| WO/2023/274152 | WHEEL ASSEMBLY DEVICE |
| WO/2013/036431 | AXLE ASSEMBLY FOR AGRICULTURAL APPLICATOR |
| GB2170400A | 1986-08-06 | |||
| US1839396A | 1932-01-05 | |||
| US4471508A | 1984-09-18 |
| 1. | An arrangement in a castor means (1) comprising a core casing (2), a mounting shank (3) projecting vertically upwards from the core casing, and castors (8,9), which are rotatably mounted in the core casing on each side of the latter extending below the lower edge of the core casing, and said castors not turning 180°C upon reversal of the travelling direction of the castors, c h a r a c t e r i z e d i n that the lower end or foot of mounting shank (3) is vertically stationary, but movable horizontally relative to the core casing inside the latter, when the core casing under a horizontal force (P) affecting the castor means in its radial central plane, is caused to turn relative to the rotational shaft (10) of the castors (8,9), said mounting shank consequently moving relative said shaft (10) from a position behind it to a position in front of it, as seen in the direction of said force (P). |
| 2. | An arrangement as stated in claim 1, c h a r a c t e r i z e d i n that foot (4) of mounting shank (3) has at least one contact face (5') resting slidably on the top face of at least one movable pulley (6) which has its rotational shaft (7) beneath shaft (10) of the castors, and that moving pulley (6), via linkage (11) is suspended from the shaft (10) of castors (8,9) on core casing (2), said mounting shank (3) being caused by said horizontal force (9), which acts on castor means (1) in its radial central plane, to move with said contact face (5) relative to moving pulley (6) and shaft (10) of castors (8, 9) to a point in front of said castors shaft, as seen in the direction of said force, the shaft (7) of said moving pulley (6) during said movement of bearing shank (3) being substantially stationary and vertically below shaft (10) of the castors (8,9), at the same time as the core casing is designed to turn about the shaft of the castors during said exertion of force. 3. An arrangement as stated in claim 1 or 2, c h a r a c t e r i z e d i n that the mounting shank (3) extends upwardly through an opening (16) in the core casing, said opening (16) having such a clearance relative to the mounting shank that the opening will always lie vertically above the lower end of the mounting shank when it moves along said path during movement of the core casing. *& 4. |
| 3. | An arrangement as stated in claim 2, c h a r a c t e r ¬ i z e d i n that an arched groove (14) engaging with a pin (15) which projects from inside the core casing, is provided on said foot (4).*& 6. |
| 4. | An arrangement as stated in claim 4, c h a r a c t e r i z e d i n that said pin (15) follows an arched path on the top of the point of rotation of the castors when the core casing turns about said point of rotation. |
The present invention relates to an arrangement in a castor means, comprising a core casing, a mounting shank projecting vertically upwards from the core casing, and castors which are rotatably mounted on each side of the core casing and extending below the lower edge of the core casing, and said castors not turning 180°C upon reversal of the travelling direction of the castors.
It is previously known that slewable castor means have a negative effect on the support, especially castors of chairs. When a chair is moved relative to a support, a damage which is not to be neglected will occur between the castors and the support, whether the support is a carpet or, e.g. a wooden floor. When the direction of chair movement is changed back and forth, the castor means will normally turn 180° on a relatively small area. This requires relatively narrow castors to reduce frictional wear in connection with such turning movement. In connection with thiε kind of wear the castors exert a high point load which may easily crush varnish, textile or wood fibres of the support and, thus, cause permanent damage.
According to the present invention an arrangement Is proposed in an arrangement of the introductory type in which improved movability and smooth movement are provided, and in which there iε furthermore provided a larger area of support than is practicable to day.
The features which characterize the invention will appear from the following claimε.
The vertical mounting shank will, thus, change sides due to the directions of load and will alw τ ayε cause the castor means to be in a dragged position. This iε achieved by the fact
that the vertical mounting shank iε mounted in the core casing which may rotate independently from castor movement. The core casing will turn across a limited angle or will, in other words, be tilted to one of the sides dependent on the direction of the load, with its centre in the wheel centre.
The invention is disclosed in more detail below with reference to the enclosed drawing.
Figures la, b, and c illustrate a section through the core casing of the castor means in various positions of the mounting shank of the castor means relative to the core casing, according to a preferred embodiment.
Figures 2 a, b, and c show the castor means according to Figure 1, as seen in the direction of the force acting on the castor means from the side, and in an opposite direction to said force, respectively.
In Figures 1 and 2 a castor means 1 is shown, comprising castors 8, 9 and a mounting shank 3, which has a foot 4 with at least one contact face 5 resting on the top face of at least one movable pulley 6, which haε its rotational axis 7 below rotational shaft 10 of castors 8, 9. Movable pulley 6 is suspended, via a linkage 11, on shaft 10 of the castors on core casing 2 of the castor means. During the horizontal pushing force P acting on castor means in itε radial central plane, mounting shank 3 will be displaced with its contact face 5 relative to movable pulley 6 and relative to shaft 10 of the castors to a point in front of shaft 10, as seen in the direction of force P. The axis of rotation 7 of the movable pulley will be substantially stationary and vertical beneath shaft 10 of the castorε during diεplacement of the mounting shank. At the same time the core casing 2 will be caused to turn about the shaft 10 of the castors during action of said force.
It will appear from Figure 1 that the distance between contact face 5 and the support 12 is constant all the time.
In order to ensure that core casing 2 may turn about shaft 10 without friction with linkage 11 and moving pulley 6, a circle sector shaped recess 13 is provided on the internal sides of core casing. Due to the load from shank 3 linkage 11 will remain substantially vertical.
In order to prevent shank 3 from being pulled upwards, e. g. into the position as shown in Figure lb, at least one curved groove 14 is provided in foot 4 of shank 3, which groove constitutes a εlideway for a pin 15 which projects from the internal wall of the core casing.
As will appear from Figure 1, there is an opening 16 in core casing 16. Said opening 16 is bevelled to cause safe locking in the extreme position, as Illustrated in Figure la and lc, at the same time as mounting shank 3 can push towards one side of the opening during movement to a new extreme position, as shown in Fig. la.
It will appear from Figure 1 that the core casing per se does not touch the support 12, and that it is, thus, only the effect of force and the inertia of the castor means which causes displacement of the bearing point of the mounting shank in the core casing.