We Claim:
1. A terminal device comprising:
a terminal block; and
a housing configured to house said terminal block,
wherein said housing is provided with an electrical cable insertion hole designed for inserting an electrical cable into said housing,
said terminal block comprising a terminal plate and a locking spring,
said terminal plate including a contact part,
said contact part having a contact surface designed to come into contact with a side of the electrical cable inserted into said housing via said electrical cable insertion hole,
said locking spring being made of a resilient metal material, and including a central part, a locking part, a touching part, and a linking section,
said central part being placed opposite to said contact surface, and having a first end close to said electrical cable insertion hole and a second end far from said electrical cable insertion hole,
said locking part extending from said first end of said central part toward said contact surface of said contact part so as to form an acute angle between said locking part and said central part, and being configured to resiliently deform away from said contact surface when pressed by the electrical cable inserted into said housing via said electrical cable insertion hole, thereby holding the electrical cable between said locking part and said terminal plate,
said touching part being placed in contact with a surface of said contact part opposite from said contact surface, and
said linking section being configured to integrally connect said touching part to said second end of said central part, characterized in that
said contact part has a first end close to said electrical cable insertion hole and a second end far from said electrical cable insertion hole,
said connection part having a first surface close to said electrical cable insertion hole and a second surface far from said electrical cable insertion hole, and
said terminal plate including a supporting part extending from said second end of said contact part so as to come into contact with said second surface of said connection part.
2. A terminal device comprising:
a terminal block; and
a housing configured to house said terminal block,
wherein said housing is provided with an electrical cable insertion hole designed for inserting an electrical cable into said housing,
said terminal block comprising a terminal plate and a locking spring,
said terminal plate including a contact part,
said contact part having a contact surface designed to come into contact with a side of the electrical cable inserted into said housing via said electrical cable insertion hole,
said locking spring being made of a resilient metal material, and including a central part, a locking part, a touching part, and a linking section,
said central part being placed opposite to said contact surface, and having a first end close to said electrical cable insertion hole and a second end far from said electrical cable insertion hole,
said locking part extending from said first end of said central part toward said contact surface of said contact part so as to form an acute angle between said locking part and said central part, and being configured to resiliently deform away from said contact surface when pressed by the electrical cable inserted into said housing via said electrical cable insertion hole, thereby holding the electrical cable between said locking part and said terminal plate,
said touching part being placed in contact with a surface of said contact part opposite from said contact surface, and

said linking section being configured to integrally connect said touching part to said second end of said central part, characterized in that
said terminal plate includes a pair of wall parts extending toward said central part from respective opposite ends of said contact part in an orthogonal direction orthogonal to a normal direction of said contact surface and a central axis direction of said electrical cable insertion hole.
3. A terminal device comprising:
a terminal block; and
a housing configured to house said terminal block,
wherein said housing is provided with an electrical cable insertion hole designed for inserting an electrical cable into said housing,
said terminal block comprising a terminal plate and a locking spring,
said terminal plate including a contact part,
said contact part having a contact surface designed to come into contact with a side of the electrical cable inserted into said housing via said electrical cable insertion hole,
said locking spring being made of a resilient metal material, and including a central part, a locking part, a touching part, and a linking section,
said central part being placed opposite to said contact surface, and having a first end close to said electrical cable insertion hole and a second end far from said electrical cable insertion hole,
said locking part extending from said first end of said central part toward said contact surface of said contact part so as to form an acute angle between said locking part and said central part, and being configured to resiliently deform away from said contact surface when pressed by the electrical cable inserted into said housing via said electrical cable insertion hole, thereby holding the electrical cable between said locking part and said terminal plate,
said touching part being placed in contact with a surface of said contact part opposite from said contact surface, and
said linking section being configured to integrally connect said touching part to said second end of said central part, characterized in that
said terminal plate includes a limiting part, said limiting part being configured to come into contact with said locking part when said locking part is pushed to a predetermined position by the electrical cable, thereby limiting a movement of said locking part in order to prevent plastic deformation of said locking spring.
4. A terminal device as set forth in anyone of claims 1 to 3, wherein
said terminal plate is configured to bias said contact part such that said contact surface is closer to a center of said electrical cable insertion hole than an inner circumferential surface of said electrical cable insertion hole is.
5. A terminal device as set forth in anyone of claims 1 to 4, wherein
said supporting part includes a base section close to said second end of said contact part and an apex section far from said second end of said contact part, and is provided with a cutout between said base section and said apex section,
said connection part including a first section in contact with said base section of said supporting part at said first surface, a second section in contact with said apex section of said supporting part at said second surface, and a linking section extending through said cutout of said supporting part so as to integrally connect said first section to said second section.
6. A terminal device as set forth in claim 2, wherein
said wall part includes a bottom section extending from said contact part toward said central part, and a top section extending from an apex of said bottom section away from said electrical cable insertion hole.

7. A terminal device as set forth in anyone of claims 1 to 6, wherein
said terminal plate includes a second wall part,
said second wall part extending from said supporting part toward said electrical cable insertion hole such that an electrical cable inserted into said housing via said electrical cable insertion hole is positioned between said contact part and said second wall part.
8. A terminal device as set forth in claim 7, wherein
a normal direction of a surface of each of said wall parts facing the electrical cable is perpendicular to a normal direction of a surface of said second wall part facing the electrical cable.
9. A terminal device as set forth in claim 7 or 8, wherein
said terminal plate is made of a metal plate,
each of said wall parts and said second wall part being formed by means of bending a part of the metal plate,
said second wall part having a dimension in an orthogonal direction orthogonal to a normal direction of said
contact surface and a central axis direction of said electrical cable insertion hole, and the dimension being greater
than a distance between the pair of said wall parts.
10. A terminal device as set forth in anyone of claims 1 to 9, further comprising a plurality of said terminal blocks,
wherein said housing is provided with an insulation wall configured to electrically insulate said terminal blocks from each other.
11. A terminal device as set forth in claim 4, further comprising a limiting means, said limiting means being
configured to come into contact with said contact part when said contact part is pushed to a predetermined position
by the electrical cable,
thereby limiting a movement of said contact part in order to prevent plastic deformation of said terminal plate.
12. A terminal device as set forth in claim 4 or 11, wherein
said contact part is provided with a slit.
13. A terminal device as set forth anyone of claims 1 to 12, wherein
said contact surface is provided with a recess configured to receive the electrical cable pressed by said locking part.
14. A terminal device as set forth in anyone of claims 1 to 12, wherein
said contact surface is provided with a groove along an orthogonal direction orthogonal to a normal direction of said contact surface and a central axis direction of said electrical cable insertion hole.
15. A terminal device as set forth anyone of claims 1 to 12, wherein
said locking part extends so as to have its apex in contact with said contact surface.
16. A terminal device as set forth anyone of claims 1 to 15, wherein
said contact surface is provided with a protrusion.
17. A terminal device as set forth in claim 16, wherein
said protrusion is formed into a hemi-cylindrical shape with a central axis extending in an orthogonal direction orthogonal to a normal direction of said contact surface and a central axis direction of said electrical cable insertion hole.
18. A terminal device as set forth in claim 17, wherein
said contact surface is provided with said two protrusions,

said two protrusions being arranged such that an apex of said locking part is positioned between said two protrusions in the central axis direction of said electric cable insertion hole while said terminal plate and said locking part hold the electrical cable therebetween.
19. A terminal device as set forth in claim 4, further comprising an unlocking member used for disconnecting the
electrical cable from said terminal block,
wherein said unlocking member comprises:
a main body portion housed in said housing so as to move between an initial position and an unlocking position;
a manipulation portion disposed outside said housing and designed to move said main body portion in response to manual operation thereof;
a first pressing portion configured to press said locking part in the opposite direction from said contact part in response to a movement of said main body portion from the initial position to the unlocking position, thereby displacing said locking part away from the electrical cable; and
a second pressing portion configured to press said contact part in the opposite direction from said locking part in response to the movement of said main body portion from the initial position to the unlocking position, thereby displacing said contact part away from the electrical cable.
20. A terminal device as set forth in claim 19, further comprising a limiting means configured to come into contact with said unlocking member, thereby limiting a movement of said first pressing portion to a position where said first pressing portion causes plastic deformation of said locking spring as well as a movement of said second pressing portion to a position where said second pressing portion causes plastic deformation of said terminal plate.
21. A terminal device as set forth in claim 20, wherein
said main body portion includes a plate section placed adjacent to said terminal block in an orthogonal direction orthogonal to a normal direction of said contact surface and a central axis direction of said electrical cable insertion hole,
said plate section having an opposite surface facing said terminal block, said first pressing portion and said second pressing portion being provided to said opposite surface, said opposite surface being provided with a protruded piece, and said protruded piece being configured to come into contact with said terminal plate when said main body portion is moved from the initial position to the unlocking position, thereby displacing said main body portion away from said locking spring.
22. A terminal device as set forth in claim 21, wherein
said main body portion includes said two plate sections,
said two plate sections being arranged opposite to each other in the orthogonal direction such that said terminal block is interposed between said plate sections, and
said manipulation portion being configured to integrally connect said two plate sections.