Asymmetrical toothed wheel
A device comprises supports (3, 4) which can be moved relative to each other, and on mutually facing walls of which toothed profiles (6, 7) are provided. Each toothed profile interacts with opposing segments (31, 32) of a rotatable gear (2), by the rotation of which the supports (3, 4) can be moved in opposite directions simultaneously in a synchronized manner. The gear (2) has a varying tip circle diameter (d) along the gear circumference, wherein the tip circle diameter (d) increases along a segment (31, 32), and an effective outer diameter (d w ) of the gear (2) is arranged between the supports (3, 4) in a clamped rotational position, so that the effective outer diameter (d w ) matches a target diameter.
1. A device with supports ( 3 , 4 ) which are capable of being moved with respect to each other and mutually facing inner walls of which have provided on them toothed profiles ( 6 , 7 ) which co-operate in each case with opposed segments ( 31 , 32 ) of a rotatable toothed wheel ( 2 ), by the rotation of which the supports ( 3 , 4 ) are capable of being simultaneously moved in synchronism in opposed directions, the toothed wheel ( 2 ) has a differing tip circle diameter (d) along its periphery, characterized in that the tip circle diameter (d) increases along a segment ( 31 , 32 ) and an effective external diameter (dw) of the toothed wheel ( 2 ) is present between the supports ( 3 , 4 ) in a clamped rotational setting and the effective external diameter (dw) corresponds to a nominal diameter.
2. A device according to claim 1 , characterized in that the tip circle diameter (d) increases in a direction of rotation along the segment ( 31 , 32 ) of the toothed wheel ( 2 ).
3. A device according to claim 2 , characterized in that the tip circle diameter (d) increases in a continuous manner along the segment ( 31 , 32 ) of the toothed wheel ( 2 ).
4. A device according to claim 3 , characterized in that one of the opposed segments ( 32 ) is capable of being imaged onto the other of the opposed segments ( 31 ) by 180° rotation about an axis of rotation of the toothed wheel ( 2 ).
5. A device according to claim 4 , characterized in that a maximum change in the tip circle diameter (d) is between 0.01 mm and 0.15 mm.
6. A device according to claim 5 , characterized in that each of the supports ( 3 , 4 ) has a clamping jaw ( 11 , 12 ), which clamping jaws ( 11 , 12 ) co-operate, and the toothed wheel ( 2 ) is rotatable between an opened rotational setting, in which the clamping jaws ( 11 , 12 ) are moved apart from each other and release the article ( 16 ), and a clamped rotational setting, in which the two clamping jaws ( 11 , 12 ) are moved so far towards each other that they clamp the article ( 16 ).