Shock absorbing endless belt for a treadmill
Disclosed is an energy absorbing endless belt comprises a polymeric gel and a substrate enveloped by a top and bottom layer. The top layer may serve as the running surface for the treadmill and may be made of a different material than the bottom layer. The substrate has a density less than that of the polymeric gel. The substrate may be formed from a foamed plastic and may be a continuous sheet or have perforations placed throughout. The energy absorbing endless belt can be formed from an epoxidized vegetable oil, a thermoplastic polymer and a prepolymer.
1 . A reinforced polymeric endless belt comprising:
a shock absorbing envelope comprising a polymer gel substantially surrounding a substrate.
2 . The reinforced polymeric belt of claim 1 , wherein the belt comprises a top layer and a bottom layer.
3 . The reinforced polymeric belt of claim 2 , wherein the layers are formed from a resilient polymeric material.
4 The reinforced polymeric belt of claim 2 , wherein the layers are formed from a woven material.
5 . The reinforced polymeric belt of claim 1 , wherein the substrate has a density less than the polymeric gel.
6 . The reinforced polymeric belt of claim 1 , wherein the substrate is formed from a foamed polymeric material.
7 . The reinforced polymeric belt of claim 6 , wherein the substrate is formed from a foamed PVC.
8 . The reinforced polymeric paid of claim 1 , wherein the polymeric material comprises at least greater than 50% by weight of an epoxidized vegetable oil, a thermoplastic polymer, and a prepolymer.
9 . The reinforced polymeric belt of claim 8 , further including an activator.
10 . The reinforced polymeric belt of claim 9 , wherein the activator is an alkyl tin compound.
11 . The reinforced polymeric belt of claim 8 , wherein the epoxidized vegetable oil is selected from the group consisting of soybean oil, linseed oil, and combinations thereof.
12 . The reinforced polymeric belt of claim 8 , wherein the prepolymer comprises an isocyanate selected from the group of aliphatic, cycloaliphatic, araliphatic, aromatic, heterocychc polyisocyamates and combinations thereof.
13 . The reinforced polymeric belt of claim 8 , wherein in the thermoplastic polymer is substantially free of a polyurethane.
14 . The reinforced polymeric belt of claim 8 , wherein the thermoplastic polymer comprises a polydiene.
15 . The reinforced polymeric belt of claim 8 , wherein the thermoplastic polymer is a polybutadiene.
16 . A reinforced polymeric endless belt comprising:
a shock absorbing envelope comprising a top and bottom layer forming the envelope containing a polymeric gel and a substrate having a density less than the density of the polymeric gel
17 . The reinforced polymeric belt of claim 16 , wherein the substrate is formed from a foamed polymeric material.
18 The reinforced polymeric belt of claim 16 , wherein the top and bottom layers are formed from a resilient non-woven material.
19 . The reinforced polymeric belt of claim 16 , comprising an epoxidized vegetable oil, a thermoplastic polymer substantially free of a polyurethane and a prepolymer
20 . The reinforced polymeric belt of claim 16 , further including an activator.
21 The reinforced polymeric belt of claim 20 , wherein the activator is an alkyl tin compound.
22 . The reinforced polymeric belt of claim 16 , wherein the prepolymer comprises an isocyanate selected from the group of aliphatic, cycloaliphatic, araliphatic, aromatic, heterocyclic polyisocyaniates and combinations thereof.
23 . The reinforced polymeric belt of claim 16 , wherein the polymeric gel comprises on a percent weight basis of the gel at least greater than about 50% of a vegetable based plasticizer, between about 20% and about 40% of a thermoplastic polymer, and between about 5% and about 20% of a prepolymer.
24 . A method of forming a reinforced polymeric belt comprising:
forming a shock absorbing envelope by sealing within a top and bottom layer a polymeric gel and a substrate having a density less than the density of the polymeric gel.
25 . The method of forming a reinforced polymeric of claim 24 wherein the polymeric gel if formed by combining an epoxidized vegetable oil, a polydiene and a cyano group
26 . The method of forming a reinforced polymeric belt of claim 24 , wherein the polydiene is selected from polybutadiene, polyisoprene, polychioroprene, polynobornene, copolymers, terpolymers and combinations thereof.
27 . The method of forming a reinforced polymeric of claim 24 , wherein the top and bottom layer are sealed by fusing the two layers along the periphery of the belt.
28 . The reinforced polymeric belt of claim 24 , wherein the gel comprises about 20% to about 40% of the polydiene.
29 . The reinforced polymeric belt of claim 24 , wherein the cyano group is an isocyanate group.
30 . The reinforced polymeric belt of claim 24 , further comprising an alkyl tin compound.
31 . The reinforced polymeric belt of claim 30 , wherein the gel comprises up to about 5% by weight of the alkyl tin compound.