Form-fit adjustment device for a caster
A formfitting securing apparatus for a caster includes a running wheel, a fork and a rotation-blocking engagement part, for rotationally blocking the running wheel of the caster with respect to a geometric impeller wheel axis. A first spring also acts on the rotation-blocking engagement part in order to move it from an initial position into an engagement position. The first spring is formed by a lever arm of a lever part, a second spring can, with the movement of the rotation-blocking engagement part into the engagement position, be tensioned for the return movement back into the initial position, and the first spring is stronger than the second spring. Furthermore, a fork-shaped ram part can have ram extensions of different lengths, with only one ram extension being arranged to act on the lever part.
1 . A caster ( 1 ) comprising a form-fit locking device ( 14 ), a running wheel ( 2 ) and a fork ( 3 ), wherein the form-fit locking device is attached to the caster, the form-fit locking device comprising:
a rotation blocking engagement part ( 43 ) configured for rotationally blocking the running wheel ( 2 ) of the caster ( 1 ) in relation to a geometric running wheel axis (y), wherein the rotation blocking engagement part ( 43 ) is movable from a starting position into an engagement position, and wherein the rotation blocking engagement part ( 43 ) is form-fittingly connected to the running wheel ( 2 ) in such a way that in the engagement position the running wheel ( 2 ) is rotationally blocked, and in the starting position the running wheel ( 2 ) is freely rotatable,
a first spring ( 58 ) that acts on the rotation blocking engagement part ( 43 ) and is configured for displacing the rotation blocking engagement part ( 43 ) from the starting position into the engagement position, wherein the first spring ( 58 ) is mounted on a pivotable lever part ( 41 ), and wherein the first spring ( 58 ) forms a lever arm ( 68 ) which is part of the first spring ( 58 ) and is itself correspondingly resilient, and
a second spring ( 59 ) mounted on the lever part, wherein, with the displacement of the rotation blocking engagement part ( 43 ) into the engagement position, the second spring ( 59 ) is tensioned for a return movement of the rotation blocking engagement part into the starting position, and wherein the first spring ( 58 ) is stronger than the second spring ( 59 ).
2 . The caster according to claim 1 , wherein both the first spring ( 58 ) and the second spring ( 59 ) are substantially detensioned in the starting position, so that the first spring ( 58 ) and the second spring ( 59 ) exert no or no significant spring force on the lever part ( 41 ) and the rotation blocking engagement part ( 43 ).
3 . The caster according to claim 1 , wherein the first spring ( 58 ) is designed as a torsion spring.
4 . The caster according to claim 1 , wherein the second spring ( 59 ) is designed as a torsion spring.
5 . The caster according to claim 1 , wherein the second spring ( 59 ) acts between the lever part ( 41 ) and a mounting part ( 45 ) fixed to the fork.
6 . The caster according to claim 5 , wherein the second spring ( 59 ) surrounds a mounting pin ( 53 ) of the mounting part ( 45 ).
7 . The caster according to claim 1 , wherein the first spring ( 58 ) and the second spring ( 59 ) respectively act on one end on the lever part ( 41 ).
8 . The caster according to claim 1 , wherein the first spring ( 58 ) acts solely between the lever part ( 41 ) and the rotation blocking engagement part ( 43 ).
9 . The caster according to claim 1 , wherein the first spring ( 58 ) is guided in a groove ( 65 ) of the lever part ( 41 ).
10 . The caster according to claim 1 , wherein the lever part ( 41 ) has a first actuating end ( 55 ), configured to act on the rotation blocking part ( 43 ) and a second actuating end ( 56 ) configured to interact with a tappet part ( 33 ), said tappet part ( 33 ) being configured for actuating the form-fit locking device ( 14 ).
11 . A caster comprising a form-fit locking device ( 14 ), a running wheel ( 2 ), and a fork ( 3 ), wherein the form-fit locking device ( 14 ) is attached to the caster ( 1 ), the form-fit locking device comprising:
a rotation blocking engagement part ( 43 ) configured for rotationally blocking the running wheel ( 2 ) of the caster ( 1 ) with respect to a geometric running wheel axis (y), wherein the rotation blocking engagement part ( 43 ) is movable from a starting position into an engagement position, and wherein the rotation blocking engagement part ( 43 ) is form-fittingly connected to the running wheel ( 2 ) in such a way that in the engagement position the running wheel ( 2 ) is rotationally blocked and in the starting position the running wheel ( 2 ) is freely rotatable,
a lever part ( 41 ) configured for displacing the rotation blocking engagement part ( 43 ) from the starting position into the engagement position and/or from the engagement position into the starting position,
wherein additionally the lever part is actuatable by means of a tappet part ( 33 ), wherein the tappet part ( 33 ) is formed in the shape of a fork, with tappet extensions ( 35 , 36 ) of different lengths, wherein only one tappet extension ( 35 , 36 ) is arranged to act on the lever part ( 41 ), wherein, in an operation state of the caster ( 1 ), the tappet extensions ( 35 , 36 ) extend substantially in a vertical direction, and wherein the tappet extensions ( 35 , 36 ) extend on both sides and along a mounting pin axis of a mounting pin ( 4 ) of the caster which defines a geometric pivot axis (x) of the caster ( 1 ), and wherein the fork ( 3 ) is pivotable around the pivot axis (x).
12 . The caster according to claim 11 , wherein the tappet part ( 33 ) is actuatable by a switching tappet ( 12 ).
13 . The caster according to claim 12 , wherein the switching tappet ( 12 ) interacts with a first return spring ( 19 ).
14 . The caster according to claim 11 , wherein the tappet part ( 33 ) interacts with a return spring ( 42 ).
15 . The caster according to claim 14 , wherein the return spring ( 42 ) interacts directly only with one of the tappet extensions ( 35 , 36 ) and the other tappet extension ( 35 , 36 ) is not directly actuated by the return spring.
16 . The caster according to claim 15 , wherein the longer tappet extension ( 36 ) has an access opening ( 69 ) for the return spring ( 42 ).
17 . The caster according to claim 11 , wherein the tappet part ( 33 ) is U-shaped and comprises a crossbar and two opposite ends, wherein the tappet extensions ( 35 , 36 ) extend from the opposite ends of the crossbar, wherein the mounting pin axis passes through the crossbar of the tappet part ( 33 ) substantially in the center.