The present invention is related to a caster which is able to durably bear the axial force and radial force coming from the support rod.
When an external force is applied to the inner ring 722, a shear force is produced between the inner ring 722 and the outer ring 721. Therefore, the ball bearing 72 will be worn out after a long period of use. The conventional caster has poor axial load capacity so that such caster can hardly bear greater load. Also, such caster cannot be durably used.
In the improved caster, the axial load capacity and lateral component force of the support bar 86 are improved by means of the taper roller bearing 85 and the ball bearing 84. However, the taper roller bearing 85 is manufactured at high cost. Therefore, it is not economic to use such caster.
It is therefore a primary object of the present invention to provide a caster which includes two bearings for durably bearing the axial force and radial force coming from the support rod.
According to the above object, the caster of the present invention includes:
The present invention can be best understood through the following description and accompanying drawings wherein:
Please refer to
The present invention further includes a wheel 2 pivotally connected between the two support arms 12 of the seat body.
The present invention further includes an upper cover 3 disposed on the connecting section 11. The upper cover 3 has a second top face 31 and a second bottom face 32. An abutting section 33 downward extends from inner circumference of the upper cover 3. The second bottom face is formed with a second groove 321 corresponding to the first groove 131. The first groove 131 and the second groove 321 together form an annular space (not shown).
The present invention further includes multiple ball bodies 4 arranged in the annular space.
The present invention further includes a bearing 5 disposed in the fixing seat 13. The bearing 5 has an inner ring 51 and an outer ring 52. The inner ring 51 has a shaft hole (not shown). The abutting section 33 of the upper cover 3 abuts against the inner ring. An inner rim of the seat body is inserted in the channel 133 of the fixing seat 13. The fixing seat 13 downward extends to enclose the outer ring of the bearing 5.
The present invention further includes a support rod 6 having a head section 61 at one end. The diameter of the head section 61 is larger than the diameter of the shaft hole of the inner ring 51. The support rod 6 is fixed in the shaft hole of the inner ring 51. The other end of the support rod 6 extends out of the connecting section 11 and the upper cover 3 and is locked with a nut 62.
The ball bodies 4 are able to bear the axial thrusting force of the support rod 6, while the bearing 5 is able to bear the radial thrusting force of the support rod 6.
When an external force is applied to the support rod 6, the axial force is transmitted from the upper cover 5 through the ball bodies 6 to the connecting section 11. Therefore, the area for bearing the axial load is larger so that the present invention is able to bear greater force. Also, when the seat body 1 is radially pushed by the support rod 6 to move, the radial force coming from the support rod 6 is transmitted through the inner ring 51 to the outer ring 52 and then to the connecting section 11. The contact area is also larger so that the bearing 5 can the radial force of the support rod 6. The present invention is manufactured at lower cost. In addition, the structure of the present invention can bear the axial force and radial force. Even after a long period of use, the support rod 4 can be still tightly fitted in the seat body 1 and the caster can be smoothly operated.
The above embodiments are only used to illustrate the present invention, not intended to limit the scope thereof. Many modifications of the above embodiments can be made without departing from the spirit of the present invention.