[0001] The present invention relates to a machine that can be used to exercise the lower
body and more particularly to a machine that can be used as a walking or training
aid or coaching aid.
[0002] At present, exercise machines for running or walking are normally in the form of
a treadmill, which simply provides a moving pavement to avoid the user having to change
location, or is a crank based system where foot supports or pedals are attached, at
least at one end, to a crank to provide circular or elliptical movement, for example
as in a Cross Trainer, or to provide a vertical displacement in Stepper machines.
[0003] A problem with the treadmill is that it only permits the user to adopt their normal
style of running or walking. The other machines in contrast dictate the path the user's
foot is to follow but this is predetermined by the mechanical arrangement of the machine
and the predetermined path that the pedals or foot supports take by being fixed to
the machine in a set manner, which is not normally changeable. These machines thus
permit strength and stamina to be increased but do not provide a machine which can
be used to train a person in a particular running or walking technique or style, for
as example as may be desirable as a professional race training aid, or as a walking
aid for people who do not have, or who have lost, the ability to walk normally.
[0004] It is an object of the present invention to provide a machine for exercising (which
term for the purposes of this specification includes training the lower body) and
which can be used to teach a person running and/or walking techniques.
[0005] According to the present invention there is provided a machine for exercising the
lower body, the machine comprising two foot supports arranged to respectively support
the left foot and right foot of a user; two cranks connected to respective foot supports;
two spindles connected to respective cranks; two mountings for the respective spindles;
mounting supports on which the mountings may move independently of each other in a
substantially linear direction; a frame for retaining the mounting supports in a fixed
position; a plurality of motors coupled to the foot supports; and a controller for
the motors, wherein the position of the foot supports are mechanically independent
of each other and the controller and motors can control the position of the foot supports
independently of each other, and wherein the linear position of the mountings and
the angular orientation of the cranks can be controlled so that the foot supports
may each have an elliptical motion.
[0006] The motors may be self contained electrical motors or could be actuators driven by
hydraulic fluid or other means, provided they can be independently controlled. The
motors, if electrical, can be servo or stepper motors so that their position can be
precisely controlled.
[0007] The present invention, in providing foot supports which are independent of each other,
can enable the foot supports to more accurately imitate the true movement of the feet
during normal running and walking. For example the feet of an individual do not necessarily
move at the same speed throughout the stride pattern and are not always diagonally
opposed to each other. This is particularly the case for example where a runner is
sprinting. A machine in accordance with the present invention therefore eliminates
the traditional mechanical linkage between the left and right feet, which most training
machines or exercise machines with foot supports employ. It also avoids impact associated
with treadmills and may also provide a non exertive exercise, which may be desirable
for central applications such as rehabilitation after injury.
[0008] The mounting supports may be in the form of shafts on which the respective mountings
can slide.
[0009] The provision of mounting supports on which the mountings may slide permits the spindles
supporting the cranks to move backwards and forwards and therefore permits the foot
rests to the prescribe an elliptical pattern. If the machine further comprises two
con rods each mechanically coupled to a respective spindle and the frame, so that
rotation of each spindle in one direction causes the respective mounting to move back
and forth in a substantially liner direction on an associated mounting support, then
the respective foot support will describe an elliptical pattern depending on the length
of the crank and the length of the con rod and where this is connected. The con rod
could be connected to the spindle via the crank to which the foot support is attached,
but may be attached to a separate crank attached to the spindle, either directly or
indirectly.
[0010] Advantageously, each spindle is driven by an associated motor. Thus, the associated
motor can be controlled so that the angular displacement between the spindles supporting
respective cranks and thus the angular position of the respective foot supports can
be varied throughout a cycle, or throughout an exercise program.
[0011] It is particularly advantageous if the distance between the spindle and the foot
support may be varied, since the foot support may then not only describe an elliptical
pattern but that elliptical pattern may be varied to imitate the actual path a person's
foot travels during natural walking or running. This may be achieved by arranging
each crank so that it is extendable and is in turn controlled by an associated motor,
such that the distance between the spindle and the foot support may be varied by being
able to control the distance between the spindle and the respective foot support.
In an alternative this may be achieved by fixing the length of each crank and controlling
the position of each foot support along the respective crank by an associated motor
such that the distance between the spindle and the foot support may be varied.
[0012] Preferably, the machine comprises sensors which permit the controller to detect the
natural movement of the feet of a user and to control the motors to control the position
of the foot supports to mimic this natural movement. The sensors may be in the form
of position, pressure, torque or load sensors and may use loading on the respective
motors to provide feedback about the pressures and torque asserted by the user, which
can then be used to calculate the user's natural movement and set the machine to mimic
this natural movement. The controller may be a programmable computer, (which term
includes for the purpose of this specification a micro processor), and preferably
is arranged to be programmed to control the position of the foot supports to perform
a desired running style. This may either be a programmed running style, generated
by a computer, or it may be a running style learnt from a model runner whose style
the user wishes to adopt. In this way, for example, a professional athletes style
can be pre-programmed into the machine and learnt by a runner wishing to adopt such
a style. Preferably, the computer can be programmed to sequentially change the style
whilst in use to imitate different styles adopted by a user during different stages
of a race or exercise program.
[0013] A program loaded into the machine may be created by using sensors mounted on a runner's
feet whilst running a particular route, for example a cross country course, the program
enabling the machine to subsequently replicate the course controlling the foot supports
to reflect the actual steps taken on the route and altering the resistance to reflect
variations in altitude.
[0014] Preferably, the frame of the machine supports side by side two mounting supports
each associated with a respective foot support, wherein the foot supports are mounted
in board of the mounting supports. This enables the foot supports to be very close
together and therefore a runner to adopt to a natural running position where the feet,
or foot and adjacent calf, are sometimes separated by less than a few centimetres.
[0015] Preferably, the transverse spacing in between the foot supports may be changed to
that desired by a particular user.
[0016] The machine may comprise a saddle arranged to support a person using the machine
or a harness arranged to support a person using the machine. This may permit a user
to become familiar with the machine while being supported so that the user does not
have to rely on the foot supports to support themselves. Gradually the dependence
on support from the saddle or harness may be reduced. A harness and/or saddle may
also be particularly suitable for supporting a person during rehabilitation where
their muscles are not able to support their full body weight.
[0017] - Preferably, the machine may comprise handles mechanically coupled to the position
of the foot supports and arranged to control the position of a user's hands in dependence
thereon. This enables the upper body to be synchronised to the actions of the lower
body and thus assist in training the upper body also.
[0018] There may be provided a counterbalance means comprising at least one mass associated
with each mounting and arranged to travel in a substantially linear direction in opposition
to the corresponding mounting. This enables smooth operation and will act to minimise
any unwanted vibrations during use.
[0019] The present invention will now be described by way of example only, with reference
to the accompanying figures, of which:
Figure 1 is a front view of a machine in accordance with a first embodiment of the
present invention;
Figure 2 is a partially cutaway side view of the machine of Figure 1 shown in use;
Figure 3 illustrates the components of the machine of Figures 1 and 2;
Figure 4 is a cross-section through the mounting and associated components of the
machine in accordance with the present invention;
Figure 5 is a perspective view of an alternative machine according to a second embodiment
of the present invention;
Figure 6 is a perspective view of the mounting of the machine of Figure 5;
Figure 7 is a rear view of the mounting of Figure 6; and
Figures 8 to 13 schematically illustrate the operation of the machine of Figures 1
to 4.
[0020] Referring to Figures 1 and 2, a machine, indicated generally as 1, for exercising
the lower body, comprises a frame 2 to which are attached mounting support shafts
3 to 6. The mounting support shafts 3 to 6 are arranged in pairs, the shafts of each
pair being arranged parallel to and vertically spaced from each other. Each pair 3,
4 and 5, 6 supporting a respective mounting 7,8.
[0021] The mountings 7 and 8 can each independently slide horizontally along the respective
pairs of support shafts 3, 4 and 5, 6 respectively.
[0022] As shown in Figure 1, mountings 7 and 8 are located on the left and right sides of
the frame respectively and are the same except insofar as the left-hand mounting and
associated components are a mirror image of the right-hand mounting and associated
components.
[0023] For clarity only the right-hand mounting 7 is described below with reference to Figures
3, 4 and 8 to13. However the left-hand mounting and associated components functions
in the same manner.
[0024] The mounting 7 is arranged to slide backwards and forwards on shafts 3 and 4 and
has a bearing 9 supporting a spindle 10 (see figure 4). On a first end of the spindle
10 is mounted a crank 11, the opposite end of which is attached to a first end of
con rod 12. The second end of the con rod 12 is anchored to a rear section of the
frame 2. Between the first end of the spindle 10 and the mounting 7 is a sprocket
locked to the spindle 10, which sprocket is driven by electric motor 14 within mounting
7, via chain 13.
[0025] To the opposite end of spindle 10 to which crank 11 is attached, there is attached
a second crank 15, to which is pivotally mounted a foot support 16 and associated
retention strap 17 for receiving and supporting a users foot. Crank 15 is extendable
by operation of a screw jack 18 controlled by electric motor 19. The power is supplied
to the electric motor 19 via slip rings 20 and 21 on the spindle 10 and associated
contacts 22 and 23 attached to the mounting 7.
[0026] Motors 14 and 19 on the mounting 7, and corresponding motors (not shown) on the mounting
8 of Figure 1 are connected to and controlled by a computer 24 mounted on the frame
2, as shown in figure 1. A user 25, as shown in Figure 1, can be primarily supported
by foot supports 16 and additionally, depending on the purpose of the exercise to
be performed on the machine, either by a harness 26 attached by wires 27 to the frame
2, shown in Figure 1, or by a saddle 28 mounted on additional longitudinal cross member
29. Alternatively, or in addition thereto, handles 30 may also provide support. These
may be fixed, pivotally mounted by pivots 31 (see Figure 3) or could be mechanically
driven in dependence on the position of foot supports 16. The frame can be adjustable
to adjust the transverse spacing between the foot supports 16.
[0027] Figure 1 shows the machine 1 in a rest position, but in operation respective motors
14 will be controlled by the computer such that cranks 15 are substantially 180° out
of phase. However, the positions of the cranks 15 are mechanically independent of
each other and are controlled solely by signals received by the respective motors
14 from the computer 24.
[0028] Referring to Figures 5 to 7, there is shown a second embodiment, which differs from
the first embodiment primarily in the mechanism for varying the distance between the
spindle and the foot support. For clarity, like features have been provided with the
same numerals as in the first embodiment.
[0029] As with the first embodiment, only the right-hand mounting 7 is described below with
reference to Figures 6 and 7. However, the left-hand mounting and associated components
function in the same manner.
[0030] As with the first embodiment, the mounting 7 is arranged to slide backwards and forwards
on shafts 3 and 4 and has a bearing (not shown) supporting a spindle 10 (see figure
7). For clarity, the shaft supports on the mountings 7, 8 (shown in Figure 5) are
not shown in Figures 6 and 7. Between the first end of the spindle 10 and the mounting
7 is a pulley 33 locked to the spindle 10, which is driven by electric motor 14 within
mounting 7, via belt 34. Crank 11 and con rod 12 are arranged as in the first embodiment.
[0031] It will be readily appreciated by the skilled person that the mountings 7, 8 in both
the first and second embodiments may be arranged to slide back and forth on wheels,
rollers or similar and that the present invention need not be limited to the arrangement
shown. For example, the shafts 3 and 4 may be replaced by one or more runners or tracks
arranged to receive wheels or rollers provided on the mountings 7, 8.
[0032] To the opposite end of spindle 10 to which crank 11 is attached, there is attached
a second crank 15, to which is pivotally mounted a foot support 16 and associated
retention strap (not shown) for receiving and supporting a users foot. Crank 15 is
locked to spindle 10 such that rotation of spindle 10 effects rotation of crank 15.
Crank 15 is of fixed length, however, the position of the foot support 16 along crank
15 may be varied under control of electric motor 19. Drive is transmitted from motor
19 using a belt 35, which is arranged to drive a secondary spindle 36 (Figure 7),
which is of tubular construction and sits over the spindle 10 to rotate independently
of spindle 10. Rotation of spindle 36 effects rotation of an associated belt 37, which
is arranged to raise and lower foot support 16 independently of rotation of crank
15.
[0033] An advantage of the second embodiment is that by mounting the motor 19 on the mounting
7 rather than on the second crank 15, as in the first embodiment, power may be supplied
directly to the electric motor 19, obviating the need for slip rings 20, 21. However,
slip rings 20, 21 and corresponding contacts may be provided in the second embodiment,
as shown, to provide power to sensors or any additional components that require power.
[0034] As with the first embodiment, motors 14 and 19 on the mounting 7, and corresponding
motors on the mounting 8 of Figure 5 are connected to and controlled by a computer
24 (not shown) which is mounted on the frame 2. A user 25, as shown in Figure 1 in
respect of the first embodiment, can be primarily supported by foot supports 16 and
additionally, depending on the purpose of the exercise to be performed on the machine,
either by a harness 26 attached by wires 27 to the frame 2, shown in Figure 1, or
by a saddle 28 mounted on additional longitudinal cross member 29. Alternatively,
or in addition thereto, handles 30 may also provide support. These may be fixed, pivotally
mounted by pivots 31 (see Figure 3) or could be mechanically driven in dependence
on the position of foot supports 16. The frame can be adjustable to adjust the transverse
spacing between the foot supports 16.
[0035] Whilst in the first embodiment chains are shown for transmission of drive from the
motors and in the second embodiment belts are shown, it will be readily appreciated
that any suitable transmission means may be used, including, for example, bevelled
gear drive shafts. Furthermore, the transmission means of the first and second embodiments
may be swapped and/or combined as desired.
[0036] In either or both of the first and second embodiments there may additionally be provided
a counter-balance mechanism (not shown) comprising at least one mass associated with
each mounting and arranged to travel in a substantially linear direction in opposition
to the corresponding mounting. The counter-balance mechanism may be of any standard
construction, as will be readily appreciated by the skilled person.
[0037] Referring now to Figures 8 to 13, there is illustrated schematically the effect of
rotation of spindle 10 on the foot support 16. As the spindle 10 rotates in an anticlockwise
direction, as shown, the foot support 16 attached to crank 15 prescribes an elliptical
path 32, as indicted by arrows 33, due to the action of the associated crank 11 acting
on con rod 12 anchored at point 34 to the frame 2. Furthermore, control of the motor
19 attached to the screw jack 18 controls the length of the crank 15, enabling the
shape of the ellipse 32 to be modified, and the position of the foot support 16 to
be controlled to mimic the actual path of a user's foot during running or walking
or any other desired path. The positions of the foot supports 16 are controlled in
the same manner but independently of each other, enabling the relative positions of
each foot of the user to be controlled as desired and in complete mechanical independence
of each other.
[0038] The computer may incorporate appropriate software such that it can be programmed
to cause the foot supports 16 to take a desired path, or alternatively sensors may
be used on the machine, or feedback obtained from the motors, whereby the motors may
be controlled such that the position of the foot support may be modified by the forces
applied by the user, such that on successive cycles the path of each foot support
may gradually be modified to the natural walking or running style of the user. This
can thus be learnt by the computer and subsequently used to control the motors, enabling
other users to subsequently be forced by the machine to adopt the walking or running
style of an earlier "model" walker or runner. Alternatively, a programme can be downloaded
to the computer from an external source.
[0039] The position of the foot support can be calculated from basic trigonometric principles.
The distance between the fixed end of the con rod 12 and the spindle 10 can be calculated.
Using the fixed length of both the crank 11 (represented by side B) and the con rod
12 (represented by side A) as the two fixed sides of a triangle, then the angle Y
between them for all 360 degrees of rotation can be calculated from
C2 =
A2 +
B2 - (2
AB cos Y)

Knowing length C, then as the crank oscillates along a fixed horizontal rail, formulae
B2 =
C2 -
A2 can be used to calculate the position of the crank, where A is the offset height
of the centreline of the spindle 10.

[0040] With each degree of rotation, the fixed point of the foot support16 moves around
in a circle. As side B and Side A and the included angle c are known, c being the
degree of rotation from the vertical, side C can be calculated from,
C2 =
A2 +
B2 - (2
AB cos c), and angle a can be calculated by SIN a = (A x SIN b) / B

[0041] As both angle a and length C are known this maps the fixed path for the foot support
used to create the cycle and the data called up.
[0042] It will be readily appreciated by the skilled person that the above description in
respect of Figures 8 to 13 is equally applicable to the arrangement of the second
embodiment as described with respect to Figures 5, 6 and 7, wherein in the second
embodiment rather than varying the length of the crank 15 to modify the shape of the
ellipse 32, the distance between the foot support 16 and the spindle 10 is varied
to enable the shape of the ellipse 32 to be modified, and the position of the foot
support 16 to be controlled to mimic the actual path of a user's foot during running
or walking or any other desired path.
[0043] The present invention has been described by way of example only and described primarily
as a training aid for professional runners. However, the machine may find general
application in gyms and may be used for general orthopaedic applications, for example
rehabilitation after an accident or other disability. Also, although specific embodiments
have been described, it will be appreciated that many modifications thereto can be
made without departing from the invention as defined by appended claims.
1. A machine for exercising the lower body, the machine comprising two foot supports
arranged to respectively support the left foot and right foot of a user, two cranks
connected to respective foot supports; two spindles connected to respective cranks;
two mountings for the respective spindles; mounting supports on which the mountings
may move independently of each other in a substantially linear direction; a frame
for retaining the mounting supports in a fixed position; a plurality of motors coupled
to the foot supports; and a controller for the motors, wherein the position of the
foot supports are mechanically independent of each other and the controller and motors
can control the position of the foot supports independently of each other, and wherein
the linear position of the mountings and the angular orientation of the cranks can
be controlled so that the foot supports may each have an elliptical motion.
2. A machine as claimed in claim 1 wherein the mounting supports are in the form of shafts
on which the respective mountings can slide.
3. A machine as claimed in claim 1 or 2 further comprising two con rods each mechanically
coupled to a respective spindle and the frame so that rotation of the each spindle
in one direction causes the respective mounting to move back and forth in a substantially
linear direction on a mounting support.
4. A machine as claimed in claim 3 wherein the con rods are mounted to respective cranks.
5. A machine as claimed in any preceding claim wherein each spindle is driven by an associated
motor.
6. A machine as claimed in any preceding claim wherein each crank is extendable and is
controlled by an associated motor such that the distance between the spindle and the
foot support may be varied.
7. A machine as claimed in any of claims 1 to 5 wherein the length of each crank is fixed
and the position of each foot support along the respective crank is controlled by
an associated motor such that the distance between the spindle and the foot support
may be varied.
8. A machine as claimed in any preceding claim wherein the frame supports side by side
two mounting supports each associated with a respective foot support and wherein the
foot supports are mounted inboard of the mounting supports.
9. A machine as claimed in any preceding claim wherein the transverse spacing between
the foot supports may be changed.
10. A machine as claimed in any preceding claim further comprising a saddle arranged to
support a person using the machine.
11. A machine as claimed in any preceding claim further comprising a harness arranged
to support a person using the machine.
12. A machine as claimed in any preceding claim further comprising handles mechanically
coupled to the position of the foot supports and arranged to control the position
of a users hands in dependence thereon.
13. A machine as claimed in any preceding claim further comprising sensors that permit
the controller to detect the natural movement of the feet of a user and control the
motors to adapt the position of the foot supports to mimic this natural movement.
14. A machine as claimed in any preceding claim wherein the controller is a programmable
computer and can be programmed to control the position of the foot supports to perform
a desired running technique.
15. A machine as claimed in claim 14 wherein the computer can be programmed to sequentially
change while in use the technique to imitate different techniques adopted by a user
during different stages of a race or exercise program.