Thread-forming screw with separate thread sprial and different part flank angles

Patent metadata

Field	Value
Publication number	US-10823219-B2
Application number	US-201615765888-A
Country	US
Kind code	B2
Filing date	Oct 4, 2016
Priority date	Oct 6, 2015
Publication date	Nov 3, 2020
Grant date	Nov 3, 2020

Abstract

A thread-forming screw has a shank which, in a front region of the shank, has a tip for insertion into a bore in a substrate, and in a rear region of the shank, has a drive for transmitting a torque to the shank. The shank has a spiral-shaped groove and a thread spiral which is inserted into the spiral-shaped groove. The spiral-shaped groove has a front flank and a rear flank disposed opposite the front flank. The front flank, at least regionally, has a different part flank angle than the rear flank.

First claim

The invention claimed is:

1. A thread-forming screw, comprising:
a shank, wherein the shank has a tip in a front region of the shank for insertion into a bore in a substrate, a drive in a rear region of the shank for transmitting a torque to the shank, a spiral-shaped groove, and a thread spiral disposable in the spiral-shaped groove;
wherein the spiral-shaped groove has a front flank and a rear flank disposed opposite the front flank and wherein the front flank has a part flank angle, at least in a region, that differs from a part flank angle of the rear flank.

2. The thread-forming screw according to claim 1 , wherein the part flank angle of the front flank differs from the part flank angle of the rear flank by at least 5°.

3. The thread-forming screw according to claim 1 , wherein the part flank angle of the front flank is greater than the part flank angle of the rear flank.

4. The thread-forming screw according to claim 1 , wherein the thread spiral has a first outer flank and a second outer flank, wherein a thread tip is formed between the first and second outer flanks, and wherein the first and second outer flanks have different part flank angles.

5. The thread-forming screw according to claim 1 , wherein the thread spiral is movable along the spiral-shaped groove.

6. The thread-forming screw according to claim 1 , wherein the thread spiral is axially fixed on the shank at the tip of the shank.

Assignees

• Hilti Ag

Inventors

• Hakenholt Christoph
• Winkler Bernhard
• Schneider Roland
• Spring Robert
• Nguyen Huu Toan

Classifications

• F16B33/02

  Shape of thread; Special thread-forms ({F16B25/00 takes precedence; used to remove paint or dirt layers F16B35/007, F16B37/002}; used as screw-locking device F16B39/30) · CPC title

• F16B25/0042

  characterised by the geometry of the thread, the thread being a ridge wrapped around the shaft of the screw · CPC title

• F16B25/0026

  the material being a hard non-organic material, e.g. stone, concrete or drywall (F16B25/0031 takes precedence) · CPC title

• F16B25/0094 Primary

  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 title

• F16B25/00

  Screws that cut thread in the body into which they are screwed, e.g. wood screws {(F16B35/065 takes precedence; joining sheets or plates using screws with two separate threads F16B5/0275, using screws with adjustment sleeves F16B5/0283)} · CPC title