Latch mechanism

Claim 2

A latch mechanism for an apparatus having cabinet means and an access door on said cabinet means operable between a generally closed position and an open position, the combination comprising: first latch means on said access door; second latch means mounted on said cabinet means comprising a latch member mounted for movement relative to said cabinet means and a latch pawl yieldingly mounted on said latch member, said latch pawl including an extended latch portion engageable with said first latch means for preventing movement of said access door to said open position under a predetermined condition and being movable with said latch member from a first posture to a nonlatching posture to retract said latch portion and permit movement of said access door from said closed position toward said open position in the absence of said predetermined condition; and stop means engageable by said latch pawl, said latch pawl being movable relative to said latch member and against said stop means to a door latching posture responsive to said predetermined condition for preventing movement of said access door to said open position.

Claim 3

A latch mechanism as defined in claim 1 wherein said second latch means includes means for biasing said latch pawl to a predetermined position relative to said latch member and operable for effecting movement of said latch member and said latch pawl together in the absence of said predetermined condition and for yieldingly opposing movement of said latch pawl relative to said latch member toward said door latching posture in the presence of said predetermined condition.

Claim 4

A latch mechanism for an apparatus having cabinet means and an access door on said cabinet means operable between a generally closed position and an open position, the combination comprising: first latch means on Said access door; second latch means mounted on said cabinet means and including a shaft pivotally mounted on said cabinet means, a pivot member mounted on said shaft for movement therewith, a latch pawl including an extended portion engageable with said first latch means and pivotally mounted on said pivot member for movement relative thereto, said latch pawl being movable with said pivot member from a first posture to a non-latching posture to retract said latch pawl and permit movement of said access door toward said open position; and stop means engageable by said latch pawl, said latch pawl under a predetermined condition being also movable relative to said pivot member and against said stop means to a door-latching posture for preventing movement of said access door to said open position.

Claim 5

A latch mechanism for an apparatus having cabinet means and an access door on said cabinet means operable between a generally closed position and an open position, the combination comprising: first latch means on Said access door; second latch means mounted on said cabinet means and including a shaft pivotally mounted on said cabinet means, a pivot member mounted on said shaft for movement therewith, a latch pawl including an extended portion engageable with said first latch means and pivotally mounted on said pivot member for movement relative thereto, said latch pawl being movable with said pivot member from a first posture to a non-latching posture to retract said latch pawl and permit movement of said access door toward said open position; and stop means engageable by said latch pawl, said latch pawl under a predetermined condition being also movable relative to said pivot member and against said stop means to a door-latching posture for preventing movement of said access door to said open position.

Claim 6

A latch mechanism as defined in claim 3 wherein said second latch means includes first means for biasing said latch pawl relative to said pivot member for engagement by said first latch means and further includes second means for biasing said second latch means into position for engagement by said first latch means.

Claim 7

A latch mechanism as defined in claim 3 wherein said first latch means includes a movable member biased to a position underlying said extended portion for engagement therewith upon an attempt to move said access door from said closed position and wherein said movable member is cammed to a second position to permit movement of said access door from said open position to said closed position.

Claim 8

A latch mechanism for an apparatus having cabinet means and an access door on said cabinet means operable between a generally closed position and an open position, the combination comprising: first latch means on said access door; second latch means mounted on said cabinet means and cooperable with said first latch means to selectively lock said access door in said closed position, said second latch means including a shaft pivotally mounted on said cabinet means, a pivot member mounted on said shaft for movement therewith, a latch pawl pivotally mounted on said pivot member for movement relative thereto and having an extended portion for engagement with said first latch means, and means for biasing said latch pawl relative to said pivot member; means for selectively restraining movement of said shaft responsive to a condition of said apparatus, said second latch means being pivotable with said shaft to retract said extended portion and permit movement of said access door from said closed position to said open position in the absence of said condition of the apparatus; and stop means engageable by said latch pawl, said latch pawl being movable relative to said pivot member and against said stop means responsive to initial movement of said access door from said closed position when movement of said shaft is restrained for preventing movement of said access door to said open position.

Claim 9

A latch mechanism for an apparatus having cabinet means and an access door on said cabinet means operable between a generally closed position and an open position, the combination comprising: first latch means on said access door; second latch means mounted on said cabinet means and cooperable with said first latch means to selectively lock said access door in said closed position, said second latch means including a shaft pivotally mounted on said cabinet means, a pivot member mounted on said shaft for movement therewith, a latch pawl pivotally mounted on said pivot member for movement relative thereto and having an extended portion for engagement with said first latch means, and means for biasing said latch pawl relative to said pivot member; means for selectively restraining movement of said shaft responsive to a condition of said apparatus, said second latch means being pivotable with said shaft to retract said extended portion and permit movement of said access door from said closed position to said open position in the absence of said condition of the apparatus; and stop means engageable by said latch pawl, said latch pawl being movable relative to said pivot member and against said stop means responsive to initial movement of said access door from said closed position when movement of said shaft is restrained for preventing movement of said access door to said open position.

Claim 10

A latch mechanism as defined in claim 6 wherein means including second biasing means is operable for locating said second latch means in a generally predetermined position relative to said cabinet means for engagement of said first latch means with said extended portion.

Claim 11

A latch mechanism as defined in claim 6 wherein said first latch means includes a movable member biased to a predetermined position on said access door for engagement with said extended portion and wherein said movable member is cammed from said predetermined position by said extended portion for permitting movement of said access door from said open to said closed position.

Claim 12

A latch mechanism as defined in claim 8 and further including energy-absorbing cushion means engageable with the movable member of the first latch means upon movement of said access door to the closed position.

Claim 13

In an apparatus including a rotatable member, the combination comprising: cabinet means substantially enclosing said rotatable member; an access door on said cabinet means operable between a generally closed position and an open Position; first latch means on said access door; second latch means movably mounted on said cabinet means and cooperable with said first latch means to selectively lock said access door in said closed position, said second latch means including a movably mounted latch member, a latch pawl yieldingly mounted on said latch member for movement relative thereto and extending from said cabinet means for engagement with said first latch means, and means for biasing said latch pawl relative to said latch member; rotation sensing control means operatively connected to said latch member for permitting movement thereof in the absence of rotation of said rotatable member and to limit movement thereof in the presence of rotation of said rotatable member, said second latch means being movable in the absence of rotation to retract said latch pawl and permit movement of said access door toward said open position; and stop means on said cabinet means engageable by said latch pawl, said latch pawl being movable relative to said latch member and against said stop means when the presence of rotation of said rotatable member limits movement of said latch member for preventing movement of said access door to said open position.

Claim 14

In an apparatus including a rotatable member, the combination comprising: cabinet means substantially enclosing said rotatable member; an access door on said cabinet means operable between a generally closed position and an open Position; first latch means on said access door; second latch means movably mounted on said cabinet means and cooperable with said first latch means to selectively lock said access door in said closed position, said second latch means including a movably mounted latch member, a latch pawl yieldingly mounted on said latch member for movement relative thereto and extending from said cabinet means for engagement with said first latch means, and means for biasing said latch pawl relative to said latch member; rotation sensing control means operatively connected to said latch member for permitting movement thereof in the absence of rotation of said rotatable member and to limit movement thereof in the presence of rotation of said rotatable member, said second latch means being movable in the absence of rotation to retract said latch pawl and permit movement of said access door toward said open position; and stop means on said cabinet means engageable by said latch pawl, said latch pawl being movable relative to said latch member and against said stop means when the presence of rotation of said rotatable member limits movement of said latch member for preventing movement of said access door to said open position.

Claim 15

In an apparatus as defined in claim 10 wherein movement of said second latch means is produced by the initial attempted movement of said access door from said closed position.

Claim 16

In an apparatus as defined in claim 10 wherein said biasing means is operable between said latch member and said latch pawl to effect unitary movement of said latch pawl and latch member when said latch member is free for movement and to permit movement of said latch pawl relative to said latch member when said latch member is restrained to effectively prevent overloading of said latch member and said rotation sensing control means while maintaining the access door latched.