GB2179321A

GB2179321A - Lifting apparatus

Info

Publication number: GB2179321A
Application number: GB08520920A
Authority: GB
Inventors: William Thomas Stanley; Philip George Tidbury
Original assignee: British Nuclear Fuels PLC
Current assignee: Sellafield Ltd
Priority date: 1985-08-21
Filing date: 1985-08-21
Publication date: 1987-03-04
Also published as: FR2586501A1; JPS6296295A; GB8520920D0; GB2179321B; DE3626805C2; DE3626805A1; FR2586501B1; JP2533093B2

Abstract

A lifting apparatus for lifting and lowering loads, such as nuclear fuel transport flasks, which have lifting trunnions of various dimensions. The apparatus comprises a telescopically extendable section (1) carrying a lifting beam (2) having depending side arms (8) moveable together along the beam. Trunnion cups (17) on the side arms enable the apparatus to cater for different trunnion diameters and lengths, by being provided with grooves (20) of different radii. The cups are formed from a fixed lower part (19) and a displaceable upper part (24). The beam is supported from a gimbal joint (9,10) and the section (1) by hooks (4) from an inverted T-hook (5). <IMAGE>

Description

SPECIFICATION An improved lifting apparatus The present invention concerns apparatus for lifting and lowering loads, such as nuclear fuel transport flasks.

According to the present invention an apparatus for lifting and lowering loads, such as nuclear fuel transport flasks, comprises a telescopicallyextendable section having means at one end thereof for remote releasable attachmentto a crane or hoist and a lifting beam pivotally supported at the other end ofthe section, the beam carrying depending side arms moveable together along the beam and each having trunnion cups cooperable with trunnions on a load, thetrunnion cups having a pluralityofdimensions whereby to cater for differenttrunnion diameters and lengths.

The invention will be described further, by way of example, with reference to the accompanying drawings; in which Figure lisa general arrangement of an embodi- mentofthe apparatus; Figure2 is a section on A-A in Figure 1 and showing an extended position oftheapparatus; Figure 3 is a section on B-B in Figure 1; and Figure4shows a trunnion cup arrangement.

A general arrangement of the apparatus is shown in Figure 1 and comprises a telescopic section 1 carrying a strongback 2 for engaging trunnions on a load, such as a nuclear fuel transport flask whereby the load can be lifted and moved by the apparatus.

At its upper end 3 the section 1 is provided with two oppositely directed hooks 4 adapted to releasably cooperate with an inverted T-shaped hook 5 of a hoist orcrane (not shown). The hooks 4 are mounted in the upper end of an elongate, substantially U-section channel mem ber 6 which forms a partofthetelesco- pically extendable section 1.

The strongback2 comprises a lifting beam 7 carrying a pair of depending side-arms 8 which are mounted for synchronised movement along the beam. The beam further carries gimbal box restraints 9 to receive the outerjournals of a gimbal box 10. An end of a stem 11, forming another part ofthetelesco- pically extendable section 1, is pivotally mounted on the inside ofthe gimbal box 10.With reference to Figure 2, the opposite end of the stem 11 terminates ata stem support block 12 having a portion 13to cooperate with correspondingly shaped supports 14 and 15 at the upper and lower ends of the U-section channel member 6. The telescopically extendable section 1 formed by the U-section channel member 6 and the stem 11 is moveable between a short length in which the support 13 engages the upper support 14 and a long length in which the support 13 engages the lower support 15.

With reference to Figures 1 and 3, the side arms 8 of the strongback are moveable together by means of a drive system which includes leadscrew 16 having right and left hand threads with manual or power operation from either end of the strongback.

Atrunnion cup 17 mounted atthe lower end of each of the side arms 8 is shown in detail in Figure 4. Each trunnion cup 17 comprises a block 18 fixed to the side arm and shaped such that a lower portion 19 ofthe block projects beyond the surface of the side arm which faces the opposing side arm. Each projection lower portion 19 constitutes a trunnion cup to receive and support a trunnion on a nuclear fuel transport flask to be lifted and transported by the apparatus.

The trunnion cup is formed with accurate grooves 20 of different radii whereby to caterfor different diameters offlasktrunnions. Atrunnion cup insert 23 is located in position by a spacer 21 which is secured by dowels 22.

An axially displaceable retaining block 24 is slidable in the block 18 and has an end face profiled to cooperate with different diameters and lengths of flasktrunnions. The block 24 is displaced axially into and out of engagement with a flasktrunnion by means of a lead screw 25 cooperablewith a captive nut 26 in the block 24 and supported for rotation in a bearing sleeve 27 mounted in a back plate 28. Hence rotation of the lead screw 25 effects axial displacement of the block 24. An indicator 29 on the block 24 can be provided to cooperate with scales fixed on the block 18 to indicate correct engagement.

In use, the assembly can function with the section 1 in its retracted or extended state. The apparatus is intended primarily for conveying nuclearfuel trans portflasksintotheareaofan inlet pond and for lowering and lifting the flasks into and out ofthe pond. The depth of immersion will determine the use of the retracted or extended state ofthetelescopic section.

To transport a flask into the pond the trunnion cups are first brought into engagement with the flask trunnions by axial adjustment of the side arms 8 on the strong back by means of the leadscrew 16. Thereafter the retaining blocks 24 are moved to abut againstthefaceoftheflasktrunnion by means ofthe leadscrew 25. The flask can then be lifted by means of a crane or hoist with the section 1 in its retracted state.

The load is supported through the gimbal box 10 and stem 11 with the portion 13 of the stem support block 12) atthe upper end ofthestem supported bythe support 14 at the upper end of the U-section channel number 6.

The inlet pond has upper and lower floor levels. To deposit a flask on the upper level the flask is lowered directly on to the floor and the assembly is allowed to pivot about an axis of the gimbal boxwherebysmall trunnions 29 on the member6 (Figure 1) come to rest against a bracket on the wall of the pond. The bracket can support the telescopic section and the hook 5 of the hoist can then be released from the hooks 4 atthe upper end of the section.

If it is required to lowertheflaskto a lower level in the inlet pond the stem is supported by a wall bracket engaging the lower surfaces 30 (Figure 1) of the stem support block 12. This causes a mechanical interlock to be disengaged to allow the section to be extended by means ofthe hoistto bringthesupport 15 atthe lower end of the channel member 6 into engagement withthestem supportblockattheupperendofthe stem. The mechanical interlock is re-engaged and thereafterwith the section 1 extended the flask can be transfered to a lower level in the inlet pond and the extended section can rest against a wall bracket cooperating with the trunnions 29 to permit decou pling of the hoist.

Claims

1. A lifting apparatus comprising a telescopically extendable section having means at one end thereof for remote releasableattachmentto a crane or hoist and a lifting beam pivotaliy supported at the other end of the section having depending side arms moveable together along the beam and each having trunnion cups cooperable with trunnions on a load, the trunnion cups having a plurality of dimensions to caterfor differenttrunnion diameters and lengths.

2. A lifting apparatus as claimed in claim 1 in which each trunnion cup comprises a blockfixed to the respective side arm,the block having a lower portion projecting outwardly beyond the surface of the side arm which facesthe opposing side arm and a displaceable upper portion selectively moveable into and out of cooperative engagement with the lower portion.

3. A lifting apparatus as claimed in claim 2 in which the upper and lower portions are formed with grooves of different radii to receive different diameters oftrunnions.

4. A lifting apparatus as claimed in any preceding claim in which the telescopically extendable section comprises a first part of having a substantially Usection channel member and a second partcomprising a stem having means atthe upper end thereof releasably cooperablewith spaced apart supports in the channel member.

5. A lifting apparatus as claimed in any preceding claim including gimbal means providing the pivotal supportatthe other end of the section.

6. A lifting apparatus constructed, arranged and adapted to operate substantially as herein described with reference to and as illustrated in the accompanying drawings.