GB2231025A

GB2231025A - Frame structure for excavator superstructure

Info

Publication number: GB2231025A
Application number: GB9007968A
Authority: GB
Inventors: Dieter Schwappach
Original assignee: O&K Orenstein and Koppel GmbH
Current assignee: CNH Industrial Baumaschinen GmbH
Priority date: 1989-04-08
Filing date: 1990-04-09
Publication date: 1990-11-07
Also published as: IT9047837A1; DE3911571A1; DE3911571C2; IT9047837A0; FR2645560A1; IT1239770B; GB9007968D0; JPH03257228A; FR2645560B1

Description

( 1 SS 12:3 I Central frame structure for the superstructure of an

excavator.

The invention relates to the central frame structure for the superstructure of an excavator.

It has already been proposed that the central frame of the superstructure of an excavator be made from two double-walled longitudinal supporting members That structure therefore has four rib walls which extend in the longitudinal direction of the frame and are secured, for example by welding, to the base plate Lateral supports for the rib walls are provided between the walls, and between each wall and the base plate.

It is an object of the invention to reduce both the material costs and the manufacturing costs of the frame structure, whilst improving the transmission of forces arising through operation of the excavator.

According to the present invention there is provided a central frame structure for the superstructure of an excavator, the structure comprising a base plate and, arranged perpendicularly thereon, a plurality of rib walls; characterised in that, on each side of the central longitudinal axis of the frame there is provided only a single rib wall.

An advantage of the invention is that forces arising from operation of the excavator are well directed into the supporting components of the central frame, imparting a high degree of solidity to the superstructure.

Further, the altogether narrower construction of the 2 - supporting central frame allows structural units such as motors, pumps, control cabinets and the like to be positioned at a lower level on the superstructure, beyond the rib walls, without exceeding predetermined maximum transport dimensions The centre of gravity for the device is thereby lowered, increasing its stability.

Finally, both the material costs and the manufacturing costs are reduced, the latter owing especially to a reduction in the number of welded seams, thereby reducing the overall expenditure on production.

Each rib wall may be rectangular in cross-section.

Advantageously the cross-sectional thickness of the rib walls varies along the length of the rib walls, and preferably is increased in the region where the boom and boom cylinder of the excavator are coupled to the rib walls.

Each rib wall may be provided with a flange member, and advantageously, the rib walls are joined, at least partly, by a common flange member The or each flange member may be provided with one or more openings.

Advantageously, the height of the rib walls decreases in the direction away from the region where the boom of the excavator is coupled to the rib walls.

The rib walls may be arranged symmetrically with respect to the central longitudinal axis of the frame.

Lateral supports may be provided for the rib walls.

The supports may extend between each rib wall and the I 3 - base plate, or between the rib walls.

At least in the region least stressed by the boom and boom cylinder, the rib walls may have a T-shaped cross-section.

The present invention further provides a superstruc- ture for an excavator, the superstructure including a central frame structure as described above.

The present invention yet further provides an excavator including a superstructure as described above and a boom and boom cylinder coupled to the rib walls of the central frame structure.

Advantageously, the or each boom cylinderis provided with forked coupling devices, each coupling device being arranged to fit around an end of a rib wall.

An embodiment of the invention will now be described, by way of example, with reference to the accompanying drawings, in which:

Fig 1 is a longitudinal cross-section through the frame structure, from one side, Fig 2 is a top plan view of the frame structure, partly broken away, Fig 2 a is a cross-section on line A-A' of Fig 2, and Fig 2 b is a cross-section on line B-B' of Fig 2.

As shown in the drawings, the profiled rib walls 2 are attached perpendicularly to the base plate 1, for example by welding The rib walls 2 are covered by a ( 4 - flange 3 which is secured thereto An aperture 4 is provided in each rib wall 2, for attachment to the boom of the excavator (not shown in the drawings) A second aperture 5 is provided in each rib wall 2 for attachment to a coupling device for the hydraulic boom cylinder The novel design of the frame makes it possible for the boom cylinder coupling devices to be forked so that they fit around the ends of the rib walls This leads to a method of fastening that is structurally simple The height of the rib walls 2 decreases in the direction away from the coupling region of the boom and the boom cylinder with rib walls.

As shown in Fig 2, the two rib walls 2, 2 a are spaced laterally from the longitudinal central axis 7 of the frame structure As can be seen in the broken- away portion in the drawing, the thickness of each of the rib walls is increased in the coupling region of the boom and the boom cylinder thereby reinforcing that region of the walls The two rib walls 2, 2 a are connected to one another at their upper edges by a common flange 3 The flange provides lateral support for the rib wall, which support can, in a manner not shown in the drawings, be supplemented by additional lateral supports on the base plate 1 Openings 6, 6 a in the flange 3 and the base plate 1 serve for the passage of connections from the superstructure to the base of the excavator.

The novel design of the central frame of the superstructure means that the excavator has relatively low production costs and is relatively economical to use.

Furthermore, providing the excavator with an overall centre of gravity that is closer to the ground means that it has a relatively wide range of industrial applica- tions.

II 6 -

Claims

CLAIMS-:

1 A central frame structure for the superstructure of an excavator, the structure comprising a base plate and, arranged perpendicularly thereon, a plurality of rib walls; characterised in that, on each side of the central longitudinal axis of the frame there is provided only a single rib wall.

2 A structure according to claim 1, in which each rib wall is rectangular in cross-section.

3 A structure according to claim 1 or claim 2, in which the cross-sectional thickness of the rib walls varies along the length of the rib wall.

4 A structure according to claim 3, in which the thickness of the rib walls is increased in the region where the boom and boom cylinder of the excavator are coupled to the rib walls.

A structure according to any preceding claim, in which each rib wall is provided with a flange member.

6 A structure according to claim 5, in which the rib walls are joined, at least partly, by a common flange member.

7 A structure according to claim 5 or claim 6, in which the or each flange member is provided with one or more openings.

8 A structure according to any one of the preceding claims, in which the height of the rib walls decreases in the direction away from the region where the boom of the 7 - excavator is coupled to the rib walls.

9 A structure according to any one of the preceding claims, in which the rib walls are arranged symmetrically with respect to the central longitudinal axis of the frame.

A structure according to any one of the preceding claims, in which lateral supports are provided for the rib walls.

11 A structure according to claim 10, in which the supports extend between each rib wall and the base plate.

12 A structure according to claim 10 or claim 11, in which the supports extend between the rib walls.

13 A structure according to any preceding claim, in which, at least in the region least stressed by the boom and boom cylinder, the rib walls have a T-shaped cross- section.

14 A central frame structure for the superstructure of an excavator, the structure being substantially as described herein with reference to, and as illustrated by, the accompanying drawings.

A superstructure for an excavator, the superstruc- ture including a central frame structure according to any one of the preceding claims.

16 An excavator including a superstructure according to claim 15 and a boom and boom cylinder coupled to the rib walls of the central frame structure.

17 An excavator according to claim 16, in which the or 8 - each boom cylinder is provided with a forked coupling device, each coupling device being arranged to fit around an end of a rib wall.

Published 1990 a&The Patent Office State House 661/71 High Holborn, London W Cl R 4 TP Further copies maybe obtainedfrom The Patent Office.

G&ies Branch, St Mazy Cray, Orplngton Kent BR 5 3RD Printed by Multiplex techniques ltd, St Mary Cray, Kent, Con 1/87