Patent Publication Number: US-10309135-B2

Title: Handle and freezer

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2015-206700, filed on Oct. 20, 2015, and International Patent Application No. PCT/JP2016/079736, filed on Oct. 6, 2016, the entire content of each of which is incorporated herein by reference. 
     BACKGROUND 
     Field of the Invention 
     The present invention relates to a handle and a freezer provided with this handle. 
     Description of the Related Art 
     In the related art, a handle is known that is used for opening and closing a door of a freezer having a storage compartment inside which is cooled to an extremely low temperature of −80 degrees Celsius or below (e.g., see Patent document 1). This handle has a structure where the closed state of the door is maintained by the engagement of a latch receiver provided on the side of a freezer main unit with a latch part provided on the side of the door. The engagement of the latch receiver and the latch part and the release of the engagement are switched by the rotation of a knob portion. 
     Patent document 1: JP 2006-275447 
     The present inventors have made intensive study on the above-stated handle for a freezer and found out that there is room for improvement in related-art handles in terms of improving the user-friendliness of a freezer. 
     SUMMARY OF THE INVENTION 
     In this background, a purpose of the present application is to provide a technology for improving the user-friendliness of a freezer. 
     To solve the problem above, one embodiment of the present application relates to a handle. The handle for a freezer provided with a freezer main unit that has an opening at a front surface thereof and a door that is rotatably connected to the freezer main unit at one end side in the horizontal direction and seals the opening in an openable and closable manner by rotating around an axis in the vertical direction, comprises: a main unit base that is fixed to a side surface of the freezer main unit on the side where the freezer main unit and the door are not connected and that has an engaging pin extending in the horizontal direction; a door base that is fixed to a side surface of the door on the side where the freezer main unit and the door are not connected and that has a rotating shaft extending in the horizontal direction; a knob portion that is displaceable, by rotating around the rotating shaft, between a door-locking position where the opening and closing of the door is restricted and a door-unlocking position where the opening and closing of the door is allowed; and a rotation stopper that determines the door-unlocking position of the knob portion. The knob portion has an engaging groove in which the engaging pin moves due to the rotation of the knob portion, the engaging groove has an open end that faces in the horizontal direction when the knob portion is located at the door-unlocking position and through which the engaging pin is retracted or enters due to the opening or closing of the door, the engaging groove and the engaging pin become engaged with each other restricting the opening and closing of the door when the knob portion is displaced from the door-unlocking position to the door-locking position, and the engagement of the engaging groove and the engaging pin is released allowing for the opening and closing of the door when the knob portion is displaced from the door-locking position to the door-unlocking position. When the knob portion is located at the door-unlocking position, the rotation stopper positions the knob portion such that the engaging pin is located inside an extension range of the open end in the vertical direction. The engaging groove has a pushing surface that pushes, when the knob portion is displaced from the door-locking position to the door-unlocking position, the engaging pin such that the horizontal direction distance between the engaging pin and the rotating shaft obtained when the knob portion is located at the door-unlocking position becomes larger than the horizontal direction distance between the engaging pin and the rotating shaft obtained when the knob portion is located at the door-locking position. 
     Another embodiment of the present application relates to a freezer. The freezer comprises: a freezer main unit that has an opening; a door that seals the opening in an openable and closable manner; and the handle according to the above embodiment. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       Embodiments will now be described, by way of example only, with reference to the accompanying drawings which are meant to be exemplary, not limiting, and wherein like elements are numbered alike in several Figures, in which: 
         FIG. 1  is a perspective view of a freezer according to an embodiment; 
         FIG. 2  is a front view of a handle according to the embodiment; 
         FIG. 3  is a perspective view of the handle viewed from the lower side of the back surface of the handle; 
         FIG. 4  is a diagram showing the internal structure of the handle; 
         FIG. 5  is an exploded perspective view of the handle; 
         FIG. 6A  and  FIG. 6B  are diagrams showing the internal structure of the handle at respective rotating positions of a knob portion; 
         FIG. 7A  and  FIG. 7B  are diagrams showing the internal structure of the handle at respective rotating positions of the knob portion; and 
         FIG. 8A  and  FIG. 8B  are diagrams for explaining a third security mechanism. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     A description will be given of an embodiment of the present invention with reference to the drawings. The same or equivalent constituting elements, members, and processes illustrated in each drawing shall be denoted by the same reference numerals, and duplicative explanations will be omitted appropriately. Reference herein to details of the illustrated embodiments is not intended to limit the scope of the claims. It should be understood that not all of the features and the combination thereof discussed are essential to the invention. Some of the members not important for the purpose of describing the embodiments are not shown in the drawings. 
       FIG. 1  is a perspective view of a freezer according to an embodiment. A freezer  1  according to the present embodiment is a freezing machine that can cool the inside of a storage compartment to an extremely low temperature of approximately −80 degrees Celsius. The freezer  1  is provided with a freezer main unit  2 , a door  4 , and a handle  100 . The freezer main unit  2  is a vertical heat insulating box and has an opening  2   a  at a front surface thereof and a storage compartment  2   b  inside thereof. The storage compartment  2   b  communicates with the outside via the opening  2   a . The door  4  is rotatably connected to the freezer main unit  2  at one end side in the horizontal direction (a direction shown by an arrow Y in  FIG. 1 ). For example, the door  4  is rotatably connected to the freezer main unit  2  via a hinge mechanism  6 , which is conventionally known. The door  4  seals the opening  2   a  in an openable and closable manner by rotating around an axis Ax 1  in the vertical direction. 
     The handle  100  is provided on respective side surfaces  2   c  and  4   c  on the side where the freezer main unit  2  and the door  4  are not connected, that is, on a side surface of the freezer  1  on the side that is opposite to the side the hinge mechanism  6  is provided. In the present embodiment, the hinge mechanism  6  is provided on a right side surface viewed from the front of the freezer  1 , and the handle  100  is provided on a left side surface. The attachment position of the hinge mechanism  6  and the attachment position of the handle  100  may be switched. The handle  100  is operated at the time of opening/closing the door  4 . A detailed explanation will be given regarding the structure of the handle  100  in the following. 
       FIG. 2  is a front view of the handle  100  according to the embodiment.  FIG. 3  is a perspective view of the handle  100  viewed from the lower side of the back surface of the handle  100 .  FIG. 4  is a diagram showing the internal structure of the handle  100 .  FIG. 5  is an exploded perspective view of the handle  100 . For the sake of convenience, the direction in which the side surfaces of the freezer  1  are lined up (a direction shown by an arrow Y in  FIG. 1 ) is referred to as a front-back surface direction of the handle  100 . Further, the side of the handle  100  that comes into contact with a side surface of the freezer  1  is a back surface of the handle  100 . Also, in  FIG. 5 , the schematic illustration of a main unit base is omitted. 
     The handle  100  for the freezer  1  is provided with a main unit base  102 , a door base  104 , and a knob portion  106 . The main unit base  102  is fixed to the freezer main unit  2 . The door base  104  is fixed to the door  4 . The knob portion  106  is connected to the door base  104 . 
     The main unit base  102  is fixed to the side surface  2   c  of the freezer main unit  2  on the side where the freezer main unit  2  and the door  4  are not connected. The main unit base  102  has a flat plate portion  108 , an engaging pin  110 , and a projecting portion  112 . One of main surfaces of the flat plate portion  108  abuts on the side surface  2   c  of the freezer main unit  2 , and the flat plate portion  108  is fixed to the freezer main unit  2  by a fastening member  114  such as a screw. The engaging pin  110  extends in the horizontal direction (in the direction shown by the arrow Y in  FIG. 1 , in other words, substantially the normal line direction of the side surface  2   c ) while being fixed to the flat plate portion  108 . The projecting portion  112  is formed integrally with the flat plate portion  108  and projects to the side of the knob portion  106 , more specifically, to the side of a restricting member  140  of the knob portion  106  or to the side of the door base  104 . In the present embodiment, the projecting portion  112  projects more toward the side of the knob portion  106  than the engaging pin  110  and further toward the side of the knob portion  106  than the flat plate portion  108 . The main unit base  102  is formed mainly of a metal material. 
     The door base  104  is fixed to the side surface  4   c  of the door  4  on the side where the freezer main unit  2  and the door  4  are not connected. The door base  104  has a flat plate portion  116  and a rotating shaft  118 . One of main surfaces of the flat plate portion  116  abuts on the side surface  4   c  of the door  4 . A first insertion hole  120  is provided on the flat plate portion  116 . By the insertion of a fastening member  122  such as a screw into the first insertion hole  120 , the door base  104  is fixed to the door  4 . The rotating shaft  118  extends in the horizontal direction (in the direction shown by the arrow Y in  FIG. 1 , in other words, substantially the normal line direction of the side surface  4   c ) while being fixed to the flat plate portion  116 . The door base  104  is formed mainly of a metal material. 
     The knob portion  106  is rotatably connected to the rotating shaft  118 . The knob portion  106  has a cover portion  124 , which has a hollow structure for covering the main unit base  102  and the door base  104 , and a grip portion  126 , which extends upward from the cover portion  124  in the vertical direction (in the direction shown by an arrow Z in  FIG. 1 ). The cover portion  124  has a bottomed cylindrical shape, and the grip portion  126  is provided on the outer circumference of the cover portion  124 . The cover portion  124  is arranged such that an open end of the cylinder faces the freezer  1 . The cover portion  124  has an insertion hole  128  for the rotating shaft  118  at the bottom surface of the cylinder. By the insertion of the rotating shaft  118  into the insertion hole  128 , the knob portion  106  is rotatably connected to the door base  104 . The knob portion  106  is formed mainly of a resin material. 
     The knob portion  106  is displaceable, by rotating around the rotating shaft  118 , between a door-locking position where the opening and closing of the door  4  is restricted and a door-unlocking position where the opening and closing of the door  4  is allowed.  FIG. 4  graphically illustrates the knob portion  106  located at the door-locking position.  FIG. 7A , which is described later, graphically illustrates the knob portion  106  located at the door-unlocking position. A user of the freezer  1  can displace the knob portion  106  between the door-locking position and the door-unlocking position by the pushing and pulling of the grip portion  126  in the front-back surface direction (in the direction shown by an arrow X in  FIG. 1 ) of the freezer  1 . 
     The knob portion  106  has an engaging groove  130  inside the cover portion  124 . The engaging groove  130  extends in the vertical direction in a state where the knob portion  106  is located at the door-locking position. The engaging groove  130  has an open end  132 . The open end  132  corresponds to a portion of the outer circumference of the cover portion  124  that has been cut out in a region where the outer circumference of the cover portion  124  and the engaging groove  130  come into contact with each other. The engaging pin  110  can enter or become retracted from the engaging groove  130  via the open end  132 . The engaging pin  110  that has entered the engaging groove  130  moves inside the engaging groove  130  due to the rotation of the knob portion  106 . 
     Further, on the cover portion  124 , a convex portion  134  projecting to the side of the door base  104  is provided at a peripheral portion of the insertion hole  128 . On the other hand, on the door base  104 , a rotation stopper  136  projecting to the side of the cover portion  124  is provided at a peripheral portion of the rotating shaft  118 . The convex portion  134  and the rotation stopper  136  are displaced in a relative manner due to the rotation of the knob portion  106  and abut on each other when the knob portion  106  is located at the door-unlocking position. Therefore, the convex portion  134  and the rotation stopper  136  function as positioning members that determine the door-unlocking position of the knob portion  106 . 
     An explanation will be given here regarding the operation of the handle  100  with reference to  FIGS. 6A, 6B, 7A, and 7B .  FIGS. 6A, 6B, 7A, and 7B  are diagrams showing the internal structure of the handle  100  at respective rotating positions of the knob portion  106 . 
     The knob portion  106  can rotate between the door-locking position shown in  FIG. 6A  and the door-unlocking position shown in  FIGS. 7A and 7B . As shown in  FIG. 6A , when the knob portion  106  is located at the door-locking position, the engaging pin  110  is located inside the engaging groove  130 , and the engaging pin  110  and the engaging groove  130  are engaged with each other. The engaging pin  110  enters all the way to the innermost part of the engaging groove  130 . Since the engaging pin  110  and the engaging groove  130  are engaged with each other, the opening and closing of the door  4  is restricted. The open end  132  faces downward in the vertical direction in a state where the knob portion  106  is located at the door-locking position. 
     As shown in  FIG. 6B , when the knob portion  106  rotates around the rotating shaft  118 , the engaging pin  110  moves inside the engaging groove  130  toward the open end  132 . The engaging pin  110  moves while abutting on a pushing surface  138 , which is the side surface of the engaging groove  130  and located between the engaging pin  110  and the rotating shaft  118 , at this time. The pushing surface  138  has a convex curved surface shape on the engaging pin  110  side. For example, the pushing surface  138  is formed of a portion of an ellipse centered at the rotating shaft  118 . Therefore, the pushing surface  138  pushes the engaging pin  110  in a direction in which the freezer main unit  2  and the door  4  become spaced apart from each other (in a direction shown by an arrow X in  FIG. 1 ) when the knob portion  106  is displaced from the door-locking position to the door-unlocking position. Also, as the knob portion  106  rotates, the convex portion  134  approaches the rotation stopper  136 . 
     As shown in  FIG. 7A , the knob portion  106  rotates until the convex portion  134  abuts on the rotation stopper  136 . The position at which the convex portion  134  abuts on the rotation stopper  136  is the door-unlocking position of the knob portion  106 . The open end  132  faces in the horizontal direction (the direction shown by the arrow X in  FIG. 1 , more specifically, the back surface direction of the freezer  1 ) when the knob portion  106  is located at the door-unlocking position. When the knob portion  106  is located at the door-unlocking position, the rotation stopper  136  positions the knob portion  106  such that the engaging pin  110  is located inside an extension range H of the open end  132  in the vertical direction. This releases the engagement of the engaging pin  110  and the engaging groove  130  and allows the opening and closing of the door  4 . 
     The engaging pin  110  moves inside the engaging groove  130  while being pushed by the pushing surface  138  in accordance with the rotation of the knob portion  106  and reaches the vicinity of the open end  132  of the engaging groove  130 . Due to the engaging pin  110  being pushed by the pushing surface  138 , a horizontal direction distance R 2  between the engaging pin  110  and the rotating shaft  118  obtained when the knob portion  106  is located at the door-unlocking position becomes larger than a horizontal direction distance R 1  between the engaging pin  110  and the rotating shaft  118  obtained when the knob portion  106  is located at the door-locking position (see  FIG. 6A ). In the present embodiment, when the engaging pin  110  is pushed by the pushing surface  138 , the freezer main unit  2  and the door  4  no longer come into contact with each other on the side of the side surfaces  2 C and  4 C on which the main unit base  102  and the door base  104  are fixed, respectively. 
     In the present embodiment, when a sealing member such as a packing material is provided at a peripheral portion of a main surface of the door  4  that faces the side of the freezer main unit  2 , the sealing member is also included in the “door”. Therefore, the state, “the freezer main unit  2  and the door  4  no longer come into contact with each other”, means a state where the freezer main unit  2  and the sealing member provided on the door  4  are spaced apart from each other. The same applies to a case where a sealing member is provided on the outer circumference of the opening  2   a  of the freezer main unit  2 . 
     When the knob portion  106  is located at the door-unlocking position, the engaging pin  110  is located inside the extension range H of the open end  132  in the vertical direction. Therefore, as shown in  FIG. 7B , the door  4  can be opened by allowing the door  4  to rotate around an axis Ax 1  (see  FIG. 1 ). Due to the opening operation of the door  4 , the engaging pin  110  is retracted from the engaging groove  130 . When the door  4  is closed, the opposite operation is performed. In other words, in a state where the knob portion  106  is located at the door-unlocking position, the engaging pin  110  enters the engaging groove  130  due to the closing operation of the door  4 . When the knob portion  106  rotates around the rotating shaft  118 , the engaging pin  110  moves inside the engaging groove  130  and reaches the innermost part. As a result, the knob portion  106  is displaced from the door-unlocking position to the door-locking position. 
     Therefore, in the handle  100 , when the knob portion  106  is displaced from the door-unlocking position to the door-locking position, the engaging groove  130  and the engaging pin  110  become engaged with each other restricting the opening and closing of the door  4 , and when the knob portion  106  is displaced from the door-locking position to the door-unlocking position, the engagement of the engaging groove  130  with the engaging pin  110  is released allowing for the opening and closing of the door  4 . 
     The center of gravity is set for the knob portion  106  such that load is applied in a direction of rotation around the rotating shaft  118  in a counter-clockwise direction at the door-locking position shown in  FIG. 6A . In other words, in a state where external load is not applied to the knob portion  106 , load is applied to the knob portion  106  in a direction in which the engaging pin  110  moves inside the engaging groove  130  to the side opposite from the open end  132 . This prevents unintentional rotation of the knob portion  106  in a situation where external load is not applied to the knob portion  106  and prevents the engaging pin  110  from being located on the open end  132  side of the engaging groove  130 . As a result, a situation can be prevented where the knob portion  106  is unintentionally displaced to the door-unlocking position thereby opening the door  4 . For example, in the freezer  1  shown in  FIG. 1 , the opening  2   a  of the freezer main unit  2  is covered by the door  4 . Further, in order to maintain the airtightness of the storage compartment  2   b , an elastic packing material is provided between the freezer main unit  2  and the door  4 . The door  4  seals the opening  2   a  of the freezer main unit  2  while pushing this packing material. Therefore, force in a direction away from the freezer main unit  2  is applied to the door  4  due to repulsive force of the packing material. For this reason, in a state where the knob portion  106  is located at the door locking position, the side surface on the freezer main unit  2  side in the engaging groove  130  and the engaging pin  110  are engaged with each other with predetermined engaging force caused by the repulsive force of the packing material. On the other hand, when the pressure inside the storage compartment  2   b  is decreased due to cooling or the like inside the storage compartment  2   b , the door  4  may be pushed onto the freezer main unit  2  side. In this case, the engaging force between the engaging pin  110  and the engaging groove  130  caused by the repulsive force of the packing material may be weakened. Even in such a case, by setting the center of gravity of the knob portion  106  as described above, a situation can be prevented where the knob portion  106  is unintentionally displaced to the door-unlocking position thereby opening the door  4 . 
     [Handle Returning Locking Mechanism] 
     An explanation will be given regarding a handle returning locking mechanism of the handle  100  with reference to  FIGS. 5, 7A, and 7B . The handle returning locking mechanism is a mechanism for restricting the displacement of the knob portion  106  located at the door-unlocking position to the door locking position. 
     One of the knob portion  106  and the door base  104  has a restricting member  140 , and the other has a restricting member receiving portion  142 . In the present embodiment, the knob portion  106  has the restricting member receiving portion  142 , and the door base  104  has the restricting member  140 . Also, the convex portion  134  provided on the knob portion  106  functions as the restricting member receiving portion  142 . In other words, the convex portion  134  is used for a positioning mechanism that determines the door-unlocking position of the knob portion  106  and for the handle returning locking mechanism. 
     The restricting member  140  is provided in a displaceable manner with respect to one of the members (the door base  104  in the present embodiment). More specifically, the restricting member  140  is rotatably connected to the rotating shaft  144  fixed to the flat plate portion  116  of the door base  104 . The restricting member  140  can be switched between a first orientation for restricting the knob portion  106  from being displaced to the door locking position by abutting on the restricting member receiving portion  142  in a state where the knob portion  106  is located at the door unlocking position (see  FIG. 7B ) and a second orientation for allowing the knob portion  106  located at the door unlocking position to be displaced to the door locking position by being spaced apart from the restricting member receiving portion  142  (see  FIG. 7A ). 
     Also, as shown in  FIGS. 7A and 7B , the restricting member  140  is at the first orientation in a state where the engaging pin  110  is retracted from the engaging groove  130 , and the orientation is switched to the second orientation when the engaging pin  110  enters the engaging groove  130 . In other words, the first orientation and the second orientation of the restricting member  140  are automatically switched to each other according to the opening degree of the door  4 . Then, in a state where the door  4  is open, the knob portion  106  located at the door-unlocking position is restricted from being displaced to the door locking position. 
     The displacement of the restricting member  140  is achieved as described in the following. In other words, as shown in  FIG. 5 , the handle  100  is provided with the biasing member  146 , which biases the restricting member  140  to be at the first orientation. In the present embodiment, the biasing member  146  is formed of a coil spring and is fixed to the door base  104  by the insertion of the rotating shaft  144 . One end of the coil spring, which forms the biasing member  146 , is engaged with the door base  104 , and the other end thereof is engaged with the restricting member  140 . Further, as shown in  FIG. 7A , the projecting portion  112  provided on the main unit base  102  is arranged at a position that has been shifted in the vertical direction from that of the rotating shaft  144  and that overlaps with the restricting member  140 . 
     In the present embodiment, the restricting member  140  is a member having an approximately V shape. Then, the rotating shaft  144  is arranged near the vertex of the V shape. Further, one end portion of the V shape abuts on the restricting member receiving portion  142 . Further, the other end portion of the V shape is pushed by the projecting portion  112 . In the restricting member  140 , the vertex of the V shape serves as a fulcrum, said one end portion serves as the point of load, and said the other end portion serves as the point of effort. 
     As shown in  FIG. 7B , the projecting portion  112  and the restricting member  140  are spaced apart from each other in a state where the engaging pin  110  is retracted from the engaging groove  130 . Therefore, the restricting member  140  is at the first orientation due to the biasing force of the biasing member  146 . At the first orientation, said one end portion of the restricting member  140  moves onto the trajectory of the restricting member receiving portion  142 , which is displaced according to the rotation of the knob portion  106 , and abuts on the restricting member receiving portion  142 . On the other hand, when the door  4  moves closer to the freezer main unit  2  so that the engaging pin  110  enters the engaging groove  130 , the projecting portion  112  pushes the restricting member  140  in a direction that is opposite to the biasing direction of the biasing member  146  in accordance with the approaching of the door  4  to the freezer main unit  2 . Thereby, the orientation of the restricting member  140  is switched to the second orientation. Due to said other end portion being pushed by the projecting portion  112 , the restricting member  140  rotates using the vertex of the V shape as a fulcrum, and said one end portion is retracted from the trajectory of the restricting member receiving portion  142 . 
     In the process of the knob portion  106  rotating so as to be displaced to the door-locking position, the door  4  and the freezer main unit  2  gradually approach each other. Therefore, as shown in  FIGS. 6A and 6B , the restricting member  140  continues to be pushed by the projecting portion  112  and maintains the second orientation. 
     [First Security Mechanism] 
     An explanation will be given regarding a first security mechanism with reference to  FIG. 2  and  FIGS. 4 to 6B . The first security mechanism is a mechanism for preventing the door  4  from opening by restricting the rotation of the knob portion  106  located at the door-locking position. 
     The handle  100  has a lock mechanism  148 , which fixes the knob portion  106  to the door base  104 . The lock mechanism  148  has a convex portion  134 , a lock pin  150 , a fixing base  152 , a rotating shaft  154 , and a lock pin rotating portion  156 . The convex portion  134  rotates along with the knob portion  106  and abuts on the rotation stopper  136  when the knob portion  106  is located at the door-unlocking position (see  FIG. 7A ) and becomes spaced apart from the rotation stopper  136  when the knob portion  106  is located at the door-locking position (see  FIG. 6A ). 
     The lock pin  150  is a member that is long in one direction, has an insertion hole  158  on one end side, has a head portion  160  on the other end side, and has an engaging slit  162  at an intermediate portion thereof. The head portion  160  projects in a direction that intersects with the extending direction of the lock pin  150 . The engaging slit  162  extends roughly along the extending direction of the lock pin  150 . By the insertion of the rotating shaft  154  into the insertion hole  158 , the lock pin  150  is rotatably connected to the rotating shaft  154 . The rotating shaft  154  is fixed to the fixing base  152 . The fixing base  152  is fixed to the knob portion  106  by a fastening member  164  such as a screw. 
     The lock pin rotating portion  156  is an approximately cylindrical member and is provided so as to penetrate the cover portion  124 . The lock pin rotating portion  156  has an engaging projection  166  on the side of one end that is arranged inside the cover portion  124  and has a key hole  168  on the side of the other end that is exposed outside the cover portion  124 . The engaging projection  166  of the lock pin rotating portion  156  is inserted into the engaging slit  162  of the lock pin  150 . By inserting a key  170  into the key hole  168  and then rotating the key  170 , the lock pin rotating portion  156  can be rotated. The rotation of the lock pin rotating portion  156  is transmitted to the lock pin  150  via the engaging projection  166  and the engaging slit  162 , and the lock pin  150  rotates around the rotating shaft  154 . 
     As shown in  FIG. 4 , the lock pin  150  allows the head portion  160  to enter a space between the convex portion  134  and the rotation stopper  136  that is created in a state where the knob portion  106  is located at the door-locking position. The entry of the head portion  160  to the space between the convex portion  134  and the rotation stopper  136  restricts the displacement of the convex portion  134  to a direction where the convex portion  134  approaches the rotation stopper  136 . Therefore, the displacement of the knob portion  106  from the door-locking position to the door-unlocking position is restricted. 
     When a user rotates the lock pin rotating portion  156  using the key  170 , the lock pin  150  rotates around the rotating shaft  154  as shown in  FIG. 6A . Then, the head portion  160  is retracted from the space between the convex portion  134  and the rotation stopper  136 . This allows the convex portion  134  to be displaced in the direction where the convex portion  134  approaches the rotation stopper  136  as shown in  FIG. 6B . In other words, the knob portion  106  can be displaced from the door-locking position to the door-unlocking position. 
     [Second Security Mechanism] 
     An explanation will be given regarding a second security mechanism with reference to  FIG. 3  and  FIG. 5 . The second security mechanism is a mechanism for preventing the door  4  from opening by locking the handle  100  using a lock such as a padlock. 
     The door base  104  has a first lock hole  172  in which a lock (not shown) for fixing the knob portion  106  to the door base  104  is mounted. Also, the knob portion  106  has a second lock hole  174  in which a lock is mounted together with the first lock hole  172 . 
     The positional relationship of the first lock hole  172  and the second lock hole  174  is defined such that, in a direction where the door base  104  and the knob portion  106  are lined up (in the direction shown by the arrow Y in  FIG. 1 ), the first lock hole  172  and the second lock hole  174  overlap with each other when the knob portion  106  is located at the door-locking position and are shifted from each other when the knob portion  106  is located at the door-unlocking position. In a state where the first lock hole  172  and the second lock hole  174  overlap with each other, that is, in a state where the knob portion  106  is located at the door-locking position, the latch of the lock is inserted into the second lock hole  174  after the first lock hole  172  or inserted into the first lock hole  172  after the second lock hole  174  so as to achieve locking. Thereby, the displacement of the knob portion  106  from the door-locking position to the door-unlocking position is restricted. 
     [Third Security Mechanism] 
     An explanation will be given regarding a third security mechanism with reference to  FIGS. 8A and 8B .  FIG. 8A  and  FIG. 8B  are diagrams for explaining the third security mechanism. The third security mechanism is a mechanism for preventing the door  4  from opening by restricting the removal of the door base  104  and the knob portion  106  from the door  4 . 
     The knob portion  106  has a second insertion hole  176  into which the fastening member  122  is inserted. The second insertion hole  176  is a hole into which the fastening member  122  is inserted when fixing the door base  104 , to which the knob portion  106  is connected, to the door  4 . A worker can fix the door base  104  and the knob portion  106  to the door  4  by inserting the fastening member  122  inside the cover portion  124  via the second insertion hole  176  and inserting the fastening member  122  into the first insertion hole  120  (see  FIG. 3 ) of the door base  104 . 
     The positional relationship of the first insertion hole  120  and the second insertion hole  176  is defined such that, in a direction where the door  4 , the door base  104 , and the knob portion  106  are lined up (in the direction shown by the arrow Y in  FIG. 1 ), the first insertion hole  120  and the second insertion hole  176  overlap with each other when the knob portion  106  is located at the door-unlocking position and are shifted from each other when the knob portion  106  is located at the door-locking position. Therefore, as shown in  FIG. 8A , when the knob portion  106  is located at the door-locking position, the second insertion hole  176  is shifted from the fastening member  122 . Therefore, the worker cannot access the fastening member  122 . On the other hand, as shown in  FIG. 8B , when the knob portion  106  is located at the door-unlocking position, the worker can approach the fastening member  122  via the second insertion hole  176 . Therefore, the worker can remove the fastening member  122 . 
     In the present embodiment, four first insertion holes  120  and four second insertion holes  176  are provided, and the positional relationship of the four first insertion holes  120  and four second insertion holes  176  is defined such that, in three pairs out of the four pairs, overlapping occurs when the knob portion  106  is located at the door-unlocking position and shifting from each other occurs when the knob portion  106  is located at the door-locking position. On the other hand, the positional relationship is defined such that, in the remaining pair located at the lowermost end, overlapping occurs when the knob portion  106  is located at the door-locking position and shifting from each other occurs when the knob portion  106  is located at the door-unlocking position. 
     This is because the second insertion hole  176  cannot be provided at a position that overlaps with the first insertion hole  120  or the fastening member  122  located at the lowermost end in a state when the knob portion  106  is located at the door-unlocking position due to arrangement space circumstances. In order to provide the second insertion hole  176  at this position, the size of the knob portion  106  needs to be increased. In other words, by arranging the second insertion hole  176  that corresponds to the first insertion hole  120  located near the peripheral portion of the knob portion  106  so as to overlap with the first insertion hole  120  when the knob portion  106  is located at the door-locking position, the size of the knob portion  106  can be reduced. 
     Also, at least one second insertion hole  176  is arranged so that the rotating shaft  144  overlaps with a trajectory occurring when the second insertion hole  176  is displaced in accordance with the rotation of the knob portion  106 . Therefore, the rotating shaft  144  can be accessed via the second insertion hole  176 . Thereby, the task of removing the entire knob portion  106  or a portion of the knob portion  106  can be omitted at the time of, for example, the maintenance of the rotating shaft  144 . 
     As explained above, the handle  100  according to the present embodiment has the knob portion  106  displaceable between the door-locking position and the door-unlocking position. The engaging groove  130  provided in the knob portion  106  has the open end  132  facing in the horizontal direction when the knob portion  106  is located at the door-unlocking position. At the open end  132 , the engaging pin  110  becomes retracted from or enters by the opening and closing of the door  4 . When the knob portion  106  is displaced from the door-unlocking position to the door-locking position, the engaging groove  130  and the engaging pin  110  become engaged with each other, and the handle  100  thus restricts the opening and closing of the door  4 . Also, when the knob portion  106  is displaced from the door-locking position to the door-unlocking position, the engagement of the engaging groove  130  and the engaging pin  110  is released, and the handle  100  thus allows for the opening and closing of the door  4 . 
     The handle  100  is provided with the rotation stopper  136 , which determines the door-unlocking position of the knob portion  106 . When the knob portion  106  is located at the door-unlocking position, the rotation stopper  136  positions the knob portion  106  such that the engaging pin  110  is located inside the extension range H of the open end  132  in the vertical direction. Thereby, a user can open and close the door  4  without fine positional adjustment of the engaging pin  110  and the open end  132  at the time of the opening and closing of the door  4 . Therefore, the user-friendliness of the freezer  1  can be improved. Particularly when the door  4  is closed, the engaging pin  110  can smoothly and surely enter inside the engaging groove  130  from the open end  132 . Therefore, damage caused by the collision of the engaging pin  110  and the knob portion  106  can be prevented. 
     Further, the engaging groove  130  has the pushing surface  138 . When the knob portion  106  is displaced from the door-locking position to the door-unlocking position, the pushing surface  138  pushes the engaging pin  110  such that the horizontal direction distance R 2  between the engaging pin  110  and the rotating shaft  118  obtained when the knob portion  106  is located at the door-unlocking position becomes larger than the horizontal direction distance R 1  between the engaging pin  110  and the rotating shaft  118  obtained when the knob portion  106  is located at the door-locking position. 
     The inside of the storage compartment  2   b  of the freezer  1  is sealed from the outside and maintained at a low temperature. Therefore, the inside of the storage compartment  2   b  is likely to become negatively pressurized. Also, in general, a magnet packing material is interposed between the freezer main unit  2  and the door  4 . Also, in some cases, frost, ice, or the like may adhere to a connecting part of the freezer main unit  2  and the door  4  Due to these factors, there are cases when the opening of the door  4  becomes difficult. Meanwhile, the handle  100  assists the opening operation of the door  4  by pushing, by the pushing surface  138 , the engaging pin  110  in the direction in which the freezer main unit  2  and the door  4  become spaced apart from each other. Therefore, the force necessary for the opening operation of the door  4  can be reduced. Therefore, the user-friendliness of the freezer  1  can be improved. 
     Further, in the present embodiment, when the engaging pin  110  is pushed by the pushing surface  138 , the freezer main unit  2  and the door  4  no longer come into contact with each other on the side of the side surfaces  2 C and  4 C on which the main unit base  102  and the door base  104  are fixed, respectively. Thereby, the force required for the opening operation of the door  4  can be reduced more certainly. Also, the pushing surface  138  is located between the engaging pin  110  and the rotating shaft  118  and has a convex curved surface shape on the engaging pin  110  side. Thereby, load that is produced by the pushing of the engaging pin  110  by the pushing surface  138  and that prevents the rotation of the knob portion  106  can be equalized throughout the displacement of the knob portion  106  from the door-locking position to the door-unlocking position. 
     The pushing surface  138  is not limited to those that have a convex curved surface shape on the engaging pin  110  side. The pushing surface  138  is only required to have a shape that allows the freezer main unit  2  and the door  4  to not come into contact with each other by pushing the engaging pin  110 . For example, the pushing surface  138  has a flat surface or a curved surface that inclines so as to protrude more toward the engaging pin  110  side than a contact point of the engaging pin  110  and the pushing surface  138  in a state where the knob portion  106  is in the middle of being displaced from the door-locking position to the door-unlocking position. The shape of the pushing surface  138  itself may be a flat surface shape that extends from one end side to the other end side without bending (i.e., formed of a single flat surface) or may have a bending portion between one end side and the other end side (i.e., formed of a plurality of flat surfaces). When the pushing surface  138  has a bending portion, the pushing surface  138  may have a convex shape or a concave shape on the engaging pin  110  side, for example, in a state where the knob portion  106  is located at the door-locking position. 
     Further, the handle  100  is provided with the handle returning locking mechanism. In other words, one of the knob portion  106  and the door base  104  has the restricting member  140 , and the other has the restricting member receiving portion  142 . The restricting member  140  can be switched between the first orientation and the second orientation. The first orientation is an orientation that restricts the knob portion  106  from being displaced to the door locking position by the restricting member  140  abutting on the restricting member receiving portion  142  in a state where the knob portion  106  is located at the door-unlocking position. The second orientation is an orientation that allows the knob portion  106  located at the door-unlocking position to be displaced to the door locking position by the restricting member  140  being spaced apart from the restricting member receiving portion  142 . 
     The handle  100  being provided with the handle returning locking mechanism can prevent a situation where, for example, the knob portion  106  goes back to the door-locking position against the user&#39;s intention while being in a state where the door  4  is open. Further, this can prevent a situation where the door  4  closes while being in a state where the knob portion  106  is back to the door-locking position causing the knob portion  106  and the engaging pin  110  to collide with each other. 
     Also, the restricting member  140  is at the first orientation in a state where the engaging pin  110  is retracted from the engaging groove  130 , and the orientation is switched to the second orientation when the engaging pin  110  enters the engaging groove  130 . In other words, the knob portion  106  is fixed such that the knob portion  106  does not go back to the door-locking position from the door-unlocking position in a state where the door  4  is open, and the fixation of the knob portion  106  is released in synchronization with the displacement of the door  4  when the door  4  closes. Therefore, the restriction of the handle rotation and the elimination of the restriction can be switched automatically in accordance with the opening degree of the door  4 . Accordingly, the user-friendliness of the freezer  1  can be further improved. 
     Further, the handle  100  is provided with the biasing member  146 , which biases the restricting member  140  to be at the first orientation. Also, the main unit base  102  has the projecting portion  112  projecting to the knob portion  106  side. The projecting portion  112  pushes the restricting member  140  in a direction that is opposite to the biasing direction of the biasing member  146  in accordance with the approaching of the door  4  to the freezer main unit  2 . Thereby, the orientation of the restricting member  140  is switched to the second orientation. According to this configuration, the switching of the restriction of the handle rotation and the elimination of the restriction in accordance with the opening degree of the door  4  can be achieved by the simple configuration. 
     Further, the handle  100  is provided with the first security mechanism. In other words, the handle  100  has the lock mechanism  148 , which fixes the knob portion  106  to the door base  104 . The lock mechanism  148  has the convex portion  134  and the lock pin  150 . The convex portion  134  rotates along with the knob portion  106  and abuts on the rotation stopper  136  when the knob portion  106  is located at the door-unlocking position and becomes spaced apart from the rotation stopper  136  when the knob portion  106  is located at the door-locking position. The lock pin  150  restricts the displacement of the knob portion  106  by entering a space between the convex portion  134  and the rotation stopper  136  while being in a state where the knob portion  106  is located at the door-locking position. This allows the security of the freezer  1  to be improved. 
     Further, the handle  100  is provided with the second security mechanism. In other words, the door base  104  has the first lock hole  172  in which a lock is mounted. The knob portion  106  has the second lock hole  174  in which a lock is mounted together with the first lock hole  172 . The positional relationship of the first lock hole  172  and the second lock hole  174  is defined such that the first lock hole  172  and the second lock hole  174  overlap with each other when the knob portion  106  is located at the door-locking position and the first lock hole  172  and the second lock hole  174  are shifted from each other when the knob portion  106  is located at the door-unlocking position. This allows the security of the freezer  1  to be improved. 
     Further, the handle  100  is provided with the third security mechanism. In other words, the door base  104  has the flat plate portion  116 , which abuts on the side surface  4   c  of the door  4 , and the first insertion hole  120  into which the fastening member  122  for fixing the door base  104  to the door  4  is inserted. The knob portion  106  has the second insertion hole  176  into which the fastening member  122  is inserted. The positional relationship of the first insertion hole  120  and the second insertion hole  176  is defined such that the first insertion hole  120  and the second insertion hole  176  overlap with each other when the knob portion  106  is located at the door-unlocking position and the first insertion hole  120  and the second insertion hole  176  are shifted from each other when the knob portion  106  is located at the door-locking position. This allows the security of the freezer  1  to be improved. 
     The invention is not limited to the above-mentioned embodiments, and additional modifications, such as a design change, may be added thereto on the basis of knowledge of those skilled in the art. It should be understood that any embodiment to which additional modifications are added is also included in the scope of the invention. New embodiments resulting from the addition of modifications to the aforementioned embodiments will provide the advantages of the embodiments and modifications combined.