Patent ID: 12222049

DESCRIPTION OF THE INVENTION

An embodiment of a press-fit connection system according to the invention is explained below with reference toFIGS.1to5.

The press-fitting system2for the non-detachable connection of a fitting to a pipe4firstly has a press jaw6which consists of two press jaw halves6aand6bwhich are part of a press tool and are held by retaining lugs8arranged on both sides, see in particularFIGS.3and4. The retaining lugs8have two bores10aand10bin which two shafts12aand12bare arranged to which the two press jaw halves6aand6bare pivotably attached. A further hole14for a fastening bolt15is also provided in the retaining lugs8. The press jaw6is thus designed as a pressing loop which can be pressed together with a pressing tool at the open ends opposite the bore14.

The drive mechanism of the pressing tool is in turn in operative connection with a pressing tool, which in particular has a double roller ram with two rollers. The double roller ram is in particular hydraulically or electrically driven, but the drive can also be realised by a toggle lever. The double roller plunger interacts with an inlet contour formed on the drive mechanism and presses the press jaw halves apart so that the press jaw halves are pressed together in the area of the press contour.

The press jaw6with the press jaw halves6aand6bhas a press contour16on the inside, which initially has a cylindrical press section16a.

Furthermore, the press-fit connection system2comprises a fitting20, wherein the fitting20is formed with a fitting base body22and a press sleeve26comprising a press chamber24. Within the press chamber24, a sealing ring28is disposed at the proximal end30of the press chamber24relative to the fitting base body22, and a cutting ring32is disposed at the distal end34of the press chamber24relative to the fitting base body22. A separating ring36is also arranged between the sealing ring28and the cutting ring32.

Circumferentially flanged sections26aformed at the distal end of the press sleeve26serve to position the elements arranged in the press chamber24.

The cutting ring32has a central cylindrical portion32a, cutting elements32barranged at the distal end and cutting elements32carranged at the proximal end.

The press contour16further comprises a conical distal press section16badjacent to the cylindrical press section16aand a conical proximal press section16cadjacent to the cylindrical press section16a. In this regard, the distal press section16bis configured to reshape the distal end of the cutting ring32radially inwardly during radial pressing of the press sleeve26and thus the press chamber24. The cylindrical press section16ais further configured to radially inwardly form the proximal end of the cutting ring32during radial compression of the press sleeve26, and the proximal press section16cis configured to radially inwardly form the sealing ring28during radial compression of the press sleeve26.

As can be seen fromFIG.1, the distal outer edge32dof the cutting ring32abuts the inner edge24aof the press chamber24and the cylindrical portion32aof the cutting ring32abuts the cylindrical portion24bof the press chamber24. The position of the inner edge24ais thereby distally outside the edge between the cylindrical press section16aand the conical distal press section16bshown by means of the dashed line. Therefore, the distal outer edge32dof the cutting ring32is deformed further radially inwards than the proximal end of the cutting ring32by the press section16adue to the conical shape of the press section16b.

FIG.1shows the state of the press-fitting system2before pressing andFIG.2shows the state of the press-fitting system2and in particular of the fitting20after pressing with the pipe4.

In the radially compressed state of the press sleeve26, the cutting ring32and the sealing ring28as well as the separating ring36are deformed radially inwards and the cutting elements32band32chave partially penetrated the tube4in the region of the cutting edge. Due to the conically formed press section16band the cylindrical press section16a, in the radially pressed state of the press sleeve26, the distal end of the cutting ring32is deformed inwards to a radius smaller than the radius of the proximal end of the cutting ring32. As a result, the distal cutting elements32bhave penetrated deeper into the tube4than the proximal cutting elements32.

InFIG.2, the penetration depths t1and t2of the cutting elements32band32care drawn, and it applies that t1is greater than t2. The asymmetrical radial deformation is also evident from the angle between the cylindrical section32aof the cutting ring32and the cylindrical section24bof the press chamber24.

In addition, due to the design of the cutting elements32band32c, it contributes to the improved holding force in the pull-out direction, to the right inFIGS.1and2. The side of the cutting element32bwith the steep cutting edge directed against the pull-out direction contributes more to the holding force of the joint than the oblique cutting edge of the cutting element32. Due to the tilting of the cutting ring32during pressing and the fact that the steep surface has a small angle to the vertical, there is an additional small force component that pulls the cutting ring32towards the tube4. Additionally, slippage of the cutting ring32has become less likely because the sloping cutting edge of the cutting element32cis more prone to lifting material from the tube4, similar to a plough, as a result of the tilting angle of the cutting ring32.

Overall, this provides a strengthened non-detachable connection between the fitting20and the pipe4, as the cutting elements32bact against the direction of extraction of the pipe4from the fitting20and penetrate deeper into the pipe4than in the prior art.

This becomes clear when comparing the previously described embodiment example of the press-fit connection system2according toFIG.1with the pressed fitting20according toFIG.2with the press-fit connection system2′ known from the prior art and shown inFIGS.6and7.

The fitting20with its elements is identical to the embodiment example according toFIGS.1to5. However, the press jaw6′ has a press contour16′ with only one cylindrical press section16a′, which altogether radially inwardly deforms the press sleeve26and thereby the sealing ring28, the separating ring28and the cutting ring32in the same manner. Therefore, the cutting elements32band the cutting elements32chave penetrated the material of the tube4to essentially the same depth. This is made clear by the penetration depths t1and t2of the cutting elements32band32cshown inFIG.7, which are of the same size.