Hand-held power tool with a rotary driven tool
First Claim
1. A hand held power tool, comprising:
- a rotary working tool;
a motor for driving the working tool;
a trigger for switching the motor on and off;
a safety element mounted for movement between a safety position, in which the trigger cannot be moved to switch on the motor, and a release position, in which the trigger can be moved to switch on the motor;
spring means for urging the safety element towards said safety position to normally block the trigger from being movable to switch on the motor;
interconnecting means for interconnecting the safety element and the trigger so that when the safety element has been moved to said release position and then the trigger moved to switch on the motor, the trigger then holds the safety element in said release position until the trigger is moved to switch off the motor, movement of the trigger to switch the motor off releasing the safety element and allowing the safety element to return to said safety position;
brake means for braking the rotary working tool by said brake means being brought into braking engagement with a rotary braking part driven by the motor; and
the safety element being mechanically coupled to the brake means so that the brake means is in braking engagement when the safety element is in said safety position and said brake means is moved out of braking engagement when the safety element is in said release position.
1 Assignment
0 Petitions
Accused Products
Abstract
A hand-held power tool with a rotary driven tool, in particular a planer or a circular saw, is arranged so that on switching off the drive, which can be switched on and off by means of a trigger (15), a brake element (34), which is ineffective when the drive is switched on, is brought into braking engagement with a brake part (51) rotatingly driven by the drive. The tool comprises a safety element (21) which co-operates with the trigger (15) and which can be displaced between a safety position in which the trigger (15) cannot be moved to switch on the drive, and a release position in which the trigger (15) can be moved into the position to switch on the drive. The safety element (21) is urged by spring pressure towards the safety position and is held in the release position when the trigger (15)L is in the switch-on position. The safety element (21) is coupled mechanically with the brake element (34) so that in the release position of the safety element the brake element is not in the braking engagement, and in the safety position it is in braking engagement.
140 Citations
20 Claims
-
1. A hand held power tool, comprising:
-
a rotary working tool; a motor for driving the working tool; a trigger for switching the motor on and off; a safety element mounted for movement between a safety position, in which the trigger cannot be moved to switch on the motor, and a release position, in which the trigger can be moved to switch on the motor; spring means for urging the safety element towards said safety position to normally block the trigger from being movable to switch on the motor; interconnecting means for interconnecting the safety element and the trigger so that when the safety element has been moved to said release position and then the trigger moved to switch on the motor, the trigger then holds the safety element in said release position until the trigger is moved to switch off the motor, movement of the trigger to switch the motor off releasing the safety element and allowing the safety element to return to said safety position; brake means for braking the rotary working tool by said brake means being brought into braking engagement with a rotary braking part driven by the motor; and the safety element being mechanically coupled to the brake means so that the brake means is in braking engagement when the safety element is in said safety position and said brake means is moved out of braking engagement when the safety element is in said release position. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
-
10. A power planer, comprising:
-
a housing containing a motor; a drive pulley rotatably driven by said motor; a cutter shaft of a cutter head; a driven pulley mounted on said cutter shaft; said driven pulley being driven from said drive pulley via an endless belt; a brake element biased to engage with one of said pulleys to brake said one pulley; an on/off switch for controlling said motor, said switch having an activator manually movable between on and off positions to energize and de-energize, respectively, said motor; a safety element interconnected with said switch activator and biased to a blocking position to block operation of said switch activator to said on position when said switch activator is in said off position; said safety element being manually movable from said blocking position to a permitting position to allow movement of said switch activator from said off position to said on position; said safety element being connected to said brake element, in said blocking position said safety element allowing said brake element to engage said one pulley, in said permitting position said safety element disengaging said brake element from said one pulley; and said safety element being biased towards said blocking position to automatically effect engagement of said brake element with said one pulley when said switch activator is moved to said off position. - View Dependent Claims (11, 12, 13, 14)
-
-
15. A hand held power tool, comprising:
-
a motor; a rotary working tool connected to be rotatably driven by said motor; an on/off switch having a switch activator movable between on and off positions to energize and de-energize, respectively, said motor; a brake biased to a braking position to brake rotation of said rotary working tool; a manually actuated safety element connected to said brake and also interconnected with said switch activator; said safety element being movable between a safety position and a release position and being biased towards said safety position; said safety element in said safety position effecting application of said brake to said braking position and simultaneously preventing movement of said switch activator from said off position to said on position; said safety element when manually held in said release position disengaging said brake to free said rotary working tool for rotation, and simultaneously allowing said switch activator to be moved from said off position to said on position; and said switch activator when in said on position locking said safety element in said release position to retain said brake disengaged as long as said switch activator is in said on position. - View Dependent Claims (16, 17, 18, 19, 20)
-
Specification