GB2046676A

GB2046676A - Battery-powered lift trucks

Info

Publication number: GB2046676A
Application number: GB8007435A
Authority: GB
Original assignee: Clark Equipment Co
Current assignee: Doosan Bobcat North America Inc
Priority date: 1979-03-27
Filing date: 1980-03-05
Publication date: 1980-11-19
Also published as: AR222692A1; FR2452463B1; ES489940A1; AU531245B2; AU5687380A; FR2452463A1; ZA801613B; BR8001783A; DE2911996A1; DE2911996C2

Abstract

The controls 10 for the lifting means 4 are located adjacent to, rather than in front of, the drivers seat 7 which is ergonomically advantageous especially when the lifting means are elevated. Seat 7 and controls 10 are located above, the hood 6 of the battery compartment, the hood is pivoted for access to the battery and the controls 10, together with the control unit therebelow, can be moved out of the lifting path of the battery. <IMAGE>

Description

SPECIFICATION Improvements in or relating to battery-powered lift trucks This invention relates to battery-powered lift trucks and, more particularly, to such a truck having a hydraulically operated lifting means, the functions of which are controlled by a control unit adapted to be operated by controls which acts directly on the control unit, and a battery compartment on a covering hood of which the driver's seat is located.

In conventional lift trucks of this kind, the control unit comprising the valves for controlling the lifting cylinder, tilting cylinders and, where applicable, the other hydraulic drives for gripper facilities or the like is disposed either on the truck steering column or on the front wall which separates the driver's legs from the lifting mast or other lifting means. The driver must therefore lean forwards to operate the controls; this is ergonomically undesirable because the operations which he is controlling often take place with the mast extended to a considerable height, thus requiring the driver to look upwards and operate the controls simultaneously. Also, the control unit occupies space and is an obstacle which the driver's knees may readily knock into.

It is the object of the invention to provide a lift truck of the kind described above in which operation of the controls is improved ergonomically.

According to the invention there is provided a battery-powered lift truck comprising hydraulically operated lifting means, the functions of which are controlled by a control unit adapted to be operated by controls which act directly on said control unit, a driver's seat located on a hood covering a battery compartment adapted to contain a battery; the arrangement being such that the controls are disposed above the hood adjacent to and in easy reach of the driver's seat, and also such that the control unit can be moved together with the controls to provide access to permit a battery to be lifted out of the battery compartment.

When operating the controls of a truck in accordance with the invention, the driver remains in a normal upright sitting posture and can operate the controls just by letting his hand "drop" on to the controls, which are within easy reach. The control unit, instead of being fixedly secured to the truck, can be moved clear of the lifting path of the battery to allow an impeded access thereto and more particularly to facilitate battery replacement, during which the battery must be lifted from its compartment.

Preferably, the control unit is located, when in an operative position, below the hood and above the battery and the controls extend through an aperture in the hood.

The hood is conveniently hingeable upwardly away from the control unit, for example by securing the control unit to some part other than the hood so that the control unit is exposed when the hood hinges up.

In an advantageous and irnportant embodiment of the invention, the control unit is so mounted on the battery compartment as to be pivotable clear of the lifting path of the battery.

To implement this feature, the control unit may be located near a front wall of the battery compartment and is rigidly connected to a retaining member which extends downwardly outside the said front wall, the retaining member being mounted at the bottom end thereof on the front of the battery compartment to be pivotable forwards.

Mounting the control unit for pivoting is a very simple and robust way of implementing the feature of control unit mobility. Because of the downwardly extending retaining member, horizontal forwards displacement in the pivoting movement is increased so that the control unit clears the lifting path of the battery at quite a small pivoting angle of considerably less than 900 - a feature which helps considerably-to reduce deformation of the hydraulic hoses which extend to the control unit.

Conveniently, to retain the conrol unit in the position where access to the battery is clear, the retaining member has an abutment which, when the control unit has been pivoted clear of the lifting path for the battery, engages said front wall.

Conveniently, the retaining member is a downwardly extending arm of an angle-member, another arm of which angle-member extends to the rear over the battery compartment and has the control unit secured thereto. The angle-member can be, for instance, a channel section metal pressing.

Pressure elements for holding down the control unit in the operative position can be provided on the underside of the hood.

The pressure elements serve to lock the control unit in its operative position. The locking is required because the control unit must not, of course, shift in response to the actuating forces of the controls acting directly on it, for any such shift would impair fineness of control considerably.

Conveniently, for aesthetic reasons, the control unit may have secured thereto a cover which substantially closes the aperture in the hood, so that the battery compartment cover as a whole is substantially uninterrupted.

So that the invention may be more readily understood, and so that further features thereof may be appreciated, a truck in accordance with the invention will now be described by way of example and with reference to the accompanying drawings, in which: FIGURE 1 is perspective view of a lift truck in accordance with the invention with part cut away; and FIGURE 2 is an enlarged schematic view in vertical section through part of the truck shown in Figure 1.

As shown in Figure 1, a battery-powered three wheeled fork, lift truck 100 has a chassis 1 of welded box-member construction and two driven but unsteered wheels 2 at the front. A single steerable wheel is provided at the back but cannot be seen in Figure 1.

A known protective roof 3 covers the chassis 1.

A lifting mast 4, comprising a slide and a fork and shown in merely disgrammatic form, is provided at the front of the chassis 1. At the centre of the chassis there is a battery compartment 5 which is covered by a covering hood 6. A driver's seat 7 is on the hood 6. When access is required to the compartment 5, for instance to change the battery, the cover 6 with the seat 7 is pivoted about back hinges located between a pair of roof supports 8. The battery is then freely accessible; to remove it, a block and tackle or a crane rope can be lowered through a recess 9 in the roof 3.

On the top of the hood 6 and close to the driver on his right hand side there is a hand control 112 level with and adjacent to the seat back 7. This hand control 12 operates a safety facility which, in the event of an emergency, for example a failure of the drive control, interrupts the power supply by disconnecting the battery from the drive.

The mast 4 is operated hydraulically. Thus, the raising of the slide, the tilting of the mast and, where applicable, other functions such as the actuation of gripper facilities are performed by means of hydraulic cylinders adapted to be supplied with hydraulic liquid by way of a hydraulic pump electrically driven by the battery.

The mast 4 is controlled by controls 10 which are placed on the right of the driver approximately level with the front edge of his seat 7 and which act directly on a control unit 11. This control unit 11 cannot be seen in Figure 1 but some details of its construction and arrangement are shown schematically in Figure 2.

The controls 10, which are hand controls, act on spindle valves 12 in the control unit 11 and which valves control the supply of hydraulic liquid through hoses 12 to the lifting cylinders, tilting cylinders and, where applicable, other actuating cylinders. The control unit 11 is located above the battery compartment 5 and below the hood 6. The controls 10 extend from the control unit 11 to the outside through a top aperture 13 in the hood 6.

The aperture 13, which is substantially closed by a cover 14 secured to the control unit 11, covers the control unit 11 and is formed with slots to enable the controls 10 to be moved.

As shown in Figure 2 the control unit 11 is mounted on a first arm 1 6 of an angle-member 1 5. This first arm 1 6 extends, in the operative position, rearwardly and substantially horizontally over the battery compartment 5, whereas a second arm 17 of the angle-member 15 extends downwardly and in front of a front wall 18 of the battery compartment 5, the second arm 17 being mounted on the front wall 1 8 at a point 19 near the bottom end of the arm for forward pivoting.

The angle member 1 5 is a sheet metal pressing and for increased stability it is of channel section.

The second arm 1 7 has at its bottom end an abutment 20. When the angle member 1 5 has made its pivoting movement, the abutment 20 abuts the battery compartment front wall 1 8 and retains the control unit 11 in the position 11', shown by a chain-dotted-line in Figure 2. The free end of the rearwardly extending arm 1 6 of the angle-member 15 has a bent part 21 which extends upwardly in Figure 2. The function of this bent part 21 is to protect the controls when the control unit 11 has been pivoted into the position 1 1', and when the battery is being removed from, or more particularly lowered into, the compartment 5. The hoses 12 take up the position 12' when the control unit is in its position 1 1'.

Because of their flexibility the hoses 12 make it possible for the control unit 11 to be moved without any need to disconnect the hose connections.

When the control unit 11 is pivoted into its ppsitibn 11', the angle-member 1 5 with the control unit 11 on it moves out of the battery compartment 5, so that the battery is free to be removed and replaced. When the control unit 11 is in its solid-line position below the hood 6, it does not occupy the driver's leg space 22 extending from the battery compartment front wall 1 8 to the truck front wall 23. As will be readily apparent from Figure 1, the controls 10 are within very easy reach of the driver's right hand.

The fact that the controls 10 are placed to the right of the seat 7 is not of course an important feature but merely corresponds to the fact that most people are right-handed. When in the operative position, the control unit 11 is held down by means of pressing elements (not shown) in the form of rubber pads or the like disposed on the inside of the hood.

Claims

1. A battery-powered lift truck comprising hydraulically operated lifting means, the functions of which are controlled by a control unit adapted to be operated by controls which act directly on said control unit, a driver's seat located on a hood covering a battery compartment adapted to contain a battery, the arrangement being such that the controls are disposed above the hood adjacent to and in easy reach of the driver's seat, and also such that the control unit can be moved together with the controls to provide access to permit a battery to be lifted out of the battery compartment.

2. A lift truck according to claim 1 wherein the control unit is located, when in an operative position, below the hood and above the battery, the controls extending through an aperture in the hood.

3. A lift truck according to claim 1 or 2 wherein the hood is hingeable upwardly away from the control unit.

4. A lift truck according to any one of claims 1 to 3, wherein the control unit is pivotably mounted on the battery compartment.

5. A lift truck according to any one of claims 1 to 4, wherein the control unit is located near a front wall of the battery compartment and is rigidly connected to a retainingmember which extends downwardly outside the said front wall, the retaining member being mounted at the bottom end thereof on the front of the battery compartment to be pivotable forwards.

6. A lift truck according to claim 5, wherein the retaining member has an abutment which when the control unit has been moved to provide access for the battery to be lifted engages said front wall.

7. A lift truck according to claim 5 or 6, comprising an angle-member provided with a first arm in the form of a downwardly extending arm and a second arm extending to the rear over the battery compartment and with the control unit secured thereto, and wherein the first arm comprises said retaining member.

8. A lift truck according to any one of claims 2 to 7, further comprising pressure elements provided on the underside of the hood for holding down the control unit in the operative position.

9. A lift truck according to any one of claims 1 to 8, wherein the control unit has secured thereto a cover which substantially closes an aperture in the hood.

10. A lift truck substantially has herein described with reference to the accompanying drawings.

11. Any novel feature or combination of features herein described.