Patent Publication Number: US-2022235575-A1

Title: Door lock with reinforced fireproof function

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a door lock and, more particularly, to a door lock mounted in a hole of a door and capable of delaying spread of fire through the hole during a fire that melt the door lock. 
     To install a lock on a door for keeping the door in a closed state, the door is drilled to form a through-hole extending from a side of the door through the other side of the door. A door lock generally includes a lock body and a latch device operatively connected to the lock body. The door lock further includes an inner operating unit and an outer operating unit. After the door lock, the latch device, and the inner and outer operating units are mounted on the door, the through-hole of the door is closed. 
     In consideration of the processing and costs, the components of door locks are generally made by casting or pressing. In either way, metals (such as zinc, copper, aluminum, magnesium, lead, or tin) of a low melting point or alloys thereof are used to permit easy heating to a fluidic form. As an example, the door locks are generally made of zinc alloys having a melting point of about 385° C. When a fire occurs, the lock body melts quickly under the high temperature at the fire site, and the door lock cannot seal the through-hole of the door when the lock body melts even if the door is fireproof. Thus, fire can spread from a side (such as the outer side) to the other side (such as the inner side) of the door. As a result, traditional door locks provide a poor effect in postponing spread of fire. 
     BRIEF SUMMARY OF THE INVENTION 
     In view of the above drawbacks, the present invention provides a door lock with reinforced fireproof function. The door lock comprises: 
     an inner chassis made of ferrous material or stainless steel, wherein the inner chassis includes a first groove formed on an outer periphery thereof; 
     an inner mounting seat coupled to the inner chassis and including a second groove aligned with the first groove in a direction parallel to a longitudinal axis of the inner chassis; 
     an outer chassis made of ferrous material or stainless steel; 
     an outer mounting seat coupled to the outer chassis, wherein the outer mounting seat includes an opening aligned with the first and second grooves in the direction parallel to the longitudinal axis of the inner chassis, wherein the outer mounting seat is coupled to the inner mounting seat, wherein the inner and outer mounting seats are configured to be received in a first through-hole of a door, and wherein the inner and outer chassis are at inner and outer sides of the door; 
     a retractor movably received between the inner and mounting seats, wherein the retractor includes an engaging portion received in the opening, wherein the engaging portion is operatively connected to a latch device; 
     an inner fixing member made of ferrous material or stainless steel and coupled to the inner chassis, wherein the inner fixing member is configured to be fixed to the inner side of the door; 
     an outer fixing member made of ferrous material or stainless steel and coupled to the outer chassis, wherein the outer fixing member is configured to be fixed to the outer side of the door and closes the first through-hole; 
     an inner operating unit coupled to the inner fixing member and including an inner handle operatively connected to the retractor; and 
     an outer operating unit coupled to the outer fixing member and including an outer handle operatively connected to the retractor. 
     After the door lock according to the present invention is mounted to the door, even if many components melt under the high temperature (such as below 1300° C.) of the fire site, the inner and outer chassis together with the inner and outer fixing members can still close the first through-hole to make the flame or smoke difficult to spread from a side to the other side of the door, slowing down the spread of fire. 
     In an example, the door lock further comprises an outer spindle including an outer driving lug. The outer chassis includes a first outer end face and a first outer axial hole extending from the first outer end face. The outer chassis further includes an outer chamber extending from another end face of the outer chassis to the second inner axial hole. The outer spindle is pivotably received in the first outer axial hole. The outer driving lug is operatively connected to the retractor. The outer mounting seat includes a second outer end face connected to the first outer end face of the outer chassis. An outer torsion spring is received in the outer chamber and configured to bias the outer spindle. An inner spindle includes an inner driving lug. The inner chassis includes a first inner end face and a first inner axial hole extending from the first inner end face. The inner chassis further includes an inner chamber extending from another end face of the inner chassis to the first inner axial hole. The inner spindle is pivotably received in the first inner axial hole. The inner driving lug is operatively connected to the retractor. The inner mounting seat includes a second inner end face connected to the first inner end face of the inner chassis. An inner torsion spring is received in the inner chamber and configured to bias the inner spindle. 
     In an example, the door lock further comprises a locking control device received in the inner spindle. The locking control device includes a control arm movable along a longitudinal axis of the inner spindle. The first outer axial hole includes an inner periphery having a limiting groove. The outer mounting seat further includes an outer movement groove extending from the second outer end face along a longitudinal axis of the first outer axial hole. The outer spindle and the control arm are coupled to pivot jointly. When the control arm is in the limiting groove, the outer handle is prevented from pivoting. When the control arm is in the outer movement groove, the outer handle is permitted to pivot. 
     In an example, the door lock further comprises two mounting posts, two bolts, and a cover. The two mounting posts are connected to the outer fixing member and face the inner fixing member. The two mounting posts are configured to be received in two connecting holes in the door. The two bolts abut the inner fixing member and engage with the two mounting posts. The cover is made of ferrous material or stainless material. The cover is coupled to and abuts a face of the inner fixing member. The cover includes an insertion portion that closes the first groove. 
     In an example, the inner mounting seat and the outer mounting seat are made of a zinc alloy or an aluminum alloy. 
     In an example, the door lock further comprises a cover made of ferrous material or stainless material. The cover is coupled to and abuts a face of the inner fixing member. The cover includes an insertion portion that closes the first groove. 
     The present invention will become clearer in light of the following detailed description of illustrative embodiments of this invention described in connection with the drawings. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an exploded, perspective view of a door lock of an embodiment according to the present invention. 
         FIG. 2  is an exploded, perspective view of a lock body of the door lock of  FIG. 1 . 
         FIG. 3  is a diagrammatic view illustrating installation of the door lock of  FIG. 1  on a door. 
         FIG. 4  sis a perspective view of the door lock of  FIG. 1  after assembly. 
         FIG. 5  is a cross sectional view taken along section line  5 - 5  of  FIG. 4 . 
         FIG. 6  is a cross sectional view taken along section line  6 - 6  of  FIG. 5 . 
         FIG. 7  is a cross sectional view taken along section line  7 - 7  of  FIG. 4 . 
         FIG. 8  is a cross sectional view taken along section line  8 - 8  of  FIG. 5 . 
         FIG. 9  is a diagrammatic cross sectional view of the door lock after melting under high temperature. 
     
    
    
     All figures are drawn for ease of explanation of the basic teachings of the present invention only; the extensions of the figures with respect to number, position, relationship, and dimensions of the parts to form the embodiments will be explained or will be within the skill of the art after the following teachings of the present invention have been read and understood. Further, the exact dimensions and dimensional proportions to conform to specific force, weight, strength, and similar requirements will likewise be within the skill of the art after the following teachings of the present invention have been read and understood. 
     Where used in the various figures of the drawings, the same numerals designate the same or similar parts. Furthermore, when the terms “first”, “second”, “inner”, “outer”, “side”, “end”, “portion”, “longitudinal”, “axial”, “radial”, “circumferential”, “annular”, and similar terms are used herein, it should be understood that these terms have reference only to the structure shown in the drawings as it would appear to a person viewing the drawings and are utilized only to facilitate describing the invention. 
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention relates to a door lock with reinforced fireproof function. Specifically, when some components of the door lock melt in a high-temperature environment caused by a fire, the flame is not apt to spread from a side of the door through gaps between the door and the door lock to the other side of the door. The door lock  11  is mounted on a door  211  ( FIGS. 5 and 7 ). With reference to  FIG. 3 , the door  211  includes an inner side  213 , an outer side  215 , and an end face  216  extending between the inner side  213  and the outer side  215 . The door  211  further includes a first through-hole  218  extending from the inner side  213  through the outer side  215 . The door  211  further includes two connecting holes  232  around the through-hole  218 . The door  211  further includes a second through-hole  230  extending from the end face  218  to the first through-hole  218 . 
     With reference to  FIGS. 1-8 , the door lock  11  comprises a lock body  21  having an inner portion  231  and an outer portion  275  coupled to the inner portion  231 . The inner portion  231  includes an inner chassis  233  and an inner mounting seat  253  coupled to the inner chassis  233 . The inner chassis  233  is made of ferrous material having a melting point higher than 1300° C. or stainless steel material having a melting point of about 1400° C. In an example, the inner chassis  233  is made of iron powders (having a melting point of about 1538° C.) formed by powder metallurgy, and the inner mounting seat  253  is made of a zinc alloy (having a melting point of about 385° C.) or an aluminum alloy (having a melting point of about 660° C.) formed by casting. 
     The inner chassis  233  includes a first inner end face  235  and a first inner axial hole  237  extending from the first inner end face  235 . The inner chassis  233  further includes an inner chamber  239  extending from another end face of the inner chassis  233  to the first inner axial hole  237 . An outer periphery of the inner chassis  233  further includes a first outer threading  236 , a first groove  251  severing the first outer threading  236 , and two first inner recessed portions  252  severing the first outer threading  236 . The first groove  251  is located between the two first inner recessed portions  252  in a circumferential direction about a longitudinal axis of the first inner axial hole  237 . Each of the first groove  251  and the two first inner recessed portions  252  extends from the first inner end face  235  to the other end face of the inner chassis  233  in a direction parallel to the longitudinal axis of the first inner axial hole  237 . 
     The inner mounting seat  253  includes a second inner end face  255  and a second inner axial hole  259  extending from the second inner end face  255  along the longitudinal axis of the first inner axial hole  237 . The second inner axial hole  257  includes an inner periphery having an inner movement groove  258  that is arcuate. The inner mounting seat  253  further includes an installation space  259  extending from another end face of the inner mounting seat  253  to the second inner axial hole  257 . The inner mounting seat  253  further includes two second inner recessed portions  260  connected to the two first inner recessed portions  252  and a second groove  272 . 
     The first inner end face  235  of the inner chassis  233  is connected to the second inner end face  255  of the inner mounting seat  253 , and the first inner axial hole  237  is coincident with the second inner axial hole  257 . In an example, four inner screws  511  extend through the inner mounting seat  253  to be in treading connection with the inner chassis  233 . After the four inner screws  511  are tightened, the first inner end face  235  tightly presses against the second inner end face  255  (see  FIG. 5 ). Thus, the inner chassis  233  are assembled with the inner mounting seat  253  as an integral member. The two first inner recessed portions  252  are contiguous to and in alignment with the two second recessed portions  260 . The first groove  251  is contiguous to and in alignment with the second groove  271 . 
     The outer portion  275  includes outer chassis  277  and an outer mounting seat  297  coupled to the outer chassis  277 . The outer chassis  277  is made of ferrous material having a melting point higher than 1300° C. or stainless steel material having a melting point of about 1400° C. In an example, the outer chassis  277  is made of iron powders (having a melting point of about 1538° C.) formed by powder metallurgy, and the outer mounting seat  297  is made of a zinc alloy (having a melting point of about 385° C.) or an aluminum alloy (having a melting point of about 660° C.) formed by casting. 
     The outer chassis  277  includes a first outer end face  279  and a first outer axial hole  291  extending from the first outer end face  279 . The outer chassis  277  further includes an outer chamber  295  extending from another end face of the outer chassis  277  to the second inner axial hole  291 . An outer periphery of the outer chassis  277  includes a second outer threading  280  and two first outer recessed portions  282  severing the second outer threading  280 . Each of the two first outer recessed portions  282  extends from the first outer end face  279  to the other end face of the outer chassis  277  in a direction parallel to the longitudinal axis of the second inner axial hole  291 . 
     The outer mounting seat  297  includes a second outer end face  299  and an outer movement groove  313  extending from the second outer end face  299  along a longitudinal axis of the first outer axial hole  291 . The outer chassis  297  further includes a movement space  315  extending from the other end face of the outer chassis  297  and in association with the inner movement groove  258 . The outer mounting seat  297  further includes an opening  317  extending from an outer periphery thereof to the movement space  315 . The outer periphery of the outer mounting seat  297  further includes two second outer recessed portions  318  connected to the two first outer recessed portions  282 . 
     The first outer end face  279  of the outer chassis  277  is connected to the second outer end face  299  of the outer mounting seat  297 , and the first outer axial hole  291  is coincident with the outer movement groove  313 . In an example, four outer screws  513  extend through the outer mounting seat  297  to be in threading connection with the outer chassis  277 . After the four outer screws  513  are tightened, the outer chassis  277  and the outer mounting seat  297  are assembled together as an integral member. The two first outer recessed portions  282  are contiguous to and in alignment with the two second outer recessed portions  318 . 
     The inner mounting seat  253  of the inner portion  231  and the outer mounting portion  297  of the outer portion  275  are coupled with each other. Two screws  359  extend through the inner mounting seat  253  to be in threading connection with the outer mounting seat  297  (see  FIG. 8 ). Thus, the inner portion  231  and the outer portion  275  are coupled together as an integral member. Furthermore, the opening  317  of the outer mounting seat  297  is aligned with the first and second grooves  251  and  271  in a circumferential direction about the longitudinal axis of the first inner axial hole  237 . A retractor  38  and a sensor  331  are movably received in the installation space  259  of the inner mounting seat  253  and the movement space  315  of the outer mounting seat  297 . The retractor  38  includes a front end having an engaging portion  38 A. The retractor  38  is biased by a plurality of springs to an initial position in which the engaging portion  38 A is in the opening  317  (see  FIGS. 3 and 7 ). The engaging portion  38 A is aligned with the first and second grooves  251  and  271  in the circumferential direction about the longitudinal axis of the first inner axial hole  237 . The sensor  331  is received in the inner movement groove  258  of the inner mounting seat  253 . Specifically, the sensor  331  is located between the inner mounting seat  253  and the retractor  38  (see  FIG. 7 ). Furthermore, a side cover  357  is disposed to the inner mounting seat  253  and is located between the sensor  331  and an inner driving lug  26 A of an inner spindle  26  of the lock body  21  along the longitudinal axis of the inner spindle  26 . 
     The inner spindle  26  of the lock body  21  is pivotably connected to the inner portion  231 . The lock body  21  further includes an outer spindle  32  pivotably connected to the outer portion  275 . The inner driving lug  26 A of the inner spindle  26  is operatively connected to the retractor  38 . The inner spindle  26  further includes an actuating portion  26 B adjacent to the sensor  331 . When the inner spindle  26  pivots, the actuating portion  26 B can actuate the sensor  331 . An inner torsion spring  26 C is disposed between the inner spindle  26  and the inner chassis  233 . The inner torsion spring  26 C is received in the inner chamber  239  of the inner chassis  233  and biases the inner spindle  26 , such that the inner driving lug  26 A is in a position in which the engaging portion  38 A of the retractor  38  can be returned by the plurality of springs to its original position inside the opening  317  of the outer mounting seat  297  (see  FIG. 7 ). 
     The outer spindle  32  includes an end having an outer driving lug  32 A operatively connected to the retractor  38 . An outer torsion spring  32 B is disposed between the outer spindle  32  and the outer chassis  277 . The outer torsion spring  32 B is received in the outer chamber  295  of the outer chassis  277  and biases the outer spindle  32 , such that the outer driving lug  32 A is in a position in which the engaging portion  38 A of the retractor  38  can be returned by the plurality of springs to its original position inside the opening  317  of the outer mounting seat  297  (see  FIG. 7 ). 
     With reference to  FIGS. 3 and 7 , the lock body  21  includes a locking control device  194  received in the inner spindle  26 . The locking control device  194  includes a control arm  335  pivotably received in the outer spindle  32  and a cable  196 . A first connector  197  and a second connector  199  are disposed on two ends of the cable  196 . The cable  196  is electrically connected to a motor (not shown) in the locking control device  194 . The control arm  335  pivots when the outer spindle  32  pivots. The locking control device  194  is configured to driving the control arm  335  to move along a longitudinal axis of the inner spindle  26 . When the control arm  335  is in the limiting groove  293  of the outer chassis  277 , the control arm  335  cannot pivot in the limiting groove  293 , and the outer spindle  32  is prevented from pivoting (see  FIG. 7 ). Thus, the door lock  11  is in a locking state. On the other hand, when the control arm  335  moves to the outer movement groove  313  of the outer mounting seat  297 , the control arm  335  can pivot in the outer movement groove  313 , such that the door lock  11  is in an unlocked state (not shown). Furthermore, an outer end cap  319  is disposed to the outer chassis  277  to close the outer chamber  295 , and an inner end cap  273  is disposed to the inner chassis  233  to close the inner chamber  239 . 
     The door lock  11  further includes a separate latch device  191  operatively connected to the lock body  21 . The latch device  191  includes a retractable latch  193  and a hook  195  for actuating the latch  193 . The latch device  191  is placed into the second through-hole  230  via the end face  216  of the door  211 . The hook  195  is received in the first through-hole  218 . The latch  193  is located outside of the end face  216  of the door  211 . The latch device  191  can be directly fixed to the end face  216  by screws. After the latch device  191  is fixed, the lock body  21  is placed into the first through-hole  218 . Provision of the first and second grooves  251  and  271  of the inner portion  231  avoid interference of the hook  21  while placing the lock body  21  into the first through-hole  218 . Furthermore, the opening  317  allows the hook  195  to extend into the outer mounting seat  297  to operatively connect with the engaging portion  38 A of the retractor  38  (see  FIGS. 3 and 7 ). Furthermore, when the engaging portion  38 A of the retractor  38  is operatively connected to the hook  195  of the latch device  191 , the inner mounting seat  253  and the outer mounting seat  297  are received in the first through-hole  218  and are located between the inner end face  213  and the outer end face  215  along the longitudinal axis of the first through-hole  218 . An end of the inner chassis  233  is outside of the inner end face  213 , and an end of the outer chassis  277  is outside of the outer end face  215 . 
     With reference to  FIGS. 1, 6, and 8 , the door lock  11  further comprises an outer operating unit  170  having an outer fixing member  52 , two mounting posts  58 , and an outer pressing ring  53 . The outer fixing member  52  is made of ferrous material having a melting point of about 1538° C. or stainless steel material having a melting point of about 1400° C. The outer fixing member  52  includes an engaging hole  54  in association with the outer chassis  277 . Two teeth  56  are formed on an inner periphery of the engaging hole  54  and are in association with the two first outer recessed portions  282 . The outer pressing ring  53  is made of ferrous material having a melting point of about 1538° C. or stainless steel material having a melting point of about 1400° C. The outer pressing ring  53  includes an inner threading in threading connection with the second outer threading  280  of the outer chassis  277 . The engaging hole  54  of the outer fixing member  52  engages with the outer chassis  277 . The two teeth  56  engage with the two outer recessed portions  282 . Thus, the outer fixing member  52  cannot rotate relative to the outer chassis  277 . Furthermore, the outer fixing member  52  abuts the outer side  215  of the door  211 . The two mounting posts  58  are coupled to the outer fixing member  52  and extend through the two connecting holes  232  of the door  211 . The outer pressing ring  53  is threadedly coupled to the outer chassis  277  and abuts the outer side  215  of the door  211 . According to the form shown, the outer pressing ring  53  is located between the outer chassis  297  and the outer fixing member  52  along the longitudinal axis of the outer spindle  32 . 
     The outer operating unit  170  further includes an outer casing  171  and an outer handle  179 . The outer casing  171  is coupled with the outer fixing member  52 . The outer handle  179  is pivotably received in the outer casing  171  and is jointly pivotable with the outer spindle  32 . Thus, the outer handle  179  can be operated to pivot the outer spindle  32  for retracting the latch  193  to thereby achieve unlatching. Furthermore, when the control arm  335  is in the limiting groove  293  of the outer chassis  277 , the outer spindle  32  cannot be pivoted by turning the outer handle  179 , such that the latch  193  remains in the extended, latching state. An electronic input device (such as Blue tooth reading device, RFID device, a keypad, etc.) can be disposed in the outer casing  171  and is electrically connected to the second connector  199 . According to the form shown, a portion of the cable  196  of the locking control device  194  is received in the first and second outer recessed portions  282  and  318  of the outer portion  275 . The cable  196  extends through the outer pressing ring  53  and is electrically connected to the electronic input device in the outer casing  171 . 
     The door lock  11  further comprises an inner operating unit  110  having an inner fixing member  44 , an inner pressing ring  62 , and a cover  351 . The inner fixing member  44  is made of ferrous material having a melting point of about 1538° C. or stainless steel material having a melting point of about 1400° C. The inner fixing member  44  includes a coupling hole  46  in association with the inner chassis  233 . Two protrusions  48  are formed on an inner periphery of the coupling hole  46  and are coupled with the two first inner recessed portions  252 , such that the inner chassis  233  cannot rotate relative to the inner fixing member  44 . The inner fixing member  44  abuts the inner side  213  of the door  211 . The inner pressing ring  62  is made of ferrous material having a melting point of about 1538° C. or stainless steel material having a melting point of about 1400° C. The inner pressing ring  62  includes an inner threading in threading connection with the first outer threading  236  of the inner chassis  233 . The inner pressing ring  62  is threadedly coupled with the inner chassis  233  and abuts a face of the inner fixing member  44 . The inner and outer pressing rings  62  and  53  are used to secure the position of the lock body  21  relative to the door  211  along the longitudinal axis of the first through-hole  218 . 
     The cover  351  is made of ferrous material having a melting point of about 1538° C. or stainless steel material having a melting point of about 1400° C. The cover  351  is annular to surround the outer chassis  277 . The cover  351  includes two ears  355  on an outer periphery thereof. The cover  355  further includes an inner periphery having an insertion portion  353  in association with the first groove  251 . The cover  355  is mounted around the outer chassis  277 , and the insertion portion  353  is coupled with the first groove  252  (see  FIGS. 6 and 7 ). Furthermore, two bolts  60  extend through the two ears  355  and the inner fixing member  44  to threadedly couple with the two mounting posts  58 . 
     The inner operating unit  110  further includes an inner casing  111  and an inner handle  177 . The inner casing  111  is coupled to the inner fixing member  44 . The inner handle  177  is pivotably received in the inner casing  111  and is jointly pivotable with the inner spindle  26 . Thus, the inner handle  177  can be operated to pivot the inner spindle  26  for retracting the latch  193  of the latch device  191  for unlatching. Furthermore, the control arm  335  of the locking control device  194  is not connected to the inner spindle  26 , such that the inner handle  177  can be operated no matter the control arm  335  is in the limiting groove  293  or the outer movement groove  313 . A microcomputer is disposed in the inner casing  111  for controlling the electric input device and the locking control device  194  and is electrically connected to the first connector  197 . According to the form shown, another portion of the cable  196  is received in the first and second inner recessed portions  252  and  260  of the inner portion  231 , and the cable  196  extends through the inner pressing ring  62  to be electrically connected to the microcomputer of the inner casing  111 . 
     With reference to  FIG. 9 , assuming that a fire occurs at the outer side of the door  211 , since the inner and outer fixing members  44  and  52 , the inner and outer pressing ring  62  and  53 , the cover  351 , and the inner and outer chassis  233  and  277  are made of ferrous or stainless material having a melting point higher than 1300° C., when the temperature at the fire site is lower than 1300° C. (such as 1200° C.), these components will not melt or burn out while the inner and outer casings  111  and  171  and other components in the inner and outer mounting seats  253  and  297  melt or burn out under the high temperature caused by the fire. Thus, the first through-hole  218  of the door  211  is still closed by the above components made of ferrous or stainless steel. As a result, spreading of the flame from the outer side through the through-hole  218  to the inner side of the door  211  or vice versa is impeded, slowing down the spread of fire. 
     With reference to  FIGS. 6 and 9 , it is noted that the insertion portion  353  of the cover  351  closes the first groove  251 , such that the flame or smoke of the fire is not apt to spread along the first and second grooves  251  and  271  of the inner side  231 . 
     After the door lock  11  according to the present invention is mounted to the door  11 , even if many components melt under the high temperature (such as below 1300° C.) of the fire site, the inner and outer chassis  233  and  277  together with the inner and outer fixing members  44  and  52  can still close the first through-hole  218  to make the flame or smoke difficult to spread from a side to the other side of the door  211 , slowing down the spread of fire. 
     The insertion portion  353  of the cover  351  closes the gaps between the first and second grooves  251  and  271  and the first through-hole  218  of the door  211 , making the flame or smoke more difficult to spread from a side to the other side of the door  211 , slowing down the spread of fire. 
     Thus since the invention disclosed herein may be embodied in other specific forms without departing from the spirit or general characteristics thereof, some of which forms have been indicated, the embodiments described herein are to be considered in all respects illustrative and not restrictive. The scope of the invention is to be indicated by the appended claims, rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are intended to be embraced therein.