Rock fixing device with hydraulic-spring combination and position-limiting chuck for direct tensile test

Patent metadata

Field	Value
Publication number	US-9714891-B2
Application number	US-201615015150-A
Country	US
Kind code	B2
Filing date	Feb 4, 2016
Priority date	Feb 9, 2015
Publication date	Jul 25, 2017
Grant date	Jul 25, 2017

Abstract

A device for fixing a rock sample, including: a lower clamp and an upper clamp; the lower clamp including a lower connector connected to a loading base at a bottom of a testing machine, a lower end cap for fixing samples, a lower chain connecting the lower connector and the lower end cap, a first spiral spring, a first central position-limit mechanism, a second central position-limit mechanism, and a first hydraulic mechanism; the upper clamp including an upper connector connected to a loading base at a top of the testing machine, an upper end cap for fixing samples, an upper chain connecting the upper connector and the upper end cap, a second spiral spring, a third central position-limit mechanism, a fourth central position-limit mechanism, and a second hydraulic mechanism.

First claim

The invention claimed is:

1. A device for fixing a rock sample, the device comprising:
a lower clamp; the lower clamp comprising: a lower connector connected to a loading base at a bottom of a testing machine, a lower end cap for fixing samples comprising a first sample fixing groove and a first connection segment, a lower chain connecting the lower connector and the lower end cap, a first spiral spring, a first central position-limit mechanism, a second central position-limit mechanism, and a first hydraulic mechanism; and
an upper clamp; the upper clamp comprising: an upper connector connected to a loading base at a top of the testing machine, an upper end cap for fixing samples comprising a second sample fixing groove and a second connection segment, an upper chain connecting the upper connector and the upper end cap, a second spiral spring, a third central position-limit mechanism, a fourth central position-limit mechanism, and a second hydraulic mechanism;
wherein
the first central position-limit mechanism, the second central position-limit mechanism, the third central position-limit mechanism and the fourth central position-limit mechanism have the same structure and all comprise a three-jaw chuck, a support and a connecting board; one end of the support is connected to the connecting board; and another end of the support is connected to the three-jaw chuck;
the first hydraulic mechanism and the second hydraulic mechanism have the same structure, which both comprise a circular piston and a circular oil cylinder assembled with the circular piston;
the first central position-limit mechanism and the loading base at the bottom of the testing machine are assembled; the three-jaw chuck in the first central position-limit mechanism contacts the loading base at the bottom of the testing machine; the lower connector is arranged in a center hole of the three-jaw chuck; free ends of three claws of the three-jaw chuck in the first central position-limit mechanism contact the external side of the lower connector respectively; the second central position-limit mechanism and the lower end cap are assembled; the three-jaw chuck in the second central position-limit mechanism contacts an outer bottom wall of the first sample fixing groove of the lower end cap; the first connection segment of the lower end cap is arranged in the center hole of the three-jaw chuck; free ends of three claws of the three-jaw chuck in the second central position-limit mechanism contact an external side of the lower end cap;
the first hydraulic mechanism is integrated with the first central position-limit mechanism or the second central position-limit mechanism; when the first hydraulic mechanism is integrated with the first central position-limit mechanism, the circular oil cylinder of the first hydraulic mechanism is connected to the connecting board of the first central position-limit mechanism; one end of the first spiral spring is connected to the circular piston of the first hydraulic mechanism, and another end of the first spiral spring is connected to the connecting board of the second central position-limit mechanism; when the first hydraulic mechanism is integrated with the second central position-limit mechanism, the circular oil cylinder of the first hydraulic mechanism is connected to the connecting board of the second central position-limit mechanism; one end of the spiral spring is connected to the circular piston of the first hydraulic mechanism, and another end of the first spiral spring is connected to the connecting board of the first central position-limit mechanism; the lower chain is arranged in a space enclosed by the first central position-limit mechanism, the first hydraulic mechanism, the first spiral spring and the second central position-limit mechanism;
the third central position-limit mechanism and the upper end cap are assembled; the three-jaw chuck in the third central position-limit mechanism contacts the outer bottom wall of the second sample fixing groove of the upper end cap; the second connection segment of the upper end cap is arranged in the center hole of the three-jaw chuck; free ends of three claws of the three-jaw chuck in the third central position-limit mechanism contact the external side of the second connection segment of the upper end cap respectively; the fourth central position-limit mechanism and the loading base at the top of the testing machine are assembled; the three-jaw chuck in the fourth central position-limit mechanism contacts the loading base at the top of the testing machine; the upper connector is arranged in the center hole of the three-jaw chuck; free ends of three claws of the three-jaw chuck in the fourth central position-limit mechanism contact the outer side of the upper connector;
the second hydraulic mechanism is integrated with the third central position-limit mechanism or the fourth central position-limit mechanism; when the second hydraulic mechanism is integrated with the third central position-limit mechanism, the circular oil cylinder of the second hydraulic mechanism is connected to the connecting board of the third central position-limit mechanism; one end of the second spiral spring is connected to the circular piston of the second hydraulic mechanism, and another end of the second spiral spring is connected to the connecting board of the fourth central position-limit mechanism; when the second hydraulic mechanism is integrated with the fourth central position-limit mechanism, the circular oil cylinder of the second hydraulic mechanism is connected to the connecting board of the fourth central position-limit mechanism; one end of the second spiral spring is connected to the circular piston of the second hydraulic mechanism, and another end of the second spiral spring is connected to the connecting board of the third central position-limit mechanism; the upper chain is arranged in a space enclosed by the third central position-limit mechanism, the second hydraulic mechanism, the second spiral spring and the fourth central position-limit mechanism.

2. The device of claim 1 , wherein the supports in the first central position-limit mechanism, the second central position-limit mechanism, the third central position-limit mechanism and the fourth central position-limit mechanism are four round rods, the connecting board is a circular board, and the four round rods are all arranged on the three-jaw chuck and a circular surface of the connecting board.

3. The device of claim 1 , wherein the supports in the first central position-limit mechanism, the second central position-limit mechanism, the third central position-limit mechanism and the fourth central position-limit mechanism are two board bodies with a circular arc cross section, the connecting board is a circular board, the two board bodies are arranged on the three-jaw chuck and a circular surface of the connecting board symmetrically.

Assignees

• Univ Sichuan

Inventors

• Liu Jianfeng
• Xie Heping
• Ju Yang
• Xu Huining
• Wang Lu
• Xu Yangmengdi
• Zou Hang
• Zhou Zhiwei
• Zhuo Yue

Classifications

• G01N2203/0405

  Features allowing alignment between specimen and chucks · CPC title

• G01N3/04 Primary

  Chucks · CPC title

• G01N3/10

  generated by pneumatic or hydraulic pressure (G01N3/18 takes precedence) · CPC title

• G01N3/08

  by applying steady tensile or compressive forces (G01N3/28 takes precedence) · CPC title

• G01N2203/0411

  using pneumatic or hydraulic pressure · CPC title