GB2334710A

GB2334710A - Skip loaders requiring simultaneous actuation of main and auxiliary control valves

Info

Publication number: GB2334710A
Application number: GB9804256A
Authority: GB
Inventors: Colin Storey
Original assignee: RJE ENGINEERING Ltd
Current assignee: RJE ENGINEERING Ltd
Priority date: 1998-02-28
Filing date: 1998-02-28
Publication date: 1999-09-01
Anticipated expiration: 2018-02-28
Also published as: GB9804256D0; GB2334710B

Abstract

Operation of apparatus (30, Fig.5) for loading and/or unloading containers, such as a skip (33), requires simultaneous actuation of both main 12 and auxiliary 10 control valve means. The apparatus comprises manually operable control means for a hydraulically driven boom (32) wherein the control means comprise main 12 and auxiliary 10 control valve means, which are preferably spool valves 20. The main control valve 12 is operable between a loading and unloading condition and the auxiliary control valve 10 is operable between a first position (Fig.2), where the boom operates at a lower speed, and a second position (Fig.4), where the boom operates at a higher speed. Preferably, the apparatus has support means driven by a secondary drive and tipping means driven by a tertiary drive, wherein these drives are operable only when the auxiliary control valve 10 is in its second position. Preferably, the auxiliary control valve 10 is actuated by levers and is biased towards a neutral position (Fig.3). The hydraulic drive means may comprise at least one piston and cylinder device 19 and preferably includes further valve means for feeding fluid to the piston and cylinder.

Description

CONTAINER HANDLING APPARATUS This invention relates to container handling apparatus for loading and unloading a container.

It is particularly suitable for use in skip loaders.

Container handling apparatus for loading and unloading a container, in which the apparatus has booms operated by hydraulic drive means, are commonly used for skip loaders.

Prior apparatus for this purpose comprises a control device with a main control valve having a manual control by which a loaded container is loaded and unloaded at a slow speed and an empty container is unloaded at a fast speed. The prior apparatus has a primary control and is arranged so that the main control valve will not operate unless the primary control is operated. The intention is that the operator uses two hands when operating the apparatus, so improving safety.

A problem with this apparatus is that operators have been known to override the primary control into a permanent operative position, so that the main control valve can be operated single-handed.

According to the present invention there is provided container handling apparatus for loading and unloading containers, the apparatus having boom means, hydraulic drive means for operating the boom means and manually operable control means for controlling the drive means, the control means including main control valve means which is operable between a loading and an unloading condition of the drive means, and an auxiliary control valve means which is operable between a first position representing a first mode of operation wherein the boom means is drivable by the drive means to load and unload a container at a slow speed and a second position representing a second mode of operation wherein the boom means is drivable by the drive means to unload a container at a fast speed, the arrangement being such that two-handed operation is required for operating the control means, the first hand for the main control valve means and the second hand for the auxiliary valve control means.

An advantage of the present invention is that, because two-handed operation is required, safety is improved.

The hydraulic drive means conveniently comprises one or more piston and cylinder devices operable to pivot the boom means in a loading/unloading operation.

Further valve means are provided for feeding fluid to the piston and cylinder devices to provide the fast and slow speed modes. In one arrangement the. fast mode is provided by feeding pressure fluid to both sides of the piston.

The main control valve means and the auxiliary control valve means may each comprise a spool valve.

Preferably the auxiliary control valve means is movable to and biased towards a neutral position between the first and second positions, the neutral position representing a neutral mode wherein the main control means is inoperable and boom means are neither able to load nor unload a container.

The auxiliary control valve means, in passing through a neutral position, avoids the situation in which the operator fixes said valve means in one operating position.

The following description of an embodiment of the invention is given by way of example only and with reference to the accompanying drawings, in which: Figure 1 is a schematic diagram of hydraulic circuit for container handling apparatus according to the invention, Figure 2 is a schematic diagram of a spool valve for an auxiliary control valve means of the container handling apparatus of Figure 1 in a first operative position, Figure 3 is a schematic diagram of the spool valve for an auxiliary control valve means of the container handling apparatus of Figure 1 according to the invention in a neutral position, Figure 4 is a schematic diagram of a spool valve for an auxiliary control valve means of the container handling apparatus of Figure 1 in a second operative position, and Figure 5 is a side view of a skip loader showing the travel of a skip during loading and unloading of the skip. Referring first to Figure 1, the hydraulic circuit for container handling apparatus is shown which has an auxiliary control valve 10, and a main control valve assembly 12. The auxiliary control valve 10 is a three-position spool valve which controls a fast off-load valve 16 operatively associated with the hydraulic supply for boom rams 19, 34.

The main control valve means 12 has four spool valves 20a, 20b, 20c, 20d, valves 20a and 20b being for operation of each of two jack leg rams, 22a, 22b respectively. Valve 20c is connected for operation of a tip hook ram 24. Valve 20d is operable to extend and contract the boom rams 19, 34 in a loading or unloading direction.

Each of the valves of valve means 12 is normally manually operable by means of an operating lever (not shown).

The hydraulic circuit further comprises a hydraulic pump 26 and a tank 28.

Referring to Figure 2, the three-position spool valve 10, constituting the auxiliary control valve, is shown in a first position corresponding to a first mode in which the booms are able to load and unload a container at a slow speed. In the first position, operation of the boom rams 19, 34 is achieved by manual actuation of the spool valve 20d toward a loading or unloading position from a neutral, non-operative position. The spool valve 20d is biased towards a central neutral position.

Referring to Figure 3, the auxiliary valve 10 is shown in a neutral position corresponding to a neutral mode in which the valves of the main control valve assembly are inoperable and, in particular, the rams 19, 34 are neither able to load nor unload a container.

Referring to Figure 4, the spool valve 10 is shown in a second position corresponding to a second mode in which valve 16 is operative and moved to a position in which the rams 19, 34 are operable to unload a container at a faster speed.

When in the second mode, operation of the boom rams 19, 34 is achieved by manual actuation of the spool valve 20d into the loading/unloading position from the neutral nonoperative position. This actuates the fast off load valve 16. Operation of the valve 16 causes operating fluid at the same pressure to be applied to both sides of the pistons of the boom rams to achieve 'regenerative' operation. It will be appreciated that in this mode full power operation of the rams is not available thereby preventing offloading of full containers in this mode but permitting fast unloading of empty containers.

Referring to Figure 5 a conventional skip loader 30 having pivotable booms 32 is shown with a container 33 in a loaded position (heavy lines) and in a partially unloaded position (broken lines). The skip loader has boom rams 34 for pivoting the booms 32, jack leg rams 36 for stabilising the vehicle during loadinglunloading and tip hook rams 38, in conventional manner. By the control arrangement described the jack leg rams 22a and 22b are operable after moving the auxiliary valve 10 to the position of Figure 2 and then operating valves 20a or 20b respectively. Similarly the tip hook ram 24 is operable with valve in the position of Figure 2 and operating valve 20c.

For the operation of the rams 19 the valve 10 is moved from the neutral position of Figure 3 towards the position of Figure 2 or Figure 4 to enable the valve 20d to be operated to load or unload the skip container 33 from the vehicle 30. In practice the Figure 4 position of the valve 10 is adopted when unloading an empty skip to obtain fast offload.

These operations are achievable in a safe manner normally requiring two handed operation.

Claims

CLAIMS 1. A container handling apparatus for loading and/or unloading containers, the apparatus having: boom means; hydraulic drive means for driving said boom means; and manually operable control means for controlling said drive means; the control means including: main control valve means, operable between a loading and unloading condition ofthe drive means; and auxiliary control valve means, operable between a first position and a second position representing first and second modes of operation respectively of the drive means; wherein in the first mode of operation, the drive means is operable to drive the boom means to load and/or unload a container at a lower speed; wherein in the second mode of operation, the drive means is operable to drive the boom means to unload a container at a higher speed; and wherein operation of the apparatus requires simultaneous actuation of said main and auxiliary control valve means.
2. Apparatus according to claim 1 further including: support means for supporting said apparatus; and secondary drive means for driving said support means; wherein in the second mode of operation only, the secondary drive means is operable to drive the support means thereby to support the apparatus.
3. Apparatus according to claim 2 further including: tipping means for tipping a container; and tertiary drive means for driving said tipping means; wherein; in the second mode of operation only, the tertiary drive means is operable to drive the tipping means thereby to tip the container.
4. Apparatus according to any preceding claim wherein the auxiliary control valve means is movable to and biased towards a neutral position between the first and second positions, the neutral position representing a neutral mode of operation wherein the main control valve means is inoperable.
5. Apparatus according to claim 4 wherein the main and auxiliary control valves are actuated by means of levers.
6. Apparatus according to any preceding claim wherein the hydraulic drive means comprises one or more piston and cylinder devices operable to pivot the boom means in a loading and/or unloading operation.
7. Apparatus according to claim 6, including further valve means for feeding fluid to the piston and cylinder devices to provide said first and second modes of operation.
8. Apparatus according to any preceding claim wherein the main and auxiliary control valves are spool valves.
9. Container handling apparatus constructed and arranged substantially as herein described with reference to and as illustrated in the accompanying drawings.