LINKAGE, PARTICULARLY FOR CLIMATISING AIR DELIVERY OUTLETS OF MOTOR VEHICLES

Abstract: This linkage of the toggle joint type, comprises a first and a second linkage member (16, 17) of a mouldable thermoplastic material which are connected to each other through a hinge joint (18) formed as a strip of plastic materi­ al, integral with the linkage members. The hinge joint strip (18) is located at the relative rotation axis of the linkage joint, while, to relieve the strip of stresses tending to tear it, the position of this axis is defined by mutually interleaved guide members (19, 20) with the shape of an arc of a circle having its centre of curvature on the relative rotation axis between the two linkage members. This linkage is therefore simple and cheap both in construction, with regard to the moulding process, and in assembling, as it requires de­ creased labour times.

Description: "LINKAGE, PARTICULARLY FOR CLIMATISING AIR DELIVERY OUTLETS OF MOTOR VEHICLES" This linkage, particularly for climatising air delivery outlets of motor vehicles is adapted for deflecting mechanical controls in general, and specifically controls for opening and closing throttle valves to cut off and throttle the air flow in delivery outlets for the climatizing air of motor vehicles. Taking the steps from the consideration that nowadays all the elements in a kinematic train for deflecting a control as specified are formed from a hat moulded plastic material, the invention is directed to provide a toggle type linkage configured to afford -- through the utilisation of the properties of said material -- a great simplification both in construction, as regards the moulding process, and in assembling, as regards decreased labour time; the whole with a significant economical advantage. Another important object of this invention is to provide an improved linkage from the functional standpoint, especially as regards smoothness of the control and reliability in operation,said control being completely free of jams even without any lubrication. To achieve these objects, and others which will be apparent from the detailed description that follows, the linkage according to the present invention is characterized in that it comprises first and second linkage members, both of a hot mouldable thermoplastic material, said members being mutually interconnected with the interposition of a hinge joint formed of a strip of a plastic material integral with both members and located at the axis of relative rotation between said members, the position of said axis being defined by mutually interleaved guide members having the profile of an arc of a cirlce with its centre of curvature on said relative rotation axis. Advantageously, according to the invention, the cooperating guide members comprise a lug in the form of an arc of a circle carried on a linkage member which penetrates a notch with a corresponding curvature carried on the other linkage member. Further features and advantages will be apparent from the detailed description that follows, with reference to the accompanying drawings, where: Figure 1 is a part-sectional view of a delivery outlet for the climatising air incorporating the toggle type linkage according to the invention; and Figure 2 is an elevational detail view of the members which make up the linkage and their mutual connection. In the drawings 10 designates the bin of a delivery outlet for the climatising air in motor vehicles, having a front base 11 whence a side half-disk 12 projects for controlling an airflow cut-off and/or throttling throttle valve 13 to cmen and close. The half-disk 12 has a portion 12a of crank-like configuration to the end of which a toggle linkage 14 is articulated which is adapted to transmit the angular displacements of said half-disk toward the pin 15 of the throttle valve 13. According to this invention, the toggle linkage 14 (Figure 2) is composed of a first linkage member 16 and a second linkage member 17 both formed from a mouldable thermoplastic material advantageously selected from the group including polypropylene homopolymer and the thermoplastics known under the trade name of "NYLON". Between said first and second linkage members there is interposed a swivel joint comprising a strip of a plastic material 18 integral with both members. Preferably, the strip 18 is made of the same material as the members 16,17. The strip 18, which is moulded with the members themselves, serves as an articulation hinge between the members of the toggle linkage and is located at the virtual axis of relative rotation between said members. The position of said axis is defined and held unchanged -- for the purpose of relieving the strip 18 of stresses tending to tear it - by cooperating guide members, in mutually interleaved relationship. Such members advantageously comprise a lug 19 in the form of an arc of a circle carried on the member 16 which penetrates a notch 20 with a corresponding curvature, carried on the other member 17 of the linkage. As clearly shown in figure 1, the centre of curvature of said lug and notch cooperating together is located on the virtual hinge axis coinciding with the neutral axis of the strip 18. The thickness of the latter is commensurate to the material selected and is in the range of 3 to 10 tenths of a millimetre.

Claims: CLAIMS 1. A linkage, particularly for climatising air delivery outlets of motor vehicles, characterized in that it comprises first and second linkage members (6,17), both of a mouldable thermoplastic material, said members being mutually connected with the interposition of a hinge Joint (18) formed of a strip of a plastic material, integral with both members and, located at the axis of relative rotation between said members (16,17), the position of said axis being defined by mutually interleaved guide members (19,20) having the profile of an arc of a circle with its centre of curvature on said relative rotation axis. 2. A linkage according to Claim 1, characterized in that the cooperating guide members comprise a lug 09) configured as an arc of a circle and carried on one linkage member (16), which penetrates a notch (20) of corresponding curvature carried on the other linkage member (17). 3. A linkage according to Claims 1 and 2, characterized in that the axis of relative rotation between said linkage members (16,17) coincides with the neutral axis of said strip forming the swivel hinge (18). 4. A linkage according to the preceding claims, characterized in that the thickness of the strip forming the swivel hinge is in the range of 3 to 10 tenths of a millimetre.

Inventors: FOGGINI, PAOLO
Applicants: FOGGINI PROGETTI S.R.L.
Application year: 1985
Main classification: B60H1
IPC codes: B60H1, F24F13