TREADMILL BELT WITH FOAMED CUSHION LAYER AND METHOD OF MAKING

• US 20090176628A1
• Filed: 01/08/2008
• Published: 07/09/2009
• Est. Priority Date: 01/08/2008
• Status: Active Grant

• Current Assignee: ContiTech USA, Inc. (Continental AG)
• Original Assignee: Veyance Technologies Incorporated (Continental AG)
• Inventors: Mutch, Steven Wayne, Radding, Peter E.
• Granted Patent: US 8,096,925 B2
• Time in Patent Office: Days
• US Class Current: 482/54
• CPC Class Codes: A63B 2071/0063 Shock absorbers
• CPC Class Codes: A63B 22/02 with movable endless bands , e.g. treadmills other training appliances for running on the spot A63B69/0028
• CPC Class Codes: A63B 22/0207 having shock absorbing means
• CPC Class Codes: A63B 22/0235 driven by a motor
• CPC Class Codes: A63B 22/0285 Physical characteristics of the belt, e.g. material, surface, indicia
• CPC Class Codes: B29C 44/24 Making multilayered articles
• CPC Class Codes: B29C 44/326 Joining the preformed parts, e.g. to make flat or profiled sandwich laminates
• CPC Class Codes: B29D 29/06 Conveyor belts
• CPC Class Codes: B32B 2038/0084 Foaming
• CPC Class Codes: B32B 2305/18 Fabrics, textiles
• CPC Class Codes: B32B 2433/02 Conveyor belts
• CPC Class Codes: B32B 38/0036 Heat treatment for heating or cooling of layers during lamination B32B37/06, B32B37/08
• CPC Class Codes: B32B 5/22 characterised by the presence of two or more layers which are next to each other and are fibrous, filamentary, formed of particles or foamed layer formed of natural mineral fibres or particles next to a foam layer B32B19/047, next to a layer made of particles B32B19/048, or next to a fibrous or filamentary layer B32B19/06; paper layer or cardboard layer next to a paper layer or cardboard layer B32B29/005, next to a foam layer B32B29/007, next to a fibrous or filamentary layer B32B29/02, or next to a particulate layer B32B29/04
• CPC Class Codes: B32B 5/24 one layer being a fibrous or filamentary layer
• CPC Class Codes: Y10T 29/49826 Assembling or joining

Abstract

The present invention is directed to a treadmill belt with foamed cushion layer and method of making same. In one embodiment, the treadmill belt includes a fabric base layer and a foamed cushion layer foamed on and integral with the fabric base layer. The foamed cushion layer includes a thermoplastic composition and has a Shore A hardness of about 20 to about 80. In one example, the first foamed cushion layer is from about 0.05 inches to about 0.35 inches thick. The thermoplastic composition, prior to being foamed, includes about 1 part to about 5 parts of a foaming agent, e.g., a chemical foaming agent, based on 100 parts thermoplastic material, e.g., polyvinyl chloride. An outer wear layer is securely adhered on the foamed cushion layer to sandwich the foamed cushion layer between the fabric base layer and outer wear layer thereby defining the treadmill belt.

Claims

1. A method of making a treadmill belt comprising:

applying at least one layer of a first unfoamed thermoplastic composition on a fabric base layer;

foaming the first unfoamed thermoplastic composition to define a first foamed cushion layer which has a Shore A hardness of about 20 to about 80; and

applying an outer wear layer on the foamed cushion layer to define the treadmill belt with first foamed cushion layer.

2. The method of claim 1 wherein foaming the first unfoamed thermoplastic composition comprises heating the first unfoamed thermoplastic composition to foam the first unfoamed thermoplastic composition and define the first foamed cushion layer.

3. The method of claim 1 wherein the first unfoamed thermoplastic composition is a first unfoamed polyvinyl chloride composition.

4. The method of claim 1 wherein the first unfoamed thermoplastic composition includes 100 parts polyvinyl chloride and about 1 part to about 5 parts foaming agent based on 100 parts polyvinyl chloride.

5. The method of claim 1 wherein the fabric base layer is a one-ply woven sheet of synthetic and/or natural material, and the outer wear layer includes a thermoplastic material or a rubber material.

6. The method of claim 1 further comprising, prior to foaming the first unfoamed thermoplastic composition, applying a fabric intermediate layer onto the first unfoamed thermoplastic composition then applying at least one layer of a second unfoamed thermoplastic composition onto the fabric intermediate layer;

simultaneously foaming the first and second unfoamed thermoplastic compositions to define first and second foamed cushion layers, respectively, which have a Shore A hardness of about 20 to about 80; and

applying the outer wear layer onto the second foamed cushion layer to define the treadmill belt with first and second foamed cushion layers.

7. The method of claim 1 further comprising applying a fabric intermediate layer onto the first foamed cushion layer then applying at least one layer of a second unfoamed thermoplastic composition onto the fabric intermediate layer;

foaming the second unfoamed thermoplastic composition to define a second foamed cushion layer which has a Shore A hardness of about 20 to about 80; and

applying the outer wear layer onto the second foamed cushion layer to define the treadmill belt with first and second foamed cushion layers.

8. The method of claim 1 wherein applying at least one layer of a first unfoamed thermoplastic composition on a fabric base layer comprises directly applying at least one layer of the first unfoamed thermoplastic composition on the fabric base layer;

and wherein applying an outer wear layer on the foamed cushion layer to define the treadmill belt with first foamed cushion layer comprises applying an outer wear layer directly onto the foamed cushion layer to define the treadmill belt with first foamed cushion layer.

9. A method of making a treadmill belt comprising:

applying at least one layer of a first unfoamed thermoplastic composition onto a fabric base layer, the first unfoamed thermoplastic composition having a first chemical foaming agent in an amount of about 1 part to about 5 parts first chemical foaming agent based on 100 parts thermoplastic material;

activating the first chemical foaming agent to foam the first unfoamed thermoplastic composition to define a first foamed cushion layer which has a Shore A hardness of about 20 to about 80; and

applying an outer wear layer onto the first foamed cushion layer to define the treadmill belt with first foamed cushion layer.

10. The method of claim 9 wherein the first unfoamed thermoplastic composition is an unfoamed polyvinyl chloride composition having the first chemical foaming agent.

11. The method of claim 10 wherein the unfoamed polyvinyl chloride based composition includes 100 parts polyvinyl chloride, about 1 part to about 5 parts first chemical foaming agent based on 100 parts polyvinyl chloride, and a plasticizer.

12. The method of claim 9 wherein the fabric base layer is a one-ply woven sheet of synthetic and/or natural material, and the outer wear layer includes a thermoplastic material or a rubber material.

13. The method of claim 9 further comprising, prior to activating the first chemical foaming agent, applying a fabric intermediate layer onto the first unfoamed thermoplastic composition then applying at least one layer of a second unfoamed thermoplastic composition onto the fabric intermediate layer;

simultaneously activating the first and second chemical foaming agent to foam the first and second unfoamed thermoplastic compositions thereby defining first and second foamed cushion layers, respectively, which have a Shore A hardness of about 20 to about 80; and

applying an outer wear layer onto the second foamed cushion layer to define the treadmill belt with first and second foamed cushion layers.

14. A treadmill belt comprising:

a fabric base layer;

a first foamed cushion layer foamed on and integral with the fabric base layer, the first foamed cushion layer including a first foamed thermoplastic composition and having a Shore A hardness of about 20 to about 80, the first thermoplastic composition, prior to being foamed, including about 1 part to about 5 parts of a foaming agent based on 100 parts thermoplastic material; and

an outer wear layer securely adhered on the first foamed cushion layer so as to sandwich the first foamed cushion layer between the fabric base layer and outer wear layer thereby defining the treadmill belt with first foamed cushion layer.

15. The treadmill belt of claim 14 wherein the thermoplastic material is a polyvinyl chloride and the foaming agent is a chemical foaming agent.

16. The treadmill belt of claim 14 wherein the fabric base layer is a one-ply woven sheet of synthetic and/or natural material, and the outer wear layer includes a thermoplastic material or a rubber material.

17. The treadmill belt of claim 14 wherein the first foamed cushion layer is from about 0.05 inches to about 0.35 inches thick.

18. The treadmill belt of claim 14 further comprising:

a fabric intermediate layer securely adhered on the first foamed cushion layer so as to sandwich the first foamed cushion layer between the fabric base layer and fabric intermediate layer;

a second foamed cushion layer foamed on and integral with the fabric intermediate layer, the second foamed cushion layer including a second thermoplastic composition and having a Shore A hardness of about 20 to about 80, the second thermoplastic composition, prior to being foamed, including about 1 part to about 5 parts of foaming agent based on 100 parts thermoplastic material; and

the outer wear layer securely adhered on the second foamed cushion layer so as to sandwich the second foamed cushion layer between the fabric intermediate layer and outer wear layer thereby defining the treadmill belt with first and second foamed cushion layers.

19. The treadmill belt of claim 14 wherein the first foamed cushion layer is foamed on and integral with a fabric intermediate layer, and wherein a first unfoamed thermoplastic layer is securely adhered between the fabric intermediate layer and fabric base layer such that the fabric intermediate layer is sandwiched between the first foamed cushion layer and the first unfoamed layer thereby defining the treadmill belt with first foamed cushion layer.

20. The treadmill belt of claim 14 wherein the first foamed cushion layer is foamed directly on and integral with the fabric base layer, and the outer wear layer is securely adhered directly on the first foamed cushion layer so as to sandwich the first foamed cushion layer between the fabric base layer and outer wear layer thereby defining the treadmill belt with first foamed cushion layer.