Patent Publication Number: US-2018030766-A1

Title: Door hinge assembly

Description:
BACKGROUND AND SUMMARY 
     The present disclosure relates to a door hinge assembly. More particularly, the present disclosure relates to a door hinge assembly that can also function as a stay to prevent an opened door from being closed and has a simplified configuration, compared to conventional door hinge assemblies in which a hinge and a stay are provided separately, to improve convenience of an operator or a user and reduce costs. 
     In general, a door hinge is a component used in a hinged door which pivots about a shaft to be opened or closed. Door hinges are widely used not only in industrial fields, such as in construction machines, but also in offices and houses, encountered during daily life. 
     A door hinge used in a construction machine, such as an excavator, functions to support a side door of the excavator to pivotally connect the side door to a door frame of a cab or an engine compartment such that the side door can be opened and closed. However, a separate door stay device is required to maintain the side door in an opened position. A purpose of the door stay device is to keep the door opened during work such that the operator can easily perform the work and to prevent the side door from being abruptly closed by strong wind, a physical impact, or the like, thereby securing a safe working environment. 
     However, in the related art, the door stay device and the door hinge are provided separately from each other, and the door stay device is installed in a separate position, thereby imposing restrictions on a space in which the door stay device is disposed. After the side door is opened via the door hinge, the door stay device must be manipulated to maintain the side door in the opened position. Thus, the problem of rather complicated manipulation is caused. In addition, the door stay device disposed separately from the door hinge causes a number of problems, such as difficulty in maintenance and increased costs for installation of the side door. 
     Accordingly, it is desirable to provide a door hinge assembly that can also function as a stay to prevent an opened door from being closed and has a simplified configuration, compared to conventional door hinge assemblies in which a hinge and a stay are provided separately, to improve convenience of an operator or a user and reduce costs. 
     According to an aspect of the present disclosure, a door hinge assembly may include: a hinge shaft; a movable leaf including a first portion, pivotably connected to the hinge shaft, and a second portion, connected to a door; and a stationary leaf including a first portion, connected to the hinge shaft, and a second portion, fixed to a door frame provided on a wall of an inner space that is opened and closed by the door. A top surface of the movable leaf has a base surface and a step-down surface, a height of which is lower than a height of the base surface. The hinge shaft has a protrusion on an outer circumferential surface thereof over the top surface of the movable leaf, the protrusion of the hinge shaft being able to be placed on the base surface. 
     With respect to an opening direction of the door, the base surface may be provided upstream, and the step-down surface may be provided downstream. 
     A circumferential width of the protrusion may be the same as or narrower than a circumferential width of the step-down surface. 
     When the door is in a closed position, the protrusion may be placed on the base surface. 
     When the door is in an opened position, the protrusion may be placed above the step-down surface. 
     When the door is opened, the base surface may slide under the protrusion while the movable leaf rotates along with the door, and then the protrusion may descend toward the step-down surface by gravity to be located above the step-down surface, in a position lower than the base surface. The top surface of the moveable leaf may further include a vertical surface defined between the base surface and the step-down surface. A rotation of the movable leaf in a closing direction of the door may be blocked by the protrusion located upstream of the vertical surface with respect to the closing direction of the door, so that the door remains in the opened position. 
     The door hinge assembly may further include a stopper unit disposed between the stationary leaf and the hinge shaft to stop further descent of the protrusion. 
     The stopper unit may include a step extending from a wall surface of the stationary leaf facing the hinge shaft and a protrusion protruding from an outer circumferential surface of the hinge shaft, the protrusion of the stopper unit allowed to be placed on the step of the stopper unit. 
     According to the present disclosure, the door hinge assembly can also function as a stay to prevent an opened door from being closed, i.e. maintain the door in an opened position, using to hinge structure to improve convenience and safety of an operator or a user. 
     In addition, according to the present disclosure, the door hinge assembly has a simplified configuration, compared to conventional door hinge assemblies in which a hinge and a stay are provided separately, to reduce costs and provide freedom from restrictions on a space in which the door hinge assembly can be disposed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS. 1 and 2  illustrate a door hinge assembly according to exemplary embodiments, in which  FIG. 1  illustrates the door hinge assembly in an opened position, while  FIG. 2  illustrates the door hinge assembly in a closed position; 
         FIGS. 3 and 4  are enlarged views of area “A” in  FIG. 1 ; 
         FIGS. 5 and 6  are enlarged views of one and the other sides of area “B” in  FIG. 2 ; 
         FIG. 7  is an enlarged view of area “C”  FIG. 1 ; and 
         FIG. 8  is an enlarged view of area “D” in  FIG. 2 . 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, a door hinge assembly according to exemplary embodiments will be described in detail with reference to the accompanying drawings. 
     In the following disclosure, detailed descriptions of known functions and components incorporated herein will be omitted in the case that the subject matter of the present disclosure may be rendered unclear by the inclusion thereof. 
     As illustrated in  FIGS. 1 and 2 , a door hinge assembly  100  according to exemplary embodiments may pivotally connect a side door of a construction machine, for example, an excavator, to a door frame of a cabin or an engine compartment, such that the cabin or the engine compartment can be opened or closed. The door hinge assembly  100  according to an exemplary embodiment functions to maintain the side door in an opened position. 
     In this regard, the door hinge assembly  100  according to an exemplary embodiment includes a hinge shaft  110 , a movable leaf  120 , and a stationary leaf  130 . 
     The hinge shaft  110  provides a hinge structure together with the movable leaf  120  connected thereto, such that the movable leaf  120  is rotatable. In this regard, the hinge shaft  110  is rod-shaped, and a tubular portion of the movable leaf  120  is coupled to the hinge shaft  110  while surrounding the hinge shaft  110 . 
     In an exemplary embodiment, the hinge shaft  110 , as illustrated in  FIG. 3 , has a protrusion  111  on a portion thereof adjacent to a top surface of the movable leaf  120 . The protrusion  111  protrudes by a distance sufficient to allow the protrusion  111  to be placed on the top surface of the movable leaf  120 . In addition, the protrusion  111  is provided to partially surround a circumference of the hinge shaft  110 . 
     In an exemplary embodiment, the protrusion  111  prevents the door from rotating from an opened position to a closed position, according to a change of a position of the top surface of the movable leaf  120 , i.e. in practice, according to a change of a position of the top surface of the movable leaf  120  located below the protrusion  111 , thereby maintaining the door in the opened position. This feature will be described in greater detail later. 
     A rotation of the movable leaf  120  allows the door to be opened and closed. In this regard, a first portion of the movable leaf  120  is connected to the hinge shaft  110 . As illustrated in the drawings, the first portion of the movable leaf  120  having a tubular shape has an opening in a longitudinally middle portion thereof such that a first portion of the stationary leaf  130  is coupled to the hinge shaft  110  in the opening. 
     A second portion of the movable leaf  120  is plate-shaped. A plurality of bolt holes  124  may be formed in the second portion of the movable leaf  120 , such that the movable leaf  120  can be fixed to the door using bolts screwed into the bolt holes  124 . The connection structure of connecting the movable leaf  120  to the door, as described above, allows the door to rotate to open and close the cabin or the engine compartment. 
     The top surface of the movable leaf  120  has different heights. Specifically, in an exemplary embodiment, the top surface of the movable leaf  120 , as illustrated in  FIG. 3 , includes a base surface  121  and a step-down surface  122 , the height of which is lower than that of the base surface  121 . With respect to the direction in which the door is opened (hereinafter, referred to as the opening direction of the door), the base surface  121  is located upstream, while the step-down surface  122  is located downstream. Thus, as illustrated in  FIGS. 5 and 6 , when the door is in a closed position, the protrusion  111  is placed on the base surface  121 . 
     As illustrated in  FIGS. 3 and 4 , when the door is opened, the movable leaf  120  rotates along with the door in the opening direction of the door, such that the base surface  121 , on which the protrusion  111  has been placed, slides along the undersurface of the protrusion  111  in the direction in which the door rotates until the step-down surface  122  is located below the protrusion  111 . The circumferential width of the protrusion  111  is determined to be the same as or smaller than the circumferential width of the step-down surface  122 . Thus, the protrusion  111  is driven downwardly toward the step-down surface  122  by gravity, to be located above the step-down surface  122  but below the base surface  121 . In this case, rotation of the movable leaf  120  in the closing direction of the door is blocked by the protrusion  111  located upstream of a vertical surface  123  defined by the base surface  121  and the step-down surface  122 , with respect to the closing direction of the door. Thus, the door remains in the opened position. In other words, according to the exemplary embodiment, the protrusion  111  of the hinge shall  110  and the step-down surface  122  of the movable leaf  120  function as a locking unit to maintain the door in the opened position or prevent the door from being closed. Then, the side door can be prevented from being unintentionally closed by strong force, wind, a physical impact, or the like while the operator is performing work relating to the cabin or die engine compartment, so that a safe working environment can be secured. 
     The stationary leaf  130  is a member connecting the hinge shaft  110 , the movable leaf  120 , and the door, which are connected together, to a door frame. In this reward, the tubular first portion of the stationary leaf  130  is connected to the hinge shaft  110 . As illustrated in the drawings, the tubular first portion of the stationary leaf  130  is fitted around the outer circumferential surface of the hinge shaft  110  exposed through the opening in the middle portion of the movable leaf  120  when the hinge shaft  110  is fitted into the first portion of the movable leaf  120 . However, this is merely illustrative, and the coupling structure comprised of the hinge shaft  110 , the movable leaf  120 , and the stationary leaf  130  may be provided in a variety of other forms. 
     A second portion of the stationary leaf  130  is plate-shaped. A plurality of bolt holes  131  may be formed in the second portion of the stationary leaf  130 , such that the stationary leaf  130  can be fixed to the door frame provided on the wall of the cabin or the engine compartment, which is opened and closed by the door, using bolts screwed into the bolt holes  131 . 
     As described above, to open the door, the movable leaf  420  is rotated along with the door in the opening direction of the door until the step-down surface  122  is located below the protrusion  111 . The height of the step-down surface  122  is lower than the height of the base surface  121  on which the protrusion  111  has been placed. Thus, the protrusion  111  naturally descends above the step-down surface  122 , the height of which is lower than that of the base surface  121 . If the protrusion  111  is allowed to descend into contact with the step-down surface  122 , the protrusion  111  may descend too far. Then, it may be difficult to move the protrusion  111  to be placed on the base surface  121  upwardly, so as to close the opened door. 
     As illustrated in  FIGS. 7 and 8 , according to an exemplary embodiment, a stopper unit  140  is further provided to deal with this issue. The stopper unit  140  is disposed between the hinge shaft  110  and the stationary leaf  130  to stop further descent of the protrusion  111 , i.e. to control a distance by which the protrusion  111  descends. 
     The stopper unit  140  according to the exemplary embodiment includes a step  141  and a protrusion  142 . The step  141  extends from an inner wall surface of the first portion of the stationary leaf  130  facing the hinge shaft  110  in the direction of the hinge shaft  110 . The protrusion  142  protrudes from an outer circumferential surface of the hinge shaft  110  in the direction of the stationary leaf  130 , such that the protrusion  142  can be caught on the step  141  extending from the stationary leaf  130 . 
     First,  FIG. 8  illustrates a coupling structure of the step  141  and the protrusion  142  when the door is in a closed position. Specifically, the protrusion  111 , provided on the upper portion of the hinge shaft  110  (in the longitudinal direction), is placed on the base surface  121  of the movable leaf  120 . Thus, when the door is in the closed position, the protrusion  142  provided on the central portion of the hinge shaft  110  (in the longitudinal direction) and the step  141  provided on the stationary leaf  130  are not in contact with and are spaced apart from each other. According to an exemplary embodiment, at this time, a distance between the step  141  and the protrusion  142  is smaller than the difference in height between the base surface  121  and the step-down surface  122 , or a distance between the protrusion  111  and the step-down surface  122 . 
     Subsequently,  FIG. 7  illustrates a coupling structure of the step  141  and the protrusion  142  when the door is in an opened position. As the protrusion  111  descends toward the step-down surface  122 , i.e. the hinge shaft  110  having the protrusion  111  descends, the protrusion  142  provided on the hinge shaft  110  descends to come into contact with and be placed on the step  141 , the position of which is fixed. When the protrusion  142  is caught on the step  141  as described above, further descent of the protrusion  111  is forcibly stopped. Since a distance between the step  141  and the protrusion  142  is smaller than a distance between the protrusion  111  and the step-down surface  122  when the door is in a closed position, when the protrusion  142  is placed on the step  141  after having descended, the protrusion  111  is located above the step-down surface  122 , the height of which is lower than that of the base surface  121 , distant from the step-down surface  122 . As described above, when the distance by which the protrusion  111  descends is controlled using such a coupling structure in which the step  141  and the protrusion  142  are coupled when the door is in an opened position, it is possible to more easily close the door from the opened position. 
     As set forth above, the door hinge assembly  100  according to an exemplary embodiment includes a locking unit comprised of the protrusion  111  provided on the hinge shaft  110  and the step-down surface  122  provided on the movable leaf  120 , i.e. a structure for maintaining a door in an opened position. The door hinge assembly  100  according to an exemplary embodiment includes the stopper unit  140  including the step  141  and the protrusion  142  to control a distance by which the protrusion  111  descends toward the step-down surface  122 . As set forth above, the door fringe assembly  100  according to exemplary embodiments has a simplified configuration, compared to the related art in which a door hinge and a stay are provided separately, and also functions as a stay to maintain an opened door in an opened position. This can consequently improve convenience and safety of an operator or a user, reduce costs, and provide freedom from restrictions on a space in which the door hinge assembly is disposed. 
     The foregoing descriptions of specific exemplary embodiments of the present disclosure have been presented with respect to the drawings and are not intended to be exhaustive or to limit the present disclosure to the precise forms disclosed, and obviously many modifications and variations are possible for a person having ordinary skill in the art in light of the above teachings. 
     It is intended therefore that the scope of the present disclosure not be limited to the foregoing embodiments, but be defined by the Claims appended hereto and their equivalents.