Abstract: A key unit is received within a key unit receiving cavity in a housing and is pivotally connected to the housing for pivotal movement between a first position in which it is substantially within the key cavity and a second position in which it extends outwardly from or is aligned with an open end in the housing. A key unit mounting pin extends across the cavity and into an opening in the head of the key unit. A spring is positioned in the mounting opening, and includes a helical portion surrounding the mounting pin. The spring has a first end portion connected to the housing and a second end portion connected to the key unit. The key unit is pivotally connected to the housing by said mounting pin, for pivotal movement between a first position in which it is substantially within the key unit receiving cavity, and a second position in which it projects outwardly from the open end of the cavity. The spring biases the key unit into the second position.

Abstract: A key head or a key head holder is received within a key unit receiving cavity in a housing and is pivotally connected to the housing for pivotal movement between a first position in which it is substantially within the key cavity and a second position in which it extends outwardly from or is aligned with an open end in the housing. A key unit mounting pin extends across the cavity and into an opening in the head of the key or an opening in the key head holder. A spring is positioned in the mounting opening, and includes a helical portion surrounding the mounting pin. The spring has a first end portion connected to the housing and a second end portion connected to the key unit. The key unit is pivotally connected to the housing by said mounting pin, for pivotal movement between a first position in which it is substantially within the key unit receiving cavity, and a second position in which it projects outwardly from the open end of the cavity.