초록 ▼

A latch has a pop-up knob that provides a handle for pulling on a door when the knob is extended. The door can be closed with the knob either up or down. With the knob up, the latch pawl can be disengaged from a keeper attached to the door frame by pulling the door open. With the knob down, the latc

A latch has a pop-up knob that provides a handle for pulling on a door when the knob is extended. The door can be closed with the knob either up or down. With the knob up, the latch pawl can be disengaged from a keeper attached to the door frame by pulling the door open. With the knob down, the latch pawl remains in an extended position behind the keeper and the door cannot be pulled open. The knob can be selectively retained in the down position, and placing the knob in the down position results in the rotational movement of the latch pawl being blocked.

대표청구항 ▼

The invention claimed is: 1. A latch assembly for releasably securing a first member in a closed position relative to a second member, the second member having a keeper in a fixed positional relationship therewith, the latch assembly comprising: an upper housing adapted for mounting to the first me

The invention claimed is: 1. A latch assembly for releasably securing a first member in a closed position relative to a second member, the second member having a keeper in a fixed positional relationship therewith, the latch assembly comprising: an upper housing adapted for mounting to the first member; a lower housing attached to said upper housing and having a cavity; a pawl supported by said cavity, said pawl being capable of pivotal and rectilinear motion relative to said cavity, and said pawl being rectilinearly movable between extended and retracted positions; a knob supported by said upper housing for rectilinear movement between retracted and extended positions, said pawl being rotationally movable between a first angular position and a second angular position when said knob in said extended position of said knob; means for selectively retaining said knob in said retracted position of said knob; and means to block rotational movement of said pawl when said knob is in said retracted position of said knob, wherein said means to block rotational movement of said pawl blocks rotational movement of said pawl toward said second angular position such that said pawl cannot move out of engagement with the keeper when said knob is in said retracted position of said knob. 2. A latch assembly according to claim 1, wherein the first member can be moved to the closed position with said knob in said retracted position, and the first member can be moved to the closed position with said knob in said extended position, when the latch assembly is installed to the first member such that in either case said pawl moves to said extended position of said pawl behind the keeper with said pawl in said first angular position. 3. A latch assembly according to claim 2, wherein said upper housing has a bore and a plurality of raised ribs, each of said raised ribs having an end, and wherein said means for selectively retaining said knob in said retracted position of said knob comprises: a shaft positioned at least in part within said bore of said upper housing, said knob being attached to said shaft; a ratchet having a central opening and a plurality of lugs distributed about the periphery thereof, said shaft passing through said central opening of said ratchet; and a spring biasing said shaft and said knob toward said extended position of said knob, wherein each of said plurality of lugs of said ratchet engages said end of a respective one of said plurality of raised ribs to retain said knob in said retracted position of said knob. 4. A latch assembly according to claim 3, wherein the latch assembly further comprises a plurality of grooves formed in said bore, each of said plurality of grooves being positioned intermediate a pair of said plurality of raised ribs, wherein said ratchet rotates incrementally responsive at least in part to said knob being depressed further into said bore of said upper housing relative to said retracted position of said knob such that each of said plurality of lugs of said ratchet is placed into registry with a respective one of said plurality of grooves to thereby allow said knob to move from said retracted position of said knob to said extended position of said knob. 5. A latch assembly according to claim 4, wherein said plurality of lugs of said ratchet have upper cam surfaces and said knob has a plurality of sloping guide surfaces that engage said upper cam surfaces of said plurality of lugs to thereby impart rotational motion to said ratchet due to rectilinear movement of said knob. 6. A latch assembly according to claim 5, wherein the latch assembly further comprises: a guide supported for rectilinear movement by said cavity of said lower housing, said guide being rectilinearly movable between extended and retracted positions corresponding to said extended and retracted positions of said pawl, respectively; and biasing means for urging said guide toward said extended position thereof. 7. A latch assembly according to claim 6, wherein said pawl has a pair of cylindrical projections that project from either side of said pawl, and said cavity of said lower housing is provided with a pair of elongated grooves on opposite sides of said cavity of said lower housing, and each of said cylindrical projections is received in a respective one of said elongated grooves to thereby allow said pawl to move pivotally while simultaneously being capable of rectilinear movement relative to said cavity of said lower housing. 8. A latch assembly according to claim 7, wherein said means to block the rotational movement of said pawl when said knob is in said retracted position of said knob comprises: a pair of resilient legs each of which is attached at one end to said guide, each of said pair of resilient legs having a free end; a pair of blocks having beveled surfaces, each of said pair of blocks being provided at said free end of a respective one of said pair of resilient legs; and a pair of extension arms attached to said pawl and extending on either side of said guide, wherein when said knob is moved to said retracted position thereof, said shaft engages said beveled surfaces and moves said blocks apart to thereby position said blocks over said extension arms and thus block rotation of said pawl from said first angular position to said second angular position when said pawl is in said extended position thereof. 9. A latch assembly according to claim 1, wherein the latch assembly further comprises: a guide supported for rectilinear movement by said cavity of said lower housing, said guide being rectilinearly movable between extended and retracted positions corresponding to said extended and retracted positions of said pawl, respectively; and biasing means for urging said guide toward said extended position thereof. 10. A latch assembly according to claim 9, wherein said pawl has a pair of cylindrical projections that project from either side of said pawl, and said cavity of said lower housing is provided with a pair of elongated grooves on opposite sides of said cavity of said lower housing, and each of said cylindrical projections is received in a respective one of said elongated grooves to thereby allow said pawl to move pivotally while simultaneously being capable of rectilinear movement relative to said cavity of said lower housing. 11. A latch assembly according to claim 10, wherein said upper housing has a bore and wherein said means to block the rotational movement of said pawl when said knob is in said retracted position of said knob comprises: a shaft positioned at least in part within said bore of said upper housing, said knob being attached to said shaft; a pair of resilient legs each of which is attached at one end to said guide, each of said pair of resilient legs having a free end; a pair of blocks having beveled surfaces, each of said pair of blocks being provided at said free end of a respective one of said pair of resilient legs; and a pair of extension arms attached to said pawl and extending on either side of said guide, wherein when said knob is moved to said retracted position thereof, said shaft engages said beveled surfaces and moves said blocks apart to thereby position said blocks over said extension arms and thus block rotation of said pawl from said first angular position to said second angular position when said pawl is in said extended position thereof. 12. A method of operating a latch assembly, the method comprising the steps of: providing a latch assembly comprising: a housing; and a pawl supported for both pivotal movement relative to the housing and rectilinear movement relative to the housing; mounting the latch assembly to a first member; and locking the latch assembly by a user selectively blocking pivotal movement of the pawl while allowing rectilinear movement of the pawl such that the first member can be moved to a closed position relative to a second member even when pivotal movement of the pawl is blocked, but the first member cannot be moved from the closed position relative to the second member to an open position relative to the second member when pivotal movement of the pawl is blocked. 13. A latch assembly for releasably securing a first member in a closed position relative to a second member, the second member having a keeper in a fixed positional relationship therewith, the latch assembly comprising: a housing adapted for mounting to a closure member; and a pawl supported for both pivotal movement relative to said housing and rectilinear movement relative to said housing, wherein the latch assembly is operable between a locked configuration and an unlocked configuration and wherein said pawl is prevented from pivotal movement but is capable of rectilinear movement when the latch assembly is in said locked configuration, and said pawl is freed to move pivotally when said latch assembly is in said unlocked configuration such that said pawl can be moved out of engagement with the keeper. 14. A latch assembly according to claim 13, further comprising: a knob supported by said housing for rectilinear movement between an extended position and a retracted position; and at least one blocking member movable in response to movement of said knob, wherein said blocking member essentially blocks pivotal movement of said pawl when said knob is in said retracted position. 15. A latch assembly according to claim 14, wherein said housing has a bore and wherein the latch assembly further comprises: a shaft positioned at least in part within said bore of said housing, said knob being attached to said shaft, wherein said blocking member is one of a pair of blocking members and each one of said pair of blocking members comprises a resilient leg that is attached at one end to a block having beveled surfaces, wherein said pawl is provided with a pair of extension arms, and wherein when said knob is moved to said retracted position thereof, said shaft engages said beveled surface of said block of each of said pair of blocking members and moves said block of each of said pair of blocking members to a position over a respective one of said extension arms in order to block rotation of said pawl from said first angular position to said second angular position when said pawl is in said extended position thereof. 16. A latch assembly according to claim 15, wherein said bore has a plurality of raised ribs, each of said raised ribs having an end, and wherein the latch assembly further comprises: a ratchet having a central opening and a plurality of lugs distributed about the periphery thereof, said shaft passing through said central opening of said ratchet; and a spring biasing said knob toward said extended position of said knob and said shaft toward a position corresponding to said extended position of said knob, wherein each of said plurality of lugs of said ratchet engages said end of a respective one of said plurality of raised ribs to retain said knob in said retracted position of said knob. 17. A latch assembly according to claim 16, wherein the latch assembly further comprises a plurality of grooves formed in said bore, each of said plurality of grooves being positioned intermediate a pair of said plurality of raised ribs, wherein said ratchet rotates incrementally responsive at least in part to said knob being depressed further into said bore of said housing relative to said retracted position of said knob such that each of said plurality of lugs of said ratchet is placed into registry with a respective one of said plurality of grooves to thereby allow said knob to move from said retracted position of said knob to said extended position of said knob. 18. A latch assembly according to claim 17, wherein said plurality of lugs of said ratchet have upper cam surfaces and said knob has a plurality of sloping guide surfaces that engage said upper cam surfaces of said plurality of lugs to thereby impart rotational motion to said ratchet due to rectilinear movement of said knob.