阅读说明：本技术 一种新型非电性密闭空间微正压控制器及调节方法 (Novel non-electric closed space micro-positive pressure controller and adjusting method ) 是由 李爽 于 2019-10-15 设计创作，主要内容包括：一种新型非电性密闭空间微正压控制器,本申请固定壳体上部有排气管,下方有外套管,外套管外侧有微压泄压限位台与快速泄压限位台,外套管上有外管斜开孔；活动透明壳体上开有网孔,活动壳体内部、网孔下方有密封限位台,活动透明壳体内部有内套管,内套管上有内管斜开孔,排气管与人防救生舱外空气相连,外套管内空气压力与救生舱外空气相通；活动透明壳体与外套管之间的空气通过网孔与救生舱内环境空气相通；环形橡胶密封塞位于活动透明壳体与外套管之间,环形橡胶密封塞位于密封限位台与快速泄压限位台下方；活动透明壳体内装有正压调节液。本申请具有灵敏度高、调节灵活、压力维持零泄漏、微泄快泄一体化、可靠性高、使用寿命长等突出优点。(A novel non-electric closed space micro-positive pressure controller is characterized in that an exhaust pipe is arranged at the upper part of a fixed shell, an outer sleeve is arranged below the fixed shell, a micro-pressure relief limiting table and a quick pressure relief limiting table are arranged on the outer side of the outer sleeve, and an outer pipe inclined hole is formed in the outer sleeve; the movable transparent shell is provided with meshes, a sealing limit table is arranged inside the movable shell and below the meshes, an inner sleeve is arranged inside the movable transparent shell, the inner sleeve is provided with an inner tube inclined hole, the exhaust pipe is connected with air outside the civil air defense rescue capsule, and the air pressure in the outer sleeve is communicated with the air outside the rescue capsule; the air between the movable transparent shell and the outer sleeve is communicated with the ambient air in the escape capsule through the meshes; the annular rubber sealing plug is positioned between the movable transparent shell and the outer sleeve and is positioned below the sealing limiting table and the rapid pressure relief limiting table; the movable transparent shell is filled with positive pressure regulating liquid. The pressure regulating valve has the outstanding advantages of high sensitivity, flexibility in regulation, zero pressure maintaining, integration of micro-leakage and quick-leakage, high reliability, long service life and the like.)

1. The utility model provides a novel closed space pressure-fired controller of nonelectricity, includes fixed casing (1), activity transparent shell (2), annular rubber sealing plug (12) and malleation regulating fluid (13), its characterized in that: an exhaust pipe (3) is welded on the upper portion of the fixed shell (1), an outer sleeve (4) is welded on the lower portion of the fixed shell, a micro-pressure relief limiting table (5) and a rapid pressure relief limiting table (6) are arranged on the outer sleeve (4), an outer pipe inclined opening (7) is formed in the outer sleeve (4), the movable transparent shell (2) is a sleeve with an upper opening and a lower sealing bottom, a mesh (8) is formed in the movable transparent shell (2), sealing limiting tables (9) are arranged inside the movable transparent shell (2) and below the mesh (8), an inner sleeve (10) is welded inside the movable transparent shell (2), and an inner pipe inclined opening (11) is formed in the inner sleeve (10); the exhaust pipe (3) is connected with the air outside the civil air defense rescue capsule, and the air pressure in the outer sleeve (4) is communicated with the air outside the rescue capsule; the air between the movable transparent shell (2) and the outer sleeve (4) is communicated with the ambient air in the rescue capsule through the meshes (8); the annular rubber sealing plug (12) is positioned between the movable transparent shell (2) and the outer sleeve (4), and the annular rubber sealing plug (12) is positioned below the sealing limit table (9) and the rapid pressure relief limit table (6); the movable transparent shell (2) is internally provided with positive pressure regulating liquid (13).

2. The novel non-electric closed space micro-positive pressure controller according to claim 1, wherein: the movable transparent shell (2) is marked with micro-pressure calibration scales, and the height difference between the liquid level of the positive pressure regulating liquid on the outer side of the outer sleeve (4) and the liquid level of the positive pressure regulating liquid on the inner side of the inner sleeve (10) can be calculated through the micro-pressure calibration scales.

3. The novel non-electric closed space micro-positive pressure controller according to claim 1, wherein: when the movable transparent shell (2) is sleeved at the micro-pressure relief limiting table (5) of the fixed shell (1), the sealing limiting table (9) and the quick pressure relief limiting table (6) are located at the same height.

4. The novel non-electric closed space micro-positive pressure controller according to claim 1, wherein: the fixed shell (1) is fixedly connected with the wall surface of the rescue capsule, the movable transparent shell (2) is sleeved at the position of the micro-pressure relief limiting table (5) of the fixed shell (1), and the staggered communication positions of the outer tube inclined opening (7) and the inner tube inclined opening (11) can be controlled through rotary operation.

5. The novel non-electric closed space micro-positive pressure controller according to claim 1, wherein: when the movable transparent shell (2) is pulled down to the position of the rapid pressure relief limiting platform (6) from the position of the micropressure pressure relief limiting platform (5) sleeved on the fixed shell (1), the air in the escape capsule is directly communicated with the air outside the capsule.

6. The novel non-electric closed space micro-positive pressure controller according to claim 1, wherein: the outer sleeve (4), the movable transparent shell (2) and the inner sleeve (10) are made of flame-retardant transparent materials, edible pigments are added into the positive pressure regulating liquid (13), and the liquid level height of the positive pressure regulating liquid (13) can be clearly observed from the outside of the movable transparent shell (2).

7. A method for adjusting a novel non-electric closed space micro-positive pressure controller is characterized by comprising the following specific steps:

the fixed shell (1) is fixedly connected with the wall surface of the escape capsule, the movable transparent shell (2) is sleeved at the position of a micro-pressure relief limiting table (5) of the fixed shell (1), at the moment, a micro-positive pressure controller is in a micro-positive pressure control state, the staggered communication position of an outer tube inclined opening (7) and an inner tube inclined opening (11) can be controlled through rotary operation, the height of the staggered communication position controls the value of the pressure relief of positive pressure and overpressure in the capsule, when the staggered communication position is at a high position, the positive pressure control value in the capsule is low, and when the staggered communication position is at a low position, the positive pressure control value in the capsule is high;

when the controller is in a micro-pressure relief state, when the pressure in a cabin is higher than the pressure outside the cabin, the liquid level of positive pressure regulating liquid (13) on the outer side of the outer sleeve (4) is lowered, the positive pressure regulating liquid (13) is pressed to the inner side of the inner sleeve (10), the liquid level of the positive pressure regulating liquid (13) on the inner side of the inner sleeve (10) is raised, when the liquid level of the positive pressure regulating liquid (13) on the outer side of the outer sleeve (4) is lower than the staggered communication position of the inclined open pore (7) of the outer pipe and the inclined open pore (11) of the inner pipe, gas in the cabin is released to the inner side of the inner sleeve (;

when the positive pressure in the capsule rises rapidly and the micropressure pressure relief rate is slower, the movable transparent shell (2) is pulled down to the rapid pressure relief limiting table (6) from the micropressure pressure relief limiting table (5) sleeved on the fixed shell (1), and at the moment, the micropressure pressure controller is in a rapid pressure relief state, the air in the escape capsule is directly communicated with the air outside the capsule, so that the rapid pressure relief and exhaust effects are realized;

the movable transparent shell (2) is sleeved at the position of the micro-pressure relief limiting table (5) of the fixed shell (1), when the pressure of toxic and harmful gas outside the rescue capsule is overhigh, the liquid level of positive pressure regulating liquid (13) at the inner side of the inner sleeve (10) is reduced, and the liquid level at the outer side of the outer sleeve (4) is increased; the annular rubber sealing plug (12) is pushed, so that the annular rubber sealing plug (12) is tightly attached to the sealing limit table (9) and the quick pressure relief limit table (6), and the negative pressure check effect in the cabin is realized.

Technical Field

The invention relates to the field of rescue capsule control equipment, in particular to a novel non-electric closed space micro-positive pressure controller and an adjusting method.

Background

A civil fire-proof rescue capsule or a safety rescue capsule for coal mines is used as an emergency danger avoiding system after accidents such as fire, toxic and harmful gas leakage and the like occur, and the purpose is to provide a safe closed space for danger avoiding personnel. The sealed space can isolate the permeation of toxic and harmful gases, the survival environment condition is provided for the risk avoiding personnel in the sealed space, and the survival probability and the rescued probability are improved. At present, the environmental control technology in a closed space is mature, but the technology used as the cabin micro-positive pressure regulation technology for preventing the invasion of external harmful gas has various defects.

The traditional micro-positive pressure adjusting technology uses a mechanical spring type pressure sensing system, the sealing performance in the cabin is influenced by the sealing performance of a physical contact surface of an adjusting valve, the sealing performance is poor due to too small mechanical pretightening force, and the micro-pressure sensing sensitivity is reduced due to too large mechanical pretightening force; the common liquid seal positive pressure control system needs to adjust pressure through supplementing liquid quantity, is difficult to operate, possibly has the condition of back pressure and reverse liquid spraying to cause equipment damage, and the control system of the liquid seal check valve has the problems of low micro-pressure sensitivity and low pressure relief speed due to the mechanical pretightening force of the check valve.

Therefore, an automatic control device and method for maintaining micro-positive pressure in a CN102182503A enclosed space are designed, and a schematic diagram is shown in fig. 8, but the following technical defects still exist;

1) in the patent, the pressure sensing device inside and outside the sensing cabin is a differential pressure sensor driven by a power supply and is an electronic component, so that the pressure sensing device needs to be driven by the power supply;

2) the process of positive pressure, overpressure and pressure relief in the cabin in the patent is as follows: the air replenishing electromagnetic valve is closed, the automatic pressure regulating controller commands the pressure relief electromagnetic valve to be opened, the air in the cabin is communicated with the air outside the cabin, the air in the cabin enters the outside of the cabin from the air inlet of the pressure relief pipe to the air outlet of the pressure relief pipe through the pressure relief electromagnetic valve, the pressure relief speed is high, and the micro-pressure slow pressure relief cannot be realized;

3) in the patent, the air tightness of the pressure relief hole is determined by the air tightness of a pressure relief electromagnetic valve, and is generally a mechanical sealing structure with poor air tightness performance; the air tightness of the electromagnetic valve is difficult to ensure during reverse stamping under overhigh pressure outside the cabin;

4) the patent mainly discloses that an electric pressure relief and air supply system needs to be driven by a power supply;

therefore, the design of the micro-positive pressure adjusting method with high sensitivity, convenient use, good air tightness and high reliability becomes one of the keys of the rescue capsule reliability design.

Disclosure of Invention

In order to solve the problems, the invention provides a novel non-electric closed space micro-positive pressure controller and an adjusting method, the novel non-electric closed space micro-positive pressure controller and the adjusting method have the advantages of high sensitivity, flexible adjustment, zero pressure maintenance, zero leakage, integration of micro-leakage and quick leakage, high reliability, long service life and the like, and in order to achieve the purpose, the invention provides the novel non-electric closed space micro-positive pressure controller which comprises a fixed shell, a movable transparent shell, an annular rubber sealing plug and positive pressure adjusting liquid, wherein an exhaust pipe is welded at the upper part of the fixed shell, an outer sleeve is welded at the lower part of the fixed shell, a micro-pressure relief limiting table and a quick relief limiting table are arranged at the outer side of the outer sleeve, an inclined opening is arranged on the outer sleeve, the movable transparent shell is a sleeve with an upper part opened and a lower part sealed bottom, meshes are arranged, sealing limit tables are arranged inside the movable transparent shell and below the meshes, an inner sleeve is welded inside the movable transparent shell, and an inner tube inclined hole is formed in the inner sleeve; the exhaust pipe is connected with the air outside the civil air defense rescue capsule, and the air pressure in the outer sleeve is communicated with the air outside the rescue capsule; the air between the movable transparent shell and the outer sleeve is communicated with the ambient air in the escape capsule through the meshes; the annular rubber sealing plug is positioned between the movable transparent shell and the outer sleeve and is positioned below the sealing limit table and the quick pressure relief limit table; the movable transparent shell is filled with positive pressure regulating liquid.

The invention is further improved, the movable transparent shell is marked with micro-pressure calibration scales, and the height difference between the liquid level of the positive pressure regulating liquid outside the outer sleeve and the liquid level of the positive pressure regulating liquid inside the inner sleeve can be calculated through the micro-pressure calibration scales.

According to the further improvement of the invention, when the movable transparent shell is sleeved at the micro-pressure relief limiting table of the fixed shell, the sealing limiting table and the quick pressure relief limiting table are positioned at the same height.

The invention further improves the structure that the fixed shell is fixedly connected with the wall surface of the rescue capsule, the movable transparent shell is sleeved at the position of the micro-pressure relief limiting table of the fixed shell, the staggered communication position of the inclined opening of the outer tube and the inclined opening of the inner tube can be controlled through rotating operation, the height of the staggered communication position controls the value of positive pressure, overpressure and pressure relief in the capsule, when the staggered communication position is at a high position, the positive pressure control value in the capsule is low, and when the staggered communication position is at a low position, the positive pressure control value in the capsule is high.

The invention further improves that when the movable transparent shell is pulled down to the position of the rapid pressure-relief limiting platform from the position of the micro-pressure-relief limiting platform sleeved on the fixed shell, the air in the escape capsule is directly communicated with the air outside the capsule, when the controller is in a micro-pressure-relief state, when the pressure in the capsule is higher than the pressure outside the capsule, the liquid level of the positive-pressure regulating liquid outside the outer sleeve is lowered, the positive-pressure regulating liquid is pressed towards the inner side of the inner sleeve, the liquid level of the positive-pressure regulating liquid inside the inner sleeve is raised, when the liquid level of the positive-pressure regulating liquid outside the outer sleeve is lower than the staggered communication position of the inclined opening of the outer sleeve and the inclined opening of the inner sleeve, the gas in the capsule is released towards the inner side of the inner sleeve through the staggered communication holes and is exhausted to the outside of the capsule, so as to realize the positive-pressure-relief overpressure effect, at the moment, the micro-positive pressure controller is in a rapid pressure relief state, and air in the escape capsule is directly communicated with air outside the capsule, so that a rapid pressure relief and exhaust effect is realized.

According to the further improvement of the invention, the outer sleeve, the movable transparent shell and the inner sleeve are all made of flame-retardant transparent materials, edible pigments are added into the positive pressure regulating liquid, and the liquid level height of the positive pressure regulating liquid can be clearly observed from the outside of the movable transparent shell.

The invention relates to a method for adjusting a novel non-electric closed space micro-positive pressure controller, which comprises the following specific steps:

the fixed shell is fixedly connected with the wall surface of the escape capsule, the movable transparent shell is sleeved at the position of a micro-pressure relief limiting table of the fixed shell, the micro-positive pressure controller is in a micro-positive pressure control state at the moment, the staggered communication position of the inclined opening of the outer tube and the inclined opening of the inner tube is controlled through rotation operation, the magnitude of the positive pressure overpressure relief in the capsule is controlled by the height of the staggered communication position, when the staggered communication position is at a high position, the positive pressure control value in the capsule is low, and when the staggered communication position is at a low position, the positive pressure control value in the capsule is;

when the controller is in a micro-pressure relief state, when the pressure in the cabin is higher than the pressure outside the cabin, the liquid level of the positive pressure regulating liquid outside the outer sleeve is lowered, the positive pressure regulating liquid is pressed to the inner side of the inner sleeve, the liquid level of the positive pressure regulating liquid inside the inner sleeve is raised, and when the liquid level of the positive pressure regulating liquid outside the outer sleeve is lower than the staggered communication position of the inclined opening of the outer pipe and the inclined opening of the inner pipe, the gas in the cabin is released to the inner side of the inner sleeve through the staggered communication holes and is exhausted outside;

when the positive pressure in the escape capsule rises rapidly and the micropressure pressure relief rate is slower, the movable transparent shell is pulled down to the rapid pressure relief limiting table from the micropressure pressure relief limiting table sleeved on the fixed shell, the micropressure pressure relief controller is in a rapid pressure relief state at the moment, and the air in the escape capsule is directly communicated with the air outside the escape capsule, so that the rapid pressure relief and exhaust effects are realized;

the movable transparent shell is sleeved at the position of the micro-pressure relief limiting table of the fixed shell, when the pressure of toxic and harmful gas outside the rescue capsule is overhigh, the liquid level of the positive pressure regulating liquid inside the inner sleeve is reduced, and the liquid level outside the outer sleeve is increased; promote annular rubber sealing plug, make annular rubber sealing plug and sealed spacing platform and the spacing platform of quick pressure release closely laminate, realize the contrary effect that ends of under-deck negative pressure.

The invention relates to a novel non-electric closed space micro-positive pressure controller and an adjusting method, wherein a rotary dislocation communication mode is used for controlling the liquid level difference inside and outside a positive pressure adjusting liquid, the controller has the characteristics of high sensitivity and flexibility in adjustment, the pressure maintains zero leakage, micro-leakage and quick-leakage integration is realized, and the controller has the characteristics of high reliability, long service life and the like, and has the following specific characteristics;

1. in the application, the pressure equipment inside and outside the sensing cabin is a micro-pressure difference controller body, and the pressure difference is reflected by the liquid level difference inside and outside the sleeve in the equipment, so that the equipment does not need to be driven by a power supply and does not have electronic components, and thus, non-electrical control can be realized;

2. this application under-deck malleation superpressure pressure release process does: when the pressure in the cabin exceeds a set pressure value (a pressure value generated by the height difference between the staggered connecting through holes and the liquid level), the liquid level of the positive pressure regulating liquid outside the outer sleeve is lowered, the positive pressure regulating liquid is pressed to the inner side of the inner sleeve, the liquid level of the positive pressure regulating liquid inside the inner sleeve is raised, and when the liquid level of the positive pressure regulating liquid outside the outer sleeve is lower than the staggered connecting position of the inclined opening of the outer pipe and the inclined opening of the inner pipe, the gas in the cabin is released to the inner side of the inner sleeve through the staggered connecting through holes and is exhausted;

3. the air tightness of the pressure relief equipment is guaranteed by liquid sealing, and zero leakage can be realized; when the pressure outside the cabin is too high and the reverse punching is carried out, the sealing ring of the equipment can be tightly sealed under the reverse pressing;

4. this application adopts non-electric formula principle, will release pressure a little and pressure relief is integrated as an organic whole fast to realize zero leakage, resistance to pressure shock's performance.

Drawings

FIG. 1 is a schematic diagram of the interior of a novel non-electrical closed space micro-positive pressure controller according to the present invention;

FIG. 2 is a partial schematic view of a non-electrical closed space micro-positive pressure controller according to the present invention;

FIG. 3 is a partial schematic view of a non-electrical closed space micro-positive pressure controller according to the present invention;

FIG. 4 is a schematic diagram of the positive pressure relief adjustment of the novel non-electrical closed space micro-positive pressure controller according to the present invention;

FIG. 5 is a schematic diagram of the adjustment operation of the dislocation connection through hole of the novel non-electrical closed space micro-positive pressure controller according to the present invention;

FIG. 6 is a schematic diagram of the operation of fast pressure release of the novel non-electrical closed space micro-positive pressure controller according to the present invention;

FIG. 7 is a schematic diagram of the operation of the back pressure stop of the non-electrical closed space micro-positive pressure controller according to the present invention;

FIG. 8 is a prior art schematic of the present invention;

in figure 1, a housing is fixed; 2. a movable transparent housing; 3. an exhaust pipe; 4. an outer sleeve; 5. a micro-pressure relief limiting platform; 6. a rapid pressure relief limiting table; 7. the outer pipe is obliquely provided with a hole; 8. mesh openings; 9. sealing the limit table; 10. an inner sleeve; 11. the inner pipe is obliquely provided with a hole; 12. an annular rubber sealing plug; 13. and (3) positive pressure regulating liquid.

Detailed Description

The invention is described in further detail below with reference to the following detailed description and accompanying drawings:

the invention provides a novel non-electric closed space micro-positive pressure controller and an adjusting method, and the novel non-electric closed space micro-positive pressure controller and the adjusting method have the advantages of high sensitivity, flexibility in adjustment, zero pressure maintaining leakage, integration of micro-leakage and quick leakage, high reliability, long service life and the like.

As shown in fig. 1-7, the novel non-electric closed space micro-positive pressure controller in the present invention comprises a fixed housing 1, a movable transparent housing 2, an annular rubber sealing plug 12, and a positive pressure regulating liquid 13; an exhaust pipe 3 is welded at the upper part of the fixed shell 1, and an outer sleeve 4 is welded at the lower part of the fixed shell; a micro-pressure relief limiting table 5 and a quick relief limiting table 6 are arranged on the outer side of the outer sleeve 4; the outer sleeve 4 is provided with an outer tube inclined opening 7; the transparent shell 2 is a sleeve with an opening at the upper part and a sealed bottom at the lower part, the movable transparent shell 2 is provided with meshes 8, a sealing and limiting table 9 is arranged in the movable shell and below the meshes 8, an inner sleeve 10 is welded in the movable transparent shell 2, and the inner sleeve 10 is provided with an inner tube inclined opening 11; when the movable transparent shell 2 is sleeved at the position of the micro-pressure relief limiting table 5 of the fixed shell 1, the sealing limiting table 9 and the quick pressure relief limiting table 6 are positioned at the same height;

the novel non-electric closed space micro-positive pressure controller exhaust pipe 3 is connected with the air outside the escape capsule, and the air pressure in the outer sleeve 4 is communicated with the air outside the escape capsule; the air between the movable transparent shell 2 and the outer sleeve 4 is communicated with the ambient air in the escape capsule through the meshes 8; the annular rubber sealing plug 12 is positioned between the movable transparent shell 2 and the outer sleeve 4, and the annular rubber sealing plug 12 is positioned below the sealing limit table 9 and the rapid pressure relief limit table 6; the movable transparent shell 2 is filled with positive pressure regulating liquid 13;

the outer sleeve 4, the movable transparent shell 2 and the inner sleeve 10 of the novel non-electric closed space micro-positive pressure controller are made of flame-retardant transparent materials, edible pigments are added into the positive pressure regulating liquid 13, and the liquid level height of the positive pressure regulating liquid 13 can be clearly observed from the outside of the movable transparent shell 2; the movable transparent shell 2 is marked with a micro-pressure calibration scale, and the height difference between the liquid level of the positive pressure regulating liquid at the outer side of the outer sleeve 4 and the liquid level of the positive pressure regulating liquid at the inner side of the inner sleeve 10 can be calculated through the micro-pressure calibration scale.

The specific working process of the invention patent is as follows:

fixed casing 1 and escape capsule wall face fixed connection, the spacing platform 5 positions of minute-pressure release of fixed casing 1 are overlapped to activity transparent casing 2, the pressure-fired controller is in pressure-fired control state this moment, the rotatory operation of accessible, the crisscross UNICOM position of the oblique trompil 7 of control outer tube and the oblique trompil 11 of inner tube, the numerical value of the interior malleation superpressure pressure release of high-low control cabin of crisscross UNICOM position, when crisscross UNICOM position is in the high order, the under-deck malleation control value is low, when crisscross UNICOM position is in the low order, under-deck malleation control value is high.

When the controller is in the minute-pressure release state, when the cabin internal pressure is higher than the pressure outside the cabin, the level of the positive pressure regulating liquid 13 outside the outer sleeve 4 descends, the positive pressure regulating liquid 13 is pressed to the inner side of the inner sleeve 10, the level of the positive pressure regulating liquid 13 inside the inner sleeve 10 ascends, when the level of the positive pressure regulating liquid 13 outside the outer sleeve 4 is lower than the staggered communication position of the inclined open pore 7 of the outer tube and the inclined open pore 11 of the inner tube, the gas in the cabin is released to the inner side of the inner sleeve 10 through the staggered communication through holes and is exhausted to the outside.

When the positive pressure in the escape capsule rises rapidly, and the micro-pressure relief rate is slower, the movable transparent shell 2 is pulled down to the position of the rapid relief limiting platform 6 from the position of the micro-pressure relief limiting platform 5 sleeved on the fixed shell 1, the micro-pressure controller is in a rapid relief state at the moment, and the air in the escape capsule is directly communicated with the air outside the capsule, so that the rapid relief exhaust effect is realized.

The movable transparent shell 2 is sleeved at the position of the micro-pressure relief limiting table 5 of the fixed shell 1, when the pressure of toxic and harmful gas outside the rescue capsule is overhigh, the liquid level of the positive pressure regulating liquid 13 inside the inner sleeve 10 is reduced, and the liquid level outside the outer sleeve 4 is increased; the annular rubber sealing plug 12 is pushed, so that the annular rubber sealing plug 12 is tightly attached to the sealing limiting table 9 and the rapid pressure relief limiting table 6, and the negative pressure check effect in the cabin is realized.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention in any way, but any modifications or equivalent variations made according to the technical spirit of the present invention are within the scope of the present invention as claimed.