A method for the continuous extrusion of an extrusion, particularly a weather strip for motor vehicle bodies and an extrusion thus obtained

Claim 2

1 . Method for the continuous extrusion of an extrusion (T), such as a weather strip for motor vehicle bodies, having successive portions (L 1 , L 2 , L 3 ) of predetermined length with respective predetermined sections, using an extrusion head (1) having adjusting means (10) which, when activated, modify the section of its extrusion orifice (6), characterised in that it comprises the following operations: providing an elongate member (0)'of a material which is substantially inextensible or extensible to a foreseeable extent; feeding the member (0) to the extrusion head (1) simultaneously with the material to be extruded so that the member (0) is incorporated in the extrusion (T) during extrusion; detecting the advance of the member (0) upstream of the extrusion head (1), and synchronising the operation of the adjusting means (10) with the advance of the member (0).

Claim 3

Method according to Claim 1, characterised in that the member (0) has marks or references (30;31; 32; 33; 50; 60) regularly spaced along the member, and the advance of the member (0) is detected by means of the detection of the passage of the marks or references at a fixed position (20;40, 42) upstream of the extrusion head (1).

Claim 4

Method according to Claim 2, characterised in that the marks or references are of a type chosen from the group comprising: metallized surface portions (33; 50) of the member (0), surface portions (33; 50) of the member (0) treated with a fluorescent substance, variations in the form or section (30; 31, 32; 60) of the member (0), portions (33, 50) of the member (0) having magnetically detectable characteristics, portions (33, 50) of the member (0) treated with a radioactive material, and portions (33, 50) of the member (0) having optically detectable characteristics.

Claim 5

Method according to Claim 1, Claim 2 or Claim 3, characterised in that the member (0) comprises a strip.

Claim 6

Method according to Claim 1, Claim 2 or Claim 3, characterised in that the member comprises at least one strand.

Claim 7

Method according to Claim 4, characterised in that the strip is of paper, polymeric material or woven material.

Claim 8

Method according to Claim 5, characterised in that the strand is a thread.

Claim 9

Method according to Claim 1 or Claim 2, for forming an extrusion of the type including a rigid strip reinforcement and having a plurality of references (60) spaced regularly along the reinforcement, the reinforcement being intended to be incorporated in the extrusion during extrusion, characterised in that the reinforcement is used as the member (0) whose advance is detected, and the activation of the adjusting means (10) is synchronised with the advance of the reinforcement.

Claim 10

Method according to Claim 1 or Claim 2, for forming an extrusion of the type including a reinforcement constituted by a woven material formed by at least partly from metal wire (80) incorporated in the extrusion during extrusion, characterised in that the reinforcement is used as the member (0) whose advance is detected, and in that the operation of the adjusting means (10) is synchronised with the advance of the reinforcement.

Claim 11

Apparatus for synchronising the variations in section of an extrusion (T) with the advance of the extrusion (T) in an extruder provided with adjusting means (10) arranged, when operated, to modify the section of the outlet orifice (6) of its extrusion head (1), characterised in that it includes: an elongate tracer member (0) of a material which is substantially inextensible or extensible to a foreseeable extent, for feeding to the extrusion head (1) simultaneously with the material to be extruded so that the member (0) is incorporated in the extrusion (T) during extrusion; detector means (20; 40, 42) located upstream of the extrusion head (1) for detecting the advance of the member (0), and control and drive means (22, 23, 24, 25, 26, 27, 28, 29) connected to the detector means (20; 40, 42) and the adjusting means (10) and arranged to operate the adjusting means (10) in a predetermined manner in dependence on the advance of the member (0).

Claim 12

Apparatus for synchronising the variations in section of an extrusion (T) with the advance of the extrusion (T) in an extruder provided with adjusting means (10) arranged, when operated, to modify the section of the outlet orifice (6) of its extrusion head (1), characterised in that it includes: an elongate tracer member (0) of a material which is substantially inextensible or extensible to a foreseeable extent, for feeding to the extrusion head (1) simultaneously with the material to be extruded so that the member (0) is incorporated in the extrusion (T) during extrusion; detector means (20; 40, 42) located upstream of the extrusion head (1) for detecting the advance of the member (0), and control and drive means (22, 23, 24, 25, 26, 27, 28, 29) connected to the detector means (20; 40, 42) and the adjusting means (10) and arranged to operate the adjusting means (10) in a predetermined manner in dependence on the advance of the member (0).

Claim 13

Apparatus according to Claim 10, characterised in that the member (0) has marks or references (30; 31; 32; 33; 50; 60) regularly spaced along the member, and in that the advance of this member (0) is detected by means of the detection of the passage of the marks or references at a fixed position (20; 40, 42) upstream of the extrusion head (1).

Claim 14

Apparatus according to Claim 11, characterised in that the marks or references are of a type chosen from the group comprising: metallized surface portions.(33; 50) of the tracer member (0), surface portions (33; 50) of the member (0) treated with a fluorescent substance, variations in the form or section (30; 32, 32; 60) of the member (0), portions (33; 50) of the member (0) treated with a radioactive material,and portions (33; .50) of the member (0) having optically detectable characteristics.

Claim 15

13 . Apparatus according to Claim 12,characterised in that the member comprises a strip.

Claim 16

1 4. Apparatus according to Claim 12, characterised in that the member comprises at least one strand.

Claim 17

15 . Apparatus according to Claim 13, characterised in that the strip is of paper, polymeric material or woven material.

Claim 18

16 . Apparatus according to Claim 14, characterised in that the strand is constituted by a thread.

Claim 19

Apparatus according to Claim 10 or Claim 11, for forming an extrusion of the type including a rigid strip reinforcement (0) baving a plurality of marks or references (60) regularly spaced therealong, the reinforcement being intended for incorporation in the extrusion during extrusion, characterised in that the reinforcement (0) is used as the member whose advance is detected, and the operation of the adjusting means is synchronised with the advance of the reinforcement.

Claim 20

Apparatus according to Claim 10 or Claim 11, for forming an extrusion of the type including a reinforcement (0) constituted by a woven material of metal wire incorporated in the strip during extrusion, characterised in that the reinforcement (0) is used as the member of which the advance is detected, and the operation of the adjusting means is synchronised with the advance of the reinforcement.

Claim 21

Extrusion, such as a weather strip for motor vehicle bodies,formed by continuous extrusion by a method according to any one of Claims 1 to 9.