AU2004100744A4 - Pit cover lifting device - Google Patents

Description

556431P JOM:MN P/00/009 Regulation 3.2

AUSTRALIA

Patents Act 1990

ORIGINAL

INNOVATION PATENT SPECIFICATION FOR AN INVENTION

ENTITLED

Invention Title: PIT COVER LIFTING DEVICE Name of Applicant: CHRISTOPHER

SCICLUNA

Address for Service: COLLISON CO. 117 King William Street, Adelaide, S.A. 5000 The invention is described in the following statement: This invention relates to a device to loosen a cover that is stuck over a pit or the like and to extract said lid from the opening of such pits. Particularly the invention is related to such covers for use with Underground Electrical Service Pits.

Pits are often referred to as some type of hole, passage or channel way under the ground of which access from time to time is required there into from authorized personnel. Access to these pits or holes are normally characterized by a cover or lid which is round in shape, made of cast metal or cement, and weighs up to 40 kgs in some instances. Due to the weight of such circular lids, extracting the lid to access the hole by hand to enter there into for maintenance purposes or the like, can be Particularly difficult and troublesome.

The problem is exasperated if the lid becomes clamped to the e hole because tar, grime, ice, mud, or the like acts as a fastening wedge to almost secure the lid over the hole.

Therefore, at first instance the problem is not only actually lifting what will be quite a heavy lid or cover by maintenance personnel from the hole pening but also the initial problem of trying to loosen this wedged material which is providing for additional fastening mechanism of keeping the lid well held to the pit or hole.

Conventionally to lift these type of lids from the hole or pit, maintenance workers or personnel have simply used screw drivers to try and lever the lid up and dislodge the debris.

As is to be expected by the person skilled in the art such conventional and unsophisticated means of levering up the lid by a screw driver is fraught with hazards, including the potential of eye injury as small pieces may be chipped off the lid and sent flying by the levering action of the screw driver.

Basically the screw driver is inserted into a drain hole or engages the peripheral edges of the circular lid or cover. As is to be expected the screw driver would need to be substantial in construction if the fulcrum it produces is to lift such a weight of the lid or at least to loosen the cover which is being wedged by the material or transport thereon as referred to above.

Generally, the lid once loosened from position is then slid away from the hole after one side has been lifted by the screw driver. In some instances a crow bar, or any other handy prying bar, is then used to lift and slide the cover away from the hole providing access to the defined space below the ground.

The use of several different tools, for example the screw driver and then the crow bar and the like, to extract the cover can result in wasted time because the tools are inappropriate for the job, or it takes repeated trips back and forth to a maintenance area away from the hole to collect and replace the necessary screw drivers or the crow bar.

As also is to be expected the action of lifting by the screw driver and then the pulling with the crow bar requires tremendous amount of force from the maintenance worker which presents the possibility of muscular strain.

As the person skilled in the art will also appreciate that when these lids or covers to be loosened and extracted from a hole are surrounded by a surface which has no firm footing, it is very difficult to wedge in the screw driver and/or the crow bar or the like, even if such inappropriate tools are applied as the means to extract and loosen the cover from the hole.

Therefore, it is an object of this invention to provide a tool for loosening and lifting a cover or lid from a manhole or the like, as an all in one tool that is easy to carry and is appropriately used to loosen such a cover that is wedges by debris or otherwise to the man hole at the top.

A further object of the invention is to provide such an all in one tool where at the same time such loosening and extraction of the cover or lid to the top of the manhole can be completed even when the surrounding surface provides no firm rigid structure, such for example wet muddy material.

Further, secondary objects and advantages of the invention will become apparent on a complete reading of this specification.

Accordingly, there is provided a lifting tool for loosening and extracting a cover or lid from a manhole or the like, said lifting tool including: an elongated rod having a hand grasping region at one end; a hook depending downwardly from the other end of said elongated rod, said hook adapted to engage a hook receiving hole of said cover or lid; a shallow bend intermediate between the hand grasping region and the hook; a fulcrum member extending in a ground engaging direction from said bend, such that when the hook engages the hole of the cover, the fulcrum member provides pivotal support independent of the user for lever age of a substantial proportion of the weight of said cover or lid during the loosening and/or lifting thereof said cover from the opening of said hole.

Preferably, the hand grasping region of the elongated rod and an upper arm of the hook depending downwardly from the shallow bend are in parallel, with the fulcrum member forming an arcuate skirt in a ground engaging direction between the respective ends of said shallow bend.

Preferably, the arcuate skirt includes a substantially flat inclined region along the skirt.

An advantage of such an arrangement is that the tool provides an all in one apparatus which is able to loosen, lift and extract the cover from the manhole.

Conventionally, a hook having two arms much like a simple lever or crow bar would have one arm engaging the hole of the cover while the other arm used by a user to then lever the cover free.

Advantageously, in this invention the shallow bend provides a means to separate the hand grasping region of the elongated bar with the hook mechanism which engages the hole of the cover.

By providing a fulcrum member or the like within this shallow bend that then acts as the support member for the hook, as it engages the lid and attempts to loosen it and extract it from the top of the hole of which it covers.

Advantageously, the maintenance worker or the like seeking access into the pit, drain or the like, no longer needs to pry open the cover using inappropriate tools such as crow bars and screw drivers. The one central all in one tool provides not only the means to which first loosen the cover, as it may be wedged in by debris or the forces of traffic thereon, but at the same time the fulcrum member will provide an adequate support structure in which to lever the weight of the cover during any lifting made by the maintenance worker.

As the fulcrum member provides the support to which the levering of the weight will be endured, a strain or the like to the worker when removing such covers is substantially avoided.

A further advantage of such a construction is that given that the tool is purposely made for removing such covers from manholes and the like, no time is wasted in first wedging or loosening the cover and then subsequently applying a different tool to then in fact lift the cover from the hole.

As the all in one tool is able to loosen and then lift the cover within the one mechanism, a screw driver no longer needs to be employed to chip away at the edges of the circular cover, thereby avoiding the risk of any eye damage or the like to maintenance personnel.

A further advantage of such an arrangement is that as the fulcrum member includes a substantially arcuate skirt which extends in the ground engaging area along the shallow bend, this provides for a greater dispersion of the weight along that pivotal support area.

This advantage is improved further once the arcuate skirt includes a substantially flat region or plate structure which is more adapted to take on the format of the contours to the surface in which it engages.

Advantageously, if the cover of the manhole is surrounded by material which is not firm, for example, wet and muddy grounds, the tool is still able to be used because the support member as a plate or the like, rather than simply sinking into this wet ground is able to displace and stabilize itself through the flat section by spreading its load over a greater area of land.

For example, if the fulcrum member was simply a rod or the like which would engage the ground, in situations where such surfaces became wet or damp the rod would simply sink in and ultimately the hand grasping area and hook region of the elongated rod would no longer be independently pivotally supported from the user.

6 Advantageously however, as the fulcrum member is being preferably defined by this arcuate skirt, again also then preferably described with a substantially flat region there along, such regions disperse the actual contact area of the tool along that pivotal support region.

The contact area of the pivotal support member with the ground has been greatly increased, thereby making the all in one loosening and extracting tool appropriate for use on all surfaces.

Preferably, the rod is made of high tensile steel that has been heated and pressed into shape.

An advantage of such an arrangement is that the tool has been specifically designed, manufactured and constructed for the purpose of being a lifting and extracting device for loosening and lifting a cover from the drain hole or other such place.

Preferably, the fulcrum member has a flat mild steel plate which has been heated and pressed into the required arcuate shape, and then welded to the shallow bend section of the bar, so as to create the medium for which pivotal leverage will be induced.

Preferably, a steel ring has been welded onto the top of the tool for easy storage within a vehicle, maintenance shop or the like.

Advantageously, the additional ring on the top of the elongated bar helps to identify, store and transport this all in one tool for the specific task of loosening and lifting the cover from the hole.

Preferably, the finished tool is then rust proofed with a zinc coating.

Figure 1 is a perspective of the lifting tool according to a preferred embodiment of the invention.

Figure 2 is a fragmentary view of figure 1 showing the fulcrum member.

Figure 3 is a side view of figure 2 showing the plate type configuration of the fulcrum member in the preferred embodiment of the invention.

7 Figure 4 is a fragmentary section of figure 1 showing the circular ring at the top of the elongated rod in the preferred embodiment of the invention.

Figure 5 is a perspective type view of figures 2 and 3 again showing the fulcrum member as an arcuate type plate member.

Figures 6, 7 and 8 are the various stages of the lifting tool loosening and extracting the plate from the manhole and the subsequent repositioning thereof as specifically shown in figure 8.

Referring to the drawings now in detail as shown in figure 1 there is a lifting tool according to the preferred embodiment of this current invention for lifting a manhole cover 12.

The tool 10 includes an elongated rod 14 having a general hand grasping region shown generally at 16 but more specifically by the broken lines between the two x's.

The elongated rod 14 at a top end includes a ring 18.

The ring 18 functions so as to be able to hang the tool 10 conveniently for example in a vehicle or in a maintenance work shop.

At the opposite end to the handle 18 there is shoulder 20 which provides for a shallow bend member 22 which is angled away from the longitudinal axis of the main elongated bar 14. At the opposite end to shoulder 20 is shoulder 24 where depending downwards therefrom is hook 26 having one arm 28 engaging shoulder 24 and the second arm 30 specifically more adapted so as to engage the hook receiving hole 32 of the cover 12.

Fulcrum member shown generally as 34 includes plate member 36 which is integrally connected at shoulder 20 and shoulder 22 respectively. The plate member includes a ground engaging section 38.

The ground engaging section 38 has terminating plate ends 40 and 42. Plate 42 is also characterized by pivot region 46. As best seen in figures 1, figures 5 and 6 there is a slight incline of the ground engaging member 38 between the pivot region 46 and the terminating plate 40 at the opposite end of the ground engaging member 38.

As best seen in figure 5 the plate member 38 is elongated but also has a substantial breadth so as to make contact with the ground over a region rather than a specific point.

The plate member 38 by being more than simply an elongated bar, as is the case with the section shown as 14 and 26 in the tool, means that in situations where pivotal support is required on ground that is not firm, rather than having the plate sinking into this unfirm substrate, it is able to disperse weight and absorbing stresses more effectively to provide enough leverage to loosen and ply out the lid 10 over the manhole 48.

As is to be envisaged by the person skilled in the art in relation to figures 6, 7 and 8, the lifting tool is grasped by a user along region 16. Arm 30 of the hook 26 is adapted to engage the hole 32 of the cover 12. Rather than having simply the two arms of the lever acting as the pivotal support member, the lifting tool in this invention includes the fulcrum member 34 to act as the main pivotal support, thereby accepting substantial portion of the weight of the lid 12 rather than passing those forces and stresses onto the user of the tool.

Once the arm 30 of the hook 26 engages the hole 32 of the cover 12, the pivotal region 46 of the fulcrum member 34 rests on the surface and is then able to be moved simply by the user depending the elongated rod 14 towards the ground.

With the fulcrum member 34 providing the pivotal support for the lifting, of what will be no doubt a substantially heavy cover 12, does not strain the user as the weight is diverted and taken by the levering mechanism provided through specifically the pivotal support region 46 coming from the fulcrum 34.

As shown by way of an example in figures 6, 7 and 8, the lifting tool 10 is still applicably usable when the adjacent area to the cover 12 is not firm. The plate member 38 provides for additional contact area between fulcrum member 34 and the ground engaging area.

Advantageously, rather than simply being a point of contact which would tend to sink in and eliminate leverage support, the plate is able to disperse its own structure thereby providing itself support on the unfirm surface.

It is to be appreciated by the person skilled in the art that numerous variations and/or modifications may be made to the lifting tool shown in this preferred embodiment without departing from the scope of the invention as currently defined here in this innovation patent.

What is significant is that rather than having a hook member simply lever about one of its own respective arms, an additional support member is incorporated into the tool so as to separate the handle end of the tool with respect to the hook which is adapted to engage the hole of the cover of the manhole.

This support member by being offset from the handling area as well as the hook region, provides its own pivotal support thereby absorbing the necessary stress and substantial weight as the cover is loosened, lifted, withdrawn or replaced over the manhole cover.

The present embodiment is therefore to be considered in all respects as illustrative and not restrictive of this innovation invention.

Claims (5)

1. A lifting tool for loosening and extracting a cover or lid from a manhole or the like, said lifting tool including: an elongated rod having a hand grasping region at one end; a hook depending downwardly from the other end of said elongated rod, said hook adapted to engage a hook receiving hole of said cover or lid; a shallow bend intermediate between the hand grasping region and the hook; a fulcrum member extending in a ground engaging direction from said bend, such that when the hook engages the hole of the cover, the fulcrum member provides pivotal support independent of the user for lever age of a substantial proportion of the weight of said cover or lid during the loosening and/or lifting thereof said cover from the opening of said hole.

2. The tool of claim 1 wherein the fulcrum member forms a substantially arcuate skirt in a ground engaging direction from said bend between the respective ends of said shallow bend.

3. The tool of claim 2 wherein the arcuate skirt includes a substantially flat inclined region along the skirt.

4. The tool of claim 1 formed of high tensile steel that has been heated and pressed into shape.

5. A tool according to the above description with references made to the accompanying illustrations. Dated this 7th day of September 2004 CHRISTOPHER SCICLUNA By his Patent Attorneys COLLISON CO