Introduction

The flattened sleeve collar is a pre-installed component specifically designed for prefabricated components in modular construction. Its core function is to achieve steel reinforcement connection or lifting positioning through mechanical extrusion or adjustable structures. It features a compact structure and convenient installation. Here is a detailed analysis:

Structural Design and Working Principle

1. The basic structure of the flattened sleeve collar usually consists of two layers of sleeves:

◦ Inner sleeve: Directly placed on the end of the steel bar, with the inner wall closely adhering to the surface of the steel bar;

◦ Outer sleeve: Pressed flat by an extrusion device, forming a mechanical interlock to enhance the connection strength.

Some models adopt adjustable designs, such as adjusting the length through telescopic mechanisms (springs, protrusions) or threaded connections, to accommodate different steel bar sizes or installation environments.

2. Key Technologies

◦ Extrusion Process: Utilizing hydraulic or mechanical extrusion equipment to apply pressure to the outer wall of the sleeve, making the inner wall closely adhere to the part of the steel bar， forming a gap-free connection；

◦ Anti-slip Design： After the end of the sleeve is flattened， a "bundle opening" structure is formed to prevent the steel bar from sliding， and at the same time， through designs such as convex slots and load-bearing hanging plates， the load is shared and the threads are protected.

Primary purpose

1. Prefabricated components are lifted and installed as embedded parts within prefabricated wall panels, staircases, etc. They are lifted together with universal lifting rings and can withstand tension ranging from 300kg to 8000kg (depending on the model). For example, sleeves with an inner diameter of 12-24mm can be adapted to HRB400 steel bars, and the length can be customized from 50 to 300mm.

2. Mechanical connection of steel bars is used in bridge, tunnel and other engineering projects for axial connection of steel bars with a diameter of 12-40mm. Through the double-layer sleeve extrusion design (as patent CN115977320A), the deformation can be reduced and the tensile strength can be increased to more than 1.1 times the standard value of the steel bar.

3. The fixed part of the diagonal brace model (such as the LSW series of Luoshi Construction) is specifically designed for the diagonal braces of cement components. Through the adjustable structure of the crossbar length (patent CN212985767U), the installation process can be simplified and the stability can be enhanced.