AN IMPROVED METHOD OF AND APPARATUS FOR TRANSMITTING MOTION
Year: 1882

page_text: LETTERS PATENT to Alexander Melville Clark, of 53, Chancery Lane, in the
County of Middlesex, Patent Agent, for an invention of "AN IMPROVED
METHOD OF AND APPARATUS FOR TRANSMITTING MOTION." A communication
from abroad by Antonio Samper, of Paris, France.
PROVISIONAL SPECIFICATION left by the said Alexander Melville Clark
at the Office of the Commissioners of Patents on the 18th April 1882.
ALEXANDER MELVILLE CLARK of 53 Chancery Lane in the County of Middlesex,
Patent Agent,
"AN IMPROVED METHOD OF AND APPARATUS FOR TRANSMITTING
MOTION [A communication from abroad by Antonio Samper, of Paris, France.]
This Invention relates to improvements in transmitting motion and consists more
particularly in the novel arrangement of apparatus herein designated an "adhesion
device" and the mode of applying the same for the transmission of motion by
means of cords and belts running on ordinary pulleys. The object of the Invention
is to guide the cords and belts and increase their adhesion and thereby to entirely
avoid the deflecting strain on the shafts and enable angles to be easily turned, and
obtain other advantages. Driving belts or cords usually run tight in order to
ensure their adhesion either by being made very short, or by means of a belt
tightener, or by both ways at once.
According to the present Invention the method employed and the result are
entirely different inasmuch as instead of tightening the cords or belts their adhesion
is increased to the greatest possible extent by causing them to embrace nearly the
whole circumference of the pulleys. When the increased adhesion thus obtained
is insufficient to transmit the motion, a slight tension is applied which serves to
regulate the adhesion and is generally incapable of exerting the least tendency to
deflect the shafta.
In order that the Invention may be more readily understood, I have represented
one example of the improved apparatus in Figures 1 to 11 of the accompanying
Drawings

page_text: The apparatus which I term an "adhesion device" is shown complete in
Figures I and 8, the frames being constructed of a pair of arms, and of a single
arm respectively. Figures 2. 3. 4. 5. 6 and 7 represent details. Figures 9 and 10
represent three different methods of transmitting motion by belts or cords with the
adhesion device" applied.
"
The device shown in Figure 1 is constructed of two arms A A mounted loose
on the shaft c one at each side of the pulley. The two arms A A shown separately
in Figures 2 and 3 may be applied without dismounting the shaft as they have an
opening to admit it which is closed by a strap d that also serves to strengthen the
arm at this point. This strap may however be dispensed with. The arms are
connected by cross bars f placed in holes g at one end of the arms and in slots h at
the other end and secured by nuts k screwing on the ends i and bearing against
washers. The arms A A may be either wood or metal; if of metal they and the
strap d may be made as shown in Figure 3. If made of wood the strap & shown
in Figure 2 is preferable as besides closing the opening e it strengthens the arm
and prevents it splitting.
If a flat belt be employed to transmit the motion, the pulley shown in Figure 4
is placed upon one of the two cross bars fas represented in Figure 1, and it is
retained on this its axis of rotation by means of two collars m fixed by set
screws as shown. Upon the other cross bar f is placed a hook n or a cord and
counterweight for obtaining the adhesion of the belt or cords.
Figure 1 represents the adhesion device for use with a flat belt. If the motion
is to be transmitted by means of a round cord or rope, the grooved pulley
represented in Figure 5 is substituted for the roller y shown in Figure 4.
When two or several belts or two or more cords are used at the same time for
the transmission of the same motion, I use in the first case rollers having a
corresponding number of shoulders like that shown in Figure 6 which has three
and is used with two belts at a time. In the second case I use pulleys linving
two or more grooves like that shown in Figure 7 which is used with three cords or
ropes at once.
The rollers or pulleys just described are also applicable as well for causing the
adhesion of the cords as for guiding them, and I therefore reserve to myself the
right to apply them if necessary without the adhesion device particularly in
the case where there are angles to avoid or to pass.
In order to apply the adhesion device, I place the cord or belt upon the pulleys,
leaving them sufficiently slack to embrace the portion of the circumference of the
pulleys on which it is desired to produce the adhesion, but the stretching of the
cord or belt must be allowed for in order to prevent the advancing and following
sides coming into contact. The arrangements shown in Figures 9, 10 and 11 may
be taken as examples.
The adhesion device proper is the roller or grooved pulley (Figures 4. 5. 6 and 7)
the other parts being the arms which carry the same. These arms may either be
mounted upon the shafts themselves or independently thereof and they may be
considerably varied in form according to circumstances. The adhesion device may
be applied in different ways viz (1) the arms loose upon the shaft itself with a
counterweight to regulate the adhesion of the belts or cords as applied to pulley S
Figure 9; (2) the arms loose upon the shaft without counter weight but fixed or
non-adjustable like that applied to pulley t Figure 9 in which the armi is secured
to a fixed point; (3) the arms fixed independent of or mounted upon the shaft like
that applied to pulley S figure 11 with adjustment by raising or lowering the
device (whether roller or pulley) in segmental slots concentric with the pulley;
(4) the arms fixed and independent of the shafts without adjustment like that
applied to the pulley t figure 11. The arms of the adhesion device of whatever
form may in all cases be mounted upon the shaft itself and be fixed either by means
of an adjustable counterweight or otherwise.
The Invention thus includes all the various forms which may be given to the
arms of the adhesion device to suit the requirements of each case.

page_text: The adhesion device with arms loose upon the shaft of pulley S figure 9 serves
to regulate the adhesion. It is provided with a counterweight suspended from one
end of the arms which causes the roller to press against the belt, said roller in turn
causing the belt to adhere to the pulley which it encircles as far as the length of
the belt will permit. If the belt stretches the greater will be its adhesion to the
pulley and the less necessity will there be for tension which is the reverse of what
obtains in the ordinary system wherein the more the cords or belts stretch, the
less becomes their adhesion and the greater the necessity for the application of
tension. The adhesion device may also be constructed with a single arm as shown
in Figure 8 in which the axis f of the roller is supported by a sleeve m fixed to
the arm by a nut k and screw o, which arrangement may be applied in all the
various possible modifications of this single arm device.
The rollers or grooved pulleys are the same in both arrangements of the device.
When flanged or grooved pulleys are employed, the plain roller s figure 4 may be
used. The flanges and grooves of the rollers should be of sufficient depth to allow
the fastenings of the cords or belts passing freely, only in certain cases for passing
angles with cords, it would be preferable to employ grooved rollers of the form
shown at Figure 5.
It is preferred to bring the rollers as close up to the grooves of, the pulleys as
possible but without compression as the closer they are, the better will the cords or
belts be guided by the flanges; in this manner increased adhesion is obtained.
The entire avoidance or diminution of tension depends upon the extent of the
circumference of the pulleys embraced by the cords or belts relatively to the force
transmitted, and it is for this reason that the adhesion device by increasing the
adhesion at will, permits of reducing the tension in certain cases and of entirely
avoiding it in others. Figure 11 represents an arrangement in which tension is
entirely avoided; in this case the arms of the two adhesion devices are fixed as
there is no advantage in their being movable, the arms of the device applied
to pulley & being slotted for the adjustment of the roller to prevent or cause
the alackening of the belt, the roller being always at the same distance from
the pulley.
Figures 10 and 10 bis represent an example of the transmission of motion from a
horizontal shaft p to a vertical shaft q. It will be seen that the roller r is plain,
the pulley t being flanged, while in Figure 10 bis which represents a plan of the
pulley a, the roller is flanged for guiding the belt, the pulley being without flanges.
It is not therefore indispensable for the pulleys to be flanged and is unnecessary
when the pulleys are flanged or grooved. The arms of the adhesion device should
be fixed in the longitudinal direction of the shafts by means of two collars m m as
shown in Figure 1. If the shafts are dismounted for the purpose of applying the
arms, they may be fixed by means of collars but if the shafte are not dismounted
cramps or other equivalent means would be employed for fixing them. The said
arms should be as close as possible to the pulleys without touching them so as to
help to guide the belte or cords when alackened for arresting the motion. The
arms of the adhesion device may also be mounted loose in the longitudinal
direction of the shaft by placing between each arm and the pulley, half rings
screwed to the same arm. These half rings render the arms independent, fix them,
and take the friction of the pulleys. To perfectly guide the cords or belts in
exceptional cases such as the loosening of the belts, two rollers or grooved pulleys
may be combined with the arm of the adhesion device by interposing a third
cross rod f.
The adhesion device differs from a belt
before mentioned, that the arms may be
because it can be conveniently applied in
little expense.
tightener for the reason, besides those
placed upon the shaft itself, and also
all cases without difficulty and at but
Under the generic term "cords" I include chains, ropes, and cables or cords of
all kinds which are circular in cross section, and under the term "belts" I include

page_text: flat bands of leather or any other material which may be substituted therefor as
well as plaited and other bands of animal, vegetable, or mineral origin.
The Invention ensures the following advantages among others :-
1st. Avoidance of tension between the shafts whereby both these and their
bearings are saved from wear, the cords or belts last longer, there is no waste of
power, more work is produced, and the shafts are not subject to vibration.
2nd. Facility for applying the cords and belts, as this system enables them to be
applied very slack.
3rd. Reduced space occupied by the leading and following portions of the cords
or belts as they work in close proximity to each other.
4th. Avoidance of loose pulleys to stop the motion as by withdrawing the
adhesion device, the cords or belts may be readily slackened.
5th. Avoidance of belt forks or other guiding devices to prevent the escape of
the driving cords or belts, this being effected by the adhesion device itself.
6th Continuity of motion even when the cords or belts are stretched as the
adhesion can only be favorably affected thereby.
7th Transmission of motion to several pulleys by means of a single cord or belt.
8th Transmission of motion at long or short distances, always without tension.
9th Increase or reduction of speed at will, always without tension.
10th Reduction of breadth and thickness of the belts.
11th Reduction in the size of the pulleys and diameter of the shafts by the
avoidance of strains due to tension.
12th Facility for change of direction by the way in which the cords or belts are
guided without tension, thereby saving the cost of gear wheels and all their
disadvantages, such as increase in the number of shafts, loss of power, vibration
and noise caused by friction &c.
In conclusion I would observe that a belt tightener can but very slightly increase
the adhesion of the cords or belts, while it deflects the shafts, does not enable a
change of direction of the motion and is always conducive to tension, whereas this
improved adhesion device never causes tension but on the contrary reduces and in
some cases even entirely prevents it.
Instead of fixing collars m by set screws they may be loose sleeves filling the
space between the roller and the arms of the frame, or instead of sleeves the roller
may have a prolongation at each end of the same diameter as the sleeves.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Alexander Melville Clark in the Great Seal Patent Office on the
18th October 1882.
ALEXANDER MELVILLE CLARK of 53 Chancery Lane in the County of Middlesex,
Patent Agent "AN IMPROVED METHOD OF AND APPARATUS FOR TRANSMITTING
MOTION A communication from abroad by Antonio Samper of Paris, France.
"
In transmitting motion by means of cords and belts applied upon revolving
surfaces without being wound spirally thereon, the adhesion of the cords or belts
is indispensable and is dependent upon the surface contact between the cords or
belts and the pulleys, and is ordinarily supplemented by applying tension which
when excessive exerts a strain upon the journals of the shafts in their bearings.
This tension increases or diminishes inversely as the circumference embraced which
is generally only that of one half of the pulley. This tension is generally applied
either by running the cords or belts tight upon the pulleys and shortening them
from time to time by cutting as they become stretched or by applying a loose
pulley or roller to press against the following portion of the cord or belt sufficiently
to produce the necessary tension. By these means the contact surface between the
cords or belts and the pulleys is not increased but the deficient frictional adhesion
is compensated by the application of tension which gives rise to numerous defects
and inconveniences in the transmission of motion. This tension roller which from
its function is designated a belt tightener is grooved when applied to a round cord
and plain when applied to a flat belt, and in this latter case it may be flanged if it
be intended to also guide the belt. This belt tightener is employed in many cases
and is carried on arms of various forms, according to the circumstances of each
case. Sometimes it is suspended by a cord or counterweighted, sometimes it is
mounted in arms more or less long, but in all cases it acts on the cord or belt at
a distance from the pulleys and never approaches near thereto but moves in an arc
of a different radius to the pulley.
Figures 1 to 5 of the drawings represent five different arrangements for trans-
mitting motion by means of balts provided with belt tighteners or tension rollera m.
In certain cases as in Figure 4, the belt tightener slightly diminishes the points or
surface of contact between the belt and the pulley; in other cases it slightly
increases it. With the ordinary belt tightener there is always one half of the
pulley out of contact with the cord or belt.
The object of the present Invention is to increase the adhesion of cords or belts
as well as to perfectly guide the same, whereby important results are obtained
differing considerably from those derived from the use of the ordinary belt
tightener before described. A. loosely rotating roller is also employed in the
present case, but it is so disposed as to increase to the greatest possible extent
the points of contact between the cords or belts and the pulleys. The roller is
applied to the following side of the cord or belt and brought up to the pulley
Bo as to touch it if desired, but pressing against it. The roller is also approached
as close as possible to the leading part of the cord or belt but without touching it,
this roller being moved in a circle concentric with the pulley and therefore always
close to it. Thus adhesion is increased without giving rise to tension, and for this
reason the term "adhesion device is applied to the roller and its adjuncts by
which this result is obtained, instead of "tension roller" or "belt tightener." The
Invention thus consists more especially in novel means of applying and arranging
these adhesion devices. By means of this Invention the cords and belts may
envelope nearly the entire circumference of the pulleys.

page_text: In order that the Invention may be more readily understood, I will proceed to
describe some examples with reference to the accompanying drawings in which
Figures 1 to 5 show, as already mentioned, five different modes of applying a
tension roller as now commonly employed. Figure 6 represents an adhesion
device g carried in frames S (Figure 6bis) mounted on a shaft Gd. Figures 7. 8.
9. 10 and 11 show four different methods of applying the adhesion device g.
Figures 12 to 16 show different views of rollers or pulleys forming the adhesion
device. The pulley Figure 15 is employed for two belts, and Figure 16 for three
cords. Figure 17 shows a novel arrangement of tension device more especially
intended for use in transmitting motion by means of spirally wound cords, as
shown in Figures 18 and 19. Figure 20 represents in plan a novel arrangement
for transmitting motion to a mill with three rolls and Figure 20 bis an elevation of
sume. Figure 21 shows the same driven in a different manner.
In Figure 6 the adhesion device is mounted loose between collars n on shaft G.
The roller g turns between collars c c on a spindle d mounted in arms 88 which
are connected or braced together by the rods or spindles d and i that are adjustably
fitted in slots j j of said arms seen in Figure 6th and are tightened up by means
of nuts on their ends. The arms are slotted to receive the shaft G, the opening
being covered by a plate 9 Figure 6t to permit of the adhesion device being
applied without the necessity of dismounting the shafting. o, Figure 6, is a hook
upon which a weight is placed to regulate the adhesion.
Figure 7 represents an arrangement in which the frame 8 of the adhesion device
of pulley x assisted by the counterweight i, causes the adhesion roller g to rise as
the band stretches. The flanges of the roller are brought close up to the edge of
the pulley and form a guide for the belt even although the roller is lowered, so
that on raising the counterweight 2, the motion will be arrested, as pulley x is the
driver, and the belt will be always maintained in position and guided by the
roller g.
b is the leading, and m the following part of the belt. The adhesion
roller 9 of pulley a is mounted in stationary bearings and is intended to ensure
the greatest possible amount of adhesion to said pulley as being the one most
requiring it. The flanges of the adhesion roller g may either face or embrace
between then the pulley a.
Figure 8 shows the method of transmitting motion from a pulley a mounted
on a vertical shaft v to a pulley a on a horizontal shaft. In this case the adhesion
device of pulley a is attached to a fixed point u while the adhesion roller g of
pulley is not flanged, the belt being guided by the flanges of said pulley x.
In Figure 9 a single adhesion roller g is employed which may be adjusted in
position in slot i as the belt stretches, only one adhesion roller being needed in this
case as it sufficiently increases the adhesion upon both pulleys. The slot i is made
concentric with the circumference of pulley a as it is on this pulley the adhesion
of the belt needs to be increased.
Figure 10 shows an arrangement in which two adhesion rollers grare employed.
The roller g which is stationary increases the surface contact between the belt and
the pulley while roller r serves as a belt tightener, being adjusted as the belt
stretches. In this case it it unnecessary to increase the adhesion of the belt upon
pulley x so long as the belt is not slack.
Figure 11 shows two adhesion devices applied one to each pulley, that applied
to pulley x moving in a slot m concentric with the pulley; the "following
portion of the belt remains slack as there is an excess of adhesion to the pulleys
relatively to the power transmitted.
Figures 17. 18. and 19 illustrate the second part of the Invention which consists
in a convenient form of apparatus for putting in tension cords wound spirally
upon the pulleys. Instead of this tightener the adhesion device represented in
Figure 6 may be employed with advantage, but as the cords when elastic are
liable to stretch too much, it is preferable to employ the tightener Figure 17 which
moreover affords every guarantee of security. The apparatus is mounted on an
intermediate shaft G and as will be seen in these three figures, the spindle n, the

page_text: pulley and the weight it carries, for the tightener and rise and fall in grooves
made in the arms, aided by the friction rollers a a, a a. The arms are loosely
mounted like those of the adhesion device Figure 6, and may be extended as in
the tightener shown in Figure 19, which is a modification of the adhesion device
shown in Figure 6 and is retained in place by its weight alone when the adhesion
of the cords is sufficient, provided that the cords have been coiled the necessary
number of turns around the pulleys.
Another part of the Invention is represented in Figures 20 and 20 bis, which
consists in a novel method of transmitting motion to grinding rollers by means of
belts. In the example shown the mill is composed of three grinding rollers, each
of which is provided with a pulley a dc of lesser diameter on which the belt
runs, the rollers or part of larger diameter turning in contact for the purpose of
grinding. In Figure 20 they are shown as mounted in a frame with a belt q
embracing about 300° of the circumference of each of the pulleys. The belt is
kept tight by the adjustable grooved pulley m The pulleys dc, d a turn in
opposite directions, but not pulleys a c, so that grinding can be performed between
rollers d c, d a, but not by a c. The pulley d is the driver and is operated by the
crank handle 8. This part of the Invention consists in the form and arrangement
of the pulleys, in the application of the tension roller m, and in the manner of
applying the belt, the whole forming a new combination. The adhesion device
proper consists of the roller or grooved pulley shown in Figures 12. 13. 14. 15. 16.
the other parts represented upon which said roller or grooved pulley is mounted,
being but accessories. The adhesion device may be applied in various ways, for
example, the arms or frames may be mounted loosely upon the transmission shaft
and a counterweight be provided to regulate the adhesion of the cords or bands
as in the arrangement applied to pulley & in Figure 7, or the arms may be loosely
mounted as before, but without any counterweight as in the adhesion device
applied to pulley a Figure 8, or the arms may be fixed adjustably and independent
of the driving shaft, as in the adhesion device acting on pulley & Figure 11, or
the arms may be rigidly fixed and be also independent of the driving shaft, as in
the adhesion device applied to pulley a Figure 11, or the adhesion device may be
otherwise applied. Thus whatever may be the form and position of the arms or
frames of the adhesion device, it will be comprised within this Invention if the
adhesion roller or pulley be applied in the novel manner herein described for
increasing the adhesion of cords or belts on the pulleys, that is to say, close up to
the pulleys, or by bringing the following part of the cord or belt close up to the
leading part, or by causing the adhesion roller or pulley to move in an arc con-
centric with the circumference of the driving pulley. Finally, I would remark
that by means of this improved system tension is avoided, the cords or belts are
perfectly guided, power is economised, and toothed gearing may be dispensed with
and its attendant noise and vibration avoided.
Having described the nature of the said Invention and the manner of performing
the same, I declare that what I claim as the Invention to be protected by the
hereinbefore in part recited Letters Patent is.
1st. In an apparatus for producing adhesion between cords and belts and their
pulleys mounted loose upon a shaft G, the combination of roller g, collars c,
spindles & and i moving in guide grooves j, collars n, and hook o, of counter-
weight with arms & having slots q as described and shown in Figures 6 and 6his.
2nd. The arrangement by which the apparatus s is attached to a fixed point u
as described and shown in Figure 8.
3rd. The arrangement of apparatus represented in Figure 9 with its adhesion
roller g mounted on a slotted support i concentric with the "following" pulley a,
as described for the purpose specified.
4th. The combination represented in Figure 10 of an adhesion roller g whose
journals are adjustably mounted in a grooved support with tension roller r
adjustable to compensate for the stretching of the belt.
5th. The arrangement represented in Figure 11 consisting in the combination

page_text: of two adhesion devices, one moving in a guide groove of its support concentric
with the motive pulley for the purpose of producing the adhesion of the belt
thereon for the purpose specified.
6th. The arrangement of apparatus represented in Figure 17 mounted loose upon
shaft G and consisting in the combination of tie rods i, spindle n, pulley c, collar d,
and friction rollers a as described.
7th. The arrangement represented in Figures 20 and 20 bis for transmitting
motion to a three roll grinding mill by means of pulleys as described.
In Witness whereof I the said Alexander Melville Clark have hereunto set
my hand and seal this sixteenth day of October, A.D. 1882.