GB2078179A - Pneumatic wheel - Google Patents

Abstract

A pneumatic wheel comprises an inflatable element 1 having a central passage 3 from the wall of which project two ridges 5 and a series of ribs 6 and two independent hub bearings 4 engaged in the passage 3 and having recesses 7 receiving the ridges 5 and ribs 8 between which fit the ribs 6. <IMAGE>

Description

SPECIFICATION Pneumatic wheel The invention relates to a new pneumatic wheel.

British Patent No. 1448603, in the name of the Societe Dunemer, describes a pneumatic wheel comprising an inflatable element of substantially toroidal shape and with a tubular central passage, as well as a hub situated in the said passage, this wheel being characterised by the face that there is no connection between the hub and the inflatable element, so that this latter can undergo free deformation in the vicinity of the hub.

This deformability is a fundamental characteristic of the inflatable element of the wheel to which the said patent relates.

The object of the first French Certificate of Addition No. 2,348,064 is to enable this wheel to be used as a driving wheel, at the same time enabling the mechanical strength of the inflatable element included therein to be increased, for which purpose the central passage of the inflatable element has at least one system of ribs projecting in planes passing through the geometric axis of the wheel and preferably has a second system of ribs projecting in a plane perpendicular to the said axis, the different ribs being housed in the hub, of which the shape is substantially complementary thereto. The first system of ribs thus opposes the sliding movement around the axis, while the second limits the sliding movement along the said axis, but no rib opposes the deformations of the inflatable element.In practice the second system of ribs comprises one single rib forming a ridge and fixed in a housing of which the profile is complementary to the hub.

The hub used with this wheel consists of two frustoconical parts rigidly integral with each other and comprising ribs of a profile complementary to those of the inflatable element, into which latter ribs they can thus be fitted.

The present invention proposes a new pneumatic wheel which, like the previous one, enables the inflatable element to undergo free deformation, but which comprises, instead of a hub consisting of two parts integral with each other, two independent bearings fitted into the inflatable element.

For this purpose, the tubular passage of the toroidal inflatable element has two ridges projecting in the direction of the rotation axis, there being associated with each of the said ridges a system of ribs projecting in planes passing through the said axis, while two independent bearings, of which the profile is complementary to the said ribs and the said ridges engage the said tubular passage.

The two ridges may or may not be symmetrical in relation to a plane perpendicular to the rotation axis. Similarly, the bearings may or may not be identical.

After the inflation of the inflatable element the said bearings are firmly held by the latter. They are rotationally integral therewith and are prevented by the ridges of the inflatable element from detaching themselves therefrom by a sliding movement according to the rotation axis. The inflatable element is nevertheless left perfectly free to undergo deformation, in the course of its rotation, in the vicinity of the bearings and in contact with the ground.

The accompanying drawings illustrate one embodiment of the invention, by way of example only. In the drawings FIGURE 1 is an exploded axial section of a pneumatic wheel in accordance with the invention; FIGURE 2 is an end view of one of the bearings of this wheel.

In this wheel the inflatable element 1 has the general shape of a torus 2, provided with a tubular passage 3, engaged by two bearings 4 symmetrically in respect of that plane of symmetry of the torus which is perpendicular to the axis.

According to the invention, two ridges 5 project symmetrically to the surface of the torus 2 in the direction of the rotation axis X-X, while associated with each ridge 5 axial ribs 6 are provided which pass through the axis X-X. In the case of Figure 1, in axial section, the ridges 5 pass through the centre of the circular sections of the torus, but they could naturally be positioned at some different angle of inclination.

Each of the bearings 4 has a profile complementary to that part of the tubular passage 3 into which it fits, i.e. it is hollowed out in a direction perpendicular to the axis X-X, as shown by the recess 7, engaged by the relevant ridge 5, and is also provided with axial ribs 8, which correspond in shape to the ribs 6.

It may thus be seen that when the toroidal element 1 is inflated to the desired pressure, leaving it free to undergo deformation, the bearings 4 are firmly held by this element 1, from which they cannot accidentally become detached, although the said element retains complete freedom of movement.

1. A pneumatic wheel comprising an inflatable element of substantially toroidal shape and having a tubular central passage, the walls of the tubular passage including two ridges projecting partially in the direction of the axis of the wheel, there being associated with each of the said ridges a system of ribs projecting in planes passing through the said axis, and including two independent bearings having profiles complementary to the said ridges and ribs to engage in the said tubular passage.

2. A pneumatic wheel in accordance with Claim 1, in which, as seen in section through an axial plane, the sections of the ridges pass through the centre of the circular sections of the torus.

3. A pneumatic wheel in accordance with either of Claims 1 and 2, in which the ridges are symmetrical with respect to a plane perpendicular to the axis of the wheel.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (5)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Pneumatic wheel The invention relates to a new pneumatic wheel. British Patent No. 1448603, in the name of the Societe Dunemer, describes a pneumatic wheel comprising an inflatable element of substantially toroidal shape and with a tubular central passage, as well as a hub situated in the said passage, this wheel being characterised by the face that there is no connection between the hub and the inflatable element, so that this latter can undergo free deformation in the vicinity of the hub. This deformability is a fundamental characteristic of the inflatable element of the wheel to which the said patent relates. The object of the first French Certificate of Addition No. 2,348,064 is to enable this wheel to be used as a driving wheel, at the same time enabling the mechanical strength of the inflatable element included therein to be increased, for which purpose the central passage of the inflatable element has at least one system of ribs projecting in planes passing through the geometric axis of the wheel and preferably has a second system of ribs projecting in a plane perpendicular to the said axis, the different ribs being housed in the hub, of which the shape is substantially complementary thereto. The first system of ribs thus opposes the sliding movement around the axis, while the second limits the sliding movement along the said axis, but no rib opposes the deformations of the inflatable element.In practice the second system of ribs comprises one single rib forming a ridge and fixed in a housing of which the profile is complementary to the hub. The hub used with this wheel consists of two frustoconical parts rigidly integral with each other and comprising ribs of a profile complementary to those of the inflatable element, into which latter ribs they can thus be fitted. The present invention proposes a new pneumatic wheel which, like the previous one, enables the inflatable element to undergo free deformation, but which comprises, instead of a hub consisting of two parts integral with each other, two independent bearings fitted into the inflatable element. For this purpose, the tubular passage of the toroidal inflatable element has two ridges projecting in the direction of the rotation axis, there being associated with each of the said ridges a system of ribs projecting in planes passing through the said axis, while two independent bearings, of which the profile is complementary to the said ribs and the said ridges engage the said tubular passage. The two ridges may or may not be symmetrical in relation to a plane perpendicular to the rotation axis. Similarly, the bearings may or may not be identical. After the inflation of the inflatable element the said bearings are firmly held by the latter. They are rotationally integral therewith and are prevented by the ridges of the inflatable element from detaching themselves therefrom by a sliding movement according to the rotation axis. The inflatable element is nevertheless left perfectly free to undergo deformation, in the course of its rotation, in the vicinity of the bearings and in contact with the ground. The accompanying drawings illustrate one embodiment of the invention, by way of example only. In the drawings FIGURE 1 is an exploded axial section of a pneumatic wheel in accordance with the invention; FIGURE 2 is an end view of one of the bearings of this wheel. In this wheel the inflatable element 1 has the general shape of a torus 2, provided with a tubular passage 3, engaged by two bearings 4 symmetrically in respect of that plane of symmetry of the torus which is perpendicular to the axis. According to the invention, two ridges 5 project symmetrically to the surface of the torus 2 in the direction of the rotation axis X-X, while associated with each ridge 5 axial ribs 6 are provided which pass through the axis X-X. In the case of Figure 1, in axial section, the ridges 5 pass through the centre of the circular sections of the torus, but they could naturally be positioned at some different angle of inclination. Each of the bearings 4 has a profile complementary to that part of the tubular passage 3 into which it fits, i.e. it is hollowed out in a direction perpendicular to the axis X-X, as shown by the recess 7, engaged by the relevant ridge 5, and is also provided with axial ribs 8, which correspond in shape to the ribs 6. It may thus be seen that when the toroidal element 1 is inflated to the desired pressure, leaving it free to undergo deformation, the bearings 4 are firmly held by this element 1, from which they cannot accidentally become detached, although the said element retains complete freedom of movement. CLAIMS

1. A pneumatic wheel comprising an inflatable element of substantially toroidal shape and having a tubular central passage, the walls of the tubular passage including two ridges projecting partially in the direction of the axis of the wheel, there being associated with each of the said ridges a system of ribs projecting in planes passing through the said axis, and including two independent bearings having profiles complementary to the said ridges and ribs to engage in the said tubular passage.

2. A pneumatic wheel in accordance with Claim 1, in which, as seen in section through an axial plane, the sections of the ridges pass through the centre of the circular sections of the torus.

3. A pneumatic wheel in accordance with either of Claims 1 and 2, in which the ridges are symmetrical with respect to a plane perpendicular to the axis of the wheel.

4. A pneumatic wheel in accordance with any one of Claims 1 to 3, in which the bearings are identical to one another.

5. A pneumatic wheel substantially as described herein with reference to or as illustrated in the accompanying drawings.