# Patent

## Title
Variable resistance exercise device

## Abstract

An exercise device for human exercise routines having an elongated pultruded plastic rod or rods fitting loosely within a plastic tube. At least one of the rods is rectangular in cross section and the tube may be covered by a soft foam plastic sleeve. The rod may be produced by the pultrusion process.

## Background
RELATED APPLICATIONS
The U.S. patent application Ser. No. 10/278,450 of Gordon L. Brown, Jr. filed Oct. 23, 2002 for an Abdominal Exercise Routine Using A Flexible Elongated Device discloses exercise routines for which this invention is particularly useful.
FIELD OF INVENTION
The disclosed invention relates to an apparatus designed to perform exercises intended to firm, strengthen and tone a person's abdominal muscles, arm muscles and other muscles of the body when the apparatus is bent, which creates a resistance for the targeted muscles. The disclosed apparatus defines a flexible elongated device which is easy for an individual to handle in that it bends in any direction in response to the forces applied to the ends of the device, or to the center of the device with the hands holding the ends, or to the ends of the device with the hand or hands positioned at or near the center of the apparatus. Also, as the apparatus bends the external shape of the apparatus changes slightly to an oval shape such that as the flat part of the oval contacts a body component, such as the thigh, a greater degree of comfort will be felt by the user.
BRIEF SUMMARY OF THE INVENTION
It is a principal object of this invention to provide an elongated variable resistant flexible exercise device that is easy to assemble and which bends in any direction when performing exercises, the exercise device preferably includes a flexible tube having rounded interior in which an elongated rod with a rectangular cross section is inserted. When the exercise device is held by the user's hands at or near the ends of the device or positioned on a modified piece of exercise equipment, such as an ‘ParaBody 900 ST abdominal contractor’, and a force is applied to the ends of the device, or to the center of the device, the device will readily bend in the intended direction as increased resistance is provided, as the distance between the ends of the device is reduced, with a resulting enhancement of the strengthening, conditioning and toning of the targeted muscles.
It is an additional objective to provide for a greater degree of comfort to the user by having the exterior of the flexible elongated device deform slightly to an oval shape when bent such that the flat part of the oval shape spreads the resistance forces over a wider area of contact with the user's body producing a more comfortable feeling. This feature is due to the use of a flexible extruded thermoplastic tube having an essentially round section cavity into which the pultruded rod loosely fits such that when the thermoplastic tube bends its shape is altered to an oval.
A preferred embodiment features an extruded thermoplastic tubular component such as extruded PVC or a thermoplastic rubber tube that has a round or nearly round section cavity. The thermoplastic tube has a durometer such that the exercise device feels comfortable when placed onto the surface of a person's body such as the front of the person's thigh. It should not be too hard but can be somewhat hard given the fact that the thermoplastic tubular device will deform to an approximate oval cross sectional shape when bent. Into the cavity of the tube there is inserted a pultruded rod having, preferably, a consistent rectangular cross-section shape extending substantially the length of the extruded thermoplastic round tube. The rod fits easily into the cavity of the extruded thermoplastic round tube and is able to rotate freely about its longitudinal axis when inside the cavity of the straight extruded thermoplastic tube. End caps are placed on each end of the tube. When the tube is bent the rectangular section rod will automatically orient itself to bend about its major cross section axis.



BRIEF DESCRIPTION OF THE DRAWINGS
The invention is illustrated in the accompanying drawings, in which:
FIG. 1 shows an individual performing an exercise routine using a flexible exercise device;
FIG. 2 is a side view of the exercise device;
FIG. 3 is a longitudinal section of the exercise device of FIG. 2;
FIG. 4 is a section taken on line 4-4 in FIG. 2;
FIG. 5 is an enlarged section of a pultruded rectangular cross section rod.
FIG. 6 is a section similar to FIG. 4 showing an embodiment of the invention having rectangular section rods in the hollow tube of the exercise device;
FIG. 7 is a section of an embodiment of the exercise device without a soft outer sleeve and having four rectangular cross section rods in a hollow tube; and
FIG. 8 is a longitudinal section showing the device of FIG. 7 bent as occurs in an exercise routine;
FIG. 9 is a section taken on line 9-9 in FIG. 8; and
FIG. 10 is a section showing a round rod and a rectangular cross section rod in a hollow tube.



DETAILED DESCRIPTION OF THE INVENTION
The invention is hereinafter described in detail by reference to the accompanying drawings. The invention is not intended to be limited to the embodiments described; rather, this detailed description is included to enable any person skilled in the art to produce a flexible elongated exercise device which will bend in any direction when each end is grasped by the user at or near each end with a force applied to each end of the device; or with the hands grasping each end and applying a force to each end with the center of the device pressed against a part of the body such as the thigh(s); or with the hand or hands positioned at or near the center of the device and the hands applying a force at or near the center of the device with the ends of the device positioned in contact with each of the thighs slightly above the knee.
A preferred embodiment of the flexible exercise device 11, shown in FIGS. 1-5, includes a soft foam plastic tubular sleeve 12, a cylindrical tube 13 and an elongated substantially rectangular section pultruded composite rod 14. The rod 14 is preferably made from a group of mixtures including a mixture of thermoplastic resin and longitudinally oriented continuous glass fiber filaments and a mixture of thermoset resin and longitudinally oriented continuous glass fiber filaments. The rod 14 is designed to be bent into the shape of a semi-circle a minimum of 10,000 times without substantial cracking of the elongated rectangular shape. A material having low hysteresis is preferred for consistency. Suitable end closures, such as plastic caps 16, are installed on the ends of the tube 13. A suitable elongated exercise device 11 for many exercise routines will be about 36 inches in length with an outside diameter of about 1 5/16 inches. A pultruded composite rod 14 for such a device will have dimensions of 0.1875 inch×0.500 inch×353⁄4 inches with the full radius edges 17 over the length of the pultruded composite rod 14. The exercise device has a wide range of application and may be 18 to 72 inches in length and from one half to 3 inches in diameter. The rod 14 has a major axis 21 and a minor axis 22 and may be constructed using PPG Industries, Inc. of Shelby, N.C. “E-glass” continuous fibers with the resin matrix being a vinyl ester resin. The fiber content is preferably 25% to 70% of the volume of the rod. The resin could alternatively be an epoxy resin, isophthalic polyester, PVC plastisol or other resin selected to give an acceptable flexural modulus and flexural fatigue performance in bending as well as minimal creep. A suitable composite rod is made by Glasforms, Inc. of San Diego, Calif. The soft, one piece smooth surface foam sleeve 12, available from Hunt-Wilde Corp. of Tampa, Fla., is slid over the outside of the extruded flexible PVC annular section tube 13 to cover substantially the full length of the extruded flexible PVC thermoplastic round tube 13 to give the exterior of the device 11 a soft feel against the individual's legs, thighs and hands. The extruded flexible PVC round tube 13, with a durometer of approximately 92 as measured on the Shore A scale, is made by Agricultural Products, Inc. of Ontario, Calif. The rod 14 provides variable resistance as the exercise device is bent. The pultruded composite rod 14 is inserted into the essentially cylindrical cavity of the extruded flexible PVC thermoplastic tube 13 defined by a radially inward facing cylindrical surface 15. The pultruded rectangular cross section rod 14 is easily inserted into the cavity of the tube 13 without deforming the shape of the tube 13 and removable PVC end caps 16 from Harman Corporation of Rochester, Mich. are placed over the ends of the tube 13. The caps 16 may be secured, as by an adhesive, if desired. The rod 14 is no longer than the tube 13.
If an exercise device requiring greater bending force is desired an additional rod 14 may be inserted in the tube 13 as shown in FIG. 6. When the tube 13 is bent, both of the rods will orient themselves to bend about their major cross sectional axes. Friction between the rods 14 during bending may be reduced by inserting a 1 to 6 millimeter thick polyethylene thermoplastic strip 18 between the rods 14. The interleaved strip 18 may be slightly wider and as long as the rods 14.
An alternative exercise device 31, shown in FIGS. 7, 8 and 9, has a larger outside diameter extruded flexible PVC thermoplastic tube 32 than the extruded flexible PVC thermoplastic tube 13 shown in FIGS. 2, 3, 4 and 6. The inside diameter of the alternate exercise device 31 can be tailored to accommodate a wider range of sizes of rectangular cross section rods than are accommodated in the extruded flexible thermoplastic tube 13. The tube 32 has a surface hardness in the range of 50 to 100 as measured by the Shore A scale. Four pultruded rectangular cross section rods 34 are inserted in the tube 32 of the alternative exercise device 31. Closures in the form of end caps 36 are then installed on the ends of the tube 32. The rods 34 are thinner in the direction of their minor axis than the rods 14 and have a greater flexural endurance than the rods 14.
FIG. 10 shows a rectangular cross section rod 46 and a round cross section rod 47 fitting loosely in a flexible PVC thermoplastic tube 48. The round cross section rod 47 may be added when a slightly stiffer exercise device 45 is desired.
When the complete device is bent by the hands applying a force at or near each end of the device, the extruded PVC thermoplastic tube 13, 32 or 48 deforms as shown in FIG. 8 without kinking and with the pultruded composite rod, or rods, orienting itself, or themselves during the initial phase of the bending in response to forces exerted on the lengthwise edges by the interior cavity surface of the extruded flexible PVC thermoplastic round tube as its mid section deforms slightly to an oval section as shown in FIG. 9 such that the pultruded composite rod or rods and the tube of the exercise device bend readily in the direction that the device is bent in response to the forces exerted on the ends of the device by the hands. In the bending exercise of the device 11, 31 or 45, the pultruded composite rod or rods will orient itself or themselves to bend about its axis or major axis 21 which is approximately parallel to the major axis 41 of the oval section shape of the deformed tube 32 as shown in FIG. 9.
Prior to insertion of the pultruded composite rod into the cavity of the tube, the rod may have a wax, such as carnauba wax, applied to its surface which allows the rod to move easier inside the cavity of the tube as the rod orients itself so it can bend around its major axis as the tube is bent by the application of forces at or near each end of the exercise device. Further, a lubricant spray, such as WD-40, may be sprayed into the cavity of the tube, instead of applying the carnauba wax to the pultruded rod, prior to or after insertion of the rod in the cavity and before the application of the end caps to permit the pultruded bar to move easier inside the cavity of the tube as the rod orients itself so it can bend around its major axis upon the application of bending forces to the exercise device.
The pultruded rectangular cross section rods 14 and 34 will automatically orient themselves in the tube by bending about their major cross sectional axes during the initial bending of the exercise device. The extruded flexible tube's material density and surface hardness can be varied as long as the extruded tubular shape does not kink when bent at least into the shape of a semi-circle or interfere with the pultruded rod's natural tendency to orient itself to bend around it's major cross sectional axis. Even when multiple rods are used, as shown in FIGS. 6 and 7, the rods will orient themselves to bend about their major cross sectional axes as the exercise device is bent during an exercise routine. The use of a plurality of thin rods 34 allows the exercise device to be tailored to individual requirements. A slight increase in bending resistance can easily be achieved by the addition of one or more small diameter rods 47. The addition of small diameter rods 47 does not prevent the rectangular cross section rods from orienting themselves to bend about their major axes.
There are additional advantages flowing from use of a plurality of relatively thin rectangular cross section rods. A thin rectangular cross section rod has a longer service life than a thick rectangular cross section rod and the use of a plurality of thin rectangular cross section rods make it easy to select the number of rods to match the stiffness desired or to change the stiffness for any reason during use.

## Claims

1. A flexible elongated exercise device for use in the exercise of the human body, having variable resistance to bending in any direction including:
an elongated extruded flexible thermoplastic tube containing essentially no continuous reinforcing fibers, said tube having opposite ends and a cylindrical interior surface defining a round section cavity, said tube being bendable in the shape of a semicircle without kinking, when bending forces are applied to the ends of said tube by grasping said tube at or near the ends of said tube,
an elongated pultruded flexible rod fitting loosely within said round section cavity and extending longitudinally substantially coextensive with the length of said tube, said rod providing said exercise device with primary bending resistance and having a rectangular cross section shape with a major axis, a minor axis and radiused longitudinal edges, said major axis dimension of said cross section of said rod being at least one and one half times the minor axis dimension of said cross section of said rod, said rod rotatively orienting itself to bend about said major axis in the direction in which said tube of said exercise device is bent in response to forces exerted against said radiused edges of said rod by said cylindrical interior surface of said tube and
a closure on each of said ends of said tube.

2. The exercise device of claim 1 wherein said rod is made of one of a group of mixtures including a mixture of thermoplastic resin and longitudinally oriented continuous fibers and a mixture of thermoset resin and longitudinally oriented continuous fibers.

3. The exercise device of claim 2 wherein said longitudinally oriented continuous fibers are selected from the group consisting of type E glass fibers, type A glass fibers, type S-2 glass fibers, Owens Corning ‘Advantex’ glass fibers, type AR glass fibers, carbon fibers, aramid fibers and polyester fibers.

4. The exercise device of claim 1 wherein the exterior shape of the flexible elongated exercise device is essentially cylindrical.

5. The exercise device of claim 1 in which the length of the flexible elongated exercise device is between 18 inches and 72 inches.

6. The exercise device of claim 1 wherein said flexible tube has an outside diameter between 1⁄2 inch and 3 inches.

7. The exercise device of claim 1 in wherein said rod has a percent volume fraction of fiber between 25% and 70%.

8. The exercise device of claim 1 wherein said closure is an end cap.

9. The exercise device of claim 1 and further comprising at least one additional rod fitting loosely in said tube, each additional rod being made of one of a group of mixtures including a mixture of thermoplastic resin and longitudinally oriented continuous fibers, a mixture of thermoset resin and longitudinally oriented continuous fibers, a thermoplastic resin containing no fibers and a thermoplastic resin with chopped fibers.

10. The exercise device of claim 1 having at least one additional rod fitting loosely within and substantially coextensive with said tube, said additional rod having a rectangular cross section shape.

11. The exercise device of claim 10 having a thin strip thermoplastic interleaved between said rods.

12. The exercise device of claim 1 wherein said interior surface defining said round section cavity of said flexible tube, when said tube is deformed by application of a bending force to each of its ends, will apply a pressure to only said radiused edges of said rod along part of the length of said rod causing said rod to orient itself within said tube so that said rod will bend around said major axis without the user needing to further change the orientation of said tube.

13. The exercise device of claim 1 wherein said rod is formed by a pultrusion process.

14. A flexible elongated exercise device for use in the exercise of the human body, having variable resistance to bending in any direction including:
an elongated extruded flexible thermoplastic tube containing essentially no continuous reinforcing fibers, said tube having opposite ends and a cylindrical interior surface defining a round section cavity, said tube being bendable in the shape of a semicircle without kinking, when bending forces are applied to the ends of said tube by grasping said tube at or near the ends of said tube,
an elongated pultruded flexible rod fitting loosely within said round section cavity and extending longitudinally substantially coextensive with the length of said tube, said rod providing said exercise device with primary bending resistance and having a rectangular cross section shape with a major axis, a minor axis and radiused longitudinal edges, said major axis dimension of said cross section of said rod being at least one and one half times the minor axis dimension of said cross section of said rod, said rod rotatively orienting itself to bend about said major axis in the direction in which said tube of said exercise device is bent in response to forces exerted against said radiused edges of said rod by said cylindrical interior surface of said tube and
a closure on each of said ends of said tube; and
having a soft sleeve covering at least nearly the entire length of said tube.

15. The exercise device of claim 14 wherein said rod is made of one of a group of mixtures including a mixture of thermoplastic resin and longitudinally oriented continuous fibers and a mixture of thermoset resin and longitudinally oriented continuous fibers.

16. The exercise device of claim 15 wherein said longitudinally oriented continuous fibers are selected from the group consisting of type E glass fibers, type A glass fibers, type S-2 glass fibers, Owens Corning ‘Advantex’ glass fibers, type AR glass fibers, carbon fibers, aramid fibers and polyester fibers.

17. The exercise device of claim 14 wherein the exterior shape of the flexible elongated exercise device is essentially cylindrical.

18. The exercise device of claim 14 in which the length of the flexible elongated exercise device is between 18 inches and 72 inches.

19. The exercise device of claim 14 wherein said flexible tube has an outside diameter between 1⁄2 inch and 3 inches.

20. The exercise device of claim 14 in wherein said rod has a percent volume fraction of fiber between 25% and 70%.

21. The exercise device of claim 14 wherein said closure is an end cap.

22. The exercise device of claim 14 further comprising at least one additional rod fitting loosely in said tube, each additional rod being made of one of a group of mixtures including a mixture of thermoplastic resin and longitudinally oriented continuous fibers, a mixture of thermoset resin and longitudinally oriented continuous fibers, a thermoplastic resin containing no fibers and a thermoplastic resin with chopped fibers.

23. The exercise device of claim 14 having at least one additional rod fitting loosely within and substantially coextensive with said tube, said additional rod having a rectangular cross section shape.

24. The exercise device of claim 23 having a thin strip thermoplastic interleaved between said rods.

25. The exercise device of claim 14 wherein said interior surface defining said round section cavity of said flexible tube, when said tube is deformed by application of a bending force to each of its ends, will apply a pressure to only said radiused edges of said rod along part of the length of said rod causing said rod to orient itself within said tube so that said rod will bend around said major axis without the user needing to further change the orientation of said tube.

26. The exercise device of claim 14 wherein said rod is formed by a pultrusion process.

27. The exercise device of claim 1 further including at least one additional rod of round cross section fitting loosely within and substantially co extensive with said tube.

28. The flexible elongated exercise device of claim 27 further having a soft sleeve covering at least nearly the entire length of said tube.