CN219777668U - Soil pH value quick-measuring instrument - Google Patents

Abstract

The utility model discloses a soil pH value quick-measuring instrument which comprises a soil pH value quick-measuring instrument body, wherein the soil pH value quick-measuring instrument body comprises an operating rod and a probe arranged and fixed in the operating rod, and a protection self-cleaning mechanism matched with the probe is arranged on the outer side of the operating rod. According to the utility model, the inner protective tube, the outer protective tube, the elastic rubber ring and the limit blocking assembly are arranged, so that the probe is conveniently and stably surrounded and protected when not in use, the risk of damage to the probe when the probe falls off accidentally during carrying is reduced, the protection effect of the probe is improved, the safety carrying is facilitated, the elastic guide support assembly and the slag scraping cleaning assembly are combined, after the locking of the outer protective tube is relieved, the outer protective tube is conveniently and automatically extruded by using elasticity when the probe is inserted into the ground for pH value detection, and soil impurities can be automatically scraped and cleaned on the outer side of the probe when the probe is pulled out after detection, so that the cleanliness is improved, the cleaning work of the outer side of the probe is not required to be independently carried out by personnel, and the use is convenient.

Description

Soil pH value quick-measuring instrument

Technical Field

The utility model relates to the technical field of soil detection, in particular to a soil pH value quick-measuring instrument.

Background

The periodic detection of the pH value of the soil is a basic monitoring means for the soil in the environment monitoring work, so that environment monitoring staff can know the basic property of the soil, in addition, the pH value of the soil is one of the extremely important basic properties in the detection of various properties of the soil, the effectiveness of nutrient elements necessary for most crops is related to the pH value of the soil, and in the soil environment monitoring work, a soil pH value quick-measuring instrument is often used for detecting the pH value of the soil.

The publication No. CN218445487U discloses a soil pH value quick-measuring instrument, which comprises a machine body, wherein the machine body consists of an operating rod and a probe, and further comprises a protection mechanism arranged on the operating rod and used for protecting the probe in the detection process and a reset mechanism used for resetting the probe, wherein the protection mechanism comprises an installation cavity arranged on the operating rod, a protection air bag is arranged in the installation cavity, and a first unidirectional mechanism and a second unidirectional mechanism are arranged on two sides of the protection air bag; this soil pH value tachometer, through protection machanism's setting, be convenient for protect the probe at the in-process of inserting soil inside, avoid the probe to offset with hard objects such as stone, rubble, metal, lead to the probe to warp and damage, improved soil pH value tachometer's life.

The soil pH value quick-measuring instrument disclosed in the above patent is used for detecting the soil pH value by inserting a probe of the soil pH value quick-measuring instrument into soil, but the soil pH value quick-measuring instrument still has some defects:

1. when the probe is not used, the probe is completely exposed outside, the risk of damage caused by impact when the probe accidentally falls down in carrying is high, the protection effect is not ideal when the probe is not used, and the safety carrying is not facilitated; 2. the structure for automatically cleaning the outer side of the probe is lacking when the probe is inserted into the soil and pulled out, so that a large amount of soil impurities are easy to adhere to the outer side of the probe when the probe is pulled out, and a person is required to independently clean the probe; in view of the above-mentioned shortcomings, the utility model is improved on the basis of the shortcomings, so that a soil pH value quick-measuring instrument is provided for solving the problems.

Disclosure of Invention

The utility model aims to provide a soil pH value quick-measuring instrument so as to solve the problems in the background technology.

In order to achieve the above purpose, the present utility model provides the following technical solutions: the soil pH value quick-measuring instrument comprises a soil pH value quick-measuring instrument body, wherein the soil pH value quick-measuring instrument body comprises an operating rod and a probe which is installed and fixed in the operating rod, other structures and principles of the soil pH value quick-measuring instrument body are the prior art, and the technology is also disclosed in the prior art CN218445487U and is not further described; the outer side of the operating rod is provided with a protection self-cleaning mechanism matched with the probe;

the protection self-cleaning mechanism comprises a fixed sleeve arranged at the bottom of the outer side of the operating rod, an inner protecting pipe is fixedly connected to the bottom of the fixed sleeve, the probe is positioned in the inner protecting pipe, an outer protecting pipe is sleeved on the inner protecting pipe in a sliding manner, a scraping cleaning component which is in movable contact with the bottom of the outer side of the probe is sleeved in the inner fixed sleeve of the outer protecting pipe, the inner protecting pipe and the outer protecting pipe are matched to form an integral surrounding and protecting structure for the probe, and the risk of collision impact damage of the probe when the probe is carried accidentally is reduced; the scraping cleaning component is used for automatically scraping and cleaning the outer side of the probe when the probe is inserted into the ground and pulled out;

the two sides of the top of the scraping and cleaning assembly are fixedly connected with elastic guide support assemblies, the inner protective tube is sleeved on the two elastic guide support assemblies in a sliding manner, the elastic guide support assemblies are used for vertically and elastically supporting the outer protective tube and providing an environment for the outer protective tube to slide on the inner protective tube when the outer protective tube is extruded by the ground, so that the effect that the probe automatically penetrates out downwards when pressure is applied downwards is achieved;

limiting grooves are formed in the inner walls of the two sides of the outer protection tube, limiting sliding blocks are fixedly connected to the bottoms of the two sides of the inner protection tube and are slidably connected in the corresponding limiting grooves, iron sheets are fixedly embedded in the left side of the limiting sliding blocks and the left inner wall of the left limiting grooves, a blocking limiting assembly is magnetically attracted to the left side of the iron sheets on the right side, the left side of the blocking limiting assembly extends out of the outer protection tube, the blocking limiting assembly is used for blocking and limiting the outer protection tube when the outer protection tube is not used, and locking of the outer protection tube when the outer protection tube is not used is facilitated.

Preferably, the scraping and cleaning assembly comprises a circular ring fixedly sleeved in the outer protective tube, an annular scraper is fixedly sleeved in the circular ring, and the inner side of the annular scraper is a cutting edge surface and is in movable contact with the bottom of the outer side of the probe; the circular ring and the annular scraper are matched, after the probe penetrates out of the test through the displacement of the outer protective tube, the annular scraper is driven to reset through the circular ring when the outer protective tube moves back, and the cleaning of the attached soil impurities is carried out on the outer side of the probe, so that the effect of automatically cleaning the probe after use is achieved.

Preferably, the elastic guide support assembly comprises guide posts, the bottom ends of the two guide posts are fixedly connected with two sides of the top of the circular ring respectively, springs are movably sleeved on the guide posts, the top ends and the bottom ends of the springs are fixedly connected with the bottom ends of the inner protection pipes and the top of the circular ring respectively, and the inner protection pipes are slidably sleeved on the two guide posts; the guide post and the spring cooperation that set up utilize the guide post to realize the vertical direction of ring to this realizes the vertical direction to outer pillar, utilize the spring to realize outer pillar elastic support through the ring, when outer pillar is not in the lock solid state, utilize elastic support, can make outer pillar and ground contact when downwards exerting pressure, utilize the interior pillar of pressure drive that applys to slide in outer pillar, and compress the spring, and drive the probe and wear out to insert in the soil test pH valve, utilize the elasticity drive outer pillar of spring to move back after the use, with this realization drive annular scraper moves back and scrapes and move the clearance work.

Preferably, the blocking limiting assembly comprises a blocking rod movably contacted with the bottom of the left limiting slide block, the left end of the blocking rod extends to the outer side of the outer protective tube and is fixedly connected with a pull head, the outer protective tube is sleeved on the blocking rod in a sliding manner, the right side of the top of the blocking rod is fixedly connected with a magnet, the right side of the magnet is adsorbed with the left side of the right iron sheet, and the magnet is matched with the left iron sheet; the stop lever and the magnet are matched, the bottom of the left limit sliding block is blocked by the stop lever, so that the locking of the outer protective tube is realized when the probe is not used, when the stop lever is pulled leftwards to separate from the left limit sliding block to release the locking, the stop lever drives the magnet to be adsorbed to the left and the left iron sheet, the condition that the outer protective tube can slide and displace on the inner protective tube can be provided after the locking is released, the locking state is utilized, the locking and displacement preventing effect of the outer protective tube can be ensured when the probe is not used, and the stable protection effect of the probe is realized when the probe is not used.

Preferably, the bottom end of the outer protective tube is fixedly adhered with an elastic rubber ring, and the bottom position of the elastic rubber ring is lower than the bottom position of the probe.

Preferably, threaded holes are formed in the inner walls of the two sides of the fixing sleeve, knob type bolts are sleeved in the threaded holes in a threaded mode, and one ends, close to the two knob type bolts, of the two knob type bolts are respectively in close contact with the two sides of the operating rod.

Preferably, guide grooves are formed in two sides of the bottom end of the inner protection tube, and the inner walls of the guide grooves are in sliding contact with the outer sides of the corresponding guide posts.

Compared with the prior art, the utility model has the beneficial effects that:

1. according to the soil pH value quick-measuring instrument, the inner protective tube, the outer protective tube, the elastic rubber ring and the blocking limiting component are matched, so that when the outer protective tube is in a locked state of the blocking limiting component, the outer protective tube can be used for forming stable surrounding protection on the probe, the phenomenon that the probe is directly impacted when the carrying accident falls is avoided, the risk of damage to the probe when the carrying accident falls is reduced, and the protection effect when the probe is not used is improved;

2. this soil pH value tachometer, through the fender limit subassembly that sets up, interior pillar, outer pillar, elastic guidance support subassembly and scrape the cooperation of sediment clearance subassembly, after utilizing fender limit subassembly to remove the lock solid to outer pillar, when inserting the probe on ground downwards, utilize the extrusion force with ground can the automatic drive outer pillar to remove the shielding to the probe, make things convenient for the probe to directly expose and insert the detection, and can utilize the elasticity drive outer pillar of spring to move back and reset when extracting after detecting, thereby realize that the drive scraper moves back to the outside of probe and scrape the clearance, realize automatic effect to the outside clearance soil impurity of probe after the use, in order to make things convenient for the detection work to soil pH value again in the soil environment monitoring work next time.

According to the utility model, the inner protective tube, the outer protective tube, the elastic rubber ring and the blocking limiting component are arranged, so that the probe can be conveniently and stably surrounded and protected when the probe is not used, the risk of damage to the probe when the probe falls off accidentally during carrying is reduced, the protection effect of the probe when the probe is not used is improved, the safety carrying is facilitated, the elastic guide supporting component and the slag scraping cleaning component are combined, after the locking of the outer protective tube is relieved, the outer protective tube is conveniently and automatically extruded by using elasticity when the probe is inserted into the ground for pH value detection, and soil impurities can be automatically scraped and cleaned on the outer side of the probe when the probe is pulled out after detection, so that the cleaning performance is improved, and the cleaning work of the outer side of the probe is not required to be independently carried out by personnel.

Drawings

FIG. 1 is a schematic overall perspective view of the present utility model;

FIG. 2 is a schematic view of a front cross-sectional structure of the present utility model;

fig. 3 is an enlarged schematic view of the portion a in fig. 2 according to the present utility model.

In the figure: 1. an operation lever; 101. a probe; 2. a fixed sleeve; 3. an inner protective tube; 4. an outer protective tube; 5. a circular ring; 6. an annular scraper; 7. a guide post; 8. a spring; 9. a guide groove; 10. a limit groove; 11. a limit sliding block; 12. a stop lever; 13. a magnet; 14. iron sheet; 15. an elastic rubber ring; 16. knob type bolts.

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.

As shown in fig. 1 to 3, the soil ph value rapid measuring instrument provided by the embodiment comprises a soil ph value rapid measuring instrument body, wherein the soil ph value rapid measuring instrument body comprises an operating rod 1 and a probe 101 installed and fixed in the operating rod 1, and a protection self-cleaning mechanism matched with the probe 101 is arranged on the outer side of the operating rod 1;

the protection self-cleaning mechanism comprises a fixed sleeve 2 arranged at the bottom of the outer side of an operating rod 1, threaded holes are formed in the inner walls of the two sides of the fixed sleeve 2, knob type bolts 16 are sleeved in the threaded holes, one ends of the two knob type bolts 16, which are close, are respectively in close contact with the two sides of the operating rod 1, the two knob type bolts 16 are used for locking the fixed sleeve 2 on the operating rod 1, the two knob type bolts 16 are used for locking the fixed sleeve 2, the fixed sleeve 2 and the operating rod 1 are conveniently detached and assembled in a follow-up mode, the inner side wall of the fixed sleeve 2 is contacted with the outer side of the operating rod 1, the bottom of the fixed sleeve 2 is fixedly connected with an inner protection tube 3, a probe 101 is positioned in the inner protection tube 3, an outer protection tube 4 is sleeved on the inner protection tube 3 in a sliding manner, the bottom end of the outer protection tube 4 is fixedly connected with an elastic rubber ring 15, the bottom position of the elastic rubber ring 15 is lower than the bottom position of the probe 101, the elastic rubber ring 15 is used for preventing the probe 101 from being damaged by direct impact when the probe 101 is not used for being accidentally dropped, the outer protection assembly is formed by the impact damage when the probe 101 is accidentally dropped, and the inner protection assembly is in contact with the outer protection tube 101, and the outer protection tube 101 is in a collision protection assembly is formed by the outer protection assembly, and the outer protection tube 101 is in a collision protection assembly, and the risk is formed by the outer protection assembly, and the outer protection tube 101 is in which is in contact with the outer protection tube, and when the probe 101, and is in the whole, and the risk is in the collision; the scraping cleaning component is used for automatically scraping and cleaning the outer side of the probe 101 when the probe is inserted into the ground and pulled out; the scraping and cleaning assembly comprises a circular ring 5 fixedly sleeved in the outer protective tube 4, an annular scraper 6 is fixedly sleeved in the circular ring 5, and the inner side of the annular scraper 6 is a cutting edge surface and is in movable contact with the bottom of the outer side of the probe 101; the circular ring 5 is matched with the annular scraper 6, after the probe 101 passes through the test by the displacement of the outer protective tube 4, and the annular scraper 6 is driven to reset by the circular ring 5 when the outer protective tube 4 moves back, so that the adhered soil impurities are scraped and cleaned on the outer side of the probe 101, and the effect of automatically cleaning the probe 101 after use is realized;

elastic guide support assemblies are fixedly connected to two sides of the top of the circular ring 5, the inner protection tube 3 is sleeved on the two elastic guide support assemblies in a sliding mode, and the elastic guide support assemblies are used for vertically elastically and elastically supporting the outer protection tube 4 and providing an environment for the outer protection tube 4 to slide on the inner protection tube 3 when being extruded by the ground, so that the effect that the probe 101 automatically penetrates out downwards when pressure is applied downwards is achieved; the elastic guide support assembly comprises guide posts 7, the bottom ends of the two guide posts 7 are fixedly connected with the two sides of the top of the circular ring 5 respectively, springs 8 are movably sleeved on the guide posts 7, the top ends and the bottom ends of the springs 8 are fixedly connected with the bottom ends of the inner protection pipes 3 and the top of the circular ring 5 respectively, the inner protection pipes 3 are slidably sleeved on the two guide posts 7, guide grooves 9 are formed in the two sides of the bottom ends of the inner protection pipes 3, and the inner walls of the guide grooves 9 are in sliding contact with the outer sides of the corresponding guide posts 7, so that the effect of vertically sliding and guiding the guide posts 7 is achieved; the guide post 7 is matched with the spring 8, the guide post 7 is used for realizing vertical guide of the circular ring 5, so that vertical guide of the outer protective tube 4 is realized, the spring 8 is used for realizing elastic support of the outer protective tube 4 through the circular ring 5, when the outer protective tube 4 is not in a locking state, the elastic support is used for driving the inner protective tube 3 to slide in the outer protective tube 4 by using the applied pressure when the outer protective tube 4 is in contact with the ground, the spring 8 is compressed, and the probe 101 is driven to penetrate out for testing the pH value in soil, and after the probe is used, the outer protective tube 4 is driven to move back by using the elastic force of the spring 8, so that the annular scraper 6 is driven to perform back-moving scraping cleaning work;

the two side inner walls of the outer protective tube 4 are provided with limit grooves 10, the two side bottoms of the inner protective tube 3 are fixedly connected with limit sliding blocks 11, the limit sliding blocks 11 are slidably connected in the corresponding limit grooves 10, iron sheets 14 are embedded and fixed on the left side of the limit sliding blocks 11 positioned on the left side and the left side inner wall of the limit groove 10 positioned on the left side, a left magnetic blocking limiting component of the iron sheet 14 positioned on the right side extends out of the outer protective tube 4, and the blocking limiting component is used for blocking and limiting the outer protective tube 4 when the outer protective tube 4 is not used and is convenient for locking the outer protective tube 4 when the outer protective tube is not used for carrying; the stop limiting assembly comprises a stop lever 12 movably contacted with the bottom of a left limit sliding block 11, the left end of the stop lever 12 extends to the outer side of an outer protective tube 4 and is fixedly connected with a pull head, the outer protective tube 4 is sleeved on the stop lever 12 in a sliding manner, a rectangular sliding hole is formed in the left inner wall of a left limit groove 10, the inner wall of the rectangular sliding hole is in sliding contact with the outer side of the stop lever 12, the outer protective tube 4 is sleeved on the stop lever 12 in a sliding manner through the rectangular sliding hole, the stop lever 12 passes through and transversely slides and guides the stop lever, a magnet 13 is fixedly connected to the right side of the top of the stop lever 12, the right side of the magnet 13 is adsorbed on the left side of an iron sheet 14 on the right side, and the magnet 13 is matched with the iron sheet 14 on the left side; the stop lever 12 and the magnet 13 are matched, the bottom of the left limit slide block 11 is blocked by the stop lever 12, so that the locking of the outer protective tube 4 when the probe is not in use is realized, when the stop lever 12 is pulled leftwards to separate from the left limit slide block 11 to release the locking, the stop lever 12 drives the magnet 13 to be adsorbed to the left iron sheet 14, the condition that the outer protective tube 4 can slide and displace on the inner protective tube 3 can be provided after the unlocking, and the locking state is utilized, so that the locking and displacement preventing effect of the outer protective tube 4 when the probe is not in use can be ensured, and the stable protection effect of the probe 101 can be realized.

The application method of the embodiment is as follows: when the probe is not used for carrying, the inner protective tube 3, the outer protective tube 4 and the elastic rubber ring 15 can form surrounding protection for the probe 101, so that the phenomenon of direct collision and impact between the probe 101 and the ground can not occur when the probe is accidentally dropped, the protection effect of the probe 101 when the probe is not used is improved, and the safety carrying is facilitated;

when the probe 101 is used for testing the pH value of soil, the pull head is pulled leftwards to drive the stop lever 12 to move leftwards and separate from the bottom of the left limit slide block 11, the stop lever 12 drives the magnet 13 to be adsorbed with the left iron sheet 14, the limiting locking of the outer protective tube 4 is relieved, the operating rod 1 is directly pressed downwards at the moment, the operating rod 1 drives the probe 101, the inner protective tube 3 and the outer protective tube 4 to move downwards, when the elastic rubber ring 15 at the bottom end of the outer protective tube 4 moves downwards to be in contact with the ground, the elastic rubber ring 15 is shielded and limited by the elastic rubber ring, so that the outer protective tube 4 does not move downwards any more, at the moment, the inner protective tube 3 which continues to move downwards slides downwards in the outer protective tube 4 and on the two guide posts 7, the spring 8 is compressed, at the moment, the probe 101 which continues to move downwards passes downwards from the annular scraper 6, and is inserted into the soil for pH value test, after the detection is finished, the elastic force of the spring 8 which drives the annular ring 5 in a compressed state to move downwards relative to the probe 101, and the annular ring 5 drives the outer protective tube 4 to slide back on the inner protective tube 3, and simultaneously, the annular ring 5 is driven by the annular scraper 6 is driven by the probe 101 to move independently, and the probe 101 is not required to be cleaned, and the outside is cleaned, and the soil is cleaned, and the outside is conveniently is cleaned by the probe 101;

after the use, push the pull head to the right and make it drive pin 12 to move back to the right, block the restriction to the spacing slider 11 on left side again, pin 12 drives magnet 13 to adsorb with the left side of the iron sheet 14 on right side mutually, realize the magnetism to pin 12 inhale fixedly, the spacing slider 11 on left side is restricted to outer pillar 4 through pin 12 this moment, realize outer pillar 4 locking restriction, outer pillar 4 this moment, interior pillar 3 and elasticity rubber ring 15 form stable surrounding again to probe 101 and keep off and protect, convenient safety carries.

Finally, it should be noted that: the foregoing description is only a preferred embodiment of the present utility model, and the present utility model is not limited thereto, but it is to be understood that modifications and equivalents of some of the technical features described in the foregoing embodiments may be made by those skilled in the art, although the present utility model has been described in detail with reference to the foregoing embodiments. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present utility model should be included in the protection scope of the present utility model.

Claims (7)

1. The utility model provides a soil pH value tachometer, includes soil pH value tachometer body, soil pH value tachometer body includes action bars (1) and installs probe (101) of fixing in action bars (1), its characterized in that: the outer side of the operating rod (1) is provided with a protection self-cleaning mechanism matched with the probe (101);

the protection self-cleaning mechanism comprises a fixed sleeve (2) arranged at the bottom of the outer side of an operating rod (1), an inner protection tube (3) is fixedly connected to the bottom of the fixed sleeve (2), a probe (101) is positioned in the inner protection tube (3), an outer protection tube (4) is sleeved on the inner protection tube (3) in a sliding manner, and a slag scraping cleaning assembly in movable contact with the bottom of the outer side of the probe (101) is fixedly sleeved in the outer protection tube (4);

the two sides of the top of the slag scraping and cleaning assembly are fixedly connected with elastic guide supporting assemblies, and the inner protection tube (3) is sleeved on the two elastic guide supporting assemblies in a sliding way;

limiting grooves (10) are formed in the inner walls of the two sides of the outer protection tube (4), limiting slide blocks (11) are fixedly connected to the bottoms of the two sides of the inner protection tube (3), the limiting slide blocks (11) are slidably connected into the corresponding limiting grooves (10), iron sheets (14) are fixedly embedded in the left side of the limiting slide blocks (11) located on the left side and the left inner wall of the limiting grooves (10) located on the left side, a limit blocking component is magnetically attracted on the left side of the iron sheets (14) located on the right side, and the left side of the limit blocking component extends out of the outer protection tube (4).

2. The soil ph value rapid measuring instrument according to claim 1, wherein: the scraping and cleaning assembly comprises a circular ring (5) fixedly sleeved in the outer protective tube (4), an annular scraper (6) is fixedly sleeved in the circular ring (5), and the inner side of the annular scraper (6) is a cutting face and is in movable contact with the bottom of the outer side of the probe (101).

3. The soil ph value rapid measuring instrument according to claim 2, wherein: the elastic guide support assembly comprises guide posts (7), the bottoms of the two guide posts (7) are fixedly connected with the two sides of the top of the circular ring (5) respectively, springs (8) are movably sleeved on the guide posts (7), the top and the bottom of each spring (8) are fixedly connected with the bottom of the inner protection tube (3) and the top of the circular ring (5) respectively, and the inner protection tube (3) is slidably sleeved on the two guide posts (7).

4. The soil ph value rapid measuring instrument according to claim 1, wherein: the stop limit assembly comprises a stop lever (12) movably contacted with the bottom of a left limit sliding block (11), the left end of the stop lever (12) extends to the outer side of an outer protection tube (4) and is fixedly connected with a pull head, the outer protection tube (4) is slidably sleeved on the stop lever (12), a magnet (13) is fixedly connected to the right side of the top of the stop lever (12), the right side of the magnet (13) is adsorbed to the left side of an iron sheet (14) on the right side, and the magnet (13) is matched with the iron sheet (14) on the left side.

5. The soil ph value rapid measuring instrument according to claim 1, wherein: the bottom end of the outer protection tube (4) is fixedly adhered with an elastic rubber ring (15), and the bottom position of the elastic rubber ring (15) is lower than the bottom end position of the probe (101).

6. The soil ph value rapid measuring instrument according to claim 1, wherein: threaded holes are formed in the inner walls of the two sides of the fixing sleeve (2), knob type bolts (16) are sleeved in the threaded holes in a threaded mode, and one ends, close to the two knob type bolts (16), of the two knob type bolts are respectively in close contact with the two sides of the operating rod (1).

7. A soil ph meter as claimed in claim 3, wherein: guide grooves (9) are formed in two sides of the bottom end of the inner protection tube (3), and the inner walls of the guide grooves (9) are in sliding contact with the outer sides of the corresponding guide posts (7).