Tie rod tension sensor
AssigneeHelm Instrument Co., Inc.
InventorDonald F. Wilhelm
Life of this patent
Estimating the term…
Abstract
A tie rod load sensor for a die-casting or other machine includes an axially-extending bore formed in the tie rod to receive a strain gauged sensing member. One end of the sensing member is countersunk to receive a ball which concentrates the load when it is forced against the bottom of the bore by a bolt threaded into the opening of the bore. The sensing member includes a narrow central shaft portion upon which a plurality of strain gauges are mounted. The bolt is utilized to pre-load the sensing member such that the strain gauges mounted thereon will measure changes in the tension on the tie rod.
Claims7
A load sensor for measuring the tension forces applied to a rod, the rod having an elongated axially-extending bore formed in one end thereof, comprising:
- a ball adapted to be inserted in the bore for contacting a closed end thereof;
- a sensing member adapted to be inserted in the bore having two end portions each tapering towards a narrower central shaft portion between said end portions, one of said end portions being countersunk to receive a portion of said ball;
- strain gauge means attached to said central shaft portion for measuring the amount of force applied thereto;
- a spacer adapted to be inserted in the bore for contacting the other of said end portions of said sensing member;
- and
- pre-loading means engageble with the rod and said spacer for compressing said sensing member by a predetermined amount, whereby the tension applied to the rod will be measured as a decrease in the pre-loaded compression force applied to said sensing member.
A method of measuring the tension forces applied to a rod including the steps of:
- a. forming an elongated axially-extending bore in one end of the rod;
- b. inserting a sensing member into the bore, said sensing member including strain gauge means for measuring the amount of force applied thereto;
- c. inserting a spacer into the bore so as to contact said sensing member;
- d. inserting a pre-loading means into the bore and compressing said sensing member and said spacer by a predetermined amount;
- and
- e. measuring the tension applied to the rod as a change in resistivity of said strain gauge means indicating a decrease in the pre-loaded compression force applied to said sensing member.
Dependencies are inferred from the claim text.