CN220130805U

CN220130805U - Press pump

Info

Publication number: CN220130805U
Application number: CN202321459058.3U
Authority: CN
Inventors: 阮荣涛; 阮棋江; 蔡毅峰; 杜宗元; 王洪凯
Original assignee: Zhejiang Jinsheng New Materials Co ltd
Current assignee: Zhejiang Jinsheng New Materials Co ltd
Priority date: 2023-06-08
Filing date: 2023-06-08
Publication date: 2023-12-05
Anticipated expiration: 2033-06-08

Abstract

The utility model discloses a pressing pump, which has the technical scheme that: the pump comprises a pump shell, a piston, a pump rod and a pressing sleeve, wherein a pumping pressure cavity is arranged in the pump shell, and the piston is arranged in the pumping pressure cavity and is connected with a piston on the inner wall of the pumping pressure cavity; the first end of the pump rod is connected with the piston, the pressing sleeve is sleeved on the periphery of the second end of the pump rod, and a gap is formed between the pressing sleeve and the pump rod; the inner periphery of the pressing sleeve is clamped with the outer periphery of the pump rod, so that bidirectional movement limiting along the length direction of the pump rod is realized. The utility model can maintain the stable and smooth operation of the piston in the pressing process of the pressing pump.

Description

Press pump

Technical Field

The utility model relates to the technical field of pumps, in particular to a pressing pump.

Background

The pressing pump is a core component of the pressing type packaging bottle such as the emulsion bottle, and is integrally arranged at the bottle cap position of the packaging bottle, so that the discharging of paste or liquid materials such as the emulsion can be realized, and the using convenience of a user can be greatly improved.

The Chinese patent of the utility model with the publication number of CN210455794U discloses a novel emulsion bottle pump core, which is technically characterized by comprising a pressing sleeve, a connecting rod, a connector and a pump body, wherein the connecting rod is inserted into the pressing sleeve and is rotationally locked and connected with the pressing sleeve, the lower end of the connecting rod is sleeved with a piston, the lower end of the pump body is provided with a water sealing cavity, a water sealing sheet is arranged in the water sealing cavity, a liquid suction port is arranged below the water sealing cavity, the connector is pressed and inserted on the pump body, the pressing sleeve is inserted in the connector, a spring is sleeved on the pressing sleeve, and the spring is arranged between the pressing sleeve and the connector.

The piston is a key component in the whole pump core structure, and pumping of liquid is realized by generating sealed piston movement between the piston and the inner wall of the pump body. The sealing state between the piston and the pump body is the key point of the normal operation of the whole pump body.

Among the present push pumps, the structure of mutual fixation is adopted between push sleeve and the connecting rod, and the suit is fixed through interference fit between the two. When in use, the connecting rod is driven to act by the pressing sleeve, so that the piston is driven to generate the pumping action of the piston.

However, if the pressure direction on the pressing sleeve is inclined at a certain angle, the inclined pressing sleeve drives the connecting rod to generate synchronous inclined deflection, and the deflected connecting rod drives the piston to generate corresponding floating deflection, so that certain floating deflection is generated between the piston and the inner wall of the pump body easily, and the sealing state between the piston and the inner wall of the pump body in the movement process of the piston can be influenced.

In order to avoid the influence of leakage possibly generated between the piston and the inner wall of the pump body, the matching precision of other parts of the middle piston needs to be improved, and the influence of deflection generated by the pressing sleeve, the connecting rod and the piston is reduced through higher precision. However, if the precision of the fitting parts is to be improved, the production cost of the pressing pump is greatly increased, and the above problems cannot be effectively solved.

There is therefore a need to propose a new solution to this problem.

Disclosure of Invention

The present utility model has been made to solve the above-mentioned problems, and an object of the present utility model is to provide a pressing pump capable of maintaining a stable and smooth operation of a piston during pressing of the pressing pump.

The technical aim of the utility model is realized by the following technical scheme: the pressing pump comprises a pump shell, a piston, a pump rod and a pressing sleeve, wherein a pumping pressure cavity is arranged in the pump shell, and the piston is arranged in the pumping pressure cavity and is connected with a piston on the inner wall of the pumping pressure cavity; the first end of the pump rod is connected with the piston, the pressing sleeve is sleeved on the periphery of the second end of the pump rod, and a relatively movable gap is formed between the inner periphery of the pressing sleeve and the periphery of the pump rod; the pressing sleeve is clamped with the pump rod mutually, so that bidirectional linkage along the length direction of the pump rod is realized.

The utility model is further characterized in that the inner periphery of the pressing sleeve is provided with a limiting protrusion, and the outer periphery of the pump rod is provided with a limiting groove; the limiting protrusion is clamped in the limiting groove and is provided with a movable space along the length direction of the pump rod.

The utility model is further characterized in that the limiting groove is of an annular structure, and the limiting protrusion is of an annular structure matched with the limiting groove.

The utility model is further arranged that the limiting protrusion is provided with a first limiting surface facing the piston and a second limiting surface facing away from the piston; the limiting groove is provided with a limiting surface III facing away from the piston and a limiting surface IV facing towards the piston, wherein the limiting surface III is opposite to the limiting surface I, and the limiting surface IV is opposite to the limiting surface II.

The utility model is further arranged that the limiting bulge is provided with a limiting surface I facing the piston, and the limiting surface I is in a flaring shape gradually expanding towards the piston; the limiting groove is provided with a limiting surface III opposite to the limiting surface I, and the limiting surface III is in a flaring shape gradually expanding towards the piston and is mutually matched with the limiting surface I.

The utility model is further arranged such that the first end of the pump rod forms a pinch portion that tapers towards the piston.

The utility model is further characterized in that the limiting protrusions are provided with a plurality of notches, and the limiting protrusions form a plurality of annular bumps which are intermittently distributed.

The utility model further provides that the first end of the pump rod is provided with a notch, and the notch extends towards the second end direction and extends to the limit groove.

The utility model is further arranged that the limiting groove is provided with a bottom surface facing the inner circumference, and the limiting protrusion is provided with a top surface facing the outer circumference; the top surface and the bottom surface face to each other, and a gap is formed.

The utility model is further arranged to further comprise a spring, a one-way valve and a mounting sleeve, wherein the spring elastically acts on the pressing sleeve towards the direction deviating from the piston; the pump shell is provided with a liquid inlet, and the one-way valve is arranged at the liquid inlet and is used for one-way conduction towards the pumping pressure cavity; the pump shell is provided with a mounting opening, and the mounting sleeve is of an annular structure and is arranged at the mounting opening and used for propping and pressing the limiting piston; the pressing sleeve extends out of the pump shell from the inner periphery of the mounting sleeve;

the utility model is further arranged that the piston is of an annular structure, the outer periphery of the piston is connected with the piston on the inner wall of the pumping pressure cavity, and the inner periphery of the piston is sleeved on the outer periphery of the pump rod; the piston can be slidingly adjusted along the length direction of the pump rod and has a sliding stroke relative to the pump rod; the second end part of the pump rod is fixedly connected with a limit seat, a stroke conical bulge part is arranged between the limit seat and the pump rod, and the sliding stroke of the piston is limited by the limit seat and the pressing sleeve; a valve hole is formed in the pump rod, the valve hole is opened towards the second end, and a through hole communicated with the valve hole is formed in the position, close to the limiting seat, of the periphery of the second end of the valve rod; and the piston abuts against the limiting seat in the sliding stroke to close the through hole and abuts against the pressing sleeve to open the through hole.

In summary, the utility model has the following beneficial effects:

through adopting mobilizable linkage structure between pressing cover and pump pole, reduce the influence that the slope beat that presses the cover received directly transmits to the piston, reduce the beat that the piston produced and float, ensure that the piston can stabilize normal work. A gap for relative movement is formed between the pressing sleeve and the pump rod, and the pressing force of the inclined deflection applied to the pressing sleeve is absorbed by the independent deflection of the pressing sleeve, so that the inclined deflection generated by the pump rod is reduced, and the influence of the pump rod on the inclined deflection of the piston is correspondingly reduced; the acting force in the pressing direction of the pressing sleeve can still be transmitted through mutual pressing, so that stable and smooth operation of the pump rod and the piston can be ensured.

Drawings

Fig. 1 is a perspective view of a pressing pump of the present utility model;

FIG. 2 is a cross-sectional view of a push pump of the present utility model;

FIG. 3 is a schematic view of the connection structure of the pressing sleeve and the pump rod of the present utility model;

FIG. 4 is an exploded view of a push pump of the present utility model;

fig. 5 is an exploded cross-sectional view of a push pump according to the present utility model.

Reference numerals: 1. a pump housing; 11. a liquid inlet; 12. a mounting port; 13. a pumping chamber; 2. a piston; 3. a pump rod; 301. a first end; 302. a second end; 31. a limit seat; 32. a tapered boss; 33. a valve hole; 34. a through hole; 35. a limit groove; 351. a limiting surface III; 352. a limit surface IV; 353. a bottom surface; 36. a notch; 37. a pinch portion; 4. pressing the sleeve; 41. a limit protrusion; 411. a first limiting surface; 412. a second limiting surface; 413. a top surface; 42. a notch; 5. a mounting sleeve; 6. a one-way valve; 61. a one-way plug; 62. a support ring; 63. a connecting sheet; 7. a gap; 8. a movable space.

Detailed Description

The following description of the embodiments of the present utility model will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present utility model, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

The embodiment discloses a pressing pump, as shown in fig. 1-5, comprising a pump shell 1, a piston 2, a pump rod 3, a pressing sleeve 4, a spring, a one-way valve 6 and a mounting sleeve 5, wherein the components are mutually combined to form the pressing pump, and liquid material pumping can be realized through pressing.

The pump housing 1 has a cylindrical structure, and a hollow pumping chamber 13 is provided therein. The pumping pressure cavity 13 is of a cylindrical structure, the piston 2 is matched with the pumping pressure cavity 13, and the piston 2 is arranged in the pumping pressure cavity 13 and forms a piston 2 connecting structure with the inner wall of the pumping pressure cavity 13.

One end of the pump shell 1 is provided with a liquid inlet 11, the other end is provided with a mounting opening 12, the liquid inlet 11 can be used for feeding liquid into a pumping pressure cavity 13, and the mounting opening 12 is used for mounting other parts. The check valve 6 is arranged at the liquid inlet 11, the check valve 6 comprises a supporting ring 62, a check plug 61 and a connecting sheet 63, the check plug 61 is connected to the inner periphery of the supporting ring 62 through the connecting sheet 63, and the floating adjustment of the check valve 6 can be realized.

The support ring 62 is embedded and fixed at the inner side of the liquid inlet 11, the unidirectional plug 61 is in a hemispherical structure, the unidirectional plug 61 is propped against the inner side of the liquid inlet 11, and the propping seal is realized with the liquid inlet 11. In the process that the liquid inlet 11 faces the pumping pressure cavity 13 to feed liquid, the liquid material pushes the one-way plug 61 open, and one-way liquid feeding can be realized at the liquid inlet 11; in the process of pressing the pumping pressure cavity 13, the liquid material presses the unidirectional plug 61 against the liquid inlet 11, so that the unidirectional sealing of the liquid inlet 11 is realized.

The installation sleeve 5 is of an annular structure, is installed at the installation opening 12, and part of the installation sleeve 5 stretches into the installation opening 12, so that the installation and the mutual clamping and fixing of the installation opening 12 can be realized. By means of the mounting sleeve 5, the movement of the piston 2 is limited, and the piston 2 is stably limited in the pumping chamber 13. The outer peripheral dimension of the pressing sleeve 4 is matched with the inner peripheral dimension of the mounting sleeve 5, so that the pressing sleeve 4 can be smoothly pressed and adjusted.

The length direction of the pump rod 3 is arranged along the moving direction of the piston 2, and the piston 2 and the pressing sleeve 4 can be connected with each other through the pump rod 3, so that the pressing sleeve 4 can drive the piston 2 to move. The first end 301 of the pump rod 3 extends into the piston 2 and is connected with the piston 2; the second end 302 of the pump rod 3 extends in the direction of the pressing sleeve 4 and is connected to the pressing sleeve 4.

The piston 2 is of an annular structure, the outer periphery of the piston 2 is connected with the piston 2 on the inner wall of the pumping pressure cavity 13, and the inner periphery of the piston is sleeved on the outer periphery of the pump rod 3. The piston 2 can be slidingly adjusted along the length direction of the pump rod 3, and has a sliding stroke relative to the pump rod 3, and the piston 2 realizes the pumping of the piston 2 in the sliding process relative to the pump shell 1.

An outwardly protruding limit seat 31 is formed at the end of the second end 302 of the pump rod 3, and the limit seat 31 has a ring structure, so that the movement of the piston 2 can be limited. The conical protruding part 32 is arranged between the limit seat 31 and the pump rod 3 in a stroke way, and when the piston 2 moves towards the limit seat 31, the lower end surface of the piston 2 can be mutually propped against the conical protruding part 32, so that the sealing between the piston 2 and the pump rod 3 is realized.

The sliding stroke of the piston 2 relative to the pump rod 3 is realized to press the limit through the limit seat 31 and the pressing sleeve 4, the upper end of the piston 2 is realized to block the limit through the lower side of the pressing sleeve 4, and the lower end is blocked and limited through the limit seat 31 and the conical protruding part 32. A valve hole 33 is formed in the pump rod 3, the valve hole 33 is opened towards the second end 302, a through hole 34 is formed in the position, close to the limiting seat 31, of the outer periphery of the second end 302 of the valve rod, and the valve hole 33 is communicated with the outer periphery of the pump rod 3 through the through hole 34, so that the valve hole 33 is communicated with the outer periphery of the pump rod 3.

In the sliding stroke of the piston 2, the piston 2 moves downwards relative to the pump rod 3 and then abuts against the limiting seat 31, the piston 2 abuts against the conical protruding portion 32, sealing between the piston 2 and the pump rod 3 is achieved, and the through hole 34 can be closed. After the piston 2 moves upwards relative to the pump rod 3, the piston 2 is propped against the pressing sleeve 4, the conical protrusions of the piston 2 are separated from each other, the through holes 34 are opened, and then liquid material output can be achieved through the pump rod 3.

The spring housing is mounted on the outer peripheral position (not shown in the figure) of the pressing housing 4, and both ends of the spring are respectively pressed against the stepped surfaces of the pressing housing 4 and the mounting housing 5. The elastic action on the pressing sleeve 4 towards the direction deviating from the piston 2 can be realized through the spring, so that the pressing sleeve 4 can realize automatic elastic reset after being pressed. And, after the pressing sleeve 4 is reset, the piston 2 is limited by the mounting sleeve 5, so that the piston 2 can seal the through hole 34 on the periphery of the first end 301 of the pump rod 3.

The pressing sleeve 4 and the pump rod 3 form a movable connecting structure, the pressing sleeve 4 is sleeved on the outer periphery of the second end 302 of the pump rod 3, and a gap 7 is formed between the inner periphery of the pressing sleeve 4 and the outer periphery of the pump rod 3, so that mutual inclination deflection movement of the moving positions can be generated between the pressing sleeve 4 and the pump rod 3. During the pressing of the pump rod 3 by the pressing sleeve 4, the pump rod 3 is axially supported by the piston 2, and the piston 2 and the pumping cavity 13 are kept in a stable connection state. Namely, when the pressing sleeve 4 generates inclined deflection in the pressing process, the pressing sleeve 4 can drive the pump rod 3 to press downwards, and then in the rising process of the pressing sleeve 4, the pump rod 3 can be driven to recover, so that the pressing sleeve 4 and the pump rod 3 are maintained to realize bidirectional linkage in the pressing and lifting processes.

The inner periphery of the pressing sleeve 4 is clamped with the outer Zhou Xianghu of the pump rod 3, so that the pressing sleeve 4 can form force transmission with the pump rod 3, and bidirectional movement limiting along the length direction of the pump rod 3 is realized.

As shown in fig. 2-5, a limit protrusion 41 is provided on the inner periphery of the pressing sleeve 4, and a limit groove 35 is provided on the outer periphery of the pump rod 3. Spacing protruding 41 and spacing sunken mutual adaptation for spacing protruding 41 can block into spacing recess 35 in, make the structure of mutual joint between pump pole 3 and the press sleeve 4. The spacing protrusion 41 is smaller than the spacing groove 35, so that a movable space 8 for movement is formed between the spacing protrusion 41 and the spacing groove 35, and a movable space 8 along the length direction of the pump rod 3 can be formed between the pressing sleeve 4 and the pump rod 3. The pressing sleeve 4 generates adaptive inclined deflection in the pressing process, the pressing sleeve 4 does not drive the pump rod 3 to generate inclined deflection, the pump rod 3 can still stably follow the movement of the piston 2, further the piston 2 cannot generate inclined deflection, and the smooth and stable movement of the piston 2 can be kept.

The limiting groove 35 is of an annular structure, the limiting protrusion 41 is of an annular structure matched with the limiting groove 35, and then an annular clamping structure is formed between the pressing sleeve 4 and the pump rod 3, so that the connection state between the pressing sleeve 4 and the pump rod 3 can be stably maintained.

The limiting projection 41 has a first limiting surface 411 facing the piston 2 and a second limiting surface 412 facing away from the piston 2. The limiting groove 35 is provided with a third limiting surface 351 and a fourth limiting surface 352, the third limiting surface 351 and the first limiting surface 411 face oppositely, and can be pressed against each other, so that pressure in the direction of the piston 2 is transmitted; the fourth limit surface 352 and the second limit surface 412 face oppositely, and can generate mutual propping, so that pressure in the direction opposite to the piston 2 is transmitted, and the pressing sleeve 4 and the pump rod 3 can be linked through propping transmission among the limit surfaces.

In addition, the limiting groove 35 also has a bottom surface 353 facing the inner periphery, and the bottom surface 353 has an annular structure; while the limit projection 41 has a top surface 413 facing the outer periphery, the top surface 413 also being of annular configuration. The top surface 413 and the bottom surface 353 face each other, and a gap 7 is formed therebetween, and by the gap 7, an adaptive tilting movement may be generated between the limit projection 41 and the limit groove 35, so that the movable linkage structure between the pressing sleeve 4 and the pump rod 3 is maintained.

Further, the first limiting surface 411 of the limiting protrusion 41 is in a flaring shape gradually expanding toward the piston 2; the third limit surface 351 at the limit groove 35 is in a flaring shape gradually expanding towards the piston 2, and the first limit surface 411 and the third limit surface 351 are mutually matched to form a conical structure which is mutually sleeved. On the one hand, the conical structure can generate a certain centering effect between the first limiting surface 411 and the second limiting surface 412 in the pressing process of the pressing sleeve 4, so that the stability of the pressing process of the pressing sleeve 4 is improved; on the other hand, the first flaring limiting surface 411 can form a guiding structure, and the pump rod 3 can play a guiding role in the process of pressing the pressing sleeve 4, so that the smoothness of clamping the two parts is improved.

Further, the first end 301 of the pump rod 3 is formed with a tapered portion 37 that gradually decreases toward the piston 2, and the tapered portion 37 can also be inclined. The shrinkage part 37 of the conical structure is mutually matched with the first limiting surface 411, so that the smoothness of the clamping connection of the pressing sleeve 4 and the pump body can be further improved.

Further, the limiting protrusion 41 is provided with a plurality of notches 42, and the limiting protrusion 41 can be divided by the notches 42, so that the limiting protrusion 41 forms a plurality of annular protruding blocks which are intermittently distributed. The lug is arc structure, and solitary lug has more nimble deformation range for the annular spacing bulge loop of whole way, and then improves spacing protruding 41 and spacing recess 35 smooth and easy in-process of mutual joint, does benefit to and presses and assembles each other between cover 4 and the pump pole 3.

Further, a notch 36 may be formed at the first end 301 of the pump rod 3, and the notch 36 extends from the end face of the second end 302 toward the second end 302 of the pump rod 3 to a position at the limit groove 35. The position of the second end 302 of the pump rod 3 can be divided into two parts by the notch 36, and a space for deformation is formed at the position of the notch 36, so that the pump rod 3 can be clamped smoothly in the process of clamping the pressing sleeve 4.

The above description is only a preferred embodiment of the present utility model, and the protection scope of the present utility model is not limited to the above examples, and all technical solutions belonging to the concept of the present utility model belong to the protection scope of the present utility model. It should be noted that modifications and adaptations to the present utility model may occur to one skilled in the art without departing from the principles of the present utility model and are intended to be within the scope of the present utility model.

Claims

1. The pressing pump is characterized by comprising a pump shell (1), a piston (2), a pump rod (3) and a pressing sleeve (4), wherein a pumping cavity (13) is arranged in the pump shell (1), and the piston (2) is arranged in the pumping cavity (13) and is connected with the piston (2) on the inner wall of the pumping cavity (13); the first end of the pump rod (3) is connected with the piston (2), the pressing sleeve (4) is sleeved on the outer periphery of the second end of the pump rod (3), and a relatively movable gap (7) is formed between the inner periphery of the pressing sleeve (4) and the outer periphery of the pump rod (3); the pressing sleeve (4) is clamped with the pump rod (3) mutually, so that bidirectional linkage along the length direction of the pump rod (3) is realized.

2. A pressing pump according to claim 1, characterized in that the inner periphery of the pressing sleeve (4) is provided with a limit protrusion (41), and the outer periphery of the pump rod (3) is provided with a limit groove (35); the limiting bulge (41) is clamped in the limiting groove (35) and is provided with a movable space (8) along the length direction of the pump rod (3).

3. A pressing pump according to claim 2, characterized in that the limit groove (35) has an annular structure, and the limit projection (41) has an annular structure adapted to the limit groove (35).

4. A pressing pump according to claim 2, characterized in that the limit projection (41) has a limit face one (411) facing the piston (2) and a limit face two (412) facing away from the piston (2); the limiting groove (35) is provided with a limiting surface III (351) facing away from the piston (2) and a limiting surface IV (352) facing the piston (2); the third limit surface (351) is opposite to the first limit surface (411), and the fourth limit surface (352) is opposite to the second limit surface (412).

5. A pressing pump according to claim 3, characterized in that the limit projection (41) has a limit face one (411) facing the piston (2), the limit face one (411) being in the form of a flaring gradually expanding toward the piston (2); the limiting groove (35) is provided with a limiting surface III (351) opposite to the limiting surface I (411), and the limiting surface III (351) is in a flaring shape gradually expanding towards the piston (2) and is mutually matched with the limiting surface I (411).

6. A push pump according to claim 3, characterized in that the first end of the pump rod (3) forms a constriction (37) tapering in the direction of the piston (2).

7. A pressing pump according to claim 3, characterized in that the limit projection (41) is provided with a plurality of notches (42), and the limit projection (41) forms a plurality of annular intermittently distributed projections.

8. A push pump according to claim 3, characterized in that the first end of the pump rod (3) is provided with a notch (36), which notch (36) extends in the direction of the second end and to the limit groove (35).

9. A pressing pump according to claim 3, characterized in that the limit groove (35) has a bottom surface (353) facing the inner periphery, and the limit projection (41) has a top surface (413) facing the outer periphery; the top surface (413) faces the bottom surface (353), and a gap (7) is formed.

10. A pressing pump according to any of claims 1-9, further comprising a spring, a non-return valve (6) and a mounting sleeve (5), said spring acting resiliently on the pressing sleeve (4) in a direction away from the piston (2); the pump shell (1) is provided with a liquid inlet (11), and the one-way valve (6) is arranged at the liquid inlet (11) and is used for one-way conduction towards the pumping pressure cavity (13); the pump shell (1) is provided with a mounting opening (12), and the mounting sleeve (5) is of an annular structure and is mounted at the mounting opening (12) and used for propping against the limiting piston (2); the pressing sleeve (4) extends out of the pump shell (1) from the inner periphery of the mounting sleeve (5);

the piston (2) is of an annular structure, the outer periphery of the piston is connected with the piston (2) on the inner wall of the pumping pressure cavity (13), and the inner periphery of the piston is sleeved on the outer periphery of the pump rod (3); the piston (2) can be slidingly adjusted along the length direction of the pump rod (3) and has a sliding stroke relative to the pump rod (3); the second end part of the pump rod (3) is fixedly connected with a limit seat (31), a stroke conical protruding part (32) is arranged between the limit seat (31) and the pump rod (3), and the sliding stroke of the piston (2) is limited by pressing the limit seat (31) and the pressing sleeve (4); a valve hole (33) is formed in the pump rod (3), the valve hole (33) is opened towards the second end, and a through hole (34) communicated with the valve hole (33) is formed in the periphery of the second end of the valve rod, close to the limit seat (31); in the sliding stroke, the piston (2) abuts against the limiting seat (31) to close the through hole (34), and abuts against the pressing sleeve (4) to open the through hole (34).