GB2202782A

GB2202782A - A lifting device

Info

Publication number: GB2202782A
Application number: GB08805340A
Authority: GB
Inventors: Peter Winston Wood
Original assignee: Individual
Current assignee: Individual
Priority date: 1987-03-05
Filing date: 1988-03-07
Publication date: 1988-10-05
Anticipated expiration: 2008-03-07
Also published as: GB2202782B; GB8705140D0; GB8805340D0

Abstract

A manhole cover lifting device comprises a handle 1 shaped to provide contact with an object to be lifted and provided with an extension 4 in which a hub 10 having spokes 9 is rotatably mounted. A key at the end of each spoke fits into an aperture in the manhole cover. Two such devices may be advantageously used to facilitate removal of the cover. <IMAGE>

Description

A LIFTING DEVICE The present invention relates to a lifting device.

The device is intended particularly, but not exclusively, for lifting manhole covers.

Lifting manhole covers is presently a two man operation. Each man has a lifter comprising a hand grip at one end and a T piece at the other. The cover to be lifted is formed at opposite sides with recesses into which the T-pieces can be inserted and rotated to engage the cover.

Because the action required is a pulling action and because the lifters are short, the men must bend over the cover to apply the lifting force. This can put undue strain which can in turn lead to injury. An object of an embodiment of the present invention is to alleviate this tendency.

According to the present invention there is provided a lifting device comprising a handle shaped to provide contact with an object to be lifted and an extension fixed to the handle the extension being provided with a key at one end for insertion into a recess or aperture in the object to be lifted and rotation to engage the object to permit lifting.

In a preferred embodiment of the invention, the handle is substantially L-shaped, one arm of the 'L' being provided with a cross-bar providing grips. The extension is rotatedly mounted in the handle. This enables the extension to be rotated independently of the handle to engage the object. It also enables the handle to be rotated independently of the extension to seek the most appropriate lifting position. Instead of a single key, keys of different shape may be formed on respective spokes radiating from a hub rotatedly mounted in the extension.

Each spoke may be formed with a shoulder over which a locking sleeve may slide to lock a chosen key in position relative to the extension for more stability.

In order that the invention may be more clearly understood, one embodiment thereof will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a side elevational view of a lifting device according to the invention, Figure 2 is a detail view of part of the device of Figure 1, Figure 3 is a detial view of an alternative part to the part of Figure 2, Figures 4a and 4b show the lifting device of Figure 1 in use in two different sets of circumstances respectively, and Figure 5 shows a modification to the device of Figure 1.

Referring to Figure 1 of the drawing, the lifting device comprises a substantially L-shaped handle 1. A cross bar 2 extends through the longer arm 3 of the 'L' to provide grips. That arm 3 of the 'L' is apertured and an extension 4 comprising two parallel plates 5 and 6 is connected to the arm 3 by means of a locking nut 7 and bolt 8 extending through the aperture. This mode of connection enables the extension 4 to rotate relative to the handle 1.

Referring additionally to Figure 2, the extension also comprises a part 11 at the lower end thereof comprising four spokes 9 radiating from a central hub 10. A bolt extends through an aperture in the hub 10 and corresponding apertures in the plates 5 and 6 to connect, with the aid of a locking nut 13, the plates 5 and 6 and part 11 together.

This connection is also such as to permit relative rotational movement between the plates 5 and 6 and the part 11. Each spoke 9 is formed at its free end with a key to give four different keys. An alternative to part 11 is shown in Figure 3 the four spokes 39 there being formed with keys of different form. Each spoke 9, 39 is formed with a shoulder 7, 37 over which a locking sleeve 18, disposed on the plates 5 and 6, may be slid to lock a chosen key in position relative to the plates 5 and 6 for more stability.

In use, two men each with a lifting device as decribed above, each rotate the spoked part of their device so that the appropriate key is downwardly dependent. The keys are then inserted into the corresponding recesses in the surface of the manhole cover to be lifted and rotated through 90" to engage the cover. The cover may then be removed by the men simply by lifting the respective devices a few inches and translating the cover a few feet to the side. When the devices are lifted, the shorter arm of each 'L' bears on the surface of the cover. Because of the ways the various parts of the devices are rotatedly connected together, it is possible for each man to manipulate his lifting device in order to avoid an obstacle such as a wall.An example of this is shown in Figure 4b, where the devices are rotated through 900 to avoid a wall as compared with their lifting position in Figure 4a.

As the above described lifting device can be used by an operator in a substantially upright position using both hands, the potential for back injury is reduced. Also, the form of the lifter enables the operator to keep his feet well clear of the cover to be lifted and walk to another position with the cover if necessary. Furthermore, the spoked rotational part enable several different types of cover to be catered for with the one device.

It will be appreciated that the above embodiment has been described by way of example only and that many variations are possible without departing from the invention. For example, the formation of each spoke 9 with a shoulder to engage a locking sleeve 18 and the sleeve itself may be dispensed with. Any consequent reduction in stability may be compensated for by increasing the area of the foot at the free end of the shorter arm of the 'L'.

The shape of the handle 1 may also be varied. An alternative shape is shown in Figure 5. By adopting this latter shape material may be saved.

Claims

1. A lifting device comprising a handle shaped to provide contact with an object to be lifted and an extension fixed to the handle the extension being provided with a key at one end for insertion into a recess or aperture in the object to be lifted and rotation to engage the object to permit lifting.

2. A lifting device as claimed in Claim 1, in which the handle comprises a part adapted to contact the object to be lifted and a part adapted to be gripped by an operator.

3. A lifting device as claimed in Claim 1 or 2, in which the extension is rotatably mounted in the handle.

4. A lifting device as claimed in Claim 3, in which a plurality of different keys are provided on the extension.

5. A lifting device as claimed in Claim 4, in which the keys are formed on respective spokes radiating from a hub rotatably mounted in the extension.

6. A lifting device as claimed in Claim 5, in which each spoke is provided with a shoulder over which a locking sleeve may slide to lock a chosen key in position relative to the extension.

7. A lifting device as claimed in any preceding claim, in which the handle is substantially reshaped one arm of the 'L' being provided with a cross-bar providing grips.

8. A lifting device substantially as hereinbefore described with reference to Figures 1,2,4a and 4b or to these figures with the modification of Figure 2 or 5 of the accompanying drawings.