AU592314B2

AU592314B2 - Horizontally arranged hydraulic cylinder system

Info

Publication number: AU592314B2
Application number: AU46238/85A
Authority: AU
Inventors: Gunter Tomysek
Original assignee: MAN Maschinenfabrik Augsburg Nuernberg AG
Current assignee: MAN AG
Priority date: 1984-08-16
Filing date: 1985-08-15
Publication date: 1990-01-11
Anticipated expiration: 2005-08-15
Also published as: DE3430037A1; AU4623885A; DE3430037C2; JPS6162605A

Description

5923 14 Form COMMONWEALTH OF AUSTRALIA PATENTS ACT 1952-69 COMPLETE SPECIFICATION

(ORIGINAL)

Class Application Number:; Lodged: rrplt SpcfcainLogd Int. Class *9 9 *9*9 ~rtOrity: itt.

Accepted: Published: Related Art This docuiment. contains the amendments made und;.r Section 49 and is correct for printing.

Narie of Applicant: Address of Applicant: M.A.N. MASCHINENFABRIK AKTI ENGES El LS CRAFT AUG SBURG -NURNB ERG Federal Republic of Germany HUNTER TOMYSEK Actual inventor:

A

Address for Service: EDWD. WATERS SONS, 50 QUEEN STREET, MELBOURNE, AUSTRALIA, 3000.

Complete Specification for the invention entitled: HORIZONTALLY ARRANGED HYDRAULIC CYLINDER SYSTEM The following statemenf is a full description of this invention, including the best method of performing it known to -:j

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2 HORIZONTALLY ARRANGED HYDRAULIC CYLINDER SYSTEM This invention relates to a horizontally disposed hydraulic cylinder system.

Conventional tongs or grab cranes with power operated tongs, such as slab handling cranes et al comprise tongs formed with two levers consisting of two-armed levers and having a hydraulic pressure cylinder disposed between the two upper arms of the levers for opening and closing the tongs. Each hydraulic cylinder consists of a cylinder housing bearing on one of the levers and a piston/piston rod unit with the head of the piston rod bearing on the other lever.

In the case of tongs cranes where wide differences exist between the maximum and minimum width of the load, the cylinder housing is supported close to its inner end in a corresponding recess in the allied tongs lever. This generally proven configuration involves drawbacks in that the clearance space required at the side of the tongs lifting beam is relatively great because the complete stroke takes place unsymmetrically to one side of the cylinder housing. Moreover, the tongs levers tend to "tilt" when moving in the non-loaded condition due to the mass being concentrated unilaterally on the cylinder side which, generally, is prevented by means of complex and expensive mechanical synchronising linkages.

The present invention has for its object to provide a hydraulic cylinder system of the type initially referred to which permitu a relatively small clearance space and where the mass distribution as the cylinder piston moves is substantially symmetrical.

In aeeer~adam ;;ith the present invent- _s objective is achieved by providing a hydraulid cylinder system characterized by a. tw l-V1inders arranged in cylinder housings disposed symmetrically to the vertical P eg nhti /ne ri j2a- -2a- 4 c :c ft C C C CrCC C C

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C;r In accordance with the present invention, this objective is achieved by providing: A hydraulic cylinder system characterized by two cylinders formed in cylinder housings which are physically separate and arranged symmetrically to a center plane each of the cylinder housings being supported on respective support members; a common (double acting) piston/piston rod tke Scomponent which is symmetrical abouta-center plane(z) and provided with two disk-shaped pistons which are symmetrical to the center plane 2 nd arranged on the ends of a piston rod forming part of said common piston/piston rod component which is immovable in an axial direction of the piston rod relative to a 15 second support means, and that the piston rod includes a rod center section formed with pressure fluid connections and in that lines connecting outer and inner cylinder spaces with the pressure fluid connections are constructed in the form of ducts in the piston rod and the disk-shaped pistons.

The advantage of this system configuration is in particular that the clearance space required is reduced due to the stroke being symmetrically divided between the two movingp-r-s, another reduction being obtained by the more advantageous arrangement of the cylinder housings and their pivoted attachment. Furthermore the masses are balanced because all components are designed and acting symmetrically; this applies also for the moving components such as the tongs levers and other components which, due to the identical suspension of (only) the cylinders can be constructed completely identically.

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-3move on symmetrical paths, specifically e upper arms of two-armed tongs levers ad b. a common piston/piston rod member f med symmetrical to the longitudinal es to disk-shaped pistons arranged s nmetrical to the vertical longitudinal c ter plane at the ends of the piston ro which is immovable relative to s support.

N 10 0 The advantage of ese features is in particular that te clearance space (a) i required is re ced due to the stroke being symmetricall divided between the two moving pa s, another reduction being obtain by the more advantageous arra gement of the cylinder housings and Vt ir pivoted attachment. Furthermore, the j /masses are balanced because all components S. are designed and acting symmetrically; this applies also for the moving components such St as the tongs levers and other components which, due to the identical suspension of (only) the cylinders can be constructed a tir itically.

Si 25 In order to ensure synchronism of the two cylinders, two parallel-connected throttling valves or similar flow ccntrol devices are provided in the pipes supplying the equal-volume central pressure spaces of the I cylinders with low-pressure fluid or discharging the fluid therefrom. Thanks to this feature, synchronism is obtained with straightforward means and without the need for expensive and complex mechanical synchronising linkages.

In another advantageous embodiment of the invention, the central part of the piston rod is provided with the pressure fluid connections and the passages connecting the outer and inner cylinder spaces with the pressure fluid connections are formed as ducts in the

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i -4- Spiston rod and the disk-shaped pistons. The pressure I fluid connections are situated for protection in the central rod region which provides increased safety. The Snecescary flexibility of the supply lines need only accommodate a relatively short distance.

A typical embodiment of the invention is schematically shown in the drawing in which: Fiq. 1 is the circuit arrangement of the hydraulic rfr cylinder, 1 0 Fig. 2 a front view of the hydraulic cylinder.

The numerals i, 2 denote the two identical 1* cr ,horizontally disposed cylinder housings of a hydraulic i cylinder system, the housings being formed with centrally arranged horizontal trunnions 3 or similar supporting and suspension means. In tongs cranes applications, these trunnions 3 register in corresponding recesses in the upper arms as schematically shown at 4 of two-armed levers of tongs. Disk-shaped pistons 5, 6 which are connected by a common horizontal piston rod 7 are provided in the cylinder CZ 20 housings 1, 2 which are arranged in line.

The cylinder housings 1, 2 are arranged symmetrically to the vertical longitudinal center plane z; the piston/piston rod member 5, 6, 7 is arranged L symmetrically to its longitudinal center axis and symmetrically to the vertical longitudinal center plane z.

The piston rod 7 is formed at its center, i.e. in the central region of the rod, with connections for the high pressure fluid for extending the cylinder housings (or closing of the tongs) and for the low pressure fluid for retracting the cylinder housings (or opening of the tongs).

The pressure fluid transfer between the corresponding cylinder spaces and the connections is by means of drilled ducts 8, 9, 10 and 11 in the piston rod 7 and the pistons 6.

The high pressure connection communicates via a pressure fluid line 12 in which a releasable check valve 13 is connected with a pressure fluid source which is not specifically shown. To release the check valve 13, there is a control pipe 14 which is branched off the low pressure power line 15. Synchronism of the two cylinders is effected by means of two flow control valves in the form of (adjustable) throttling valves 16. The two throttling valves 16 are connected in parallel and arranged in connecting lines 17a, 17b between the low-pressure power r line 15 and the low-pressure connections.

For closing the tongs, high pressure fluid is delivered via the power line 12 and the drilled ducts 8, 9 into the outer spaces (remote from the piston rod) of the cylinders, whereas the inner pressure spaces are emptied r via the drilled ducts 10, 11 and the throttling valves 16 and the power line 15. For opening the tongs, the inner pressure spaces are supplied with pressure fluid through the low pressure power line 15, the throttling valves 16 and the drilled ducts 10, 11, whereas the pressure fluid can drain from the outer pressure spaces via the drilled ducts 8, 9 and the releasable check valve 13.

The common piston rod 7 is guided in the example of a tongs lifting beam centrally on the yoke 18 (crosshead) of the tongs lifting beam by means of a guide trunnion 19 which registers in a corresponding recess in the yoke 18 in a manner that no forces are transmitted. The trunnions which form the horizontal tongs pivots in a conventional manner are supported in the yoke 18 which is Smounted on the tongs lifting beam. (Since a tongs lifting beam is fitted with several tongs, all tongs are each 30 equ-ipped with a piston/cylinder system).

The piston/cylinder system according to the invention lends itself to all applications where components are provided which have to be moved on symmetrical paths, specifically apart from lifting beams with power operated tongs for the operation of bulkheads and ramps in marine engineering.

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Claims

1989. MAN MASCHINENFABRIK AUGSBURG-NURNBERG AKTIENGESELLSCHAFT WATERMARK PATENT TRADEMARK ATTORNEYS Queen Street, MELBOURNE. VIC. 3000. AUSTRALIA. SKP:JZ (9.15) r C C) Zr Q~ U 00 16N