As a regular user of glue guns, I wanted to work mainly on the force applied on the trigger in order to squeeze the glue out. In order to overcome this shortcoming, I designed a glue gun that is automatic in its functioning, requiring less or no force to be applied due to the elimination of the trigger. 

In my final design, I used the paper stapler with a sliding button mechanism.

 

My design showcases an automatic glue gun, rather than traditional manual glue gun wherein the glue stick needs to be manually triggered out of the gun.It is automatic in the way where the glue stick path/holder is attached at both ends using a spring ( just as in the paper stapler mechanism, where the staple pin are installed in a spring path).

 

You simply pull the path apart, insert the glue stick and let the spring squeeze the stick out of the gun as and when it melts. In order to stop the path from squeezing/pushing the stick further, the sliding knob mechanism is used in which you slide the knob attached to the path into the slits created at the top of the gun.