The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 24, 1988
Filed:
Jun. 16, 1986
Max Ruf, Obereisesheim, DE;
Erwin Korostenski, Oedheim, DE;
Audi AG, Ingolstadt, DE;
Abstract
In an internal combustion engine, the cylinder head 1 is screw-fastened to the cylinder crank case 2 by means of differential screws 8, each of which has two threaded sections 11 and 12, of which section 11 has a larger outside diameter and a smaller pitch than the second section 12. The threaded sections 11 and 12 cooperate with corresponding internal threads 13 or 10 in the cylinder head 1 or in the cylinder crank case 2. As a result of the different pitches of the two threaded sections 11 and 12, there occurs a joint tensioning of the cylinder head 1 with the cylinder crank case 2, without a bearing surface for a screw head or a nut being required. The space requirement for the cylinder head fastening thereby becomes exceptionally small, so that the fastening can be provided at points, for example, between adjacent valves, at which no space would otherwise be available for a bearing surface for screw heads or nuts. Between the threaded sections 11 and 12 the shank of the differential screw 8 can be provided with a profile 17 which increases the 'flow length' of the screw, whereby manufacturing tolerances with regard to the position of the internal threads 13 and 10 relative to each other can be compensated.