APPARATUS f_OR TRAINING MUSCLES
The technical field of the invention
This invention refers to a muscles training apparatus of the type comprising a support-forming post having at least two vertically spaced-apart pulley wheels, a lower one of which is adjustable and securable in varying positions of height along the post so as to locate a free end of a pull rope or the like extending between said pulley wheels at a level desired by a training person, said rope being, at its end being opposite to the free end, connected to a counter-loading means having the . purpose to exert a counter-force when the rope is pulled.
Background of the invention Training apparatuses of the above mentioned type are advantageous insofar as they are comparatively cheap to manufacture and all-round in respect of their fields of application since they can, by a simple adjustment of the adjustable pulley wheel, be used by persons having most differing statures and for training several different parts of the body, such as arms and legs. The conventional training apparatuses of this type are, however, also associated with a plurality of disadvantages • being founded on the fact that counter-weights are used as counter-loading means, i.e. bodies exerting the necessary counter-force by their deadweight. When the apparatus is used by different persons and when one and the same person shall use the apparatus for various training actions respectively it is necessary to change the number of counter weights; a work which is troublesome and takes considerable time to carry out. Another disadvantage being maybe more serious is that such counterweights give a less favourable training result from a physiological point of wiev in as much as the muscles of the training person will be differently loaded during one and the same motion. If a person is going to train for instance a leg by pulling the pull rope of the apparatus therewith
on repeated occasions the leg muscles in question are differently strong during each single motion depending on the instantaneous angle that the lower part of the leg has in relation to the femur. When the leg is stretched the power is accordingly considerably smaller than at e.g an angle of 60° between the lower part of the leg and the femur. Since the counterweight always exerts an invariable counter force this means that the muscles during certain phases of an individual motion are loaded to a maximum, while they during other phases - when the power is increased - are loaded considerably less. A . maximum loading of the muscles during the entire indivi¬ dual motion is therefore impossible to obtain in the apparatuses known.
Brief description of the concept of invention
The present invention aims at setting aside the above mentioned disadvantages of the previously known training apparatuses of the type related in the preamble and creating an apparatus which is simple and easy to handle and gives a training result being optimal from the physiological point of wiev. According to the inven¬ tion these and other aims are obtained by the fact that the counterloading means consists of a piston-cylinder mechanism being provided with a check valve and operating with a pressure medium and that the pull rope is connected to the piston-cylinder mechanism by way of a multiple pulley block means in order to obtain a large transmission ratio between on one hand the maximum distance that the free end of the rope can be pulled out and, on the other hand, the stroke of the piston rod of said mechanism.
Brief description of the attached drawing
In the drawing Fig. 1 is a perspective view of the training apparatus according to the invention and Fig. 2 a diagram illustrating the function of the piston-cylinder mechanism.
Detailed description of a preferred embodiment of the invention
In the drawing 1 generally designates a support in the form of a long post, while 2 designates a pull rope having a free end which advantageously may have a handle 3. The post 1 is attached to a bottom plate 4 being fixable to a floor and has at its upper part two bracket-shaped arms 5,5' which may be attached to a wall. Four pulley wheels or means are associated with the post 1, namely two stationary pulley wheels 6,7 mounted in the area of the upper part of the post and two movable pulley wheels 8,9 arranged at opposite sides of the post 1. More precisely the two movable pulley wheels are each arranged on a sled-like element 10 which is displaceable along a guide-forming groove 11 and has a locking mechanism 12 by means of which the same can be locked in arbitralily positions along the post. The pull rope 2 extends from the first adjustable pulley wheel 8 to the second adjustable pulley wheel 9 by way of the first stationary wheel 6 and further to a counter- loading means, designated 13 in its entirety, by way of the second stationary pulley wheel 7. By the fact that the pull rope in this manner runs over two pulley wheels being vertically adjustable it is guaranteed that the free end of the pull rope in its initial position extends out from the post an equally long distance irrespectively of whether the first adjustable pulley wheel is located high or low, because if the first adjustable pulley wheel 8 is lowered then the second adjustable pulley wheel 9 can be raised and vice versa.
As far as the apparatus is hitherto described the same is per see previously known.
As a main component in the counter loading means for the pull rope 2 a piston-cylinder mechanism, the cylinder of which is designated 14 and the piston-rod of which is designated 15, is included according to the
principle or the invention, said mechanism preferably operating with a hydraulic pressure medium. In the example shown the cylinder 14 is mounted on a U-shaped frame 16 the two shanks of which are stationary affixed, preferably on the bottom plate 4. More precisely the cylinder 14 is turned upside down so that the piston rod 15 projects vertically down from the overhead part 17 of the frame 16.
In order to create a great transmission ratio, suitably 4:1 a 6:1 between on one hand the maximum distance which the handle 3 of the pull rope 2 can be pulled out and on the other hand the stroke of the piston rod 15, the rope 2 is connected to the piston-cylinder mechanism by way of a multiple pulley block means which comprises a number of stationary blocks 18 attached to the overhead part 17 as well as a number of movable blocks 19 attached to a cross piece 20 which is movable along the shanks of the frame 16, said shanks serving as guides. In practice the handle 3 should be capable of being pulled out 2 to 3 metres from its initial position when using a piston-cylinder mechanism the piston rod of which has a stroke of 0.5 metre.
In the example shown the piston-cylinder mechanism is of the single-acting type having a separate tank 21 mounted above the cylinder, e.g on the wall in question. The cylinder 14 is connected to the tank 21 through a conduit 22 in which a check valve 23 as well as a non- return valve 24 are arranged, said nonreturn valve making a pressure medium flow from the cylinder to the tank impossible, but allowing a free flow in the reversed direction. By means of the check valve 23 it is extremely simple to adjust the resistance that the pressure medium exerts when the piston is moved upwardly through the cylinder.
Advantageously the cross piece 20 has a consider¬ able weight so as to automatically return the piston rod 15 to an initial position pulled out of the cylinder as soon as the tractive force in the rope 2 ceases. Possibly the cross piece can be completed with one or more springs for providing the same function.
The function and advantages of the apparatus according to the invention When the two pulley wheels 8,9 have been adjusted so that a suitable level is obtained for the free end of the pull rope 2 and when the check valve 23 has been adjusted into a desired position for the person in question and the training action respectively, training starts by the fact that the person in question pulls the handle 3. This pulling is by way of the pulley block means 18,19 transformed into a movement of the piston rod 15 inwardly in the cylinder 14, the pressure medium therein exerting the necessary resistance against the tractive force in the rope. This resistance is not constant but will vary in dependence of the variations of the tractive force in the rope, meaning that the muscles in the part of the body being trained will be equably and maximally loaded during the entire path of motion of the bodypart in question. In other words the training action will get an isokinetic character, which is extremely advantageous in physiological respect.
Conceivable modifications of the invention Of course the invention is not limited merely to the embodiment described and shown in the drawing. Thus it is conceivable to arrange the piston-cylinder mechanism in another manner than the one shown in the drawing. Further it is conceivable to use air or gas as a pressure medium in the piston-cylinder mechanism instead of hydraulic oil.