Leak-preventing device for a pump   

Abstract: A pump includes a shell, an air-pumping device, a cover, a valve and a buoyant. The air-pumping device is used for pumping air out of the shell and therefore pumping liquid into the shell. The cover includes an opening and channel defined therein. The cover is attached to the shell and the air-pumping device. The shell is in communication with the exterior thereof via the opening. The shell is in communication with the air-pumping device via the channel. The valve is movable between a first position for releasing the channel and a second position for blocking the channel. The valve is in the second position as the pump is in an inverted position. The buoyant is used for moving the valve to the second position as the pump is almost full of liquid in an upright position.

1. Field of Invention

The present invention relates to a pump and, more particularly, to a leak-preventing device for a pump.

2. Related Prior Art

Referring to FIG. 1, a conventional pump 10 is located in an inverted position. The pump 10 includes a shell 11 formed with an upper end 12 and a lower end (not shown). The upper end 12 of the shell 11 is an open end. A check valve (not shown) is located in an aperture (not shown) defined in the lower end of the shell 11. A cylinder 14 is located in the shell 11. A lower end of the cylinder 14 is attached to the lower end of the shell 11. Thus, the space defined in the cylinder 14 is separated from the space defined in the shell 11. The check valve is located in the cylinder 14. A flexible piston (not shown) is located in and movable along the cylinder 14. The flexible piston is connected to an end of a rod while a handle is connected to an opposite end of the rod. An annular buoyant 13 is located around and movable along the cylinder 14. A cover 20 is connected to the shell 11 and the cylinder 14. The space defined in the shell 11 is in communication with the space defined in cylinder 14 through a channel 22 defined in the cover 20. The cover 20 includes an opening 21 defined therein. A valve 18 is used to close a first end of the channel 22 located in the space defined in the shell 11. A lever 17 is connected to the valve 18 at an end and connected to another buoyant 16 at an opposite end. The pump is useful in pumping liquid such as used oil 15 out of an oil pan of an engine of for example.

In use, the pump is located in an upright position. A plug (not shown) is fit in the opening 21. A flexible pipe (not shown) is inserted through the plug. An end of the flexible pipe is located in the space defined in the shell 11 while another end of the flexible pipe is located in the used oil 15 contained in the oil pan. The flexible piston is reciprocated in the cylinder 14 to pump air out of the space defined in the cylinder 14 and hence out of the space defined in the shell 11. Some of the used oil 15 is hence pumped from the oil pan into the space defined in the shell 11.

When the space defined in the shell 11 is almost full of the used oil 15, the channel 22 is blocked by the valve 18 lifted by the buoyant 16 and the annular buoyant 13 floating on the used oil 15 contained in the pump 10. Thus, the used oil 15 cannot be pumped into the space defined in the shell 11.

Referring to FIG. 2, to pour the used oil from the pump 10, the plug is removed from the opening 21, and the pump 10 is tilted or even inverted. The used oil is supposed to leave the pump 10 through the opening 21 only. However, there is inevitably leak of the used oil from the pump 10 through the channel 22 because the channel 22 is released from the valve 18 moved with the buoyant 16.

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

SUMMARY

It is the primary objective of the present invention to provide a pump that can prevent leak.

To achieve the foregoing objective, the pump includes a shell, an air-pumping device, a cover, a valve and a buoyant. The air-pumping device is used for pumping air out of the shell and therefore pumping liquid into the shell. The cover includes an opening and channel defined therein. The cover is attached to the shell and the air-pumping device. The shell is in communication with the exterior thereof via the opening. The shell is in communication with the air-pumping device via the channel. The valve is movable between a first position for releasing the channel and a second position for blocking the channel. The valve is in the second position as the pump is in an inverted position. The buoyant is used for moving the valve to the second position as the pump is almost full of liquid in an upright position.

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

The present invention will be described via detailed illustration of seven embodiments versus the prior art referring to the drawings wherein:

FIG. 1 is a partial, cross-sectional view of a conventional pump in an upright position;

FIG. 2 is a partial, cross-sectional view of the conventional pump of FIG. 1 in an inverted position;

FIG. 3 is a partial, cross-sectional view of a pump equipped with a leak-preventing device in accordance with the first embodiment of the present invention;

FIG. 4 is a partial, cross-sectional view of the pump in an inverted position opposite to that is shown in FIG. 3;

FIG. 5 is a cross-sectional view of a pump equipped with a leak-preventing device in accordance with the second embodiment of the present invention;

FIG. 6 is a partial, cross-sectional view of the pump of FIG. 5 but shows the leak-preventing device in a second position;

FIG. 7 is an enlarged, cross-sectional view of the leak-preventing device shown in FIG. 6;

FIG. 8 is an enlarged, exploded view of the leak-preventing device shown in FIG. 7;

FIG. 9 is a partial, cross-sectional view of the pump in an inverted position opposite to the upright position shown in FIG. 5 and shows the leak-preventing device in a second position;

FIG. 10 is a partial, cross-sectional view of a pump equipped with a leak-preventing device in accordance with the third embodiment of the present invention;

FIG. 11 is a partial, cross-sectional view of the pump in an inverted position opposite to the upright position shown in FIG. 10;

FIG. 12 is a partial, cross-sectional view of a pump equipped with a leak-preventing device in accordance with the fourth embodiment of the present invention;

FIG. 13 is a partial, cross-sectional view of the pump in an inverted position opposite to the upright position shown in FIG. 12;

FIG. 14 is a partial, cross-sectional view of a pump equipped with a leak-preventing device in accordance with the fifth embodiment of the present invention;

FIG. 15 is a partial, cross-sectional view of the pump in an inverted position opposite to the upright position shown in FIG. 14;

FIG. 16 is a partial, cross-sectional view of a pump equipped with a leak-preventing device in accordance with the sixth embodiment of the present invention;

FIG. 17 is a partial, cross-sectional view of the pump in an inverted position opposite to the upright position shown in FIG. 16;

FIG. 18 is a partial, cross-sectional view of a pump equipped with a leak-preventing device in accordance with the seventh embodiment of the present invention; and

FIG. 19 is a partial, cross-sectional view of the pump in an inverted position opposite to the upright position shown in FIG. 18.

DETAILED DESCRIPTION

Referring to FIGS. 3 and 4, an inverted-position leak-preventing device in accordance with a first embodiment of the present invention is shown. The inverted-position leak-preventing device is used in the conventional pump 10 discussed in the Related Prior Art with reference to FIGS. 1 and 2. The inverted-position leak-preventing device includes a weight A movably located in a pocket B intersecting the channel 22. The pocket B is substantially located below the channel 22 as the pump 10 is the upright position shown in FIG. 3.

As shown in FIG. 3, the space defined in the shell 11 is almost full of the used oil 15, the channel 22 is blocked by the valve 18 lifted by the buoyant 16 and the annular buoyant 13 floating on the used oil 15 contained in the pump 10. Thus, the used oil 15 cannot be pumped into the space defined in the shell 11.

As shown in FIG. 4, to pour the used oil from the pump 10, the plug is removed from the opening 21, and the pump 10 is inverted so that the weight A falls and blocks the channel 22. Hence, the used oil leaves the pump 10 only through the opening 21. That is, there is no leak of the used oil from the pump 10 through the channel 22.

Referring to FIGS. 5 through 9, there is shown a pump 30 in accordance with a second embodiment of the present invention. The pump 30 includes a shell 31, a cover 40, an air-pumping device and a leak-preventing device 60.

The shell 31 is formed with a lower end 32 and an upper end 35. The shell 31 includes a base 33 formed at the lower end 32. A check valve 34 is located in an opening (not shown) defined in the lower end 32 of the shell 31. The upper end 35 of the shell 31 is an open end.

The air-pumping device includes a cylinder 50, a handle 51, a rod 52 and a flexible piston 53. The cylinder 50 is located in the shell 31. A lower end of the cylinder 50 is attached to the lower end 32 of the shell 31 by welding for example. Thus, the space defined in the cylinder 50 is separated from the space defined in the shell 31. The check valve 34 is located in the cylinder 50. The flexible piston 53 is located in and movable along the cylinder 50. The rod 52 is connected to the flexible piston 53 at an end and connected to the handle 51 at another end.

The cover 40 includes a handle 41 formed thereon, an aperture defined therein axially, an opening 42 defined therein longitudinally, a channel 43 defined therein in a radial direction, an upper port defined therein longitudinally, and a lower port defined therein longitudinally. The channel 43 is in communication with the aperture at an end and in communication with both of the upper and lower ports at an opposite end. The cover 40 is connected to the shell 31 and the cylinder 50 so that the space defined in the shell 31 is in communication with the space defined in the cylinder 50 through the channel 43. The rod 52 is inserted through the aperture. A relief valve 44 is located in the upper port.

The leak-preventing device 60 is used to close the second end of the channel 43. As clearly shown in FIGS. 5 through 8, the leak-preventing device 60 includes a short tube 61, a ring 66, a long tube 80, a valve 70 and a buoyant 71. The short tube 61 extends from a lower face of the cover 40 so that the short tube 61 includes a tunnel in communication with the channel 43. The tunnel defined in the short tube 61 includes two sections 62 and 63. The diameter of the first section 62 is smaller than that of the second section 63, thus forming an annular shoulder on an internal side of the short tube 61 between the sections 62 and 63. The short tube 61 further includes slots 64 in communication with the second section 63 of the tunnel of the short tube 61. There is a thread 65 extending on an internal side of the short tube 61.

The ring 66 includes a cylindrical aperture 67 defined therein and a frusto-conical aperture 68 in communication with the cylindrical aperture 67. The cylindrical aperture 67 is made with a constant diameter throughout its axis. The frusto-conical aperture 68 is made with a diameter that decreases toward the cylindrical aperture 67. Thus, the cylindrical aperture 67 and the frusto-conical aperture 68 together define a tunnel that looks like an inverted funnel when the pump 30 is located in the upright position. The ring 66 is fit in the second section 63 of the tunnel of the short tube 61 and abutted against the annular shoulder. Thus, the liquid is not allowed to go between the ring 66 and the short tube 61. The tunnel defined in the ring 66 is in communication with the tunnel defined in the short tube 61.

The valve 70 is in the form of a ball. The valve 70 is made of a material with a density larger than that of liquid to be pumped into the pump 30. That is, the valve 70 along does not float on the liquid. Preferably, the valve 70 is made of metal. The valve 70 is movably located in the second section 63 of the tunnel defined in the short tube 61.

The buoyant 71 includes an upper section 72 and a lower section 73. The diameter of upper section 72 is smaller than that of the lower section 73. The upper section 72 of the buoyant 71 is movably inserted in the second section 63 of the tunnel defined in the short tube 61.

The long tube 80 includes a thread 81 extending on an internal side near an open upper end thereof, an aperture 82 defined in a lower end, and slots 83 defined therein. The thread 81 is engaged with the thread 65, thus connecting the long tube 80 to the short tube 61. The buoyant 71 is movably located in the long tube 80.

The pump 30 is useful in pumping liquid such as used oil out of an oil pan of an engine of for example. Referring to FIG. 5, in use, the pump 30 is located in an upright position. The lower port defined in the cover 40 and hence the channel 43 is released from the valve 70. As shown in a phantom line in FIG. 5, a plug is fit in the opening 42, and a flexible pipe C is inserted through the plug. An end of the flexible pipe C is inserted in the space defined in the shell 31 while another end of the flexible pipe C is inserted in the used oil contained in the oil pan. By operating the handle 51, the flexible piston 53 is reciprocated in the cylinder 50 to pump air out of the space defined in the cylinder 50 and hence out of the space defined in the shell 31, i.e., vacuum is created in the space defined in the shell 31. Therefore, some of the used oil is pumped from the oil pan into the space defined in the shell 31.

Referring to FIG. 6, as the space defined in the shell 31 is almost full of the used oil, the lower port defined in the cover 40 and hence the channel 43 is blocked by the valve 70 lifted by the buoyant 71 floating on the used oil contained in the space defined in the shell 31. Thus, no more air can be pumped out of the space defined in the cylinder 50 and hence out of the space defined in the shell 31. Therefore, no more used oil can be pumped from the oil pan into the space defined in the shell 31 by operating the handle 51.

Referring to FIG. 9, to pour the used oil from the pump 30, the plug is removed from the opening 42, and the pump 30 is tilted or inverted. The first section 62 of the first pipe 61 is closed by the valve 70 that sinks into the used oil. Accordingly, the channel 43 is closed. Hence, the used oil leaves the pump 30 through the opening 42 only. There is no leak of the used oil from the pump 30 through the channel 43.

Referring to FIGS. 10 and 11, there is shown a leak-preventing device 60 in accordance with a third embodiment of the present invention. The third embodiment is like the second embodiment except several things. At first, there is formed a short tube 62a instead of the short tube 61. The short tube 62a extends much shorter than the short tube 61. Moreover, the tunnel defined in the short tube 62a is made with a constant internal diameter. Secondly, there is used a valve 70a instead of the valve 70. The valve 70a is in the form of a piston. Thirdly, the ring 66 is omitted. Fourthly, there is used a buoyant 71a instead of the buoyant 71. The buoyant 71a is in the form of a cylinder with a constant external diameter.

Referring to FIGS. 12 and 13, there is shown a leak-preventing device 60 in accordance with a fourth embodiment of the present invention. The fourth embodiment is like the third embodiment except several things. At first, there is used a valve 70b instead of the valve 70a. The valve 70b includes a first section 74 and a second section 75 made with a diameter smaller than that of the first section 74. The first section 74 of the valve 70b is used for contact with the short tube 62a. The second section 75 of the valve 70b is inserted through the aperture 82. Secondly, there is used an annular buoyant 13 instead of the buoyant 71a. The annular buoyant 13 is located around and movable along the cylinder 50 as in the first embodiment.

Referring to FIGS. 14 and 15, there is shown a leak-preventing device 60 in accordance with a fifth embodiment of the present invention. The fifth embodiment is like the fourth embodiment except including a valve 70c instead of the valve 70b. The valve 70c is identical to the valve 70b except including a boss 76 extending from the first section 74 thereof. The boss 76 can be inserted in the short tube 62a.

Referring to FIGS. 16 and 17, there is shown a leak-preventing device 60 in accordance with a sixth embodiment of the present invention. The sixth embodiment is like the fifth embodiment except two things. At first, there is used a valve 70d instead of the valve 70c. The valve 70d is identical to the valve 70c except including a recess 77 defined in the first section 74 thereof. Secondly, there is a solid ball 78 located in recess 77. The solid ball 78 can be inserted in the short tube 62a.

Referring to FIGS. 18 and 19, there is shown a leak-preventing device 60 in accordance with a seventh embodiment of the present invention. The seventh embodiment is like the sixth embodiment except including a hollow ball 79 instead of the solid ball 78.

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.