阅读说明：本技术 减振器、减振司机室及内燃机车 (Shock absorber, damping cab and diesel locomotive ) 是由 陈保霖 罗宏亮 崔玉萌 周佳 吴悠 王峰 李鹏 耿庆厚 马青军 徐廷 张维维 于 2019-11-22 设计创作，主要内容包括：本发明提供了一种减振器、减振司机室及内燃机车,属于轨道车辆技术领域。减振器包括芯轴、套设于芯轴上的弹性体、套设于芯轴上的第一安装座,以及第二安装座；第一安装座位于弹性体的上方、用于与司机室连接；第二安装座的顶部与弹性体的中部连接,底部用于与车体连接。减振司机室包括厢体,以及设置在厢体底部的减振器,减振器用于连接厢体和车体。内燃机车包括车体和设置在车体上的减振司机室。本发明提供的减振器、减振司机室及内燃机车,隔离了轮轨、发动机、空压机等振动源通过车体传递至厢体的传递路线,减振效果好。(The invention provides a shock absorber, a shock absorption cab and a diesel locomotive, and belongs to the technical field of railway vehicles. The shock absorber comprises a mandrel, an elastic body sleeved on the mandrel, a first mounting seat sleeved on the mandrel and a second mounting seat; the first installation seat is positioned above the elastic body and is used for being connected with the cab; the top of the second mounting seat is connected with the middle part of the elastic body, and the bottom of the second mounting seat is used for being connected with a vehicle body. The vibration reduction cab comprises a carriage body and a vibration reducer arranged at the bottom of the carriage body, wherein the vibration reducer is used for connecting the carriage body and a vehicle body. The diesel locomotive comprises a locomotive body and a damping cab arranged on the locomotive body. The vibration absorber, the vibration reduction cab and the diesel locomotive provided by the invention isolate the transmission route of the vibration sources such as the wheel rail, the engine and the air compressor which are transmitted to the carriage body through the vehicle body, and the vibration reduction effect is good.)

1. The shock absorber, its characterized in that: the elastic body is sleeved on the mandrel, and the first mounting seat and the second mounting seat are sleeved on the mandrel; the first installation seat is positioned above the elastic body and is used for being connected with a cab; the top of the second mounting seat is connected with the middle of the elastic body, and the bottom of the second mounting seat is used for being connected with a vehicle body.

2. The damper of claim 1, wherein: the elastic body comprises a first elastic sleeve and a second elastic sleeve located below the first elastic sleeve, a first groove body is arranged at the bottom of the first elastic sleeve, a second groove body is arranged at the top of the second elastic sleeve, and the second groove body and the first groove body are surrounded to form a slot with an outward opening and used for being in plug-in fit with the second mounting seat.

3. The damper of claim 2, wherein: the elastomer is still including pasting to locate first metal holder on the inner wall of first cell body, and paste and locate second metal holder on the inner wall of second cell body, first metal holder with second metal holder respectively with the butt of second mount pad.

4. The damper of claim 3, wherein: the first elastic sleeve and the second elastic sleeve are respectively conical sleeves, and the diameters of the conical sleeves are gradually reduced from one end connected with the second mounting seat to the other end.

5. The damper according to any one of claims 1-4, wherein: the mandrel comprises a bolt, an upper gasket, a sleeve, a lower gasket and a nut which are sequentially sleeved on the bolt, and the elastic body is sleeved on the sleeve;

the number of the upper gaskets is two, and the first mounting seat is arranged between the two upper gaskets;

the upper gasket and the lower gasket are respectively positioned above and below the elastic body, and the upper gasket and the lower gasket positioned below are used for cooperatively clamping the elastic body under the action of the nut;

the sleeve can slide up and down along the axial direction of the bolt, and the middle part of the sleeve is connected with the second mounting seat through a connecting piece penetrating through the elastic body.

6. The damper according to any one of claims 1-4, wherein: the shock absorber further comprises a protective cover arranged outside the first mounting seat in a covering mode, and the elastic body and the second mounting seat are located in a cavity defined by the protective cover.

7. Damping cab, its characterized in that: the shock absorber comprises a carriage body and the shock absorber of any one of claims 1 to 6, wherein the shock absorber is arranged at the bottom of the carriage body and is used for connecting the carriage body and a vehicle body.

8. The vibration reducing cab of claim 7, wherein: the compartment body is provided with a vehicle door, the first installation seat is positioned under the vehicle door, and one end of the first installation seat extends to the outer side of the compartment body to form a step for the vehicle door to get in and out.

9. The vibration reduction cab according to claim 7 or 8, wherein: a sound insulation layer is arranged on or in the side wall of the compartment body; the bottom of the compartment body is provided with a detachable vibration reduction floor; and a lifting ring is arranged at the top of the carriage body.

10. Diesel locomotive, its characterized in that: comprising a vehicle body and a vibration damping cab according to any one of claims 7 to 9 arranged on said vehicle body.

Technical Field

The invention belongs to the technical field of railway vehicles, and particularly relates to a shock absorber, a shock absorption cab and a diesel locomotive.

Background

Although a large number of electric locomotives are put into use today with highly developed electrification, diesel locomotives are still one of the leading members of a locomotive team due to their advantages that are not possessed by electric locomotives, such as high mobility, low one-time investment, and fast marching. At the beginning of the use of the internal combustion engine, the requirements for controlling the vibration during the operation of the engine are not high due to the low operation speed and the low traction power. Along with the increase of the running speed of the diesel locomotive and the increase of the power of the diesel locomotive, the vibration generated by the diesel locomotive body in the running process is more and more emphasized by people.

In the process of implementing the invention, the inventor finds that at least the following problems exist in the prior art: the driver room and the vehicle body of the diesel locomotive mostly adopt a welding structure, and the vibration reduction effect is poor.

Disclosure of Invention

The embodiment of the invention aims to provide a shock absorber, a shock absorption cab and a diesel locomotive, and aims to solve the technical problem that the current cab is poor in shock absorption effect.

In one aspect, a shock absorber is provided, comprising: the elastic body is sleeved on the mandrel, and the first mounting seat and the second mounting seat are sleeved on the mandrel; the first installation seat is positioned above the elastic body and is used for being connected with a cab; the top of the second mounting seat is connected with the middle of the elastic body, and the bottom of the second mounting seat is used for being connected with a vehicle body.

As another embodiment of this application, the elastomer includes first elastic sleeve, and is located the second elastic sleeve of first elastic sleeve below, the bottom of first elastic sleeve is provided with first cell body, second elastic sleeve top is provided with the second cell body, the second cell body with first cell body encloses into the opening outwards, be used for with the complex slot is pegged graft to the second mount pad.

As another embodiment of this application, the elastomer is still including pasting and locating first metal holder on the inner wall of first cell body, and paste and locate second metal holder on the inner wall of second cell body, first metal holder with second metal holder respectively with the butt of second mount pad.

As another embodiment of the present application, the first elastic sleeve and the second elastic sleeve are respectively tapered sleeves, and a diameter of each tapered sleeve gradually decreases from one end connected to the second mounting seat to the other end.

As another embodiment of the application, the mandrel comprises a bolt, and an upper gasket, a sleeve, a lower gasket and a nut which are sequentially sleeved on the bolt, wherein the elastic body is sleeved on the sleeve;

the number of the upper gaskets is two, and the first mounting seat is arranged between the two upper gaskets;

the upper gasket and the lower gasket are respectively positioned above and below the elastic body, and the upper gasket and the lower gasket positioned below are used for cooperatively clamping the elastic body under the action of the nut;

the sleeve can slide up and down along the axial direction of the bolt, and the middle part of the sleeve is connected with the second mounting seat through a connecting piece penetrating through the elastic body.

As another embodiment of the present application, the shock absorber further includes a protective cover covering the first mounting seat, and the elastic body and the second mounting seat are both located in a cavity surrounded by the protective cover.

One of the above technical solutions has the following beneficial effects: compared with the prior art, the shock absorber for connecting the vehicle body and the cab is arranged. The second mount pad is connected with the middle part of elastomer for when the second mount pad is influenced and takes place the vibration because of receiving vibration sources such as wheel rail on the automobile body, engine, air compressor machine, no matter rebound or move down can not take place hard collision with the dabber, thereby blocked the transmission route that vibration source passes through second mount pad, first mount pad on the automobile body and transmits to the driver's cabin, and then guaranteed the good damping effect of shock absorber.

In another aspect, a vibration reduction cab is provided, including: the carriage body, and set up in carriage body bottom the shock absorber, the shock absorber is used for connecting carriage body and automobile body.

As another embodiment of the present application, a vehicle door is disposed on the compartment, the first installation seat is located right below the vehicle door, and one end of the first installation seat extends to an outer side of the compartment to form a step for entering and exiting the vehicle door.

As another embodiment of the present application, a sound insulation layer is disposed on or in the side wall of the compartment body; the bottom of the compartment body is provided with a detachable vibration reduction floor; and a lifting ring is arranged at the top of the carriage body.

One of the above technical solutions has the following beneficial effects: compared with the prior art, the vibration damper has the advantages that the vibration source such as the wheel rail, the engine and the air compressor is isolated from a transmission line which is transmitted to the carriage body through the carriage body, and the vibration damping effect is good.

In another aspect, a diesel locomotive is provided, comprising: the vibration reduction cab comprises a vehicle body and the vibration reduction cab arranged on the vehicle body.

One of the above technical solutions has the following beneficial effects: compared with the prior art, the vibration reduction cab has the same beneficial effects basically, and is not repeated herein.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed for the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

FIG. 1 is a schematic vertical sectional view of a shock absorber according to an embodiment of the present invention;

FIG. 2 is a schematic view of a vertical cross-section of a mandrel used in an embodiment of the present invention;

fig. 3 is a schematic top view of the vibration reduction cab provided in the embodiment of the present invention with the top of the cab body removed;

FIG. 4 is a cross-sectional structural view taken along line A-A of FIG. 3 (seat not shown);

fig. 5 is a sectional structural view taken along line B-B in fig. 3 (fire extinguisher apparatus is not shown).

In the figure: 100. a shock absorber; 110. a mandrel; 111. a bolt; 112. an upper gasket; 113. a sleeve; 114. a lower gasket; 115. a nut; 120. an elastomer; 121. a first elastic sleeve; 122. a second elastic sleeve; 123. a first metal base; 124. a second metal base; 130. a first mounting seat; 140. a second mounting seat; 150. a connecting member; 160. a protective cover; 300. a compartment body; 310. a vehicle door; 340. a hoisting ring; 350. an observation window; 360. a wiper; 370. a sun screen; 380. folding the rearview mirror; 390. a front driver station; 400. a rear driver station; 410. a seat; 420. an air conditioner.

Detailed Description

In order to make the technical problems, technical solutions and advantageous effects to be solved by the present invention more clearly apparent, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Referring to fig. 1 and 2 together, a shock absorber 100 according to an embodiment of the present invention will now be described. The damper 100 includes a core shaft 110, an elastic body 120 sleeved on the core shaft 110, a first mounting seat 130 sleeved on the core shaft 110, and a second mounting seat 140; the first mounting seat 130 is located above the elastic body 120 and used for connecting with a cab; the top of the second mounting seat 140 is connected to the middle of the elastic body 120, and the bottom is used for connecting to the vehicle body.

When the cab mounting structure is used, the top of the first mounting seat 130 is connected with the bottom of the cab, and the bottom of the second mounting seat 140 is connected with a vehicle body. When the vehicle body is stressed and transmitted to the cab, the vibration of the vehicle body is absorbed by the elastic body 120, and the effect of vibration reduction of the cab is achieved.

Compared with the prior art, the shock absorber 100 provided by the embodiment of the invention is provided with the shock absorber 100 for connecting the vehicle body and the cab. Second mount pad 140 is connected with the middle part of elastomer 120 for when second mount pad 140 takes place the vibration because of receiving vibration sources influences such as wheel rail on the automobile body, engine, air compressor machine, no matter rebound or move down can not take place hard collision with dabber 110, thereby blocked the transmission route that vibration sources passes through second mount pad 140, first mount pad 130 on the automobile body and transmits to the cab, and then guaranteed the good damping effect of shock absorber 100.

Specifically, the elastic body 120 may be made of rubber, a spring, or other elastic objects that can achieve a vibration damping effect. The second mounting base 140 can be formed by welding together plates, and is connected with the vehicle body by a fillet welding structure after welding. The first mounting seat 130 may be connected to the cab framework by screws or welded.

Further, the elastic body 120 is in spaced fit with the core shaft 110, so that it is stretched or compressed along with the movement of the second mounting seat 140, thereby ensuring a good damping effect of the damper 100.

Referring to fig. 1 and fig. 2 together, as an embodiment of the shock absorber 100 provided by the present invention, the elastic body 120 includes a first elastic sleeve 121 and a second elastic sleeve 122 located below the first elastic sleeve 121, a first groove is disposed at a bottom of the first elastic sleeve 121, a second groove is disposed at a top of the second elastic sleeve 122, and the second groove and the first groove form a slot with an outward opening for being inserted into and matched with the second mounting seat 140.

The insertion of the second mounting base 140 and the elastic body 120 is realized by the arrangement of the insertion slot, so that an operator can conveniently connect or separate the second mounting base 140 and the elastic body 120 according to needs, and the elastic body 120 can be conveniently damaged or replaced.

The elastic body 120 employs a first elastic sleeve 121 and a second elastic sleeve 122 which are spaced apart, so that the first elastic sleeve 121 and the second elastic sleeve 122 may not be affected by each other during use. When one elastic sleeve is worn, the corresponding elastic sleeve can be replaced without replacing the whole elastic body 120, so that the maintenance cost of the shock absorber 100 is effectively reduced; and when one of the elastic sleeves is worn, the shock absorber 100 still has a certain shock absorbing effect and can be continuously used for a period of time.

Referring to fig. 2, as an embodiment of the shock absorber 100 provided by the present invention, the elastic body 120 further includes a first metal seat 123 attached to the inner wall of the first groove, and a second metal seat 124 attached to the inner wall of the second groove, and the first metal seat 123 and the second metal seat 124 are respectively abutted against the second mounting seat 140.

The arrangement of the first metal seat 123 and the second metal seat 124 prevents the first elastic sleeve 121 and the second elastic sleeve 122 from directly contacting the second mounting seat 140, so that the risk of abrasion of the first elastic sleeve 121 and the second elastic sleeve 122 is avoided, and the long service life of the shock absorber 100 is ensured.

Specifically, the first metal base 123 and the second metal base 124 may be bonded to the first elastic sleeve 121 and the second elastic sleeve 122 by glue, or may be bonded to the first elastic sleeve 121 and the second elastic sleeve 122 by a vulcanization molding process.

Referring to fig. 1 and 2, as an embodiment of the shock absorber 100 provided by the present invention, the first elastic sleeve 121 and the second elastic sleeve 122 are respectively conical sleeves, and the diameters of the conical sleeves gradually decrease from one end connected with the second mounting seat 140 to the other end.

The first elastic sleeve 121 and the second elastic sleeve 122 are respectively conical sleeves, and the diameters of the first elastic sleeve 121 and the second elastic sleeve 122 are respectively gradually reduced from one end connected with the second mounting base 140 to the other end, so that the pressure applied to the connected surfaces of the first elastic sleeve 121 and the second elastic sleeve 122 and the second mounting base 140 is smaller, the risk of damage to the first elastic sleeve 121 and the second elastic sleeve 122 is reduced, and the longer service life of the shock absorber 100 is ensured.

Referring to fig. 2, as an embodiment of the shock absorber 100 provided by the present invention, the mandrel 110 includes a bolt 111, and an upper gasket 112, a sleeve 113, a lower gasket 114 and a nut 115 sequentially sleeved on the bolt 111, and the elastic body 120 is sleeved outside the sleeve 113.

Two upper gaskets 112 are provided, and a first mounting seat 130 is installed between the two upper gaskets 112. The upper and lower washers 112 and 114 are respectively located above and below the elastic body 120, and the upper and lower washers 112 and 114 located below are used for cooperatively clamping the elastic body 120 under the action of the nut 115. The sleeve 113 can slide up and down along the axial direction of the bolt 111, and the middle portion of the sleeve 113 is connected to the second mounting seat 140 by a connection member 150 passing through the elastic body 120.

The second mounting base 140 is connected with the sleeve 113 through the connecting piece 150, so that the second mounting base 140 is prevented from being separated from the slot in the using process, and the stability of the relative position of the second mounting base 140 and the elastic body 120 in the using process is ensured. The arrangement of the upper gasket 112 prevents the first mounting seat 130 from directly contacting the first elastic sleeve 121, thereby preventing the first elastic sleeve 121 from being worn during use. The lower washer 114 prevents the second elastic sleeve 122 from directly contacting the nut 115, thereby preventing the second elastic sleeve 122 from being worn during use.

Referring to fig. 1, as an embodiment of the shock absorber 100 provided by the present invention, the shock absorber 100 further includes a protective cover 160 covering the first mounting seat 130, and the elastic body 120 and the second mounting seat 140 are both located in a cavity surrounded by the protective cover 160.

The protective cover 160 prevents the elastomer 120 from being exposed to direct ultraviolet rays and rain during use, and prolongs the service life of the elastomer 120.

Referring to fig. 1, as an embodiment of the damper 100 provided in the present invention, two mandrels 110 are provided, and the two mandrels 110 are arranged in parallel and connected through a first mounting seat 130 and a second mounting seat 140.

As a specific embodiment of the shock absorber 100 provided by the invention, the axial stiffness ratio and the radial stiffness ratio of the shock absorber 100 are 2:1, the axial static stiffness range is 1800 +/-360N/mm, the radial static stiffness range is 900 +/-180N/mm, and the dynamic-static ratio of the shock absorber 100 is 1.5 +/-0.3. Both the first elastic sleeve 121 and the second elastic sleeve 122 may be made of neoprene.

The embodiment of the invention also provides a vibration reduction cab. Referring to fig. 3 to 5, the vibration damping cab includes a compartment 300 and a vibration damper 100 disposed at the bottom of the compartment 300, wherein the vibration damper 100 is used for connecting the compartment 300 and a vehicle body.

According to the vibration reduction cab provided by the embodiment of the invention, the vibration reducer 100 is adopted, so that the transmission route of the vibration sources such as wheel rails, an engine and an air compressor to the carriage body 300 through the vehicle body is isolated, and the vibration reduction effect is good.

In this embodiment, a plurality of dampers 100 may be disposed at the bottom of the carriage 300, and the specific number may be set according to the use requirement.

Further, the bottom of the carriage 300 is provided with four supporting points, and each supporting point is connected with the vehicle body through the shock absorber 100. The four supporting points are positioned at four top corners of the carriage body 300

Referring to fig. 3 and 5, as an embodiment of the damping cab provided by the present invention, a door 310 is disposed on the cab 300, the first mounting seat 130 is located right below the door 310, and one end of the first mounting seat 130 extends to an outer side of the cab 300 to form a step for getting in and out of the door 310.

The shield 160 also acts as a step to facilitate the driver's entry and exit.

Further, an anti-slip structure is arranged on the outer wall of the protective cover 160, and the anti-slip structure can be anti-slip lines, anti-slip pads and the like, as long as the above effects can be achieved.

Further, the cover of the shock absorber 100 is formed by welding corrugated plates, so that the anti-skid function is achieved.

Referring to fig. 4, as a specific embodiment of the damping cab according to the present invention, two doors 310 are provided and are arranged diagonally, each door 310 is provided with an observation window 350, and a wiper 360 is provided outside each observation window 350. The arrangement of the window wiper 360 facilitates the driver to observe the line condition in rainy days.

The compartment 300 is further provided with a sun-shading curtain 370 for shading the observation window 350, so that the driver can control the external sunlight to directly irradiate the driver according to the requirement.

Referring to fig. 4 and 5, as a specific embodiment of the damping cab provided in the present invention, a sound insulation layer is disposed on or in a sidewall of the car body 300; the bottom of the carriage body 300 is provided with a detachable vibration reduction floor; the top of the carriage 300 is provided with a hanging ring 340.

The setting up of puigging has improved the driver's cabin fall make an uproar, damping and heat preservation function, and then has improved the travelling comfort of driver in driver's cabin work. The vibration damping floor can further intercept the vibration transmitted into the carriage body 300 from the transmission path of the vibration from the vehicle body, the vibration damper 100, the carriage body 300 bottom plate, articles in the carriage body 300 and a driver, thereby further improving the vibration damping effect of the cab. The vibration damping floor is detachably connected with the carriage body 300, so that the vibration damping floor can be conveniently replaced after being damaged, and an operator can overhaul equipment positioned under the vibration damping floor. After the vibration reduction cab is assembled, the lifting ring 340 can be arranged to lift the whole vibration reduction cab through the lifting equipment and mount the vibration reduction cab on a vehicle body.

The sound insulation layer in this embodiment can be damping thick liquid, porous aluminum plate or the combination of both, can also be other on the market can play the sound absorption, one or more material of winter protection effect is made. Wherein, the damping thick liquid still can play the winter protection effect, has further increased the travelling comfort of cab.

The carriage body 300 comprises a framework and a skin covering the framework, and the damping floor is detachably connected with the framework. The interior of the compartment 300 is made of porous aluminum plates at the front, rear, left and right sides as wall plates. The car body 300 is mounted and fixed to the car body by bolts with external torque applied thereto. During assembly, after welding of the skin is completed, damping slurry can be sprayed outside the skin.

Specifically, a porous aluminum plate may be used as the inner wall panel of the compartment 300, and damping paste is used to fill the gap between the framework and the skin, thereby achieving the effects of sound insulation and cold protection.

Further, the vibration reduction floor is connected with the bottom framework of the carriage body 300 through the rubber damping pad, and the transmission of vibration from the framework to the floor is further blocked by the arrangement of the rubber damping pad, so that the vibration reduction effect of the vibration reduction cab is further improved.

Referring to fig. 3 to 5, as a specific embodiment of the vibration reduction cab provided by the present invention, a folding rear view mirror 380 is disposed on the cab body 300. The carriage 300 is provided therein with a front driver platform 390, a rear driver platform 400, a seat 410, a fire extinguisher device, an air conditioner 420 and a heating device.

The arrangement of the folding rearview mirror 380 facilitates the driver to observe the rear line condition in the driving process. In addition, the folding rear view mirror 380 can be folded when not in use, avoiding damage.

The front driver platform 390 is used for controlling the locomotive to run forwards, the rear driver platform 400 is used for controlling the locomotive to run backwards, and the arrangement of the two driver platforms is convenient for a driver to control the locomotive to run forwards or backwards according to actual conditions. The air conditioner 420 and the heating device are arranged to control the temperature inside the compartment 300. Wherein, the heating equipment can be an electric heater and the like. The fire extinguisher device can be convenient for a driver to timely handle the fire condition according to the actual condition. The seat 410 can be a seat which is available on the market and can realize front and back movement, height adjustment, backrest angle adjustment and left and right rotation.

The interior of a traditional cab comprises a complex air pipeline control system, an electric pipeline control system of a locomotive, a cold-proof and sound-proof material, a console, a driver seat, cab glass, a lighting lamp and the like in a steel structure of the cab, and the relevance among all assembly processes is strong. In the prior art, when the driver cab is assembled in the process, operators are all assembled in a small space, the operation types are more, interference exists between the operators, and the efficiency is low.

All parts in the vibration reduction cab provided by the embodiment of the invention can be produced in a modularized manner, different module combinations are selected according to requirements during assembly, different functions are realized, and the expansion and the upgrade of the functions of the vibration reduction cab are conveniently realized. After the assembly of the vibration reduction cab is completed, the vibration reduction cab is integrally installed on the vehicle body through the hanging ring 340, so that the manpower and material resources of the locomotive can be greatly saved.

The modular production of the cab refers to the steps of independently dividing the cab into designated assembly areas, independently assembling each system in the cab, and finally integrally hoisting the cab to be installed on a vehicle body. The cab can provide comfortable driving space for a driver, and is convenient to install. Under the condition that the market economic competition is increasingly severe at present, the modular assembly of the cab ensures that companies create higher value and the cab occupies a favorable position in the market competition.

The embodiment of the invention also provides the diesel locomotive. The diesel locomotive comprises a locomotive body and a damping cab arranged on the locomotive body.

The diesel locomotive provided by the embodiment of the invention adopts the vibration reduction cab, and has basically the same beneficial effects as the vibration reduction cab, and the details are not repeated.

Furthermore, the vibration reduction cab and the vehicle body are fastened outside the vibration reduction cab through bolts, and torque is conveniently applied.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.