Patent Publication Number: US-2023158673-A1

Title: Safety switch device

Description:
TECHNICAL FIELD 
     This disclosure relates to a safety switch device. 
     BACKGROUND 
     There is a known robot operation unit which is removably attached to a commercially available mobile terminal and composes a teaching device of the robot (See Japanese Unexamined Patent Application, Publication No. 2017-202550, for example). 
     This robot operation unit includes an operation unit main body having an emergency stop button or the like, and an attachment which attaches the operation unit main body to the mobile terminal. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG.  1    is a front view showing a safety switch device according to a first embodiment of the present invention. 
         FIG.  2    is a side view of the safety switch device of  FIG.  1   . 
         FIG.  3    is a rear view of the safety switch device of  FIG.  1   . 
         FIG.  4    is a rear view showing a state where a device main body of the safety switch device is held by an operator. 
         FIG.  5    is a partial enlarged view showing a first holding portion of the safety switch device of  FIG.  1   . 
         FIG.  6    is a perspective view showing a back side of a first elastic member provided in the first holding portion of  FIG.  5   . 
         FIG.  7    is a perspective view explaining that the first holding portion of the first elastic member of  FIG.  6    is attached to a protruded contact surface. 
         FIG.  8    is a longitudinal sectional view showing a part of the first holding portion of  FIG.  5   . 
         FIG.  9    is an enlarged view partially showing a second holding portion of the safety switch device of  FIG.  1   . 
         FIG.  10    is an enlarged view partially explaining a modified example of the first elastic member of  FIG.  6   . 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     In order to attach an operation unit main body to various mobile terminals of different sizes, an attachment is provided so as to be movable in a width direction of a mobile terminal with respect to an operation unit main body, and the mobile terminal is inserted between the operation unit main body and the attachment by resilient force of a coil spring. 
     The mobile terminal attached to the operation unit is not directly held by the operator, but is operated in a state in which the mobile terminal is indirectly held by holding the operation unit. Accordingly, it is preferable that the mobile terminal is not displaced not only in a direction of sandwiching by the operation unit main body and the attachment, but also in a three-dimensional direction with respect to the operation unit when the mobile terminal is operated by the operator. 
     One aspect of this disclosure is a safety switch device including a device main body; and a movable portion capable of moving in a predetermined moving direction with respect to the device main body, wherein the device main body is provided with a back surface supporting portion having a supporting surface which supports a back surface of a mobile terminal and a main-body-side holding portion which pushes one side of the mobile terminal in a state where the mobile terminal is supported by the back surface supporting portion, the movable portion is provided with a movable-portion-side holding portion which is located at a position opposite to the main-body-side holding portion in the moving direction and which pushes the other side of the mobile terminal, each of the main-body-side holding portion and the movable-portion-side holding portion is provided with an inclined surface which comes into close contact with the one side or the other side of the mobile terminal, each of the inclined surfaces inclines in a direction where the inclined surfaces get close to each other in the moving direction as being distant from the supporting surface in a direction orthogonal to the supporting surface, and a processing which makes an area of the supporting surface have a friction coefficient higher than that of surfaces of other portions of the device main body is performed, the area coming into close contact with the back surface of the mobile terminal. 
     A safety switch device  1  according to a first embodiment of the present invention will be described below with reference to the accompanying drawings. 
     As shown in  FIG.  1   , the safety switch device  1  of this embodiment includes a device main body  2  having a longitudinal direction, and a slider (a movable portion)  3  which is attached to the device main body  2  so as to be movable along the longitudinal direction (moving direction: Y direction). The device main body  2  and the slider  3  are made of a hard plastic material, for example. 
     As shown in  FIG.  1   , the device main body  2  is provided with an emergency stop button  4  at a front surface side, and as shown in  FIGS.  2  and  3   , the device main body  2  is provided with a dead man switch  5  at a back surface side. The emergency stop button  4  is placed at a position in a vicinity of one end side of the device main body  2  in the longitudinal direction. A cable  6  for connecting the emergency stop button  4  and the dead man switch  5  to a control unit (not shown) is provided at the other end side of the device main body  2  in the longitudinal direction. 
     As shown in  FIG.  4   , the dead man switch  5  is placed at a position where a point finger or a thumb of the hand of an operator holding the device main body  2  is just placed when holding the device main body  2  in the right hand or the left hand. When the operator pushes the dead man switch  5  by using his/her point finger or thumb of the hand holding the device main body  2 , operation of a mobile terminal  100  is allowed, and when the operator releases the finger from the dead man switch  5 , the device main body  2  becomes in a state of emergency stop. 
     As shown in  FIGS.  1  and  2   , the front surface side of the device main body  2  is provided with a back surface supporting portion  7  which supports a back surface of the mobile terminal  100  when attaching the mobile terminal  100  to the device main body  2 , and a first holding portion (main-body-side holding portion)  8  placed at one end side of the back surface supporting portion  7  in the longitudinal direction. The back surface supporting portion  7  includes a flat surface (a supporting surface)  7   a  extends in two directions which are a Y direction and an X direction orthogonal to the Y direction. 
     A sheet  9  made of a material, such as a silicon rubber, with higher friction coefficient than surfaces of the other portions of the device main body  2 , is fixed to the flat surface  7   a.    
     As shown in  FIGS.  5  and  7   , the first holding portion  8  includes a protruded contact surface (a base portion at the main body side)  10  which extends from one end of the flat surface  7   a  in the Y direction and in Z directions which are orthogonal to the flat surface  7   a  so that the protruded contact surface  10  comes into contact with one end edge of the mobile terminal  100 . Also, the first holding portion  8  includes a first elastic member  11  which is removably attached to the protruded contact surface  10 , and which is made of an elastic material. 
     As shown in  FIGS.  7  and  8   , a protrusion (a protruding portion)  12  which protrudes in the Y direction is provided on the protruded contact surface  10 , and hook parts  13  are provided on the protrusion  12 . The hook parts  13  are arranged at two positions with a space in the X direction so as to protrude in a direction getting close to the flat surface  7   a  along a Z direction. 
     As shown in  FIG.  5   , the first elastic member  11  includes an inclined surface  14  which is a plane surface inclined so as to be distant from the protruded contact surface  10  in the Y direction as being distant from the flat surface  7   a  in the Z direction in a state where the first elastic member  11  is attached to the protruded contact surface  10 . 
     Also, as shown in  FIG.  6   , the first elastic member  11  is provided with a recessed portion  15  having a shape (a shape complementary with the protrusion  12  and the hook parts  13 ) into which the protrusion  12  and the hook parts  13  of the protruded contact surface  10  are fitted. The first elastic member  11  is attached to the protruded contact surface  10  by fitting the protrusion  12  and the hook parts  13  in the recessed portion  15  while deforming the recessed portion  15  by elastic deformation and restoring the elastically deformed shape of the recessed portion  15 . 
     As shown in  FIG.  1   , the slider  3  includes a strip-shaped sliding portion  16  which is housed in a groove (not shown) provided in the device main body  2  so as to be movable in the Y direction, and a second holing portion (movable-portion-side holding portion)  17  provided at one end of the sliding portion  16 . As shown in  FIG.  9   , the second holding portion  17  also includes a protruded contact surface (a base portion at the movable portion side)  18  which extends from the sliding portion  16  in the Z directions orthogonal to the Y direction so that the protruded contact surface  18  abuts against one end edge of the mobile terminal  100 , and a second elastic member  19  which is removably attached to the protruded contact surface  18 , and which is made of an elastic material. 
     The second elastic member  19  also has an inclined surface  20  which is a plane surface inclining in a direction so as to be distant from the protruded contact surface  18  in the Y direction as being distant from the flat surface  7   a  of the device main body  2  in the Z direction in a state where the second elastic member  19  is attached to the protruded contact surface  18 . 
     Also, similar to or the same as the protruded contact surface  10 , the protruded contact surface  18  also includes a plate-like protrusion which protrudes in the Y direction, and hook parts are provided on the protrusion. The hook parts are arranged at two positions with a space in the X direction so as to protrude in a direction getting close to the flat surface  7   a  along the Z direction. 
     The second elastic member  19  is provided with a recessed portion having a shape into which the protrusion and the hook parts of the protruded contact surface  18  are fitted. The second elastic member  19  is removably attached to the protruded contact surface  18  by fitting the protrusion and the hook parts into the recessed portion while deforming the recessed portion by elastic deformation, and restoring the elastically deformed shape of the recessed portion. The figures of the protrusion of the protruded contact surface  18  and the recessed portion of the second elastic member  19  are omitted because the shapes thereof are similar to or the same as those of the protruded contact surface  10  and the first elastic member  11 . 
     As shown in  FIGS.  1  and  2   , the first holding portion  8  and the second holding portion  17  are placed at positions opposite to each other in the Y direction. Therefore, the inclined surface  14  of the first elastic member  11  provided in the first holding portion  8  and the inclined surface  20  of the second elastic member  19  provided in the second holding portion  17  are inclined in the direction in which the inclined surfaces  14  and  20  get close to each other as getting distant from the flat surface  7   a  in the Z direction. 
     The operation of the safety switch device  1  according to this embodiment having the above mentioned configuration will be described below. 
     The safety switch device  1  according to this embodiment is used with the mobile terminal  100  attached thereto. 
     Multifunctional mobile phones (smart phones) or tablet terminals or the like can be used as the mobile terminal  100 . In order to attach the mobile terminal  100  to the safety switch device  1 , the slider  3  is pulled in the device main body  2  in the Y direction, and the back surface of the mobile terminal  100 , which is placed between the first holding portion  8  and the second holding portion  17 , comes into close contact with the sheet  9  of the flat surface  7   a.    
     In this state, the slider  3  is pushed against the device main body  2  in the Y direction, and the mobile terminal  100  is held between the first holding portion  8  and the second holding portion  17 . By this, the mobile terminal  100  is attached to the safety switch device  1 . The position of the slider  3  with respect to the device main body  2  can freely be changed in the Y direction. Therefore, it is possible to attach mobile terminals  100  of different sizes to the safety switch device  1  easily. 
     In this state, the inclined surface  14  of the first elastic member  11  provided in the first holding portion  8  comes into close contact with one end edge of the mobile terminal  100  in the Y direction as shown in the  FIG.  5   . On the other hand, the inclined surface  20  of the second elastic member  19  provided in the second holding portion  17  comes into close contact with the other end edge of the mobile terminal  100  in the Y direction as shown in  FIG.  9   . 
     The two inclined surfaces  14 ,  20  are inclined in the direction so that the inclined surfaces  14 ,  20  get close to each other as getting distant from the flat surface  7   a , therefore, as shown in  FIG.  8   , at a point where each of the inclined surfaces  14 ,  20  and the mobile terminal  100  come into close contact with each other, a pressure force F is acted on the mobile terminal  100  from the side of the inclined surfaces  14 ,  20  in a direction orthogonal to the inclined surfaces  14 ,  20 . The pressure force F generates force components fy, fz in the Y direction and the Z direction. The force component fy in the Y direction is acted on the first holding portion  8  and that on the second holding portion  17  at an equal magnitude in the opposite directions, therefore the force component fy acted on the first holding portion  8  and that on the second holding portion  17  are counterbalanced with each other. 
     The mobile terminal  100  is pushed against the flat surface  7   a  of the device main body  2  by the force component fz in the Z direction. By this, the mobile terminal  100  is fixed so as not to move with respect to the device main body  2  in the Z direction. Also, the sheet  9  made of a material with higher friction coefficient is fixed to the flat surface  7   a , large friction force is acted between the device main body  2  and the mobile terminal  100  in the X and Y directions. That is to say, the mobile terminal  100  cannot be moved in the X and Y directions unless force exceeding the large friction force is acted with respect to the device main body  2 , and therefore the mobile terminal  100  is fixed to the device main body  2  more certainly. 
     Also, since the inclined surfaces  14 ,  20  coming into contact with one edge and the other edge of the mobile terminal  100  are provided in the first elastic member  11  and the second elastic member  19 , the first elastic member  11  and the second elastic member  19  are elastically deformed at a position contacting with the mobile terminal  100  so as to increase a contact area with the mobile terminal  100 . By this, the friction force generated between the first elastic member  11  and the second elastic member  19 , and the mobile terminal  100 , especially the friction force in the X direction is increased, which prevents the mobile terminal  100  from being moved with respect to the device main body  2  in the X direction more effectively. 
     Further, a ratchet mechanism (not shown) may be placed between the device main body  2  and the a slider  3  in order to move the slider  3  with respect to the device main body  2  in the Y direction and maintain the slider  3  at the moved position. In this case, an interval between the first holding portion  8  and the second holding portion  17  is adjusted gradually at a pitch of teeth of the ratchet mechanism. 
     In this case, by providing the first elastic member  11  to the first holding portion  8  and the second elastic portion  19  to the second holding portion  17 , the mobile terminal  100  can be inserted between the first holding portion  8  and the second holding portion  17  even when the distance therebetween is adjusted in a stepwise manner, which is advantageous. 
     And, since the first elastic member  11  and the second elastic member  19  are removably attached to the protruded contact surfaces  10 ,  18 , the first and the second elastic members  11 ,  19  can be replaced by an elastic member with an ideal shape or material in accordance with the thickness of the mobile terminal  100  which is to be attached or the shape of the edge thereof. In this case, the first elastic member  11  and the second elastic member  19  are elastically deformed and removed from the protrusion  12  and the hook portions  13 , and the attachment thereof is easily performed by elastically deforming the first elastic member  11  and the second elastic member  19  so that the protrusion  12  and the hook portions  13  are fitted into the recessed portion  15 . 
     And, the first elastic member  11  and the second elastic member  19  receive a reaction force fz′ generated in a direction which is opposite to the force component fz generated in the direction pushing the mobile terminal  100  against the flat surface  7   a.    
     In this embodiment, the hook portions  13  extend in the direction opposite to the reaction force fz′ acted on the first elastic member  11  and the second elastic member  19  so as to be fitted into the recessed portion  15 , which prevents the protrusion  12  from coming out from the recessed portion  15  due to the reaction force. 
     As shown in  FIG.  4   , in order to use the mobile terminal  100  which is in a state where the safety switch device  1  is attached thereto, the operator holds the device main body  2  of the safety switch device  1  placed at the back surface of the mobile terminal  100  by using the left hand or the right hand. And the operator uses the pointing finger or the thumb of the hand holding the device main body  2  to press the dead man switch  5 . By this, the operator is allowed to operate the mobile terminal  100 , and therefore the operator can teach the robot and the like. 
     Also, when the emergency stop button  4  provided in the safety switch device  1  is pushed, or the dead man switch  5  is no longer pushed while teaching the robot, the robot can be in the state of emergency stop. 
     In this state, the operator directly holds the device main body  2  only, but does not hold the mobile terminal  100  directly. According to this embodiment, the above configuration allows the device main body  2  to stably hold the mobile terminal  100  so that the mobile terminal  100  is not displaced in any of the directions X, Y, Z with respect to the device main body  2  when its own weight or large external force is applied to the mobile terminal  100 , which is advantageous. 
     Also, in this embodiment, the first elastic member  11  and the second elastic member  19  include the flat and inclined surfaces  14 ,  20 , however, instead of this, inclined surfaces  14 ,  20  having a curved surface may be provided. In this case, as shown in  FIG.  10   , the inclined surfaces  14 ,  20  may be curved in such a form that an angle between each of the inclined surface and the flat surface  7   a  of the device main body  2  becomes smaller as the inclined surfaces are distant from the flat surface  7   a  in the Z direction. 
     By this, as shown in  FIG.  10   , it is possible to increase the force component in the Z direction which is applied to the mobile terminal  100  from the first elastic member  11  and the second elastic member  19  as the thickness of the mobile terminal  100  which is to be attached becomes greater and the weight thereof becomes heavier. Accordingly, the mobile terminal  100  can be held by the larger force in the XYZ directions, which is advantageous. 
     Also, the inclined surfaces  14 ,  20  are provided in the first elastic member  11  and the second elastic member  19  which are removable from the protruded contact surfaces  10 ,  18 , but instead of this, the first elastic member  11  and the second elastic member  19  may be fixed to the protruded contact surfaces  10 ,  18 . Also, the protruded contact surfaces  10 ,  18  themselves may be the inclined surfaces  14 ,  20  without providing the first elastic member  11  and the second elastic member  19 . 
     Further, each of the protrusion  12  includes the hook portions  13  located at two positions with a space in the X direction, however, any number more than one of the hook portions  13  may be provided.