Pump

Abstract

A pump includes a cylinder including at least one upper aperture and lower aperture. A piston is movable in the cylinder. A rod is connected to the piston. A ring is provided around the rod and fit in the cylinder. An upper collar is formed with at least one countersink hole and provided around the cylinder. At least one upper threaded bolt is driven into the ring through the countersink hole, the upper aperture and an upper elastic washer. A base includes a reduced portion fit in the cylinder. A check valve is provided on the reduced portion of the base. A lower collar is formed with at least one countersink hole and provided around the cylinder. At least one lower threaded bolt is driven into the reduced portion of the base through the countersink hole of the lower collar, the lower aperture and a lower elastic washer.

Description

BACKGROUND OF INVENTION

1. Field of Invention

The present invention relates to a pump and, more particularly, to a pump including a fastening device for fastening a ring or base to a cylinder so that the wall of the cylinder can be made thin and light and the making and assembly of the parts are easy and inexpensive.

2. Related Prior Art

Referring to FIG. 10, a conventional pump includes a cylinder 70, a piston 71 movable in the cylinder 70, a rod 72 connected to the piston 71, a base 73 connected to a lower end of the cylinder 70, a flexible pipe 77 connected to the base 73, a ring 75 connected to an upper end of the cylinder 70. The base 73 is formed with a thread 74 engaged with a thread 702 formed on the internal side of the lower end of the cylinder 70. The ring 75 is formed with a thread 76 engaged with a thread 701 formed on the internal side of the upper end of the cylinder 70. To tape the threads 701 and 702, the wall of the cylinder 70 is inevitably made thick and therefore heavy. Accordingly, the base 73 and ring 75 are made big and therefore heavy. The cylinder 70, base 73 and ring 75 are expensive for using a lot of material. Moreover, it requires a special machine, takes a lot of time and therefore costs a lot of money to tape the threads 701, 702, 76 and 74. It is troublesome to assemble the parts.

Referring to FIG. 11, another conventional pump includes a cylinder 80, a piston 81, a rod 82, a base 85, a connector 83, a rigid tube 88 and a flexible pipe 90. The base 85 includes a socket 92 thereon, a conduit 86 next to the socket 92 and a bowl 84 on the conduit 86. The piston 81 is movable in the cylinder 80. The rod 82 is connected to the piston 81. The connector 83 is disposed in a lower end of the cylinder 80 that is inserted in the socket 92. The rigid tube 88 is transversely inserted through the base 85, cylinder 80, connector 83 and conduit 86. The flexible pipe 90 is connected to the tube 88. The cylinder 80, connector 83, socket 92, rigid tube 88, conduit 86 and bowl 84 are in communication of fluid with one another. This conventional pump includes a complicated structure consisting of a lot of parts. It consumes a lot of material, takes a lot of time and therefore costs a lot of money to make these parts. It also takes a lot of time and therefore costs a lot of money to assemble the parts. Moreover, pressurized air travels from the cylinder 80 to the flexible pipe 90 through the connector 83 and the rigid tube 88. The pressurized could easily leak.

The present invention is therefore intended to obviate or at least alleviate the problems encountered in prior art.

SUMMARY OF INVENTION

It is an objective of the present invention to provide an inexpensive pump for using a small amount of material.

It is another objective of the present invention to provide a pump with parts that are made and assembled in a short period of time with a small amount of effort.

It is another objective of the present invention to provide a secure pump from which leak is limited.

To achieve the foregoing objectives of the present invention, a pump includes a cylinder including at least one upper aperture and lower aperture. A piston is movable in the cylinder. A rod is connected to the piston. A ring is provided around the rod and fit in the cylinder. An upper collar is formed with at least one countersink hole and provided around the cylinder. At least one upper threaded bolt is driven into the ring through the countersink hole, the upper aperture and an upper elastic washer. A base includes a reduced portion fit in the cylinder. A check valve is provided on the reduced portion of the base. A lower collar is formed with at least one countersink hole and provided around the cylinder. At least one lower threaded bolt is driven into the reduced portion of the base through the countersink hole of the lower collar, the lower aperture and a lower elastic washer.

Other objectives, advantages and features of the present invention will become apparent from the following description referring to the attached drawings.

BRIEF DESCRIPTION OF DRAWINGS

The present invention will be described via the detailed illustration of three embodiments referring to the drawings.

FIG. 1 is a perspective view of a pump according to the first embodiment of the present invention.

FIG. 2 is an exploded view of the pump shown in FIG. 1.

FIG. 3 is an enlarged partial view of the pump shown in FIG. 2.

FIG. 4 is another enlarged partial view of the pump shown in FIG. 2.

FIG. 5 is a cross-sectional view of the pump shown in FIG. 1.

FIG. 6 is a cross-sectional view of the pump shown in FIG. 3.

FIG. 7 is a cross-sectional view of the pump shown in FIG. 4.

FIG. 8 is an exploded view of a pump according to the second embodiment of the present invention.

FIG. 9 is a cross-sectional view of a pump according to the third embodiment of the present invention.

FIG. 10 is a perspective view of a conventional pump.

FIG. 11 is a perspective view of another conventional pump.

DETAILED DESCRIPTION OF EMBODIMENTS

Referring to FIGS. 1 through 7, a pump includes a cylinder 30, a piston 31, a piston ring 34, a rod 32, a handle 33, a ring 40, an upper fastening device 60, a base 10, a lower fastening device 50 and a flexible pipe 20 according to a first embodiment of the present invention.

The cylinder 30 includes two opposite apertures 54 in a lower end thereof and two opposite apertures 64 in an upper end thereof.

The piston 31 is movable in the cylinder 30. The piston ring 34 is provided on the piston 31. The rod 32 is connected to the piston 31. The handle 33 is connected to the rod 32.

The ring 40 includes a reduced portion 41 and two opposite hexagonal recesses 61 in the reduced portion 41. The reduced portion 41 of the ring 40 is fit in the upper end of the cylinder 30 so that hexagonal recesses 61 are in communication with the apertures 64. The rod 32 is inserted through the ring 40.

The upper fastening device 60 includes a collar 66, two hexagonal nuts 62, two elastic washers 63 and two threaded bolts 65. Each of the hexagonal nuts 62 and a related one of the elastic washers 63 are fit in a related one of the hexagonal recesses 61. The collar 66 includes two opposite countersink holes 67 therein and two opposite clips 68 thereon. The collar 66 is provided on the upper end of the cylinder 30 so that the countersink holes 67 are in communication with the apertures 64. The threaded bolts 65 are inserted through the countersink holes 67 and 64 and elastic washers 63 and engaged with the hexagonal nuts 62. The elastic washers 63 are made of rubber for example. The elastic washers 63 are expanded in a radial direction when they are compressed axially. Thus, the wall of each of the hexagonal recesses 61 is pressed by the external side of a related one of the elastic washers 63, and each of the threaded bolts 65 is pinched by the internal side of a related one of the elastic washers 63.

The base 10 includes a passageway 11 therein, a tread 12 at a lower end thereof, a reduced portion 13 at an upper end thereof and two opposite hexagonal recesses 51 in the reduced portion 13. A check valve 14 is provided on the reduced portion 13 of the base 10. The reduced portion 13 of the base 10 is fit in the lower end of the cylinder 30 so that hexagonal recesses 51 are in communication with the apertures 54.

A first end of the flexible pipe 20 is connected to the base 10 so that the passageway of the flexible pipe 20 is in communication of fluid with the passageway 11 of the base 10. A second end of the flexible pipe 20 is connected to a nozzle 21 for receiving a valve of an inflatable object such as a tire. The flexible pipe 20 can be clipped by any of the clips 68 during storage and transportation.

The lower fastening device 50 includes a collar 56, two hexagonal nuts 52, two elastic washers 53 and two threaded bolts 55. Each of the hexagonal nuts 52 and a related one of the elastic washers 53 are fit in a related one of the hexagonal recesses 51. The collar 56 includes two opposite countersink holes 57 therein. The collar 56 is provided on the lower end of the cylinder 30 so that the countersink holes 57 are in communication with the apertures 54. The threaded bolts 55 are inserted through the countersink holes 57 and 54 and elastic washers 53 and engaged with the hexagonal nuts 52. The elastic washers 53 are made of rubber for example. The elastic washers 53 are expanded in a radial direction when they are compressed axially. Thus, the wall of each of the hexagonal recesses 51 is pressed by the external side of a related one of the elastic washers 53, and each of the threaded bolts 55 is pinched by the internal side of a related one of the elastic washers 53.

In use, a user maneuvers the handle 33 to reciprocate the piston 31 in the cylinder 30 via the rod 32. In a downward stroke, the piston 31 pressurizes air in the cylinder 30 while the check valve 14 avoids leak of the pressurized air from the cylinder 30. The pressurized air leaves the cylinder 30 only through the flexible pipe 20. In an upward stroke, the piston 31 reduces the pressure in the cylinder 30 while the check valve 14 allows air to go into the cylinder 30 because of the reduced pressure.

Referring to FIG. 8, there is shown a pump according to a second embodiment of the present invention. The second embodiment is like the first embodiment except two things. Firstly, the hexagonal nuts 52 are embedded in the reduced portion 13 of the base 10 when the base 10 is molded of plastic or metal. The elastic washers 53 are located against the hexagonal nuts 52. Secondly, the nuts 62 are embedded in the reduced portion 41 of the ring 40 when the ring 40 is molded of plastic or metal. The elastic washers 63 are located against the hexagonal nuts 62.

Referring to FIG. 9, there is shown a pump according to a third embodiment of the present invention that is like the first embodiment except two things. Firstly, the reduced portion 13 of the base 10 includes two screw holes 59 instead of the hexagonal recesses 51. The elastic washers 53 are located against the reduced portion 13 of the base 10. The threaded bolts 55 are driven into the screw holes 59 through the elastic washers 53. Accordingly, the hexagonal nuts 52 are omitted. Secondly, the reduced portion 41 of the ring 40 includes two screw holes 69 instead of the hexagonal recesses 61. The elastic washers 63 are located against the reduced portion 41 of the ring 40. The threaded bolts 65 are driven into the screw holes 69 through the elastic washers 63. Accordingly, the hexagonal nuts 62 are omitted.

The pump according to the present invention exhibits several advantages. Firstly, it is inexpensive for using a small amount of material since no thread is made on the internal side of the cylinder 30 so that the wall of the cylinder 30 is made thin.

Secondly, its parts are made and assembled in a short period of time with a small amount of effort made since a screwdriver is all it needs to assemble the small number of parts.

Thirdly, it is secure. The pressurized air goes through the base 10 from which leak is limited. Moreover, the elastic washers 53 and 63 pinch the threaded bolts 55 and 65, respectively to render firm the connection of the cylinder 30 to the base 10 and ring 40, respectively.

The present invention has been described via the detailed illustration of the embodiments. Those skilled in the art can derive variations from the embodiments without departing from the scope of the present invention. Therefore, the embodiments shall not limit the scope of the present invention defined in the claims.

Claims

1. A pump comprising: a cylinder comprising at least one upper aperture and lower aperture;a piston movable in the cylinder;a rod connected to the piston;a ring provided around the rod and fit in the cylinder;at least one upper elastic washer;an upper collar formed with at least one countersink hole and provided around the cylinder;at least one upper threaded bolt driven into the ring through the countersink hole, the upper aperture and the upper elastic washer;a base comprising a reduced portion fit in the cylinder;a check valve provided on the reduced portion of the base;at least one lower elastic washer;a lower collar formed with at least one countersink hole and provided around the cylinder; andat least one lower threaded bolt driven into the reduced portion of the base through the countersink hole of the lower collar, the lower aperture and the lower elastic washer.

2. The pump according to claim 1, wherein the base comprises a tread opposite to the reduced portion.

3. The pump according to claim 1 comprising a flexible pipe connected to the base.

4. The pump according to claim 3 comprising a nozzle connected to the flexible pipe.

5. The pump according to claim 1, wherein the ring comprises at least one recess for receiving the upper threaded bolt.

6. The pump according to claim 5 comprising at least one upper nut non-rotationally disposed in the recess and engaged with the upper threaded bolt.

7. The pump according to claim 6, wherein the recess is a non-circular recess, and the upper nut is a non-circular nut disposed in the non-circular recess.

8. The pump according to claim 6, wherein the upper elastic washer is disposed in the recess.

9. The pump according to claim 1 comprising an upper nut embedded in the ring and engaged with the upper threaded bolt.

10. The pump according to claim 1, wherein the ring comprises a screw hole for receiving the upper threaded bolt.

11. The pump according to claim 1, wherein the base comprises at least one recess for receiving the lower threaded bolt.

12. The pump according to claim 11 comprising at least one lower nut non-rotationally disposed in the recess and engaged with the lower threaded bolt.

13. The pump according to claim 12, wherein the recess is a non-circular recess, and the lower nut is a non-circular nut disposed in the non-circular recess.

14. The pump according to claim 12, wherein the lower elastic washer is disposed in the recess.

15. The pump according to claim 1 comprising a lower nut embedded in the base and engaged with the lower threaded bolt.

16. The pump according to claim 1, wherein the base comprises a screw hole for receiving the lower threaded bolt.

17. The pump according to claim 1 comprising a handle connected to the rod.