Adhesive bonding and miscellaneous chemical manufacture – Methods – Surface bonding and/or assembly therefor
Reexamination Certificate
2001-07-25
2003-10-14
Crispino, Richard (Department: 1734)
Adhesive bonding and miscellaneous chemical manufacture
Methods
Surface bonding and/or assembly therefor
Reexamination Certificate
active
06632317
ABSTRACT:
CROSS-REFERENCE TO RELATED APPLICATION
This application claims priority to PCT Application No. PCT/EP99/09088 filed Nov. 24, 1999, which claims priority to German Patent Application No. 19854191.0 filed Nov. 24, 1998.
FIELD OF USE
The invention concerns a set comprising a plurality of mutually juxtaposed, generally flat, plate-shaped components which are fixedly connected together, and a process for the production thereof.
In industrial uses, it frequently happens that a large number of mutually juxtaposed, often very thin, plate-shaped components have to be handled in conjunction with each other, for example in the bed of a knitting machine or when dealing with knitting members. For that purpose, a plurality of such components are joined together to form a set or array, thereby considerably facilitating handling and in particular replacement thereof. That is an important aspect in particular when the components are wearing parts and accordingly replacement has to be effected relatively frequently. Production from the solid material, for example by means of milling, is often no longer possible or is not economical, in particular when dealing with thin components.
In that respect, there are hitherto known different possible ways of connecting together those components which mostly comprise metal, in particular a carbon-bearing hardenable steel.
In that respect, welding is a rather unusual procedure as the welding temperature required can give rise to distortion of the components and in particular also the welding operation can mean that the relative position of the components with respect to each other can very easily change.
Another option involves individually glueing the components together in succession, but that is also a time-consuming procedure having regard to a large number of components in each set.
It is further known for the components to be joined together to form a set by the components being cast into another material, for example at the free ends of the components. If the demands in regard to load-bearing capability are low, casting can be effected using plastic material, while when a higher load-bearing capability is required the components are cast into a metal alloy with a low melting point, for example a lead alloy, or nickel silver.
A disadvantage here is that the casting material drastically increases the weight of the set, in particular when the components are cast into metal. In that respect, the cast set is not infrequently ten times as heavy as the set without the casting material, precisely when the components are very thin and small items such as for example the needles of a knitting machine.
The disadvantage here is that the casting operation preferably has to be effected at the free ends of the components as a casting procedure in the central region thereof is very much more complicated and in addition it is necessary to take account in regard to the dimensions involved of shrinkage of the casting material upon cooling, which requires a great deal of experience. It is however precisely the free end regions of the components that frequently serve as operational surfaces and have to be freely accessible.
It is further known for the components to be threaded on to dowel or fitting pins by a procedure whereby mutually aligned bores are provided in the components, with the pins being passed through the bores. The desired spacing between the individual components can be achieved by respective interposed spacer sleeves.
A further disadvantage is that the dowel pins required must be produced with very tight dimensional tolerances and are correspondingly expensive. Furthermore, arranging spacer sleeves between the needles in the operation of threading the components on to the pins is a difficult and time-consuming procedure. In addition that situation involves the problem of cumulative error in regard to the spacer sleeves.
It is further known for the components to be threaded on to a fitting tube by a procedure whereby aligned bores are provided in the components, through which the tube is passed. The components are fixed on the tube by subsequently expanding the tube radially outwardly by means of an expanding taper member or by an expanding bar which is pushed through the tube.
The disadvantage here however is that the length of the tube is decreased overall by virtue of expansion thereof, in other words, the initial length of the set does not correspond to the final length thereof, and accordingly the spacings of the components relative to each other are also altered during expansion of the tube. Due to that cumulative error only sets of limited length can be produced.
A further disadvantage is that on the one hand a certain minimum wall thickness and, because of a minimum inside diameter of the tube for the expansion element, thus a certain minimum outside diameter of the tube, are required to afford a sufficiently strong and stable connection. The mechanical loading of the edge regions of the components which are to be threaded on to the tube, around the orifice thereof, also means that the width of the components in the region of the orifices cannot be less than a certain minimum value.
a) Technical Object
Therefore the object of the present invention is to provide a set and a process for the production thereof, wherein production is easy and inexpensive to carry into effect and thus also the entire set can be produced on the one hand inexpensively and on the other hand sufficiently accurately in terms of fit.
b) Attainment of the Object
That object is attained by the features of claims 1 and 24. Advantageous embodiments are set forth in the appendant claims.
The fact that a bar is inserted into the mutually aligned orifices in the components and the bar is then glued to the set of components in such a way that the individual components are fixedly carried on the bar affords marked advantages over the previous fixing methods.
In that respect, the bar used for being pushed through the components must be less accurate in terms of fit than a dowel or fitting pin as it is not the clearance between the outside diameter of the bar in the initial condition and the inside diameter of the orifice in the components that determines the subsequent clearance of motion of the components within the set, as when using a fitting pin.
On the contrary, in making the connection, the individual components only have to be arranged in the correct relative position with respect to each other, more specifically in the desired final position relative to each other. On the one hand, insertion of the bar is a simple procedure as there may be sufficient clearance, approximately between one and five hundredths of a millimeter, between the outside diameter of the bar and the inside diameter of the orifice. On the other hand, the connection to the components is first completed by virtue of glueing to the bar, and thus even minor positional or dimensional deviations in the orifices in the components are compensated thereby. That simplifies and reduces the cost of production of the individual components. In addition the bar itself, in respect of its outside diameter, is only required to satisfy demands which are markedly below the close tolerances of a snugly fitting pin.
For example the diameter of the bar in contrast will change relatively greatly with the size of the components and is at least 4 mm. A usual diameter for components which are of a height of between about 10 and 20 mm is 3 mm.
While the individual components mostly comprise a carbon-bearing, that is to say hardenable steel which however is unhardened when making the connection, such as C
80
or C
100
, a chromium-nickel steel is generally used for the bar.
The fact that no mechanical forces worth mentioning are applied to the clamping components when the bars are being inserted into the mutually aligned orifices or when the set is being glued means that the individual components do not have to be supported in the region of the orifices therethrough, but it is sufficient to position the individual components and fix
Chan Sing P.
Head Johnson & Kachigian
Saxonia Umformtechnik GmbH
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