An Improved Dynamometer for Testing Physical Strength, in which the of an Introduced Coin.
Year: 1888

page_text: Date of Application, 11th Dec., 1888
Complete Specification Left, 10th Sept., 1889-Accepted, 19th Oct.. 1889
. PROVISIONAL SPECIFICATION.
An Improved Dynamometer for Testing Physical Strength, in
which the Indicator Records the Result by the Action of an
Introduced Coin.
I, JOHN MACKENZIE, of Eaglescliffe, in the County of Durham, Engineer, do hereby
declare the nature of this invention to be as follows:-
My Invention relates to machines or apparatus for measuring force, in which the
result is recorded by an indicator which is brought into operation by the insertion
of a coin, and is especially applicable for registering physical force, such as is exerted
by the grip of the hand.
In carrying out my invention I employ a lever of the first order pivotted on a pin
passing through the corresponding part of a similar bar which is fixed in position,
the fixed bar and the lever together presenting the appearance of a pair of shears.
Between the lever and the fixed bar I provide spiral spring or its equivalent so
fixed as to resist the closing of the lever onto the fixed bar, the resistance offered
affording the means for testing the amount of force applied to the apparatus.
al
In order that the force may be conveniently applied by the human hand, the ends
of the fixed bar and the lever not adjoining the spiral spring, which may be termed
the outer ends, are furnished with an artificial hand fastened at about the wrist to
the case or frame of the apparatus and slipped over the projecting parts of the fixed
bar and lever like a glove, so that when the artificial hand is pressed or gripped the
spiral spring connected to the other end of the lever is brought into resistance
corresponding to the proportion of leverage applied and force exerted.
In order to record the amount of force so exerted only when a coin is introduced
into the apparatus to pay for the test, I provide in any suitable position in the
apparatus above the lever before described, which may be termed the principal lever,
another lever also of the first order so proportioned that when a coin of a certain
weight, say a penny, is introduced into the machine and lodges on the end of the long
arm of the lever, the tendency of the long arm of the lever is to descend whilst the
short arin correspondingly rises. In the absence of the presure due to the weight of
the coin the lever has no tendency to move.
In order that the travel of the indicator lever may correspond with that of the
principal lever it is supported between the coin and the fulcrum by means of a bar
or pin extending vertically from the principal lever and terminating in a fork which
receives the relatively horizontal bar of the indicator lever, the short arm of which is
connected by a wire or other means to a dial indicator of the usual type and actuates
the pointer thereof. The end of the indicator lever which receives the coin is provided
with a flap or tray supported on prongs and hinged to one of them, so that the other
edge which is free can be tilted up by a fixed pin or finger catching the opposite edge
thereof in the upward or return stroke of the lever, by which each coin which has
carried the indicator lever down is tipped out to admit of the reception of the next
coin to pay for the next test obtained from the apparatus.
Tate this 18th day of December 1888.
G. J. CLARKSON,
Agent for the Applicant.

page_text: COMPLETE SPECIFICATION.
An Improved Dynamometer for Testing Physical Strength, in
which the Indicator Records the Result by the Action of an
Introduced Coin.
-
1, JOHN MACKENZIE, of Eaglescliffe, in the County of Durham, Engineer, dor
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:-
.
My Invention relates to machines or apparatus known as dynamometers of the
class in which the amount of force applied is recorded by coin freed indicating
mechanism, and is especially adapted for testing physical force such as is exerted by
the grip of the hand.
A machine constructed according to my invention consists in a combination of new
or improved mechanism for testing the force exerted by the grip of the band with
suitable coin actuated mechanism for recording the result and for enabling the
machine to take its own toll each time, it is used in the well known manner, in which
no result is obtainable unless a coin of the required weight or size, such as a penny
piece, is first introduced into the apparatus to unlock the indicating mechanism.
In carrying my invention into effect I provide a lever of the first order pivotted on
a pin passing through the corresponding part of a bar of similar form or design, but
which is a fixture with the case or frame of the apparatus; the fixed bar and the lever
together presenting the appearance of a pair of shears, only one member of which is
moveable. In order that the force exerted by the grip of the hand can be conveniently
applied to my improved dynamometer, the ends of the fixed bar and the lever which
extend beyond the case or frame of the apparatus, which may be termed their outer
ends, are fitted up with an artificial hand terminating at about the wrist and fitting
close up to the case of the apparatus. This artificial hand forms part of or is slipped
over the projecting ends of the fixed bar and lever like a glove so that when the said
artificial hand is pressed or gripped to bring the lever and fixed bar together; a spiral
spring which is fitted between the said lever and fixed bar is brought into resistance
and tests the force so applied. The movement of the lever when the artificial hand is
gripped is communicated to the indicating mechanism, which accordingly rogisters
the amount of force exerted. The mechanism for registering may be of any suitable
design or arrangement of the coin freed type by which the machine is enabled to take
its own toll each time it is made use of.
And in order that my invention may be fully understood; I will refer to the
accompanying drawing in which Figure 1 illustrates the machinery employed as seen
from behind the apparatus when the back of the case in which it is enclosed is
removed, and Figure 2 is a vertical section through the case but showing the
mechanism in side elevation; a is the force testing lever pivotted on the pin bas a
fulcrum, c is the corresponding fixed bar, which for the sake of symmetry is of the
same form and design as the lever a; d is a spiral spring of known strength fixed
between the inner ends of the lever a and fixed bar c, the resistance of which tests
the force applied to the lever a when the artificial hand is gripped or pressed. When
the artificial hand is constructed of rigid material such as metal the little finger a
which must be moveable and serves as the outer end of the lever a works separately
from the rest of the hand c which is a fixture to the case of the apparatus and serves
as the outer extremity of the fixed bar c, as is clearly illustrated in Figure 2;
otherwise if the artificial hand be composed of elastic material such as india rubber
the moveable little finger a¹ need not form a separate part to the rest of the hand c¹.
When the artificial hand is gripped the little finger al is pressed towards the rest of
the hand and the physical force so exerted is tested by the resistance of the spiral
spring.
The means by which the motion of the force testing lever a can be communicated
to suitable mechanism to indicate the result are well known and I do not confine

page_text: myself to the use of any particular mechanism to effect this purpose, but by way of
example I illustrate in the accompanying drawing in what manner the motion of the
said lever is communicated to the coin freed mechanism which is described with
reference to the accompanying drawings in the Specification of Richard Howson and
Edward Crowe No. 12,273 of 1887.
The mechanism illustrated to effect this purpose consists of a lever or rocking
bar e mounted upon a standard f, which is double legged to stand astride of the
lever a and the bar e above which the rocking bar e is balanced so as to occupy a
horizontal or approximately horizontal position when the force testing lever a is at
rest, at the end of the lever a is furnished the strut or fork g to support and guide
the tail end of the rocking bar e against the pressure of the counter weight h, which
is attached to the tail and of the rocking har e to tilt up the opposite arm of the
rocking bar which opposite arm by means of a pin and double eye or the like
connection operates the vertical spindle of the indicating mechanism.
The action of the hereinbefore described mechanism is as follows:
When the coin such as a penny piece is inserted in the apparatus the indicating
mechanism is unlocked and in a state, of readiness to register on the outside dial
whatever force is represented by the upward movement imparted to the spindle k,
which upward movement corresponds through the tilting of the rocking bar e with
the movement of the force testing lever a in compressing the spiral spring d, and
therefore represents the force exerted when the grip is applied to the artificial-hand
outside the apparatus. The indicator may if desired be retained at the maximum
point to which it has been driven in indicating the force applied to the artificial hand
until released at will, by means of the rachet wheel 1, pawl m, and pusher rod n,
combined and operating in the manner described with reference to the accompanying
drawings in the Specification of William Porritt Ingham No. 8315 of 1888, in which
case it is desirable that the spindle & shall be free to slide down to its original position
to relieve the indicating mechanism from sustaining the weight h. It is of course
obvious that any suitable indicating mechanism which can be similarly operated by
the upward motion of the vertical spindle can be substituted for the particular
indicating mechanism hereinbefore described and illustrated by way of example whilst
employing precisely the same mechanism to connect the action of the force testing
mechanism with the indicating mechanism.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
:
Firstly The use of the mechanism for testing the force exerted by the grip of
the hand in connection with suitable coin freed indicating mechanism, substantially.
as hereinbefore described and by way of example illustrated in the accompanying
drawings.
Secondly The use of the artificial hand to enable the grip of the human hand
to be conveniently applied to force testing mechanism, substantially in the manner as
herein before described.
Thirdly The general arrangement and combination of parts constituting the
improved dynamometer, for testing the grip of the hand substantially as hereinbefore
described and illustrated in the annexed sheet of drawings.
Dated this 9th day of Septembe- 1990.
G. J. CLARKSON,
Stockton-on-Tees, Agent for the Applicant.