AU761229B2 - Spare wheel retention bolt and head - Google Patents

Description

Wd 00/63062 PCT/AUOO/00328 1 SPARE WHEEL RETENTION BOLT AND HEAD Field of the Invention This invention relates generally to a retention bolt of a kind which is especially useful for clamping down objects onto an underlying support. In such an application of particular although certainly not exclusive interest, the invention is concerned with the mounting of spare wheels in vehicles.

Background Art A common arrangement for storing the spare wheel in-board of a vehicle is to clamp the wheel in a matching well in the floor of the boot space, or in the floor of the rear compartment of a stationwagon or estate style of vehicle. Typically, a single long bolt engages an internally threaded stand off-set from the floor of the well, and carries a plate, panel or cup assembly which is clamped by the bolt onto the spare wheel hub.

One form of retention bolt presently employed, for example in some vehicles of the Toyota make, has a head formed from plate steel. It is shaped into a channel of generally inverted-U cross-section fitted onto the end of the bolt shank, and is bent out at each side of its inner end to provide a partial rim or flange. This bolt configuration is inexpensive to manufacture and is comfortable to manipulate by hand, but has at least two disadvantages. Disengagement and reapplication of the bolt can be somewhat slow and tedious, and first time release of the bolt may be quite difficult or even impossible by hand because of the initial tool-aided fastening of the retention bolt on the assembly line.

Examples of spare wheel retention bolts of a broadly similar type are disclosed in US patents 5845825 and 4738382.

Long-thread bolts have been used externally of the spare wheel to fix other kinds of clamping devices. In a still further variation, in some vehicles the spare wheel is mounted in a cradle under the vehicle and the cradle is lowered by multiple rotations of one or more long threaded bolts. In these and other W0'00/63062 PCT/AUOO/00328 2 arrangements it is known to provide the bolts with a conventional solid hexagonal head to permit use of the conventional spark-plug spanner or wheel wrench typically found in motor vehicle tool kits. These more traditional bolts are, however, relatively more expensive to manufacture than the aforementioned Toyota bolt and are not suited to comfortable hand operation, even where this may be more convenient.

It is accordingly an object of the invention to provide an improved retention bolt which is particularly adaptable to the mounting of vehicle spare wheels and which is an improvement on the aforedescribed arrangements.

Summary of the Invention The invention provides, in a first aspect, a retention bolt, including: a body having a shank that defines an axis of the body, which shank is threaded at one end and has a head at the other; wherein said head includes an engagement portion adapted to be gripped between fingers or between a thumb and a finger for rotating said body, which portion intersects and is symmetrically disposed with respect to said axis, being relatively longer and relatively thinner in respective mutually orthogonal directions transverse to said axis; and wherein, at each end in said longer dimension, said engagement portion has respective formations that extend generally parallel to said axis and are of tapered cross-section, for being positively engaged by opposite internal angles of a plug spanner, preferably a hexagonal plug spanner, for effecting removal and installation of the bolt.

Preferably, the shank and threaded end are provided by a solid metal rod.

Advantageously, the head including the engagement portion is formed from a flat segment of metal, eg plate steel, in which the engagement portion is of generally inverted-U cross-section, receives said shank and is welded to the shank adjacent WO- 00/63062 PCT/AU00/00328 3 the end opposite the threaded end.

Preferably, the head further includes rim or flange means, typically in a plurality of complementary parts, about the inner end of the head. This rim or flange means is preferably configured with an extemal hexagonal periphery cooperable with the intemrnal cross-section of the hexagonal plug spanner for which said formations are adapted to be positively engaged.

Said respective formations may, especially in the case of said engagement portion of inverted-U cross-section, comprise respective protrusions at each end of the base of the inverted U. These protrusions may typically define respective ridges extending generally parallel to the axis of the shank. The ridges are preferably rounded sufficiently to reduce their sharpness while maintaining said positive engagement with opposite internal angles of a plug spanner.

The engagement portion is preferably shaped to define a cavity for receiving the associated end of said shank in a firm fit.

The head is preferably welded to the shank.

In a second aspect, the invention provides a head for a retention bolt, including an engagement portion generally in the shape of a channel of generally inverted-U cross-section defining a notional centre plane, said channel including a base web and spaced side walls, wherein, at each end of said base web, there are respective formations that extend generally parallel to said centre plane and are of tapered cross-section, for being positively engaged by opposite internal angles of a plug spanner, preferably a hexagonal plug spanner, for effecting removal and installation of the bolt.

The head of the second aspect of the invention is advantageously formed from a flat segment of metal, eg plate steel, in which the engagement portion is of generally inverted-U cross-section.

In the second aspect, the rim or flange means is preferably configured with WO'00/63062 PCT/AU00/00328 4 an external hexagonal periphery co-operable with the internal cross-section of the hexagonal plug spanner for which said formations are adapted to be positively engaged. Said formations are preferably symmetrically bisected by said plane and may comprise protrusions that typically define respective ridges extending generally parallel to the said plane. The ridges are preferably rounded sufficiently to reduce their sharpness while maintaining said positive engagement with opposite internal angles of a plug spanner.

Brief Description of the Drawings The invention will be further described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is an isometric view of a spare wheel retention bolt according to an embodiment of the invention; Figure 2 is a plan or end elevation of the bolt; Figure 3 is a diagram of the bolt in use to retain a spare wheel in its well; Figure 4 is a diagrammatic cross-section illustrating the positive engagement between the head of the retention bolt and a hexagonal plug spanner of a kind typically found in a motor vehicle tool kit; and Figure 5 is a plan view of a blank for the head of the bolt, cut from a sheet of metal but yet to be bent into its shape before being welded to a threaded rod to form the bolt.

Description of Embodiments The illustrated spare wheel retention bolt 10 comprises a body 11 having a solid cylindrical shank 12 which defines a central axis 9, carries a head 20 at one end and is extemally threaded over an extended portion 14 at the other end.

Shank 12 is a length of uniform steel rod, while head 20 is formed, as will be further described, from plate steel, and is spot welded (eg. at 19) to the WO 00/63062 PCU/AUOO/00328 unthreaded or outer end 13 of shank 12.

Head 20 comprises an engagement portion 22 in the form of an inverted channel of generally inverted-U cross-section, with a laterally enlarged central cavity 21 that receives the unthreaded end 13 of shank 12. Engagement portion 22 is relatively longer and relatively thinner in respective mutually orthogonal directions transverse to axis 9. The head is completed at the open end of the channel-shaped engagement portion 22 by a pair of oppositely directed flange portions 24, 25 that are complementary so as to define a hexagonal rim or flange 26 at the inner end of the head. Two of the opposed apices of this hexagon are on the centre plane of symmetry of engagement portion 22, which itself includes axis 9.

It will be seen that the outer base or web 23 of the channel of engagement portion 22 has a large aperture 28 in which the tip of shank 12 lies nearly or substantially flush with the outer transverse extremity of engagement portion 22.

At each end of the base or web 23 of engagement portion 22 of head symmetrically disposed on the transverse centre plane of the head, are respective formations 30, 31 which form protuberances or bulges from the respective edges of the steel plate but are of outwardly tapering cross-section to define respective ridges 32, 33 extending generally parallel to axis 9. The shape of these formations is best seen in Figure 2 and it will moreover be seen from Figure 4 how these formations are arranged to be positively engaged by opposite internal angles 54, of a hexagonal plug spanner 50 for effecting rotation of, and thereby removal and installation of, the bolt. Moreover, rim or flange 26 is arranged with respect to formation 30, 31 so that on further receipt of head 20 into the socket of the plug spanner, the socket will neatly and operatively engage hexagonal flange or rim 26.

Ridges 32, 33 of formations 30, 31 are rounded so as to reduce their sharpness while still ensuring the aforementioned positive engagement with opposite internal angles of the hexagonal plug spanner.

Figure 3 illustrates how the retention bolt 10 is used to clamp a spare wheel W0'00/63062 PCT/AUOO/00328 6 in place in its mounting well 9 in the floor 7 of a vehicle boot or rear compartment.

The bolt is passed through the centre hole of the wheel and its threaded end threadably engages the usual internally threaded pedestal 40 fixed to the floor 9a of the well. The rim or flange 26 of the head acts on an underlying plate 42 carried by shank 12 to clamp it centrally against the hub 45 of the wheel 8, and thereby hold the wheel firmly in place. Head 20 is recessed below the surrounding floor 7.

Head 20 is of a shape which is comfortable to grip between two fingers,.or more typically between a thumb and a finger, for manually rotating it to remove or install the bolt for releasing or reclamping the wheel. However, by virtue of formations 30, 31, the bolt can also be readily rotated by means of a plug spanner 50 or wheel brace (Figure 4) by bringing the socket 52 of the tool into positive operative engagement with formations 30, 31, and furthermore with hexagonal flange or rim 26, except perhaps when the latter is substantially firmly against the plate 42 at the initial stages of release or the final stages of reapplication.

In an alternative arrangement, used with certain types of wheel, plate 42 is not used and there is instead an integral moulded cup to match a centre hole of the wheel and to sit flush with the outer face of the wheel.

By virtue of the illustrated bolt head construction, the vehicle manufacturer is able to provide a driver with the option of either manual or tool assisted operation of the bolt whilst still providing the bolt in a relatively inexpensive form manufactured from threaded rod and a plate steel head. This option may be a particular advantage for first time removal of the bolt after it was originally installed on the assembly line with powered tool assistance.

Figure 5 depicts a flat blank 20' for head 20 after it has been cut to define the subsequent co-operative hexagonal shape of rim or flange 26, the protruding formations 30, 31 and the aperture 28. Thereafter, the blank is folded over to form the inverted channel portion 22, and this portion pressed out centrally to create the cylindrical cavity below aperture 28 to receive shank 12. Portions 24, 25 are bent out at right angles to the channel on fold lines 38 into a common plane to form rim or flange 26.

Claims (1)

1. Claims

   A retention bolt, including:

   a body having a shank that defines an axis of the body, which shank is threaded at one end and has a head at the other;

   wherein said head includes an engagement portion adapted to be gripped between fingers or between a thumb and a finger for rotating said body, which portion intersects and is symmetrically disposed with respect to said axis, being relatively longer and relatively thinner in respective mutually orthogonal directions transverse to said axis;

   and wherein, at each end in said longer dimension, said engagement portion has respective formations that extend generally parallel to said axis and are of tapered cross-section, for being positively engaged by opposite internal angles of a plug spanner for effecting removal and installation of the bolt.

   A retention bolt according to claim 1 wherein said respective formations are adapted to be positively engaged by opposite internal angles of a hexagonal plug spanner for effecting removal and installation of the bolt.

   A retention bolt according to claims 1 or 2, wherein said shank and threaded end are provided by a solid metal rod.

   A retention bolt according to claims 1 , 2 or 3, wherein said head including the engagement portion is formed from a flat segment of metal in which the engagement portion is of generally inverted-U cross-section, receives said shank and is welded to the shank adjacent the end opposite the threaded end.

   A retention bolt according to any preceding claim wherein said head further includes rim or flange means, typically in a plurality of complementary parts, about the inner end of the head.

   A retention bolt according to claim 5 wherein said rim or flange means is configured with an external hexagonal periphery co-operable with the internal cross-section of a hexagonal plug spanner for which said formations are adapted to be positively engaged.

   A retention bolt according to any preceding claim, wherein said respective formations comprise respective protrusions at each end of the base of the inverted U.

   A retention bolt according to claim 7 wherein said protrusions define respective ridges extending generally parallel to the axis of the shank.

   A retention bolt according to claim 8 wherein said ridges are rounded sufficiently to reduce their sharpness while maintaining said positive engagement with opposite internal angles of a plug spanner.

   A retention bolt according to any preceding claim, wherein said engagement portion is shaped to define a cavity for receiving the associated end of said shank in a firm fit.

   A retention bolt according to any preceding claim, wherein said head is welded to the shank.

   A head for a retention bolt, including an engagement portion generally in the shape of a channel of generally inverted-U cross-section defining a notional centre plane, said channel including a base web and spaced side walls, wherein, at each end of said base web, there are respective formations that extend generally parallel to said centre plane and are of tapered cross-section, for being positively engaged by opposite internal angles of a plug spanner for effecting removal and installation of the bolt.

   A head for a retention bolt according to claim 12, wherein said respective formations are adapted to be positively engaged by opposite internal angles of a hexagonal plug spanner for effecting removal and installation of the bolt.

   A head for a retention bolt according to claims 12 or 13, formed from a flat segment of metal in which the engagement portion is of generally inverted-

   U cross-section.

   A head for a retention bolt according to claims 12, 13 or 14, wherein said rim or flange means is configured with an external hexagonal periphery co- operable with the internal cross-section of a hexagonal plug spanner for which said formations are adapted to be positively engaged.

   A head for a retention bolt according to any one of claims 12 to 15, wherein said formations are symmetrically bisected by said plane and comprise protrusions that define respective ridges extending generally parallel to the said plane.

   A head for a retention bolt according to claim 16, wherein said ridges are rounded sufficiently to reduce their sharpness while maintaining said positive engagement with opposite internal angles of a plug spanner.

   A blank for a head for a retention bolt, said bolt being a flat segment of metal shaped for formation into a head according to claim 13, or to any one of claims 14 to 17 when appended directly or indirectly to claim 13.