Improvements in Exercising Apparatus for Therapeutic Purposes.
Year: 1897

page_text: PROVISIONAL SPECIFICATION.
Improvements in Exercising Apparatus for Therapeutic Purposes.
I, DR. MAX HERZ, of IX Schwarzspanierstrasse 18, Vienna, in the Austrian
Empire, Physician, do hereby declare the nature of this invention to be as
follows:-
Mechanico therapeutical apparatus such that the patient has to perform a
definite and measurable amount of work by overcoming resistances in certain
movements, are objectionable, because the intensity of this work does not vary
during the prescribed movement in accordance with the variation of the capacity
of the muscles for work, as the part of the body which exerts the power changes
its position by the movement.
Thus the forearm which in one part of its movement is extended, in another
part is bent inwards on the elbow joint and in other positions of the muscles and
joint different exertions of power are required to effect like results.
The laws according to which the actions of the joints and muscles vary in
exerting power have hitherto been based only hypothetically on theoretical con-
siderations and experiments on animals, and mechanico-therapeutic apparatus
have been constructed in accordance with these laws.
The improvements forming the subject of the present invention have for their
object to avoid the objection above stated and to ensure that, in working with such
apparatus during the whole movement the muscles shall be exerted in accordance
with their momentary tension or pulling force.
The inventor has determined empirically the actual variations of the pulling
force in human beings, and the resistance in his apparatus can be altered exactly
according to these variations.
This may be effected in various ways. In all cases the load (the resistance) is
caused to act upon a kinematic intermediate link or momber the movement of
which due to the motion of that part of the body which is exerting power
produces a compensating alteration leverage. Such intermediate members are
cams or their equivalents.
In the accompanying drawings, Figs. 1 and 2, are respectively a side and a
front elevation of an apparatus according to my invention for mechanico
therapeutical treatment of the arm. Figs. 3, 4, 5 and 6, shew modified arrange-
ments of parts of the apparatus.
A is a standard or frame on the upper portion of which a shaft a with crank
handle C is mounted the shaft carrying the compensating kinematic intermediato
member which is a cam a¹. A lever a pivotted on the frame A, and loaded by a
weight e, is connected by a cord, chain, rope or strap to the cam a¹. By shifting
the weight e along the lever d the work performed by turning the crank
handle can be varied as desired.
If for instance the work consists in turning the crank c¹ in the direction of the
arrow Fig. 1, so raising the weight e by moving the fore arm at the elbow joint,

page_text: the radii of the cam a¹ corresponding to the various angular positions of the
forearm, are determined so that the effort always remains the same.
Instead of a weighted lever (Figs. 1 and 2) weights e¹ (Fig. 3) such as metal
discs may be employed, these being suspended in number corresponding to the
desired work, on a cord, chain, or rope fastened to the periphery of the cam a¹.
Fig. 4 represents an arrangement in which the weights are on a rack b¹ which
is pressed by a spring or weight against the periphery of a toothed cam a³.
In the arrangement shewn in Fig. 5 the weight takes the form of a roller
mounted on a lever f and pressing on the periphery of the cam a¹.
In the form of the apparatus partly shewn in Fig. 6, the cam a³ is a cylindrical
drum a³ in which is cut a helical groove g of varying depth the loaded lever d is
connected by a cord fastened in the groove.
In order that when the drum a³ rotates the cord b notwithstanding the helical
form of the groove may always remain vertical, the shaft a has a screw thread a³
of the same pitch working in the bearing a*, so that the shaft as it rotates moves
also lengthwise.
improvements in Exercising apparatus for inerapeutic Purposes.
I, DR. MAX HERZ, of IX Schwarzspanierstrasse 18, Vienna, in the Austrian
Empire, Physician, do hereby declare the nature of this invention and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement: -
Mechanico therapeutical apparatus such that the patient has to perform a
definite and measurable amount of work by overcoming resistances in certain
movements, are objectionable, because the intensity of this work does not vary
during the prescribed movement in accordance with the variation of the capacity
of the muscles for work, as the part of the body which exerts the power changes
its position by the movement.
Thus the forearm which in one part of its movement is extended, in another
part is bent inwards on the elbow joint and in other positions of the muscles and
joint different exertions of power are required to effect like results.
The laws according to which the actions of the joints and muscles vary in
exerting power have hitherto been based only hypothetically on theoretical con-
siderations and experiments on animals, and mechanico-therapeutic, apparatus
have been constructed in accordance with these laws.
The improvements forming the subject of the present invention have for their
object to avoid the objection above stated and to ensure that, in working with such
apparatus during the whole movement the muscles shall be exerted in accordance
with their momentary tension or pulling force.
The inventor has determined empirically the actual variations of the pulling
force in human beings, and the resistance in his apparatus can be altered exactly
according to these variations.
This may be effected in various ways. In all cases the load (the resistance) is
caused to act upon a kinematic intermediate link or member the movement of
which due to the motion of that part of the body which is exerting power
produces a compensating alteration leverage. Such intermediate members are

page_text: cams or their equivalents such as unround discs, unround wheels grooved cylinders
and the like.
In the drawings accompanying my Provisional Specification Figs. 1 and 2, are
respectively a side and a front elevation of an apparatus according to my inven-
tion for mechanico therapeutical treatment of the arm. Figs. 3, 4, 5 and 6, shew
modified arrangements of parts of the apparatus.
A is a standard or frame on the upper portion of which a shaft a with crank
handle c is mounted the shaft carrying the compensating kinematic intermediate
member which is a cam ¹ or unround disc capable of rotation. A lever d
pivotted on the frame A, and loaded by a weight e, is connected by a cord, chain,
rope or strap 6 to the periphery of the cam a'. By shifting. the weight e along the
lever d the work performed by turning the crank handle c¹ can be varied as desired.
If for instance the work consists in turning the crank in the direction of the
arrow Fig. 1, so raising the weight e by moving the fore arm at the elbow joint,
the radii of the cam a corresponding to the various angular positions of the
forearm, are determined empirically so that the effort always remains the same.
Instead of a weighted lever (Figs. 1 and 2) weights e¹ (Fig. 3) such as metal
dises may be employed, these being suspended in number corresponding to the
desired work, on a cord, chain, or rope fastened to the periphery of the cam a¹.
Fig. 4 represents an arrangement in which the weights e are on a rack b¹ which
is pressed by a spring or weight against the periphery of a toothed cam a³.
In the arrangement shewn in Fig. 5 the weight e³ takes the form of a roller
mounted on a lever f and pressing on the periphery of the cam a¹.
In the form of the apparatus partly shewn in Fig. 6, the cam a¹ is replaced by a
cylindrical drum a³ in which is cut à helical groove g of varying depth the loaded
lever d is connected by a cord c fastened in the groove.
In order that when the drum a³ rotates the cord b notwithstanding the helical
form of the groove may always remain vertical, the shaft a has a screw thread a³
of the same pitch working in the bearing a*, so that the shaft as it rotates moves
also lengthwise.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is:-
Exercising apparatus for therapeutical purposes wherein an intermediate
kinematic member such as a cam or unround disc such as a¹, or unround wheel
such as a³, or a drum such as ³ with a groove of varying depth, is provided, upon
which the resistance acts and by the movement of which the length of leverage
of the load is so varied as to compensate for the empirically determined
inequalities of muscular strain due to the varying positions of the part of the
body by which force is exerted, substantially as described.
Dated thin 17th dow of V... 1000