Note: Descriptions are shown in the official language in which they were submitted.
FIELD OF TEIE INVENTION
This invention relates to the mounting of thermal insulation
material end panels to the axial end faces of a heatable dryer
cylinder for drying a paper web or the like passing over the
periphery of the dryer, and more particularly to an improved
mechanical clamping means for mechanically locking the end panel
to the end face of the dryer cylinder.
BACKGROUND OF TEIE I~JVENTIO~I
In view of the energy crisis, attempts have been made to
reduce heat loss from processing machinery. In the area of paper
manufacture or web drying, it is conventional to feed a wet paper
web or the like over a seriès of cylinders which rotate about their
axes and wherein means are provided for heating the periphery of the
dryer cylinder so as to dry the weh during transport. Conventionally,
a large amount of heat is lost axially of the machine, that is, by
radiation and convection at both ends of the machine dryer cylinder.
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Attempts have been made to mount thermal insulation material end
panels to the cylinders and to thereby restrict convection and
practically eliminate thermal radiation at the cylinder ends.
The panels may be readily applied to a cylinder while in place,
and in such case, the thermal panels r,ormally are constructed of
two or more segments, as for instance hemispheric sections. The
sections are applied to the cylinder from opposite sides of the
shaft mounting the cylinder for rotation, with the end panel sections
being joined at their abutting edges by means of joint covers. In
order to insure that the thermal panel will continue to overlie the
axial ends of the machine dryer cylinders, means have been provided
~or coupling the face of the panel to the cylinder in a type of
disconnect coupling or connection, permitting the end panels to be
easily removed for machine maintenance and repair.
One such assem~ly involves the use of cuplike permanent
magnets which are affixed to the face of the thermal insulation
material panels with the cup cavities opening outwardly of the panel,
and wherein the magnets are sized to the approximate diameter of the
bolt heads which project from the end wall of the cylinder drum,
such that the magnets are magnetically clamped to the bolt heads
(and to the metal end plates for the cylinder). The permanent
magnets are spaced on the panel at similar circumferential positions
to the bolt heads projecting from the ends of the dryer cylinder such
that when assembled, the magnets surround the bolt heads and
magnetically lock the thermal insulation material end panel to the
axial ends of the dryer cylinder.
While this method of assembly permits ease in removal of the
thermal insulation material end pane s from the end faces of the
dryer cylinder, the coupling is not one which is positive in nature.
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The retention force is quite small, and there is no assurance that
during operation inadvertently the thermal insulation material end
panels will become disengaged, eliminating the thermal barrier and
possibly interfering with machine operation, or in some cases,
resulting in machine malfunction.
It is, therefore, a primary object of the present invention
to provide an improved thermal insulation material end panel assembly
which essentially prevents convection and radiation heat loss to
a dryer cylinder bearing the same.
It is a further object of the present invention to provide an
improved thermal insulation material end panel assembly which may
be easily mounted and removed from the dryer cylinder, and in which
a positive mechanical connection may be achieved with relatively
high coupling strength, greatly reducing the possibility of separation
of the panel from the cylinder during machine operation.
It is a further object of the present invention to provide
an improved thermal insulation material end panel assembly which
insures conservation of thermal energy, provides a cooler working
environment, and which functions to insure uniform drying completely
across the web of material to be dried as it passes over the dryer
cylinder bearing the panels at opposite ends.
SUr~MARY OF THE IIIVENTION
The invention is directed to the combination of a heatable
dryer cylinder for drying a web passing over the peripheral surface
of the dryer cylinder and a thermal insulation material end panel
mounted on an axial end face thereof. The dryer cylinder bears a
plurality of bolt heads which project axially from end faces thereof
at spaced circumferential positions. A plurality of stud clamps
fixed to the side of the thermal insulation material end panel and
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projecting axially therefrom at circumferential positions
corresponding to the bolt heads are frictionally clamped to the
bolt heads for mechanically locking the panel to the end of the -
dryer cylinder.
Each stud clamp comprises an arcuate clamping body including
a radial slot extending outwardly from a circular opening within
the body having a diameter slightly in excess of the diameter of the
bolt head, a screw threadably extending trans~-ersely to the axis of
the hole and threadably couples said sides of said body at said radial
slot, so as to vary the diameter of the circular opening by closing
off or opening the slt. A stud fixed to one side of the body and
projecting axially therefrom is coupled to the panel. The circular
opening receives the bolt head, and the screw reduces the diameter
of the opening to mechanically frictionally lock the arcuate clamping
body to the bolt head within the stud clamp opening.
Preferably, the stud terminates in an enlarged diameter disc
whose diameter is slightly smaller than that of the hole, with the
disc being welded along one edge to one-half of the arcuate body alon~
the periphery of the opening within the arcuate body and being free
of the other half of the arcuate body such that the stud clamp is
free to open and close but provides the same axial center line for
the stud as the dryer head bolt center line when connected thereto.
Preferably, the panel includes a tube assembly projecting
through the panel from one side to the other, and the stud on the
end opposite the disc projects through the tube assembly and bears
a washer having an outside diameter in excess of the sleeve assembly
tube and terminates in a threaded nut bearing on the washer and forcin,
the washer against the tube to lock the tube to the disc.
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The invention is also directed to such stud clamps for
clamping to bolt heads or the like, such that the stud center
line corresponds to that of the bolt center line.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is an exploded perspective ~-iew of the improved
thermal end panel assembly for a paper machine dryer cylinder or
the like and the stud clamps forming a portion thereof constituting
a preferred embodiment of the present invention.
Figure 2 is an end view of the assembly illustrated
in Figure 1.
Figure 3 is a horizontal sectional view of a portion of the
assembly of Figure 2, taken about line 3-3.
Figure 4 is a perspective view of the improved stud clamp
of the present invention.
Figure 5 is a front end view of the improved stud clamp
of Figure 4.
DESCRIPTION OF THE PREFERRED E~qBODIr~ENT
The present invention has particular application to heatable
dryer cylinders for the drying of paper webs and the like, and in
that regard, referring to Figure 1, there is shown a portion of one
such cylinder as indicated generally at 10, the dryer cylinder 10
including a metal cylindrical body 12 and being connected to a
central shaft 14 for rotation about the shaft axis through end bells
16 which are coupled to the body 12 by means of a plurality of bolts
indicated generally at 18 and which form a circumferentially spaced
array on the end bell 16 and facing axially outwardly of the dryer
cylinder 10.
Referring further to Figure 1, the thermal panel indicated
generally at 20 comprises an assembly of two arcuate thermal panel
sections or halves as at 22, 24, the sections including faces as at
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22a, 24a which abut each other and when coupled tosether by way of
joint covers 26, form a ringli~e assembly which surrounds a
projecting hub portion 16a of the end bell 16. The thermal panel 20
thermally blocks a major portion of heat from escaping from the ends
of the dryer cylinder 10, either by way of radiation or convection.
A seal ring 28 is applied to the joined sections 22, 24, receives
the projecting shaft 14, and acts to assist in thermally sealing off
the heat trying to escape from the ends of the dryer cylidner, with
most thermal insulation coming from the panel halves 22, 24.
~ very important aspect of the present invention are the
stud clamps indicated generally at 30, Figure 1, which function to
mechanically lock the thermal panel 20 to the end bell 16 of the
cylinder 10, and in this case within the recessed end of the
cylindrical body 12. In this embodiment, the end bell 16 is axially
remote from the edge 12a of the cylindrical body 12 so as to form
an annular recess 32. It is within this recess 32 that the thermal
panel 20 resides. The panel 20 is symmetrical about a joint line
as defined by the abutting end faces 22a, 24a of panel halves 22 and
24, respectively. The assembly of the end panel and its coupling to
the dryer cylinder may be visually appreciated by reference to
Figures 1, 2 and 3. The thermal panels 20 defined by sections 22
and 24, are formed of sheet metal as hollow casings but bear heavy
thermal insulation internally as seen in Figure 3. In that regard,
the panel section 24 comprises an outer metal shell 34 and an inner
metal shell 36. The shells 34 and 36 overlap each other slightly as
at 38 and are filled with a suitable thermal insulation material as
at 40. The panel halves 22, 24 are formed in mirror image Eashion
and each includes a plurality of spacers of tubular form as indicated
generally at 42. In that respect, the sheet metal shells 34 and 36
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bear circular holes as ~t 44 and 46. The spacers 42 constitute
telescoping tubes as at 48 and 50, being welded together as at 52
and being peripherally notched as at 54 and 56, respectively, within
which the edges of the sheet metal shells 34 and 36 are received.
This locks the spacers 42 in proper axial position within the thermal
panel halves. Further, the telescoping tubes 48 and 50 form a
shoulder as at 5~, defined by the end of tube 50. Further, the other
end of tube 50 extends beyond the sheet metal shell 36 of the panel
half. End 60 projects beyond the sheet metal section shell 36 of
the thermal insulated metal panel sections 22 and 24.
In order to lock the panel halves to the end bells 16 at both
axial ends of the dryer cylinder 10, the present invention advantag-
eously employs specially formed stud clamps, as indicated at 30,
Figure 1. Figures 4 and 5 show a stud clamp more fully. Each stud
clamp 30 is formed principally by an arcuate clamping body 62 in
the form of an arcuate or slotted ring bearing a slot 64 which extends
radially from an offset circular opening or hole 66 within the body,
on the thickened side of the body 62. The narrowmost part of the
arcuate body occurs diametrically opposite slot 64. The opening or
hole 66 is on the order of the diameter of the bolt head 68 of
mounting bolt 18 employed in mounting the end hells 16 to the
cylindrical body of each dryer cylinder 10, but terminates short of
one side forming an annular lip or rim 67.
Referring again to Figure 4, the arcuate body 62 therefore
forms two halves, a left half 62a and a right half 62b, with the
halves being movable slightly towards and away from each other by
flexing at the narrowmost portion 62c of that body. One of the body
halves has its periphery recessed as at 62d, and that half is
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drilled at the recess so as to form a transversely extending hole
70 through which passes the threaded shaft portion 72 of a socket
head adjustment screw, indicated generally at 74. The head 76 of
the screw abuts face 62e defined by recess 62d within which the
hole 70 is bored. The opposite or left side 62a is tapped and
threaded at 78 so as to receive the threaded end of the shaft portion
72 of the screw 74. As may be appreciated, by positioning of a
suitable hex-shaped tool within the opening 76a of head 76 of the
screw, the screw 74 can be rotated such that the shaft 72 projects
more or less within the tapped and threaded hole 78 within the body
section 62a, thus causing the body sections to come together at
the slot 64, and narrowing that slot gap.
The stud clamp 30 is completed by a headed stud indicated
generally at 80 and comprised of a shaft portion 82 being threaded
at 82a on an outer end, and bearing at its opposite end a thin metal
disc 84 having a diameter slightly less than the diameter of the
opening 66 within the body 62. The body 62 is provided with the
circular opening 66 almost the full thickness of that body. However,
the annular rim 67, Figure 3, outlines a circular hole 69 which is
of slightly less diameter than that o hole 66 and is of a diameter
in excess of the diameter of the disc 84 received within hole 66.
The disc 66 is welded at three circumferentially spaced locations
as at 86, to the rim of one of the halves, in this case half 62b of
arcuate body 62. The right hand edge of disc 84 is therefore fixed
to the body half 62b, and when the adjustment screw 74 is rotated
counterclockwise, Figure 4, looking in from the head, the axis of
the disc and therefore the axis of the stud shaft 82 tends to shift ar(
to move slightly relative to the left hand section half 62a as
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slot 64 gap enlarges. This also enlarges the diameter of the
opening 66 which receives the bolt head 6~ during coupling of the
stud clamp to the bolts 18. Each stud clamp stud shaft 82 preferably
carries an MF two-way lock nut 88 and a washer 90, the washer 90
having an outside diameter less than the internal diameter o~ tube
48 but being in excess of the internal diameter of tube 50 such that
it abuts the shoulder 58, when a given panel half such as panel
half 24 is mounted thereto by causing the stud 80 to enter the
cylindrical opening of spacer 42.
Previously, it is necessary to fasten the stud clamps to the
individual heads 68 of the mounting bolts 18 which mount end bell 16
to the dryer cylinder at both ends. The socket head screws 74 are
tightened down on the bolt heads 68, and then a given half as at 2
of the thermal panel is impaled over the clamp studs 80 and
loosely fastened with the lock nuts 88 and washers 90.
This-is followed b~ the mating half,as for instance half 22,
being mounted to the left side of the dryer cylinder via its three
spacers as indicated at 42, Figure 2. Subsequent to the loose
fastening by way of lock nuts and washers 88, 90, and with both
panels 22 and ~4 in place, the panel halves are mechanically locked
together through the use of the two joint covers 26. Screws 92
pass through openings 94 within the joint covers and with the screws
92 received within mounting holes 96 adjacent the flattened end
faces 22a, 24a of respective sectionsor halves 22, 24. Subsequently,
the seal ring 28 is mounted to the panel by the use of further
screws 92 which pass through the seal ring, and are received within
screw holes 98 provided within the panel sections or halves 22, 24
adjacent the arcuate cut outs 100 of those members. With tne two
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joint covers 26 securely fastened to both halves of the thermal
panel 20, final tightening of the stud clamp stud lock nuts 88
occurs. This completes the installation of one thermal panel
to one end of the dryer cylinder 10. The opposite end is similarly
treated.
While the invention has been particularly shown and described
with reference to a preferred embodiment thereof, it will be
understood by those skilled in the art that various changes in
form and details may be made therein without departing from the
spirit and scope of the invention.
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