United States Patent 3747924

Leg exercising device for improving a person's balance having two pedals for accepting the feet, each pedal being hinged on a four-bar mechanism. The pedals are interconnected by a cable passing over a pulley combination so that, by transferring weight from one pedal to the other the pedals oscillate in a vertical plane in 180° out-of-phase relationship, the pedals remaining horizontal throughout oscillation. Change in length of the cable changes the amplitude of oscillation.

Application Number:
Publication Date:
Filing Date:
Primary Class:
International Classes:
A63B23/04; A63B23/035; (IPC1-7): A63B23/04
Field of Search:
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US Patent References:
3316898Rehabilitation and exercise apparatus1967-05-02Brown
3112108Exercising apparatus with crankshaft operable selectively by foot pedals or hand levers1963-11-26Hanke
2832595Portable exercising device1958-04-29Hastings
2453771Exerciser1948-11-16White et al.
1909190Exercising apparatus1933-05-16Sachs

Primary Examiner:
Pinkham, Richard C.
Assistant Examiner:
Kramer, Arnold W.
I claim

1. An exercising device adapted primarily for use by a person for leg exercise and balance improvement, the device having a base having a longitudinal axis, right and left pedals to accept right and left feet of the person exercising, each pedal being supported above and coupled to the base through a hinge means including:

2. An exercising device as claimed in claim 1 in which:

3. An exercising device as claimed in claim 1 in which:

4. An exercising device as claimed in claim 3 in which:

5. An exercising device as claimed in claim 1 in which:

6. An exercising device as defined in claim 5 including:

7. An exercising device as defined in claim 6 in which the length adjustment means includes:

8. An exercising device as claimed in claim 1, in which the hinge means has:


1. Field of the Invention

The invention relates to an exercising device particularly adapted for, but not limited to, exercising legs and improving balance of players of ball games.

2. Prior Art

Many types of exercising devices are available, some of these being used to strengthen particular muscles by permitting the muscles to work against a controllable force. Rehabilitation exercisers, such as those described in U.S. Pat. Nos. 3,316,898, issued to J.W. Brown in 1967, and 2,892,455 issued to L.L. Hutton in 1959, include devices having pedals to carry feet of a person exercising, the pedals being powered by an electric motor for oscillation through a particular motion between fixed limits. These are ingenious and effective devices, however, they are not easily portable, are relatively expensive, and limits of movement are not easily adjustable to persons of different sizes.


The invention reduces difficulties and disadvantages of prior art exercisers known to the present inventor, by providing an exercising device, operable by the person to be exercised, thus not requiring external power, and having limits of pedal travel that are easily adjustable for persons of different sizes. The device is relatively compact, portable and inexpensive, and is intended primarily for improving balance and leg co-ordination.

One embodiment of the invention includes a flat horizontal base and a pair of pedals, each pedal being supported by, and forming, one link of a four-bar mechanism. The mechanisms are inter-connected by a cable running over pulleys. The pedals are restricted to swing in a vertical plane, in limited arcs about the base, remaining parallel to the base and oscillating in a 180° out-of-phase relationship.

A detailed description following, related to drawings, gives exemplification of apparatus according to the invention which, however, is capable of expression in structure other than that particularly described and illustrated.


FIG. 1 is a simplified fragmented side elevation of an exercising device according to the invention,

FIG. 2 is a simplified plan of the exercising device, one pedal being removed,

FIG. 3 is a perspective of the device.


Figs. 1 and 2

An exercising device 10 according to the invention has a horizontal base 11 having a central longitudinal axis 12. The base has a vertical frame 13 at a forward end, the frame being supported by inclined braces 14, 15, and 16 extending from longitudinal stiffeners 17, 18 and 19, respectively. The vertical frame 13 has transverse members 20 and 20.1 to provide support for a plurality of pulleys, described with reference to FIG. 3.

Left and right pedals 21 and 22 accept left and right feet 23 and 24, shown in broken outline, of a person using the device. The pedals are supported above and coupled to the base 11 by left and right four-bar mechanisms 26 and 27.

The left mechanism 26 is described as follows. The left pedal 21 has on a lower face a forward pedal hinge 31 on a pedal axis 32, and spaced rear pedal hinges 33 and 34 straddling the pedal axis, the pedal hinges being secured to lower face of the pedal. A forward link 36 is hinged at an upper end of the forward hinge 31, and is hinged at a lower end on a forward base hinge 37 secured to the base 11. Spaced parallel rear links 39 and 40 are hinged at upper ends to the rear hinge 33 and 34, and are hinged at lower ends to rear base hinges 42 and 43 respectively, the rear links appearing partially to straddle the forward link when viewed from above as seen in FIG. 2. The base hinges are secured to an upper face of the base. The forward and rear hinges at opposite ends of the links are pin joints providing sufficient articulation to permit swinging of the links through arcs of about 30°.

The forward and rear links 36, 39, and 40 have equal lengths, and horizontal spacing between pins of the forward and rear hinges of the pedal and forward and rear hinges on the base are also equal, thus forming a closed four-bar mechanism having opposite sides or links of equal length -- i.e., arranged as a parallelogram. The four-bar mechanism serves as a hinge means for the pedal, a portion of the pedal between the pedal hinges forming one link, and a portion of the base between the base hinges forming an opposite link. When the pedal 21 swings about the base it describes an arc about the forward and rear hinges on the base, the pedal 21 being maintained parallel to the base. Loci of hinge pins of the hinges 31, 33 and 34 are shown as broken lines 46 and 47 (FIG. 1 only). A cable 48 (broken line) secured to the pedals has upper and lower portions 50 and 49, and passes around a roller means 51 (broken outline) on the frame 13, the cable 48 serving as a flexible tension link coupling the pedals together (see FIG. 3).

The right four-bar mechanism is also as above.

Figs. 2 and 3

The roller means 51 has four pulleys, disposed so as to turn the cable 48 through 180° in a horizontal plane and about 30° in a vertical plane without derailing the roller means. With reference to FIG. 3, a first upper pulley 52 has a horizontal axis disposed perpendicularly to the axis 12 of the base, and is spaced above a first lower pulley 53 having a horizontal axle parallel with the axis 12. Thus the upper pulley is journalled for rotation in a plane perpendicular to the base and containing the lower portion 49 of the cable, and the lower pulley is journalled for rotation in a plane perpendicular to the base and perpendicular to the plane of the upper pulley. As seen in FIG. 2, the pulley 52 is aligned with the lower portion 49 of the cable 48, one portion of the cable passing over the pulley.

Peripheries of the upper and lower pulleys are aligned thus permitting a taut cable to extend between the pulleys, such alignment hereinafter being referred to as peripheral alignment.

A similar pair of second upper and lower pulleys 55 and 56 are mounted on the frame 13, the pulley 55 being aligned with the upper portion 50 of the cable 48 extending from the pedal 21. All four pulleys are mounted on undesignated brackets. One end 59 of the cable 48 is secured to the pedal 21 and passes over the upper pulley 55, downwards and around the lower pulley 56, then extends parallel to the frame 13 to the pulley 53 and upwards to the pulley 52 as shown in FIG. 3. An opposite end 62 of the cable 48 is secured to a turnbuckle 63 which is hinged to the pedal 22.

Coupling of the platforms by the cable 48 results in simultaneous oscillation of the pedals about the limited arcs, movement being 180° out of phase, the pedals moving in opposite directions. The turnbuckle 63 is used to change effective length of the coupling cable, adjustment of the turnbuckle changes amplitude of motion of the pedals, which amplitude is between two limits of travel. A lower limit of travel of a particular pedal is governed by contact of the pedal with the base 11, and an upper limit, when the pedal is weighted, is set by length of the cable and relative position of the roller means 51. Within limits set mainly by the base and the relative positions of the pulleys 52 and 55, when the cable 48 is shortened, the amplitude of oscillation of each pedal is increased. This permits the device to be easily adjusted for use by persons of different sizes.

Best results have been attained when the upper pulleys 52 and 55 are in a position about half way between a maximum upper limit of the pedal stroke and the base, which serves as a lower limit of the pedal stroke. This results in the pedals describing arcs, disposed essentially equally above and below a horizontal plane (not shown) passing through the axles of the upper pulleys.


The base 11 is placed on level ground and the person using the device faces the frame 13 and stands with one foot, for example his right foot 24, on the pedal 22 which is resting on the base. The left foot 23 is then lifted and placed on the left pedal 21 which is at an upper limit on its stroke. The person's weight is then transferred from the right foot to the left foot and the left pedal then descends, causing the right pedal simultaneously to rise in the out-of-phase relationship described. The left pedal contacts the base at the end of its downward stroke, simultaneously the right pedal reaching an upper limit of its stroke. The above procedure is reversed by transferring the weight back onto the right foot, which causes the right pedal to descend to the base again. Thus, by transferring weight alternately from one pedal to the next, the pedals oscillate over the limited arcs and the person exercising maintains balance. In this manner, the person practices a technique of maintaining balance when positions of the feet oscillate -- speed of oscillation being controlled by the person exercising.


The roller means 51 as described and illustrated has four pulleys 52, 53, 55, 56, disposed so as to permit the cable extending between the pedals to be turned through 180° in a horizontal plane and a limited angle of about 30° in a vertical plane in order to accommodate 180° out-of-phase oscillations of the pedals as described. Other roller means adapted to attain the same result are known.

Other means to change lengths of cable are known, such as an eye screw provided with a swivel to reduce twisting of the cable. The cable can be secured to the links instead of the pedals, and, if desired, semi-permanent cable securing means such as cable clamps can be used.