EXERCISE DEVICE WITH ADJUSTABLE DAMPING FORCE

Information

  • Patent Application
  • 20220168607
  • Publication Number
    20220168607
  • Date Filed
    November 27, 2020
    4 years ago
  • Date Published
    June 02, 2022
    2 years ago
Abstract
An exercise device with adjustable damping force has a main tube, an operating rod assembly slidably mounted on the main tube, an upper hole seat mounted on an upper end of the main tube and having multiple upper damping holes, a lower hole seat mounted on a lower end of the main tube and having multiple lower damping holes, at least one upper blocking element mounted on the upper hole seat, and at least one lower blocking element mounted on the lower hole seat. By adjusting an area where each upper damping hole is covered and an area where each lower damping hole is covered, the damping force provided by the exercise device as described can be adjusted according to different needs of users, and the exercise device is easy to carry and is versatile.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention

The present invention relates to an exercise device, especially to an exercise device with damping force that can be adjusted by adjusting air flow rate in and out of the exercise device.


2. Description of the Prior Art(s)

Advance in technology has brought a lot of convenience to modern life. In people's lives, there are many things that can be done without labor, which causes people's muscle endurance to be lower than before and various diseases of affluence to be derived. Therefore, fitness has gradually become popular in recent years. A variety of gyms are set up in the cities, so as to encourage people to improve physical and mental health through exercise and fitness. Moreover, to people in certain jobs, it is hard for them to spare time to work out in the gym or outdoors, and they would choose to buy exercise equipment, such as dumbbells, and exercise at home or in the office in their limited free time.


However, take the exercise equipment that has fixed weight, such as the dumbbells, for example, as muscle endurance of an exerciser has improved after a period of training, the weight of the exercise equipment becomes relatively light and is hard for the exerciser to continue building muscles. Thus, the exerciser has to buy heavier exercise equipment again and again for training. As a result, the lighter exercise equipment that is purchased earlier becomes redundant, which not only causes wastes of resources and money, but also takes up storage space.


To overcome the shortcomings, the present invention provides an exercise device with adjustable damping force to mitigate or obviate the aforementioned problems.


SUMMARY OF THE INVENTION

The main objective of the present invention is to provide an exercise device with adjustable damping force. The exercise device has a main tube, an operating rod assembly, an upper hole seat, a lower hole seat, at least one upper blocking element, and at least one lower blocking element. The main tube is hollow and has an upper opening and a lower opening. The operating rod assembly includes a piston slidably mounted in the main tube and a rod having an inner end connected to the piston. The upper hole seat is mounted on an upper end of the main tube to cover the upper opening of the main tube and has a mounting hole and multiple upper damping holes. The rod is slidably mounted through the mounting hole. The upper damping holes are separately disposed beside the mounting hole. The lower hole seat is mounted on a lower end of the main tube to cover the upper opening of the main tube and has multiple lower damping holes. The at least one upper blocking element is mounted on the upper hole seat and selectively closes or opens the upper damping holes. The at least one lower blocking element is mounted on the lower hole seat and selectively closes or opens the lower damping holes.


By adjusting an area where each upper damping hole is covered and an area where each lower damping hole is covered, the damping force provided by the exercise device as described can be adjusted according to different needs of users, and the exercise device is easy to carry and is versatile.


Other objectives, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings,





BRIEF DESCRIPTION OF THE DRAWINGS


FIG. 1 is a perspective view of a first embodiment of an exercise device with adjustable damping force in accordance with the present invention;



FIG. 2 is an exploded perspective view of the exercise device in FIG. 1;



FIG. 3 is an enlarged side view in partial section of the exercise device in FIG. 1;



FIG. 4 is another enlarged side view in partial section of the exercise device in FIG. 1;



FIG. 5 is an operational top view of an upper hole seat and an upper blocking element of the exercise device in FIG. 1;



FIG. 6 is another operational top view of the upper hole seat and the upper blocking element of the exercise device in FIG. 1;



FIG. 7 is a perspective view of a second embodiment of an exercise device with adjustable damping force in accordance with the present invention;



FIG. 8 is a perspective view of a third embodiment of an exercise device with adjustable damping force in accordance with the present invention;



FIG. 9 is an enlarged side view in partial section of the exercise device in FIG. 8;



FIG. 10 is a perspective view of a fourth embodiment of an exercise device with adjustable damping force in accordance with the present invention; and



FIG. 11 is an enlarged perspective view of the exercise device in FIG. 10.





DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

With reference to FIGS. 1 and 2, a first preferred embodiment of an exercise device with adjustable damping force in accordance with the present invention is shown. The exercise device comprises a main tube 10, an operating rod assembly 20, an upper hole seat 30, a lower hole seat 40, at least one upper blocking element 50, at least one lower blocking element 70, and an attaching element 60.


As shown in FIG. 2, the main tube 10 is hollow and cylindrical and has an upper opening 11 and a lower opening 12. The upper opening 11 and the lower opening 12 fluidly communicate with an interior of the main tube 10.


With reference to FIGS. 2 and 3, the operating rod assembly 20 includes a piston 21 and a rod 22. The piston 21 is slidably mounted in the main tube 10 and divides the interior of the main tube 10 into an upper inner space defined between the piston 21 and the upper opening 11 of the main tube 10 and a lower inner space defined between the piston 21 and the lower opening 12 of the main tube 10. Since the piston 21 is a conventional standard component, a detailed description of the piston 21 is omitted. The rod 22 has an inner end connected to the piston 21 and an outer end connected with a handle 23.


The upper hole seat 30 is formed as a cap, is mounted on an upper end of the main tube 10 to cover the upper opening 11 of the main tube 10, and has a mounting hole 31, an upper mounting protrusion 32, multiple upper damping holes 33, and at least one air inlet 34. The mounting hole 31 is formed through a center of the upper hole seat 30. The rod 22 is slidably mounted through the mounting hole 31. The upper mounting protrusion 32 is formed on an outer end surface of the upper hole seat 30 and around the mounting hole 31. The upper damping holes 33 are separately disposed beside the mounting hole 31 and are formed through the upper mounting protrusion 32.


With further reference to FIG. 5, the at least one air inlet 34 of the upper hole seat 30 is formed through the upper hole seat 30 and fluidly communicates the upper inner space of the main tube 10 and an exterior of the main tube 10. Each of the at least one air inlet 34 of the upper hole seat 30 is mounted with an upper one-way valve 35. The upper one-way valve 35 only allows air to flow into the upper inner space through the air inlet 34 of the upper hole seat 30 and does not allow the air to flow out of the upper inner space through the air inlet 34 of the upper hole seat 30.


In the first preferred embodiment, each of the upper damping holes 33 is circular, and the upper damping holes 33 are disposed on two opposite sides of the mounting hole 31 and are disposed at intervals. However, an arrangement of the upper damping holes 33 is not limited to the above-mentioned arrangement and the upper damping holes 33 may be disposed according to the needs of users.


With reference to FIGS. 2 and 4, the lower hole seat 40 is formed as a cap, is mounted on a lower end of the main tube 10 to cover the upper opening 11 of the main tube 10, and has a connector 41, a lower mounting protrusion 42, multiple lower damping holes 43, and at least one air inlet 44. The connector 41 is hollow and tapered and has a proximal end and a distal end 411. The proximal end of the connector 41 is attached to an outer end surface of the lower hole seat 40. The distal end 411 of the connector 41 may be formed as a ball. In the first preferred embodiment, the connector 41 is a universal joint. However, the connector 41 is not limited to the universal joint and may be other types of connectors that meet the needs of the users. The lower mounting protrusion 42 is formed on the outer end surface of the lower hole seat 40 and around the connector 41. The lower damping holes 43 are separately disposed beside the connector 41 and are formed through the lower mounting protrusion 42.


The at least one air inlet 44 of the lower hole seat 40 is formed through the lower hole seat 40 and fluidly communicates the lower inner space of the main tube 10 and the exterior of the main tube 10. Each of the at least one air inlet 44 of the lower hole seat 40 is mounted with a lower one-way valve 45. The lower one-way valve 45 only allows air to flow into the lower inner space through the air inlet 44 of the lower hole seat 40 and does not allow the air to flow out of the lower inner space through the air inlet 44 of the lower hole seat 40.


In the first preferred embodiment, each of the lower damping holes 43 is circular, and the lower damping holes 43 are disposed on two opposite sides of the connector 41 and are disposed at intervals. However, an arrangement of the lower damping holes 43 is not limited to the above-mentioned arrangement and the lower damping holes 43 may be disposed according to the needs of the users.


With reference to FIGS. 2 to 4 and 5, each of the at least one upper blocking element 50 and each of the at least one lower blocking element 70 are substantially the same in shape and in use.


The at least one upper blocking element 50 is mounted on the upper hole seat 30 and selectively closes or opens the upper damping holes 33. In the first preferred embodiment, the at least one upper blocking element 50 includes one upper blocking element 50. The upper blocking element 50 is annular and is mounted on the upper mounting protrusion 32 of the upper hole seat 30 and has multiple upper orifices 51 and multiple upper skidproof protrusions 52. The upper orifices 51 are formed through the upper blocking element 50. Each of the upper orifices 51 selectively communicates with at least one corresponding one of the upper damping holes 33 of the upper hole seat 30. The upper skidproof protrusions 52 are formed on an outer side surface of the upper blocking element 50.


The at least one lower blocking element 70 is mounted on the lower hole seat 40 and selectively closes or opens the lower damping holes 43. In the first preferred embodiment, the at least one lower blocking element 70 includes one lower blocking element 70. The lower blocking element 70 is annular and is mounted on the lower mounting protrusion 42 of the lower hole seat 40 and has multiple lower orifices 71 and multiple lower skidproof protrusions 72. The lower orifices 71 are formed through the lower blocking element 40. Each of the lower orifices 71 selectively communicates with at least one corresponding one of the lower damping holes 43 of the lower hole seat 40. The lower skidproof protrusions 72 are formed on an outer side surface of the lower blocking element 70.


In the first preferred embodiment, each of the upper orifices 51 and each of the lower orifices 71 are, but not limited to, elongated and arced.


The attaching element 60 is used for attaching to a predetermined place, is connected to the distal end 411 of the connector 41 of the lower hole seat 40, and has a mounting disk 61 and a connecting recess 62. The mounting disk 61 is used for attaching to the predetermined place and has multiple fastening holes formed through the mounting disk 61. The connecting recess 62 is formed in an end surface of the mounting disk 61. The ball-shaped distal end 411 of the connector 41 is rotatably fitted in the connecting recess 62. Otherwise, in other embodiments, the attaching element 60 may be a sucking disk that is attachable to said predetermined place.


With reference to FIGS. 1 and 2, when using the exercise device of the present invention, the attaching element 60 is securely attached to the predetermined place by mounting multiple fasteners (not shown) through the fastening holes of the mounting disk 61 respectively and fixing the fasteners to the predetermined place. An exerciser holds the handle 23 on the rod 22 and then pushes and pulls the operating rod assembly 20 repeatedly, so as to train muscles in arms, chest, or back.


With further reference to FIGS. 4 and 5, by turning the upper blocking element 50 and the lower blocking element 70, damping force provided by the exercise device can be adjusted. Specifically, take the upper blocking element 50 for example, when the upper blocking element 50 on the upper hole seat 30 is turned to allow all of the upper damping holes 33 to fluidly communicate with the upper orifices 51, flow rate of an airflow flowing in and out of the upper inner space of the main tube 10 is the largest. Therefore, the exerciser is able to easily pull the operating rod assembly 20. The lower blocking element 70 works in the same way.


With further reference to FIG. 6, when the upper blocking element 50 is turned to only allow some of the upper damping holes 33 to fluidly communicate with the upper orifices 51, the flow rate of the airflow flowing in and out of the upper inner space of the main tube 10 is reduced. Thus, the exerciser has to pull the operating rod assembly 20 with greater force. Accordingly, the damping force provided by the exercise device is increased.


The damping force provided by the exercise device as described can be adjusted according to different needs of users, and the exercise device is easy to carry and is versatile. Moreover, the way to fix the attaching element 60 can be changed according to different training environment and different training methods, so as to train different muscle groups. Furthermore, the upper skidproof protrusions 52 of the upper blocking element 50 and the lower skidproof protrusions 72 of the lower blocking element 70 allow the exerciser to stably hold and turn the upper blocking element 50 and the lower blocking element 70.


With further reference to FIG. 7, a second preferred embodiment of an exercise device with adjustable damping force in accordance with the present invention is shown. The main tube 10A, the operating rod assembly 20A, the upper hole seat 30A, the lower hole seat 40A, and the attaching element 60A in the second preferred embodiment are substantially the same as the main tube 10, the operating rod assembly 20, the upper hole seat 30, the lower hole seat 40, and the attaching element 60 in the first preferred embodiment. The main differences between the second preferred embodiment and the first preferred embodiment lie in the upper blocking element 50A and the lower blocking element.


Each of the at least one upper blocking element 50A includes an upper guiding tube 53A and at least one upper valve 54A. The upper guiding tube 53A has two ends. One of the ends of the upper guiding tube 53A is inserted in a corresponding one of the upper damping holes 33A of the upper hole seat 30A and is sealingly connected with the upper hole seat 30A. The at least one upper valve 54A is mounted on the other end of the upper guiding tube 53A and selectively closes or opens the corresponding upper damping hole 33A. Similar to the upper blocking element 50A, each of the at least one lower blocking element includes a lower guiding tube 73A and at least one lower valve 74A. The lower guiding tube 73A has two ends. One of the ends of the lower guiding tube 73A is inserted in a corresponding one of the lower damping holes of the lower hole seat and is sealingly connected with the lower hole seat. The at least one lower valve 74A is mounted on the other end of the lower guiding tube 73A and selectively closes or opens the corresponding lower damping hole. The upper valve 54A and the lower valve 74A are conventional standard components, and thus detailed descriptions of the upper valve 54A and the lower valve 74A are omitted. The upper valve 54A and the lower valve 74A may be any component that has sealing function.


In addition to extend air flow path so as to increase the damping force, the damping force may also be adjusted by closing or opening the upper damping holes 33A via the upper valve 54A and by closing or opening the lower damping holes via the lower valve 74A.


With further reference to FIGS. 8 and 9, a third preferred embodiment of an exercise device with adjustable damping force in accordance with the present invention is shown. The main tube 10B, the operating rod assembly 20B, the upper hole seat 30B, the lower hole seat 40B, and the attaching element 60B in the third preferred embodiment are substantially the same as the main tube 10, the operating rod assembly 20, the upper hole seat 30, the lower hole seat 40, and the attaching element 60 in the first preferred embodiment. The main differences between the third preferred embodiment and the first preferred embodiment lie in that the upper blocking element 50B and the lower blocking element are columnar. For instance, the upper blocking element 50B and the lower blocking element may be components such as screws or plugs that have sealing function.


The upper hole seat 30B has multiple inner threads defined around the upper damping holes 33B respectively. Each of the at least one upper blocking element 50B is inserted in one of the upper damping holes 33B of the upper hole seat 30B and has an outer thread engaging with the inner thread that is defined around the upper damping hole 33B in which the upper blocking element 30B is inserted. Similar to the upper hole seat 30B and the upper blocking element 50B the lower hole seat 40B has multiple inner threads defined around the lower damping holes respectively and each of the at least one lower blocking element is inserted in one of the lower damping holes of the lower hole seat 40B. Each of the at least one lower blocking element has an outer thread engaging with the inner thread that is defined around the lower damping hole in which the lower blocking element is inserted.


In the third preferred embodiment, each of the at least one upper blocking element 50B is a bolt and has two guiding surfaces 55B. The two guiding surfaces 55B are formed on opposite sides of the upper blocking element 50B and are inclined. Thus, the bolt-shaped upper blocking element 50B tapers to an inner end of the upper blocking element 50B. Each of the at least one lower blocking element is also a bolt and tapers to an inner end of the lower blocking element.


Take the upper blocking element 50B for example, when the upper blocking element 50B is tightened, the upper blocking element 50B closes the upper damping hole 33B. When the upper blocking element 50B is loosened (i.e. the guiding surface 55B leaves the inner thread in the upper damping hole 33B and the upper blocking element 50B has not been fully tightened), a clearance exists between the guiding surface 55B of the upper blocking element 50B and the upper hole seat 30B. Thus, by loosening or tightening the upper blocking element 50B, said clearance and the flow rate of the airflow can be adjusted. Otherwise, as the upper blocking element 50B and the lower blocking element are plugs, the upper damping hole 3313 and the lower damping hole can be sealed.


With further reference to FIG. 10, a fourth preferred embodiment of an exercise device with adjustable damping force in accordance with the present invention is shown. The main tube 10C, the operating rod assembly 20B, the upper blocking element 50C, and the attaching element 60C in the fourth preferred embodiment are substantially the same as the main tube 10, the operating rod assembly 20, the upper blocking element 50, and the attaching element 60 in the first preferred embodiment. Each of the upper damping holes 33C of the upper hole seat 30C is elongated and arced. Similarly, each of the lower damping holes of the lower hole seat 40C is elongated and arced.


Since each of the upper orifices 51C of the upper blocking element 50C is also elongated and arced each of the lower orifices of the lower blocking element is also elongated and arced, a size of an aperture formed by one upper orifice 51C and a corresponding one of the upper damping holes 33C or formed by one lower orifice and a corresponding one of the lower damping holes can be adjusted by turning the upper blocking element 50C or the lower blocking element. Accordingly, the flow rate of the airflow can be adjusted.


Even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and features of the invention, the disclosure is illustrative only. Changes may be made in the details, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.

Claims
  • 1. An exercise device with adjustable damping force, and the exercise device comprising: a main tube being hollow and having an upper opening and a lower opening, and the upper opening and the lower opening fluidly communicating with an interior of the main tube;an operating rod assembly including: a piston slidably mounted in the main tube; anda rod having an inner end connected to the piston;an upper hole seat mounted on an upper end of the main tube to cover the upper opening of the main tube and having: a mounting hole, wherein the rod is slidably mounted through the mounting hole; andmultiple upper damping holes separately disposed beside the mounting hole;a lower hole seat mounted on a lower end of the main tube to cover the upper opening of the main tube and having multiple lower damping holes;at least one upper blocking element mounted on the upper hole seat and selectively closing or opening the upper damping holes; andat least one lower blocking element mounted on the lower hole seat and selectively closing or opening the lower damping holes.
  • 2. The exercise device as claimed in claim 1, wherein each of the upper damping holes is circular and the upper damping holes are separately arranged around the mounting hole of the upper hole seat;each of the lower damping holes is circular;each of the at least one upper blocking element is columnar and is inserted in one of the upper damping holes of the upper hole seat; andeach of the at least one lower blocking element is columnar and is inserted in one of the lower damping holes of the lower hole seat.
  • 3. The exercise device as claimed in claim 2, wherein the upper hole seat has multiple inner threads defined around the upper damping holes respectively;the lower hole seat has multiple inner threads defined around the lower damping holes respectively;each of the at least one upper blocking element has an outer thread engaging with the inner thread that is defined around the upper damping hole in which the upper blocking element is inserted; andeach of the at least one lower blocking element has an outer thread engaging with the inner thread that is defined around the lower damping hole in which the lower blocking element is inserted.
  • 4. The exercise device as claimed in claim 3, wherein each of the at least one upper blocking element is a bolt and tapers to an inner end of the upper blocking element; andeach of the at least one lower blocking element is a bolt and tapers to an inner end of the lower blocking element.
  • 5. The exercise device as claimed in claim 1, wherein each of the upper damping holes is circular and the upper damping holes are separately arranged around the mounting hole of the upper hole seat;each of the lower damping holes is circular;each of the at least one upper blocking element includes an upper guiding tube having two ends, and one of the ends of the upper guiding tube inserted in a corresponding one of the upper damping holes of the upper hole seat and sealingly connected with the upper hole seat; andat least one upper valve mounted on the other end of the upper guiding tube; andeach of the at east one lower blocking element includes a lower guiding tube having two ends, and one of the ends of the lower guiding tube inserted in a corresponding one of the lower damping hole of the lower hole seat and sealingly connected with the lower hole seat; andat least one lower valve mounted on the other end of the upper guiding tube.
  • 6. The exercise device as claimed in claim 1, wherein the upper hole seat has an upper mounting protrusion formed on an outer end surface of the upper hole seat and around the mounting hole, wherein the upper damping holes of the upper hole seat are formed through the upper mounting protrusion;the lower hole seat has a lower mounting protrusion formed on an outer end surface of the lower hole seat, wherein the lower damping holes of the lower hole seat are formed through the lower mounting protrusion;the at least one upper blocking element includes one upper blocking element, the upper blocking element is mounted on the upper mounting protrusion of the upper hole seat and has multiple upper orifices, the upper orifices are formed through the upper blocking element, and each of the upper orifices selectively communicates with at least one corresponding one of the upper damping holes of the upper hole seat; andthe at least one lower blocking element includes one lower blocking element, the lower blocking element is mounted on the lower mounting protrusion of the lower hole seat and has multiple upper orifices, the lower orifices are formed through the lower blocking element, and each of the lower orifices selectively communicates with at least one corresponding one of the lower damping holes of the lower hole seat.
  • 7. The exercise device as claimed in claim 6, wherein the upper mounting protrusion of the upper hole seat is annular and is formed around the mounting hole;each of the upper damping holes of the upper hole seat is elongated and arced;each of the lower damping holes of the lower hole seat is elongated and arced;the upper blocking element is annular and each of the upper orifices of the upper blocking element is elongated and arced;the lower blocking element is annular and each of the lower orifices of the lower blocking element is elongated and arced;the upper blocking element has multiple upper skidproof protrusions formed on an outer side surface of the upper blocking element; andthe lower blocking element has multiple lower skidproof protrusions formed on an outer side surface of the lower blocking element.
  • 8. The exercise device as claimed in claim 1, wherein the exercise device further comprises an attaching element; andthe lower hole seat has a connector having a proximal end and a distal end, the proximal end of the connector is attached to an outer end surface of the lower hole seat and the distal end of the connector is connected to the attaching element.
  • 9. The exercise device as claimed in claim 2, wherein the exercise device further comprises an attaching element; andthe lower hole seat has a connector having a proximal end and a distal end, the proximal end of the connector is attached to an outer end surface of the lower hole seat and the distal end of the connector is connected to the attaching element.
  • 10. The exercise device as claimed in claim 5, wherein the exercise device further comprises an attaching element; andthe lower hole seat has a connector having a proximal end and a distal end, the proximal end of the connector is attached to an outer end surface of the lower hole seat and the distil end of the connector is connected to the attaching element.
  • 11. The exercise device as claimed in claim 6, wherein the exercise device further comprises an attaching element; andthe lower hole seat has a connector having a proximal end and a distal end, the proximal end of the connector is attached to an outer end surface of the lower hole seat and the distal end of the connector is connected to the attaching element.
  • 12. The exercise device as claimed in claim 8, wherein the connector is a universal joint and the attaching element is a sucking disk.
  • 13. The exercise device as claimed in claim 9, wherein the connector is a universal joint and the attaching element is a sucking disk.
  • 14. The exercise device as claimed in claim 10, wherein the connector is a universal joint and the attaching element is a sucking disk.
  • 15. The exercise device as claimed in claim 11, wherein the connector is a universal joint and the attaching element is a sucking disk.
  • 16. The exercise device as claimed in claim 8, wherein the connector is a universal joint; andthe attaching element has a mounting disk having multiple fastening holes formed through the mounting disk; anda connecting recess formed in an end surface of the mounting disk, wherein the distal end of the connector is fitted in the connecting recess.
  • 17. The exercise device as claimed in claim 11, wherein the connector is a universal joint; andthe attaching element has a mounting disk having multiple fastening holes formed through the mounting disk; anda connecting recess formed in an end surface of the mounting disk, wherein the distal end of the connector is fitted in the connecting recess.
  • 18. The exercise device as claimed in claim 1, wherein the piston of the operating rod assembly divides the interior of the main tube into an upper inner space defined between the piston and the upper opening of the main tube and a lower inner space defined between the piston and the lower opening of the main tube;the upper hole seat has at least one air inlet formed through the upper hole seat and fluidly communicating the upper inner space of the main tube and an exterior of the main tube, each of the at least one air inlet of the upper hole seat is mounted with an upper one-way valve, and the upper one-way valve only allows air to flow into the upper inner space through the air inlet of the upper hole seat.
  • 19. The exercise device as claimed in claim 17, wherein the upper hole seat has at least one air inlet formed through the lower hole seat and fluidly communicating the lower inner space of the main tube and the exterior of the main tube, each of the at least one air inlet of the lower hole seat is mounted with a lower one-way valve, and the lower one-way valve only allows air to flow into the lower inner space through the air inlet of the lower hole seat.