Patent Number: 050013513
Section: claims

1. An object holder for positioning an object in a radiation beam comprising: a base;  means for securing a plate member to the base, said plate member having a planar face surface;  an X-guide movably secured to the base and translatable in X-directions relative to said plate member, said guide including first slide means for sliding in abutting relation on said face surface in said X-directions; and  a Y-guide secured to the X-guide and translatable in Y-directions, said Y-guide including second slide means for sliding in abutting relation on said face surface in said Y-directions;  one of said guides including means to receive said object to be positioned in said radiation beam.  a base;  means for securing a plate member to the base, said plate member having a planar face surface;  an X-guide movably secured to the base and translatable in X-directions relative to said plate member;  an X-transporter secured to said guide;  first slide means secured to the X-transporter for sliding in abutting relation on said face surface in said X-directions;  a Y-guide secured to the X-transporter and translatable in Y-directions;  a Y-transporter secured to said Y-guide;  second slide means secured to the Y-transporter for sliding in abutting relation on said face surface in said Y-directions; and  means for rotatably securing an object support table to said Y-guide. 2. The object holder of claim 1 wherein said X-guide includes an X-transporter and means for securing the first slide means to the X-transporter and the Y-guide includes a Y-transporter and means for securing the second slide means to the Y-transporter. 3. An object holder as claimed in claim 2, including permanent magnets which are secured to the X-transporter and to the Y-transporter and which magnets bear on the supporting face of the supporting plate via intermediate sliding pieces. 4. An object holder as claimed in claim 1, further including a rotation mechanism for rotating the supporting plate about an axis extending transversely of the supporting face thereof. 5. An object holder as claimed in claim 4, characterized in that rotation has an extent of at least 360.degree.. 6. An object holder as claimed in claim 1, further including a tilt mechanism for tilting the supporting plate about an axis extending parallel to the supporting face thereof. 7. An object holder as claimed in claim 6, characterized in that said tilt mechanism includes a plurality of bushings for providing a tilting movement, said bushings having cut-outs which act as passages for a radiation beam. 8. The object holder of claim 1 wherein said first and second slide means each include magnet means for magnetically forcing the X and Y slide means in said abutting relations. 9. The object holder of claim 8 wherein said magnet means are permanent magnets, said sliding means each including sliding members intermediate said magnets and said face surface. 10. The object holder of claim 1 wherein said Y-guide is to receive said means adapted to receive said object. 11. An object holder for positioning an object in a radiation beam comprising: 12. The object holder of claim 11 wherein said first and second slide means each include magnet means and ductile interface means, said magnet means being secured to said transporters and said ductile means being secured to said magnet means intermediate said magnet means and said face surface, said ductile means for sliding on said face surface.