Safety retracting mechanism for the lower guard of a portable saw

Claim 2

A guard retracting mechanism for a portable saw of the type having a circular blade, a fixed upper guard and a lower guard mounted for swinging movement back and forth between open and closed positions, said mechanism comprising: a. an actuator movable back and forth between closed and open positions; b. a force transmitting assembly connected to said lower guard; c. spring means for urging said lower guard to its closed position; d. releasable means connecting said actuator with said force transmitting assembly, which releasable means include force transmitting elements normally interengaged whereby movement of said actuator to its open position causes swinging movement of said lower guard to its open position; e. said releasable means including cam means for disengaging said elements in response to movement of said lower guard toward its open position independently of said actuator, whereby said spring means is permitted to swing said lower guard to its closed position irrespective of the position of said actuator; and f. other cam means operable in response to movement of said actuator toward its closed position for engaging said elements.

Claim 3

The mechanism according to claim 1 further defined by: a. said releasable means including a shaft and a collar mounted thereon for both rotation and axial movement relative to the shaft, which shaft has a diametrically disposed bore therein; b. said actuator being connected with said collar and said shaft being connected with said force transmitting assembly; c. said collar including a recess having a first wall and a camming wall, the latter forming part of said camming means; d. a pin received in said bore; e. second spring means in said bore engaged with said pin normally urging the latter outwardly with one end of the pin received in said recess and engaged with said first wall, which first wall and the engaged surface of said pin constitute said force transmitting elements; f. third spring means urging said collar in one axial direction and being adapted to shift said collar in said one direction when said pin is forced from said recess by the action of said camming wall resulting from rotation of said shaft relative to said collar; and g. second camming means for shifting said collar in its other direction in response to movement of said actuator toward its closed position.

Claim 4

The mechanism according to claim 2 wherein said force transmitting assembly includes linkage connecting said shaft with said lower guard.

Claim 5

A guard retracting mecHanism for a portable saw of the type having a circular blade, a fixed upper guard and a lower guard mounted for swinging movement back and forth between open and closed positions, said mechanism comprising: a. an actuator mounted on the saw housing for movement back and forth between open and closed positions; b. spring means urging the lower guard to its closed position; c. force transmitting means connecting said actuator with said lower guard such that movement of the former toward its open position causes corresponding movement of the lower guard; d. said force transmitting means including releasable means operable to disconnect said actuator from said lower guard in response to movement of the latter toward its open position independently of the former, whereupon said spring means is permitted to swing said lower guard to its closed position irrespective of the position of said actuator; and e. reset means operable in response to movement of said actuator toward its closed position for re-establishing the connection between said actuator and said lower guard.

Claim 6

A guard retracting mecHanism for a portable saw of the type having a circular blade, a fixed upper guard and a lower guard mounted for swinging movement back and forth between open and closed positions, said mechanism comprising: a. an actuator mounted on the saw housing for movement back and forth between open and closed positions; b. spring means urging the lower guard to its closed position; c. force transmitting means connecting said actuator with said lower guard such that movement of the former toward its open position causes corresponding movement of the lower guard; d. said force transmitting means including releasable means operable to disconnect said actuator from said lower guard in response to movement of the latter toward its open position independently of the former, whereupon said spring means is permitted to swing said lower guard to its closed position irrespective of the position of said actuator; and e. reset means operable in response to movement of said actuator toward its closed position for re-establishing the connection between said actuator and said lower guard.

Claim 7

A guard retracting mechanism for a portable saw of the type having a circular blade, a fixed upper guard and a lower guard mounted for swinging movement back and forth between open and closed positions, said mechanism comprising: a. spring means connected with said lower guard for urging the same to its closed position; b. a shaft; c. linkage connecting said shaft with said lower guard such that rotation of the former causes swinging movement of the latter; d. an actuator including a collar mounted on said shaft for rotation and for axial movement relative thereto, which actuator is mounted for swinging movement back and forth between open and closed positions and thereby imparts corresponding rotation to said collar; e. releasable means connecting said collar with said shaft for rotation in unison such that swinging movement of said actuator to its open position causes corresponding movement of said lower guard; f. said releasable means including first cam means for disconnecting said collar from said shaft in response to rotation of the latter relative to the former; and g. second cam means for re-establishing the connection between said collar and said shaft in response to rotation of the former relative to the latter.

Claim 8

A guard retracting mechanism for a portable saw of the type having a circular blade, a fixed upper guard and a lower guard mounted for swinging movement back and forth between open and closed positions, said mechanism comprising: a. spring means connected with said lower guard for urging the same to its closed position; b. a shaft; c. linkage connecting said shaft with said lower guard such that rotation of the former causes swinging movement of the latter; d. an actuator including a collar mounted on said shaft for rotation and for axial movement relative thereto, which actuator is mounted for swinging movement back and forth between open and closed positions and thereby imparts corresponding rotation to said collar; e. releasable means connecting said collar with said shaft for rotation in unison such that swinging movement of said actuator to its open position causes corresponding movement of said lower guard; f. said releasable means including first cam means for disconnecting said collar from said shaft in response to rotation of the latter relative to the former; and g. second cam means for re-establishing the connection between said collar and said shaft in response to rotation of the former relative to the latter.

Claim 9

The mechanism according to claim 5 further defined by: a. said releasable means being defined by a pin yieldably mounted in a bore formed in said shaft and by a recess formed in said collar, one end of the pin being normally received in said recess; b. said first cam means including a camming wall forming part of said recess, said camming wall being adapted to force said pin out of said recess in response to movement of the shaft relative to the collar; c. said releasable means also including other spring means for shifting the collar axially in one direction upon disengagement of said pin from said recess; and d. said second cam means including a cam and cam follower for shifting said collar axially in the other direction.

Claim 10

The mechanism according to claim 6 wherein said collar is mounted for said axial movement relative to said actuator, said other spring means being interposed between said actuator and said collar.