The present invention relates to gooseneck hitch balls which are removable from a vertical socket in the bed of the towing vehicle. Removable gooseneck hitch balls are known, such as disclosed in U.S. Pat. Nos. 5,016,898 and 6,969,090, both incorporated by reference. In general, the gooseneck hitch ball is purchased with a base or shank which matches and mates with the specific shape of the socket of the hitch: CURT Manufacturing of Eau Claire, Wisconsin has for several years sold a line of removable gooseneck hitches with a socket and base/shank which are circular in horizontal cross-section, secured with two pins through the base/shank, whereas B&W Trailer Hitches of Humboldt, Kansas has for several years sold a line of removable gooseneck hitches with a socket and base/shank which is square in horizontal cross-section, secured with a single pin through the base/shank.
More recently, improvements have been devised which allow relative movement between a hitch ball and its base/shank, as disclosed in U.S. Pat. No. 11,192,408, incorporated by reference. The hitches of U.S. Pat. No. 11,192,408 include a compressible insert placed within the structure to compressibly resist the relative movement.
The present invention is a removable gooseneck hitch ball, with a hitch ball extending over a neck and supported by a shank. The shank has a unique shape enabling it to be received in different gooseneck hitch ball sockets of different shapes. In particular, the shank has a contact surface extending around its central axis for making contact with the socket. The contact surface includes a plurality of arc surfaces and a plurality of flat surfaces. The plurality of arc surfaces collectively define a cylinder centered on the central axis. Each of the flat surfaces is parallel to the central axis and inside the cylinder defined by the arc surfaces. By having this unique shape, the shank can be matingly received in a cylindrical socket of the towing vehicle with the arc surfaces in contact with the cylindrical socket or can be matingly received in a prism shaped socket with the flat surfaces in contact with the prism shaped socket.
While the above-identified drawing figures set a forth preferred embodiment, other embodiments of the present invention are also contemplated, some of which are noted in the discussion. In all cases, this disclosure presents the illustrated embodiments of the present invention by way of representation and not limitation. Numerous other minor modifications and embodiments can be devised by those skilled in the art which fall within the scope and spirit of the principles of this invention.
A preferred embodiment of a removable gooseneck hitch ball 10 is shown in
The ball 12 extends above a neck 22, which jointly define a generally vertical towing pivot axis 24, i.e., intended to be vertical when the towing vehicle (not shown) is on level ground, but the orientation of which will obviously change as the towing vehicle traverses over hills, troughs, slopes, etc. The ball 12 is received in a towed vehicle or trailer coupler (not shown) as known in the art, with the trailer coupler pivoting about the towing pivot axis 24 during turns of the towing vehicle. The ball 12 generally has a spherical outer profile, in which various portions of the ball 12 may be recessed relative to the sphere defined by the ball 12, and in which use and impacts may dent or otherwise deform that ball 12 so as to not be entirely spherical. For instance, the preferred ball 12 has a flat top 26, embossed with information such as the manufacturer, ball size and rated towing load as best shown in
The shank 16 defines a central axis 28 which defines the insertion direction of the shank 16 into the towing socket 18A, 18B, which in the preferred embodiment extends vertically and coincident with the towing pivot axis 24. In other embodiments for use with sockets which are not perpendicular to the bed of the towing vehicle, the central axis may not be vertical. Similarly, in other embodiments the central axis 28 of the shank 16 may be in front, behind or to the side of the towing pivot axis 24, for use in towing vehicles where mounting arrangements or other components lead to placement of the socket offset from the desired towing pivot axis 24.
The preferred embodiment fixes the ball 12 on a pivoting head 30 as taught in U.S. Pat. No. 11,192,408, incorporated by reference. For instance, the ball 12 can be separately formed by machining and then welded to a cast head 30. In this embodiment, the pivot axis 32 for the head 30 is defined by a pivot pin 34, located in front of the towing pivot axis 24 and the shank central axis 28. To assist users in correctly orienting the removable gooseneck hitch ball 10 when installed into the socket 18A, 18B of the towing vehicle, the head 30 includes an arrow 36 which when installed points toward the front of the towing vehicle. A grease zerk 38 is included to lubricated the pivoting motion of the head 30 relative to the base 20. A compressible insert 40 is placed into a pocket 42 defined between the base 20 and the head 30. The compressible insert 40 is made of a polymer material which can compress significantly more than the metal material of the base 20 and the head 30. For instance, the compressible insert 40 can be about one inch thick and formed of durometer Shore 95-100A polyurethane, while the base 20 and the head 30 are formed of 5140 steal heat treated to 24-28 Rockwell C. In the preferred embodiment as shown in
The shape of the shank 16 allows the removable gooseneck hitch ball 10 to be retrofit and used with existing gooseneck hitch sockets in the field, including with both the most common socket 18A of CURT and the most common socket 18B of B&W.
The preferred embodiment has four arc surfaces 50 and four flat surfaces 52, with the four flat surfaces 52 defining a square. The preferred cross-sectional shape can thus be referred to as a “squircle”, combining a square and a circle. The intersecting edges between the arcs 50 and flats 52 define eight vertically extending edge lines 54 visible on the contact surface 48 of the shank 16; these eight vertically extending edge lines 54 will take the most load as the direction of the towing force changes during towing, as the vehicles accelerate and decelerate and proceed around corners. The squircle shape and size was chosen to correspond with a combination of the square (2.5×2.5 inches) cross-sectional shape of the common existing B&W shanks and the circle (2.75 inch diameter) cross-sectional shape of the common existing CURT shanks, with the eight edge lines 54 located at the eight intersection points when a 2.5×2.5 inch square is overlaid on a 2.75 inch diameter circle. The squircle shape should make significant contact with both square and circular sockets 18A, 18B, such as four contact areas (either 50 or 52) each having contact lengths of at least ½ inch circumferentially, and more preferably four contact areas (either 50 or 52) each having contact lengths of at least 0.8 inches circumferentially. The significant contact lengths help transfer the variable loads placed on the ball 12 during towing between the shank 16 and its socket 18A, 18B. The most preferred squircle shape includes four flats 52, each having a contact length of 28.5 mm when used with the common existing B&W socket 18B, as well as four arcs 50, each making a contact length of 25.1 mm when used with the common existing CURT socket 18A. Other embodiments could have the flats arranged in a rectangle with a different length and width rather than a square, allowing mating into a rectangular cross-sectioned socket (not shown). Similarly, other embodiments could have a different number of arcs and flats, such as having three flats arranged in a triangle, five flats arranged in a pentagon, or six flats arranged in a hexagon, for use with differently shaped sockets (not shown). The key aspect is that the shank 16 can mate into cylindrical sockets 18A or into prism shaped sockets 18B at the election of the user, in situations where just matching the size/shape of the cylindrical shape would not fit into the size of the prism shaped socket and just matching the size/shape of the prism shape would not fit into the size of the cylindrical socket. The characteristic shape of the shank 16 thus allows a single product to be used with more sockets than the prior art would allow.
The shank 16 needs to be long enough in the vertical direction both to withstand the towing moments placed on the ball 12 and to receive whatever securing structure is provided by the sockets 18A, 18B in which the removable gooseneck hitch ball 10 is used. For instance, the shank 16 should be at least 3 inches in length, with the preferred embodiment having a shank length sl of 121.7 mm. The preferred shank 16 has three transverse through-holes 56A, 56B, 56C, each 17.5 mm in diameter. As shown in
On one side of the bottom through-hole 56C, an additional vertical recess 58 is provided. As shown in
The bottom of the shank 16 is configured for optionally adding a two-piece adaptor 46 shown in
Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention. In particular, all of the dimensions and materials, unless included in the claims, are exemplary only.
The present application claims priority from U.S. Provisional Application No. 63/331,986 entitled REMOVABLE GOOSENECK HITCH BALL filed Apr. 18, 2022, incorporated herein by reference.
Number | Date | Country | |
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63331986 | Apr 2022 | US |