Abstract: A coupling element connects a connection piece with an insertable end of a connection tube having a toroidal flange for contacting the connection piece in the tube inserting direction. A plug-in fork can be inserted into the coupling element to releasably secure the inserted tube end area against the tube inserting direction, with the tube torus held in place by the plug-in fork. For this purpose, pairs of plug-through openings are provided on side walls of the connection piece opposite one another, so that one prong of the plug-in fork can be inserted into each opening. Inserting bevels are assigned to at least a portion of the plug-through openings, which inserting bevels are shaped such that they cause a forced movement of the plug in fork in the tube inserting direction during its insertion in the plug-in fork inserting direction.

Abstract: 1. Heating and/or air-conditioning installation, especially for a passenger compartment of a motor vehicle.2.1 In known installations for heating and/or cooling, hinged flaps are employed as control means for distributing the air, which flaps need a large mounting space.2.2 It is proposed that a mounting frame with hinged or sliding lamellae be inserted into the free cross-sections of each of the channels to be controlled.2.3 Use of the motor vehicle air-conditioning systems.

Abstract: A housing for a heating or air conditioning unit for a motor vehicle is provided, which housing is disposed under the windshield at the middle of the vehicle and includes portions extending adjacent the lower or passenger foot region. This housing is provided with air outlet nozzles for directing warm (or cooled) air into the passenger foot region. The housing includes two upper housing parts separated by a separation plane extending perpendicular to the vehicle travel direction and a lower foot level housing part for the air outlets at the foot level. These three separate housing parts are form fittingly assembled together by slidably interengageable housing parts. With this arrangement, the foot level housing part can be assembled with the other housing parts without the need of additional work tools and is so integrated into the complete housing assembly that, with the slidable connection of the housing parts together, the foot level housing part is also securely and rigidly assembled.