Ground engaging surface for endless tracks and wheels

A hollow, resilient, ground-engaging, load-bearing element for a closed-loop, mobile, multiple-element, support system comprising a closed-loop member mountable for cyclical movement about an axis extending through a support structure, said closed-loop member having a peripheral support surface for receiving a plurality of said ground-engaging load-bearing elements, one or a number of which elements durably support the mobile apparatus in a ground-engaging position, with cushioning, said ground-engaging element comprising:

• a) an inner element portion securable to said closed-loop member to bear on said support surface to transmit ground-engaging loads to said support surface;
• b) an outer element portion with a discrete outer surface for engaging the ground, said outer element portion being positioned in an outward direction radially outward of said support structure, away from said inner element portion in spaced relationship to said inner element portion said outer portion having a thickness in the radial direction with respect to said closed loop member;
• c) load-bearing side walls configured to be deformed, positioned in facing spaced relationship to each other and extending between said inner and outer element portions, said side walls being deformable to permit movement of said outer element portion towards said inner element portion in response to loads said deformable side walls having a side wall thickness, a height in the radial direction and a width, said sidewall thickness being smaller than the thickness of said outer element portion, said sidewalls deforming under load to support said closed loop member with said outer element portion in engagement with said support surface;
• and
• d) a ventilation cavity defined between said inner and outer element portions and said side walls, said cavity having an opening, said opening being positioned to put said cavity in pneumatic communication with ambient air adjacent said ground-engaging element for ventilating said element, said cavity having a cavity height in said radial direction, said cavity height being greater than said thickness of said outer portion and providing a clear heat-dissipating volume within said cavity;
• said discrete outer surfaces of said plurality of ground-engaging elements extending along and defining an outer ground-contacting periphery of said support system when said plurality of elements is secured to said support surface, wherein deformation of said side walls in response to said normal, straight-line, direction-of-travel loads reduces said cavity height while maintaining a clear heat-dissipating volume within said cavity whereby a plurality of said elements received on to said support system absorb ground-engaging loads in said outward direction in a resilient, cushioning manner.

In combination, a vehicle wheel rim, a composite non-pneumatic tire secured to said wheel rim and clamping member and securing means, said composite non-pneumatic tire comprising multiple tire segments each said tire segment being tubular and being clampable against said rim by a clamp member locatable internally of said segment, multiple said tire segments being mountable around said wheel rim to lie across said wheel rim in side-by-side relationship and to open to ambient on either side of said rim, thereby providing said composite tire, said tire segment comprising:

• a) an outer ground-engaging portion bearing a ground-engaging surface delimited by corners said outer portion having a thickness in the radial direction with respect to said closed loop member;
• b) an inner load-bearing portion to bear on said wheel rim to transmit loads to said wheel rim, said inner portion being radially apertured to receive said tire segment securing means
• c) a tubular ventilation cavity between said outer ground-engaging portion and said inner load-bearing portion, said cavity opening to ambient on either side of said rim and having a cavity height greater than said thickness of said outer portion;
• d) deformable side walls extending between said inner load bearing portion and said outer ground-engaging portion and embracing said ventilation cavity said deformable side walls having a side wall thickness, a height in the radial direction and a width, said sidewall thickness being smaller than the thickness of said outer element portion, said sidewalls deforming under load to support said closed loop member with said outer element in engagement with said support surface;
• e) aperturing in said inner load-bearing portion opening into said ventilation cavity, said clamp member securing means having an extension projecting through said aperturing, whereby said securing means can extend from said ventilation cavity and through said aperturing to cooperate with said adapted rim and secure said clamping member to hold said tire segment against said rim;
• wherein said ventilation cavity is dimensioned to receive said clamping member and said extension for mounting said segments around said rim, and wherein said side walls deform under load permitting said outer ground-engaging portion to move toward said inner load-bearing portion, said clamping members and securing means being located internally of said tire segments, with said extensions extending through said inner load-bearing portions of said tire segments and engaging with said wheel rim.