AIR COMPRESSORS

Abstract

An air compressor may include a compressor unit and an external tank unit connectible with the compressor unit. The external tank unit may include an external tank and a battery. The battery may supply electric power to the compressor unit.

Description

This application claims priority to Japanese patent application serial number 2011-254731, the contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

Embodiments of the present invention relate to air compressors that may be used, for example, for supplying compressed air to pneumatic tools, such as nailers and tackers that can be driven by compressed air.

2. Description of the Related Art

There have been provided simplified air compressors. Simplified air compressors may have smaller discharge outputs than stationary large-sized air compressors. However, because simplified air compressors are light and small and can be easily carried about, they can be conveniently used when performing simple and light duty work involving pneumatic tools. U.S. Pat. No. 7,140,845 and JP-A-2-108878 teach techniques relating to simplified air compressors that have batteries (DC power sources) as power sources.

The simplified air compressors disclosed in the above documents typically have an electric motor and a compressing device that are disposed within a resin case. The compressing device may convert the rotational output of the electric motor into a reciprocating movement of a piston within a cylinder for discharging compressed air. The compressed air discharged from the compressing device may be directly supplied to a pneumatic tool. Therefore, the air compressor can be lightweight because there is no need for a storage tank for storing the compressed air.

In addition, the user may carry the simplified air compressor on his or her shoulder or back. Therefore, it is possible to supply the compressed air to a pneumatic tool, such as a nailer, at a place, such as a building site, where no electric outlet is available. Hence, there would be no restriction with respect to the place for use. In this way, it is possible to efficiently perform light duty works, such in the repairing of items or structures.

JP-A-2006-220202 teaches a technique of providing an external auxiliary tank at an AC powered air compressor that is relatively small in size but is of a stationary type having an internal storage tank. By providing the external auxiliary tank, it may be possible to stably supply a larger output of compressed air.

The air compressors disclosed in the above documents still require improvements. For example, if an external auxiliary tank is connected to the battery driven air compressor for supplying a larger output of compressed air, a larger electric power is necessary to be supplied by the battery. In this case, it may be possible to cause lack of residual power in the battery. For this reason, it is necessary to frequently recharge or replace the battery. As a result, it is necessary to frequently stop the work, leading to low productivity.

Therefore, there has been a need in the art for a technique for fixing the lack of power in an air compressor that results when an external tank is used.

SUMMARY OF THE INVENTION

In one aspect according to the present teachings, an air compressor may include a compressor unit and an external tank unit connectible with the compressor unit. The external tank unit may include an external tank and a battery, The battery may supply an electric power to the compressor unit.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram showing the configuration of an air compressor according to a first embodiment, in which a pneumatic tool is connected to an external tank unit;

FIG. 2 is a diagram showing the configuration of an air compressor according to a second embodiment, in which a pneumatic tool is connected to a compression unit; and

FIG. 3 is a diagram showing the configuration of an air compressor according to a third embodiment, in which a compression unit is schematically shown.

DETAILED DESCRIPTION OF THE INVENTION

Each of the additional features and teachings disclosed above and below may be utilized separately or in conjunction with other features and teachings to provide improved air compressors. Representative examples of the present invention, which examples utilize many of these additional features and teachings both separately and in conjunction with one another, will now be described in detail with reference to the attached drawings. This detailed description is merely intended to teach a person of skill in the art further details for practicing preferred aspects of the present teachings and is not intended to limit the scope of the invention. Only the claims define the scope of the claimed invention. Therefore, combinations of features and steps disclosed in the following detailed description may not be necessary to practice the invention in the broadest sense, and are instead taught merely to particularly describe representative examples of the invention. Moreover, various features of the representative examples and the dependent claims may be combined in ways that are not specifically enumerated in order to provide additional useful examples of the present teachings. Various examples will now be described with reference to the drawings.

In one example, an air compressor may include a compressor unit and an external tank unit. The compressor unit may supply a compressed air to a pneumatic tool. The external tank unit may be connectible with the compressor unit. The external tank unit may include an external tank and a battery. The external tank may store the compressed air. The battery may supply an electric power to the compressor unit.

Therefore, when the external tank is connected to the compressor unit for enabling the compressor unit to supply a larger output of compressed air to the pneumatic tool, it is possible to supply electric power to the compressor unit from the battery of the external tank unit. In this way, it is possible to supply a larger output of compressed air to the pneumatic tool without causing a lack of electric power for driving the compressor unit. As a result, it is possible to avoid interruption of the work performed by the pneumatic tool. Therefore, productivity can be improved.

The compressor unit may include an air-compressing device and a battery serving as a power source for driving the air-compressing device. With this arrangement, it is possible to use the air-compressing device at a place where no AC power source is available. In this way, the workability can be improved. In addition, the battery of the external tank unit and the battery of the compressor unit can be used simultaneously or exchangeably for driving the air-compressing device.

In the case where the battery of the external tank unit and the battery of the compressor unit are interchangeably used for driving the air-compressing device, one of the batteries can be recharged or replaced with another battery during driving of the air-compressing device by the other battery. Therefore, it is possible to operate the air-compressing device continually for a long time in a manner similar to the case where an AC power source is used.

The external tank unit may include a battery charger capable of charging the battery of the external tank unit. With this arrangement, it is possible to charge the battery of the external tank unit without needing to remove the battery from the external tank unit. Therefore, the operability of the air compressor can be improved.

The external tank unit may be configured to be able to connect an electric device that is a different device from the compressor unit, so that electric power can be supplied from the battery of the external tank unit to the electric device. In this way, it is possible to further improve the usability of the external tank unit and the air compressor.

The battery of the external tank unit may be removably mounted to the external tank unit. With this arrangement, it is possible to replace the battery with another battery or to recharge by a separate battery charger.

Embodiments will now be described with reference to FIGS. 1 to 3. Referring to FIG. 1, there is shown an air compressor 1 according to a first embodiment. The air compressor 1 may generally include a compressor unit 10 and an external tank unit 30 connected to the compressor unit 10. The external tank unit 30 may be mechanically connected to the external tank unit 30 via an air hose 11. In addition, the external tank unit 30 may be electrically connected to the compressor unit 10 via a power cord 11.

An air-compressing device 14 may be disposed within the compressor unit 10 and may be driven by an electric motor 13 that serves as a drive source for the compressor unit 10. A control circuit 15 may control the operation of the electric motor 13. A main battery or an internal battery 16 may supply electric power to the electric motor 13. The compressor unit 10 may include a power switch 22, so that electric power may be supplied from the internal battery 16 to the electric motor 13 when the power switch 22 is switched on. The internal battery 16 can be removed from the compressor unit 10 for recharging by a charger (not shown) provided separately from the compressor unit 10, so that the internal battery 16 can be used repeatedly.

The compressor unit 10 may further include a power input terminal 23. The electric cord 12 can be connected to the power input terminal 23, so that external power can be supplied to a power source circuit of the control circuit 15 via the electric cord 12. It may be possible to drive the electric motor 13 also by the external power. In this embodiment, an external battery 37 provided at the external tank unit 30 can be used to supply external power.

The compressed air produced by the air-compressing device 14 may be stored in a storage tank 17. A pressure sensor 18 may detect the pressure of the compressed air stored in the storage tank 17 and may output a detection signal that may be input to the control circuit 15. When the pressure of the compressed air within the storage tank 17 becomes lower than a predetermined value, the control circuit 15 may output a control signal to the electric motor 13, so that the storage tank 17 can be replenished with compressed air.

The compressed air stored within the storage tank 17 may be regulated to a given pressure by a pressure regulator 19. The compressed air having the regulated pressure may be discharged from an air coupler 20 that serves as an air outlet of the compressor unit 10. A pressure gauge 21 may detect the pressure of the compressed air discharged from the air coupler 20. The pressure gauge 21 may have a display that can display the detected pressure. The compressed air discharged from the air couple 20 may be supplied to the external tank unit 30 via the air hose 11 that is connected to the air coupler 20.

The external tank unit 30 serves as an auxiliary tank unit for storing the compressed air produced by the air compressing device 14 and for supplying the compressed air to a pneumatic tool T. The external tank unit 30 may have an air coupler 34 that can be connected to the air hose 11. The compressed air supplied from the compressor unit 10 to the external tank unit 30 via the air hose 11 may be stored in a storage tank 32. The compressed air stored in the storage tank 32 may be regulated to a given pressure by a pressure regulator 33 and may then be discharged from the external tank unit 30 via an air coupler 34. The air coupler 34 may be connected to the pneumatic tool T via an air hose, so that the compressed air discharged from the external tank unit 30 may be supplied to the pneumatic tool T. A pressure gauge 35 may detect the pressure of the compressed air discharged from the air coupler 34. The pressure gauge 35 may have a display that can display the detected pressure. The pneumatic tool T may be a nailer, a tacker or any other tool that may be driven by the compressed air.

The electric power of the external battery 37 of the external tank unit 30 may be supplied to the compressor unit 10 via a power output terminal 38 and the power cord 12. In this way, the external battery 37 can be used as a power source for the compressor unit 10. Also, the external battery 37 can be removed from the external tank unit 30 for recharging by a separate charger, so that the external battery 37 can be repeatedly used.

The control circuit 15 may monitor the residual power level of the internal battery 16 and also the residual power level of the external battery 37. When the residual power level of either the internal battery 16 or the external battery 37 becomes less than a given level, the control circuit 15 may automatically switch the supply of electric power to the electric motor 13 from one to the other of the batteries 16 and 37.

The compressor unit 10 may be used without the external tank unit 30. In such a case, the external tank unit 30 may be disconnected from the compressor unit 10. In this situation, only the internal battery 16 can be used as a power source. The air coupler 20 may be connected directly to the pneumatic tool T via the air hose 11. Therefore, the compressed air stored within the storage tank 17 may be directly supplied to the pneumatic tool T. If the supply of compressed air from the compressor unit 10 is insufficient, the user can connect the external tank unit 30 to the compressor unit 10.

As described above, according to the air compressor 1 of the first embodiment, the external tank unit 30 can be connected to the compressor unit 10. In this embodiment, the compressor unit 10 has the internal battery 16 and can be used by itself (without the external tank unit 30). By connecting the external tank unit 30 to the compressor unit 10, it is possible to supply a larger output of compressed air to the pneumatic tool T. In addition to or alternative to the internal battery 16, the external battery 37 can be used as a power source for the electric motor 13. Therefore, it is possible to use the air compressor 1 for a long time without causing a lack of supply in electric power. As a result, the user can efficiently perform the work using the pneumatic tool T without interruption during use.

The first embodiment can be modified in various ways. For example, in the first embodiment, the pneumatic tool T is connected to the external tank unit 30 having the storage tank 32. In this way, the compressed air stored in the storage tank 32 can be used for driving the pneumatic tool T. Thus, the external tank unit 30 is used as an auxiliary tank for the compressor unit 10. However, an air compressor 50 according to a second embodiment shown in FIG. 2 is configured such that the pneumatic tool T may be connected to the compressor unit 10 and an external tank unit 60 serving as an expansion tank may be connected to the connector body 10.

In the case of the second embodiment, the external tank unit 60 may be connected to the storage tank 17 of the compressor unit 10 via an air hose 51. The pneumatic tool T may be connected to the air coupler 20 of the compressor unit 10. In another aspect, the compressor unit 10 may be configured to be the same as that of the first embodiment. Therefore, in FIG. 2, like members are given the same reference numerals as the first embodiment and the description of these members will not be repeated.

The external tank unit 60 of the second embodiment may be substantially the same as the external tank 30 of the first embodiment except that the external tank unit 60 does not include the pressure regulator 33, the air coupler 34 and the pressure gauge 35. The external tank unit 60 may include an air coupler 61 for connection with an air hose 51 and may further include a power output terminal 62 for connection with the power cord 12.

One end of the air hose 51 may be connected to the storage tank 17 of the compressor unit 10 via an air coupler (not shown). The other end of the air hose 51 may be connected to a storage tank 63 of the external tank unit 60 via the air coupler 61, In this way, the storage tank 17 of the compressor unit 10 and the storage tank 63 of the external tank unit 60 may be connected to each other via the air hose 51. Therefore, the compressed air produced at the air-compressing device 14 of the compressor unit 10 may be stored in both the storage tank 17 of the compressor unit 10 and the storage tank 63 of the external tank unit 60.

The external tank unit 60 may have an external battery 64 connected to the power output terminal 62, so that electric power can be supplied from the external battery 64 to the compressor unit 10 via the power cord 12. The external battery 64 may be removed from the external tank unit 60 for recharging by a charger, so that the external battery 64 can be repeatedly used.

With the air compressor 50 according to the second embodiment, the external tank unit 60 can be connected to the compressor unit 10. The compressor unit 10 has the internal battery 16 and can be used by itself (without the external tank unit 60). By connecting the external tank unit 60 to the compressor unit 10, it is possible to supply a larger output of compressed air to the pneumatic tool T. In addition to or alternative to the internal battery 16, the external battery 64 can be used as a power source for the electric motor 13. Therefore, it is possible to use the air compressor 50 during a long time without causing a lack of supply in electric power. As a result, the user can efficiently perform work using the pneumatic tool T without any significant interruption.

As described above, in the case of the second embodiment, the pneumatic tool T may be directly connected to the compressor unit 10. Therefore, the external tank unit 60 serves as an expansion unit for supplementing the storage capacity of the storage tank 17.

The second embodiment may be further modified. FIG. 3 shows an air compressor including an external tank unit 70 according to a third embodiment. The external tank unit 70 is a modification of the external tank unit 30 of the first embodiment and may be used in combination with the compressor unit 10 as described in the first embodiment.

The external tank unit 30 of the first embodiment has the external battery 37 that can be removed for recharging by a charger that may be provided separately from the external tank unit 30. In contrast, the external tank unit 70 of the third embodiment includes a charger 39 that can recharge the external battery 37. Therefore, it is not necessary to remove the external battery 37 for the purpose of recharging. In this way, it is possible to improve the operability of the air compressor. The charger 39 may be connected to an external AC power source, such as an electric outlet (not shown), via a suitable connector.

In addition, as shown in FIG. 3, the external tank unit 70 may have an additional power output terminal 40. An external electric device K may be connected to the additional power output terminal 40. In this way, the external battery 37 can be used as a DC power source for the external electric device K. Therefore, it is possible to further improve the usability of the external tank unit 70 and the air compressor 1. The external electric device K may be lighting equipment, AV equipment such as a radio or a television, cooking equipment such as a coffee maker or an electric pot, a dust collector, a fan, a blower or any other electric device.

The above embodiments may be further modified. For example, an AC power source may be use for the compressor unit 10 in place of the internal battery 16.

The storage tank 17 may be omitted from the compressor unit 10. In the case that the storage tank 17 is omitted from the compressor unit 10 in the first embodiment or the third embodiment, the entire amount of compressed air produced by the air-compressing device 14 may be stored in the storage tank 32 of the external tank unit 30. The compressed air is supplied from the air-compressing device 14 to the storage tank 32 via the air hose 11. In the case that the storage tank 17 is omitted from the compressor unit 10 in the second embodiment, the compressed air produced at the air-compressing device 14 may be initially stored in the storage tank 63 of the external tank unit 60 and then may be supplied to the pneumatic tool T via the compressor unit 10 when needed.

Further, in the above embodiments, when the residual power level of either the internal battery 16 or the external battery 37 becomes less than a given level, the control circuit 15 may automatically switch the supply of electric power to the electric motor 13 from one to the other of the batteries 16 and 37. However, the user may manually switch the supply of electric power themselves. In addition, in some cases, it may be possible to configure the compressor unit 10 such that the internal battery 16 and the external battery 37 may be simultaneously used as power sources.

As noted above, an AC power source may be use for the compressor unit 10 in place of the internal battery 16. In the case that an AC power source is used, the external battery 37 of the external tank unit 30 (60, 70) may be used as an auxiliary power source in the event that the supply of the AC power is interrupted because of the power outage or some other reason.

Further, the compressor unit 10 without the storage tank 17 can be used by itself when the external tank 30 is disconnected. In such a case, the compressed air produced by the air-compressing device 14 may be directly supplied to the pneumatic tool T via the air hose 11. In this case, a sufficient output of compressed air can be supplied to the pneumatic tool T as long as the pneumatic tool T is used for a relatively light duty work.

Claims

1. An air compressor comprising:

a compressor unit configured to supply compressed air to a pneumatic tool; and

an external tank unit connectible with the compressor unit;

wherein the external tank unit includes:

an external tank capable of storing the compressed air; and

a first battery configured to supply electric power to the compressor unit.

2. The air compressor according to claim 1, wherein the compressor unit includes an air-compressing device and a second battery serving as a power source for driving the air-compressing device.

3. The air compressor according to claim 2, wherein the first battery and the second battery can be used interchangeably for supplying electric power to the air-compressing device.

4. The air compressor according to claim 1, wherein the external tank unit includes a battery charger capable of charging the first battery.

5. The air compressor according to claim 1, wherein the external tank unit is configured to be able to connect an electric device that is a different device from the compressor unit, so that electric power can be supplied from the first battery to the electric device.

6. The air compressor according to claim 1, wherein the first battery is removably mounted to the external tank unit.

7. A compressor unit used for a pneumatic tool and connectible with an external tank unit having a first storage tank and a first battery, the compressor unit comprising:

an air-compressing device configured to be electrically driven;

a second battery serving as a power source for driving the air-compressing device;

a second storage tank capable of storing compressed air;

an input terminal electrically connected to the air-compressing device and connectible with the first battery of the external tank unit, so that the air-compressing device can be driven by electric power supplied from the first battery of the external tank; and

an air coupler connectible with the external tank, so that compressed air produced by the air-compressing device can be stored in both the first storage tank of the external tank unit and the second storage tank of the compressor unit for driving a pneumatic tool.

8. The compressor unit according to claim 7, wherein the air coupler is also connectible with the pneumatic tool.

9. An external tank unit connectible with a compressor unit used for a pneumatic tool, comprising:

a storage tank configured to store compressed air produced by the compressor unit; and

a battery configured to supply electric power to the compressor unit.

10. The external tank unit according to claim 9, wherein the external tank unit further includes an air coupler connectible with a pneumatic tool.