WO2006003455A1

WO2006003455A1 - Tool monitoring device

Info

Publication number: WO2006003455A1
Application number: PCT/GB2005/002660
Authority: WO
Inventors: Michael James Jones; Antony GENT; Matthew Butler
Original assignee: Five Sides Industrial Ltd
Priority date: 2004-07-07
Filing date: 2005-07-07
Publication date: 2006-01-12
Also published as: CN100583169C; CN101023450A; EP1782391A1; GB0415190D0

Abstract

A device for monitoring the usage of a pneumatically or electrically operated power tool comprises a sensor for sensing the supply of the pneumatic or electrical power from a source to the tool and monitoring means responsive to the sensor for recording the time elapsed during the supply of power.

Description

Tool Monitoring Device

The present invention relates to a device for monitoring the usage of a power tool.

The safe use of power tools, such as pneumatic drills and the like, is an important aspect of health and safety within the workplace. One particular aspect of increasing concern is the effect of vibration from power tools on users, which can result in debilitating injuries such as vibration white finger if not properly monitored.

The level of vibration experienced by a user from a particular power tool is dependent upon a number of factors, including whether the tool or work piece on which the tool is used is suitably supported or mounted during operation of the tool. The maintenance history of a power tool can also significantly effect the level vibration experienced during use of the tool. Certain power tools may exhibit in excess of two to three times greater levels of vibration after prolonged periods of use than when the tool is first manufactured or is in a newly repaired condition has only recently been serviced or repaired.

There is an increasing move to periodic "preventative" maintenance of power tools, rather than maintenance in the event of breakdown of a power tool, in order to counter or reduce the negative effects of vibration from power tools. For example, power tools can be allotted a recommended lifespan after which the tool should be serviced' or replaced. In other cases, or in addition, it may be recommended that a particular tool is used up to a maximum number of hours within a given time span, such as a number of hours per day, depending on the age of the tool or the time elapsed since the tool was last serviced.

A problem generally associated with such preventative maintenance is that the recall of a power tool for servicing is typically based on a set time period of use, for example a 6 month interval, and no real account is given to the number of hours a tool may actually have been used within that period.

This itself has inherent problems, particularly in the case of companies or users who keep an array of identical power tools in cabinets or on shadow boards. For example, one power drill could be used for 10 hours within a given six month period, whereas another drill stored in the same cabinet could be used for 200 hours.

It is an object of the invention to provide a device for use with power tools, which can assist in monitoring the use of a particular tool.

In a first aspect of the invention there is provided a device for monitoring the usage of a pneumatically or hydraulically operated power tool, the device comprising: means for sensing the supply of said pneumatic or hydraulic power from a source of said power to said tool; and monitoring means responsive to said sensing means for recording the time elapsed during said supply of said power.

In a preferred form of the invention the device further comprises: an input for connection to said source of pneumatic or hydraulic power; an output for connection to said tool for supplying said pneumatic or hydraulic power from said source to said tool; and said sensing means is operable to sense the supply of said pneumatic or hydraulic power from said input to said output.

Advantageously, said pneumatic or hydraulic power is compressed gas.

Preferably, said sensing means comprises means sensing said gas flow through the device.

Advantageously, said sensing means comprises first means displaceable between first and second positions in response to flow of said pneumatic or hydraulic power; said first means is biased towards said first position; and said monitoring means is operable to monitor the time elapsed whilst said first means is in said second position.

Said first means may comprise piston means movable from said first position to said second position in response to the flow of pneumatic or hydraulic power from said power source to said power tool and said sensing means may further comprise biasing means biasing said piston means towards said first position; and said monitoring means is operable to monitor the time elapsed whilst said piston means is in said second position.

Preferably, said monitoring means operates in response to movement of said piston means.

Advantageously, said monitoring means includes switch means actuable in response to movement of said first means.

Preferably, said monitoring means includes second recording means for recording the cumulative time elapsed during use of the power tool.

Advantageously, the device further comprises reset means for resetting the second recording means.

In a further embodiment, the device further comprises security means for preventing unauthorised're-setting of the recorded time.

Advantageously, the device further comprises means for displaying the monitored time.

Advantageously, the device further comprises control means for inhibiting operation of said tool in response to said recorded time exceeding a predetermined value. Preferably, said control means includes valve means for preventing flow of pneumatic or hydraulic power from said input to said output in response to said recorded time exceeding a predetermined value.

Advantageously, the device further comprises microprocessor means for enabling downloading of said recorded time to an external device.

In a second aspect of the invention there is provided a device for monitoring the usage of an electrically operated power tool, the device comprising: means for sensing the supply of said electrical power from a source of said power through a supply line to said tool, said sensing means being adapted to be inductively " coupled to said supply line for sensing current flow through said supply line; and monitoring means responsive to said sensing means for recording the time elapsed during said supply of said pneumatic or hydraulic power.

Advantageously, the device is adapted to be arranged in connection with a power supply cable for said electrically operated power tool, for directly detecting the supply of current to the tool.

Preferably, the device further comprises: an input for connection to said source of electrical power; an output for connection to said tool for supplying said electrical power from said source to said tool; and said sensing means is operable to sense the flow of current from said input to said output.

In a preferred embodiment of the invention, said sensing means is operable to convert current from the power supply into an output signal for indicating that power is being supplied to the tool, and said monitoring means includes second recording means for recording the cumulative time elapsed during use of the power tool. Advantageously, the device further comprises reset means for resetting the second recording means.

Preferably, the device further comprises security means for preventing unauthorised re-setting of the recorded time.

Advantageously, the device further comprises control means for inhibiting operation of said tool in response to said recorded time exceeding a predetermined value.

Preferably, the device further comprises microprocessor means for enabling downloading of said recorded time to an external device.

Other preferred features of the invention will be apparent from the following description and the dependent claims. The invention will be described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 is a schematic cross-sectional view of a device according to a first preferred embodiment of the invention, in use, showing the device in an inoperative condition; '

Figure 2 is a view similar to Figure 1 , showing the device in an operative condition;

Figure 3 is a schematic view of a second preferred embodiment of the invention; and Figure 4 is a schematic view of a third preferred embodiment of the invention.

Referring to Figures 1 and 2, a device according to a first embodiment of the invention is indicated generally at 10. The device 10 is shown in use with a power tool 12, which in this embodiment is a pneumatic drill. The tool 12 is connected to a source 13 of pneumatic power such as compressed gas (in this case air) by a dedicated supply pipe 14, for supplying operative power to the drill 12, that is to say, for driving the drill 12.

The device 10 consists of a dedicated unit or housing having an input 17 which is connectable to the power source 13 and an output 19 connectable to the power tool 12. The device has internal passage means 21 , which couple the input and output 17, 19 such that when the power source 13 is connected to the input 17, compressed gas is passed through the passage means 21 to the power tool 12. The housing 16 is conveniently located adjacent the drill 12 and at a remote distance from the compressed air source 13, so as to be readily visible to an operator of the tool, in use.

The passage 21 has sensing means for sensing the supply of pneumatic power from the source 13 to the tool 12 through the passage 21. The sensing means comprises a cylinder 18 arranged in the line of the supply of compressed air to the drill 12, and a first means formed by a piston 20 mounted in the cylinder 18 for movement between a first closed position, as shown in Figure 1 , and a second, open position, as shown in Figure 2, as will be described in more detail below. A biasing means formed by a return spring 22 is provided in the cylinder 18 connected to a first end of the piston 20, for biasing the piston 20 to the first closed position shown in Figure 1.

A monitoring means which is responsive to the sensing means records the time elapsed during supply of power to the tool. The monitoring means comprises first recording means in the form of a digital counter 24 mounted in the housing 16, for recording and storing the time elapsed during power operated use of the drill 12, as will be described in more detail below. The counter 24 includes display means for displaying the time elapsed during use of the tool 12. In addition, a second recoding means 25 is provided for recoding the cumulative total of every instance of power-operated use of the drill 12. The display means may also be configured to display the cumulative time for use of the drill 12. As will be appreciated, these values can be easily monitored by an operator during use of the drill 12, since the device 10 is located adjacent the drill 12. The counter 24 includes battery means for providing power to the counter 24.

Switch means 26, which is actuable in response to movement of the piston 20 between its first and second positions is provided for actuating and deactuating the recording means. In the preferred embodiment the switch means is in the form of a reed switch 26 is provided in operative communication between the cylinder 18 and the counter 24, for actuating and deactivating the timing function of the counter 24. The switch 26 includes contacts having an open position and a closed position. When the switch contacts are in the open position, the counter 24 is inactive, but when the switch contacts are in the closed position, the counter 24 is activated.

The piston 20 includes a magnetic contact 28 arranged for magnetic cooperation with the contacts of the switch 26.

The device 10 is configured to sense when compressed air is supplied to the drill for powered operation of the drill, and to monitor the time during which operative power, in this case compressed air, is supplied to the drill.

Operation of the device 10 in conjunction with the drill 12 will now be described.

When the drill 12 is not in use, there is no airflow through the cylinder 18 and the piston 20 is held in the closed position shown in Figure 1 under action of the return spring 22. With the piston 20 in the closed position, the magnetic contact 28 on the piston 20 occupies a first 'inoperative' position relative to the switch 26. In this position, the switch contacts are open and the counter 24 is dormant.

When a user wishes to use the drill 12, trigger means 29 on the drill 12 is depressed which causes compressed air, indicated at A in Figure 2, to flow through the housing 16, via the cylinder 18, so that operative power is supplied to the drill 12.

As compressed air flows through the cylinder 18, the biasing force of the return spring 22 is overcome by the compressed air and the piston 20 is moved to the open position shown in Figure 2. As the piston 20 moves, the magnetic contact

28 moves to a second 'operative' position over the switch 26. Movement of the magnetic contact 28 in this manner causes the contacts in the switch 26 to close and thereby activate the timing function of the counter 24. Hence, the counter 24 functions in response to movement of the piston 20.

The counter 24 monitors the time in hours, minutes and seconds, during which the compressed air is supplied to the drill 12 and the contacts of the switch 26 are closed. The monitored values are visible to the operator of the drill 12 via the display means.

If the flow of compressed air to the drill, via the device 10, is stopped or otherwise interrupted, the biasing force of the return spring 22 causes the piston 20 to return to the closed position shown in Figure 1. This causes the magnetic contact 28 on the pistorf 20 to pass back over the switch 26 to the first position and out of magnetic communication with the switch contacts, so that the contacts open and the timing function of the counter 24 is deactivated.

The above cycle is repeated for each instance of the supply of operative power to the tool 12, that is to say each power operated use of the tool 12. It will be understood that the invention is advantageous in that it provides a simple, straightforward method of monitoring the actual usage time of a particular power tool. This enables an operator and/or an employer to monitor a tool's usage, on an accumulative basis, to enable the tool to be recalled for servicing after a predetermined number of hours of actual operational use, for example.

The device 10 may also include a microprocessor 27 or other suitable means to enable the information stored in the recording means 24, 25 to be downloaded to an external device such as a computer by way of a cable link or optical or radio link.

In addition, whilst the embodiment of figures 1 and 2 has been described with reference to a pneumatically operated tool, it will be appreciated that the invention can apply equally to the monitoring of fluid flow for a hydraulically operated tool.

It will also be appreciated that the device 10 can be used in any orientation and does not have to be maintained in a particular orientation such as horizontal.

The second recording means 25 may have a reset for enabling resetting of the count of the recording means. In addition, a security device may be provided to prevent unauthorised resetting of the count of the second recording means 25.

A control means may also be provided in the device 10, which is actuated when the count on the recording means 25 reaches a predetermined level to close the passage 21 and prevent further supply of power to the tool 12. Thus, the device

10 can prevent further operation of the tool once it has reached its predetermined use time. Closing of the passage 21 can be effected by actuation of a simply valve. The invention is also suited for use with electrically driven power tools, as will now be described with reference to Figure 3, which shows a device according to a second embodiment of the invention, indicated at 30. The device 30 is arranged in use with a power tool, indicated at 32, which in this embodiment is a hand operated electric drill. The drill 32 is connected to an electrical power source 34 by an electric cable indicated at 36, for driving the drill 32, and the device 30 is mounted across the cable 36, directly in the line of the supply of operative power to the drill 32.

The electric cable 36 includes a pair of conductor wires 38. The device 30 includes a current transformer 40, and the device is arranged with one of the wires 38 passing through the transformer 40. A digital counter unit 42 is in communication with the transformer 40 via an electrical circuit indicated at 44. The components of the circuit will be readily apparent to the skilled reader from Figure 3 and the following description.

In use, when electrical current passes through the cable 36 to the drive the drill 32, the transformer 40 generates a small AC voltage. This voltage is rectified and passed to a load resistor in the circuit 44, which is in parallel with a capacitor. The result is a smoothed DC voltage whenever the drill 32 is in a state of driven operation.

The DC voltage is sampled onto a base of an NPN transistor through a resistor, to generate an open collector output from the circuit 44. The counter 42 uses the output to measure the time for which the drill 32 receives a supply of operative power.

As with the embodiment of Figures 1 and 2, the counter 42 is configured to display the length of time for which power has been supplied to the tool 32 for each given operational use of the tool 32, as well as an accumulated time value for the operational life of the tool 32.

As will be appreciated, the device 30 has largely the same advantages as the device 10. The device 30 is shown as being mounted across one of the conductors 38 in the power supply cable 36, so as to be generally integral with the power supply cable 36. However, in accordance with a third preferred embodiment of the invention illustrated in Figure 4, a similar electrical device can be housed in a dedicated unit adapted to be selectively connected between a power tool and a power source for said tool.

The device in Figure 4, indicated at 50, comprises a dedicated housing 52. An electrical circuit corresponding substantially with the circuit 44 shown in Figure 3 is provided in the housing 52, and therefore the circuit will not be described in detail and is shown largely in block diagram form. Where possible, the same reference numerals used in Figure 3 to describe the electrical components within the device 30 and the circuit 44 have been used to describe components in Figure 4.

A first end of the housing 52 includes a connector socket 54, which is configured for receiving a plug-type connector 56 from an electrical power tool 58. An electrical cable 60 having a plug-type connector 62 extends from a second end of the housing 52, for connection with a power source (not shown) for the power tool, or a power cable from the power source. A pair of conductors 64 extend within the housing 52 and provide a means of electrical communication between provide first and second ends of the housing 52, i.e. between the socket 54 and cable 60. Otherwise, the device 50 is substantially the same as the device 30 in Figure 3, having a current transformer 40 connected across one of the conductors 64, with a counter unit 42 in communication with the transformer 40 via an electrical circuit 44.

The device 50 can be plugged directly into an AC power supply, or into an extension cable, for example, and the cable 56 can be of any suitable length, as required. Operation of the device 50 will be readily understood by the skilled reader, having regard for the description of Figures 3 and 4.

The devices according to the invention described above are preferably of a suitably robust construction to withstand an industrial environment. In both embodiments, the housing encasing the operative components of the device can be adapted for use as an intermediate connection between a power tool and a power source for the tool. The device will preferably be in the form of a small self-contained unit, with the dimensions of the housing being of the order of 50mm long, 40 mm high and 20 mm deep, for example.

The device may also be in the form of a small magazine-type unit that can be connected directly to the handle portion or other portion of a power tool, with the unit having connector means for receiving a supply cable from an electrical or pneumatic power source.

A device according to the invention is preferably a self-contained, dedicated unit, which is conveniently portable and adapted for movement with a power tool for use at a remote workstation. However, it will be appreciated that a device according to the invention may also be incorporated directly into a power tool. In either case, the device is adapted to operate in the supply line of operative power to the tool, with limited physical restriction to an operator of the tool.

Although not illustrated, a device according to the invention may also include a secure reset means, for example a key-operated switch, which can be locked to prevent an operator from resetting the timer means.

Alternative embodiments of the invention may incorporate a pre-set alarm with an audio or visual warning, which can be programmed to activate once a pre-set value has been detected by the timer means, to enable the tool with which the device is operating to be recalled for maintenance. A device according to the invention may also include a programmable shut off means, for example a shut-off valve or switch, for preventing the further supply of operative power through the device, after a predetermined period of operational use has been detected.

In a modification to the embodiment of figures 1 and 2, monitoring of the flow of pneumatic or hydraulic fluid to the tool is by way of a pressure sensor, which may sense changes in pressure in the supply power 14, for example, by way of a suitable membrane or diaphragm which flexes with changes in pressure.

Claims

1 A device for monitoring the usage of a pneumatically or hydraulically operated power tool (12), the device (10) comprising: means (18, 20, 22, 28) for sensing the supply of said pneumatic or hydraulic power from a source (13) of said power to said tool (12); and monitoring means (24, 26) responsive to said sensing means (18, 20, 22, 28) for recording the time elapsed during said supply of said power.

2 A device as claimed in claim 1 further comprising: an input for connection to said source (13) of pneumatic or hydraulic power; an output for connection to said tool (12) for supplying said pneumatic or hydraulic power from said source (13) to said tool (12); and said sensing means (18, 20, 22, 28) is operable to sense the supply of said pneumatic or hydraulic power from said input to said output.

3 A device as claimed in claim 1 or 2 wherein said pneumatic or hydraulic power is compressed gas.

4 A device as claimed in claim 3 wherein said sensing means (18, 20, 22, 28) comprises means (20) sensing said gasflow through the device (10).

5 A device as claimed in claim any of claims 1 to 4 wherein: said sensing means (18, 20, 22, 28) comprises first means (20) displaceable between first and second positions in response to flow of said pneumatic or hydraulic power; said first means (20) is biased towards said first position; and said monitoring means (24, 26) is operable to monitor the time elapsed whilst said first means is in said second position.

6 A device as claimed in claim 5 wherein: said first means comprises piston means (20) movable from said first position to said second position in response to the flow of pneumatic or hydraulic power from said power source (13) to said power tool (12) and said sensing means (18, 20, 22, 28) further comprises biasing means (22) biasing said piston means (20) towards said first position; and said monitoring means (24, 26) is operable to monitor the time elapsed whilst said piston means (20) is in said second position.

7 A device as claimed in claim 6 wherein said monitoring means (24, 26) operates in response to movement of said piston means (20).

8 A device as claimed in claim 5, 6 or 7 wherein said monitoring means (24, 26) includes switch means (26) actuable in response to movement of said first means (20).

9 A device as claimed in any of claims 1 to 8 wherein said monitoring means (24, 26) includes second recording means for recording the cumulative time elapsed during use of the power tool (12).

10 A device as claimed in claim 9 further comprising reset means for resetting the second recording means.

11 A device as claimed in any of claims 1 to10 further comprising security means for preventing unauthorised re-setting of the recorded time.

12 A device as claimed in any of claims 1 to 11 further comprising means for displaying the monitored time.

13 A device as claimed in any of claims 1 to 12 further comprising control means for inhibiting operation of said tool (12) in response to said recorded time exceeding a predetermined value. 14 A device as claimed in claim 13 when appendant to claim 2 wherein said control means includes valve means for preventing flow of pneumatic or hydraulic power from said input to said output in response to said recorded time exceeding a predetermined value. 15 A device as claimed in any of claims 1 to 14 further comprising microprocessor means for enabling downloading of said recorded time to an external device (10).

16 A device for monitoring the usage of an electrically operated power tool (32), the device (30, 50) comprising: means (40) for sensing the supply of said electrical power from a source (34) of said power through a supply line to said tool (32), said sensing means being adapted to be inductively coupled to said supply line for sensing current flow through said supply line; and monitoring means (42) responsive to said sensing means (40) for recording the time elapsed during said supply of said pneumatic or hydraulic power.

17 A device as claimed in claim 16, wherein the device is adapted to be arranged in connection with a power supply cable (36) for said electrically operated power tool, for directly detecting the supply of current to the tool.

18 A device as claimed in claim 16 or 17 further comprising: an input for connection to said source (34) of electrical power; an output for connection to said tool (32) for supplying said electrical power from said source (34) to said tool (32); and said sensing means (40) is operable to sense the flow of current from said input to said output.

19 A device as claimed in claim 16, 17 or 18 wherein said sensing means is operable to convert current from the power supply into an output signal for indicating that power is being supplied to the tool. 20 A device as claimed in any of claims 16 to 19 wherein said monitoring means (42) includes second recording means for recording the cumulative time elapsed during use of the power tool (32).

21 A device as claimed in claim 20 further comprising reset means for resetting the second recording means.

22 A device as claimed in any of claims 16 to21 further comprising security means for preventing unauthorised re-setting of the recorded time.

23 A device as claimed in any of claims 16 to 22 further comprising means for displaying the monitored time.

24 A device as claimed in any of claims 16 to 23 further comprising control means for inhibiting operation of said tool (32) in response to said recorded time exceeding a predetermined value.

25 A device as claimed in any of claims 16 to 24 further comprising microprocessor means for enabling downloading of said recorded time to an external device.