Improvements in Billiard Cushions.
Year: 1899

page_text: Improvements in Billiard Cushions.
I, DUDLEY KAVANAGHI, of 115, Broadway, City of New York (Borough of Man-
hattan), County and State of New York, United States of America, Gentleman,
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:-
My invention relates to billiard-table cushions of that type which is now and
has been for some years almost wholly the kind made and used-namely,
cushions composed each of a strip of vulcanized-rubber compound having a
cross-sectional shape approximately triangular and arranged, in conjunction
with the cushion-rail and bed of the billiard-table, in such a manner that a ball
such as used on the table will when caused to roll on the table-bed and to contact
with the cushion have the initial point of contact between itself and the nose
or upper edge of the cushion's work face at an elevation above the table-bed
somewhat greater than that at which lies the center of the ball.
"
As is well known to those skilled in the art of making billiard-tables and
understanding the game of billiards, the necessary elements of a satisfactorily-
operating cushion are accuracy in the angles of incidence and reflection when
a ball is played against the cushion, the greatest practicable degree of repellent
power that is, a capacity in the cushion to afford as much legs" to the ball
thrown off as possible-responsiveness when delicate strokes are played-that is,
the capacity of the cushion in an eminent degree to properly repel or throw off
either an object or the cue ball when the ball may strike the cushion with very
little force a capacity to throw off a ball at the correct angle when it shall
have approached the cushion at an exceedingly acute angle, non-liability to
cause or permit a ball to "jump "when played with great force against the
cushion, and a capacity to retain for a comparatively long time all these essen-
tial qualities with which the cushion may be endowed when new, or, in other
words, great durability. As it is a fact in practice that a cushion possessing in
the greatest possible degree some one or more of these desirable qualities must
therefore be lacking to an undesirable extent some other one or more of such
qualities, it follows that to produce the best possible cushion practically the
latter must embody the happiest possible combination of these individually
somewhat antagonistic structural features. In other words, to produce the most
satisfactory results these several and separately desirable but in some measure

page_text: antagonistic qualities or characteristic features must be combined in such pro-
portions as to produce a harmonious whole from which the best results desirable
from a combination of such elements (the quality of each of which is in some
measure necessary) may be obtained.
In order that a ball played with considerable force against the cushion shall
not jump, the latter must have its working face located in a plane oblique to
that of the table-bed. or must form an angle with the table-bed considerably
less than a right angle, (in the well-known manner), into which angle the ball
is "wedged," so to speak, when it strikes and is more or less embedded in the
cushion; but inasmuch as the ball will be repelled or thrown off by the cushion
with less and less speed just in proportion as the degree of obliquity of the
cushion's working face is increased therefore it is important that this degree of
obliquity be reduced to the minimum. If that part of the cushion's face with
which the ball contacts in the case of the hardest strokes played at such angle
as tends to a very forcible impact of the ball and cushion were perpendicular to
the plane of the table-bed, the reactive power of the cushion on the ball-i.e.,
its capacity to quickly and forcibly throw off the ball-would be the greatest
possible; but such form or arrangement of this part of the cushion's face is
entirely impracticable, because with it the balls would jump to such an extent
that the table would be useless for the game of billiards. Hence the departure
from the perpendicular to the oblique form of the cushion's working face must
be only to the extent necessary to avoid the jumping of the ball, thus rendering
the cushion capable of repelling or throwing off the ball with the greatest prac-
ticable speed. In other words, the degree of obliquity of the face of the cushion
must be such that the cushion will be as
"fast"
a one as possible without
liability of the balls jumping.
While it is necessary or unavoidable that the ball shall be embedded in the
upper part of the working face of the cushion, this embedment should be as
little as possible, especially in the case of a stroke with the angles of incidence
and reflection comparatively non-acute, since this embedment impairs accuracy
in the angles of the stroke, and many ways have been devised and used to
render the cushion capable of powerful repellent action without getting per-
ceptible and undesirable inaccuracy in the angles of the stroke. Most of the
devices or means employed for this purpose are generally denominated "face-
hardening devices, and some such means for the specific purpose of prevent-
ing too much embedment of a ball striking the cushion with considerable force
and at an angle not very acute may be employed in the construction of my
improved cushion if found to be expedient, though in my improved cushion the
necessity for the presence of some face-hardening means is not so necessary as
in the cases of all previously-devised cushions that I know of, because in my
cushion, as will be presently explained, less embedment of the ball can occur
with a given degree of repellent capacity.
As is well known, the incorporation of face-hardening devices in the molded
cushion-strip of rubber compound as a general rule leads to the objections that
the cushion, though it may work well when new will soon lose its life-that is,
will grow slow in action and will soon work imperfectly and unsatisfactorily,
owing mainly, as I understand the matter, to the practical impossibility in most
cases of making a cushion so that the rubber compound of the strip will remain
in perfect union with the face-hardening device. In order that in playing a
ball against the cushion at a very acute angle it shall promptly leave the point
of contact therewith at a correct angle, (and not slide on the contacted surface
to the least extent,) I deem it necessary to have the working surface of the
cushion exceedingly impressible-that is, highly elastic. and very responsive to
the touch of the ball-and this quality is also very necessary where the ball has
to be played very easily against the cushion even at a nearly or quite right
angle and is required to rebound only a short distance. Therefore if any face-
hardening device be employed it should be molded in or placed so far in rear

page_text: of the actual working face of the rubber strip as not to interfere with the struc
tural qualities just explained to be very important, while at the same time
operating perhaps to render the cushion quicker when very hard strokes may
be played.
"
As the material of the cushion-strip is perfectly incompressible, though highly
elastic, by reason of the great mobility of the particles of the mass and the
power and rapidity with which they resume their normal relationship after dis-
tortion of the shape of the mass-as, for instance, by the impact of a ball
against the nose and upper working face of the cushion-the practical problem
presented for solution in the devisement of a billiard-cushion that shall be as
near perfection in all particulars as possible has ever been to construct the
cushion so that while possessing in an eminent degree the peculiarities I have
explained as being necessary the manner of displacement of the particles of the
mass shall be such that in resuming their normal relationship the cushion
will act with the greatest possible ball-repellent force. In other words,
in order to make the cushion act on the ball with the greatest
possible degree of repellent force it must be made SO that when
the ball strikes it the displacement of the particles in or the disbursing of the
mass of rubber compound shall be such that in resuming the normal condition
the cushion will exert the greatest possible action on the ball in the right direc-1
tion and in the best possible manner for the purpose desired. Now, as is well
understood, the cushion being made necessarily with an oblique working face
and a comparatively sharp working upper edge or nose" the effects of a ball
striking the nose or working face of the cushion are to bend upwardly and back-
wardly the extreme forward edge or nose and at the same time to displace the
particles of the mass so as to produce a hump in the top surface of the mass
in rear of the nose or working edge. Now when under these conditions the
mass of rubber compound resumes its normal shape, thereby repelling or throw-
ing off the ball, its action on the ball operates in a large measure to press the
ball downwardly toward or against the bed of the table, because the upturned
nose and the upwardly displaced particles (or the hump above alluded to) in the
resumption by the mass of its normal shape necessarily produces this effect;
but, as I have above explained, the best possible repellent action of the cushion
is attained when in the resumption of its normal shape or condition the move-
ment of the displaced particles shall be such as will cause them to press against
the ball in a direction approximately, horizontal. In other words, to get the most
desirable action practically possible the construction and operation of the cushion
should be such that when struck by the ball the particles of the mass shall be
forced as nearly rearwardly or backwardly in a horizontal direction as practicable,
so that in the reaction of the cushion on the ball they will move forwardly as
nearly as practicable in a horizontal direction. By such mode of action "not
only is the ball not wedged in beneath the nose of the cushion, so that less of
the reactive power of the cushion will be expended in "unwedging the ball," so
to speak, but, furthermore, a maximum proportion of the reactive force of the
cushion operates to throw off the ball in a plane approximately parallel with
that of the table-bed, and hence the ball will leave the cushion with more legs
or at a greater speed than under other conditions, and upon this theory of the
principle of construction, and mode of operation rests my invention, which may
be said to consist, essentially, in the combination, with the rubber cushion-strip,
of means for preventing the particles of the mass from being displaced upwardly
in rear of the nose when the ball strikes against the latter and for causing a
displacement of the particles of the mass in an approximately rearward direc.
tion, so that in resuming its normal shape the particles of the rubber strip will
move and act so as to repel the ball as nearly as possible in a horizontal direc-
tion, all as will be hereinafter more fully explained and as will be most parti-
cularly pointed out in the claims of this specification.
To enable those skilled in the art to make and use my improved cushion, I

page_text: will now proceed to more fully describe my invention, referring by letters and
figures to the accompanying drawings, which form part of this specification and
in which I have shown my improvement carried into effect in that precise form
of cushion in which I have so far practiced it, though it may be carried out
either wholly or in part under some modifications thereof,
In the drawings, Figure 1 is a vertical cross-sectional view of so much of a
billiard-table as it is necessary to show in order to illustrate my invention in
one form of it or carried out as to the main part of it. Fig. 2 is a similar view,
but showing the invention embodied as to both of its features or parts. Fig. 3
is a cross-sectional view illustrating the natural tendency and action relatively
to the displacement of the particles of the rubber mass composing a cushion
strip of the modern approved form when struck by a ball. Fig. 4 is a top
view of what is illustrated in vertical section of Fig. 3. Fig. 5 is a similar
cross section to Fig. 3, but showing how the displacement of the particles of
rubber occurs in my improved cushion-strip.
In the several figures the same part will be found always designated by the
same letters and figures of reference, and in some of the figures I have illus-
trated by circular, full, and dotted lines a billiard-ball coacting with the
cushion.
a is the rubber cushion-strip, made of vulcanized-rubber compound and of
about the usual approved size and cross-sectional shape and secured in the usual
manner to the wooden lining of the cushion-rail b; that is bolted (in the ordi-
nary way) to the bed of the table, the playing-surface of which is illustrated
by the line c. It may, however, be remarked right here that in making my
improved cushion I prefer that it be of the maximum size of cushion-strips
and contain a comparatively large percentage of pure rubber; also, that the
recess or concavity at e in the rear surface of the molded strip, which is usually
(though not invariably) formed in the strip a, is of very great advantage in
my improved construction of cushion and is preferably made comparatively
large, since the use of my cushion the displacement of the particles of the
rubber mass is so different from that in other cushions as to render it quite
desirable that this cavity e (between the rear surface of the cushion and the
plane surface of the wooden cushion-rail lining) be comparatively large.
By reference now to Fig. 3 it will be understood that when a ball, such as
illustrated by the full circular line 1, forcibly contacts with the nose or work-
ing surface of the rubber strip the latter will be distorted from its normal
cross-sectional shape shown in full lines to the shape or condition illustrated
by the dotted lines, and it will be seen that when the rubber particles resume
their normal positions the tendency and action of the cushion during its resto-
ration to its natural shape is to press downwardly and forwardly on the sur-
face of the ball (illustrated by the dotted line 2) in repelling or throwing off
the ball, and that therefore a large percentage of the repellent power and
action of the cushion is consumed in unwedging the ball (as I have herein-
before expressed the idea) from between the bed-surface of the table and
that part of the oblique face of the cushion, which was in forcible contact with
the ball's surface at a locality wholly (and some distance) above the center
of the sphere, and it will also be readily understood that while perhaps a very
small amount of displacement of the rubber particles may occur in a rear-
ward direction and be dissipated at the rear surface, imperceptibly changing
the shape of the mass at the vicinity of the rear recess or cavity e, practically
about all the displacement of particles amounts merely to a translation of the
particles normally occupying the approximately triangular area yz, Fig. 3,
to the somewhat similarly-shaped area marked sa in the same figure. Of
course I can only describe, and illustrate this approximately correct manner of
displacement with substantial, not mathematical, accuracy, and it will be
observed that for the sake of distinctness in my illustrations I have not shown
in the drawings the green cloth covering which always envelops the oblique

page_text: working face and the top surface of every billiard-cushion in a finished and
operative condition, and while it is true that the operation or action of a
naked cushion when struck by a billiard-ball is modified by the presence of
the usual cloth covering what I am describing and illustrating is substantially
correct with reference to the covered or finished cushion-strip.
As I have made the accompanying drawings on a scale of full size as to
the cushion and the ball it presents to the eye just about the actual conditiona
herein described.
By reference especially to Fig. 4 it will be seen that the displacement of
the rubber particles diminishes laterally from the point w in either direction
to where the dotted circle 2 of the ball runs out of contact with the cushion,
and it will be understood, of course, that the vertical cross-sectional views are
made on planes which coincide with the point w of the top view, Fig. 4. f is
a narrow strip or ribbon-like piece of some textile fabric, preferably a toler
able thin but strong quality of canvas, that is molded onto the top surface of
the rubber strip a at about the locality shown. In practice this strip of canvas
is properly placed in the mold in which the plastic or dough-like rubber com-
pound is put in 'the usual process of manufacture of cushion-strips and in
which the strip, with its adjuncts, is subjected to the vulcanizing process. The
canvas g, which by preference covers the entire oblique surface of the rubber
strip a, is also applied in like manner during the process of manufacture, all
in such manner that in the finished cushion the interstices of the woven fabrics f
and will be filled in with the rubber compound. In other words, so that in
the finished article as to both the top and the oblique faces of the cushion-
strip these surfaces will be. composed of rubber and canvas, the outermost
particles of both of which materials will be flush with each other or lie in
the same plane.
By reference now to Fig. 5, where I have shown the normal configuration
of the cushion in full lines and its distorted shape (caused by the impact of
the ball) in dotted lines, it will be seen that the particles are displaced almost
imperceptibly in an upward direction at the top surface of the cushion, to a
greater extent downwardly at the locality of the oblique working face of the
strip, and perceptibly in a rearward direction, so as to lessen the area of the
cavity or recess e in the back side of the cushion-strip, and it will be under-
stood that under such conditions as to the manner in which the shape of the
cushion is distorted by the impact of the ball in resuming its normal shape,
and thereby throwing off the ball 2, my improved cushion operates in a much
more efficacious and desirable manner than cushions of the previously-known
constructions. In the first place, in resuming its normal condition the cushion
pushes on the ball in an almost wholly horizontal direction, while it operates
to rather counteract the enforcement downwardly of the ball onto the bed c
(which of course by the friction created consumes a portion of the ball-repel-
lent power of the cushion) in lieu of augmenting this undesirable condition,
as does a cushion such as those heretofore made and used, and, in the second
place, the contacting and impacted portion of the cushion not being elevated
as heretofore this nearly horizontal repellent force of the cushion is initially
applied to the ball at a point lower down on its spherical surface more nearly
in line horizontally with the ball's center of gravity, and hence with more
effect on the ball bodily to throw it off.
Although the presence in my cushion of the canvas or other facing g, of
non-stretchable material, is very desirable, since it performs the function of
preventing even the slight lifting or turning upwardly and backwardly of the
extreme edge or nose of the cushion, yet with this device omitted my improved
cushion, by reason of the combination with the rubber mass, in the manner
shown and described, of the top strip f of canvas or other suitable non-
stretchable fabric, will produce greatly-improved results, since by reason of
this combination alone preventing the displacement of the particles of rubber

page_text: upwardly at the top surface of the cushion the latter is made to operate, as I
have just above explained, to repel the ball more nearly horizontally than
cushions heretofore made.
The canvas facing g, molded on, as described, is, I know, not new, per se, in
a billiard-cushion and it has heretofore been suggested that such a facing
operates to tie down or prevent the uprising of the nose of the cushion when
the latter may be struck by a ball; but, in the first place, such a cushion as
heretofore made is not efficient for any such purpose, because when such a
cushion has its nose forced upwardly and backwardly, as illustrated at Fig. 3,
the canvas facing will move approximately into the plane of a radius of a
circle whose center is nearly coincident with the lower point or root of the
strip a, and when moved in this manner its upper edge will be higher rela-
tively to the bed c of the table than before, and hence will not prevent the
upper forward part of the cushion from assuming the higher position into
which the impacting ball tends to lift it. In my improved cushion; however,
any initial bulging up of the top surface of the cushion immediately in rear
of the nose or extreme working edge being prevented by the function of the
strip f, as the ball proceeds to embed its impacting surface in the rubber mass
the particles of the latter are naturally displaced downwardly, and this sort
of displacement operating, necessarily, to throw the non-stretchable facing g
into a curved condition, as illustrated by the dotted line at Fig. 5, an inevi-
table consequence of this changed condition shortening the distance (mca-
sured in a straight line) between the upper and lower (immovable) edges of
the strip is to pull downward the nose of the cushion in opposition to the
effort of the impacting ball to lift it.
Of course in the manufacture of my improved cushion the proportions of
the parts and the precise relative positions or arrangement thereof may be
varied some without materially changing the mode of operation peculiar to
my invention, and hence without departing from the spirit of the latter, and
although, as I have said, the best results follow from the combination, with
the rubber strip a, of both the non-stretchable front facing g and the top
strip for preventing an undue displacement of the particles of the mass at
the top of the cushion, a cushion comprising only the strip a and the said top-
bulging preventive for its equivalent will give vastly better results that any
billiard-cushion heretofore made that I know of.
It will be observed from an inspection of Fig. 5, which illustrates with
substantial correctness the action of the cushion when distorted by a compara-
tively hard blow of a ball and automatically returned by its elasticity to its
normal shape, that mainly by the prevention of the usual upward bulging of
the top surface of the rubber mass the latter has its particles displaced mostly
in a rearward direction, and hence so that in resuming their former positions
the cushion is made to reflect or throw off the ball more nearly in a horizontal
manner, and hence so as to give the reflected ball more legs than possibly
obtainable with other prior kinds of cushions.
If it should be found expedient and desirable to incorporate within the
molded mass a some sort of face-hardening device, the addition of such device
would not of course make the concrete structure any the less within the scope
of my invention. I. however, do not deem the addition of any such device
necessary, and should its presence be deemed possibly of benefit I should advise
its incorporation in such manner as not to materially interfere with the
described operations and effects of the structure I have herein shown and
described.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is: ---
·
1 T billiard-cushion the combination, with a strip of suitable rubber

page_text: compound, or other allied gum, of a strip of suitable, non-elastic, material,
arranged at the top surface of the cushion, and in rear of the nose thereof, in
substantially the manner specified; for the purpose set forth..
2. The combination, with a strip of rubber compound, or other allied gum,
of a device operating to prevent any material displacement upwardly, at the
top surface of, but in rear of the nose of said strip, of the particles composing
the latter; and a non-stretchable facing, to the oblique forward surface of said
strip; all in substantially the manner and for the purposes set forth.
Signed this 11th day of September 1899.
DUDLEY KAVANAGH.
H. D. Fitzpatrick,
100, Wellington Street, Glasgow, Agent.