GB2055140A

GB2055140A - A lockable protective cap for the towing mechanisms on trailers

Info

Publication number: GB2055140A
Application number: GB8020720A
Authority: GB
Original assignee: Granberg O T
Current assignee: Granberg O T
Priority date: 1979-06-29
Filing date: 1980-06-25
Publication date: 1981-02-25
Also published as: SE7905718L; GB2055140B; DE3022986A1; DE3022986C2

Abstract

The present invention relates to a lockable protective cap (20) which may be put over the ball socket (10) on the tow-bar of a trailer vehicle in order to prevent its unauthorised connection to a towing vehicle. The protective cap is made from a length of tube (22), which is fixed securely onto the shanks (34) of a U-shaped bar (32), which, together with a transverse locking housing (30) in which the ends of the shanks are accommodated in a known way, forms a padlock-type of construction. In the locked state the protective cap (20) has a gap (24) between the length of tube (22) and the locking housing (30), through which the lifting and manoeuvring handle (11) of the ball socket (10) projects upwards. <IMAGE>

Description

SPECIFICATION A lockable protective cap for the towing mechanisms on trailers The present invention relates to towing arrangements on trailer vehicles, and more particularly to a lockable protective cap for the coupling element which connects the trailer vehicle to the towing vehicle. The invention constitutes a development and a simplification of the lockable protective cap used for the same purpose, which is described in Swedish Patent .... (Patent Application 77 05 928-5).

As indicated in the above-mentioned Patent, locking arrangements of the type concerned are already known, for example, from Swedish published specification 7302 187-5 and British Patent 1 224940. In addition to the fact that these arrangements leave much to be desired regarding their security against unauthorised engagement, they are difficult to put on and to manipulate, as they consist, in addition to a locking bolt, of at least three parts which are loose or movable relative to each other and which have to be fitted into specific places when the locking arrangement is assembled and rendered effective.

Compared with these earlier arrangements, the lockable protective cap described in the abovementioned Swedish Patent application constitutes a significant advance, in that not only is it simply to manipulate, but it also has a significantly extended protective effect, due to the fact that it prevents access not only to the vital coupling parts of the towing arrangements, but also to at least one part of the screw-connection which normally connects the coupling parts to the tow-bar on the towed vehicle.

Obviously, in this way more complete protection from theft is provided, since it is impossible simply to unscrew the locked towing coupling from the tow-bar, which is a danger which may arise when using the previously-known protective arrangements.

The protective cap according to the Swedish Patent Application has functioned well and reliably in practice, but from the point of view of cost, simplification has proved to be desirable. The aim of the invention is therefore to provide a lockable protective casing for towing arrangements on trailer vehicles which is as effective with regard to protection against theft as the arrangement according to Patent Application 77 05 928-5, butwhich is significantly simpler and therefore cheaper to manufacture than that arrangement. This aim is achieved, and an effective, cheap and easily-managed locking arrangement of the type in question is provided due to the fact that the protective cap according to the invention is endowed with the characteristics indicated in Patent Claim 1.

The invention will now be described by way of example with reference to the attached Drawing, on which Figure 1 shows a perspective exploded view of the parts of a protective cap according to the invention, together with the co-acting, so-called ball socket connected to the tow-bar of a trailer. Figure 2 is a side view of the protective cap shown in Figure 1, mounted on the ball socket.

Figure 1 is thus a comprehensive illustration of the protective cap according to the invention and the co-acting ball socket, which is shown schematically in dashed lines. The ball socket, which is designated 10 as a whole, comprises a housing 12 which is fixed by means of a horizontal bolt 14 and a vertical bolt 15 on the end of a tubular bar 16 which fits into the tow-bar on the trailer vehicle. On the underside the housing 12 has an opening 18 to accommodate a so-called towing ball connected to the towing frame on the trailer vehicle. A locking heel housing inside the ball socket and not shown in detail is designed to engage with the ball, the heel being connected in a known way to a combined manoeuvring and carrying handle 11 on the upper face of the ball socket.

The lockable cap according to the invention, which is designated 20 as a whole, is composed of two main parts, namely, a U-shaped locking bar 32 with an associated, suitably key-operated locking housing 30, and a steel tube sleeve 22. The ends of the shanks 34 of the locking bar 32 are designed to be pushed into and fixed in the locking housing 30. The bar is advantageously made of hardened steel, and together with the associated locking housing 30 forms a unit of the padlock type which is known and well-proven per se, and which is extremely difficult to force orto pick open with unauthorised means, being used successfully, for example, for locking motorcycles. The other main part of the lockable cap, the steel tube sleeve 22, consists quite simply of a cut-off piece of suitable steel tube with standard dimensions.The casing and the shanks 34 of the locking bar 32 are welded together so that the latter extend in the longitudinal direction of the tubular casing. In the embodiment described by way of example the shanks 34 are securely welded to the outside of the casing, but they may just as well be welded on the inside of the casing, if the relative dimensions make this more suitable. The tubular housing 22 is provided with a recess 24 between the end sections of the shanks 34, for a purpose which will become apparent from the following.

In Figure 2 the protective cap 20 is shown in the mounted state on the ball socket 10. As can be seen, the cap has been threaded onto the ball socket from the front, with the locking shanks 34 on either side of the manoeuvring handle 11 of the socket, which projects upwards, still accessible, through the said cut-out 24 in the tubular casing 22. The locking housing 30 has then been pushed onto the ends of the bar under the handle 1 1, as shown in Figure 2, and is locked. The lockable cap 20 is now securely connected to the ball socket 10 and cannot be unlocked from it by unauthorised persons without extensive mechanical intervention.At the same time, the part 26 of the tubular casing 22 which projects out under the cut-out24forms a protective shield overthe fixing bolt 15, and the above mentioned"short-cuttt of releasing the ball socket from the tow-bar is thereby made impossible. Certainly, the primary protective function is fulfilled, namely, to prevent a towing ball from being inserted in the opening 18 of a ball socket without authority.

In the mounted state on the ball socket 10 (see Figure 2), the described embodiment of the protec tive cap 20 comes to rest somewhat at an angle relative to the longitudinal direction of the ball socket and its tow-bar. In orderto line up the two components in a more mutually parallel position, the ends 34 of the locking bar 32 can be bent upwards slightly, and in general the protective cap according to the invention may be adapted particularly simply to the shape of the coupling element involved, which is connected to the trailer vehicle.

As will be appreciated, the lockable cap according to the invention can be manipulated conveniently and, when it is not mounted on the ball socket of a trailer vehicle, it may be transported easily, due to the curved part of the locking bar 32 which acts as a convenient carrying handle.

Naturally, the invention is not limited to the embodiment shown, but further modifications are possible within the scope of the attached Patent

Claims

Claims. CLAIMS

1. A lockable protective cap for the coupling element known as the ball socket in a towing arrangement on a trailer vehicle, this cap being designed to be put on the coupling element to protect it from damage and unauthorised connection, and of the kind comprising a casing for locating over and at least partially enclosing the ball socket which is equipped with a lifting or manoeuvring handle and is connected to the towing arrangement by means of fixing components such as bolts, for example, and also a locking or bolting element designed to co-act with the casing so as to fix it, and with it the protective cap as a whole, on the ball socket in the locked state in which the cap conceals or screens off both the opening provided in the socket for the insertion of the coupling part on a towing vehicle, known as the towing ball, and also at least one of the said fixing bolts, characterised in that the cap consists of a length of tu be, while the locking element consists of a U-shaped bar, the two shanks of which are securely fixed on the piece of tube with the ends of the shanks left free and suitable for insertion in a locking housing and to be secured in it in a known way, for example, with a key-operated bolt mechanism accommodated in the locking housing, there being a cap between the locking housing and the piece of tube to accommodate part of the manipulating handle of the ball socket.

2. A protective cap according to Claim 1 characterised in that the length of tube comprises a piece of steel tube cut-off from a drawn or welded steel tubing of standard type, and in that the U-shaped bar is of hardened steel.

3. A protective cap according to Claim 1 or 2, characterised in that the said space between the locking housing attached to the ends of the bar shanks and the length of tube is formed by a cut-out in the end of the length of tube which is nearest the locking housing in such a way that the end section of the length of tube which is located under the cut-out forms the said shield for the fixing bolt or bolts of the ball socket.

4. Aprotectivecapforthe ball socket coupling element of a trailer towing arrangement constructed, arranged and adapted for use substantially as hereinbefore described with reference to the accompanying drawings.