DEVICE FOR FASTENING A LOAD CARRIER

Abstract: A device for fastening a load carrier on a ball hitch (1) on a vehicle has a base portion (4) and a locking portion (5) each with an engagement member (6 and 7, respectively) designed so as to surround the ball of the ball hitch (1). The base portion (4) and the locking portion (5) are pivotally (12) connected at their one ends and have, at their other ends, a clamping device (14, 15, 18, 19) which, on activation, presses the base portion (4) and the locking portion (5) towards one another. The engagement members (6, 7) are located in the central region of the base portion (4) and the locking portion (5). The base portion (4) has anchorages for the load carrier while the locking portion (5) has a pivotal operating arm (20) for the clamping device (14, 15, 18, 19).

Description: DEVICE FOR FASTENING A LOAD CARRIER TECHNICAL FIELD The present invention relates to a device for fastening a load carrier, such as a cycle bracket, on a ball hitch of a vehicle, comprising two engagement members of which at least one is of a shape at least partly surrounding the ball of the ball hitch and possibly also its shaft, and which are positionally fixingly tightenable from opposing directions about the ball by means of a clamping device. BACKGROUND ART A device of the type mentioned by way of introduction is shown in Swedish Registered Design No. 40371. This device is designed as a cycle bracket which is clamped in place on the ball of the ball hitch of a vehicle. The cycle bracket according to this Registered Design has two annular engagement members which are secured in the lower ends of two rods disposed approximately in the shape of a V, the rods having a connecting link just above the engagement members and further having, a distance above this connecting link, a clamping device in the form of a knee joint. By depressing the knee joint, the upper portions of the rods are displaced away from one another, for which reason the portions of the rods located beneath the link are clamped about the ball of the ball hitch by the engagement members. The construction according to this Registered Design functions satisfactorily but is of limited flexibility in its application since it can hardly be employed as a general anchorage or fastening device for mounting different types of load carriers. The reason for this is that there is no stationary part in which the load carrier in question could be fastened. An additional element of risk in the device according to the Registered Design resides in the fact that the annular engagement members can damage the ball of the ball hitch by linear contact therewith. The device according to the Registered Design also lacks the possibility of after- adjustment to counter wear on both the engagement members and the ball of the ball hitch. A construction of similar type is disclosed in Danish printed application No. DK-B-148531. In the construction according to this publication, the engagement members are divided into three, with an upper portion which, in approximately hemispherical fashion, surrounds the upper half of the ball of the hitch, while the lower parts of the engagement members are designed as two clamping jaws movable in a direction towards and away from one another and grasping, from the sides, about the lower half of the ball of the hitch and a portion of its shaft. Otherwise, the construction coincides with that according to the above-considered Registered Design. PROBLEM STRUCTURE The present invention has for its object to realize a device of the type mentioned by way of introduction, the device being designed in such a manner as to obviate the drawbacks inherent in the above-considered prior art constructions. The present invention further has for its object to realize a device which, fastened on the ball of the hitch, may constitute an adapter for mounting different types of load carriers. Furthermore, the present invention has for its object to realize a device which is theft-proof, is simple and economical in manufacture and permits after-adjustment to counter wear and dimensional tolerances and which, finally, makes for convenient operation. SOLUTION The objects forming the basis of the present invention will be attained if the device intimated by way of introduction is characterized in that the engagement members are disposed one each on a base portion and a locking portion; that the base portion and the locking portion are pivotally interconnected with one another at their one ends; that the clamping device is located at their other end while the engagement members are disposed between the ends; and that at least one of the base portion and the locking portion has at least one anchorage for fastening the load carrier proper. In one preferred embodiment, it also suitably applies that the base portion is provided with the anchorage for the load carrier while the locking portion is provided with an operating mechanism for the clamping device. Further advantages will be attained if the subject matter of the present invention is also given one or more of the characterizing features as set forth in appended Claims 1 to 8. BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS The present invention will now be described in greater detail hereinbelow, with particular reference to the accompanying Drawings, in which: Fig. 1 shows the subject matter of the present invention seen from the side, mounted on the ball of the ball hitch of a vehicle; Fig. 2 shows the subject matter of the present invention seen straight from behind, mounted on the ball of the ball hitch of a vehicle; Fig. 3 is a top plan view of the subject matter of the present invention in the locked state, certain interior parts having been intimated by broken lines; and Fig. 4 is a top plan view of the subject matter of the present invention in a partly opened position. DESCRIPTION OF PREFERRED EMBODIMENT In Fig. 1, reference numeral 1 refers to a ball hitch on a vehicle. The ball hitch has a downwardly directed shaft 2 which is secured in a beam 3 which extends out in a direction rearwardly from the rear end of the vehicle. The ball hitch has standardized dimensions, but the remainder of its detailed appearance may vary from vehicle to vehicle. The fastening device or adapter according to the present invention comprises two major components, viz a base portion 4 and a locking portion 5. Both the base portion and the locking portion are in the form of short pieces of U-beams which, in Fig. 1, are seen from the one short end. The longitudinal direction of the base portion and the locking portion 5 thus extends transversely of the direction of travel of the vehicle. For cooperation with the ball hitch 1 , both the base portion and the locking portion have engagement members 6 and 7, respectively. These engagement members are preferably designed as mutual mirror images of one another and partly surround the ball of the hitch 1. Hereby, the engagement members are In the form of cup-shaped depressions in the web portions 8 and 9, respectively of the base portion 4 and the locking portion 5, these cup-shaped formations having an inner defining surface which is substantially complementary ' to the surface of the ball of the hitch 1 and preferably also the upper portion of the shaft 2. Given that the engagement members 6 and 7 thus at least partly surround the ball of the hitch 1 and a part of the shaft 2 with surface contact from opposing directions, there will be obtained, when the base portion 4 and locking portion 5 are forced towards one another, a reliable fastening of the device according to the present invention on the ball of the hitch. The only movement which is technically possible between the ball hitch and the fastening device is a twisting about the substantially vertical centre line of the shaft 2 and the ball hitch 1_ With sufficiently great clamping force between the base portion and the locking portion, there will, however, be achieved such a high level of friction between these parts and the ball hitch that even this twisting movement is precluded. As is clearly apparent from Figs. 1 and 3, the base portion and the locking portion 4 and 5, respectively, have mutually facing lugs 10 and 11 which are interconnected with one another via joints 12 so that these parts are pivotal about an axis which, in the operative position, is substantially vertical and preferably approximately parallel with the vertical centre axis of the ball hitch 1 and the shaft 2. It is principally 'apparent from Figs. 3 and 4 that the joints 12 are located laterally as far out as possible from the centre of the ball hitch 1. At the opposite end of the base portion 4 and the locking portion 5, there is disposed a clamping device 13 which acts between these portions and which, in " its activated, locked position, powerfully draws the base portion and the locking portion towards one another so that extreme clamping force is generated against the ball hitch 1 and preferably also against the upper portion of the shaft 2. The clamping device 13 comprises a bolt 14 extending in the vertical direction and pivotally secured in the shanks of the base portion, in which bolt a drawbar 15 is anchored and directed towards the locking portion 5. In this instance, the drawbar 15 extends in the locked position through recesses 16 and 17 in the web portions 8 and 9, respectively, of the base portion 4 and the locking portion 5. The drawbar 15 has a threaded end portion which engages in an anchorage portion 18 in the form of a pivot pin whose two opposing ends are accommodated in an excenter device 19. The excenter device includes two cam portions or excenter portions 19 which, in the locked position, urge against the web portion 9 of the locking portion. The excenter portions 19 are united via a handle 20 which also serves as an operator for pivoting or operating the excenter device. In Fig. 3, the handle is shown in the closed position, where it is located with its main part in between both shanks of the web portion 5. In Fig. 4, the handle 20 is pivoted approximately 90° in a clockwise direction (the opening direction) so that the excenter portions 19 have become disengaged from the web portion 9 of the locking portion. In this position, the excenter device can be pivoted in a clockwise direction about the bolt 14, the drawbar 15 being pivoted out of the two recesses 16 and 17 in the web portions 8 and 9, respectively. Once the excenter portions 19 have been pivoted completely free from the locking portion, the locking portion can be pivoted in a counterclockwise direction with the aid of the joints 12 so much that the fastening device can be removed entirely from the ball hitch, or conversely be placed over the ball of the hitch before the locking portion 5 is once again pivoted in the opposite direction for mounting and the drawbar 15 is once again inserted in the recesses 16 and 17. It will be apparent from the foregoing discussion that the engagement members 6 and 7 are placed between the joints 12 and the clamping device 13 preferably approximately mid-between them. The device according to the present invention has been described above as a fastening device, for example for fastening a cycle bracket. Such cycle brackets include downwardly directed tubular parts which may be fastened in anchorages 21 in the base portion 4. In Fig. 2, both of the downwardly directed tubes of the cycle bracket are intimated at reference numeral 22. The anchorages 21 include suitably shaped holes in the upper shank of the base portion 4. Corresponding, but smaller holes for accommodating pin shaped projections on the lower ends of the tubes 22 may also be provided in the lower shank of the base portion, but it is naturally also possible to place suitable accommodation spaces, sleeves or the like interiorly between the shanks, these spaces or sleeves laterally guiding both of the tubes 22 of the cycle bracket. Regardless of the detailed design of these anchorages, It is assumed that the tubes 22 are downwardly dispiaceable in the anchorages to a certain depth and that further downward movement is prevented by suitable abutments. In order to prevent the tubes 22 from being - either unintentionally or in connection with attempted theft - lifted up from the anchorages, locking means are provided in the form of pins 23 which, in locked positions, extend in inside the contour of the anchorages 21 and which are hereby intended to extend through corresponding openings in the tubes 22 so that these are impeded from both rotating and lifting. The pins 23 can, in one embodiment, be secured on the handle 20 so that they are movable together with the handle in a pivotal, movement. This implies that, when the handle 20 has been opened only partly, the pins 23 will have been brought out of the locking position in the anchorages 21 , but the excenter portions or cam members 19 still lie in full engagement against the web portion 9 of the locking portion so that the fastening device according to the present invention still rests positionally fixed on the ball hitch 1. In this position, it is thus possible to dismount and mount the load carrier, for example a cycle bracket, which the fastening device is temporarily intended to carry. It is further apparent from Figs. 2 and 3 that the end of the handle 20 located a distance from the excenter device has a key lock 24 by means of which the free end of the handle can be locked fixedly in the locking portion 5, preferably in a tongue 25 which is punched out from the web portion 9 thereof. One drawback inherent in prior art designs and constructions has been the risk that the annular and sharp-edged engagement members might damage the surface of the ball hitch 1. By designing the engagement members 6 and 7 as cup-shaped formations which are preferably in surface contact against the ball hitch 1 , this element of risk is eliminated. Another drawback, namely the unavailability of after-adjustment, is also readily obviated according to the present invention, in that the drawbar 15 is threaded so that its effective length may easily be adjusted in dependence upon wear to the engagement members, the ball hitch, the excenter portions 19, the joints 12 and possibly also to the web portion 9 of the locking portion 5. Thus, it is a simple matter, by turning the drawbar, to set the abutment pressure between the engagement members and the ball hitch at such a level as affords a secure and reliable fastening on the ball hitch. DESCRIPTION OF ALTERNATIVE EMBODIMENTS In the foregoing, it has been presupposed that the pins 23 are secured on the handle 20. However, this is not necessary according to the present invention, since the pins may easily be disposed to be displaceable transversely, or preferably normal to the web portion 9 of the locking portion 5, for example under spring loading in suitably designed sleeves in which the spring loading strives to lift out the pins 23 from the anchorages 21. The length of the pins is, in such instance, adapted so that their ends facing away from the anchorages will come into abutment against the handle 20 when this is located in the final phase of its closing movement, whereby the pins 23 are forced in against the spring action, into the anchorages 21 during the final phase proper of the closure of the handle. According to the present invention, the key lock 24 need not be disposed in the handle 20. Instead, the handle may be rendered somewhat longer in the vertical direction and be designed in such a manner that it can be enclosed behind a protective cover which can either surround the shanks of the locking portion or extend in between them. This protective cover is then in turn fixedly lockable by means of a key lock in the locking portion 5 and enclose the operating device. In the alternative with the protective cover, the arrangement with the pins 23 may follow that described above, but it is also possible to make the pins longer and cause their ends facing away from the anchorages 21 to extend through corresponding apertures in the handle so as to be affected by the protective cover. In the alternative with the protective cover, it is also possible to replace the above-described clamping device with the excenter portions 19 and the handle 20 by a conventional bolt joint which draws the locking portion 5 and the base portion 4 towards one another. Such a bolt joint would, in its simplest design, entail that the thread on the drawbar is extended and that the drawbar is provided with a washer and a suitable nut for urging against the web portion 9 in the locking portion 5. Another alternative would entail that the counterpart to the drawbar quite simply extended through suitable apertures, possibly slot-shaped, like the apertures 16 and 17 in the web portions of the base portion and the locking portion. No matter how such a bolt joint is arranged, it is, nevertheless enclosed by the protective cover so that operation of the bolt joint is made impossible when the protective cover is locked in place. Even if the location of the anchorages 21 in the base portion 4 entails advantages inasmuch as the anchorages are always disposed at the same mutual spacing, it is, naturally, also possible to place an anchorage in the base portion and one in the locking portion. If, for example, particularly heavy loads are to be carried, it may also be possible to employ two anchorages in each of the base portion and the locking portion. According to the invention, it is also possible to design the fastening device to be asymmetric so that, for example, the clamping device is located on the same side of the engagement members 6 and 7 as the joints 12. Furthermore, a construction is conceivable in which the joints 12 are placed relatively close to the engagement members 6 and 7 while the clamping device is placed outside the joints and consists of a pressure mechanism which forces the base portion 4 and the locking portion 5 from each other. Even if the above-described embodiment of the engagement members 6 and 7 is advantageous, it is possible to dispense with the cup-shaped formations in the web portions 8 and 9 and replace them with corresponding apertures whose edges will abut against the ball hitch and its shaft. In order to reduce the risk of damage to the ball, it is appropriate to shape the edges of the openings to be complementary to the shape of the ball so that band-shaped contact surfaces are created rather than linear contact surfaces. Above, the fastening device according to the invention has been described as an adapter which serves for fastening and carrying, for instance, a cycle bracket. Of course, this adapter may also be employed for fastening and supporting other types of loads carriers, for example a load platform, a load board, an upright ski bracket or the like. This latter field of application may be particularly attractive if the device according to the invention is employed on a vehicle of the bus type. Further modifications to the subject matter of the present invention may be made without departing from the spirit and scope of the appended Claims.

Claims: CLAIMS 1. A device for fastening a load carrier (22) such as a cycle bracket, on a ball hitch (1) of a vehicle, comprising two engagement members (6, 7) of which at least one is of a shape at least partly surrounding the ball (1 ) of the ball hitch and possibly also its shaft (2), and which are positionally fixingly tightenable from opposing directions about the ball hitch by means of a clamping device (13), characterized in that the engagement members (6 . 7) are disposed one each on a base portion (4) and a locking portion (5); that the base portion (4) and the locking portion (5) are pivotally (12) interconnected with one another at their one ends; that the clamping device (13) is located at their other end, while the engagement members (6, 7) are disposed between the ends; and that at least one of the base portion (4) and the locking portion (5) has at least one anchorage (21) for fastening the load carrier (22). 2. The device as claimed in Claim 1, characterized in that the base portion (4) is provided with the anchorage (21) for the load carrier (22), while the locking portion (5) is provided with an operating device (20) for the clamping device (13). 3. The device as claimed in Claim 1 or 2, characterized in that the operating device (20) is lockable (24) In order, in a locked position, to prevent operation of the clamping device (13). 4. The device as claimed in Claim 1 or 2, characterized in that the locking portion (5) has a lockable safety device which, in the locked position, is operative to prevent access to the operating device (20). 5. The device as claimed in any one of Claims 1 to 4, characterized in that the anchorage (21) is disposed for releasable fastening of the load carrier (22); and that there is provided for the anchorage (21) a locking member (23) which is switchable between a locked position in which the load carrier (22) is fastened, and an unlocked position in which the load carrier (22) is releasable from the anchorage (21 ). 6. The device as claimed in Claim 5, characterized in that the locking device (23) is maneuverable between the unlocked and the locked position by means of the operating device (20) or the safety device. 7. The device as claimed in any one of Claims 1 to 6, characterized in that the clamping device (13) includes a drawbar (15) secured in the base portion (4), the drawbar being, with a threaded portion, adjustably secured in an anchorage portion (18) pivotal in an excenter device (19), the excenter device being, with a substantially excentric locking surface, in abutment against the locking portion (5) in order, on rotation, respectively to clamp and release the locking portion (5) and the base portion (4) to and from one another, respectively, the operating device (20) being a handle which is connected to the excenter device (19) for pivoting thereof. 8. The device as claimed in any one of Claims 1 to 6, characterized in that the clamping device (13) is a screw disposed between the base portion (4) and the locking portion (5) respectively for clamping and releasing the base portion (4) and the locking portion (5) to and from one another, respectively, the screw having an operating device designed for cooperation with a twisting tool.

Inventors: FISCHABER BENGT, FISCHABER, BENGT
Applicants: THULE IND AB, INDUSTRI AB THULE
Application year: 1992
Main classification: B60R9
IPC codes: B60R9