Casting Study: Slave Lock Mechanism

The initial design brief for the slave lock was that it had to have suitable mechanical properties to meet security door standards, have minimum design complexity and use the most logical material for the purpose. Initially a hybrid construction was considered, using zinc diecast housing with pressed metal cover plate and investment cast gears. However making all parts in zinc provided the following potential benefits: 1. All parts could be cast in a family die, so that one shot gives one lock. 2. The use of one tool would use only one tool, greatly reducing cost. 3.Maintenance of only one tool would be needed. Prototyping indicated that the strength requirements were more than met, and in fact, impact strength was greater than expected. Tooling costs were in line with expectations and trials delivered a product that justified development of the unit in all zinc.