SWIVEL ROLLER WITH PROTECTED DIRECTION BOLTING DEVICE

The present invention relates to a caster wheel assembly including a wheel directional locking pivotable about a vertical pivot axis substantially orthogonal to the axis of rotation of the wheel and offset relative thereto, a bearing support having at least one reversed annular bowl which, at its central portion, is fixed to the bottom end of said pivot axis, a bearing block having at least one side member whose lower end carries the said wheel and also having a skirt disposed about the lower end of the pivotal axis, said skirt being connected to the upper end of said flange and cooperating with the rolling elements of said bearing, a blade spring disposed in the space between the bearing support and the tread of the wheel and articulated at its middle portion on the clevis, said blade spring having a first end bearing on the skirt and a second end having a locking bolt bearing slidably against the lower edge of the cup and engageable in a depression provided on said lower edge.

Such a caster wheel is described in the French patent application published under number FR's to-2 703,300. This document shows in Figures 4th 7 and a locking bolt into a roll to roll on the lower edge of a cup secured to the pivot axis. The roll shaft is supported by two vertical support plates disposed above the end of the blade spring. As a result of dirt may lodge in the space delimited by the support plates, the blade spring and the roll, resulting in premature wear of the roller or a jamming of the roll preventing free rotation of the roller in the latch release position. On the other hand, it is not provided with means for protecting the roll against impact.

The aim of the present invention is to alleviate these drawbacks.

The invention achieved its intended purpose in that the safety catch having a roller mounted to rotate freely about a roller axis, by the fact that said roller pin is fixed on one end of the spring strip cambered and by the fact that there is provided means for protecting said roller side impact.

With this arrangement, the roller is disposed in a plane substantially parallel to the cambered end of the spring strip. The space beneath the roller is fully exposed, thereby suppressing the lodging of dirt in this area. On the other hand, the curve of the end of the blade spring allows a good contact of the roller locking with the lower edge of the bowl.

The protection of the roller locking may be provided by a cover attached to the free end of the roller pin, either by riveting, welding, snap. It can also be provided by two flaps of sheet metal cut out of the clevis and extending laterally on each side of the roller.

Preferably, the protection of the roller locking is provided by a bracket attached to the cap via welding, snap, or riveting. Advantageously, the caliper is fixed to the ends of a shaft mounted on the cap parallel to the axis of rotation of the wheel and which is pivotally mounted on the middle portion of the blade spring.

Other advantages and features of the invention will be apparent in the following description made by way of example and with reference to the accompanying drawings in which:

1. figure 1 is a view in side elevation and partial vertical section of a wheel equipped with locking means directional and protective means of the locking roller according to the invention;
2. figure 2 is a view in side elevation of the wheel of Figure 1;
3. figure 3 is a perspective view of the preferred embodiment of the protective means;
4. figure 4 is a perspective view of a caster according to an alternative embodiment wherein the protection means are fixed to the roller axis;
5. figure 5 is a perspective view of another alternative embodiment of the protective means; and
6. figure 6 is a partial front view showing the locking means of the caster wheel.

The caster 1 shown in the drawings comprises a wheel 2 which is capable of pivotal movement about a vertical pivot axis substantially orthogonal to the axis 3 horizontal rotation 4 of the wheel 2. the ends of the axis of rotation 4 are carried by at least one side member, and preferably two side cheeks 5, a yoke 6 whose upper part is in the form of a skirt 7 mounted via a support bearing 8 on the lower end of the vertical pivot axis 3.

In the present specification, by pivot axis can also be used to rod or plate for securing the wheel 1 on a carriage or other mobile platform not shown on the drawing.

As can be seen in the drawings, the support bearing includes a first annular pan 8 9 and a second annular pan 10 set as the first, fixed on the lower end of the pivot axis the two troughs 3.9 and 10 are opened downward. The first well 9 is disposed above the second pan 10 and has a bell-shaped outer skirt 9a, which is adjoined to the top, an annular bottom turns down 9b which, in the inner opening region rests on the bottom of the cuvette 10a annular bottom 10. The two troughs 9, 10 are fixed to the pivot axis 3 and are enclosed with their inner edges between two annular shoulders 3a, 3b the vertical axis 3. has its lower end, the lower bath 10 has an annular flange 10b which, by its upper face, serves as a roller track with a first series of rolling balls or similar means 11 on the bearing skirt 7 of the support shell 6. in the junction zone between the bell ring and said annular base 9a 9b, the upper shell 9 defines a raceway groove-like 12 in which is received a second set of bearing balls 13 resting on the upper face of the skirt 7. the upper shell 9 surrounds and covers the skirt 7 and the lower bath 10.

The caster wheel 1 also includes locking means 16 of the yoke 6 at least in a predetermined direction relative to the pivot axis 3.

According to the embodiment shown in Figure 1, the blocking means 16 comprise a blade spring 17 generally planar and disposed in the space between the bearing support 8 and the tread of the wheel 2 . 2a the spring strip 17 is articulated at its middle portion on the clevis 6 via a hinge axis 18 substantially parallel to the axis of rotation 4 of the wheel 2. a first end 19 of the spring 17 is supported on the lower edge of the skirt 7 while its other end 20 comprises a locking catch 21 which is held in contact against the lower free edge 22 of the upper cup 9. this edge 22 comprises at least one depression 23 adapted to the shape of the locking bolt 21 and made in the form of a notch having ramps sloping side 24 to 45 degrees, to allow the unlocking of the pivoting of the wheel 2 by exerting a torque on the yoke 6 or the pivot axle 3.

The skirt 7 comprises in the vicinity of the locking bolt 21, a notch 25 of rectangular shape for guiding the end 20 of the spring 17.

The blade spring 17 is mounted on the hinge pin 18 by means of a cam 26 having the flat prismatic comprise at least one tab 30 cooperating with a hole in the blade spring 17.

As seen in Figure 1, the end 20 of the spring 17 is bent downwardly. The safety catch 21 is formed of a roller 31 mounted to rotate freely on a roller pin 32 attached to the cambered end 20 of the spring. The roller 31 includes a counterbore for receiving the head of the roller pin 32, thereby avoiding any protruding portion 33 on the rear face of the roller 31. A shoulder 34 on the front face of the roller 31, lying opposite to the end 20 of the spring eliminates contact of the roller 31 with the clevis 6. the roller 31 is disposed in a substantially vertical plane and parallel to the end 20 of the spring. Thus the periphery of the roller 31 is in contact with the lower edge 22 precise bowl 9. the reference 35 denotes a protective device disposed facing the back side of the roller 31 and 33 to protect the roller 31 against lateral impact.

According to a first embodiment shown in fig. 4, the protective device 35 is constituted by a cover 36 attached to the roller pin 32, the latter extending in this case rearwardly.

According to a second embodiment shown in fig. 5, the protective device 35 is constituted by two sheet metal flaps 37a, 37b cut from the clevis 6 and extending rearwardly of each lateral side of the roller 31.

According to a preferred embodiment shown in Figures 2 and 3, the protective device 35 is provided by a bracket 38 39 the ends of which are fixed on the ends of the hinge pin 18 of the spring 17.

The clevis 6 comprises in the vicinity of these shaft ends two stampings 39 into which the ends of the caliper 38 are completely immobilized relative to the yoke 6. the caliper 38 advantageously comprises a stiffening ring 40 to its rigidity.

The protective device 35, like the other frame components that participate in pivoting, receives a thermochemical treatment specific, which increases its mechanical strength and ensuring its corrosion resistance properties. The thermochemical treatment is preferably carried out in the manner described in EP-A 0 077,627.