US2832628A

US2832628A - Manhole cover lifter

Info

Publication number: US2832628A
Application number: US532704A
Authority: US
Inventors: John H Turnbull
Original assignee: Individual
Current assignee: Individual
Priority date: 1955-09-06
Filing date: 1955-09-06
Publication date: 1958-04-29
Anticipated expiration: 1975-04-29

Description

April 29, 1958 J. H. TURNBULL MANHOLE QOVER LIFTER Filed Sept. 6, 1955 mvmron John H. Turn/bu]! Unite MANHOLE CGVER LIFTER John H. Turnbull, Eugene, Oreg.

Application September 6, H55, Serial No. 532,704

2 Claims. (Cl. 294-17) hooks is preferably carried by one end of the chain,

while the other is preferably positionable at a desired point along the chain, toward or away from the other hook, for readily spacing apart the other hook, for readily spacing apart the two hooks, so as to accommodate the different distances between the holes or notches in manhole covers of different size.

The lifter also comprises a hand operated pry lever having one or more chain engaging hooks thereon, this lever also having a ground engaging pry point, useful in initially loosening the manhole cover.

Further features of the invention will be described in connection with the accompanying drawings wherein:

Fig. 1 is a plan view of the preferred form of chain of the manhole cover lifter of this invention;

Fig. 2 is a view of a detail;

Fig. 3 is a plan view similar to Fig. 1 showing a modifieation;

Fig. 4 is a side view of the operating lever of this invention;

Figs. 5, 6 and 7 are perspective views showing the lifter of this invention in use in lifting different types of manhole covers.

Referring now to these drawings, a chain 2 is provided at one end with a manhole cover engaging hook 4, and if desired, with a ring 6 at the other end.

A second manhole cover engaging hook 8 is provided, which is variably positionable on the chain 2; hook 8 has an eye 16 through which passes an adjustable loop 12, the loop having an enlarged part 14 and a narrowed throat 16. This loop 12 is for positioning hook 8 at any desired point on the chain, at an appropriate distance from hook 4, for accommodating manhole covers of different sizes. To change the position of hook 8 on the chain, the loop 12 is moved laterally of the chain until the links are in part 14, which is large enough to allow the loop to be moved to the right or left over the chain links. When the desired point is reached, the loop 12 is moved perpendicularly to the chain so that the throat 16 engages over a particular link, whereby it is locked against further movement to the right or left.

In the modification of Fig. 3, a third hook 20 is provided, having a throat 21 adapted to engage over any desired intermediate link of the chain for foreshortening the chain, for providing the most effective operating length for the chain 2.

Fig. 4 shows the pry lever 22, preferably tubular, which may have an intermediate offset ortion 24 and States Patent is provided with several chain engaging hooks 26 and a loop 28 welded thereto. The pry lever is provided with a pry point 30 of tool steel welded at one end thereof.

The operation of the apparatus is shown in Figs. 5 6 and 7. In each case, the manhole cover if stuck in place, may be loosened by pry point 30, engaged in any available hole or notch in the manhole cover.

In Fig. 5, hook 8 is placed on chain 2 at the proper distance from hook 4 so that the hooks engage in opposite notches 32 in manhole cover 34. The chain 2 is engaged with one of the hooks 26 and lever 22 lifted to lift the cover and the lever 22 moved laterally to remove the cover from the manhole.

In Fig. 6, the

hooks

4 and 8 are engaged in holes 36 of cover 38, chain 2 being engaged in one of the hooks 26 and the lever lifted to loosen, lift and remove the cover.

In Figs. 5 and 6, hook 26 is nearer hook 8 than to hook 4, to apply more force to one side of the cover than the other, for more readily loosening the cover.

In Fig. 7, one of the hooks is passed through a central hole 40 in manhole cover 42 and the lever operated to lift and remove the cover.

Greater leverages may be obtained by selecting hooks 26 nearer the ground engaging point 30. If the chain is too long for any particular cover, it may be foreshortened by use of hook 20, Fig. 3.

While the invention has been described in detail, it should be understood that changes may be made as falling within the scope of the appended claims.

I claim as my invention:

1. A manhole cover lifter comprising, a chain having a load end and an end to be lifted, a first hook on the load end of said chain, a second hook provided with means for fixing it along said chain whereby the chain is adapted in one operative position to lift a manhole cover with a single hook and also adapted in other operative positions to lift a manhole cover with one hook at each side of a manhole cover and whereby varying the position of said second hook on said chain will adapt the lifter to fit manhole covers of varying diameters when used in said other operative positions, said second hook in said other operative positions being fixed on a link at a distance from said first hook less than the distance defined by the diameter of the manhole cover to be lifted whereby a lifting force exerted on the end to be lifted will be effective at each of said hooks, and a hand-operated pry lever including an operating handle at one end and a fulcrum at the other end with a plurality of hooks spaced at intervals intermediate said ends to provide a lever of the second class, the end of said chain to be lifted for exerting a lifting force in its operative position being engaged with one of said lever hooks for placing said fulcrum in a ground-engaging position beyond the edges of the manhole cover.

2. The method of lifting and removing a manhole cover from a manhole opening which comprises attaching a hook carried by one end of a flexible member to one marginal edge of a manhole cover, and positioning a second hook along said flexible member at an intermediate point a distance from said first hook of less than the diameter of the manhole cover to be lifted and attaching said second hook to said manhole cover at a point on the periphery of the manhole cover opposite said first hook, and applying a lifting force with a lever of the second class by placing the fulcrum end of said lever at a point beyond said opening and applying the lifting force to that portion of the flexible member extending beyond said second hook whereby said lifting force will lift one side of the manhole cover ahead of r 3 7 4 the other to tilt it and thereafter, while said lifting force References Cited in the file of this patent is efiective, swinging the lever in a direction generally UNITED STATES PATENTS perpendicular to an imaginary line drawn between said first and second hooks to swing the manhole cover off the 733,989 Moms M313 7, 1903 manhole while it is tilted for ease of swinging motion. 5 1,355,053 Lawson 5, 1920 V 1,933,384 Moylan Oct. 31, 1933 2,655,399 McMillan Oct. 13, 1953