Check rail lock

Claim 2

A lock for a double hung window having a bottom sash with a top rail and a top sash with a bottom rail, said lock including a catch means adapted to be affixed to the bottom rail of said top sash, a two-part latch means for selective engagement with said catch means, a mounting base for the latch means adapted to be affixed to the top rail of said bottom sash, said latch means when in locked position lying generally horizontal in a plane generally normal to the planes of the upper and lower sashes and including a first part movably mounted on said base for pivotal movement and having a slot normal to said base with angularly related portions, a first pin on said base and mounted in said slot to define an axis fixed vertically relative to the base to enable the first part to rotate into and out of engagement with said catch means in a plane normal to said base and to enable generally horizontal movement to draw the sashes together after initial engagement between the catch means and latch means, and a second latch part pivotally mounted on said first pin and carrying a second pin movable in said slot to apply force in line with the horizontal movement of the first part to positively move said first part horizontally to lock the sashes as the second latch part pivots in a plane normal to said base.

Claim 3

The lock of claim 1 including means defining an upwardly facing abutment surface on said base and a downwardly facing abutment surface on the first part of said latch means, said surfaces being disposed between said axis and the point of engagement of said first part and said catch means, said surfaces being in abutment when said sashes are locked together whereby said abutting surfaces, said vertically fixed axis, and said catch means all cooperate to provide a three point block against movement of the top sash downwardly relative to the bottom sash.

Claim 4

The lock of claim 1 wherein at least the portion of said slot adjacent said second pin when said sashes are locked together, is tapered inwardly to prevent said second pin from riding up said slot and loosening said lock when generally horizontal forces are exerted on the lock.

Claim 5

The lock of claim 1 wherein said slot is generally L-shaped having a generally horizontal portion extending generally perpendicular to said sashes and a generally vertical portion extending upwardly from one end of said horizontal portion, said first pin extends into said horizontal portion to permit said horizontal movement of the first part relative to the base to draw the sashes together, and said second pin extends into said vertical slot portion whereby pivotal movement of said second part causes said second pin means to bear against the vertical sides of said vertical slot portion and positively move said first part horizontally to lock and unlock the sashes.

Claim 6

The lock of claim 4 wherein the vertical portion of said L-shaped slot adjacent said second pin when said sashes are locked together is tapered inwardly to prevent said second pin from riding up said vertical portion and loosening said lock when generally horizontal forces are exerted on the lock.

Claim 7

The lock of claim 4 wherein said base has means defining a camming surface on which said second pin rides as the second part of said latch means is pivoted to move the first part horizontally to lock and unlock the sashes.

Claim 8

A lock for a double hung window having a bottom sash with a top rail and a top sash with a bottom rail, said lock iNcluding a catch means adapted to be affixed to the bottom rail of said top sash, a two-part latch means for selective engagement with said catch means, a mounting base for the latch means adapted to be affixed to the top rail of said bottom sash, said latch means when in locked position lying generally horizontal in a plane generally normal to the planes of the upper and lower sashes and including a first part movably mounted on said base for pivotal movement, a first pin and an elongate slot one on said base and the other on said first part defining an axis extending parallel and transversely to the base to enable the first part to rotate into and out of engagement with the catch means in a plane normal to said base and to enable generally horizontal movement to draw the sashes together after initial engagement between the catch means and latch means, and a second latch part pivotally mounted on said base and having a second pin, an elongate generally vertical cam surface on said first part engaged by said second pin whereby rotation of said second part in a plane normal to said base causes movement of the second pin along the cam surface to cause horizontal movement of the first part.

Claim 9

A lock for a double hung window having a bottom sash with a top rail and a top sash with a bottom rail, said lock iNcluding a catch means adapted to be affixed to the bottom rail of said top sash, a two-part latch means for selective engagement with said catch means, a mounting base for the latch means adapted to be affixed to the top rail of said bottom sash, said latch means when in locked position lying generally horizontal in a plane generally normal to the planes of the upper and lower sashes and including a first part movably mounted on said base for pivotal movement, a first pin and an elongate slot one on said base and the other on said first part defining an axis extending parallel and transversely to the base to enable the first part to rotate into and out of engagement with the catch means in a plane normal to said base and to enable generally horizontal movement to draw the sashes together after initial engagement between the catch means and latch means, and a second latch part pivotally mounted on said base and having a second pin, an elongate generally vertical cam surface on said first part engaged by said second pin whereby rotation of said second part in a plane normal to said base causes movement of the second pin along the cam surface to cause horizontal movement of the first part.

Claim 10

The lock of claim 7 wherein said cam surface is defined by an angularly related portion of said slot.

Claim 11

The lock of claim 8 wherein said first pin is on said base and the second latch part is pivoted to said first pin.

Claim 12

The lock of claim 7 including means defining an upwardly facing abutment surface on said base and a downwardly facing abutment surface on the first part of said latch means, said surfaces being disposed between said axis and the point of engagement of said first part and said catch means, said surfaces being in abutment when said sashes are locked together whereby said abutting surfaces, said vertically fixed axis, and said catch means all cooperate to provide a three point block against movement of the top sash downwardly relative to the bottom sash.