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1. IN1563/CHENP/2005 - CLAMP FOR FASTENING AND CONNECTING TUBES

Note: Texte fondé sur des processus automatiques de reconnaissance optique de caractères. Seule la version PDF a une valeur juridique

[ EN ]
The present invention is concerned with a clamp for attaching and joining of tubes: in particular, for fixing a tube for connection to a heat exchanger provided in an automotive vehicle.Figs. 5 through 7 show a conventional tube 101 in assembled condition serving for interconnecting two tubes 102. 103 of a heat exchanger in an automotive vehicle. One of the said tubes 102, at the end thereof, is provided with a first flange 104 while the second of said tubes 103 slightly telescoped within the said first tube 102 and somewhat spaced from the end thereof, is provided with a circumferential bead forming a second flange 105 which is of smaller outer diameter than the said first flange 104, Clamp 101 is a punched bending portion made of sheet metal and being of a symmetrical configuration. Clamp 101 comprises a plurality of bent tongues 106 and two slots 107 extending in the longitudinal direction of the clamp 101, provided in the end area 108 of clamp 101 for positioning clamp 101 and for compressing the two tubes 102.103, For the purpose of simplifying the assembly, clamp 101. in each case, has an inlet slant 109 formed in the end area 108. Moreover, all edges are rounded off to secure a better handling. Although it is easy to handle a clamp of this type, it is subject to further improvement with a view to misuse, such as inadvertent withdrawal of the clamp.It is the object of the invention to provide an improved clamp for fixing and joining of tubs.This problem, in the practice of the invention, is solved by a clamp comprising the features of claim 1. Advantageous embodiments are described in the dependent claims.The invention provides for a clamp for attaching and interconnecting of tubes wherein at least one end area of the clamp is bent back: with the clamp embracing both tubes preferably slightly telescoped, and the bent-back end area, preferably being in abutment with the outer cylindrical surface of a flange of at least one of the tubes to be joined. The clamp, despite an inlet slant reduced compared to the verified state of art, is easily mounted on and caught within the pre-positioned tubes. Due to the fact that the end area protrudes outwardly to a lesser degree, the clamp is not easily seized or removed thus being less vulnerable to inadvertent use. Moreover, the end area of the bent end of the clamp is supported on the flange or on the bead of the tube, clawing on the tube once removal of the clamp is attempted, thereby hampering its removal by inadvertence.Preferably, the clamp, in the bent-back end area thereof, in particular, in the flange-abutment area, comprises a sharp-edged rim. Once the clamp is caught, during the assembling process, in its end position, preferably a slight plastic deformation of the flange in view of the engagement of the sharp edge will occur, i.e. the clamp firmly "clings" to the flange. For safety enhancing purposes with a view to non-authorized removal, no or, at best, one outwardly projecting tongue is provided on the clamp, thereby rendering difficult the removal thereof for lack of any points of attack.Preferably, the end areas of the clamp are bent back so as to form an approximately rounded-off triangle, with none of the angles of the triangle, preferably, being in excess of 90°. Preferably, the triangle is of the isosceles type, i.e. all angles are in the range of about 60° H-/-10°. The triangles are formed in a plane normal to the transverse axis.Preferably, a slot is provided in the region of at least one end area of the clamp, that extends in longitudinally of the clamp. At least one of the said flanges is accommodated within the said slot, securing correct positioning of the clamp. The slot, preferably, extends across two sides of the corresponding triangle, terminating approximately in the area of the radially outermost corner of the triangle.The clamp, preferably, is substantially in symmetry with a transverse axis, i.e. it is readily possible also to provide a non-symmetrically arranged member, such as a tongue: however, the end areas are formed mirror-invented, with the transverse axis, in assembled condition, extending in parallel to the longitudinal axis of the tubes to be interconnected and blocked.The invention will now be described in greater detail relative to one example of embodiment with reference to the drawing, wherein Fig. 1 shows a clamp of the invention;Fig. 2 shows the clamp of Fig, 1 in assembled condition:Fig. 3 is a schematically shown plan view of the assembled clamp of Fig. 2;Fig. 4 is a centrally cut view of a detail of the clamp according to Fig. 1;Fig. 5 is a view of a state-of-the-art clamp corresponding to Fig, 1;Fig. 6 is a view of the conventional clamp of Fig. 5 in assembled condition; andFig. 7 is a schematically shown plan view of the conventional clamp shown inassembled condition, corresponding to Fig. 6.A clamp 1 of the invention of the type as shown in Figs. 1 through 4. especially serves for interconnecting two tubes 2 and 3 or one tube and a connector of an automotive heat exchanger, wherein one of the tubes 2, in accordance with the verified state of art, at the one end thereof, is provided with a first flange 4, while the second tube 3 slightly telescoped within the said first tube 2 and slightly spaced from the end thereof, is provided with a circumferential bead forming a second flange 5, which is of an outer diameter smaller than that of the said first flange 4,Clamp 1 is substantially in symmetry relative to the transverse axis, with the transverse axis extending, in assembled condition, in parallel to the longitudinal axis of the tubes 2, 3 to be interconnected and blocked. Clamp 1 comprises a plurality of tongues 6 that are bent, serving for positioning and fixing the tubes 2, 3, Moreover, formed in symmetry relative to the transverse axis, are two slots 7 extending in the longitudinal direction of clamp 1 and are provided in the two end areas 8 of clamp 1. The said slots 7 embrace the first flange 4. serving for positioning and fixing clamp 1 relative to tube 2.In view of the symmetrical configuration only one end area 8 of clamp 1 will be described hereinafter. The end area 8 of clamp 1 is bent back as shown in Fig. 4, with the end area 8 being approximately in the form of a rounded-off right-angled triangle. Slot 7 extends across two of the three sides of the triangle, terminating approximately in the outermost comer, viewed in the radial direction. The end 10 of clamp 1 is bent so as to be in abutment with one edge thereof with flange 4 (s. fig. 3). The edge is of a sharp-edged configuration so that a plastic deformation of flange 4 is likely to occur during assembly-such that clamp 1 "firmly clings". However, the other edges of clamp 1 are rounded off securing easier handing thereof.To facilitate the assembly, a slight inlet slant 9 is provided on the radically inner side of the triangle formed by end area 8.For the puq^oses of assembly, tubes 2 and 3 will be positioned, with clamp 1 pushed there above in clip-type manner. To test the joint, the withdrawal force is checked by a (pulling) mandrel 11 as shown, in Fig. 3. LIST OF REFERENCE NUMERALS1,101 clamp 2. ] 02 rube3.103 tube4.103 flange5.103 flange 6., 106 tongue7.107 slot8.107 end area9.107 inlet slant10 end11 (pulling) mandrel