Device for fixing work in position

A device for fixing a work in position on a base having a protrusion and a hole formed adjacent the protrusion for mounting the device, comprising:

• a rotational member mountable in the hole of the base and rotatable around the axis of the hole, said rotational member having
• a shank insertable into the hole of the base,
• a head disposed on an upper end of said shank and having a lateral surface for pressing the work against the protrusion, the distance from the rotational axis of said rotational member to said lateral surface being varied in a circumferential direction of said head,
• an engaging recess formed on said head coaxially with said shank and opened at its upper portion for engagement with a tool for rotating said rotational member, and
• a threaded hole extending from said head to said shank along the rotational axis of said rotational member and joined to the bottom portion of said engaging recess;
• a screw member threadably engaged with said threaded hole of said rotational member and having an engaging portion for engagement with another tool for rotating said screw member, said engaging portion being disposed at the upper end of said screw member and being disposed on an axis of said screw member;
• and
• expanding means provided with said shank of said rotational member and operably by said screw member for expanding laterally so as to prohibit rotation of said rotational member in accordance with the axial movement of said screw member;
• whereby said screw member can be positioned below said engaging recess when said rotational member is rotated by said tool through engagement with said engaging recess, and said screw member can be rotated by said another tool to operate said expanding means through engagement with said engaging portion via said engaging recess after said rotational member has been rotated to position said lateral surface of said head in contacting relation to the work.