Depression container

Abstract

In an aspect, a depression container includes a vessel, a cover, a pump, a pressure-activated switch and a power supply. The vessel includes an open end. The cover is used for sealing the open end of the vessel. The pump is used for drawing air out of the vessel. The pressure-activated switch is used for controlling ON and OFF of the pump. The pressure-activated switch detects the pressure in the vessel, and turns on the pump when the pressure is higher than a predetermined upper limit, and turns off the pump when the pressure is lower than a predetermined lower limit. The pressure-activated switch and the pump are powered by the power supply. In another aspect, a depression container includes a vessel, a cover, a pump, a pressure-activated switch and a power supply. The vessel includes an open end. The cover is used for sealing the open end of the vessel. The pump is used for drawing air out of the vessel. The pressure-activated switch and the pump are powered by the power supply. The pressure-activated switch is used for controlling ON and OFF of the pump. The pressure-activated switch detects a pressure difference resulting from closure of the open end of the vessel by the cover, and turns on the pump so as to draw air out of the vessel, and turns off the pump when the pressure in the vessel is lower than a predetermined lower limit.

Description

CROSS REFERENCE

[0001] This is a continuation-in-part application of U.S. patent application Ser. No. 09/883,813 filed on Jun. 18, 2001.

BACKGROUND OF INVENTION

[0002] 1. Field of Invention

[0003] The present invention relates to a depression container equipped with a pump that can be activated when the pressure in the depression container is above a value.

[0004] 2. Related Prior Art

[0005] A typical depression container includes a check valve. A user draws air out of the depression container via the check valve with a manual pump including a piston and a cylinder, thus reducing the pressure in the depression container to a low valve. This reduces the risk of articles in the depression container getting wetted or rotten, thus lengthening the preservation period. It is, however, troublesome and labor-intensive for the user to reciprocate the piston relative to the cylinder. In addition, the user cannot know the pressure in the depression container. Furthermore, the depression container cannot provide an adequate sealing effect so that the pressure in the depression container may rise after some time and adversely affect the preservation of the articles therein.

SUMMARY OF INVENTION

[0006] It is an objective of the present invention to provide a depression container that can automatically draw air out of it after a cover seals its open end. The pressure in the depression container is reduced to a predetermined value.

[0007] It is another objective of the present invention to provide a depression container that shows the value of the pressure. Moreover, the depression container allows a user to set a value of the pressure desired for preserving articles.

[0008] It is a further objective of the present invention to provide a depression container that can maintain the pressure therein under a predetermined valve for a long time.

[0009] In accordance with a first aspect of the invention, a depression container includes a vessel, a cover, a pump, a pressure-activated switch and a power supply. The vessel includes an open end. The cover is used for sealing the open end of the vessel. The pump is used for drawing air out of the vessel. The pressure-activated switch is used for controlling ON and OFF of the pump. The pressure-activated switch detects the pressure in the vessel, and turns on the pump when the pressure is higher than a predetermined upper limit, and turns off the pump when the pressure is lower than a predetermined lower limit. The pressure-activated switch and the pump are powered by the power supply.

[0010] In accordance with a second aspect of the invention, a depression container includes a vessel, a cover, a pump, a pressure-activated switch and a power supply. The vessel includes an open end. The cover is used for sealing the open end of the vessel. The pump is used for drawing air out of the vessel. The pressure-activated switch and the pump are powered by the power supply. The pressure-activated switch is used for controlling ON and OFF of the pump. The pressure-activated switch detects a pressure difference resulting from closure of the open end of the vessel by the cover, and turns on the pump so as to draw air out of the vessel, and turns off the pump when the pressure in the vessel is lower than a predetermined lower limit.

[0011] In the second aspect of the present invention, when the pressure rises and exceeds an upper limit, the pressure-activated switch turns on the pump again until the pressure is reduced to the lower limit. Thus, the articles in the vessel can be preserved for a long time by means of maintaining the pressure in the vessel under a predetermined low pressure suitable for preservation of articles.

[0012] Other objects, novel features and advantages of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS

[0013] FIG. 1 is a perspective view of a depression container in accordance with the present invention.

[0014] FIG. 2 is an exploded perspective view of the depression container in accordance with the present invention.

[0015] FIG. 3 is a sectional view of an upper portion of the depression container in accordance with the present invention.

[0016] FIG. 4 is a sectional view similar to FIG. 3, illustrating operation of the depression container upon closing of a cover.

[0017] FIG. 5 is a sectional view similar to FIG. 4, wherein the cover is moved to its completely closed position.

[0018] FIG. 6 is a perspective view illustrating a modified embodiment of the depression pump in accordance with the present invention.

[0019] FIG. 7 is an exploded perspective view illustrating a further modified embodiment of the depression pump in accordance with the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0020] Referring to FIGS. 1 through 3, in accordance with a first embodiment of the present invention, a depression container includes a vessel 2, a cover 4, a pump 6 and a pressure-activated switch 8.

[0021] The vessel 2 defines a compartment 10 for receiving articles to be preserved. The vessel 2 includes a closed lower end and an open upper end.

[0022] The cover 4 can be mounted on the open upper end of the vessel 2 so as to close the compartment 10. An annular seal 12 can be mounted on the open upper end of the vessel 2 before the cover 4 in order to seal the compartment 10.

[0023] A box 14 is formed on the vessel 2. The box 14 defines a space 16 in order to receive the pump 6 and the pressure-activated switch 8. A first orifice 18 and a second orifice 20 are defined in the vessel 2. The compartment 10 is communicated with the space 16 through the first orifice 18 and the second orifice 20. Two parallel first walls 22 and two parallel second walls 24 are formed on the vessel 2, located in the box 14, best shown in FIG. 2. Each of the first walls 22 includes two slots 26, for example. Each of the second walls 24 includes two slots 28.

[0024] The pump 6 includes a casing 30 and a duct 32 extending from the casing 30. The casing 30 includes two parallel sides on each of which two engaging members 34 are formed. The engaging members 34 are engaged with the slots 26 so as to securely mount the pump 6 on the vessel 2, in the box 14. Further referring to FIG. 4, an airtight sleeve 36 is mounted on the duct 32. The sleeve 36 is inserted through the first orifice 18 in order to prevent leakage of air through the first orifice 18.

[0025] The pressure-activated switch 8 includes a casing 38 and a duct 40 extending from the casing 38. The casing 38 includes two parallel sides on each of which an engaging member 42 is formed. The engaging members 42 are engaged with the slots 28 so as to securely mount the pressure-activated switch 8 on the vessel 2, in the box 14. Further referring to FIG. 5, an airtight sleeve 44 is mounted on the duct 40. The sleeve 44 is inserted through the second orifice 20 in order to prevent leakage of air through the second orifice 20.

[0026] The pressure-activated switch 8 includes a differential type pressure transducer 46 that includes a sensor 48. The differential type pressure transducer 46 is received in the casing 38 so that the sensor 48 is received in the duct 40. The pressure-activated switch 8 includes a control chip 50 received in the casing 38. The differential type pressure transducer 46 is electrically connected with the sensor 48 and the control chip 50. The control chip 50 is electrically connected with the pump 6 through female and male connectors 52 and 54.

[0027] A wire 56 includes an end electrically connected with the control chip 50 and an opposite end electrically connected with an adaptor 58. The control chip 50 can be electrically connected with an external AC power supply (not shown) via the wire 56 in order to power the pump 6 and the pressure-activated switch 8.

[0028] The pressure transducer 46 outputs a voltage in response to a difference between a reference pressure (the pressure in the atmosphere for example) and a detected pressure in the compartment 10 of the vessel 2. Namely, the output voltage of the pressure transducer 46 is in proportion to the pressure difference. In an embodiment, the output voltage is 3.3V if the detected pressure is equal to or above a first threshold (1.15 atm for example). The output voltage is 1.2 V if the detected pressure is equal to or below a second threshold (0.1 atm for example). The output voltage is 1.5V if the detected pressure is equal to or above a third threshold (0.25 atm for example).

[0029] A set of controlling programs is recorded in the control chip 50. The control chip 50 can be switched between two logic control modes M1 and M2 via operation of a switch 60 electrically connected with the control chip 50. The switch 60 is mounted on a panel 62 that can be attached to the box 14 in order to close the space 16. In the control mode M1, the pump 6 is activated when the output voltage of the pressure transducer 46 is higher than or equal to 3.3 V. The pump 6 is turned off when the output voltage of the pressure transducer 46 is lower than or equal to 1.2 V. In the control mode M2, the pump 6 is activated when the output voltage of the pressure transducer 46 is higher than or equal to 1.5 V. The pump 6 is turned off when the output voltage of the pressure transducer 46 is lower than or equal to 1.2 V.

[0030] In use, referring to FIG. 6, the switch 60 is firstly switched to the control mode M1, and the cover 4 is mounted on and thus encloses the vessel 20. During closing of the cover 4, i.e., the cover 4 is moved downward relative to the vessel 20, the air inside compartment 10 of the vessel 2 is compressed and thus generates a temporary pressure greater than 1.15 atm. The pressure transducer 46 of the pressure-activated switch 8 detects such a temporary pressure and outputs a voltage higher than 3.3 V. The pump 6 is thus activated under the control of the control chip 50, thus drawing air out of the vessel 2. The pressure in the vessel 2 is accordingly reduced. When the pressure in the vessel 2 is equal to or below 0.1 atm, the output voltage of the pressure transducer 46 is lower than 1.2 V. The pump 6 is thus turned off.

[0031] Referring to FIGS. 4 and 5, the switch 60 is switched to the control mode M2 after depression. If the pressure in the vessel 2 rises as a result of entrance of ambient air into the vessel 2, the sensor 44 detects the pressure and the pump 6 is turned on when the pressure in the vessel 2 is equal to or above 0.25 atm upon outputting an output voltage higher than 1.5 V. When the pressure inside the vessel 2 is equal to or lower than 0.1 atm, the pressure transducer 46 outputs a voltage lower than 1.2 V to turn off the pump 6. Thus, the pressure in the vessel 2 is kept at about 0.1 atm.

[0032] The switch 60 and the control modes M1 and M2 can be simplified. For example, the control mode M1 is OFF and the control mode M2 is ON. More specifically, the pressure transducer 46 is turned on when in the control mode M2 and is turned off when in the control mode M1. Thus, when in use, the user may attach the cover 4 to the vessel 2 and switch to the control mode M2 after the cover 4 is in position. The pump 6 is turned on when the pressure in the vessel 2 is equal to or above 0.25 atm and the pump 6 is turned off when the pressure in the vessel 2 is equal to or lower than 0.1 atm.

[0033] FIG. 7 shows a depression container according to a second embodiment of the present invention. The second embodiment is different from the first embodiment in that the first plates 22 are replaced with a collar 64 including a thread 66 formed on an internal face, that the casing 30 is replaced with a cylindrical casing 68 including a thread 70 formed thereon, that the second plates 24 are replaced with a collar 72 including a thread 74 formed on an internal face and that the casing 38 is replaced with a cylindrical casing 76 including a thread 78 formed thereon. The thread 70 can be engaged with the thread 66, thus mounting the casing 68 on the collar 64. The thread 78 can be engaged with the thread 74, thus mounting the casing 68 on the collar 64. The second embodiment is otherwise identical to the first embodiment.

[0034] Although the invention has been explained in relation to its preferred embodiment, it is to be understood that many other possible modifications and variations can be made without departing from the scope of the invention as hereinafter claimed.

Claims

1. A depression container including:

a vessel including a compartment with an open end;

a cover for enclosing the open end of the vessel, thus sealing the compartment;

a pump mounted on and communicated with the vessel for drawing air from the compartment; and

a pressure-activated switch mounted on and communicated with the vessel for detecting a pressure in the compartment, turning on the pump when the pressure is higher than an upper limit, and turning off the pump when the pressure is lower than a lower limit.

2. The depression container according to claim 1 wherein the vessel defines an orifice communicated with the compartment, and the pump includes a duct inserted through the orifice.

3. The depression container according to claim 2 including an airtight sleeve mounted on the duct and inserted through the orifice.

4. The depression container according to claim 1 wherein the vessel defines an orifice communicated with the compartment, and the pressure-activated switch includes a duct inserted through the orifice.

5. The depression container according to claim 4 including an airtight sleeve mounted on the duct and inserted through the orifice.

6. The depression container according to claim 1 wherein the vessel includes a collar with a thread formed on an internal face, and the pump includes a cylindrical casing formed with a thread for engagement with the thread of the collar.

7. The depression container according to claim 1 wherein the vessel includes a collar with a thread formed on an internal face, and the pressure-activated switch includes a cylindrical casing formed with a thread for engagement with the thread of the collar.

8. The depression container according to claim 1 including a box formed on the vessel for receiving the pump.

9. The depression container according to claim 1 including a box formed on the vessel for receiving the pressure-activated switch.

10. A depression container including:

a vessel including a compartment with an open end;

a cover for enclosing the open end of the vessel, thus sealing the compartment;

a pump mounted on and communicated with the vessel for drawing air from the compartment; and

a pressure-activated switch mounted on and communicated with the vessel for detecting a pressure difference resulting from a motion of closing the vessel via the cover, turning on the pump so as to draw air out of the compartment, and turning off the pump when an pressure in the compartment detected by the pressure-activated switch is lower than a lower limit.

11. The depression container according to claim 10 wherein the pressure-activated switch includes a differential type pressure transducer and a control chip electrically connected with the pump, and the pressure transducer includes a sensor inserted into the compartment for detecting the pressure in the compartment and sending a voltage to the control chip in response to a difference between a reference pressure and the pressure detected by the sensor.

12. The depression container according to claim 11 wherein the reference pressure is the atmosphere pressure.

13. The depression container according to claim 10 wherein the vessel defines an orifice communicated with the compartment, and the pump includes a duct inserted through the orifice.

14. The depression container according to claim 13 including an airtight sleeve mounted on the duct and inserted through the orifice.

15. The depression container according to claim 10 wherein the vessel defines an orifice communicated with the compartment, and the pressure-activated switch includes a duct inserted through the orifice.

16. The depression container according to claim 15 including an airtight sleeve mounted on the duct and inserted through the orifice.

17. The depression container according to claim 10 wherein the vessel includes a collar with a thread formed on an internal face, and the pump includes a cylindrical casing formed with a thread for engagement with the thread of the collar.

18. The depression container according to claim 10 wherein the vessel includes a collar with a thread formed on an internal face, and the pressure-activated switch includes a cylindrical casing formed with a thread for engagement with the thread of the collar.

19. The depression container according to claim 7 including a box formed on the vessel for receiving the pump.

20. The depression container according to claim 7 including a box formed on the vessel for receiving the pressure-activated switch.