Frame and shell for a trigger head dispensing device

A frame for a trigger head of a dispensing device for a liquid product, comprising:

• a frame base orthogonal to a central axis;
• a cylindrical pressure chamber having a chamber axis orthogonal to the central axis, annularly delimited by a chamber wall, above the frame base, the cylindrical pressure chamber having an opening at a front thereof and a chamber bottom at a back thereof;
• an intake duct, an outlet duct and a dispensing duct having an extension along a dispensing axis, spaced from and parallel to the chamber axis and delimited by a dispensing wall;
• and
• a shoulder consisting of a shoulder wall, which protrudes at the back from a rear zone of the frame base to form a backing for a hand of a user gripping the trigger head while dispensing the liquid product,
• wherein the shoulder comprises a rear coupling for a shell of the trigger head adapted to make a snap-on connection with the shell,
• wherein the shoulder wall has an arched lower face adapted to support a zone of the hand of the user between a thumb and a forefinger, and an opposite upper face,
• wherein the rear coupling consists of a hook wall projecting above from the upper face, and a facing wall projecting above from the upper face, facing the hook wall and flexible to make the snap-on connection with the shell, and
• wherein the shoulder further comprises a rear support behind the rear coupling for making a support for the shell.