Linear displacement measuring apparatus

Patent metadata

Field	Value
Publication number	US-9989345-B2
Application number	US-201615278675-A
Country	US
Kind code	B2
Filing date	Sep 28, 2016
Priority date	Sep 30, 2015
Publication date	Jun 5, 2018
Grant date	Jun 5, 2018

Abstract

There is provided a linear displacement measuring apparatus which notifies a user when being installed defectively. A slider includes a traveling body which travels along a main scale on the main scale, a carriage part mounted on an object, and coupling means which couples the traveling body with the carriage part. The coupling means allows relative displacement between the traveling body and the carriage part and biases the traveling body towards the main scale. The coupling means has a connecting rod arranged so as to couple the traveling body with the carriage part via a ball joint. The slider further has misalignment detecting means which detects that the relative displacement between the traveling body and the carriage part exceeds a prescribed allowable range. The misalignment detecting means is a pair of projecting pieces arranged in a vicinity of the connecting rod so that the displacement of the connecting rod is regulated within a predetermined range.

First claim

The invention claimed is:

1. A linear displacement measuring apparatus comprising:
an elongate main scale mounted on one of two objects which linearly relatively move; and
a slider mounted on the other of the two objects and configured to slide along the main scale and detect a relative displacement amount with respect to the main scale, wherein
the slider comprises;
a traveling body configured to travel on the main scale along the main scale;
a carriage part mounted on the other of the two objects;
coupling means for coupling the traveling body with the carriage part, the coupling means allowing relative displacement between the traveling body and the carriage part and biasing the traveling body toward the main scale, and
misalignment detecting means for detecting that the relative displacement between the traveling body and the carriage part exceeds a prescribed allowable range.

2. The linear displacement measuring apparatus according to claim 1 , wherein
the coupling means has a connecting rod arranged so as to couple the traveling body with the carriage part via a ball joint, and
the misalignment detecting means is a pair of projecting pieces arranged in a vicinity of the connecting rod so that displacement of the connecting rod is regulated within a predetermined range.

3. The linear displacement measuring apparatus according to claim 2 , wherein
the pair of projecting pieces is disposed on a frame of the traveling body so as to face with each other with a predetermined distance to receive the connecting rod therebetween.

4. The linear displacement measuring apparatus according to claim 2 , wherein the misalignment detecting means is a pressing plate fixedly arranged at an opposite side to a frame of the traveling body while interposing the connecting rod.

5. The linear displacement measuring apparatus according to claim 1 , wherein
the misalignment detecting means comprises;
a hole provided on the traveling body and one side of the carriage part; and
a pin provided on the traveling body and the other side of the carriage part, wherein
a head part of the pin is freely fitted in the hole.

6. The linear displacement measuring apparatus according to claim 1 , wherein
the coupling means has a connecting rod arranged so as to couple the traveling body with the carriage part via a ball joint, and
the misalignment detecting means is a sensor configured to detect displacement exceeding a predetermined range of the connecting rod.

7. The linear displacement measuring apparatus according to claim 1 , wherein
the coupling means comprises:
a connecting rod arranged so as to couple the traveling body with the carriage part via a ball joint; and
an elastic member configured to bias the connecting rod toward the main scale, and
the misalignment detecting means is a strain gauge fixed on the connecting rod or the elastic member.

Assignees

• Mitutoyo Corp

Inventors

• Kikuchi Kazushi

Classifications

• G01D5/34753

  Carriages; Driving or coupling means · CPC title

• G01D5/347

  using displacement encoding scales · CPC title

• G01D5/24442 Primary

  by mounting means · CPC title

• G01B11/02 Primary

  for measuring length, width or thickness (G01B11/08 takes precedence) · CPC title

• G01B3/08 Primary

  extensible · CPC title