Installation of non-round anti-slip studs in a vehicle tire

A combination for installing anti-slip studs, said combination comprising:

• an air-filled vehicle tire, provided with a tread with a rolling surface, and a plurality of premade stud recesses in the tread;
• anti-slip studs, provided with an outer head and an inner head, and in the inner head a bottom flange and in the outer head a top bowl, the bottom flange in the tread being deeper from the rolling surface and the top bowl being nearer to the rolling surface;
• said anti-slip studs having a stud length and a stud center line parallel to said stud length, and the bottom flange having a cross-sectional shape perpendicular to the stud center line, which cross-sectional shape is composed of:
• a number of at least two first side portions with center regions at a shorter distance from said stud center line, and of a number of at least two edge portions;
• and
• an installation tool by which said anti-slip studs are installed in said tread,
• said combination further comprising:
• a number of jaw fingers in said installation tool, which number is equal to the number of said edge portions;
• and
• said jaw fingers being in contact with at least two such first side portions of the bottom flange of the anti-slip stud where said center regions are located at a shortest distance from said stud center line, in order to keep the bottom flange and hence the anti-slip stud in a predetermined constant position between said jaw fingers.

A method for installing non-round anti-slip studs in a vehicle tire tread, said method comprising the steps of:

• providing an air-filled vehicle tire with a tread and a plurality of premade stud recesses in the tread, said tire having a rotation axis line;
• utilizing an installation tool comprising:
• a number of at least three jaw fingers provided with narrowing tip portions, said jaw fingers being radially movable along their mutual jaw center line and radially away therefrom, and
• a plunger pin that is movable in parallel with the jaw center line and in the mutual interval between the jaw fingers;
• inserting said tip portions of the installation tool in said stud recesses, one recess at a time;
• entering an anti-slip stud provided with a top bowl and a bottom flange in the mutual interval, so that the bottom flange proceeds foremost;
• pressing said anti-slip stud by a plunger pin into the stud recess, along said mutual interval, so that the jaw fingers expand the stud recess;
• allowing said plunger pin to hold the anti-slip stud in the recess at the same time as the jaw fingers are pulled out of the stud recess, from around the anti-slip stud;
• and
• proceeding to install the next anti-slip stud in the next stud recess, or terminating the installation of the studs in this tire,
• said method further comprising the steps of:
• using anti-slip studs of a type having an oval or polygonal bottom flange that is at least partly wider than said top bowl, and with a non-round hard cermet piece arranged on a cross-sectional plane perpendicular to the stud center line, said shape of the hard cermet piece being in a constant position with respect to the shape of the bottom flange;
• and
• turning at least the jaw fingers of the installation tool around the jaw center line by a predetermined toe-out angle or without said toe-out angle in respect to said rotation axis line of the tire,
• in order to orientate the hard cermet piece of the studs in a predetermined position in the tire with respect to said rotation axis line.

A method for installing non-round anti-slip studs in a vehicle tire tread, said method comprising the steps of:

• providing an air-filled vehicle tire with a tread and a plurality of premade stud recesses in the tread, said tire having a rotation axis line;
• utilizing an installation tool comprising:
• a number of at least three jaw fingers provided with narrowing tip portions, said jaw fingers being radially movable along their mutual jaw center line and radially away therefrom, and
• a plunger pin that is movable in parallel with the jaw center line and in the mutual interval between the jaw fingers;
• inserting said tip portions of the installation tool in said stud recesses, one recess at a time;
• entering an anti-slip stud provided with a top bowl and a bottom flange in the mutual interval, so that the bottom flange proceeds foremost;
• pressing said anti-slip stud by a plunger pin into the stud recess, along said mutual interval, so that the jaw fingers expand the stud recess;
• allowing said plunger pin to hold the anti-slip stud in the recess at the same time as the jaw fingers are pulled out of the stud recess, from around the anti-slip stud;
• and
• proceeding to install the next anti-slip stud in the next stud recess, or terminating the installation of the studs in this tire,
• said method further comprising the steps of:
• using anti-slip studs of a type having an oval or polygonal bottom flange that is at least partly wider than said top bowl, and a hard cermet piece that is non-round on the cross-sectional plane perpendicular to the stud center line;
• maintaining at least the position of the jaw fingers of the installation tool in a constant position in respect to said rotation axis line of the tire;
• and
• changing the type of the anti-slip studs to be installed, so that studs where the shape of the hard cermet piece is rotated by a predetermined toe-out angle with respect to the shape of the bottom flange are replaced by studs where said toe-out angle does not exist, or vice versa,
• in order to orientate the hard cermet piece of the studs in a predetermined position in the tire with respect to said rotation axis line.