Carrying case and a method of making thereof

BACKGROUND OF THE INVENTION

The present invention relates to a carrying case and a method of manufacturing thereof, and more particularly to a bag and method of manufacturing soft-sided bags particularly adapted for outdoor activities.

People engaged in outdoor activities usually carry a number of items, such as food supplies, ammunition for hunting guns, and other similar items that need to be protected from moisture. Under such conditions, provision of a moisture-impermeable carrying case or container becomes essential.

Conventional carrying cases or containers are not, as a general rule, completely watertight. Moisture can seep through the line of closure, through zippers, openings under the zippers and cause deterioration of the contents of the carrying case. Even bags or carrying cases constructed from water repellent material suffer from imperfections in construction, as they do not allow creation of truly a watertight enclosure.

The present invention contemplates elimination of drawbacks associated with the prior art and provision of a carrying case and a method of manufacturing a moisture-impermeable bag that can serve as a container for moisture-sensitive items.

SUMMARY OF THE INVENTION

It is, therefore, an object of the present invention to provide a bag and a method of manufacturing a moisture-impermeable carrying case.

It is another object of the present invention to provide a carrying case and a method of making same, such the bag is moisture-impermeable.

It is a further object of the present invention to provide a bag and a method of manufacturing a moisture-impermeable carrying case with a flexible body.

These and other objects of the present invention are achieved through a provision of a bag and a method for manufacturing soft-sided moisture-proof carrying case. The method comprises the steps of forming a main body having opposite narrow ends and elongated sides. The main body is made from material cut on a bias.

A pair of end panels, having a generally drop-shaped configuration are cut from the same material. Each end panel is attached to a respective narrow end of the main body by dielectric welding. To avoid wrinkles in the finished product, the narrow ends of the main body are stretched to confirm to the size and shape of the end panel.

The soft-sided bag can be manufactured with one or more handles, each carrying securing buckles, if desired. A zip-lock closure member is secured by dielectric welding to the open end of the bag after the end panels have been secured. The closure member can be made from extruded plastic material and provided with pull-out tabs to facilitate opening of the bag.

To prevent tearing of the closure adjacent its line of attachment to the main body, an end sleeve is secured to the main body and to the closure member, slightly overlapping the closure member and the main body. The end sleeve is provided with a reservoir to accommodate melted material, which is created when the closure element is exposed to radio frequency, or dielectric welding.

The soft-sided carrying case manufactured in accordance with the method of the present invention can be made in the shape of a duffel bag, a gun carrying case, or any other desired shape. By using double-coated embossed polyurethane for the main body and the end panels, as well as zip-lock closure member, a moisture-impermeable body is created. The main body is coated with #420 denier nylon for better appearance and variations in color and texture.

BRIEF DESCRIPTION OF THE DRAWINGS

Reference will now be made to the drawings, wherein like parts are designated by like numerals, and wherein

FIG. 1

is a perspective view of the bag manufactured in accordance with the present invention.

FIG. 2

is a top view of the bag main body, before welding.

FIG. 3

is a second end piece for use in the bag manufactured in accordance with the present invention.

FIG. 4

is a side view of a closure member.

FIG. 5

is a detail cross-sectional view of the closure member taken along line

5

—

5

of FIG.

4

.

FIG. 6

is a perspective detail view of an end sleeve and the corner of the bag, wherein the sleeve is positioned.

FIG. 7

is a perspective detail view of the end sleeve secured on the main body.

FIG. 8

is a detail view showing a bag corner construction with the closure element and pull-out tabs.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Turning now to the drawings in more detail, reference will now be made to the drawings, presented for illustrative purposes only, wherein numeral

10

designates the bag manufactured according to the method of the present invention. The main body of the bag

11

is made from a moisture-impermeable material, for example, double coated embossed polyurethane, with a base layer of #420 denier nylon. Of course, other materials can be used to manufacture bags of the present invention, as long as the materials are similar in physical and chemical characteristics to polyurethane.

The main body

11

is provided with four corner tabs

12

, which are used for stretching the main body

11

over a weld form, as will be explained in more detail hereinafter. The main body

11

is cut from a sheet of polyurethane material, cut on a bias of approximately 45 degrees. By cutting the material on a bias, certain stretching and “giving” of the material is achieved, which facilitates wrinkle-free attachment of the end panels to the main body

10

.

FIGS. 3

illustrates the drop-shaped end panels

14

and

16

that are attached to the main body

11

during making of the bag

10

. The end panels

14

and

16

comprise a rounded portion

14

a

and

16

a

, as well as an elongated extended portions

14

b

and

16

b.

FIG. 1

illustrates a first handle

20

secured on the main body

11

. The handle

20

is made from a narrow strip of a strong, tear-resistant fabric that can be folded in two, if necessary, and stitched together to provide further thickness and strength to the handle

20

. The main body of the handle is secured to attachment elements

22

, which are made from scraps of the same material as the main body

11

. The ends of the handle

20

carry female buckle elements

24

secured to the handle

20

in a conventional manner.

Although not shown in the drawings, a second carrying handle, made from the same material as the handle

20

is attached, at the opposite side of the main body

11

, in a mirror-image position to the handle

20

. Each end of the second handle carries a male end of a buckle. The buckle elements of the second handle are sized and shaped to engage with the female buckle elements

24

of the handle

20

to facilitate carrying of the bag.

FIGS. 4 and 5

illustrate a zip-lock closure member

30

. The zip-lock closure member comprises a first portion

32

and a second portion

34

. The first portion

32

is provided with a pair of elongated ribs

36

and

38

extending in a parallel relationship along the length of the portion

32

. The second portion

34

is provided with three parallel ribs

40

,

42

and

44

, spaced from each other and defining engagement channels

46

and

48

for receiving the ribs

36

and

38

therein when the lock is closed. The closure member

30

has a length substantially equal to or smaller than the length of the main body

11

.

A pair of pull out tabs

50

is provided on each portion

32

and

34

for grasping by a user to pull the two portions of the closure elements apart and allow the user to gain access to the interior of the bag

10

, once it is constructed.

To prevent tearing of the closure member

30

during repeated opening of the bag

10

, an end sleeve

52

is provided for attachment to the bag main body

11

and the closure member

30

about the line of attachment between these two structural members. The sleeve

52

comprises a folded piece of material stitched adjacent one end, as at

54

(see

FIGS. 6 and 7

) and open at the opposite end

56

. During manufacture, the end sleeve

52

is positioned over a corner

60

and the closure element

30

adjacent its end (see FIG.

6

). A similar end sleeve

62

is secured on the opposite end of the bag

10

(see FIG.

1

).

If desired, the end sleeves

52

and

62

can carry a male element

58

and

64

, respectively, of a buckle for engagement with female buckle elements

66

(only one is shown in FIG.

1

), which are fixedly attached to the end panels

14

and

16

.

In the manufacturing process of the present invention, the elements are secured together with the use of radio frequency in a process conventionally identified as RF, or dielectric welding. This method is used for joining polymers that have strong dipoles, including polyurethane. During dielectric welding method, a high intensity alternating electromagnetic field is applied to the dipoles. As the dipoles alternate with the changing field polarity, some of the field energy is converted into heat creating a weld seam between the two items. The weld times usually range from 1-6 seconds, depending on the material, thickness of the material, as well as the area being welded.

The apparatus for performing dielectric welding is available on the market, from, for example, Hall Dielectric Machinery Co., Inc. of Rock Hill, S.C. The instrumentation uses microprocessors to insure the necessary control during the weld cycle and wrinkle-free welding. The RF frequency generating machines can generate frequency in the range of 27.120 MHz ±0.06%. The instrumentation produces under 1 MW/sq. cm. of magnetic and electric radiation.

Turning now to the process of making the bag

10

, the main body

11

is cut on a bias, and four corner tabs

12

are made in the body

11

. Then, end panels

14

and

16

are either cut or stamped out of the remainder of material, after the main body

11

has been cut. The attachment members

15

,

22

and end sleeves

52

,

62

are cut from scraps remaining after the end panels

14

and

16

have been cut out.

The process continues with the attachment of the handles

20

and

26

to the main body

10

. The handles, having secured thereon the buckles

24

are secured to the attachment members

22

. One of the handles is then positioned adjacent a first narrow end

70

on the main body

11

, so that the underside of the attachment piece

22

lies flat against the outer surface of the main body

11

.

The position of the handle

20

and the attachment members

22

may be temporarily secured by removable conductor members formed from a material suitable for conducting radio waves therethrough. The body

11

with the handle

20

positioned at a predetermined location thereon is exposed to radio frequency waves for 2-4 seconds, allowing a cool down time of 1-2 seconds after the welding has been completed.

Once exposed to the radio frequency waves, the attachment members

22

become welded to the main body

11

in a secure, seamless manner. The same procedure is completed for the second handle, which is positioned adjacent a second narrow end

72

of the main body

11

, in a mirror-image position to the handle

20

. Of course, simultaneous positioning of both handles and exposure of the attachment members

22

to radio frequency waves can be accomplished, if desired.

The process continues with the securing of the female portions of buckles

66

to the end panels

14

and

16

. The attachment members

15

are positioned with their inner surfaces contacting the outer surfaces of the end panels, in the central portions

14

a

and

16

a

. A RF-conductive conductive member is then positioned on top of the attachment elements

15

, and the end panels

14

and

16

are exposed to radio frequency waves. The welding process continues for 2-4 seconds after which time the attachment members

15

become fused, or welded to the end pieces

14

and

16

, thereby fixedly securing the buckle portions

15

on the end panels.

The process continues with attachment of the end panels

14

and

16

to the main body

11

. First, the body

11

is secured on a vertically oriented RF-conductive stand (not shown), while the material of the main body

11

is stretched to conform to the stand configuration. The narrow end

70

or

72

, while being stretched, approximates the size and shape of the end panel

14

or

16

.

The tabs

12

are secured on the stand with a clamp, preventing shifting of the main body

11

during welding. The end piece

14

is then laid over the stand, covering at least a portion of the main body

11

. An RF-conductive member is then positioned over the end piece

14

, and the main body

11

with the end piece

14

is then exposed to RF waves for a predetermined period of time of about 2-4 seconds, followed by a cool-down time of about 1-2 seconds. During this step, the end piece

14

becomes permanently attached, in effect fused to the main body

11

.

The same process is repeated for the second end panel, which is secured to the opposite narrow end

72

of the main body

10

. The ends of the bag are formed as drop-shaped portions, which is different from conventional round end portions typically found in a duffel bag. The tabs

12

are then trimmed off, so as to present a neat overall appearance of the end portions of the bag

10

.

The next step in the process is the attachment of the zip-lock closure member

30

to the bag body

11

. For this purpose, the elongated sides

74

and

76

of the main body

11

are brought together, with one side

74

contacting one portion

32

of the closure

30

, with the opposite elongated side

76

contacting the opposite portion

34

of the closure member

30

. An elongated RF-conductive platen is then removably positioned between the closure portions

32

and

34

. An additional RF-conductive platen is positioned under the main body

11

and a third RF-conductive platen is positioned over the four-layered fold.

This fold is then exposed to RF waves for a predetermined period of time, 4-6 seconds. The longer exposure is necessary to insure fusion or welding of the closure member

30

to the main body

11

. During testing, it was observed that some of the material of the closure member

30

melts and tends to form an unsightly drop of molten plastic. To prevent such an undesirable effect, the present invention provides for a small reservoir

80

formed in each end sleeve

52

and

62

(see FIGS.

4

and

7

). The reservoirs

80

are formed in the interior of the sleeves

52

and

62

and are large enough to accommodate the melted plastic from the closure member

30

.

The bag manufactured in accordance with the present invention is flexible, somewhat stretchable, watertight and allows to retain a number of moisture-sensitive objects therein. It can be easily carried to a desired location by the flexible handles, transporting the supplies and/or sport ammunition to an outdoor location. Of course, other shapes can be used for the manufacture of the carrying case of the present invention. For example, a gun-carrying case can be made according to the same method and using dropshaped end panels. The method of manufacturing the soft-sided bag, or carrying case takes advantage of the radio frequency, or dielectric welding for the production of a seamless, wrinkle-free bag.

The types of materials used in the method of the present invention for the manufacturing of the bag can vary, depending on the particular purpose of the bag. The plastic material, double-coated embossed polyurethane is readily available on the market from, for example, URETEK, Inc. of New Haven, Conn. One of the tested materials had a polyether polyurethane coating of 4 oz./ sq. yd. The fabric layer was #420 denier nylon, 50×40 threads/inch. The weight of the fabric was 8 oz./sq. yd. The material tested with the method of the present invention has a tensile strength warp 400 lbs., fill 300 lbs., puncture resistance—80 lbs. The zip-lock closure member

30

made from extruded plastic is likewise readily available on the market in a roll form, allowing to cut the required length for manufacturing of a designated size of a bag. The buckles can be conventional slide release buckles with D-rings; they are readily available from a number of manufacturers.

Depending on the desired size of the resultant product, the dimensions of the main body

11

and the end panels

14

and

16

would differ, as well as the length of the handles and of the closure member

30

.

Many changes and modifications can be made in the design and method of the present invention without departing from the spirit thereof. We, therefore, pray that our rights to the present invention be limited only by the scope of the appended claims.