Conduit connection to a cassette for perforating sheets

A conduit connector is provided so that a heat medium source, a drain and/or a vacuum pressure source are in fluid communication with a cassette containing rotatable cylinders for producing corrugated paperboard. The cassette is insertable in a frame. At least one plug and associated socket are mounted in a first plate and a second plate, respectively. Each plug is secured to an end of a conduit, and the conduit has another end in communication with the cassette. Each socket is in communication with the source. The first plate is fixed relative to the cassette, and the second plate is fixed relative to the source. The plug and the socket are configured to engage each other upon an insertion of the cassette into the frame so that the conduit is in fluid communication with the source.

BACKGROUND OF THE INVENTION 
The present invention generally relates to a connection between conduits. 
More specifically, the present invention relates to a connection for a 
conduit that carries a heat exchange medium or vacuum into one or more 
fluted cylinders in an apparatus for producing corrugated paperboard. 
Furthermore, the present invention specifically relates to a conduit 
connection in relation to cylinder cassettes configured for frequent 
changeover. 
In known processes for corrugated cardboard or paperboard, a first sheet of 
paper is corrugated by rolling it between first and second intermeshing 
fluted cylinders. After the sheet has been corrugated, it is then retained 
in the flutes of the second cylinder as the cylinder continues to rotate. 
A gluing cylinder applies glue along the crests of the corrugated sheet as 
it is held in the flutes. A cover sheet is then applied to the corrugated 
sheet by pressing the cover sheet to the glued crests of the corrugated 
sheet by a pressure cylinder, which coacts with the second fluted 
cylinder. 
The above described process is known as "single facing," as it results in a 
corrugated board having only one flat side. With a subsequent step, 
"double facing" is achieved by applying another sheet to the single-faced 
sheet so that both sides of the corrugated sheet are covered. 
In order to provide effective and efficient gluing during a "single-facing" 
process, the fluted cylinders, and sometimes the pressure cylinder, are 
heated. It is know to heat such cylinders by circulating pressurized, 
superheated steam within an interior cavity of such a cylinder. 
Condensation from the heat exchange medium, such as steam, is withdrawn 
from the cavity. 
Also, it is known to apply a vacuum through small holes in the surface of a 
fluted cylinder in order to retain the corrugated sheet within the flutes 
as the cover sheet is being pressed to contact therewith by the pressure 
cylinder. For instance, such devices are disclosed in U.S. Pat. No. 
4,381,212, whose disclosure is incorporated by reference thereto, German 
Patent DE 28 23 674, and U.S. Pat. No. 4,917,664. 
U.S. Pat. No. 4,917,664, whose disclosure is incorporated by reference 
thereto and which claims priority from the application resulting in French 
patent document 2,622,145, relates to a fluted cylinder having an inner 
chamber which is permanently linked to a vacuum source and has a series of 
radial suction apertures which open on a peripheral surface of the 
cylinder. Furthermore, the cylinder includes a series of axial channels 
having a permanent circulation of steam which enters and leaves through 
two coaxial channels arranged on the supporting shaft. Typically, prior 
art devices have conduits which are fitted in permanent or semi-permanent 
manner. 
Depending on the type of a cardboard product to be produced, a particular 
corrugation configuration must be provided. Therefore, it is desirable to 
quickly exchange fluted cylinders in a "single-facing" apparatus for 
cylinders having a different size or shape corresponding to the desired 
corrugation. In order to exchange cylinders quickly, it is known to 
provide a single cassette which houses a pair of fluted cylinders with 
their bearings and driving motors. Such cassettes are configured to be 
inserted and received by a frame of a machine which performs other steps 
such as feeding paper to the cassette, etc. For such a cassette, it is 
known to provide a cooperative system of rails and rollers between a 
cassette carriage and the frame so that the cassette can be easily 
inserted and removed. It is further known to provide a machine which 
utilizes multiple cassettes. A first cassette can be fitted in an upper 
space of the machine, having a second cassette positioned below. A 
mechanism provides for lowering the second cassette in an orthogonal 
direction. 
To change cassettes, it is necessary to disconnect and reconnect the 
conduits which supply and return steam or vacuum pressure to the side of a 
cassette adjacent trunnion bearings for the cylinders. Because such 
connections are traditionally semi-permanent, connecting each conduit 
involves the insertion of a flange in a bushing and tightening a nut. This 
can be tedious work, resulting in a slow exchange of cassettes and lost 
production time. 
SUMMARY OF THE INVENTION 
The object of the invention consists of a conduit connection device for a 
cassette containing fluted cylinders used in a "single-faced" corrugated 
sheet making process, which can be inserted or removed quickly and easily. 
Another object of the invention is to provide a connection for such a 
cassette which is reliable, having a close tightness and fit for 
delivering superheated steam. 
To this end, a connector is provided for joining a conduit from a source to 
a cassette which is insertable in a frame of a machine for forming 
corrugated paperboard such as single face corrugated paperboard. The 
connector has a first connector member secured to an end of the conduit. 
The conduit has another end in communication with the cassette. A second 
connector member is in communication with the source. A first plate which 
is fixed relative to the cassette holds the first connector member. A 
second plate which is fixed relative to the source holds the second 
connector member. The first connector member and the second connector 
member are configured to engage each other upon an insertion of the 
cassette into the frame so that the first conduit is in fluid 
communication with the source. 
In an embodiment, a tubular nose extends from the first connector member, 
and a duct in the second connector member is configured to receive the 
nose. Also, the first and second plates are positioned to contact each 
other when the cassette reaches a point of full insertion into the frame. 
The first plate is offset from the cassette by a bracket, and a foot holds 
the second plate at a position away from the frame. 
In an embodiment, a tenon or positioning member extends from one of the 
first or second plates. An orifice in the center of the opposite plate is 
configured to receive the tenon for aligning the first connector member 
relative to the second connector member upon an insertion of the cassette 
into the frame. 
In another embodiment, a connector is provided to allow fluid communication 
between a cassette containing fluted cylinders for corrugating paperboard 
and a frame configured to receive the cassette. A first plate is secured 
to the cassette. At least one plug is secured in the first plate. Each 
plug is also secured to a conduit which is in fluid communication with an 
interior cavity of one of the cylinders in the cassette. A second plate is 
secured to the frame. A socket for each plug is secured in the second 
plate. The first plate and the second plate are arranged so that each 
socket receives each associated plug in a sealed engagement to provide 
fluid communication between each socket and each respective conduit when 
the cassette is inserted into the frame of the machine. 
In an embodiment, a tubular nose extends from each plug. The nose has a 
chamfered front edge. A length of the nose is at least half its outer 
diameter. An inner duct in said socket is configured to receive and engage 
a periphery of the nose. A ring shaped seal is set in an annular groove of 
the inner duct. 
An advantage of the present invention is that it provides a quick-change 
connection of supply and return conduits which carry a heat exchange 
medium or vacuum pressure to a cassette. 
Another advantage of the present invention is that it provides a conduit 
connection which is tightly sealed. 
A further advantage of the present invention is that it provides a conduit 
connection which is reliable. 
Still another advantage of the present invention is that it provides a 
conduit connection which is simple to use in conjunction with the 
insertion or removal of a cassette. 
Additional features and advantages of the present invention are described 
in, and will be apparent from, the detailed description of the presently 
preferred embodiments and from the drawings.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS 
In accordance with the invention described with reference to the 
accompanying figures wherein like numerals designate like parts, FIG. 1 
illustrates a cassette 10 which contains a lower fluted cylinder 80 and an 
upper fluted cylinder 82. The cassette 10 is received and guided on rails 
18 in a frame 20 of a "single-facing" station of a machine that produces 
corrugated paperboard. The cylinders inside the cassette engage one 
another to intermesh their respective flutes with a sheet of paper 
material in between. Rolling the sheet through the upper and lower 
cylinders results in the forming of that sheet in a corrugated shape. The 
upper and lower cylinders are configured to be heated internally by steam 
up to about 150.degree. C. 
The steam is delivered from a source A by a main supply duct 1 under a 
pressure of approximately sixteen bars. The conduit 1 is connected to a 
splitting connector 90 from which the superheated steam supply flow is 
split into main supply conduits 2 and 3. The main supply conduits 2 and 3 
are secured to a connector 100. The connector 100 provides a sealed fluid 
communication from main supply conduit 2 to cassette supply conduit 6, and 
from main supply conduit 3 to cassette supply conduit 4. 
The cassette supply conduit 4 delivers superheated steam to the upper 
cylinder 82 through a connector 92. Similarly, the cassette supply conduit 
6 delivers steam to the lower cylinder 80 through a connector 92. The 
steam flow from the supply conduits 4 and 6 is thereby directed into an 
interior cavity (not shown) of each cylinder near the top of a supporting 
trunnion for heating each respective cylinder. 
The steam condenses in the interior cavities as a result of heat transfer. 
The condensed, cooler steam is withdrawn from the interior cavities near 
the bottom of the supporting trunnions of the respective cylinders. The 
cassette return conduit 5 withdraws condensed steam from the upper 
cylinder 82 through a connector 92. Similarly, the cassette return conduit 
7 withdraws condensed steam from the lower cylinder 80 through a connector 
92. Furthermore, the conduits 4, 5, 6, 7 can each be provided in multiple 
sections joined together by connectors 90A. 
The cassette return conduits 5 and 7 are each secured to the connector 100 
which provides sealed fluid communication from cassette return conduit 5 
to a main return conduit 9. Similarly, the connector 100 also provides 
sealed fluid communication from cassette return conduit 7 to a main return 
conduit 8. The main return conduits 8 and 9 are in communication with a 
source B which provides a vacuum pressure or drain to withdraw the 
condensed steam. 
Main supply ducts 2 and 3 and main return conduits 8 and 9 are fixed 
relative to the frame 20. Cassette supply ducts 4 and 6 and cassette 
return conduits 5 and 7 are fixed relative to the cassette 10. The 
connector 100 provides fluid communication between main conduits 2, 3, 8, 
9 and cassette conduits 6, 4, 7, 5 respectively. 
The connector 100 has a first plate 30 which is secured to the cassette 10. 
Referring to FIG. 2, the connector 100 also has a second plate 40 which is 
secured to the frame 20. The first plate 30 lies against the second plate 
40. 
Each conduit is tightened to a respective connecting member such as a plug 
50 or a socket 60 (see FIG. 2) by means of a nut 95. The nut 95 provides a 
semi-permanent connection of each conduit to its respective plug 50 or 
socket 60 which only requires dismantling for the purpose of repair. 
Referring back to FIG. 2, the connection 100 is illustrated in greater 
detail. A foot 22 is secured to the frame, and extends outwardly 
therefrom. An intermediate plate 24 is secured at an end of the foot 22. 
The second plate 40 is secured to the intermediate plate 24. The foot 22 
is rigid. The connector 100 is offset so that the cassette 10 can be 
inserted and removed without interference from the second plate 40. 
The first plate 30 is secured to the cassette 10 by a bracket which 
includes a post 12 and crossbeam 14, however the bracket rigidly holds the 
first plate 30 at a position offset from the cassette 10. Fixture clips 16 
extend from the post 12 and crossbeam 14. Threaded rods 70 extend from the 
first plate 30 through holes 71 in the fixture clips 16. A nut 72 and a 
lock-nut 74 are threaded onto each threaded rod 70 to secure the first 
plate 30 to the fixture clips 16. 
The holes 71 are preferably oblong to allow the first plate 30 to shift in 
a plane parallel thereto approximately ten millimeters relative to the 
crossbeam 14. This allows a slight amount of "play" during engaging or 
disengaging the cassette 10 from the frame 20, or for allowing a shifting 
of the cassette 10 during operation. During such a shift, the first plate 
30 can remain secured to the second plate 40, although the post 12 and 
crossbeam 14 move relative to the cassette 10. Thus, the sealing effect of 
the connector 100 remains intact during a vertical shift of the cassette 
10. 
As illustrated in FIG. 2, the post 12, foot 22 and the crossbeam 14 may be 
tubular, T-shaped, or H-shaped members so long as their dimensions and 
thickness are such that the post 12, foot 22 and crossbeam 14 are highly 
rigid. 
As illustrated in FIG. 2, the height of the post 12 and the height of the 
foot 22 are correspondingly sized so that the plates 30 and 40 contact 
face to face at the point of full insertion of the cassette 10 into the 
frame 20. Moreover, the height of the foot is such that a curved conduit 
can be installed at the back of a socket 60. 
Each of the cassette-fixed conduits 4, 5, 6, 7, has an end secured to a 
plug 50. Each plug 50 resides in the first plate where it is retained by a 
bolt 34. Similarly, each of the frame-fixed conduits 2, 3, 8, 9 is linked 
at its end to a socket 60. Each socket 60 resides in the second plate 40 
where it is retained by a bolt 44. 
Each plug 50 is fitted with a threaded bore 52, and each socket 60 is 
fitted with a threaded bore 62. The threaded bores 52, 62 are configured 
to receive a tube tightening nut 95 on each conduit 2, 3, 4, 5, 6, 7, 8, 
9. Each plug 50 has a tubular nose 54 which extends opposite the threaded 
bore 52. The nose 54 preferably has a chamfered outer edge. 
Correspondingly, each socket 60 has an inner duct configured to receive one 
of the tubular noses 54. The inner duct is sized to cooperatively receive 
and sealably engage the respective tubular nose 54. Preferably, the 
diameter of the inner duct of the socket 60 and the outer diameter of the 
tubular nose 54 are manufactured within a tolerance of 0.1 millimeter. 
Moreover, the inner tube of the socket 60 is preferably slightly tapered 
in shape, increasing in diameter in the direction toward the plug 50. 
Also, a seal 64 shaped as an O-ring is interposed between the outer 
surface of the nose 54 and inner surface of the duct. As illustrated, the 
seal 64 can be held in place by a ring 66 within an annular groove located 
close to the inlet of the inner duct; however, the groove could be 
provided in the nose 54. The seal 64 engages the tubular nose 54 to 
prevent the escape of fluid, such as steam, passing through the connector 
100. 
In order to ensure a flat engagement between the first plate 30 and the 
second plates 40 for proper sealing between the plugs 50 and the sockets 
60, the first plate 30 and the second plate 40 are precisely aligned by a 
centering tenon or positioning member 32. The tenon 32 is secured to the 
first plate 30 at one end and has a frustoconical tip at the other. The 
tenon 32 tightly resides in a centering orifice 46 machined in the second 
plate 40. 
The tenon 32 provides for very accurate centering of the first and second 
plates 30 and 40. The aforementioned "play" allows the first plate 30 to 
shift as the tenon 32 centers into position. In another embodiment which 
is not shown, centering is achieved by two tenons 32 which reside in two 
centering orifices 46. 
So that the cassette 10 operates only when the connection 100 is secure, an 
electrical connection or a proximity sensor (not shown) can be provided in 
the foot 22 adjacent the centering orifice 46, for actuation by the 
corresponding tenon 32. This insures proper operation by actuating the 
cassette 10 only upon full insertion of the cassette 10 in the frame 20. 
The plugs 50, sockets 60, first plate 30 and second plate 40 are aligned 
in the same direction of travel of the cassette 10 on the rails 18 during 
insertion and removal so that a proper sealing engagement is achieved 
between the socket 60 and plugs 50. Furthermore, the centering tenon 32 
insures proper positioning during the action of inserting the cassette 10 
for proper sealing engagement. Kinetic energy of the travel cassette 10 
sufficiently provides that the O-ring seals 64 are fully engaged by the 
tubular extensions 44. 
The cassette 10 locks in its inserted position within the frame 20 to a 
tolerance of at least 0.1 millimeter. This locking retains the tightness 
of the connection 100. The connection 100 provides fluid communication 
between the conduits, the communication being sealed from the atmosphere 
by the cooperative engagement between the tubular nose 54 and the inner 
duct of the socket 60, particularly by the ring shaped seals 64. 
Various embodiments of the invention could include more or fewer mating 
plugs and sockets, depending on the conduits needed for a particular 
cassette. The conduits and connection 100 described could be used for 
providing only vacuum pressure to either of the cylinders 82 or 80, 
instead of steam. Only one conduit per cylinder would be needed to provide 
a vacuum. Such a configuration can be used to hold a sheet within the 
flutes of one cylinder during a particular process. Also, the plates 30 
and 40 could have another shape such as the shape of a regular polygon. 
Furthermore, the first plate 30 and second plate 40 could be positioned at 
another side of the cassette, other than that shown in FIGS. 1 and 2. 
In an alternative embodiment (not shown), the sockets 60 are mounted in the 
first plate 30, and the plugs 50 are mounted in the second plate 40. The 
plugs 50 and sockets 60 can be any cooperative shapes, which sealably 
engage each other. 
It should be understood that various changes and modifications to the 
presently preferred embodiments described herein will be apparent to those 
skilled in the art. Such changes and modifications may be made without 
departing from the spirit and scope of the present invention and without 
dimensioning its attendant advantages. It is, therefore, intended that 
such changes and modifications be covered by the appended claims.