Pipe joints or couplings – Essential catch – Leaf spring
Reexamination Certificate
1998-12-18
2001-12-11
Luu, Teri Pham (Department: 3627)
Pipe joints or couplings
Essential catch
Leaf spring
C285S921000
Reexamination Certificate
active
06328349
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a separable pipe joint, in particular a separable pipe joint for air-conducting pipes.
BACKGROUND INFORMATION
A pipe joint is disclosed in European Patent No. 04 52 172 B1. The pipe joint, in which two adjacent pipe segments are tightly joined together, contains a collet which embraces the pipe segment ends that fit into each other. In order to prevent an unintended axial separating of the joint, lugs are formed on the collet extending radially inward, which extend into latching recesses provided on both pipe ends. The latching recesses consist of a peripheral detaining groove in the area of the first pipe end and a latching opening in the area of the second pipe end. It is necessary to line up the detaining groove and the latching opening so that the lug of the collet can extend through the latching opening into the detaining groove and so that the two pipe ends are held together in a form-locking fit.
Consequently, it is problematic that a reliable joint can only be produced when the latching opening and the detaining groove are lined up radially and axially; otherwise, no form-locking fit and consequently no reliable joint in either axial direction of the pipe segments is produced. As a result, not only the axial but also the radial assembly positions of the pipe segments are stipulated in the design and must be observed during assembly. Particularly with curved pipe segments, this joint demands a high degree of manufacturing precision and accurate positioning of the assembly parts, the radial positions being limited to one or a few specified ones in accordance with the number and distribution of the latching recesses.
A further disadvantage is that the lug must be designed with a length such that it extends through the latching openings of the radial, external pipe segment and can also engage in the detaining groove of the radial, internal pipe segment. But this makes both assembly and disassembly of the joint difficult because the collet must be widened to the point that it can be slipped over the two pipe segments without being hindered by the lug. Due to the rigidity of the collet, it is difficult to greatly widen the collet, which is necessary for the joint. In addition, there is the risk of premature wear as a result of the formation of cracks.
SUMMARY OF THE INVENTION
The present invention provides a separable pipe joint with a low rate of wear, permitting a variable assembly of adjoining pipe segments.
More specifically, the present invention provides a separable pipe joint, in particular for air-conducting pipes, having two pipe segments (
2
,
3
) that can be inserted one into the other and a gasket-seal (
4
) arranged between the pipe segments (
2
,
3
). A collet (
5
), which is arranged so that it can be adjusted between a separated position (
6
) and a clamped position (
7
), and latching means (
8
,
9
) to fix the pipe segments (
2
,
3
) axially also are provided. As the latching means (
8
,
9
), provision is made on the collet (
5
) for at least two latching members (
8
,
9
) extending radially to the inside and set apart axially. The latching members, in the clamped position (
7
) of the collet (
5
), in each case, grip from behind a radially elevated clamping step (
10
,
11
) on the external surface (
12
,
13
) of each pipe segment (
2
,
3
).
Since at least two latching members in two parallel planes are formed on the collet, it is possible to assign each latching member to one of the two pipe segments and thus to keep the connection between one of the two pipe segments and the collet independent of the corresponding connection to the other pipe segment. The consequence of this is that the position of the two pipe segments relative to one another is only indirectly determined by the latching device with the assistance of the collet, so that the angular position of the two pipe segments can be set substantially independent of the geometry of the pipe segments and essentially dependent only on the design shape of the collet. The variability of the pipe segments in assembly is increased.
Furthermore, it is advantageous that, in order to form a form-locking joint, the latching members on the collet only have to grip from behind one clamping step on one of the pipe segments. Therefore, it is sufficient to arrange the latching members radially to the inside only to the point that a secure form-locking fit with the respective clamping step in the axial direction is possible. The latching members do not extend far to the side, so that the collet does not need to be widened much in going from the separated position to the clamped position, and the other way around. Thus the risk of wear is reduced.
If, in accordance with one embodiment of the present invention, the latching members are formed in the area of the axial front ends of the collet, across from each other. One of the latching members can function to guard against loss of the collet in the separated position of the clamp-type latching arrangement, in that this latching member, even in the separated position of the collet, grips the clamping step of one pipe segment from behind, the clamping step extending radially over the external surface of this pipe segment. The collet can be rotated about its axis without being hindered by the clamping step, and an axial displacement is possible in the direction of the pipe end of the connecting piece facing away from the clamping step, but not a displacement beyond the clamping step.
Preferably, provision is made for a plurality of individual latching members, in particular three, in the area of each front end of the collet. These latching members can be distributed equally across the periphery, in each case in a plane that is perpendicular to the pipe axis. This embodiment has the advantage that the clamping forces are transmitted equally over the periphery of the collet and that an incorrect latching of the collet, in which the collet axis runs at an angle to the pipe axis, is avoided.
The latching members opposite the front ends are preferably arranged so as to be displaced one with respect to one from another, in order that across the periphery of the collet an approximately equal distribution of rigidity is achieved in the wall of the collet.
It is preferable that the collet can be elastically widened radially in order to make it possible to thrust the collet over the radially elevated clamping step on the second pipe segment. In this embodiment, a bayonet catch is not necessary. The elasticity in the radial direction is expediently achieved in the design by arranging the latching members on one front end on axially protruding tongues, which can be elastically bent up with little expenditure of force. In addition, provision can be made for axial slip joints in the wall of the collet.
To make it easier to convey the collet into its clamped position, the latching members can be configured so as to be ramp-shaped, as seen in the axial direction, so that during overthrust the latching members are continually bent up and, after reaching the clamped position, snap back into their initial radial position, in which the latching members in a form-locking fit grip the clamping step from behind. The latching members preferably engage in the contact grooves, which are configured on one of the pipe segments and extend radially up to the radius of the clamping step.
In order to make separating the joint easier, one side of the contact grooves is configured as an unlatching ramp, whose gradient intersects the longitudinal axis of the pipe joint. For separating, the collet is rotated so that the latching member is pushed onto the unlatching ramp and effectively reaches the radial level of the clamping step. From this position, the collet can be pulled off axially so that the pipe joint is separated.
REFERENCES:
patent: 4711472 (1987-12-01), Schnell
patent: 4786085 (1988-11-01), Sauer et al.
patent: 5711552 (1998-01-01), Hogue et al.
patent: 5725257 (1998-03-01), Sakane et al.
patent: 5735555 (1998-04-01), Answine et al.
pa
Bandlow Reiner
Blume Gerhard
Coermann Georg
Fischer Jurgen
Haseki Mehmet
Daimler-Chrysler AG
Luu Teri Pham
LandOfFree
Separable pipe joint, in particular for air-conducting pipes does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Separable pipe joint, in particular for air-conducting pipes, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Separable pipe joint, in particular for air-conducting pipes will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2601078