CA2155244A1 - Manhole cover lifter - Google Patents
Manhole cover lifterInfo
- Publication number
- CA2155244A1 CA2155244A1 CA 2155244 CA2155244A CA2155244A1 CA 2155244 A1 CA2155244 A1 CA 2155244A1 CA 2155244 CA2155244 CA 2155244 CA 2155244 A CA2155244 A CA 2155244A CA 2155244 A1 CA2155244 A1 CA 2155244A1
- Authority
- CA
- Canada
- Prior art keywords
- manhole cover
- manually operable
- attached
- shaped
- hook
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B66—HOISTING; LIFTING; HAULING
- B66F—HOISTING, LIFTING, HAULING OR PUSHING, NOT OTHERWISE PROVIDED FOR, e.g. DEVICES WHICH APPLY A LIFTING OR PUSHING FORCE DIRECTLY TO THE SURFACE OF A LOAD
- B66F19/00—Hoisting, lifting, hauling or pushing, not otherwise provided for
- B66F19/005—Lifting devices for manhole covers
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D29/00—Independent underground or underwater structures; Retaining walls
- E02D29/02—Retaining or protecting walls
- E02D29/0258—Retaining or protecting walls characterised by constructional features
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D29/00—Independent underground or underwater structures; Retaining walls
- E02D29/12—Manhole shafts; Other inspection or access chambers; Accessories therefor
- E02D29/14—Covers for manholes or the like; Frames for covers
- E02D29/1445—Tools for positioning or removing cover frames
Landscapes
- Engineering & Computer Science (AREA)
- Life Sciences & Earth Sciences (AREA)
- Structural Engineering (AREA)
- Environmental & Geological Engineering (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Mining & Mineral Resources (AREA)
- Paleontology (AREA)
- Civil Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Geology (AREA)
- Mechanical Engineering (AREA)
- Underground Structures, Protecting, Testing And Restoring Foundations (AREA)
Abstract
A manually operable manhole cover lifter includes an elongate rigid member with two ends. A base for contacting the ground is attached to the first end. A handle is attached to the second end. Suspended from the elongate rigid member between the base and the handle is a chain. Attached to the end of the chain is a T-shaped hook for engaging a central hole in a manhole cover. Two chains with J-shaped hooks may also be used. Attaching the hooks to a manhole cover and lifting the handle causes a manhole cover to be raised above the ground. A stabilizer made up of two L-shaped members pivotably attached to the T-shaped hook or to one of the J-shaped hooks may be used to maintain the manhole cover in a horizontal orientation.
Description
1319-1 21552~1 MANHOLE COVER LIFTER
FIELD OF THE INVENTION
This invention relates to an apparatus for lifting and moving objects such as manhole covers and the like. In particular, the invention relates to a manhole cover lifter for attaching to a manhole cover, lifting the manhole cover, moving it generally horizontally away from the manhole, and placing the manhole cover on a ground surface.
BACKGROUND OF THE INVENTION
Companies and municipalities maintaining underground services such as water, sewer, telephone and other utilities frequently need to remove manhole covers to gain access to underground tunnels, hardware and machinery. Manhole covers are generally made of cast iron and are therefore very heavy, often weighing two hundred pounds or more. Because of their weight, manhole covers are very difficult to remove and replace. Compounding the problem is the fact that manhole covers are usually quite flat, having only onQ or more small access holes or lifting pins. As a result, few tools are capable of engaging manhole covers.
Manhole covers are generally removed and replaced manually by service personnel using a simple metal pick with a pointed end. The pick is inserted through an access hole or lifting pin and then used to pry the manhole cover up. The manhole cover is then manually dragged away from the opening. Due to the strenuous and awkward movements associated with removing and replacing manhole covers, back and other injuries are common among service personnel whose duties involve the removal and replacement of manhole covers.
215524~
_ Another tool that may be used to remove manhole covers essentially consists of a vertically oriented metal pole, one end of which is designed to rest on a ground surface without damaging the surface. A metal rod is pivotally attached to the pole at a point between the two ends of the pole. The free end of the rod is then attached to the manhole cover, and the upper end of the pole is pulled away from the manhole cover, thus dragging the manhole cover away from the hole. Such a device is not capable of lifting a manhole cover clear of the ground, nor of depositing it beside a manhole without sliding it over the ground.
SUMMARY OF THE INVENTION
The object of the invention is to provide a manually operable tool for lifting and moving objects. In particular, an object is to provide a manhole cover lifter for removing and replacing manhole covers.
According to the invention, there is provided a manually operable manhole cover lifter comprising: an elongate rigid member having a first end and a second end; a base, located at the first end for contacting a ground surface; a handle located at the second end; means for suspending a manhole cover from the elongate rigid member at a suspension point between the first and second ends; wherein the base, handle and suspension point lie in a substantially vertical plane; and wherein pivoting of the handle about the base in the ~lane away from the manhole cover causes the manhole cover to be raised above the ground surface.
According to the invention, there is further provided a manually operable manhole cover lifter comprising: a T-shaped hook defining a plane and comprising a first end adapted to engage a manhole cover and a second end attached to a suspension means; a stabilizer having two L-shaped members 215~214 pivotably suspended from the second end of the hook such that each L-shaped member is pivotable in the plane defined by the hook and such that the L-shaped members form an inverted T-shape; and lifting means attached to the suspension means for raising and lowering the hook.
According to the invention, there is further provided a manually operable manhole cover lifter comprising: two J-shaped hooks, each defining a plane and comprising a first end adapted to engage a manhole cover and a second end attached to a suspension means; a stabilizer having two L-shaped members pivotably suspended from the second end of one of the hooks such that each L-shaped member is pivotable in the plane defined by the hook and such that the L-shaped members form an inverted T-shape; and lifting means attached to the suspension means for raising and lowering the hooks.
According to the invention, there is further provided a manually operable manhole cover lifter comprising: an elongate rigid member having a base end adapted to pivot relative to a ground surface, a handle end, and a central axis passing through the base end and the handle end of the member; a rigid arm attached to the member and extending away from the central axis of the member; suspending means for suspending a manhole cover from the suspension point of the body; and rotating means for rotating the suspension point of the body about the central axis of the body.
Several advantages are associated with the present invention. Firstly, manhole covers may be removed and replaced without the operator being subjected to strenuous or awkward movements.
Secondly, manhole covers may be removed and replaced without dragging them along a ground surface.
215524'1 Thirdly, the manhole cover lifter is versatile and may therefore be used with most designs of manhole covers.
Fourthly, substantial control is exercised over the manhole cover during removal from and replacement on manholes.
Fifthly, the elongate and uncomplicated shape of the manhole cover lifter renders it light and convenient to store.
Lastly, the simple design of the manhole cover lifter and the nature of the materials necessary to construct it render the invention economical to build.
Other advantages, objects and features of the present invention will be readily apparent to those skilled in the art from a review of the following detailed descriptions of the preferred embodiments of the invention in conjunction with the accompanying drawings and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The embodiments of the invention will now be described with reference to the accompanying drawings, i~ which:
Figure 1 is a perspective view of one embodiment of the invention with side hooks in operation;
Figure 2 is a perspective view of the embodiment of Figure 1 with a centre hook in operation;
Figure 3 is a side elevation view of the embodiment of Figure 1;
Figure 4 is a side elevation view of a side hook;
Figure 5 is a side elevation view of a centre hook;
215524'1 Figure 6 is a side elevation view of a stabilizer;
Figure 7 is a perspective view of a centre hook and stabilizer;
Figure 8 is a side elevation view of a clip, chain, side hook and stabilizer assembly;
Figure 9 is a side elevation view of a chain, centre hook and stabilizer assembly;
Figure 10 is a side elevation view of a second embodiment of the invention; and Figure 11 is a side elevation view of a third embodiment of the invention.
Similar references are used in different figures to denote similar components.
DETAILED DESCRIPTION OF THE INVENTION
Referring to Figures 1 through 5, which illustrate a first embodiment of the invention, a manhole cover lifter 1 includes an elongate rigid member 2 having four fifteen degree bends 17.
The member 2 may be constructed of square steel tubing.
Secured over one end of the member 2 is a plastic handle 4 for convenient operation of the manhole cover lifter 1. Other shapes of handle, such as a T-shape, could be used to increase the amount of control exercised by the operator over the manhole cover. A more complicated structure could increase the weight of the manhole cover, however, and has been found to be unnecessary. Attached to the other end of the member 2 is a base 5. The base 5 consists of a section of round steel tubing welded perpendicularly to the member 2. Attached to the underside of the member 2 is a support bracket 15 having adjustment holes 16. The support bracket 15 consists of an elongate section of steel plate which is welded to the member 2. The adjustment holes 16 are drilled through the support bracket 15, and may be greater or fewer in number than illustrated, depending on the degree of adjustability desired.
Passing through one of the adjustment holes 16 is a steel clip 8. If the clip 8 is spring loaded, easy removal of the clip 8 is facilitated, but alternat-ive hardware such as a removable chain link or an S-hook could be used. Suspended from the clip 8 are three chains 9. The chains 9 must be strong enough to bear the weight of a manhole cover. Alternatives to chains, such as cables or belts, could be used. Referring to Figures 2, 3 and 5, attached to one of the chains 9 is a T-shaped centre hook 10, which is designed to fit through the central access hole of a manhole cover. The centre hook 10 consists of a square steel rod 18 welded to a second steel rod 19. A
steel ring 20 is welded to the end of the rod 19. Referring to Figures 1, 3 and 4, attached to each of two chains 9 is a J-shaped side hook 11, which is designed to fit through a side access hole of a manhole cover. Each side hook 11 consists of a bent and sharpened square steel rod 28 to which is welded a steel ring 20.
In operation, the base 5 is placed beside a manhole with a manhole cover. The manhole cover lifter 1 is positioned such that the member 2 extends over the manhole cover such that the clip 8 is positioned substantially centrally over the manhole cover. If the manhole cover has one central hole, the centre hook 10 is placed through the central hole. If the manhole cover has two diametrically opposed side holes, the side hooks 11 are placed through the two side holes. The operator then lifts the handle 4 upwards, such that the member 2 pivots about the base 5. The tension in the chain or chains 9 causes the manhole cover to be lifted above the ground surface. Due to the leverage obtained from the fact that the distance from the handle 4 to the base 5 is greater than the distance from the 21~24'1 -support bracket 15 to the base 5, the upward force exerted by the operator is less than the weight of the manhole cover.
Selection of an adjustment hole 16 closer to the base 5 decreases the lifting force required of the operator. However, if a large manhole cover is being lifted, an adjustment hole 16 closer to the handle 4 may have to be selected to allow sufficient clearance between the manhole cover and the member 2. The positioning of the handle 4 eliminates the need for any awkward movement by the operator during lifting. The fact that the clip 8 is centrally located over the manhole cover enables the manhole cover to be lifted vertically, so that it does not drag over the ground surface. The operator then pivots the handle 4 about the base 5 in a substantially horizontal plane so that the manhole cover is moved generally parallel to the ground surface away from the manhole. Alternatively, the base 5 may be slid along the ground surface. The operator then lowers the handle 4, thereby placing the manhole cover on the ground. To replace the manhole cover, the above steps are reversed.
The length of the base 5 determines the amount of pressure that will be exerted on the ground surface. It has been found that a base 5 of approximately ten inches is sufficient to keep the manhole cover lifter 1 stable during operation and yet is not so long as to increase the weight of the manhole cover unnecessarily. Also, if the clip 8 is positioned above the axis running through the centre of the base 5 and the handle 4, a base 5 is necessary to maintain the stability of the manhole cover lifter 1 during operation. However, if the clip 8 is below this axis, then it would not be necessary for the base 5 to provide stability to the manhole cover lifter 1.
Alternatively, the base 5 could comprise one or more wheels or castors to assist in sliding the base 5 over the ground surface during operation.
If a manhole cover has a central access hole, and is therefore lifted using a centre hook 10, or if the manhole cover has two diametrically opposed access holes, and is therefore lifted using two side hooks 11, the manhole cover may not remain entirely horizontal during its removal or replacement. If it is desired to maintain the manhole cover in a substantially horizontal orientation, a stabilizer 21, as illustrated in Figures 1, 2, 6, 7, 8 and 9, can be used. Only one stabilizer 21 need be used. The stabilizer 21 consists of two L-shaped steel members 22 having vertical arms 23 and horizontal arms 24. A hole 25 is located at the free end of each vertical arm 23, and a second hole 26 is lo_ated generally centrally in the vertical arm 23. A chain 9 is secured by a bolt passing through the first holes 25. A side hook 11 or a centre hook 10 is secured between both second holes 26 by a bolt passing through both second holes 26.
Referring to Figure 10, which illustrates another embodiment of the invention, a manhole cover lifter 1 includes a elongate rigid member 2, an arm 3, a handle 4, and a base 5.
The arm 3 is rigidly attached to the member 2 at the joint 6.
To increase rigidity, a rigid gusset 7 is attached both to the member 2 and the arm 3. Attached to the free end of the arm 3 is a steel clip 8. Attached to the clip 8 are chains 9, a centre hook 10 and two side hooks 11. A centre hook 10 and a side hook 11 are illustrated in further detail in Figures 4 and 5 respectively.
In operation, the base 5 is placed beside a manhole (not shown) covered with a manhole cover (not shown). The manhole cover lifter 1 is positioned such that the member 2 extends generally upward. The arm 3 extends over the manhole cover such that the clip 8 is positioned substantially centrally over the manhole cover. If the manhole cover has one central hole (not shown), the centre hook 10 is placed through the central hole. If the manhole cover has two side holes, the side hooks 21~524'1 11 are placed through the two side holes. The operator then places his or her foot on the base 5 to stabi~ize the base 5 and to ensure that the base 5 does not move relative to the ground. The operator then pulls the handle 4 away from the manhole cover such that the member 2 pivots about the base 5.
The tension in the chains 9 causes the manhole cover to be lifted above the ground surface. The fact that the clip 8 is centrally located over the manhole cover enables the manhole cover to be lifted vertically, so that it does not drag over the ground surface. The operator then turns the handle 4 so that the manhole cover is moved generally parallel to the ground surface away from the manhole. The operator then uses the handle 4 to lower the manhole cover, thereby placing the manhole cover on the ground. To replace the manhole cover, the above steps are reversed.
Figure 11 illustrates a collapsible version of the embodiment of Figure 8. The gusset 7 of the embodiment of Figure 1 is replaced with a support chain 12. The joint 6 of the embodiment of Figure 1 is replaced with a pivotable joint 13. The joint 13 allows the arm 3 to pivot toward and away from the member 2, while restricting other movement of the arm 3 relative to the member 2. Fasteners 14 are provided to secure the arm 3 to the member 2 during storage or transportation of the manhole cover lifter 1.
Numerous modifications, variations and adaptations may be made to the particular embodiment of the invention described above without departing from the scope of the invention, which is defined in the claims.
FIELD OF THE INVENTION
This invention relates to an apparatus for lifting and moving objects such as manhole covers and the like. In particular, the invention relates to a manhole cover lifter for attaching to a manhole cover, lifting the manhole cover, moving it generally horizontally away from the manhole, and placing the manhole cover on a ground surface.
BACKGROUND OF THE INVENTION
Companies and municipalities maintaining underground services such as water, sewer, telephone and other utilities frequently need to remove manhole covers to gain access to underground tunnels, hardware and machinery. Manhole covers are generally made of cast iron and are therefore very heavy, often weighing two hundred pounds or more. Because of their weight, manhole covers are very difficult to remove and replace. Compounding the problem is the fact that manhole covers are usually quite flat, having only onQ or more small access holes or lifting pins. As a result, few tools are capable of engaging manhole covers.
Manhole covers are generally removed and replaced manually by service personnel using a simple metal pick with a pointed end. The pick is inserted through an access hole or lifting pin and then used to pry the manhole cover up. The manhole cover is then manually dragged away from the opening. Due to the strenuous and awkward movements associated with removing and replacing manhole covers, back and other injuries are common among service personnel whose duties involve the removal and replacement of manhole covers.
215524~
_ Another tool that may be used to remove manhole covers essentially consists of a vertically oriented metal pole, one end of which is designed to rest on a ground surface without damaging the surface. A metal rod is pivotally attached to the pole at a point between the two ends of the pole. The free end of the rod is then attached to the manhole cover, and the upper end of the pole is pulled away from the manhole cover, thus dragging the manhole cover away from the hole. Such a device is not capable of lifting a manhole cover clear of the ground, nor of depositing it beside a manhole without sliding it over the ground.
SUMMARY OF THE INVENTION
The object of the invention is to provide a manually operable tool for lifting and moving objects. In particular, an object is to provide a manhole cover lifter for removing and replacing manhole covers.
According to the invention, there is provided a manually operable manhole cover lifter comprising: an elongate rigid member having a first end and a second end; a base, located at the first end for contacting a ground surface; a handle located at the second end; means for suspending a manhole cover from the elongate rigid member at a suspension point between the first and second ends; wherein the base, handle and suspension point lie in a substantially vertical plane; and wherein pivoting of the handle about the base in the ~lane away from the manhole cover causes the manhole cover to be raised above the ground surface.
According to the invention, there is further provided a manually operable manhole cover lifter comprising: a T-shaped hook defining a plane and comprising a first end adapted to engage a manhole cover and a second end attached to a suspension means; a stabilizer having two L-shaped members 215~214 pivotably suspended from the second end of the hook such that each L-shaped member is pivotable in the plane defined by the hook and such that the L-shaped members form an inverted T-shape; and lifting means attached to the suspension means for raising and lowering the hook.
According to the invention, there is further provided a manually operable manhole cover lifter comprising: two J-shaped hooks, each defining a plane and comprising a first end adapted to engage a manhole cover and a second end attached to a suspension means; a stabilizer having two L-shaped members pivotably suspended from the second end of one of the hooks such that each L-shaped member is pivotable in the plane defined by the hook and such that the L-shaped members form an inverted T-shape; and lifting means attached to the suspension means for raising and lowering the hooks.
According to the invention, there is further provided a manually operable manhole cover lifter comprising: an elongate rigid member having a base end adapted to pivot relative to a ground surface, a handle end, and a central axis passing through the base end and the handle end of the member; a rigid arm attached to the member and extending away from the central axis of the member; suspending means for suspending a manhole cover from the suspension point of the body; and rotating means for rotating the suspension point of the body about the central axis of the body.
Several advantages are associated with the present invention. Firstly, manhole covers may be removed and replaced without the operator being subjected to strenuous or awkward movements.
Secondly, manhole covers may be removed and replaced without dragging them along a ground surface.
215524'1 Thirdly, the manhole cover lifter is versatile and may therefore be used with most designs of manhole covers.
Fourthly, substantial control is exercised over the manhole cover during removal from and replacement on manholes.
Fifthly, the elongate and uncomplicated shape of the manhole cover lifter renders it light and convenient to store.
Lastly, the simple design of the manhole cover lifter and the nature of the materials necessary to construct it render the invention economical to build.
Other advantages, objects and features of the present invention will be readily apparent to those skilled in the art from a review of the following detailed descriptions of the preferred embodiments of the invention in conjunction with the accompanying drawings and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The embodiments of the invention will now be described with reference to the accompanying drawings, i~ which:
Figure 1 is a perspective view of one embodiment of the invention with side hooks in operation;
Figure 2 is a perspective view of the embodiment of Figure 1 with a centre hook in operation;
Figure 3 is a side elevation view of the embodiment of Figure 1;
Figure 4 is a side elevation view of a side hook;
Figure 5 is a side elevation view of a centre hook;
215524'1 Figure 6 is a side elevation view of a stabilizer;
Figure 7 is a perspective view of a centre hook and stabilizer;
Figure 8 is a side elevation view of a clip, chain, side hook and stabilizer assembly;
Figure 9 is a side elevation view of a chain, centre hook and stabilizer assembly;
Figure 10 is a side elevation view of a second embodiment of the invention; and Figure 11 is a side elevation view of a third embodiment of the invention.
Similar references are used in different figures to denote similar components.
DETAILED DESCRIPTION OF THE INVENTION
Referring to Figures 1 through 5, which illustrate a first embodiment of the invention, a manhole cover lifter 1 includes an elongate rigid member 2 having four fifteen degree bends 17.
The member 2 may be constructed of square steel tubing.
Secured over one end of the member 2 is a plastic handle 4 for convenient operation of the manhole cover lifter 1. Other shapes of handle, such as a T-shape, could be used to increase the amount of control exercised by the operator over the manhole cover. A more complicated structure could increase the weight of the manhole cover, however, and has been found to be unnecessary. Attached to the other end of the member 2 is a base 5. The base 5 consists of a section of round steel tubing welded perpendicularly to the member 2. Attached to the underside of the member 2 is a support bracket 15 having adjustment holes 16. The support bracket 15 consists of an elongate section of steel plate which is welded to the member 2. The adjustment holes 16 are drilled through the support bracket 15, and may be greater or fewer in number than illustrated, depending on the degree of adjustability desired.
Passing through one of the adjustment holes 16 is a steel clip 8. If the clip 8 is spring loaded, easy removal of the clip 8 is facilitated, but alternat-ive hardware such as a removable chain link or an S-hook could be used. Suspended from the clip 8 are three chains 9. The chains 9 must be strong enough to bear the weight of a manhole cover. Alternatives to chains, such as cables or belts, could be used. Referring to Figures 2, 3 and 5, attached to one of the chains 9 is a T-shaped centre hook 10, which is designed to fit through the central access hole of a manhole cover. The centre hook 10 consists of a square steel rod 18 welded to a second steel rod 19. A
steel ring 20 is welded to the end of the rod 19. Referring to Figures 1, 3 and 4, attached to each of two chains 9 is a J-shaped side hook 11, which is designed to fit through a side access hole of a manhole cover. Each side hook 11 consists of a bent and sharpened square steel rod 28 to which is welded a steel ring 20.
In operation, the base 5 is placed beside a manhole with a manhole cover. The manhole cover lifter 1 is positioned such that the member 2 extends over the manhole cover such that the clip 8 is positioned substantially centrally over the manhole cover. If the manhole cover has one central hole, the centre hook 10 is placed through the central hole. If the manhole cover has two diametrically opposed side holes, the side hooks 11 are placed through the two side holes. The operator then lifts the handle 4 upwards, such that the member 2 pivots about the base 5. The tension in the chain or chains 9 causes the manhole cover to be lifted above the ground surface. Due to the leverage obtained from the fact that the distance from the handle 4 to the base 5 is greater than the distance from the 21~24'1 -support bracket 15 to the base 5, the upward force exerted by the operator is less than the weight of the manhole cover.
Selection of an adjustment hole 16 closer to the base 5 decreases the lifting force required of the operator. However, if a large manhole cover is being lifted, an adjustment hole 16 closer to the handle 4 may have to be selected to allow sufficient clearance between the manhole cover and the member 2. The positioning of the handle 4 eliminates the need for any awkward movement by the operator during lifting. The fact that the clip 8 is centrally located over the manhole cover enables the manhole cover to be lifted vertically, so that it does not drag over the ground surface. The operator then pivots the handle 4 about the base 5 in a substantially horizontal plane so that the manhole cover is moved generally parallel to the ground surface away from the manhole. Alternatively, the base 5 may be slid along the ground surface. The operator then lowers the handle 4, thereby placing the manhole cover on the ground. To replace the manhole cover, the above steps are reversed.
The length of the base 5 determines the amount of pressure that will be exerted on the ground surface. It has been found that a base 5 of approximately ten inches is sufficient to keep the manhole cover lifter 1 stable during operation and yet is not so long as to increase the weight of the manhole cover unnecessarily. Also, if the clip 8 is positioned above the axis running through the centre of the base 5 and the handle 4, a base 5 is necessary to maintain the stability of the manhole cover lifter 1 during operation. However, if the clip 8 is below this axis, then it would not be necessary for the base 5 to provide stability to the manhole cover lifter 1.
Alternatively, the base 5 could comprise one or more wheels or castors to assist in sliding the base 5 over the ground surface during operation.
If a manhole cover has a central access hole, and is therefore lifted using a centre hook 10, or if the manhole cover has two diametrically opposed access holes, and is therefore lifted using two side hooks 11, the manhole cover may not remain entirely horizontal during its removal or replacement. If it is desired to maintain the manhole cover in a substantially horizontal orientation, a stabilizer 21, as illustrated in Figures 1, 2, 6, 7, 8 and 9, can be used. Only one stabilizer 21 need be used. The stabilizer 21 consists of two L-shaped steel members 22 having vertical arms 23 and horizontal arms 24. A hole 25 is located at the free end of each vertical arm 23, and a second hole 26 is lo_ated generally centrally in the vertical arm 23. A chain 9 is secured by a bolt passing through the first holes 25. A side hook 11 or a centre hook 10 is secured between both second holes 26 by a bolt passing through both second holes 26.
Referring to Figure 10, which illustrates another embodiment of the invention, a manhole cover lifter 1 includes a elongate rigid member 2, an arm 3, a handle 4, and a base 5.
The arm 3 is rigidly attached to the member 2 at the joint 6.
To increase rigidity, a rigid gusset 7 is attached both to the member 2 and the arm 3. Attached to the free end of the arm 3 is a steel clip 8. Attached to the clip 8 are chains 9, a centre hook 10 and two side hooks 11. A centre hook 10 and a side hook 11 are illustrated in further detail in Figures 4 and 5 respectively.
In operation, the base 5 is placed beside a manhole (not shown) covered with a manhole cover (not shown). The manhole cover lifter 1 is positioned such that the member 2 extends generally upward. The arm 3 extends over the manhole cover such that the clip 8 is positioned substantially centrally over the manhole cover. If the manhole cover has one central hole (not shown), the centre hook 10 is placed through the central hole. If the manhole cover has two side holes, the side hooks 21~524'1 11 are placed through the two side holes. The operator then places his or her foot on the base 5 to stabi~ize the base 5 and to ensure that the base 5 does not move relative to the ground. The operator then pulls the handle 4 away from the manhole cover such that the member 2 pivots about the base 5.
The tension in the chains 9 causes the manhole cover to be lifted above the ground surface. The fact that the clip 8 is centrally located over the manhole cover enables the manhole cover to be lifted vertically, so that it does not drag over the ground surface. The operator then turns the handle 4 so that the manhole cover is moved generally parallel to the ground surface away from the manhole. The operator then uses the handle 4 to lower the manhole cover, thereby placing the manhole cover on the ground. To replace the manhole cover, the above steps are reversed.
Figure 11 illustrates a collapsible version of the embodiment of Figure 8. The gusset 7 of the embodiment of Figure 1 is replaced with a support chain 12. The joint 6 of the embodiment of Figure 1 is replaced with a pivotable joint 13. The joint 13 allows the arm 3 to pivot toward and away from the member 2, while restricting other movement of the arm 3 relative to the member 2. Fasteners 14 are provided to secure the arm 3 to the member 2 during storage or transportation of the manhole cover lifter 1.
Numerous modifications, variations and adaptations may be made to the particular embodiment of the invention described above without departing from the scope of the invention, which is defined in the claims.
Claims (16)
1. A manually operable manhole cover lifter comprising:
an elongate rigid member having a first end and a second end;
a base, located at the first end for contacting a ground surface;
a handle located at the second end;
means for suspending a manhole cover from the elongate rigid member at a suspension point between the first and second ends;
wherein the base, handle and suspension point lie in a substantially vertical plane; and wherein pivoting of the handle about the base in the plane away from the manhole cover causes the manhole cover to be raised above the ground surface.
an elongate rigid member having a first end and a second end;
a base, located at the first end for contacting a ground surface;
a handle located at the second end;
means for suspending a manhole cover from the elongate rigid member at a suspension point between the first and second ends;
wherein the base, handle and suspension point lie in a substantially vertical plane; and wherein pivoting of the handle about the base in the plane away from the manhole cover causes the manhole cover to be raised above the ground surface.
2. A manually operable manhole cover lifter as defined in claim 1, the elongate rigid member comprising a steel tube having four 15 degree bends.
3. A manually operable manhole cover lifter as defined in claim 1, the base comprising a round steel tube attached perpendicularly to the elongate rigid member.
4. A manually operable manhole cover lifter as defined in claim 1, the suspending means comprising a chain having a first end attached to the suspension point and a second end attached to a T-shaped hook.
5. A manually operable manhole cover lifter as defined in claim 4, the suspending means further comprising a stabilizer.
6. A manually operable manhole cover lifter as defined in claim 5, the stabilizer comprising two L-shaped members pivotably attached to the T-shaped hook.
7. A manually operable manhole cover lifter as defined in claim 1, the suspending means comprising two chains of equal length, each chain having a first end attached to the suspension point and a second end attached to a J-shaped hook.
8. A manually operable manhole cover lifter as defined in claim 7, the suspending means further comprising a stabilizer.
9. A manually operable manhole cover lifter as defined in claim 8, the stabilizer comprising two L-shaped members pivotably attached to one of the J-shaped hooks.
10. A manually operable manhole cover lifter comprising:
a T-shaped hook defining a plane and comprising a first end adapted to engage a manhole cover and a second end attached to a suspension means;
a stabilizer having two L-shaped members pivotably suspended from the second end of the hook such that each L-shaped member is pivotable in the plane defined by the hook and such that the L-shaped members form an inverted T-shape;
and lifting means attached to the suspension means for raising and lowering the hook.
a T-shaped hook defining a plane and comprising a first end adapted to engage a manhole cover and a second end attached to a suspension means;
a stabilizer having two L-shaped members pivotably suspended from the second end of the hook such that each L-shaped member is pivotable in the plane defined by the hook and such that the L-shaped members form an inverted T-shape;
and lifting means attached to the suspension means for raising and lowering the hook.
11. A manually operable manhole cover lifter comprising:
two J-shaped hooks, each defining a plane and comprising a first end adapted to engage a manhole cover and a second end attached to a suspension means;
a stabilizer having two L-shaped members pivotably suspended from the second end of one of the hooks such that each L-shaped member is pivotable in the plane defined by the hook and such that the L-shaped members form an inverted T-shape; and lifting means attached to the suspension means for raising and lowering the hooks.
two J-shaped hooks, each defining a plane and comprising a first end adapted to engage a manhole cover and a second end attached to a suspension means;
a stabilizer having two L-shaped members pivotably suspended from the second end of one of the hooks such that each L-shaped member is pivotable in the plane defined by the hook and such that the L-shaped members form an inverted T-shape; and lifting means attached to the suspension means for raising and lowering the hooks.
12. A manually operable manhole cover lifter comprising:
an elongate rigid member having a base end adapted to pivot relative to a ground surface, a handle end, and a central axis passing through the base end and the handle end of the member;
a rigid arm attached to the member and extending away from the central axis of the member;
suspending means for suspending a manhole cover from the suspension point of the body; and rotating means for rotating the suspension point of the body about the central axis of the body.
an elongate rigid member having a base end adapted to pivot relative to a ground surface, a handle end, and a central axis passing through the base end and the handle end of the member;
a rigid arm attached to the member and extending away from the central axis of the member;
suspending means for suspending a manhole cover from the suspension point of the body; and rotating means for rotating the suspension point of the body about the central axis of the body.
13. A manually operable manhole cover lifter as defined in claim 12, the suspending means comprising a chain having a first end attached to the suspension point of the body and a second end attached to a hook adapted to engage a manhole cover.
14. A manually operable manhole cover lifter as defined in claim 12, the rotating means comprising a T-shaped handle attached to the handle end of the body.
15. A manually operable manhole cover lifter as defined in claim 12, the base end of the body comprising a base adapted to rest stationary on a ground surface.
16. A manually operable manhole cover lifter as defined in claim 12, wherein the arm is pivotable toward the handle end of the body.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2155244 CA2155244A1 (en) | 1995-08-02 | 1995-08-02 | Manhole cover lifter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2155244 CA2155244A1 (en) | 1995-08-02 | 1995-08-02 | Manhole cover lifter |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2155244A1 true CA2155244A1 (en) | 1997-02-03 |
Family
ID=4156348
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2155244 Abandoned CA2155244A1 (en) | 1995-08-02 | 1995-08-02 | Manhole cover lifter |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2155244A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US11905149B2 (en) | 2020-09-30 | 2024-02-20 | Mag Lift, LLC | Manhole cover lifting device |
-
1995
- 1995-08-02 CA CA 2155244 patent/CA2155244A1/en not_active Abandoned
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US11905149B2 (en) | 2020-09-30 | 2024-02-20 | Mag Lift, LLC | Manhole cover lifting device |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Dead |
Effective date: 19980803 |