GB2492801A - Vehicle seats and seat leg assemblies - Google Patents

Abstract

A seat leg assembly 80 is disclosed for supporting a vehicle seat 82 and for attachment to an elongate anchorage rail 10 fixed to a floor of the vehicle. The assembly comprises: an elongate bottom rail 38 for extending along the anchorage rail with various devices 50,58,68 for releasably attaching the bottom rail to the anchorage rail; a front upright 22F and a rear upright 22R, each upright being fixed at a lower end to the bottom rail; and brackets 88 for attaching an upper end of each upright to the seat. Each upright is an extrusion with the extrusion direction extending between the upper and lower ends of the upright, and with the width of the extrusion extending in the longitudinal direction of the bottom rail and being substantially greater than the thickness of the extrusion.

Description

TITLE

Vehicle seats and seat leg assemblies therefor

DESCRIPTION

This invention relates to vehicle seats and seat leg assemblies therefor.

In some vehicles, such as minihuses, buses, aircraft and ferries, it is desirable to have the facility to remove and replace passenger seats and to adjust the spacing between the seats. A common system to enable this employs two or more anchorage rails which are fixed to the vehicle floor, and seats which are designed to be removably secured to a pair of tbe rails at any position (or at any of a number of predetermined positions) along the rails. Each seat typically has a squab and back provided by an upholstered welded tubular steel frame, welded tubular steel legs which extend downwardly from the squab of the seat, and welded tubular cross-braces between the legs to resist detörmation in the fore-and-aft direction upon sudden deceleration of the vehicle. The lower ends of the legs on the right and left sides of the seat are bolted or welded to right and left lower rails which are releasably attachable to the anchorage rails. Seat belts used with seats of this type are usually anchored to the seat (rather than directly to the structure of the vehicle), and extremely high loadings can therefore he placed on the legs. cross braces and the attachment points to the anchorage rails. The welding therefore needs to be of good quality. A seat of the above type involves a significant amount of fabrication work and ideally the use of jigs to hold the legs and braces in position while they are being welded together. Seats of different heights require: different jigs; legs and braces cut to different lengths; and braces angled differently at their ends. Also, the finished article is considered by some not to he particularly pleasing aesthetically.

An aim of the present invention, or at least of specific embodiments of it, is to provide a seat leg assembly and a finished seat which is simpler to construct, which does not require different jigs for constructing similar seats but of different heights, which is strong, which is not reliant on good quality welding of the seat leg assembly, and which is aesthetically pleasing.

In accordance with a first aspect of the present invention, there is provided a seat leg assembly for supporting a vehicle seat and for attachment to an elongate anchorage rail fixed to a floor of the vehicle. The seat leg assembly comprises an elongate bottom rail for extending along the anchorage rail and having means for releasably attaching the bottom rail to the anchorage rail; a front upright and a rear upright, each upright being fixed at a lower end thereof to the bottom rail; and means for attaching an upper end of each upright to the seat. The invention is characterised in that each upright is an extrusion with the extrusion direction extending between the upper and lower ends of the upright, and with the width of the extrusion extending in the longitudinal direction of the bottom rail and being substantially greater than the thickness of the extrusion.

It has been firnnd that, with such an arrangement, it is possible to produce a seat leg assembly which is sufficiently strong and rigid without being cumbersome and without needing any cross-bracing between the front and rear uprights. The use of an extrusion enables the uprights to have a complex cross-section which can he designed to provide an optimal balance between: weight; cost; overall strength and rigidity; position of attachment to the bottom rail and to the seat; strength of attachment to the bottom rail and to the seat; and aesthetic appearance. Preferably each upright has a thickness which undulates between a front edge of the upright and a rear edge of the upright.

The means for releasably attaching the bottom rail to the anchorage rail preferably also serves to attach the bottom rail to the uprights. For example, the means for releasably attaching the bottom rail to the anchorage rail may include a plurality of securing pins, with each securing pin comprising an exposed headed portion which projects downwardly from the bottom rail for engaging the anchorage rail, an intermediate portion wbich passes through a respective hole in the bottom rail, and a screw-threaded portion which is secured in a screw-threaded hole in one of the uprights. Each pin may have a shoulder between the exposed portion of the pin and the intermediate portion of the pin, the shoulder engaging the underside of the bottom rail to secure the bottom rail to the respective upright. This simplifies assembly and also means that any tensile forces between the upright and anchorage rail are carried directly by the securing pins without placing any load on the bottom rail, which might cause deformation or fracture of the bottom rail.

In the case where the extrusion has an undulating thickness, the screw-threaded holes for the securing pins are preferably formed in thicker portions of the upright so that the upright is more readily able to withstand tensile loads placed on it by the securing pins. Also, the means for attaching the upper end of each upright to the seat preferably includes at least one screw-threaded hole formed in a thicker portion of the upright. More particularly, the means for attaching the upper end of each upright to the seat may include a strap for extending over a cross-member of the seat, and a pair of screws engaging in a pair of such screw-threaded holes at the upper end of the upright for attaching the strap to the upright. By contrast, in the typical known seat leg described above, a bracket is welded to the top of each tabular seat leg, and a strap is used to attach the seat cross-member to the bracket using a pair of bolts passing through holes in the straps and brackets. The known construction is therefore more complicated.

The screw-threaded holes for the securing pins and/or for attaching the seat preferably extend parallel to the extrusion direction.

Each end of each upright is preferably normal to the extrusion direction of the upright.

This simplifies construction and results in less waste when cutting the extruded stock into uprights.

The front and rear uprights preferably have substantially identical cross-sections. This simplifies construction.

A second aspect of the invention provides a vehicle seat having first and second spaced-apart seat leg assemblies according to the first aspect of the invention attached to the seat. The uprights of the first and second leg assemblies preferably have substantially identical cross-sections. Again, this simplifies construction.

A third aspect of the invention provides a set of vehicle seats according to the second aspect of the invention, wherein at least one of the seats has uprights of substantially identical cross-section but different lengths to at least one other of the seats.. The seats can he identical, apart from the extrusion being cut to different lengths for different seats. This simplifies the construction of seats having different seat heights.

A specific embodiment of the present invention will now he described, purely by way of example, with reference to the accompanying drawings, in which: Figures lA-E are a plan view, a side view, and end view and two cross-sectioned views of an anchorage rail, the cross-sections of Figures ID and iF being taken on the section lines ID-ID and iF-lu shown in Figure lÀ: Figures 2A-C are a side view, and underplan view and a plan view of a front upright; Figures 3A-C are a side view, and underplan view and a plan view of a rear upright; Figures 4A-C are a plan view, a side view and an end view of a bottom rail; Figure 5 is a side view of a securing pin; Figure 6A-D side views and plan views of a locking device, with the device shown in it unlocked state in Figures GA-B and in its locked state in Figures 6C-D: Figures 7A-B are a side view and plan view of an anti-rattle device: Figure 8 is a side view of an un-upholstered seat: Figure 9 is an isometric view of part of the seat and anchorage rail; and Figures 1 OA-1 2B are sectioned views through the seat of Figure 8 and the anchorage rail taken on the section lines 10-10, 11-11 and 12-12 with the seat shown in its unlocked position in Figure bA, 1 1A and I 2A and in its locked position in Figures lOB, I1B and 12B.

Referring to Figures IA-E, an anchorage rail 10 of known design is formed by extruding aluminium alloy with a profile as shown in Figure 1 C and then machining the extrusion as shown in Figures IA, 1D and 1E. The extruded profile is in the form of a channel 12 with in-turned flanges 14 and out-turned flanges 16 at the mouth of the channel. The in-turned flanges 14 are bored away at intervals C of 1" (25.4mm) to form widened openings 18 into the channel 12. The base of the channel 12 is bored and countersunk at intervals of 4C to form holes 20 by which the anchorage rail 10 can he secured to a vehicle floor, for example directly or via a floor strengthening rail.

Referring to Figures 2A-C, a front upright 22F is formed hy extruding aluminium alloy with a profile as shown in Figures 2B-C, cutting the extrusion to a required length with square ends and then drilling and tapping the ends. In the example shown in the drawings, the upright has width of about 3.7C and a maximum thickness of about 0.SSC. However, the upright 22F does not have a uniform thickness, hut instead has two bulges 24,26 in its thickness towards its edges, and two intermediate bulges 28,30. The bulges 24-30 are not necessarily circular and may he stretched in the width direction of the upright 22F. However, the centres of the bulges 24-30 are approximately spaced by the amount C. At the lower end of the upright 22F. the front and rear bulges 24,26 are drilled in a direction parallel to the extrusion direction 32 of the upright 22F with a spacing 3C and are tapped with, for example, M8 screw threads to form a pair of threaded holes 34. At the upper end of the upright 22F, the front intermediate bulge 28 and the rear bulge 26 are drilled in a direction parallel to the extrusion direction 32 of the upright 22F with a spacing S slightly greater than 2C and are tapped with. tbr example, M8 screw threads to form a pair of threaded holes 36.

Referring to Figures 3A-C, a rear upright 22R is identical to the front upright 22F except that: (a) three threaded holes 34 are formed at the lower end of the rear upright 22R. in the front bulge 24, the rear intermediate bulge 30 and the rear bulge 26 with centre spacings of 2C and C respectively; and (h) the two threaded holes 36 at the upper end of the upright 22R are formed in the front bulge 24 and the rear intermediate bulge 30, again with a spacing of S. Referring to Figures 4A-C, a lower rail 38 is formed by a length of rectangular bar of aluminium alloy having a width of about 30mm and a thickness of about 10mm. Five plain holes 40 each having a clearance diameter for 8mm are formed through the lower rail 38 at spacings of 3C, 7C, 2C and C, counting from the front, for receiving securing pins to be described below. Also, an M10 screw-threaded hole 42 is formed at a spacing of 8C from the front hole 40 for receiving an anti-rattle device to he described below. Furthermore, a larger diameter plain locking hole 44 is formed at a spacing of 5LC from the front hole 40, for receiving a locking device to be described below, with a pair of threaded fixing holes 46 to either side of the locking hole 44.

Referring now to Figure 5, a securing pin 48 has: a head portion 50 which is a sliding fit along the channel 12 of the anchorage rail 10; an intermediate portion 52 of a diameter of, for example, 10mm which is a clearance fit between the in-turned flanges 14 of the anchorage rail 10; and portion 54 of a diameter of, for example, 8mm which is threaded with an MS thread towards its end. A shoulder 56 is therefore formed between the intermediate portion 52 and the threaded portion 54. The length of the intermediate portion 52 is such that, when the head portion 50 is in the channel 12 of the anchorage rail 10, disposed half-way between an adjacent pair of the widened openings 1 8 and the securing pin 48 is pulled upwardly so that the head portion 50 engages underneath the in-turned flanges 14, then the shoulder 56 protrudes slightly, for example by hmm, above the anchorage rail 10.

Referring now to Figures 6A-D, a locking device 58 of known design comprises a base 60, a knob 62 rotatable and slidable relative to the base 60, and a plunger 64 connected to the knob 62 and projecting below the base 60. the base having a pair of fixing holes 66. In either of two angular positions of the knob 62 180 degrees apart, as shown in Figures 6A-B, the plunger 64 projects a small distance, less than the thickness of the lower rail 38, below the base 60.

When the knob 62 is turned 90 degrees from those positions, a cam (not shown) in the locking device 58 allows the knob 62 and the plunger 64 to descend and a spring (not shown) urges the knob 62 and plunger 64 downwardly so that the plunger 64 projects a larger distance, greater than the thickness of the lower rail 38, below the base 60. as shown in Figures 6C-D. With a further turn of the knob 62 through 90 degrees. the cam returns the knob 62 and plunger 64.

against the action of the spring, to the position shown in Figures 6A-B. The diameter of the plunger 64 is greater than the gap between the opposed in-turned flanges 14 of the anchorage rail 10, but less than the diameter of the widened openings 18.

Referring to Figures 7A-B, an anti-rattle device 68 of known design comprises a pin 70 having a head portion 72 similar to the head portion 50 of the securing pins 48 and a threaded portion 74 formed with, for example, an M10 thread. A knob 76 is fixed to the distal end of the threaded portion 74, for example using the thread and a roll-pin 78.

Referring now to Figures 8-9, a seat leg assembly 80 comprises a lower rail 38 as described above with reference to Figures 4A-C; front and rear uprights 22F,R as described above with reference to Figures 2A-3C: five securing pins 48 as described above with reference to Figure 5; a locking device 58 as described above with reference to Figures 6A-ÔD; and an anti-rattle device 68 as described above with reference to Figures 7A-B. The losver rail 38 is rigidly attached to the uprights 22F.R by the securing pins 48 passing through the holes 40 in the lower rail 38 into the screw-threaded holes 34 in the lower ends of the uprights 22F,R, with the shoulders 56 on the pins 48 being hard up against the underside of the lower rail 38 (as shown in the inset to Figure lOB). The locking device 58 is attached to the lower rail 38 by a pair of screws engaging the holes 46 50 that the plunger 64 of the locking device 58 projects into the large locking hole 44 of the lower rail 38 and either projects below the lower rail 38 or is concealed in the locking hole 44 depending on whether the locking device 58 is in its locked or unlocked position. The threaded portion 74 of the anti-rattle device 68 is engaged in the threaded hole 42 in the lower rail 38 so that the distance of the headed portion 72 of the anti-rattle device 68 below the lower rail 38 can he adjusted by turning the knob 76.

Still referring to Figures 8-9, a vehicle seat 82 has a squab and back frame 84 of welded tubular steel construction with a pair of parallel cross-members 86F,R in the squab portion of the frame 84. The frame 84 is shown only schematically in the drawings. A respective seat leg assembly 80 is attached to each side of the seat 82, with the front upright 22F being attached to the front cross-member 86F, and the rear upright 22R being attached to the rear cross-member 86R. each by a bent steel-strip strap 88 and a pair of M8 cap screws 90. The cap screws 90 pass through holes in the straps 88 having a centre spacing B and are threaded into the threaded holes 36 at the upper ends of the uprights 22F,R. The spacing F of the centres of the cross-members 86F,R is not necessarily an integer multiple of C (i.e. an integer number of inches), and in the example shown is about 9V8C.

The seat 82 can he fitted to a pair of parallel anchorage rails 10, as described above with reference to Figure lA-F, having the same centre spacing as the centre spacing of the seat leg assemblies 80. With the locking devices 58 in the unlocked position and with the headed-portions 72 of the anti-rattle devices 68 at the same level as, or slightly below, the headed portions 50 of the securing pins 48, the seat 82 is positioned so that the lower rails 38 are over the anchorage rails 10 and so that the headed portions 50.72 of the securing pins 48 and anti-rattle devices 68 are aligned with respective widened openings 18 in the anchorage rails 10.

This is possible due to the spacings (3C, SC, 2C or IC) of the headed portions 50,72 on each lower rail 38 being integer multiples of the pitch (C) of the widened openings 18 in each anchorage rail 10. The seat 82 is then lowered so that the headed portions 50.72 pass through the widened openings 18 into the channel 12 of the respective anchorage rail 10, a shown in Figures bA and 12A. It will he seen from Figure hA that the plungers 64 of the locking devices 58 do not at this stage engage with the anchorage rails 10. The seat 82 and leg assemblies 80 can then he slid along the anchorage rails 10 to a desired position. The knobs 62 of the locking devices 58 are then turned through a right angle so that the plungers 64 of the locking devices 58 are urged down onto the upper surface of the anchorage rails 10. The seat 82 is then slid forwards or backwards by a distance of up to C so that the plungers 64 of the locking devices 58 become aligned with, and are each urged into, one of the widened openings 18 in the respective anchorage rail 10, as shown in Figure 1 IB, so that the longitudinal position of the seat 82 along the anchorage rails 10 becomes fixed. It will be noted that, because the headed portions 50,72 of the securing pins 48 and anti-rattle devices 68 are spaced an odd multiple of /iC from the respective locking plunger 64. each headed portion 50,72 will be disposed half-way between an adjacent pair of the widened openings 18 in the respective anchorage rail 10. As can be seen from Figures lOB and 12B. the headed portions 50,72 therefore prevent the seat 82 lifting away from the anchorage rails 10. However, the seat 82 may rattle due to the clearance 92 (see Figure lOB) between the headed portions 50 of the securing pins 48 and the underside of the in-turned flanges 14 of the anchorage rails 10. To prevent such rattling, the knobs 76 of the anti-rattle devices 68 are turned so that the in-turned flanges 14 of the anchorage rails 10 are squeezed between the headed portions 72 of the anti-rattle devices 68 and the underside of the lower rails 38, as shown in Figure 12B.

In order to adjust the position of the seat 82 along the anchorage rails 10, the locking devices 58 are turned to the unlocked positions and the anti-rattle devices 68 are loosened, so that the seat 82 can he slid along the anchorage rails 10 to a different position. The seat can then he re-locked in position as described above.

In order to remove the seat 82, the Locking devices 58 are turned to the unlocked positions and the anti-rattle devices 68 are loosened. The seat 82 is then slid along the anchorage rails 10, finwards or backwards, through a distance of I 2C, whereupon the headed portions 50,72 of the securing pins 48 and anti-rattle devices 68 become aligned with respective widened openings 18 in the anchorage rails, and the seat 82 can then he lifted away from the anchorage rails 10.

A seat 82 as described above is most heavily loaded when occupied by a person wearing a seat belt anchored to the seat and when there is a frontal impact of the vehicle. The inertia of the occupier urges the upper ends of the uprights forwardly relative to the lower ends of the uprights. The arrangement described above is readily capable of withstanding such loading particularly due to the uprights 22F,R having a substantial width (as viewed from the side of the seat), due to the substantial spacing of 3C between the foremost and rearmost securing pins 48 of each upright 22F,R. and due to the securing pins 48 directly carrying the tensile load between the upright 22F,R and the anchorage rail 10. Also, the inertia of the occupier upon severe frontal impact can place the rear uprights 22R completely in tension. Again, the arrangement described above is readily capable of withstanding such loading particularly due to there being three securing pins 48 for each rear upright 22R. and due to those securing pins 48 directly carrying the tensile load between the upright 22R and the anchorage rail 10.

Many modifications and developments may he made to the embodiment of the invention described above. For example, the shape of the extrusion for the front and rear uprights 22F,R may be modified. Different shaped extrusions may he employed for the front and rear uprights 22F,R. Different types of locking devices 58 and anti-rattle devices 68 may be used. The seat cross-members 86F,R may he secured to the uprights 22F,R in different ways., for example using a screw passing though a hole in the cross-member and into a screw-threaded hole tapped into the upright 22F,R, thus obviating the need for the straps 88.

It should be noted that the embodiment of the invention has been described above purely by way of example and that many other modifications and developments may be made thereto within the scope of the present invention.

Claims (1)

1. <claim-text>CLAIMSI. A seat leg assembly for supporting a vehicle seat and for attachment to an elongate anchorage rail fixed to a floor of the vehicle, the seat leg assembly comprising: an elongate bottom rail for extending along the anchorage rail and having means for releasably attaching the bottom rail to the anchorage rail: a front upright and a rear upright, each upright being fixed at a lower end thereof to the bottom rail; and means for attaching an upper end of each upright to the seat; characterised in that: each upright is an extrusion with the extrusion direction extending between the upper and lower ends of the upright, and with the width of the extrusion extending in the longitudinal direction of the bottom rail and being substantially greater than the thickness of the extrusion.</claim-text> <claim-text>2. An assembly as claimed in claim I, wherein: each upright has a thickness which undulates between a front edge of the upright and a rear edge of the upright.</claim-text> <claim-text>3. An assembly as claimed in claim 1 or 2, wherein: the means for releasably aLLaching the bottom rail Lo the anchorage rail also serves to attach the bottom rail co the uprights.</claim-text> <claim-text>4. An assembly as claimed in claim 3, wherein: the means for releasably attaching the bottom rail to the anchorage rail includes a plurality of securing pins; and each securing pin comprises an exposed headed portion which projects downwardly from the bottom rail for engaging the anchorage rail, an intermediate portion which passes through a respective hole in the bottom rail, and a screw-threaded portion which is secured in a screw-threaded hole in one of the uprights.</claim-text> <claim-text>-10 - 5. An assembly as claimed in claim 4, wherein: each pin has a shoulder between the exposed portion of the pin and the intermediate portion of the pin, the shoulder engaging the underside of the bottom rail to secure the bottom rail to the respective upright.</claim-text> <claim-text>6. An assembly as claimed in claim 4 or 5. wherein: the screw-threaded holes for the securing pins extend parallel to the extrusion direction.</claim-text> <claim-text>7. An assembly as claimed in any of claims 4 to 6 when directly or indirectly dependent on claim 2, wherein: the screw-threaded holes for the securing pins are formed in thicker portions of the upright.</claim-text> <claim-text>8. An assembly as claimed in claim 2, or any of claims 3 to 7 when directly or indirectly dependent on claim 2, wherein: the means for attaching the upper end of each upright to the seat includes at least one screw-threaded hole formed in a thicker portion of the upright.</claim-text> <claim-text>9. An assembly as claimed in claim 8, wherein: the screw-threaded holes for attaching the seat extend parallel to the extrusion direction.</claim-text> <claim-text>10. Any assembly as claimed in claim 8 or 9. wherein: the means for attaching the upper end of each upright to the seat includes: a strap for extending over a cross-member of the seat, and a pair of screws engaging in a pair of such screw-threaded holes at the upper end of the upright for attaching the strap to the upright.</claim-text> <claim-text>11. An assembly as claimed in any preceding claim, wherein: each end of each upright is normal to the extrusion direction of the upright. -11-</claim-text> <claim-text>12. An assembly as claimed in any preceding claim, wherein: the front and rear uprights have substantially identical cross-sections.</claim-text> <claim-text>13. A seat leg assembly, substantially as described with reference to the drawings.</claim-text> <claim-text>14. A vehicle seal having first and second spaced-apan seal leg assemblies as claimed in any preceding claim attached to the seat.</claim-text> <claim-text>15. A vehicle seat as claimed in claim 14, wherein: the uprights of the first and second leg assemblies have substantially identical cross-sections.</claim-text> <claim-text>16. A set of vehicle seats as claimed in claim 14 or 15, wherein: at least one of the seats has uprights of substantially identical cross-section but different lengths to at least one other of the seats.</claim-text>