Note: Descriptions are shown in the official language in which they were submitted.
CA 02758142 2011-11-10
PATENT APPLICATION
STRIDE ADJUSTMENT MECHANISM
This application is a divisional of Canadian Application Serial No.
2,479,323 filed in Canada on August 26, 2004 and published March 11, 2005.
Field of the Invention
This invention generally relates mechanisms to control exercise
equipment and in particular to programs for controlling stride adjustment of
elliptical exercise equipment.
Background of the Invention
There are a number of different types of exercise apparatus that exercise
a user's lower body by providing a circuitous stepping motion. These
elliptical
stepping apparatus provide advantages over other types of exercise
apparatuses. For example, the elliptical stepping motion generally reduces
shock
on the user's knees as can occur when a treadmill is used. In addition,
elliptical
stepping apparatuses exercise the user's lower body to a greater extent than,
for
example, cycling-type exercise apparatuses.
Examples of elliptical stepping apparatuses are shown in United States Patent
Nos. 3,316,898; 5,242,343; 5,383,829; 5,499,956; 5,529,555, 5,685,804;
5,743,834, 5,759,136; 5,762,588; 5,779,599; 5,577,985, 5,792,026; 5,895,339,
5,899,833, 6,027,431, 6,099,439, 6,146,313, and German Patent No. DE 2 919
494.
An important feature in an elliptical stepping apparatus is the ability to
adjust stride length. Naturally, different people have different stride
lengths and
the exercise apparatus needs to accommodate each user so that they have a
more comfortable and efficient workout. It is also important that the user can
change the stride length during the operation of the elliptical stepping
device.
When the user increases the speed, then naturally he will have a longer stride
length and the machine needs to adjust to this change in length. A problem
with
elliptical exercise machines used in the past is that they can not adjust
horizontal
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stride length without significantly changing vertical height of the foot
motion. It is
therefore advantageous for the user to minimize the vertical displacement of
the
footpath when stride length changes because it allows for more natural and
comfortable motion.
Summary of the Invention
It is therefore an object of the invention to minimize the vertical
displacement of the footpath when the stride length changes.
A further object of the invention is to use a dynamic link mechanism to
adjust stride length which allows for a smooth transition of stride lengths
during
operation and minimizes the vertical displacement when stride length changes.
A still further object of the invention is to allow a runner to adjust cadence
independently while changing stride length.
An additional object of the invention is to allow the use sensors and a
processor to compare stride lengths of the left and right pedal and
automatically
adjust them to be equal.
In one aspect, the present invention resides in an exercise apparatus
comprising: a frame; a pivot axle supported by said frame; a pedal lever
including a first, a central and a second portion; a pedal secured to said
central
portion of said pedal lever; a reciprocating guide mechanism coupled to said
first
portion of said pedal lever effective to guide said first portion of said
pedal lever
in a generally horizontal reciprocating motion; a crank rotationally connected
to
said pivot axle at a first end of said crank and adapted to support said
second
portion of said pedal lever at second end of said crank; an attachment
assembly
effective to connect a second end of said crank to said second portion of said
pedal lever effective to maintain a predetermined distance between said second
end of said crank and said second portion of said pedal lever such that said
pedal moves in a generally elliptical path having a substantially greater
horizontal portion than a vertical portion; and a stride adjustment mechanism,
operatively associated with said attachment assembly effective to selectively
alter said predetermined distance thereby being effective to change said
horizontal portion of said elliptical path to a substantially greater extent
than said
vertical portion of said elliptical path wherein said stride adjustment
mechanism
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includes a control link assembly having a first and second driven timing
pulley
joined by a connection member and connected by a flexible member.
In another aspect, the present invention resides in an exercise apparatus
comprising: a frame; a pivot axle supported by said frame; a pedal lever
including a first, a central and a second portion; a pedal, secured to said
central
portion of said pedal lever; a reciprocating guide mechanism coupled to said
first
portion of said pedal lever effective to guide said first portion of said
pedal lever
in a generally horizontal reciprocating motion; a crank rotationally connected
to
said pivot axle at a first end of said crank and adapted to support said
second
portion of said pedal lever at second end of said crank; an attachment
assembly
effective to connect a second end of said crank to said second portion of said
pedal lever effective to maintain a predetermined distance between said second
end of said crank and said second portion of said pedal lever such that said
pedal moves in a generally elliptical path having a substantially greater
horizontal portion than a vertical portion; a stride adjustment mechanism,
operatively associated with said attachment assembly effective to selectively
alter said predetermined distance thereby being effective to change said
horizontal portion of said elliptical path to a substantially greater extent
than said
vertical portion of said elliptical path; wherein said stride adjustment
mechanism
includes a control link assembly that is connected to said link crank and is
connected to said crank; and wherein said control link assembly includes a set
of
pulleys including a first driven timing pulley rigidly attached to said link
crank,
and rotationally attached to said control link and a second driven timing
pulley
rigidly attached to said crank, and rotationally attached to said control
link.
In a further aspect, the present invention resides in an exercise apparatus
comprising: a frame; a control system; a pivot axle supported by said frame; a
pedal lever; including a first, a central and a second portion; a pedal,
secured to
said central portion of said pedal lever; a reciprocating guide mechanism
coupled to said first portion of said pedal lever effective to guide said
first portion
of said pedal lever in a generally horizontal reciprocating motion; a crank
rotationally connected to said pivot axle at a first end of said crank and
adapted
to support said second portion of said pedal lever at second end of said
crank;
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an attachment assembly including a dynamic link pivotally secured to said
crank
and including a link crank pivotally secured to said second portion of said
pedal
lever such that the distance between the attachment to said crank and the
attachment to said pedal lever changes cyclically as said crank rotates and
wherein said pedal moves in a generally elliptical path having a substantially
greater horizontal portion than a vertical portion; a stride adjustment
mechanism,
operatively associated with said control system and said attachment assembly
effective to selectively alter the phase angle between said crank and said
link
crank thereby being effective to change said horizontal portion of said
elliptical
path; and wherein said stride adjustment mechanism includes a control link
assembly having a connection member connecting a first and second driven
timing pulley connected by a flexible member.
In still a further aspect, the present invention resides in an exercise
apparatus comprising: a frame; a control system; a pivot axle supported by
said
frame; a pedal lever; including a first, a central and a second portion; a
pedal,
secured to said central portion of said pedal lever; a reciprocating guide
mechanism coupled to said first portion of said pedal lever effective to guide
said
first portion of said pedal lever in a generally horizontal reciprocating
motion; a
crank rotationally connected to said pivot axle at a first end of said crank
and
adapted to support said second portion of said pedal lever at second end of
said
crank; an attachment assembly including a dynamic link pivotally secured to
said
crank and including a link crank pivotally secured to said second portion of
said
pedal lever such that the distance between the attachment to said crank and
the
attachment to said pedal lever changes cyclically as said crank rotates and
wherein said pedal moves in a generally elliptical path having a substantially
greater horizontal portion than a vertical portion; a stride adjustment
mechanism
operatively associated with said control system and said attachment assembly
effective to selectively alter the phase angle between said crank and said
link
crank thereby being effective to change said horizontal portion of said
elliptical
path; wherein said stride adjustment mechanism includes a control link
assembly
connected to said link crank and to said crank; and wherein said control link
assembly includes a set of pulleys including a first driven timing pulley
rigidly
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attached to said link crank, and rotationally attached to said control link
and a
second driven timing pulley rigidly attached to said crank, and rotationally
attached to said control link.
In another aspect, the present invention resides in an exercise apparatus
comprising: a frame; a pivot axle supported by said frame; a control system; a
first pedal lever including a first, a central and a second portion; a first
and
second rocker; a second pedal lever; including a first, a central and a second
portion; a first pedal, secured to said central portion of said first pedal
lever; a
second pedal, secured to said central portion of said second pedal lever; a
first
crank rotationally connected to said pivot axle; a second crank rotationally
connected to said pivot axle; a first and second stride adjustment mechanism,
operatively associated with said first and second pedal levers and said first
and
second cranks effective to change the horizontal portion of the elliptical
path of
said first and second pedal lever thereby altering the stride length of said
first
and second pedal levers; and a first and second sensor mechanism operatively
connected to said control system including a first and a second sensor
operatively associated with each of said pedal levers respectively for
generating
a first stride length signal representing the stride length of said first
pedal lever
and a second stride length signal representing the stride length of said
second
pedal lever.
In yet another aspect, the present invention resides in an exercise
apparatus comprising: a frame; a pivot axle supported by said frame; a control
system; a first pedal lever including a first, a central and a second portion;
a
second pedal lever; including a first, a central and a second portion; a first
pedal,
secured to said central portion of said first pedal lever; a second pedal,
secured
to said central portion of said second pedal lever; a first crank rotationally
connected to said pivot axle; a second crank rotationally connected to said
pivot
axle; a first and second stride adjustment mechanism, operatively associated
with said first and second pedal levers and said first and second cranks
effective
to change the horizontal portion of the elliptical path of said first and
second
pedal lever; and a first and a second sensor mechanism operatively associated
with each of said pedal levers respectively and connected to said control
system
CA 02758142 2011-11-10
3 ,
for generating a signal representing the stride length of said first and
second
pedal levers respectively such that the stride length of said first and second
pedal levers can be calculated individually by said control system.
Brief Description of the Drawings
Fig. 1 is a side perspective view of an elliptical stepping exercise
apparatus;
Fig. 2 is a schematic and block diagram of representative mechanical and
electrical components of an example of an elliptical stepping exercise
apparatus
in which the method of the invention can be implemented;
Fig. 3 is a plan layout of a display console for use with the elliptical
exercise apparatus shown in Fig. 2;
Figs. 4 and 5 are views of the preferred embodiment of dynamic link
mechanism for use in adjusting stride length in an elliptical stepping
apparatus of
the type shown in Fig. 1;
Figs. 6 and 7 are views of the secondary embodiment of dynamic link
mechanism for use in adjusting the stride length in an elliptical stepping
apparatus of the type shown in Fig. 1;
Figs. 8A, 8B, 8C and 8D are schematic diagrams illustrating the operation
of the dynamic link mechanism of Figs. 4-7 for a 180 degree phase angle;
Figs. 9A, 9B, 9C and 9D are schematic diagrams illustrating the operation
of the dynamic link mechanism of Figs. 4-7 for a 60 degree phase angle;
Figs. 10A, 1OB, 10C and 1OD are schematic diagrams illustrating the
operation of the dynamic link mechanism of Figs. 4-7 for a zero degree phase
angle;
Fig. 11 is a pair of perspective view of a linear guide assembly for use
with the mechanisms of Figs. 4-7;
Fig. 12 is a view of an additional embodiment for a stride adjustment
mechanism;
Fig. 13 is a side view of the elliptical exercise apparatus with a different
stride adjustment mechanism than shown in Fig. 1;
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Fig. 14-16 are views of different actuators for use in the stride adjustment
mechanisms;
Figs. 17A, 17B and 17C are a set of schematic diagrams illustrating angle
measurements that can be used to determine stride length in an elliptical
stepping apparatus of the type shown in Fig. 4; and
Fig. 18 is perspective view of mounting assembly for use with the dynamic
linck mechanism of Figs. 4 and 5.
Detailed Description of the Invention
Fig. 1 depicts a representive example of an elliptical step exercise
apparatus 10 of the type that can be modified to have the capability of
adjusting
the stride or the path of the foot pedal 12. The exercise apparatus 10
includes a
frame, shown generally at 14. The frame 14 includes vertical support members
16, 18A and 18B which are secured to a longitudinal support member 20. The
frame 14 further includes cross members 22 and 24 which are also secured to
and bisect the longitudinal support member 20. The cross members 22 and 24
are configured for placement on a floor 26. A pair of levelers, 28A and 28B
are
secured to cross member 24 so that if the floor 26 is uneven, the cross member
24 can be raised or lowered such that the cross member 24, and the
longitudinal
support member 20 are substantially level. Additionally, a pair of wheels 30
are
secured to the longitudinal support member 20 of the frame 14 at the rear of
the
exercise apparatus 10 so that the exercise apparatus 10 is easily moveable.
The exercise apparatus 10 further includes the rocker 32, an attachment
assembly 34 and a resistance or motion controlling assembly 36. The motion
controlling assembly 36 includes the pulley 38 supported by vertical support
members 18A and 18B around the pivot axle 40. The motion controlling
assembly 36 also includes resistive force and control components, including
the
alternator 42 and the speed increasing transmission 44 that includes the
pulley
38. The alternator 42 provides a resistive torque that is transmitted to the
pedal
12 and to the rocker 32 through the speed increasing transmission 44. The
alternator 42 thus acts as a brake to apply a controllable resistive force to
the
movement of the pedal 12 and the movement of the rocker 32. Alternatively, a
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resistive force can be provided by any suitable component, for example, by an
eddy current brake, a friction brake, a band brake or a hydraulic braking
system.
Specifically, the speed increasing transmission 44 includes the pulley 38
which is
coupled by the first belt 46 to the second double pulley 48. The second double
pulley 48 is then connected to the alternator 42 by a second belt 47. The
speed
increasing transmission 44 thereby transmits the resistive force provided by
the
alternator 42 to the pedal 12 and the rocker 32 via the pulley 38. The pedal
lever
50 includes a first portion 52, a second portion 54 and a third portion 56.
The
first portion 52 of the pedal lever 50 has a forward end 58. The pedal 12 is
secured to the top surface 60 of the second portion 54 of the pedal lever 50
by
any suitable securing means. In this apparatus 10, the pedal 12 is secured
such
that the pedal 12 is substantially parallel to the second portion of the pedal
lever
54. A bracket 62 is located at the rearward end 64 of the second portion 54.
The third portion 56 of the pedal lever 50 has a rearward end 66.
In this particular example of an elliptical step apparatus, the crank 68 is
connected to and rotates about the pivot axle 40 and a roller axle 69 is
secured
to the other end of the crank 68 to rotatably mount the roller 70 so that it
can
rotate about the roller axle 69. The extension arm 72 is secured to the roller
axle
69 making it an extension of the crank 68. The extension arm 72 is fixed with
respect to the crank 68 and together they both rotate about the pivot axle 40.
The rearward end of the attachment assembly 34 is pivotally connected to the
end of the extension arm 72. The forward end of the attachment assembly 34 is
pivotally connected to the bracket 62.
The pedal 12 of the exercise apparatus 10 includes a toe portion 74 and a
heel portion 76 so that the heel portion 76 is intermediate the toe portion 74
and
the pivot axle 40. The pedal 12 of the exercise apparatus 10 also includes a
top
surface 78. The pedal 12 is secured to the top surface 60 of the pedal lever
50
in a manner so that the desired foot weight distribution and flexure are
achieved
when the pedal 12 travels in the substantially elliptical pathway as the
rearward
end 66 of the third portion 56 of the pedal lever 50 rolls on top of the
roller 70,
traveling in a rotationally arcuate pathway with respect to the pivot axle 40
and
moves in an elliptical pathway around the pivot axle 40. Since the rearward
end
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66 of the pedal lever 50 is not maintained at a predetermined distance from
the
pivot axis 40 but instead follows the elliptical pathway, a more refined foot
motion
is achieved. It should be understood however that the invention can be
implemented on other configurations of elliptical step apparatus having a
variety
of mechanisms for connecting the pedal lever 50 to the crank arm 68 including
a
direct attachment.
Fig. 2 is a combination schematic and block diagram that provides an
environment for describing the invention and for simplicity shows in schematic
form only one of two pedal mechanisms typically used in an elliptical stepping
exercise apparatus such as the apparatus 10. In particular, the exercise
apparatus 10 described herein includes motion controlling components which
operate in conjunction with an attachment assembly to provide an elliptical
stepping exercise experience for the user. Included in this example of an
elliptical stepping exercise apparatus 10 are the rocker 32, the pedal 12
secured
to the pedal lever 50, the pulley 38 supported by the vertical support members
18A and 18B and which is rotatable on the pivot axle 40. This embodiment also
includes an arm handle 80 that is connected to the rocker 32 at a pivot point
82
on the frame of the apparatus 10. The crank 68 is generally connected to one
end of the pedal lever 50 by an attachment assembly represented by the box 34
and rotates with the pulley 38 while the other end of the pedal lever 50 is
pivotally attached to the rocker 32 at the pivot point 84.
The apparatus 10 as represented in Fig. 2 also includes resistive force
and control components, including the alternator 42 and the speed increasing
transmission 44 that includes the pulley 38. The alternator 42 provides a
resistive torque that is transmitted to the pedal 12 and to the rocker 32
through
the speed increasing transmission 44. The alternator 42 thus acts as a brake
to
apply a controllable resistive force to the movement of the pedal 12 and the
movement of the rocker 32. Alternatively, a resistive force can be provided by
any suitable component, for example, by an eddy current brake, a friction
brake,
a band brake or a hydraulic braking system. Specifically, the speed increasing
transmission 44 includes the pulley 38 which is coupled by a first belt 46 to
a
second double pulley 48. A second belt 47 connects the second double pulley
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48 to a flywheel 86 of the alternator 42. The speed increasing transmission 44
thereby transmits the resistive force provided by the alternator 42 to the
pedal 12
and the rocker 32 via the pulley 38. Since the speed increasing transmission
44
causes the alternator 42 to rotate at a greater rate than the pivot axle 40,
the
alternator 42 can provide a more controlled resistance force. Preferably the
speed increasing transmission 44 should increase the rate of rotation of the
alternator 42 by a factor of 20 to 60 times the rate of rotation of the pivot
axle 40
and in this embodiment the pulleys 38 and 48 are sized to provide a
multiplication in speed by a factor of 40. Also, size of the transmission 44
is
reduced by providing a two stage transmission using pulleys 38 and 48.
Fig. 2 additionally provides an illustration of a control system 88 and a
user input and display console 90 that can be used with elliptical exercise
apparatus 10 or other similar elliptical exercise apparatus to implement the
invention. In this particular embodiment of the control system 88, a
microprocessor 92 is housed within the console 90 and is operatively connected
to the alternator 42 via a power control board 94. The alternator 42 is also
operatively connected to a ground through load resistors 96. A pulse width
modulated output signal on a line 98 from the power control board 94 is
controlled by the microprocessor 92 and varies the current applied to the
field of
the alternator 42 by a predetermined field control signal on a line 100, in
order to
provide a resistive force which is transmitted to the pedal 12 and to the arm
80.
When the user steps on the pedal 12, the motion of the pedal 12 is detected as
a
change in an RPM signal which represents pedal speed on a line 102. It should
be noted that other types of speed sensors such as optical sensors can be used
in machines of the type 10 to provide pedal speed signals. Thereafter, as
explained in more detail below, the resistive force of the alternator 42 is
varied
by the microprocessor 92 in accordance with the specific exercise program
selected by the user so that the user can operate the pedal 12 as previously
described.
The alternator 42 and the microprocessor 92 also interact to stop the
motion of the pedal 12 when, for example, the user wants to terminate his
exercise session on the apparatus 10. A data input center 104, which is
CA 02758142 2011-11-10
operatively connected to the microprocessor 92 over a line 106, includes a
brake
key 108, as shown in Fig. 3, that can be employed by the user to stop the
rotation of the pulley 38 and hence the motion of the pedal 12. When the user
depresses the brake key 108, a stop signal is transmitted to the
microprocessor
92 via an output signal on the line 106 of the data input center 104.
Thereafter,
the field control signal 100 of the microprocessor 92 is varied to increase
the
resistive load applied to the alternator 42. The output signal 98 of the
alternator
provides a measurement of the speed at which the pedal 12 is moving as a
function of the revolutions per minute (RPM) of the alternator 42. A second
output signal on the line 102 of the power control board 94 transmits the RPM
signal to the microprocessor 92. The microprocessor 92 continues to apply a
resistive load to the alternator 42 via the power control board 94 until the
RPM
equals a predetermined minimum which, in the preferred embodiment, is equal
to or less than 5 RPM.
In this embodiment, the microprocessor 92 can also vary the resistive
force of the alternator 42 in response to the user's input to provide
different
exercise levels. A message center 110 includes an alpha-numeric display
screen 112, shown in Fig. 3, that displays messages to prompt the user in
selecting one of several pre-programmed exercise levels. In the preferred
embodiment, there are twenty-four pre-programmed exercise levels, with level
one being the least difficult and level 24 the most difficult. The data input
center
104 includes a numeric key pad 114 and a pair of selection arrows 116, shown
in
Fig. 3, either of which can be employed by the user to choose one of the pre-
programmed exercise levels. For example, the user can select an exercise level
by entering the number, corresponding to the exercise level, on the numeric
keypad 114 and thereafter depressing a start/enter key 118. Alternatively, the
user can select the desired exercise level by using the selection arrows 116
to
change the level displayed on the alpha-numeric display screen 112 and
thereafter depressing the start/enter key 118 when the desired exercise level
is
displayed. The data input center 104 also includes a clear/pause key 120, show
in Fig. 3, which can be pressed by the user to clear or erase the data input
before the start/enter key 118 is pressed. In addition, the exercise apparatus
10
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includes a user-feedback apparatus that informs the user if the data entered
are
appropriate. In this embodiment, the user feed-back apparatus is a speaker
122,
that is operatively connected to the microprocessor 92. The speaker 122
generates two sounds, one of which signals an improper selection and the
second of which signals a proper selection. For example, if the user enters a
number between 1 and 24 in response to the exercise level prompt displayed on
the alpha-numeric screen 112, the speaker 122 generates the correct-input
sound. On the other hand, if the user enters an incorrect datum, such as the
number 100 for an exercise level, the speaker 122 generates the incorrect-
input
sound thereby informing the user that the data input was improper. The alpha-
numeric display screen 112 also displays a message that informs the user that
the data input was improper. Once the user selects the desired appropriate
exercise level, the microprocessor 92 transmits a field control signal on the
line
100 that sets the resistive load applied to the alternator 42 to a level
corresponding with the pre-programmed exercise level chosen by the user.
The message center 110 displays various types of information while the
user is exercising on the apparatus 10. As shown in Fig. 3, the alpha-numeric
display panel 124, shown on Fig. 3, is divided into four sub-panels 126A-D,
each
of which is associated with specific types of information. Labels 128A-K and
LED indicators 130A-K located above the sub-panels 126A-D indicate the type of
information displayed in the sub-panels 126A-D. The first sub-panel 126A
displays the time elapsed since the user began exercising on the exercise
apparatus 10 or the current stride length of the apparatus 10. One of the LED
indicators 130A or 130K is illuminated depending if time or stride length is
being
displayed. The second sub-panel 126B displays the pace at which the user is
exercising. In the preferred embodiment, the pace can be displayed in miles
per
hour, minutes per mile or equivalent metric units as well as RPM. One of the
LED indicators 130B-130D is illuminated to indicate in which of these units
the
pace is being displayed. The third sub-panel 126C displays either the exercise
level chosen by the user or, as explained below, the heart rate of the user.
The
LED indicator 130F associated with the exercise level label 128E is
illuminated
when the level is displayed in the sub-panel 126C and the LED indicator 130E
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associated with the heart rate label 128F is illuminated when the sub-panel
126C
displays the user's heart rate. The fourth sub-panel 126D displays four types
of
information: the calories per hour at which the user is currently exercising;
the
total calories that the user has actually expended during exercise; the
distance,
in miles or kilometers, that the user has "traveled" while exercising; and the
power, in watts, that the user is currently generating. In the default mode of
operation, the fourth sub-panel 126D scrolls among the four types of
information.
As each of the four types of information is displayed, the associated LED
indicators 130G-J are individually illuminated, thereby identifying the
information
currently being displayed by the sub-panel 126D. A display lock key 132,
located within the data input center 104, shown in Fig. 2, can be employed by
the user to halt the scrolling display so that the sub-panel 126D continuously
displays only one of the four information types. In addition, the user can
lock the
units of the power display in watts or in metabolic units ("mets"), or the
user can
change the units of the power display, to watts or mets or both, by depressing
a
watts/mets key 134 located within the data input center 104.
In the preferred embodiment of the invention, the exercise apparatus 10
also provides several pre-programmed exercise programs that are stored within
and implemented by the microprocessor 92. The different exercise programs
further promote an enjoyable exercise experience and enhance exercise
efficiency. The alpha-numeric display screen 112 of the message center 110,
together with a display panel 136, guide the user through the various exercise
programs. Specifically, the alpha-numeric display screen 112 of the message
center 110, together with a display panel 136, guide the user through the
various
exercise programs. Specifically, the alpha-numeric display screen 112 prompts
the user to select among the various preprogrammed exercise programs and
prompts the user to supply the data needed to implement the chosen exercise
program. The display panel 136 displays a graphical image that represents the
current exercise program. The simplest exercise program is a manual exercise
program. In the manual exercise program the user simply chooses one of the
twenty-four previously described exercise levels. In this case, the graphic
image
displayed by the display panel 136 is essentially flat and the different
exercise
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levels are distinguished as vertically spaced-apart flat displays. A second
exercise program, a so-called hill profile program, varies the effort required
by
the user in a pre-determined fashion which is designed to simulate movement
along a series of hills. In implementing this program, the microprocessor 92
increases and decreases the resistive force of the alternator 42 thereby
varying
the amount of effort required by the user. The display panel 136 displays a
series of vertical bars of varying heights that correspond to climbing up or
down
a series of hills. A portion 138 of the display panel 136 displays a single
vertical
bar whose height represents the user's current position on the displayed
series
of hills. A third exercise program, known as a random hill profile program,
also
varies the effort required by the user in a fashion which is designed to
simulate
movement along a series of hills. However, unlike the regular hill profile
program,
the random hill profile program provides a randomized sequence of hills so
that
the sequence varies from one exercise session to another. A detailed
description of the random hill profile program and of the regular hill profile
program can be found in U.S. Patent No. 5,358,105.
A fourth exercise program, known as a cross training program, urges the
user to manipulate the pedal 12 in both the forward-stepping mode and the
backward-stepping mode. When this program is selected by the user, the user
begins moving the pedal 12 in one direction, for example, in the forward
direction. After a predetermined period of time, the alpha-numeric display
panel
136 prompts the user to prepare to reverse directions. Thereafter, the field
control signal 100 from the microprocessor 92 is varied to effectively brake
the
motion of the pedal 12 and the arm 80. After the pedal 12 and the arm 80 stop,
the alpha-numeric display screen 112 prompts the user to resume his workout.
Thereafter, the user reverses directions and resumes his workout in the
opposite
direction.
Two exercise programs, a cardio program and a fat burning program, vary
the resistive load of the alternator 42 as a function of the user's heart
rate.
When the cardio program is chosen, the microprocessor 92 varies the resistive
load so that the user's heart rate is maintained at a value equivalent to 80%
of a
quantity equal to 220 minus the user's age. In the fat burning program, the
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resistive load is varied so that the user's heart rate is maintained at a
value
equivalent to 65% of a quantity equal to 220 minus the user's heart age.
Consequently, when either of these programs is chosen, the alpha-numeric
display screen 112 prompts the user to enter his age as one of the program
parameters. Alternatively, the user can enter a desired heart rate. In
addition,
the exercise apparatus 10 includes a heart rate sensing device that measures
the user's heart rate as he exercises. The heart rate sensing device consists
of
heart rate sensors 140 and 140' that can be mounted either on the moving arms
80 or a fixed handrail 142, as shown in Fig 1. In the preferred embodiment,
the
sensors 140 and 140' are mounted on the moving arms 80. A set of output
signal on a set of lines 144 and 144' corresponding to the user's heart rate
is
transmitted from the sensors 140 and 140' to a heart rate digital signal
processing board 146. The processing board 146 then transmits a heart rate
signal over a line 148 to the microprocessor 92. A detailed description of the
sensors 140 and 140' and the heart rate digital signal processing board 146
can
be found in U.S. Patent Nos. 5,135,447 and 5,243,993. In addition, the
exercise
apparatus 10 includes a telemetry receiver 150, shown in Fig. 2, that operates
in
an analogous fashion and transmits a telemetric heart rate signal over a line
152
to the microprocessor 92. The telemetry receiver 150 works in conjunction with
a telemetry transmitter that is worn by the user. In the preferred embodiment,
the
telemetry transmitter is a telemetry strap worn by the user around the user's
chest, although other types of transmitters are possible. Consequently, the
exercise apparatus 10 can measure the user's heart rate through the telemetry
receiver 150 if the user is not grasping the arm 80. Once the heart rate
signal
148 or 152 is transmitted to the microprocessor 92, the resistive load 96 of
the
alternator 42 is varied to maintain the user's heart rate at the calculated
value.
In each of these exercise programs, the user provides data that determine
the duration of the exercise program. The user can select between a number of
exercise goal types including a time or a calories goal or, in the preferred
embodiment of the invention, a distance goal. If the time goal type is chosen,
the alpha-numeric display screen 112 prompts the user to enter the total time
that he wants to exercise or, if the calories goal type is selected, the user
enters
CA 02758142 2011-11-10
the total number of calories that he wants to expend. Alternatively, the user
can
enter the total distance either in miles or kilometers. The microprocessor 92
then implements the selected exercise program for a period corresponding to
the
user's goal. If the user wants to stop exercising temporarily after the
microprocessor 92 begins implementing the selected exercise program,
depressing the clear/pause key 120 effectively brakes the pedal 12 and the arm
80 without erasing or changing any of the current program parameters. The user
can then resume the selected exercise program by depressing the start/enter
key 118. Alternatively, if the user wants to stop exercising altogether before
the
exercise program has been completed, the user simply depresses the brake key
108 to brake the pedal 12 and the arm 80. Thereafter, the user can resume
exercising by depressing the start/enter key 118. In addition, the user can
stop
exercising by ceasing to move the pedal 12. The user then can resume
exercising by again moving the pedal 12.
The exercise apparatus 10 also includes a pace option. In all but the
cardio program and the fat burning program, the default mode is defined such
that the pace option is on and the microprocessor 92 varies the resistive load
of
the alternator 42 as a function of the user's pace. When the pace option is
on,
the magnitude of the RPM signal 102 received by the microprocessor 92
determines the percentage of time during which the field control signal 100 is
enabled and thereby the resistive force of the alternator 42. In general, the
instantaneous velocity as represented by the RPM signal 102 is compared to a
predetermined value to determine if the resistive force of the alternator 42
should
be increased or decreased. In the presently preferred embodiment, the
predetermined value is a constant of 30 RPM. Alternatively, the predetermined
value could vary as a function of the exercise level chosen by the user. Thus,
in
the presently preferred embodiment, if the RPM signal 102 indicates that the
instantaneous velocity of the pulley 38 is greater than 30 RPM, the percentage
of
time that the field control signal 100 is enabled is increased according to
Equation 1.
Equation 1
field control duty cycle = field control duty cycle +
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((Iinstantaneous RPM - 30/)/2)2 * field control duty cycle)
256
where field duty cycle is a variable that represents the percentage of time
that
the field control signal 100 is enabled and where the instantaneous RPM
represents the instantaneous value of the RPM signal 98.
On the other hand, in the presently preferred embodiment, if the RPM
signal 102 indicates that the instantaneous velocity of the pulley 38 is less
than
30 RPM, the percentage of time that the field control signal 100 is enabled is
decreased according to Equation 2.
Equation 2
field control duty cycle = field control duty cycle -
((Iinstantaneous RPM - 30/)/2)2 * field control duty cycle)
256
where field duty cycle is a variable that represents the percentage of time
that
the field control signal 100 is enabled and where the instantaneous RPM
represents the instantaneous value of the RPM signal 102.
Moreover, once the user chooses an exercise level, the initial percentage
of time that the field control signal 100 is enabled is pre-programmed as a
function of the chosen exercise level as described in U.S. Patent No.
6,099,439.
Manual and Automatic Stride Length Adiustment
In these embodiments of the invention, stride length can be varied
automatically as a function of exercise or apparatus parameters. Specifically,
the control system 88 and the console 90 of Fig. 2 can be used to control
stride
length in the elliptical step exercise apparatus 10 either manually or as a
function
of a user or operating parameter. In the examples of Figs.1 and 2 the
attachment assembly 34 generally represented within the dashed lines can be
implemented by a number of mechanisms that provide for stride adjustment such
as the stride length adjustment mechanisms depicted in Figs. 4-7, 8A-D, 9A-D
and 10A-D. As shown in Fig. 2, a line 154 connects the microprocessor 92 to
the electronically controlled actuator elements of the adjustment mechanisms
in
the attachment assembly 34. Stride length can then be varied by the user via a
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CA 02758142 2011-11-10
manual stride length key 156, shown in Fig. 3, which is connected to the
microprocessor 92 via the data input center 104. Alternatively, the user can
have stride length automatically varied by using a stride length auto key 158
that
is also connected to the microprocessor 92 via the data input center 104. In
one
embodiment, the microprocessor 92 is programed to respond to the speed signal
on line 102 to increase the stride length as the speed of the pedal 12
increases.
Pedal direction, as indicated by the speed signal can also be used to vary
stride
length. For example, if the microprocessor 92 determines that the user is
stepping backward on the pedal 12, the stride length can be reduced since an
individuals stride is usually shorter when stepping backward. Additionally,
the
microprocessor 92 can be programmed to vary stride length as function of other
parameters such as resistive force generated by the alternator 42; heart rate
measured by the senors 140 and 140'; and user data such as weight and height
entered into the console 90.
Adjustable Stride Programs
Adjustable stride mechanisms make it possible to provide enhanced pre-
programmed exercise programs of the type described above that are stored
within and implemented by the microprocessor 92. As with the previously
described exercise programs, the alpha-numeric display screen 112 of the
message center 110, together with a display panel 136, can be used to guide
the
user through the various exercise programs. Specifically, the alpha-numeric
display screen 112 prompts the user to select among the various pre-
programmed exercise programs and prompts the user to supply the data needed
to implement the selected exercise program. The display panel 136 also
displays a graphical image that represents the current exercise program. For
example, the graphic image displayed by the display panel 136 representing
different exercise levels can include the series of vertical bars of varying
heights
that correspond to resistance levels that simulate climbing up or down a
series of
hills. In this embodiment, the portion 138 of the display panel 136 displays a
single vertical bar whose height represents the user's current position on the
displayed series of hills. Adjustable stride length programs can be selected
by
18
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the user utilizing a stride program key 160, as shown in Fig. 3, which is
connected to the microprocessor 92 via the data input center 104.
A first program can be used to simulate hiking on a hill or mountain. For
example, the program can begin with short strides and a high resistance to
simulate climbing a hill then after a predetermined time change to long
strides at
low resistance to simulate walking down the hill. The current hill and
upcoming
hills can be displayed on the display panel 136 where the length of the stride
and
the resistance change at each peak and valley. In one implementation, the
initial
or up hill stride would be 16 inches and the down hill stride would be 24
inches,
where the program automatically adjusts the initial stride length to 16 inches
at
the beginning of the program. Also, the program can return the stride length
to a
home position, for instance 20 inches, during a cool down portion of the
program.
A second program can be used to change both the stride length and the
resistance levels on a random basis. Preferably, the changes in stride length
and resistance levels are independent of each other. Also in one embodiment,
the changes in stride length occur at different time intervals than the
changes in
resistance levels. For example, a random stride length change might occur
every even minute and a random resistance level change might occur at every
odd minute of the program. Preferably, the changes in increments will be plus
or
minus 2 inches or more. Again, the program can return the stride length to a
home position, for instance 20 inches, during a cool down portion of the
program.
A third program can be used to simulate interval training for runners. In
one embodiment, by using stride length changes in the longer strides and
having
the processor 92 generates motivating message prompts on the display 136,
interval training and the gentle slopes and intervals one would experience
when
training as a runner outdoors are mimicked. For example, the program spans
the stride range of 22" - 26" with an initial warm-up beginning at 22" then
moving
to 24". Here the program then alternate between the 24" and 26" strides thus
mimicking intervals at the longer strides such as those experienced by a
runner
in training. In addition, the display 136 can alert the user to "Go faster"
and "Go
19
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slower" at certain intervals. As indicated here, it is preferable that the
prompts
be used to encourage faster and slower pedal speeds. A representative
example of such a program is provided below:
Warm-up:
Prompt "Warm Up" message
Minute 00:00 = 22" stride (If machine is not at 22" at program start-up,
then it will adjust to the 22" stride length at program start.)
Minute 03:00 = 24" stride
Minute 03:30 = prompt "Go faster" message
Intervals:
Minute 04:00 = 26" stride
Minute 08:30 = prompt "Go slower" message
Minute 09:00 = 24" stride
Minute 10:30 = prompt "Go faster" message
Minute 11:00 = 26" stride
Minute 15:30 = prompt "Go slower" message
where the first change is initiated at the 03:00 minute mark, during the warm-
up
phase. Other aspects of this particular interval program include: stride
adjustment increments of 2"; minimum duration of 10 minutes; and repeating the
interval phase for the selected duration of the program.
Operation of the Apparatus
The preferred embodiment of the exercise apparatus 10 further includes a
communications board 162 that links the microprocessor 92 to a central
computer 164, as shown in Fig. 2. Once the user has entered the preferred
exercise program and associated parameters, the program and parameters can
be saved in the central computer 164 via the communications board 162. Thus,
during subsequent exercise sessions, the user can retrieve the saved program
and parameters and can begin exercising without re-entering data. At the
conclusion of an exercise program, the user's heart rate and total calories
expended can be saved in the central computer 164 for future reference.
CA 02758142 2011-11-10
Similarly, the central computer 164 can be used to save the total distance
traveled along with the user's average miles per hour and minutes per mile
pace
during the exercise or these quantities can be tabulated to show the user's
pace
over the distance or time of the exercise. In addition, the communications
board
162 can be used to compare distance traveled or pace for the purpose of
comparison with other users on other step apparatus or even other types of
exercise machines in real time in order, for example, to provide for simulated
races between users.
In using the apparatus 10, the user begins his exercise session by first
stepping on the pedal 12 which, as previously explained, is heavily damped due
to the at-rest resistive force of the alternator 42. Once the user depresses
the
start/enter key 128, the alpha-numeric display screen 112 of the message
center
110 prompts the user to enter the required information and to select among the
various programs. First, the user is prompted to enter the user's weight. The
alpha-numeric display screen 112, in conjunction with the display panel 136,
then lists the exercise programs and prompts the user to select a program.
Once a program is chosen, the alpha-numeric display screen 112 then prompts
the user to provide program-specific information. For example, if the user has
chosen the cardio program, the alpha-numeric display screen 112 prompts the
user to enter the user's age. After the user has entered all the program-
specific
information such as age, weight and height, the user is prompted to specify
the
goal type (time or calories), to specify the desired exercise duration in
either total
time or total calories, and to choose one of the twenty-four exercise levels.
Once
the user has entered all the required parameters, the microprocessor 92
implements the selected exercise program based on the information provided by
the user. When the user then operates the pedal 12 in the previously described
manner, the pedal 12 moves along the elliptical pathway in a manner that
simulates a natural heel to toe flexure that minimizes or eliminates stresses
due
to unnatural foot flexure. If the user employs the moving arm handle 80, the
exercise apparatus 10 exercises the user's upper body concurrently with the
user's lower body. The exercise apparatus 10 thus provides a wide variety of
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CA 02758142 2011-11-10
exercise programs that can be tailored to the specific needs and desires of
individual users.
Elliptical Stepping Mechanism
In addition to measuring distance traveled on an elliptical exercise
apparatus such as the apparatus 10 in Fig. 1 that has a fixed pedal path, the
principles discussed above can apply to the calculation of distance traveled
in an
elliptical exercise apparatus that has an adjustable stride length. The
ability to
adjust the stride length in an elliptical step exercise apparatus is desirable
for a
number of reasons. First, people, especially people with different physical
characteristics such as height, tend to have different stride lengths when
walking
or running. Secondly, the length of an individuals stride generally increases
as
the individual increases his walking or running speed. As suggested in U.S.
Patent Nos. 5,743,834 and 6,027,431, there are a number of mechanisms for
changing the geometry of an elliptical step mechanism in order to vary the
path
the foot follows in this type of apparatus.
Stride Length Adjustment Mechanisms
The ability to adjust the stride length in an elliptical step exercise
apparatus is desirable for a number of reasons. First, people, especially
people
with different physical characteristics such as height, tend to have different
stride
lengths when walking or running. Secondly, the length of an individuals stride
generally increases as the individual increases his walking or running speed.
As
suggested in U.S. Patent Nos. 5,743,834 and 6,027,431, there are a number of
mechanisms for changing the geometry of an elliptical step mechanism in order
to vary the path the foot follows in this type of apparatus.
Figs. 4-7, 8A-D, 9A-D and 1 OA-D depict a pair of stride adjustment
mechanisms 166 and 166' which can be used to vary the stride length, i.e.
maximum foot pedal displacement, without the need to adjust the length crank
68. Essentially, the stride adjustment mechanisms 166 and 166' replace the
stroke link used to move the pedal lever 50 in earlier machines of the type
shown
in Fig. 1. This approach permits adjustment of stride length independent of
the
22
CA 02758142 2011-11-10
motion of the machine 10 regardless as to whether the machine 10 is
stationary,
the user is pedaling forward, or pedaling in reverse. One of the significant
features of the stride adjustment mechanisms 166 and 166' is a dynamic link,
that is, a linkage system that changes its length, or the distance between its
two
attachment points, cyclically during the motion of the apparatus 10. The
stride
adjustment mechanisms 166 and 166' are pivotally attached to the pedal lever
50 by a link crank mechanism 168 at one end and pivotally attached to the
crank
extension 72 at the other end. The maximum pedal lever's 50 excursion, for a
particular setting, is called a stroke or stride. The stride adjustment
mechanism
166 and the main crank 68 with the crank extension 72 together drive the
maximum displacement/stroke of the pedal lever 50. The extreme points in
each pedal lever stroke correspond to extreme points between the Main Crank
Axis 40 and a Link Crank - Pedal Lever Axis 169. By changing the dynamic
phase angle relationship between the link crank 168 and the crank extension
72,
it is possible to add to or subtract from the maximum displacement/stroke of
the
pedal lever 50. Therefore by varying the dynamic phase angle relationship
between the link crank 168 and the crank extension 72, the stroke or stride of
the
pedal lever 50 varies the length of the major axis of the ellipse that the
foot pedal
12 travels.
The preferred embodiment of the stride adjustment mechanism 166
shown in Figs. 4 and 5 takes full advantage of the relative rotation between
the
crank extension 72 and a control link assembly 170 of the stride adjustment
mechanism 166 as the user moves the pedals 12. In this embodiment,
attachment adjustment mechanism 166 includes the control link assembly 170
and two secondary crank arms, the link crank assembly 168 and the crank
extension 72. The control link assembly 170 includes a pair of driven timing-
pulley shafts 172 and 174, a pair of toothed timing-pulleys 176 and 178 and a
toothed timing-belt 180 engaged with the timing pulleys 176 and 178. For
clarity,
the timing belt is not shown in Figs. 4 but is shown in Fig. 5. Also included
in
the link crank assembly 168 is a link crank actuator 182. One end of the crank-
extension 72 is rigidly attached to the main crank 68. The other end of the
crank-extension 72 is rigidly attached to the rear driven timing-pulley shaft
174
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CA 02758142 2011-11-10
and the pulley 178. Also, the rear driven timing-pulley shaft 174 is
rotationally
attached to the rearward end of the control link assembly 170. The forward end
of the control link assembly 170 is rotationally attached to the forward
driven
timing-pulley shaft 172 and pulley 176. The two timing-pulleys 176 and 178 are
connected to each other via the timing-belt 180. The forward driven timing-
pulley shaft 172 is pivotally attached to the link crank 168, but held in a
fixed
position by the link crank actuator 182 when the actuator 182 is stationary;
the
link crank 168 operates as if it were rigidly attached to the forward driven
timing-
pulley shaft 172. The other end of the link crank 168 is pivotally attached to
the
pedal lever 50 at the pivot axle 169. As an alternative to directly connecting
the
a link crank mechanism 168 directly to the pedal lever 50, a method of
attachment to reduce the effects of misalignment can be used such as a
compliant mounting assembly 183 as shown in Fig. 18. In this case, the
compliant mounting assembly 183 includes a number of resilient components
indicated at 185 secured between a pair of support plates 187 that absorb and
compensate for any misalignment between the main crank 68 and the pedal
lever 50. In this particular embodiment of the elliptical step apparatus 10
shown
in Figs. 4 and 5, the main crank 68 via a revolute joint on a linear slot
supports
the rearward end of the pedal lever 50. Here, this is in the form of a roller
&
track interface indicated generally at 184. When the apparatus 10 is put in
motion, there is relative rotation between the crank extension/rearward timing-
pulley 178 and the control link 170. This timing-pulley rotation drives the
forward
driven timing-pulley 176 via the timing-belt 180. Since the forward driven
timing-
pulley 176 is rigidly attached to one end of the link crank 168, the link
crank 168
rotates relative to the pedal lever 50. Because the control link 170 is a
rigid
body, the rotation of the link crank 168 moves the pedal lever 50 in a
prescribed
motion on its support system 184. In order to facilitate installation, removal
and
tension adjustment of the belt 180 on the pulleys 176 and 178, the control
link
170 includes an adjustment device such as a turnbuckle 186 that can be used to
selectively shorten or lengthen the distance between the pulleys 176 and 178.
In this mechanism 166, there exists a relative angle indicated by an arrow
188 shown in Fig. 4 between the link crank 202 and the crank extension 70.
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This relative angle 188 is referred to as the LC-CE phase angle. When the link
crank actuator 182 is stationary, the LC-CE phase angle 188 remains constant,
even if the machine 10 is in motion. When the actuator 182 is activated, the
LC-
CE phase angle 188 changes independent of the motion of the machine 10.
Varying the LC-CE phase angle 188 effects a change in the motion of the pedals
10, in this case, changing the stride length.
In the embodiment, shown in Fig. 5, the link crank actuator 182 includes a
gear-motor, preferably an integrated motor and gearbox 190, a worm shaft 192,
and a worm gear 194. Because the link crank actuator 190 rotates about an axis
relative to the pedal lever 50, a conventional slip-ring type device 196 is
preferably used to supply electrical power, from for example the power control
board 94 shown in Fig. 2, across this rotary interface to the DC motor of the
gear-motor 190. When power is applied to the gear-motor 190, the worm shaft
192 and the worm gear 194 rotate. The rotating worm shaft 192 rotates the
worm gear 194, which is rigidly connected to the driven timing pulley 176. In
addition, the worm gear 194 and the forward pulley 176 rotate relative to the
link
crank 168 to effect the LC-CE Phase Angle 188 change between the crank
extension 72 and the link crank 168. A reverse phase angle change occurs
when the motor 190 is reversed causing a reverse stride change, that is, a
decrease in stride length. In this embodiment, less than half of the 360
degrees
of the possible phase angle relationship between the link crank 168 and the
crank extension 72 is used. In some mechanisms using more or the full range of
possible phase angles may provide different and desirable ellipse shapes.
Another embodiment of the stride adjustment mechanism 166', shown in
Fig. 6 and 7 of the invention takes similar advantage of the relative rotation
between the crank extension 72 and a control link assembly 170' of the stride
adjustment mechanism 166' as the user moves the pedals 12. In this
embodiment, the stride adjustment mechanism 166' includes the control link
assembly 170', the link crank assembly 168' and the crank extension 72'. The
control link assembly 170' includes a set of four toothed timing pulleys 198,
200,
202, 204, a pair of back-side idler pulleys, 206 and 208, and a toothed timing-
belt 210 engaged with the all six pulleys. All of the pulleys are rotationally
CA 02758142 2011-11-10
attached to the control link plate 212. The back-side idler pulleys, 206 and
208,
are rigidly connected to each other through a slot 214 in the control link
plate
212, as shown in Fig. 7 which is a backside view of the control link assembly
170' of Fig. 6. Being rigidly connected, the back-side idler pulleys 206 and
208
can move as a pair along the slot 214. Also included in the control link
assembly
170' is a linear actuator 216. One end of the crank-extension 72 is rigidly
attached to the main crank 68. The other end of the crank-extension 72 is
rigidly attached to the rear timing-pulley 204. Also, the rear timing-pulley
204 is
rotationally attached to the rearward end of the control link assembly 170'.
The
forward end of the control link assembly 170' is rotationally attached to the
forward timing-pulley 200. The forward timing-pulley 200 is pivotally attached
to
the link crank 168', but held in a fixed position by the linear actuator 216
when
the actuator 216 is stationary. In this case, the link crank 168' operates as
if it
were rigidly attached to the forward timing-pulley 200. The other end of the
link
crank 168' is pivotally attached to the pedal lever. When the apparatus 10 is
put
in motion, there is relative rotation between the crank extension 72' rearward
timing-pulley 204 and the control link 170'. This timing-pulley rotation
drives the
forward driven timing-pulley 200 via the timing-belt 210. Since the forward
driven timing-pulley 200 is rigidly attached to one end of the link crank
168', the
link crank 168' rotates relative to the pedal lever 50. Because the control
link
170' is a rigid body, the rotation of the link crank 168' moves the pedal
lever 50 in
a prescribed motion on its support system.
The schematics of Figs. 8A-D, 9A-D and 10A-D illustrate the effect of the
phase angle change between the crank extension 72 and the link crank 168 for a
180 degree, a 60 degree and a 0 degree phase relationship respectively. Also,
Figs. 8A, 9A, and 10A display the crank at 180 degree position; Figs. 8B, 9B,
and 10B show the crank at 225 degree position; Figs. 8C, 9C, and 10C show the
crank at a 0 degree position; and Figs. 8D, 9D, and 10D show the crank at a 90
degree position. In Figs. 8A-D the elliptical path 218 represents the path of
the
pedal 12 for the longest stride; in Figs. 9A-D the elliptical path 218'
represents
the path of the pedal 12 for an intermediate stride; and in Figs. 10A-D the
elliptical path 218" represents the path of the pedal 12 for the shortest
stride.
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In certain circumstances, characteristics of stride adjustment mechanisms
of the type 166 and 166' can result in some undesirable effects. Therefore, it
might be desirable to implement various modifications to reduce the effects of
these phenomena. For example, when the stride adjustment mechanism 166 is
adjusted to the maximum stroke/stride setting, the LC-CE Phase Angle is 180
degrees. At this 180-degree LC-CE Phase Angle setting, the components of the
stride adjustment mechanism 166 will pass through a collinear or toggle
condition. This collinear condition occurs at or near the maximum forward
excursion of the pedal lever 50, which is at or near a maximum acceleration
magnitude of the pedal lever 50. At slow pedal speeds, the horizontal
acceleration forces are relatively low. As pedal lever speeds increase,
effects of
the condition increase in magnitude proportional to the change in speed.
Eventually, this condition can produces soft jerk instead of a smooth
transition
from forward motion to rearward motion. To overcome this potential problem
several approaches can be taken including: limit the maximum LC-CE phase
angle 188 to less than 180 degrees, for example, restrict stride range to 95%
of
mechanical maximum; change the prescribed path shape 218 of the foot pedal
12; or reduce the mass of the moving components in the stride adjustment
mechanism 166 and the pedal levers 50 to reduce the acceleration forces.
Another problem can occur when the stride adjustment mechanism 166 is
in motion and where the tension side of the timing-belt 180 alternates between
the top portion and the lower portion. This can be described as the tension in
the belt 180 changing cyclically during the motion of the mechanism 166. At
slow speeds, the effect of the cyclic belt tension magnitude is relatively
low. At
higher speeds, this condition can produce a soft bump perception in the motion
of the machine 10 as the belt 180 quickly tenses and quickly relaxes
cyclically.
Approaches to dealing with this belt tension problem can include: increase the
timing-belt tension using for example the turnbuckle 186 until the bump
perception is dampened; increase the stiffness of the belt 180; increase the
bending stiffness of the control link assembly 170; and install an active
tensioner
device for the belt 180.
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A further problem can occur when the stride adjustment mechanism 166
is in motion where a vertical force acts on the pedal lever 50. The magnitude
of
this force changes cyclically during the motion of the mechanism 10. At long
strides and relatively high pedal speeds, this force can be sufficient to
cause the
pedal lever 50 to momentarily lift off its rearward support roller 70. This
potential
problem can be addressed in a number of ways including: install a restrained
rearward support such as a linear bearing and shaft system, linear guides rail
system 220, as shown in Fig. 11, roller-trammel system 184, as shown in Fig.
4;
limit the maximum LC-CE phase angle 188 to less than 180 degrees; restrict
stride range to 95% of mechanical maximum; and reduce the mass of the
moving components in the stride adjustment mechanism and the pedal levers.
A third embodiment to modify stride length, as illustrated in Fig. 12, is a
pedal actuation assembly 222. In this case, an extension arm 224 extends
directly from a crank 68'. Because the extension arm 224 extends to and
beyond the pivot axle 40, it is possible to move a pivotal connection point
226 of
the stroke link 228 along the extension arm 224, by a mechanism or actuator
depicted at 230 in a slot 232, and along the crank 68' to the pivot axle 40.
When
the connection point 226 is aligned with the pivot axle 40 the pedal lever 50
will
not move in a longitudinal direction thus resulting in a purely vertical
movement
of the foot pedal 12. If the pivot point 226 is moved past the axle 40, the
foot
pedal 12 moves in a longitudinal direction opposite of the arm handles 80
shown
in Fig. 1. As a result, the pedal actuation assembly 222 provides added
flexibility
to an elliptical step apparatus. An alternate method of providing a stride
adjustment capability in the pedal actuation assembly 222 is to fit an
actuator
233 to the stroke link 228. The actuator 233 can adjust the length of the
stroke
link 228, thus changing the distance between a fixed point on the pedal lever
50
and the crank 68' which would change the stride length of the elliptical path
218.
Fig. 13 illustrates another elliptical step apparatus 10' having a modified
pedal actuation assembly 222'. Included in the pedal actuation assembly 222'
is
a first link 234 pivotally connected to the pedal lever 50 at a pivot point
235 and
to a crank 68' at a pivot point 236. A second link 238 is pivotally connected
at
one end to the frame 14' at a pivot 240 and at its other end to the first link
234 at
28
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a pivot point 242. A detailed description of the operation of this type of
actuation
assembly 222' is provided in U.S. Patent No. 5,895,339. Stride adjustment is
provided by a mechanism such as an actuator 244 fitted on the first link 234.
By
adjusting the mechanism 244 to increase the length of the first link 234, the
length of the horizontal movement of the pedals 12 can be increased.
In addition to manually operable mechanisms such as a pin and hole
arrangement, there are a number of electorally operated actuators can be used
for the actuators 230, 233 and 244. Figs. 14-16 provide additional examples of
such actuators.
Fig. 14 is a schematic view of a first actuator 246 that can be mounted for
example on the extension arm 224 or the crank 68' of the pedal actuation
assembly 222 of Fig. 12. In this actuator 246, a hydraulic fluid indicated at
248
contained in a cylinder 250 flows through a line 252 to control the position
of a
piston 254 in the piston cylinder 256 which in turn is connected to the
extension
arm 224 or the crank 68' by a piston rod 256. Flow of the fluid 248 is
regulated
by a valve 258. In the preferred embodiment of this actuator 246, the valve is
opened when the extension arm 224 or the crank 68' is under tension and closed
when they are under compression. This will serve to lengthen the extension arm
224 or the crank 68' thereby increasing stride length. Reducing the length of
the
extension arm 224 or the crank 68' is accomplished by reversing the process.
It
should be noted that variations on this actuator 246 can be used such as
replacing the hydraulic fluid 248 with a pheonetic magnetic fluid where the
fluid is
controlled by a flow channel in the piston 254. One advantage of this actuator
246 is that it does not require a source of outside energy to move the piston
254
but only enough energy to operate the valve 258. This type of actuator can be
especially useful in self powered apparatus where power is only obtained from
the alternator 42 when a user is moving the pedals 12.
Fig. 15 is a schematic view of a second actuator 260 mounted for
example on the extension arm 224 or the crank 68' of the pedal actuation
assembly 222. In this embodiment, a spring 262 is attached to extension arm
224 and to the end the crank 68'. To increase stride length, a switch or latch
(not shown) is opened and the point of attachment of the extension arm 224 on
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the crank 68' moves outwardly due to centrifugal force as the pulley 38
rotates.
To decrease stride length, the switch is opened when pulley 38 is not rotating
or
rotating very slowly and the spring will retract the extension arm 224 towards
the
pivot axle 40. As with the actuator 246, this actuator 260 can be used on a
self
powered machine.
Fig. 16 is a schematic view of a third actuator 264 that can be used for
example on the pedal actuation assembly 222. In this embodiment a pair of
extension links 266 are pivotally connected to the extension arm 224 and the
crank 68'. A magnetic fluid control disk 268 controls the separation of the
extension links 266 and therefore the connection point 232 of the extension
arm
224 on the crank 68'. As with the actuators 246, centrifugal force will move
the
extension arm 224 outwardly along the crank 68' when the pulley 38 rotates on
the axle 40 and the fluid disk 268 will then hold the extension links 266 and
hence the extension arm 224 in place. Stride length can then be shortened
when the pulley 38 is stopped and the fluid disk 268 permits a spring 270 to
move the extension links 266 toward each other. As with the actuators 246 and
260, this actuator 264 can be used on a self powered machine.
Adjustable Stride Length Control
With reference to the control system 88 shown in Fig. 2, a mechanism is
described whereby stride length can be controlled by the user or automatically
modified in an elliptical step apparatus where stride length can be adjusted
such
as the type of machine 10 shown in Fig.1. In one aspect of the invention
stride
length is adjusted to take into account the characteristics of the user or the
exercise being performed. In the preferred embodiment of the invention, the
control system 88 and the console 90 of Fig. 3 can be used to control stride
length in the elliptical step exercise apparatus 10 either manually or as a
function
of a user or operating parameter. In Fig.1 an attachment assembly generally
represented within a dashed line 34 can be implemented by a number of
mechanisms that provide for stride adjustment such as the stride adjustment
mechanism 166 described above. It should also be noted that this aspect of the
invention can be implemented using various other stride adjustment mechanisms
CA 02758142 2011-11-10
such as those shown in Figs. 12-16. As depicted in Fig. 2, a line 154 connects
the microprocessor 92 to the attachment assembly 34 which in the case of the
stride adjustment mechanism 166 would be the DC motor 190 as shown in Fig.
5. Stride length can then be varied by the user via a manual stride length key
156 which is connected to the microprocessor 92 via the data input center 104.
Alternatively, the user can have stride length automatically varied by using a
stride length auto key that is also connected to the microprocessor 92 via the
data input center 104. In one embodiment, the microprocessor is programed to
respond to the speed signal on line 102 to increase the stride length as the
speed of the pedals 12 increases. Pedal direction, as indicated by the speed
signal can also be used to vary stride length. For example, if the
microprocessor
92 determines that the user is stepping backward on the pedals 12, the stride
length can be reduced since an individuals stride is usually shorter when
stepping backward. Additionally, the microprocessor 92 can be programmed to
vary stride length a function of other parameters such as resistive force
generated by the alternator 42; heart rate measured by the senors 140 and
140';
and user data such as weight and height entered into the console 90.
Another important aspect of the adjustable stride length control is a
feedback mechanism to provide the processor 92 with information regarding the
stride length of the apparatus 10. The measurement of stride length on an
elliptical step apparatus can be important for a number of reasons including
insuring that both pedal mechanisms have the same stride length. In the
context
of the apparatus 10 shown in Fig. 1 stride length information can be
transmitted
over the line 154 from the attachment assembly 34 to the processor 92.
There are a number of methods of acquiring stride length information the
utility of which can be dependent on the particular mechanical arrangement of
the elliptical step apparatus including the mechanism for adjusting stride
length.
The preferred method for obtaining this information from an apparatus
employing
the stride adjustment mechanism 166 involves the use of the link crank angle
188 as shown in Fig. 4. Referring to Fig. 1 and 8A, the angular relation
between
the crank extension 72 and each of the link cranks 168 is proportional to the
stride length. A sensor system such as reed switches and magnets can be
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CA 02758142 2011-11-10
mounted to each of the cranks 68 and feedback from each, along with the speed
signal on the line 98 from the alternator 42, can be used by the processor 92
to
calculate stride length of each pedal 12. The link crank 168 and crank
extension
72 rotate with the same angular velocity because they are mechanically linked,
but they can trigger their respective reed switches and magnets at different
times
depending on the link crank angle 188. For every revolution of the alternator
42,
there are a set number of AC taps. The number of AC taps between the link
crank 168 and the crank extension 72 triggering their respective reed switches
and magnets can be made into a theoretical chart deriving link crank angle 188
and stride length.
With reference to Fig. 11, a second method involves using a linear
encoder 272. This method uses the relative motion between the pedal lever 50
and a linear guide assembly 220 that replaces the roller 70 shown in Fig. 4.
The
linear guide 220 supports the pedal lever 50 during its travel. The distance
that
the linear guide 220 travels along the pedal lever 50 can be related to the
stride
length. The encoder 272 would reside on the pedal lever 50 and the movable
mechanism for the encoder will be connected to the linear guide assembly 220.
A sensor system can be placed on the pedal lever 50 and used as an index
position. Then, for example, if 3 index pulses are generated, the crank 68
will
have traveled one complete revolution. The distance traveled by the linear
guide
220 can then be determined by adding the encoder pulses seen for every 3
index pulses and looking this up in a table that would be created. In this
manner
the stride length feedback signal can be provided to the processor 92.
Fig. 17 A-C provides an illustration of a third method of determining stride
length. This method measures the maximum and minimum angle between the
rocker arms 32 and 32' and pedal levers 50 and 50' respectively for various
stride lengths. These angles, as shown in Fig. 17A-C can then be used to
determine the stride length of the pedal 12 from this angular information.
Commercially available shaft angle encoders can be mounted at the pivot points
between the pedal levers 50 and 50' and the rocker arms 32 and 32'.
A fourth method of determining stride length can make use of the speed
of the pedal lever 50. This method measures the speed of the pedal 12 using
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the tachometer signal on the line 98 through fastest point of travel on the
elliptical path 218 which changes with stride length. The pedal speed at the
bottom most point of travel on the ellipse will increase as stride length
increases.
For example, the speed of the pedal 12 can be measured by placing 2 magnets
on the pedal 12 twelve inches apart such that the two magnets will cross a
certain point in space close to the bottom most point of pedal travel. A
sensor
can then be placed at that point in space (in the middle of the unit) such
that
each magnet will trigger the sensor. The number of AC Tap pulses on line 98
for
example received between the two sensor activation signals can be measured
and thus the stride length calculated. A Hall effect sensor can be used as the
sensor.
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