Blood sampling assembly
By designing a cross-pivot structure and locking mechanism between the sheath and needle in the blood collection assembly, the problem of accidental needle tip injury after use of the venous blood collection needle is solved, achieving safe and efficient needle storage and improving safety and ease of operation.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-11
- Publication Date
- 2026-03-24
AI Technical Summary
After use, the needle tip of existing intravenous blood collection needles may accidentally injure staff, leading to accidental injury or blood disease infection.
Design a blood collection assembly including a blood collection needle and a sheath. The sheath intersects the extension direction of the needle tube via a pivot axis, allowing it to rotate around the pivot axis and store the needle tube. Combined with a locking mechanism and an anti-dislodgement protrusion, it ensures that the needle tube is safely stored in the receiving groove.
It reduces the possibility of needlestick injuries to medical staff and improves safety and ease of use.
Smart Images
Figure CN224023569U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to medical instrument technical field especially, and it is blood sampling assembly. BACKGROUND
[0002] The intravenous blood sampling needle is one of the most widely used medical instruments in medical institutions, which is mainly used with disposable vacuum blood collection tubes.
[0003] In the related art, the blood sampling needle may injure the staff when removing and discarding the blood sampling needle after use, resulting in accidental injury or blood disease infection. SUMMARY
[0004] The utility model aims at at least one of the technical problems existing in the prior art. To this end, one object of the utility model is to provide a blood sampling assembly, which drives the sheath to rotate towards one side of the needle tube when removing and discarding the blood sampling needle, and the needle tip can be accommodated into the accommodation groove through the mounting port, thereby improving the safety of the blood sampling assembly.
[0005] The utility model provides a kind of blood sampling assembly, and blood sampling assembly includes blood sampling needle and sheath.The blood sampling needle includes needle seat and needle tube connected;The sheath defines accommodation groove and the mounting port communicated with the accommodation groove;The sheath can be pivotally connected on the needle seat, the pivot axis of the sheath and the extension direction of the needle tube intersect, the mounting port is located at the side of the sheath towards the needle tube, so that the needle tube can be accommodated into the accommodation groove through the mounting port.
[0006] In some embodiments, the pivot axis of the sheath and the extension direction of the needle tube are perpendicular.
[0007] In some embodiments, the blood sampling assembly further includes a locking mechanism, which is arranged between the sheath and the needle seat and is used to fix the relative position of the sheath and the needle seat when the needle tube is accommodated into the accommodation groove.
[0008] In some embodiments, the locking mechanism includes a radial clamping protrusion arranged on the outer circumferential surface of the needle seat and a clamping hook arranged on the sheath; when the needle tube is accommodated into the accommodation groove, the clamping hook hooks the radial clamping protrusion.
[0009] In some embodiments, the radial clamping protrusion is arranged at least two along the circumferential direction of the needle seat; the sheath is provided with at least two clamping hooks; when the needle tube is accommodated into the accommodation groove, at least two clamping hooks are respectively hooked on at least two radial clamping protrusions.
[0010] In some embodiments, the mounting port is provided with an anti-disengagement protrusion on at least one of the two sides, and the anti-disengagement protrusion is used to block the side of the needle tube towards the mounting port.
[0011] In some embodiments, the anti-disengagement convex is arranged on one of the two opposite sides of the mounting port, and the anti-disengagement convex has a guide portion; the guide portion and the other of the two opposite sides of the mounting port form a guide channel, and the width of the guide channel gradually decreases away from the side of the mounting port.
[0012] In some embodiments, the anti-disengagement convex further has an arc-shaped groove, and the opening of the arc-shaped groove is communicated with the end of the guide channel away from the mounting port; the arc-shaped groove is used for clamping the needle tube.
[0013] In some embodiments, the blood sampling assembly further comprises wing plates; the wing plates are symmetrically arranged on the outer surface of the sheath, and the side of the wing plates away from the mounting port is a pressing surface.
[0014] In some embodiments, the pressing surface comprises a first arc-shaped surface and a second arc-shaped surface connected with each other, and the first arc-shaped surface and the second arc-shaped surface protrude towards each other and towards the side of the mounting port.
[0015] It can be seen from the technical scheme that the embodiments provided by the utility model have the following advantages: (1) the needle tube is inserted into the elbow of a patient along the extension direction of the needle tube, the pivot axis of the sheath intersects with the extension direction of the needle tube, the sheath can rotate around the pivot axis to the side away from the needle tube and offset the sheath as a whole to the side of the needle tube, so as to avoid shielding the field of vision of medical staff or contacting the skin of the patient, and the medical staff can more conveniently insert the needle tube into the elbow vein of the patient;
[0016] (2) after blood sampling is completed, the medical staff moves the sheath to the side towards the needle tube, since the mounting port is arranged on the side of the sheath towards the needle tube, when the sheath is moved to the side towards the needle tube, the mounting port is close to the needle tube, and the needle tube is received into the accommodating groove through the mounting port, so as to reduce the possibility of the blood needle tip pricking the medical staff. BRIEF DESCRIPTION OF DRAWINGS
[0017] In order to more clearly illustrate the technical scheme in the embodiments of the utility model or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced below, and obviously, the drawings in the following description are only some embodiments of the utility model, and those skilled in the art can also obtain other drawings according to these drawings without paying creative labor.
[0018] Figure 1 is the overall structure schematic view of the blood sampling assembly according to the embodiments of the utility model, and at this time, the needle tube is located outside the accommodating groove;
[0019] Figure 2is a sectional view of the blood sampling assembly according to the embodiment of the present application, at this time the needle tube is located in the accommodating groove;
[0020] Figure 3 is a whole structure schematic view of the blood sampling assembly according to the embodiment of the present application, at this time the needle tube is located in the accommodating groove;
[0021] Figure 4 is a whole structure schematic view of the blood sampling assembly according to the embodiment of the present application, at this time the needle tube is located outside the accommodating groove.
[0022] Reference signs:
[0023] Blood sampling assembly 100;
[0024] Blood sampling needle 1, needle seat 11, needle tube 12, catheter 13;
[0025] Sheath 2, accommodating groove 21, mounting port 22, pivot shaft 23, anti-dropping lug 24, guide portion 241, arc-shaped groove 242;
[0026] Locking mechanism 3, radial clamping lug 31, clamping hook 32;
[0027] Wing plate 4, pressing surface 41, first arc-shaped surface 411, second arc-shaped surface 412. DETAILED DESCRIPTION
[0028] The embodiments of the present application are described in detail below, examples of which are shown in the drawings, wherein the same or similar reference signs represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present application, and cannot be understood as a limitation of the present application.
[0029] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application. In addition, the features limited as "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise stated, the meaning of "a plurality of" is two or more.
[0030] In the description of the utility model, it is necessary to explain, unless another explicit provision and limitation, the term "installation", "link", "connection" should do broad sense understanding, for example, can be fixed connection, also can be detachable connection, or integrally connected;Can be mechanical connection, also can be electrical connection;Can be directly connected, also can pass through the intermediate medium indirectly connected, can be two elements inside the communication.For the ordinary skilled in the art, the above-mentioned terms can be understood in the specific meaning of the utility model according to the specific circumstances.
[0031] In the related art, there are two kinds of venous blood sampling needles, one is a hose connected venous blood sampling needle, and the other is a pen type needle. When using the venous blood sampling needle, the sterile package and the cap are removed, and the medical staff holds the venous blood sampling needle to pierce the elbow vein at an angle of about 30°. The blood sampling needle is connected to a vacuum blood collection tube. When the blood in the vacuum blood collection tube reaches the predetermined capacity, the vacuum blood collection tube is removed, and then the blood sampling needle is removed from the vein and discarded.
[0032] After the blood sampling needle is used, the blood-stained needle tip may injure the worker during removal and disposal, causing accidental injury or blood-borne disease infection.
[0033] Reference is made below to Figures 1-4 A blood sampling assembly 100 according to an embodiment of the utility model is described.
[0034] As Figure 1 and Figure 2 shown, the embodiment provides a blood sampling assembly 100, which comprises a blood sampling needle 1 and a sheath 2. The blood sampling needle 1 comprises a needle holder 11 and a needle tube 12, and the needle tube 12 is fixedly connected to the needle holder 11.
[0035] Referring to Figure 1 , the sheath 2 has a receiving groove 21 and a mounting port 22, and the mounting port 22 communicates with the receiving groove 21.
[0036] Referring to Figure 2 , the sheath 2 is rotatably connected to the needle holder 11 through a pivot shaft 23, the pivot shaft 23 of the sheath 2 intersects with the extension direction of the needle tube 12, and the sheath 2 can rotate around the pivot shaft 23 to move away from or towards the needle tube 12 from the side of the needle tube 12. The mounting port 22 is arranged on the side of the sheath 2 facing the needle tube 12, so that the needle tube 12 can be received into the receiving groove 21 through the mounting port 22.
[0037] It needs to be further explained that when blood is collected, the medical staff holds the needle holder 11 to pierce the elbow vein at an angle of about 30°, and the piercing direction of the needle tube 12 is consistent with the extending direction of the needle tube 12. The pivoting shaft 23 of the sheath 2 intersects with the extending direction of the needle tube 12, and the sheath 2 can move away from the needle tube 12 from the side of the needle tube 12, so as to avoid the interference between the elbow and the sheath 2 in the piercing process of the needle tube 12. Correspondingly, if the pivoting shaft 23 of the sheath 2 is consistent with the extending direction of the needle tube 12 (i.e., parallel to each other), the rotating track of the sheath 2 will rotate around the axial direction of the needle tube 12 (i.e., the piercing direction of the needle tube 12), and the sheath 2 will wrap the needle tube 12 when located in the circumferential direction of the needle tube 12, so that the sheath 2 will block the needle tube 12 or contact the skin during the blood collection process, thereby hindering the puncture action.
[0038] In a specific application scenario, the pivoting shaft 23 of the sheath 2 intersects with the extending direction of the needle tube 12, and the sheath 2 can move away from the needle tube 12 from the side of the needle tube 12, so that the medical staff can more conveniently pierce the needle tube 12 into the elbow vein of the patient. After the blood collection is completed, the medical staff pushes the sheath 2 to move towards the side of the needle tube 12, the mounting port 22 is arranged on the side of the sheath 2 facing the needle tube 12, so as to drive the needle tube 12 to be capable of being received into the accommodating groove 21 through the mounting port 22, thereby reducing the possibility of the blood-carrying needle tip pricking the medical staff.
[0039] It can be seen from the technical scheme that the embodiments provided by the utility model have the following advantages:
[0040] (1) The needle tube 12 pierces the elbow of the patient along the extending direction of the needle tube 12, the pivoting shaft 23 of the sheath 2 intersects with the extending direction of the needle tube 12, the sheath 2 can rotate towards the side away from the needle tube 12 around the pivoting shaft 23 and make the sheath 2 as a whole deviate to the side of the needle tube 12, so as to avoid blocking the field of vision of the medical staff or contacting the skin of the patient, and the medical staff can more conveniently pierce the needle tube 12 into the elbow vein of the patient;
[0041] (2) After the blood collection is completed, the medical staff pushes the sheath (2) to move towards the side of the needle tube (12), and since the mounting port 22 is arranged on the side of the sheath 2 facing the needle tube 12, when the sheath 2 moves towards the side of the needle tube 12, the mounting port 22 is close to the needle tube 12, until the needle tube 12 is received into the accommodating groove 21 through the mounting port 22, thereby reducing the possibility of the blood-carrying needle tip pricking the medical staff.
[0042] Referring to Figure 2 In a specific example, the blood collection needle 1 further comprises a catheter 13, the catheter 13 and the needle tube 12 are arranged at two ends in the axial direction of the needle holder 11, the catheter 13 is in communication with the needle tube 12, and the catheter 13 can be inserted into a vacuum blood collection tube (not shown in the figure).
[0043] Referring to Figure 2In one specific example, the catheter 13 and the needle tube 12 are integrated.
[0044] Referring to Figure 2 Further, the pivot axis 23 of the sheath 2 is perpendicular to the extending direction of the needle tube 12. Compared with the case where the pivot axis 23 is not perpendicular to the extending direction of the needle tube 12, this perpendicular design further reduces the interference between the elbow and the sheath 2 during the process of the needle tube 12 piercing, and the structure is more simple and ingenious.
[0045] Embodiment Two
[0046] Referring to Figure 1 and Figure 2 Further, the blood sampling assembly 100 further comprises a locking mechanism 3, which is arranged between the sheath 2 and the needle holder 11. When the needle tube 12 is received into the accommodating groove 21, the locking mechanism 3 fixes the relative position of the sheath 2 and the needle holder 11. Thus, by arranging the locking mechanism, the possibility of the needle tube 12 sliding out of the sheath 2 can be reduced, and the stability and reliability of the needle tube 12 received into the sheath 2 can be improved.
[0047] Referring to Figure 2 and Figure 3 Further, the locking mechanism 3 comprises a radial clamping protrusion 31 arranged on the outer circumferential surface of the needle holder 11 and a clamping hook 32 arranged on the sheath 2, and the clamping hook 32 hooks the radial clamping protrusion 31 when the needle tube 12 is received into the accommodating groove 21. By hooking the radial clamping protrusion 31 with the clamping hook 32, the relative position of the sheath 2 and the needle holder 11 is fixed, the possibility of the needle tube 12 sliding out of the sheath 2 can be reduced, and the stability and reliability of the needle tube 12 received into the sheath 2 can be improved; at the same time, the clamping hook 32 and the radial clamping protrusion 31 have low manufacturing cost, which is conducive to reducing the cost of the whole product.
[0048] Referring to Figure 3 Further, the radial clamping protrusion 31 comprises at least two radial clamping protrusions 31 arranged at intervals in the circumferential direction of the needle holder 11, and the sheath 2 is provided with at least two clamping hooks 32, and the at least two clamping hooks 32 are respectively hooked on the at least two radial clamping protrusions 31 when the needle tube 12 is received into the accommodating groove 21. By matching the plurality of clamping hooks 32 and radial clamping protrusions 31, the stability and reliability of the locking mechanism 3 can be improved.
[0049] In one specific example, the number of radial clamping protrusions 31 is two, and the two radial clamping protrusions 31 are symmetrically arranged about the axis of the needle holder 11. The number of clamping hooks 32 is two, one clamping hook 32 is used to hook one radial clamping protrusion 31, and the other clamping hook 32 is used to hook the other radial clamping protrusion 31. This symmetrical structure can make the locking force uniformly distributed around the needle holder 11, which not only enhances the locking effect, but also ensures that the relative position of the sheath 2 and the needle holder 11 is more accurate and stable in the locked state, avoiding the problems of looseness or deviation caused by uneven force.
[0050] Embodiment Three
[0051] Referring to Figure 1 and Figure 2 Further, the anti-disengaging protrusion 24 is arranged on at least one of the two sides of the mounting port 22, and the anti-disengaging protrusion 24 is arranged on the side of the needle tube 12 facing the mounting port 22. That is, the anti-disengaging protrusion 24 can be arranged on one side of the mounting port 22, and the anti-disengaging protrusion 24 protrudes from the one side; the anti-disengaging protrusion 24 can be arranged on the other side of the mounting port 22, and the anti-disengaging protrusion 24 protrudes from the other side; the anti-disengaging protrusion 24 can be arranged on one side of the mounting port 22, and the anti-disengaging protrusion 24 protrudes from the one side; the anti-disengaging protrusion 24 can be arranged on the other side of the mounting port 22, and the anti-disengaging protrusion 24 protrudes from the other side. By arranging the anti-disengaging protrusion 24, the possibility of the needle tube 12 disengaging from the mounting port 22 can be reduced, and the stability and reliability of the needle tube 12 being accommodated in the accommodating groove 21 can be improved.
[0052] In combination with the above-mentioned embodiment two, the locking mechanism 3 and the anti-disengaging protrusion 24 are arranged simultaneously, a double locking structure can be formed, and the stability and reliability of the needle tube 12 being accommodated in the accommodating groove 21 can be improved.
[0053] Referring to Figure 1 and Figure 2 Further, the anti-disengaging protrusion 24 is arranged on one of the two sides of the mounting port 22, and the anti-disengaging protrusion 24 has a guide portion 241; the guide portion 241 and the other side of the two sides of the mounting port 22 form a guide channel, and the width of the guide channel gradually decreases away from the mounting port 22. That is, the guide channel is a gradually changing width channel, which is beneficial for accommodating needle tubes 12 with different diameters. Since the width of the guide channel gradually decreases away from the mounting port 22, the needle tube 12 will be gradually guided to the correct accommodation position along the channel after entering the guide channel close to the mounting port 22. The guide channel can automatically guide the needle tube 12 into the accommodating groove 21, without the need to spend extra effort to accurately align the needle tube 12 and the mounting port 22, so that the medical staff can operate more conveniently.
[0054] Specifically, the guide portion 241 has a guide slope, the interval between the guide slope and the other side of the two sides of the mounting port 22 gradually decreases away from the mounting port 22, and the guide slope and the other side of the two sides of the mounting port 22 form a guide channel.
[0055] Referring to Figure 2Further, the anti-escape convex 24 is further provided with an arc-shaped groove 242, an opening of the arc-shaped groove 242 is communicated with one end of the guide channel away from the mounting port 22, and the arc-shaped groove 242 is used for clamping the needle tube 12. The guide channel guides the needle tube 12 to move to the accommodating groove 21, when the needle tube 12 reaches the end of the guide channel, the needle tube 12 enters and is fixed in the arc-shaped groove 242 through the opening of the arc-shaped groove 242, the arc-shaped groove 242 can clamp the needle tube 12, and the difficulty of the needle tube 12 escaping from the accommodating groove 21 is increased, so that the accidental exposure of the needle tip with blood is effectively avoided.
[0056] Embodiment three
[0057] Referring to Figure 4 Further, the blood sampling assembly 100 further comprises wing plates 4, the wing plates 4 are symmetrically arranged on the outer surface of the sheath 2, and one side of the wing plates 4 away from the mounting port 22 is a pressing surface 41. When a medical staff operates the blood sampling assembly 100, the fingers can be placed on the pressing surface 41 of the wing plates 4, and when the needle tube 12 is accommodated into the accommodating groove 21 by moving the sheath 2 towards the needle tube 12 after blood sampling is completed. After the wing plates 4 are arranged, the medical staff mainly contacts the wing plates 4 in the operation process (the process of removing and discarding the blood sampling assembly 100), instead of directly contacting the part of the sheath 2 close to the needle tube 12, so that the risk of accidentally contacting the needle with blood by the hand is reduced, and the safety of the medical staff is ensured. Especially in the process of accommodating the needle tube 12 after blood sampling is completed, the sheath 2 is pushed by pressing the wing plates 4, so that the direct contact between the fingers and the needle is effectively avoided, and the risk of being pricked is prevented.
[0058] Referring to Figure 4 Further, the pressing surface 41 comprises a first arc-shaped surface 411 and a second arc-shaped surface 412 connected with each other, and the first arc-shaped surface 411 and the second arc-shaped surface 412 protrude along one side away from each other and towards the mounting port 22. The design of the first arc-shaped surface 411 and the second arc-shaped surface 412 can better fit the natural shape of the fingers, and the design that the two arc-shaped surfaces protrude along one side away from each other and towards the mounting port 22 can provide clear placement guidance for the fingers. When the operator picks up the blood sampling assembly 100, the fingers will naturally be placed in the appropriate position along the guidance of the arc-shaped surfaces without deliberately seeking the best pressing point. This makes the operation more natural and smooth, and reduces the possibility of operation failure.
[0059] Other configurations and operations of the blood sampling assembly 100 according to the embodiments of the present application are known to those skilled in the art, and will not be described in detail herein. In the description of the present application, the “first feature” and the “second feature” can comprise one or more features. Among them, the up-down direction, the left-right direction and the front-rear direction are based on the up-down direction, the left-right direction and the front-rear direction shown in the drawings.
[0060] In the description of the utility model, unless another definite provision and limitation, first feature is on second feature " above " or " below " can include first and second feature direct contact, also can include first and second feature is not direct contact but is through their between another feature contact. Moreover, first feature is on second feature " above ", " above " and " above " include first feature is on second feature directly above and oblique above, or just indicate first feature horizontal height is higher than second feature.
[0061] In the description of the utility model, the description of reference term " one embodiment " " some embodiments " " illustrative embodiment " " example " " specific example " or " some examples " etc. means that the specific feature, structure, material or characteristic described in conjunction with the embodiment or example is contained in at least one embodiment or example of the utility model. In the specification, the illustrative description of the above-mentioned term does not necessarily refer to the same embodiment or example. Moreover, the specific feature, structure, material or characteristic described can be combined in any one or more embodiments or examples in a suitable way.
[0062] Although the embodiments of the utility model have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, replacements and variations can be made to these embodiments without departing from the principles and purposes of the utility model, and the scope of the utility model is defined by the claims and its equivalents.
Claims
1. A blood collection assembly, characterized in that, include: Blood collection needle (1), including a connected needle hub (11) and needle tube (12); Sheath (2), the sheath (2) defines a receiving groove (21) and a mounting port (22) communicating with the receiving groove (21); The sheath (2) is pivotally connected to the needle hub (11). The pivot axis (23) of the sheath (2) intersects with the extension direction of the needle tube (12). The mounting port (22) is located on the side of the sheath (2) facing the needle tube (12), so that the needle tube (12) can be received into the receiving groove (21) through the mounting port (22).
2. The blood collection assembly according to claim 1, characterized in that, The pivot axis (23) of the sheath (2) is perpendicular to the extension direction of the needle (12).
3. The blood collection assembly according to claim 1, characterized in that, It also includes locking mechanisms (3); The locking mechanism (3) is located between the sheath (2) and the needle seat (11) and is used to fix the relative position of the sheath (2) and the needle seat (11) when the needle tube (12) is housed in the receiving groove (21).
4. The blood collection assembly according to claim 3, characterized in that, The locking mechanism (3) includes a radial protrusion (31) on the outer peripheral surface of the needle seat (11) and a hook (32) on the sheath (2). When the needle tube (12) is housed in the receiving groove (21), the hook (32) engages the radial protrusion (31).
5. The blood collection assembly according to claim 4, characterized in that, At least two radial protrusions (31) are arranged circumferentially along the needle seat (11); The sheath (2) is provided with at least two of the hooks (32); When the needle tube (12) is received in the receiving groove (21), at least two of the hooks (32) are hooked onto at least two of the radial protrusions (31).
6. The blood collection assembly according to claim 1 or 3, characterized in that, The mounting port (22) has an anti-dislodgement protrusion (24) on at least one of its two opposite sides, the anti-dislodgement protrusion (24) being used to block the side of the needle tube (12) facing the mounting port (22).
7. The blood collection assembly according to claim 6, characterized in that, The anti-detachment protrusion (24) is provided on one of the two opposite sides of the mounting port (22), and the anti-detachment protrusion (24) has a guide portion (241). A guide channel is formed between the guide portion (241) and the other side of the mounting port (22) on opposite sides, and the width of the guide channel gradually decreases on the side away from the mounting port (22).
8. The blood collection assembly according to claim 7, characterized in that, The anti-detachment protrusion (24) is also provided with an arc-shaped groove (242), and the opening of the arc-shaped groove (242) is connected to the end of the guide channel away from the mounting port (22); The arc-shaped groove (242) is used to engage the needle tube (12).
9. The blood collection assembly according to claim 1, characterized in that, It also includes the wing plate (4); The wing plates (4) are two symmetrically arranged on the outer surface of the sheath (2), and the side of the wing plate (4) facing away from the mounting port (22) is the pressing surface (41).
10. The blood collection assembly according to claim 9, characterized in that, The pressing surface (41) includes a first arcuate surface (411) and a second arcuate surface (412) connected together, the first arcuate surface (411) and the second arcuate surface (412) protruding along one side facing each other and towards the mounting opening (22).