Monk gets kettle switch production automated

Monk Automation have recently installed a linear assembly line to assemble and test the thermostatic switch used in the latest domestic kettle bases.

Monk Automation have recently installed a linear assembly line in a UK company.

The line assembles and tests the thermostatic switch used in the latest domestic kettle bases.

The switch has 16 component parts and the production rate is 1800 assemblies each hour.

The line is 23 metres long and combines 20 operators at manual work stations with 20 fully automatic stations.

The cycle time is 4 seconds per pallet with 3 seconds for the operator to load components and 1 second for the pallet to index.

The entire system is based on the Monk single lane palletised linear assembly system.

Pallets are transported on twin steel braced belts with cushioned stops at the working stations.

The pallets are 225mm long and 130mm wide with fixtures supporting two assemblies located on pins.

The pallet system is built using free standing modular sections of 3.6 metres and 4.5 metres long.

Each section is self contained and powered by an individual drive motor.

Each manual station pitch is 900mm, this is a comfortable space for one operator or will house two automatic stations.

At the end of the line pallets are turned through 180 degrees and returned empty by a conveyor to the beginning of the line where they are once again turned and transported to the first station.

All work surfaces are manufactured from 16mm thick resin plastic with melamine type textured facing.

The control system uses the Mitsubishi PLC with remote input and output modules.

The PLC is housed at the end of the line with a twisted pair of wires carrying all the signals to and from the remote I/O modules.

These are situated under each automatic station mounted on a panel together with the Festo pneumatic control valves.

This makes a very neat and simple arrangement.

The system can be very easily modified or upgraded, manual stations can be changed to automatic operation.

Automatic stations can be developed on a special test line in our Godalming factory and then installed into the existing line with the minimum of down-time.

The line can also be extended by adding extra linear modules.

Many standard units can be simply bolted onto the basic linear modules to enable all types of actions to take place, these include the automatic placing of parts, pressing, printing, labelling, cleaning.

Here's the operating sequence.

1 and 2 Two operators load the Earth and Mains power connections.

3 Operator loads the Main Moulding and thermostat sub-assembly.

The operator is supplied with parts pre-assembled by two operators situated at an auxiliary workstation with conveyor transfer.

4 Operator loads the Connecting Tabs.

5 Operator loads the Live Leaf Spring.

The operator is supplied with parts pre-assembled by two operators situated at an auxiliary workstation with conveyor transfer.

6 Operator loads Neutral Connecting Tab.

7 Operator loads Neutral Leaf Spring.

The operator is supplied with parts pre-assembled by two operators situated at an auxiliary workstation with conveyor transfer.

8 Automatically stake the Leaf Springs into the moulding.

9 Automatically stake the Tabs into the moulding.

The fixed tabs are restrained from above and staked from below.

10 and 11 Two operators load the Trip Levers.

12 Operator loads the 'C' Spring.

13 Automatically insert the 'C' Spring into position (one type).

The 'C' springs are pushed home by independent light duty presses.

14 Automatically insert the 'C' Spring into position (second type).

The 'C' springs are pushed home by independent light duty presses.

15 Automatically load the plastic Plunger into the moulding.

The plungers are fed from one bowlfeeder, gated and blow fed to the two positions.

16 Automatically load two Pushrods into the moulding.

The pushrods are fed from one bowlfeeder, gated and blow fed to the four positions.

17 Automatically load a Spring (first type).

The springs are fed from one bowlfeeder, gated, inserted into the main mouldings and pressed into position.

18 Automatically load a Spring (second type).The springs are fed from one bowlfeeder, gated, inserted into the main mouldings and pressed into position.

19 Operator loads the Indicator Connector.

20 Operator loads the Mounting Plate.

The operator is supplied with parts pre-assembled by two operators situated at an auxiliary workstation with conveyor transfer 21 Spare station.

22 Automatically stake the Mounting Plate tabs.

23 Automatically carry out a pick-up test.

This test checks the finished socket retention force.

A unit will rise and engage a free floating weighted gauge into the socket, the assembly will be picked up and the retention of the gauge sensed, the assembly will be passed or failed.

24 Automatic transfer.

The finished assemblies are automatically transferred and loaded into a pallet on the test machine or placed on the reject conveyor.

25 Automatic electrical conditioning and continuity test.

26 Automatic Steam Thermostat function test.

A hot air jet heats the steam blade - the steam blade should operate breaking continuity to both live and neutral within set times.

27 Automatic Steam Thermostat reset test, cool air is blown onto the thermostat - the switch should reset within a set time and continuity be restored.

28 Automatic Boil Dry Thermostat position check.

The thermostat is deflected the datum, continuity should not be broken.

29 Automatic Boil Dry Thermostat temperature test.

The thermostat is heated by a hot air jet - continuity though the live and neutral contacts should be broken within set times.

30 Automatic Boil Dry Thermostat reset test, cool air is be blown onto the thermostat - the switch should reset within a set time and continuity be restored.

31 Automatic Inspect Vision System.

Inspect the X-Y contact position of the leaf spring in element simulated position.

32 Automatic Unload.

Passed switches are unloaded onto a conveyor for printing and packing.

Any rejects are placed into a locked container for examination.

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