CN112958297A

CN112958297A - Convenient five metals of changing sprays paint and uses shower nozzle

Info

Publication number: CN112958297A
Application number: CN202110321562.6A
Authority: CN
Inventors: 苏清贵
Original assignee: Individual
Current assignee: Individual
Priority date: 2021-03-25
Filing date: 2021-03-25
Publication date: 2021-06-15

Abstract

The invention provides a conveniently-replaced spray nozzle for hardware paint spraying, which structurally comprises a fixed main body, a spray nozzle, a positioning rod, an adjusting knob and a clamping rod, wherein the outer wall of the rear end of the spray nozzle is fixedly embedded and clamped on the inner wall of the front end of the fixed main body, the right side of the positioning rod is fixedly welded on the left side of the fixed main body, and the outer wall of the left side of the clamping rod is fixedly fixed on the inner wall of the right side of the fixed main body through threads. And the device is taken out, so that the self-dredging of the device is realized.

Description

Convenient five metals of changing sprays paint and uses shower nozzle

Technical Field

The invention relates to the field of paint spraying processing in hardware production, in particular to a conveniently-replaced hardware spray nozzle for paint spraying.

Background

The spray painting is a phenomenon that spray painting is pushed into a spray gun by air, the spray painting entering the spray painting is beaten into uniform and fine fog drops by the thrust of the air, the spray painting is covered to the surface of a workpiece needing to be sprayed by the guidance of a nozzle, a spray head is a most critical part in a spray painting process, indexes such as spray painting modes, spray painting thickness, uniformity and the like are hooked with the spray head due to the spray painting, the spray painting modes different from those required by different workpieces are dealt with, the spray head is usually replaced by changing the spray head, the spray painting spraying mode is changed by changing the spray head, when the spray head is replaced, partial spray painting residues exist in the spray head due to the operation mode of the spray painting, after the spray head is replaced, the spray painting in the spray head cannot be completely cleaned, and when the spray head is not used for a long time, the spray painting residual in the spray head can be solidified due to standing for a long time, after the solidification of spraying paint, when assembly shower nozzle once more carries out the use, the condition that the inside pipeline of slice messenger shower nozzle appears blockking up can be presented in the spraying paint of solidification, behind the solid-state shower nozzle that blocks up of slice spraying paint, partial position can spray paint, nevertheless makes the spraying paint technology of shower nozzle changed because of the separation that solid-state sprayed paint for the shower nozzle can't be fully complete process the work piece and cause the unable even condition of covering to the work piece surface of spraying paint to appear.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides the hardware spray nozzle convenient to replace, and the hardware spray nozzle solves the problems that after the spray nozzle is replaced, the internal spray paint cannot be completely removed, when the spray nozzle is not used for a period of time, the spray paint remained in the spray nozzle can be solidified due to long-time standing, after the spray paint is solidified and the spray nozzle is assembled again and used, the solidified spray paint can be in a sheet shape, so that a pipeline in the spray nozzle is blocked, after the spray nozzle is blocked by the sheet-shaped solid spray paint, part of the spray paint can be partially sprayed, but the spray paint process of the spray nozzle is changed due to the blocking of the solid spray paint, so that the spray nozzle cannot fully and completely process a workpiece and cannot uniformly cover the spray paint on the surface of the workpiece.

Aiming at the above purpose, the invention is realized by the following technical scheme: a conveniently-replaced hardware spray-paint spray nozzle structurally comprises a fixed main body, a spray nozzle body, a positioning rod, an adjusting knob and a clamping rod, wherein the outer wall of the rear end of the spray nozzle body is fixedly embedded and clamped on the inner wall of the front end of the fixed main body;

the sprayer comprises a positioning block, a fixed plate and a spraying structure, wherein the rear end of the positioning block is welded and fixed on the outer walls of the upper end and the lower end of the spraying structure, the rear end of the fixed plate is fixedly embedded and clamped on the surface of the front end of a fixed main body, the outer wall of the rear end of the spraying structure is movably clamped on the surface of the front end of the fixed plate, the number of the positioning blocks is two, and the two positioning blocks are arranged on the outer walls of the upper end and the lower end of.

Preferably, the injection structure comprises a positioning seat, an end plate, a speed-increasing valve and an injection hole, wherein the outer wall of the rear end of the positioning seat is attached and fixed on the surface of the front end of the fixed plate, the outer wall of the end plate is nested and clamped on the inner wall of the front end of the positioning seat, the surface of the front end of the speed-increasing valve is movably attached to the outer wall of the rear end of the end plate, and the injection hole and the end plate are of an integrated structure.

Preferably, the speed increasing valve comprises a guide mechanism, a ball and a positioning ring, wherein the outer wall of the guide mechanism is nested and matched with the outer wall of the ball, the outer wall of the ball is movably clamped on the inner wall of the positioning ring, and the outer wall of the front end of the positioning ring is fitted and matched with the outer wall of the rear end of the end plate.

Preferably, the guide mechanism comprises an embedded ring, a guide tube, an integrated hole, an inner disc and a rotating mechanism, wherein the outer wall of the embedded ring is movably matched with the surface of the outer wall of the ball, the guide tube and the inner disc are of an integrated structure, the integrated hole and the guide tube are of an integrated structure, the outer wall of the inner disc is embedded and fixed on the inner wall of the embedded ring, the outer wall of the rotating mechanism is movably clamped on the inner wall of the inner disc, the number of the guide tubes is three, the guide tubes are annularly arranged on the outer wall of the rotating mechanism, and the structure of the guide tubes is an impeller-shaped structure.

Preferably, the rotating mechanism comprises a rotator, a limiting groove, a rotating ball and a limiting ring, the front end surface of the rotator is movably matched with the outer wall of the rear end of the rotating ball, the limiting groove and the rotator are of an integrated structure, the outer wall of the rear end of the rotating ball is movably matched with the inner wall of the limiting groove, the outer wall of the rear end of the limiting ring is attached and fixed to the central outer walls of the front end and the rear end of the rotator, and the three rotating balls are arranged on the front end surface of the rotator in a triangular mode.

Preferably, the rotator comprises a ring body, a rotating ring, a sliding rod, three guides and three blades, wherein the centers of the outer walls of the front end and the rear end of the ring body are fitted and fixed between the limiting rings, the outer wall of the rotating ring is movably matched with the inner wall of the ring body, the outer wall of the sliding rod is nested and clamped on the inner wall of the rotating ring, the outer wall of each guide is fixedly embedded on the inner wall of the rotating ring, the outer walls of the blades are welded and fixed on the inner wall of the sliding rod, and the blades are structurally in a fish fin structure and are annularly arranged on the inner wall of the rotating.

Preferably, the guider comprises a driver, a sealing end plate and a positioning hole, wherein the outer wall of the driver is fixedly embedded and clamped on the inner wall of the rotating ring, the outer wall of the rear end of the sealing end plate is fixedly attached to the outer walls of the front end and the rear end of the driver, and the positioning hole and the sealing end plate are of an integrated structure.

Preferably, the driver comprises a rotating impeller, a shell, an opening and closing hinge, a fixed shaft and a stretching bar, wherein the inner wall of the rotating impeller is nested and matched with the inner wall of the center of the shell, the outer wall of the upper end of the shell is movably matched with the outer wall of the lower end of the opening and closing hinge, the inner wall of the opening and closing hinge is embedded and clamped on the outer walls of the two ends of the fixed shaft, the outer wall of the fixed shaft is nested and fixed on the inner wall of the upper end of the stretching bar, the inner wall of the lower end of the stretching bar is nested and matched on the inner walls of the two ends of the shell in.

Advantageous effects

Compared with the prior art, the invention has the following beneficial effects:

the device can be fixed under the limitation of forces at two ends through the positioning rods and the clamping rods arranged at two ends, after the device is fixed, the spray paint in the spray gun is pushed into the device through the airflow, the airflow entering the device and the spray paint are guided by the speed increasing valve, the spray paint and the airflow rotate, the flow velocity of the spray paint and the airflow at the periphery of the air is increased through rotation, the condition that the airflow at the periphery of the spray paint and the airflow at the periphery of the air is reduced is caused, the residual flaky spray paint in the spray nozzle is drawn through the reduced airflow and is taken out of the device, and self-dredging of the device is realized.

Drawings

Fig. 1 is a schematic structural diagram of a conveniently replaceable hardware spray nozzle for paint spraying.

Fig. 2 is a schematic front view of the showerhead of the present invention.

Fig. 3 is a schematic structural view of the inventive spray structure.

Fig. 4 is a schematic structural view of the speed increasing valve of the invention.

Fig. 5 is a schematic sectional structure view of the inventive guide mechanism.

Fig. 6 is a schematic structural diagram of the rotating mechanism of the invention.

Fig. 7 is a schematic sectional structure view of the inventive rotor.

Fig. 8 is a schematic structural view of the inventive guide.

Fig. 9 is a schematic cross-sectional structure of the inventive actuator.

In the figure: the device comprises a fixed main body-1, a spray head-2, a positioning rod-3, an adjusting knob-4, a clamping rod-5, a positioning block-21, a fixed plate-22, a spray structure-23, a positioning seat-a 1, an end plate-a 2, a speed-increasing valve-a 3, a spray hole-a 4, a guide mechanism-b 1, a ball-b 2, a positioning ring-b 3, an embedded ring-c 1, a guide pipe-c 2, an integrated hole-c 3, an inner disc-c 4, a rotating mechanism-c 5, a rotator-d 1, a limiting groove-d 2, a rotating ball-d 3, a limiting ring-d 4, a ring-e 1, a rotating ring-e 2, a sliding rod-e 3, a guide-e 4, a blade-e 5, a driver-f 1, a sealing end plate-f 2, a positioning hole-f 3, a rotating-g 1, a rotating impeller, Outer shell-g 2, hinge-g 3, fixed shaft-g 4 and stretching strip-g 5.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it is obvious that the described embodiments are some, not all embodiments of the present invention, and all other embodiments obtained by those skilled in the art without creative efforts based on the embodiments of the present invention belong to the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

Example 1

As shown in fig. 1 to 5, the invention provides a conveniently-replaced spray nozzle for hardware paint spraying, which structurally comprises a fixed main body 1, a spray nozzle 2, a positioning rod 3, an adjusting knob 4 and a clamping rod 5, wherein the outer wall of the rear end of the spray nozzle 2 is fixedly embedded and clamped on the inner wall of the front end of the fixed main body 1, the right side of the positioning rod 3 is welded and fixed on the left side of the fixed main body 1, the outer wall of the lower end of the adjusting knob 4 is embedded and clamped on the inner wall of the upper end of the fixed main body 1, and the outer wall of the left side of the clamping rod 5 is fixed on the;

the sprayer 2 comprises a positioning block 21, a fixing plate 22 and a spraying structure 23, the rear end of the positioning block 21 is welded and fixed on the outer walls of the upper end and the lower end of the spraying structure 23, the rear end of the fixing plate 22 is fixedly embedded and clamped on the surface of the front end of the fixing main body 1, the outer wall of the rear end of the spraying structure 23 is movably clamped on the surface of the front end of the fixing plate 22, two positioning blocks 21 are arranged, the two positioning blocks are arranged on the outer walls of the upper end and the lower end of the spraying structure 23 in a mirror image mode, and the positioning blocks 21 arranged at the upper end and the lower.

The injection structure 23 is composed of a positioning seat a1, an end plate a2, a speed-increasing valve a3 and an injection hole a4, wherein the outer wall of the rear end of the positioning seat a1 is attached and fixed on the surface of the front end of the fixed plate 22, the outer wall of the end plate a2 is nested and clamped on the inner wall of the front end of the positioning seat a1, the surface of the front end of the speed-increasing valve a3 is movably attached to the outer wall of the rear end of the end plate a2, and the injection hole a4 and the end plate a2 are of an integrated.

The speed increasing valve a3 comprises a guide mechanism b1, a ball b2 and a positioning ring b3, wherein the outer wall of the guide mechanism b1 is nested and matched with the outer wall of the ball b2, the outer wall of the ball b2 is movably clamped and matched with the inner wall of the positioning ring b3, and the outer wall of the front end of the positioning ring b3 is in fit and matched with the outer wall of the rear end of an end plate a 2.

The guide mechanism b1 comprises an embedded ring c1, a guide tube c2, an integrated hole c3, an inner disc c4 and a rotating mechanism c5, wherein the outer wall of the embedded ring c1 is movably matched with the surface of the outer wall of a ball b2, the guide tube c2 and the inner disc c4 are in an integrated structure, the integrated hole c3 and the guide tube c2 are in an integrated structure, the outer wall of the inner disc c4 is fixedly embedded in the inner wall of the embedded ring c1, the outer wall of the rotating mechanism c5 is movably clamped in the inner wall of the inner disc c4, the three guide tubes c2 are annularly arranged on the outer wall of the rotating mechanism c5, the structure is an impeller-shaped structure, and the guide tube c2 arranged at three ends can push the guide tube c2 to rotate from three points after paint and gas enters the guide tube c 2.

The following examples are set forth: when equipment is replaced, the positioning rod 3 and the clamping rod 5 of the equipment are fixed, so that the position of the equipment is limited, after the position of the equipment is limited, a spray gun can be connected to the rear end of the equipment, the equipment is fixed, after the equipment is fixed, the positioning block 21 is screwed to adjust the spraying structure 23, after the spraying structure 23 is adjusted to a certain degree, the spray gun can be opened, the air in the spray gun pushes the spray paint to enter the inside of the speed increasing valve a3 through the opening of the spray gun, the spray paint and the air entering the inside of the speed increasing valve a3 firstly enter the guide pipe c2, the guide pipe c2 at the three ends guides the spray paint to enable the guide pipe c2 to enter the guide pipe c2 in a spiral manner, and the guide pipe c2 is pushed to rotate through the spiral movement of the spray paint, so that the guide mechanism b1 rotates, and the paint entering into the guide pipe c2 is also influenced by the rotation of the guide pipe c2 by the rotation of the guide pipe c2 through the rotation of the guide mechanism b1, and enters into the rotating mechanism c5 through the guide pipe c2 through the rotating state and triggers the rotating mechanism c5 to work, and when the paint is rotated, the rotating paint increases the flow speed of the paint due to the rotating force, and the chip-shaped debris inside the equipment is pushed to move through the increase of the flow speed.

Example 2

As shown in fig. 6 to 9: the rotating mechanism c5 comprises a rotator d1, a limiting groove d2, a rotating ball d3 and a limiting ring d4, the front end surface of the rotator d1 is movably matched with the outer wall of the rear end of the rotating ball d3, the limiting groove d2 and the rotator d1 are of an integrated structure, the outer wall of the rear end of the rotating ball d3 is movably matched with the inner wall of the limiting groove d2, the outer wall of the rear end of the limiting ring d4 is fixedly attached to the central outer walls of the front end and the rear end of the rotator d1, the three rotating balls d3 are arranged in total and are arranged on the front end surface of the rotator d1 in a triangular mode, the three-point positioning condition is presented by the rotating ball d3 arranged at the three ends, and the stability of the rotating ball d3 and the rotator d1 is improved by.

The rotator d1 comprises a ring body e1, a rotating ring e2, a sliding rod e3, a guide device e4 and blades e5, the centers of the outer walls of the front and rear ends of the ring body e1 are attached and fixed between the limiting rings d4, the outer wall of the rotating ring e2 is movably matched with the inner wall of the ring body e1, the outer wall of the sliding rod e3 is nested and clamped on the inner wall of the rotating ring e2, the outer wall of the guide device e4 is embedded and fixed on the inner wall of the rotating ring e2, the outer wall of the blades e5 is welded and fixed on the inner wall of the sliding rod e3, the blades e5 are fin-shaped structures, the number of the blades e 73742 is three, the three blades are annularly arranged on the inner wall of the rotating ring e2, and the fin-shaped structures can guide the paint contacted with the surface of the rotator d1 so.

The guider e4 comprises a driver f1, a sealing end plate f2 and a positioning hole f3, the outer wall of the driver f1 is fixedly embedded in the inner wall of the rotating ring e2, the outer wall of the rear end of the sealing end plate f2 is attached and fixed to the outer walls of the front end and the rear end of the driver f1, and the positioning hole f3 and the sealing end plate f2 are of an integrated structure.

The driver f1 comprises a rotating impeller g1, a shell g2, an opening and closing hinge g3, a fixed shaft g4 and a stretching strip g5, wherein the inner wall of the rotating impeller g1 is nested and matched with the central inner wall of the shell g2, the outer wall of the upper end of the shell g2 is movably matched with the outer wall of the lower end of the opening and closing hinge g3, the inner wall of the opening and closing hinge g3 is fixedly embedded and clamped on the outer walls of two ends of the fixed shaft g4, the outer wall of the fixed shaft g4 is nested and fixed on the inner wall of the upper end of the stretching strip g5, the inner wall of the lower end of the stretching strip g5 is nested and embedded in the inner walls of two ends of the shell g2 in an interference mode, three blades are arranged on the surface of the rotating impeller g1, a reinforcing plate is arranged at the rear ends of the blades, the blades can be rotated by means of force applied.

The following examples are set forth: when paint enters the inside of the equipment and is influenced by parts arranged inside the equipment to rotate, the paint rotates preliminarily to be contacted with the outer wall of a rotator d1 and enters the inside of a rotator d1 under the guidance of a through hole of the rotator d1, after the paint enters the inside of the rotator d1, the paint enters a guide e4 and is blocked by a guide e4, when the paint is blocked by the guide e4, the paint entering the inside of the guide e4 pushes the upper end of a driver f1, so that the two ends of an opening and closing loose-leaf g3 arranged at the upper end of the driver f1 are pushed by the paint and move downwards, the paint can enter the inside of an opening and closing loose-leaf g3 through a gap opened by an opening and closing loose-leaf g3 after the opening and closing loose-leaf g3 is opened, and the paint entering the inside of a shell g2 is guided by a radian of a shell g2 so as to be contacted with a rotating impeller g1, so that the rotating impeller g1 rotates, the rotary impeller g1 rotates to drive paint spraying to rotate, the rotary paint spraying is pushed to enter the ring body e1, the paint spraying can be contacted with the pull blade e5, the push blade e5 enables the blade e5 to drive the sliding rod e3 to rotate, the blade e5 rotates to stir the paint spraying, the paint spraying is enabled to rotate at a high speed, the air on the surface of the paint spraying rotating at a high speed is lower than the external air pressure, the sheet paint spraying inside the equipment is pumped by the low pressure, the sheet paint spraying discharging equipment is wrapped, and the blockage of the equipment is avoided.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.

Claims

1. A hardware spray-paint spray nozzle convenient to replace structurally comprises a fixed main body (1), a spray nozzle (2), a positioning rod (3), an adjusting knob (4) and a clamping rod (5), wherein the outer wall of the rear end of the spray nozzle (2) is fixedly embedded and clamped on the inner wall of the front end of the fixed main body (1), the right side of the positioning rod (3) is fixedly welded on the left side of the fixed main body (1), the outer wall of the lower end of the adjusting knob (4) is embedded and clamped on the inner wall of the upper end of the fixed main body (1), and the outer wall of the left side of the clamping rod (5) is fixedly arranged on the inner wall of the right side of the;

the sprayer (2) is composed of a positioning block (21), a fixed plate (22) and a spraying structure (23), the rear end of the positioning block (21) is welded and fixed on the outer walls of the upper end and the lower end of the spraying structure (23), the rear end of the fixed plate (22) is fixedly embedded and clamped on the surface of the front end of the fixed main body (1), and the outer wall of the rear end of the spraying structure (23) is movably clamped on the surface of the front end of the fixed plate (22).

2. The convenient-to-replace spray head for hardware paint spraying according to claim 1, characterized in that: injection structure (23) comprise positioning seat (a1), end plate (a2), speed-increasing valve (a3), jet orifice (a4), positioning seat (a1) rear end outer wall laminating is fixed in and decides solid board (22) front end surface, end plate (a2) outer wall nested joint in positioning seat (a1) front end inner wall, speed-increasing valve (a3) front end surface activity laminating is in end plate (a2) rear end outer wall, jet orifice (a4) and end plate (a2) structure as an organic whole.

3. The convenient-to-replace spray head for hardware paint spraying according to claim 2, characterized in that: the speed increasing valve (a3) is composed of a guide mechanism (b1), a ball (b2) and a positioning ring (b3), wherein the outer wall of the guide mechanism (b1) is in nested fit with the outer wall of the ball (b2), the outer wall of the ball (b2) is movably clamped on the inner wall of the positioning ring (b3), and the outer wall of the front end of the positioning ring (b3) is in fit with the outer wall of the rear end of an end plate (a 2).

4. The convenient-to-replace spray head for hardware paint spraying according to claim 3, characterized in that: the guide mechanism (b1) comprises an embedded ring (c1), a guide tube (c2), an integration hole (c3), an inner disc (c4) and a rotating mechanism (c5), wherein the outer wall of the embedded ring (c1) is movably matched with the outer wall surface of a ball (b2), the guide tube (c2) and the inner disc (c4) are of an integrated structure, the integration hole (c3) and the guide tube (c2) are of an integrated structure, the outer wall of the inner disc (c4) is fixed on the inner wall of the embedded ring (c1) in a nested mode, and the outer wall of the rotating mechanism (c5) is movably clamped on the inner wall of the inner disc (c 4).

5. The convenient-to-replace spray head for hardware paint spraying according to claim 4, characterized in that: the rotating mechanism (c5) comprises a rotator (d1), a limiting groove (d2), a rotating ball (d3) and a limiting ring (d4), wherein the surface of the front end of the rotator (d1) is movably matched with the outer wall of the rear end of the rotating ball (d3), the limiting groove (d2) and the rotator (d1) are of an integrated structure, the outer wall of the rear end of the rotating ball (d3) is movably matched with the inner wall of the limiting groove (d2), and the outer wall of the rear end of the limiting ring (d4) is attached and fixed to the outer walls of the centers of the front end and the rear end of the rotator (d 1).

6. The convenient-to-replace hardware spray nozzle of claim 5, which is characterized in that: the rotator (d1) comprises a ring body (e1), a rotating ring (e2), a sliding rod (e3), a guider (e4) and a blade (e5), wherein the centers of the outer walls of the front end and the rear end of the ring body (e1) are attached and fixed between limiting rings (d4), the outer wall of the rotating ring (e2) is movably matched with the inner wall of the ring body (e1), the outer wall of the sliding rod (e3) is nested and clamped on the inner wall of the rotating ring (e2), the outer wall of the guider (e4) is fixedly embedded and fixed on the inner wall of the rotating ring (e2), and the outer wall of the blade (e5) is fixedly welded on the inner wall of the sliding rod (e 3).

7. The convenient-to-replace hardware spray nozzle of claim 6, which is characterized in that: the bullnose (e4) comprises driver (f1), sealed end plate (f2), locating hole (f3), driver (f1) outer wall is embedded and is blocked in swivel (e2) inner wall, both ends outer wall around sealed end plate (f2) rear end outer wall laminating is fixed in driver (f1), locating hole (f3) and sealed end plate (f2) are the integrated structure.

8. The convenient-to-replace spray head for hardware paint spraying according to claim 7, characterized in that: the driver (f1) is composed of a rotating impeller (g1), a shell (g2), an opening-closing hinge (g3), a fixed shaft (g4) and a stretching strip (g5), wherein the inner wall of the rotating impeller (g1) is in nested fit with the central inner wall of the shell (g2), the outer wall of the upper end of the shell (g2) is in movable fit with the outer wall of the lower end of the opening-closing hinge (g3), the inner wall of the opening-closing hinge (g3) is in embedded and clamped with the outer walls of the two ends of the fixed shaft (g4), the outer wall of the fixed shaft (g4) is in nested fit with the inner wall of the upper end of the stretching strip (g5), and the inner wall of the lower end of the stretching strip (g 5).