A number of power tools have been produced to facilitate forming a work piece into a desired shape. One such power tool is a table saw. A wide range of table saws are available for a variety of uses. Some table saws such a cabinet table saws are very heavy and relatively immobile. Other table saws, sometimes referred to as jobsite table saws, are relatively light. Jobsite table saws are thus portable so that a worker can position the table saw at a job site. Some accuracy is typically sacrificed in making a table saw sufficiently light to be mobile. The convenience of locating a table saw at a job site, however, makes job site table saws very desirable in applications such as general construction projects.
All table saws, including cabinet table saws and job site table saws, present a safety concern because the saw blade of the table saw is typically very sharp and moving at a high rate of speed. Accordingly, severe injury such as severed digits and deep lacerations can occur almost instantaneously. A number of different safety systems have been developed for table saws in response to the dangers inherent in an exposed blade moving at high speed. One such safety system is a blade guard. Blade guards movably enclose the saw blade, thereby providing a physical barrier that must be moved before the rotating blade is exposed. While blade guards are effective to prevent some injuries, the blade guards can be removed by a user either for convenience of using the table saw or because the blade guard is not compatible for use with a particular shaping device. By way of example, a blade guard is typically not compatible with a dado blade and must typically be removed when performing non-through cuts.
Table saw safety systems have also been developed which are intended to stop the blade when a user's hand approaches or touches the blade. Various stopping devices have been developed including braking devices which are physically inserted into the teeth of the blade. Such approaches are extremely effective. Upon actuation of this type of braking device, however, the blade is typically ruined because of the braking member. Additionally, the braking member is typically destroyed.
In response to the shortcomings of the above described devices, table saw safety systems have been developed which rapidly move a saw blade or other shaping device below the surface of the work support surface in response to a sensed condition. One such device is disclosed in U.S. Pat. No. 8,297,159, which issued on Oct. 30, 2012, the entire contents of which are herein incorporated by reference.
The system disclosed in the '159 patent is highly effective in moving a saw blade or other shaping device away from a user by moving a swing arm assembly within the saw housing.
In view of the foregoing, it would be advantageous to provide a power tool with movable swing arm that moves more efficiently. It would be further advantageous for a power tool to provide efficient movement of a swing arm while improving accuracy of the swing arm in a latched position.