Abstract: In order to test whether a push-fit joint has been correctly assembled, a test device is assembled as part of the joint. The test device is constructed with an included rupturable region which will rupture at a predetermined pull-out force. After assembly of the joint, the test device is pulled. If the joint has been misassembled, then the pull out force will be sufficient to disassemble the joint, but if the joint has been correctly made, then the test device will break at the rupturable point. The absence of the visible end of the test device will then indicate that the joint has been correctly assembled and the assembly has been tested.

Abstract: The invention relates to a filler cap 10 for a fuel tank of a motor vehicle, the mouth of the filler spout 16 of which is arranged in a recess 18 in the vehicle body.The filler cap 10 comprises a body 12 to fit over the mouth of the filler spout 16, and a lock mechanism 16 rotatable relative to the body 12 for locking the filler cap body 10 to the spout 16. A cover plate 20 hinged on the body 12 is pivotable between a first position in which the cover plate 20 is flush with the vehicle body and covers the fuel spout recess 18, and a second position in which access may be gained to the lock mechanism 16.