Load sensing probe
First Claim
1. In a machine tool having a back-up member arranged to support a tool at a working station during a working period by sustaining work forces and subject to strain from the work forces applied to the tool, the back-up member having a cavity formed therein, a load sensing probe confined in said cavity for measuring the work forces applied to the back-up member comprising:
- a generally cylindrical member adapted for insertion in the cavity including an elongate stem and sensing portions disposed at one end of said stem, said member having a slot formed between said sensing portions and a part of said stem to define a pair of sensing arms;
strain gauge means attached to each of said sensing portions of said sensing arms for measuring the amount of force applied thereto; and
preloading means for flexibly moving said sensing arms outwardly such that said sensing portions engage an inside wall of the cavity at a predetermined initial level of compression, whereby when work forces applied to the back-up member cause relative closing movement of the cavity, said closing movement can be measured as a change from the amount of preload compression applied to said sensing portions.
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Accused Products
Abstract
A load sensing probe for monitoring working forces in compressive elements such as found in presses and other machine tools is disclosed. The probe has an elongate configuration which allows it to be mounted at a point remote from its load sensing end and enables it to be conveniently used with a plurality of similar probes in relatively confined spaces. A split plug includes a slot defining two sensing arms, which arms are pushed outwardly into engagement with an accommodating cavity formed in a back-up member of the machine tool. The probe is sensitive to relative closing movement of the cavity caused by compressive strain in the back-up member.
31 Citations
17 Claims
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1. In a machine tool having a back-up member arranged to support a tool at a working station during a working period by sustaining work forces and subject to strain from the work forces applied to the tool, the back-up member having a cavity formed therein, a load sensing probe confined in said cavity for measuring the work forces applied to the back-up member comprising:
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a generally cylindrical member adapted for insertion in the cavity including an elongate stem and sensing portions disposed at one end of said stem, said member having a slot formed between said sensing portions and a part of said stem to define a pair of sensing arms; strain gauge means attached to each of said sensing portions of said sensing arms for measuring the amount of force applied thereto; and preloading means for flexibly moving said sensing arms outwardly such that said sensing portions engage an inside wall of the cavity at a predetermined initial level of compression, whereby when work forces applied to the back-up member cause relative closing movement of the cavity, said closing movement can be measured as a change from the amount of preload compression applied to said sensing portions. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. In a machine tool having a back-up member arranged to support a tool at a working station during a working period by sustaining work forces and subject to strain from the work forces applied to the tool, the back-up member having a cavity formed therein extending laterally from a point adjacent the working station to an exposed face on the back-up member, a load sensing probe confined in said cavity for measuring the work forces applied to the back-up member comprising:
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a split plug member adapted for insertion in the cavity including an elongate stem and sensing portions disposed at one end of said stem, said split plug having a longitudinally-extending aperture formed therethrough and having a slot formed between said sensing portions and a part of said stem defining a pair of sensing arms; strain gauge means attached to each of said sensing portions of said sensing arms for measuring the amount of force applied thereto; and a plug pin adapted for insertion through said split plug aperture for flexibly moving said sensing arms outwardly such that said sensing portions engage an inside wall of the cavity at a predetermined initial level of compression, whereby when work forces applied to the back-up member cause relative closing movement of the cavity, said closing movement can be measured as a change in the amount of preloaded compression applied to said sensing portions. - View Dependent Claims (13, 14, 15)
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16. A method of measuring the work forces applied to a back-up member in a machine tool, the back-up member being arranged to support a tool at a working station during a working period by sustaining work forces, comprising the steps of:
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a. forming an elongate cavity in the back-up member, the cavity extending laterally from a point adjacent the working station to a face of the back-up member; b. inserting a generally cylindrical member into the cavity, said cylindrical member including an elongate stem, sensing portions disposed at one end of the stem, a slot formed between the sensing portions and a part of the stem defining a pair of sensing arms, and strain gauge means attached to each of the sensing portions of the sensing arms for measuring the amount of force applied thereto; c. flexibly moving the sensing arms outwardly such that the sensing portions engage an inside wall of the cavity at a predetermined initial level of compression; and d. measuring the work forces applied to the back-up member as relative closing movement of the cavity caused by work forces applied to the back-up member, which movement can be measured as a change in the amount of the predetermined initial level of compression applied to the sensing portions. - View Dependent Claims (17)
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Specification