Expansion appliance for correcting tooth misalignments

Expansion appliance for correcting tooth misalignments having the following features:

• a first member (1);
• a second member (2);
• a spindle (3) which, for changing the relative distance between the first (1) and the second member (2), engages in the two members (1,2) in such a way that the distance can be varied by a predeterminable limited magnitude in the longitudinal direction of the spindle (3) while the spindle (3) is in a stationary position,
• there are provided two parallel guide rods (21), located on both sides of the spindle (3);
• for guiding the first member (1) and the second member (2) in straight alignment the guide rods (21) are received and guided in holes (20) in the two members (1,2), which extend in parallel one to the other and each of which is open toward the respective other member (2, 1);
• a compression spring (22) is tensioned between at least one end of each guide rod (21) and the respective opposite end of the hole (20), this end of the hole (20) being closed;
• wherein
• the spindle (3) comprises an actuating section (5) and, projecting therefrom, a threaded section (6);
• the actuating section (5) of the spindle (3) is arranged in an orifice (32) in the second member (2);
• the threaded section (6) sits in a threaded bore (31) provided in the first member (1);
• the actuating section (5) of the spindle (3) can be displaced in that orifice (32) by rotation of the spindle (3);
• a stop (33) for the actuating section (5) is provided in the orifice (32) between the actuating section (5) of the spindle (3) and the first member (1).

Expansion appliance for correcting tooth misalignments having the following features:

• a first member (1);
• a second member (2);
• a spindle (3) for varying the relative spacing between the first (1) and the second member (2);
• the spindle (3) comprises an actuating section (5) and projecting therefrom, two threaded sections (6,7), which extend in opposite directions and have oppositely directed threads;
• the threaded sections (6,7) extend into orifices (8,9) provided in the two members (1,2);
• each of the two orifices (8,9) accommodates a nut (16,17) that is screwed onto threaded section (6,7) located in the respective orifice (8,9);
• the nut (16,17) is secured against rotation in the orifice (8,9) and displaceable along the threaded section (6,7) of the spindle (3) by rotation of the spindle (3);
• a stop (18,19) for the nut (16,17) is provided in the orifices (8,9) between the actuating section (5) of the spindle (3) and the respective nut (16,17);
• there are provided two parallel guide rods (21), located on both sides of the spindle (3);
• for guiding the first member (1) and the second member (2) in straight alignment the guide rods (21) are received and guided in holes (20) in the two members (1,2), which extend in parallel one to the other and each of which is open toward the respective other member (2, 1);
• a pseudoelastic compression spring (22) is tensioned between at least one end of each guide rod (21) and the respective opposite end of the hole (20), this end of the hole (20) being closed.

Expansion appliance for correcting tooth misalignments having the following features:

• a first member (1);
• a second member (2);
• a spindle (3) for varying the relative spacing between the first (1) and the second member (2);
• the spindle (3) comprises an actuating section (5) and, projecting therefrom, a threaded section (6);
• the actuating section (5) of the spindle (3) is arranged in an orifice (32) of the second member (2);
• there are provided two parallel guide rods (21), located on both sides of the spindle (3);
• for guiding the members (1, 2) in straight alignment the guide rods (21) are received and guided in holes (20) in the two members (1, 2), which extend in parallel one to the other and each of which is open toward the respective other member (2, 1);
• the threaded section (6) sits in a threaded bore (31) provided in the first member (1),
• the actuating section (5) of the spindle (3) can be displaced in the orifice (32) by rotation of the spindle (3);
• a stop (33) for the actuating section (5) is provided in the orifice (32) between the actuating section (5) of the spindle (3) and the first member (1);
• a compression spring (22) is tensioned between at least one end of each guide rod (21) and the respective opposite end of the hole (22), this end of the hole (20) being closed.

Expansion appliance for correcting tooth misalignments having the following features:

• a first member (1);
• a second member (2);
• a spindle (3) for varying the spacing between the first (1) and the second member (2);
• the spindle (3) comprises an actuating section (5) and, projecting therefrom, a threaded section (6);
• the actuating section (5) of the spindle (3) is arranged in an orifice (32) in the second member (2);
• the threaded section (6) extends into an orifice (8) provided in the first member (1);
• a nut (16) is provided in the orifice (8), the nut being screwed onto the threaded section (6) located in the orifice (8);
• the nut (16) is secured against rotation in the orifice (8) and can be displaced along the threaded section (6) of the spindle (3) by rotation of the spindle (3);
• a stop (18) for the nut (16) is provided in the orifice (8) between the actuating section (5) of the spindle (3) and the nut (16).