U.S. patent application number 09/978533 was filed with the patent office on 2002-02-14 for flexing base skate.
This patent application is currently assigned to K-2 Corporation. Invention is credited to Meibock, Antonin A., Svensson, John E..
Application Number | 20020017764 09/978533 |
Document ID | / |
Family ID | 22245112 |
Filed Date | 2002-02-14 |
United States Patent
Application |
20020017764 |
Kind Code |
A1 |
Svensson, John E. ; et
al. |
February 14, 2002 |
Flexing base skate
Abstract
A first embodiment of a flexing base skate (10) includes an
upper shoe portion (12) mounted on a base (14). The base includes a
forefoot region (20) secured to a forward frame segment (26)
carrying forward wheels (18a, 18b). A heel region (24) of the base
is secured to a rearward frame segment (28) that carries rearward
wheels (18c, 18d). The base defines and flexes at a reduced
thickness metatarsal head portion (22), with the skater's heel and
the rearward frame segment elevating freely relative to the forward
frame segment. A spring (72) incorporated into the base biases the
skate to the unflexed configuration. The forward frame section
overlaps the rearward frame section for lateral stability. An
alternate embodiment provides a rigid full length frame (112) and a
flexible base (104) mounted only at the forefoot region (106) to
the frame. The base (104) flexes at a metatarsal head portion
(108), and is constructed to form an integral spring biasing the
base against the frame. The base includes a guide (118) for lateral
alignment of the heel region (110) with the frame.
Inventors: |
Svensson, John E.; (Vashon,
WA) ; Meibock, Antonin A.; (Alberta, CA) |
Correspondence
Address: |
CHRISTENSEN, O'CONNOR, JOHNSON, KINDNESS, PLLC
1420 FIFTH AVENUE
SUITE 2800
SEATTLE
WA
98101-2347
US
|
Assignee: |
K-2 Corporation
|
Family ID: |
22245112 |
Appl. No.: |
09/978533 |
Filed: |
October 15, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09978533 |
Oct 15, 2001 |
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09589864 |
Jun 8, 2000 |
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09589864 |
Jun 8, 2000 |
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09094425 |
Jun 9, 1998 |
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6120040 |
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09094425 |
Jun 9, 1998 |
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08957436 |
Oct 24, 1997 |
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6082744 |
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Current U.S.
Class: |
280/11.224 ;
280/11.221 |
Current CPC
Class: |
A63C 17/067 20130101;
A63C 17/1436 20130101; A43B 5/1641 20130101; A63C 17/062 20130101;
A63C 1/28 20130101; A63C 17/065 20130101 |
Class at
Publication: |
280/11.224 ;
280/11.221 |
International
Class: |
A63C 017/02 |
Claims
The embodiments of the invention in which an exclusive property or
privilege is claimed are defined as follows:
1. A roller skate having a shoe portion for receiving a skater's
foot and a plurality of wheels, comprising: a base having an upper
surface securable to an underside of the shoe portion for
supporting the received skater's foot, the base including a heel
region and a forefoot region, the forefoot region having a
metatarsal head portion; and a frame secured to an underside of the
base at least below the forefoot region of the base such that the
base can flex intermediate of the forefoot region and heel region
during skating to permit elevation of the skater's heel, the frame
extending below the base and rotatably receiving the plurality of
wheels, with at least one forward wheel disposed below the forefoot
region of the base and at least one rearward wheel disposed below
the heel region of the base, wherein the metatarsal head portion of
the base defines a stress concentrating contour that focuses
flexure of the base at the metatarsal head portion.
2. The skate of claim 1, wherein the frame mounts at least first
and second forward wheels below the forefoot region of the base,
the second forward wheel being disposed between the first forward
wheel and the rearward wheel, an axis of rotation of the second
forward wheel being directly below or rearward of the stress
concentrating contour of the metatarsal head portion of the
base.
3. The skate of claim 1, wherein the stress concentrating contour
comprises a reduced thickness section of the base extending
transversely substantially across the metatarsal head portion of
the base.
4. The skate of claim 3, wherein the stress concentrating contour
further comprises an aperture defined through the metatarsal head
portion of the base.
5. The skate of claim 1, wherein the stress concentrating contour
of the base comprises an aperture defined through the metatarsal
head portion of the base.
6. The skate of claim 1, further comprising a biasing member
coupled to the base to bias the heel region of the base to a lower
position, in which the heel region of the base bears on the frame,
the rearward wheel and the ground.
7. The skate of claim 6, wherein the biasing member is incorporated
into the forefoot region of the base.
8. The skate of claim 7, wherein the base is constructed of a
resilient material and integrally defines the biasing member.
9. The skate of claim 6, wherein the biasing member comprises a
strip of resilient material secured along the base.
10. The skate of claim 9, wherein the biasing member is removable
from the base for interchangeability.
11. The skate of claim 6, wherein the biasing member exerts a
downward preload on the heel region of the base when the heel
region is in the lower position.
12. The skate of claim 1, wherein the frame comprises a rigid frame
extending below the base from the toe region to the heel region,
and flexure of the base during skating results in elevation of the
skater's heel between a lower position in which the heel region of
the base bears on the frame, and an upper position in which the
heel region of the base is elevated relative to the frame.
13. The skate of claim 12, further comprising a guide secured to
one of the frame and the heel region of the base and projecting
toward and slidably engaging the other of the frame and the heel
region of the base during flexure of the base.
14. The skate of claim 13, wherein the guide depends downwardly
from the base.
15. The skate of claim 14, wherein the guide is slidably received
within an aperture defined in the frame.
16. The skate of claim 15, wherein the aperture defines a slot,
further comprising an elastomeric cushion surrounding a perimeter
of the slot and projecting upwardly above a surface of the frame
for contacting the base when the base is in the lower position.
17. The skate of claim 14, wherein the guide comprises first and
second flanges projecting downwardly from the base on opposing
first and second sides of the frame.
18. The skate of claim 12, further comprising a shock absorption
member secured to one of the frame or base to absorb shock between
the frame and base when the heel region of the base is moved to the
lower position.
19. The skate of claim 18, wherein the shock absorption member
comprises an elastomeric material.
20. The skate of claim 12, further comprising a brake arm carrying
a brake pad for selectively engaging against the ground or a wheel,
wherein the brake arm is secured to the shoe portion or the base
and is carried with the shoe portion or the base during flexure of
the base.
21. The skate of claim 12, further comprising a biasing member
coupled to the base to bias the heel region of the base to the
lower position and against the frame.
22. The skate of claim 1, wherein the frame comprises an elongate
frame having a forward segment secured to the underside of the base
below the forefoot region of the base, and a rearward segment
secured to the underside of the base below the heel region, the
forward and rearward segments of the frame mounting the forward and
rearward wheels, respectively, flexing of the base resulting in
elevation of the heel region on the base and the rearward frame
segment relative to the forefoot region of the base.
23. The skate of claim 22, further comprising a longitudinal
projection extending from one of the forward or rearward frame
segments toward and slidably engaging the other of the forward and
rearward frame segments when the heel region of the base is lowered
and the forward and rearward segments of the frame are
substantially longitudinally aligned, the forward and rearward
frame segments freely sliding and pivoting relative to each other
during flexure of the base.
24. The skate of claim 23, wherein the longitudinal projection
comprises first and second stabilizing flanges projecting from one
of the forward or rearward frame segments toward and overlapping
opposing first and second sides of the other of the forward and
rearward frame segments.
25. The skate of claim 24, further comprising a low friction
bearing surface defined on an exterior of each of the overlapped
opposing first and second sides of the forward or rearward frame
segment, or on an interior of the first and second stabilizing
flanges.
26. The skate of claim 24, further comprising a transverse
reinforcement spanning between and secured to the first and second
stabilizing flanges.
27. The skate of claim 26, wherein the overlapped first and second
sides of one of the forward or rearward frame segments each define
a recess that accommodates the transverse reinforcement of the
stabilizing flanges when the forward and rearward frame segments
are longitudinally aligned.
28. The skate of claim 24, further comprising a locking element
selectively engageable with the forward and rearward frame segments
when the forward and rearward frame segments are substantially
longitudinally aligned to prevent flexure of the base.
29. The skate of claim 22, wherein at least one of the forward and
rearward segments of the frame are mounted to the base for
adjustable positioning in both the longitudinal and lateral
directions.
30. The skate of claim 29, wherein the other of the forward and
rearward segments of the frame is also mounted to the base for
adjustable positioning in both the longitudinal and lateral
directions.
31. The skate of claim 22, further comprising: at least one
intermediate wheel mounted on one of the rearward and forward frame
segments between the forward and rearward wheels; and a biasing
member coupled to the base to bias the heel region of the base
downwardly such that when the forward and rearward segments of the
frame are substantially longitudinally aligned, the intermediate
wheel is slightly elevated relative to the forward and rearward
wheels before a skater's weight is applied to the base.
32. A roller skate having a shoe portion for receiving a skater's
foot and a plurality of wheels for traversing the ground,
comprising: a base having an upper surface securable to an
underside of the shoe portion for supporting the received skater's
foot, the base including a heel region and a forefoot region, the
forefoot region having a metatarsal head portion; a frame secured
to an underside of the base at least below the forefoot region of
the base, the frame extending below the base and rotatably
receiving the plurality of wheels with at least one forward wheel
disposed below the forefoot region of the base and at least one
rearward wheel disposed below the heel region of the base, wherein
the frame is secured to the base such that the base can flex
intermediate of the forefoot region and heel region during skating
to permit elevation of the skater's heel between a lower position
in which the heel region of the base bears on the frame, the
rearward wheel and the ground, and an upper position in which the
heel region of the base is elevated relative to the forefoot region
of the base; and a biasing member coupled to the base to bias the
heel region of the base to the lower position and that exerts a
downward preload on the heel region of the base when the heel
region is in the lower position.
33. A roller skate having a shoe portion for receiving a skater's
foot and a plurality of wheels, comprising: a base having an upper
surface securable to an underside of the shoe portion for
supporting the received skater's foot, the base including a heel
region and a forefoot region, the forefoot region having a
metatarsal head portion; a frame secured to an underside of the
base at least below the forefoot region of the base, the frame
extending below the base and rotatably receiving the plurality of
wheels with at least one forward wheel disposed below the forefoot
region of the base and at least one rearward wheel disposed below
the heel region of the base, wherein the frame is secured to the
base such that the base flexes at the metatarsal head portion
during skating to permit elevation of the skater's heel between a
lower position in which the heel region of the base bears on the
frame, the rearward wheel and the ground, and an upper position in
which the heel region of the base is elevated relative to the
forefoot region of the base; and a biasing member coupled to the
base to bias the heel region of the base to the lower position.
34. A skate having a shoe portion for receiving a skater's foot and
a plurality of wheels, comprising: a base having an upper surface
securable to an underside of the shoe portion for supporting the
received skater's foot, the base including a heel region and a
forefoot region, and being adapted to flex intermediate of the heel
region and forefoot region to permit elevation of the heel region
relative to the forefoot region during skating; and a frame having
a forward segment secured to an underside of the base below the
forefoot region of the base, and a rearward segment secured to the
underside of the base below the heel region, the forward frame
segment mounting at least one forward wheel below the forefoot
region of the base and the rearward segment mounting at least one
rearward wheel below the heel region of the base, wherein one of
the forward or rearward frame segments includes first and second
stabilizing flanges that extend toward and slidably overlap
opposing first and second sides of the other of the forward and
rearward frame segments, the forward and rearward frame segments
freely sliding and pivoting relative to each other during flexure
of the base.
35. The skate of claim 34, wherein the one of the forward or
rearward frame segments that includes the first and second
stabilizing flanges includes first and second sidewalls, each
sidewall having a first portion in which one or more wheels are
journalled and a second portion extending laterally outward and
then parallel to the first portion for overlapping the other of the
forward or rearward frame segments.
36. The skate of claim 34, further comprising a low friction
bearing surface defined on an exterior of each of the overlapped
opposing first and second sides of the forward or rearward frame
segment, or on an interior of the first and second stabilizing
flanges.
37. The skate of claim 34, further comprising a transverse
reinforcement spanning between and secured to the first and second
stabilizing flanges.
38. The skate of claim 37, wherein the overlapped first and second
sides of the one of the forward or rearward frame segments each
define a recess that accommodates the transverse reinforcement of
the stabilizing flanges when the forward and rearward frame
segments are longitudinally aligned.
39. The skate of claim 34, further comprising a locking element
selectively engageable with the forward and rearward frame segments
when the forward and rearward frame segments are substantially
longitudinally aligned to prevent flexure of the base.
40. The skate of claim 34, further comprising: at least one
intermediate wheel mounted on one of the rearward and forward frame
segments between the forward and rearward wheels; and a biasing
member coupled to the base to bias the heel region of the base
downwardly such that when the forward and rearward segments of the
frame are substantially longitudinally aligned, the intermediate
wheel is slightly elevated relative to the forward and rearward
wheels before a skater's weight is applied to the base.
41. The skate of claim 34, wherein the forefoot region of the base
includes a metatarsal head portion defining a stress concentrating
contour that focuses flexure of the base at the metatarsal head
portion.
42. The skate of claim 41, wherein the forward frame segment mounts
at least first and second forward wheels below the forefoot region
of the base, the second forward wheel being disposed between the
first forward wheel and the rearward wheel, an axis of rotation of
the second forward wheel being directly below or rearward of the
stress concentrating contour of the metatarsal head portion of the
base.
43. The skate of claim 34, wherein at least one of the forward and
rearward segments of the frame are mounted to the base for
adjustable positioning in both the longitudinal and lateral
directions.
44. The skate of claim 43, wherein the other of the forward and
rearward segments of the frame is also mounted to the base for
adjustable positioning in both the longitudinal and lateral
directions.
45. A skate having a shoe portion for receiving a skater's foot and
a plurality of wheels, comprising: a base having an upper surface
securable to an underside of the shoe portion for supporting the
received skater's foot, the base including a heel region and a
forefoot region, and being adapted to flex intermediate of the heel
region and forefoot region to permit elevation of the heel region
relative to the forefoot region during skating; and an elongate
frame having a forward segment secured to an underside of the base
below the forefoot region of the base, and a rearward segment
secured to the underside of the base below the heel region, the
forward frame segment mounting at least one forward wheel below the
forefoot region of the base and the rearward segment mounting at
least one rearward wheel below the heel region of the base, wherein
one of the forward or rearward frame segments includes a
longitudinal projection extending toward and slidably engaging the
other of the forward and rearward frame segments when the heel
region of the base is lowered and the forward and rearward segments
of the frame are substantially longitudinally aligned, the forward
and rearward frame segments freely sliding and pivoting relative to
each other during flexure of the base.
46. The skate of claim 45, further comprising: at least one
intermediate wheel mounted on one of the rearward and forward frame
segments between the forward and rearward wheels; and a biasing
member coupled to the base to bias the heel region of the base
downwardly such that when the forward and rearward segments of the
frame are substantially longitudinally aligned, the intermediate
wheel is slightly elevated relative to the forward and rearward
wheels before a skater's weight is applied to the base.
47. The skate of claim 45, wherein the forefoot region of the base
includes a metatarsal head portion defining a stress concentrating
contour that focuses flexure of the base at the metatarsal head
portion.
48. The skate of claim 47, wherein the forward frame segment mounts
at least first and second forward wheels below the forefoot region
of the base, the second forward wheel being disposed between the
first forward wheel and the rearward wheel, an axis of rotation of
the second forward wheel being directly below or rearward of the
stress concentrating contour of the metatarsal head portion of the
base.
49. A skate having a shoe portion for receiving a skater's foot and
a plurality of wheels for traversing the ground, comprising: a base
having an upper surface securable to an underside of the shoe
portion for supporting the received skater's foot, the base
including a heel region and a forefoot region; and an elongate
frame having a forward segment secured to an underside of the base
below the forefoot region of the base, and a rearward segment
secured to the underside of the base below the heel region, the
forward frame segment mounting at least one forward wheel below the
forefoot region of the base and the rearward segment mounting at
least one rearward wheel below the heel region of the base, and at
least one of the rearward and forward frame segments mounting an
intermediate wheel between the forward and rearward wheels, wherein
the base is adapted to flex intermediate of the forefoot region and
heel region during skating to permit elevation of the skater's heel
between a lower position in which the heel region of the base bears
on the rearward segment of the frame, the rearward wheel and the
ground, and an upper position in which the heel region of the base
and rearward segment of the frame is elevated relative to the
forefoot region of the base; a longitudinal member coupling the
forward frame segment to the rearward frame segment for increased
torsional stiffness of the frame; and a biasing member coupled to
the base to bias the heel region of the base to the lower
position.
50. A skate having a shoe portion for receiving a skater's foot and
a plurality of wheels, comprising: a base having an upper surface
securable to an underside of the shoe portion for supporting the
received skater's foot, the base including a heel region and a
forefoot region having a metatarsal head portion, the base being
adapted to flex at the metatarsal head portion during skating; a
frame secured to an underside of the base at the forefoot region of
the base and rotatably receiving the plurality of wheels, the heel
region of the base bearing on the frame in a lower position and
elevating away from the frame to an upper position upon flexure of
the base during skating; and a guide secured to one of the frame
and the heel region of the base and projecting toward and slidably
engaging the other of the frame and the heel region of the base
during flexure of the base.
51. The skate of claim 50, wherein the guide depends downwardly
from the base.
52. The skate of claim 51, wherein the guide is slidably received
within an aperture defined in the frame.
53. The skate of claim 52, wherein the aperture defines a slot,
further comprising an elastomeric cushion surrounding a perimeter
of the slot and projecting upwardly above a surface of the frame
for contacting the base when the base is in the lower position.
54. The skate of claim 51, wherein the guide comprises first and
second flanges projecting downwardly from the base on opposing
first and second sides of the frame.
55. The skate of claim 50, further comprising a shock absorption
member secured to one of the frame or base to absorb shock between
the frame and base when the heel region of the base is moved to the
lower position.
56. The skate of claim 55, wherein the shock absorption member
comprises an elastomeric material.
57. The skate of claim 50, further comprising a brake arm carrying
a brake pad for selectively engaging against the ground or a wheel,
wherein the brake arm is secured to the shoe portion or the base
and is carried with the shoe portion or the base during flexure of
the base.
58. The skate of claim 50, further comprising a biasing member
coupled to the base to bias the heel region of the base to the
lower position and against the frame.
59. The skate of claim 50, wherein the forefoot region of the base
includes a metatarsal head portion defining a stress concentrating
contour that focuses flexure of the base at the metatarsal head
portion.
60. A skate having a shoe portion for receiving a skater's foot and
a plurality of wheels, comprising: a base having an upper surface
securable to an underside of the shoe portion for supporting the
received skater's foot, the base including a heel region and a
forefoot region having a metatarsal head portion, the base being
adapted to flex at the metatarsal head portion during skating; a
frame secured to an underside of the base at the forefoot region of
the base and rotatably receiving the plurality of wheels, the heel
region of the base bearing on the frame in a lower position and
elevating away from the frame to an upper position upon flexure of
the base during skating; and a biasing member coupled to the base
to bias the heel region of the base to the lower position and that
preloads the heel region of the base against the frame when the
heel region is in the lower position.
61. A skate including a plurality of wheels for traversing the
ground, comprising: a shoe portion for receiving a skater's foot; a
base having an upper surface securable to an underside of the shoe
portion for supporting the received skater's foot, the base
including a heel region and a forefoot region having a metatarsal
head portion, the base being adapted to flex at the metatarsal head
portion during skating; a frame secured to an underside of the base
at the forefoot region of the base and rotatably receiving the
plurality of wheels, the heel region of the base bearing on the
frame in a lower position and elevating away from the frame to an
upper position upon flexure of the base during skating; and a brake
arm carrying a brake pad for selectively engaging against the
ground or a wheel, wherein the brake arm is secured to the shoe
portion or the base and is carried with the shoe portion or the
base during flexure of the base.
62. A skate having a shoe portion for receiving a skater's foot and
a plurality of wheels, comprising: a base having an upper surface
securable to an underside of the shoe portion for supporting the
received skater's foot, the base including a heel region and a
forefoot region having a metatarsal head portion, the base being
adapted to flex at the metatarsal head portion during skating; a
frame secured to an underside of the base at the forefoot region of
the base and rotatably receiving the plurality of wheels, the heel
region of the base bearing on the frame in a lower position and
elevating away from the frame to an upper position upon flexure of
the base during skating; and a shock absorption member secured to
one of the frame or base to absorb shock between the frame and base
when the heel region of the base is moved to the lower position.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] The present application is a continuation-in-part of
co-pending U.S. application Ser. No. 08/957,436 filed Oct. 24,
1997, priority of the filing date of which is hereby claimed under
35 U.S.C. .sctn. 120.
FIELD OF THE INVENTION
[0002] The present invention relates to roller skates, and more
particularly to in-line roller skates with flexible bases.
BACKGROUND OF THE INVENTION
[0003] Conventional in-line roller skates include an upper boot
secured to or integrally formed with a rigid or semi-rigid base.
The base in turn is secured along its length, including at heel and
toe ends, to a rigid frame. A plurality of wheels are journalled
along a common longitudinal axis between the sidewalls of the
frame. During use the skater alternatingly strokes on the left and
right skates, thrusting off of one skate while gliding on the
opposing skate. The ability to fully complete a thrust and thereby
achieve maximum forward momentum is limited, however, because of
the rigid frame being secured to the heel and toe of the skater's
foot.
[0004] Because of the rigid, inflexible securement of the frame and
base of such skates, a skater attempting to achieve optimal speed
during skating may adopt a skating stroke that does not entail
plantarflexing of his or her ankle during the push-off phase of the
stroke. The term "plantarflex" refers to the rotation of the foot
relative to the leg within a plane defined by the leg, where the
forefoot moves distally relative to the leg. By avoiding
plantarflexion at the ankle, all skate wheels remain on the ground,
with the skate base and frame parallel to the ground. The skate
thus does not pivot significantly on the forwardmost wheel.
Alternately, a skater may adopt a stroke style entailing
plantarflexion of his or her ankle during the skate stroke,
allowing the forefoot to move distally of the leg, thereby allowing
the calf muscles to generate more power during the skate stroke.
Due to the rigid nature of the frame and base however, this causes
the skater's ankle to elevate excessively off the ground, and may
be uncomfortable for the skater. This also entails excessive
movement of the skater's upper body and legs, and entails excess
wear of the front wheel.
[0005] In-line skates with wheels supported on first and second
separate frame sections, secured beneath the toe and heel of the
skate, such that the foot can flex during the skating stroke, have
been proposed. For example, U.S. Pat. No. 5,634,648 discloses a
skate including a boot having a rigid toe portion pivotally coupled
at the lateral sides of the foot to a rigid heel portion. A first
frame segment supporting two wheels is secured beneath the toe
section, and a second frame segment supporting two additional
wheels is secured beneath the heel section. A tab extends
rearwardly from the base of the toe section and is received within
a corresponding slot formed in the base of the heel section. During
use the skater is able to flex the foot at the sidewall pivot point
of the upper, with the tab flexing along its length, so that the
heel and rear frame section can elevate off of the ground. While
permitting flexion of the foot, flexion is not centralized or
primarily occurring at the metatarsal head of the skater's foot, as
is anatomically preferred. Thus flexing may be uncomfortable.
Additionally, because the boot flexes rearwardly of the front frame
and wheels, an unstable platform is provided by the forward segment
of the frame during thrusting with the heel elevated. Further,
because the two frame segments are separated and uncoupled at all
times, there is no lateral rigidity of the frame, even when both
frame sections are on the ground. Thus, except to the limited
extent provided by the pivot joints between the heel and toe
sections of the upper and the forward to rearward tab, there is no
torsional rigidity of the skate, as would be desired for straight
tracking of the skate.
[0006] An alternate flexing skate has been proposed in European
patent application EP 0 778 058 A2. A skate is disclosed having an
upper boot with a separate toe segment that is slidably received
within the forward end of a rear boot segment, and which is
pivotally joined to the rear boot segment immediately below the
base of the skate. Forward and rearward frame sections are secured
beneath the forward and rearward segments of the boot. The rear
ends of the sidewalls of the forward frame section overlap the
forward ends of the sidewalls of the rear frame section. A second
pivot pin is secured through aligned apertures in the forward frame
section sidewalls and through corresponding slots in the overlapped
sidewalls of the rear frame section. During use the boot pivots to
allow the foot to flex during thrusting, with the slotted rearward
frame section moving on the second pivot pin retained by the
forward frame section. Thus, a limited degree of flexure is
provided, with the pivotal coupling of the frame segments also
providing a degree of lateral stability and torsional
stiffness.
[0007] The degree of flexion of such a skate disclosed in the
European '058 application is limited, however, by the relatively
short length of the slots formed in the rearward frame section.
Further, the upper or lower positioning of the rear end of the
skate is controlled solely by force applied by the user's foot and
leg. During the portion of the skating stroke where the user would
desire the wheels to be commonly aligned on the ground in a flat
line, the rear of the skate may thus undesirably bump upwardly and
downwardly. An alternate embodiment of a skate disclosed in the
same European '058 application has a rigid full-length frame and an
unsecured rear boot portion which can be lifted off of the frame
for flexure during the stroke. However, there is no provision for
laterally stabilizing the heel of the boot relative to the frame,
such that undesired torsional or lateral movement of the boot
relative to the frame may be encountered. Additionally, as in the
segmented frame embodiment, the heel may lift undesirably from the
frame at inappropriate times.
SUMMARY OF THE INVENTION
[0008] The present invention provides a roller skate having a shoe
portion for receiving a skater's foot and a base having an upper
surface securable to an underside of the shoe portion for
supporting the received skater's foot. The base includes a heel
region and a forefoot region, the forefoot region having a
metatarsal head portion. A frame is secured to an underside of the
base at least below the forefoot region of the base such that the
base can flex intermediate of the forefoot region and heel region
during skating to permit elevation of the skater's heel. The frame
extends below the base and rotatably receives a plurality of
wheels. At least one forward wheel is disposed below the forefoot
region of the base, and at least one rearward wheel is disposed
below the heel region of the base. The metatarsal head portion of
the base defines a stress concentrating contour that focuses
flexure of the base at the metatarsal head portion.
[0009] In a further aspect of the present invention, the skate
includes a biasing member coupled to the base to bias the heel
region of the base to a lower position, in which the heel region of
the base bears on the frame, the rearward wheel and the ground. The
biasing member preferably exerts a downward preload on the heel
region of the base when the heel region is in the lower
position.
[0010] In a first preferred embodiment of the present invention,
the frame of the skate includes a forward segment secured to an
underside of the base below the forefoot region of the base, and a
rearward segment secured to the underside of the base below the
heel region. The forward segment mounts the at least one forward
wheel below the forefoot region of the base, while the rearward
segment mounts the at least one rearward wheel below the heel
region of the base. One of the forward or rearward frame segments
includes first and second stabilizing flanges that extend toward
and slidably overlap opposing first and second sides of the other
of the forward and rearward frame segments. The forward and
rearward frame segments freely slide and pivot relative to each
other during flexure of the base.
[0011] In an alternate preferred embodiment to the present
invention, the skate includes a frame secured to an underside of
the base at the forefoot region of the base. The heel region of the
base bears on the frame in a lower position, and elevates away from
the frame to an upper position upon flexure of the base during
skating. A guide is secured to one of the frame and the heel region
of the base and projects toward and slidably engages the other of
the frame and the heel region of the base during flexure of the
base.
[0012] The present invention thus provides skates having bases that
flex, preferably below the metatarsal head of the skater's foot, in
conformity with the anatomy of the foot. In a first preferred
embodiment, the frame is split into two segments which overlap each
other for lateral stability, yet which freely and slidably pivot
relative to each other during flexure. In an alternate embodiment,
the heel of the shoe portion lifts away from the frame during
flexure, and a guide is preferably provided that maintains lateral
positioning of the upper relative to the frame during this
movement. Thus the skates of the present invention provide for
increased thrust during the skating stroke due to the ability to
flex the foot, and concentrate flexing at the foot at the point
most anatomically desirable and efficient. The preferred
embodiments of the present invention include a biasing member, such
as a spring plate, that preloads the heel of the skate in the lower
position, such that after each stroke during skating the heels snap
back downwardly for full engagement with the frame and ground.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The foregoing aspects and many of the attendant advantages
of this invention will become better understood by reference to the
following detailed description, when taken in conjunction with the
accompanying drawings, wherein:
[0014] FIG. 1 provides a side view of a skate constructed in
accordance with a first preferred embodiment of the present
invention, having a flexing base and split frame, with the skate
illustrated in the non-flexed and non-loaded configuration;
[0015] FIG. 2 provides a side view of the skate of FIG. 1 with the
skate in the flexed configuration;
[0016] FIG. 3 provides an exploded pictorial view of the skate of
FIG. 1;
[0017] FIG. 4 provides a top plan view of the base of the skate of
FIG. 1;
[0018] FIG. 5 provides a top plan view of an alternate embodiment
of the base suitable for incorporation into the skate of FIG. 1
with interchangeable spring elements;
[0019] FIG. 6 provides a side view of a skate constructed in
accordance with a second preferred embodiment of the present
invention having a rigid frame and flexing base, with the heel end
of the base being free of the frame, shown in the unflexed
configuration;
[0020] FIG. 7 provides a side view of the skate of FIG. 6 in the
flexed configuration;
[0021] FIG. 8 provides a side view of alternate configuration of
the skate of FIG. 6 including a brake element mounted on the base
of the skate, in the unflexed configuration; and
[0022] FIG. 9 provides a detailed, partial cross-sectional side
elevation view of the skate of FIG. 8 in the flexed configuration,
with the guide member shown in phantom.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0023] A first preferred embodiment of a flexing base skate 10
constructed in accordance with the present invention is illustrated
in FIGS. 1 and 2. The skate 10 includes an upper shoe portion 12
that receives and surrounds a skater's foot and ankle, and which is
mounted on and secured to a base 14 that is flexible at least at
one point along its length. The base 14 underlies and supports the
user's foot. The base 14 is in turn secured to a split frame
assembly 16 extending longitudinally beneath the base 14. A
plurality of wheels 18a, 18b, 18c and 18d are journalled between
first and second opposing longitudinal sidewalls of the frame
assembly 16.
[0024] The base 14 includes a forefoot region 20 that underlies and
supports the ball and toes of the user's foot. The forefoot region
20 of the base includes a metatarsal head portion 22 that underlies
the zone corresponding to the metatarsal head of a skater's foot.
The base 14 extends rearwardly, terminating in a heel region 24
underlying the skater's heel. The frame assembly 16 includes a
forward frame segment 26 secured to the forefoot region 20 of the
base 14, and a rearward frame segment 28 that is secured to the
heel region 24 of the base 14. As used herein throughout, "forward"
refers to the direction of the forefoot region 20 of the skate,
while the term "rearward" refers to the opposing direction of the
heel region 24 of the skate.
[0025] The inclusion of a forward frame segment 26 and a rearward
frame segment 28, and the formation of the base 14 to permit
flexure intermediate of the forward and rearward ends of the base
14, permits the skater's foot and the upper shoe portion 12 to flex
during the skating stroke. The base 14 and upper shoe portion 12
flex from a lower position, illustrated in FIG. 1 in which the
front and rear frame segments 26, 28 are longitudinally aligned,
and a flexed, upper position illustrated in FIG. 2, in which the
heel region 24 of the base 14 and rearward frame segment 28 pivot
upwardly relative to the forefoot region 20 of the base 14 and
forward frame segment 26. Each of the components of the skate 10
will now be described in greater detail.
[0026] Referring to FIGS. 1 and 2, the upper shoe portion 12 is of
conventional construction, surrounding the toes, sides, heels and
ankle of a user's foot. The upper shoe portion 12 includes a vamp
29, a tongue and a closure such as a lace system. The upper shoe
portion 12 illustrated is supported by a rigid or semi-rigid
internal heel cup and ankle cuff (not shown), which helps
vertically stabilize the skate. Other conventional upper shoe
portion constructions are also within the scope of the present
invention, including flexible uppers reinforced by external ankle
cuffs and heel cups. The upper shoe portion 12 is constructed at
least partially from flexible materials so that the upper shoe
portion 12 will flex together with the base 14.
[0027] The base 14 is best viewed in FIGS. 1, 3 and 4. The base 14
has an upper surface 30 (FIG. 4) that receives and supports the
undersides of the upper shoe portion 12. The base 14 is secured to
the upper shoe portion 12 by any conventional method, including
bolting, riveting, stitching and adhesive lasting. While the base
14 is illustrated as separate from the upper shoe portion 12, it
should also be understood that the base 14 could be integrally
formed with the upper shoe portion 12, so long as the upper shoe
portion 12 and base 14 accommodate flexing in the manner to be
described further herein. The upper surface 30 of the base 14 is
bordered by a raised lip surrounding the perimeter of the base 14.
The lip extends upwardly at the rear and forward ends to partially
surround the lower edges of the toes and heels of the user.
[0028] As best illustrated in FIGS. 1 and 3, the base 14 includes a
lower surface 39 that is supported by longitudinally oriented ribs
40 extending along the inner and outer longitudinal sides of the
lower surface 40 of the base 14. The ribs 40, formed as increased
thickness sections of the base 14, serve to rigidize the heel
region 24 and a forward portion of the forefoot region 20 of the
base 14. However, the ribs 40 do not extend longitudinally below
the metatarsal head portion 22 of the forefoot region 20 of the
base. Thus, the effective thickness of the metatarsal portion 22 of
the base 14 is reduced relative to the thickness of the surrounding
regions of the base 14. This reduced thickness enables the base 14
to flex at the metatarsal head portion 22, and more specifically
focuses the flexure of the base 14 at the metatarsal head portion
22, in a gradual arc along the length of the metatarsal head
portion, as illustrated in FIG. 2.
[0029] The ability of the metatarsal head portion 22 to flex is
further enhanced by the formation of a transverse, elongate
aperture 42 through the metatarsal head portion 22. The aperture 42
extends transversally and centrally across approximately half of
the width of the metatarsal head portion 22, and also extends
forwardly and rearwardly across the majority of the length of the
metatarsal head portion 22. This aperture 42 serves to further
concentrate the stress of flexure on the metatarsal head portion
22. Moreover, the aperture 42 is formed with a transverse elongate
ovoid configuration, serving to further focus the flexure along the
centerline of the metatarsal head portion 22. Thus, as illustrated
in FIG. 2, the base 14 and upper shoe portion 12 flex at the
anatomically preferred position just below the metatarsal head,
following the natural contour of the metatarsal head as it
flexes.
[0030] Attention is now directed to FIG. 3 to describe the
construction of the split frame assembly 16. Each of the forward
frame segment 26 and the rearward frame segment 28 has an
independent torsion box construction. The forward frame segment 26
has a top wall 31 extending rearwardly from immediately below a
forward toe portion of the forefoot region 20 of the base 14, to
just forwardly of the metatarsal head portion 22. The forward frame
segment 26 further includes left and right opposing sidewalls 32
that are oriented longitudinally relative to the length of the base
14. The rear frame segment 28 correspondingly includes a top wall
34 and longitudinal left and right sidewalls 36. The top wall 34
runs from beneath an arch portion of the heel region 24 of the base
14, to the rear end of the heel region 24. A weight reducing
aperture 38 is cut out from the center of the top wall 34.
[0031] The top walls 31 and 34 of the forward and rearward frame
segments 26 and 28 are horizontally oriented, with the sidewalls 32
and 36 projecting perpendicularly downward therefrom. Each frame
segment 26, 28 is completed by a series of lower horizontal braces
40 spanning between the left and right sidewalls 32 of the forward
frame segment 26 and the left and right sidewalls 36 of the
rearward frame segment 28. The lower braces 40 are parallel to and
spaced downwardly from the top walls 31 and 34, and are oriented
between the wheels 18a, 18b, 18c and 18d.
[0032] Specifically, the forward frame segment 26 carries a first
forward wheel 18a and a second forward wheel 18b journalled between
the opposing sidewalls 32. Each wheel includes a center hub and
bearing assembly 44 that is mounted rotatably on an axle 45 that is
inserted through aligned apertures 46 of the sidewalls 32 and is
retained by cap screws 48. In the forward segment 26 of the frame,
a single horizontal brace 40 (not shown) is disposed between the
first forward wheel 18a and the second forward wheel 18b. The
rearward frame segment 28 similarly carries a first rearward wheel
18c and a second rearward wheel 18d journalled between its
sidewalls 36 on axles 45. A first horizontal brace 40 is formed
between the sidewalls 36 just forwardly of the first rearward wheel
18c, and a second horizontal brace (not shown) is formed between
the first and second rearward wheels 18c and 18d. The top walls,
sidewalls and lower horizontal braces of the forward and rearward
segments 26, 28 thus complete for each frame segment a stiff
elongate box-like structure having good torsional rigidity. The
torsional rigidity provided by the horizontal braces 40 is
desirable, but a frame constructed without crossbracing would also
be within the scope of the present invention. Likewise, alternate
crossbracing, such as diagonal internal crossbracing, or external
braces extending down from the base 14 could be utilized. The frame
segments 26, 28 can be formed from any suitable rigid material,
such as aluminum, titanium, other metals and alloys, engineering
thermoplastics, and fiber reinforced thermoplastics or
thermosetting polymers.
[0033] Referring still to FIG. 3, the forward frame segment 26
includes left and right stabilizing flanges 50 secured to or
integrally formed with the sidewalls 32 to form rearward extensions
thereof. The stabilizing flanges 50 extend rearwardly of the
innermost, i.e., second forward wheel 18b, towards the innermost,
i.e., first rearward wheel 18c. The stabilizing flanges 50 can be
welded (for metal materials), screwed, adhered or riveted to the
sidewalls 32 of the forward frame segment 26. Alternately, the
forward frame segment 26 including the stabilizing flanges 50 can
be integrally cast, molded or machined. The stabilizing flanges 50
have an internal spacing separating the two flanges such that they
closely and slidably receive the forward ends of the sidewalls 36
of the rearward frame segment 28. In the preferred embodiment, the
spacing between the stabilizing flanges 50 of the forward frame
segment 26 is greater than the spacing between the remainder of the
sidewalls 32 of the forward frame segment 26. Thus the sidewalls
effectively expand externally, bending first laterally outward and
then rearwardly, to define the stabilizing flanges 50.
[0034] FIG. 1 illustrates the stabilizing flanges 50 overlapping
the forward ends of the sidewalls 36 of the rear frame segment 28.
The overlap fit of the stabilizing flanges 50 and sidewalls 36 of
the rear frame segment 28 is close, with the width from the outer
surface of the left sidewall 36 to the outer surface of the right
sidewall 36 being just slightly less than the width between the
inner surfaces of the stabilizing flanges 50. This close fit is
desirable so that the rearward frame segment 28 is substantially
prevented from pivoting laterally, i.e., off longitudinal axis,
relative to the forward frame segment 26. Thus, the stabilizing
flanges 50 serve to torsionally couple the independent frame
segments 26 and 28, particularly where the base 14 is unflexed as
illustrated in FIG. 1. The frame segments 26 and 28 are coupled
only by this overlap, and by virtue of both being secured to the
base 14, and are preferably otherwise independent. This stabilizing
overlap continues at least partially during all stages of flexure
of the base 14.
[0035] To further increase the torsional rigidity of the frame
assembly 16, the stabilizing flanges 50 are reinforced by a
transverse stabilizing pin 52 inserted through aligned apertures
formed through lower edge portions of the flanges 50. The
stabilizing pin 52 is retained in place by a head on one end, and a
cap screw or a flare formed on the other end. The stabilizing pin
52 prevents the stabilizing flanges 50 from undesirably flaring
outward or bending away from each other during use, maintaining
them in spaced parallel disposition.
[0036] The forward ends of the sidewalls 36 of the rearward frame
segment 28 each include a notch-like recess 54 that receives and
accommodates the stabilizing pin 52 when the frame segments 26 and
28 are longitudinally aligned in the unflexed configuration, as
shown in FIG. 1. This notch 54 allows the stabilizing pin 52 to be
set rearwardly as far as possible for maximum transverse
stabilization. In the preferred embodiment illustrated in FIG. 3,
the rearward ends of the stabilizing flanges 50 taper downwardly in
vertical width as they extend rearwardly. Conversely, the forward
ends of the sidewalls 36 taper forwardly and upwardly in vertical
width as they extend forwardly. This construction allows for
maximum overlapping of the stabilizing flanges 50 and sidewalls 36.
However, other configurations, including blunt ends on both the
stabilizing flanges 50 and sidewalls 36, are possible. Further,
rather than including distinct stabilizing flanges 50, as
illustrated in FIG. 3, the sidewalls 32 of the forward frame
segment 26 could simply have a greater width, or a rearward portion
of the sidewalls 32 can be bent to define a greater width, to
accommodate the rearward frame segment 28, all within the scope of
the present invention.
[0037] Further, the stabilizing flanges could alternately be
mounted on the rearward frame segment 38, and overlap the forward
frame segment 26. Additionally, rather than side flanges, differing
longitudinal projection(s) could be included on either the forward
or rearward frame segment 26 or 28 to be closely and slidably
received within a corresponding slot, recess or space in the other
of the forward or rearward frame segments.
[0038] Other than the overlapping of the stabilizing flanges 50,
the forward and rearward frame segments 26 and 28 are independent
of each other. Thus, the forward and rearward segments 26 and 28
are free to pivot and slide relative to each other during flexure
of the base 14, without restriction. To further facilitate this
sliding pivotal movement of the forward and rearward frame segments
26 and 28, a low friction surface, such as a Teflon.TM. fluoride
polymer pad 56, is preferably applied to the exterior of the
forward ends of each of the sidewalls 36 of the rearward frame
segment 28. Alternately, the low friction pads 56 can be applied to
the interior of the stabilizing flanges 50, or to both the
stabilizing flanges 50 and the rear frame segment 28. Although low
friction materials, such as nylon pads, or bearings, could also be
utilized. Thus, frictional resistance between movement of the
forward and rearward frame segments 26 and 28 is minimized. The
flexure of the base 14 is limited only by the skater's foot
positioning and activity, and the biasing of the base 14 (to be
discussed below) rather than by the frame assembly 16.
[0039] Referring to FIGS. 1 and 3, the frame assembly 16 includes a
mechanism for selectively locking the forward frame segment 26 to
the rearward frame segment 28, so that the frame assembly 16
becomes rigid along its length. This may be desired, for instance,
by beginning skaters who may be more comfortable on a rigid frame.
In the preferred embodiment illustrated, a locking pin 58 having a
head on one end and spring loaded detent ball on the opposing end,
may be inserted if desired through aligned apertures 60 formed in
each of the stabilizing flanges 50 and the forward ends of the
sidewalls 36 of the rear frame segment 28. When the base 14 is
unflexed such that the forward and rearward frame segments are
longitudinally aligned, as shown in FIG. 1, the locking pin may be
inserted if desired. Removal of the locking pin 58, by pushing of
the locking pin 58 with an alien wrench or other tool from the
detent side, restores the skate to the flexing configuration.
[0040] Referring again to FIG. 3, each of the forward and rearward
frame segments 26 and 28 is mounted to the base 14 for independent
lateral and horizontal adjustment. For this purpose, the base 14
includes a spaced series of four transverse mounting slots 62. Each
mounting slot 62 is bordered by a downwardly projecting boss. Each
mounting slot 62 is reinforced by a corresponding slotted metal
plate molded or adhered within the base 14, midway between the
upper surface 30 and the lower surface 40. The reinforcing plates
may be suitably formed of a metal such as aluminum, and each
defines a lip 63 projecting internally about the perimeter of the
corresponding slot 62. The head of a stud 64 is received within
each slot from the upper surface of the base 14, and rests on the
lip 63 defined by the reinforcing plate. Each stud 64 includes an
internally threaded stem that extends downwardly through the slot
62 and lip 63. The studs 64 can be slid laterally from side to side
along the length of the slots 62.
[0041] The top wall 31 of the forward frame segment 26 includes two
longitudinally oriented mounting slots 66. The top wall 34 of the
rearward frame segment 28 includes two longitudinally oriented
mounting slots 66 as well. The longitudinal mounting slots 66 at
the forward frame segment 26 are alignable with the two forwardmost
transverse mounting slots 62 formed in the base 14. These
forwardmost mounting slots 62 are formed within the forefoot region
20 of the base 14, just below the toes and just forwardly of the
metatarsal head portion 22. Mounting bolts 68 are inserted from the
underside of the forward frame segment 26, through the longitudinal
slots 66 into the corresponding studs 64 to mount the forward frame
segment 26 to the forefoot region 20 of the base 14. When the bolts
28 are loosely received in the studs 64, the forward frame segment
26 can be slid forwardly and rearwardly along the length of the
slot 66, and can also be slid transversely left or right along the
length of the slots 62. When the desired forward and rearward
location and side to side location, as well as angulation, is
achieved, the bolts 68 are tightened into the studs 64 to retain
the forward frame segment in this position.
[0042] Similarly, mounting bolts 68 are inserted through the
longitudinal slots 66 in the rearward frame segment 28, and into
the studs 64 retained in the two rearmost transverse slots 62 of
the heel region 24 of the base 14. The two rearmost transverse
slots 62 are defined immediately below the heel and below the arch
of the base 14. The rearward frame segment 28 can be
longitudinally, laterally and angularly adjusted just as can the
forward frame segment 26. The forward and rearward frame segments
26 and 28 can be adjusted independently of each other.
[0043] The adjustable mounting of the forward and rearward frame
segments 26 and 28 makes possible the lengthening and shortening of
the frame assembly 16 of the skate 10. A longer frame may be
desired for increased speed, while a shorter frame may be desired
for increased maneuverability. Likewise, the left and right
positioning of the frame segments may be desired for individual
skating styles to facilitate straight tracking or turning.
[0044] Referring to FIGS. 1 and 2, the mounting of the forefoot
region 20 of the base 14 to the forward frame section 26 provides
for a stable platform from which to push off of during the thrust
portion of a skating stroke. Specifically, the point of flexure of
the base 14, at the metatarsal head portion 22, is disposed either
just above or forwardly of the axis of rotation of the innermost
forward wheel 18b of the forward frame segment 26. The axis of
rotation of the innermost forward wheel 18b is defined by the
corresponding axle 45, and corresponds to the point of contact of
the innermost forward wheel 18b with the ground. Thus, during
flexure of the skate, when the rearward frame segment 28 and
rearward wheels 18c and 18d are lifted off of the ground, a stable
platform is still provided because the rearwardmost contact point
with the ground provided by the wheel 18b is either immediately
below or behind the point of flexure at the metatarsal head portion
22. This prevents the forward frame segment 26 from undesirably
tipping upward, so that the forwardmost forward wheel 18a would
raise off the ground, during the thrust portion of the stroke.
[0045] Referring to FIGS. 2 and 4, the flexing skate 10 of the
present invention preferably includes a biasing member to urge the
base 14 downwardly to the lower or unflexed configuration of FIG.
1, and away from the upper or flexed configuration of FIG. 2.
Preferably, this biasing is provided by a spring incorporated into
the base 14 that is coplanar with the base 14. For example, the
base 14 can be constructed from a resilient composite material,
such as a thermosetting or thermoplastic polymer reinforced by
fibers. One suitable example of such a resilient composite material
is an epoxy reinforced with plys of carbon fibers, woven at
45.degree. angles relative to the longitudinal axis of the base 14.
This construction results in the transverse metatarsal head portion
22 still retaining torsional stiffness, while also resiliently
flexing longitudinally.
[0046] An alternate method of incorporating a spring into the base
14 is illustrated in FIG. 4. Specifically, a wide, elongate recess
70 is formed in the upper surface 30 of the base 14. The recess 70
extends across a majority of the width of the base 14, and from the
forward end of the toe region 20 of the base 14, just behind the
forwardmost mounting slot 64, to approximately midway along the
length of the base 14, just forwardly of the third mounting slot
64. This shallow recess 70 receives a spring plate 72 which spans
the width and most of the length of the recess. The spring plate 72
passes over and is centered on the metatarsal head portion 22. The
spring plate 72 may be suitably formed as a strip of spring steel,
or alternately may be a strip of other resilient material such as a
reinforced composite. The spring plate 72 is suitably adhered in
place, or may be retained by rivets. In the preferred embodiment,
the spring plate is adhered between the base 14 and the upper shoe
portion 12 on both the upper and lower surfaces during the lasting
process. Additionally, four rivets 74 are inserted through the base
14 and each corner of the spring plate 72 through corresponding
short longitudinal slots 76 formed in the spring plate 72. This
allows some longitudinal shifting of the spring plate 72 relative
to the base 14 during flexure of the base 14. The recess 70 may
also include two transverse elastomeric strips 78 positioned
forwardly and rearwardly of, and abutting, the forward and rearward
ends of the spring plate 72. These elastomeric strips 78 compress
and absorb the longitudinal movement of the spring 72, as permitted
by the slots 76, during flexure of the base 14. Upon return of the
base 14 to the unflexed configuration, the elastomeric strips 78
decompress, thereby further urging the spring 72 to its original
configuration with additional force.
[0047] Referring to FIGS. 1 and 2, the spring plate 72 acts to urge
the heel region 24 of the skate 10 downwardly to the unflexed
configuration of FIG. 1. Moreover, the spring plate 72 is
preferably preloaded such that it biases the heel region 24 of the
base 14 downward sufficiently to introduce a negative camber to the
longitudinal orientation of the wheels 18a, b, c, and d.
Specifically, FIG. 1 illustrates a planar ground surface 76 across
which a skater may traverse. Before the weight of the skater's body
is introduced to the base 14, the skate 10 is biased by the spring
plate 72 such that the intermediate wheels 18b and c are elevated
slightly relative to the forwardmost wheel 18a and rearwardmost
wheel 18d. Thus, the bottom surfaces of the wheels define a plane
arcing slightly downwardly, as illustrated by line 78 in FIG. 1. As
soon as the user's weight is applied to the base 14, the
intermediate wheels 18b and 18c move downwardly as the preload of
the spring plate 72 is overcome, until all wheels reside on the
ground in an even planar configuration. The preloading of the
spring plate 72 in this manner eliminates rockering of the skate
10, and may be utilized when an anti-rockering skate is desired.
During each stroke as the skate begins to touch the ground, the
intermediate wheels 18b and 18c will not initially contact the
ground, eliminating undesired tracking during that portion of the
stroke. The initial cambering of the wheels 18 ensures that proper
contact of the forward and rearward wheels with the ground remains
at all time.
[0048] While the preferred embodiment in FIG. 1 has been
illustrated with four wheels, a differing number of wheels more or
less could be utilized. For instance, a greater number of wheels,
such as five wheels, may be desired for greater speed.
[0049] During skating on the flexing skate 10, the base 14 flexes
about a laterally extending axis defined transverse to the
longitudinal axis of the split frame assembly 16. However, the
reduced thickness stress concentrating contour of the metatarsal
head portion 22 may be oriented alternately, such as with a slight
angle relative to the longitudinal axis of the frame assembly 16.
This would thereby define a slightly angled transverse rotational
axis that still more closely follows the contour of the metatarsal
head of the skater's foot. The center of rotation of the base 14
and skate 10 is at a plane immediately below the metatarsal head of
the skater's foot, and is preferred because centering rotation at
other locations may cause the skater's foot to cramp. During
skating, as the skater enters the push off phase of the skating
stroke, the skater utilizing the flexing skate 10 of the present
invention may plantarflex his or her ankle, while flexing his or
her foot above the metatarsal head portion 22 of the base 14. The
forward frame segment 26 remains firmly on the ground as the
rearward frame segment 28 elevates off the ground. The weight of
the skater's foot pivots off the metatarsal head of the foot, and
the weight of the skater bears down on the forward frame segment
26. A stable platform is provided by the two forwardmost wheels
18a, 18b, from which the skater is able to propel himself or
herself forward. This skating action is more fully described in
co-pending application Ser. No. 08/957,436, the disclosure of which
is hereby expressly incorporated by reference.
[0050] During this push off or thrusting portion of the stroke, as
the heel is lifted and the foot flexes, the spring plate 72 permits
thrusting off of the forward end of the skate with greater power.
The spring plate 72 bends at the metatarsal head portion 22 of the
skate, and the skate front loads the metatarsal head forward onto
the remainder of the forefoot region 20 of the base 14. As soon as
the stroke is completed and the user releases the tension from his
or her foot, the spring 72 causes the heel region 24 of the base 14
to rebound to the unflexed configuration of FIG. 1, with energy
being returned to the skate for a continued forward stride.
Moreover, the preloading of the spring plate 72 causes the skate 10
to snap down firmly and positively into the aligned, unflexed
configuration.
[0051] Utilization of the flexing base 14 of the skate 10 provides
for greater control, particularly during longer strokes. The skate
remains firmly under the weight of the user during the full length
of a stroke, and the user is better able to maintain his or her
center of gravity in a straight line. Thus longer strokes and
greater speed are provided by use of the flexing skate 10 relative
to a conventional rigid frame skate. Moreover, the split frame
assembly 16 and flexing base 14 of the present invention provides
the skater the ability to jump off of the forward frame segment 26,
utilizing the spring action of his or her legs and feet as the foot
is flexed during upward jumping movement, and rebounding after
weight is removed from the skate to the unflexed configuration.
Thus, jumping in the skate 10 of the present invention is possible
even without the utilization of a ramp or other elevating device.
The user instead simply springs off of the forward frame segment
26.
[0052] An additional benefit of the split frame configuration 16
and flexing base 14 is that the skate 10 thereby provides an
integral suspension system. As the skate 10 passes over bumps and
protrusions in the ground during skating, either of the forward
frame segment 26 or rearward frame segment 28 can lift relative to
the other, with the base 14 flexing as required accordingly, to
dampen shock and impact to the skater's foot. Thus greater control
and higher speeds are possible. The heel of the skater's foot is
able to move up and down freely of the toe of the skater's foot.
Full arcuate flexing of the foot is provided by the skate of the
present invention, for enhanced maneuverability, speed, and jumping
abilities.
[0053] FIG. 5 provides a variation on the base 14 of the skate of
FIG. 10. FIG. 5 illustrates an alternate base 80 that is configured
the same as the base 14 previously described in most respects.
However, rather than a single longitudinal recess 70 and spring
plate 72, left and right narrow elongate spring strips 82 and 84
are mounted within corresponding elongate recesses along the left
and right edges of the skate, again in the forefoot region 20 of
the skate and centered over the metatarsal head portion 22. The
narrow spring strips 82 and 84 are inserted laterally into the base
80 through slots defined in the perimeter of the base 80. To this
end, each of the spring strips 82 and 84 may include a tab 86 that
is manually grasped, or grasped with pliers, for removal and
installation of the spring strips 82 and 84. Once installed, the
spring strips 82 and 84 are closely received within the recesses,
and the preloading of the springs 82 and 84 retains them in this
position. This construction enables the spring strips 82 and 84 to
be removed and interchanged with differing spring strips having a
higher or lower spring constant for more or less biasing force, as
may be desired for particular users or applications. Other forms of
interchangeable or adjustable biasing elements may be utilized,
such as piezoelectric transducers, all within the scope of the
present invention. Piezoelectric transducers would serve the
functions of dampening vibration and controlling the amount of
flexure and the amount of return flex or camber preload in response
to varying surface conditions, providing a responsive suspension
system.
[0054] An alternate embodiment of a flexing base skate 100 is
illustrated in FIGS. 6 and 7. The skate 100 again includes an upper
102 secured along its underside to a base 104. The upper 102 and
the base 104 are constructed substantially similar to the upper 12
and base 14 of the previously described embodiment of the skate 10.
In the skate illustrated in FIGS. 6 and 7, the upper 102 is
configured as a racing skate boot; however other configurations of
skate boots such as that illustrated in FIG. 1 may alternately be
utilized. The base 104 is constructed similarly to the base 14
illustrated in FIG. 1, and includes a forefoot region 106 having a
metatarsal head portion 108 and a heel region 110. The base 104
incorporates a spring, which may suitably be the same as the
previously described spring plate 72 illustrated in regard to the
embodiment of FIGS. 1 through 4. Alternately, a differing spring
construction, such as the use of a resilient composite material is
suitable for use in the embodiment of FIG. 6 to form the base 104
and integral spring.
[0055] FIG. 6 illustrates such a composite base and spring,
suitably constructed from a composite with fibers oriented at
45.degree. relative to the longitudinal axis of the skate. Thus,
the base 104 is of one piece construction, with the contour of the
base 104 at the metatarsal head portion 108 providing for flexure
of the base below the metatarsal head of the foot, and the
composite material utilized to form the base 104 providing the
spring force for biasing of the base 104 to the unflexed
configuration shown in FIG. 6. The base 104 is also preferably
longitudinally reinforced so that it is rigid in front of and
rearwardly of the flexible metatarsal head portion 108.
Longitudinal reinforcement may be had through the incorporation of
ribs, as in the previously described embodiment. Alternately,
syntactic foam reinforcing strips or other reinforcing members may
be incorporated into the structure of the base 104 rearwardly and
forwardly of the metatarsal head portion 108.
[0056] Skate 100 also includes a rigid longitudinal frame 112.
Unlike the previously described embodiment, the frame 112 has a one
piece construction aid extends the full length of the skate. The
frame 112 may suitably be formed from a composite material having a
downwardly opening, U-shaped, elongate channel configuration to
define opposing left and right sidewalls. Alternate frame
constructions, such as a torsion box construction such as that
previously described, but extending in one piece along the length
of the skate, may be utilized. The skate 100 further includes a
plurality of wheels 114 journalled on axles 116 between the
opposing sidewalls of the frame.
[0057] The forefoot region 106 of the base 104 is secured to the
forward end of the frame 112. The securement may be by two bolts
(not shown) that are longitudinally spaced, which pass through
apertures defined in the upper wall of the frame 112 and which are
received within threaded inserts molded into or captured above the
upper surface of the base 104. Alternate constructions, such as
studs that extend downwardly from the base 104 and which receive
nuts received within the frame 112, or riveting, may be utilized.
The base 104 is fixedly secured to the frame 112 only at the
forefoot region 106. The base 104 is not secured and is free of the
frame 112 at the metatarsal head portion 108 and rearwardly behind
the metatarsal head portion 108, including the heel region 104.
Thus, the heel region 110 of the base 104 may be elevated or lifted
above and away from the frame 112, with the base 104 flexing at the
metatarsal head portion 108, as shown in the flexed configuration
of FIG. 7. Just as in the previously described embodiment, the user
may flex his or her foot to lift his or her heel during the skating
stroke. However, the full length of the frame 112 remains parallel
to the ground, with all of the wheels 114 contacting and rolling on
the ground.
[0058] Although the heel region 104 of the base is able to elevate
from the frame 112 during skating, it is still desired to maintain
the heel region 104 centered above the base 112, and to avoid
torsional twisting of the base 104 that would result in the heel
region 110 being displaced laterally to either side of the frame
112. Torsional rigidity is provided to the base 104 in part by the
selection of materials utilized to construct the base 104. Thus, in
the preferred embodiment utilizing a composite material, the
reinforcing fibers provide a high degree of torsional rigidity
while permitting flexing at the metatarsal head portion 108.
Further lateral stability and alignment of the base 104 relative to
the frame 112 is provided by a guide member 118 secured to the
lower surface of the base 104, immediately below the rear end of
the heel region 110.
[0059] The guide member 118 of the preferred embodiment illustrated
has an elongate U-shaped configuration, including a center top
portion 120 that is bolted, riveted, or otherwise secured to the
base 104. The guide 118 further includes first and second side
flanges 122 that depend perpendicularly downwardly from the top
portion 120, on either side of the frame 112. The frame 112 is
slidably and closely received between the left and right side
flanges 122. The guide 118 is preferably constructed with a high
degree of rigidity. The guide 1118 may suitably be constructed from
a laminate of syntactic foam surrounded and encapsulated within
inner and outer layers of reinforced composite material. Other
materials such as aluminum may alternately be utilized. Preferably,
a low friction surface is formed on either the frame 112 sidewalls
or the interior of the guide 118, so that the two members slide
easily relative to each other.
[0060] During flexure of the skate between the lower, unflexed
configuration of FIG. 6 and the upper, flexed configuration of FIG.
7, the frame 112 remains fully or partially between the opposing
side flanges 122 of the guide 118. The heel region 110 of the base
104 thus remains centered over the frame 112, with a high degree of
lateral stability. The ability to lift the heel of this flexing
base skate 100 provides an unencumbered movement of the heel, due
to the low weight carried by the heel. The spring incorporated into
the base 104 provides the same benefits as in the previously
described embodiment, serving to bias the base 104 downwardly to
the lower position of FIG. 6. The spring incorporated into the base
104 is preferably preloaded such that the base 104 is biased
positively against the frame 112. The advantages provided by
flexing the base 104 and skate upper 102 at the metatarsal head
portion are also provided by this embodiment of the present
invention. However, in the embodiment of FIGS. 6-7 all wheels
maintain contact with the ground until the very end of the skating
stroke, for added power and stability, and which tracks well for
fitness and racing applications.
[0061] FIG. 8 illustrates the flexing base skate 100 that is
provided with a brake assembly 130. The brake assembly 130 includes
a brake arm 132 having an upper end secured to the heel region 110
of the base 104, and that extends rearwardly and downwardly
therefrom, terminating rearwardly of the rearmost wheel 114. An
elastomeric brake pad 134 is mounted, such as by a screw, to the
rear end of the brake arm 132.
[0062] The construction and mounting of the brake arm 132 is
illustrated in FIG. 9. The brake arm 132 has a flattened upper
portion 136 that is secured by a bolt 138 to the heel region 110 of
the base 104. The guide 118 is integrally formed with the brake arm
132. Thus the upper portion 136 of the brake arm 132 serves as the
top surface 120 of the guide element 118. The side flanges 122 of
the guide depend downwardly from the upper surface 136 on either
side of the frame 112. To further guide the alignment of the base
104 relative to the frame 112 during the initial stages of flexure,
the brake arm 132 also includes a tapered cylindrical guide boss
140 projecting centrally downward from the top surface 136. The
guide boss 140 does not extend downwardly as far as the side
flanges 122. The guide boss 140 is slidably received within a
slotted aperture 142 defined in the upper wall of the frame 112.
Thus, when the skate is in the unflexed configuration of FIG. 8,
the guide boss 140 is received within the slotted aperture 142, and
further laterally fixes the base 104 relative to the frame 112. In
this configuration, as shown in FIG. 8, the brake pad 134 is
adjacent the ground. By rocking back on the rearwardmost wheel 114,
the user can bring the pad 134 into engagement with the ground for
braking action. During flexing of the skate 100, the brake assembly
130 travels upwardly with the heel of the skate. This construction
avoids the excessive lever arm effect that may alternately result
if the brake assembly were instead mounted to the frame 112.
[0063] It should be readily apparent that the centered guide boss
140 could also be incorporated into the guide 118 of FIGS. 6 and 7,
whether or not the brake arm 132 is incorporated.
[0064] The free heel flexing skate of FIGS. 6 through 9 provides a
shock absorption system similarly to the first preferred embodiment
described previously. Thus, the heel of the skate can pivot
upwardly off of the frame 112 upon passing over protuberances in
the ground. The biasing of the spring incorporated into the frame
104 however prevents undesirable chattering of the base 104
relative to the frame 112. Further shock absorption may be provided
by an elastomeric dampening element mounted between the base 104
and the frame 112. Thus, FIG. 9 illustrates an elastomeric grommet
144 that is fitted about the perimeter of the slotted aperture 142,
including an upper lip that projects above the frame 112. When the
base 104 is pivoted downwardly to the lower position, it contacts
the elastomeric grommet 144, which serves to cushion the two
members and dampen vibrations and shock therebetween.
[0065] It should be readily apparent to those of ordinary skill in
the art that alterations could be made to the above-described
embodiment. For instance, an elastomeric member could be mounted to
other locations of the frame or on the base 104. Further, the guide
member could be mounted on the frame to extend downwardly on either
side of the base, rather than the guide member projecting
downwardly on either side of the frame. Also, a guide member could
alternately project upwardly from the frame and engage an aperture
defined in a rearward extension of the base.
[0066] While the preferred embodiments of the invention have been
illustrated and described, it will be appreciated that various
changes can be made therein without departing from the spirit and
scope of the invention.
* * * * *