GB2383264A

GB2383264A - Seat suspension system

Info

Publication number: GB2383264A
Application number: GB0130516A
Authority: GB
Inventors: David Edward Richards
Original assignee: Frazer Nash Consultancy Ltd
Current assignee: Frazer Nash Consultancy Ltd
Priority date: 2001-12-20
Filing date: 2001-12-20
Publication date: 2003-06-25
Anticipated expiration: 2021-12-20
Also published as: GB0130516D0; GB2383264B

Abstract

A suspension system for a seat (28) comprises a pair of guide rails in the form of rods (1), a seat support structure (11) slidably mounted on the rods (1), a first suspension strut (14) connected to the seat support structure (11) and to a first support (4) for the rods (1) and a second suspension strut (15) connected to the seat support structure (11) and to a second support (9) for the rods (1). The height of the seat (28) can be adjusted and the guide rods (1) can be connected to a framework (3) which is adapted to be mounted in a vessel or a vehicle.

Description

Title : SEAT SUSPENSION SYSTEM This invention relates to seat suspension systems intended primarily for vessels at sea.

A problem encountered at sea under adverse weather conditions, is to control the vessel when buffeted by waves.

The present invention aims to provide a suspension system for a seat which is designed to absorb, at least to a substantial extent, the impacts caused by a marine vessel crashing into waves.

According to the invention, there is provided a suspension system for a seat which comprises at least one guide rail, seat support means slidably mounted on the guide rail (s), a first suspension strut connected to the seat support means and to a first support for the guide rail (s) and a second suspension strut connected to the seat support means and to a second support for the guide rail (s).

Preferably two guide rails are provided, the seat support means being slidably mounted, at each side, on a respective one of the guide rails. The first and second supports desirably serve to interconnect the two guide rails.

Each guide rail is preferably provided with means for connection to a bracing strut.

The first suspension strut desirably takes the form of a telescopic hydraulic or pneumatic damper.

The second suspension strut preferably comprises at least one set of springs.

According to a preferred embodiment of the invention, the suspension system further includes a framework which is adapted to be secured to a suitable part of a vessel or vehicle in which the system is to be mounted, a pair of guide rails are secured to the framework and a respective bracing strut is connected to each of the guide rails and to the framework.

Means are preferably provided for adjusting the height of the seat support means and, hence, of the seat itself. The height adjustment means preferably comprise a screw-threaded rod secured at one end to the first support and at the other end to a third support interconnecting the guide rods, a nut engaged on the screw thread and a collar mounted on the rod and secured to the seat support means, at least one set of springs being interposed between the nut and the collar, the arrangement being such that turning the nut is effective to displace it axially along the screw-threaded rod which in turn is effective to displace the collar axially along the rod in the same direction.

The invention will now be described in detail, by way of example, with reference to the drawings, in which :- Fig. 1 is a front perspective view of one embodiment of a seat suspension system according to the invention; Fig. 2 is a rear perspective view of the seat suspension system shown in Fig. 1 and showing the seat support means in one position; Fig. 3 is a side elevation of the seat suspension system shown in Figs. 1 and 2 but with the framework and braising struts omitted; Fig. 4 is a rear perspective view of the seat suspension system similar to Fig. 2 but showing the seat support means in a second position and again with the framework and braising struts omitted; and Fig. 5 is a graph showing typical spring force plotted against displacement.

In the drawings, like parts are denoted by like reference numerals.

Referring to the drawings, the seat suspension system according to the invention comprises a pair of guide rails in the form of rods 1 each of which is provided, at its lower end, with a connector 2 for connecting the respective guide rod 1 to a framework 3. A first support in the form of a substantially horizontal bar 4 interconnects the guide rods 1 adjacent to the connectors 2. Connectors 5 are located on the guide rods 1, intermediate their ends, and a bracing frame is connected to these connectors and to the framework 3. The bracing frame is substantially rectangular, the longer sides serving as bracing struts 6 which are interconnected by the shorter sides 7 and braced by diagonals 8.

A seat support structure 11 is slidably mounted on the guide rods 1 by means of upper collars 12 and lower collars 13 which are connected to sides of the seat support structure 11. An hydraulic damper 14 is secured at one end to the base of the seat support structure 11 and, at the other end, to the first support bar 4. A second substantially horizontal support bar 9 interconnects the guide rods 1, the bar 9 being adjacent to but spaced from the bar 4, and a third substantially horizontal support bar 10 interconnects the upper end of the guide rods 1.

One end of a screw-threaded rod 15 is mounted in a socket 16 on the second support bar 9 and the other end of the rod 15 is mounted in a socket 17 on the third support bar 10. A collar 18 is freely mounted on the rod 15 and is connected to the collars 12 and 13 by connecting strips 19. A first compression spring 20 is mounted on the rod 15, one end of the spring bearing against the collar 18 and the other end engaging a nut 21 movably mounted on the rod 15. A second compression spring 22 is also mounted on the rod 15 bearing at one end against the collar 18 and at the other end against a disc 23 and a third compression spring 24 is also mounted on the rod 15 bearing at one end on the disc 23 and at the other end against a further disc 25 which is also mounted on the rod 15. Mounted on the rod 15 below the disc 25 are a series of disc springs which are housed within a cylinder 26. Finally, a nut 27 is engaged with the screw thread of

the rod 15 below the cylinder 26. A seat 28 is mounted on the seat support structure 11.

The nut 27 enables the height of the seat 28 to be adjusted. Figs. 1 to 3 show the seat in a comparatively low position. By turning the nuts 21 and 27 on the rod 15, the nuts, the springs 20,22 and 24, the disc springs and the collar 18 can be displaced axially along the rod to, for example, the raised position shown in Fig. 4. As can be seen, the seat in Fig. 4 is considerably higher than the seat shown in Figs. 1 to 3.

When the seat suspension system shown in the drawings is installed in a vessel, the guide rods 1 should be set at such an angle that the seat support structure 11 can absorb forwards as well as downwards slamming loads. The angle can be adjusted by providing the framework 3 with a pair of rails 31 in which a series of apertures 32 are provided and by providing the lower ends of the braising struts 6 with connectors 33 which can be connected to the rails 31 by pins 34. By choosing an appropriate pair of apertures 32 in which to insert the pins 34, the angle of the guide rods 1 to the framework 3 can be selected.

The spring 24 is stiffer than the spring 22 and the disc springs in the cylinder 26 are arranged to be progressively stiffer. As a result, the spring system allows increasing spring rate characteristics which offers maximum comfort with minimum spring loads as indicated by the graph shown in Fig. 5. The spring and damping characteristics can be tailored to meet the characteristics of the vessel on which the seat suspension system is to be installed and are dependent on the size and shape of the vessel. The first compression spring 20 serves to absorb rebound loads, and the damper 14 serves to dampen movement in both directions and to limit the degree of movement of the seat support structure 11 on the guide rods 1.

The nuts 21 and 27 can be adjusted separately in order to pre-compress the springs and set a pre-load in the seat. This has the effect of not causing a displacement when an occupant is simply resting on the seat thereby enabling the maximum possible available stroke within the space limits of the vessel to be utilised to absorb shock loads.

The framework 3 is further provided with apertured lugs 35 by means of which it can be secured to the deck of a vessel.

With the seat suspension system according to the invention, any fore or aft or side load that is imposed on the seat is reacted through a structure which is separate from the height and suspension system as opposed to the existing adjustable pedestals which are generally a single leg design and are more susceptible to damage.

The invention is not restricted to the above-described embodiment but variations and modifications may be made without departing from the scope of the invention. For example, although a manual means of adjusting the height of the seat has been disclosed, height adjustment could be achieved by means of a motor arranged to drive either the nuts 21 and 27 or the screw-threaded rod 15. Further, the guide rails need not take the form of rods but other forms of guide rail could be utilised. Moreover, the framework 3 is not essential and the connectors 2 for the guide rods 1 and the bracing struts 6 could be mounted directly on a vessel.

It should also be noted that the invention is not restricted to use in marine vessels. A seat suspension system according to the present invention could be installed in a motor vehicle.

Claims

1. A suspension system for a seat which comprises at least one guide rail, seat support means slidably mounted on the guide rail (s), a first suspension strut connected to the seat support means and to a first support for the guide rail (s) and a second suspension strut connected to the seat support means and to a second support for the guide rail (s).

2. A suspension system according to claim 1, wherein two guide rails are provided, the seat support means being slidably mounted, at each side, on a respective one of the guide rails.

3. A suspension system according to claim 2, wherein the first and second supports interconnect the two guide rails.

4. A suspension system according to claim 2 or claim 3, wherein each guide rail is provided with means for connection to a bracing strut.

5. A suspension system according to claim 4, wherein the suspension system further includes a framework which is adapted to be secured to a suitable part of a vessel or vehicle in which the system is to be mounted.

6. A suspension system according to claim 5, wherein the guide rails are secured to the framework and a respective bracing strut is connected to each of the guide rails and to the framework.

7. A suspension system according to any one of claims 2 to 6, wherein means are provided for adjusting the height of the seat support means.

8. A suspension system according to claim 7, wherein the height adjustment means comprise a screw-threaded rod secured at one end to the first support and at the other end to a third support interconnecting the guide rails, a nut engaged on the screw thread and a collar mounted on the rod and secured to the seat support means, the arrangement being such that turning the nut is effective to displace the collar axially along the rod.

9. A suspension system according to claim 8, wherein at least one set of springs is interposed between the nut and the collar.

10. A suspension system according to claim 8 or claim 9, wherein the nut is arranged to be driven by a motor.

11. A suspension system according to any one of claims 2 to 10, wherein the guide rails take the form of rods.

12. A suspension system for a seat substantially as described herein with reference to the drawings.

12. A suspension system according to any one of the preceding claims, wherein the first suspension strut takes the form of a telescopic hydraulic or pneumatic damper.

13. A suspension system according to any one of the preceding claims, wherein the second suspension strut comprises at least one set of springs.

14. A suspension system for a seat substantially as described herein with reference to the drawings.

Amendments to the claims have been filed as follows CLAIMS

1. A suspension system for a seat which includes a pair of guide rails; first and second supports each in the form of a respective bar which interconnect the guide rails in a spaced-apart relationship; seat support means slidably mounted on the guide rails and comprising a back portion and a base portion; a first suspension strut connected to the first support and to the base portion of the seat support means; and a second suspension strut connected to the second support and to the back portion of the seat support means.

2. A suspension system according to claim 1, wherein each guide rail is provided with means for connection to a bracing strut.

3. A suspension system according to claim 2, wherein the suspension system further includes a framework which is adapted to be secured to a suitable part of a vessel or vehicle in which the system is to be mounted.

4. A suspension system according to claim 3, wherein the guide rails are secured to the framework and a respective bracing strut is connected to each of the guide rails and to the framework.

5. A suspension system according to any one of the preceding claims, wherein means are provided for adjusting the height of the seat support means.

6. A suspension system according to claim 5, wherein the height adjustment means comprise a screw-threaded rod secured at one end to the first support and at the other end to a third support interconnecting the guide rails, a nut engaged on the screw thread and a collar mounted on the rod and secured to the seat support means, the arrangement being such that turning the nut is effective to displace the collar axially along the rod.

7. A suspension system according to claim 6, wherein at least one set of springs is interposed between the nut and the collar.

8. A suspension system according to claim 6 or claim 7, wherein the nut is arranged to be driven by a motor.

9. A suspension system according to any one of the preceding claims, wherein the guide rails take the form of rods.

10. A suspension system according to any one of the preceding claims, wherein the first suspension strut takes the form of a telescopic hydraulic or pneumatic damper.

11. A suspension system according to any one of the preceding claims, wherein the second suspension strut comprises at least one set of springs.