GB2050997A - Sack lift - Google Patents

Abstract

In order to provide a readily mounted sack lift for use on an agricultural tractor 1, a jib 6 is pivotally mounted on a post 5, which itself is supported by a vertically extending support 10 with lateral extensions 22. The assembly is supported on the upper link 3 and lower links 4 of the conventional three point linkage and at 27 and 25 provides three points in the manner of the three point linkage for attachment of an implement shown as a spreader 11. When the hopper of the spreader 11 needs refilling the tractor 1 is driven adjacent a sack of the appropriate material and the linkage 3, 4 lowered so that both the spreader 11 and the support 10 are in contact with the ground. Hydraulic pressure supplied through line 9 from the tractor 1 to cylinder 8 raises the jib 6 to lift the attached sack over the spreader 11 for emptying therein. <IMAGE>

Description

SPECIFICATION Sack lift This invention relates to sack lifts for mounting on agricultural tractors.

An agricultural tractor normally has a so-called three point linkage formed by a pair of hydraulically liftable lower links and a top link. This linkage is used for carrying or towing fully and semi-mounted implements of various types. A tractor normally also has hydraulic and mechanical power take-off points for driving implements and attachments of various types.

In the use of agricultural implements which incorporate hoppers to be filled with granular material, such as seed, feed or fertilizers, one problem is the re-charging of the hopper from sacks of the granular material. Such sacks frequently come in quarter ton, half ton or ton sizes and therefore need hoisting over the hopper, and hitherto this has normally meant the use of a separate hoist or lift powered from and supported by a second tractor. Alternatively, the same tractor can be used, but the implement needs to be disconnected first. Such procedures are timeconsuming and expensive. There have been prior proposals for tractor mounted sack hoists but they have not been wholly satisfactory in operation and the cost has been excessive.

According to the present invention, there is provided a sack lift comprising ajib pivotally mounted on a post, the post being mounted on a support having alternate points so as to be supported from a three point linkage of an agricultural tractor and also having attachment points for connection of agricultural implements in the manner of three point linkage whereby the implement may be connected to the tractor through the intermediary of the post support.

Preferably, the post support also includes a central gap to allow access to a drawbar of the tractor.

The invention also includes the combination of a sack lift according to the invention as set forth above and an agricultural tractor.

The invention will be further described with reference to the accompanying drawings which show a preferred embodiment of the invention and in which: Figure lisa side elevation of a rear portion of the tractor having attached thereto an implement and a form of sack lift according to the invention, showing the implement in the transport and use position; Figure 2 is a view similar two Figure 1 showing the sack lift implement in a charging position; and Figures 3,4 and 5 are perspective views showing various details of the sack lift and its attachment to the tractor.

Figure 1 shows the rear portion of a tractor includ ing part of a tractor cab 1 and rear wheel 2. Atop link of a three point linkage shown at 3 and one lower link at 4. A sack lift comprises a post 5 and a jib 6 pivoted on the post 5 at an axis 7. An hydraulic piston and cylinder unit pivoted to the post 5 and jib 6 is shown at 8. This unit is single acting and hydraulic fluid is supplied and discharged through a line 9 to an hydraulic power take-off point (not shown) on the tractor. Preferably, a restricted orifice is provided between the line 9 and the unit 8 so that in the event of damage to the hydraulic system, the unit 8 will empty only slowly and the load carried by the lift will not fall rapidly to the ground.

The post 5 is mounted on a support 10 to be described in more detail hereinafter, and also mounted on the post and support 10 is an agricultural implement, here shown as a fertilizer spreader 11 which includes a hopper to be filled by sacks lifted by the illustrated sack lift.

In the position of Figure 1, the arrangement is shown in the use position with the three point linkage raised so as to carry a spreader 11 and support 10 clear of the ground.

When the hopper needs to be re-filled, the tractor is driven adjacent a sack of the appropriate material and the linkage lowered so that both the spreader 11 and the support 10 are in contact with the ground. A sack 14 is then attached to a hook 15 on the jib 6 by means of an appropriate spider arrangement 16, and hydraulic pressure is then applied to the unit 8 to expand it and pivotthe jib about the axis 7 until the jib reaches a vertical position shown in Figure 2 when the sack will be over the hopper of the spreader 11 and the material can be fed from the bottom of the sack in known manner.

When the hopper has been re-filled, the line 9 is open to exhaust and the jib 6 allowed to return to the Figure 1 position. After unhooking the spider arrangement 16, the operator then raises the three point linkage backtothe Figure 1 position and is ready to re-start.

It will be seen, particularly from Figures 3, 4 and 5 that the support 10 comprises an inverted U-shaped part 21 and a pair of lateral extensions 22. The extensions 22 carry bracket arrangements 23 which present a forwardly extending clevis 24 with an attachmentto a lower link 4, and a rearwardly extending eye 25 to receive the mounting pins of the spreader 11 or other implement.

At the base of the post 5, or on the transverse part of the U-shaped part 21 there is mounted a forwardly extending plate 26 having holes to present mounting points forthe upper link 3 ofthe three point linkage.

Atthe rear side of the base of the post, there is provided a further eye 27 for attachment to the top connecting point of the spreader 11 or implement.

The eye 27 is preferably vertically adjustable, although not shown as such in the drawings.

It will thus been seen that the support 10 is arranged to be mounted on the three point linkage of a tractor, and to present three points for connection of the implement, so that effectively the support is integrated with the three-point linkage of the tractor.

The bracket arrangement 23 are preferably laterally adjustable on the extensions 22 to enable the lift to be used on various types of tractor and the provision of selective connections on the plate 26 also assist in this regard.

The bracket arrangements 23 may also be provided with rollers beneath the extensions 22 so that the tractor may be manoeuvred when the lift is in the lower position.

The inverted U-shape of the part 21 provides a tunnel to allow the part 5 to be lifted and lowered without interfering with a possible drawbar or other connection extending rearwardly from the tractor to the implement.

Various modifications may be made within the scope of the invention.

Claims (4)

1. A sack lift comprising a jib pivotally mounted on a postthe post being mounted on a support having arrachment points so as to be supported from a three point linkage of an agricultural tractor and also having attachment points for connection of agricultural implements in the manner of the three point linkage whereby the implement may be connected to the tractor through the intermediary of the post support.

2. A sack lift as claimed in claim 1, in which the post support includes a central gap.

3. A sack lift substantially as hereinbefore described with reference to the accompanying drawings.

4. Acombination of a sack lift as claimed in any of the preceding claims and an agricultural tractor.