GB1570904A - Lifting attachment - Google Patents

Description

(54) LIFTING ATTACHMENT (71) I, ROBERT RONALD CAMP BELL of Beechgrove, Dungannon, County Tyrone, Northern Ireland, a British Subject do hereby declare the invention, for which I pray that a patent may be granted to me, and the method by which it is to be performed, to be particularly described in and by the following statement:: This invention relates to an oscillation control or damping unit in a lifting attachment of the type having a mounting mechanism from which a mechanism for clamping, gripping, supporting or holding (hereinafter referred to simply as "a clamping mechanism"). is pivotally suspended, there being provided on the mounting mechanism a web having two spaced apart, downwardly extending, apertured arms or the like and on the clamping mechanism two similarly spaced apart, upwardly extending, apertured arms or the like, coupling means being provided having two passages or pairs of apertures, the axes of which are at right angles to each other, and to each which passage or pair of apertures two arms are pivotally connected whereby the coupling means and clamping mechanism can pivot relative to the mounting mechanism in one direction, and the clamping mechanism can pivot relative to the mounting mechanism and coupling means in a direction at right angles to said first direction, the apertured arms or the like on the clamping mechanism being provided on two spaced apart upstanding plates extending between the inside flanges of two pairs of transversely spaced apart upstanding flanges, the height of said flanges being similar and greater than the height of the upstanding plates.

Hereinafter in the specification and claims, a lifting attachment as above-described will be referred to as "a lifting attachment of the type aforesaid".

The invention is particularly, but not exclusively, for use with a lifting attachment of the type aforesaid as described in my British Patent No. 1,251,325.

A lifting attachment of the type aforesaid is for mounting on a land vehicle, such as a fork lift truck. In use, swinging movement of the lifting attachment out of the perpendicular does occur due to and under the influence of external forces, such as when the land vehicle starts off, stops, turns sharply, negotiates uneven surfaces, or negotiates obstacles, for example, rail car lines.

The ability of the clamping mechanism to deviate from the perpendicular under the influence of horizontally applied external forces is advantageous since, when loaded with stacked articles, such as bricks or blocks, this greatly reduces the effect of said forces on the load, thereby lessening considerably the possibility of load spillage.

However, a continual swinging movement is a disadvantage and an uncontrolled oscillation may become cumulative with the possibility of load spillage and even damage to the lifting attachment itself, cumulative oscillatory movement occurring if, for example, the vehicle turns sharply in one direction and then turns sharply in another direction.

It is an object of the present invention to obviate or mitigate the above disadvantages.

According to the present invention, there is provided a lifting attachment of the type aforesaid which includes an oscillation control unit comprising three dashpots located on one side of the mounting mechanism and clamping mechanism, a first dashpot extending between the mounting mechanism and that part of the coupling means to which the arms of the mounting mechanism are pivotally connected, and second and third dashpots respectively extending between one of the inner flanges and that part of the coupling means to which the arms of the mounting mechanism are pivotally connected.

An embodiment of the present invention will now be described, by way of example, with reference to the accompanying drawing in which: Figure 1 is a front view of a lifting attachment of the type aforesaid and according to the present invention incorporating an oscillation control unit; Figure 2 is a perspective view of the lifting attachment shown in Figure 1.

An oscillation control or damping unit in a lifting attachment of the type aforesaid comprises three dashpots located on one side of the mounting mechanism 10 and clamping mechanism 11, namely that side on which one of the arms (not shown) of the clamping mechanism 11 is located. A first bracket 12 is welded in an inclined upwardly and outwardly position from one side of the web 10B of the mounting mechanism 10 and is formed simply of two limbs 12A converging towards their outer ends and having a web 12B located therebetween across their upper edges, the limbs 12A terminating at their outer ends in an anchorage 13 to which the cylinder 14A of a first dashpot 14 is pivotally mounted, a second bracket 15 is welded to the opposite sides of that part of the coupling means 16 to which the arms 10A of the mounting mechanism 10 are pivotally mounted and extends therefrom in an outward and then a downward direction to a level adjacent to the bottom of the upstanding plate 17. The second bracket 15 is formed of two spaced limbs 15A terminating in a union formation 15B of three anchorages 21, 22 and 23, one anchorage 21 being at right angles to the others and facing outwardly away from said upstanding plate 17, and each other anchorage 22 and 23 being laterally positioned and facing a respective inside flange 18 and 19. An anchorage 20 is provided on the top of each inside flange 18, 19.The piston 14B of the first dashpot 14 is pivotally mounted to the outward facing anchorage 21 of the union formation 15B and a second and third dashpot 24 and 25 have their cylinders 24A and 25A pivotally mounted to the anchorage 20 on the respective inside flange 18 and 19, and their pistons 24B and 25B pivotally mounted to the respective laterally facing anchorages 22 and 23. The first dashpot 14 is substantially upright and the second and third dashpots 24 and 25 are arranged converging towards the union formation 15B.

In use. the dashpots 14, 24 and 25 damp out or reduce the amount of any oscillatory movement of the clamping mechanism 11 relative to the mounting mechanism 10, which is created by external forces as above-described.

The mounting mechanism 10 may be associated with a rotating mechanism (not shown) to rotate said mounting mechanism 10 and said clamping mechanism 11.

WHAT I CLAIM IS: 1. A lifting attachment of the type aforesaid which includes an oscillation control unit comprising three dashpots located on one side of the mounting mechanism and clamping mechanism, a first dashpot extending between the mounting mechanism and that part of the coupling means to which the arms of the mounting mechanism are pivotally connected, and second and third dashpots respectively extending between one of the inner flanges and that part of the coupling means to which the arms of the mounting mechanism are pivotally connected.

2. A lifting attachment substantially as hereinbefore described with reference to the accompanying drawing.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (2)

**WARNING** start of CLMS field may overlap end of DESC **. mounting mechanism are pivotally connected. An embodiment of the present invention will now be described, by way of example, with reference to the accompanying drawing in which: Figure 1 is a front view of a lifting attachment of the type aforesaid and according to the present invention incorporating an oscillation control unit; Figure 2 is a perspective view of the lifting attachment shown in Figure 1. An oscillation control or damping unit in a lifting attachment of the type aforesaid comprises three dashpots located on one side of the mounting mechanism 10 and clamping mechanism 11, namely that side on which one of the arms (not shown) of the clamping mechanism 11 is located. A first bracket 12 is welded in an inclined upwardly and outwardly position from one side of the web 10B of the mounting mechanism 10 and is formed simply of two limbs 12A converging towards their outer ends and having a web 12B located therebetween across their upper edges, the limbs 12A terminating at their outer ends in an anchorage 13 to which the cylinder 14A of a first dashpot 14 is pivotally mounted, a second bracket 15 is welded to the opposite sides of that part of the coupling means 16 to which the arms 10A of the mounting mechanism 10 are pivotally mounted and extends therefrom in an outward and then a downward direction to a level adjacent to the bottom of the upstanding plate 17. The second bracket 15 is formed of two spaced limbs 15A terminating in a union formation 15B of three anchorages 21, 22 and 23, one anchorage 21 being at right angles to the others and facing outwardly away from said upstanding plate 17, and each other anchorage 22 and 23 being laterally positioned and facing a respective inside flange 18 and 19. An anchorage 20 is provided on the top of each inside flange 18, 19.The piston 14B of the first dashpot 14 is pivotally mounted to the outward facing anchorage 21 of the union formation 15B and a second and third dashpot 24 and 25 have their cylinders 24A and 25A pivotally mounted to the anchorage 20 on the respective inside flange 18 and 19, and their pistons 24B and 25B pivotally mounted to the respective laterally facing anchorages 22 and 23. The first dashpot 14 is substantially upright and the second and third dashpots 24 and 25 are arranged converging towards the union formation 15B. In use. the dashpots 14, 24 and 25 damp out or reduce the amount of any oscillatory movement of the clamping mechanism 11 relative to the mounting mechanism 10, which is created by external forces as above-described. The mounting mechanism 10 may be associated with a rotating mechanism (not shown) to rotate said mounting mechanism 10 and said clamping mechanism 11. WHAT I CLAIM IS:

1. A lifting attachment of the type aforesaid which includes an oscillation control unit comprising three dashpots located on one side of the mounting mechanism and clamping mechanism, a first dashpot extending between the mounting mechanism and that part of the coupling means to which the arms of the mounting mechanism are pivotally connected, and second and third dashpots respectively extending between one of the inner flanges and that part of the coupling means to which the arms of the mounting mechanism are pivotally connected.

2. A lifting attachment substantially as hereinbefore described with reference to the accompanying drawing.