PACK THE KNIFE - Stanley Tools employs robotic automation

A new robotic process at Stanley Tools has significantly reduced handling operations and improved productivity in knife blade dispenser packaging operations. AA Robotics, and one of it's System Integrators, Aylesbury Automation, has designed and installed automated packaging technology using DENSO robots to maximise the benefits of ‘lean manufacturing’, reduced stock holding and shortening delivery lead times of blade dispensers for Stanley Tools at Rotherham. 

Stanley Tools manufactures and markets tools, hardware and speciality products worldwide for both the home improvement market and industrial and professional use. Founded by Frederick Trent Stanley in 1843 in Connecticut USA to manufacture door bolts and other wrought iron products, Stanley Tools is a global brand. Demand for replacement blades for the ‘Stanley Knife’ is growing and it was this increased demand which led to the requirements for improved automation.

The current machine cycle, plus machine loading time, has been reduced by 75% with the new automated technology. This allows Stanley Tools to process and pack, 4x more products per hour with a 100% quality check of component parts. Previously a semi automatic machine had been used for the assembly and packaging process which involved routine manual handling of components into the machine.

“The process we had was quite labour intensive,” said (Nick Vickers – Plant manager) of Stanley Tools. “With demand for replacement blades increasing and bearing in mind the health and safety aspects of increased manual handling, robotic automation was the obvious route to follow. AA Robotics was able to supply a solution which performs the task with the minimum of manual intervention. What’s more, we have the flexibility to change the assembly and packaging process easily as products and demands change.” 

The new automated process uses DENSO robots to load and unload components. A storage hopper trickle feeds plastic cases on demand into a vibratory bowl feeder. After being sorted in the bowl, into one of two orientations, the cases are delivered onto an infeed conveyor. Here the first DENSO robots picks up a case, so that sensors can check its orientation and condition. Components failing a specification check are rejected. The robot then presents the good case to the next stage of the assembly operation.

Dispensers are also fed from a vibratory storage hopper and bowl into correct orientation for insertion into the cases. The blades from the blade-grinding machine are delivered in trays and automatically fed by conveyor into an upload station where they are prepared for loading into the cases. At the same time a strip of steel feeds into a press where it is cut to form the spring, which is inserted in the case behind the blades.

The case is then closed and checks are made to ensure the spring and blades are correctly inserted. A final robot palletises the cases, six layers deep with 28 cases to a layer, into a tote bin which is orientated correctly for final packaging.

“AA Robotics designers brought a great deal of experience in automated assembly and robotic packaging to the job, and they have succeeded in providing a solution which is extremely efficient and cost-effective,” said (Howard Walker – Senior Engineer).

AA Robotics distributes DENSO robots in the UK and Ireland. Their range is from 3Kg up to 20Kg payload in 4-axis or 6-axis arm configurations with a reach from 400mm to 1300mm. Denso robots have a fast 0.3 seconds pick and place operation which is repeatable to 0.015mm.