Apparatus for muscle stimulation

In an apparatus for muscle stimulation with at least one motor and with two motor-operated drives, wherein each of these drives and a stepping plates are mounted in a frame and each of these drives is a revolving linkage square and the driven drive member is in each case a crank mounted in the frame, a crank and a stepping plate are in each case connected in an articulated manner by means of a coupling member providing for an apparatus for muscle stimulation with stepping plates that can be operated both with low and also with high stroke frequencies.

This is a continuation-in-part application of pending international patent application PCT/DE2011/000310 filed Mar. 23, 2011 and claiming the priority of German patent application 10 2910 012 676.4 filed Mar. 21, 2010.

BACKGROUND OF THE INVENTION

The invention relates to an apparatus for muscle stimulation including a motor with two motor-operated drives wherein each of these drives comprises a frame and a stepping plate supported in the frame.

U.S. Pat. No. 3,540,436 A1 discloses such an apparatus. The individual drive is a three-member cam drive with a fully wrap-around cam surface. The manufacture of such a cam however requires special machinery and therefore is expensive to manufacture. In order to prevent a lift-off of the stepping plate, the stepping plate is pulled by a tension spring onto the rotating cam disc. Still, a high lift frequency may lead to lift-off of the stepping plate resulting in chatter noises.

It is therefore the object of the present invention to provide an apparatus for muscle stimulation, which can be operated at low as well as high frequencies.

SUMMARY OF THE INVENTION

This object is achieved with an apparatus having motor operated drives, wherein each drive comprises a quadrilateral linkage with a driven drive member being a crank supported in the frame. Furthermore, in each case, one crank and a stepping plate are pivotally interconnected by a coupling member.

The invention will become more readily apparent from the following description with reference to the schematic drawings:

DESCRIPTION OF A PARTICULAR EMBODIMENT

FIG. 1shows a perspective view of an apparatus10for muscle stimulation. The apparatus10comprises a bottom plate11on which a motor20is disposed and two stepping plates81,181which are each driven by the motor20and a drive30,130. The operating elements of the apparatus10and the enclosure are not shown.

The motor20which is for example screwed to the bottom plate11is in the shown embodiment a frequency-controlled three-phase motor. By varying the control frequency of the magnetic field of the motor20, the speed of the motor20can be increased or decreased synchronously with the frequency. The apparatus10may also have two motors20. Then each of the two motors20drives one stepping plate81,181by way of a drive30,130. The two servomotors20may be synchronized with each other.

The individual motor may be a gear drive motor which drives for example directly an integral step-down gearing. The output speed of the gear drive motor, is then for example smaller than the described synchronous motor speed. The step-down gearing is a gear drive with parallel, cross-over or intersecting axes.

Also, the use of one or two DC motors with adjustable speed is possible.

In the arrangement as shown inFIG. 1, the motor20is connected to the drives30,130by a pull member drive21. The pull member drive21is in the exemplary embodiment a belt drive, which comprises a belt pulley23disposed on the motor shaft22, a belt24and a belt pulley25disposed on the input shaft41of coupling drive30,130. The belt drive21may include a V-belt or a flat belt etc. The pull member drive21may also be a chain drive.

In the exemplary embodiment, the two belt pulleys23,25are V-belt rib pulleys23,25, wherein the driven pulley25has for example 2.2 times the diameter of the drive pulley23of the motor. The ribbed V-belt24may for example have a steel inlay.

For adjusting the belt tension, the motor20may be movable for example in the longitudinal direction of the apparatus10. The pull means24may also be tensioned by means of a self-tensioning arrangement, seeFIGS. 2 and 3. It comprises for example a tensioning roller26and a spring27.

InFIGS. 2 and 3, the apparatus10is shown in each case in a side view, however with different drive positions. InFIG. 2, the front stepping plate81facing the viewer is shown in its upper end position whereas the rear stepping plate181is shown in its lower end position. InFIG. 3, the drive30,130is advanced to such an extent that the front stepping plate81is in its lower end position whereas the rear stepping plate181is in its upper end position.

The individual drive30,130—seeFIGS. 1-5, is a revolvable quadrilateral linkage square with a frame31,131, a crank32,132, a connecting member33,133and a further drive element formed by the stepping plate81,181and its support flanges82,83,182,183. The individual frame31,131is formed in the exemplary embodiment by the bottom plate11, a front bearing support12and a rear bearing support13. The support flanges82,83,182,183and the bearing supports12,13may comprise several parts. In the frame31,131, the crank32,132, on one hand, the crank32,132is rotatably supported in the crank joint35,135and, on the other hand, the stepping plate element81,181is rotatably supported in the frame joint38,138. In accordance withFIGS. 1-5, the pivot axis and the axes of rotation of all of the joints35-38;135-138extend normal to a vertical longitudinal center plane of the apparatus10.

The crank32,132is formed by the drive shaft41with an eccentrically arranged bearing mount42,142. The input drive shaft41which, in accordance with the sectional representation ofFIG. 4, interconnects the two drives30,130carries at one end thereof the belt pulley25. It is rotatably supported in the front bearing support12for example by means of two grooved ball bearing43,44. The inner rings45of the bearings43,44abut a shaft shoulder45and are axially fixed on the shaft41by means of a locking ring47. In the exemplary embodiment the outer rings48abut the bearing support12.

The eccentrically arranged bearing mounts42,142are disposed in the exemplary embodiment outside the bearings43,44. They may for example be displaced relative to each other in a direction normal to the virtual center line49at the drive shaft41. In the exemplary embodiment, the extremities of the two eccentrically arranged bearing mounts42,142with respect to a rotational phase angle of the drive shaft41are displaced by 180°. The length of the32,132is the distance between the centerline49of the drive shaft41and the centerline of the eccentrically arranged bearing mount42,142of the respective coupling drive30,130. In the exemplary embodiment shown inFIGS. 1-5, the sum of the diameter of an eccentrically arranged bearing mount42,142and twice the eccentricity is smaller than the diameter of the bearing support51of the input drive shaft (41).

The eccentrically arranged bearing mounts42,142support in the representation ofFIG. 4each a non-friction bearing52,152, which again carries each a support plate53,153. The support plate53,153forms the connecting member33,133, which is supported rotatably on the crank32,132by means of the connecting joint36,136. A second support mount54,154of the support plate53,153supports, by means of another non-friction bearing55, a pivot bolt59,159of the front stepping plate support structure84,184. The distance between the pivot axes of the bearings52,55,152,155, which extend parallel to each other is the length of the connecting member33,133. The non-friction bearings43,44,52,55,152,155are in the exemplary embodiment grooved ball bearings which are sealed at both sides. But roller bearings, inclined ball bearings, needle bearings etc., may also be used.

Each stepping plate81,181is supported on one hand via the connecting member33,133by means of a front stepping plate joint37,137an on the frame31,131by means of a frame pivot joint38,138. The frame support joints38,138comprise each a pivot bolt86,186supported in the rear by the rear bearing support (13), for example multipart support flange83,183by means of friction bearing sleeves85,185which consist of POM.

The two stepping plates81,181are arranged axially symmetrically with respect to a vertical longitudinal center plate of the apparatus10. For example, the constant distance of the two stepping plates81,181from each other is less than 2 millimeters. The individual stepping plate81,181is an at least approximately rectangular plate which consists for example of an aluminum alloy. In the exemplary embodiment, its length is 490 mm, its width is 200 mm and its thickness is 10 mm. Its top side87,187has a recessed surface area onto which a slip-resistant rubber mat88,188is cemented. At the top side87,187of the stepping plates81,181in each case one or several rope ears or hooks may be arranged into which a grommet of a rope provided with a handle may be hooked.

During assembly, for example, first the bearing supports12,13and the motor20are mounted onto the bottom plate11. The drive shaft41is then placed into the front bearing support12and a grooved ball bearing43,44is slipped onto the bearing supports51from the two shaft ends and in each case secured by means of a locking ring47. After the mounting of the support plates53,153, the grooved ball bearings52,152are slipped onto the eccentrically arranged bearing mounts42,142and secured for example by means of locking rings58,158. After sliding in the bearings55,155, the stepping plates81,181are put in place. In each case, a flange bolt59,159is inserted and secured for example by a hexagonal unit61,161. In the frame31,131, the individual stepping plate81,181is secured by means of the bolt86,186.

After installation and securing of the belt pulleys23,25and the belt24, the belt24is tensioned for example by a displacement of the motor20.

During operation of the apparatus10, the user stands with each foot on one of the stepping plates81,181. The motor20drives by means of the pull member drive21the two coupling drives30,130. In this way, with each rotation of the input drive shaft41, each crank is turned by one turn. The two connecting members33,133are positively actuated by the cranks32,132so that the stepping plate joints37,137are moved up and down from, for example, a neutral start out position. During one rotation of a crank, the respective support plate joint37,137reaches a maximum and a minimum. The overall stroke of the stepping plate joint37,137is for example 7 millimeter. The stroke frequency of the stepping plate81,181is between 3 Hz and 30 Hz.

During the oscillating stroke movement each of the two stepping plates pivots about the frame pivot joint38,138. The pivot angle out of the neutral position is for example +/− one angular degree.

The stroke frequency of the stepping plates81,181changes proportionally with the drive speed of the motor20. In this way, the stimulation of the muscles of the user is influenced.

FIG. 13shows a stepping plate81with a support flange83wherein a pressure sensor89is arranged between the two components81,83. If for example at high frequency, the foot of the user is partially lifted off the stepping plate81, the load on the stepping plate is reduced and is suddenly reapplied when the foot load is reinstated. The electrical output signal of the sensor, which for example is in the form of a pressure sensor cell or an expansion measurement strip, is changed. This signal change causes the control arrangement of the motor20for example to reduce the motor speed. Only when the feet of the user are again fully disposed on the stepping plates the original signal level of the sensor89which reacts to deformations is again re-established.

Such sensors89may be arranged in, or on, the frame-side stepping plate support joint38as well as at the coupling-side stepping plate support joint37. The summing signal of the two sensors89then is to a large extent independent of the position of the user on the stepping plate81,181.

For the evaluation, a control signal depending on the mass or, respectively, the mass moment of inertia of the user may be determined but only after an initial operation of for example 10 seconds.

FIG. 6shows a partial sectional view of an apparatus10in the area of a drive shaft41which comprises coaxial cylindrical sections. On the drive shaft41, eccentric ring71is disposed, which carries the stepping plate bearing52and which abuts a shaft shoulder72and is secured by means of a shaft nut73and a locking plate74. The eccentric ring71may be provided at the nut- and/or shoulder side with a planar teeth structure which is engaged by a counter-tooth structure provided on the shaft shoulder72or a locking ring74of the shaft unit73. The eccentric ring71may be positioned on the drive shaft41for example by means of a fitting spring. The eccentric ring71may be exchangeable for example by another eccentric ring with different eccentricity.

In order to adjust the eccentricity and consequently the length of the crank32, the shaft unit23is loosened. The eccentric ring71can then be steplessly rotated for example on the basis of a scale. When the new crank length is adjusted, the crank unit73is again tightened. With a form-locking structure disposed for example between the eccentric ring71and the shaft should72, a step-wise adjustment of the crank length is possible. With an adjustability of the eccentricity of the connecting joint36, the stroke of the stepping plate81is adjustable. In the exemplary embodiment, a stroke adjustment of between two and seven millimeter is possible.

The two drives30,130may have different crank length. To this end, the eccentric rings71may be adjusted differently. As a result, the stroke travel of the two stepping plates81,181may be different.

The two drives30,130may also be so adjusted that the phase displacement of the two maxima and/or minima differs from 180 degrees. To this end, the two stepping plates81,181are so adjusted that the maximum of the one stepping plate does not coincide, time wise, with the minimum of the other stepping plate81,181. In this case, the drive shaft41may be provided with an eccentric weight for mass compensation.

FIG. 7shows a drive shaft41with an eccentric ring71which is fixed by means of a front cup75. The front cup75is mounted cup75is mounted to the front end77of the drive shaft41for example by means of a screw76. A connection by means of two screws, a form-locking element, for example a locking pin and a screw76etc. . . . is also possible. Also, in this case a scale may be provided on the front cup75on the basis of which the eccentric ring71may be adjusted by means of counter marks.

The eccentric ring71may also be fixed by means of a rapid clamping arrangement. Herein the eccentric ring71may be operated from outside of the apparatus10by loosening or clamping of an operating handle. Also, the eccentric adjustment may be performed for example from the outside by means of a tool.

FIG. 8shows the support of two stepping plates81,181by way of elastically deformable elements90,190. They are two composite bodies101,201formed each by an elastomer body102,202with metal plates103,104,203,204vulcanized onto the front sides thereof. The upper metal plate103,203has for example a threaded bore105,205. The lower metal plate104,204carries a threaded pin106,206which projects from the elastomer body106,206and which is threaded into the respective bearing support13. Into the threaded bore105,205in each case a mounting screw107,207for mounting the stepping plate81,181is threaded. The elastomer body102,202has for example a hardness of between 40 and 60 shore. The composite body101,201prevents in this way abrupt strike exposures of the user which could occur at reversal points of the stepping plate movements.

During operation of the apparatus10with such a frame- and/or coupling-side stepping plate support arrangement37, the elastomer body102,202also permits an inclined position of the two metal plates103,104,203,204relative to each other up to an angle of, for example, three degrees. The composite body101,201could therefore replace the friction or non-friction bearing support of the stepping plates81,181as shown inFIG. 5. But it may also be provided in addition to the bearings.

FIG. 9shows a double-sided stepping plate support arrangement37which comprises as elastically deformable elements90,190two plate spring packets111. Here, for example, in each case, a screw112is threaded from the bottom through the support flange82and the plate spring packet111into the stepping plate81. The pretension of the plate spring packet111is adjustable by means of the screws112. In this way, the stepping plate support37can be adjusted to be harder or softer.

As shown inFIG. 9, in each case one plate spring113of a plate spring packet111is oriented upwardly whereas the adjacent plate spring114is oriented downwardly. But it is also possible to combine and orient two adjacent plate springs113upwardly and the next two adjacent ones114downwardly.

In the arrangement ofFIG. 9, the coupling-side stepping plate joint or support37may be provided, instead of by a non-friction bearing55, by a leaf spring. The leaf spring is then attached to the support plate53and the support flange82. The bending line then extends for example parallel to the bottom plate11.

The screw head115may for example be disposed on an arched washer116provided with an elongated opening, seeFIG. 10. The washer may have a surface with a small friction coefficient. In the embodiment of the stepping plate support37,38without friction and/or antifriction bearing the described support structure may also take on the joint function.

Also, the use of a composite body with an elastomer body and front metal plates with a throughbore instead of the plate spring packets111is possible.

FIGS. 11 and 12show an apparatus10whose coupling-side stepping plate joints37comprise leaf springs121. InFIG. 11, the belt pulley25and the support bearing64are removed.FIG. 12shows a partial sectional view ofFIG. 1in the area of the support plate53. The individual elastically deformable element90,190, that is, the individual bent leaf spring121,221, is mounted to the support plate53so as to extend for example at least approximately vertically. In addition, it is locked by means of a locking sheet122. In the exemplary embodiment, the support plate53is vertically guided by means of a guide bolt62in the front support12.

At the stepping plate side, the leaf springs121,221are supported at the bottom side of the stepping plates81,181, for example, in each case in two guide tracks123,223. An adjustment sheet124which is adjustable in the longitudinal direction of the stepping plate81,181is pressed onto the leaf spring121by means of the guide elements123so that the leaf spring position relative to the stepping plate81,181is maintained. By an axial adjustment of the adjustment sheet124, the spring length of the leaf spring and as a result the spring stiffness can be adjusted. The shorter the spring length, the higher is the stiffness of the support.

Also a multi-layer leaf spring pack may be used. In order to increase the stiffness of the support, two or several leaf springs121may also be arranged in parallel relationship.

Such a coupling-side stepping plate arrangement37may be combined for example with a frame-side stepping plate support38including a composite body101.

FIG. 12discloses three identical non-friction bearings43,53,63for supporting a stepping plate81,181. The support bearing64in the form of a loose bearing has in the exemplary embodiment has with regard to these bearings a smaller inner and outer diameter. However, it also possible to use identical bearing elements for all non-friction bearing locations.

Also, in such an apparatus10, the crank length and/or the phase angle difference may be adjustable.

The pull member drive21may be arranged between the two drives30,130. It is also possible to provide a pull member drive21for each drive30,130. It is also possible not to use any pull member drive21for the apparatus10.

Also combinations of the various exemplary embodiments are possible.