Tread profile for winter tires

• US 5,454,411 A
• Filed: 03/02/1994
• Issued: 10/03/1995
• Est. Priority Date: 03/02/1993
• Status: Expired due to Fees

• Current Assignee: Pirelli Reifenwerke GmbH & Co. KG. (Pirelli & C SPA)
• Original Assignee: Pirelli Reifenwerke GmbH & Co. KG. (Pirelli & C SPA)
• Inventors: Weyrich, Frank, Banerjee, Gopal, Sallein, Otto
• Primary Examiner(s): Ball, Michael W.
• Assistant Examiner(s): Lorin, Francis J.
• Application Number:
  US08/204,538
• Time in Patent Office: 580 Days
• Field of Search: 152/209 R, 152/209 A, 152/209 D, D12/147, D12/151
• US Class Current: 152/209.18
• CPC Class Codes: B60C 11/11 in which the raised area of the pattern consists only of isolated elements, e.g. blocks B60C11/12, B60C11/13 take precedence
• CPC Class Codes: B60C 2011/1213 sinusoidal or zigzag at the tread surface
• CPC Class Codes: Y10S 152/902 Non-directional tread pattern having no circumferential rib and having blocks defined by circumferential grooves and transverse grooves
• CPC Class Codes: Y10S 152/903 Non-directional tread pattern having non-circumferential transverse groove following smooth curved path

Abstract

A tread profile for winter tires of motor vehicles, in particular vehicles of the pickup truck or light truck class, includes at least four circumferentially extending longitudinal grooves and transverse grooves demarcating profile blocks. The transverse grooves extend helically with an approximately Z-shaped kink in the middle of the width of the tread. The longitudinal grooves have a given groove width and have individual segments between two of the transverse grooves. Each of the segments are staggered alternatingly to the left and to the right relative to one another by at least one-half of the given groove width.

Claims

1. In a winter tire for motor vehicles having a tread, the tread having a width and the width having a middle region, a tread profile, comprising:

an imaginary center line of the tread defined in the middle region and circumferentially extending about the tire;

four circumferential grooves, said circumferential grooves being spaced apart in a lateral direction and defining two middle and two outer longitudinal grooves;

transverse grooves extending transversely to said circumferential grooves, said transverse grooves being spaced apart in a circumferential direction and demarcating profile blocks therebetween;

each of said transverse grooves extending with an approximately Z-shaped kink in the middle region of the width of the tread, and each having spaced-apart kink points disposed on different sides of said center line;

substantially Z-shaped grooves connecting said kink points of mutually adjacent transverse grooves disposed on opposite sides of said center line;

each of said Z-shaped grooves being formed by two groove segments initially branching off circumferentially from said kink points of said mutually adjacent transverse grooves and a connecting groove diagonally intersecting said center line;

two identically shaped middle blocks being mirror symmetrical with respect to said connecting groove of said Z-shaped grooves, said middle blocks being demarcated by said two inner circumferential grooves and by said Z-shaped middle groove between each two of said transverse grooves;

said longitudinal grooves having a given groove width and having individual segments, each of said segments being staggered alternatingly to the left and to the right relative to one another by at least one-half of said given groove width.

2. The tread profile according to claim 1, wherein said two middle longitudinal grooves are approximately twice as wide as said two outer longitudinal grooves.

3. The tread profile according to claim 1, wherein said Z-shaped kinks and said complementary Z-grooves form a water shedding system.