IMPROVEMENTS IN APPARATUS FOR MEASURING AND REGISTERING POWER TRANSMITTED BY DRIVING BELTS.
Year: 1882

page_text: LETTERS PATENT to Charles Vernon Boys of Wing near Oakham in the
County of Rutland for an Invention of IMPROVEMENTS IN APPARATUS FOR
MEASURING AND REGISTERING POWER TRANSMITTED BY DRIVING BELTS.
"
PROVISIONAL SPECIFICATION left by the said Charles Vernon Boys at
the Office of the Commissioners of Patents on the 31st October 1882.
CHARLES VERNON BOYS of Wing near Oakhan in the County of Rutland
IMPROVEMENTS IN APPARATUS FOR MEASURING AND REGISTERING POWER
TRANSMITTED BY DRIVING BELTS
"
My invention relates to apparatus for measuring and registering power trans-
mitted to driving belts. For this purpose, when the power to be measured is
comparatively small, I transmit it from one pulley to another by an elastic belt
which, stretching more in its driving than in its following portion necessarily has
a somewhat different speed in those two portions. By causing those two portions
to drive each a pulley by contact therewith the advance of one of those pullies
beyond the other will indicate the excess of travel of the one portion of the belt
over that of the other and will consequently be a measure of both the stretch of
the belt and of its velocity that is to say of the work transmitted by it. Other-
wise the elastic belt may be applied to drive a pulley and an inclastic belt driven
from the same drum may drive in the opposite direction another pulley loose on
the shaft which carries the pulley driven by the elastic belt, and the difference of
travel of these two pullies indicated by sun and planet gear will in like manner
shew the work transmitted. When the power to be measured is considerable, so
that it would be practically difficult to employ an elastic belt for transmitting the
whole of it, I use an elastic belt for transmitting a known fraction of the whole
power in the following manner. On either of the shafts which carry the main

page_text: pullies connected by an ordinary belt, I mount loosely a pulley connected with a
pulley on the other shaft by an elastic belt and I connect this pulley through sun
and planet multiplying gear to the shaft on which the main pulley carrying the
planet wheel is loose. Thus the elastic belt has only a fraction of the tota!
driving strain determined by the ratio of the multiplying gear. The difference of
travel of the two pullies will then as before measure the work transmitted.
According to another method I apply guide rollers to deflect the main driving belt,
these rollers being mounted on a frame connected to a friction brake on a shaft
driven by an elastic. band, and measuring as above described the strain to which
the olastic band is subjected in overcoming the resistance of the brake, I thus
obtain an indication of a known fraction of the work transmitted by the main
driving belt.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Charles Vernon Boys in the Great Seal Patent Office on the 30th April
1883.
CHARLES VERNON BOYS of Wing near Oakham in the county of Rutland
"IMPROVEMENTS IN APPARATUS FOR MEASURING AND REGISTERING POWER
TRANSMITTED BY DRIVING BELTS
"
My invention relates to apparatus for measuring and registering power trans-
mitted by driving belts. For this purpose, when the power to be measured is
comparatively small, I transmit it from ono pulley to another by an elastic belt,
which, stretching more in its driving than in its following portion, necessarily has
a somewhat different speed in those two portions. By causing those two portions
to drive each a pulley by contact therewith, the advance of one of those pullies
beyond the other will indicato the excess of travel of the ono portion of the belt
over that of the other and will consequently bo a measure of both the stretch of
the belt and of its velocity, that is to say of the work transmitted by it. Other-
wise, the elastic belt may be applied to drive a pulley and another belt driven from
the same drum may drive in the opposite direction another pulley loose on the
shaft which carries the pulley driven by the elastic belt and the difference of
travel of these two pullies indicated by sun and planet gear will, in like manner,
shew the work transmitted. When the power to be measured is considerable, so
that it would be practically difficult to employ an elastic belt for transmitting the
whole of it, I use an elastic belt for transmitting a known fraction of the whole
power in the following manner. On either of the shafts which carry the maiu
pullies connected by an ordinary belt, I mount loosely a pulley connected with a
pulley on the other shaft by an elastic belt, and I connect this pulley through sun
and planet multiplying gear to the shaft on which the main pulley carrying the
planet wheel is loose. Thus, the elastic belt has only a fraction of the total driving
strain determined by the ratio of the multiplying gear. The difference of travel of
the two pullies will them, as before, measure the work transmitted. According to
another method, I apply guide rollers to deflect the main driving belt, these rollers
being mounted on a frame connected to a friction brake on a shaft driven by an
elastic band, and measuring, as above described, the strain, to which the elastic
band is subjected in overcoming the resistance of the brake; I thus obtain an
indication of a known fraction of the work transmitted by the main driving belt.
The accompanying drawings shew various forms of apparatus by which my
invention may be carried out in practice.
In the arrangement shewn in fig. 1, A and B are two pullies connected by an
elastic band, so that their circumferential speeds differ by a quantity proportional
to the velocity and the stretch of the band under the driving strain. On their
respective shafts,. 1 fix proportional pullies a and b driving pullies C and D by
bands which, being subject to very small strain, may be considered practically
inextensible. The pullies C and D are loose on a spindle E, on which is fixed a
sleeve e carrying a bevil wheel gearing with bevil wheels on the pullies C and D.
The spindle E works the train of a counter F, having dials and indices which
register the number of revolutions of E. The number of revolutions thus registered
is manifestly that due to the difference of the speed of C and D, which difference is
proportional to the product of the speed and strain of the band connecting A and B,
and therefore is a measure of the work transmitted by it.
In the arrangement shown in fig. 2, G is a drum loose on the shaft H, but driven
by a strong band which may be considered as practically inextensible. On the

page_text: shaft H is fixed a toothed wheel h, gearing with pinions on spindles i mounted in
bearings in the sides of the drum G. On the spindles i are fixed wheels I which
gear with a pinion fixed on a pulley J which is loose on the shaft H. A pulley j
fixed on J and another pulley k fixed on the shaft H are connected to a counter
through sun and planet gear in the same way as the two pulleys a and b in Fig. 1.
The pulley J, being driven by an elastic band from the same motor as that from
which the drum G is driven by an inextensible band, will have a speed less than
that of G by an amount depending on the extension of the elastic band,' and there-
fore proportional to the strain on it and to the velocity. This strain is however
only a fraction of the total strain required to drive the shaft H as determined by
the proportions of the gearing connecting h to J. Hence the counter worked from:
the pullies J and will register a corresponding fraction of the total work transmitted
to the shaft H.
According to the arrangement shewn in Fig. 3, a driving belt L is tightened by
two rollers mounted on a frame M which is balanced and connected to a' friction
brake on a spindle N. On this spindle, is a pulley n connected by an elastic band
to a pulley p fixed on the same shaft with the pulley or drum P, which drives or is
driven by the belt L. Assuming the belt L to travel in the direction of the arrow,'
so that its upper part is the tight part, this, tending to straighten itself, will strain
the roller frame M upwards with a force proportional to the strain on the belt and
consequently will apply to the spindle N a proportional frictional resistance tending
to retard it whilst it is caused to revolve by the band connecting it to p, the
elasticity of this band permitting such retardation. The difference of the speeds of
the shaft of P and of the spindle N, registered. by a counter in a manner similar
to that described with reference to fig 1, will then afford a measure of a known
fraction of the work transmitted by the belt L.
=
Having thus described the nature of my invention and in what manner the same
-is-to-be performed, I claim:
First: Tho herein described method of measuring-and registering power trans-
mitted by driving bolts, by arranging a counter worked by differential
gear, so as to indicate the excess of travel of the driving part of an elastic
belt over that of its driven part, the said elastic belt being applied to
transmit either the whole or a know fraction' of the power to be measured.
Second The combination of a counter with differential gear driven from two
shafts one of which is driven by an elastic belt from the other, substan-
tially as and for the purpose set forth with referenco to fig. 1.
Third-For measuring a known fraction of the power transmitted by a belt, the
construction and arrangement of apparatus, substantially as described with
reference to fig. 2.
Fourth For measuring a known fraction of the power transmitted by a belt,
the construction and arrangement of apparatus' substantially as herein
described, with reference to fig. 3
In Witness whereof, I the said Charles Vernon Boys have hereunto set my
hand and seal this Twenty eighth day of April in the year of our Lord, one
thousand, eight hundred and eighty-three.