AU2004213065B2

AU2004213065B2 - Panel lifter lock

Info

Publication number: AU2004213065B2
Application number: AU2004213065A
Authority: AU
Inventors: Andrew Coumaros; Richard Paul
Original assignee: ITW Construction Systems Australia Pty Ltd
Current assignee: ITW Construction Systems Australia Pty Ltd
Priority date: 2003-02-21
Filing date: 2004-02-23
Publication date: 2009-12-03
Anticipated expiration: 2024-02-23
Also published as: WO2004074160A1; CA2519006C; NZ542089A; EP1603824A1; AU2004213065A1; CA2519006A1; EP1603824A4; AU2010200672A1

Description

WO 2004/074160 PCT/AU2004/000224 PANEL LIFTER LOCK The present invention relates to a lock for use in concrete panel lifting systems, in particular in relation to lifting links or lifting eyes (hereinafter "lifting eyes"), 5 which connect to anchors embedded in a concrete panel. Precast concrete panels are now commonly used in the building industry, in the construction of building walls, normally of large commercial buildings or factories. The panels normally are cast on site, or off-site at a panel casting 10 facility and they are generally cast horizontally. This means that when the panels have cured, they have to be lifted, either for positioning in place if the panels have been cast on-site, or for transport to the site of construction if the panels have been cast off-site. The panels are usually of great weight and therefore they are normally lifted by a crane. Figure la provides an example 15 illustration of a concrete panel 10 which has been lifted by a rolling crane 11, at each of four anchor points. Figure lb shows a panel supported for mid air rotation in the direction shown by the arrow A. The panel 12 is supported along its broad edge by a single lifting eye 13 and along its narrow edge by a pair of lifting eyes 14 and 15. The rotation applied to the panel 12 is to position it to 20 stand on its narrow edge from its transport position on it broad edge. Because of the weight in concrete panels of the above kind, it is important that the lifting arrangement employed is secure, otherwise the panel could drop, potentially both jeopardising the safety of the construction personnel in the 25 immediate vicinity and damaging the panel itself and other equipment and construction elements where the panel falls. The lifting arrangements now employed for such panels typically now include lifting anchors or the like which are embedded in the casting, and which are suitable for engagement by a lifting eye which is connected by chain or rope to the crane. Various types of 30 anchors, and lifting eyes suitable to engage such anchors are known. The present invention relates to a particular style of lifting eye, which includes a lever for shifting an anchor engagement mechanism between an engaged position and a released position relative to an anchor which is embedded in a concrete panel.

2 In lifting eyes of the above kind, construction personnel are concerned to ensure that the lever that can shift the anchor engagement mechanism to the released position, is prevented from doing so when a concrete panel is in a lifted condition. This might occur for example, if the lever becomes tangled in the lifting ropes or chains attached 5 to the crane, or if the load on the lifting eye is relaxed or released and subsequently reapplied. If the latter occurs, the engagement load between the anchor engagement mechanism and the embedded anchor may reduce sufficiently that the lever may shift under its own weight to release the anchor. The possibility of a lifting eye being released is most likely during mid air rotations of panels when a panel is rotated 10 through its broad plane while it is suspended above the ground. While release of a single anchor is unlikely to result in the concrete panel being dropped, it is nevertheless necessary that the lifting eyes be properly reattached to the anchor as soon as release becomes apparent, which thereby interrupts the construction process. 15 It is an object of the invention to overcome or at least alleviate the problems associated with the prior art. It is a particular object of the invention that the possibility of inadvertent lifting eye release be eliminated, or at least reduced. 20 According to the present invention there is provided a lock for use with a lifting eye which has a casing defining an arcuate channel having an open channel section and a closed channel section, and an anchor engagement facility at least partly enclosed by the casing and secured thereto, the anchor engagement facility including an anchor engagement element and a lever connected to that element, and the anchor 25 engagement element being accommodated in the arcuate channel and being movable relative to the casing by movement of the lever between respective anchor engaged and anchor released positions, wherein said lock has an operative locking position in which said lock is disposed within the open channel section and in which said lock cooperates with an abutment of the lifting eye casing and the anchor 30 engagement element to prevent said lever from moving from the anchor engaged position to the anchor released position, the lock being configured to permit cooperation between the anchor engagement element and the lock by wedging of a portion of the lock between an end section of the element and a facing surface of the arcuate channel defined by the casing within which the end section is disposed in the <filename> 3 anchor engaged position, and wherein said lock is arranged to cooperate with the lifting eye in said operative locking position, to resist dislodgement from said operative locking position to an inoperative position until an operator initiated dislodgement load is applied to dislodge said lock to said inoperative position. 5 The present invention further provides in combination, a lifting eye which has a casing defining an arcuate channel having an open channel section and a closed channel section, and an anchor engagement facility at least partly enclosed by the casing and secured thereto, the anchor engagement facility including an anchor engagement 10 element and a lever connected to that element, and the anchor engagement element being accommodated in the arcuate channel and being movable relative to the casing by movement of the lever between respective anchor engaged and anchor released positions, and a lock, wherein said lock has an operative locking position in which said lock is disposed within the open channel section and in which said lock 15 cooperates with an abutment of the lifting eye casing and the anchor engagement element to prevent said lever from moving from the anchor engaged position to the anchor released position, the lock being configured to permit cooperation between the anchor engagement element and the lock by wedging of a portion of the lock between an end section of the element and a facing surface of the arcuate channel defined by 20 the casing within which the end section is disposed in the anchor engaged position, and wherein said lock is arranged to cooperate with the lifting eye in said operative locking position, to resist dislodgement from said operative locking position to an inoperative position until an operator initiated dislodgement load is applied to dislodge said lock to said inoperative position. 25 The present invention further provides a method of using a lifting eye for lifting a concrete panel into position, wherein said concrete panel includes one or more lifting anchors for engagement by a respective lifting eye and the or each said lifting eye has a casing defining an arcuate channel having an open channel section and a 30 closed channel section, and an anchor engagement facility at least partly enclosed by the casing and secured thereto, the anchor engagement facility including an anchor engagement element and a lever connected to that element, and the anchor engagement element being accommodated in the arcuate channel and being movable relative to the casing by movement of the lever between respective anchor O'ne-ino 3a engaged and anchor released positions, said method including positioning a said lifting eye relative to an anchor of the concrete panel, shifting said lever of said anchor engagement facility from said anchor released position to said anchor engaged position to engage said anchor engagement element with the anchor of said concrete 5 panel, applying a lock to said lifting eye into an operative locking position in which said lock is disposed within the open channel section and in which said lock cooperates with an abutment of the lifting eye casing and the anchor engagement element to prevent said lever from moving from the anchor engaged position to the anchor released position, the lock being configured to permit cooperation between the 10 anchor engagement element and the lock by wedging of a portion of the lock between an end section of the element and a facing surface of the arcuate channel defined by the casing within which the end section is disposed in the anchor engaged position, and wherein said lock is arranged to cooperate with the lifting eye in said operative locking position, to resist dislodgement from said operative locking position to an 15 inoperative position, lifting said concrete panel into position and when removal of said lifting eye from said anchor is required, dislodging said lock from said operative locking position to said inoperative position, shifting said lever from said anchor engaged position to said anchor released position and thereafter removing said lifting eye from said anchor. 20 A lock according to the present invention obstructs lever movement when the anchor engagement element is in the anchor engaged position, so that movement of the anchor engagement element to the anchor release position is prevented, until a deliberate dislodgment load is applied. Accordingly, only when it is appropriate to 25 permit movement of the anchor engagement element to the anchor released position, will the lock of the present invention facilitate that. The safety of a lifting eye is therefore improved. The lock of the invention has been developed for a known lifting eye, an illustration of 30 which is shown in Figure 2. It should be appreciated however, that the invention could have wider application and should not therefore be <fdenams> WO 2004/074160 PCT/AU2004/000224 4 understood as being limited to use with the example lifting eye of the following discussion. The lifting eye 20 of Figure 2 includes a casing 21 which defines an arcuate 5 channel 22, which is partly open and partly closed. The channel 22 partly accommodates an anchor engagement facility 23 for engaging an anchor which is embedded in a cast concrete panel. The anchor engagement facility 23 includes an arcuate anchor engagement element 24 and a lever 25. The anchor engagement element 24 extends from an anchor receiving recess 26, to 10 the lever 25 and the arrangement is such that the lever 25 is connected, such as by welding, to the anchor engagement element 24. The channel 22 is terminated at either side of the anchor receiving recess 26 and is open at a position spaced from the recess 26, to form an arcuate lever passage 27. The casing 21 defines a central opening 28 through which extends a cable link 15 member 29 which is connectable to the lifting cable (not shown) of a crane or other lifting apparatus. The lifting eye 20 is operable as follows. The lever 25 is moved from the position shown in Figure 2, anti-clockwise, to fully withdraw the anchor 20 engagement element 24 from the anchor receiving recess 26, or to withdraw it sufficient for receipt of an anchor (not shown). The lifting eye 20 is then placed over an anchor embedded in a concrete panel, whereafter the lever 25 is moved clockwise to engage the anchor engagement element 24 with the anchor, by extending the anchor engagement element 24 fully across the 25 recess 26 and into the opposite side of the closed channel 22. The lever 25 is rotated until it reaches the position at which it engages against the casing abutment 30. At that position, the element 24 extends fully across the recess 26 and well into the closed channel on the opposite side of the recess, and the anchor is non-releasably captured by the element 24 while the element remains 30 in that position. To release the element 24 from engagement with the anchor, the lever 25 is returned from engagement with the abutment 30 to a position slightly further rotated to that shown in Figure 2, to completely withdraw the element 24 from 5 the recess 26. The lifting eye 20 actually includes a pin 31 which extends across the channel 22, and which forms an abutment for the lever 25 in the anchor release position of the element 24. 5 In use, a rope (not shown) is attached to the end of the lever 25 through the opening 32 and when a concrete panel to which the lifting eye 20 has been attached, has been successfully raised, the rope is pulled to move the lever 25 so as to displace the anchor engagement element 24 to the anchor release position, thereby permitting release of the lifting eye from the concrete panel. 10 By using a lock according to the invention, movement of the lever 25 to the anchor release position is only permitted at such time as an operator involved in the panel installation, dislodges the lock from the lifting eye to allow lever movement. Otherwise, lever movement is effectively eliminated. 15 If the lock of the invention is to be utilised with a lifting eye of the kind similar to that shown in Figure 2, the channel provided in such a lifting eye is arcuate (albeit that the channel is partly open and partly closed). A lock according to the invention is arranged for receipt within an open channel portion of the lifting eye and therefore can ?0 also be generally arcuate. In that arrangement, the lock is only partially received within the channel, so that a portion extends out of the channel in order to make the lock clearly visible to construction personnel. The casing abutment with which the lock cooperates can be formed in any suitable 25 manner and in one preferred form, the abutment is formed at the point of closure of the open channel. The lock can therefore be received with the open portion of the channel and to abut against the wall of the casing which radially closes the channel. Other abutment arrangements could however be employed, and while not as 30 convenient as the abutment discussed above, alternative abutments could be formed from, or provided to extend from, other sections of the casing or channel. A pin could, for example, extend across the channel to form an appropriate abutment. cfiiefl=me 6 The lock is also arranged to cooperate with the anchor engagement element to wedge between that element and the radially inner surface of the channel in which the anchor engagement element is disposed. Advantageously this wedging arrangement can be operable so that the wedging load between the anchor engagement element 5 and the radially inner surface of the channel, increases with any load applied to the lever to return the lever to an anchor release position while the lock is in the operative position. In other words, if the wedging load increases, the lock will be more firmly held in position, rather than less firmly, or rather than being dislodged. Accordingly, the security of the connection of the lock to the lifting eye is high, even though the 10 lever may experience loads tending to move it towards the anchor release position. To facilitate wedge engagement, the lock can include a tapered end region, which can fit between the radially inner surface of the anchor engagement element and the inner channel surface. The tolerance of the fit between that element and the channel will 15 influence the shape of the end taper required. The lock preferably includes an arcuate internal surface complementary to the radially inner arcuate surface of the channel. The arcuate surface preferably extends through the tapered end, so that the taper is provided from the outer lock surface to the inner 20 arcuate lock surface. The provision of a tapered end to locate between the anchor engagement element and the channel can also satisfy the requirement that the lock cooperate with the lifting eye to resist dislodgement. However, it is preferred that a separate arrangement 25 be provided to achieve this. In one form of the invention, use is made of a member or a projection formed or provided on the 'fdenanls' WO 2004/074160 PCT/AU2004/000224 7 lifting eye, such as the pin (reference numeral 31 of Figure 2), which is disposed across the channel of the known lifting eye, to act as a lever stop when the anchor engaging element has been withdrawn to the anchor release position. The lock may therefore include a recess which opens into the radially inner 5 surface of the lock and which is sized to frictionally engage and hold the pin. Advantageously, the lock can be constructed from a material such that the side walls of the recess will flex to accept the pin, so increasing the frictional grip of the lock on the pin. The recess may also be formed wider at a position radially inwardly thereof, so as to promote resilient flexing of the walls of the recess to 10 accept the pin. The recess can be arranged so that the pin is comfortably accommodated deeper into the recess. In this arrangement the pin is captured within the recess and provides the primary mechanism by which the lock is secured to the lifting eye. 15 Other arrangements could alternatively be employed to secure the lock to the lifting eye, and for example, the abutment surface of the lock which is arranged for abutment with the casing, may include a lip or the like, that engages underneath the closed channel part of the casing. Still alternatively, the lock may include clip type arms, which clip over the side faces of the casing. 20 In one preferred form, the lock is formed with a magnet, which attracts the lock to the operative position when the lifting eye is formed including ferrous materials, which typically will be the case. In a lock which is generally arcuate, the magnet can be provided at any suitable position along the arcuate length of 25 the lock, although in the preferred arrangement, the lock includes a pair of magnets, disposed approximately at either arcuate end of the lock. The use of magnets can be combined with, but more likely as an alternative to the recess arrangement discussed above, in which the recess frictionally engages and holds a pin which extends across the casing channel. It has been found that 30 such pins are not always accurately located, making it difficult in some cases to properly fix the lock to the lifting eye. By eliminating the need for cooperation of the lock with the pin, the accuracy of pin positioning becomes irrelevant to location and fixing of the lock to the lifting eye.

WO 2004/074160 PCT/AU2004/000224 8 If magnets are employed in combination with the pin and recess arrangement, then they provide a complimentary fixing mechanism to secure the lock in place relative to the lifting eye. In contrast, if magnets are employed as the sole mechanism for securing the lock in place, appropriate selection of the type and 5 number of magnets and their positioning, will adequately secure the lock in the operative position. Preferably two magnets are employed, but equally one magnet may be sufficient, or three or more magnets may be used. In the preferred arrangement, rare earth magnets are employed, but other magnet types may also be appropriate. 10 Clearly the use of magnets requires the manufacture of the lifting eye substantially from ferrous materials. However, typically lifting eyes are manufactured from mild steel so that the use of magnets is entirely appropriate. 15 One of the advantageous features of a lock according to the invention is that it can be arranged for remote operator dislodgement in a manner similar to the manner in which the (ever of a lifting eye is presently moved to shift the anchor engagement element to the anchor release position when the concrete panel has been fully installed. Advantageously, the lock may be connected to a rope 20 or the like and when lifting eye release is required, the operator may dislodge the lock by a firm pull on the rope and thereafter move the lever to the anchor release position. Accordingly, while an additional release step is required to employ the lock according to the invention, that step is simple and almost identical with the lever release step already employed. The present'invention 25 therefore also provides a method of using a lifting eye which employs a lock. The above approach provides a further advantage, in that the connection of the lock to a rope or the like, means that if the lock is not fitted to the lifting eye prior to a panel installation, the lock will clearly be visible to an operator, because it 30 will dangle from the end of the rope to which it is connected, providing clear visual evidence of the non-application of the lock. To further enhance this visual indication, the lock can be manufactured from highly visible material, such as fluorescent polypropylene or polyethylene.

WO 2004/074160 PCT/AU2004/000224 9 The attached drawings show an example embodiment of the invention of the foregoing kind. The particularity of those drawings and the associated description does not supersede the generality of the preceding broad description of the invention. 5 Fig. 1 shows a rolling crane lifting a concrete panel, to illustrate the context in which the present invention is to be employed. Fig. 2 illustrates a lifting eye and cable link member as presently used. Fig. 3 is a side perspective view of a lock according to the present 10 invention. Fig. 3a is a side perspective view of a lock according to an alternative embodiment of the present invention. Fig. 4 is a perspective view of a lifting eye which employs the lock shown in Fig. 3. 15 Referring to Fig. 3, a lock 40 is shown having an outer arcuate surface 41 and an inner arcuate surface 42. Each of the outer and inner surfaces 41 and 42 have the same axis of curvature, so that the thickness T of the lock 40 is generally constant. Moreover, the curvature of the inner surface 42 is 20 complementary to the curvature of a chaInnel, formed in a lifting eye to which the lock is applied. For example, and with reference to Fig. 2, the curvature of the inner surface 42 could be arranged to match the curvature of the channel 22 of the lifting eye 20. 25 The width W of the lock 40 is also arranged so that the lock 40 can be received within a channel of a lifting eye. The width W may be arranged to be a friction fit within such a channel, or a loose fit as required. The inner surface 42 is shown as being tapered from a central peak 43 to each 30 of the sidewalls 44 and 45. That tapering arrangement is provided for the lock 40 to be received within a channel which has a semi-circular base, so that the peak can rest against the radially inner centre of that channel.

WO 2004/074160 PCT/AU2004/000224 10 The lock 40 includes opposite ends 46 and 47. The end 46 is a flat or planar end, which is arranged for abutting engagement with an abutment formed in the lifting eye casing. The opposite end 47 of the lock 40 is tapered to form a tongue 48 which is arranged in use to be wedged between the anchor engaging 5 element of the lifting eye and the channel of the lifting eye within which that element is accommodated. The tongue 40 further includes a recess 49 which opens into the inner surface 42 and which is arranged to accept an abutment pin which extends across the 10 channel of a lifting eye to which the lock 40 can be fitted. The channel 49 is arranged to grip such a pin, so as to prevent dislodgement of the lock 40 from a lifting eye to which it is fitted, unless a significant dislodgement load is applied externally, such as by the crane operator, or other construction personnel. The recess 49 could be otherwise shaped to ensure proper gripping of the pin and to 15 securely maintain connection of the lock 40 to a lifting eye, although testing to date indicates that a recess of the kind shown will adequately maintain engagement between the lock 40 and a lifting eye. While the arrangement of the recess 49 to receive an abutment pin can 20 adequately secure the lock to the lifting eye, in some cases as discussed earlier, the pin may not always be positioned accurately for receipt within the recess. In this respect, the pin 31 of the lifting eye 20 of Figure 2, which in use is received within the recess 49, does not need to be precisely positioned for proper operation of the lifting eye. However, precise positioning of the pin 31 is 25 important to ensure its proper receipt within the recess 49. Accordingly, an alternative version of the lock 40 is shown in Figure 3a, in which like parts are given the same reference numeral, plus 100. The alternative lock 100, includes a pair of openings 101 for respective receipt 30 of a pair of magnets 102. The magnets 102 are fitted within the openings 101 in any suitable manner, such as by adhesive, or simply by a friction fit. The latter arrangement is preferred if the lock is formed from polyethylene, as the adhesives which are compatible with polyethylene are not generally also compatible with the metal of magnets.

WO 2004/074160 PCT/AU2004/000224 11 The openings 101 can be blind openings, such that they are open at one end only for receipt of each magnet but not at the other, or they can be open at each end. If they are open at each end, it is preferred that one end has a reduced 5 opening compared to the other, so that the reduced end forms an abutment against which one end of each magnet abuts for location, in the fitted position of the magnets 102 within the openings 101. The openings 101 may alternatively be formed to open into one of the side walls 10 44 or 45, so that the magnets can be press fitted into the openings. In this latter arrangement, the opening into the side wall can be of a width less than the diameter of the magnet so that the magnet must be forced past the edges of the side wall opening into the actual opening. Heat may be applied to close the side wall opening (not necessarily fully) in order to secure the magnet in place. 15 Fig. 4 shows the lock 40 of Fig. 3 as applied to a lifting eye of a similar kind to that shown in Fig. 2. In Fig. 4, the lifting eye 50 is generally circular, and defines a channel 51 and a central opening 52, for receipt of a portion 53 of a cable link member. The lifting eye 50 further includes an anchor engaging 20 facility, which comprises an anchor engagement element 54 and a lever 55 which is connected thereto. The anchor engagement element 54 is arcuate and is arranged to extend about the lifting eye 50, in particular to bridge the recess 56 formed in the casing 57 to engage an anchor (not shown), which is received within the recess 56. In this respect the operation of the lifting eye 50 is the 25 same as the lifting eye 20 of Fig. 2. The lifting eye 50 as shown in Fig. 4, has the anchor engagement element 54 and the lever 55 disposed in the anchor engaged position. In that position, the lever 55 is rotated fully clockwise and is in engagement with a casing abutment 30 58. In the position shown, the lock 40 of Fig. 3 can be inserted into the channel 51 with the tongue 48 thereof disposed between the radially inner surface of the channel 51 and an underneath surface 59 of the anchor engagement element 54.

WO 2004/074160 PCT/AU2004/000224 12 The end 46 of the lock 40 is engaged against a further casing abutment of the same kind as the abutment 58, but diametrically opposite thereto. Moreover, the recess 49 of the lock 40 which is not visible in Fig. 4, is in receipt of the pin 60 which extends laterally across the channel 51 and which is shown in broken 5 outline. It will be appreciated that the lock 40 is the lock shown in Figure 3, but that the lock could alternatively be the lock 100 shown in Figure 3a. If the lock 100 was employed, then there would be no recess engagement of the pin 60, but instead, the lock 100 would be secured in place at least partly by the magnetic attraction of the magnets 102 to the casing 57. 10 It will be appreciated also that the lock 40 is engaged against the casing 57 at the end 46 thereof, and is wedged between the channel surface and the underneath surface 59 of the anchor engagement element 54 at the other end 48 thereof. Additionally, the lock 40 (rather than the lock 100) is in frictional 15 engagement with the pin 60 by that pin being received within the recess 49. By this arrangement, it will be apparent that the lock 40 is firmly held in place and that the lever 55 is prevented from anti-clockwise rotation while the lock 40 remains located in place. Even if a load is applied to the lever 55 to rotate it in an anti-clockwise direction, that will only increase the wedging load which exists 20 between the radially inner surface of the channel 51 and the underneath surface 59 of the anchor engagement element 54, thereby even more firmly securing the lock 40 in place. Accordingly, the lever 55 is prevented from anti-clockwise rotation until such time as the lock 40 is dislodged from within the channel 51. This may be achieved by an operator applying a dislodgement force to the lock 25 40, such as by applying a pull force to a rope connected to the lock 40, whereafter anti-clockwise rotation of the lever 55 to disengage an anchor to which the lifting eye 50 is attached, may be completed. It will be appreciated that the locks 40 or 100 may be manufactured from a wide 30 variety of materials, but advantageously, manufacture as a moulding from polypropylene or polyethylene provides a lock which is robust and strong, and not prone to corrosion or deterioration. Additionally, the locks as shown are very simple to fit, simply by inserting the lock in place, whereafter engagement as described, holds the lock in place. Dislodgement also is quite simple, for WO 2004/074160 PCT/AU2004/000224 13 example by attaching a rope in any suitable manner to the lock, such as by moulding a rope eyelet to the outer surface 41 of the lock 40, so that a pull force dislodges the lock 40 from the lifting eye 50. Once the lock 40 has been removed, the lifting eye can be operated as normal to initiate anti-clockwise 5 movement of the lever 55 to release the lifting eye from the anchor. The invention described herein is susceptible to variations, modifications and/or additions other than those specifically described and it is to be understood that the invention includes all such variations, modifications and/or additions which 10 fall within the spirit and scope of the above description.

Claims

1. A lock for use with a lifting eye which has a casing defining an arcuate channel having an open channel section and a closed channel section, and an anchor 5 engagement facility at least partly enclosed by the casing and secured thereto, the anchor engagement facility including an anchor engagement element and a lever connected to that element, and the anchor engagement element being accommodated in the arcuate channel and being movable relative to the casing by movement of the lever between respective anchor engaged and anchor released 10 positions, wherein said lock has an operative locking position in which said lock is disposed within the open channel section and in which said lock cooperates with an abutment of the lifting eye casing and the anchor engagement element to prevent said lever from moving from the anchor engaged position to the anchor released position, the lock being configured to permit cooperation between the anchor 15 engagement element and the lock by wedging of a portion of the lock between an end section of the element and a facing surface of the arcuate channel defined by the casing within which the end section is disposed in the anchor engaged position, and wherein said lock is arranged to cooperate with the lifting eye in said operative locking position, to resist dislodgement from said operative locking position to an inoperative 20 position until an operator initiated dislodgement load is applied to dislodge said lock to said inoperative position.

2. A lock according to claim 1, said lock being formed generally arcuately. 25

3. A lock according to claim 2, said lock having an outer arcuate surface and an inner arcuate surface which respective surfaces have generally the same radius of curvature, said lock further having generally planar and parallel side walls extending between said inner and outer arcuate surfaces, and having longitudinally spaced end regions for respective cooperation with the abutment of the lifting eye casing and the 30 anchor engagement element.

4. A lock according to any one of claims 1 to 3, said lock being arranged for partial projection from the open channel section. 15

5. A lock according to any one of claims 1 to 4, wherein the lock is arranged to cooperate with the casing abutment of the lifting eye which is formed by an edge of the channel at the point of closure between the open channel section and the closed channel section. 5

6. A lock according to any one of claims 1 to 4, wherein the casing abutment of the lifting eye is formed by a pin which extends laterally across the arcuate channel.

7. A lock according to any one of claims 1 to 6, wherein said lock includes a tapered 10 end region for wedging between the end section of the anchor engagement element and the surface of the arcuate channel, said end region tapering to a narrow distal end.

8. A lock according to any one of claims 1 to 7, wherein said lock includes a recess 15 for frictional receipt of a member of the lifting eye, for resisting dislodgement of said lock from said operative locking position.

9. A lock according to claim 8 when dependent on claim 3, wherein said recess extends from said inner arcuate surface towards said outer arcuate surface. 20

10. A lock according to claim 8 or claim 9, wherein said recess is formed narrower at the opening thereof relative to an inner portion of the recess inward of said opening.

11. A lock according to any one of claims 1 to 10, wherein said lock includes a portion 25 which, in the operative locking position, extends into said closed channel section and engages a radially outer surface within the closed channel section.

12. A lock according to any one of claims 1 to 7, said lock including a magnet for attracting said lock to a lifting eye having a ferrous component. 30

13. A lock according to claim 12, said lock including a pair of magnets, one said magnet being positioned generally adjacent each end of said lock. -rderwne, 16

14. A lock according to any one of claims 1 to 13, said lock including a line connection for connecting said lock to a line for remote dislodgement of said lock from said operative locking position to said inoperative position by an operator. 5

15. A lock according to claim 14, said line being a rope which extends in connection with said lock to the operator.

16. In combination, a lifting eye which has a casing defining an arcuate channel having an open channel section and a closed channel section, and an anchor 10 engagement facility at least partly enclosed by the casing and secured thereto, the anchor engagement facility including an anchor engagement element and a lever connected to that element, and the anchor engagement element being accommodated in the arcuate channel and being movable relative to the casing by movement of the lever between respective anchor engaged and anchor released 15 positions, and a lock, wherein said lock has an operative locking position in which said lock is disposed within the open channel section and in which said lock cooperates with an abutment of the lifting eye casing and the anchor engagement element to prevent said lever from moving from the anchor engaged position to the anchor released position, the lock being configured to permit cooperation between the ?0 anchor engagement element and the lock by wedging of a portion of the lock between an end section of the element and a facing surface of the arcuate channel defined by the casing within which the end section is disposed in the anchor engaged position, and wherein said lock is arranged to cooperate with the lifting eye in said operative locking position, to resist dislodgement from said operative locking position to an 25 inoperative position until an operator initiated dislodgement load is applied to dislodge said lock to said inoperative position.

17. A method of using a lifting eye for lifting a concrete panel into position, wherein said concrete panel includes one or more lifting anchors for engagement by a 30 respective lifting eye and the or each said lifting eye has a casing defining an arcuate channel having an open channel section and a closed channel section, and an anchor engagement facility at least partly enclosed by the casing and secured thereto, the anchor engagement facility including an anchor engagement element and a lever connected to that element, and the anchor engagement element being 17 accommodated in the arcuate channel and being movable relative to the casing by movement of the lever between respective anchor engaged and anchor released positions, said method including positioning a said lifting eye relative to an anchor of the concrete panel, shifting said lever of said anchor engagement facility from said 5 anchor released position to said anchor engaged position to engage said anchor engagement element with the anchor of said concrete panel, applying a lock to said lifting eye into an operative locking position in which said lock is disposed within the open channel section and in which said lock cooperates with an abutment of the lifting eye casing and the anchor engagement element to prevent said lever from moving 10 from the anchor engaged position to the anchor released position, the lock being configured to permit cooperation between the anchor engagement element and the lock by wedging of a portion of the lock between an end section of the element and a facing surface of the arcuate channel defined by the casing within which the end section is disposed in the anchor engaged position, and wherein said lock is arranged 15 to cooperate with the lifting eye in said operative locking position, to resist dislodgement from said operative locking position to an inoperative position, lifting said concrete panel into position and when removal of said lifting eye from said anchor is required, dislodging said lock from said operative locking position to said inoperative position, shifting said lever from said anchor engaged position to said 20 anchor released position and thereafter removing said lifting eye from said anchor.

18. A method according to claim 17, wherein said lock is connected to a line which extends to an operator and said lock is dislodged from said operative locking position to said inoperative position by a pull load applied to said line. 25

19. A lock substantially as herein described with reference to the accompanying drawings. 'fjenams-