Chain-type door fastening device

Claim 2

A chain-type door fastening device for use with a door having a door frame and a door knob, said device comprising: chain means and means for attaching said chain means to said door frame at a point substantially in alignment with said door knob and adjacEnt to said door knob when said door is in the closed position against said door frame, said chain means being disposed in a loop extendable outwardly from said door frame, said loop being of a first length sufficient to extend about said door knob when said door is in said closed position, and chain shortening and fastening means attachable to said door frame and engageable with said chain means for shortening said chain means to define said loop in a second length shorter than said first length and to fasten said chain in said short length, whereby said loop can be drawn taut about said door knob to said second length and fastened thereat when said door is in said closed position to preclude opening of said door, said door being openable a small amount when said loop is disengaged from said chain shortening and fastening means.

Claim 3

The chain-type door fastening means of claim 1 wherein said door frame has a recess for receiving a door knob operated latch means installed on said door, and wherein said means for attaching said chain means comprises flange means extendable into said recess and engageable therewith.

Claim 4

The chain-type door fastening device of claim 1 wherein said means for attaching said chain means comprises a chain mounting plate, said chain means and said chain shortening and fastening means being attached to said chain mounting plate.

Claim 5

The chain-type door fastening device of claim 3 wherein said chain shortening and fastening means comprises a pawl engageable with said chain means.

Claim 6

The chain-type door fastening device of claim 3 wherein said means for attaching said chain means further comprises a strike plate mounted on said door frame and engageable with door knob operated latch means installed on said door, said chain mounting plate being attached to said strike plate.

Claim 7

The chain type door fastening device of claim 5 wherein said door frame has a recess for receiving door knob operated latch means installed on said door and wherein said strike plate comprises: a strike plate opening aligned with said recess, and a flange attached to said strike plate along that edge of said strike plate opening that lies in the direction said door opens, said flange being substantially perpendicular to said strike plate and extending into said recess.

Claim 8

The chain-type door fastening device of claim 3 wherein said chain mounting plate is spaced laterally from the line of travel of the edge of said door whereby said chain when hanging from said chain mounting plate hanges spaced from said door so as not to inhibit movement of said door.

Claim 9

A chain-type door fastening device for use with a door having a door frame, a door knob having a neck portion and door knob operated latch means, and a recess in said door frame for receiving the door knob operated latch means, said device comprising: chain mounting means comprising a strike plate attachable to said door frame, said strike plate having a strike plate opening alignable with said recess and a flange attached along that edge of said strike plate opening that lies in the direction said door opens, said flange being substantially perpendicular to said strike plate and extendable into said recess, a lock plate attached to said strike plate and extending outwardly therefrom in the direction said door opens, said lock plate having a portion inclined away from said door to cam said door knob operated latch means inwardly as said door is closed, and a chain mounting plate attached to said lock plate, a loop of chain attached to said chain mounting plate, said loop being of a first length sufficient to extend about said door knob when said door is in the closed position, and chain shortening and fastening means mounted on said chain mounting means and engageable with said chain to shorten said loop to a second length closely about said neck portion of said door knob, whereby when said loop is in said first length said door can be partially opened, but when said loop is in said seconD length said door is fastened substantially in the closed position.

Claim 10

A chain-type door fastening device for use with a door having a door frame, a door knob having a neck portion and door knob operated latch means, and a recess in said door frame for receiving the door knob operated latch means, said device comprising: chain mounting means comprising a strike plate attachable to said door frame, said strike plate having a strike plate opening alignable with said recess and a flange attached along that edge of said strike plate opening that lies in the direction said door opens, said flange being substantially perpendicular to said strike plate and extendable into said recess, a lock plate attached to said strike plate and extending outwardly therefrom in the direction said door opens, said lock plate having a portion inclined away from said door to cam said door knob operated latch means inwardly as said door is closed, and a chain mounting plate attached to said lock plate, a loop of chain attached to said chain mounting plate, said loop being of a first length sufficient to extend about said door knob when said door is in the closed position, and chain shortening and fastening means mounted on said chain mounting means and engageable with said chain to shorten said loop to a second length closely about said neck portion of said door knob, whereby when said loop is in said first length said door can be partially opened, but when said loop is in said seconD length said door is fastened substantially in the closed position.