GB2065037A - An operating device for a multi- panel piggy-back hatch cover - Google Patents

Abstract

An operating device for a multi- panel piggy-back hatch cover includes at least one pair of actuators for stacking and discharging the panels (11). Each actuator includes a power operated slide (15) vertically displaceable in a guide (14) at the coaming (10) surrounding the hatch opening and having a head (17) pivotable about a horizontal axis (16) at its upper end, so it can swing between an active, panel engaging position, and an inactive, panel passing position. The head has a cam surface (22), intended during a downward movement of the slide to engage a seat (12) of a panel to swing the head from its active to its inactive position, and also a finger (23) intended during an upward movement of the slide along one panel, to engage the seat (12) of the panel to swing the head from its inactive position to its active position below a seat (12) of a superposed panel. <IMAGE>

Description

SPECIFICATION An operating device for a multi-panel piggy-back hatch cover The present invention relates to an operating device for a multi-panel piggy-back hatch cover and including at least one pair of actuators for stacking and discharging the panels, each actuator comprising a power operated slide, vertically displaceable in a guide at the coaming surrounding the hatch opening, and having a head pivotable about a horizontal axis at its upper end, between an active, panel engaging position and an inactive, panel passing position.

Some ships are provided with hatch covers comprising a number of panels, which are movable horizontally, carried by wheels at two opposite sides of a coaming surrounding the hatch opening. By lifting one panel a distance slightly exceeding its height, an adjacent panel may be slid in below the first mentioned panel, whereby a portion of the hatch opening will be accessible. The first panel is then lowered onto the second panel, and both panels are lifted by the same actuators, so a third panel may be slid in below the second panel, and so on until all panels are stacked at one end, or with very long openings at both ends, of the opening, making a major part of the hatch opening accessible.

When the opening is to be closed the next but lower-most panel, with the panels resting thereon, is lifted sufficient to make it possible to pull out the lowermost panel, whereupon the next but lowermost panel is lowered onto the coaming, and the action is repeated until all panels are brought to a covering position.

Hatch covers of this type are usually referred to as piggy-back covers. The full stack of panels may of course be displaced to a ramp outside the hatch opening, so the latter will be fully accessible.

When the slide of the actuator moves up and down along the stack the head must be located differently depending upon whether the action is a stacking or a discharging operation. Actuators hitherto used for this purpose have been complicated and cumbersome, and have often included springs, which easily will deteriorate in the salty atmosphere, where they are expected to function.

A problem associated with automatic operation of the stacking and discharging steps is that it must be possible for the head to pass the lowermost panel, which necessitates some kind of selective actuation.

The panels are usually very heavy and impose a considerable load upon the actuators, which therefore must be constructed in a sturdy and reliable manner. On occasions it is desirable, for instance in tween-decks, to arrange the panels flush with the surrounding deck. This makes manual supervision of the actuators difficult and requires special reliability in operation.

An object of the present invention is to provide an operating device for hatch covers of the type above referred to, which may be used with flush covers as well as with covers carried by a coaming projecting above a deck, which reduces the drawbacks of known devices, has a reliable design requiring small space, and which is easily combined with conventional fluid operated rams, available on the market.

The invention is characterised in the head being provided with means intended, during an upward movement of the slide along one panel, in use, to engage a portion thereof for transferring the head from an inactive position to an active position below a seat at a superposed panel.

A displaceable stop member may be provided which is intended in a forward position to extend into the path of the head and during a downward movement of the slide to swing the head from its inactive position to an active position below a seat at the lowermost panel.

The transferring means is preferably intended at a downward movement of the slide during a discharging operation, to co-operate with a portion of the coaming for transferring the head from its active position to its inactive position.

The head is preferably provided with a cam surface intended, during a downward movement of the slide, to engage a portion of a panel for swinging the head from its active towards its inactive position.

The head may be so designed that its centre of gravity during the downward movement will be moved from a position inward of its pivot axis to a position outward of the same to complete the tilting movement. Alternatively the head may be so designed that its centre of gravity will remain inward of a vertical plane through the centre line of its pivot shaft, for bringing the head back into its active position during the later part of the downward movement.

The slide is preferably formed as a square-section tube, obiiquely cut at its upper end to form an inward U-shaped supporting face, continued by a downwardly/outwardly inclined surface, and the head is formed a a saddle structure, a roof of which is intended to engage the seat at the panel when resting upon said support surface, and the side members of which are pivotably connected to the slide, at least one of said side members being formed with a cam surface merging into a finger, which is the transferring means.

An embodiment of the invention will now be described, by way of example, with reference to the accompanying drawings, in which Figure 1 schematically shows a perspective view of an operating device constructed according to the invention; Figure 2 a-c show operating sequences at a piggy-back hatch cover and; Figures 3 - 7 show positions of the actuator components of the operating device during different operating steps.

A portion of a piggy-back cover intended for use on a weatherdeck is schematically shown in Figure 1.

A coaming 10 projects above the deck, and supports a number of panels 11 (only one of which is shown in this figure). Each panel is provided with lifting seats 12, located at its side parallel to the coaming, and each having a substantially horizontal face 13. The seats extend approximately to an outward side plate 10a of the coaming, at which guides 14 of rectangu lar cross-section are fitted.

Within each of the guides a vertically displaceable slide 15 is fitted, having at its upper end a head 17, which is pivotable about a horizontal shaft 16, parallel to the coaming. The slide 15 is a tubular member of rectangular cross-section, mating with that of guide 14. The shaft 16 is carried bytwo oppositely locates side walls 15a of the slide arranged transversley to the coaming 10. The ends 1 6a of shaft 16 project beyond these side walls, and form mountingsforthe head 17.

The latter is formed as a saddle structure having a roof formed as a substantially plane plate. Its side members 19 are located in parallel relationship to, and outside of the side walls 15a of the slide, to which they are attached by means of the projecting ends 16a of shaft 16.

The head will, in use, swing between an active position for engagement with the panels and an inactive position in which the slide may pass a panel.

When the head 17 is brought to its active position, i.e. with the roof 18 substantially horizontal, the head will rest upon a U-shaped support surface 20, at the portion of the upper end of slide 15 adjacent to the coaming. The support surface 20 is thus formed by the upper edge of a side wall 15b (turned towards the coaming) and the portion of side walls 15a closest thereto. In orderto facilitate the swinging of the head to its inactive position the remainder of the upper edges of side walls 15a, from approximately a vertical plane through the centre of shaft 16, are obliquely cut downwardly at 21, so the upper edge of the outward sidewall 15c of the slide will extend about to the level of shaft 16 only.

The saddle roof 18 will, in the active position of the slide, present an active portion 18a beneath seat 12, for cooperation with its horizontal face 13.

The side members 19 of the head are uniformly shaped, and each of their inward edges 19a includes a cam surface 22 merging into a lowerfinger23, which is partly defined by an outward edge 19b of the associated side member. In the active position of the head the cam surface 22 will be located directly below the active portion 18a, and approximately level with the shaft 16. The finger 23, which is directed obliquely downwardlylinwardly has such an extension that it will not contact any seat 12, when the head is in its active position.

When the head is swung to its inactive position it will rest against a stop face 24 formed by the upper part of side wall 15c. A stop member 25, formed as an axially displaceable bolt mounted in brackets 26 atthecoaming 10, will, in its forward position, extend into the path of movement of the head 17, and will then prevent the head reaching its full inactive position.

The actuator is operated by means of a vertically mounted, pressure fluid ram 27, for instance a hydraulic ram of conventional type (as shown in Figure 1), a piston rod 28 of which is mounted upon shaft 16 by means of a journal bearing 29. The lower end of ram 27, enclosing the cylinder, is provided with a mounting 30, which is journalled upon a shaft 32 carried by two brackets 31, projecting from the deck.

The supply and return flow of fluid occurs by way of conduits 33 from a pressure fluid source (not shown), and connected to the ram by couplings 34, preferably of the quick-connect, self closing type.

The upper edge 14a of guide 14 is cut to the same contour as that of the edges 19b of the side members 19 of the head, and will aid in supporting the head, when in its inactive position, and will also serve as a stop for slide 15 with its head 17, during a downward movement thereof, if bolt 25 is retracted. In order to reduce friction losses the guide 14 may be formed so it maintains only a spotwise, or linear, contact with the slide. The guide is preferably mounted so that its upper end is approximately level with a top plate 10b of the coaming. This will reduce the overall length of the slide, which will be selected so a safe guiding is obtained also when the slide is brought to its uppermost position.

As mentioned above, the panels 11 are movable by means of wheels 35 running along the top plate 10b of the coaming. The panels are provided with conventional packings 36, and in order to bring those into contact with the coaming, or two break the contact for moving the panels, respectively, the wheels are vertically displaceable in certain positions of the panels by means of actuators 37 built into the coaming, as indicated in Figure 1.

There should be provided at least two, preferably four actuators operating in unison, for performing the stacking and the discharging of the panels.

Figures 2 a-c show a piggy-back cover during stacking and discharging operations of its five panels denoted by 11 i-v The operating device is generally denoted at 40, an includes two pairs of actuators (only one unit of each pair being shown in the drawing), arranged at one end of the hatch opening in such a way that they will be substantially uniformly loaded during stacking and discharging.

Panel 111, which in its closed position rests above the operating device 40, is not provided with any wheels, as it is not expected to be moved horizontally.

Figure 2a shows how the first panel 111 has been lifted by the four actuators of device 40 a distance somewhat exceeding the height of the other panels, which will have to be lifted slightly by devices 37, so that the packing are disengaged from the coaming.

The adjacent panel liii may now be slid in below panel 111, and the actuators are shifted for engaging panel 11". How this is performed will be evident from description below. All panels may be moved towards the stacking place simultaneously, as is shown in Figure 2b, or the panels may be moved individually.

The stacking operation is repeated until all panels have been brought together whereby 4/5-ths of the hatch opening will be made available.

When the opening is to be closed again the actuators are first made to engage panel 11into lift the same and the panels resting thereon sufficient to make it possible to slide panel 11 v out. (Figure 2c).

Thereafter the stack is lowered so panel 111V wil I rest with its wheels upon the coaming. The actuators are then brought to engage panel 11111 and lift this together with panels 11" and 111 sufficient to permit a withdrawal of panel 111V. The action is repeated until all panels have been discharged and brought to their proper places.

Figures 3 - 7 show more in detail the positions of the slide 15 and the head 17 during various opera tions. Each figure shows two consecutive steps, of which the later one is shown in broken lines and the components are marked with an index sign (').

Figure 3 is an elevation of an actuator, and will explain the geometrical design described in connec tion with Figure 1. Figures 4 - 7 will show the upper end of the slide with the head only in relation to the panels. Figure 3 shows in full lines the slide 15 during an upward movement with the head engag ing seat 12 at panel 111. As the ram 27,28 is mounted in journals at shafts 16 and 32 only small bending moments and frictional forces will occur. During stacking operations bolt 25 is moved to its forward position.

When the slide has reached its top position its lower end is still safely retained in guide 14, which is evident from the location of the lower edge 15d of the slide in relation to the guide (Figure 3). Hereby instability at the actuator is prevented.

The next panel 1111 can now be slid in below the raised panel 111 and as a first step the slides are retracted so this panel can rest upon panel 1111.

During the continued downward movement of the slide, cam surface 22 will contact the edge of seat 12 at panel 1111,which makes the head 17 tilt outwards.

The centre of gravity, G, of the head is so located with respect to a vertical plane through the centre of shaft 16, that the tilting movement caused by cam 22 will bring the centre of gravity past said plane (Figure 4). The head will then, due to its own weight, continue the swinging movement.

The sinking movement of the slide prevents the finger 23 from engaging seat 12. A continued sinking movement of the slide brings edge 1 9b of one of the head side members 19 into contact with bolt 25, which tilts the head back to its active position, ready to lift panel 11". (Figure 5).

Alternatively the centre of gravity "G" may, as also indicated in Figure 4, be so located, that it will not be brought past the vertical plane through shaft 16.

Hereby the head will automatically swing back to active position, as soon as it has sunk below the level of the seat 12 at the next panel to be lifted. Bolt 25 will then serve as a stop for the downward move ment only.

When initiating a discharging operation the slide is supposed to rest in its lowermost position, with bolt 25 withdrawn so the head 17 can rest in inactive position against the stop surface 24 provided at the "slide (Figure 6).

An initial raising movement of the slide 15, will bring the finger 23' into contact with the seat 12 at the lowermost panel 11which makes the head swing into active position below seat 12' at panel 111V. This, with the other panels resting thereon, will be raised somewhat, so panel 11V can be slid out, whereupon the remainder of the stack is lowered onto the coaming.

Continued sinking movement of the slide brings finger 23 into contact with the edge of the top plate 1 orb at the coaming, which makes the head tilt outwards to its full in active position (Figure 7).

When the slide is again raised the steps described in connection with Figure 6 is repeated, i.e. the head will now engage panel 11111, which is next in turn.

All actuators belonging to an operating device 40 are controlled by the same governing member, and will move in unison. The arrangement is well suited for remote control, and very little manual labour is required. In order further to facilitate automatic operation bolt 25 may be connected to a pressure fluid servomotor, which also may be remotely controlled.

The actuators are shown as permanently attached to the coaming at one end of the hatch opening. It is however possible to provide the actuators as movable units, which may be attached to suitable fitting at the coaming at selected position so as to make possible a lifting of an individual panel, to make just one part of the hatch available. With very long hatch openings it may be desirable to provide stacking spaces at both ends of the opening, and as mentioned before also the lowermost panel may be provided with wheels so the full stack can be moved to a stowing ramp outside the opening.

Claims (9)

1. An operating device for a multi-panel piggyback hatch cover and including at least one pair of actuators for stacking and discharging the panels, each actuator comprising a power operated slide vertically displaceable in a guide at the coaming surrounding the hatch opening, and having a head pivotable about a horizontal axis at its upper end, between an active, panel engaging position, and an inactive, panel passing position, characterised in the head being provided with means intended, during an upward movement of the slide along one panel, in use, to engage a portion thereof for transferring the head from an inactive position to an active position below a seat at a superposed panel.

2. A device as claimed in claim 1, comprising a displaceable stop member intended in a forward position to extend into the path of the head and during a downward movement of the slide to swing the head from its inactive position to an active position below a seat at the lowermost panel.

3. A device as claimed in either claim 1 or claim 2 wherein said means is intended at a downward movement of the slide during a discharging operation, to co-operate with a portion of the coaming for transferring the head from its active position to its inactive position.

4. A device as claimed in anyone of claims 1 to 3, wherein the head is provided with a cam surface intended, during a downward movement of the slide, to engage a portion of a panel for swinging the head from its active position towards its inactive position.

5. A device as claimed in claim 4, wherein the head is so designed that its centre of gravity during the downward movement will be moved from a position inward of its pivot axis to a position outward of the same.

6. A device as claimed in claim 4, wherein the head is so designed that its centre of gravity will remain inward of a vertical plane through the centre line of its pivot shaft for bringing the head back into its active position during the later part of the downward movement.

7. A device as claimed in any one of the preceding claims, wherein the slide is formed as a squaresection tube, obliquely cut at its upper end to form an inward U-shaped supporting face, continued by a downwardlyxoutwardly inclined surface, the head is formed as a saddle structure, a roof of which is intended to engage the seat at the panel when resting upon said support surface, and the side members of which are pivotably connected to the slide, at least one of said side members being formed with a cam surface merging into a finger, which is the transferring means.

8. A device as claimed in any one of the preceding claims, wherein the pivot axis is a shaft, connected to a pressure fluid ram intended to displace the slide.

9. An operating device for a multi-panel piggyback hatch cover substantially as hereinbefore described with reference to and as shown in the accompanying drawings.