Flush lock for casement window having a low-profile lock handle and method of operating the same
A flush mount or low-profile actuating window lock for casement windows having a casing with an upper housing and a lower housing, and a detent mechanism housing extending from the bottom surface of the upper housing, incorporating a sleeve, a plunger, a ratchet, and a spring of a detent mechanism. The detent mechanism provides a push-push activation for latching and unlatching a lever, where the lever is flush mounted when the window lock is in a locked position. Upon activation for unlocking, the lever is pressed below the top surface of the casing housing, and the detent mechanism pushes the lever to a “popped” or “open” position for grasping and rotating by a user. Upon activation for locking, the lever is returned to the initial position and pressed below the top surface of the casing housing where the detent mechanism receives the lever and returns it to a flush mounted position.
1 . A flush lock for a casement window, said flush lock comprising:
a handle or a lever arm;
a casing including:
an upper housing having a bottom surface, and a lower housing having first and second sidewalls; and
a detent mechanism housing extending from said bottom surface of said upper housing;
said lower housing including an elongated aperture or slot to accommodate a full range of motion of said handle or said lever arm, said first sidewall or said second sidewall having a guide tracks to confine movement of a fork component or an actuator component;
said fork component or said actuator component slidable in a longitudinal direction parallel with said elongated aperture or slot of said lower housing, is configured to engage a lock bar, and has a body configured for slidably engaging said guide tracks, said fork component or said actuator component including a formed lifter guide track for slidably receiving a lifter, such that said lifter is slidably engaged to move in a direction perpendicular to said longitudinal direction, upwards towards said handle or said lever arm; and
a detent mechanism forming a push-push activation of said handle or said lever arm, said detent mechanism including a sleeve, a plunger, a ratchet, a spring, and a cap, said detent mechanism housed within said detent mechanism housing.
2 . The flush lock of claim 1 , wherein said sleeve slidably interacts with said plunger, said sleeve being a shell having an internal cavity, and internal segments extending axially along a center axis of said sleeve and radially inwards.
3 . The flush lock of claim 2 , wherein said internal segments of said sleeve are separated by gaps, and said internal segments extend axially less than a full length of said sleeve.
4 . The flush lock of claim 3 , wherein said internal segments comprise a first set of segments and a second set of segments, wherein said first set of segments are longer in an axial direction along the center axis of the sleeve than said second set of segments.
5 . The flush lock of claim 3 , wherein said plunger is configured to be received by said internal cavity of said sleeve, said plunger having fixed guides extending radially outwards about a base of said plunger, said fixed guides slidably interact with said gaps of said sleeve during said push-push activation.
6 . The flush lock of claim 1 , wherein said plunger includes a bottom or base portion having saw-toothed teeth protruding beyond said bottom or base portion, said saw-toothed teeth configured to form a camming action with said ratchet, wherein upon activation of said plunger, said camming action rotates said plunger.
7 . The flush lock of claim 6 , wherein said plunger includes two internal cylindrical cavities, a first cavity having a smaller cavity diameter than a larger second cavity, wherein together, said first and second cavities form an internal shelf structure.
8 . The flush lock of claim 2 , wherein said sleeve forms a polygon shape at least on an outside surface.
9 . The flush lock of claim 6 , wherein said ratchet includes a base portion and a cylindrical stem extending from said base portion, said base portion having an outer diameter larger than an outer diameter of said cylindrical stem, and axially directed keys extending radially outwards from a bottom to a top surface of said base portion, and each including a radially inward segment at said top surface of said base portion-top, said radially inward segment extending to an outer surface of cylindrical stem.
10 . The flush lock of claim 9 , wherein said axially directed keys of said ratchet include inclined surfaces on ends of said keys that are angled in an axial direction towards a top surface of each corresponding radially inward segment of said ratchet, such that said inclined surfaces form said camming action; when placed in contact with said saw-toothed teeth of said plunger.
11 . The flush lock of claim 9 , wherein a first cavity of said plunger receives said cylindrical stem of said ratchet.
12 . The flush lock of claim 1 , wherein said spring provides a resilient force to said ratchet and plunger at one end, and to the cap at an opposite end, said cap sealing said spring within said detent mechanism housing.
13 . The flush lock of claim 1 , wherein horizontal movement of said fork component or said actuator component is controlled by one of said guide tracks of said first sidewall or said second sidewall of said lower housing, and wherein said first sidewall or said second sidewall of said lower housing includes a guide track for receiving an extension of a lifter cooperating with said fork component or said actuator component and having at least an angled section and a partially horizontal section.
14 . A flush lock for a casement window, said flush lock comprising:
a lever arm;
a casing including:
an upper housing; and
a lower housing including an elongated aperture or slot to accommodate a full range of motion of said lever arm, sidewalls having guide tracks to confine movement of a fork component or an actuator component, and a detent mechanism housing extending from a bottom surface of said lower housing, said detent mechanism housing secured at a bottom end by a cap;
a restrictor arm pivotally attached at one end to said lever arm; and pivotally attached at an opposite end to said lower housing; and
a detent mechanism forming a push-push activation of said lever arm, said detent mechanism including:
a sleeve being substantially a shell having an internal cavity and internal segments extending axially along a center axis of said sleeve, said internal segments extending radially inwards and being separated by gaps, and extending axially less than a full length of said sleeve, each of said internal segments having a top surface;
a plunger, configured to be received by said internal cavity of said sleeve, said plunger includes fixed guides extending circumferentially radially outwards about a base of said plunger, said fixed guides slidably interact with said gaps of said sleeve during activation, said plunger includes a bottom or base portion having teeth protruding beyond said bottom or base portion, said teeth configured to form a camming action with a ratchet, rotating said plunger;
said ratchet having a base portion and a cylindrical stem extending from said base portion, said base portion having an outer diameter larger than an outer diameter of said cylindrical stem, and axially directed keys extending radially outwards from a bottom to a top surface of said base portion, said axially directed keys each having a radially inward segment at said top surface of said base portion, said radially inward segments extending to an outer surface of cylindrical stem, wherein each of said axially directed keys includes an inclined surfaces that is angled axially upwards along a side of said corresponding one of said axially directed keys to a top surface of said radially inward segment, such that said inclined surfaces form a camming action when placed in contact with said teeth of said plunger, thereby rotating said plunger; and
a spring providing a resilient force to said ratchet and said plunger at one end; and to said cap at an opposite end, said cap sealing said spring within said detent mechanism housing.
15 . The flush lock of claim 14 , further comprising an escutcheon attached to said upper housing of said casing, said escutcheon having a top surface and a slot or aperture for receiving said lever arm.
16 . The flush lock of claim 15 , wherein said casing has a depth for receiving said lever arm below said top surface of said escutcheon, and said detent mechanism allowing for said lever to be pushed below said top surface of said escutcheon.
17 . The flush lock of claim 15 , wherein said detent mechanism provides a structural block for a vertically upward extension of said plunger, such that upon an open activation, said lever arm is raised above said escutcheon top surface to enable grasping by a user.
18 . A method of unlocking a flush lock in combination with a casement window, said method comprising:
providing said flush lock having a lever arm for actuating a fork component associated with a locking tie bar of said casement window, and a detent mechanism configured for push-push activation, said detent mechanism including a sleeve, a plunger, a ratchet, a spring, and a cap, said detent mechanism housed within a detent mechanism housing of a casing of said flush lock;
pushing said lever arm from an initial position flush with a top surface of an escutcheon that forms part of a top surface of said casing towards said casing and below said top surface of said escutcheon to release said lever arm, wherein said plunger and said ratchet are biased by said spring in a direction towards said lever arm, and wherein the pushing of said lever arm comprises pushing said lever arm in a direction towards said casing and comprises lowering said plunger against said ratchet' such that said plunger rotates relative to said sleeve in a camming action;
releasing said lever arm, such that said detent mechanism acts on said lever arm to extend said lever arm above said top surface of said escutcheon, exposing said lever arm in an open position away from said escutcheon top surface for grasping by a user; and
rotating said lever arm to an unlocked position to unlock said casement window.
19 . The method of claim 18 , wherein:
said sleeve includes an internal cavity and internal segments extending axially along a center axis of said sleeve, said internal segments extending radially inwards and being separated by gaps, and extending axially less than a full length of said sleeve, and said internal segments including a first set of internal segments axially longer than a second set of internal segments, each of said internal segments having a top surface; and
wherein said plunger includes fixed guides extending circumferentially radially outwards about a base of said plunger;
and wherein said method further comprises:
slidably interacting said fixed guides with said gaps of said sleeve during activation, said plunger having a bottom or base portion having teeth protruding beyond said bottom or base portion, said teeth configured to form the camming action with said ratchet, thereby rotating said plunger; and
situating said plunger fixed guides on a top surface of said first set of internal segments, such that said plunger raises said lever arm above said top surface of said escutcheon.
20 . A method of locking a flush lock in combination with a casement window, said method comprising:
providing said flush lock having a lever arm for actuating a fork component associated with a locking tie bar of said casement window, and a detent mechanism configured for push-push activation, said detent mechanism including a sleeve, a plunger, a ratchet, a spring, and a cap, said detent mechanism housed within a detent mechanism housing of a casing of said flush lock,
wherein said sleeve includes an internal cavity and internal segments extending axially along a center axis of said sleeve, said internal segments extending radially inwards and being separated by gaps extending axially less than a full length of said sleeve, and said internal segments including a first set of internal segments axially longer than a second set of internal segments, each of said internal segments having a top surface, and
wherein said plunger includes fixed guides extending circumferentially radially outwards about a base portion of said plunger, said base portion of said plunger further having teeth protruding beyond said base portion and configured to form a camming action with said ratchet, thereby rotating said plunger;
rotating said lever arm towards said flush lock;
slidably interacting said fixed guides of said plunger with said gaps of said sleeve;
pushing said lever arm from an initial position above a top surface of an escutcheon that forms part of a top surface of said casing towards said casing and below said a-top surface of said escutcheon; and
releasing said lever arm, such that said detent mechanism acts on said lever arm to align a top surface of said lever arm with said top surface of said escutcheon, such that said top surface of said lever arm is flush with said top surface of said escutcheon,
wherein said fixed guides of said plunger are situated on a top surface of said first set of internal segments, such that said plunger raises said lever arm to a level of said top surface of said escutcheon.