Rotatable pressure vessel

A rotatable pressure vessel has an opening and an internal movable cover therefor attached to a lever which is pivoted to the exterior of the vessel. For closing the cover, there is an actuating element movable to engage the lever, and mounted on a stationary support adjacent the vessel.

DESCRIPTION 
The invention relates to a rotatably mounted pressure vessel with a feed 
opening and an internally movable cover to close the opening from inside 
the vessel. 
German laid-open Patent Specification discloses such a vessel with a lever 
to support the cover and mounted pivotally on the outside of the vessel. 
The cover is movable by means of a double-acting piston-cylinder device 
fastened to the outside of the pressure vessel. This means that the supply 
of pressure medium must turn with rotation of the pressure vessel. In such 
a construction the cover is forcibly opened by the piston-cylinder device, 
so that opening is possible before the pressure in the vessel is fully 
reduced, while a connecting line is necessary between the piston-cylinder 
device and the stationary parts adjacent the vessel. 
The object of this invention is to provide a rotatable pressure vessel with 
a simple closing mechanism and no need to supply pressure medium thereto. 
According to the present invention there is provided a rotatably mounted 
pressure vessel comprising a feed opening, a cover within said vessel, 
said cover being movable within said vessel between first and second 
positions in which respectively, it closes and opens said opening, a lever 
movably supporting said cover, a pivot for the lever on the outside of the 
vessel such that when the cover is in said second position the cover 
extends into said vessel, a stationary support adjacent said vessel and, 
mounted on said support, an actuating element to move said cover to said 
first position to close said opening. 
With this invention there is no need to provide any permanent connection to 
vessel, for opening or closing, and in particular no opening or closing 
device extends to the vessel which it rotates. Also, the closing mechanism 
is reliable to operate and easy to make. 
Preferably said cover is mounted so that, when said pressure vessel is in a 
predetermined orientation, said cover falls essentially under its own 
weight from said first to said second position. This has the advantage 
that there is no real need for a forcibly acting device to open the cover. 
The cover then opens only if the pressure prevailing in the pressure 
vessel has diminished to such an extent that the cover can fall into the 
open position due to its own weight, and it is impossible for the cover to 
be forcibly opened by mistake when a high pressure prevails. 
The pressure vessel of the invention is especially appropriate as a steam 
skinner or pressure cooker, but its use is not restricted to these 
applications. In such applications, however, the problem arises that 
during filling and emptying, the opening and cover can come in contact 
with the product to be treated. Due to residual moist and sticky product 
remains, it can happen that the cover sticks somewhat, in the closed 
state, to the margin of the feed opening. To ensure that no delay occurs 
when the cover is to open due to its own weight, the pressure vessel has, 
according to a preferred feature of the invention, an additional actuating 
device which urges the cover towards the open position, at least when it 
is in the closed state. This prestressing can be sufficient to overcome 
the immediate effects of any sticking, as soon as the pressure is relieved 
within the pressure vessel. 
According to another preferred feature of the invention a blocking element 
is provided which locks the cover in the opened position after opening. It 
is thus ensured that the open cover cannot fall back by mistake into the 
closed position when the pressure vessel is turned into an emptying 
orientation in which the opening is situated at the underside.

The embodiment illustrated in FIGS. 1 and 2 will be described first. The 
pressure vessel 1 is conventionally mounted rotatably, about a 
substantially horizontal axis, in bearings, via two laterally flanged 
hollow shafts 2. The pressure vessel 1 has a feed opening 3 to which a 
feed funnel 4 is flanged. A gasket 5 is provided conventionally on the 
inside of the feed opening. A cover 6, which is connected to one end 7 of 
a lever 8 by means of a joint 9, serves to close the feed opening 3. This 
lever 8 is connected at its other end 10 to a swivel joint 11 which is 
connected on the outside to the pressure vessel or to the flange 12 
limiting the feed opening 3. 
The lever 8 is pivotable to and fro about the swivel joint 11 between the 
two positions shown respectively by broken and unbroken lines in FIG. 2, 
the cover being open in the position illustrated by unbroken lines and 
being closed in the position illustrated by broken lines. The lever 8 is 
curved and the centre point of the curvature lies approximately in the 
axis of the swivel joint 11. The radius of the curved lever is such that 
on its inside the lever does not contact the wall of the feed opening and 
that on its outside it does not scrape along the housing. Furthermore, the 
radius is such that the cover 6 is offset to the side from the feed 
opening in the manner illustrated in FIGS. 1 and 2. 
To fill it with fruit, the pressure vessel is pivoted to the left in the 
direction of the arrow 13 until the inclined plane 14 formed by a part of 
the wall of the pressure vessel lies approximately vertically, or even is 
moved beyond the vertical so that it serves as a chute for filling the 
pressure vessel with fruit. The swivel joint 11 and the lever 8 connected 
thereto are arranged on the side of the pressure vessel lying opposite the 
inclined plane 14, so that during the filling and emptying of the material 
to be treated the lever 8 and the cover 6 do not interfere or come in 
contact with this material. 
As may be seen especially in FIG. 1, the cover 6 falls automatically, due 
to its own weight, into the opened position under the force of gravity 
when the pressure vessel 1 is in a turning position lying between 
approximately 11 o'clock and 3 o'clock as viewed on a clock face, in the 
event that no pressure which holds the cover in the closing position from 
inside prevails in the pressure vessel. In the embodiment illustrated in 
FIGS. 1 and 2 there is provided additionally an actuating device in the 
form of a compression spring 15 which is connected at its one end to a 
flange 16 connected to the pressure vessel and at its other end to a 
flange 17 attached to the lever 8. The compression spring 15 is adjusted 
so that, when the cover is closed, the spring prestresses the lever 8 and 
consequently the cover 6 into the position shown in FIG. 1, in such a way 
that any sticking of the cover and cover margin due to product remains is 
overcome. The prestressing can also be effected in such a way that, when 
the pressure vessel is turned through 360.degree. in the direction of the 
arrow against the force of gravity of the cover, the cover remains held in 
the opened position. 
A double-acting piston-cylinder device 19 is fastened, by means of a flange 
20, to a stationary frame 18 surrounding the pressure vessel. Furthermore, 
fastened to the frame is a fork-shaped mounting 21 which holds a shaft 22 
arranged substantially parallel to the axis of rotation of the vessel, an 
element in the form of a double lever 23 being pivotable about this shaft. 
The lever 23 is connected jointedly at its one end 24 to the end of the 
piston rod 25 of the piston-cylinder device 19, so that the opposite end 
26 of the lever 23 is movable to and fro between the position shown in 
FIG. 1 and the position shown by broken lines in FIG. 2. 
Engagement elements 27 in the form of rollers are attached to the lever 8 
on the two transverse sides. The lever 23 has such a length that, when the 
lever is pressed down, as shown in FIG. 2, from the position shown by 
unbroken lines into the position shown by broken lines, it engages with 
the rollers 27 by means of sliding faces 28 provided on the underside of 
the fork-shaped ends. 
A protective wall 29 is provided between the pressure vessel and the 
double-acting piston-cylinder device 19, so that the piston-cylinder 
device is protected against steam which escapes when the pressure vessel 
is opened. 
The pressure vessel is, in a known manner, loaded with the pressure medium 
via the hollow shafts 2 and vented via these hollow shafts. A pressure 
gauge 30 provided on the hollow shaft generates a signal in dependence on 
the pressure prevailing on the inside of the pressure vessel. 
In operation, after the pressure vessel has been vented the cover 6 moves, 
due to its own weight, into the opened position shown in FIG. 1 and is 
held thus by means of the compression spring 15 during the further 
rotation of the pressure vessel. When the pressure vessel is to be closed, 
it is moved into the position shown in FIG. 1. Its position can be 
indicated on a control, not shown, by means of position indicators which 
can be designed, for example, as proximity switches. After this position 
is reached, the double-acting piston-cylinder device 19 is loaded via the 
line 31 with a hydraulic medium so that the lever 23 grips the rollers 27 
in the manner illustrated in FIG. 2 and moves the lever 8 against the 
force of the spring 15 into the closed position shown by broken lines. The 
pressure medium is subsequently supplied to the inside of the pressure 
vessel so that the cover is held in the closed position by means of the 
prevailing internal pressure. As soon as the pressure gauge 30 indicates a 
predetermined internal pressure which holds the cover in the closed 
position, the piston-cylinder device 19 is loaded with pressure medium via 
a line 32 and the line 31 is vented, the device 19 being moved back into 
the starting position shown in FIG. 1. The closed pressure vessel can 
subsequently rotate. 
To ensure that the cover 6 can sit as centrally as possible on the gasket 
5, the lever 8 and the cover 6 are connected to one another by means of a 
joint 9. 
The embodiment illustrated in FIG. 4 is identical in respect of the 
construction of the pressure vessel, the lever 8 and the piston-cylinder 
device 19 closing it together with the lever 23. For the sake of 
simplification, the corresponding parts are designated by the same 
reference numerals. The embodiment illustrated in FIG. 4 differs from the 
first embodiment in that the cover is not held in the opened position by a 
compression spring 15, but a blocking element, namely a pawl 33, connected 
to the pressure vessel is provided, which pawl is mounted pivotably about 
an axis of rotation 34 arranged substantially parallel to the axis of 
rotation of the pressure vessel. The pawl has such a form that, when the 
pressure vessel is in the position in which the cover falls into the 
opened position due to its own weight, the pawl pivots due to its own 
weight towards the lever 8, into the position shown in FIG. 4, and engages 
with a notch 34 of the lever, thereby causing the cover to be locked in 
the opened position when the pressure vessel turns in the direction of the 
arrow 13 in all its rotational positions. The free end 35 of the pawl has 
such a length that in the closing action corresponding to the illustration 
of FIG. 2 the lever 23, by means of its fork-shaped end, first pushes the 
pawl out of the catching position and then engages with the rollers 27 and 
presses the lever 8 down so that the cover assumes the closed position. 
The embodiment illustrated in FIG. 5 differs from the embodiment 
illustrated in FIG. 2 only in that a toggle-lever linkage 36, which is 
prestressed into an elongated position by a tension spring 37, is used 
instead of the compression spring 15. The tension spring has such a 
tension that without pressure on the inside of the pressure vessel the 
cover 6 is held in the opened position independently of the rotational 
position of the pressure vessel. 
Closing is effected in the same way as in the embodiment described with 
reference to FIGS. 1 and 2. In principle, the toggle-lever linkage can be 
designed in such a way that it is fully elongated in the opened position, 
so that a lock is obtained independently of the tension spring 37, the 
lock being released due to the fact that the lever 23 is so designed that 
it first acts on the toggle-lever linkage so as to move this out of the 
elongated position into the angled position, and subsequently engages with 
the rollers 27 and closes the cover as described above. 
The embodiment illustrated in FIG. 6 differs from that previously 
illustrated in that it possesses a modified construction of the mechanism 
for locking the cover 6 in its opened position. A pawl 51 attached to a 
pillow block 50 connected to the pressure vessel is pivotable about an 
axle 52 in such a way that the pawl is directed towards the rollers 27, 
viewed from the axle 52. The lever 8 has, on its surface, notch-like 
depressions with engagement faces 49. The plane of the engagement face 49 
which is indicated by the extended line 55 is inclined to the imaginary 
plane 56 passing through the axis of the swivel joint 11 and the base of 
the engagement face 49, by the angle .alpha.. The locking face 53, of the 
pawl 51, which interacts with the engagement face 49 is inclined so that 
the locking face 53 and the engagement face 49 are parallel to one another 
when the pawl engages with the engagement face in the manner illustrated 
in FIG. 6. The pawl is prestressed into the locking position by means of a 
spring 54 which acts thereon. As may be seen in FIG. 6, due to the 
friction between the locking face 43 and engagement face 49, which is 
further increased as a result of the adjustable force of the spring 54, 
the pawl is held in the locking position until the frictional force is 
overcome because of the engagement of the lever 23 on the rollers 27 and 
the cover is moved into its closed position. The angle .alpha. and the 
corresponding force of the spring 54 are selected so that the cover 6 is 
held in the opened position in every rotational position of the pressure 
vessel and cannot move automatically into the closing position due to its 
own weight, but also, on the other hand, so that the connection is 
released when the cover is closed by means of the lever. The especial 
advantage of this embodiment consists in that it is possible to lock the 
cover 6 in the opened position by means of the pawl 51 without the need 
for direct action of the lever 23 on the pawl in order to close the cover. 
As can best be seen from FIG. 3, the pressure vessel is mounted rotatably 
in bearings 39, 40 via shafts 2, 38 connected to pipe connections. The 
shaft 38 accommodates a steam supply line 40, not rotating therewith, 
which is mounted within the shaft 38 in a plain bearing, not shown, and 
which is sealed by means of a gland or retaining ring. From the hollow 
shaft 38 a high-pressure line 42, rotating with the pressure vessel, leads 
to a stream outlet opening 43 provided in the bottom region of the 
pressure vessel 1. The other hollow shaft 2 is connected to a stationary 
line 44, not rotating therewith, via a plane bearing which is not shown, 
the sealing being effected again in a known manner, for example by means 
of a gland or retaining ring. The line 44 is connectable, in dependence on 
a control not show, via a valve 45 to a steam supply line 46 or via a 
valve 47 to a venting line 48. Since the mechanism actuating the cover 
does not rotate with the pressure vessel but is stationary, and since the 
two shafts 2 and 38 are therefore not required for supplying the actuating 
medium to the piston-cylinder device 19, it is possible to use the two 
shafts 2 and 38 for supplying the pressure medium in the above-described 
way, thereby achieving a considerable advantage. In the embodiment shown 
in FIGS. 7 and 8, the pressure vessel is supported and constructed just as 
in the preceeding embodiments. The pressure vessel 1 is closed by cover 6, 
moved by lever 8 which is supported and swivel joint 11 which, in this 
embodiment, is supported in a supporting flange 57 secured on the pressure 
vessel, in a manner best seen from FIG. 8. The swivel joint 11 is formed 
as a shaft 58 rigidly secured on lever 8 and supported in two arms 59, 60 
rigidly connected with flange 57. A gear wheel 61 is mounted on one end of 
shaft 58. A second gear wheel 62 secured on a shaft 63 is in engagement 
with gear wheel 61. Shaft 63 is mounted in bearings on arm 60 and a 
further arm 64. A lever 65 is mounted on the end of shaft 63 opposite the 
pressure vessel. The length of lever 65 exceeds the distance between shaft 
63 and the diameter 66 of the outermost portions of the pressure vessel 
indicated in interrupted lines in FIG. 7, but the length of lever 65 is 
less than the smallest distance of shaft 63 from those portions of frame 
18 lying above the orbit of lever 65. In a manner shown in FIGS. 7 and 8, 
lever 65 extends substantially normally with respect to the rotating axis 
of the pressure vessel 1. 
An abutment pawl 67 is provided on frame 18 extending in the orbit of lever 
65 and mounted on frame 18 via a shaft 68 connected with frame 18, in such 
a manner that such abutment pawl 67 may be pivoted away in a direction 
indicated by arrow 69, whereas, in a direction opposite to arrow 69, pawl 
67 rests on the frame 18 through its base in the manner shown in FIG. 7 to 
form a rigid abutment for lever 65. 
The abutment pawl 67 is of such length that, in the position shown in FIG. 
7 and upon clockwise rotation of the pressure vessel, the pawl engages 
lever 65 extending beyond diameter 66. Upon counter-clockwise rotation of 
the pressure vessel, however, lever 65 will pivote the abutment pawl 67 in 
the direction of arrow 69 about shaft 68 moving pawl 67 away from the 
orbit of lever 65 and returning by gravity into its position shown in FIG. 
7 when lever 65 is moved further. 
Operation of the device is as follows: 
The pressure vessel 1 is filled while being in the position shown in FIG. 
7. The filled pressure vessel is rotated in clockwise direction, and lever 
65 extending beyond diameter 66 will engage the abutment pawl 67 and will 
be urged thereby in the direction of arrow 69 to move the cover in its 
closed position through shaft 63, engaging gears 62, 61, shaft 58 and 
lever 8. The ratio of gears 61 and 62 is selected to provide a rotating 
movement through the engagement of lever 65 and pawl 67 which is just 
sufficient to move the cover from its shown open position into its closed 
position. 
Rotation of the pressure vessel 1 is stopped under control of a suitably 
arranged micro switch or sensor as soon as the cover is in its closed 
position. Subsequently, the pressure vessel is moved in a 
counter-clockwise direction in accordance with the direction of arrow 69. 
After closing of the cover, the pressure vessel is filled with steam, and 
the pressure within the pressure vessel will maintain the cover in its 
closed position. As the abutment pawl 67 may be pivoted away on its shaft 
68, the movement of the pressure vessel will not be hindered by the 
abutment. At the end of the processing, e.g. peeling of fruit, the 
pressure within the pressure vessel is released, and by turning the 
pressure vessel into a position in which its feed opening 3 is directed 
upwardly, as shown in FIG. 7, the cover 6 will return in its open position 
through gravity, and lever 65 will return in its position shown in FIG. 7. 
A friction clutch (not shown) is provided between motor drive 70 and the 
shaft 2 of the pressure vessel. The friction clutch will prevent the cover 
from being forced in case of jamming or sticking upon engagement of lever 
65 and pawl 67, in which case the clutch would be overdriven. 
For maintaining cover 6 in its opened position blocking or biasing means 
may be provided just as with the preceeding embodiments. 
The embodiment disclosed with reference to FIGS. 7 and 8 provides opening 
and closing of the pressure vessel without any supply of pressure medium. 
Moreover, this embodiment provides a very simple and reliable opening and 
closing device for a pressure vessel of the kind disclosed. 
The pressure vessel is preferably, though not exclusively, used as a steam 
peeler or pressure cooker.