Grass trimming head and grass trimmer having the same

A long-rod type power tool, comprising:

• a front end device comprising an output assembly for outputting power and a front housing supporting the output assembly;
• a rear end device comprising a motor for driving the output assembly and a rear housing supporting the motor;
• and
• a connecting rod assembly comprising a connecting rod connecting the front housing and the rear housing and a transmission shaft connecting the motor and the output assembly and transmitting power between the motor and the output assembly;
• wherein the transmission shaft is at least partially arranged in the connecting rod, and a ratio of a total weight of the connecting rod and the transmission shaft to a length of the connecting rod is greater than or equal to 300 g/m and less than or equal to 480 g/m.

A grass trimmer, comprising:

• a front end device comprising an output assembly and a front housing supporting the output assembly, wherein the output assembly comprises a trimming head for trimming grass;
• a rear end device comprising a motor for driving the output assembly and a rear housing supporting the motor;
• and
• a connecting rod assembly comprising a connecting rod connecting the front housing and the rear housing and a transmission shaft connecting the motor and the output assembly and transmitting power between the motor and the output assembly;
• wherein the transmission shaft is at least partially arranged in the connecting rod, and a ratio of a total weight of the connecting rod assembly and the front end device to a weight of the grass trimmer without a power source device is greater than or equal to 0.3 and less than or equal to 0.42.