Related Application(s)

The entire content of Australian provisional patent application no. 2019901519, filed 3 May 2019 and entitled "Lubricated Ball Connector", is incorporated herein by reference.

Field of the Invention

The present invention relates to a ball connector, mateable with a socket connector whereby the connectors form a ball-and-socket joint, and configured such that lubricant can be supplied therethrough to an interface between the connectors. The invention also relates to an assembly, comprising the ball connector and a support to which that connector is secured, and a method of forming such an assembly. The invention has particular, though not exclusive, application to towing couplings, in which the ball connector comprises a tow ball, the socket connector typically comprises a hood, and the assembly thus comprises a tow hitch.

Background

In the design of lubricated ball-and-socket joints, particularly grease-lubricated tow balls, it is difficult to locate the lubricant input point (typically a grease nipple) at a workable position and to locate the grease output point such that the grease is administered at a suitable or optimum position to lubricate the bearing formed by the spherical surface of the ball and the complementary surface within the socket component which mates therewith. The lug or bracket to which a tow ball is typically mounted is prone to damage including, particularly in heavy-duty truck haulage - e.g. semi-trailer - applications, deformation resulting from jack-knifing of the truck and trailer coupled via the tow ball and hood, and is thus not an ideal mount for the grease input point. Also, configuring of the hood/socket such that the lubricant flows therethrough to be supplied to the bearing, as is conventional, can give rise to a stress raiser in - or otherwise weaken - the hood/socket, particularly in the region of the output point through the bearing surface of the hood/socket. Summary of the Invention

According to a first aspect of the present invention, there is provided a ball connector, comprising a body which defines a ball and a base, the base being secured or securable to a support whereby the ball is mounted to receive thereover a mating socket, such that there is defined a coupling, comprising the ball and socket, the ball connector including an inlet through which lubricant can be supplied under pressure, wherein the body is configured with at least one internal fluid passage a downstream end of which opens through a surface of the ball, thereby defining an outlet, and an upstream end of which is arranged to be in fluid communication with the inlet, whereby the lubricant flows through the passage so as to be output, through the outlet, to lubricate between the ball and socket within the coupling.

Preferably, the body is of unitary construction.

Preferably, the ball connector includes a fastener connected or connectable to the support such that the base is secured to the support. Preferably, the fastener is configured to extend between the base and the support to be connected to the support. Preferably, the fastener is configured to project from the base to be connected to the support.

Preferably, the body is configured with a bore into which the or each passage opens at the upstream end thereof, and the fastener is configured to extend along the bore such that defined between the fastener and the body is a gap via which the inlet and said upstream end(s) are in fluid communication, the gap being arranged to receive said lubricant.

Preferably, the fastener and bore are configured such that the gap is annular.

Preferably, the bore extends centrally through the body.

Preferably, the or each passage is diagonal to an axis of the bore.

Preferably, the fastener comprises a shank connected or connectable to the support such that the base is secured to the support. Preferably, an end portion of the shank is received or receivable in or through a mounting hole in said support to be connected to the support. Preferably, the end portion is arranged to extend through the mounting hole and is engaged or engageable with a fastening element whereby the support is clamped between the base and fastening element and the base is thus secured to the support. Preferably, the end portion is configured with a thread engaged or engageable with a complementary thread with which the fastening element is configured, such that the end portion engages the fastening element. Preferably, the thread with which the end portion is configured is external such that the complementary thread is internal.

Preferably, the shank comprises a portion which is intermediate opposite ends of the fastener and defines a smooth outer face of the shank, and the body is configured with a smooth inner face bounding said bore whereby the gap is defined between the smooth outer face and smooth inner face.

Preferably, the ball connector includes said fastening element. Preferably, the fastening element comprises a nut. Preferably, the fastener comprises a bolt.

Preferably, the end portion is disposed at a leading end of the fastener.

Preferably, the bore comprises a distal section, which opens through the ball at an outer end thereof, and a proximal section, which opens into or through the base and into which the or each passage opens at the upstream end thereof, the proximal section being configured such that said gap is defined therewithin, the body is configured with an internal seat which defines an inner end of the distal section, and the fastener includes a head inserted or insertable into the distal section through said outer end so as to abut the seat such that the base is secured to the support.

Preferably, the head is disposed at a trailing end of the fastener, and wherein the fastener is inserted or insertable, leading end-first, into the outer end so as to extend through the bore whereby said head is received in said distal section to abut said seat and said leading end is connected or connectable to the support such that the base is secured to the support. Preferably, said seat is defined by an internal shoulder.

Preferably, said head and said distal section are formed so as to interlock rotationally when the head is received in the distal section, such that the body precludes rotation of the fastener relative thereto about a central axis of the fastener. Preferably, the head and distal section are complementarily formed.

Preferably, the ball connector further comprises a seating element attached or attachable to the support such that a face of the base seats thereagainst when the base is secured to the support. Preferably, the seating element is welded or weldable, around a perimeter thereof, to a face of the support to be attached to the support. Preferably, the seating element is configured with an opening such that the fastener extends therethrough when the base is secured to the support. Preferably, the seating element is configured in the form of a ring. Preferably, the base is formed with a spigot which projects away from a plane in which said face of the base lies, to be received in said opening when the base is secured to the support. Preferably, the seating element is configured such that an edge thereof which bounds the opening engages the spigot when received in the opening, whereby the body is locked against rotation about the central axis of the ball, the edge thereby defining a locator precluding rotational misalignment between the body and the seating element. Preferably, the seating element is configured with a marker to facilitate correct rotational orientation thereof with respect to said support. Preferably, the marker is defined by a notch in the seating element. Preferably, the edge and spigot are complementarily formed. Preferably, the ball connector comprises an input fitting which defines said inlet and which is configured to be coupled to an output fitting of an apparatus for supplying said lubricant. Preferably, the fitting comprises a grease nipple.

Preferably, the body is configured with a passageway extending from the fitting to the bore so as to interconnect fluidly the fitting and the gap. Preferably, the fitting is mounted to said body.

Preferably, the fitting is arranged at a forward position on said body.

Preferably, the fitting is mounted to said base.

Preferably, formed into said surface is at least one recess in which the, each, or at least one said, outlet is disposed, or into which the, each or at least one said passage opens, configured such that a lubricant reserve therein is arranged adjacent the interface to apply lubricant thereto.

The, each or at least one said recess may comprise at least one pocket.

The, each or at least one said recess may comprise at least one channel.

Preferably, the base is secured or securable to said support on a vehicle whereby the ball is mounted to receive thereover a mating hood defining said socket, such that a load is connected via the coupling to the vehicle to be towable thereby.

According to a second aspect of the present invention, there is provided a tow ball comprising said ball connector, wherein the base is secured or securable to said support on a vehicle whereby the ball is mounted to receive thereover a mating hood defining said socket, such that a load is connected via the coupling to the vehicle to be towable thereby.

According to a third aspect of the present invention, there is provided an assembly comprising:

the ball connector or two ball; and

said support,

wherein the base is secured to said support whereby the ball is mounted to receive thereover said mating socket such that said coupling is defined. According to a fourth aspect of the present invention, there is provided a tow hitch, comprising:

said tow ball; and

said support,

wherein the base is secured to said support whereby the ball is mounted to receive thereover said mating hood such that said coupling is defined.

Preferably, the ball connector is coupled to an/said apparatus for supplying the lubricant thereto. Preferably, the apparatus is provided on said vehicle.

According to a fifth aspect of the present invention, there is provided a method of forming said assembly or tow hitch, comprising securing the base to said support whereby the ball is mounted to receive thereover said socket such that said coupling is defined.

According to a sixth aspect of the present invention, there is provided a method of providing lubrication between a ball and a socket received thereover in a ball-and-socket coupling, the method comprising supplying lubricant to the ball connector, said ball connector and said mating socket defining the ball and socket respectively in said ball-and-socket coupling, whereby the lubricant flows through the passage(s) and is output, through the outlet(s), to lubricate between the ball and socket within the coupling.

Brief Description of the Drawings

The invention will now be described, by way of non-limiting example only, with reference to the drawings, in which:

Figure l is a perspective view showing details of an assembly comprising a tow hitch, which includes a tow ball according to either of first and second preferred embodiments of the present invention, and a hood coupled to the tow ball for towing of a load;

Figure 2 is an exploded view showing components of the assembly including the tow ball of the first embodiment;

Figure 3 is a view through the section marked“3” in Figure 2, showing details of the assembly including the tow ball of either of the first and second embodiments; Figure 4 is a view through the section marked“4” in Figure 2, likewise showing details of the assembly including the tow ball of either of the first and second embodiments;

Figures 5A to 5C show successive stages of flow/accumulation of lubricant in the tow ball of either of the first and second embodiments;

Figures 6A and 6B show details of lubricant seals formed adjacent lower and upper ends, respectively, of a bolt of the tow ball of either of the first and second embodiments;

Figure 7 shows a body of the tow ball of the second embodiment; and

Figure 8 shows details of an alternative hood to be coupled to the tow ball of either of the first and second embodiments for towing of a load, as well as an exploded view of an assembly comprising a tow hitch, which includes that tow ball and the alternative hood.

Detailed Description of the Preferred Embodiments

Shown in Figure 1 is an assembly 100 comprising a tow hitch 10, which consists of a bracket 17, connected or connectable to a rear part of a vehicle, and a tow ball 1 mounted to the bracket 17, and a connector 18 comprising a hood 20 coupled to the tow ball 1, such that there is defined a coupling, between the tow ball 1 and connector 18 via which a load is articulatedly connected to the vehicle/connected to the vehicle in an articulated manner. The connector 18 is arranged at a front end of a trailer or other apparatus which is to be towed by the vehicle.

The tow ball 1 is configured such that, when mounted to the bracket 17, it can be supplied with lubricant in order to output the lubricant to an interface between the tow ball 1 and hood 20, thereby lubricating the bearing surfaces of the tow ball 1 and hood 20 and thus the coupling.

Referring to Figure 2, the tow ball 1 comprises a unitary body 11 which is formed/machined from a solid piece of steel, as may be consistent with standard tow balls, and which defines a ball 11 A and a base 1 IB that underlies the ball 11 A. Referring to Figures 3 and 4, the base 1 IB is configured with a downwardly facing, preferably machined, smooth and flat annular surface 1 IB 1 and a spigot 11B2 which is radially inward of the annular surface 1 IB 1 and projects downwardly from a plane in which the surface 11B1 lies. The body 11 is configured with a vertical bore 11C which extends therethrough, the bore having an upper or distal section 11C1, which opens through an upper end of the ball 11 A, and a lower or proximal section 11C2 which extends downwardly from the upper section 11C1, through the base 1 IB. The body 11 is configured with an internal annular shoulder 11C3 at a lower end of the upper section 11C1.

The tow ball 1 further comprises a bolt 13 having a head 13 A, at a trailing end of the bolt 13, and a shank 13B which projects from the head 13 A and which has a main portion 13B1, the exterior surface of which is smooth, and an end portion 13B2 which is threaded, which portions define or can be considered an intermediate portion and an end portion, respectively, of the bolt 13.

The tow ball 1 additionally comprises a seating ring 12 which is configured to be secured, via a fillet weld 12B, around a perimeter edge 12A thereof, to the bracket 17, whereby a lower face 12C of the ring 12 abuts an upper face 17A of the bracket 17 and a hole 12D through the ring 12 is concentric with a mounting hole 17B through the bracket 17. The hole 12D is substantially circular though shaped such that an interior edge 12E of the ring 12 which bounds that hole defines radially inwardly projecting opposed lobes 12F. The spigot 11B2 is likewise circular and is configured with opposed scallops 11B3 each of which is arranged to engage a respective one of the lobes 12F when the spigot 11B2 is received in the opening 12D, the remaining (arcuate) portions of the interior edge 12E engaging the remaining (arcuate) portions of the spigot side face, whereby there is a mating fit between the spigot 11B2 and the edge 12E which locates the body 11 relative to the ring 12 (and thus to the bracket 17 to which that ring is attached) and precludes rotation of the body 11, about a central vertical axis of the ball 11 A, relative to the ring 12 and bracket 17. In other embodiments of the invention, the interengaging keying portions with which the body 11 or base 11B and ring 12 are configured (to locate/lock rotationally the former to the latter), defined in the present embodiment by the scallops/recesses 11B3 and lobes/projections 12F respectively, can be of different form - or may be omitted altogether (with reliance being placed instead on friction between the base and ring, or a tool or other component, to hold the body in position rotationally during tightening) - as will be appreciated by a person skilled in the art. The spigot 11B2 has a depth which is less than a depth/thickness of the ring 12, whereby, when it is so received, the downwardly facing surface 1 IB 1 abuts a smooth, flat upper face 12G of the ring 12.

The ring 12, referring again to Figure 2, is configured with a locating notch 12H positioned such that when the opening 12D is arranged to be concentric with the opening 17B and the notch 12H is aligned with a datum on the bracket 17 - which datum in this case is a rear end of the bracket 17 -the ring 12 is orientated correctly for welding to the bracket, i.e. whereby, when the base 1 IB and ring 12 interengage, the body assumes the correct rotational orientation about axis A, as will be described in further detail later. The notch 12H thus defines a marking facilitating correct rotational orientating of the ring 12 for the securing thereof to the bracket 17.

Material (typically metal) of which the ring 12 is comprised may have a hardness different from - preferably less than - the hardness of material of which the body/base is comprised, whereby sealing, owing to the abutment, therebetween is promoted/reliable/ensured.

The ring 12, advantageously, provides a reliable sealing surface, namely face 12G (owing to its being smooth and flat), in preference over the upper face of the bracket 17, which may be damaged or distorted giving rise to leakage. That said, possible are embodiments of the invention in which there is no ring, and the base and bracket are arranged/configured such that the sealing/seating surface of the base (which in the present embodiments is surface 1 IB 1) and upper surface of the bracket are in abutting relation such that the requisite seal is formed therebetween.

The head 13 A is configured with a hexagonal upper portion 13A1 and a cylindrical lower portion 13A2. The body 11, correspondingly, is configured with serrations 11C1A, which bound an upper/distal part of the distal section 11C1, and a smooth curved interior face 11C1B which bounds a lower/proximal part of the distal section 11C1. With the ring 12 located and attached to the bracket 17 and the base 11B mating therewith, downward insertion of the bolt 13, lower end-first, through the open upper end of the bore 11C results in the shank 13B extending along the proximal bore section 11C2 and through the base 1 IB and mounting hole 17B, whereby the threaded lower end 13B2 projects beyond the bottom surface 17C of the bracket 17 and the head 13A is received in the bore upper section 11C1. The hexagonal portion 13A1 thus engages the serrations or corrugations 11C1A whereby the bolt 13 is precluded from rotation, about central axis A, relative to the body 11, and the cylindrical portion 13A2 is closely received in the proximal/lower part 11C IB, whereby an annular lower face 13A3 of the head 13A abuts the upwardly facing annular surface of the shoulder 11C3.

The tow ball 1 additionally comprises a nut 15 which is secured to the threaded lower shank portion 13B2 and tightened to a significant torque - about 800Nm, for instance, in the case of the embodiments described herein in detail - which is in keeping with the preload requirement of the bolt 13, to draw the bolt head lower annular face 13A3 into tight engagement with the upwardly facing annular surface 11C3 of the shoulder, whereby a seal is formed between those abutting surfaces, and to draw the downwardly facing annular surface 11B1 of the base into tight engagement with the ring upper face 12G, whereby there is a seal likewise formed between those abutting surfaces. Without departure from the invention, the tow ball (in each embodiment) may include a seal configured to be received between the bolt head annular face 13 A3 and the annular surface 11C3 of the shoulder - e.g. at least one sealing element, such as an o-ring or gasket - to provide the sealing between face 13A3 and surface 11C3, and/or a seal configured to be received between the surface 11B1 of the base and the upper face 12G (or, where there is no ring 12, as discussed above, between the seating/sealing surface of the base and the bracket face) - e.g. at least one sealing element, such as an o-ring or gasket - to provide the sealing between the said surface and face. In the case of an o-ring (at either or each location), either or each of the face and surface between which the o-ring is received may be configured with a circumferential groove or channel therein within which the o-ring seats, as will be understood and appreciated by a person skilled in the art.

A washer 14 is received over the bolt lower end portion, between the nut 15 and bracket 17, the washer 14 thus being compressed between the nut 15 and bracket 17, whereby the abutting upper surface 14A of the washer 14 and lower surface 17C of the bracket 17 form an annular seal, and the abutting lower surface 14B of the washer 14 and upper surface 15A of the nut likewise form an annular seal, the two annular seals precluding radially outward egress of lubricant between the bracket 17 and nut 15 at the lowermost end of the main (unthreaded) portion of the shank 13B.

In other embodiments of the invention, the interengaging/interlocking portions with which the fastener 13 or head 13A and body 11 or ball 1 1 A are configured (to lock rotationally the former to the latter), defined in the present embodiment by the and hexagonal/polygonal portion 13A1 and corrugations/serrations 11C1 A respectively, can be of different form - or may be omitted altogether (e.g., with reliance being placed instead on friction between the head and body, at the interface therebetween, or a tool or other component, to hold the fastener 13 in position rotationally during tightening) - as will be appreciated by a person skilled in the art.

The bore 11C is machined to a level of precision such that when the bolt 13 is received therein and the bolt head thus seats against the internal shoulder (as previously described), there is an annular narrow gap G between the unthreaded portion of the shank and the body 11, within and along which lubricant can flow, as will be described in further detail later.

The body 11 is configured with a passage P which, at an upstream (lower) end PI thereof, opens into the proximal/lower section of the bore (and thus into the gap G) and opens, at a downstream (upper) end P2 thereof through the spherical surface of the ball 11 A. The passage P extends diagonally from the lower end PI to the upper end P2 thereof. A recess R is formed into the ball surface at the upper end P2, the recess R being configured such that a lubricant reserve, comprising a small pool or volume of accumulated lubricant, therein lies in contact with the mating complementary interior surface 20A in the hood 20, promoting application of the lubricant to the interface between the surfaces 20A and 11A1.

In other embodiments of the invention, the tow ball may have a plurality of passages P, each extending from a respective position where it opens into the bore/annular gap G to a respective position where it opens through the ball surface. The annular gap G may have a cross-sectional area of at least 10mm ² , to promote satisfactory flow of the lubricant therethrough.

The tow ball further comprises a connection point, comprising a fitting 16, in the form of a grease nipple, mounted to the base 1 IB so as to project radially outwardly from a front end portion thereof, and the body 11 is further configured with a fluid passage Q which fluidly interconnects the fitting 16 and the bore proximal/lower section/gap G.

In the embodiments described in detail herein, each of passages P and Q and the bore 11C may have diameters of, for example, 3.00mm and 32.05mm (±0.05mm) respectively, and the unthreaded portion of the shank 13B may have a diameter of 31 73mm (±0.02mm). For the purposes of showing exemplary dimensioning, the drawings may be considered substantially to scale.

The nipple 16, advantageously, is located at a forward position on the body l l/base 11B, whereby it is less prone to being inadvertently struck or knocked, and thus protected from damage, and is readily accessible both for serviceability and for coupling to a corresponding fitting of a device, such as a grease gun or canister, or an automatic lubricant supply apparatus, which may, advantageously, form part of an onboard lubrication system of the vehicle. Advantageously, owing to the supplying of the lubrication on the "vehicle side" of the coupling, it can be readily ensured that the tow ball, as well as the socket received thereover, is adequately lubricated for any load/trailer that is coupled to the tow ball.

Referring to Figure 5 A, when the nipple 16 and corresponding fitting are coupled, grease 50 (which may be standard grease or, if longevity thereof is to be relatively long, trunnion grease) can be supplied through the nipple 16, so as to flow along the passage Q, and into and within the gap G, whereby the passages Q and P become filled with grease, as shown in Figure 5B. Referring to Figure 5C as well as Figures 6A and 6B, the grease, as the supply thereof through the nipple 16 continues, flows into and fills annuli al and a2, defined between the spigot and the bracket/ring and between the intermediate portion of the shank 13B and the interior faces of bracket 17 and washer 14 (defined by the openings therethrough) respectively, and flows through opening PI, into and within the passage P, so as to fill that passage, and is discharged through the opening P2 into the pocket RP to lubricate the interface between the spherical ball surface 11 A1 and the surface 20A.

The/each pocket RP, which in the present example defines the (/a respective) recess at the outlet end of the (/a respective) passage P, is substantially hemispherical.

The grease may be standard industrial grease and the pressure at which it is supplied may be that applied by a standard grease gun (which may be the aforementioned device connected to the ball connector (via nipple 16).

Advantageously, owing to the configuration of the grease passage through the tow ball, particularly the radial arrangement of the/each passage P and the central disposition of the gap G, the configuring of the tow ball with the passage does not adversely affect its strength; problems associated with the aforementioned stress raisers in/weakening of the hood (as a result of configuring that component for supply of the grease therethrough) are eliminated.

Advantageously, the tightness of the connection between the tow ball and the bracket effects the sealing between the bolt head and shoulder, the sealing between the body base and ring, and the sealing between the washer and bracket and the washer and nut.

Shown in Figure 7 is the body 1 G of a tow ball G (see Figures 1, 3, 4, 5A to 5C, 6A and 6B also) according to a second preferred embodiment of the present invention, which body is identical to the body 11 in the tow ball 1 except that the/each recess, R’, formed into the surface, 11AG, of the ball portion, 11A’, at the upper end of the (/a respective) passage P2, comprises - either instead of pocket RP or additional thereto (as shown) - one or more channels RC, into and along which the lubricant flows so as to accumulate in the channel (s) RC, whereby the/each resulting reserve of lubricant adjacent/against the hood interior surface 20A, to promote application of the lubricant to the interface between the surface 20A and ball portion surface, (which in the previous example is within the pocket(s) RP) occupies the channel(s) RC (as well as the pocket(s) RP, if present). Because of the extension along/over/around the exterior of the ball portion 11 A’ of the channel(s) RC, and thus of the reserve of lubricant accumulated in the recess(es) R’, comprising channel(s) RC, the distribution of lubricant to the interface can be widespread (for a given recess) and can be relatively even or uniform.

Shown in Figure 8 is a different hood 20' which can be employed instead of hood 20 in the tow hitch. The hood 20' comprises a first component 21, which is received over the ball 11A/11A’ and configured with an opening 21 A therethrough, and a second component 22, which comprises a cover portion 22A, arranged to be received against the first component 21 to cover the opening 21 A, a screw 22B, having a shank formed with an external thread engaged with an internal thread of a hole which is formed through the cover portion 22A and centred on the hood rotational axis, a handle 22C, connected to an upper end of the shank and rotatable to turn the screw so as to displace it downwardly or upwardly with respect to the cover portion 22A, and a spring 22D, captive between the handle 22C and cover portion 22A. The external thread extends to the tip or lower end portion of the shank such that, when the cover portion 22A is received against the first component 21 and the handle is rotated in a direction so as to advance the shank relative to the cover portion 22A, the tip/lower end portion is received and advanced in an upwardly opening hole 13C formed centrally in the head 13A, that hole being formed with a corresponding internal thread which engages with the shank external thread. As the screw/shank is advanced, the spring 22D is compressed between the handle 22C and the cover portion 22A, such that it biases the cover portion 22 A against the first component 21, and thus the first component 21 against the ball 1 \AJ\ 1 A’, with progressively increasing force.

While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example only, and not by way of limitation. It will be apparent to a person skilled in the relevant art that various changes in form and detail can be made therein without departing from the spirit and scope of the invention. Thus, the present invention should not be limited by any of the above described exemplary embodiments.

Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" and "comprising", will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

The reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as an acknowledgment or admission or any form of suggestion that that prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of endeavour to which this specification relates.