GB2365073A

GB2365073A - Rod seal leak recovery system

Info

Publication number: GB2365073A
Application number: GB0113351A
Authority: GB
Inventors: L John Koutsky
Original assignee: Sears Manufacturing Co
Current assignee: Sears Manufacturing Co
Priority date: 2000-07-19
Filing date: 2001-06-01
Publication date: 2002-02-13
Also published as: GB0113351D0; DE10134155A1

Abstract

A seat suspension leak recovery apparatus for use in connection with a hydraulic cylinder 26 having a main piston rod seal 28 through which a piston rod 30 extends. The apparatus includes a housing 32 which is mountable to the hydraulic cylinder and defines a chamber 40 which surrounds the main piston rod seal to recover fluid which leaks past the seal. To prevent fluid from leaking out of the housing a second piston rod seal 42 is located on the housing through which the piston rod extends. A vent 44 may also be provided on the housing to assist in draining recovered fluid through a drain 46 and drain tube 52 to a fluid recovery system 60.

Description

2365073

Background of the Invention

The present invention relates to a seat suspension which uses a hydraulic cylinder as an actuator or as a dampener and has a fluid leak recovery system. More specifically, the present invention provides a cap or housing located on a hydraulic cylinder which is used to capture or recover fluid which leaks past a main rod seal.

Summ,aU of the Invention In seat suspensions used in vehicles and other types of equipment, hydraulic cylinders are often used as actuators and as dampening devices on the seat suspensions to absorb shock. However, hydraulic cylinders often develop leaks in the main rod seal resulting in fluid loss. This lost fluid presents several problems. For example, the fluid may spread through the operating area and it may also lead to the failure of the dampener.

The present invention provides a seat suspension leak recovery apparatus for use in connection with a hydraulic cylinder having a main piston rod seal through which a piston rod extends, comprising: a housing mountable to the hydraulic cylinder to define a chamber for receiving fluid which leaks past the piston rod seal; a second piston rod seal on said housing for surrounding the piston rod outwardly of the chamber; and a drain in said housing communicating with the chamber to convey fluid received in the chamber to a fluid collection system. A particular embodiment of the present invention reduces the detrimental affects of fluid leaks by providing a housing or cap that is mountable to the hydraulic cylinder. A cavity is provided in the housing which covers the main piston rod seal and in which lost fluid is recovered. A second cylinder or rod seal is also provided. Recovered fluid is then conveyed by a drain through a drain tube to a fluid recovery system. A vent is also provided which assists in the free flow of recovered fluid.

Description of the Drawings

These and other features, objects and advantages of the present invention will become apparent from the following description and drawings wherein like reference numerals represent like elements in several views, and in which:

Figure 1 is a perspective view with portions removed to show various aspects of one embodiment of the present invention; Figure 2 is an exploded view of the embodiment shown in Figure I; Figure 3 is a partial cross-sectional view taken along line 3-3 as shown in Figure 1; Figure 4 is a partial cross-sectional view taken along line 4-4 as shown in Figure 3; and Figure 5 is a front view of the embodiment shown in Figure 1.

0 Description of the Preferred Embodiments

Set forth below is a description of what are currently believed to be the preferred embodiments or best examples of the invention claimed. Future and present alternatives and modifications to the preferred embodiments are contemplated. Any alternates or modifications having insubstantial changes in function, in purpose, in structure or in result are intended to be covered by the claims of this patent.

Fluid recovery device 10 may be used in connection with scat suspensions (not shown) which use hydraulic cylinders 26 as an actuator to raise a scat in height, as a dampener to absorb shock, or 2 in other ways known to those of skill in the art. Typical set suspensions are shown in United States Patent Nos. 4,943,037, 5,580,027 and 5,735,509, which are incorporated herein by reference.

As shown in Figures 1-3, hydraulic cylinder 26 is used as an actuator and includes a main piston rod seal 28 through which piston rod 30 extends. To recover fluid which leaks past seal 28, a cap or housing 32 is provided which may be made of metal, plastic or other materials known to those of skill in the art. Housing 32 may be mountable to cylinder 26 by fasteners 33 - 36 or in. other ways known to those of skill in the art. Housing 32 defines a cavity 40 in which fluid is recovered and which encloses seal 28. Housing 32 also includes second piston rod seal 42 which prevents fluid from leaking out of the housing and a vent 44 and drain 46.

In use, fluid that leaks past seal 28 is recovered in chamber or cavity 40. The fluid may then be conveyed by gravity or suction through drain 46 and into drain tube 52 where it is conveyed to fluid collection system 60 wIiich may be a storage tank 61 or some other suitable container. Fluid collection system 60 may also be remot ely located from the seat suspension on the vehicle or equipment. A vacuum source may also be used to recover fluid.

In addition, fluid collection system 60 may also be configured throu'gh piping 62 and the like to convey the recovered fluid back to cylinder 26. In this manner, the risk of hydraulic cylinder failure due to a lack of fluid is reduced.

While the invention has been described with reference to the preferred embodiments thereof, it will be appreciated that numerous variations, modifications, and alternate embodiments are possible, and accordingly, all such variations, modifications, and alternate embodiments are to be regarded as being within the spirit and scope of the invention.

4

Claims

What is Claimed is:

1. A seat suspension leak recovery apparatus for use in connection with a hydraulic cylinder having a main piston rod seal through which a piston rod extends comprising: a housing mountable to the hydraulic cylinder defining a chamber which encloses the piston rod seal and which recovers fluid which leaks past the piston rod seal; a second piston rod seal located on said housing; a vent on said housing; and a drain on said housing, said drain conveys recovered fluid recovery system.

2. The apparatus of claim 1 further including a drain tube which conveys fluid recovered in said chamber to the fluid recovery system.

3. The apparatus of claim 1 or 2 wherein said fluid recovery system is a storage tank.

4. The apparatus of any one of claims 1 to 3 wherein the recovered fluid is conveyed to a storage tank which is remotely located from the seat suspension.

5. A seat suspension leak recovery apparatus for use in connection with a hydraulic cylinder having a main piston rod seal through which a piston extends comprising; a housing mountable to the hydraulic cylinder defining a chamber which surrounds the main piston rod seal to recover fluid which leaks past the seal; a piston rod seal located on the housing through which the piston rod extends; a vent in communication with said chamber; a drain positioned on said housing to convey fluid recovered in said chamber to drain tube; and 6 said drain tube conveys recovered fluid to a fluid collection system.

6. The apparatus of claim 5 wherein recovered fluid is conveyed to a storage tank.

7. The apparatus of claim 5 wherein the recovered fluid is conveyed to a storage tank which is remotely located from the seat suspension.

8. The apparatus of any one of the previous claims wherein the recovered fluid is conveyed from the fluid collection system to the hydraulic cylinder.

9. A seat suspension leak recovery apparatus for use in connection with a hydraulic cylinder having a main piston rod seal through which a piston rod extends, comprising: a housing mountable to the hydraulic cylinder to define a chamber for receiving fluid which leaks past the piston rod seal; a second piston rod seal on said housing for surrounding the piston rod outwardly of the chamber; and a drain in said housing communicating with the chamber to convey fluid received in the chamber to a fluid collection system.

10. The apparatus of any one of claims 1 to 8 wherein the vent is situated in an upper region of the housing.

11. The apparatus of any one of the preceding claims wherein the drain is situated in a lower region of the housing.

12. The apparatus of any of the preceding claims wherein the fluid recovery system is situated at a lower level than the drain.

13. A scat suspension leak recovery apparatus substantially as herein described with reference to the accompanying drawings.