Abstract An optically protective viewing glass is slidably mounted in slides vertically fixed at the sides of a viewing slot in a face shield. The viewing glass is driven between opposite work performing and work viewing positions by a motor and synchronized side gear trains to prevent jamming of the glass in the slides. The motor is mounted on the face shield and energized from a power source, similarly mounted, through circuit means having two parallel branches, one branch for energizing the motor to drive the viewing glass to one of its opposite positions, and the other branch to the other of its opposite positions. Limiting switches, respectively connected in the parallel branches and mounted on the face shield at the respective opposite positions of the viewing glass, are operable by the viewing glass reaching either of said positions to open the limit switch in the parallel branch energized to drive said glass to the position just reached and simultaneously to close the limit switch in the other parallel branch. An energizing switch is mounted on the face shield and connected in both branch circuits to alternately close the circuit of one of said parallel branches and open the other as it is mouth-operated by a welder. The limiting and energizing switches are coordinated to alternately drive the viewing glass to opposite positions each time the energizing switch is operated.
An improved welder''s mask, having eye protective viewing glass vertically slidable in a face shield between offosite working and viewing positions, comprising in combination: similar side gear train means synchronously driven and mounted adjacent vertical sides of a viewing slot defined in said face shaield for sliding said eye protective viewing glass without jamming to said viewing and working positions respectively over and above said viewing slot; reversible motor means mounted for rotation of said side gear train means on said face shield; power means mounted on said face shield for energizing said reversible motor means; circuit means having parallel branches connecting said power means to said motor means; switching means connected in said circuit means and semiautomatically controllable to alternately energize said parallel branches with reversible power for sequentially rotating said motor means in opposite directions of rotation and said viewing glass to opposite viewing and working positions.
Claim 2
Dependent Claim
149 words
An improved welder''s mask, having eye protective viewing glass vertically slidable in a face shield between offosite working and viewing positions, comprising in combination: similar side gear train means synchronously driven and mounted adjacent vertical sides of a viewing slot defined in said face shaield for sliding said eye protective viewing glass without jamming to said viewing and working positions respectively over and above said viewing slot; reversible motor means mounted for rotation of said side gear train means on said face shield; power means mounted on said face shield for energizing said reversible motor means; circuit means having parallel branches connecting said power means to said motor means; switching means connected in said circuit means and semiautomatically controllable to alternately energize said parallel branches with reversible power for sequentially rotating said motor means in opposite directions of rotation and said viewing glass to opposite viewing and working positions.
Claim 3
Dependent Claim
36 words
An improved welder''s mask as described in claim 1 wherein said reversible motor means is an electric motor adapted to reverse its direction of rotation by reversing polarity of said power flow from said power means.
Claim 4
Dependent Claim
18 words
An improved welder''s mask as described in claim 1 wherein said power means is a dry cell battery.
Claim 5
Dependent Claim
201 words
An improved welder''s mask as described in claim 1 wherein said switching means comprise: a double throw, double pole energizing switch connected in said circuit to said power means and parallel branches and adapted to sequentially and oppositely energize said respective parallel branches when said energizing switch is operated by a welder; a pair of limit switches respectively connecting and disconnecting in said circuit the parallel branches to said motor means alternately and simultaneously, said limit switches being respectively mounted on said face shield at the limits of travel at said working and viewing positions of said viewing glass and operable by said viewing glass as it reaches each position respectively to open said circuit means between the motor means and one parallel branch that is closed by a side of said double throw double pole energizing switch and thereby stopping said motor means, and to reversely close the circuit means between the motor means and the other parallel branch that is open by the other side of said energizing switch, whereby operating said energizing switch from side to side respectively, alternately causes the viewing glass to slide to opposite positions and to automatically stop said motor means at each position.