Fire door lock structure and latch assembly thereof

A fire door lock structure includes a stopper disposed at a door frame and a latch assembly disposed at a fire door, wherein the latch assembly comprises a lock base, a latch unit, a blocking member, a pair of male and female means and a linking set. The latch unit includes a latch bolt. The latch unit and the blocking member are swingably disposed at an accommodating slot of the lock base. The blocking member is fastened at the stopper by the pair of male and female means, wherein the male means comprises a fastener formed at the blocking member. In the locked state, the fastener of the male means can be fastened at the stopper to prevent the stopper from being unable to block the latch bolt caused by a deformed fire door or deformed door frame under a fire condition.

FIELD OF THE INVENTION

The present invention is generally relating to a fire door lock structure, wherein a fastener of a latch assembly disposed at a fire door is fastened at a stopper of a door frame to prevent the stopper from being unable to block a latch bolt of the latch assembly via deformed fire door or deformed door frame under a fire condition.

BACKGROUND OF THE INVENTION

Taiwan patent publication No. 568160 disclosed that a “structure of fireproof doors” is relevant to a fire door lock. Two latch bolts are disposed at an upper end and a lower end of a fire door separately, and the latch bolts can be blocked by two stoppers disposed at a door frame therefore forming a locked state. Usually, the blocked latch bolts departs from the stoppers and leads to an unlocked state via the actuation of a main lock. With reference toFIG. 1, a fire door lock comprises a stopper20disposed at a door frame10and a latch40disposed at a fire door30. A latch bolt41of the latch40can be blocked by the stopper20to prevent the fire door30from being opened therefore possessing burglarproof and fireproof functions. With reference toFIG. 2, the latch bolt41disposed at the fire door30merely blocks the stopper20disposed at the door frame10, once a fire occurred, the fire would burn and deform the door frame10or the fire door30. Accordingly, the stopper20cannot block the latch bolt41of the latch40disposed at deformed fire door30. Therefore, the fireproof function of the fire door30would be all lost.

SUMMARY

The primary object of the present invention is to provide a fire door lock structure comprising a stopper disposed at a door frame and a latch assembly disposed at a fire door, wherein the latch assembly comprises a lock base, a latch unit, a blocking member, a pair of male and female means and a linking set. The latch unit comprises a latch bolt. The latch unit and the blocking member are swingably disposed at an accommodating slot of the lock base. The blocking member is fastened at the stopper by the pair of male and female means, wherein the male means comprises a fastener formed at the blocking member. In the locked state, the fastener of the male means can be fastened at the stopper to prevent the stopper from being unable to block the latch bolt caused by a deformed fire door or deformed door frame under a fire condition.

Additionally, an accommodating space can be defined between the blocking member and the latch bolt, and the stopper can be fitted in the accommodating space. The stopper comprises a rear surface adjacent to the fire door and a front surface opposite to the rear surface. The female means comprises an accommodating portion formed at the rear surface and the fastener can be fastened into the accommodating portion.

DETAILED DESCRIPTION OF THE INVENTION

With reference toFIGS. 3,4and5, a fire door lock structure in accordance with a preferred embodiment of the present invention comprises a latch assembly100disposed at a fire door300and a stopper200disposed at a door frame400, wherein the latch assembly100can be fastened with the stopper200. The latch assembly100comprises a lock base110, a latch unit120, a blocking member130, a pair of male and female means A, B and a linking set140. The lock base110comprises a bottom portion111, a first lateral portion112, a second lateral portion113opposite to the first lateral portion112, a top portion115and an accommodating slot114defined by the bottom portion111, the first lateral portion112and the second lateral portion113, wherein the bottom portion111of the lock base110is disposed at the fire door300. The latch unit120comprises a latch bolt121having a blocking surface121aand a limiting surface121bin communication with the blocking surface121a. The latch bolt121can be blocked by the stopper200. The latch bolt121and the blocking member130are swingably disposed at the accommodating slot114of the lock base110. The blocking member130comprises a main body131, at least one lateral body132protruded to the main body131, a contacting portion133and a restricted slot134positioned beneath the main body131. The blocking member130is fastened at the stopper200by the pair of male and female means A, B. In this embodiment, the stopper200of the door frame400comprises a rear surface220adjacent to the fire door300and a front surface210opposite to the rear surface210, the female means B comprises an accommodating portion B1formed at the rear surface210. The male means A comprises a fastener A1formed at the blocking member130, the fastener A1can be fastened at the accommodating portion B1, wherein the fastener A1of the male means A and the contacting portion133are formed at the lateral body132.

The quantity of mentioned lateral body132and the male means A are two separately. A length of the main body131is smaller than that of the lateral body132to lead an incomplete connection between the main body131and the lateral body132therefore forming the restricted slot134. The fastener A1is protruded to the top portion115of the lock base110. The contacting portion133can be a cantilever. The cantilever is protruded to the lateral body132and faces toward the second lateral portion113. When the latch bolt121projects from the accommodating slot114of the lock base110, an accommodating space S can be defined between the blocking member130and the latch bolt121, and the stopper200can be fitted inside the accommodating space S to enable the fastener A1to fasten with the stopper200. In this embodiment, the latch unit120further comprises an elastic member125. The elastic member125is disposed at the accommodating slot114of the lock base110and comprises a first end125a. Besides, the elastic member125can be a torsion spring. The first end125ais coupled to the contacting portion133of the blocking member130. In this embodiment, a recess133ais recessed into the cantilever of the blocking member130, and the first end125ais fastened to the recess133a. The blocking member130is actuated by elasticity of the elastic member125to enable the fastener A1to fasten with the stopper200. The linking set140is pivotally connected with the latch unit120and disposed at the accommodating slot114.

With reference toFIGS. 3,4and5, the latch unit120further comprises a combining pin122, two actuating boards123and a penetrating bolt124. The penetrating bolt124is penetrated through the actuating boards123and the latch bolt121to form a mutual link between the actuating boards123and the latch bolt121. In addition, the combining pin122comprises two end portions122a, the first lateral portion112of the lock base110comprises a first sliding slot112a, and the second lateral portion113of the lock base110comprises a second sliding slot113a. Each of the end portions122ais limited within the first sliding slot112aand the second sliding slot113aseparately. The linking set140comprises a first linking member141and a second linking member142pivotally connected with the first linking member141. The combining pin122is pivotally connected with the first linking member141of the linking set140and the actuating boards123of the latch unit120. When the combining pin122is actuated by the first linking member141of the linking set140, the latch bolt121can be driven by the combining pin122simultaneously. Therefore, the latch bolt121may project from the accommodating slot114of the lock base110.

Further, the latch assembly100of the fire door lock structure further comprises a fixing rod150having two terminals151, and the fixing rod150is pivotally connected with the lateral body132of the blocking member130and the first linking member141of the linking set140. Each of the terminals151is coupled to the first lateral portion112and the second lateral portion113respectively, and the blocking member130is swingable via the fixing rod150serving as a shaft. The elastic member125further comprises a second end125band a barrel portion125cdisposed around the fixing rod150, and the second end125bis coupled to the combining pin122of the latch unit120. Additionally, the latch assembly100of the fire door lock structure further comprises a linking rod160and a pivoting rod170, and the linking rod160is pivotally connected with the second linking member142via the pivoting rod170. The first lateral portion112and the second lateral portion113of the lock base110comprise a longitudinal sliding slot116respectively, the pivoting rod170comprises two tips171, and each of the tips171is slidably disposed at each of the longitudinal sliding slots116.

With reference toFIGS. 5 and 6,FIG. 5andFIG. 6illustrate a normally locked state of the fire door300, wherein the bottom portion111of the lock base111is disposed at the fire door300. The latch bolt121of the latch unit120is protruded to the lock base110, and the stopper200is located between the latch bolt121and the blocking member130. In this embodiment, the blocking surface121ais utilized for contacting against the front surface210of the stopper200. Therefore, the latch bolt121can be blocked by the stopper200to prevent the fire door300from being opened. Firmly fastened relationship between the stopper200and the latch bolt121may prevent the stopper200from being unable to block the latch bolt121via deformed fire door300or deformed door frame400under a fire condition. Referring toFIG. 7, owing to deformed fire door300, the relative position between the latch bolt121and the front surface210of the stopper200might be changed, but the fastener A1is still fastened at the accommodating portion B1. Accordingly, the locked state of the fire door300can be remained, and the flame will be restrained by the fire door300under fire condition to achieve a fireproof function.

Furthermore, the accommodating portion221is formed inside the stopper200. When the fastener A1is fastened at the accommodating portion B1, a big contact area between the blocking member130and the accommodating portion B1is generated to increase overall friction force to avoid the fastener A1to be departed from the stopper200. Therefore, the fire door300is steadily maintained in the locked state.

When the latch bolt121projects from the lock base110, the combining pin122of the latch unit120is positioned far from the contacting portion133of the blocking member130. Besides, for the reason that the contacting portion133of the blocking member130is pressed by the first end125aof the elastic member125and the second end125bof the elastic member125is coupled by the combining pin122of the latch unit120, the elastic member125can be formed into a stretched state. The stretched elastic member125may generate an elasticity to pull the blocking member130back to the direction of the latch bolt121. Accordingly, the fastener A1can be firmly fastened at the accommodating portion B1to enable the fire door300to be firmly maintained in the locked state.

With reference toFIG. 8,FIG. 8illustrates a normally unlocked state for an unfastened condition between the latch assembly100of fire door lock and the stopper200. Referring toFIGS. 8,9and10, the pivoting rod170can be driven by the linking rod160to move upwardly along each of the longitudinal sliding slots116, in the meantime, the second linking member142of the linking set140is driven by the pivoting rod170to pivot toward the bottom portion111of the lock base110. Besides, the first linking member141is pivotally connected with the second linking member142to enable the first linking member141to swing via the fixing rod150serving as a shaft. Due to the interconnection between the combining pin122, the first linking member141of the linking set140and the actuating boards123of the latch unit120and the movement limitation of the combining pin122within the first sliding slot112aand the second sliding slot113a, when the combining pin122is actuated by the first linking member141, the combining pin122moves outwardly along the first sliding slot112aand the second sliding slot113a, and the actuating boards123can be actuated by the combining pin122at the same time. Therefore, the latch bolt121can be actuated by the actuating boards123to retract into the lock base110.

With the outward movement of the combining pin122along with the first sliding slot112aand the second slot113a, the blocking member130cannot be limited by the combining pin122. The elasticity of the elastic member125enables the blocking member130to swing toward the latch bolt121via the fixing rod150serving as a shaft. Furthermore, the latch bolt121is fitted into the restricted slot134of the blocking member130, and the main body131of the blocking member130contacts against the limiting surface121bof the latch bolt121. In this embodiment, the limiting surface121bcan be blocked by the blocking member130to prevent the latch bolt121from projection. When the state of the fire door300is changed from the unlocked state to the locked state, the blocking member130props against the stopper200to enable the latch bolt121to depart from the restricted slot134of the blocking member130. Eventually, the latch bolt121is protruded to the lock base110, and the stopper200is located between the latch bolt121and the blocking member130to form a normally locked state.

In this invention, when the fire door lock structure is situated in the locked state, the fastener A1can be firmly fastened at the accommodating portion B1. When the fire door300or the door frame400are deformed via burning under a fire condition, the locked state of the fire door lock structure can be still maintained to prevent the fire door300from being opened.

While this invention has been particularly illustrated and described in detail with respect to the preferred embodiments thereof, it will be clearly understood by those skilled in the art that is not limited to the specific features shown and described and various modifications and changes in form and details may be made without departing from the spirit and scope of this invention.