GB1597114A

GB1597114A - Loadhandling vehicle

Info

Publication number: GB1597114A
Application number: GB1632877A
Authority: GB
Original assignee: BONSER ENG Ltd
Current assignee: BONSER ENG Ltd
Priority date: 1978-05-30
Filing date: 1978-05-30
Publication date: 1981-09-03

Description

(54) LOAD-HANDLING VEHICLE (71) We, BONSER ENGINEERING LIM ITED, a British Company of Giltbrook, Nottingham NG16 2GX, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to a load-handling vehicle such as a fork-lift truck.

Such vehicles are usually provided with a mast, on which is vertically reciprocated a carriage carrying, for example, a load platform or lifting forks. It is known for such vehicles to have a mast with two (or more) stages, e.g. an outer stage fixed to the vehicle body, and an inner stage vertically raisable relative to the outer stage, the carriage being reciprocable on the inner stage. The present invention is concerned with a vehicle of this general type, having a multiple stage mast.

The invention resides in a load-handling vehicle including a multiple-stage mast, a carriage raisable on the first stage of the mast, the first stage being raisable relative to a second stage of the mast and the second stage being raisable relative to a third stage of the mast, a fluid-pressure-operable multiple-cylinder ram, a first pulley and flexible element arrangement through which one cylinder of the ram is operable to raise the carriage on the first stage without extension of the mast, and a second pulley and flexible element arrangement through which another cylinder of the ram is operable to raise simultaneously the first stage relative to the second stage, the second stage relative to the third stage and the ram relative to the third stage.

Reference is now made to the accompanying drawings, wherein.

Figure 1 is a plan view of a multiple-stage mast of a fork-lift truck, with parts removed for clarity; Figure 2 is a perspective view of a ram for effecting lift, showing the location of the ram and the passage of chains and hydraulic hoses; Figures 3A to 3C are diagrammatic side views showing the ram in three different positions; Figures 4A to 4C are diagrammatic front views showing the mast in three different positions corresponding respectively to the positions shown in Figures 3A to 3C; and Figure 5 is a diagrammatic sectional side view, showing the passage of the hydraulic hoses.

Referring to figure 1, there is shown an outer stage 1. Rollers la on the outer mast mount an intermediate stage 4 for vertical, reciprocal movement. Rollers 4a on the intermediate stage mount an inner stage 5 for vertical, reciprocal movement and rollers 5a guide a carriage 39 on the inner stage, also for vertical reciprocal movement. The carriage 39 is provided with forks 41 for supporting a load. Centrally of the mast arrangement is mounted a multiple-cylinder ram 81 for effecting a lifting operation.

Referring to figure 2, the ram is shown having an inner cylinder 18, an intermediate cylinder 15 and an outer cylinder 19. The outer cylinder 19 carries pulleys 85 over which pass first chains 86, each first chain being connected at one end to the carriage 39, as at 88 and at the opposite end 89 to a plate l5d on the intermediate cylinder 15.

The intermediate cylinder 15 abuts and acts on the inner stage 5 and the inner cylinder 18 is fixed to the intermediate stage 4. Hydraulic fluid is introduced to the ram through the inner cylinder 18 at 18a.

When hydraulic pressure is applied to the ram, the pressure is firstly transmitted to the outer cylinder 19, which is initially caused to move towards the top of the intermediate cylinder 15 taking the carriage 39 towards the top of the inner stage 5, with no movement of the mast stages or of the inner and intermediate cylinders. This movement of the carriage causes no raising of the height of the mast and allows the carriage, whilst loaded and raised, to be carried through doorways, for example. The fully lowered position of the carriage 39 is shown in Figures 3A and 4A. A raised position of the outer cylinder 19 relative to the intermediate cylinder 15 is shown in figure 3B. It can be seen that the carriage 39 has been raised relative to the fixed outer stage 1, by virtue of the pulley 85 being lifted with the outer cylinder 19.Figure 4B also shows the raised positions of the outer cylinder 19 and the carriage 39, the three stages 1, 4, 5, being shown in unchanged positions between figures 4A and 4B.

Further application of hydraulic pressure causes the intermediate cylinder 15, together with the outer cylinder 19, to be raised relative to the inner cylinder 18. The intermediate cylinder bears on the inner stage 5, so the latter is lifted by the intermediate cylinder, the inner mast sliding relative to the intermediate stage 4.

In addition, however, the intermediate stage 4 is caused to be raised relative to the outer stage 1. Referring back to figure 2, this is because second chains 91 are provided, each of which is fixed at one end 93 to the plate 15d fixed to the intermediate cylinder 15. The chains pass over pulleys 90 provided on the intermediate stage 4. The opposite ends 92 of the second chains are secured to the top of the fixed, outer stage 1. This arrangement is diagrammatically shown in figure 3B. Figure 3C illustrates what happens as the intermediate cylinder 15 is raised. The pulleys, 85, 90 have separated, and, in addition, the bottom pulley 90 has itself been raised relative to the outer stage 1 by means of the second chains 91, thereby lifting the whole of the ram.

This movement is also illustrated by means of figures 4B and 4C, corresponding to the same positions as are shown in figures 3B and 3C. It can be seen, in figure 4C, that the ram has extended, raising the inner stage 5 relative to the intermediate stage 4. Simultaneously, the intermediate stage 4 has been raised relative to the outer stage 1, the inner cylinder 18 (and hence the whole ram) having been raised together with the intermediate stage, by the chains 91 raising the pulleys 90.

Referring again to figure 2, hydraulic fluid is fed to the ram at 1 8a at the external end of the inner cylinder 18. Since the whole ram is raised during operation, the hydraulic supply to the inner cylinder also has to be raised.

The hydraulic fluid is fed at 101 into a vertical rigid hose 100 fixed to the outer stage 1. The hose leads to a union 99 in a channel 103. A loop of flexible pipe 102 is connected to the rigid hose 100 at the union 99 in the channel. The pipe 102 leads to a rigid pipe 104 fixed to the intermediate stage 4 and leading to the ram at 18a. As the intermediate stage 4 is raised, the flexible pipe 102 is fed into the channel 103 and is protected thereby.

The carriage 39 is provided with hydraulic connectors for connection of operable devices on the carriage instead of the forks. For example, a tipping back plate or a tipping container may be mounted on the carriage, extra hydraulic feed and return lines being required to operate the tipping device. Since the carriage is raisable to a considerable height, a long hose is required to run from the carriage to the hydraulic feed and return points and the hoses need to be controlled during raising and lowering.

Figures 2 and 5 show hydraulic feed and return points 110 on the carriage 39 and a hydraulic feed and return point 113 at the top of the outer stage 1. From each point 113 on the outer stage, a hose 114 runs round the pulleys 90 at the bottom of the intermediate stage 4 to a corresponding union 116 on the plate 15d. A hose 117 runs from each union 116 over the pulleys 85 on the outer cylinder 15 to the points 110 on the carriage.

It will be seen that each hose 117 follows a parallel path to the first chains 86 and each hose 114 follows a parallel path to the second chains 91. The hoses are, therefore, guided and controlled at all times with no necessity to take up any surplus lengths of hoses when the mast is retracted.

As shown in figure 5, fixed hoses 112 on the outer stage 1 run from the unions 113 to other unions 111 at the bottom of the mast.

The hoses and their pulleys are located close to the ram within the inner stage of the mast, so that the hoses are protected by the mast from being damaged by catching on machinery or the like.

The outer cylinder 15 is moved first, and since this is the portion of the ram which would cause most obstruction to visibility through the mast, this feature allows good visibility as compared with an arrangement in which the inner cylinder moves first.

WHAT WE CLAIM IS: 1. A load-handling vehicle including a multiple-stage mast, a carriage raisable on the first stage of the mast, the first stage being raisable relative to a second stage of the mast and the second stage being raisable relative to a third stage of the mast, a fluid-pressureoperable multiple-cylinder ram, a first pulley and flexible element arrangement through which one cylinder of the ram is operable to raise the carriage on the first stage without extension of the mast, and a second pulley and flexible element arrangement through which another cylinder of the ram is operable to raise simultaneously the first stage relative to the second stage, the second stage relative to the third stage and the ram relative to the third stage.

2. A load-handling device according to Claim 1, wherein the second pulley and flexible element arrangement comprises a pulley on the second stage and a flexible element passing round the pulley and being fixed at opposite ends above the pulley relative to the first and third stages, respec

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. relative to the fixed outer stage 1, by virtue of the pulley 85 being lifted with the outer cylinder 19. Figure 4B also shows the raised positions of the outer cylinder 19 and the carriage 39, the three stages 1, 4, 5, being shown in unchanged positions between figures 4A and 4B. Further application of hydraulic pressure causes the intermediate cylinder 15, together with the outer cylinder 19, to be raised relative to the inner cylinder 18. The intermediate cylinder bears on the inner stage 5, so the latter is lifted by the intermediate cylinder, the inner mast sliding relative to the intermediate stage 4. In addition, however, the intermediate stage 4 is caused to be raised relative to the outer stage 1. Referring back to figure 2, this is because second chains 91 are provided, each of which is fixed at one end 93 to the plate 15d fixed to the intermediate cylinder 15. The chains pass over pulleys 90 provided on the intermediate stage 4. The opposite ends 92 of the second chains are secured to the top of the fixed, outer stage 1. This arrangement is diagrammatically shown in figure 3B. Figure 3C illustrates what happens as the intermediate cylinder 15 is raised. The pulleys, 85, 90 have separated, and, in addition, the bottom pulley 90 has itself been raised relative to the outer stage 1 by means of the second chains 91, thereby lifting the whole of the ram. This movement is also illustrated by means of figures 4B and 4C, corresponding to the same positions as are shown in figures 3B and 3C. It can be seen, in figure 4C, that the ram has extended, raising the inner stage 5 relative to the intermediate stage 4. Simultaneously, the intermediate stage 4 has been raised relative to the outer stage 1, the inner cylinder 18 (and hence the whole ram) having been raised together with the intermediate stage, by the chains 91 raising the pulleys 90. Referring again to figure 2, hydraulic fluid is fed to the ram at 1 8a at the external end of the inner cylinder 18. Since the whole ram is raised during operation, the hydraulic supply to the inner cylinder also has to be raised. The hydraulic fluid is fed at 101 into a vertical rigid hose 100 fixed to the outer stage 1. The hose leads to a union 99 in a channel 103. A loop of flexible pipe 102 is connected to the rigid hose 100 at the union 99 in the channel. The pipe 102 leads to a rigid pipe 104 fixed to the intermediate stage 4 and leading to the ram at 18a. As the intermediate stage 4 is raised, the flexible pipe 102 is fed into the channel 103 and is protected thereby. The carriage 39 is provided with hydraulic connectors for connection of operable devices on the carriage instead of the forks. For example, a tipping back plate or a tipping container may be mounted on the carriage, extra hydraulic feed and return lines being required to operate the tipping device. Since the carriage is raisable to a considerable height, a long hose is required to run from the carriage to the hydraulic feed and return points and the hoses need to be controlled during raising and lowering. Figures 2 and 5 show hydraulic feed and return points 110 on the carriage 39 and a hydraulic feed and return point 113 at the top of the outer stage 1. From each point 113 on the outer stage, a hose 114 runs round the pulleys 90 at the bottom of the intermediate stage 4 to a corresponding union 116 on the plate 15d. A hose 117 runs from each union 116 over the pulleys 85 on the outer cylinder 15 to the points 110 on the carriage. It will be seen that each hose 117 follows a parallel path to the first chains 86 and each hose 114 follows a parallel path to the second chains 91. The hoses are, therefore, guided and controlled at all times with no necessity to take up any surplus lengths of hoses when the mast is retracted. As shown in figure 5, fixed hoses 112 on the outer stage 1 run from the unions 113 to other unions 111 at the bottom of the mast. The hoses and their pulleys are located close to the ram within the inner stage of the mast, so that the hoses are protected by the mast from being damaged by catching on machinery or the like. The outer cylinder 15 is moved first, and since this is the portion of the ram which would cause most obstruction to visibility through the mast, this feature allows good visibility as compared with an arrangement in which the inner cylinder moves first. WHAT WE CLAIM IS:

1. A load-handling vehicle including a multiple-stage mast, a carriage raisable on the first stage of the mast, the first stage being raisable relative to a second stage of the mast and the second stage being raisable relative to a third stage of the mast, a fluid-pressureoperable multiple-cylinder ram, a first pulley and flexible element arrangement through which one cylinder of the ram is operable to raise the carriage on the first stage without extension of the mast, and a second pulley and flexible element arrangement through which another cylinder of the ram is operable to raise simultaneously the first stage relative to the second stage, the second stage relative to the third stage and the ram relative to the third stage.

tively.

3. A load-handling vehicle according to Claim 1 or 2, wherein said one cylinder is the outermost cylinder of the ram.

4. A load handling vehicle according to any preceding claim including at least one hydraulic take-off point on the carriage, a hydraulic fluid line between a fixed point on the vehicle and the carriage, the fluid line including a flexible part supported by pulleys co-axial with those of said first and second pulley and flexible element arrangements for paying out the flexible part of the fluid line during raising and lowering operations.

5. A load-handling vehicle according to Claim 4, including a plurality of said hydraulic fluid lines all arranged within the confines of the innermost of said stages of the mast.

6. A load-handling vehicle constructed substantially as herein described with reference to the accompanying drawings.