Bite block for clinical gastrointestinal endoscopy

Abstract

The invention relates to the field of medical instruments, in particular to a dental pad for clinical gastrointestinal endoscopy, which comprises a dental pad block, and the center of the dental pad block is communicated with a channel tube for conveying a gastroscope; a pressing plate used for pressing the root of the tongue is arranged below the channel pipe, and a pressing mechanism used for controlling the pressing and supporting force of the pressing plate is arranged between the pressing plate and the channel pipe. The channel pipe comprises a supporting pipe and a contact pipe, the supporting pipe is in sliding fit with the contact pipe, the supporting pipe is fixedly connected with the tooth cushion block, and the contact pipe is located in the supporting pipe; a recovery mechanism for retracting based on gastroscope recovery is arranged in the supporting tube; the tongue depressor is used for preventing the occurrence of tongue depressor in the gastrointestinal endoscopy process and reducing the discomfort of a patient after resuscitation.

Description

Technical Field

[0001] The present invention relates to the field of medical appliances, and particularly to a dental pad for clinical gastroscopy and colonoscopy examinations. Background Art

[0002] In existing painless gastroscopy and colonoscopy examinations, general anesthesia or local anesthesia is usually required to ensure that the patient remains quiet and comfortable during the examination, so as to ensure the smooth progress of the examination and the safety of the patient.

[0003] Due to the influence of anesthetic drugs, the relaxation of the tongue muscles will occur, resulting in an increased risk of tongue posterior prolapse. Moreover, during the examination, the patient is in a supine position, which may make the tongue move backward more easily and cause posterior prolapse. In addition, due to factors such as age growth and enlarged tongue body, tongue posterior prolapse is more likely to occur during gastroscopy and colonoscopy examinations.

[0004] In the prior art, to prevent the patient from biting the gastroscope during the examination, a dental pad is usually used to support the oral cavity, facilitating the doctor to smoothly insert the gastroscope into the digestive tract during the examination; some dental pads directly form a pressing plate to separate the root of the tongue and the upper part of the esophagus to prevent the occurrence of tongue posterior prolapse. The patient will not feel discomfort under anesthesia, but after the patient wakes up, the discomfort may increase due to physical compression. Therefore, the present invention provides a dental pad for clinical gastroscopy and colonoscopy examinations that is easy to use, prevents the occurrence of tongue posterior prolapse during gastroscopy and colonoscopy examinations, and reduces the discomfort of the patient after recovery. Summary of the Invention

[0005] To solve the above problems, the present invention provides a dental pad for clinical gastroscopy and colonoscopy examinations, which is used to prevent the occurrence of tongue posterior prolapse during gastroscopy and colonoscopy examinations and reduce the discomfort of the patient after recovery.

[0006] To achieve the above object, the technical solution of the present invention is as follows: A dental pad for clinical gastroscopy and colonoscopy examinations includes a dental pad block, and a channel tube for conveying a gastroscope is communicated at the center of the dental pad block; a pressing plate for pressing against the root of the tongue is arranged below the channel tube, and a pressing mechanism for controlling the pressing and supporting force of the pressing plate is arranged between the pressing plate and the channel tube;

[0007] The channel tube includes a support tube and a contact tube, the support tube and the contact tube are slidably matched, the support tube is fixedly connected to the dental pad block, and the contact tube is located inside the support tube; a recovery mechanism for shrinking based on the recovery of the gastroscope is arranged inside the support tube

[0008] Further, the contact tube is arc-shaped, and the end of the contact tube away from the dental pad block is lower than the end of the contact tube close to the dental pad block;

[0009] The recovery mechanism includes a plurality of clamping plates rotatably matched with the support tube, a first spring is arranged between the clamping plate and the support tube, and a plurality of transfer plates corresponding to the clamping plates are slidably matched on the support tube, and the transfer plates are located at the junction of the support tube and the contact tube;

[0010] A second spring is fixedly connected between the transfer plate and the support tube. A hook block is fixedly connected to one side of the transfer plate close to the contact tube, and a fixing groove corresponding to the hook block is formed on the contact tube.

[0011] A clamping block is slidably fitted on the contact tube, and a third spring is provided between the clamping block and the contact tube.

[0012] When the contact tube and the clamping plate are both in the initial state, the clamping plate is separated from the transfer plate, and the clamping block is fixedly connected to the contact tube; when the gastroscope is inside the support tube, the clamping plate abuts against the gastroscope, and the clamping plate contacts the transfer plate; when the gastroscope is inside the contact tube, the clamping plate coincides with the inner wall of the contact tube, the transfer plate is separated from the contact tube, and the gastroscope abuts against the clamping block.

[0013] Furthermore, a magnet block is provided between adjacent transfer plates and clamping plates, and the magnet blocks are respectively fixedly connected to the transfer plates and the clamping plates.

[0014] A separation plate is fixedly connected to one end of the contact tube close to the transfer plate. When the contact tube is in the initial state, the separation plate is located between the magnet block and the clamping plate.

[0015] Furthermore, the contact tube is a deformable tube, and a conical rubber membrane is fixedly connected to one end of the contact tube away from the support tube. The side of the rubber membrane close to the contact tube is higher than the side of the rubber membrane away from the contact tube.

[0016] Furthermore, the pressing mechanism includes a central shaft fixedly connected to the pressing plate. The central shaft is rotatably fitted with the support tube, and a torsion spring is sleeved on the central shaft.

[0017] When the contact tube is in the initial state, the pressing plate abuts against the contact tube, and the torsion spring is in a compressed state; when the contact tube is in the longest extended state, the pressing plate is separated from the contact tube, and the torsion spring is in a relaxed state; and one end of the pressing plate is inside the support tube, and the other end of the pressing plate moves to the farthest point from the contact tube.

[0018] Furthermore, horizontal planes are provided on one sides of the support tube and the contact tube close to the pressing plate.

[0019] Furthermore, the dental cushion block includes a first block and a second block that are clamped with each other. A placement groove is formed at the centers of the first block and the second block, and the contact tube is located inside the placement groove.

[0020] Furthermore, an arc-shaped biting groove is formed on one side of the first block and the second block.

[0021] Furthermore, blocking blocks are fixedly connected to both sides of the first block and the second block, and the length of the blocking plate is greater than the lengths of the first block and the second block.

[0022] Furthermore, an installation groove is formed on one side of the blocking block away from the dental cushion block, and an elastic band is detachably connected inside the installation groove. The elastic band is located on both sides of the blocking block.

[0023] The above - mentioned solution has the following beneficial effects:

[0024] 1. In this solution, the tooth pad is used to support the teeth, providing a support space for the channel tube, which facilitates the gastroscope to enter the digestive tract through the inside of the channel tube for examination.

[0025] 2. In this solution, during the examination, the gastroscope slides inside the channel tube, so that the contact tube slides inside the support tube. The extended channel tube facilitates the delivery of the gastroscope to the inside of the digestive tract, reducing the contact damage to the upper esophageal curvature during the insertion of the gastroscope; at the same time, through the movement of the gastroscope after the examination is completed, the channel tube is retracted, so as to reduce the contact stimulation of the channel tube to the upper esophagus after the patient's recovery and reduce the discomfort of the patient.

[0026] 3. In this solution, during the examination, the pressing plate presses against the root of the tongue to reduce the occurrence of the tongue falling back and blocking the trachea, ensuring the safety of the patient during the examination; through the adjustment of the pressing degree of the root of the tongue, that is, keeping the tongue separated from the upper esophagus during the examination and also reducing the compression of the root of the tongue after the examination is completed, reducing the discomfort of the patient after recovery.

[0027] The additional aspects and advantages of the present invention will be partly given in the following description, partly will become obvious from the following description, or will be understood through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is an axonometric view of an embodiment of the tooth pad for clinical gastroscopy and colonoscopy of the present invention;

[0029] Figure 2 is a top view of an embodiment of the tooth pad for clinical gastroscopy and colonoscopy of the present invention;

[0030] Figure 3 is Figure 2 a schematic cross - sectional view taken along the A - A direction in

[0031] Figure 4 is Figure 3 a schematic diagram of the rotation of the pressing plate in

[0032] Figure 5 is Figure 3 an enlarged schematic view of the partial area B in

[0033] Figure 6 is Figure 4 an enlarged schematic view of the partial area C in

[0034] The reference numerals in the accompanying drawings of the specification include: 1, dental cushion block; 11, first block; 12, second block; 13, blocking block; 14, mounting groove; 15, occlusal groove; 2, channel tube; 21, support tube; 22, contact tube; 23, engaging plate; 24, rubber membrane; 25, clamping block; 26, separation plate; 3, pressing plate; 31, central shaft; 4, transfer plate; 41, hook block; 42, magnet block. Detailed implementation manners

[0035] The technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0036] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0037] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "installation", "connection", "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0038] The following will be further described in detail through specific implementation manners:

[0039] Embodiment 1:

[0040] As shown in the Figures 1 to 6 accompanying drawings: A dental pad for clinical gastroscopy examination includes a dental cushion block 1. The dental cushion block 1 includes a first block 11 and a second block 12 that are clamped with each other. A placement groove is opened at the center of the first block 11 and the second block 12, and a channel tube 2 for conveying a gastroscope is clamped in the placement groove; a pressing plate 3 for pressing against the root of the tongue is provided below the channel tube 2.

[0041] The channel tube 2 includes a support tube 21 and a contact tube 22. A horizontal plane is provided on the side of the support tube 21 and the contact tube 22 close to the pressing plate 3. The support tube 21 is in sliding fit with the contact tube 22. The support tube 21 is fixedly connected to the dental pad 1, and the contact tube 22 is located inside the support tube 21. The contact tube 22 is arc-shaped, and the end of the contact tube 22 away from the dental pad 1 is lower than the end of the contact tube 22 close to the dental pad 1. A recovery mechanism for contraction based on the recovery of the gastroscope is provided inside the support tube 21. The recovery mechanism includes a number of engaging plates 23 rotatably fitted with the support tube 21. A first spring (not shown in the figure) is provided between the engaging plate 23 and the support tube 21. A number of transfer plates 4 corresponding to the engaging plates 23 are slidably fitted on the support tube 21. The transfer plate 4 is located at the junction of the support tube 21 and the contact tube 22. A second spring (not shown in the figure) is fixedly connected between the transfer plate 4 and the support tube 21. A hook block 41 is fixedly connected to the side of the transfer plate 4 close to the contact tube 22. A fixing groove corresponding to the hook block 41 is opened on the contact tube 22. A clamping block 25 is slidably fitted on the contact tube 22. A third spring is provided between the clamping block 25 and the contact tube 22.

[0042] When both the contact tube 22 and the engaging plate 23 are in the initial state, the engaging plate 23 is separated from the transfer plate 4, and the clamping block 25 is fixedly connected to the contact tube 22. When the gastroscope is inside the support tube 21, the engaging plate 23 abuts against the gastroscope, and the engaging plate 23 contacts the transfer plate 4. When the gastroscope is inside the contact tube 22, the engaging plate 23 coincides with the inner wall of the contact tube 22, the transfer plate 4 is separated from the contact tube 22, and the gastroscope abuts against the clamping block 25.

[0043] A pressing mechanism for controlling the pressing force of the pressing plate 3 is provided between the pressing plate 3 and the channel tube 2. The pressing mechanism includes a central shaft 31 welded to the pressing plate 3. The central shaft 31 is rotatably fitted with the support tube 21. A torsion spring (not shown in the figure) is sleeved on the central shaft 31.

[0044] When the contact tube 22 is in the initial state, the pressing plate 3 abuts against the contact tube 22, and the torsion spring is in a compressed state. When the contact tube 22 is in the longest extended state, the pressing plate 3 is separated from the contact tube 22, and the torsion spring is in a relaxed state. And one end of the pressing plate 3 is inside the support tube 21, and the other end of the pressing plate 3 moves to the farthest point from the contact tube 22.

[0045] The specific implementation process is as follows: First, during the use of the device, the teeth are brought into contact with the dental pad 1 to provide a support space for the channel tube 2, facilitating the entry of the gastroscope into the digestive tract through the channel tube 2 for examination. The tongue is brought into contact with the horizontal plane to increase the contact area between the support tube 21 and the contact tube 22 when they come into contact with the tongue, improving the stability during the use of the device. And through the detachable first block 11 and second block 12, it is convenient to disassemble and install the dental pad 1 and the contact tube 22 during use, facilitating the disassembly of the device during use and recycling and disinfecting the recyclable parts to achieve continuous recycling of resources.

[0046] During the examination, the gastroscope is slid inside the channel tube 2 to facilitate the sliding of the contact tube 22 inside the support tube 21. The extended channel tube 2 is used to convey the gastroscope to the interior of the digestive tract, reducing the contact damage to the upper esophageal bend during the insertion of the gastroscope.

[0047] When the gastroscope successively passes through the support tube 21 and the contact tube 22 and enters the digestive tract, the gastroscope comes into contact with the clamping plate 23 inside the support tube 21, causing the clamping plate 23 to fit against the surface of the support tube 21. At the same time, the clamping plate 23 gradually abuts against the transfer plate 4, pushing the hook block 41 on the transfer plate 4 to separate from the contact tube 22. At this time, the clamping plate 23 coincides with the inner wall of the contact tube 22, which is convenient for the subsequent continuous movement of the gastroscope and also reduces the obstruction of the clamping plate 23 to the gastroscope during the recycling of the gastroscope. When the gastroscope continuously enters the contact tube 22, the gastroscope abuts against the clamping block 25. Due to the supporting effect of the third spring on the clamping block 25 and the fact that the contact tube 22 is no longer fixed by the hook block 41, the clamping block 25 obstructs the movement of the gastroscope. Thus, before the gastroscope overcomes the limit of the third spring, it can push the contact tube 22 to slide inside the support tube 21 by the clamping block 25 to extend the length of the contact tube 22 to shield and protect the pharynx. When the gastroscope is recycled, the clamping force of the clamping block 25 on both sides of the gastroscope is utilized to drive the contact tube 22 to be recycled and received inside the support tube 21 by the pulling force during the recycling of the gastroscope, facilitating automatic recycling and storage. At the same time, after the gastroscope leaves the support tube 21, the clamping plate 23 releases the pressure on the transfer plate 4 under the elastic support of the compressed first spring, and the clamping plate 23 is reset by the elastic force of the second spring to fix the contact tube 22 again. This protects against the risk of the contact tube 22 falling back and blocking the airway after detection; it also helps to reduce the contact irritation of the channel tube 2 to the upper esophagus after the patient's recovery, reducing the discomfort of the patient.

[0048] During the movement of the pressing plate 3, when the contact tube 22 extends out under the push of the gastroscope, the clamping and fixing of the pressing plate 3 are released, so as to utilize the compressive elastic force of the torsion spring to push the pressing plate 3 to move towards the side away from the contact tube 22, so as to press and fix the root of the tongue to prevent the occurrence of glossoptosis; when the contact tube 22 is in a normal state or the contact tube 22 is retracted, the pressing plate 3 is supported and limited by the contact tube 22, so that the pressing plate 3 retracts and fits with the contact tube 22, maintaining a certain force limit on the root of the tongue and reducing the restriction on the root of the tongue with a large force, so as to reduce the discomfort of the patient during subsequent resuscitation.

[0049] Embodiment 2:

[0050] The difference from Embodiment 1 is that a magnet block 42 is provided between the adjacent transfer plate 4 and the engaging plate 23, and the magnet block 42 is adhesively bonded to the transfer plate 4 and the engaging plate 23 respectively; a separating plate 26 is welded to one end of the contact tube 22 close to the transfer plate 4. When the contact tube 22 is in the initial state, the separating plate 26 is located between the magnet block 42 and the engaging plate 23.

[0051] The specific implementation process is as follows: during the movement of the engaging plate 23 under the push of the gastroscope, through the adsorption and fixing action of the magnet block, the adsorption and fixing of the engaging block are maintained, reducing the obstruction to the recovery of the gastroscope during the reset process of the engaging block and improving the processability during the recovery of the gastroscope; when the contact tube 22 is completely retracted, the separating plate 26 is used to insert between the engaging block and the transfer plate 4 to cut off the magnetic adsorption of the magnet block 42, so as to facilitate the reset of the engaging plate 23 to its original state.

[0052] Embodiment 3:

[0053] The difference from Embodiment 2 is that the contact tube 22 is a deformable tube. In this embodiment, one end of the contact tube 22 away from the support tube 21 is a corrugated tube, and a conical rubber film 24 is adhesively bonded to one end of the contact tube 22 away from the support tube 21. The side of the rubber film 24 close to the contact tube 22 is higher than the side of the rubber film 24 away from the contact tube 22.

[0054] The specific implementation process is as follows: during the contact of the flexible contact tube 22 with the external tissue, it is convenient for the hard contact of the contact tube 22 during the contact with the external tissue, so as to reduce possible injuries; by utilizing the height characteristics of the rubber film 24, it is convenient for the gastroscope to enter the digestive tract. Then, by utilizing the deformation characteristics of the rubber film 24, it is convenient for the contact tube 22 to be retracted during the recovery of the gastroscope, so as to realize the automatic recovery of the contact tube 22.

[0055] Embodiment 4:

[0056] The difference from Embodiment 3 is that an arc-shaped engaging groove 15 is provided on one side of the first block 11 and the second block 12. Blocking blocks 13 are welded on both sides of the first block 11 and the second block 12, and the length of the blocking plate is greater than the lengths of the first block 11 and the second block 12; an installation groove 14 is provided on the side of the blocking block 13 away from the dental cushion block 1, and an elastic band (not shown in the figure) is detachably connected in the installation groove 14, and the side of the elastic band away from the blocking block 13.

[0057] The specific implementation process is as follows: During the installation of the dental cushion block 1, the engaging groove 15 provides a placement space for the occlusion of teeth, facilitating the support and fixation during the patient's examination; and due to the depth setting of the engaging groove 15, when it is necessary to remove the dental cushion block 1, the dental cushion block 1 can be removed only after the upper and lower teeth of the patient are both disengaged from the engaging groove 15, improving the stability during the use of the device. By using the setting of the blocking plate, the placement of the dental cushion block 1 can be fixed and supported to reduce the movement of the dental cushion block 1 towards the inside of the mouth due to loosening, ensuring the safety of the patient during use. Then, through the detachable connection between the elastic band and the installation groove 14, the device can be bound to the head by the elastic band during use, facilitating the gastroscopy examination operation by the physician.

[0058] Obviously, the above embodiments are merely examples given for clear illustration and not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation manners here. And the obvious changes or modifications derived therefrom are still within the protection scope of the present invention.

Claims

1. A dental pad for clinical gastrointestinal endoscopy, comprising a dental pad block (1), wherein the center of the dental pad block (1) is connected to a channel tube (2) for conveying a gastroscope; characterized in that: A pressure plate (3) for supporting the tongue root is provided below the channel tube (2), and a clamping mechanism for controlling the clamping support force of the pressure plate (3) is provided between the pressure plate (3) and the channel tube (2); The channel tube (2) comprises a support tube (21) and a contact tube (22), the support tube (21) and the contact tube (22) are slidably matched, the support tube (21) is fixedly connected to the tooth pad block (1), and the contact tube (22) is located inside the support tube (21); a recovery mechanism for recovering and retracting the gastroscope is provided inside the support tube (21).

2. The mouthpiece for clinical gastrointestinal endoscopy according to claim 1, characterized in that: The contact tube (22) is arc-shaped, and an end of the contact tube (22) away from the tooth pad block (1) is lower than an end of the contact tube (22) close to the tooth pad block (1); The recovery mechanism comprises a plurality of snap-fit ​​plates (23) rotatably matched with the support tube (21), a first spring is provided between the snap-fit ​​plates (23) and the support tube (21), a plurality of transfer plates (4) corresponding to the snap-fit ​​plates (23) are slidably matched on the support tube (21), and the transfer plates (4) are located at the junction of the support tube (21) and the contact tube (22); A second spring is fixedly connected between the transfer plate (4) and the support tube (21); a hook block (41) is fixedly connected to one side of the transfer plate (4) close to the contact tube (22); and a fixing groove corresponding to the hook block (41) is formed on the contact tube (22); A clamping block (25) is slidably fitted on the contact tube (22), and a third spring is provided between the clamping block (25) and the contact tube (22); When the contact tube (22) and the engaging plate (23) are both in the initial state, the engaging plate (23) is separated from the transfer plate (4), and the clamping block (25) is fixedly connected to the contact tube (22); when the gastroscope is located in the support tube (21), the engaging plate (23) abuts against the gastroscope, and the engaging plate (23) contacts the transfer plate (4); when the gastroscope is located in the contact tube (22), the engaging plate (23) overlaps with the inner wall of the contact tube (22), the transfer plate (4) is separated from the contact tube (22), and the gastroscope abuts against the clamping block (25).

3. The dental pad for clinical gastrointestinal endoscopy according to claim 2, characterized in that: A magnet block (42) is provided between adjacent transfer plates (4) and snap-fit ​​plates (23), and the magnet block (42) is fixedly connected to the transfer plate (4) and the snap-fit ​​plate (23) respectively; A separation plate (26) is fixedly connected to one end of the contact tube (22) close to the transfer plate (4); when the contact tube (22) is in an initial state, the separation plate (26) is located between the magnet block (42) and the clamping plate (23).

4. The mouthpiece for clinical gastrointestinal endoscopy according to claim 3, characterized in that: The contact tube (22) is a deformable tube. One end of the contact tube (22) away from the support tube (21) is fixedly connected to a conical rubber membrane (24). The side of the rubber membrane (24) close to the contact tube (22) is higher than the side of the rubber membrane (24) away from the contact tube (22).

5. The mouthpiece for clinical gastrointestinal endoscopy according to claim 4, characterized in that: The clamping mechanism comprises a central shaft (31) fixedly connected to the pressing plate (3), the central shaft (31) and the supporting tube (21) are rotatably matched, and a torsion spring is sleeved on the central shaft (31); When the contact tube (22) is in an initial state, the pressure plate (3) abuts against the contact tube (22), and the torsion spring is in a compressed state; when the contact tube (22) is in a longest extended state, the pressure plate (3) is separated from the contact tube (22), and the torsion spring is in a relaxed state; and one end of the pressure plate (3) is located in the support tube (21), and the other end of the pressure plate (3) moves to the farthest point from the contact tube (22).

6. The mouthpiece for clinical gastrointestinal endoscopy according to claim 5, characterized in that: A horizontal surface is provided on one side of the support tube (21) and the contact tube (22) close to the pressure plate (3).

7. The mouthpiece for clinical gastrointestinal endoscopy according to claim 6, characterized in that: The tooth pad block (1) comprises a first block (11) and a second block (12) which are clamped together. A placement groove is provided at the center of the first block (11) and the second block (12), and the contact tube (22) is located inside the placement groove.

8. The mouthpiece for clinical gastrointestinal endoscopy according to claim 7, characterized in that: One side of the first block (11) and the second block (12) is provided with an arc-shaped engaging groove (15).

9. The mouthpiece for clinical gastrointestinal endoscopy according to claim 8, characterized in that: Blocking blocks (13) are fixedly connected to both sides of the first block (11) and the second block (12), and the length of the blocking plates is greater than the length of the first block (11) and the second block (12).

10. The mouthpiece for clinical gastrointestinal endoscopy according to claim 9, characterized in that: A mounting groove (14) is formed on one side of the blocking block (13) away from the tooth pad block (1), and an elastic band is detachably connected in the mounting groove (14), and the elastic band is located on both sides of the blocking block (13).

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