Strength/weight measuring scale

A scale selectively operative in a weighing mode to measure body weight and in a strength mode to measure muscular strength. The scale includes a base which rests on the ground, above which is a depressible platform to compress a spring interposed between the platform and the base. The degree to which the spring is compressed, either by the platform or by the base, is converted into an analog or digital readout. Anchored on the base and extending through an opening in the platform is an upright post terminating in a handle that is elevated relative to the platform. Also provided is an adjustable stop which is coupled to the platform. When actuated, the stop engages the ground to prevent depression of the platform. In the weighing mode, the stop is disabled, and when an individual steps on the platform, the resultant readout indicates his body weight. In the strength mode, the stop is actuated, and when the individual steps on the platform and then exerts an upward force on the handle in accordance with his strength, the resultant readout is indicative of strength and is independent of body weight.

BACKGROUND OF INVENTION 
1. Field of Invention 
This invention relates generally to scales which provide a reading of body 
weight, and more particularly to a scale of this type which is selectively 
operable to provide a reading of muscular strength independent of body 
weight. 
2. Status of Prior Art 
Exercise and body development for maintaining fitness and in assisting in 
physical growth can be practiced at home. Thus, tension-resisting devices 
of various types are commonly used for the development of back, shoulder 
and arm muscles. 
When undergoing a program of exercise, it is desirable to keep tabs on the 
effect thereof on the body weight of the exerciser. Thus, if one 
undertakes an exercise program with a view not only to gaining muscular 
strength but also toward reducing body weight, the increase in strength 
may be accompanied by a gain rather than a loss in weight. In some 
instances one seeks to increase body weight when following a program of 
muscular development. Hence, the correlation of changing strength to 
weight is of concern to the serious exerciser. 
The use of a home or bathroom scale to measure body weight is commonplace. 
But the measurement of strength normally requires a separate scale. Thus, 
the patent to Newman, U.S. Pat. No. 2,784,592, discloses a muscle tester 
having a handle which is grasped by the user and pushed, the resultant 
force being indicated on a gauge. 
To make it possible to use a conventional bathroom weighing scale as a hand 
grip testing device, Richard et al., in U.S. Pat. No. 3,848,468, provides 
a grip accessory that is attachable to a body weighing scale. This 
accessory includes a plunger which when pressed downwardly by a gripping 
action causes the dial of the scale to indicate the strength of the grip. 
In order to use the scale to measure body weight, the accessory must be 
detached therefrom and the scale placed on the ground. 
Bradley et al., in U.S. Pat. No. 3,785,644, also uses a weighing scale to 
measure strength, and for this purpose an overhead bar is tied by ropes to 
the ground. The user, when raising the bar, stands on the weighing scale 
between the ropes. In this arrangement, in order to measure strength, 
after the individual steps on the scale it must then be zero set, so that 
regardless of the user's weight, the scale reads zero until he lifts the 
bar and imposes a force on the spring-operated scale that causes it to 
read above zero. 
Hence, should the user, after measuring his strength, now wish to measure 
his weight, the scale must be reset so that it reads zero in the absence 
of body weight. This requirement represents a practical drawback, 
particularly since as the user changes weight in the course of an exercise 
program, it becomes necessary to provide a different zero setting each 
time the scale is used to measure strength. 
SUMMARY OF INVENTION 
In view of the foregoing, the main object of this invention is to provide a 
strength/weight measuring scale which makes use of a conventional body 
weighing scale that need not be re-zeroed each time a reading of body 
weight or muscular strength is taken. 
More particularly, an object of this invention is to provide a selective 
scale of the above type in which the user steps on the scale to either 
measure weight or muscular strength, the user when measuring muscular 
strength grasping a handle to exert a force of the scale. 
Also, an object of the invention is to provide a dual-purpose scale of the 
above type which requires only a relatively minor and inexpensive 
modification of an existing bathroom scale, so that a scale of this type 
can be manufactured and sold at relatively low cost. 
Briefly stated, these objects are attained in a scale selectively operative 
in a weighing mode to measure body weight or in a strength mode to measure 
muscular strength. The scale includes a base which rests on the ground, 
above which is a depressible platform to compress a spring interposed 
between the platform and the base. The degree to which the spring is 
compressed, either by the platform or by the base, is converted into an 
analog or digital readout. 
Anchored on the base and extending through an opening in the platform is an 
upright post terminating in a handle that is elevated relative to the 
platform. Also provided is an adjustable stop which is coupled to the 
platform. When actuated, the stop engages the ground to prevent depression 
of the platform. In the weighing mode, the stop is disabled, and when an 
individual steps on the platform, the resultant readout indicates his body 
weight. In the strength mode, the stop is actuated, and when the 
individual steps on the platform and then exerts an upward force on the 
handle in accordance with his strength, the resultant readout is 
indicative of strength and is independent of body weight.

DESCRIPTION OF INVENTION 
Scale Structure 
Referring now to FIGS. 1 and 2, there is shown a scale in accordance with 
the invention constituted by a base 10 which rests on the ground G, and a 
depressible platform 11 thereabove provided on either side with pivoted 
stops 12, which are adjustable. The stops, when retracted, are disabled 
and permit the platform to be depressed by a person standing thereon, and 
when rendered operative by swinging the stops downwardly to engage ground 
G, the platform is held at its normally raised position above the base. 
The scale is provided with a digital readout 13 mounted at the back end of 
the platform so that it is readable by one who stands on the platform. 
Also provided is an upright post 14 that is anchored in base 10 at a 
center position adjacent the back end thereof. Post 14 extends upwardly 
through an opening 15 in the platform and terminates in a handle 16 which 
is elevated above the platform to a convenient height. In practice, the 
readout may be mounted on the handle at its junction with the post. 
As shown in FIG. 3 which exposes the internal mechanism of the scale, 
platform 11 is supported by four corner pieces 17 carried on levers 18. 
Though intermediate edges 19, one end of each lever is pivotally supported 
on a corner bracket 20 mounted on base 10. Levers 18 are coupled by rings 
21 to a hanger 22, the action of the levers being applied by the hanger to 
a main spring 23. The compression of the main spring is transmitted to a 
link lever 24 pivotally supported on a frame 25 within which the lever is 
seated, this transmission being effected through link pins 26, the link 
lever 24 acting to translate a toothed rack 27. This scale arrangement is 
similar to that disclosed in U.S. Pat. No. 4,113,039. 
As rack 27 is translated, this acts through a pinion (not shown) to rotate 
the shaft 28 of a graduated sector plate 29 to an extent determined by the 
degree of spring compression. Graduated plate 29 is provided with a series 
of indicia 30 in slit form, so that if the plate were exposed to view and 
rotated relative to a fixed pointer, it would provide an analog readout 
for the scale. 
However, to provide a digital readout, associated with scale plate 27 is a 
photodetector station 31. This includes a light source that projects a 
light beam through the slit aligned therewith, this beam being intercepted 
by a photodiode to generate a pulse each time a slit on the rotating scale 
plate is aligned with the photodetector station. Thus, when the scale 
operates, if the scale plate is caused to rotate to an extent causing 128 
slits to traverse the photodetector station, then 128 pulses will be 
transmitted to a resettable electronic counter 32. The total count of 
counter 32 is applied to digital readout 13 to provide a reading of 128 
pounds. 
In practice, counter 32 may be provided with a hold button 33 to retain the 
count accumulated therein so that the reading is held for the convenience 
of the user, and a reset button 34 to reset the counter to zero 
preparatory to a subsequent reading. These buttons may be mounted on the 
platform so that the can can be actuated by the foot of the user. 
Scale Operation 
When the scale is to be used in the weighing mode, stops 12 are disabled so 
that the platform is free to depress; hence when the user then steps on 
the scale, the depressed platform compresses the main spring to provide a 
reading of body weight in the fashion of a conventional bathroom scale. 
When the same scale is to be used to measure the strength of the user, the 
user first actuates the stops 12 so as to prevent depression of the 
platform. He then steps on the platform and grasps handle 16 and pulls on 
it to exert a force that depends on his strength. This action causes 
displacement of base 10 relative to the then fixed platform 12 to compress 
the main spring 23. The resultant readout on digital indicator 13 then 
represents the strength of the user and is independent of body weight. In 
other words, if the strength readout is, say, 150 lbs., that is equivalent 
to the user lifting a 150 lb. weight. 
In order to provide a progress report in which the body weight of the 
exerciser is correlated with his changing weight, the output of digital 
indicator 13 may be fed to a printing recorder 35 which cooperates with a 
calendar clock 36, thus when the recorder is rendered operative, it will 
then record and print out the body weight reading and the strength 
reading, each reading being printed against a time, day and date 
indication. In this way, the user will have a running record of his 
progress in the course of an exercise program. 
Where there has been shown a spring-type mechanical weighing scale, in 
practice the invention may be realized in an electronic scale using an 
electromagnetic, a capacitive, or a piezoelectric transducer to convert 
the displacement of the platform relative to the base to a weight or 
strength reading.