Patent Publication Number: US-8967681-B2

Title: Locking apparatus for openable window

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a locking apparatus for an openable window that is disposed in a cabin provided with a beam. 
     2. Description of the Related Art 
     JP 2005-146781A discloses a window opening and closing apparatus in a cabin that is provided with an openable window and a locking arm, wherein the openable window can be opened and closed while being swingably supported on a frame forming the cabin, and the locking arm locks this openable window in a half-closed state. This window opening and closing apparatus is provided for an openable window functioning as a rear window of a tractor cabin. The window opening and closing apparatus is provided with the locking arm that is swingably supported on an upper face of a lower frame (a beam made of square pipe). The front end side of the locking arm has a half-lock striker that locks the rear window in a half-closed state, and the base end side has a full-lock striker that locks the rear window in a fully-closed state (closed state). A swinging axis of the locking arm is in a direction orthogonal to a longitudinal direction of the lower frame (a normal direction of the frame upper face). With such a configuration, when the half-lock striker and the rear window become engaged with each other by the rotation of the locking arm along the upper face of the lower frame, the rear window is locked in the half-closed state. Furthermore, when the full-lock striker and the rear window become engaged with each other, the rear window is locked in the fully-closed state. 
     However, according to the apparatus described in JP 2005-146781A, the locking arm extends along the upper face of the lower frame when the rear window is in the fully-closed state. That is to say, the locking arm is positioned on the upper side of the lower frame throughout the full length of the locking arm, and, thus, this locking arm obstructs rear vision. 
     In view of these circumstances, there is a demand for a locking apparatus in a cabin, which, to the fullest extent possible, does not obstruct vision through an openable window that is to be locked. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to a locking apparatus for an openable window disposed in a cabin provided with a beam that has a first face and a second face, comprising: a lock main body that is attached to the first face so as to be swingable about a center of a swinging shaft formed on a first face side of the beam between a closed position and a half-closed position; a full-lock striker that is engageable with an operation piece provided on the openable window, when the lock main body is at the closed position; and a half-lock striker that is disposed on the lock main body at a point farther from the center of the swinging shaft than is the full-lock striker, the half-lock striker being engageable with the operation piece when the lock main body is at the half-closed position, and being positioned on a second face side of the beam when the lock main body is at the closed position. 
     With the locking apparatus, when shifting the lock main body to the closed position in order to fully close the openable window, the half-lock striker of the lock main body is positioned on the second face side. Accordingly, constituent components of the locking apparatus present on the first face side can be reduced in number compared with those in conventional apparatuses. When the first face is taken as one frame side of the vision frame, vision through that vision frame is improved. 
     According to a preferred embodiment of the present invention, the lock main body includes a flange portion that is coupled to the swinging shaft, and an arm portion that connects the flange portion and the half-lock striker, and the arm portion is positioned on the second face side when the lock main body is at the closed position, and is positioned on a side opposite the second face when the lock main body is at the half-closed position. It is more preferable that the arm portion, together with the half-lock striker, surrounds the beam when the lock main body is at the closed position. When the arm portion of the lock main body and the half-lock striker are shaped in this manner, the locking apparatus at the closed position is made compact, so that the space around the locking apparatus is not obstructed. 
     According to a preferred embodiment, the arm portion of the lock main body is configured by a first arm portion that is positioned on the first face side, and a second arm portion that extends so as to be bent from the first arm portion, the first arm portion has a first stopper face for positioning the lock main body at the half-closed position through contact with the beam, and the second arm portion has a second stopper face for positioning the lock main body at the closed position through contact with the beam. With this configuration, the closed position and the half-closed position can be easily and accurately set. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side view showing a tractor provided with a locking apparatus. 
         FIG. 2  is a perspective view showing a cabin frame. 
         FIG. 3  is a front view showing the cabin frame. 
         FIG. 4  is a side cross-sectional view showing a rear support column. 
         FIG. 5  is a perspective view showing the locking apparatus when an openable window is in a fully-closed (closed) state. 
         FIG. 6  is a side cross-sectional view showing the locking apparatus when the openable window is in the fully-closed (closed) state. 
         FIG. 7  is a perspective view showing the locking apparatus when the openable window is in a half-closed state. 
         FIG. 8  is a side cross-sectional view showing the locking apparatus when the openable window is in the half-closed state. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     Hereinafter, a preferred embodiment of the present invention will be described with reference to the drawings. 
     In this embodiment, a locking apparatus  23  is applied to a rear openable window  20  of a cabin  6  that is installed in a tractor. The openable window  20  is configured by a curved glass sheet whose peripheral edge is attached with a sealing member made of elastic rubber. Hereinafter, this openable window  20  is referred to as a “rear glass  20 ”. 
     As shown in  FIG. 1 , the tractor is provided with a traveling chassis  1 . The traveling chassis  1  has right and left front wheels  2  and right and left rear wheels  3 . A front portion of the traveling chassis  1  has a hood  4 . An engine  5  is disposed below the hood  4 . A rear portion of the traveling chassis  1  has the cabin  6 . A steering wheel  7  and a driver&#39;s seat  8  are arranged in the cabin  6 . 
     Furthermore, right and left front frames  9  extend forward from lower side portions of the engine  5 . The front frames  9  are provided with a front axle case (not shown) that supports the front wheels  2 . Furthermore, a rear portion of the engine  5  is coupled to a clutch housing  10 , a transmission case  11 , and a rear axle case  12  that supports the rear wheels  3 . Right and left lift arms  13  and a PTO shaft  14  are arranged behind the transmission case  11 . 
     As shown in  FIGS. 1 ,  2 , and  3 , the cabin  6  is provided with a cabin frame  15  made of a profile beam such as a square pipe. The cabin frame  15  is a so-called four-column structure having right and left front support columns  16  and right and left rear support columns  17 . A front glass  18 , right and left side glasses  19 , the above-described rear glass  20 , and a roof  21  are attached to the cabin frame  15 . The right and the left side glasses  19  can be opened and closed with their rear portions being swingably supported. Furthermore, the rear glass  20  can be opened and closed, and its upper portion is swingably supported on the cabin frame  15 . The rear glass  20  is opened by being swung outward from a closed position, and is closed by being swung inward from an opened position. As clearly shown in  FIGS. 4 and 5 , a beam  22  made of, in this embodiment, square pipe (a type of profile beam) in the shape of an arch in conformity with a lower end shape of the rear glass  20  is attached to lower portions of the right and the left rear support columns  17 . The beam  22  has an upper face corresponding to a first face, a lower face corresponding to a second face, an inner face corresponding to a third face, and an outer face corresponding to a fourth face. The locking apparatus  23  is disposed between the beam  22  and a lower end region of the rear glass  20 . 
     As shown in  FIG. 3 , the front support columns  16  each have a straight line portion  16   a  and an arc-shaped portion  16   b . The straight line portion  16   a  is formed in the shape of a straight line that extends upward while being inclined outward in a front view. The arc-shaped portion  16   b  is formed in the shape of an arc that continues from the upper end portion of the straight line portion  16   a  and is curved so as to be convex outward. The straight line portion  16   a  and the arc-shaped portion  16   b  are connected to each other at a point in a lower portion of the front support column  16  (portion lower than the center of the front support column  16  in the upper-lower direction). With this configuration, the width between the right and the left front support columns  16  increases at the height near the eyes of the driver who is sitting in the driver&#39;s seat  8 , and, thus, the front vision can be improved. 
     As shown in  FIG. 4 , the rear support columns  17  are each covered by a rear support column cover (garnish)  24  made of resin. A hook  24   a  made of resin is integrally formed on the rear support column cover  24 . A bag, a coat, and the like can be hooked on the hook  24   a . The hook  24   a  and the rear support column cover  24  are formed in a vertically symmetrical shape. With this configuration, since the rear support column cover  24  and the hook  24   a  are integrally made of resin, these constituent components can be produced at a low cost. Furthermore, since the hook  24   a  and the rear support column cover  24  are in a vertically symmetrical shape, the rear support column cover  24  attached with the hook  24   a  can be commonly used for the left and the right columns. 
     Next, the locking apparatus  23  will be described with reference to  FIGS. 5 to 8 . 
     As shown in  FIGS. 5 to 8 , the locking apparatus  23  is provided with a lock main body  25 , a half-lock striker  26 , a full-lock striker  27 , and a handle  28 . 
     The handle  28  includes a base portion  28 A that is fixed to a glass face of the rear glass  20  and an operation portion  28 B that is disposed on the cabin side. The operation portion  28 B is supported rotatably about a swinging axis Z formed in the base portion  28 A. The swinging axis Z extends orthogonal to the glass face of the rear glass  20 . The operation portion  28 B has a handle arm  28   a  that is in the shape of a lever and an operation piece  28   b  that extends in a radial direction relative to the swinging axis Z. The handle arm  28   a  extends in a radial direction relative to the swinging axis Z, but is curved in a direction away from the glass face of the rear glass  20  in order to increase the space between the handle arm  28   a  and the rear glass  20  and to make it easy to grip the handle arm  28   a . The operation piece  28   b  also extends in a radial direction of the swinging axis Z, but is shifted from the handle arm  28   a  by an angle of approximately 45 degrees. 
     The full-lock striker  27  is a block member in the shape of an approximately rectangular solid, and is fixed to an upper face  22   a  corresponding to the first face of the beam  22  made of square pipe. The full-lock striker  27  is oriented so as to extend in the longitudinal direction (direction of an axis X) of the beam  22 , and is positioned so as to be able to be in contact with the operation piece  28   b  of the handle  28  on the rear glass  20  at the closed posture. 
     A pair of left and right support portions  29  are fixed to the upper face  22   a  of the beam  22  so as to sandwich the full-lock striker  27  in the longitudinal direction. The support portions  29  function as bearing brackets of a swinging shaft  29   a  having a swinging axis X. Caps  30  are attached to the respective support portions  29 . 
     The lock main body  25  is supported on the support portions  29  so as to be swingable about the swinging axis X between a closed position and a half-closed position. The lock main body  25  has an arm portion  25 A that is in the shape of a plate bent substantially at 90 degrees, and flange portions  25   d  that are coupled to the swinging shaft  29   a  at the front end side of the arm portion  25 A. The flange portions  25   d  are each a tongue piece bent from the arm portion  25 A at 90 degrees. The arm portion  25 A has a first arm portion  25   a  that is, at the closed position, positioned on the upper face  22   a  (first face) side of the beam  22 , and a second arm portion  25   b  that extends so as to be bent from the first arm portion  25   a  substantially at 90 degrees. The half-lock striker  26  is fixed to the free end of the second arm portion  25   b.    
     The half-lock striker  26  is formed by folding a plate material in an approximate U-shape. That is to say, the half-lock striker  26  has a convexly curved bottom plate  26   a  that is curved outward, and a pair of flat plate portions  26   b  that are arranged with the convexly curved bottom plate  26   a  interposed therebetween. The second arm portion  25   b  of the lock main body  25  is coupled to the outer face of one of the flat plate portions  26   b . The half-lock striker  26  is positioned such that the opening of the U-shaped cross-section faces a side (left in this embodiment) of the traveling chassis  1 . In other words, as clearly shown in  FIG. 6 , the opening of the U-shaped cross-section of the half-lock striker  26  extends in the transverse direction of the beam  22 . 
     When the lock main body  25  is at the closed position (see  FIG. 6 ), the arm portion  25 A has a shape that, together with the half-lock striker  26 , surrounds the beam  22 , specifically, the upper face  22   a , an inner face  22   c , and a lower face  22   b  of the beam  22 . When the lock main body  25  is at the closed position, the first arm portion  25   a  opposes the upper face  22   a , the second arm portion  25   b  opposes the inner face  22   c , and the half-lock striker  26  opposes the lower face  22   b , and, thus, the rear glass  20  can be freely opened and closed. When the rear glass  20  comes to the closed position in a state where the lock main body  25  is at the closed position, the operation piece  28   b  of the handle  28  is positioned such that its face opposing the rear glass  20  can be engaged with the inner face of the full-lock striker  27 . 
     As shown in  FIGS. 7 and 8 , when the lock main body  25  is at the half-closed position, the first arm portion  25   a  opposes an outer face  22   d  of the beam  22 , the second arm portion  25   b  extends outward from the beam  22 , and the half-lock striker  26  is away from the outer face  22   d  of the beam  22  by a predetermined distance. This predetermined distance realizes the half-closed state of the rear glass  20 . When the lock main body  25  is at the half-closed position, the operation piece  28   b  of the handle  28  is positioned such that its face opposing the rear glass  20  can be engaged with the inner flat plate portion  26   b  of the half-lock striker  26 . 
     A cut-out portion  25   c  is formed on the edge portion on the free end side of the first arm portion  25   a  in order to avoid interference with the full-lock striker  27 . The full-lock striker  27  is disposed so as to be accommodated in the space inside the swing trajectory of the cut-out portion  25   c  about the swinging axis X, and, thus, the full-lock striker  27  does not obstruct rotation of the lock main body  25  about the swinging axis X. 
     Next, a method for fixing the rear glass  20  to the fully-closed state and the half-closed state will be described in detail with reference to  FIGS. 5 to 8 . 
     As shown in  FIGS. 5 and 6 , when the lock main body  25  is swung downward (as indicated by an arrow A shown in  FIG. 6 ), the lock main body  25  is switched to the closed position where the half-lock striker  26  does not become engaged with the rear glass  20  that is in the fully-closed state. 
     When the lock main body  25  is at the closed position, the half-lock striker  26  is positioned on the side opposite the swinging axis X of the lock main body  25  such that the lock main body  25  wraps around the beam  22 . Accordingly, the half-lock striker  26  is accommodated outside the range of vision (below the beam  22 ), and the lock main body  25  is made compact, and, thus, when the rear glass  20  is in the fully-closed state, the half-lock striker  26  does not obstruct the vision. Furthermore, the handle  28  can be rotated from a non-operation posture at which the operation piece  28   b  is away from the full-lock striker  27  to an operation posture at which the operation piece  28   b  is in contact with the full-lock striker  27 . At the operation posture, the operation piece  28   b  is engaged with the full-lock striker  27 , and, thus, the rear glass  20  is kept in the fully-closed state. 
     A face of the second arm portion  25   b  opposing the beam  22  functions as a stopper face for positioning the lock main body  25  at the closed position, through the contact with the inner face  22   c  of the beam  22 . In this embodiment, the second arm portion  25   b  of the lock main body  25  is attached with, as stopper face, a rubber member  31  that can be in contact with the beam  22 . When the rubber member  31  is in contact with the beam  22  in a state where the rear glass  20  is fixed to the fully-closed state, a function of preventing vibration of the lock main body  25  is also obtained. 
     Furthermore, as shown in  FIGS. 7 and 8 , when the lock main body  25  is swung upward (as indicated by an arrow B shown in  FIG. 8 ), the lock main body  25  is switched to the half-closed position in which the half-lock striker  26  becomes engaged with the rear glass  20  that is in the half-closed state. 
     When the lock main body  25  is at the half-closed position, the handle  28  can be rotated from a non-operation posture at which the operation piece  28   b  is away from the half-lock striker  26  to an operation posture at which the operation piece  28   b  is in contact with the half-lock striker  26  in a state where the rear glass  20  is kept in the half-closed state by the lock main body  25 . At the operation posture, the flat plate portions  26   b  of the half-lock striker  26  are sandwiched between the handle  28  (the operation piece  28   b ) and the rear glass  20 , and, thus, the rear glass  20  is kept in the half-closed state. When keeping the rear glass  20  in the half-closed state, the operation piece  28   b  is caused to be engaged with the half-lock striker  26  by the swinging of the handle  28  about the axis Z, and, at that time, the movement of the operation piece  28   b  is guided by the curved face of the convexly curved bottom plate  26   a . The operation piece  28   b  smoothly moves from the curved face of the convexly curved bottom plate  26   a  to the flat face of the flat plate portion  26   b  as the handle  28  is swung about the axis Z. Specifically, when the handle  28  is rotated counterclockwise in a front view, the operation piece  28   b  moves from above to below, slides on the curved face of the convexly curved bottom plate  26   a , and is guided to the flat plate portion  26   b . In this example, a trim  20   a  as a sealing member made of elastic material is disposed on the lower edge portion of the rear glass  20 , and the flat plate portions  26   b  of the half-lock striker  26  are sandwiched between the operation piece  28   b  of the handle  28  and the rear glass  20  via the trim  20   a.    
     Note that the first arm portion  25   a  functions as a stopper face for positioning the lock main body  25  at the half-closed position, through the contact with the outer face  22   d  of the beam  22 . Thus, the first arm portion  25   a  also may be attached with a rubber member. 
     Although the locking apparatus  23  is applied to the rear glass  20  that is opened by being swung outward in the foregoing embodiment, the locking apparatus  23  according to the invention may be applied to a rear glass  20  that is opened by being swung inward. 
     Although the locking apparatus  23  is provided in the cabin  6  of a four-column type in the foregoing embodiment, the locking apparatus  23  according to the invention may be provided in a cabin of a six-column type. For example, in the case of a cabin of a six-column type, the locking apparatus  23  according to the invention may be applied to a side glass. In this case, specifically, the side glass can be opened and closed with its front portion being swingably supported, and the locking apparatus  23  is disposed between a rear portion of the side glass and a vertical frame (vertical beam) in the vertical orientation (upper-lower orientation). At that time, the lock main body  25  is swingably supported about a swinging axis (vertical axis) that is along the longitudinal direction (upper-lower direction) of the vertical frame.