This invention relates to trailers for cycles, and is particularly concerned with collapsible trailers for cycles.

According to one aspect of the present invention there is provided a collapsible cycle-trailer wherein a chassis of the trailer has two side-wing sections which carry wheels of the trailer and which in the erected condition of the trailer extend outwardly laterally from a central section of the chassis, the side-wing sections for collapse of the trailer folding downwardly of the central section with the wheels folded up and under the side-wing sections such that the trailer is of an inverted-U configuration in its collapsed condition, and wherein means for pivotally coupling the chassis to a towing arm from the cycle is selectively settable with collapse of the trailer to enable the chassis to pivot downwardly relative to the towing arm and thus be drawn upwardly behind the arm when raised for stowing on the cycle in the inverted-U configuration.

The trailer according to the invention is of especial relevance to cycles having two wheels, whether driven by pedal and/or engine, in that the inverted-U configuration of the collapsed trailer allows it to be conveniently stowed on the cycle straddling the rear wheel.

In the latter respect also, and according to another aspect of the invention there is provided a collapsible cycle-trailer coupled to a bicycle or other two-wheeled cycle, wherein a chassis of the trailer has two side-wing sections which carry wheels of the trailer and which in the erected condition of the trailer extend outwardly laterally from a central section of the chassis, the

side-wing sections for collapse of the trailer folding downwardly of the central section with the wheels folded up and under the side-wing sections such that the trailer is of an inverted-U configuration in its collapsed condition, and wherein the chassis is pivotally coupled to a towing arm that is pivotally attached to the cycle at or near the axle of its rear wheel, pivoting, of the arm to move it upwardly and then forwardly over such axle, drawing the collapsed trailer upwardly behind the arm to stow it in the inverted-U configuration straddling the rear wheel of the cycle.

The pivotal coupling between the chassis and the arm in either of the above aspects of the invention may be provided by a coupling joint having two pivot axes at right angles to one another, where a first of the axes provides an axis for movement of the erected trailer in roll relative to the arm. The second axis in these circumstances may be selectively settable with either a substantially vertical orientation for movement of the erected trailer in yaw relative to the arm or a substantially horizontal orientation to provide an axis for pivoting of the collapsed chassis downwardly relative to the towing arm. More particularly, the second axis may be provided by a pivot axle which is carried by a carrier that is mounted for angular displacement about the first, roll axis, and with the pivot axle mounted resiliently on the carrier such as to permit small, heavily damped pitching movements of the chassis relative to the towing arm in the erected condition of the trailer.

The chassis may be of an open-frame construction, and may be, for example, of tubular light alloy.

A collapsible cycle-trailer according to the present invention will now be described, by way of example, with reference to the accompanying drawings, in which:

Figure 1 is illustrative of the trailer when in use in its erected condition, coupled to a bicycle;

Figure 2 is an isometric view of the erected trailer; and

Figures 3 and 4 are side and rear views respectively, illustrating the trailer in its collapsed condition, stowed straddling the rear wheel of the bicycle.

Referring to Figures 1 and 2, the erected trailer 1 is towed behind the rear wheel 2 of the bicycle, being coupled by a forked towing arm 3 that extends either side of the wheel 2. The arm 3 is pivotally clamped to either end of the axle 4 of the wheel 2; as an alternative, for example, it may be correspondingly clamped to the mudguard-anchoring lugs (not shown) that are normally located on the bicycle seat-stay 5 near the axle drop¬ out.

The trailer 1 has a chassis of light-alloy tube comprising a central section 6 and two side-wing sections 7 that extend outwardly laterally from the central section 6. The side-wing sections 7, which are both formed as an open tubular frame with a bounding tube 8 of a C-configuration crossed by a straight, strut tube 9, carry the two trailer-wheels 10. Each wheel 10 is carried at the lateral extremity of its side-wing section 7 on a downwardly-extending flap 11. The flap 11 is clamped to the tube 8 of the respective section 7 in a selectively-rotatable joint 12.

The tubes 8 of the two sections 7 butt up to one another end to end across the central section 6, with the tubes 9

extending parallel to one another longitudinally of the trailer 1. The tubes 9 are held fast spaced apart and parallel by two bent tubes 13 and 14 of the central section 6, being clamped to the ends of the rearmost tube 13 in rotatable joints 15 and to the ends of the tube 14 in rotatable-and-slidable joints 16. The tube 14 extends forwardly from the side-wings 7 and is coupled to the towing arm 3 by way of a universal joint 17.

The central pivot pin 18 of the joint 17, which is clamped by a thumb-screw 19 to the tube 14 with a substantially vertical orientation, is carried by a yoke 20 pivotally mounted on the arm 3. The yoke 20 is mounted on the arm 3 for rotation about a pivot pin 21 which, being aligned substantially horizontally longitudinally of the bicycle, gives freedom for relative roll between the bicycle and the erected trailer. With the central pivot pin 18 of the joint 17 substantially vertical in this condition, there is also freedom for relative yaw, but there is little freedom in the joint 17 for relative pitch. What freedom there is in pitch within the joint 17 arises from resilient mounting of the pin 18 within rubber bushes 22 on the yoke 20, and is heavily damped by the bushes 22.

For collapse of the trailer, the thumb-screw 19 is relaxed to allow the joint 17 to be turned through ninety degrees to bring the pin 18 into a substantially horizontal orientation. The thumb-screw 19 is now tightened to hold the pin 18 with this orientation, and the clamping joints 16 are released. Release of the joints 16 allows the tube 14 to be telescoped into them to reduce the overall length of the trailer 1.

The wheels 10 are next folded up. In this respect the joints 12 on the wheel flaps 11 each involve a spring- restrained pin-and-gate mechanism permitting the flap 11

to be locked to the respective tube 8 either with its wheel 10 vertical for the erected condition of the trailer 1, or folded flat against the underneath of the respective section 7. Thus, by simple manipulation of the joints 12, the wheels 10 can be readily folded up and under the side-wing sections 7 to lie flat with them.

Once the wheels 10 have been folded up, the side-wing sections 7 are folded downwardly of the central section 6 to give the trailer 1 an inverted-U configuration as illustrated in Figures 3 and 4.

Referring now also to Figures 3 and 4, the side-wing sections 7 fold downwardly of the central section 6, about the clamps 15 and 16. However, before this can be done, two slides 23 that in the erected condition of the trailer 1 are active between the pairs of abutting ends of the tubes 8, are to be withdrawn. The slides 23 are located within the two ends respectively of one of the tubes 8, and in the erected condition extend into the respectively abutting ends of the other tube 8, thereby ensuring chassis rigidity. Thumb-screws 24 are carried with the slides 23 and clamp them in the extended state, and as a necessary preliminary to folding the side-wing sections 7 down therefore, the screws 24 are released and moved to retract the slides 23 from engagement.

Once the trailer 1 has been collapsed to the inverted-U configuration, it is ready to be stowed on the bicycle. This simply involves pivoting the arm 3 upwardly and then forwardly over the rear-wheel axle 4. The collapsed trailer 1 is lifted as it is drawn with the arm 3 to straddle the wheel 2 of the bicycle; in order to keep it substantially level for this movement it is pivoted downwardly with respect to the arm 3 about the substantially-horizontal pin 18 of the joint 17. The arm 3 is now secured by a releasable attachment 25 to the

seat stay 5, this being adequate to hold the collapsed trailer rigidly on the bicycle. Pins 26 that project at right angles from the tubes 8 engage frictionally with holes 27 in the arm 3 in the stowed condition, for retaining the side-wing sections 7 flat onto the bicycle.

The stowed trailer is erected simply by following through the steps for collapsing, in essentially the reverse order.

The framework of the chassis of the trailer 1 may be covered, and in this respect the covering may conveniently be with stretched fabric. More particularly, panels of fabric such as a polyamide fabric, may be stretched across the individual sections 6 and 7, or a single panel may be extended across them all, to provide a load-carrying platform for the erected trailer. Also, pannier bags attached to the two sections 7 may be fastened together across the central section 6 in the erected trailer; for collapse of the trailer, the bags may be unfastened from one another, and then as still attached to the sections 7, will form side-panniers of the bicycle.

It is to be noted in the latter respect, and generally, that the outside of the collapsed trailer is the upper surface of the trailer when erected, so that dirty surfaces from the underside of the erected trailer are contained and not exposed in the collapsed condition. Furthermore, it is to be noted that the rear end of the erected trailer remains to the rear in the collapsed and stowed condition; this is of importance from the point of view of ensuring exposure of existing reflectors and other markings or devices that are required by law and/or for safety.