AU1472302A - Lifting and/or removal device - Google Patents

Description

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT Applicant: BARWON REGION WATER AUTHORITY Invention Title: LIFTING AND/OR REMOVAL DEVICE The following statement is a full description of this invention, including the best method of performing it known to us: 2 LIFTING AND/OR REMOVAL DEVICE The present invention relates generally to a lifting and/or removal device for lifting and/or removing items, particularly items located in situ out of doors.

More particularly, the present invention relates to a combined lifting and removal device and to methods of using such devices to lift and remove items exposed to the weather in outdoor locations during maintenance or servicing of systems having the item as one component.

More particularly, the present invention relates to devices and methods of using such devices for lifting and removing manhole covers, particularly sewerage manhole covers, in situ. The present invention finds particular application as a lifting device which not only breaks the seal of a sewerage manhole cover but also assists in o lifting and removing the manhole cover from its seat or rim when access to the drainage system and/or other system is required, such as for example, during routine servicing and maintenance of the system or in emergency situations involving the system.

Although the present invention will be described with particular reference to one form of the lifting device of the present invention it is to be noted that the 0.0. 0 25 scope of the present invention is not restricted to the "0000 described embodiment but rather the present invention is more extensive so as to include other forms of the lifting odevice, other arrangements or assemblies of the components forming the lifting device and the use of all such devices for other purposes.

Many systems have manhole covers or inspection plates or other apertures or ports having covers or lids allowing access internally to the system, such as for example, systems having conduits for conducting or conveying materials. Typical examples of systems having manhole covers are sewerage systems, drainage systems, telecommunication cable systems, including fibre optics, 3 electrical supply systems, water reticulation systems, or other systems involving underground conduits and the like.

Although the present invention will be described with particular reference to sewerage systems having inspection manhole covers it is to be noted that the present invention is not limited to the use of lifting devices to remove inspection manhole covers for sewerage systems but the lifting device of the present invention can be used to lift and remove a wide variety of different items generally, and in particular a wide variety of different manhole covers for numerous and various systems.

Existing manhole covers for sewerage systems are currently available in a range of different types and configurations. The manhole covers are also referred to 15 as covers, lids, pit covers and other similar terms.

Different lifting implements, such as for example, J i°•o hooks, picks, crowbars, sledgehammers and specialised lifters are used to lift the existing manhole covers depending upon the type of cover in use. As an example concrete type manhole covers are lifted with one or more of J hooks, picks and crowbars, either used alone or in combination with each other whereas cast iron type manhole covers can be lifted with one or more of picks, crowbars and sledgehammers, again used alone or in combination with 25 each other or other tools.

Owing to the harsh environment in which existing manhole covers are located the manhole covers either are subjected to corrosion in which critical parts, of the covers, such as lifting pins and the like, corrode or break under lifting loads or the covers are sealed to their seats, rims or frames in which they are located, ie.

such as for example, by rusting or being covered with debris and other material. Currently excessive force and inappropriate manual tools are used to lift and remove the manhole covers which presents many problems. The most common problems which occur include the following. The pins in concrete covers corrode and break under lifting 4 loads. In situ built concrete lids are often made out-ofshape for the seat, rim or framework receiving such lids and the essential lift point is often located off-centre resulting in the lid being unstable, making the lid hard to handle. Cast iron lids are usually located on the surface of roads or other carriageways and are usually sealed in their frames by road resurfacing or other materials used to make or repair the road surface and often require a crane truck or similar heavy duty machinery to free them. Additionally such cast iron lids are heavy. Covers provided with specialised lift points are often also provided with removable protective covers, flaps or similar which are often damaged or lost so that the lifting points can fill with debris or other materials 15 which cause corrosion and results in difficulty in fitting specialised lifters to the lift points to lift and remove the manhole covers.

If no suitable lifting point is available either through corrosion, damage or wear, it is sometimes necessary to form a hole in the cover by drilling, or brute force or by other means to create a lifting point in the manhole cover. The formation of this additional hole allows the opportunity for water infiltration into the sewer or for other unwanted materials or debris to be 25 admitted into the sewer. This further adds to the problems of lifting the covers on later occasions.

Large rectangular concrete lids are very heavy and because of their shape are likely to fall into the pit when being moved by existing inappropriate manual implements.

The existing ways of lifting manhole covers suffer from one or more of the above disadvantages.

Furthermore, when excessive force is used to break the seal or lift the manhole covers by using inappropriate tools such as picks, crowbars and the like there is a great chance that workmen using such tools can suffer injury, particularly back injury caused by exerting 5 excessive force or accidental injury when the component parts of the lids or the tools break, fracture or the like which can result in a sudden movement, causing injuries such as whiplash, broken bones or the like. Similarly, such tools can slip in use which can also cause similar accidental injury and damage.

Another problem of existing tools is that a workman using the tools must be in a crouched or stooped position to use the tools so that when the workman exerts full lifting force or load on the tool there is a greater risk of injury than if the workman or operator is in an upright or substantially upright position. Thus, the use of existing tools in a crouched or stooped position increases the risk of work related injuries.

15 Thus, there is a need to provide a lifting device and a method of using a lifting device to safely break the seal of the manhole cover and to lift and remove the manhole cover from the seat or rim without causing injury to the operator or workmen. Further, it is desirable that the device is adaptable to be used in removing manhole covers of a variety of different shapes, sizes, types and configurations in a variety of different situations.

Therefore, it is an aim of the present invention 25 to provide a lifting and/or removal device, particularly a device that is adapted to lift and remove manhole covers, without requiring the application of excessive force by a 0workman or similar, particularly when the workman is in a crouched position and which is sufficiently flexible to be able to be used in connection with a variety of different manhole cover types to lift and remove the covers.

According to the present invention there is provided a lifting device for lifting and/or removing an item, particularly a device that is adapted to lift and/or remove a manhole cover located in situ, said device including a base portion for stably contacting a substrate, particularly the substrate in which the item is 6 located in situ, to support the lifting device in use, an elongate member movably connected to the base portion and being provided with at least one attachment point for connecting the device to the item to be lifted by a connection means and a lifting means for raising the elongate member wherein operation of the lifting means raises the elongate member and the connection means to lift the item from the substrate.

According to a further aspect of the present invention there is provided a method of lifting an item including the steps of placing a lifting device adjacent or in close proximity to the item to be lifted, connecting the item by a connection means to an attachment point provided on an elongate member moveably connected to a base portion and operating a lifting means in contact with the elongate member to raise the elongate member and the connection means to lift the item.

Typically, the item to be lifted is a manhole cover, more typically a sewerage manhole cover and even S. 20 more typically a partially damaged, corroded or obscured manhole cover. Even more typically, the manhole cover is made from concrete, metal, or other suitable material.

Typically, the lifting device is suitable for both lifting and removing the manhole cover as well as breaking the seal of the manhole cover in its seat.

Typically the base portion is a disc and post arrangement in which the post extends substantially axially from the plane of the disc and the disc is capable of being stably located on the substrate, typically in a position adjacent to or on the apron of the manhole cover.

Typically the elongate member is movably connected to the post of the base portion. More typically, the movable connection of the elongate member to the post allows the elongate member to move substantially pivotally axially with respect to the post and substantially pivotally radially with respect to the post ie. upwards and downwards as well as around the post.

7 Typically the elongate member is a lever, arm, bar or the like and typically has at least one, preferably two, three, four or more attachment points. Typically the attachment points are adjustable collars, clamps or brackets axially slidably along the length of the lever or arm to adjust the position of the attachment points.

Typically the item is connected to the attachment points by a connection means, including connectors. Typically, the connectors are flexible, such as for example, chains. More typically, the chains are provided with interchangeable keys.

Typically the arm or bar is provided with a handle, more typically the handle is located off-centre from the lengthwise extending axis of the bar allowing the 15 item to be lifted and/or transported whilst the workman is standing in an upright position or when in a more upright posture.

Typically the lifting means is a jack, such as for example, a hydraulic jack, a screw jack, or other 20 lifting device or means for applying a lifting force to the lifting device of the present invention, particularly to the arm or bar, more particularly to the underside of the bar.

Typically, the lifting device is capable of one man operation to both break the seal of the manhole cover, to lift the manhole cover from its seat or rim and to remove the manhole cover away from the seat or rim to provide access through the manhole or pit or similar closed by the manhole cover.

The present invention will now be described by way of example with reference to the accompanying drawings in which: Figure 1 is a side elevation view of one form of the lifting device of the present invention; and Figure 2 is a top plan view of the device of figure i.

One form of the lifting device of the present 8 invention is illustrated in the accompanying drawings. It is to be noted that the lifting device can take other forms. The illustrated lifting device, generally denoted as 2, includes a base subassembly 4 comprising a circular disc-like base 5 for enabling the device 2 to be stably supported on a suitable substrate (not shown), such as for example, the concrete apron surrounding the manhole cover seat or rim or the earth located around the entrance to the manhole or pit or the road surface in which the manhole cover is located. Disc base 5 is of a sufficient diameter to rigidly support device 2 when lifting the manhole cover. A vertically extending post 6 of circular o. cross-section extends from the centre of disc 5 to a :height sufficient to enable the manhole cover to be lifted clear of its seat or rim. Circular post 6 is provided with a plurality of substantially vertically or axially spaced apart apertures 8 for receiving there through pin to support collar 12 at a predetermined height on post 6. Post 12 is received in the circular opening of collar 20 12 allowing collar 12 to rotate about the lengthwise extending axis of post 6. Depending upon the height to which the manhole cover is required to be lifted, pin is located in one selected aperture 8 to adjust the height of collar 12. Collar 12 is free to pivot or swivel radially around post 6 to move the manhole cover laterally away from the manhole as will be described in more detail S* later.

Swivel collar 12 is provided with two substantially triangular projections 14 extending radially from the outside wall of collar 12 in parallel spaced apart relationship to form a yoke. Each projection 14 is provided with an aperture (not shown) at or towards the distal apex for receiving pin 16 there through to connect the proximal end of bar 20 to swivel collar 12 by the bar being received in the yoke. Bar 20 is provided with one or more apertures which when in register with the two apertures of extensions 14 allow pin 16 to be received 9 through the apertures when aligned with each other Pin 16 is removable from the end of bar 20 and extensions 14 to assist in connecting bar 20 to extensions 14 so as to disassemble the lifting device for ease of transport and removal as well as to assist in connecting bar 20 to extensions 14 so as to assemble the lifting device in preparation for use. Bar 20 is free to pivot substantially vertically about the lengthwise extending axis of post 6 so that the distal end of bar 20 can be raised and lowered whist the proximal end remains connected to collar 12.

Bar 20 is provided with at least one, and preferably two or more lifting subassemblies located or S locatable at more or less regularly spaced apart locations 15 along the length of bar 20. The position of the lifting subassemblies are adjustable to accommodate lifting and/or removing a variety of differently sized, shaped and configured manhole covers, such as for example, to accommodate whether the lift points of the covers are 20 located in the centre of the cover or at or towards one side or along the wall of the cover.

One form of the lifting subassemblies includes a connection means in the form of a chain 24 having one end fixedly connected to the under surface of bar 20 by a ring, loop or similar fitting 22 at a point partway between the centre of bar 20 and the proximal end of bar 20. Another lift point is located between the centre point of bar 20 and the distal end of bar 20 where a second chain 30 and ring fastener 33 are located.

In this form of the lifting device a fixed lift point is located at the centre of bar 20 in the form of a lifting subassembly having a depending downwardly chain 26 extending from the under surface of bar 20 and connected thereto by a link received through a loop, ring or the like 28.

Another form of the lifting subassembly includes one or more, preferably two axially, slidably adjustable 10 collars 31, clamps or brackets located at predetermined or preselected points along the length of bar Preferably, one collar 31, clamp or bracket is located at the centre point of bar 20 and another collar, clamp or bracket is located intermediate the centre point and the distal end or bar 20. However, the position of collars 31 is adjustable. Each clamp or bracket is provided with a ring 22, 33 through which a link of a downwardly depending chain is received.

An interchangeable key 32 is located at the lower or distal end of downwardly depending chain 26. The interchangeable key 32 is adapted to correspond to the particular type of manhole cover being lifted and accordingly is selected in accordance with the type of 15 manhole cover to be lifted and the shape of the lifting point of the cover so as to be complimentary in shape.

Interchangeable key 32 can be connected to chain 26 by any suitable fastener.

A jack lift point in the form of a lift plate 34 20 is provided on the undersurface of bar 20 at or towards the distal end. A suitable jacking or lifting means such as for example a hydraulic jack 35, screw jack or similar having an extendable ram is inserted under bar 20 at or towards its distal end so that the extending ram of the jack 35 contacts the lift plate 34 to lift the distal end of bar 20 and the manhole cover in use as will be described in more detail later.

A removable handle 36 extends outwardly from the distal end of bar 20. In one form removable handle 36 takes the form of a pair of substantially parallel portions 38,40, interconnected together by a central transverse portion 42 located intermediate the end of parallel portions 38,40 so as to form a bent or crooked configuration.

In operation of the device 2 of the present invention, the base assembly 4 is located adjacent the manhole cover to be lifted. The position of collar 12 is 11 adjusted so as to be at an appropriate height to enable the manhole cover to be lifted. The proximal end of bar is attached to extensions 14 by pin 16 and is rotated into a position so as to extend over the manhole cover.

If the centre fixed lift point is to be used a chain is connected to the centre lift point and the other end of chain is provided with an interchangeable key appropriate for the manhole cover being lifted which is inserted into the complementary shaped receiving portion of the manhole cover and locked into position. If one of the adjustable lift points are being used the collar or clamp is axially moved along the length of bar 20 to an appropriate .position and the bar is connected to the manhole cover by S. a chain having the correct interchangeable key.

15 The removable handle 34 is connected to the distal end of bar The lift jack is located beneath lift plate 34 and operated to raise the distal end of bar 20. As bar is pivotally raised about pin 16 by the lift jack a 20 lifting force is applied to the manhole cover by means of the chain 26 interconnecting the cover to the bar 20. By using the jack to apply increasing pressure to bar 20 the seal between the manhole cover and its seat or rim is gradually broken until the cover is completely separated from the seat or rim around the periphery of the cover thereby allowing the manhole cover to be jacked completely free of its seat or rim and removed. When the manhole cover is completely free of its seat or rim a workman grasps the distal end of handle 34 and rotates bar about post 6 to swivel the manhole cover away from the manhole. Owing to the bent shape of handle 34 the workman is able to swivel the manhole cover whilst standing in an upright or substantially upright position. The manhole can then be lowered onto the substrate forming the apron to the manhole. Full access is now provided to the manhole.

By using the lifting device of the present 12 invention it is possible to break the seal of the manhole from its seat or rim, lift and remove the manhole cover from the manhole and safely place it adjacent the manhole without there being risk of injury to the workman either by an inappropriate tool breaking or slipping or part of the cover breaking under the strain or by the workman or operator being in a crouched or stooped position.

When it is necessary to replace the cover, handle 34 can be grasped to lift the cover from the substrate and swivel it so as to return it to a position immediately above the manhole whereupon it can be lowered into the manhole to snugly rest within the seat or rim.

Thus, by using the lifting device of the present invention it is possible for a single operator to remove 15 and replace the manhole cover without suffering injury or causing damage.

Advantages of the present invention include the following.

The lifting device is applicable to a wide 20 variety of different covers or lids by the use of interchangeable keys located at the end of the lifting chains. By replacing the interchangeable key with an appropriate key for the particular cover each lid can be lifted safely.

The use of a mechanical lifting means such as hydraulic jack removes the need to use inappropriate manual tools to break the seal of the cover from its seat or rim and to raise the cover.

The workman or operator can remove the cover whilst standing or being in an upright position.

The described arrangement has been advanced by explanation and many modifications may be made without departing from the spirit and scope of the invention which includes every novel feature and novel combination of features herein disclosed.

Those skilled in the art will appreciate that the invention described herein is susceptible to 13 variations and modifications other than those specifically described. It is understood that the invention includes all such variations and modifications which fall within the spirit and scope.

*o *o* o o ooooo *o*

Claims (21)

1. A lifting device for lifting and/or removing an item, including: a base portion for stably contacting a substrate to support the lifting device in use; an elongate member movably connected to the base member, said elongate member being provided with at least one attachment point for a connection means interconnecting the elongate member and the item to be lifted; and a lifting means for applying a lifting force to ".the elongate member so as to move the elongate member, wherein operation of the lifting means causes corresponding movement of the elongate member and the connection means to lift the item.

2. A method of lifting an item, including the steps of: placing a base portion of a lifting device 20 adjacent or in close proximity to the item to be lifted; connecting the item to the lifting device by a connection means extending between an attachment point provided on an elongate member movably connected to the base portion and the item, and operating a lifting means in contact with the elongate member so as to move the elongate member and the connection means to thereby lift the item.

3. A method or device according to any preceding claim, in which the item to be lifted is a manhole cover, preferably a sewerage manhole cover, and more preferably, a partially damaged, corroded, hidden, misshapen or similar manhole cover.

4. A method or device according to any preceding claim, in which the manhole cover is made from concrete, metal or combinations thereof. A method or device according to any preceding claim, in which the lifting device is adapted for both lifting and removing the manhole cover, as well as breaking the seal of the manhole cover when located in its seat.

7. A method or device according to any preceding claim, in which the base portion is a disc and post arrangement, in which the post, preferably a circular post, extends substantially outwardly from the plane of the disc, and wherein the disc is capable of being located on a suitable substrate close to the item to be lifted in a stable manner.

8. A method or device according to any preceding claim, in which the device is locatable in a position adjacent to or on the apron of the manhole cover or on the substrate surrounding the manhole cover.

9. A method or device according to any preceding claim, in which the post is provided with a multiplicity or plurality of spaced apart apertures for receiving a pin therethrough to adjust the height of the elongate member connected to the post. 20 10. A method or device according to any preceding claim, in which the elongate member is pivotally connected to the upstanding post of the base portion, preferably to S• a position intermediate the top of the post and the disc base. 25 11. A method or device according to any preceding see* claim, in which the elongate member is capable of pivoting movement, preferably pivoting movement, both substantially horizontally and vertically with respect to the lengthwise extending direction of the post.

12. A method or device according to any preceding claim, in which the elongate member is a lever, arm, rod, bar, fulcrum or similar, pivotally connected to a collar arrangement through which is received the upstanding post wherein the collar is pivotally moveable with respect to the post.

13. A method or device according to any preceding claim, in which the pin connects the collar to the post. 16

14. A method or device according to any preceding claim, in which the collar is provided with a yoke arrangement preferably having a pair of spaced apart substantially triangular plates arranged in substantially parallel relationship for receiving the elongate member therebetween. A method or device according to any preceding claim, in which the triangular plates are provided with apertures for receiving pins therethrough to pivotally mount the end of the elongate member to the upstanding post.

16. A method or device according to any preceding 0 claim, in which the elongate member is provided with one or more attachment points for connecting the connection means thereto for lifting the manhole cover.

17. A method or device according to any preceding claim, in which the attachment points are adjustable collars, clamps, brackets or similar, axially slidable along the length of the elongate member in order to adjust 20 the position of the attachment point of the connection means to the elongate member.

18. A method or device according to any preceding claim, in which the attachment points are fixedly connected to the elongate member at fixed spaced apart locations over the length of the elongate member.

19. A method or device according to any preceding claim, in which the connection means is a connector, preferably a flexible connector, such as a chain, depending downwardly from the elongate member.

20. A method or device according to any preceding claim, in which the chains or flexible connectors are connected to the elongate member by rings, loops, or other suitable fasteners and the other end of the chains are provided with interchangeable keys located at or towards one end of the chains.

21. A method or device according to any preceding claim, in which the elongate member is provided with a 17 handle located at or towards one end of the elongate member, preferably the end opposite to the end closer to the connection means or the other end to the end pivotally connected to the support assembly or base portion.

22. A method or device according to any preceding claim, in which the handle is located off centre from the lengthwise extending axis of the elongate member, thereby allowing the item to be lifted and/or transported by pivoting movement of the elongate member, whilst the workman operating the device is standing in a more or less upright position holding the handle, thereby reducing or eliminating the risk of injury, particularly back injury :00 to the workman.

23. A method or device according to any preceding 15 claim, in which the elongate member is provided with a lifting portion, preferably in the form of a lifting plate, located at or towards one end of the elongate member, preferably the end of the elongate member having the handle. -20 24. A method or device according to any preceding claim, in which the lifting device is a jack, including a hydraulic jack, a screw jack or other similar lifting ooooo* device or means for applying a lifting force to the elongate member, particularly to the lifting plate provided on the under surface of the elongate member.

25. A method or device according to any preceding claim, in which the device is capable of one man operation to break the seal of the manhole cover, to lift the manhole from its seat or rim, and to remove the manhole cover away from the seat or rim, to provide access through the manhole using the lifting device in the one position supported by the base assembly located adjacent to the site of the manhole cover.

26. A lifting device, substantially as herein described with reference to the accompanying drawings. 18

27. A method of lifting an item using a lifting device, substantially as herein described with reference to the accompanying drawings. Dated this 30th day of January 2002 BARWON REGION WATER AUTHORITY By their Patent Attorneys GRIFFITH HACK Fellows Institute of Patent and Trade Mark Attorneys of Australia 9 oo 0*