GB2040261A - Fork assembly for fork lift truck - Google Patents

Abstract

The invention provides a fork lift truck having one or more L-shaped fork members including a load-supporting tine 1 and a supporting arm which has an apertured boss 4 at the upper end so that the fork member or members can be secured in position by engaging the boss of the or each arm with a substantially horizontal rod 6 and the or each fork member can be adjusted as to position by sliding movement along the rod 6. <IMAGE>

Description

SPECIFICATION Improvements in or relating to fork lift trucks This invention relates to fork lift trucks. It will be understood that in this specification the term fork lift truck is used broadly to include any mobile lifting and moving vehicle including an L-shaped fork or forks to lift and support articles. For example the term includes among others a vehicle with forks mounted on a carriage which is directly connected to the vehicle and also includes a vehicle with forks mounted on a carriage disposed at the end of a telescopic boom.

In conventional fork lift trucks it is usually necessary for the fork members to be adjustable towards and away from one another. However the fork members are heavy and cumbersome and in the past adjustment of the position of the fork members has been a difficult matter.

It is an objection of this invention to improve the adjustability of the fork members.

In accordance with the present invention there is provided a fork lift truck with one or more L-shaped fork member including a load supporting tine normally arranged in a substantially horizontal position and a supporting arm normally arranged in a substantially vertical position, wherein the supporting arm of the or each fork member has an apertured boss at the upper end arranged so that the fork member is secured to a fork lift carriage by engagement of the apertured boss with a substantially horizontal rod provided on the carriage.

The invention also includes a fork lift truck comprising a fork lift carriage and at least one and preferably two L-shaped fork members, the or each fork member having a tine and a supporting arm, wherein the supporting arm of the or each fork member has an apertured boss at the upper end by means of which it is connected to a substantially horizontal rod in the carriage, the rod being passed through the aperture in the boss, the arrangement being such that the position of the or each fork member can be adjusted by sliding the fork member along the rod, means being provided to lock the or each fork member in position to prevent unwanted movement.

Preferably the carriage includes a castellated bar arranged adjacent to the rod which supports the or each fork member and preferably the or each supporting arm has a locking member e.g. a locking lug on the outer surface of its apertured boss for engagement with the castellated bar. Alternatively the or each locking member may be a spring loaded plungerorthe like.

In one embodiment of the invention using two fork members two horizontal fork-supporting rods may be provided each rod being supported in the carriage in bearings provided in the outer frame of the carriage and at the centre. If desired means may be included whereby the fork carrier i.e. the horizontal rod or rods and the castellated bar are able to float in the vertical direction by arranging a suitably slotted connection between the rods or rods and the castellated bar on the one hand and the frame of the carriage on the other hand.

Therefore in a preferred embodiment in accordance with this invention a fork lift truck is provided with two L-shaped fork members each of which has a load-supporting tine which is usually in a more or less horizontal position and a connecting arm which is usually in a more or less vertical position. Each supporting arm has an apertured boss at the upper end so arranged that the fork members can be secured onto a fork lift carriage by engagement of the apertured bosses with hotizontal rods provided for the purpose on the carriage. In this way when it is desired to adjust the position of a fork member it is only necessary to slide the fork member along the rod, means being provided to lock each fork member in position to prevent unwanted movement of the fork members.

In order that the invention may be more clearly understood reference is now directed by way of example to the accompanying drawings in which: Figure 1 is a perspective view of a fork lift carriage showing the fork members in two positions and Figure 2 is a detail view.

In the drawings 1 are the load-supporting tines of the fork members and 2 is the fork lift carriage.

Reference 3 indicates a castellated bar, the castellations of which are adjacent to the fork at any point along its length. The connecting arm of each fork member terminates in an apertured boss 4 by means of which each connecting arm may be engaged with a horizontal bar 6 by passing the bar 6 through the aperture in the boss of a fork member. Each boss 4 has a locking lug 5 which may be engaged with the castellated bar 3 when the fork member is in a desired position as shown at the left hand end of Figure 1. A suitable bearing 8 is provided at the outer end of each bar 3 and a quick release pin 7 locks the parts in position.

With both the fork members in the position shown at the left hand side of Figure 1, the apparatus is ready for use. In this position the weight of the fork members and the weight of the load holds the lugs 5 in engagement with the castellations. To adjust the position of a fork member the operator lifts the outer end of the load-supporting tine which rotates the fork relative to the rod 6 to disengage the lug 5 from the castellations. When in this position as shown at the right hand side of Figure 1 the fork member can be slid either to the right or to the left along the bar 6 into a new position.

In our load handling vehicles known under our T.M. Giraffe a further improvement will be found in that the fork carriage can be moved through an arc of a circle in the vertical plane so that the carriage can tuck itself under the boom to bring the connecting arms into a substantially vertical position which makes it easier for the operator to lift up the tines to adjust the fork members.

Twill be noted that art a centre portion of the fork carriage there is a bearing to support the two rods 6.

Naturally instead of having two rods 6 a single rod may be provided extending from side to side of the carriage.

In the above description a reference has been made to two fork members but it will be understood that if desired for special purposes a carriage may be provided having a single fork member adjustablee from side to side as described above or having more than two adjustable fork members.

The invention also includes the provision of a fork lift truck constructed as described above and provided with means whereby the fork carrier (Item 6) is able to float in a vertical direction and the castellated bar (Item 3) moves with the carrier (Item 6).

This floating action may be achieved by mounting the rod or rods and the bar in slotted bearings in the carriage so that the rod or rods and the bar can move or float up and down to a limited extent.

It will be understood that the locking lug 5 is simply a means whereby the fork member can be locked in position against further horizontal movement, by engagement of the lug 5 in castellation of the rod. The lug 5 is therefore simply a locking member and any other suitable locking device such as a spring loaded plunger may be used.

1. A fork-lift truck with one or more L-shaped fork member including a load-supporting tine normally arranged in a substantially horizontal position and a supporting arm normally arranged in a substantially vertical position, wherein the supporting arm of the or each fork member has an apertured boss at the upper end arranged so that the fork member is secured to a fork lift carriage by engagement of the apertured boss with a substantially horizontal rod provided on the carriage.

2. A fork-lift truck comprising a fork lift carriage and at least one and preferably two L-shaped fork members, the or each fork member having a tine and a supporting arm, wherein the supporting arm of the or each fork member has an apertured boss at the upper end by means of which it is connected to a substantially horizontal rod in the carriage, the rod being passed through the aperture in the boss, the arrangement being such that the position of the or each fork member can be adjusted by sliding the fork member along the rod, means being provided to lock the or each fork member in position to prevent unwanted movement.

3. A fork-lift truck according to claim 1 or 2 wherein the carriage includes a castellated bar arranged adjacent to the rod which supports the or each fork member and wherein the or each supporting arm has a locking member e.g. a locking lug on the outer surface of its apertured boss for engagement with the castellated bar.

4. A fork-lift truck according to claim 3 wherein the locking member on the or each apertured boss is in the form of a spring loaded plunger.

5. A fork-lift truck according to any of the preceding claims wherein two substantially horizontal rods are provided.

6. A fork-lift truck according to any of the preceding claims wherein suitable bearings are provided to support the or each horizontal rod.

7. Afork lift truck according to any of the preceding claims including means whereby the fork carrier i.e. the horizontal rod or rods and the castellated bar are able to float in a vertical direction by arranging a suitably slotted connection between the rods or rods and the castellated bar on the one hand and the frame of the carriage on the other hand.

8. A fork lift truck substantially as hereinbefore described with reference to the accompanying drawings.

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

Claims (8)

**WARNING** start of CLMS field may overlap end of DESC **. that if desired for special purposes a carriage may be provided having a single fork member adjustablee from side to side as described above or having more than two adjustable fork members. The invention also includes the provision of a fork lift truck constructed as described above and provided with means whereby the fork carrier (Item 6) is able to float in a vertical direction and the castellated bar (Item 3) moves with the carrier (Item 6). This floating action may be achieved by mounting the rod or rods and the bar in slotted bearings in the carriage so that the rod or rods and the bar can move or float up and down to a limited extent. It will be understood that the locking lug 5 is simply a means whereby the fork member can be locked in position against further horizontal movement, by engagement of the lug 5 in castellation of the rod. The lug 5 is therefore simply a locking member and any other suitable locking device such as a spring loaded plunger may be used.

1. A fork-lift truck with one or more L-shaped fork member including a load-supporting tine normally arranged in a substantially horizontal position and a supporting arm normally arranged in a substantially vertical position, wherein the supporting arm of the or each fork member has an apertured boss at the upper end arranged so that the fork member is secured to a fork lift carriage by engagement of the apertured boss with a substantially horizontal rod provided on the carriage.

2. A fork-lift truck comprising a fork lift carriage and at least one and preferably two L-shaped fork members, the or each fork member having a tine and a supporting arm, wherein the supporting arm of the or each fork member has an apertured boss at the upper end by means of which it is connected to a substantially horizontal rod in the carriage, the rod being passed through the aperture in the boss, the arrangement being such that the position of the or each fork member can be adjusted by sliding the fork member along the rod, means being provided to lock the or each fork member in position to prevent unwanted movement.

3. A fork-lift truck according to claim 1 or 2 wherein the carriage includes a castellated bar arranged adjacent to the rod which supports the or each fork member and wherein the or each supporting arm has a locking member e.g. a locking lug on the outer surface of its apertured boss for engagement with the castellated bar.

4. A fork-lift truck according to claim 3 wherein the locking member on the or each apertured boss is in the form of a spring loaded plunger.

5. A fork-lift truck according to any of the preceding claims wherein two substantially horizontal rods are provided.

6. A fork-lift truck according to any of the preceding claims wherein suitable bearings are provided to support the or each horizontal rod.

7. Afork lift truck according to any of the preceding claims including means whereby the fork carrier i.e. the horizontal rod or rods and the castellated bar are able to float in a vertical direction by arranging a suitably slotted connection between the rods or rods and the castellated bar on the one hand and the frame of the carriage on the other hand.

8. A fork lift truck substantially as hereinbefore described with reference to the accompanying drawings.