Abstract: Compact inertial device for muscle training, consisting of a pulling body (1) and a drive rope (2). The pulling body (1) in turn comprises a rotating main shaft (4), a reel (8) mounted on the main shaft (4), an inertia element (6) linked solidly to one end of the main shaft (4) for accumulation of kinetic energy from the rotation of the main shaft (4), and a planetary gear (5), which in turn comprises a central gear mounted on the main shaft (4), for multiplication of the transmission speed from the main shaft (4) driven by the reel (8) to the inertia element (6). In its preferred embodiment, the spool (8) is a conical spool with a smaller diameter sector to which one end of the rope (2) is solidly attached.

Abstract: It is equipped with two openings (1, 10) and has an external surface of several stretches of reduced thickness and consistent in each one of its radial cross-sections. It is of flexible material and comprises a bumpy first stretch (5) defined by parallel perimeter grooves (14). It can be used on tools, especially screwdrivers, and facilitates the coupling of the screw head to the screwdriver through one of its openings or optionally through the magnetic attraction exerted by a built-in magnet (8). Likewise, it can be applied to writing tools, such as propelling pencils or ballpoint pens.

Abstract: It is equipped with two openings (1, 10) and has an external surface of several stretches of reduced thickness and consistent in each one of its radial cross-sections. It is of flexible material and comprises a bumpy first stretch (5) defined by parallel perimeter grooves (14). It can be used on tools, especially screwdrivers, and facilitates the coupling of the screw head to the screwdriver through one of its openings or optionally through the magnetic attraction exerted by a built-in magnet (8). Likewise, it can be applied to writing tools, such as propelling pencils or ballpoint pens.