Global Patent Index - EP 0274719 A3

EP 0274719 A3 19891220 - THREAD-FORMING METHOD AND TUBULAR BODY PROVIDED WITH A THREAD

Title (en)

THREAD-FORMING METHOD AND TUBULAR BODY PROVIDED WITH A THREAD

Publication

EP 0274719 A3 19891220 (DE)

Application

EP 87118889 A 19871219

Priority

DE 3700758 A 19870113

Abstract (en)

[origin: EP0274719A2] The production of the internal thread of a connection sleeve (4), which is used as a coupling element for parts of a rock support or of a drill rod, by machine-forming, in particular by thread-cutting, entails great effort since, in the round thread used here, a considerable amount of machining work is required. Furthermore, it is disadvantageous in this application in the machining of the thread that the long-term strength of the connection sleeve is considerably impaired due to the notch effect in the base region of the thread turns. A connection sleeve and a method for its production are proposed, in which the internal thread is produced without machining by shaping the outside of the connection sleeve (4) in the manner of a thread so that the image of this shaping forms the internal thread to be produced on the inside. Apart from the increase in strength caused by the non-cutting shaping, which is usually cold shaping, due to material reinforcement, the further advantage results that the shaping required here can be applied in a single operation so that the production costs of connection sleeves (4) of this type can be reduced. Furthermore, it is advantageous that the external thread, interacting with the internal thread of the connection sleeve, of the components to be connected to one another can have a basic shape which corresponds to the outside thread-type shaping of the connection sleeve (4). <IMAGE>

IPC 1-7

B21D 15/04

IPC 8 full level

B21H 3/00 (2006.01); B21D 11/06 (2006.01); B21D 15/04 (2006.01); B21D 53/24 (2006.01); E21B 17/042 (2006.01); E21B 17/08 (2006.01); E21B 17/22 (2006.01); E21D 21/00 (2006.01); F16L 15/06 (2006.01)

CPC (source: EP)

B21D 15/04 (2013.01); E21B 17/0426 (2013.01); E21B 17/22 (2013.01)

Citation (search report)

Designated contracting state (EPC)

AT ES FR GB

DOCDB simple family (publication)

EP 0274719 A2 19880720; EP 0274719 A3 19891220; EP 0274719 B1 19930623; AT E90891 T1 19930715; AU 1024688 A 19880714; AU 600070 B2 19900802; CA 1333652 C 19941227; DE 3700758 A1 19880721; DE 3700758 C2 19881124; ES 2041259 T3 19931116; JP H069719 B2 19940209; JP S63180334 A 19880725

DOCDB simple family (application)

EP 87118889 A 19871219; AT 87118889 T 19871219; AU 1024688 A 19880113; CA 556034 A 19880107; DE 3700758 A 19870113; ES 87118889 T 19871219; JP 32661187 A 19871223