초록 ▼

This invention is a compact and portable apparatus directed toward measuring the coefficients of both static and sliding friction or slip resistance occurring between two surfaces. Means are provided for determining and recording data to establish such friction accurately, repeatably, and in a form

This invention is a compact and portable apparatus directed toward measuring the coefficients of both static and sliding friction or slip resistance occurring between two surfaces. Means are provided for determining and recording data to establish such friction accurately, repeatably, and in a form suitable for computer entry and data processing. Improvement over the prior art is provided with respect to mechanical configuration, ease of use, plus the acquisition and analysis of data, particularly for conditions involving wet or damp surfaces. A method is disclosed for essentially automatic determination of coefficient of friction.

대표청구항 ▼

[ What is claimed is:] [1.] An apparatus for measuring coefficients of static and sliding friction between (1) a test surface, and (2) a removable and interchangeable selected test sample and comprising in combination:(a) a friction foot assembly whose total dead weight applies an essentially pure a

[ What is claimed is:] [1.] An apparatus for measuring coefficients of static and sliding friction between (1) a test surface, and (2) a removable and interchangeable selected test sample and comprising in combination:(a) a friction foot assembly whose total dead weight applies an essentially pure and separate normal force to said test surface; said friction foot assembly further comprising a removable and interchangeable weight, a structural frame that holds said weight plus said test sample, and further includes (1) an internal containment chamber that serves as a mechanical guide for a central block and (2) guides for a plurality of retractable feet; said friction foot assembly further comprising means for both applying and removing said test sample with respect to said test surface;(b) means for applying and measuring an essentially pure and separate lateral force to said friction foot assembly comprising a cable means disposed essentially parallel to said test surface, the first end of said cable means is attached to said friction foot assembly and the second end of which is circumferentially attached to a pulley means by which said lateral force is applied to said cable means; inserted within the length of said cable is a force transducer that provides an electrical output proportional to tension in said cable, which is a measure of lateral force; wherein said force transducer can also be used measure the dead weight of said friction foot assembly to make the said apparatus self-calibrating with respect to applied normal force;(c) a combined electronic and mechanical means for controlling, measuring, and recording said lateral force comprising a programmable electro-mechanical clutch means that can turn said pulley means and that is driven by an electric motor, that in turn is controlled by an electronic power conditioner means that in turn is controlled by an electronic master control means;(d) said combined electronic and mechanical means further comprising an electronic amplifier that receives the output from said force transducer; the output of said amplifier is sent to an analog to digital converter, whose output is in turn delivered to a random access memory (RAM); wherein in the said RAM are stored and contained in digital form all amplified and processed original data from the said force transducer, normal force as pre-determined by the same force transducer, and results for coefficient of friction computed by the said electronic master control means; through an output connector, said processed original data and results are available on demand for subsequent recording and computer analysis;(e) said combined electronic and mechanical means further comprising an electronic clock that provides chronological data (both time and date) that are sent to said random access memory and to said master control means, plus a battery to supply power;(f) a cabinet means comprising said amplifier, said analog-to-digital converter, said random access memory, said master control means, said power conditioner means, said battery, said clock, plus control and activation buttons available to the operator.