The present invention relates to a tool for piercing nuts according to the preamble to claim 1.
Therefore, an object of the present invention is to eliminate the drawbacks of the prior art tool for piercing nuts.
According to the invention, this object is achieved by a tool for piercing nuts according to claim 1.
The invention will now be described in more detail with reference to the accompanying drawings, in which
In the tool for piercing nuts according to the in-vention, the shims 1, mentioned by way of introduction, of the prior art tool for piercing nuts 2 in
The gas spring 3 comprises, as will be seen, three pistons 5-7 which are movably arranged in a cylinder 8-10 each. The cylinders 8-10 are in a manner not illustrated in detail connected with each other (connected in series) to be able to be pressurised by a common source of com-pressed air (not shown). This source of compressed air makes it possible to set in the cylinders 8-10 a pressure acting on the pistons 5-7 with a force that is suitable for the case of operation in question.
The advantage of the gas spring 3 is that it makes it possible to exactly adjust the pressure exerted upon a piercing nut by the tool for piercing nuts 4. It will be appreciated that the pressure exerted by the gas spring 3 is dependent not only by the actual gas pressure but also by the surface area of the pistons 5-7. It will also be appreciated that the gas spring 3, when the tool for piercing nuts 4 bottoms when fastening a piercing nut, can perform a certain damping motion, the size of which greatly exceeds the damping motion which is allowed by the prior art shims (about 1.5 mm against about 0.1 mm).
Owing to the invention, just a single initial adjustment is therefore necessary, and subsequently appearing minor deviations will not be important since they can be com-pensated for by the gas spring 3.
The maximum stroke of the pistons 5-7 of the shown gas spring 3 is about 12 mm. This means in practice that not even a case where two piercing nuts inadvertently land on top of each other in the tool for piercing nuts 4 will cause damage that will require stoppage for repair or even, as in the prior art tool for piercing nuts 2 with the shims 1, exchange of the entire tool.
The above-mentioned connection in series of a plu-rality of cylinders 8-10 renders it possible to make the gas spring 3 elongate so that it well fits the tool for piercing nuts 4 as such and also a press line, in which the tool for piercing nuts 4 can be included as one among a large number of other tools and in which therefore the available space is extremely restricted.
A person skilled in the art understands that the above-described tool for piercing nuts 4 according to the invention can be modified in various ways within the scope of the claims and, for instance, that the number of cylinders 5-7 in the gas spring 3 can be different from the one shown.
Filing Document | Filing Date | Country | Kind | 371c Date |
---|---|---|---|---|
PCT/SE02/01580 | 9/5/2002 | WO | 9/16/2005 |