Two-steel screw with an extrusion connection and method for producing said screw

• US 10,451,101 B2
• Filed: 02/10/2015
• Issued: 10/22/2019
• Est. Priority Date: 03/12/2014
• Status: Active Grant

• Current Assignee: EJOT GmbH & Company KG (EJOT Holding GmbH & Company KG)
• Original Assignee: EJOT GmbH & Company KG (EJOT Holding GmbH & Company KG)
• Inventors: Grotmann, Dieter, Kettner, Tobias
• Primary Examiner(s): Estremsky, Gary W
• Application Number:
  US15/122,952
• Publication Number:
  US 20170074311A1
• Time in Patent Office: 1,715 Days
• Field of Search: 411424
• CPC Class Codes: B21K 1/44 bolts, studs, or the like making screw-thread B21K1/56; making U-bolts B21K1/74
• CPC Class Codes: B21K 1/56 screw-threaded elements
• CPC Class Codes: B21K 25/00 Uniting components to form integral members, e.g. turbine wheels and shafts, caulks with inserts, with or without shaping of the components uniting by interference- or press-fitting B23P11/02, B21K19/02
• CPC Class Codes: F16B 25/0094 the screw being assembled or manufactured from several components, e.g. a tip out of a first material welded to shaft of a second material
• CPC Class Codes: F16B 25/103 by means of a drilling screw-point, i.e. with a cutting and material removing action
• CPC Class Codes: F16B 35/00 Screw-bolts; Stay-bolts; Screw-threaded studs; Screws; Set screws F16B33/008 takes precedence; joining sheets or plates using screws with two separate threads F16B5/0275; using screws with adjustment sleeves F16B5/0283; thread cutting screws F16B25/00

Abstract

The invention relates to a two-steel screw comprising a top part and a cutting part, the top part consisting of a corrosion-resistant material and having a screw head and a shank portion, and the cutting part consisting of a hardenable material, the top part being permanently connected to the cutting part in the region of the shank portion by way of impact extrusion.

Claims

1. A two-steel screw comprising a top part and a cutting part, the top part consisting of a corrosion-resistant material and having a screw head and a shank portion, and the cutting part consisting of a hardenable material, wherein the top part is permanently connected to the cutting part in the region of the shank portion by way of impact extrusion,

wherein the cutting part has a lug-like projection and the top part has a cup-shaped recess on the shank portion,

wherein the lug-like projection is arranged in the cup-shaped recess and axially undercuts the top part in the region of the cup-shaped recess at least partially,

wherein, in cross-section, the cup-shaped recess has an engaging profile with a plurality of engaging segments, and

wherein circular segments are provided between the engaging segments.

2. The two-steel screw according to claim 1, wherein the lug-like projection fills the shape of the cup-shaped recess completely.

3. The two-steel screw according to claim 1, wherein the cutting part is hardened and has at least one drill bit.

4. The two-steel screw according to claim 1, wherein the engaging segments and the circular segments are arranged at an angle of 120°

relative to one another in the circumference of the recess.

5. The two-steel screw according to claim 1, wherein, in cross-section, the cup-shaped recess has an engaging profile with three engaging segments.

6. A two-steel screw comprising a top part and a cutting part, the top part consisting of a corrosion-resistant material and having a screw head and a shank portion, and the cutting part consisting of a hardenable material, wherein the top part is permanently connected to the cutting part in the region of the shank portion by way of impact extrusion,

wherein the cutting part has a lug-like projection and the top part has a cup-shaped recess on the shank portion,

wherein the lug-like projection is arranged in the cup-shaped recess and axially undercuts the top part in the region of the cup-shaped recess at least partially,

wherein, in cross-section, the cup-shaped recess has an engaging profile with a plurality of engaging segments,

wherein circular segments are provided between the engaging segments, and

wherein the cup-shaped recess has a first radius in the region of the circular segments and has a second reducing radius which is smaller than the first radius in the region of the engaging segments.

7. A two-steel screw comprising a top part and a cutting part, the top part consisting of a corrosion-resistant material and having a screw head and a shank portion, and the cutting part consisting of a hardenable material, wherein the top part is permanently connected to the cutting part in the region of the shank portion by way of impact extrusion,

wherein the cutting part has a lug-like projection and the top part has a cup-shaped recess on the shank portion,

wherein the lug-like projection is arranged in the cup-shaped recess and axially undercuts the top part in the region of the cup-shaped recess at least partially,

wherein, in cross-section, the cup-shaped recess has an engaging profile with three engaging segments.