HORNE, Wayne Edwin (4 Havercroft Road, Hunnanby YO14 0NE, GB)
JENNINGS, Lawrence (61 Eastway, Eastfield, Scarborough YO11 3LS, GB)
WILSHART, Anthony George (11 Silkstone Way, Crossgates, Leeds LS15 8TN, GB)
HORNE, Wayne Edwin (4 Havercroft Road, Hunnanby YO14 0NE, GB)
JENNINGS, Lawrence (61 Eastway, Eastfield, Scarborough YO11 3LS, GB)
| Claims: 1. A power interrupt apparatus for controlling supply of power to a welding set including a welding trigger coupled to a welding rectifier, the power interrupt apparatus comprising a timer control unit arranged: when in an active configuration to enable supply of power to the welding rectifier; when in an inactive configuration to enable interruption of supply of power to the welding rectifier; and to switch from the active configuration to the inactive configuration after a time delay, characterised in that when the timer control unit is in the inactive configuration it is operatively coupled to the welding trigger such that operation of the welding trigger causes the timer control unit to switch to the active configuration. 2. The power interrupt apparatus of claim 1 , wherein the timer control unit is arranged such that when in the active configuration operation of the welding trigger does not cause switching from the active configuration to the inactive configuration. 3. The power interrupt apparatus of claim 1 or claim 2, wherein the timer control unit is arranged such that when in the active configuration it is operatively coupled to the welding trigger such that operation of the welding trigger extends the time delay. 4. The power interrupt apparatus of claim 1 , 2 or 3, wherein the time delay comprises a predetermined period and wherein the timer control unit is arranged such that periods during which the welding trigger is in use are not counted as part of the predetermined period. 5. The power interrupt apparatus of any preceding claim, comprising connecting means operative to selectively allow or interrupt supply of power to a welding rectifier under control of the timer control unit and/or the welding trigger. 6. The power interrupt apparatus of any preceding claim, wherein in the inactive configuration the timer control unit is arranged to operate the connecting means to allow power to be supplied to the welding rectifier by transmitting a control signal thereto over a first signal path. 7. The power interrupt apparatus of claim 6, wherein in the inactive configuration the timer control unit is arranged to establish a portion of a second signal path for transmitting a control signal to the connecting means to allow power to be supplied to the welding rectifier, and wherein the timer control unit is operatively coupled to the welding trigger such that the second signal path is completed in response to operation of the welding trigger. 8. The power interrupt apparatus of claim 7, wherein the timer control unit is arranged such that in the inactive configuration, completion of the second signal path by operation of the welding trigger activates the timer control unit to switch to the active configuration. 9. The power interrupt apparatus of claim 7, or 8, wherein the timer control unit arranged such that in the inactive configuration, operation of the welding trigger is arranged to break the portion of the second signal path established by the timer control unit. 10. The power interrupt apparatus of claim 7, 8 or 9, wherein the timer control unit is arranged such that in the inactive control state operation of the welding trigger re-establishes the first signal path and provide a control signal over the first signal path to allow power to be supplied to the welding rectifier. 1 1. A welding set comprising a welding trigger coupled to a welding rectifier and a power interrupt apparatus according to any one of claims 1-10. 12. A method of controlling supply of power to a welding set including a welding rectifier, a welding trigger and a timer control unit, the method comprising: arranging the timer control unit in an active configuration to enable supply of power to the welding rectifier; switching the timer control unit from the active configuration to an inactive configuration after a time delay, wherein in an inactive configuration supply of power to the welding rectifier is interrupted; and switching the timer control unit from the inactive configuration to the active configuration by operating the welding trigger. 13. A power interrupt apparatus or welding set including the same, substantially as herein described, with particular reference to the accompanying drawings. |
Set
Field of the Invention
The present invention relates to power interrupt apparatus for controlling supply of power to a welding set, to welding sets incorporating the same, and to related methods.
Background to the Invention
Welding sets for MIG welding typically include a high voltage rectifier. When such welding sets are switched on the rectifier will typically consume energy even when no welding operation is being performed. Energy consumed in this way may be described as stand-by losses. Over long periods of time, and where many welding sets are being used cumulative stand-by losses become significant.
A complete shut-down of the welding sets between welding operations would eliminate standby losses, but with currently available welding sets this would require manual intervention at the welding rectifier. In practice the welding rectifier is unlikely to be located within reach of the location where welding operations are being performed, meaning a user would be significantly inconvenienced by moving back and forth to shut down and power up the welding set. Provision of an automatic timer on a welding rectifier to shut down welding sets, e.g. overnight will reduce stand-by losses, but for short breaks between welding operations provision of a timer may also lead to user inconvenience as the user ends up having to reset or disable the timer before being able to recommence welding.
It is an aim of example embodiments of the invention to address at least one problem associated with the prior art whether identified herein, or otherwise. Summary of the Invention
According to a first aspect of the present invention there is provided a power interrupt apparatus for controlling supply of power to a welding set including a welding trigger coupled to a welding rectifier, the power interrupt apparatus comprising a timer control unit arranged: when in an active configuration to enable supply of power to the welding rectifier;
when in an inactive configuration to enable interruption of supply of power to the welding rectifier; and
to switch from the active configuration to the inactive configuration after a time delay, characterised in that when the timer control unit is in the inactive configuration it is operatively coupled to the welding trigger such that operation of the welding trigger causes the timer control unit to switch to the active configuration. Suitably, the timer control unit is arranged such that when in the active configuration operation of the welding trigger does not cause switching from the active configuration to the inactive configuration.
Suitably, the timer control unit is arranged such that when in the active configuration it is operatively coupled to the welding trigger such that operation of the welding trigger extends the time delay.
Suitably, the time delay comprises a predetermined period. Suitably, the timer control unit is arranged such that periods during which the welding trigger is in use are not counted as part of the predetermined period.
Suitably, the power interrupt apparatus comprises connecting means operative to selectively allow or interrupt supply of power to a welding rectifier under control of the timer control unit and/or the welding trigger.
Suitably, in the inactive configuration the timer control unit is arranged to operate the connecting means to allow power to be supplied to the welding rectifier by transmitting a control signal thereto over a first signal path. Suitably, in the inactive configuration the timer control unit is arranged to establish a portion of a second signal path for transmitting a control signal to the connecting means to allow power to be supplied to the welding rectifier, and wherein the timer control unit is operatively coupled to the welding trigger such that the second signal path is completed in response to operation of the welding trigger.
Suitably, the timer control unit is arranged such that in the inactive configuration, completion of the second signal path by operation of the welding trigger activates the timer control unit to switch to the active configuration. Suitably, the timer control unit arranged such that in the inactive configuration, operation of the welding trigger is arranged to break the portion of the second signal path established by the timer control unit. Suitably, the timer control unit is arranged such that in the inactive control state operation of the welding trigger re-establishes the first signal path and provide a control signal over the first signal path to allow power to be supplied to the welding rectifier. According to a second aspect of the present invention there is provided a welding set comprising a welding trigger coupled to a welding rectifier and a power interrupt apparatus according to the first aspect of the present invention.
According to a third aspect of the present invention there is provided a method of controlling supply of power to a welding set including a welding rectifier, a welding trigger and a timer control unit, the method comprising:
arranging the timer control unit in an active configuration to enable supply of power to the welding rectifier;
switching the timer control unit from the active configuration to an inactive configuration after a time delay, wherein in an inactive configuration supply of power to the welding rectifier is interrupted; and
switching the timer control unit from the inactive configuration to the active configuration by operating the welding trigger. According to the present invention there is provided an apparatus and method as set forth in any appended claims. Other features of the invention will be apparent from the any dependent claims, and the description which follows.
Brief Introduction to Drawings
For a better understanding of the invention, and to show how embodiments of the same may be carried into effect, reference will now be made, by way of example, to the accompanying diagrammatic drawings in which: Figure 1 shows a schematic view of a welding set according to an example embodiment of the present invention, including a power interrupt apparatus;
Figure 2 shows a schematic view of the power interrupt apparatus according to an example embodiment of the present invention, comprising a timer control unit arranged in an active configuration;
Figure 3 shows steps in the operation of the power interrupt apparatus of Figure 2 in response to switching of the timer control unit from the active configuration to an inactive configuration; Figure 4 shows the power interrupt apparatus of Figure 2, but with the timer control unit arranged in the inactive configuration; Figure 5 shows steps in the operation of the power interrupt apparatus of Figure 4 in response to a operation of the welding trigger;
Figure 6 shows a schematic view of a power interrupt apparatus according to another example embodiment of the invention, incorporating a timer control unit pause unit;
Figure 7 is a schematic view of a power interrupt apparatus suitable for building into a welding set during manufacture; and
Figure 8 is a flow chart illustrating a method of controlling supply of power to a welding rectifier of a welding set to enable interruption of supply of power, according to an example embodiment of the present invention.
Figure 1 shows a schematic view of a welding set 10 according to an example embodiment of the present invention. The welding set 10 comprises a welding rectifier 12, a welding trigger 14, a wire feed unit 16 coupled to a supply of welding wire 18, a welding head 19 and a power interrupt apparatus 100. The welding set 10 is in use coupled to a supply of mains electricity.
When coupled to a supply of mains electricity and powered on, operation of the welding trigger 14 causes the welding rectifier 12 and wire feed unit 16 to supply power and welding wire 18 respectively to the welding head 19.
After a predetermined time has elapsed during which no welding operations have been performed the power interrupt apparatus 100 disconnects mains power from the welding rectifier 12 to reduce stand-by losses. Thereafter, subsequent operation of the welding trigger 14 causes power to be supplied to the welding rectifier 12 and to enable welding operations to continue as if the welding rectifier had never been powered down.
Operation of the power interrupt apparatus 100 will now be described in more detail, with reference to Figures 2-5.
Figure 2 shows a schematic view of the power interrupt apparatus 100, comprising a timer control unit 1 10. In Figure 2 the timer control unit 1 10 is arranged in an active configuration. The timer control unit 1 10 comprises a time switch 1 12 made up of a counter 1 1 1 and a time switch contact 1 13 and a relay switch 1 14 made up of a relay 1 15 and a relay switch contacts 1 16.
The power interrupt apparatus 100 further comprises a mains power input unit 120, an isolation unit 130 and a connecting means 140. Figure 2 also shows the welding rectifier 12 and welding trigger 14 of the welding set 10.
In use the mains power input unit 120 is coupled to a supply of mains electricity. Mains power is selectively provided to the welding rectifier 12 according to the configuration of the connecting means 140, which is controlled according to the configuration of the timer control unit 1 10 in conjunction with operation of the welding trigger 14. Mains power is also provided from the mains power input unit 120 to the power interrupt apparatus 100 via the isolation unit 130. The isolation unit 130 comprises a voltage step down transformer 132 and circuit beakers 133, 134.
As shown in Figure 2 the timer control unit 1 10 is in an active configuration. In the active configuration the time switch 1 12 is arranged such that the time switch contact 1 13 enables power to be supplied to the counter 1 1 1. In this way the counter 1 1 1 is caused to count. After a predetermined delay the counter 1 1 1 reaches count limit, causing the time switch 1 12 to change state. The time switch 1 12 changes state by moving the time switch contact 1 13 such that the counter 1 1 1 is isolated from the supply of power and is off. Switching the in this way comprises switching of the timer control unit 1 10 from the active configuration to the inactive configuration. With the timer control unit 1 10 in the active configuration the time switch contact 1 13 is also coupled to the connecting means 140. The connecting means 140 comprises a contactor, arranged to close when power is supplied thereto. When supplied with power the connecting means 140 couples the mains electrical supply from the mains power input unit 120 to the welding rectifier 12. Configuration of the timer control unit 120 in this way provides a first signal path by which the connecting means 140 is energised, the first signal path running through the time switch contact 1 13.
When the timer control unit 120 switches from the active configuration to the inactive configuration a number of changes occur in the power interrupt apparatus 100. Figure 3 sets out the changes that occur in more detail.
At step S301 the time switch contact 1 13 is disconnected from the counter 1 1 1. This causes the power interrupt apparatus 1 10 to assume a time-invariant state, from which it will not change over time without the provision of external input. At step S302 the first signal path to the connecting means 140 is broken, and the connecting means 140 isolates the welding rectifier 12 from the mains power supply. At step S303 the relay 1 15 is energised, causing the relay switch contacts 1 16 to close. Closing of the relay switch contacts 1 16 enables operation of the welding trigger 12 to reset the timer control unit 120 to the active configuration, as will be described in more detail below.
After the steps of Figure 3 have taken place, the timer control unit 120 is in the inactive configuration, as shown in Figure 4. In this configuration the connecting means 140 is isolated, meaning that power supply to the welding rectifier 12 is interrupted.
Figure 5 sets out the changes that occur to reset the timer control unit 120 to the active configuration in response to operation of the welding trigger 14.
At step S501 closing of the welding trigger 14 establishes a second signal path by which the connecting means 140 is energised.
At step S502 the energised connecting means 140 enables the mains electrical supply to be provided from the mains power input unit 120 to the welding rectifier 12.
At step S503 closing the welding trigger 14 further activates the counter 1 1 1 and resets the time switch contact 1 13. At step S504 resetting the time switch contact 1 13 disconnects the relay 1 15.
At step S505 disconnecting the relay 1 15 opens the relay switch contacts 1 16.
Following these steps the timer control unit 120 is restored to the active configuration, in which closing and opening of the welding trigger 14 does not affect the supply of power to the welding rectifier 12. After a predetermined delay the counter 1 1 1 times out, and the timer control unit 120 will return to the inactive configuration. The predetermined delay may be of the order of seconds, 10s of seconds or of minutes, for example being 5, 10 or more minutes. It is desirable that the timer control unit 120 does not switch to the inactive configuration while the welding set 10 is in use in performing a welding operation. Figure 6 shows a schematic view of a power interrupt apparatus 200 according to another example embodiment of the invention, incorporating a timer control unit pause unit 160 to avoid this problem. The timer control unit pause unit 160 comprises a switch 161 that is operatively coupled to the welding trigger 14 such that while the welding trigger 14 is operated a pause signal is supplied to the counter 1 1 1 . This means that periods of time during which the welding trigger 14 is operated are not counted towards the predetermined period counted by the counter 1 1 1 . In the example embodiment of Figure 6 the switch 161 is coupled to a relay 162 that is in line with wire feed unit 16, such that operation of the welding trigger 14 operates the wire feed unit 16 and energises the relay 162 and thereby closes the switch 161. From the configuration of Figure 6, in which the welding trigger 14 is closed, the relay 162 driven along with the wire feed motor 16, and the switch 161 closed and the counter 1 1 1 paused, release of the welding trigger 14 cuts power to the relay 162 and wire feed motor 16, opens the switch 161 and removes the pause signal supplied to the counter 1 1 1. Removal of the pause signal causes the counter 1 1 1 to resume operation.
Figure 7 is a schematic view of a power interrupt apparatus suitable for building into a welding set during manufacture. Rather than the mains coupling unit and isolation unit the power interrupt apparatus has connections 170, 171 , and 172 which are the supply in, connection to the connection means 140 and the neutral connection respectively. The operation of the timer control unit and other parts of the power interrupt apparatus 300 are as described above in relation to the embodiments of Figures 1-6. Figure 8 is a flow chart illustrating a method of controlling supply of power to a welding rectifier of a welding set to enable interruption of supply of power, according to an example embodiment of the present invention. Figure 8 shows the step S801 of arranging the timer control unit in an active configuration to enable supply of power to the welding rectifier; and the step S802 of switching the timer control unit from the active configuration to an inactive configuration after a time delay, wherein in an inactive configuration supply of power to the welding rectifier is interrupted; and step S803 of switching the timer control unit from the inactive configuration to the active configuration by operating the welding trigger.
As described above, a simple and effective apparatus for controlling supply of power to a welding rectifier has been described. The apparatus can reduce stand-by losses, and is convenient to use. Furthermore, the apparatus is easily built into, or retrofitted to welding sets. Although a few preferred embodiments have been shown and described, it will be appreciated by those skilled in the art that various changes and modifications might be made without departing from the scope of the invention, as defined in the appended claims. Attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive. Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features. The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.
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