal portion 183 of the body of the head 180 has a cylindrical lateral face 183A around the X-axis and a free, flat face 183B perpendicular to the X-axis. The cylindrical lateral face 183A has a height H1 (see [Fig. 9]). The free face flat 183B of the distal part 183 of the body of the head 180 bears two bayonets 185 arranged symmetrically with respect to the X axis.Each bayonet 185 has a curved external sliding surface 185A extending lengthwise (or heightwise) parallel to the X-axis and a flat sliding surface 185C extending perpendicularly to the X-axis, extending beyond the flat free face 183B of the cylindrical distal portion 183. Each bayonet 185 has a curved internal surface 185B that delimits a portion of the conduit 181 and that fits around a portion of the cylindrical body 171 of the stud 170 engaged in said conduit 18L. Finally, each bayonet 185 has at one distal end a flat surface 185D forming the free distal face of the head 180.
[0095] The curved external sliding surface 185A and the flat sliding surface 185C of each bayonet 185 form the first mounting means provided on the head 180.
[0096] As shown in Figures 10, 11, 14 and 16, the central recess 210 of the plate 200 is delimited over most of its height by a cylindrical wall 21 IA of a first diameter and over a small part of its height by a cylindrical wall 21 IB of a second diameter greater than the first diameter to form an enlargement opening onto the distal face 202 of said plate 200 (see [Fig. 14]). In the cylindrical wall 21 IA of the central recess 210, two longitudinal grooves 214 are cut, extending vertically along the Y-axis of the disc and having a rounded bottom whose shape is complementary to the rounded shape of the curved sliding external surfaces 185A of said bayonets 185 of the head 180. In addition, two radial notches are provided in the cylindrical wall 21 IA of the central recess 210 to form two flat sliding surfaces 217 extending perpendicularly to the longitudinal axis of said longitudinal grooves 214. Each notch is associated with a longitudinal groove 214 so that each flat sliding surface 217 is associated with a longitudinal groove 214.
[0097] The flat sliding surfaces 185C, 217 of the bayonets 185 and of the plate 200 extend in an arc of a circle.
[0098] Each pair of longitudinal groove 214 and flat sliding surface 217 provided in the central recess 210 of the plate 200 forms the second mounting means provided on the plate 200 and adapted to cooperate with said first means of the head 180.
[0099] As shown in Figures 17 and 18, the plate 200 is brought close to the head 180 of the handle 100 with its proximal face 201 turned towards the head 180 and the central recess 210 of the plate 200 is engaged in translation along the X axis on the head 180 such that the bottoms of the longitudinal grooves 214 provided in the central recess 210 slide on the curved external sliding surfaces 185A of said bayonets 185 until the two flat sliding surfaces 217 provided in the central recess 210 are positioned just above the level of the flat sliding surfaces 185C of said bayonets 185.
[0100] In this engaged position, the proximal face 201 of the plate 200 is positioned against the flat free face 182B of the proximal part 182 truncated cone of the head 180 (see [Fig. 18]).
[0101] Said bayonets 185 advantageously form keying features to engage the plate 200 correctly on the head 180 of the handle 100 of the instrument 1.
[0102] As shown in Figures 19 to 22, after being engaged on the head 180 (as explained above), the plate 200 is then rotated around the X axis clockwise. During this rotation, the two flat sliding surfaces 217 provided in the central recess 210 of the plate 200 slide on said flat sliding surfaces 185C of the bayonets 185 so that at the end of the rotation, a part of these two flat sliding surfaces 217 remains wedged behind the flat sliding surfaces 185C to lock the plate 200 onto said bayonets 185 and thus lock the plate 200 onto the head 180 of the handle 100 of the instrument 1.
[0103] Here, the rotational stroke A of the plate 200 around the axis X between its engaged position and its locked position on the head 180, is between 50 and 60 degrees, preferably on the order of 55 degrees.
[0104] Furthermore, advantageously, said mounting means comprise, on the head 180 of the handle 100, a cylindrical guide surface 183A, and, on the plate 200, a complementary cylindrical surface 215 suitable for sliding on said cylindrical guide surface 183 A.
[0105] More particularly, the cylindrical guiding surface of the head 180 is formed by the cylindrical lateral face 183A of the distal part 183 of the body of the head 180 and the complementary cylindrical surface 215 of the plate 200 is formed by parts of the cylindrical wall 21 IA of the central recess 210, located at the plane sliding surfaces 217, as shown in Figures 10 and 14. The height h of the complementary cylindrical surface 215 of the plate 200 is identical to the height H1 of the cylindrical lateral face 183A of the distal part 183 of the body of the head 180.
[0106] During the translational engagement of the plate 200 on the head 180, the complementary cylindrical surface 215 of the plate 200 comes to be positioned against the cylindrical lateral face 183A of the distal part 183 of the body of the head 180.
[0107] Then, during the rotation of the plate 200 around the X axis, the complementary cylindrical surface 215 of the plate 200 slides on the cylindrical lateral face 183A of the distal part 183 of the body of the head 180 so that the plate 200 is guided in rotation by the head 180.
[0108] Preferably, said mounting means comprise indexing elements belonging to the head 180 and the plate 200, adapted to cooperate with each other at the end of the rotational stroke of the plate 200 around the X axis to fix the locked position of the plate 200 on the head 180 of the handle 100 of the instrument 1.
[0109] Here, the indexing elements comprise, on the one hand, two notches 216, each notch 216 being formed in a recess in the complementary cylindrical surface 215 of the plate 200 and associated with a flat sliding surface 217 (see [Fig. 14]), and, on the other hand, two ribs 184 provided projecting on the cylindrical lateral face 183A of the distal part 183 of the body of the head 180. Each rib 184 is associated with a bayonet 185 and positioned in a determined manner relative to the flat sliding surface 185C of this bayonet 185.
[0110] The shape of the ribs 184 corresponds to that of the notches 216 so that at the end of the rotation of the plate 200, the ribs 184 of the head 180 engage in the notches 216 of the plate 200 by triggering a passage of a hard point (notch effect) indicating to the practitioner that the plate 200 is locked onto the head 180 of the handle 100 of the instrument 1.
[0111] According to another advantage of the present invention, at least two radial stop surfaces 213A are provided in the central recess 210 of the plate 200 and the block 170 has, correspondingly, two radial stop surfaces 172A provided on a slide 172 and adapted to be positioned opposite said radial stop surfaces 213A of the plate 200 when said block 170 is moved in translation along the X axis in said conduit 181 of the head on which said plate 200 is locked.
[0112] This cooperation of radial stop surfaces forms an anti-pull-out means for the plate 200 locked onto the head 180 since it prevents any rotation of the plate 200 as long as the pin 170 is held by the lever 130 in the retracted position in the conduit 181 of the head 180.
[0113] As shown in [Fig.10], the radial stop surfaces 213A of the plate 200 are formed by the opposing lateral surfaces of two slides 213 whose bottom 213B forms an inclined surface.
[0114] Two platforms 212 are provided in the central recess 210 of the plate 200, positioned symmetrically with respect to the Y-axis of the disc (see Figures 10 and 14). The two platforms 212 reduce the cross-section of the central recess 210 to the cross-section of the cylindrical body 171 of the block 170. Each platform 212 has a recessed notch 213 forming a slide for a slider 172 of the block 170. The two notches 213 are positioned opposite each other. They have bottoms 213B in the form of surfaces inclined towards the Y-axis so that, in cross-sectional view, as shown in [Fig. 14], the cross-section of the sliders 172 is reduced from the distal face 202 of the plate 200 to its proximal face 201.
[0115] The slides 172 of the block 170 have corresponding inclined end surfaces 172B (see [Fig.8]) adapted to slide on the inclined bottoms 213B of the notches 213 of the plate 200 when the block 170 is moved in translation along the X axis in said conduit 181 of the head 180 on which said plate 200 is locked (see [Fig.24]).
[0116] Said notches 213 forming slides have lateral surfaces 213A which, when the plate 200 is locked onto the head 180, closely frame the slides 172 of the block 170 when the latter is moved in translation along the X-axis from its extended position to its retracted position. In the retracted position of the block 170, the lateral surfaces 172A of each slide 172 are blocked by the lateral surfaces 213A of the slides of the plate 200 locked onto the head 180 of the handle 100 of the instrument 1.
[0117] The platforms 212 and the notches 213 of the plate 200 are positioned in such a way within the central recess 210 that, when the plate 200 is engaged in translation on the head 180, which houses the pin 170 in the extended position, said notches 213 are angularly offset relative to the slides 172 of the pin 170 (see [Fig. 17]). Said notches 213 are also offset along the X-axis by being positioned above the level of the slides 172.
[0118] The rotation around the X-axis of the plate 200 on the head 180, from its engaged position to its locked position on the head 180 of the handle 100 of the instrument 1, causes the angular displacement of said notches 213 of the plate 200 to align them angularly with the slides 172 of the block 170 placed in the extended position (see [Fig. 19]). These notches 213, however, remain positioned along the X-axis, just above the slides 172 (see [Fig. 23]). Subsequently, as soon as under the action of the lever 130 which is pivoted from its open position to its closed position, the stud 170 is moved along the X axis in the conduit of the head 180 from its extended position to its retracted position, the slides 172 engage in the notches 213 and slide on the inclined bottoms 213B of these notches 213 (see [Fig.24] ) exerting a pressure force on said plate 200 to expand it radially in the direction of the cup 20 on which it rests (see [Fig.25]).
[0119] The expansion of the plate 200 causes the cup 20 to be wedged on it by the cooperation of the rim 209 of the plate 200 with the groove 21 of the cup 20.
[0120] To release the cup 20 of the instrument 1, it is sufficient to release the lever 130 from its closed position (in which it is locked against the connecting rod 140) so that it automatically returns to the open position under the action of the spring blade 150, which pushes the connecting rod 140 out of the arm 120. This release causes the pin 170 to return to its extended position, in which the slides 172 are disengaged from the notches 213 of the plate 200 so that they no longer exert any radial pressure on said plate 200. The plate 200 then elastically returns to its original, unexpanded state, and its rim 209 disengages from its contact with the groove 21 of the cup 20. The plate 200, still locked onto the head 180 at the distal end of the handle 100, can then be removed from the cup. 20.
[0121] The present invention is not limited to the embodiment described and represented in the various figures, but a person skilled in the art will be able to make any variation in accordance with their spirit.
Claims
Demands
1. Instrument (1) for manipulating and impacting a cup comprising: - an arm (120), - a head (180), fixed to one end of the arm (120), through which a conduit (181) passes along an axis X, - an expanding plate (200) generally in the form of a one-piece disc made of plastic material having a central recess (210) by which it is adapted to be attached to the head (180) and a slot (207) extending radially lengthwise from the central recess (210) to the edge of the disc and vertically through the entire thickness of the disc, - mounting means (183A, 185A, 185C, 215, 214, 217) operating between the head (180) and the plate (200), - pressure means capable of exerting radial pressure on the plate (200) mounted on the head (180), these pressure means comprising a movable stud (170) that translates along the X axis in said conduit (181) of the head (180) under the action of a lever (130) mounted on the arm (120),characterized in that said mounting means are of the bayonet type comprising first means (185B, 185C) belonging to the head (180) and second means (214, 217) provided in the central recess (210) of the plate (200), adapted to cooperate together according to two combined movements, one of translation along the X axis and the other of rotation around the X axis, of the plate (200) to secure the latter to the head (180).
2. Instrument (1) according to claim 1, wherein said mounting means comprise indexing elements (184,216) belonging to the head (180) and the plate (200), adapted to cooperate with each other at the end of the rotational stroke of the plate around the X axis to fix the locked position of the plate on the head.
3. Instrument (1) according to claim 2, wherein the indexing elements comprise at least one notch (216) and at least one rib (184) whose shapes correspond.
4. Instrument (1) according to any one of claims 1 to 3, wherein the rotational stroke of the plate (200) about the X axis between its engaged position and its locked position on the head is between 50 and 60 degrees.
5. Instrument (1) according to any one of claims 1 to 4, wherein said first means comprise at least one bayonet (185) having a curved external sliding surface (185A) extending lengthwise parallel to the X axis and a flat sliding surface (185C) extending perpendicularly to the X axis, and, wherein, the second means comprise, on the one hand, at least one longitudinal groove (214) the bottom of which has a shape complementary to the curved external sliding surface (185A) of said bayonet (185) and, on the other hand, at least one flat sliding surface (217) extending perpendicularly to the longitudinal axis of said longitudinal groove (214), capable of sliding on said flat sliding surface (185C) of said bayonet (185).
6. Instrument (1) according to any one of the preceding claims, wherein said mounting means comprise on the head (180) a cylindrical guide surface (183A) and on the plate a complementary cylindrical surface (215) capable of sliding on said cylindrical guide surface (183A).
7. Instrument (1) according to any one of the preceding claims, wherein at least two radial stop surfaces (213 A) are provided in the central recess (210) of the plate (200), and wherein said block (170) has corresponding radial stop surfaces (172A) provided on a slide (172) and adapted to be positioned opposite said radial stop surfaces (213A) of the plate (200) when said block (170) is moved in translation along the X axis in said conduit (181) of the head (180) on which said plate (200) is locked.
8. Instrument (1) according to the preceding claim, wherein the radial stop surfaces of the plate are formed by the lateral surfaces (213A) opposite a slide (213) the bottom of which forms an inclined surface (213B) on which slides a complementary inclined surface (172B) of the slider (172) of said block (170) when the latter is moved in translation along the X axis in said conduit (181) of the head (180) on which said plate (200) is locked.
9. Instrument (1) according to any one of the preceding claims, wherein the plate (200) has at least one elongated radial recess (208) extending from the central recess (210) into a portion of the disc.
10. Instrument (1) according to the preceding claim, wherein the turntable includes a collar (204) forming an external peripheral rim (205) provided with gripping notches (206).