U.S. patent application number 10/822531 was filed with the patent office on 2005-10-13 for trampoline mat and method of making same.
Invention is credited to James, Thomas A..
Application Number | 20050227812 10/822531 |
Document ID | / |
Family ID | 35061292 |
Filed Date | 2005-10-13 |
United States Patent
Application |
20050227812 |
Kind Code |
A1 |
James, Thomas A. |
October 13, 2005 |
Trampoline mat and method of making same
Abstract
An improved trampoline mat capable of being attached to a
trampoline frame using a plurality of coil springs. The trampoline
mat includes a flexible bed having an outer portion being folded
over and connected to an inner portion of the flexible bed so as to
provide a channel about the periphery of the flexible bed. The
channel extends around the circumference of the flexible bed and
has a filament disposed therein. The filament is configured and
arranged to distribute a load to the channel. The filament extends
the length of the channel and forms a loop. A plurality of notches
are formed in the channel to expose portions of the filament to
provide locations at which the flexible bed is coupled to the
frame.
Inventors: |
James, Thomas A.; (Rockwell,
TX) |
Correspondence
Address: |
IPSOLON LLP
805 SW BROADWAY, #2740
PORTLAND
OR
97205
US
|
Family ID: |
35061292 |
Appl. No.: |
10/822531 |
Filed: |
April 12, 2004 |
Current U.S.
Class: |
482/27 |
Current CPC
Class: |
A63B 21/023 20130101;
A63B 5/11 20130101 |
Class at
Publication: |
482/027 |
International
Class: |
A63B 005/11 |
Claims
What is claimed is:
1. An improved trampoline mat capable of being attached to a
trampoline frame using a plurality of coil springs, the mat
comprising: a flexible bed having an outer portion, the outer
portion being folded over and connected to an inner portion of the
flexible bed so as to define a channel about the periphery of the
flexible bed, the channel extending around the circumference of the
flexible bed; a filament disposed within the channel, the filament
configured and arranged to distribute a load to the bed, the
filament extending the length of the channel and meeting at
opposite ends of the filament to form a loop; and a plurality of
notches formed in the bed to provide access to an interior of the
channel, the notches being configured and arranged to expose a
plurality of corresponding portions of the filament where the load
is applied to the filament.
2. The trampoline mat of claim 1, wherein the flexible bed has no
stitching that bears a substantial portion of the load.
3. The trampoline mat of claim 2, wherein the flexible bed has no
grommet, elastomer or webbing that bears a substantial portion of
the load.
4. The trampoline mat of claim 1, wherein the connection between
the inner portion and the outer portion defines a connected portion
of the flexible bed, the connected portion consisting essentially
of a single material.
5. The trampoline mat of claim 4, wherein the single material is
polypropylene.
6. The trampoline mat of claim 1, wherein the outer portion is
connected to the inner portion by ultrasonic welding.
7. The trampoline mat of claim 1, wherein the outer portion is
connected to the inner portion with heat.
8. The trampoline mat of claim 1, wherein the outer portion is
connected to the inner portion with an adhesive.
9. The trampoline mat of claim 1, wherein the filament is a metal
cable.
10. The trampoline mat of claim 1, wherein each portion of the
filament exposed by the notches forms a v-ring.
11. The trampoline mat of claim 1, further comprising a sheath
disposed in the channel around the filament.
12. The trampoline mat of claim 1, wherein the ends of the filament
are connected.
13. The trampoline mat of claim 1, wherein the flexible bed in a
folded position is substantially circular.
14. The trampoline mat of claim 1, wherein said outer portion is
connected to said inner portion using a stitch.
15. An improved trampoline mat capable of being attached to a
trampoline frame using a plurality of coil springs, the mat
comprising: a flexible bed having an outer portion, the outer
portion being folded over and connected to an inner portion of the
flexible bed so as to define a channel about the periphery of the
flexible bed; a filament disposed within the channel, the filament
being configured and arranged to distribute a load to the bed; a
plurality of notches formed in the folded portion of the bed to
provide access to an interior of the channel, the notches being
configured and arranged to expose a plurality of corresponding
portions of the filament where the load is applied to the filament;
and wherein the flexible bed has no stitching that bears a
substantial portion of the load.
16. The trampoline mat of claim 15, wherein the flexible bed has no
grommet, elastomer or webbing that bears a substantial portion of
the load.
17. The trampoline mat of claim 15, wherein the inner portion is
connected to the flexible bed by ultrasonic welding.
18. The trampoline mat of claim 15, wherein the outer portion is
connected to the inner portion with heat.
19. The trampoline mat of claim 15, wherein the flexible bed is
constructed of a material having a plurality of fibers exposed at
at least one edge, wherein substantially all the exposed fibers at
the at least one edge are bonded to adjacent fibers.
20. The trampoline mat of claim 19, wherein the adjacent fibers are
bonded by an ultrasonic cutter, a plasma cutter, or by heat.
21. The trampoline mat of claim 20, wherein substantially all the
exposed fibers on substantially all the exposed edges have adjacent
fibers bonded.
22. The trampoline mat of claim 15, wherein the filament is a
braided metal cable.
23. The trampoline mat of claim 15, further comprising a sheath
disposed in the channel around the filament.
24. The trampoline mat of claim 15, wherein the ends of the
filament are connected.
25. A trampoline with an improved trampoline mat, the trampoline
comprising: a trampoline frame; a flexible bed having a outer
portion, the outer portion being folded over and connected to an
inner portion of the flexible bed by sonic welding so as to define
a channel about the periphery of the flexible bed, the channel
extending around the circumference of the flexible bed; a filament
disposed within the channel, the filament configured and arranged
to distribute a load to the bed, the filament extending the length
of the channel and connecting at opposite ends of the filament to
form a loop; wherein the flexible bed has no stitching that bears a
substantial portion of the load; a plurality of notches formed in
the bed to provide access to an interior of the channel, the
notches being configured and arranged to expose a plurality of
corresponding portions of the filament where the load is applied to
the filament; and a plurality of coil springs, each spring being
connected to the trampoline frame at one end and to the exposed
portions of the filament at the other end, the plurality of springs
capable of resiliently supporting the trampoline mat above a
surface.
26. The trampoline mat of claim 25, wherein the connection between
the outer portion and the inner portion defines a connected portion
of the flexible bed, the connected portion consisting essentially
of a single material and a filler.
27. The trampoline mat of claim 25, further comprising a sheath
disposed in the channel around the filament.
28. The trampoline mat of claim 25, wherein the flexible bed is
substantially circular.
29. A method for making an improved trampoline mat, the method
comprising: cutting a sheet of bed material to form a flexible bed
having an inner portion, an intermediate portion, and an outer
portion, the flexible bed being cut to a desired shape; cutting a
plurality of notches in the intermediate portion, the plurality of
notches being spaced about the intermediate portion; disposing a
filament on the intermediate portion; folding the outer portion
over and connecting it to the inner portion to form a channel about
the periphery of the flexible bed, the outer portion being folded
over such that the intermediate portion is on the periphery of the
bed and the filament is disposed within the channel, wherein the
folding also positions the notches such that they expose
corresponding spaced portions of the filament; and connecting the
filament to form a loop.
30. The method of claim 29, wherein the steps of disposing the
filament and connecting the outer portion to the inner portion are
performed simultaneously.
31. The method of claim 29, wherein the step of cutting the bed
material comprises cutting the bed material with an ultrasonic
cutter, a plasma cutter, or by heat.
32. The method of claim 29, wherein cutting the bed material bonds
substantially all adjacent exposed fibers at an edge of the cut bed
material.
Description
BACKGROUND OF THE INVENTION
[0001] 1. The Field of the Invention
[0002] The present invention relates to trampoline mats. More
specifically, embodiments of the present invention relate to a sewn
or non-sewn trampoline mat that distributes a load to a frame using
a filament.
[0003] 2. The Related Technology
[0004] Trampolines are well known devices used for bouncing,
jumping and performing other acrobatic maneuvers. Trampolines are
often used for entertainment, exercising, or athletic training.
[0005] Many versions of trampolines exist. A typical trampoline has
a mat attached to a frame using coil springs. The springs support
the mat and give the trampoline its resilient characteristics. Of
course other resilient mechanisms have bean used in place of coil
springs, such as elastic straps.
[0006] Trampolines are often subject to substantial wear and tear.
In particular, the mat of a trampoline is generally subject to the
most wear. Thus, the mat of a trampoline is often the first
component of the trampoline to fail. The mat can be subject to wear
and tear from users and items placed on the trampoline. For
instance a users shoes, toys, clothing, and the like can
potentially damage the mat. In addition, weather conditions such as
temperature and UV light significantly affect the durability of
trampoline mats used outdoors.
[0007] A trampoline mat is usually constructed as a single piece;
therefore, when one portion fails, the entire mat fails. To create
a bouncing surface the mat is created such that a force applied to
the center of the mat is transferred radially to the springs. The
springs exert a force on the mat to keep the mat suspended above
the ground, for example. Consequently, when a tear or hole is made
in the mat, the tear or hole tends to expand quickly. If the damage
is not repaired the entire mat may fail. For the forgoing reasons,
enhancing the durability of the trampoline mat is an effective
mechanism to enhance the durability of the trampoline.
[0008] Existing mats are often constructed from polypropylene
because of its high strength, relatively lightweight, and UV
resistance. However, existing trampoline mats are constructed using
other materials and structural features, which are likely to fail.
For instance, most trampoline beds are hemmed or stitched to
provide an attachment place for coil springs. Various mechanisms
have been used to secure an attachment location for coil springs
and the like. For instance, some trampolines have grommets crimped
into the mat near its edge, while other mats use elastomers or
webbing extending from the mat.
[0009] Sewing a stitch into the mat creates defined areas of stress
in the mat. Over time, the areas of higher stress are more likely
to fail, which reduces the durability of the mat. Furthermore, the
localized attachment cites for springs creates bias in the weave of
the bed fabric. The bias is created in the fabric around each
spring attachment site. The fabric stretches non-uniformly to
transfer the resilient force across the mat. The bias force
absorbed by the fabric reduces the bounce and distributes a
non-uniform force across the mat.
[0010] Using various materials to provide attachment sites for the
springs also decreases durability of the mat. When multiple
materials are used to make the trampoline mat, some materials will
likely deteriorate faster than other materials. For instance, the
stitching on a trampoline mat often fails before the bed material.
One reason stitching fails before bed material is because it is
usually less UV resistant.
[0011] Another weakness with existing mats is their tendency to
fray or unravel at the edges. When a trampoline is made, it is cut
out of a larger sheet of material. The exposed fibers are
susceptible to fraying. Fraying is often prevented by hemming the
trampoline mat at the edge of the cut. Failure of the stitch used
to hem the trampoline mat often results in fraying.
[0012] Finally the stitching methods used to make existing
trampoline mats, increases the cost of a trampoline because of the
steps that are required to construct them. For instance, many
trampolines are manufactured by hand thus requiring intensive labor
to manufacture the mat. In addition, the current processes for
manufacturing trampoline mats cannot produce a mat with a
consistent size and shape. For example, the attachment site for
springs can be slightly off in various locations on the mat, which
increases stress and the likelihood that the mat will fail.
[0013] Therefore, what is needed is a more durable trampoline mat
that reduces localized stress in the bed fibers and can be easily
and affordably manufactured.
BRIEF SUMMARY OF THE INVENTION
[0014] The improved trampoline mat of the present invention and
method of making the same overcome the problems discussed above by
providing a durable mat with superior bounce. In an exemplary
embodiment, the trampoline mat includes a bed and a filament. The
bed is configured for jumping and performing acrobatic
maneuvers.
[0015] A portion of the bed is folded over and connected to the bed
to define a channel at the periphery of the bed. The filament is
disposed within the channel and continues about the periphery of
the bed to form a loop. A plurality of holes or notches are formed
along the channel to expose portions of the filament.
[0016] The trampoline mat is configured to be connected to a
trampoline frame using a plurality of coil springs. The coil
springs can be attached to the mat at the exposed portions of the
filament. The force of the coil springs on the filament creates a
load that is distributed by the filament to the periphery of the
bed.
[0017] In an exemplary embodiment, the folded portion of the bed is
connected to the bed by ultrasonic welding. The ultrasonic weld is
continuous with the channel that extends about the periphery of the
bed. The weld uses no stitching, grommets, or webbing. Instead, the
weld fuses the fibers of the outer portion of the bed to the inner
portion of the bed. Since there is no stitch in the weld, there is
no thread that can deteriorate and cause the trampoline mat to
fail. The bed can have webbing sewn thereon for decorative or other
non-load bearing purposes.
[0018] The loop formed by the filament is continuous about the
periphery of the bed. The plurality of coil springs attaches to the
filament and creates tension therein. The tension and continuous
nature of the filament allows the filament to more evenly
distribute the load about the periphery of the bed. Distributing
the load and continuing the weld about the periphery of the bed
reduces the areas of localized stress in the bed. Reducing the
areas of localized stress reduces the amount of bounce that is
absorbed by the mat and increases the amount of bounce that is
transferred to the trampoline user. A user bouncing on the
trampoline mat of the present invention will experience a better
bounce because the bounce will be more powerful and more uniform
about the mat. Furthermore the user can use the mat over a longer
period of time at less cost because the mat is more durable.
[0019] In one embodiment, a method of making a trampoline mat is
provided. The method includes cutting a piece of bed material to a
desired shape, cutting notches in an outer portion of the bed,
folding the outer portion and welding it to the bed using an
ultrasonic welder to form a channel, and disposing a filament in
the channel. The filament is connected at the ends to form a
loop.
[0020] Various steps of the method of the present invention can be
performed simultaneously using an automated manufacturing device.
For example, the trampoline mat can be manufactured by
simultaneously performing the steps of cutting the bed material,
disposing the filament, folding the outer portion, and welding the
outer portion to the bed. The one-step approach to manufacturing
the trampoline mat of the present invention reduces manufacturing
time and costs.
[0021] These and other features of the present invention will
become more fully apparent from the following description and
appended claims, or may be learned by the practice of the invention
as set forth hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] To further clarify the above and other advantages and
features of the present invention, a more particular description of
the invention will be rendered by reference to specific embodiments
thereof which are illustrated in the appended drawings. It is
appreciated that these drawings depict only typical embodiments of
the invention and are therefore not to be considered limiting of
its scope. The invention will be described and explained with
additional specificity and detail through the use of the
accompanying drawings in which:
[0023] FIG. 1 shows an exemplary trampoline mat of the present
invention attached to a trampoline frame using coil springs;
[0024] FIG. 2 shows a partial bottom view of the trampoline mat,
frame, and springs of FIG. 1;
[0025] FIG. 3 shows a cut sheet of bed material used to make the
trampoline mat of FIG. 1;
[0026] FIG. 3A is a detail view of an edge portion of the bed
material of FIG. 3;
[0027] FIG. 4 shows a cross-sectional view of the trampoline mat of
FIG. 1; and
[0028] FIG. 5 shows an exemplary manufacturing system for making
the trampoline mat of FIG. 1.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0029] Exemplary embodiments of the present invention relate to an
improved trampoline mat 10. As shown in FIG. 1, the trampoline mat
10 includes a flexible bed 12 and a filament 14 extending about the
periphery of flexible bed 12. In an exemplary embodiment flexible
bed 12 and filament 14 are attached to a trampoline frame 15 using
a plurality of coil springs 16.
[0030] Flexible bed 12 is formed from a sheet of flexible, durable
bed material, which provides a rebounding surface on which a
trampoline user can bounce or perform acrobatic maneuvers. Flexible
bed 12 is shown in FIG. 1 as being circular. However, flexible bed
12 may be of any desired shape including any polygon such as
square, rectangular, hexagonal, octagonal, and the like. The size
of flexible bed 12 can also be any desired size. Flexible bed 12 is
configured to be attached to the interior of trampoline frame
15.
[0031] Generally, trampoline mat is shaped similar to trampoline
frame 15 and sized smaller to accommodate springs 16. Trampoline
mat 10 can be configured to work with a rigid frame, such as a
metal frame, or any frame capable of suspending trampoline mat 10
over a surface. The trampoline frame 15 can be any desired material
or shape and can be placed in or above the ground. Furthermore,
coil springs 16 may be any type of resilient member. For instance,
trampoline mat 10 can be attached to trampoline frame 15 using a
plurality of elastic straps or any other device that can support
the mat and return to its original position after being flexed.
[0032] The bed material used to form flexible bed 12 has properties
that enhance trampoline performance and wear. For instance, in an
exemplary embodiment, the bed material is lightweight thereby
minimizing the amount of resilience needed by coil springs 16 to
suspend flexible bed 12. This configuration provides a user with a
better bounce. The bed material is also durable such that it will
withstand the normal harsh conditions that the flexible bed 12 may
be subject to. For instance, the bed material is UV resistant to
prevent deterioration of the material when exposed to sunlight. In
one embodiment, the bed material is polypropylene, which exhibits
the foregoing properties.
[0033] Filament 14 is a cable or wire disposed in flexible bed 12
at the periphery of flexible bed 12. Filament 14 extends around
flexible bed 12 and connects to itself to form a loop. The
trampoline mat 10 is suspended above a surface by attaching coil
springs 16 to filament 14. Filament 14 can be made of various types
of material so long as the material is capable of withstanding the
load applied to filament 14 when a user or users are jumping on
trampoline mat 10. In one presently preferred embodiment, filament
14 consists of a vinyl covered braided steel cable having a
diameter of approximately 1/8.sup.th of an inch.
[0034] FIG. 2 shows a section of the bottom outer part of flexible
bed 12. Flexible bed 12 has a folded portion 18 that has been
folded over and connected so as to form a channel 20 at the
periphery of flexible bed 12. (Folded portion 18 includes outer
portion 32 and intermediate portion 34 discussed in detail below).
A plurality of notches 24 are formed in folded portion 18 so as to
provide access to the interior of channel 20 at a plurality of
locations spaced about the periphery of trampoline bed 10. Notches
24 may be a hole, a cutaway, or any desired shape that provides
access to the interior of channel 20. Notches 24 expose filament 14
to create exposed portions 26 of filament 14. Coil springs 16
attach to filament 14 at exposed portions 26. When coil springs 16
are extended, coil springs 16 exert a load on filament 14. While
filament 14 has been illustrated as a smooth loop disposed
completely within channel 20, it should be understood, that
filament 14 can be formed to have a different shape. Furthermore,
portions of filament 14 disposed in channel 20 can extend outside
channel 20, such as v-shaped bends that extends through notches
24.
[0035] As used herein, the terms "outer portion 32" and "outer
peripheral portion 32" shall refer to a circular strip of the
material (cut to the overall desired shape of trampoline bed 10 and
laid out flat) from which flexible bed 12 is formed and that
extends around the periphery of the material and is immediately
adjacent the outer peripheral edge of the material, and which is
best illustrated in FIGS. 3 and 3A.
[0036] As used herein, the terms "intermediate portion 34" and
"intermediate peripheral portion 34" shall refer to a circular
strip of the material (cut to the overall desired shape of
trampoline bed 10 and laid out flat) from which flexible bed 12 is
formed and that extends around the periphery of the material and is
located inside of, and adjacent to, outer portion 32, and which is
best illustrated in FIGS. 3 and 3A.
[0037] As used herein, the terms "inner portion 36" and "inner
peripheral portion 36" shall refer to a circular strip of the
material (cut to the overall desired shape of trampoline bed 10 and
laid out flat) from which flexible bed 12 is formed and that
extends around the periphery of the material and is located inside
of, and adjacent to, intermediate portion 34, and which is best
illustrated in FIGS. 3 and 3A.
[0038] The dashed lines shown in FIGS. 3 and 3A are for purposes of
illustrating the aforementioned portions of flexible bed 12
only.
[0039] FIGS. 3 and 3A show an exemplary flexible bed 12 in a cut
and unfolded position. In an unfolded position, flexible bed 12 has
an outer peripheral portion 32, an intermediate peripheral portion
34, and an inner peripheral portion 36. In an exemplary embodiment,
outer peripheral portion 32 has substantially the same radial
thickness as inner portion 36. Outer portion 32 and inner portion
36 are substantially the same radial thickness such that outer
portion 32 and inner portion form surfaces of similar width for
bonding. In a folded position, outer portion 32 is folded over and
bonded to inner portion 36.
[0040] Notches 24 are circular cuts formed and centered in
intermediate portion 34. Centering notches 24 in intermediate
portion 34 positions notches 24 to be on the fold at the outer
peripheral edge, which is created when outer peripheral potion 32
is folded over and bonded to inner peripheral portion 36.
[0041] FIG. 4 shows a cross-section of bed 12 in the folded and
bonded position. Outer portion 32 is folded over and bonded to
inner portion 36 to define channel 20 at the periphery of flexible
bed 12. With outer portion 32 folded over, intermediate portion 34
lies on the periphery of flexible bed 12.
[0042] Filament 14 is disposed in channel 20. The load applied to
filament 14 causes filament 14 to abut the outermost part of
channel 20. Filament 14 has a sheath 28 around it to provide a
protective layer between filament 14 and channel 20. Sheath 28 can
be tubing or a coating that is affixed to filament 14. The sheath
28 helps prevent damage to the channel 20 by filament 14 and
provides a better surface around filament 14 for attaching coil
springs 16 and the like.
[0043] Outer portion 32 and inner portion 36 are bonded together to
create a connected portion 22. The dashed lines representing
connected portion 22 in FIG. 4 are for illustrative purposes
only.
[0044] The bond between outer portion 32 and inner portion 36 at
connected portion 22 is strong enough to keep outer portion 32 and
inner portion 36 from separating when trampoline mat 10 is in use.
In an exemplary embodiment, outer portion 32 is connected to inner
portion 36 by ultrasonic welding. When outer portion 32 is
connected to inner portion 36 using ultrasonic welding, the fibers
of the two layers of soften and/or melt together to form bonded
fibers. Since outer portion 32 is connected to inner portion 36
using ultrasonic welding, flexible bed 12 has no stitching,
grommets, or webbing that bears a substantial portion of the
load.
[0045] In a trampoline bed that uses connection means such as
stitching, grommets, or webbing, the connection means bears a
substantial portion of the load if when it deteriorates, the
deterioration creates a weak spot in the bed where the trampoline
mat 10 fails to support the load. In other words, sewn stitching,
grommets or webbing that are aesthetic, or integrated purely for
purposes of attaching something other than the filament and/or coil
springs and the like, is not a portion of the bed that bears a
substantial portion of the load. The failure of these portions
would not affect the integrity of the mat with respect to the load
applied by the coil springs.
[0046] In another embodiment, outer portion 32 is connected to
inner portion 36 using a different type of thermal joining, or
adhesive. In yet another embodiment, folded portion 18 is connected
to flexible bed 12 by sewing a stitch. Stitching the fold in some
cases can be beneficial since sewing can be relatively inexpensive.
In addition, some bed materials are not suitable for thermal
joining and thus cannot be connected using a thermal weld.
[0047] Outer portion 32 is shown folded under inner portion 36 in
FIG. 3. Folding outer portion 32 under flexible bed 12, instead of
over flexible bed 12, provides a smooth upper bouncing surface for
users. However, trampoline mat 10 of FIG. 3 is capable of being
attached to trampoline frame 15 with either side up. In other
embodiments, the trampoline mat may be capable of only attaching
with the top surface up and may have the outer portion folded under
or over flexible bed 12.
[0048] In one type of use, trampoline mat 10 is attached to
trampoline frame 15 using coil springs 16. Trampoline frame 15 and
coil springs 16 suspend flexible bed 12 over a surface so a user
can bounce thereon or perform other acrobatic maneuvers. In use, a
user on trampoline mat 10 uses his or her weight to flex the
trampoline mat 10 downward.
[0049] A user bouncing on trampoline mat 10 causes coil springs 16
to expand. As coil springs 16 expand, a force is applied to
filament 14. Filament 14 is continuous such that the resilient
force of coil springs 16 creates a distributed load through
filament 14. In addition, channel 20 and connected portion 22 are
continuous about the periphery. Because of the continuous nature of
channel 20 and connected portion 22 the load distributed by
filament 14 is more evenly distributed across flexible bed 12. The
evenly distributed load in flexible bed 12 reduces localized areas
of strain or bias in the bed material.
[0050] The ability of the trampoline mat 10 to transfer energy more
evenly about the periphery of flexible bed 12 gives trampoline mat
10 a better bounce. Furthermore, distributing the load about
filament 14 increases the durability of trampoline mat 10 since
diminishing localized areas of strain decreases the likelihood that
flexible bed 12 will fail at an area of localized strain.
[0051] The improved elements found in trampoline mat 10 enable it
to be efficiently manufactured. An exemplary trampoline mat 10 is
made by first cutting a sheet of bed material to form flexible bed
12 in an unfolded position. (FIG. 3) Notches 24 are cut into outer
peripheral portion 36 such that when outer peripheral portion 36 is
folded over and connected to inner peripheral portion 34, the
notches 24 will be formed in the resulting outer peripheral edge of
the fold.
[0052] Filament 14 is then disposed on outer peripheral portion 36
over notches 24. Outer peripheral portion 36 is folded over
filament 14 and connected to inner peripheral portion 34 using an
ultrasonic welder. Ultrasonic welding fuses the overlapping double
layers to form connected portion 22 having bonded bed material
fibers. Notches 24 expose portions 16 of filament 14. (FIG. 2)
[0053] In an exemplary embodiment, filament 14 is connected to form
a loop. In one version of trampoline mat 10, the ends of filament
14 are crimped together to form the loop. In another version, the
ends of filament 14 are connected by overlapping the ends and
securing one or both of the ends to filament 14. The particular
order in which the step of disposing filament 14 is performed is
not critical. For instance, filament 14 may be disposed in flexible
bed 12 before or after peripheral outer portion 36 is folded over
and connected to inner peripheral portion 34. The order in which
notches 24 are cut is also not critical. For instance, notches 24
can be cut before or after the bed material is cut to the desired
shape.
[0054] In an exemplary embodiment, fibers in the bed material
benefit from the ultrasonic cutting or plasma cutting. When the bed
material is cut by other means such as scissors or purely
mechanical cutting mechanisms, the fibers at the edge of the cut
are susceptible to fraying. However, by using an ultrasonic cutter
or a plasma cutter, cutting the bed material also results in the
fibers at the edge of the cut being bonded together. As the
ultrasonic cutter or plasma cutter cuts the material, adjacent
fibers on the edge of the bed material are bonded together. This
bonding, prevents the cut edges from fraying, thereby increasing
the durability of the material. Fraying can also be prevented by
applying a heat treatment to the cut edge.
[0055] FIG. 5 shows an exemplary manufacturing apparatus 40 for
performing the foregoing method of manufacturing the trampoline mat
10. A bulk roll 42 contains a roll of uncut bed material 44. The
uncut bed material 44 is spread out and fed onto vacuum platen 46.
A take-up roll pulls the scrap material across the vacuum platen 46
and a scrap shear cuts scrap bed material and drops it on conveyor
58. Conveyor 58 moves scraps to the hopper 60.
[0056] A process device 48 is configured to perform cutting and
welding operations. Process device 48 rotates about an axis at the
center of the vacuum platen 46 and can rotate both clockwise and
counterclockwise. Process device 48 has a cutter 50, such as a
plasma cutter and/or ultrasonic cutter, at an end thereof. The
cutter 50 can move horizontally along an arm 49 of process device
48.
[0057] The horizontal movement of the cutter 50 on arm 49 and the
circular movement of process device 48 enables cutter 50 to cut any
desired shape inside the maximum circumference of process device
48. For instance, the cutter 50 may cut the uncut bed material 44
in the shape of a circle or any polygon such as a square,
rectangle, octagon, etc.
[0058] Process device 48 also has a welder (not shown), such as an
ultrasonic welder, which is capable of moving horizontally on arm
49. Similar to the cutter 50, the welder can weld any shape by
moving annularly and horizontally. In one embodiment process device
48 has separate heads for welding and cutting, thus cutter 50 moves
independent of the welder. In another embodiment, the cutter 50 and
welder are a single unit.
[0059] In another version of the invention, process device 48 may
move in both planar directions using a mechanism other than
rotating about an axis. For instance, the process device could move
linearly in both directions on a pair of guides.
[0060] Process device 48 also feeds filament 14 from a reel of
filament 54. The filament 14 may be fed through the center of
process device 48 such that process device 48 can rotate without
entangling filament 14. Process device 48 may also be configured to
fold outer portion 36.
[0061] In one embodiment, manufacturing apparatus 40 performs the
following steps substantially simultaneously as process device 48
rotates about the axis: (i) process device 48 cuts uncut material
44, (ii) feeds filament 14 from reel 54 and disposes filament 14 on
outer peripheral portion 36, (iii) folds outer portion 36, and (iv)
connects outer peripheral portion 36 to inner peripheral portion 34
by ultrasonic welding. In this embodiment, cutter 50 and welder 52
operate substantially simultaneously to perform the various
steps.
[0062] In another embodiment, cutter 50 and welder 52 form a single
head for performing operations. In this embodiment, the steps of
cutting and welding are performed at different instances. However,
performing any or all of the foregoing steps simultaneously can
reduce manufacturing time and costs.
[0063] In an exemplary embodiment, the steps for making the
improved trampoline mat are automated and computer controlled. A
microprocessor precisely controls the cutting, folding and welding
of trampoline mat 10 by controlling the movement of process device
48, cutter 50, and the welder. Because the manufacturing of
trampoline mat 10 is precisely controlled, trampoline mat 10 has a
uniform and consistent size and shape. Irregularities that cause
stress in the prior art trampolines is reduced or nearly eliminated
with the process of the present invention.
[0064] The foregoing process also allows easy repairs to be
performed in the field, a benefit not available to prior methods of
manufacturing and repairing trampoline mats. Finally, trampoline
mat 10 produced according to methods of the present invention
reduces manufacturing costs because it uses less raw materials. The
precise manufacturing and unique process produces a trampoline mat
with much less waste than the prior processes known in the prior
art. As a result, the process of the present invention can produce
trampoline mat more cost effectively.
[0065] The present invention may be embodied in other specific
forms without departing from its spirit or essential
characteristics. The described embodiments are to be considered in
all respects only as illustrative and not restrictive. The scope of
the invention is, therefore, indicated by the appended claims
rather than by the foregoing description. All changes which come
within the meaning and range of equivalency of the claims are to be
embraced within their scope.
* * * * *