AU2003204217A1 - A seat adjusting mechanism - Google Patents

Description

AUSTRALIA

Patents Act 1990 KING FURNITURE (AUSTRALIA) PTY LTD COMPLETE SPECIFICATION STANDARD PATENT Invention Title: A seat adjusting mechanism The following statement is a full description of this invention including the best method of performing it known to us:- Field of the Invention This invention relates to an adjustable seat. More particularly, the invention relates to a seat adjusting mechanism for a seat assembly.

Background to the Invention Reclining chairs or seat portions of sofas make use of a complicated cam and lever assembly to effect movement of a seat bottom relative to a base of the chair or sofa. Such adjustment mechanisms are awkward to operate and, in particular, when in a reclining position, it can be difficult to return the seat to a non-reclining position to enable a person to egress the seat.

In this specification, a seat assembly is to be understood as, unless the context clearly indicates otherwise, comprising a base and at least a seat bottom adjustably mounted on the base.

Summary of the Invention According to the invention, there is provided a eat adjusting mechanism for a seat assembly of the type described, the seat adjusting mechanism including: a guide member mountable on the base of the seat assembly; a guide element mountable on an operatively lower region of the seat bottom for cooperating with the guide member to facilitate sliding action of the seat bottom relative to the base; and a locking arrangement carried, in use, on the lower region of the seat bottom, the locking arrangement including a locking element slidably arranged on the guide member and being displaceable between a first position in which sliding action of the seat bottom relative to the base in at least one direction is possible and a second position in which sliding displacement of the seat bottom relative to the base in two, opposed directions is possible, the locking arrangement further including an urging means for urging the locking element into its first position.

The guide member may be in the form of a guide tube, the guide tube carrying mountiing formations at or adjacent its opposed ends for mounting on a frame of the base of the seat assembly.

The guide element may be in the form of a guide rod slidably received in the tube, the guide rod being secured, in use, via its opposed ends, to a seat frame of the seat bottom.

The locking element of the locking arrangement may include a locking plate that frictionally engages the guide tube when the locking element is in its first position. The m:\speccomplete\ 14406cmpchb.doc locking plate may be substantially L-shaped having a pair of webs arranged at an angle to each other. A first web may define an aperture through which the sleeve passes with rattling clearance. The aperture may be in the form of a bore through the web or, for ease of manufacture, the aperture may be in the form of a slot opening out into a side or bottom edge of the web. A second web may carry the urging means. The urging means may be in the form of a coil spring.

The spring may be received over a receiving formation that is receivable in an opening in the seat frame of the seat bottom. The receiving formation may, conveniently, be in the form of a threaded stud.

The locking arrangement may include a carrier element which carries the threaded stud. The carrier element may be in the form of a carrier plate which projects from a side of the second web.

The carrier element may mount a handle for facilitating displacement of the locking element from its first position to its second position, against the action of the urging means. The handle may be formed of a member, in the form of a rod, shaped to be a snug fit between a side bolster of the seat assembly and the seat bottom. With this arrangement, the handle is obscured from view so as not to detract from the appearance of the seat assembly.

The invention extends also to a seat assembly including a seat adjusting mechanism as described above.

Brief Description of the Drawings The invention is now described by way of example with reference to the accompanying drawings in which: Figure 1 shows a schematic, side view of a seat assembly, including a seat adjusting mechanism, in accordance with the invention; and Figure 2 shows a three dimensional view of a part of a locking arrangement of the seat adjusting mechanism of Figure 1.

Detailed Description of the Drawin2s In Figure 1 of the drawings, reference numeral 10 generally designates a seat adjusting mechanism in accordance with the invention. The seat adjusting mechanism in use, forms a part of a seat assembly 12. The seat assembly 12 comprises a seat bottom 14 mounted on a base 16. The seat bottom 14 is carried on a seat frame 18.

The assembly 12 includes a backrest 20 which is hingedly mounted relative to the seat bottom 14 and the seat frame 18 by a hinge 22.

m:\specRcomplete\1 14406cmpchb.doc The seat adjusting mechanism 10 includes a guide member in the form of a guide tube 24 which is mounted via mounting lugs 26 to the base 16 of the assembly 12. A guide element in the form of a guide rod 28 is slidably received through the guide tube 24. The guide rod 28 has its first end connected via a mounting lug 30 to the hinge 22 on the seat frame 18. An opposed end of the guide rod 28 is connected to, and fast with, a front part 32 of the seat bottom 14. Accordingly, it will be appreciated that the guide rod 28 can slide bi-directionally relative to the guide tube 24 in the direction of arrows 34.

The seat adjusting mechanism 10 includes a locking arrangement 36. The locking arrangement 36 includes a locking element in the form of an angled, locking plate 38 (shown in greater detail in Figure 2 of the drawings) slidably mounted about the guide tube 24. The locking plate 38 is substantially L-shaped and has a first web and a second web 42 extending at an included angle relative to the first web While the included angle is shown in Figure 2 of the drawings as exceeding 90', it is not necessary for this to be the case and the included angle could be at least 900.

An aperture in the form of a bore 44 is defined through the first web 40 to facilitate sliding mounting of the plate 38 over the guide tube 24. It will be appreciated that, with this configuration the plate 38 needs to be mounted on the guide tube 24 before the fitting of one or both of the mounting lugs 26. To overcome this, the aperture could, instead, be in the form of a slot opening out into a side or bottom edge of the web The bore 44 has a larger diameter than an outer diameter of the guide tube 24 so that the plate 38 is a rattling fit on the guide tube 24. The locking arrangement 36 includes an urging means in the form of a coil spring 46. The coil spring 46 is mounted on a receiving formation in the form of a stud 48 projecting from the web 42. A free end 48.1 of the stud 48 is received in a blind passage (not shown) in the seat frame 18.

The stud 48 is carried on a carrier plate 50 which protrudes through an opening (not shown) in the web 42. The carrier plate 50 and the stud 48 are locked in position by a lock nut 52 received on the threaded stud 48.

The spring 46, which is maintained under slight compression, urges the first web of the plate 38 into an angular disposition relative to the guide tube 24 to have an angle of attack relative to the guide tube 24. This, in turn, causes the bore 44 of the first web 40 to have a corresponding angle of attack relative to the guide tube 24 so that a part of a rim of the bore 40 is in frictional engagement with the outer surface of the guide tube 24. More particularly, an upper, inner edge 44.1 and a lower, outer edge 44.2 of the rim of the bore 44 frictionally engage the guide tube 24 and, even though it m:\speci\complete\ 14406cmpchb.doc is metal-to-metal contact, movement in the direction of arrow 54 is inhibited when the plate 38 is in its rest condition, under the action of the coil spring 46. These edges 44.1 and 44.2 act as knife edges and inhibit sliding movement of the seat adjusting mechanism 36 in the direction of the arrow 54. As a result, when the locking arrangement 36 is in its first, locking position, the seat bottom 14 is inhibited from moving in the direction of the arrow 54 relative to the base 16 of the seat assembly 12.

Nevertheless, if the seat bottom 14 is not at its rearmost limit of sliding displacement relative to the base 16, due to the angle of attack of the bore 44 relative to the guide tube 24, sliding displacement of the locking arrangement 36 in the direction of arrow 56 is possible even without displacing the locking plate 38 from its first, locking position.

To facilitate reclining of the backrest 20 of the seat 14 relative to the base 16, the seat adjusting mechanism 10 includes a handle 58 mounted on the carrier plate To slide the seat bottom 14 in the direction of arrow 54, the handle is raised in the direction of arrow 60 thereby causing the plate 38 to pivot to a second, non-locking position and removing, or at least reducing, the frictional engagement of the edges 44.1 and 44.2 on the guide tube 24. This allows the seat bottom 14 to slide in the direction of the arrow 54 relative to the base 16 to cause the backrest 20 to move to a reclined position relative to the seat bottom 14. When the seat bottom 14 has reached its desired position relative to the base 16, the handle 58 is released and the edges 44.1 and 44.2 of the bore 44 of the plate 38 are urged, under the action of the spring 46, back into frictional engagement with the guide tube 24. This inhibits further displacement of the seat bottom 14 relative to the base 16 in the direction of the arrow 54.

As indicated above, due to the angle of attack of the edges 44.1 and 44.2 relative to the guide tube 24, sliding displacement of the seat bottom 14 in the direction of the arrow 56 is facilitated without the need for raising the handle 58. Thus, should it be desired to urge the seat bottom 14 in the direction of the arrow 56, pressure needs merely be applied to a front of the seat bottom 14 in the direction of the arrow 56 and the locking arrangement 36 slides along the guide tube 24 in the direction of the arrow 56.

The plate 38 is made of a relatively "soft" metal relative to the guide tube 24 so as to inhibit scoring of the guide tube 24 by the plate 38 when the seat adjusting mechanism 36 is in its first, locking position. For example, the plate 38 may be of an aluminium material while the guide tube 24 may be of stainless steel or galvanised steel.

m:\speci\complete\ 14406cmpchb.doc The handle 58 is made of a stainless steel rod and is dimensioned so that the handle 58 can fit between a side of the seat bottom 14 and a side bolster (not shown) of the seat assembly 12 so that the seat adjusting mechanism 10 is unobtrusive thereby imparting an attractive finish to the seat assembly 12.

It will be appreciated that the seat assembly 12 could either be an armchair or a reclining part of a couch or sofa.

It is an advantage of the invention that a seat adjusting mechanism 10 is provided which uses few moving parts, is simple to operate and, counter- intuitively, locks the seat bottom 14 in position against sliding movement in a first direction relative to the seat base 16. Still further, the seat adjusting mechanism 10 is sufficiently compact to be mounted in an unobtrusive position on the seat assembly 12.

It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the invention as shown in the specific embodiments without departing from the spirit or scope of the invention as broadly described. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.

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Claims (13)

1. A seat adjusting mechanism for a seat assembly of the type described, the seat adjusting mechanism including: a guide member mountable on the base of the seat assembly; a guide element mountable on an operatively lower region of the seat bottom for cooperating with the guide member to facilitate sliding action of the seat bottom relative to the base; and a locking arrangement carried, in use, on the lower region of the seat bottom, the locking arrangement including a locking element slidably arranged on the guide member and being displaceable between a first position in which sliding action of the seat bottom relative to the base in at least one direction is possible and a second position in which sliding displacement of the seat bottom relative to the base in two, opposed directions is possible, the locking arrangement further including an urging means for urging the locking element into its first position.

2. The mechanism of claim 1 in which the guide member is in the form of a guide tube, the guide tube carrying mounting formations for mounting on the base of the seat assembly.

3. The mechanism of claim 2 in which the guide element is in the form of a guide rod slidably received in the tube, the guide rod being secured, in use, to the seat bottom.

4. The mechanism of claim 2 or claim 3 in which the locking element of the locking arrangement includes a locking plate that frictionally engages the guide tube when the locking element is in its first position.

The mechanism of claim 4 in which the locking plate is substantially L-shaped having a pair of webs arranged at an angle to each other.

6. The mechanism of claim 5 in which a first web defines an aperture through which the sleeve passes with rattling clearance.

7. The mechanism of claim 6 in which a second web carries the urging means.

8. The mechanism of claim 7 in which the urging means is received over a receiving formation that is receivable in an opening of the seat bottom. m:\speci\complete\ 1 4406cmpchb.doc

9. The mechanism of claim 8 in which the locking arrangement includes a carrier element which carries the receiving formation.

10. The mechanism of claim 9 in which the carrier element mounts a handle for facilitating displacement of the locking element from its first position to its second position, against the action of the urging means.

11. The mechanism of claim 10 in which the handle is formed of a member shaped to be a snug fit between a side bolster of the seat assembly and the seat bottom.

12. A seat adjusting mechanism substantially as described herein with reference to the accompanying drawings.

13. A seat assembly including a seat adjusting mechanism as claimed in any one of the preceding claims. Dated this twenty-fourth day of April 2003 King Furniture (Australia) Pty Ltd Patent Attorneys for the Applicant: F B RICE CO m:\speccomplete\ 14406cmpchb.doc