Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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CHEWABLE TOY FOR ANIMAL
This invention relates to a chewable toy or
simulated bone for an animal, which is highly resistant
to destruction by being chewed and is harmless if swallowed,
; 5 and in particular relates to such a toy comprising an art-
matte flavored polyurethane appealing to the animal, and to
a method for making the toy.
; BACKGROUND AND OBJECTS OF THE INVENTION
: Numerous chewable toys for animals fabricated from
rubber, plastics, rawhide and the like have long been avail-
10 able for the purpose of massaging the gums and strengthening
; the teeth of the animal, but each such toy has been subject
to various objections, such as the inherent bad taste ox
rubber, susceptibility to destruction when chewed, and hard-
I: news or brittleness, as for example when made from Nylon
which could damage the animal's teeth. The rawhide "bone"
has been in common use, but it disintegrates rapidly when
chewed, and like some of the plastics used heretofore, large
sections can be torn away and if swallowed can get caught in
the dog' 5 throat.
An important object of the present invention has
: been to provide an improved durable chewable toy or "bone"
for pets, which avoids the above-noted objections, which
may be molded from polyurethane to simulate a real bone
having an elongated body with enlarged bifurcated ends to
I: 25 provide chewing protuberances for small dogs and curved
exterior surfaces adapted to conform to and massage the gums
: l of larger dogs, and wherein the elongated body curves in
opposite directions from its mid-region to effect oppositely
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directed compound or three-dimensional curvatures, which in
cooperation with the enlarged ends prevent accidental.swal-
lowing of the simulated bone by large dogs.
Another object is to take advantage of the unique
physical properties of polyurethane to provide such a toy,
which can be a ball or other shape as well as a simulated
bone in appearance and which is molded from an elastomeric
polyurethane to provide a super-tough toy highly resistant
to chewing and in fact essentially indestructible by chewing
except by very large dogs, wherein the polyurethane itself
is odorless, tasteless, and chemically inert in the digest-
ivy system so as to be harmless if swallowed. The polyp
urethane has a moderate hardness darter to assure the
desired flexibility and compressibility in a chewable toy,
so as to massage a pet's gums without undue wearing of the
teeth and to provide a toy that can be caught in the air by
a dog for example without breaking the dog's teeth-, in
contrast to similar bones of hard material such as NylonTM
which can chip a dog's teeth. On the other hand, the polyp
urethane also has large coefficients of tensile strength
and resistance to shearing to enable the to Jo be stretched
; twisted and compressed within the limits of its elasticity
by sharp teeth and strong jaws without disintegrating while
being chewed, so as to outlast comparable toys of rubber,
rawhide and even Nylon , and has the resiliency to enable
Jo return of the toy essentially to its undeformed condition
after being chewed.
Another object is to provide a molded polyurethane
toy or "bone" of the above character impregnated with air
bubbles so as to be lighter than water and useful for
example in water games with a dog or for training a dog to
retrieve. Although the aerated bone is more readily
destroyed by chewing, it is somewhat softer and more spongy
and is thus ideal for older dogs.
Another object is to provide an improved chewable
polyurethane toy of the above character having a surface-
migrating flavoring agreeable to the animal and uniformly
distributed throughout the volume of the toy, whereby as
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the surface flavoring is removed during the chewing process,
the flavoring is replaced at the surface by flavoring from
the interior of the toy.
Another object is to provide an improved method
of manufacturing such a toy wherein an aromatic extract such
as catnip or a meat flavoring is added to and uniformly
distributed throughout the polyurethane material to comprise
a homogeneous portion of the toy.
Another and more specific object is to add the
aromatic flavoring extract during the initial formulation
of-the polyure~ane, whereby the extract is thoroughly
mixed with the components of the polyurethane, first during
the mixing of said components during the initial formulation,
and thereafter during the granulation and mixing of the
polyurethane in preparation for the final molding operation.
By virtue of the foregoing, a thorough mixing of the extract
within the polyurethane is assured and the necessity of pro-
voiding a specific mixing procedure for mixing the extract
within the polyurethane is eliminated. Inasmuch as the come
pennants in the formulation of the polyurethane must be thoroughly mixed in any event, the same mixing procedure is
utilized both for mixing the polyurethane components with
themselves and for mixing the extract with the components.
The flavoring extract is usually highly concentrated, such
that thorough mixing is important. Otherwise localized con-
cent rations of the extract can overpower the sensory nerves
of the animal and effect a disagreeable reaction rather than
the intended taste or aroma that is pleasing to the animal.
Where the extract loses its aroma or flavor in
consequence of heating, the flavoring extract is initially
added and thoroughly mixed with the granulated polyurethane
when the latter is heated and melted immediately prior to
the molding operation. A satisfactory distribution of the
extract can be accomplished by such a procedure and the
extract is only subjected to a single heating cycle, i.e.,
the heating required to melt the polyurethane prior to the
molding. The extract is spared the heat of the exothermic
reaction resulting from mixing the aforesaid coTilponents
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during the formulation of the polyurethane.
In some conventional molding operations, the polyp
urethane comprises two or more liquid components that are
mixed by being fed simultaneously at measured rates directly
into the mold. In such instances the liquid flavoring
extract is likewise fed into the mold along with the liquid
components to effect a thorough mixing of the liquid extract
and components for the polyurethane in a single mold filling
operation.
THE PRIOR ART
The prior art is replete with molded pet toys and
dog bones, but -the concept of utilizing the unique proper-
ties of polyurethane to provide a toy or dog bone as desk
cried herein, or of providing such a toy having a surface-
migrating flavoring extract homogeneously distributed through-
out the polyurethane as a part of the toy, and the fabric-
lion of the toy by mixing the flavoring extract with the
liquid components of the polyurethane during the initial
formulation of the latter, as described herein, is nowhere
suggested by the art known to applicant.
United States Patents to Ruler, 2,194,736; Jones,
2,610,851; Fisher, 3,104,648; and Axelrod, 3,871,334 are
typical of the known art. Ruler, for example, discloses a
"bone" molded from a porous elastic material such as rubber.
A material that gives off an odor agreeable to a dog may be
placed in a hollow part of the porous material. Jones,
Fisher and Axelrod similarly disclose a toy of rubber or
other resilient material, including Nylon and resin, that
may be conventionally flavored to entice the dog. There is
no hint in these patents of utilizing the superior character-
is tics of polyurethane to provide an essentially in destruct-
isle and harmless bone, nor of how the toy is flavored,
except that it is conventionally flavored, meaning a surface
coating or impregnation under pressure, as in Axelrod, which
is a costly and time consuming procedure, or the insertion
of aromatic pellets into a hollow chamber of a porous toy
which by reason of its porosity is also readily destroyed
when chewed or gnawed.
I 9
Other objects of this invention will appear in
the following description and appended claims, reference
being had to the accompanying drawings forming a part of
this specification wherein live reference characters
designate corresponding parts in the several views.
SUMMARY OF THE INVENTION
The present invention relates to a molded one-
piece bone having an elongated body and enlarged opposite
end portions The bone also has opposite lateral surfaces
and upper and lower surfaces curving in compound curvatures.
The curvatures of the upper and lower surface on the elongated
body extend in one direction from the mid-region of the body
curving upwardly and the upper and lower surfaces of the end
portion in the one direction curving upwardly and downwardly
respectively. The last named lower surface recurves down-
warmly from the upward curvature of the lower surface of
the body. The upper and lower surfaces of the end portion
in the opposite direction curve upwardly and downwardly
respectively. The last named upper surface recurves upwardly
from the downward curvature of the upper surface of the body.
The last named lower surface is comprised of a continuation
of the downward curvature of the lower surface of the body.
In another embodiment of the present invention a
chewable toy is provided which is comprised of a molted
elastomeric polyurethane material containing a surface-
migrating flavoring extract dispersed within the molecular
; structure of the elastomeric polyurethane material.
BRIEF DESCRIPTION OF THE DRAINS
FIG. l is a perspective view of a duos bone
embodying the present invention.
FIG. 2 is a optima view of the bone of jig. l.
FIG. 3 is a transverse section through the mid-
region of the bone of Fig. l.
FIG. 4 is a side view of the bone of Fig. l.
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pa
It is to be understood that the invention is not
limited in its application to the details of construction
and arrangerllent of parts illustrated in the accompanying
drawings, since the invention is capable of other embody-
mints and of being practiced or carried out in various ways.
Also it is to be understood that the phraseology ox terming
logy employed herein is for the purpose of description and
not of limitation.
INSCRIPTION OF A PREFERRED El`iBODI~FNT
Referring to the drawings, a dog bone erl~odying
the present invention comprises an elongated central portion
10 having enlarged opposite end portions 11 and 12 bifurc-
axed to provide a pair of flared endues enlarging project-
ions ha and fib spaced by a notch tic at the enlarged end
11, and similar flared endues enlarging projections aye and
12b spaced by a notch 12c at the opposite enlarged end 12.
The r.lid-region at the upper or top portion of the bone in
Fig. 1 is provided with an upwardly opening channel or
Jo groove 13 that extends the major length of the portion 10.
From the upper portions of the walls of the groove 13, the
lateral surfaces of the bone diverge from each other approx-
; irately to the longitudinal mid-regions 14 of the opposite
lateral surfaces, which surfaces when converge downwardly
toward each other to a centrally located lowermost or bottom
ridge 15, thereby to provide a somewhat heart-shaped cross
section Figure 3.
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By comparing Figures 1 and 4, it may be observed that
the bone curves three-dimensionally in oppositely directed
compound curvatures from its transverse mid-region to its
enlarged ends 11 and 12. From the aforesaid transverse mid-
region in Figure 1, the longitudinal portion 10 curves at downwardly toward the end 11. Similarly the longitudinal
portion 10 curves at 17 upwardly from its transverse mid-
region toward the enlarged end 12. The concave surfaces of
the curvatures 16 and 17 curve continuously with the
surfaces of the flared end portion fib and 12b respectively,
whereas the convex surfaces of the curvature 16 and 17
recurve slightly at their junctures with the surface of the
flared end portions ha and 12. The upper surfaces of the
end portions 11 and 12 curved upwardly and the lower
surfaces of end portions 11 and 12 curve downwardly in the
endues directions. The complex curvature described
provides a bone that is difficult to swallow. If one end
of the bone does enter a dog's throat, it may be readily
pulled out by the dog holding the enlarged outer or
opposite end of the bone with the paws while pulling the
head backward, which apparently is an instinctive
reaction.
The paired bifurcated end portions ha, fib and aye
12b are flared endues to provide chewable extensions that
can be gripped in the mouth of a comparatively small dog.
The total transverse sectional area of either pair of pro-
sections ha, fib or Ahab is approximately equal to the
area of the transverse section through the longitudinal
portion 10, Figure 2. By virtue of the notches tic and 12c,
either of the paired extensions ha, b or aye, b can be bent
resiliently toward each other in the chewing process within
their limits of elasticity, and tune parts will return to
their undeformed shapes after being chewed. Also the buffer-
acted projections can be readily received between the jaws
of a dog, and by virtue of the curvature of the bone I
adjacent its end portions, the lateral and menial surfaces
of the bone will engage and massage-both the labial and
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lingual gums of the dog during the chewing process.
The groove or channel 13 reduces the total cross-
sectional mass of the polyurethane material similarly to
the action of the grooves tic and 12c, and facilitates flex-
- 5 in of the upper portions of the bone portion 10 at opposite
sides of the groove 13 to provide a satisfying crunching
effect to the chewer even if the bone is fabricated from a
comparatively hard elastomers that would otherwise have very
little yield ability when subjected to a normal chewing
force.
Although the bone shaped as described above can
obviously be molded from any of the elastomeric materials
utilized heretofore for such toys, an important concept of
the invention is the use of a preferred elastomers comprising
a polyurethane having among other qualities the unique
Jo distinction of being essentially indestructible by ordinary
. chewing forces; will yield resiliently within its limits of
elasticity and return to its unreformed condition when the
deforming force is terminated; and is extremely resistant to
shearing by sharp teeth that would normally disintegrate
elastomers used heretofore, such as the various rubber-like
compounds resins, and polyethylene.
Animal toys of various shapes and sizes, including
; the above-described bone shape, various other bone shapes,
; 25 and spheres or balls have been formed in accordance with
the present invention from polyurethane having a hardness
or dormitory ranging between approximately 35 and 60 Shore
D as measured by ASTM (American Society of Testing Materials
Test 2240; an ultimate tensile strength between approximately
20 and I spa omega Pascals3 measured by ASTM Test D 412;
an ultimate elongation ranging between approximately 500%
and 600~; a tensile strength between approximately 6.9 and
16.5 Ma at 100~ elongation; and between approximately 10.3
and 19 Ma at 300~ elongation; a tensile set of approximate-
lye 3% to 18~ at 50~ elongation; a tear strength of between approximately 80 and 140 Kim kilo Newtons per meter)
measured by ASTM Test D 624-Die C; an a compression set of
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between approximately 30% and 40~ at ~0C over a 22 hour
period
Polyurethane having physical properties within the
ranges specified above are usually satisfactory for chewable
animal toys and are preferred for typical situations.
However, the dormitory range can be widener to between 10
and 80 Shore D where desired, and such widening of the
hardness range will obviously widen the ranges for other
physical characteristics such a tensile strength, long-
anion, tensile sell tear strength, and compression set.
The preferred polyurethane having the physical characteristics enumerated above are slightly heavier than
water and have specific gravities raying between 1.1 for
the softer polyurethane, and 1.2 for the harder puller-
thanks. Another concept of the present invention is to provide a toy as described herein useful in water sports or
for training an animal to retrieve. Accordingly foaming
agents are employed or air bubbles are blown or worked into
the polyurethane by conventional procedures during the
molding operation to provide a floating toy lighter than
water.
Although animals accustomed to gnawing and chewing
will chew on polyurethane toys which in themselves are
tasteless and odorless, another concept of this invention
is to increase the attractiveness of such toys to animals
by utilizing additional unique characteristics of the polyp
urethanes and to flavor the toy with flavoring or aromatic
oils which are dispersed uniformly and preferably homogen-
ouzel throughout the toy in accordance with the process
described below to provide a flavor that will remain appeal-
in to the animal without appreciable diminishing effective-
news essentially for the life of the durable polyurethane
material of the toy
Polyurethane are characterized by the methane link-
age (-NH-C=O). This typical linkage is formed by the
reaction of an isocynate group (R-N=C=O) with a hydroxyl
containing compound UGH While reaction with a hydroxyl
~3Z4~3~
compound is primary, isocyanates will also react with any
compound containing an active hydrogen atom. Thrower
functional groups such as the urea, aside, allophanate,
barter and other groups may become important parts of the
polyurethane polymer. In addition, most of the hydroxyl
containing compounds are polymers in themselves These are
generally polyethers and polyesters, but other hydroxyl
containing polymers, such as castor oil, can be part of the
polyurethane complex.
In formulating a urethane compound, there are several
different types of materials that either must be or can be
used. These materials can generally be classified into the
following: isocyanates, polyols, chain extenders, catalysts,
blowing agents, functional additives, fillers, and non-
functional additives. All of these with the exception of
the fillers and non-functional additives, comprise the
polymer network where their independent structures react
into and become an integral part of the resultant urethane
polymer. This polymer structure is responsible for the
basic physical nature of the polyurethane, ire., its strength,
elasticity, toughness, resiliency, and other physical kirk-
teristics.
Fillers and non-functional additives do not enter
into the polymer reaction, but do affect the physical
nature of the final urethane compound. Although these
latter additives are not reacted or chemically bound to
the polymer structure, they are held by the polymer struck
lure by physical entrapment and, in some cases, by secondary
chemical association.
~xhmples of these latter additives are colorants or
pigments, nonreactive blowing agents, fillers such as
calcium carbonate, clays, mica, and others, and lubricants.
Most of these additives are permanently locked into the
polymer structure, but some are actually insoluble and
incompatible in the urethane compound. the incompatibility
might be due to the urethane groups present or to other ox
the many functional groups present. In any event, the
glue
insolubility of such additives causes the same to work
gradually to the surface of the polyurethane.
Traditional examples of such surfacing of insoluble
or incompatible components are referred to as "bloom" where-
in a pigment or colorant is provided in a Sax or oil-based
carrier that migrates to the surface to form an off-color
haze. The haze can generally be wiped off, but will return
with time; and "self-lubrication" wherein an oil formulated
into a polyurethane compound continually migrates to the
surface. If the surface is cleaned, the oil will reappear
in time.
Flavors or odors, hereinafter referred to as
"aromatic extracts", are complex organic compounds that can
be soluble in many oils. Some of the aromatic extracts
function as surface-migrating substances. The incomputable-
fly of the urethane compound and the aromatic extract could
possibly be due to the extract's basic chemical structure,
or to the greater volubility of the aromatic extract in its
oil or wax carrier, which in turn is incompatible with the
polyurethane and conveys the extract to the surface.
The migrating nature of the oil-based aromatic
extract makes the flavored urethane unique. The aromatic
extract can be added to many if not all plastics, but to be
effective the molecules of the aromatic extract must be
available at the surface of the chewable toy. In most
plastics, when the flavoring molecules on the surface are
removed, the flavor or aroma is lost regardless that many
other flavoring molecules may still be locked in the plastic.
In the flavored urethane, when the surface molecules of the
flavoring are removed, they are replaced by new flavoring
molecules migrating from the compound's interior.
The rate of migration is a function of various
factors, including temperature and the polymer molecular
astute The temperature and molecular activity is increase
Ed by the frictionally induced build-up of internal energy
resulting from bending, flexing and compressing the toy.
Therefore such actions as chewing and the howdy heat of the
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11
animal's mouth can increase the migration of the aromatic
extract to the surface, thereby increasing the satisfaction
of the chewer. An animal can learn that the harder it
chews, the more satisfying will be the taste.
In the manufacture or fabrication of an animal toy
embodying the present invention, the various above-noted
components known to be required for the formulation of a
polyurethane having the desired physical characteristics
specified herein are mixed together in measured quantities
while in a liquid phase, thereby to initiate an exothermic
reaction resulting from the polymerization of the components.
The initial reaction in the liquid phase requires but a few
minutes until solidification takes place. During the
initial mixing of the liquid components and while these are
still in the liquid phase, the aromatic extract usually in
a wax or oil carrier, is added as a liquid or pulverized
solid and also mixed thoroughly with the reacting coupon-
ens. The extract may be any of numerous flavoring extracts
known to the art and incompatible with the polyurethane to
effect the surface-migrating action as noted above. The
flavoring itself can be a surface-migrating substance of the
type described above, i.e., incompatible with the resulting
urethane compound, or it may be highly soluble in its oil
or wax carrier, which in turn must be non-compatible with
the resulting urethane so as to migrate with the flavoring
to the surface o the toy. The incompatibility referred to
herein thus pertains to surface-migrating substances that
apparently do not combine chemically with the components
that form the polyurethane.
The flavor or aroma of the extract will, ox course,
be agreeable to the animal for which the toy is intended
and may impart a meat or catnip flavor or aroma, for example.
Only a small quantity of the extract is required, amounting
usually to about one-half of a percent by weight of the
total composition. Accordingly if a wax carrier is employed
the small quantity of wax is quickly melted by the reaction
heat and dispersed uniformly throughout the liquid coupon-
ens in the reaction and is thus distributed homogenouslythroughout the resulting solidified polyurethane.
The solidified polyurethane is then generally cured
for a few days to assure stabilization of the reaction or
polymerization process, although the reaction can be adjusted
by means known to the art to permit stabilization more rapid-
lye The cured polyurethane is then ground into granules and
fed preferably to an injection molding machine wherein the
granules are heated and melted and finally injected under
pressure in a liquid form into an injection molding die.
Although the toy in many shapes can be molded conventionally
at atmospheric pressure, conventional injection molding is
preferred because of the speed of the molding cycle and the
versatility of toe process that enables the formation of
essentially any shape desired.
In the process known as Reaction Injection Molding
(RIM) the composition of the polyurethane is selected to
avoid the aforesaid few days curing time. In -such a process
the liquid components for the polyurethane are thoroughly
mixed by being simultaneously injected at measured rates into
a mixing head of an injection molding machine from which the
mixed components are then forced into a die to form the
finished chewable toy. In such a process, the flavoring
extract is also added at a measured rate into the mixing
head simultaneously with other components for the puller-
than. In a variation of RIM known as casting, the flavoring
extract and liquid components are poured simultaneously into
an open mold at atmospheric pressure, whereby the components
and extract are thoroughly mixed as they are poured into the
mold that forms the chewable toy. In the latter process, as
well as in the RIM process, the primary curing takes place
in the mood and may continue for a limited time after the
toy is removed from the die or mold.
Alternatively to adding the flavoring extract during
' 35 the mixing of the initial liquid components from which the
; polyurethane is fonnulated, the extract can be added to the
cured granules and thoroughly fixed therewith prior to the
3Z~99
13
injection molding process. Such a procedure requires an
additional mixing procedure which is avoided in the first
method described above and for that reason is usually not
preferred. In certain instances, as for example where the
flavoring tends to be decomposed by the heat of the ego-
thermic reaction, the second alternative procedure may be
preferred.
It is apparent from the foregoing that a particularly
durable, long-lasting chewable toy for an animal has been
provided in combination with a flavoring that is satisfying
to the animal and capable of being replenished at the
surface of the toy over an extended time period which for
all practical purposes will usually equal the life of the
toy. The toy is non-toxic, has superior toughness, resist-
ante to shearing, and excellent elasticity that enables into return to its original shape after being chewed. The -
polyurethane can be comparatively soft, can be caught in
the air by a dog without breaking a tooth, does not splinter,
and cannot be torn apart except by unusually large dogs.
Even if a part is pulled loose by a dog, it does not present
sharp edges and passes readily through the digestive system
intact and without harm to the dog.
In regard to brittleness, polyurethane retain their
elasticity or chewability for years and resist "drying out"
or hardening and becoming brittle, as compared to rubber-
like materials or resins used heretofore. Likewise, by
virtue of the surface-migrating aspect of the flavoring
extract dispersed uniformly throughout the toy, the
extract does not dry out within the body of the toy and is
continuously replenished at the surface of the toy if the
surface extract dries during an extended time when the toy
is not in use.
