Patent attributes
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. The key unit is hand movable from the second position into the first position and this movement of the key unit stores energy into the spring. The stored energy in the spring moves the key unit from its first position into its second position.