Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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BACKGROUND OF THE INVENTION
Typically, Eeed sys tems for feeding sheet-like
materlals, such as paperboard, or paper or plastic sheets
and the like, comprise at least one feed roller or one or
more idler rollers in combinat-ion therewith. For example,
the Eeed roller may comprise a driven hard roller on the
bot-tom, such as a steel roller having a knurled surface, or
a hard elastomeric suface roller with an idler roller posi-
tioned above the feed roller. Where the feed system is to
feed sheet materials, for example, of various -thickness,
adjustments can be made to the feed or idler roller to
provide for different thicknesses. Of-ten such feed ma-terial
requires an energy source to adjust the tension or surface
pressure on the material to be fed when the material changes
in thickness or dimension. Such adjustment of surface
pressure or tension is accomplished by mechanical, electri-
cal or hydraulic systems, or by merely removing and respac-
ing the distance between the feed and idler rollers to
obtain the desired surface pressure for feeding purposes.
Such systems require constant adjustment as material of
different dimensions are fed through the system or require
complex systems to adjust the tension or surface pressure.
A self-adjusting roller, ei-ther as a feed roller
or an idler roller, would be desirable where such a roller
would conform to various thicknesses of materials being used
in the system, that is, being rolled over or under without
any outside energy sources for adjusting or moving -the
roller.
Resilient-type rollers have been developed for
various purposes. For example, U.S. Patent 2,572,276
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discloses a resilien-t roller prepared from an extrudable
ma-terial, the roller having a corrugated surface and having
a central opening -through the shaft and surrounded by a
pluralit-y oE pear-shaped openings. Resilient rollers have
a]so been employed in handling fragile-type ma-terials such
as eggs, as shown in U.S. Patent 3,272,309, wherein a trans--
port member comprises a core portion and has a plurality of
generally circular openings about the outer portion of the
roller. The roller is formed of resilient material and has
circular openings of such dimensions that the eggs to be
transported may be moved under the roller without damage.
_UMMARY OF THE INVENTION
My invention relates to a self-adjusting resilient
roller and to a feed system containing the roller and to the
method of use of the roller. In particular, my invention
concerns a self-adjusting resilient roller which will con-
form to various thicknesses of material being rolled over or
under the roller without any outside energy sources for
adjustment of the roller.
My invention comprises a resilient roller which
may be either used alone or in conjunction with other
rollers, either as an idler or a feed roller, and to a
roller system. My roller will conform to various thick-
nesses of material being rolled under or over a roller. Thedesign of my self-adjusting roller, coupled with the mechan-
ical advantages of the material of the rollerl provides for
a roller which is self-adjusting and which deflects more
readily than a solid material or a foam material when under
compression, but yet which retains its generally cylindrical
shape except where compression occurs. The design of my
roller permits deflection in use of up to 40% deflection of
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the roller circumference.
The design of my self-adjusting roller, made of
resilient material, provides a substantially uniform resili-
ence under compression by providing substantially uniEorm
wall thickness between various peripheral openings toward
the outer peripheral surEace oE -the roller. The self-
adjusting roller oE the invention comprises a generally
cylindrical roller of a resilient ma-terial, the roller
having a peripheral outer surface, which surface may be
smooth, corrugated, knurled or otherwise as desired. The
roller is characterized by a series of passageways and
openings which comprise a central axial passageway, gener-
ally the largest opening extending through the material, and
which passageway is adapted to receive a shaEt, which is a
drive shaft or idler shaft, about which the roller may be
driven or revolve.
The roller design also includes a plurali-ty of
generally uniform, spaced-apart, generally circular openings
extending axially through the resilien-t material of the
roller. The circular openings are positioned generally
uniformly about the cen-tral axial passageway and in close
approximation with the outer peripheral wall surface of -the
roller, a portion of the wall about the circular opening
constituting an arcuate portion of the outer wall surEace
forming the peripheral outer surface of the roller of
desired thickness. The circular openings may vary in number
and dimensions and generally are smaller in dimension than
the axial passageway and may comprise from, e.g., about 6 in
a 3" roller to 12 or 18 or more depending on the diameter of
the roller employed. For example, the ratio of the diameter
of the axial passageway to the diameter of the circular
openings may range, for example, from abou-t 3 -to 1, and more
particularly, 2 to 1.25.
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My roller design also includes as an essen-tial
feature a plurality oE generally uniform openings which are
smaller than the circular openings and which ex-tend axially
through the resilient materia] oE the rol]er. These small
peripheral openings are preferably triangular-like :in shape,
and positioned -toward the outer peripheral surEace of the
roller, with each opening spaced between the adjacent circu-
lar openings. These peripheral openings are shaped and
dimensioned and posi-tioned together with the axial passage-
way, so as -to provide a general]y uniform wall thickness of
resilient material about and surrounding the circular open-
ings to provide a roller which uniformly compresses, or is
uniformly resilient under pressure, so as the en-tire roller
will not be deEormed. Where the wall thickness between -the
circular openings is substantially uniform, then the roller
may be subject to deformation under compression to much
greater extent than a roller of a foam material, or a
resilient material, that does no-t have the peripheral open-
ings and substantially uniform wall thickness.
The peripheral openings may vary in size and
shape; however, in one preferred embodiment, the triangular
opening is formed with the sides of -the triangular opening
arcuate in nature, with one side following the general
radius of the outer periphery oE the roller and the other
sides following the general exterior radius of the circular
openings on either side. The axial passageway, the circular
openings and the peripheral openings should be such tha-t a
substantial portion oE the roller represents void space,
such as for example, over about 70%, more typically over
80%. The circular openings are so placed so that the wall
thickness surrounding the circular openings; that is, the
ribs of material forming the interior of the roller in a
cross-section view, are generally uniform in wall thickness,
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except where adjoininy ribs meet. In one embodiment, the
arcuate por-tion of the circular opening toward the exterior
surface of -the roller is slightly thicker, in order to
provide a roller of long life by increasing the peripheral
surface thickness oE the material.
A variety of natural or synthetic materials may be
employed as resilien~ materials of which t~he roller is
formed, but typically the roller is Erom a molded synthetic
material, such as elastomeric material like an elastomeric
urethane polymer. The resilient material may be solid or
foam, or a combination of the two, but more particularly is
a polymeric elastomeric material typically having a Shore
hardness range of 25A minimum, to a maximum of 95A, more
particularly, for example, about ~OA to abou-t 65A. The
exact nature of the hardness depends on the diameter of the
roller and how much pressure is to be exerted against the
roller in the particular system to which the roller is
employed; that is, depending on the variations of -the thick-
ness of the material handled by the self-adjusting roller.
Typical suitable elastomeric materials include, but are not
limited to, neoprene rubber, gum rubber, butyl rubber,
butadiene-styrene rubbers, vinyl-chloride resins and other
material.
My self-adjusting roller design may be employed
alone or in combination with a feed or idler roller, or
other system, -Eor feeding sheet material, such as paper
sheets, plastic sheets, paper board or the like, where the
material may vary in thickness. Typically in a roller
system, the feed roller may comprise an idler roller placed
in a spaced relationship to a driven hard roller which
forces sheet materials between the spaced rollers, such as
by the use of a knurled surface or by an elastomeric
friction-type surface, in the feed or driven roller. The
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roller may comprise a driven Feed roller or an idler rolLer
whose func-tion is lo act as a hold-down roller. The design
oF my self--adjusting roller permits -the roller, on compres-
sion, -to deflect internally on compression without substan-
tial deFlection of l-he rubber surEace not under pressure.
Il- has been found l-hat where the resilient roller does not
have the peripheral openings, then the resilient roller has
such a variation of wall thickness that it does not permit
substantial deflection within itself for uniform compres-
sion. Thus, my feed roller requires, for its proper opera-
tion, a substantial]y uniform wall thickness, with the use
of the peripheral openings generally uniformly spaced about
the spaced circular openings.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a perspective view of the self-adjusting
roller of the invention;
Fig~ 2 is a generally sectional view of a feed
system employing the self-adjusting roller of the invention;
and
Fig. 3 is a generally sectional view of a feed
system employing the self-adjusting roller of the invention,
wherein the self-adjusting roller is internally compressed
by a sheet of greater thickness.
DESCRIPTION OF THE EMBODIMENTS
Fig. 1 shows a self-adjusting roller 10 of the
invention molded from a solid elastomeric polyurethane
resin, which roller is characteri7ed by an axial passageway
12 adapted to receive a shaft, either an idler shaft or a
driven shaft, and a plurality of smaller circular openings
14 and a plurality of generally triangular-shaped openings
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16. The triangular-shaped openings have arcuate sides, with
the outer arcuate side following the radius of the smoo-th
outer peripheral surface 18 of the roller. As illustrated,
the arcuate sides oE triangular openLngs 16 follow the
5 radius oE the adjacent circular openings. The
selE-adjusting roller illustrated has a diameter oE approxi-
ma~-ely 3 1/2 inches and axial passageway oE 1 l/D. inches,
circular openings of 3/4 inches and the material has a Shore
h ardness of about 60A.
Fig. 2 is a sectional view oE a feed sys-tem, with
the self-adjus-ting roller 10 as an idler -ro:Ller on an idler
shaEt 24 and spaced above a rlgid feed roller 20, with a
driving shaft 22 with a sheet material 26 of one thickness
shown driven through the feed system, with the
15 self-adjus-ting roller 10 in a substantially noncompressed
position, exerting sufficient surface pressure and -tension
for -the feeding of the sheet material 26.
Fig. 3 shows the feed system of Fig. 2, with the
material 28 of thicker dimensions, and illustrates the
20 inward compression area 30 of the roller 10, as the roller
is pressed inwardly in area 30 by the thicker material 28,
without the need to readjust the position or spacing of the
roller 10 or feed roller 20.
