Sash lock

Claim 2

A sash lock for double hung window sash with upper and lower sash comprising a strike member attachable to the meeting rail of the upper sash and having a bridge section overlying and spaced from an upstanding locking lug, and a rotatable locking lever pivotally attachable to the meeting rail of the lower sash, said locking lever having a smooth continuous and non-grooved upper surface with an inclined peripheral edge to progressively wedge under said bridge section as the locking lever is pivoted toward locked position, and a downwardly depending flange on said locking lever and extending downwardly to the plane of said locking lug for engaging behind said locking lug during rotation of the locking lever to locked position.

Claim 3

A sash lock as defined in claim 1 wherein said depending flange is curved and shaped to be progressively at a shorter distance from the pivot point for the locking lever whereby said sash are drawn together as the locking lever is rotated to locked position.

Claim 4

A sash lock as defined in claim 2 including means to yieldably hold said locking lever in either locked or unlocked position.

Claim 5

A sash lock for double hung window sash including a base member, a locking lever pivotally mounted on said base member by means of a pivot pin, said locking lever having a pair of cam surfaces, one of said cam surfaces being defined by a peripheral section of a smooth continuous top surface of the locking lever with the peripheral section being arcuate and upwardly sloped from a leading edge thereof, the other of said cam surfaces being defined by a depending arcuate flange at the perimeter of said locking lever which starts at the same location as said leading edge and along its length gradually approaches said pivot pin, a keeper member having a lug and an overlying bridge section whereby rotation of said locking lever toward locked position causes the other cam surface to move behind said lug and draw the keeper member toward the base member while said one cam surface moves beneath the bridge section and brings the keeper member and base member to a predetermined orientation lengthwise of the pivot pin.

Claim 6

A sash lock for double hung window sash including a base member, a locking lever pivotally mounted on said base member by means of a pivot pin, said locking lever having a pair of cam surfaces, one of said cam surfaces being defined by a peripheral section of a smooth continuous top surface of the locking lever with the peripheral section being arcuate and upwardly sloped from a leading edge thereof, the other of said cam surfaces being defined by a depending arcuate flange at the perimeter of said locking lever which starts at the same location as said leading edge and along its length gradually approaches said pivot pin, a keeper member having a lug and an overlying bridge section whereby rotation of said locking lever toward locked position causes the other cam surface to move behind said lug and draw the keeper member toward the base member while said one cam surface moves beneath the bridge section and brings the keeper member and base member to a predetermined orientation lengthwise of the pivot pin.

Claim 7

A sash lock as defined in claim 4 wherein said parts are of plastic.

Claim 8

A sash lock as defined in claim 5 wherein said locking lever and keeper member are each formed as a unitary plastic member.

Claim 9

A sash lock as defined in claim 5 wherein said pivot pin has a pair of opposite flat surfaces with spring means mounted in the base member to coact therewith and hold the locking lever in either locked or unlocked position.

Claim 10

A sash lock as defined in claim 5 wherein a pair of integral spaced pins extend upwardly from the base member to limit the arc of movement of the locking lever.