A balancer for tools includes a rotary drum for winding and unwinding a cable, which is adapted with a free end thereof to support a tool. The balancer also includes a spring, wound around the main rotation axis of the drum, which is adapted to develop an elastic reaction contrasting the unwinding of the cable.

A balancer for tools includes a rotary drum for winding and unwinding a cable, which is adapted with a free end thereof to support a tool. The balancer also includes a spring, wound around the main rotation axis of the drum, which is adapted to develop an elastic reaction contrasting the unwinding of the cable.

The invention discloses a force adjustable universal displacement tensioner, including a suction cup assembly 1 and a housing 2; outer gear spring cover 3, coil spring covers and a rope puller 4 are arranged in the housing 2 coaxially through a coil spring shaft; coil springs are disposed in both the outer gear spring cover 3 and the coil spring cover; a pulling rope is disposed on the rope puller 4; one end of the pulling rope which extends out of the housing 2 is connected to a handle 5.