Abrading – Attachment – To the work
Patent
1997-07-24
1999-08-03
Scherbel, David A.
Abrading
Attachment
To the work
451430, 451440, B24B 2118, B24B 3300, B24B 4726, B24B 5500
Patent
active
059317280
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
The present invention concerns an arrangement for machining a valve seat in a valve housing having a circular opening which is concentric with the seat and about which is disposed a flat annular surface, the arrangement comprising a support, disposed so as to be centred relative to the opening and secured with the valve housing, and a tool pillar which is connected to the support and which, at its distal end, is provided with a machining tool, the support being arranged such that in a direction which, when the arrangement is in use, is perpendicular to the annular surface, it holds the tool pillar such that it can be adjusted in this direction, and the tool is arranged so as to rotate about the tool pillar.
BACKGROUND OF THE INVENTION
An arrangement of this type has already been disclosed by DE-240 420. In this case the support for centring the tool pillar comprises a cone, which is displaceable along the tool pillar and whose tip is directed downwards, and horizontal jaws which cooperate with the conical surface of the cone and which are disposed such that, when the cone moves downwards, they are pressed with very great force against the circular opening in the valve housing in order thus to bring about the desired centring. In order to ensure centring, however, the machining tool has to cooperate with the opening which is delimited by the valve seat. This obviously gives rise to serious restrictions in terms of performance of the machining tool. A further disadvantage is that the cone and jaws with holders therefor render it substantially more difficult to inspect the interior of the valve when the valve seat is being machined.
A further example from the technical point of view is disclosed by U.S. Pat. No. 742 313 and U.S. Pat. No. 4,715,149. In the case of the arrangement according to the fire of these publications, jaws in the form of levers are used to secure and centre the arrangement, the jaws being provided with teeth and arranged so that they are urged outwards against the wall of the valve opening, the wall being provided with a thread.
In the case of further known devices of the above-mentioned type, the support is arranged so as to be secured to the valve housing by means of a mounting plate, or a yoke as in the case of the latter publication. The plate or yoke is secured in different ways depending on the design of the valve housing. If the housing is constructed with screws, they can naturally be used but this assumes that the plate has been provided with bores located such that they match the location of the screws. This presents problems if the instrument is to be used for different valve sizes, in particular if it is considered that the tool pillar below the instrument has to be located exactly in the centre of the opening. The instrument can even be secured by means of chains and belts but this evidently involves a serious risk of unsatisfactory machining results.
A difficult problem is that the machining tool wears down comparatively rapidly, such that the arrangement has to be disconnected from the valve housing so that the tool can be changed. This in turn means that, when the tool has been changed, the arrangement has to be re-aligned accurately relative to the housing and the part thereof to be machined. It is awkward and time-consuming to bring about this realignment with the necessary degree of accuracy, in particular as the known centring and securing members generally cover the entire opening in the housing, which makes it difficult to see thereinto.
SUMMARY OF THE INVENTION
The object of the present invention is to provide an arrangement of the initially mentioned type which enables the above-mentioned disadvantages to be overcome. This object is achieved in that the support comprises firstly a main part with three wings which are uniformly distributed about the tool pillar, in order to bring about at least the centring, and each of which comprises a first wing part, which is secured to the main part and has at least a first sliding surface incline
REFERENCES:
patent: 742313 (1903-10-01), Hagspiel
patent: 1658141 (1928-02-01), Skinner
patent: 4169487 (1979-10-01), Watson
patent: 4338961 (1982-07-01), Karpenko
patent: 4346728 (1982-08-01), Sulzer
patent: 4715149 (1987-12-01), Kelsey
Larslap AB
Scherbel David A.
LandOfFree
Device for carrying out mechanical tooling of a valve seat does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Device for carrying out mechanical tooling of a valve seat, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Device for carrying out mechanical tooling of a valve seat will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-843682